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. OXIDATION OF URANIUM ALLOYS IN CARBON DIOXIDE AND AIR

    Microsoft Academic Search

    J. E. Antill; K. A. Peakall

    1961-01-01

    Weight gain--time curves were obtained for alloys of uranium containing ; up to 7.3% silicon, 10% titanium, 5% vanadium, 10% zirconium, 15% molybdenum, 10% ; niobium, and 1% copper in carbon dioxide at 500--1000 deg C and in air at 500 deg ; C. Additions of titanium, molybdenum, niobium, and copper reduced the attack by ; carbon dioxide at 680--1000

  3. Moisture swing sorbent for carbon dioxide capture from ambient air.

    PubMed

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

    2011-08-01

    An amine-based anion exchange resin dispersed in a flat sheet of polypropylene was prepared in alkaline forms so that it would capture carbon dioxide from air. The resin, with quaternary ammonium cations attached to the polymer structure and hydroxide or carbonate groups as mobile counterions, absorbs carbon dioxide when dry and releases it when wet. In ambient air, the moist resin dries spontaneously and subsequently absorbs carbon dioxide. This constitutes a moisture induced cycle, which stands in contrast to thermal pressure swing based cycles. This paper aims to determine the isothermal performance of the sorbent during such a moisture swing. Equilibrium experiments show that the absorption and desorption process can be described well by a Langmuir isothermal model. The equilibrium partial pressure of carbon dioxide over the resin at a given loading state can be increased by 2 orders of magnitude by wetting the resin. PMID:21688825

  4. Modeling of carbon dioxide based air-to-air air conditioners

    Microsoft Academic Search

    Douglas MacArthur Robinson

    2000-01-01

    The world-wide agreement to restrict the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) has prompted recent research exploring the possibilities of replacement refrigerants, particularly those occurring naturally in the environment. One such natural refrigerant, carbon dioxide, has been considered for certain refrigeration and air conditioning applications. In order to evaluate the potential performance of a refrigeration cycle based on carbon

  5. Optical properties of heated air, carbon dioxide, and argon

    Microsoft Academic Search

    L. I. Kiselevskii; V. D. Shimanovich

    1997-01-01

    Stable-plasma generators, spectroscopic measuring equipment, and methods for determining the optical properties of an extremely\\u000a heated medium with a given composition have been developed. The spectral coefficients of absorption and emission of heated\\u000a air, carbon dioxide, and argon were studied. A comparison with the data of other theoretical and experimental investigations\\u000a has been performed.

  6. REGIONAL AIR POLLUTION STUDY. CARBON DIOXIDE EFFECTS ON RAMS (REGIONAL AIR MONITORING SYSTEM) SULFUR MONITORS

    EPA Science Inventory

    Effects of carbon dioxide (CO2) content of the air on the response of flame photometric sulfur gas analyzers of two types, the Tracor model 270 HA sulfur chromatograph and the Meloy model SA 185 total sulfur analyzer, were studied. These analyzers were used in the Regional Air Mo...

  7. Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil

    Microsoft Academic Search

    Jan Siemens; Andreas Pacholski; Katia Heiduk; Anette Giesemann; Ulrike Schulte; René Dechow; Martin Kaupenjohann; Hans-Joachim Weigel

    Increasing leaching losses of carbon from soils due to accelerated weathering and increasing concentrations of dissolved carbon\\u000a as a result of intensified soil respiration are suspected to provide a negative feedback on rising atmospheric CO2 concentrations. We tested this hypothesis by studying concentrations of dissolved carbon and groundwater recharge at the\\u000a Braunschweig free air carbon dioxide enrichment (FACE) experiment under

  8. 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.

  9. Simulations for thermodynamic analyses of transcritical carbon dioxide refrigeration cycle and reheat dehumidification air conditioning cycle

    Microsoft Academic Search

    Mark Brown

    2006-01-01

    Carbon dioxide is a natural refrigerant that has been considered for certain\\u000arefrigeration and air conditioning applications. The coefficient of performance (COP) of\\u000acarbon dioxide cycles is low compared to classical vapor compression cycles. The aim of\\u000athis portion of the thesis is to present a thermodynamic analysis of carbon dioxide cycles\\u000ain order to evaluate the potential performance of

  10. Reconstriction of atmospheric carbon dioxide and isotopic carbon-13 dioxide from air occluded in ice cores from Greenland and Antarctica

    SciTech Connect

    Wahlen, M. [Univ. of California, La Jolla, CA (United States)

    1994-12-31

    Carbon dioxide (CO{sub 2}) dioxide (CO{sub 2}) mixing ratio and isotopic carbon-13 dioxide {delta}{sup 13}CO{sub 2} was measured in the air extracted form ice cores from Greenland (GISP 2, Greenland Ice Sheet Project 2) and from Antarctica (Vostok). The goals are to determine the phasing between temperature and atmospheric CO{sub 2} changes during periods of different climatic conditions and to gain insight into the mechanisms producing the observed CO{sub 2} variations. Experimentally, the dry extraction technique at low temperature for CO{sub 2} was used. The extracted air is then condensed quickly at 35{degrees}K and subsequently released into a cell, where the CO{sub 2} mixing ratio is determined by tunable diode infrared laser spectroscopy on a single vibrational-rotational transition in the 4.3-micrometer ({mu}m) band by measuring the absorbance relative to standards. Three standards are processed identically to samples with every three samples. The experimental uncertainty is {plus_minus}3 parts per million (ppm). {delta}{sup 13}/CO{sub 2} is measured in duplicate by using a dry air extraction technique similar to Etheridge, Pearman, and de Silva on larger samples. CO{sub 2} is separated cryogenically from the extracted air, and {delta}{sup 13}CO{sub 2} is measured by stable isotope ratio mass spectrometry. Severe extraction fractionation is observed. It is controlled and accounted for by admitting standard air samples over the ice; the standard air samples are then processed in the same manner as the extracted air samples are then processed in the same manner as the extracted air samples. The {delta}{sup 13}CO{sub 2} results are corrected for nitrous oxide mass interferences and for gravitational fractionation. The experimental uncertainty is better then {plus_minus}0.1 permil. 5 refs., 3 figs.

  11. The characteristics of time series of carbon dioxide and the relationship between air temperature and carbon dioxide

    Microsoft Academic Search

    M. Hasebe; Y. Suzuki

    2003-01-01

    The increase of the carbon dioxide concentration is the problem that is important for the global warming. Carbon dioxide concentration is gradually increasing for the rapid production activity in agriculture and industry from the latter half in the eighteenth century, in which industrial revolution began in the United Kingdom. The increase of carbon dioxide concentration seems to be mainly caused

  12. 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…

  13. Carbon dioxide as an alternative refrigerant for automotive air conditioning systems

    Microsoft Academic Search

    G. D. Mathur

    2000-01-01

    Thermodynamic performance of a typical automotive air conditioning system has been simulated using carbon dioxide as the working fluid. The performance of the carbon dioxide system is compared with a base case with R-134a as the refrigerant. A cooling capacity of 5.3 kW (1.5 ton) is used for this study. For the base case, evaporation and condensing temperatures of 6.7°C

  14. Temperature VS Carbon Dioxide

    NSDL National Science Digital Library

    In this activity, students examine the relationship between carbon dioxide levels and global temperature change by studying a graph of these two variables. They will discover that by using data from ice cores, scientists can determine temperature and carbon dioxide levels in the air as far back as a hundred thousand years in the past. The students try to predict which variable is the independent one and then make a graph of temperature change and carbon dioxide levels. After making their graph, students describe the relationship between temperature and carbon dioxide levels in the atmosphere to determine if their predictions were correct.

  15. Quantification of carbon dioxide poisoning in air breathing alkaline fuel cells

    Microsoft Academic Search

    A. Tewari; V. Sambhy; M. Urquidi Macdonald; A. Sen

    2006-01-01

    Carbon dioxide intolerance has impeded the development of alkaline fuel cells as an alternate source of power supply. The CO2, in a fuel cell system, could come from the anode side (if “dirty” H2 is used as fuel), from the cathode side (if air instead of pure O2 is used as an oxidant) or from inside the electrolyte (if methanol

  16. Carbon dioxide

    NSDL National Science Digital Library

    Arie Melamed-Katz (None; )

    2007-06-19

    Bubbles are an indicator of a chemical reaction. An indicator is an object, material, or organism that tells you if a specific substance is present. In the sugar test, carbon dioxide gas release is an indicator that yeast is using sugar to grow. The more gas produced, the more sugar a specific substance contains.

  17. 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.

  18. Design and Development of an air-cooled Temperature-Swing Adsorption Compressor for Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.

    2003-01-01

    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 closing the air-loop. We have a developed a temperature-swing adsorption compressor (TSAC) for performing these tasks that is energy efficient, quiet, and has no wearing parts. This paper discusses the design features of a TSAC hardware that uses air as the cooling medium and has Space Station application.

  19. Measurement Of Total Column Carbon Dioxide Using Atmospheric Infrared Sounder (AIRS) Data

    NASA Astrophysics Data System (ADS)

    Datta, S.; Barnet, C.

    2002-12-01

    The Atmospheric Infrared Sounder (AIRS) was launched on May 04, 2002 from California's Vandenberg Air Force base onboard the Earth Observing System's (EOS) AQUA platform. AIRS has a nominal mission life of 5 years, flying in a 705 km polar orbit with 41 km nadir field of view for standard products and broad spectral coverage of 15.4 to 3.7 ?m (649 to 2700 cm-1). AIRS has unique capability of obtaining global measurements with simultaneous knowledge of the atmosphere, surface and clouds. AIRS is extremely stable on orbital and daily scales. For clear scenes, the total instrument noise is significantly less than 0.1 K for the majority of channels. The current AIRS physical retrieval algorithm simultaneously retrieves temperature, moisture, and ozone profiles; surface skin temperature, spectral emissivity, reflectivity and NDVI; cloud height and cloud fraction. Outgoing Long-wave Radiation (OLR), and clear sky OLR are computed from these products. In addition to these core products AIRS will produce a number of research products, primary among these are trace constituent profiles of methane (CH4), carbon monoxide (CO) and total column carbon dioxide (CO2). The retrieval of trace gas products, specifically CO2 and CH4, could improve the core products of AIRS. While retrieval of CO2 from a thermal sounder involves higher levels of uncertainty, the potential of a global long-term total column CO2 product is vital to the understanding of global carbon cycle. The current presentation discusses the methodology, limitations and current skills of estimating total column carbon dioxide using the AIRS instrument.

  20. Brookhaven National Laboratory free-air carbon dioxide enrichment forest prototype -- Interim report

    SciTech Connect

    Hendrey, G.R.; Lewin, K.F.; Nagy, J.

    1994-08-01

    A variety of approaches have been used in fumigation experiments to quantify the effects of increasing atmospheric carbon dioxide concentration ([CO{sub 2}]{sub atm}) on plants. Mot of these approaches, reviewed elsewhere (Allen 1992), entail some type of enclosure or chamber. Chambers provide containment of the CO{sub 2}-enriched air and in this way reduce the amount of CO{sub 2} required for the experiment. At the same time, chambers alter microclimate conditions in a variety of ways so that there is a significant chamber effect on the plants within. Free-air carbon dioxide enrichment (FACE) is an alternative experimental strategy in which CO{sub 2}-enriched air is released into the ambient environment in such a way as to provide effective experimental control over [CO{sub 2}]{sub atm} without causing any change in other environmental variables. Early types of free-air exposure systems were built in the Netherlands and England for exposing vegetation to elevated concentrations of atmospheric trace gases. The FACE Program at Brookhaven National Laboratory (BNL) considered these original ideas in designing the BNL FACE systems. The purpose of the current BNL project in the Duke Forest is to develop a FACE system that can provide adequate control over [CO{sub 2}]{sub atm} in a tall forest setting. This report is a preliminary overview of the data and much remains to be done in the analysis.

  1. Carbon Dioxide Capture and Disposal

    Microsoft Academic Search

    K. S. Lackner

    2002-01-01

    Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air

  2. Lubricity effect of carbon dioxide used as an environmentally friendly refrigerant in air-conditioning and refrigeration compressors

    Microsoft Academic Search

    Emerson Escobar Nunez; Kyriaki Polychronopoulou; Andreas A. Polycarpou

    2010-01-01

    Environmental concerns have increased the interest in alternative natural refrigerants for air-conditioning and refrigeration compressors. Carbon dioxide (CO2) or R744 is an attractive candidate to replace harmful hydrofluorocarbon refrigerants, which will need to be replaced in the near future due to their high global warming potential. In this paper the tribological behavior of gray cast iron in the presence of

  3. Non-equilibrium viscous air and carbon dioxide hypersonic flows about blunted bodies

    NASA Astrophysics Data System (ADS)

    Golovachov, Yu. P.

    The paper deals with numerical investigation of air and carbon dioxide flows about blunted bodies at flight speed 4 less than or equal to V(sub infinity) less than or equal to 7 km/s and ambient density 10(exp -5) less than or equal to rho(sub infinity) less than or equal to 10(exp -2) kg/cu m. The conditions correspond to the space vehicle flight in the Earth's atmosphere at altitudes 60 less than or equal to H less than or equal to 100 km and to aerodynamic deceleration in the Martian atmosphere. Under the above flight conditions, the shock layer flow is greatly influenced by various physical and chemical processes occurring through the particle collisions. Their relaxation times are determined by the ambient density. With decreasing density, one has to take into account both the rarefaction and relaxation effects.

  4. Porosity control in nanoporous carbide-derived carbon by oxidation in air and carbon dioxide

    SciTech Connect

    Osswald, S.; Portet, C. [Department of Materials Science and Engineering, A. J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104 (United States); Gogotsi, Y., E-mail: gogotsi@drexel.ed [Department of Materials Science and Engineering, A. J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104 (United States); Laudisio, G. [Department of Materials Science and Engineering, A. J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA 19104 (United States); Singer, J.P.; Fischer, J.E. [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Sokolov, V.V.; Kukushkina, J.A.; Kravchik, A.E. [Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2009-07-15

    Carbide-derived carbons (CDC) allow a precise control over the pore size through the selection of the carbide precursor and varying of the synthesis conditions. However, their pore volume is limited by the carbide stoichiometry. While activation of carbons derived from various organic precursors has been widely studied, this process may similarly be able to increase the pore volume and specific surface area of CDC. Oxidation of carbide-derived carbon in air and CO{sub 2} at different temperatures and times allows for significant increase in pore volume and specific surface area as well as control over average pore size with subnanometer accuracy. The effect of activation and associated changes in the pore volume and surface area on the hydrogen uptake are also discussed. - Graphical abstract: Carbide-derived carbons (CDC) provide great potential for sorption of toxicants and gas storage applications. Activation of CDC in air and CO{sub 2} at different temperatures and times is applied in order to maximize pore volume and specific surface area, and control the average pore size with subnanometer accuracy.

  5. Soil gas fluxes of N 2 O, CH 4 and CO 2 beneath Lolium perenne under elevated CO 2 : The Swiss free air carbon dioxide enrichment experiment

    Microsoft Academic Search

    P. Ineson; P. A. Coward; U. A. Hartwig

    1998-01-01

    Fluxes of nitrous oxide, methane and carbon dioxide were measured from soils under ambient (350 µL L-1) and enhanced (600 µL L-1) carbon dioxide partial pressures (pCO2) at the ‘Free Air Carbon Dioxide Enrichment’ (FACE) experiment, Eidgenössische Technische Hochschule (ETH), Eschikon, Switzerland in July 1995, using a GC housed in a mobile laboratory. Measurements were made in plots of Lolium

  6. Carbon Dioxide Removal

    NSDL National Science Digital Library

    American Museum of Natural History

    In this experiment, students will observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Students will learn that the carbon cycle is a fundamental Earth process. Throughout Earth's history, the balance of carbon has kept the atmosphere's carbon dioxide (CO2) and Earth's temperature within relatively narrow ranges.

  7. Capturing Carbon Dioxide

    NSDL National Science Digital Library

    Austen Saltz

    2010-01-01

    In this activity, learners investigate carbon sequestration by creating a carbonated beverage out of apple juice and dry ice. This experiment illustrates how carbon dioxide can be stored in a substance. Learners compare and contrast the results to determine if liquid carbonation is an effective method for carbon sequestration. Safety note: this activity involves dry ice; please follow recommended guidelines.

  8. 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.

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

    SciTech Connect

    Sotomayor, D. [Univ. of Puerto Rico, Mayagueez (Puerto Rico). Agronomy and Soils Dept.; Rice, C.W. [Kansas State Univ., Manhattan, KS (United States). Dept. of Agronomy

    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.

  10. Molecular Structure of Carbon Dioxide

    NSDL National Science Digital Library

    2002-08-15

    Carbon dioxide was first described in the 17th century by Jan Baptist van Helmont, a Belgium chemist. The chemical CO2 is released into the atmosphere when carbon-containing fossil fuels like oil, natural gas, and coal are burned in air. It is also produced by various microorganisms in fermentation and is breathed out by animals. Plants absorb carbon dioxide during photosynthesis, using both the carbon and the oxygen to construct carbohydrates. Every year the amount of CO2 in the atmosphere is increasing. CO2 build-up in the atmosphere is caused by deforestation, therefore reducing the number of trees available to absorb CO2. Excess CO2 in the environment causes Global Warming and the Greenhouse Effect. It is also toxic to humans since inhalation of large amounts of CO2 can cause suffocation. Some beverages, such as beer and sparkling wine contain carbon dioxide as a result of fermentation.

  11. 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.

  12. 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.)…

  13. Production of Carbon Dioxide

    NSDL National Science Digital Library

    The Science House

    2014-01-28

    In this chemistry activity, learners use common chemicals to produce carbon dioxide and observe its properties. This resource includes brief questions for learners to answer after the experiment. Use this activity to introduce learners to carbon dioxide and its use as a fire extinguisher. Note: this activity involves an open flame.

  14. Carbon Dioxide Emission Estimates

    NSDL National Science Digital Library

    The Carbon Dioxide Information Analysis Center of the Oak Ridge National Laboratory provides this new data on carbon dioxide emissions from fossil fuel burning, hydraulic cement production, and gas flaring in 1995. Data for one degree grid cells can be downloaded from the site in addition to code for analysis of the data.

  15. Carbon Dioxide Exchange at the Air–Sea Interface: Flux Augmentation by Chemical Reaction

    Microsoft Academic Search

    J. A. Quinn; N. C. Otto

    1971-01-01

    Numerical results for typical ocean conditions indicate that for film thicknesses less than, say, 400tz. oceanic exchange is not influenced by the hydration\\/dehydration reactions of dissolved carbon dioxide. This conclusion is in substantial agreement with the approximate analysis of Bolin [1960]. However, if suitable catalysts are present in the ocean (there is recent evidence to suggest that this may be

  16. Carioca buoy: Carbon dioxide monitor - multiple-sensor autonomous system monitors carbon dioxide concentration at the ocean sea-air interface

    Microsoft Academic Search

    L. Merlivat; P. Brault

    1995-01-01

    Concentrations of carbon dioxide in the atmosphere are increasing largely because of fossil-fuel combustion, but the rate of increase is only about half of the total emission rate. The balance of the carbon must be taken up in the oceans and the terrestrial biosphere, but the relative importance of each of these sinks - as well as their geographic distribution

  17. 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

  18. 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.

  19. Commuters' Exposure to Carbon Monoxide and Carbon Dioxide in Air-conditioned Buses in Hong Kong

    Microsoft Academic Search

    M. Y. Chan

    2005-01-01

    The summer in Hong Kong is hot and humid with temperatures over 30°C and relative humidity over 70%. Air-conditioned buses were first introduced in the early 1990s and have become more and more popular. Everyday, millions of passenger-trips are taken in such buses and the air quality and thermal environment in them has become a public health issue. One major

  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. 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.

  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. The Change in Carbon Dioxide Levels

    NSDL National Science Digital Library

    In this lesson students discover that ice cores can help us learn not only the temperature of the Earth in times past, but also the amount of Carbon Dioxide trapped in the air bubbles in the ice. This activity uses as source data a plot of each versus time, and asks the students to plot the Temperature variable versus the other variable which is the Carbon Dioxide content. Students can fit the data to a line y = mx + b to see how changes in Temperature and related to changes in Carbon Dioxide. After they make a graph of Carbon Dioxide concentration as a function of time, they will learn about linear trends in the data, as well as the annual variation of Carbon Dioxide and will then predict the level of Carbon Dioxide in a future year from the data.

  4. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)

    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).

  5. 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 central Arctic Ocean in very high latitudes. Thus it appears that the Arctic Ocean has a strong potential capacity of absorbing atmospheric CO2 in the future.

  6. Capture of Carbon Dioxide from Air and Flue Gas in the Alkylamine-Appended Metal-Organic Framework mmen-Mg2(dobpdc)

    E-print Network

    Capture of Carbon Dioxide from Air and Flue Gas in the Alkylamine- Appended Metal-Organic Framework, stationary sources like coal-fired power plants, carbon capture and sequestration (CCS) has been proposed.4 storage.5 For the retrofit of existing power plants, post-combustion CO2 capture is a likely configuration

  7. 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 ...

  8. Insufflation using carbon dioxide versus room air during colonoscopy: comparison of patient comfort, recovery time, and nursing resources.

    PubMed

    Lynch, Isabelle; Hayes, Ann; Buffum, Martha D; Conners, Erin E

    2015-01-01

    The standard of practice for colonoscopy is room air insufflation. Recent research demonstrates safety and significant decrease in postcolonoscopy discomfort from distention when carbon dioxide (CO2) is used during insufflation. Reducing abdominal pain after colonoscopy may lead to increased acceptance of colonoscopy screening for colorectal cancer. This study aims to compare patient comfort intra- and postprocedure, length of recovery, and nursing time in patients undergoing colonoscopy using room air vs. CO2 insufflation. This study uses an experimental design with patients randomly assigned to either room air or CO2 during colonoscopy. Physician endoscopists, postprocedure nurses, and patients were blinded to assignment. Prior bowel surgery, inflammatory bowel disease, or inability to consent excluded participants. Outcome measures included discomfort assessment, nursing tasks, and recovery time.Of 191 participants, 177 were men and 14 were women; 94 received room air; 97 received CO2. Patients insufflated with room air reported higher levels of some measures of discomfort: (a) during colonoscopy (p = .02), (b) on admission to recovery (p = .001), and (c) on discharge from recovery (p = .001). Patients receiving room air required more nursing tasks in recovery (p = .001) and more total nursing time (p = .001).Compared with room air, CO2 insufflation increases patient comfort and decreases nursing tasks and time. PMID:25946475

  9. The role of carbon dioxide capture from ambient air in the portfolio of mitigation options

    NASA Astrophysics Data System (ADS)

    Kriegler, E.; Stolaroff, J. K.

    2007-12-01

    CO2 capture from ambient air acts directly on the atmospheric CO2 concentration, and thus provides increased leverage to control the carbon cycle. We ask the question how the increased leverage will be utilized when CO2 air capture is added to a portfolio of classic mitigation options: increasing energy efficiency, substitution of fossil fuels, and carbon capturing and storage at point sources. It can be expected that the value of CO2 air capture will strongly depend on its costs, the long-term climate policy target, and climate sensitivity. The coupled economy-climate model MIND1.2 allows the investigation of cost-effective mitigation policies for achieving ambitious temperature and concentration targets. We have upgraded the model with a stylized CO2 air capture module based on the work of Stolaroff and Keith (J. K. Stolaroff, Capturing CO2 from ambient air: A feasibility assessment, PhD thesis, Carnegie Mellon University). We use the upgraded model to explore the cost-effective use of CO2 air capture vs. classic mitigation options for various targets and climate sensitivities.

  10. Carbon Dioxide Exercise

    NSDL National Science Digital Library

    Randy Richardson

    In this activity, students work in groups, plotting carbon dioxide concentrations over time on overheads and estimating the rate of change over five years. Stacked together, the overheads for the whole class show an increase on carbon dioxide over five years and annual variation driven by photosynthesis. This exercise enables students to practice basic quantitative skills and understand how important sampling intervals can be when studying changes over time. A goal is to see how small sample size may give incomplete picture of data.

  11. 8, 73157337, 2008 Carbon dioxide

    E-print Network

    Paris-Sud XI, Université de

    ACPD 8, 7315­7337, 2008 Carbon dioxide distributions over Europe C. Gurk et al. Title Page Abstract distributions of carbon dioxide over Europe C. Gurk1 , H. Fischer1 , P. Hoor1 , M.G. Lawrence1 , J. Lelieveld1 Publications on behalf of the European Geosciences Union. 7315 #12;ACPD 8, 7315­7337, 2008 Carbon dioxide

  12. Arnold Schwarzenegger THE CARBON DIOXIDE

    E-print Network

    i Arnold Schwarzenegger Governor THE CARBON DIOXIDE ABATEMENT POTENTIAL OF CALIFORNIA'S MID, Afzal Siddiqui, and Judy Lai. 2011. The Carbon Dioxide Abatement Potential of California's Mid/Agricultural/Water EndUse Energy Efficiency · Renewable Energy Technologies · Transportation The Carbon Dioxide

  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. Carbon Dioxide Increases

    NSDL National Science Digital Library

    In this problem set, learners will analyze the Keeling Curve showing carbon dioxide concentration in the atmosphere since 1985 to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  15. 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)

  16. 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

  17. 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...

  18. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    Microsoft Academic Search

    Yoichi Shimazaki

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of

  19. The Limiting Carbon Dioxide Concentration for Photosynthesis

    Microsoft Academic Search

    Dale N. Moss

    1962-01-01

    MANY reports1-5 indicate that plants in a closed system will reduce the concentration of carbon dioxide in the air to a minimum value between 50 and 100 p.p.m. Gabrielsen2 postulates ``there exists a threshold value for carbon dioxide in photosynthesis, which for elder leaves is about 0.0090 volume per cent. Below the threshold no assimilation takes place. Thus it seems

  20. 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

  1. 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.

  2. High resolution measurements of methane and carbon dioxide in surface waters over a natural seep reveal dynamics of dissolved phase air-sea flux.

    PubMed

    Du, Mengran; Yvon-Lewis, Shari; Garcia-Tigreros, Fenix; Valentine, David L; Mendes, Stephanie D; Kessler, John D

    2014-09-01

    Marine hydrocarbon seeps are sources of methane and carbon dioxide to the ocean, and potentially to the atmosphere, though the magnitude of the fluxes and dynamics of these systems are poorly defined. To better constrain these variables in natural environments, we conducted the first high-resolution measurements of sea surface methane and carbon dioxide concentrations in the massive natural seep field near Coal Oil Point (COP), California. The corresponding high resolution fluxes were calculated, and the total dissolved phase air-sea fluxes over the surveyed plume area (?363 km(2)) were 6.66 × 10(4) to 6.71 × 10(4) mol day(-1) with respect to CH4 and -6.01 × 10(5) to -5.99 × 10(5) mol day(-1) with respect to CO2. The mean and standard deviation of the dissolved phase air-sea fluxes of methane and carbon dioxide from the contour gridding analysis were estimated to be 0.18 ± 0.19 and -1.65 ± 1.23 mmol m(-2) day(-1), respectively. This methane flux is consistent with previous, lower-resolution estimates and was used, in part, to conservatively estimate the total area of the dissolved methane plume at 8400 km(2). The influx of carbon dioxide to the surface water refutes the hypothesis that COP seep methane appreciably influences carbon dioxide dynamics. Seeing that the COP seep field is one of the biggest natural seeps, a logical conclusion could be drawn that microbial oxidation of methane from natural seeps is of insufficient magnitude to change the resulting plume area from a sink of atmospheric carbon dioxide to a source. PMID:25083936

  3. 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.

  4. Carbon Dioxide Reduction Through Urban Forestry

    E-print Network

    Standiford, Richard B.

    Carbon Dioxide Reduction Through Urban Forestry: Guidelines for Professional and Volunteer Tree; Simpson, James R. 1999. Carbon dioxide reduction through urban forestry of Agriculture; 237 p. Carbon dioxide reduction through urban forestry--Guidelines for professional and volunteer

  5. [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

  6. 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.

  7. Carbon dioxide and terrestrial ecosystems

    Microsoft Academic Search

    G. W. Koch; H. A. Mooney

    1996-01-01

    This book is a summary of the current research which addresses the effects of elevated carbon dioxide on terrestrial ecosystems and an identification of significant unresolved issues. Chapters address the carbon dioxide effects on trees and forests, unmanaged herbaceous ecosystems, and crops. Included are experimental studies, conceptual models, general mathematical models, dynamic simulation models.

  8. Carbon Dioxide: Friend or Foe?

    Microsoft Academic Search

    C. Muller

    1983-01-01

    Carbon Dioxide: Friend or Foe is a short rnonograph on the so-called carbon dioxide greenhouse effect. The author challenges the established view that the present CO2 increase would, in the long term, lead to a global ground temperature increase. S. B. Idso, from four sets of observations, has deduced that the temperature response to an increased received energy at the

  9. Coral reefs and carbon dioxide

    SciTech Connect

    Buddemeier, R.W. [Kansas Geological Survey, Lawrence, KS (United States)

    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.

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

    Microsoft Academic Search

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

    2002-01-01

    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

  11. Effect of Dilution by Nitrogen and\\/or Carbon Dioxide on Methane and Iso-Octane Air Flames

    Microsoft Academic Search

    F. Halter; F. Foucher; L. Landry; C. Mounaïm-Rousselle

    2009-01-01

    The impact of dilution on laminar burning speed of two different fuels (methane and isooctane) is studied. In the present study, three different diluents are used—nitrogen, carbon dioxide, and a mixture representative of exhaust gases issued from a stoichiometric combustion of methane. Experimental results and PREMIX computations of the CHEMKIN package, using two different kinetic schemes, are presented and compared

  12. Measuring correlations between atmospheric oxygen and carbon dioxide mole fractions: A preliminary study in urban air

    Microsoft Academic Search

    Ralph F. Keeling

    1988-01-01

    On 25 and 26 October 1986 the air in Cambridge, Massachusetts was monitored for O2 and CO2 mole fraction. O2 concentrations were detected from changes in the relative refractivity of dried air between two lines of 198Hg at 2537.269 and 4359.562 Å using dual-wavelength interferometry. Changes in oxygen mole fraction were resolved with two-minute time resolution to a precision of

  13. 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.

  14. Spectroscopic carbon dioxide sensor for automotive applications

    Microsoft Academic Search

    Michael Arndt; Maximilian Sauer

    2004-01-01

    In this paper, we present the first spectroscopic carbon dioxide sensor designed for automotive applications. The sensor is based on the well known infrared measurement principle. It includes a new robust infrared gas-detector and a corresponding, newly developed, ASIC. First application studies show its suitability for automatic vehicle ventilation systems and for leak detection in R744 air conditioning systems.

  15. 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.

  16. 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 for analysis at 4h intervals for about 1 month. Two logging systems sampling cave air from 13 locations over a vertical range of 275m have run continuously for up to 5 years and return a very detailed picture of cave ventilation patterns and their responses to local weather and seasonal change.

  17. Evaluation of indoor air quality using the decibel concept based on carbon dioxide and TVOC

    Microsoft Academic Search

    M. V. Jokl

    2000-01-01

    Two new units are proposed for the evaluation of indoor air quality using the decibel concept, which give a much better approximation of the human perception of odour intensity, compared to the CO2 and TVOC concentration scales: the decicarbdiox and the decitvoc. On the Psycho-Physical Scale according to Yaglou, the weakest odour that can be detected by the human smell

  18. Carbon dioxide removal from air by microalgae cultured in a membrane-photobioreactor

    Microsoft Academic Search

    Lihua Cheng; Lin Zhang; Huanlin Chen; Congjie Gao

    2006-01-01

    Elevated CO2 levels in a closed space or room are of big concerns in many situations. Controlling the CO2 level within a certain range is one of the most important tasks in a life support system. In this paper, a 10l photobioreactor integrated with a hollow fiber membrane module was constructed to remove CO2 from air by using the photosynthetic

  19. FREE-AIR CARBON DIOXIDE ENRICHMENT OF SOYBEAN: INFLUENCE OF CROP VARIETY ON RESIDUE DECOMPOSITION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Elevated atmospheric CO2 can result in larger plants returning greater amounts of residues to the soil. However, the effects of elevated CO2 on carbon (C) and nitrogen (N) cycling for different soybean varieties has not been examined. Aboveground residue of eight soybean varieties (Glycine max [L....

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

    PubMed

    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

  1. 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

  2. Homogeneous hydrogenation of carbon dioxide

    Microsoft Academic Search

    Philip G. Jessop; Takao. Ikariya; Ryoji. Noyori

    1995-01-01

    Carbon dioxide (COâ) is of the greatest interest as a C⁠feedstock because of the vast amounts of carbon which exist in this form and because of the low cost of bulk COâ. Currently, toxic carbon monoxide, the main competitor for many processes, is used in industry instead because COâ is perceived to be less reactive and its efficient catalytic

  3. Photosynthesis and growth responses of mustard (Brassica juncea L. cv Pusa Bold) plants to free air carbon dioxide enrichment (FACE).

    PubMed

    Ruhil, Kamal; Sheeba; Ahmad, Altaf; Iqbal, Muhammad; Tripathy, Baishnab C

    2014-12-01

    Increased atmospheric [CO2] is likely to affect photosynthesis, plant growth, and yield potential of plants. Mustard (Brassica juncea L.) is an important oil seed crop that is widely grown in India. Therefore, the impact of elevated [CO2] (585 ?mol mol(-1)) on pigment and protein content, chlorophyll a fluorescence, photosynthetic electron transport reactions, CO2 assimilation, biomass production, and seed yield potential was measured in B. juncea cv Pusa Bold, grown inside free air carbon dioxide enrichment (FACE) rings installed on the campus of Jawaharlal Nehru University, New Delhi, India. Plants were grown for three consecutive winter seasons (2010-2013), in ambient (385 ?mol mol(-1)) or elevated [CO2], in field conditions. Elevated [CO2] had no significant effect on the minimal chlorophyll fluorescence (F 0), while the quantum efficiency of Photosystem II, measured as variable fluorescence (F v?=?F m-F 0) to maximum fluoresence (F m), increased by 3 %. Electron transport rate, photosystem I, photosystem II, and whole chain electron transport rates increased by 8 % in elevated [CO2]. However, the net photosynthesis rate increased by ?50 % in three growing seasons under elevated [CO2] condition. The stomatal conductance and transpiration rate decreased resulting in higher photosynthetic water use efficiency. The photosynthesizing surface, i.e., leaf area index substantially increased leading to higher biomass and seed yield under elevated [CO2] condition. Acclimatory downregulation of photosynthesis and plant productivity was not observed in three consecutive growing years suggesting that in the absence of nutrient limitation, B. juncea is highly responsive to elevated CO2 whose yield potential shall increase in changing climatic conditions. PMID:25471475

  4. NASA Satellite Sees Carbon Dioxide

    NSDL National Science Digital Library

    2012-08-03

    In this problem set, learners will analyze a map of atmospheric carbon dioxide derived from satellite data. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  5. Carbon dioxide sequestration in concrete in different curing environments

    E-print Network

    Wisconsin-Milwaukee, University of

    Carbon dioxide sequestration in concrete in different curing environments Y.-m. Chun, T.R. Naik, USA ABSTRACT: This paper summarizes the results of an investigation on carbon dioxide (CO2) sequestration in concrete. Concrete mixtures were not air entrained. Concrete mixtures were made containing

  6. Carbon dioxide escape and avoidance behavior in the brown rat

    Microsoft Academic Search

    Peter Van Sommers

    1963-01-01

    Rats were restrained in a small chamber through which various gas mixtures could be pumped. 3 rats were exposed to concentrations of carbon dioxide of 8%, 10%, and 15%. They successfully learned to escape regularly for 30-sec. periods by touching a metal tube. They were subsequently trained to avoid the onset of air containing similar carbon dioxide concentrations by pressing

  7. Construction and testing of a wet-compression absorption carbon dioxide refrigeration system for vehicle air conditioner

    Microsoft Academic Search

    Niu Yongming; Chen Jiangping; Chen Zhijiu; Chen Huanxin

    2007-01-01

    The environmental benefits of the transcritical carbon dioxide (CO2) refrigeration cycle are considerable. But its application is greatly challenged by the high operation pressure, which could be as high as 120bar. A wet-compression absorption (WCA) CO2 refrigeration cycle was constructed by adding a non-volatile liquid into a CO2 refrigeration cycle. CO2 is highly soluble in the liquid and easily absorbed

  8. 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.

  9. Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide from the post-

    E-print Network

    Carbon Dioxide Sequestration Industrial-scale processes are available for separating carbon dioxide dioxide separation and sequestration because the lower cost of carbon dioxide separation from for injection of carbon dioxide into oil or gas-bearing formations. An advantage of sequestration involving

  10. Seventh International Carbon Dioxide Conference

    NSDL National Science Digital Library

    Organized by NOAA's Climate Monitoring and Diagnostic Laboratory (CMDL), the Seventh International Carbon Dioxide Conference is planned September 25-30 in Broomfield, Colo. At this website, scientists involved in various aspects of the global carbon cycle, especially the current increases of carbon dioxide in the atmosphere, are encouraged to attend. Users can read the preliminary announcement and can learn about the themes of the conference. Researchers can learn about abstract submissions and accommodations. The Brief Conference History link offers a nice synopsis of the accomplishments of past conferences.

  11. Carbon dioxide recovery by vacuum swing adsorption

    Microsoft Academic Search

    Cheng-Tung Chou; Chao-Yuh Chen

    2004-01-01

    According to an investigation by the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide is the most significant greenhouse gas produced as a result of human activities. The amount of carbon dioxide emissions has to be reduced to meet global treaty. The concentration and recovery of carbon dioxide from flue gases is the first important step in solving the carbon

  12. Determination of carbon monoxide, methane and carbon dioxide in refinery hydrogen gases and air by gas chromatography

    Microsoft Academic Search

    Marian Kami?ski; Rafa? Kartanowicz; Daniel Jastrz?bski; Marcin M. Kami?ski

    2003-01-01

    This paper illustrates a method for determining trace amounts of CO, CH4 and CO2 with the detection limit of 0.15, 0.15 and 0.20 ?g\\/l, respectively, in refinery hydrogen gases or in air. A simple modification of a gas chromatograph equipped with a flame-ionization detector is presented. A Porapak Q column, additionally connected with a short molecular sieve 5A packed column

  13. 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.

  14. VAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE FROM

    E-print Network

    VAPOR + LIQUID EQUILIBRIUM OF WATER, CARBON DIOXIDE, AND THE BINARY SYSTEM WATER + CARBON DIOXIDE the vapor-liquid equilibrium of water (between 323 and 573 K), carbon dioxide (between 230 and 290 K) and their binary mixtures (between 348 and 393 K). The properties of supercritical carbon dioxide were determined

  15. 2, 18491865, 2005 Carbon dioxide in

    E-print Network

    Paris-Sud XI, Université de

    BGD 2, 1849­1865, 2005 Carbon dioxide in southern Poland L. Chmura et al. Title Page Abstract is licensed under a Creative Commons License. 1849 #12;BGD 2, 1849­1865, 2005 Carbon dioxide in southern urban environment with numerous local sources of carbon dioxide. Despite of relative proximity of those

  16. 7Carbon Dioxide Increases The Keeling Curve,

    E-print Network

    7Carbon Dioxide Increases The Keeling Curve, shown to the left, shows the variation in concentration of atmospheric carbon dioxide since 1958-1974. It is based on continuous measurements taken of rapidly increasing carbon dioxide levels in the atmosphere. Additional measurements by scientists working

  17. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and...Specific Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2 , CAS Reg....

  18. SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW

    E-print Network

    Santos, Juan

    SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1 1 Department of Mathematics, Purdue University, USA Purdue University, March 1rst, 2013 SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12 (North Sea). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. II CO2 is separated

  19. SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW

    E-print Network

    Santos, Juan

    SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW J. E. Santos1, G. B. Savioli2, J. M. Carcione3, D´e, Argentina SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. I Storage of CO2). SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW ­ p. #12;Introduction. II CO2 is separated from natural

  20. Carbon dioxide fluxes across the air-water interface and its impact on carbon availability in aquatic systems

    SciTech Connect

    Portielje, R.; Lijklema, L. [Agricultural Univ., Wageningen (Netherlands)

    1995-06-01

    Diffusion of CO{sub 2} across the air-water interface was analyzed with a model that simulates both transport and reaction of CO{sub 2} in a stagnant boundary layer. The atmospheric C influx was determined in relation to several environmental variables: pH, total dissolved inorganic C, temperature, and the thickness of the stagnant boundary layer in relation to ambient windspeed. We used the model to calculate the atmospheric CO{sub 2} influx into experimental ditches for a period of 6 to 8 months, starting in early spring. Three of the six ditches were dominated by aquatic macrophytes and three by benthic algae. Each series received three levels of external N and P input. A comparison with net C assimilation during the same period, as estimated from continuous oxygen measurements, showed that, especially in the ditches dominated by submersed macrophytes, a sizable fraction of the C requirements during this period could have been obtained from atmospheric CO{sub 2}. In the ditches dominated by benthic algae, this fraction was considerably less, but nonetheless substantial, and was related to the level of N and P loading. Increased primary production due to enhanced external N and P loading increased the atmospheric C input due to the resultant higher pH values. The trophic state with respect to N and P and the availability of C are therefore interrelated. 25 refs., 8 figs., 5 tabs.

  1. Determination of carbon monoxide, methane and carbon dioxide in refinery hydrogen gases and air by gas chromatography.

    PubMed

    Kami?ski, Marian; Kartanowicz, Rafal; Jastrzebski, Daniel; Kami?ski, Marcin M

    2003-03-14

    This paper illustrates a method for determining trace amounts of CO, CH4 and CO2 with the detection limit of 0.15, 0.15 and 0.20 microg/l, respectively, in refinery hydrogen gases or in air. A simple modification of a gas chromatograph equipped with a flame-ionization detector is presented. A Porapak Q column, additionally connected with a short molecular sieve 5A packed column and a catalytic hydrogenation reactor on the Ni catalyst have been applied. The principle of the analytical method proposed is the separation of CO from O2 before the introduction of CO to the methanizer. The analytical procedure and examples of the results obtained have been presented. The modification applied makes it possible to use the GC instrument for other determinations, requiring utilization of the Porapak Q column and the flame-ionization detector. In such cases, the short molecular sieve 5A column and the methanizer can be by-passed. PMID:12650260

  2. Carbon dioxide and oxygen fluxes in the Southern Ocean: Mechanisms of interannual variability

    E-print Network

    Follows, Mick

    Carbon dioxide and oxygen fluxes in the Southern Ocean: Mechanisms of interannual variability A) to highlight the importance of convective mixing in inducing anomalous air-sea fluxes of carbon dioxide (2007), Carbon dioxide and oxygen fluxes in the Southern Ocean: Mechanisms of interannual variability

  3. 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…

  4. 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 50-5000ppm 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

  5. Carbon Dioxide: Friend or Foe?

    NASA Astrophysics Data System (ADS)

    Muller, C.

    Carbon Dioxide: Friend or Foe is a short rnonograph on the so-called carbon dioxide greenhouse effect. The author challenges the established view that the present CO2 increase would, in the long term, lead to a global ground temperature increase. S. B. Idso, from four sets of observations, has deduced that the temperature response to an increased received energy at the ground should be less than or equal to 0.113 K (W/m2). If this result is combined with the 2.28 W/m2 of increased radiation expected from CO2 doubling, he finds a temperature increase of 0.26 K, which cannot be distinguished form the natural temperature fluctuation. This conclusion is in disagreement with virtually all the current mathematical models that predict a ground temperature response of an order of magnitude or more higher.

  6. in press, Global Biogeochemical Cycles, April 18, 2007 Carbon dioxide and oxygen fluxes in the Southern Ocean

    E-print Network

    Marshall, John

    in press, Global Biogeochemical Cycles, April 18, 2007 Carbon dioxide and oxygen fluxes College, London, UK Abstract. We analyze the variability of air-sea fluxes of carbon dioxide and oxygen. The Southern Annular Mode (SAM), known to impact the variability of air-sea fluxes of carbon dioxide, is also

  7. 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.

  8. Carbon dioxide and climate

    Microsoft Academic Search

    Gregg Marland; Ralph M. Rotty

    1979-01-01

    During the years 1975–1978 concern over the increase of CO2 in the atmosphere expanded from the laboratory into the public policy arena. This was a period during which a profusion of international symposia, technical papers, and public-policy-oriented discussions drew wide attention to the potential dangers of unchecked growth of atmospheric CO2 and man's alterations of the global carbon cycle. At

  9. Carbon dioxide concentration for manned spacecraft using a molten carbonate electrochemical cell

    SciTech Connect

    Winnick, J.; Toghiani, H.; Quattrone, P.D.

    1982-01-01

    A high-temperature molten carbonate electrochemical cell has been tested for use as a carbon dioxide concentrator in a manned spacecraft. Carbon dioxide is removed from a stream of cabin air supplied to the cathode of the bench scale cell. It is then concentrated through the molten carbonate electrolyte to the anode. The anode is fed either hydrogen (energy producer) or nitrogen (substance producer). Performance variation with gas flow rate, cell temperature, carbon dioxide partial pressure, and current are presented and analyzed. 18 refs.

  10. Carbon-dioxide-controlled ventilation study

    SciTech Connect

    McMordie, K.L.; Carroll, D.M.

    1994-05-01

    The In-House Energy Management (IHEM) Program has been established by the U.S. Department of Energy to provide funds to federal laboratories to conduct research on energy-efficient technology. The Energy Sciences Department of Pacific Northwest Laboratory (PNL) was tasked by IHEM to research the energy savings potential associated with reducing outdoor-air ventilation of buildings. By monitoring carbon dioxide (CO{sub 2}) levels in a building, outdoor air provided by the heating, ventilating, and air-conditioning (HVAC) system can be reduced to the percentage required to maintain satisfactory CO{sub 2} levels rather than ventilating with a higher outdoor-air percentage based on an arbitrary minimum outdoor-air setting. During summer months, warm outdoor air brought into a building for ventilation must be cooled to meet the appropriate cooling supply-air temperature, and during winter months, cold outdoor air must be heated. By minimizing the amount of hot or cold outdoor air brought into the HVAC system, the supply air requires less cooling or heating, saving energy and money. Additionally, the CO{sub 2} levels in a building can be monitored to ensure that adequate outdoor air is supplied to a building to maintain air quality levels. The two main considerations prior to implementing CO{sub 2}-based ventilation control are its impact on energy consumption and the adequacy of indoor air quality (IAQ) and occupant comfort. To address these considerations, six portable CO{sub 2} monitors were placed in several Hanford Site buildings to estimate the adequacy of office/workspace ventilation. The monitors assessed the potential for reducing the flow of outdoor-air to the buildings. A candidate building was also identified to monitor various ventilation control strategies for use in developing a plan for implementing and assessing energy savings.

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

    SciTech Connect

    Nuckols, M.L. [Naval Academy, Annapolis, MD (United States). Dept. of Naval Architecture, Ocean and Marine Engineering

    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.

  12. Optimize carbon dioxide sequestration, enhance oil recovery

    E-print Network

    - 1 - Optimize carbon dioxide sequestration, enhance oil recovery January 8, 2014 Los Alamos simulation to optimize carbon dioxide (CO2) sequestration and enhance oil recovery (CO2-EOR) based on known production. Due to carbon capture and storage technology advances, prolonged high oil prices

  13. 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)

  14. Carbon Cycle: Exchanging Carbon Dioxide between the Atmosphere and Ocean

    NSDL National Science Digital Library

    This lab investigates the exchange of carbon dioxide between the atmosphere and the ocean's surface. It is based on the fact that carbon dioxide dissolves in the ocean and provides the source of that plants and plankton living in the ocean rely on for photosynthesis. Students will discover that the amount of carbon dioxide the ocean can contain depends on the temperature of the water and its salinity (whether it is sea water or fresh water) and that cold water can hold more carbon dioxide in solution than warm water. They will observe that when carbon dioxide dissolves in water, it forms carbonic acid which makes the water acidic, and they will test for the acidity caused by the presence of dissolved carbon dioxide using Universal Indicator, which turns yellow when the solution is acidic. This activity tests whether sea water or fresh water absorbs more carbon dioxide.

  15. The influence of carbon dioxide on smoke formation and stability in methane-oxygen-carbon dioxide flames

    Microsoft Academic Search

    Douglas Hainsworth; M. Pourkashanian; Andrew P. Richardson; Joanne L. Rupp; Alan Williams

    1996-01-01

    The effect of replacing nitrogen in combustion air by carbon dioxide in a laminar, atmospheric methane diffusion flame was investigated experimentally and by numerical modelling. Measurements included flame temperature, carbon monoxide concentrations and direct observation and photographic investigation of the flame shape and behaviour. The experimental results indicate a substantial reduction of scattered light intensity and flame volume. When a

  16. Climate models should include carbon dioxide increases

    NSDL National Science Digital Library

    Narisma et al.

    The specific impacts of elevated atmospheric carbon dioxide concentrations during the Australian summer were examined. It was found that plant response to increased carbon dioxide influences atmospheric temperatures and the climate in ways that are not currently captured by climate models. The authors suggest that local and global climate models should include a measure of vegetation response to natural and man-made carbon dioxide increases to accurately account for biospheric feedback.

  17. 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 resource consumption, electricity generation, and energy consumption within each economic sector. Flow charts of state-level energy usage and explanations of the calculations and assumptions utilized can be found at: http://flowcharts.llnl.gov. This information is translated into carbon dioxide emissions using ratios of carbon dioxide emissions to energy use calculated from national carbon dioxide emissions and national energy use quantities for each particular sector. These statistics are reported annually in the U.S. EIA's Annual Energy Review. Data for 2008 (US. EIA, 2010) was updated in August of 2010. This is the first presentation of a comprehensive state-level package of flow charts depicting carbon dioxide emissions for the United States.

  18. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  19. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  20. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  1. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... false Carbon monoxide and carbon dioxide analyzer specifications. 86...316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made...

  2. 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 measurement time) and 100 ppmv for water vapor (1 second measurement time). The stability of the instrument allows for reliable averaging over longer periods for applications that require even higher accuracy and precision.

  3. Improvement of a retrieval method of the column-averaged dry air mole fractions of carbon dioxide and methane from Greenhouse gases Observing SATellite (GOSAT) observation

    NASA Astrophysics Data System (ADS)

    Yoshida, Y.; Eguchi, N.; Ota, Y.; Morino, I.; Uchino, O.; Watanabe, H.; Yokota, T.

    2010-12-01

    Column-averaged dry air mole fractions of carbon dioxide and methane (XCO2 and XCH4) are retrieved globally from the short-wavelength infrared spectrum data observed by the Greenhouse gases Observing SATellite (GOSAT). When we use only the carbon dioxide 1.6 ? m band or methane 1.67 ? m band in the retrievals, the retrieved XCO2 and XCH4 values show large variabilities (-35% to +15% from the average) due to aerosol and cloud influences. Equivalent optical path length changes due to cloud and aerosol have two contrary effects; the multiple-scattering of cloud and aerosol extends the equivalent optical path length, while the scattering event at high altitude shortens it. The former effect is obvious over the Sahara desert and its surroundings where the dust particles are rich, and the latter effect is spread over the tropics where the frequency of cirrus occurrence is high. Overestimated (underestimated) equivalent optical path length brings negative (positive) biases in the retrieved XCO2 and XCH4 values. In order to minimize these biases, pre-processed cloud screening criterion is optimized to detect and exclude relatively thin cirrus case, and the observed spectrum at the oxygen A-band (0.76 ? m) is utilized in the retrieval to correct the optical path modification. These improvements eliminate most of the largely deviated retrieval results and make the variabilities of the retrieved XCO2 and XCH4 smaller (-7% to +5% from the average). Data products retrieved with the improved method (GOSAT SWIR L2 V01.xx Products) are available to get via https://data.gosat.nies.go.jp.

  4. Design and experimental analysis of a carbon dioxide transcritical chiller for commercial refrigeration

    Microsoft Academic Search

    Luca Cecchinato; Manuel Chiarello; Marco Corradi

    2010-01-01

    Carbon dioxide is an interesting solution for commercial refrigeration and in perspective for air-conditioning systems. In this paper a newly developed carbon dioxide transcritical air cooled chiller for refrigerating propylene glycol down to ?8°C supply temperature is described. The aim of the project was at optimising the cycle energy efficiency while assuring reliable operation and simple management of the unit.

  5. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89...Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. ...and bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be...

  6. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 131.817 ...and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  7. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431...EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

  8. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  9. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide, refrigerated liquid. 179...114 and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid...

  10. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 false Chemical; carbon dioxide. 313.5 Section 313...LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling...

  11. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 131.817 ...and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  12. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 78.47-11...Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8...Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  15. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 108.626 ...Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a)...

  17. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  18. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 97.37-11...Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  19. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 78.47-11...Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  20. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section...DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device...

  1. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 97.37-11...Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  2. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  3. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 91...Test Equipment Provisions § 91.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

  4. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 89...Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. ...and bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8...Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  6. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86...Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior...service and monthly thereafter the NDIR carbon dioxide analyzer shall be...

  7. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90...Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

  8. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 ...Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space...

  9. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169...Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179...114 and 120) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid...

  11. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 90...Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

  12. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Chemical; carbon dioxide. 313.5 Section 313...LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling...

  13. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169...Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space...

  14. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91...Test Equipment Provisions § 91.320 Carbon dioxide analyzer calibration. ...certification test, calibrate the NDIR carbon dioxide analyzer as follows:...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide storage. 193.15-20...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a)...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431...EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

  17. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping...Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified:...

  18. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping...Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified:...

  19. Carbon dioxide disposal in solid form

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Sharp, D.H. [Los Alamos National Lab., NM (United States); Wendt, C.H. [Auxon Corp., (United States)

    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.

  20. The Carbon Dioxide Greenhouse: Is It Effective?

    NSDL National Science Digital Library

    This activity allows students to compare the thermal properties of carbon dioxide with those of air, and can be extended to compare water vapor as well. Students discover that the gas which absorbs the most heat (infrared radiation) is the most effective greenhouse gas because in the atmosphere it would absorb more infrared coming from the surface of the Earth. This activity could be used as either a demonstration or a laboratory activity depending on the availability of equipment. Either a data logger is used to record the changing temperature of air and of carbon dioxide in plastic bottles as they are heated using electric lamps, and then allowed to cool, or if a data logger is not available, then thermometers can be used instead and monitored by students. The site contains teacher notes and instructions with a list of materials and a photograph showing the setup. It also has an introduction for the students and questions for them to answer along with a glossary.

  1. Sorption of carbon dioxide onto sodium carbonate

    SciTech Connect

    Sang-Wook Park; Deok-Ho Sung; Byoung-Sik Choi; Kwang-Joong Oh; Kil-Ho Moon [Pusan National University, Busan (Republic of Korea). Division of Chemical Engineering

    2006-07-01

    Sodium carbonate was used as a sorbent to capture CO{sub 2} from a gaseous stream of carbon dioxide, nitrogen, and moisture. The breakthrough data of CO{sub 2} were measured in a fixed bed to observe the reaction kinetics of CO{sub 2}-carbonate reaction. Several models such as the shrinking-core model, the homogeneous model, and the deactivation model in the non-catalytic heterogeneous reaction systems were used to explain the kinetics of reaction among CO{sub 2}, Na{sub 2}CO{sub 3}, and moisture using analysis of the experimental breakthrough data. Good agreement of the deactivation model was obtained with the experimental breakthrough data. The sorption rate constant and the deactivation rate constant were evaluated by analysis of the experimental breakthrough data using a nonlinear least squares technique and described as Arrhenius form.

  2. Trading coalbed methane for carbon dioxide

    SciTech Connect

    Greenberger, L.S.

    1991-08-15

    This article discusses a proposal for reducing methane emissions in coal mining activities and at the same time reducing the burden on utilities to cut carbon dioxide emissions. Emission credits would be issued to mines that recover the methane for use. These credits could then be bought by utilities and exchanged for the right to emit carbon dioxide.

  3. Interglacials, Milankovitch Cycles, and Carbon Dioxide

    E-print Network

    Gerald E. Marsh

    2010-02-11

    The existing understanding of interglacial periods is that they are initiated by Milankovitch cycles enhanced by rising atmospheric carbon dioxide concentrations. During interglacials, global temperature is also believed to be primarily controlled by carbon dioxide concentrations, modulated by internal processes such as the Pacific Decadal Oscillation and the North Atlantic Oscillation. Recent work challenges the fundamental basis of these conceptions.

  4. Polymer synthesis: Chaining up carbon dioxide

    NASA Astrophysics Data System (ADS)

    Dove, Andrew P.

    2014-04-01

    The development of methods for efficiently using carbon dioxide in synthesis would enable chemists to tap into this abundant resource. Now, an indirect route to the copolymerization of alkenes with carbon dioxide shows how this greenhouse gas may prove useful in the search for new 'green' materials.

  5. Carbon dioxide in northeastern New Mexico

    Microsoft Academic Search

    ROY W. FOSTER; JAMES G. JENSEN

    1972-01-01

    Carbon dioxide is known to occur in many parts of northeastern New Mexico. The main producing areas include the Bueyeros field in Harding County, Des Moines field in Union County, and Estancia field in Torrance County. In recent years, production has been limited to the Bueyeros field. Wildcat oil tests also have encountered carbon dioxide in Cofax, Mora, and San

  6. 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.

  7. DEVELOPMENT AND INTEGRATION OF NEW PROCESSES CONSUMING CARBON DIOXIDE IN

    E-print Network

    Pike, Ralph W.

    DEVELOPMENT AND INTEGRATION OF NEW PROCESSES CONSUMING CARBON DIOXIDE IN MULTI-PLANT CHEMICAL........................................................ 8 C. Carbon Dioxide ­ A Greenhouse Gas................................................ 9 1. Sources

  8. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

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

    2001-06-15

    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 major objectives of the 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 coal 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. The specific accomplishments of this project during this reporting period are summarized below in three broad categories outlining experimentation, model development, and coal characterization. (1) Experimental Work: Our adsorption apparatus was reassembled, and all instruments were tested and calibrated. Having confirmed the viability of the experimental apparatus and procedures used, adsorption isotherms for pure methane, carbon dioxide and nitrogen on wet Fruitland coal were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 2%. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on two other coals. (2) Model Development: The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, two-dimensional cubic equations of state, and the local density model. In general, all models performed well for Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). However, for pressures higher than 8.3 MPa (1200 psia), carbon dioxide produced multilayer adsorption behavior similar to Type IV adsorption. Our results to date indicate that the SLD model may be a suitable choice for modeling multilayer coalbed gas adsorption. However, model improvements are required to (a) account for coal heterogeneity and structure complexity, and (b) provide for more accurate density predictions. (3) Coal Characterization: We have identified several well-characterized coals for use in our adsorption studies. The criteria for coal selection has been guided by the need for coals that (a) span the spectrum of properties encountered in coalbed methane production (such as variation in rank), and (b) originate from coalbed methane recovery sites (e.g., San Juan Basin, Black Warrior Basin, etc.). At Pennsylvania State University, we have completed calibrating our instruments using a well-characterized activated carbon. In addition, we have conducted CO{sub 2} and methane uptakes on four samples, including (a) a widely used commercial activated carbon, BPL from Calgon Carbon Corp.; (b) an Illinois No.6 bituminous coal from the Argonne Premium Coal sample bank; (c) a Fruitland Intermediate coal sample; (d) a dry Fruitland sample. The results are as expected, except for a greater sensitivity to the outgassing temperature. ''Standard'' outgassing conditions (e.g., 383.2 K, overnight), which are often used, may not be appropriate for gas storage in coalbeds. Conditions that are more representative of in-situ coal (approximately 313.2 K) may be much more appropriate. In addition, our results highlight the importance of assessing the degree of approach to adsorption equilibrium.

  9. 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).

  10. Development of a new model for investigation of the performance of carbon dioxide as a refrigerant for residential air conditioners

    Microsoft Academic Search

    Thomas Manuel Ortiz

    2002-01-01

    This study presents the development, validation and application of a new model for simulating the performance of residential air-to-air CO 2 air conditioners and heat pumps. Validation of the model has been accomplished using recent experimental data for a gas cooler and evaporator, each tested as stand-alone components, as well as CO2 system data. Heat exchanger capacities were predicted within

  11. Homogeneous hydrogenation of carbon dioxide

    SciTech Connect

    Jessop, P.G.; Ikariya, Takao; Noyori, Ryoji [Research Development Corp. of Japan, Toyota (Japan). ERATO Molecular Catalysis Project

    1995-03-01

    Carbon dioxide (CO{sub 2}) is of the greatest interest as a C{sub 1} feedstock because of the vast amounts of carbon which exist in this form and because of the low cost of bulk CO{sub 2}. Currently, toxic carbon monoxide, the main competitor for many processes, is used in industry instead because CO{sub 2} is perceived to be less reactive and its efficient catalytic conversion has remained elusive. Because CO{sub 2} is a highly oxidized, thermodynamically stable compound, its utilization requires reaction with certain high energy substances or electroreductive processes. Catalytic hydrogenation is one of the most promising approaches to CO{sub 2} fixation. Recent research has shown that high catalytic efficiency, yields, and rates of reaction can be obtained from CO{sub 2} with optimum conditions and catalysts. This review will describe the simplest and most studied reactions of CO{sub 2}: the catalytic reactions with H{sub 2} in the presence or absence of other reactive species. The mechanisms of homogeneously catalyzed reactions will be emphasized. Subjects which will not be covered, aside from brief mentions, include stoichiometric reactions of CO{sub 2} with complexes, the reverse water gas shift reaction, hydrosilylation, and electrochemical or photochemical reductions of CO{sub 2}. 132 refs.

  12. Microfluidic studies of carbon dioxide.

    PubMed

    Abolhasani, Milad; Günther, Axel; Kumacheva, Eugenia

    2014-07-28

    Carbon dioxide (CO2) sequestration, storage and recycling will greatly benefit from comprehensive studies of physical and chemical gas-liquid processes involving CO2. Over the past five years, microfluidics emerged as a valuable tool in CO2-related research, due to superior mass and heat transfer, reduced axial dispersion, well-defined gas-liquid interfacial areas and the ability to vary reagent concentrations in a high-throughput manner. This Minireview highlights recent progress in microfluidic studies of CO2-related processes, including dissolution of CO2 in physical solvents, CO2 reactions, the utilization of CO2 in materials science, and the use of supercritical CO2 as a "green" solvent. PMID:24961230

  13. 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...

  14. Aeration with carbon dioxide-supplemented air as a method to control pH drift in toxicity tests with effluents from wastewater treatment plants.

    PubMed

    Elphick, James R; Bailey, Howard C; Hindle, Amanda; Bertold, Stanley E

    2005-09-01

    Environment Canada methods for acute toxicity tests with rainbow trout require continuous aeration of test solutions during exposure. Depending on the sample, this procedure can result in an increase in pH as dissolved carbon dioxide (CO2) is stripped from solution as a result of aeration. In samples that contain ammonia, the pH may increase to the point where the unionized fraction results in artifactual toxicity. Consequently, aeration with air supplemented with different CO2 concentrations was investigated as a method for maintaining pH at the level found in the original sample without adversely affecting other water quality parameters. Aeration with CO2 was an effective method for maintaining pH during exposure, depending both on the concentration of CO2 and the alkalinity of the sample. A multiple regression conducted on the data determined an equation that was effective at calculating the CO2 concentration necessary in an aeration mixture to maintain a target pH value as a function of sample alkalinity. PMID:16193749

  15. Mercury accumulation in grass and forb species as a function of atmospheric carbon dioxide concentrations and mercury exposures in air and soil.

    PubMed

    Millhollen, A G; Obrist, D; Gustin, M S

    2006-10-01

    The goal of this study was to investigate the potential for atmospheric Hg degrees uptake by grassland species as a function of different air and soil Hg exposures, and to specifically test how increasing atmospheric CO(2) concentrations may influence foliar Hg concentrations. Four common tallgrass prairie species were germinated and grown for 7 months in environmentally controlled chambers using two different atmospheric elemental mercury (Hg major; 3.7+/-2.0 and 10.2+/-3.5 ng m(-3)), soil Hg (<0.01 and 0.15+/-0.08 micro g g(-1)), and atmospheric carbon dioxide (CO(2)) (390+/-18, 598+/-22 micro mol mol(-1)) exposures. Species used included two C4 grasses and two C3 forbs. Elevated CO(2) concentrations led to lower foliar Hg concentrations in plants exposed to low (i.e., ambient) air Hg degrees concentrations, but no CO(2) effect was apparent at higher air Hg degrees exposure. The observed CO(2) effect suggests that leaf Hg uptake might be controlled by leaf physiological processes such as stomatal conductance which is typically reduced under elevated CO(2). Foliar tissue exposed to elevated air Hg degrees concentrations had higher concentrations than those exposed to low air Hg degrees , but only when also exposed to elevated CO(2). The relationships for foliar Hg concentrations at different atmospheric CO(2) and Hg degrees exposures indicate that these species may have a limited capacity for Hg storage; at ambient CO(2) concentrations all Hg absorption sites in leaves may have been saturated while at elevated CO(2) when stomatal conductance was reduced saturation may have been reached only at higher concentrations of atmospheric Hg degrees . Foliar Hg concentrations were not correlated to soil Hg exposures, except for one of the four species (Rudbeckia hirta). Higher soil Hg concentrations resulted in high root Hg concentrations and considerably increased the percentage of total plant Hg allocated to roots. The large shifts in Hg allocation patterns-notably under soil conditions only slightly above natural background levels-indicate a potentially strong role of plants in belowground Hg transformation and cycling processes. PMID:16631233

  16. Carbon dioxide emission scenarios: limitations of the fossil fuel resource

    Microsoft Academic Search

    Christopher Vernon; Erica Thompson; Sarah Cornell

    2011-01-01

    Contemporary increases in atmospheric carbon dioxide concentration are in large part the result of anthropogenic carbon dioxide emissions from fossil fuel combustion. Scenario analysis is commonly used to generate projections of future carbon dioxide emissions, the resulting atmospheric concentrations and climate impact. In most scenario modelling published to date, carbon dioxide emission scenarios are based on demand-side (socioeconomic and technology)

  17. Carbon Dioxide Effects Research and Assessment Program. Carbon Dioxide Research Progress Report, fiscal year 1979

    Microsoft Academic Search

    R. C. Dahlman; T. Gross; L. Machta; W. Elliott; M. MacCracken

    1980-01-01

    Research on the global carbon cycle and the effects of increased carbon dioxide on the global climate system is reported. Environmental and societal effects related to COâ and environmental control technology for COâ are also discussed. Lists of research projects and reports and publications of the Carbon Dioxide and Climate Research Program are included. An expanded COâ monitoring network is

  18. LIFETIME OF EXCESS ATMOSPHERIC CARBON DIOXIDE

    EPA Science Inventory

    We explore the effects of a changing terrestrial biosphere on the atmospheric residende time of carbon dioxide using three simple ocean carbon cycling models and a model of global terrestrial carbon cycling. e find differences in model behavior associated with the assumption of a...

  19. 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.

  20. Atmospheric carbon dioxide record from flask measurements at Lampedusa Island

    NSDL National Science Digital Library

    Chamard, Paolo.

    2001-01-01

    Air samples from Lampedusa Island, located south of Sicily in the Mediterranean sea, were collected weekly from May 1992 through December 2000 and analyzed for carbon dioxide content. "On the basis of annual averages calculated from monthly averages, CO2 levels at Lampedusa Island have risen from 360.80 in 1993 to 371.27 in 2000. The data show an average trend of +1.5 ppmv/y." The data from the study, newly available this month from the Carbon Dioxide Information Analysis Center (CDIAC), include a plot of mean carbon dioxide concentration (ppmv) against time and a text table of the annual mean values. Methods, notes, and references are also provided.

  1. Carbon Dioxide Emission Factors for Coal

    EIA Publications

    1994-01-01

    The Energy Information Administration (EIA) has developed factors for estimating the amount of carbon dioxide emitted, accounting for differences among coals, to reflect the changing "mix" of coal in U.S. coal consumption.

  2. Regulating carbon dioxide capture and storage

    E-print Network

    De Figueiredo, Mark A.

    2007-01-01

    This essay examines several legal, regulatory and organizational issues that need to be addressed to create an effective regulatory regime for carbon dioxide capture and storage ("CCS"). Legal, regulatory, and organizational ...

  3. Threshold Value of Carbon Dioxide Concentration in Photosynthesis of Foliage Leaves

    Microsoft Academic Search

    E. K. Gabrielsen

    1948-01-01

    How much can the carbon dioxide concentration of the atmosphere be diminished by photosynthesis of green leaves? Blackman1, in his researches in vegetable assimilation and respiration, observed that leaves exposed to sunlight took up completely all the carbon dioxide molecules from an enclosed volume of air in a very short time. Reinau2 did not accept this result which, he thought,

  4. Temporal Integration in Nasal Lateralization and Nasal Detection of Carbon Dioxide

    Microsoft Academic Search

    Paul M. Wise; Tomas Radil; Charles J. Wysocki

    2004-01-01

    Two experiments examined time\\/concentration trading for the detection of carbon dioxide, an irritant with little or no odor. Experiment 1 employed the nasal lateralization method: subjects attempted to determine which nostril received carbon dioxide and which received pure air when presented simultaneously. Experiment 2 employed a temporal, two-alternative, forced- choice, detection paradigm with monorhinal stimulation. In both experiments, stimulus duration

  5. Displacement of crude oil by carbon dioxide 

    E-print Network

    Omole, Olusegun

    1980-01-01

    DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Submitted to the Graduate College of Texas ASM University in part';al fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1980 Major Subject...: Petroleum Engineering DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Approved as to style and content by: hairman of Committee / (Member (Member (Member (Hea o Depart ent December 1980 ABSTRACT Displacement of Crude Oil...

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

    SciTech Connect

    Ziska, L.H. [USDA-ARS, Beltsville, MD (United States); Namuco, O.; Moya, T.; Quilang, J. [International Rice Research Inst., Manila (Philippines)

    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.

  7. Historical and present developments of ejector refrigeration systems with emphasis on transcritical carbon dioxide air-conditioning applications

    Microsoft Academic Search

    Stefan Elbel

    2011-01-01

    This paper gives an overview of historical and present developments on how ejectors can be utilized to improve the performance of air-conditioning and refrigeration systems. Research on ejector refrigeration cycles that utilize low-grade energy sources to produce cooling is summarized. Another major class of ejector refrigeration cycles that is described tries to recover expansion work by means of a two-phase

  8. 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

  9. The effect of free air carbon dioxide enrichment and nitrogen fertilisation on the chemical composition and nutritional value of wheat and barley grain.

    PubMed

    Wroblewitz, Stefanie; Hüther, Liane; Manderscheid, Remy; Weigel, Hans-Joachim; Wätzig, Hermann; Dänicke, Sven

    2013-08-01

    A rising atmospheric CO2 concentration might influence the nutrient composition of feedstuffs and consequently the nutritional value for livestock. The present study investigates the effects of atmospheric CO2 enrichment on the chemical composition and nutritional value of winter wheat cv. "Batis" and winter barley cv. "Theresa". Both cereals were grown at two different atmospheric CO2 concentrations (ambient CO2 [AMBI]: 380 ppm and enriched CO2 [free air carbon dioxide enrichment, FACE]: 550 ppm) for two growing seasons. The influence of two different nitrogen (N) fertilisation levels (adequate N supply [N100] and nearly 50% of adequate N supply [N50]) were studied as well. A significant effect was observed for the crude protein content, which declined at FACE condition in a range of 8-16 g kg(-1) in wheat and of 10-20 g kg(-1) in barley. A reduced N fertilisation level resulted in a strong reduction of crude protein concentration in both cereal species. In wheat, a decrease in N supply significantly enhanced the concentration of starch and crude fibre. In barley, only the concentration of fructose increased under FACE condition and reduced N fertilisation. The FACE did not have major effects on the concentrations of minerals, while the influence of N fertilisation was different for both cereals. Whereas no effects could be observed for barley, a reduced N supply caused a significant reduction in concentrations of zinc, manganese and iron in wheat. Furthermore, an undirected effect of atmospheric CO2 and N fertilisation levels were found for the amino acid concentrations. Based on these results, future scenarios of climate change would have an impact on the nutritional value of cereal grains. PMID:23870025

  10. Education, Convergence and Carbon Dioxide Growth per Capita

    E-print Network

    Paris-Sud XI, Université de

    65 Education, Convergence and Carbon Dioxide Growth per Capita Kinda Somlanare Romuald Abstract dioxide emissions around the world, and that education is not a factor in carbon dioxide emissions growth, there is no convergence, and that education is not a factor in carbon dioxide growth. In developed countries, we find

  11. Passive colorimetric dosimeter tubes for ammonia, carbon monoxide, carbon dioxide, hydrogen sulfide, nitrogen dioxide, and sulfur dioxide

    Microsoft Academic Search

    E. S. McKee; I. M. Pritts

    1981-01-01

    Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an 8-h period for several inorganic airborne contaminants in the range of their threshold limit values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NHâ), carbon monoxide (CO), carbon dioxide (COâ), hydrogen sulfide (HâS), nitrogen dioxide

  12. Context and renewal of conditioned fear: an experimental evaluation using 20% carbon dioxide-enriched air as an unconditioned stimulus.

    PubMed

    Finlay, Carlos G; Forsyth, John P

    2009-08-01

    This analogue experiment used fear conditioning and extinction procedures to establish and reduce fearful responding and then test for fear renewal following a context change. Healthy undergraduates (N=61) underwent a differential fear conditioning procedure using geometric shapes as conditioned stimuli (CS) and inhalations of 20% CO(2)-enriched air as an aversive unconditioned stimulus (US). Across phases (i.e., habituation, acquisition, extinction, and test), red and green ambient lighting served as contextual stimuli, and electrodermal and evaluative ratings were assessed as indices of conditioned fear. The control group underwent extinction and test phases under identical conditions (i.e., no context changes). The experimental groups either underwent acquisition and test phases in one context and the intervening extinction phase in a different context (A-B-A), or underwent acquisition and extinction phases in one context and the test phase in a novel context (A-A-B). Consistent with expectation, fear renewal was observed when the test context matched the acquisition context. This effect was modest for electrodermal responses, but reasonably robust for evaluative responses. The role of context in the subsequent renewal of fear following exposure-based treatment is discussed. PMID:19342193

  13. Carbon Dioxide- Where Does it All Go?

    NSDL National Science Digital Library

    In this problem set, learners will use a diagram of carbon fluxes, which shows the sources that contribute to current atmospheric carbon dioxide levels, to answer a series of questions. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  14. Hydroelectric Reservoirs -the Carbon Dioxide and Methane

    E-print Network

    Fischlin, Andreas

    Hydroelectric Reservoirs - the Carbon Dioxide and Methane Emissions of a "Carbon Free" Energy an overview on the greenhouse gas production of hydroelectric reservoirs. The goals are to point out the main how big the greenhouse gas emissions from hydroelectric reservoirs are compared to thermo-power plants

  15. Where in the World is Carbon Dioxide?

    NSDL National Science Digital Library

    This three part activity has students set up experiments to help them better understand the atmospheric portion of the carbon cycle. From this activity, they will be able to explain the concept of sources and sinks as they relate to carbon dioxide, the use of indicator solution bromothymol blue (BTB) to reveal the presence of carbon dioxide, and the qualitative differences between animal and fossil fuel sources of global carbon dioxide. The student guide has an overall description of all three parts of the activity, lists of materials, the procedure and observations and questions. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

  16. Reaction of yttrium polonides with carbon dioxide

    SciTech Connect

    Abakumov, A.S.; Khokhlov, A.D.; Reznikova, N.F.

    1986-09-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800/sup 0/C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430/sup 0/C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested.

  17. Reaction of titanium polonides with carbon dioxide

    SciTech Connect

    Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

    1987-05-01

    It has been ascertained that heating titanium and tantalum in carbon dioxide to temperatures of 500 or 800/sup 0/C alters the composition of the gas phase, causing the advent of carbon monoxide and lowering the oxygen content. Investigation of the thermal stability of titanium polonides in a carbon dioxide medium has shown that titanium mono- and hemipolonides are decomposed at temperatures below 350/sup 0/C. The temperature dependence of the vapor pressure of polonium produced in the decomposition of these polonides in a carbon dioxide medium have been determined by a radiotensimetric method. The enthalpy of the process, calculated from this relationship, is close to the enthalpy of vaporization of elementary polonium in vacuo.

  18. 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 in the science and engineering of materials are critical for these new energy technologies, and specific examples are given for all three examples. With sufficient advances, and institutional and political support, such scientific and technological innovations could help to regulate/stabilize the CO2 levels in the atmosphere and thereby extend the use of fossil-fuel-derived feedstocks. PMID:20566515

  19. 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.

  20. 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

  1. Global deforestation: contribution to atmospheric carbon dioxide

    Microsoft Academic Search

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

    1983-01-01

    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 1960 and 1980 was between 135 X 10¹⁵ and 228 X 10¹⁵ grams. Between 1.8 X 10¹⁵ and 4.7 X 10¹⁵ grams of carbon were released in 1980, of which nearly

  2. Carbon Dioxide Fluxes in the Global Ocean

    Microsoft Academic Search

    Andrew J. Watson; James C. Orr

    \\u000a Atmospheric carbon dioxide concentration is one of the key variables of the ‘Earth system’ — the web of interactions between\\u000a the atmosphere, oceans, soils and living things that determines conditions at the Earth surface. Atmospheric CO2 plays several roles in this system. For example, it is the carbon source for nearly all terrestrial green plants, and the\\u000a source of carbonic

  3. Do Plants Really Use Carbon Dioxide?

    NSDL National Science Digital Library

    American Educational Products

    1992-01-01

    This experiment demonstrates that plants use carbon dioxide during photosynthesis. Four Teaching Tanks (commercially available, narrow tanks) are filled with water and bromthymol blue indicator, and Elodea plants are added to two of the tanks. Blowing through a straw into each tank dissolves carbon dioxide into the water and turns the indicator yellow. The tanks are sealed with clay, and a pair of tanks—one tank with Elodea and one without—is put in sunlight, while the other pair is put in darkness. After an hour, the tank with Elodea in sunlight will have returned to blue color. Learners can infer that the carbon dioxide in that tank has been used by the Elodea, since the water in "control" tanks remains yellow. Though designed as a demonstration, this activity could be adapted to allow varying degrees of learner hands-on involvement, and higher grade learners could potentially do all the steps without a demonstrator.

  4. Reduction of Atmospheric Radiocarbon Concentration by Fossil Fuel Carbon Dioxide and the Mean Life of Carbon Dioxide in the Atmosphere

    Microsoft Academic Search

    G. J. Fergusson

    1958-01-01

    It is generally accepted that the combustion of fossil fuels over the period 1860 to 1954 has produced an amount of carbon dioxide, containing no radiocarbon, that is equal to approximately 13% of the carbon dioxide in the atmosphere. The addition of this 'old' carbon dioxide to the atmosphere has observably disturbed the steady-state distribution of carbon-14 in nature. In

  5. Energy levels, intensities, and linewidths of atmospheric carbon dioxide bands

    Microsoft Academic Search

    L. S. Rothman; R. L. Hawkins; R. B. Wattson; R. R. Gamache

    1992-01-01

    Spectroscopic constants are given for eight isotopic variants of carbon dioxide which provide energy levels for transitions required for terrestrial atmospheric IR absorption. A new tabulation is also furnished with bands considered for the latest HITRAN molecular database. This list provides improved band intensities and Herman-Wallis coefficients generated from recent high-resolution measurements and theoretical calculations. Rotationally-dependent air- and self-broadened halfwidths

  6. 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.

  7. Leaf and canopy conductance in aspen and aspen-birch forests under free-air enrichment of carbon dioxide and ozone.

    PubMed

    Uddling, Johan; Teclaw, Ronald M; Pregitzer, Kurt S; Ellsworth, David S

    2009-11-01

    Increasing concentrations of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3) have the potential to affect tree physiology and structure, and hence forest feedbacks on climate. Here, we investigated how elevated concentrations of CO2 (+45%) and O3 (+35%), alone and in combination, affected conductance for mass transfer at the leaf and canopy levels in pure aspen (Populus tremuloides Michx.) and in mixed aspen and birch (Betula papyrifera Marsh.) forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). The study was conducted during two growing seasons, when steady-state leaf area index (L) had been reached after > 6 years of exposure to CO2- and O3-enrichment treatments. Canopy conductance (g(c)) was estimated from stand sap flux, while leaf-level conductance of sun leaves in the upper canopy was derived by three different and independent methods: sap flux and L in combination with vertical canopy modelling, leaf 13C discrimination methodology in combination with photosynthesis modelling and leaf-level gas exchange. Regardless of the method used, the mean values of leaf-level conductance were higher in trees growing under elevated CO2 and/or O3 than in trees growing in control plots, causing a CO2 x O3 interaction that was statistically significant (P < or = 0.10) for sap flux- and (for birch) 13C-derived leaf conductance. Canopy conductance was significantly increased by elevated CO2 but not significantly affected by elevated O3. Investigation of a short-term gap in CO2 enrichment demonstrated a +10% effect of transient exposure of elevated CO2-grown trees to ambient CO2 on g(c). All treatment effects were similar in pure aspen and mixed aspen-birch communities. These results demonstrate that short-term primary stomatal closure responses to elevated CO2 and O3 were completely offset by long-term cumulative effects of these trace gases on tree and stand structure in determining canopy- and leaf-level conductance in pure aspen and mixed aspen-birch forests. Our results, together with the findings from other long-term FACE experiments with trees, suggest that model assumptions of large reductions in stomatal conductance under rising atmospheric CO2 are very uncertain for forests. PMID:19773339

  8. Carbon dioxide opacity of the Venus' atmosphere

    NASA Astrophysics Data System (ADS)

    Snels, Marcel; Stefani, Stefania; Grassi, Davide; Piccioni, Giuseppe; Adriani, Alberto

    2014-11-01

    Venus' atmosphere consists of about 95% of carbon dioxide, which accounts for most of the absorption of the radiation emitted by its hot surface. The large densities and high temperatures of Venus' atmosphere make the absorption much more complex than for low density atmospheres such as Earth or Mars. Available experimental data are at present insufficient and theoretical models inadequate to describe complex absorption line shapes and collision-induced phenomena. Here we present a survey of all absorption and scattering processes which influence the transparency of Venus' atmosphere for what concerns carbon dioxide.

  9. 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.

  10. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Environment 19 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  11. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  12. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  13. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Environment 20 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  14. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Environment 20 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524...Light-Duty Trucks; Idle Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration...

  15. 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.

  16. 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.

  17. 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.

  18. A methodology for forecasting carbon dioxide flooding performance 

    E-print Network

    Marroquin Cabrera, Juan Carlos

    1998-01-01

    A methodology was developed for forecasting carbon dioxide (CO2) flooding performance quickly and reliably. The feasibility of carbon dioxide flooding in the Dollarhide Clearfork "AB" Unit was evaluated using the methodology. This technique is very...

  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. Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and carbon isotope records

    E-print Network

    Jain, Atul K.

    Model-based estimation of the global carbon budget and its uncertainty from carbon dioxide and the terrestrial biosphere based on carbon dioxide and carbon isotope records, and prior information on model of carbon dioxide and the resulting atmospheric concentration of carbon dioxide determined from the behavior

  1. 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.

  2. U.S. Energy-Related Carbon Dioxide Emissions

    EIA Publications

    2014-01-01

    U.S. Energy Information Administration releases its online analysis of 2012 energy-related carbon dioxide emissions today. It indicates U.S. carbon dioxide emissions from the consumption of fossil fuels were 5,290 million metric tons carbon dioxide in 2012, a decrease of almost 4% from the 2011 level. Energy-related carbon dioxide emissions have declined in five of the last seven years and are the lowest they have been since 1994.

  3. Tuning Organic Carbon Dioxide Absorbents for Carbonation and Decarbonation

    PubMed Central

    Rajamanickam, Ramachandran; Kim, Hyungsoo; Park, Ji-Woong

    2015-01-01

    The reaction of carbon dioxide with a mixture of a superbase and alcohol affords a superbase alkylcarbonate salt via a process that can be reversed at elevated temperatures. To utilize the unique chemistry of superbases for carbon capture technology, it is essential to facilitate carbonation and decarbonation at desired temperatures in an easily controllable manner. Here, we demonstrate that the thermal stabilities of the alkylcarbonate salts of superbases in organic solutions can be tuned by adjusting the compositions of hydroxylic solvent and polar aprotic solvent mixtures, thereby enabling the best possible performances to be obtained from the various carbon dioxide capture agents based on these materials. The findings provides valuable insights into the design and optimization of organic carbon dioxide absorbents. PMID:26033537

  4. Tuning organic carbon dioxide absorbents for carbonation and decarbonation.

    PubMed

    Rajamanickam, Ramachandran; Kim, Hyungsoo; Park, Ji-Woong

    2015-01-01

    The reaction of carbon dioxide with a mixture of a superbase and alcohol affords a superbase alkylcarbonate salt via a process that can be reversed at elevated temperatures. To utilize the unique chemistry of superbases for carbon capture technology, it is essential to facilitate carbonation and decarbonation at desired temperatures in an easily controllable manner. Here, we demonstrate that the thermal stabilities of the alkylcarbonate salts of superbases in organic solutions can be tuned by adjusting the compositions of hydroxylic solvent and polar aprotic solvent mixtures, thereby enabling the best possible performances to be obtained from the various carbon dioxide capture agents based on these materials. The findings provides valuable insights into the design and optimization of organic carbon dioxide absorbents. PMID:26033537

  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. 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. (Univ. of Texas, Galveston (United States))

    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.

  7. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Still wines containing carbon dioxide. 26.222 Section 26.222... § 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...

  8. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Still wines containing carbon dioxide. 26.222 Section 26.222... § 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...

  9. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Still wines containing carbon dioxide. 26.52 Section 26.52...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...

  10. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Still wines containing carbon dioxide. 26.52 Section 26.52...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...

  11. Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by

    E-print Network

    Paris-Sud XI, Université de

    Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by Tetrahydrofuran, Cyclopentane;______________________________________________________________________ ____________________________________________________________________________________ 2 Abstract Gas clathrate hydrate dissociation pressures are reported for mixtures of carbon dioxide) equilibrium data are presented for the ternary system of water-cyclopentane-carbon dioxide at temperatures

  12. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  13. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  14. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  15. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  18. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  19. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

  20. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  1. Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere

    E-print Network

    Olver, Peter

    Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline,840 · Oxygen (O2) 209,460 · Argon (Ar) 9340 · Carbon dioxide (CO2) 394 · Methane (CH4) 1.79 · Ozone (O3) 0 wavelength of interest is about 400 times the size of a carbon dioxide molecule. Interaction is via

  2. Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis

    E-print Network

    Electrostatic Stabilization of Colloids in Carbon Dioxide: Electrophoresis and Dielectrophoresis in supercritical fluid carbon dioxide (scCO2). Herein we demonstrate that colloids may also be stabilized in CO2 the behavior of steric stabilization in compressed supercritical fluids1-3 including carbon dioxide,4

  3. Thermal Properties of Supercritical Carbon Dioxide by Monte Carlo Simulations

    E-print Network

    Lisal, Martin

    Thermal Properties of Supercritical Carbon Dioxide by Monte Carlo Simulations C.M. COLINAa,b, *, C and speed of sound for carbon dioxide (CO2) in the supercritical region, using the fluctuation method based: Fluctuations; Carbon dioxide; 2CLJQ; Joule­Thomson coefficient; Speed of sound INTRODUCTION Simulation methods

  4. Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in

    E-print Network

    Rochelle, Gary T.

    Copyright by Chukwuemeka I. Okoye 2005 #12;Carbon Dioxide Solubility and Absorption Rate _______________________ Nicholas A. Peppas #12;Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O for. #12;iii Carbon Dioxide Solubility and Absorption Rate in Monoethanolamine/Piperazine/H2O

  5. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Carbon dioxide record. 24.319 Section 24.319...WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a...

  6. World Energy Consumption and Carbon Dioxide Emissions: 1950 2050

    E-print Network

    . Stoker, andRuth A. Judson* Emissions of carbon dioxide from combustion of fossil fuels, which mayWorld Energy Consumption and Carbon Dioxide Emissions: 1950 Ñ 2050 Richard Schmalensee, Thomas M-U" relation with a within- sample peak between carbon dioxide emissions (and energy use) per capita and per

  7. Estimated Carbon Dioxide Emissions in 2008: United States

    Microsoft Academic Search

    C A Smith; A J Simon; R D Belles

    2011-01-01

    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

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

    E-print Network

    Designed amyloid fibers as materials for selective carbon dioxide capture Dan Lia,b,c,1 , Hiroyasu demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence

  9. Potassium intercalation of carbon onions ‘opened’ by carbon dioxide treatment

    Microsoft Academic Search

    Yu. V. Butenko; Amit K. Chakraborty; N. Peltekis; S. Krishnamurthy; V. R. Dhanak; M. R. C. Hunt; L. Šiller

    2008-01-01

    The potassium intercalation of onion-like carbon (OLC) samples consisting of aggregates of carbon onions is studied with photoemission spectroscopy. OLC samples were initially prepared by annealing nanodiamonds (3–20nm in diameter) at 1800K in vacuum. The resulting OLC consists of closed fullerene-like shells. The ‘closed’ OLC was subsequently treated with carbon dioxide at 1020K in order to open the carbon shells

  10. Carbon dioxide emission from european estuaries

    PubMed

    Frankignoulle; Abril; Borges; Bourge; Canon; Delille; Libert; Theate

    1998-10-16

    The partial pressure of carbon dioxide (pCO2) in surface waters and related atmospheric exchanges were measured in nine European estuaries. Averaged fluxes over the entire estuaries are usually in the range of 0.1 to 0.5 mole of CO2 per square meter per day. For wide estuaries, net daily fluxes to the atmosphere amount to several hundred tons of carbon (up to 790 tons of carbon per day in the Scheldt estuary). European estuaries emit between 30 and 60 million tons of carbon per year to the atmosphere, representing 5 to 10% of present anthropogenic CO2 emissions for Western Europe. PMID:9774261

  11. The Swedish carbon dioxide tax: effects on biofuel use and carbon dioxide emissions

    Microsoft Academic Search

    Folke Bohlin

    1998-01-01

    The Swedish carbon dioxide tax was introduced in 1991, by adjusting the existing energy taxation to consider the carbon load of fuels. The tax was initially set at a general level of US $13311The exchange rate used in this paper is US $1=7.5 SEK (Swedish krona) per ton carbon (tc). It was differentiated in 1993, with the result that industry

  12. Modelling carbon dioxide accumulation at Sleipner: Implications for underground carbon storage

    E-print Network

    Huppert, Herbert

    Modelling carbon dioxide accumulation at Sleipner: Implications for underground carbon storage Mike dioxide; Viscous flow; Gravity flow 1. Introduction Disposal of carbon dioxide in geological reservoirs;questions about the environmental benefits of this process concern the fate of the carbon dioxide over

  13. 78 FR 28143 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Sulfur Dioxide and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ...Plans; Indiana; Sulfur Dioxide and Nitrogen Dioxide Ambient Air Quality Standards...state implementation plan (SIP) for nitrogen dioxide (NO 2 ) and sulfur dioxide... and SO 2 NAAQS revised by EPA? Nitrogen Dioxide (NO2) On February 9,...

  14. Paleoclimatic warming increased carbon dioxide concentrations

    Microsoft Academic Search

    D. M. Lemoine

    2010-01-01

    If climate-carbon feedbacks are positive, then warming causes changes in carbon dioxide (CO2) sources and sinks that increase CO2 concentrations and create further warming. Previous work using paleoclimatic reconstructions has not disentangled the causal effect of interest from the effects of reverse causality and autocorrelation. The response of CO2 to variations in orbital forcing over the past 800,000 years suggests

  15. Large growth seen for carbon dioxide pipelines

    Microsoft Academic Search

    Boecker

    1984-01-01

    A new and fast growing potential market for the pipeline industry is for lines for transporting carbon dioxide which has proven to be an excellent and economic method of enhanced recovery in older oil fields. The technical feasibility of such pipelines has been established with two large systems completed in the US last year and many more now in the

  16. Carbon Dioxide Capture, Transport and Storage

    Microsoft Academic Search

    Li He-nan; Li Fang-qin; Ren Jian-xing; Hao Zhi-wu

    2010-01-01

    It is known to all that potential global climate change has a great deal to do with anthropogenic emissions of CO2. The carbon dioxide emissions from the exhaust gases of the fossil fuel-fired power plants account for about a third of global CO2 emissions and are increasing in the last decades. At this context, this work presents a survey on

  17. Carbon dioxide storage potential of shales

    Microsoft Academic Search

    Andreas Busch; Sascha Alles; Yves Gensterblum; Dirk Prinz; David N. Dewhurst; Mark D. Raven; Helge Stanjek; Bernhard M. Krooss

    2008-01-01

    Options for the geologic storage of carbon dioxide vary from saline aquifers and depleted oil and gas reservoirs to unminable coal seams and abandoned coal mines. Important aspects include the sealing integrity of the cap rock and potential changes in this integrity, owing to the interaction with CO2.In this study, diffusive transport and gas sorption experiments on one well characterised

  18. CDIAC: Carbon Dioxide Information Analysis Center

    NSDL National Science Digital Library

    This site is the homepage of the Carbon Dioxide Information Analysis Center (CDIAC) which includes the World Data Center for Atmospheric Trace Gases. CDIAC is the primary global-change data and information analysis center of the U.S. Department of Energy (DOE). CDIAC responds to data and information requests from users from all over the world who are concerned with the greenhouse effect and global climate change. CDIAC's data holdings include records of the concentrations of carbon dioxide and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of carbon dioxide to the atmosphere; long-term climate trends; the effects of elevated carbon dioxide on vegetation; and the vulnerability of coastal areas to rising sea level. In operation since 1982, CDIAC: obtains, evaluates, and archives data, compiles and distributes digital numeric data packages and computer model packages, provides data management support to global-change related scientific projects, distributes related reports, produces the newsletter, CDIAC Communications, and in general acts as the information focus for the U.S. DOE Global Change Research Program. CDIAC is supported by DOE's Environmental Sciences Division of the Office of Biological and Environmental Research. CDIAC represents DOE in the multi-agency Global Change Data and Information System.

  19. The Emission Spectrum of Carbon Dioxide

    Microsoft Academic Search

    H. D. Smyth

    1931-01-01

    The emission spectrum of carbon dioxide has been studied by the electron beam excitation method used by Smyth and Arnott. The whole range of the spectrum from 6500 to 1400 has been examined and only the bands reported by Fox, Duffendack and Barker in the region from 2700 to 5000 have been observed. A particular effort was made to get

  20. Acid sorption regeneration process using carbon dioxide

    DOEpatents

    King, C. Judson (Kensington, CA); Husson, Scott M. (Anderson, SC)

    2001-01-01

    Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.

  1. Atmospheric carbon dioxide record from Mauna Loa

    NSDL National Science Digital Library

    The Scripps Institute of Oceanography has released these data consisting of monthly carbon dioxide concentrations at Mauna Loa 1958-1999. Measurements were made using a nondispersive infrared gas analyzer with a water vapor freeze trap. The data are available as graphs or tables. The text includes a brief overview of the methods and a reference list.

  2. Ocean Acidification: The Other Carbon Dioxide Problem

    NSDL National Science Digital Library

    NOAA

    This NOAA video discusses how the ocean absorbs the increased amount of carbon dioxide released into the atmosphere, thereby changing the pH and buffering action of the ocean. These changes in pH are impacting calcifying organisms, such as corals and shellfish, and related food chains and ecosystems.

  3. Carbon dioxide emissions of Antarctic tourism

    Microsoft Academic Search

    R. Farreny; J. Oliver-Solà; M. A. J. Lamers; B. Amelung; X. Gabarrell; J. Rieradevall; M. Boada; J. Benayas

    2011-01-01

    The increase of tourism to the Antarctic continent may entail not only local but also global environmental impacts. These latter impacts, which are mainly caused by transport, have been generally ignored. As a result, there is a lack of data on the global impacts of Antarctic tourism in terms of energy consumption and carbon dioxide emissions. This paper presents and

  4. Recent Events: a Perspective on Carbon Dioxide

    NSDL National Science Digital Library

    2012-08-03

    In this problem set, learners will compare the carbon dioxide produced as a result of two 2010 events: the eruption of the Eyjafjalla Volcano and the burning of oil on the ocean surface to address the Gulf of Mexico oil spill. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  5. Synthetic fuels, carbon dioxide and climate

    Microsoft Academic Search

    Alex R. Sapre; John R. Hummel; Ruth A. Reck

    1982-01-01

    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

  6. Synthetic fuels, carbon dioxide and climate

    Microsoft Academic Search

    Alex R. Sapre; John R. Hummel; Ruth A. Reck

    1982-01-01

    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

  7. The Transport Properties of Carbon Dioxide

    Microsoft Academic Search

    V. Vesovic; W. A. Wakeham; G. A. Olchowy; J. V. Sengers; J. T. R. Watson; J. Millat

    1990-01-01

    The paper contains new, representative equations for the viscosity and thermal conductivity of carbon dioxide. The equations are based in part upon a body of experimental data that have been critically assessed for internal consistency and for agreement with theory whenever possible. In the case of the low-density thermal conductivity at high temperatures, all available data are shown to be

  8. Carbon Dioxide Corrosion and Inhibition Studies

    E-print Network

    Petta, Jason

    · Corrosion inhibition very important in the oil industry · Film forming inhibitors containing nitrogen inhibitor for CO2 corrosion · Electrochemistry provides useful ways to study corrosion · At room temperatureCarbon Dioxide Corrosion and Inhibition Studies Kristin Gilida #12;Outline · Background

  9. Sterilization using high-pressure carbon dioxide

    Microsoft Academic Search

    Jian Zhang; Thomas A. Davis; Michael A. Matthews; Michael J. Drews; Martine LaBerge; Yuehuei H. An

    2006-01-01

    Sterility is required for medical devices use in invasive medical procedures, and for some situations in the food industry. Sterilization of heat-sensitive or porous materials or devices, such as endoscopes, porous implants, liquid foodstuff, and liquid medicine, poses a challenge to current technologies. There has been a steady interest in using high-pressure carbon dioxide as a process medium for new

  10. CORROSION OF ALLOY STEELS IN CARBON DIOXIDE

    Microsoft Academic Search

    A. Draycott; B. J. Fox; R. W. Hubery

    1962-01-01

    The corrosion of 1% Cr, 1\\/2% Mo and 2 1\\/4% Cr, 1% Mo steels in carbon ; dioxide was measured within the temperature range 450 to 500 deg C and the ; pressure range 0 to 15 atmospheres. The effects of gas velocity, surface ; preparation, and water content of the gas were also determined. Some results of ; a

  11. Photobiological hydrogen production and carbon dioxide sequestration

    Microsoft Academic Search

    Halil Berberoglu

    2008-01-01

    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

  12. CARBON DIOXIDE SEQUESTRATION: WHEN AND HOWMUCH?

    Microsoft Academic Search

    Klaus Keller; Zili Yang; Matt Hall; David F. Bradford

    2003-01-01

    We analyze carbon dioxide (CO sequestration as a strategy to manage future climate change in an optimal economic growth framework. We approach the problem in two ways: first, by using a simple analytical model, and second, by using a numerical optimization model which allows us to explore the problem in a more realistic setting. CO sequestration is not a perfect

  13. Carbon dioxide exchange in a peatland ecosystem

    Microsoft Academic Search

    N. J. Shurpali; S. B. Verma; J. Kim; T. J. Arkebauer

    1995-01-01

    Micrometeorological measurements of carbon dioxide exchange were made in an open peatland in north central Minnesota during two growing seasons (1991 and 1992). The vegetation at the site was dominated by Sphagnum papillosum, Scheuchzeria palustris, and Chamaedaphne calyculata. The objective of the study was to examine the diurnal and seasonal variations in canopy photosynthesis (P) and develop information on the

  14. 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.

  15. Passive Colorimetric Dosimeter Tubes for Ammonia, Carbon Monoxide, Carbon Dioxide, Hydrogen Sulfide, Nitrogen Dioxide and Sulfur Dioxide

    Microsoft Academic Search

    PAUL W. McCONNAUGHEY; ELMER S. McKEE; IRVIN M. PRITTS

    1985-01-01

    Colorimetric, stain length, personal dosimeters operating by gas diffusion have been developed to determine worker exposure for up to an eight-hour period for several inorganic airborne contaminants in the range of their Threshold Limit Values. Length of stain, colorimetric dosimeters have been made for the detection of ammonia (NH3), carbon monoxide (CO), carbon dioxide (CO2), hydrogen sulfide (H2S), nitrogen dioxide

  16. Carbon Dioxide Production at Home

    NSDL National Science Digital Library

    2012-08-03

    In this problem set, learners will consider the "Carbon Footprint" of a family of four in a given context, as well as the US and global averages, and compare that with their own to answer a series of questions. They will use an online Carbon Footprint calculator to determine their own per-capita carbon production. Answer key is provided. This problem is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  17. High Levels of Carbon Dioxide Threaten Oyster Survival

    NSDL National Science Digital Library

    APS Communications Office (American Physiological Society Communications Office)

    2010-08-04

    It has been widely reported that the build up of carbon dioxide (CO2) in the air, which is caused by human behavior, will likely lead to climate change and have major implications for life on earth. But less focus has been given to global warmingÂ?s evil twin, ocean acidification, which occurs when CO2 lowers the pH of water bodies, thus making them more acidic. This lesser known phenomenon may have catastrophic effects on all sea life. Inna Sokolova, associate professor of biology at the University of North Carolina at Charlotte, studies the affect of high carbon dioxide on oyster survival, growth and shell hardness. The results of her research suggest that creatures once thought to be fairly adaptable to changes in the environment, may be in serious trouble.

  18. Mechanistical studies on the formation and destruction of carbon monoxide (CO), carbon dioxide (CO2), and carbon trioxide (CO3)

    E-print Network

    Kaiser, Ralf I.

    Mechanistical studies on the formation and destruction of carbon monoxide (CO), carbon dioxide (CO2 monoxide (CO), carbon dioxide (CO2), and molecular oxygen (O2) with varying carbon-to-oxygen ratios from 1 and destruction pathways of carbon monoxide (CO), carbon dioxide (CO2), and carbon trioxide (CO3

  19. Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide ices

    E-print Network

    Kaiser, Ralf I.

    Untangling the formation of the cyclic carbon trioxide isomer in low temperature carbon dioxide of the cyclic carbon trioxide isomer, CO3(X 1 A1), in carbon-dioxide-rich extraterrestrial ices and in the atmospheres of Earth and Mars were investigated experimentally and theoretically. Carbon dioxide ices were

  20. Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes

    E-print Network

    Follows, Mick

    Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes), Analytical relationships between atmospheric carbon dioxide, carbon emissions, and ocean processes, Global Biogeochem. Cycles, 22, GB3030, doi:10.1029/2008GB003184. 1. Introduction [2] Atmospheric carbon dioxide

  1. Modeling the selectivity of activated carbons for efficient separation of hydrogen and carbon dioxide

    E-print Network

    Wu, Jianzhong

    the separation of hydrogen and carbon dioxide via adsorption in activated carbons. In the simulations, both hydrogen and carbon dioxide molecules are modeled as Lennard-Jones spheres, and the activated carbons essentially no preference over the two gases and the selectivity of carbon dioxide relative to hydrogen falls

  2. Carbon dioxide capture from fossil fuel power plants using dolomite

    Microsoft Academic Search

    Drupatie Latchman

    2010-01-01

    The main objective of this research is to develop a simple and cost effective separation method that captures carbon dioxide from power plant flue gas, as a pure stream that can be stored using regenerable dolomite (calcium magnesium carbonate) as the sorbent. The developed dolomite sorbent was evaluated for carbon dioxide capture capacity using muti-cycle tests of cyclical carbonation\\/calcination experiments

  3. Carbon Dioxide Capture DOI: 10.1002/anie.201000431

    E-print Network

    ] Carbon capture and storage (CCS) schemes embody a group of technologies for the capture of CO2 from power environmental concerns of our age. Carbon capture and storage (CCS) from large point sources such as powerCarbon Dioxide Capture DOI: 10.1002/anie.201000431 Carbon Dioxide Capture: Prospects for New

  4. 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.

  5. Carbon Dioxide: Production and Sequestration

    NSDL National Science Digital Library

    2012-08-03

    In this problem set, learners will refer to a satellite image to calculate the rate of carbon sequestration in the areas of bare land and forested lawn shown to answer a series of questions. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

  6. Limiting future atmospheric carbon dioxide

    Microsoft Academic Search

    Jorge L. Sarmiento; C. L. Quere; Stephen W. Pacala

    1995-01-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric COâ at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear

  7. 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 conditions, have achieved roughly 83% conversion of heat treated serpentine and 84% conversion of olivine to the carbonate in 6 hours. The results from the current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, or some combination of the two. Future tests are intended to examine a broader pressure/temperature regime, various pretreatment options, as well as other mineral groups.

  8. Carbon Dioxide Absorption from Anæsthetic Atmospheres 1

    PubMed Central

    Waters, Ralph M.

    1936-01-01

    A safe and practical technique for the application of carbon dioxide absorption from anæsthetic atmospheres is described. It has been found satisfactory in over 20,000 administrations over a period of fifteen years. High-grade soda lime is utilized as the chemical absorbent. Granules are placed in a canister between face mask, and breathing bag. The canister is carefully checked for efficiency by both chemical analyses and physical experiments. Its size, shape and arrangement is shown to be important for safety and maximum efficiency. Detailed techniques are described for the use of various agents. Advantages of carbon dioxide absorption are set forth. The “Apnœa” suggested by Guedel is described under the term “Controlled Respiration” and attention is called to certain of its advantages. ImagesFig. 2Fig. 6Fig. 7Fig. 8 PMID:19990907

  9. Climate Impact of Increasing Atmospheric Carbon Dioxide

    Microsoft Academic Search

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

    1981-01-01

    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

  10. Transport of Carbon Dioxide and Radioactive Waste

    Microsoft Academic Search

    Darío R. Gómez; Michael Tyacke

    \\u000a A comparative assessment of carbon dioxide (CO2) and radioactive waste transport systems associated with electricity generation was undertaken on the basis of 15 criteria\\u000a grouped under three areas, namely the transport chain, policy aspects and state of the technology. For CO2, we considered exclusively the transport that would take place under a future large-scale capture and storage infrastructure.\\u000a Our study

  11. World Carbon Dioxide Emissions: 1950-2050

    Microsoft Academic Search

    Richard Schmalensee; Thomas M. Stoker; Ruth A. Judson

    1998-01-01

    Emissions of carbon dioxide from the combustion of fossil fuels, which may contribute to long-term climate change, are projected through 2050 using reduced-form models estimated with national-level panel data for the period of 1950-1990. Using the same set of income and population growth assumptions as the Intergovernmental Panel on Climate Change (IPCC), we find that the IPCC's widely used emissions

  12. Carbon dioxide neutral, integrated biofuel facility

    Microsoft Academic Search

    E. E. Powell; G. A. Hill

    2010-01-01

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO2 from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce

  13. Sequestration — The Underground Storage of Carbon Dioxide

    Microsoft Academic Search

    Sam Holloway

    Underground storage of industrial quantities of carbon dioxide in porous and permeable reservoir rocks has been taking place\\u000a for the last 11 years at the Sleipner West gas field in the North Sea. A further commercial-scale CO2 storage project has recently begun at In Salah, Algeria, and the Snohvit field, Barents Sea, is to begin injecting CO2 underground in late

  14. Carbon dioxide absorption kinetics in potassium threonate

    Microsoft Academic Search

    A. F. Portugal; F. D. Magalhães; A. Mendes

    2008-01-01

    The absorption of carbon dioxide in potassium threonate aqueous solutions is studied at concentrations ranging from 0.1 to 3M and temperatures from 293 to 313K. This study includes experimental density, viscosity, solubility of N2O and absorption kinetics of CO2 (using a stirred cell reactor) data obtained for the various potassium threonate solutions. The diffusion coefficients of CO2 and potassium threonate

  15. 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.

  16. Carbon dioxide makes heat therapy work

    Microsoft Academic Search

    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°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

  17. Improved immobilized carbon dioxide capture sorbents

    Microsoft Academic Search

    M. L. Gray; Y. Soong; K. J. Champagne; H. Pennline; J. P. Baltrus; R. W. Stevens Jr.; R. Khatri; S. S. C. Chuang; T. Filburn

    2005-01-01

    The capture of carbon dioxide from simulated flue gas streams has been achieved by using immobilized and aminated-SBA-15 solid sorbents. SBA-15, a mesoporous silica material with a uniform pore size of 21 nm and a surface area of 200?230 m2\\/g. The solid sorbents prepared in this study exhibit similar or improved capacities relative to those already used to control CO2

  18. Carbon dioxide capture with concentrated, aqueous piperazine

    Microsoft Academic Search

    Stephanie A. Freeman; Ross Dugas; David H. Van Wagener; Thu Nguyen; Gary T. Rochelle

    2010-01-01

    Concentrated, aqueous piperazine (PZ) has been investigated as a novel amine solvent for carbon dioxide (CO2) absorption. The CO2 absorption rate of aqueous PZ is more than double that of 7m MEA and the amine volatility at 40°C ranges from 11 to 21ppm. Thermal degradation is negligible in concentrated, aqueous PZ up to a temperature of 150°C, a significant advantage

  19. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following... (1) All plates for tank, manway nozzle and anchorage...section of the printed volume and at...

  20. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following... (1) All plates for tank, manway nozzle and anchorage...section of the printed volume and at...

  1. 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.

  2. Fluid Mechanical Modelling of Carbon Dioxide Sequestration

    NASA Astrophysics Data System (ADS)

    Huppert, H. E.

    2007-12-01

    The flow of supercritical carbon dioxide against an impermeable caprock will be considered from a theoretical and experimental point of view. A series of fundamental problems will be presented, along with some laboratory simulations. It will be shown that in the simplest case, when the caprock is totally impermeable and horizontal, with viscosity differences between the supercritical carbon dioxide and the fluid into which it is intruding neglected, the radius of the spreading of carbon dioxide increases like the square root of time. We will then consider the influence of a sloping caprock, where for time short compared to some critical time, ?c, the spreading pool is close to axisymmetric, while for times very much greater than ?c it is approximately three times larger in the upslope than cross-slope direction. For typical geological conditions, ?c can vary from between days and years, and hence the observed shape will depend on details at the injection site. A discussion of the effects of different viscosities of the intruding and intruded fluid will be presented and the important non- dimensional physical parameters outlined. The talk will conclude with a discussion of very recent research on the effects of heterogeneous porosity in the ambient and an application of the results to the analysis of the observations at Sleipner. The talk will be illustrated by colour movie sequences of experiments and a real desk- top experiment.

  3. Carbon Dioxide Aquariums Greenhouse Gas Lesson

    NSDL National Science Digital Library

    Orzali, Joe

    2009-01-01

    This classroom activity looks at carbon dioxide and its role in climate change. Students will perform an in-class experiment using aquariums. CO2 gas will be added to one aquarium, and measurements are taken of both aquariums over a one or two week period. This lesson includes step by step instructions on carrying out the experiment. The unit is a good introduction to the concepts of the carbon cycle, heat transfer, energy flow in ecosystems, the human impact on ecosystems and climate, non-renewable energy, resource consumption and pollution. This document may be downloaded in PDF file format. A class worksheet is included with the document.

  4. Carbon dioxide sensitivity of zeolitic imidazolate frameworks.

    PubMed

    Mottillo, Cristina; Friš?i?, Tomislav

    2014-07-14

    Zeolitic imidazolate frameworks of zinc, cobalt, and cadmium, including the framework ZIF-8 commercially sold as Basolite Z1200, exhibit surprising sensitivity to carbon dioxide under mild conditions. The frameworks chemically react with CO2 in the presence of moisture or liquid water to form carbonates. This effect, which has been previously not reported in metal-organic framework chemistry, provides an explanation for conflicting reports on ZIF-8 stability to water and is of outstanding significance for evaluating the potential applications of metal-organic frameworks, especially for CO2 sequestration. PMID:24889776

  5. 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.

  6. Carbon dioxide on the early earth.

    PubMed

    Walker, J C

    1985-01-01

    This paper uses arguments of geochemical mass balance to arrive at an estimate of the partial pressure of carbon dioxide in the terrestrial atmosphere very early in earth history. It appears that this partial pressure could have been as large as 10 bars. This large estimate depends on two key considerations. First, volatiles were driven out of the interior of the earth during the course of earth accretion or very shortly thereafter. This early degassing was a consequence of rapid accretion,which gave the young earth a hot and rapidly convecting interior. Second, the early earth lacked extensive, stable continental platforms on which carbon could be stored in the form of carbonate minerals for geologically significant periods of time. In the absence of continental platforms on the early earth, the earth's carbon must have been either in the atmosphere or ocean or in the form of shortlived sedimentary deposits on ephemeral sea floor. PMID:11542014

  7. Changes in Strawberry Anthocyanins and Other Polyphenols in Response to Carbon Dioxide Treatments

    Microsoft Academic Search

    Maria I. Gil; Deirdre M. Holcroft; Adel A. Kader

    1997-01-01

    Carbon dioxide-enriched atmospheres are used to reduce the incidence and severity of decay and to extend the postharvest life of strawberries. The influence of CO2 on the postharvest quality parameters of strawberries, particularly the stability of anthocyanins and other phenolic compounds, was investigated. Freshly harvested strawberries were placed in jars ventilated continuously with air or air enriched with 10%, 20%,

  8. Carbon dioxide solubility and carbon isotope fractionation in basaltic melt

    SciTech Connect

    Mattey, D.P. (Univ. of London, Egham Hill (United Kingdom) Univ. of Tasmania, Hobart (Australia))

    1991-11-01

    Carbon dioxide solubility and isotope fractionation data for a MORB composition at 1,200-1,400C and 5-20 kbar have been obtained using piston-cylinder apparatus and stepped-heating mass spectrometry. Carbon dioxide solubility in basalt melt at 5, 10 and 20 kbar is 0.15-0.17%, 0.45-0.51%, and 1.49%, respectively. Values for {Delta}Co{sub 2}(vap) - CO 2/3{sup {minus}} (basalt melt), obtained from the difference between the isotopic compositions for coexisting vapor and melt, vary from 1.8% to 2.2%. A review of measured and estimated values for carbon isotope fractionation between CO{sub 2} vapor and carbon dissolved in basic melts shows variation from 1.8% to 4.6%. Results of this study and other considerations favor relatively small equilibrium CO{sub 2} vapor melt fractionation factors around 2%.

  9. Limiting future atmospheric carbon dioxide

    NASA Astrophysics Data System (ADS)

    Sarmiento, Jorge L.; Le QuéRé, Corinne; Pacala, Stephen W.

    1995-03-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric CO2 at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear dependence of oceanic and terrestrial biospheric uptake on CO2 concentration, the uptake by these two sinks decreases substantially at higher atmospheric CO2 levels. The uptake also decreases with increased atmospheric CO2 growth rate. All the stabilization scenarios require a substantial future reduction in emissions.

  10. Carbon dioxide uptake efficiency by outdoor microalgal cultures in tubular airlift photobioreactors

    Microsoft Academic Search

    T. Mazzuca Sobczuk; F. García Camacho; F. Camacho Rubio; F. G. Acién Fernández; E. Molina Grima

    2000-01-01

    The influence of solar irradiance and carbon dioxide molar fraction of injected CO2-air mixtures on the behavior of outdoor continuous cultures of the mi- croalga Phaeodactylum tricornutum in tubular airlift pho- tobioreactors was analyzed. Instantaneous solar irradi- ance, pH, dissolved oxygen, temperature, biomass con- centration, and the mass flow rates of both the inlet and outlet oxygen and carbon with

  11. 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.

  12. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    Norby, Richard J [ORNL; Jastrow, Julie D [ORNL; Miller, Michael R [ORNL; Matamala, Roser [Argonne National Laboratory (ANL); Boutton, Thomas W [Texas A& M University; Rice, Charles W [ORNL; Owensby, Clenton E [Kansas State University

    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.

  13. Carbon dioxide-methane mixture adsorption on activated carbon

    Microsoft Academic Search

    V. Goetz; O. Pupier; A. Guillot

    2006-01-01

    In this work, we report new experimental data of pure and binary adsorption equilibria of carbon dioxide and methane on the\\u000a activated carbon RB2 at 273 and 298 K. The pressure range studied were 0–3.5 MPa for pure gases and 0–0.1 MPa for mixtures.\\u000a The combination of the generalized Dubinin model to describe the pure CO2 and CH4 isotherms with

  14. Carbon dioxide disposal in carbonate minerals

    Microsoft Academic Search

    Klaus S. Lackner; Christopher H. Wendt; Darryl P. Butt; Edward L. Joyce; David H. Sharp

    1995-01-01

    We introduce a safe and permanent method of CO2 disposal based on combining CO2 chemically with abundant raw materials to form stable carbonate minerals. Substantial heat is liberated in the overall chemical reaction so that cost will be determined by the simplicity and speed of the reaction rather than the cost of energy. Preliminary investigations have been conducted on two

  15. Atmospheric Carbon Dioxide and Carbon Reservoir Changes

    Microsoft Academic Search

    Minze Stuiver

    1978-01-01

    The net release of CO2 from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 × 109 tons of carbon per year. During this interval, changes in land use reduced the total terrestrial biomass by 7 percent. There has been a smaller reduction in biomass over the last few decades. In the middle 19th

  16. Limiting future atmospheric carbon dioxide

    SciTech Connect

    Sarmiento, J.L.; Quere, C.L.; Pacala, S.W. [Princeton Univ., NJ (United States)] [Princeton Univ., NJ (United States)

    1995-03-01

    We estimate anthropogenic carbon emissions required to stabilize future atmospheric CO{sub 2} at various levels ranging from 350 ppm to 750 ppm. Over the next three centuries, uptake by the ocean and terrestrial biosphere would permit emissions to be 3 to 6 times greater than the total atmospheric increase, with each of them contributing approximately equal amounts. Owing to the nonlinear dependence of oceanic and terrestrial biospheric uptake on CO{sub 2} concentration, the uptake by these two sinks decreases substantially at higher atmospheric CO{sub 2} levels. The uptake also decreases with increased atmospheric CO{sub 2} growth rate. All the stabilization scenarios require a substantial future reduction in emissions. 57 refs., 20 figs., 3 tabs.

  17. [Colonoscopy with carbon dioxide insufflation: luxury or neccesity?].

    PubMed

    Herráiz, Maite

    2013-01-01

    Colonoscopy is an essential diagnostic and therapeutic tool for many gastrointestinal diseases and is also a key element in the prevention and early diagnosis of colon cancer. Despite numerous technical advances, colonoscopy continues to be uncomfortable for patients, both during and after the procedure. To a large extent, the discomfort of colonoscopy depends on the need to distend the colon, which usually produces abdominal pain. Although ambient air is usually employed to expand and inflate the colon, in the last few years devices that allow carbon dioxide (CO(2)) insufflation in colonoscopy have been developed. This gas is a highly attractive option for pain-free colonoscopy. PMID:23218772

  18. 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.

  19. 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

  20. Robust carbon dioxide reduction on molybdenum disulphide edges.

    PubMed

    Asadi, Mohammad; Kumar, Bijandra; Behranginia, Amirhossein; Rosen, Brian A; Baskin, Artem; Repnin, Nikita; Pisasale, Davide; Phillips, Patrick; Zhu, Wei; Haasch, Richard; Klie, Robert F; Král, Petr; Abiade, Jeremiah; Salehi-Khojin, Amin

    2014-01-01

    Electrochemical reduction of carbon dioxide has been recognized as an efficient way to convert carbon dioxide to energy-rich products. Noble metals (for example, gold and silver) have been demonstrated to reduce carbon dioxide at moderate rates and low overpotentials. Nevertheless, the development of inexpensive systems with an efficient carbon dioxide reduction capability remains a challenge. Here we identify molybdenum disulphide as a promising cost-effective substitute for noble metal catalysts. We uncover that molybdenum disulphide shows superior carbon dioxide reduction performance compared with the noble metals with a high current density and low overpotential (54?mV) in an ionic liquid. Scanning transmission electron microscopy analysis and first principle modelling reveal that the molybdenum-terminated edges of molybdenum disulphide are mainly responsible for its catalytic performance due to their metallic character and a high d-electron density. This is further experimentally supported by the carbon dioxide reduction performance of vertically aligned molybdenum disulphide. PMID:25073814

  1. 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

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

    NASA Astrophysics Data System (ADS)

    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.

  3. 78 FR 28173 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Sulfur Dioxide and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ...Quality Implementation Plans; Indiana; Sulfur Dioxide and Nitrogen Dioxide Ambient Air Quality Standards AGENCY: Environmental...to revise the Indiana state implementation plan (SIP) for nitrogen dioxide (NO 2 ) and sulfur dioxide (SO 2 )...

  4. Carbon Dioxide Production in the Oxidation of Organic

    E-print Network

    Steinbock, Oliver

    Carbon Dioxide Production in the Oxidation of Organic Acids by Cerium(IV) under Aerobic are oxidized to carbon dioxide. Hence, the determination of the stoichiometry between produced CO2 and reduced The study of oxidation of relatively low molecular weight carbonic acids by metal ions has been an active

  5. Development of a Carbon Dioxide Monitoring Rotorcraft Unmanned Aerial Vehicle

    E-print Network

    Zimmer, Uwe

    stage to prevent potential danger to workforce and material, and carbon capture and sequestration (CCSDevelopment of a Carbon Dioxide Monitoring Rotorcraft Unmanned Aerial Vehicle Florian Poppa and Uwe the development of a carbon dioxide (CO2) sensing rotorcraft unmanned aerial vehicle (RUAV) and the experiences

  6. www.sciam.com SCIENTIFIC AMERICAN 49 Pumping carbon dioxide

    E-print Network

    O'Donnell, Tom

    increasing attention: capturing carbon dioxide and storing, or seques- tering, it underground rather than re for capture and storage already exists and that the obstacles hindering implementa- tion seem to be surmountable. Carbon Dioxide Capture the combustion of fossil fuels pro- duces huge quantities of carbon

  7. Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study

    E-print Network

    1 Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha Kothandaraman Students #12;2 #12;3 Carbon Dioxide Capture by Chemical Absorption: A Solvent Comparison Study by Anusha with electricity generation accounting for 40% of the total1 . Carbon capture and sequestration (CCS) is one

  8. Carbon dioxide: A substitute for phosgene

    SciTech Connect

    Aresta, M.; Quaranta, E. [Univ. of Bari (Italy)

    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.

  9. Carbon dioxide exchange and early old-field succession

    Microsoft Academic Search

    Ryan E. Emanuel; John D. Albertson; Howard E. Epstein; Christopher A. Williams

    2006-01-01

    Old-field succession is a widespread process active in shaping landscapes in the eastern United States, contributing significantly to the terrestrial sink of atmospheric carbon dioxide, particularly at midlatitudes. However, few studies document ecosystem-scale carbon dioxide exchange during the early years of old-field succession, particularly during the temporal transition from cultivation to abandonment. Rates of carbon dioxide exchange were measured for

  10. Carbon Dioxide Sequestration and ECBM in the Powder River Basin

    Microsoft Academic Search

    L. B. Colmenares; M. D. Zoback

    2003-01-01

    Coal seams are both a source of coal bed methane (CBM) and a potential carbon dioxide sink. For sub-bituminous coals like those in the Powder River Basin (PRB), the CO2\\/CH4 adsorption ratio is approximately 10:1, which indicates the significant potential for sequestering carbon dioxide. In addition, injected carbon dioxide would also enhance the production of methane from the coal seam

  11. 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.

  12. Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao

    E-print Network

    Barthelat, Francois

    Carbon Dioxide Sequestration in Concrete Using Vacuum-Carbonation Alain Azar, Prof. Yixin Shao promising carbon uptake results and is a viable option for carbonation curing. Carbon sequestration increase in Carbon dioxide (CO2) emissions over the past five decades, specific ways to reduce

  13. 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 ?m. 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

  14. 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.

  15. 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.

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

    PubMed

    Carlson, R W

    1999-02-01

    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. PMID:9933159

  17. Carbon dioxide utilization in the chemical industry

    SciTech Connect

    Aresta, M.; Quaranta, E.; Tommasi, I. [Univ. of Bari (Italy)

    1996-12-31

    Carbon dioxide as a raw material for the Chemical Industry is receiving growing attention because: (i) if recovery of CO{sub 2} from flue gases will be implemented, huge amounts of CO{sub 2} will be available; (ii) environmental issues urge to develop new processes/products, avoiding toxic materials. Several uses of CO{sub 2} appear to be responding to both (i) and (ii), i.e. use as a solvent (supplanting organic solvents) use as a building block for carboxylates/carbonates (supplanting phosgene); use as carbon-source in the synthesis of fuels (supplanting CO or coal/hydrocarbons). These options will be evaluated and their potentiality discussed.

  18. Containment removal from solid waste by supercritical carbon dioxide

    SciTech Connect

    Smith, H.M.; Olson, R.B. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.; Adkins, C.L.J.; Russick, E.M. [Sandia National Labs., Albuquerque, NM (United States)

    1994-05-01

    Large quantities of solid wastes such as rags, kimwipes, swabs, coveralls, gloves, etc., contaminated with oils, greases and hazardous solvents are generated by industry and the government. If the hazardous components (offs, greases and solvents) could be segregated from the much larger bulk of non-hazardous material, then these solid materials could potentially be handled as sanitary waste, at a significant cost savings. AlliedSignal KCP, a typical DOE manufacturing site, spent several hundred thousand dollars in CY92 for disposal of contaminated solid wastes. Similarly, Naval Air Station North Island, San Diego, also spent several hundred thousand dollars in CY91 for disposal of rags. Under the Department of Energy (DOE)/United States Air Force (USAF) Memorandum of Understanding, the objective of this joint AlliedSignal KCP/Sandia National Laboratories project is to demonstrate the feasibility of using supercritical carbon dioxide (SC-CO{sub 2}) to segregate hazardous oils, greases, and organic solvents from non-hazardous solid waste such as rags, wipes, swabs, coveralls, gloves, etc. Supercritical carbon dioxide possesses many of the characteristics desired in an ``environmentally acceptable`` solvent system. It is nontoxic, inexpensive, and recyclable. Carbon dioxide possesses a moderate critical temperature (31{degrees}C) and pressure (1071 psi). At 37{degrees}C and pressures greater than 2000 psi, the density is greater than 0.8 g/cc. Contaminants dissolved in the supercritical CO{sub 2} solvent are separated out by expansion of the fluid to a subcritical pressure where CO{sub 2} is a gas and the dissolved materials precipitate out (usually as a liquid or solid). The gaseous CO{sub 2} can then be recompressed and recycled.

  19. Carbon dioxide inhalation causes pulmonary inflammation.

    PubMed

    Abolhassani, Mohammad; Guais, Adeline; Chaumet-Riffaud, Philippe; Sasco, Annie J; Schwartz, Laurent

    2009-04-01

    The aim of this study was to assess whether one of the most common poisons of cellular respiration, i.e., carbon dioxide, is proinflammatory. CO(2) is naturally present in the atmosphere at the level of 0.038% and involved in numerous cellular biochemical reactions. We analyzed in vitro the inflammation response induced by exposure to CO(2) for 48 h (0-20% with a constant O(2) concentration of 21%). In vivo mice were submitted to increasing concentrations of CO(2) (0, 5, 10, and 15% with a constant O(2) concentration of 21%) for 1 h. The exposure to concentrations above 5% of CO(2) resulted in the increased transcription (RNase protection assay) and secretion (ELISA) of proinflammatory cytokines [macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, MIP-2, IL-8, IL-6, monocyte chemoattractant protein-1, and regulated upon activation, normal T cell expressed, and, presumably, secreted (RANTES)] by epithelial cell lines HT-29 or A549 and primary pulmonary cells retrieved from the exposed mice. Lung inflammation was also demonstrated in vivo by mucin 5AC-enhanced production and airway hyperreactivity induction. This response was mostly mediated by the nuclear translocation of p65 NF-kappaB, itself a consequence of protein phosphatase 2A (PP2A) activation. Short inhibiting RNAs (siRNAs) targeted toward PP2Ac reversed the effect of carbon dioxide, i.e., disrupted the NF-kappaB activation and the proinflammatory cytokine secretion. In conclusion, this study strongly suggests that exposure to carbon dioxide may be more toxic than previously thought. This may be relevant for carcinogenic effects of combustion products. PMID:19136578

  20. Capture of carbon dioxide by hybrid sorption

    DOEpatents

    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.

  1. 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.

  2. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...transportation of hazardous liquids or carbon dioxide. 195.4 Section 195.4...transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid...

  3. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868...Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor...

  4. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide fire extinguishing system requirements...Prevention Requirements § 167.45-45 Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2 ) smothering...

  5. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...transportation of hazardous liquids or carbon dioxide. 195.4 Section 195.4...transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid...

  6. 46 CFR 108.627 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 108.627...Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be identified by...

  7. 46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 97.37-9...Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  8. 46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 97.37-9...Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  9. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and halon fire extinguishing systems...for Particular Materials § 147.65 Carbon dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders...

  10. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 78.47-9...Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  11. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Bicarbonate/carbon dioxide test system. 862.1160 ...Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device...

  12. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide and halon fire extinguishing systems...for Particular Materials § 147.65 Carbon dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders...

  13. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 78.47-9...Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  14. 46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 196...Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using carbon dioxide or clean agent complying...

  15. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2) analyzer...Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2 ) analyzer...Identification. An indwelling blood carbon dioxide partial pressure PCO2...

  16. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868...Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor...

  17. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide fire extinguishing system requirements...Prevention Requirements § 167.45-45 Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2 ) smothering...

  18. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43...Radiation and Radiation Sources § 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used...

  19. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Bicarbonate/carbon dioxide test system. 862.1160 ...Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device...

  20. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2...Diagnostic Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2... (a) Identification. An indwelling blood carbon dioxide partial pressure...

  1. 76 FR 55846 - Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    ...Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities AGENCY: Environmental...to conditionally exclude carbon dioxide (CO 2 ) streams...to conditionally exclude carbon dioxide (CO 2 )...

  2. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2...Diagnostic Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2... (a) Identification. An indwelling blood carbon dioxide partial pressure...

  3. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2...Diagnostic Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2... (a) Identification. An indwelling blood carbon dioxide partial pressure...

  4. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  5. 46 CFR 131.815 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 131.815 ...and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  6. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  7. 46 CFR 131.815 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 131.815 ...and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  8. 46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 196...Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using carbon dioxide or clean agent complying...

  9. 46 CFR 108.627 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 ...Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be identified by...

  10. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Carbon dioxide and certain other gases. 201.161...LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

  11. Effects of carbon dioxide on peak mode isotachophoresis: Simultaneous preconcentration and separation

    E-print Network

    Santiago, Juan G.

    Effects of carbon dioxide on peak mode isotachophoresis: Simultaneous preconcentration ions resulting from dissolved atmospheric carbon dioxid e to weakly disrupt isotachophoretic the hydration and carbamation reaction of dissolved atmospheric carbon dioxide, respectively. The width

  12. 46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 78.47-9...Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire extinguishing...

  13. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  14. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  15. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Carbon dioxide; exemption from the requirement...From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the...

  16. Climatic and phenological controls on coherent regional interannual variability of carbon dioxide flux

    E-print Network

    Wisconsin at Madison, University of

    Climatic and phenological controls on coherent regional interannual variability of carbon dioxide carbon dioxide flux observations from five different ecosystems (deciduous forest, northern hardwood), Climatic and phenological controls on coherent regional interannual variability of carbon dioxide flux

  17. 21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Indwelling blood carbon dioxide partial pressure (PCO2...Diagnostic Devices § 868.1150 Indwelling blood carbon dioxide partial pressure (PCO2... (a) Identification. An indwelling blood carbon dioxide partial pressure...

  18. Monitoring Troposphere Carbon Dioxide Spatial and Temporal Distribution Changes over China

    NASA Astrophysics Data System (ADS)

    Jiang, Y.; El-Askary, H. M.

    2013-12-01

    Carbon dioxide is an important component of the Earth's atmosphere because it absorbs and emits infrared radiation at wavelengths of 4.26 ?m and 14.99 ?m, thereby playing a role in the greenhouse effect. The concentration of the carbon dioxide in the Earth's atmosphere has reached 391 ppm (parts per million) as of October 2012 and rose by 2.0 ppm/yr during 2000-2009. Global carbon dioxide emissions are widely seen as a major factor responsible for an increase in world temperatures. The carbon dioxide emissions in China have grown strongly in the past decade. It overtakes the United States and has become the world's largest energy consumer. In this work we analyze atmospheric carbon dioxide concentration variability on both temporal and spatial scale over China. AIRS mid-tropospheric Carbon Dioxide (CO_2) Level 3 Monthly Gridded data showed that the average distribution of carbon dioxide concentration in the middle troposphere over China from January 2003 to December 2011 was extremely uneven showing a great seasonal component. High consistency of the seasonal variation characteristics was observed between the AIRS data and Waliguan close ground station data from 2003 to 2011. High concentrations were observed over the northeast plain, Inner Mongolia autonomous region and Xinjiang Uygur autonomous region March to May as compared to the lower values over the southern region. Over the 35°N-45°N range there were significant enhancements, yet Tibetan plateau and Yunan showed lower carbon dioxide concentration. In summer, Inner Mongolia, Xinjiang Uygur and northern Gansu showed high concentrations, yet in September and October, the high value was still concentrated in the north area about latitude 40°N. During the winter season high carbon dioxide concentrations fluctuated between eastern regions in December and the western Xinjiang, Qinghai province and in most parts of the eastern area during January and February. Hence, we have found that spring concentrations are highest while the winter ones are the lowest. Further analysis is undergoing between the carbon dioxide concentrations and the surface average temperature. Preliminary results show that the carbon dioxide average concentration has linear rising trend over the past 9 years and have an obvious seasonal variability.

  19. Photocatalytic oxidation of bacteria, bacterial and fungal spores, and model biofilm components to carbon dioxide on titanium dioxide-coated surfaces.

    PubMed

    Wolfrum, Edward J; Huang, Jie; Blake, Daniel M; Maness, Pin-Ching; Huang, Zheng; Fiest, Janene; Jacoby, William A

    2002-08-01

    We report carbon mass balance and kinetic data for the total oxidation of cells, spores, and biomolecules deposited on illuminated titanium dioxide surfaces in contact with air. Carbon dioxide formation by photocatalytic oxidation of methanol, glucose, Escherichia coli, Micrococcus luteus, Bacillus subtilis (cells and spores), Aspergillus niger spores, phosphatidylethanolamine, bovine serum albumin, and gum xanthan was determined as a function of time. The quantitative data provide mass balance and rate information for removal of these materials from a photocatalytic surface. This kind of information is importantfor applications of photocatalytic chemistry in air and water purification and disinfection, self-cleaning surfaces, and the development of self-cleaning air filters. PMID:12188373

  20. Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice analog samples

    E-print Network

    Kaiser, Ralf I.

    Mechanistical studies on the formation of carbon dioxide in extraterrestrial carbon monoxide ice with extraterrestrial, carbon monoxide bearing ices. The chemical modifications were monitored on line and in situ via of carbon monoxide and on the formation of carbon dioxide in extraterrestrial ice analog samples. 1

  1. Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON DIOXIDE1*2

    E-print Network

    commercial carbons and their gasification rates with carbon dioxide at a series of temperatures between 900 2' of the desired value. The carbon dioxide flow rate through the reactor was maintained constantMar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON

  2. 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.

  3. 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.

  4. Fixation of carbon dioxide by producing hydromagnesite from serpentinite

    Microsoft Academic Search

    Sebastian Teir; Sanni Eloneva; Carl-Johan Fogelholm; Ron Zevenhoven

    2009-01-01

    Fixing carbon dioxide (CO2) as carbonates using silicate-based materials is an interesting alternative option for storage of carbon dioxide. Suitable magnesium-rich rocks are distributed throughout the world. The magnesium silicate deposits in Eastern Finland alone could be sufficient for storing 10Mt CO2 each year during a period of 200–300 years. Rocks potentially suitable for carbonation are already mined, processed, piled,

  5. Six-fold coordinated carbon dioxide VI

    SciTech Connect

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

    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.

  6. 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.

  7. 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.

  8. Climate Science in a Nutshell: Where Carbon Dioxide Come From?

    NSDL National Science Digital Library

    Planet Nutshell

    This short video discusses where carbon dioxide, the gas that is mainly responsible for warming up our planet and changing the climate, comes from. It discusses how the rise in atmospheric carbon dioxide comes directly from the burning of fossil fuels and indirectly from the human need for energy.

  9. A monitoring and diagnostic expert system for carbon dioxide capture

    Microsoft Academic Search

    Q. Zhou; C. W. Chan; P. Tontiwachiwuthikul

    2009-01-01

    The research objective is to design and construct a knowledge-based decision support system for monitoring, control and diagnosis of the carbon dioxide capture process, which is a complicated task involving manipulation of sixteen components and their operating parameters. Since manipulation of critical parameter values directly impacts performance of the plant and carbon dioxide capture efficiency, it is important to effectively

  10. Atmospheric carbon dioxide concentrations over the past 60 million years

    Microsoft Academic Search

    Paul N. Pearson; Martin R. Palmer

    2000-01-01

    Knowledge of the evolution of atmospheric carbon dioxide concentrations throughout the Earth's history is important for a reconstruction of the links between climate and radiative forcing of the Earth's surface temperatures. Although atmospheric carbon dioxide concentrations in the early Cenozoic era (about 60 Myr ago) are widely believed to have been higher than at present, there is disagreement regarding the

  11. 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.

  12. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Still wines containing carbon dioxide. 26.222 ...From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram...

  13. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Still wines containing carbon dioxide. 26.52 Section...Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram...

  14. A Tenuous Carbon Dioxide Atmosphere on Jupiter's Moon Callisto

    Microsoft Academic Search

    Robert W. Carlson

    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 CO, v,, band was observed up to 100 km above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10\\

  15. Physiological Responses to Elevated Carbon Dioxide Levels in Buildings

    Microsoft Academic Search

    Saul Stricker; Marc Bourgeau; Eric Fonberg; Denis Parent

    1997-01-01

    Comparative tests were conducted involving 22 persons sleeping in a normal and in an elevated carbon dioxide (CO2) environment to determine respirato ry and urinary responses. Carbon dioxide levels in bedrooms with 2 occupants with the bedroom doors and windows closed can rise to 4,500 ppm during the night. The results indicate that the exposure levels encountered in these bedrooms

  16. Open Nanoporous Morphologies from Polymeric Blends by Carbon Dioxide Foaming

    Microsoft Academic Search

    B. Krause; K. Diekmann; N. F. A. van der Vegt; M. Wessling

    2002-01-01

    We report the formation of open nanoporous polymer films composed of homogeneous polysulfone\\/polyimide blends. Porosity is introduced by expansion of carbon dioxide-saturated films at elevated temperatures. To interpret details of the porous morphologies in terms of the experimental conditions during expansion, the glass transition temperature and carbon dioxide solubility of the dense film were examined at various blend compositions. We

  17. 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...

  18. Carbon Dioxide, Global Warming, and Michael Crichton's "State of Fear"

    E-print Network

    Rust, Bert W.

    Carbon Dioxide, Global Warming, and Michael Crichton's "State of Fear" Bert W. Rust Mathematical- tioned the connection between global warming and increasing atmospheric carbon dioxide by pointing out of these plots to global warming have spilled over to the real world, inviting both praise [4, 17] and scorn [15

  19. Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine

    E-print Network

    Rochelle, Gary T.

    i Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine Topical Report Prepared Pilot Plant Study of Carbon Dioxide Capture by Aqueous Monoethanolamine Ross Edward Dugas, M capture using monoethanolamine (MEA). MEA is an appropriate choice for a baseline study since

  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. Supercritical carbon dioxide explosion as a pretreatment for cellulose hydrolysis

    Microsoft Academic Search

    Yizhou Zheng; Ho-Mu Lin; Jingquan Wen; Ningjun Cao; Xuezhi Yu; George T. Tsao

    1995-01-01

    Cellulosic material Avicel was treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. 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. This explosion pretreatment enhances the rate of

  2. 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...

  3. Solubility of carbon dioxide in propylene carbonate at elevated pressures and higher than ambient temperatures

    SciTech Connect

    Mantor, P.D.; Abib, O. Jr.; Song, K.Y.; Kobayashi, R.

    1982-07-01

    The solubility of carbon dioxide in propylene carbonate at elevated pressures and higher than ambient temperatures may assume increasing significance for the processing of carbon dioxide-rich gases issuing from natural reservoirs and/or carbon dioxide enhanced oil processing streams. Despite the fact that propylene carbonate has been used as solvent for its selective absorption of carbon dioxide from natural gases, the solubility data for carbon dioxide in propylene carbonate are highly restricted with respect to pressure, with respect to accuracy, and/or with respect to the number of isotherms studied. Data on the solubility of carbon dioxide in propylene carbonate are accordingly presented for several isotherms to cover reasonable processing pressures and temperatures.

  4. 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.

  5. 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 ? = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when ? = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at ? = 0.5, while no effect is found at ? = 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.

  6. Combining power plant water needs and carbon dioxide storage using saline formations: Implications for carbon dioxide and water management policies

    Microsoft Academic Search

    Peter H. Kobos; Malynda A. Cappelle; Jim L. Krumhansl; Thomas A. Dewers; Andrea McNemar; David J. Borns

    2011-01-01

    Research involving management of carbon dioxide has increased markedly over the last decade as it relates to concerns over climate change. Capturing and storing carbon dioxide (CO2) in geological formations is one of many proposed methods to manage, and likely reduce, CO2 emissions from burning fossil fuels in the electricity sector. Saline formations represent a vast storage resource, and the

  7. Master index for the carbon dioxide research state-of-the-art report series

    Microsoft Academic Search

    1987-01-01

    Four State of the Art (SOA) reports, ''Atmospheric Carbon Dioxide and the Global Carbon Cycle,'' ''Direct Effects of Increasing Carbon Dioxide on Vegetation,'' ''Detecting the Climatic Effects of Increasing Carbon Dioxide,'' and ''Projecting the Climatic Effects of Increasing Carbon Dioxide,'' and two companion reports, ''Characterization of Information Requirements for Studies of COâ Effects: Water Resources, Agriculture, Fisheries, Forests and Human

  8. 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 system of the solution was controlled by both, degassing and carbonate precipitation, still leading to an enrichment of the heavier carbon isotope in the residual DIC. The experimental results are evaluated for both periods, and the influence of salinity and pH is extracted. Acknowledgement: Parts of this study were supported by BMBF within the BIOACID project

  9. 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 irradiance and CO2 concentration. Kinetic models were successfully developed based on the Monod model and on a novel scaling analysis employing the CO2 consumption half-time as the time scale. Finally, the growth and hydrogen production of Anabaena variabilis have been compared in a flat panel photobioreactor using three different nutrient media under otherwise similar conditions. Light to hydrogen energy conversion efficiency for Allen-Arnon medium was superior by a factor of 5.5 to both BG-11 and BG-11o media. This was attributed to the presence of vanadium and larger heterocyst frequency observed in the Allen-Arnon medium.

  10. From carbon dioxide to C{sub 2} organic molecules

    SciTech Connect

    Gong, J.K.; Wright, C.A.; Thorn, M. [Southeast Missouri State Univ., Cape Girardeau, MO (United States)] [and others

    1996-12-31

    Research on the conversion of carbon dioxide into C{sub 2} or higher organic molecules has received much attention in recent years. The key to the success of this research is carbon-carbon coupling. This paper reports the modified synthesis of a nickel carbon dioxide complex, (Cy{sub 3}P){sub 2}NiCO{sub 2}, (Cy = cyclohexane) and the {open_quotes}Wittig Reaction{close_quotes} of this coordinated nickel carbon dioxide complex. The formed nickel ketene complex, (Cy{sub 3}P){sub 2}Ni[{eta}{sup 2}- (C,O)-CH{sub 2}=C=O], has an unusual {eta}{sub 2}-C,O bonding mode instead of the normal {eta}{sup 2}-C,C for the later transition metals. The pathway of this {open_quotes}Witting Reaction{close_quotes} is an unprecedented example for a transition metal carbon dioxide complex.

  11. 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.

  12. Does carbon dioxide pool or stream in the subsurface?

    E-print Network

    Cardoso, Silvana S S

    2014-01-01

    Pools of carbon dioxide are found in natural geological accumulations and in engineered storage in saline aquifers. It has been thought that once this CO2 dissolves in the formation water, making it denser, convection streams would transport it efficiently to depth, but this may not be so. Here, we assess the impact of natural chemical reactions between the dissolved CO2 and the rock formation on the convection streams in the subsurface. We show that, while in carbonate rocks the streaming of dissolved carbon dioxide persists, the chemical interactions in silicate-rich rocks may curb this transport drastically and even inhibit it altogether. New laboratory experiments confirm the curtailing of convection by reaction. Wide and narrow streams of dense carbon-rich water are shut-off gradually as reaction strength increases until all transport of the pooled carbon dioxide occurs by slow molecular diffusion. These results show that the complex fluid dynamic and kinetic interactions between pooled carbon dioxide an...

  13. Global carbon dioxide emissions from inland waters.

    PubMed

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

    2013-11-21

    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(+0.25)(-0.25)? petagrams of carbon (Pg?C) per year from streams and rivers and 0.32(+0.52)(-0.26)? 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. PMID:24256802

  14. 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.

  15. 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.

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

    SciTech Connect

    Komemushi, Atsushi, E-mail: kome64@yo.rim.or.jp; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi [Kansai Medical University, Department of Radiology (Japan)

    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.

  17. 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

  18. Regional carbon dioxide fluxes from aircraft measurements in southwest France

    NASA Astrophysics Data System (ADS)

    Vellinga, O. S.; Hutjes, R. W. A.; Elbers, J. A.

    2009-04-01

    In 2007, the CarboEurope-IP Regional Component organised the second edition of the CERES measurement campaign in the southwest of France. This was a follow-up of the initial campaign in 2005. CERES'07 consisted of two intensive observational periods (IOPs), of which one in spring and the other one in summer. During both IOPs, ground stations, tall towers, radiosondes and a number of aircrafts were used, including our own environmental research aircraft (ERA). The ERA is a small aircraft flying at low altitudes and low air speeds, equipped to measure fluxes of carbon dioxide, latent heat and sensible heat using the eddy-correlation technique. In addition, instruments are on board for measuring ground temperature, net radiation and photosynthetically active radiation (PAR). Flux data obtained with the ERA during CERES'07 have been analyzed and will be presented here. In the data analysis, we present regional fluxes of carbon dioxide focussing at seasonal trends in relation to landscape elements. To achieve this, flight tracks were split into homogeneous segments based on land cover, topography and soil type. During both IOPs, weather conditions were constant. This gives us the possibility to average data in each segment across all flights, though the issue of diurnal variation in surface fluxes and radiation still remains. In short, the analysis strategy on our airborne flux data from CERES'07 will be addressed in this presentation together with its results focussing at drivers for these fluxes at landscape scale.

  19. 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.

  20. 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.

  1. Simultaneous requirement of carbon dioxide and abscisic acid for stomatal closing in Xanthium strumarium L

    Microsoft Academic Search

    Klaus Raschke

    1975-01-01

    Open stomata of detached leaves of Xanthium strumarium L. closed only when carbon dioxide and abscisic acid (ABA) were presented simultaneously. Three parameters of stomatal closing were determined after additions of ABA to the irrigation water of detached leaves, while the leaves were exposed to various CO2 concentrations ([CO2]s) in the air; a) the delay between addition of ABA and

  2. A numerical comparison study of cloud seeding by silver iodide and liquid carbon dioxide

    Microsoft Academic Search

    Xueliang Guo; Guoguang Zheng; Dezhen Jin

    2006-01-01

    A comparison study on dynamic and microphysical effects of cloud seeding by silver iodide (AgI) and liquid carbon dioxide (liquid CO2) was made using a 3D cloud model with seeding processes. The model was initialized based on the rawinsonde sounding taken from Pinliang station located in the western China on 20 April 2001. The sounding air reflects moist and stable

  3. 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. ...

  4. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J. (Seattle, WA)

    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.

  5. 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

  6. 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.

  7. Viscosity behavior of carbon dioxide treated Cut Bank crude oil

    SciTech Connect

    Cady, G.V.; Mosawi, H.

    1995-12-31

    Carbon dioxide injection, either by huff and puff or displacement operations, results in a crude oil viscosity reduction at pressures below the miscibility conditions. Carbon dioxide miscibility occurs in reservoirs at miscible temperature and pressure, but these conditions are not possible in shallow reservoirs. Improved oil recovery in a shallow reservoir depends on the degree of viscosity reduction at the reservoir temperature and pressure. A recovery project`s success depends on the interaction between the carbon dioxide and the reservoir system. A research project carried out at Montana Tech to study the viscosity reduction and carbon dioxide solubility in Cut Bank crude oil at the reservoir`s prevailing temperature and near fracture pressure shows a viscosity reduction ratio (crude-carbon dioxide mixture to original dead oil viscosity) of 0.22 at a pressure of 1,000 psig and 90 F. An original mobility of 20 Md/cp improves to 91 Md/cp under a carbon dioxide recovery process at or near the reservoir`s fracture pressure. Based on the authors` research, improved oil recovery operations in the Cut Bank Field, Montana, is viable when using a commercial on site carbon dioxide recovery or generating system to minimize the cost of CO{sub 2} transportation. The major benefits are oil viscosity reduction, mobility ratio improvement, gas drive, and crude oil swelling.

  8. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1991-09-01

    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.

  9. Alkali metal carbon dioxide electrochemical system for energy storage and/or conversion of carbon dioxide to oxygen

    NASA Astrophysics Data System (ADS)

    Hagedorn, Norman H.

    1993-05-01

    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.

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

    SciTech Connect

    David A. Green; Thomas Nelson; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta

    2005-04-01

    This report describes research conducted between January 1, 2005 and March 31, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Engineered sorbents composed of sodium carbonate on a ceramic support were tested in a laboratory fluidized bed reactor system and found to be capable of essentially complete removal of carbon dioxide at 60 C in a short residence time. Upon breakthrough the sorbents can be thermally regenerated to recover essentially all of the absorbed carbon dioxide. An optimized supported sorbent tested in a pilot-scale entrained bed absorber retained its reactivity in multicycle tests and experienced no attrition. Removal of >90% of carbon dioxide in simulated flue gas was achieved in an entrained bed reactor.

  11. Temperature Dependences for Air-broadened Widths and Shift Coefficients in the 30013 - 00001 and 30012 - 00001 Bands of Carbon Dioxide near 1600 nm

    Microsoft Academic Search

    M. Devi; A. Predoi-Cross; R. McKellar; C. Benner; C. E. Miller; R. A. Toth; L. R. Brown

    2008-01-01

    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

  12. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water

    E-print Network

    Heng, Kevin

    2015-01-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres. We construct analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios (from 0.1 to 100), we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if th...

  13. Cholesterol Aggregation and Interaction with Cholesterol Oxidase in Supercritical Carbon Dioxide

    Microsoft Academic Search

    T. W. Randolph; D. S. Clark; H. W. Blanch; J. M. Prausnitz

    1988-01-01

    High-pressure EPR spectroscopy indicates that cholesterol forms aggregates in supercritical carbon dioxide. In pure carbon dioxide, changes in cholesterol aggregate size or packing structure are observed with changing pressure. Near the critical point of carbon dioxide, cholesterol solubility is too low to permit significant aggregation, and monomeric cholesterol is observed. Addition of small amounts of dopants to supercritical carbon dioxide

  14. CARBON DIOXIDE -CO2 MSDS (DOCUMENT #001013) PAGE 1 OF 12 MATERIAL SAFETY DATA SHEET

    E-print Network

    Choi, Kyu Yong

    CARBON DIOXIDE - CO2 MSDS (DOCUMENT #001013) PAGE 1 OF 12 MATERIAL SAFETY DATA SHEET Prepared to U in an emergency? 1. PRODUCT IDENTIFICATION CHEMICAL NAME; CLASS: CARBON DIOXIDE - CO2, GASEOUS CARBON DIOXIDE - CO2, CRYOGENIC CARBON DIOXIDE - CO2, SOLID Document Number: 001013 PRODUCT USE: For general analytical

  15. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    SciTech Connect

    Aines, Roger D. (Livermore, CA); Bourcier, William L. (Livermore, CA)

    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.

  16. 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.

  17. 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

  18. 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.

  19. High temperature carbon dioxide separation membrane

    NASA Astrophysics Data System (ADS)

    Wade, Jennifer Lynn

    High temperature membranes for CO2 separation can potentially lead to more efficient energy conversion systems and more effective means of CO2 capture in power plants. A novel technology has been successfully demonstrated for the separation of carbon dioxide, CO2, in the temperature range of 600-900°C. The transport of CO2 is accomplished with a dual-ion transport mechanism between carbonate ions in a molten carbonate phase and oxide ions in an oxide conducting ceramic coupled with a surface reaction converting CO2 to CO32- with O2- from an oxide crystal lattice. The transport of such a system was modeled, and an analytical expression was derived for the flux of CO2 in a bulk diffusion limited system. Dual-phase membranes were fabricated by first creating a porous solid oxide structure using tape casting techniques. The structure was engineered to immobilize the molten carbonate phase in the pore space. Membranes comprised of either 8-mol% yttria stabilized zirconia (YSZ) or 10-mol% gadolinia doped ceria (CGO) and a tertiary mixture of alkali metal carbonates (Li2CO 3,Na2CO3,K2CO3) were able to selectively permeate CO2 at temperatures over 600°C. The flux of CO2 across these membranes increased exponentially with temperature, reaching permeabilities of 1.0 x 10-11 mol m -1 s-1 Pa-1 (or permeance of 3.6 x 10 -8 mol m-2 s-1 Pa-1) with YSZ based membranes and 7.0 x 10-12 mol m-1 s-1 Pa-1 (or permeance of 2.3 x 10-8 mol m-2 s-1 Pa-1) with CGO based membranes at 850°C. It was also discovered that alumina, Al2O3, a non-oxide conducting ceramic, was unable to selectively permeate CO2, providing support for the role of an oxide conducting phase in the transport mechanism. Finally, the chemical reactivity between YSZ and CGO with various mixtures of alkali metal carbonates was examined with thermogravimetric (TGA) and x-ray diffraction (XRD) analysis in order to understand the chemical reactivity and how it relates to the performance of these materials as composite, CO 2 selective membranes. It was revealed that a lack of reactivity between electrolyte pairs does not preclude these materials from functional separation membranes, yet irreversible chemistry can negatively impact long-term CO 2 permeance.

  20. Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog

    E-print Network

    Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog MIT warming Carbon mitigation Low carbon energy technologies Carbon dioxide capture and storage (CCS) Carbon. Introduction Carbon dioxide (CO2) capture and storage (CCS) is a process consisting of the separation of CO2

  1. 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.

  2. Atmospheric response to deep-sea injections of fossil-fuel carbon dioxide

    Microsoft Academic Search

    Martin I. Hoffert; Yeong-Cherng Wey; Andrew J. Callegari; Wallace S. Broecker

    1979-01-01

    The possibility of controlling atmospheric carbon dioxide accumulation and attendant climatic effects from fossil-fuel burning by diverting a fraction of the combustion product and injecting it into the deep-ocean, as proposed by Marchetti, is analyzed using an atmosphere\\/mixed layer\\/diffusive deep-ocean model for the carbon cycle. The model includes the nonlinear buffering of CO2 at the air\\/sea interface, and considers the

  3. Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone

    Microsoft Academic Search

    Kurt Pregitzer; Wendy Loya; Mark Kubiske; Donald Zak

    2006-01-01

    The aspen free-air CO2 and O3 enrichment (FACTS II–FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO2) and elevated tropospheric ozone (O3) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the

  4. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...On emerging from the carbon dioxide tunnel, the animals shall be in a state of...dioxide gas shall be administered in a tunnel which is designed to permit the effective exposure of the animal. Two types of tunnels, based on the same principle, are in...

  5. 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 (KEITI), Ministry of Environment, Republic of Korea.

  6. Pretreatment for cellulose hydrolysis by carbon dioxide explosion

    SciTech Connect

    Zheng, Y.; Lin, H.M.; Tsao, G.T. [Purdue Univ., West Lafayette, IN (United States). Lab of Renewable Resources Engineering] [Purdue Univ., West Lafayette, IN (United States). Lab of Renewable Resources Engineering

    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.

  7. 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.

  8. 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

  9. Infrared energy levels and intensities of carbon dioxide

    Microsoft Academic Search

    L. S. Rothman; W. S. Benedict

    1978-01-01

    Updated tables of vibrational energy levels, molecular constants, band origins, and intensities for carbon dioxide in the infrared region of the spectrum are presented. These tables are references for the AFGL Atmospheric Absorption Line Parameters Compilation.

  10. Infrared energy levels and intensities of carbon dioxide.

    PubMed

    Rothman, L S; Benedict, W S

    1978-08-15

    Updated tables of vibrational energy levels, molecular constants, band origins, and intensities for carbon dioxide in the infrared region of the spectrum are presented. These tables are references for the AFGL Atmospheric Absorption Line Parameters Compilation. PMID:20203829

  11. Mechanisms for mechanical trapping of geologically sequestered carbon dioxide

    E-print Network

    Cohen, Yossi

    Carbon dioxide (CO[subscript 2]) sequestration in subsurface reservoirs is important for limiting atmospheric CO[subscript 2] concentrations. However, a complete physical picture able to predict the structure developing ...

  12. Electrochemically-mediated amine regeneration for carbon dioxide separations

    E-print Network

    Stern, Michael C. (Michael Craig)

    2014-01-01

    This thesis describes a new strategy for carbon dioxide (CO?) separations based on amine sorbents, which are electrochemically-mediated to facilitate the desorption and regeneration steps of the separation cycle. The ...

  13. Atmospheric concentrations of carbon dioxide, methane and nitrous oxide

    NSDL National Science Digital Library

    IPCC (Intergovernmental Panel of Climate Change)

    This is a figure from the 2007 IPCC Assessment Report 4 on atmospheric concentrations of carbon dioxide, methane and nitrous oxide over the last 10,000 years (large panels) and since 1750 (inset panels).

  14. Synthesis of Amides and Lactams in Supercritical Carbon Dioxide

    E-print Network

    Mak, Xiao Yin

    Supercritical carbon dioxide can be employed as an environmentally friendly alternative to conventional organic solvents for the synthesis of a variety of carboxylic amides. The addition of amines to ketenes generated in ...

  15. Porosity Development in Activated Carbons Prepared from Walnut Shells by Carbon Dioxide or Steam Activation

    Microsoft Academic Search

    Juan F. Gonza?lez; Silvia Roma?n; Carmen M. Gonzalez-Garcõ ´; J. M. Valente Nabais; Angel L. Ortiz

    2009-01-01

    The influence of carbon dioxide and steam as activating agents on the porosity development of activated carbons produced from walnut shells was investigated. The study was made covering a wide range of burnoff (12-76%) and employing different temperatures and times: in carbon dioxide activation, 850 °C varying the activation time in the range 60-480 min, and in steam activation, 700,

  16. Air Quality and Power Production in the United States: Emissions Trading and State-Level Initiatives in the Control of Acid-Producing Emissions, Mercury, and Carbon Dioxide

    Microsoft Academic Search

    Daniel Sosland

    Recently, the U.S. federal government has pursued a determined strategy toward increased energy production while paying little\\u000a heed to the impact of this strategy on air quality and failing to take effective measures to reduce emissions of pollutants\\u000a from the fossil-fueled power plants that dominate U.S. energy generation. While the evolution of the Clean Air Act and its\\u000a important amendments—particularly

  17. Membranes for separation of carbon dioxide

    DOEpatents

    Ku, Anthony Yu-Chung (Rexford, NY); Ruud, James Anthony (Delmar, NY); Ramaswamy, Vidya (Niskayuna, NY); Willson, Patrick Daniel (Latham, NY); Gao, Yan (Niskayuna, NY)

    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.

  18. Diffusion of ethanol–carbon dioxide in silica gel

    Microsoft Academic Search

    P. Wawrzyniak; G. Rogacki; J. Pruba; Z. Bartczak

    1998-01-01

    Extraction of a primary solvent with liquid or supercritical carbon dioxide is the most difficult to control stage in low-temperature silica aerogel production. Diffusion of primary ethanol through alcogel structure to surrounding CO2 was investigated in carefully controlled experiments with cylindrical alcogel samples. Changes of the alcohol concentration in carbon dioxide leaving the autoclave were followed with on-line chromatograph analysis

  19. Seawater pH and Anthropogenic Carbon Dioxide

    E-print Network

    Gerald E. Marsh

    2013-07-18

    In 2005, the Royal Society published a report titled "Ocean acidification due to increasing atmospheric carbon dioxide". The report's principal conclusion-that average ocean pH could decrease by 0.5 units by 2100-is demonstrated here to be consistent with a linear extrapolation of very limited data. It is also shown that current understanding of ocean mixing, and of the relationship between pH and atmospheric carbon dioxide concentration, cannot justify such an extrapolation.

  20. Detection of aerosolized cells during carbon dioxide laparoscopy

    Microsoft Academic Search

    Sayeed Ikramuddin; Joel Lucas; E. Christopher Ellison; William J. Schirmer; W. Scott Melvin

    1998-01-01

    Laparoscopic surgery for malignancy has been complicated by port-site recurrences. The exact mechanism has yet to be defined.\\u000a In vitro studies suggest that carbon dioxide-induced tumor cell aerosolization may play a role. We have attempted to document\\u000a this in a human model. Patients scheduled for elective laparoscopy underwent port placement and abdominal insufflation with\\u000a carbon dioxide. A suction trap was

  1. Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration

    Microsoft Academic Search

    R. H. Johnson; D. E. Lincoln

    1990-01-01

    Summary  Seed- and clonally-propagated plants of Big Sagebrush (Artemisia tridentata var.tridentata) were grown under atmospheric carbon dioxide regimes of 270, 350 and 650 ?l l?1 and fed toMelanoplus differentialis andM. sanguinipes grasshoppers. Total shrub biomass significantly increased as carbon dioxide levels increased, as did the weight and area\\u000a of individual leaves. Plants grown from seed collected in a single population exhibited

  2. Carbon dioxide solubility in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

    Microsoft Academic Search

    Allan N. Soriano; Bonifacio T. Doma Jr.; Meng-Hui Li

    2009-01-01

    In this work, we present new solubility results for carbon dioxide in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate for temperatures ranging from (303.2 to 343.2)K and pressures up to 5.9MPa using a thermogravimetric microbalance. Carbon dioxide solubilities were determined from absorption saturation (equilibrium) results at each fixed temperature and pressure. The buoyancy effect was accounted for in the evaluation of the

  3. Extraction of lemongrass essential oil with dense carbon dioxide

    Microsoft Academic Search

    Luiz Henrique Castelan Carlson; Ricardo Antonio Francisco Machado; Cinthia Bittencourt Spricigo; Lia Krücken Pereira; Ariovaldo Bolzan

    2001-01-01

    Lemongrass (Cymbopogon citratus) essential oil was extracted with dense carbon dioxide at 23–50°C and 85–120 bar. The composition of samples collected during the first and the last hours of the extraction experiments was analyzed by gas chromatography–mass spectrometry, and coextraction of cuticular waxes was observed. Liquid carbon dioxide extracts had a larger quantity of coextracted waxes than the supercritical extracts.

  4. Stomatal response to carbon dioxide: aperature and chloroplast structure

    E-print Network

    Spence, Richard Douglas

    1982-01-01

    STOMATAL RESPONSE TO CARBON DIOXIDE: APERTURE AND CHLOROPLAST STRUCTURE A Thesis by RICHARD DOUGLAS SPENCE, JR. Submitted to the Graduate College of Texas ARM Univeristy in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1982 Major Subject: Bioengineering STOMATAL RESPONSE TO CARBON DIOXIDE: APERTURE Ah!D CHLOROPLAST STRUCTURE A Thesis by RICHARD DOUGLAS SPENCE, JR. Approved as to style and content by: P. J. . Shar pe (Chairman of Committee...

  5. 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.

  6. Cycling Carbon: Seeing How Plants Use Carbon Dioxide in the Lab

    NSDL National Science Digital Library

    This activity discusses the nature of carbon, the different types of compounds in which it exists (e.g. charcoal, glucose, carbon dioxide), the biochemical reactions in which it takes part (photosynthesis and respiration), the range of processes that carbon and carbon compounds are involved in on Earth, and how these link together to form the carbon cycle. This activity demonstrates the uptake of carbon dioxide by plants, using Elodea as the example. Students are reminded that Elodea is a pond plant that lives below the water surface and thus extracts dissolved carbon dioxide from the water rather than directly from the atmosphere as terrestrial plants do. The students will discover that the carbon exchange between living things and the atmosphere mostly happens through photosynthesis and respiration. During the growing season leaves take up carbon dioxide and carbon is then stored in the living biomass.

  7. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-03-31

    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/tCO{sub 2} in carbon utilization. By the use of self?concentrating absorption technology, high purity CO{sub 2} can be produced at a price below $40/t. With low cost CO{sub 2} 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 CO{sub 2}/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  8. Carbon Dioxide Reforming of Methane to Syngas by Thermal Plasma

    NASA Astrophysics Data System (ADS)

    Sun, Yanpeng; Nie, Yong; Wu, Angshan; Ji, Dengxiang; Yu, Fengwen; Ji, Jianbing

    2012-03-01

    Experiments were conducted on syngas preparation from dry reforming of methane by carbon dioxide with a DC arc plasma at atmospheric pressure. In all experiments, nitrogen gas was used as the working gas for thermal plasma to generate a high-temperature jet into a horizontal tube reactor. A mixture of methane and carbon dioxide was fed vertically into the jet. In order to obtain a higher conversion rate of methane and carbon dioxide, chemical energy efficiency and fuel production efficiency, parametric screening studies were conducted, in which the volume ratio of carbon dioxide to methane in fed gases and the total flux of fed gases were taken into account. Results showed that carbon dioxide reforming of methane to syngas by thermal plasma exhibited a larger processing capacity, higher conversion of methane and carbon dioxide and higher chemical energy efficiency and fuel production efficiency. In addition, thermodynamic simulation for the reforming process was conducted. Experimental data agreed well with the thermodynamic results, indicating that high thermal efficiency can be achieved with the thermal plasma reforming process.

  9. Carbon Dioxide Effects Research and Assessment Program: proceedings of the carbon dioxide and climate research program conference

    Microsoft Academic Search

    Schmitt

    1980-01-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased COâ; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of COâ; social responses to the COâ problem; a scenario for atmospheric COâ to

  10. The solid carbon dioxide penetrator: A technological option?

    SciTech Connect

    Murray, C.N.; Bidoglio, G.; Ribeiro, J. [Commission of the European Communities, Varese (Italy). Joint Research Centre; Visintini, L. [Aermacchi S.p.A., Varese (Italy)

    1994-12-31

    A solution for permanently sequestering anthropogenic carbon dioxide may be proposed on the basis of the observation of the occurrence of carbonate-rich sediments, which are ubiquitous in sedimentary formations of the ocean at depths above the carbonate compensation depth at around 4 km, and which form a natural net sink of carbon. Thus to circumvent the uncertainty related to presently studied ocean disposal options based on pumping of liquid carbon dioxide or hydrate slurry injection at depth, with the risk of short-term physical and biological oceanographic processes returning an important fraction of it to the atmosphere, techniques for disposal should concentrate on using the natural geochemical storage properties of deep marine geological formations. It is proposed that the concept of disposal of anthropogenic carbon dioxide in marine geological formations could be investigated making u of solid carbon dioxide free fall penetrators. The technique proposed would depend on the fact that carbon dioxide can be obtained as a solid by cooling to {minus}78.5 C. The overall density is approximately one and a half times {approximately} 1.56 kg.dm{sup {minus}3} that of seawater. If the solid was shaped as a torpedo and then left to fall through the water column it would penetrate quite deeply into the soft sediments. This conclusion is based on in-situ investigations using penetrators that were studied as a disposal option for other solid wastes. 40 refs., 3 figs.

  11. Using carbon dioxide as a building block in organic synthesis.

    PubMed

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

    2015-01-01

    Carbon dioxide exits in the atmosphere and is produced by the combustion of fossil fuels, the fermentation of sugars and the respiration of all living organisms. An active goal in organic synthesis is to take this carbon--trapped in a waste product--and re-use it to build useful chemicals. Recent advances in organometallic chemistry and catalysis provide effective means for the chemical transformation of CO? and its incorporation into synthetic organic molecules under mild conditions. Such a use of carbon dioxide as a renewable one-carbon (C1) building block in organic synthesis could contribute to a more sustainable use of resources. PMID:25600683

  12. Miscibility of Polymers in Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Defelice, Jeffrey; Lipson, Jane

    2014-03-01

    We have developed a simple model that allows us to correlate underlying thermodynamic behavior with trends in miscibility, which we have applied to mixtures of polymers and supercritical carbon dioxide (scCO2) . scCO2 is considered a ``green'' solvent, making it an attractive choice over familiar organic solvents. Experimental cloud point investigations have determined the miscibility of a diverse array of polymers in scCO2. Properties of these polymers such as fluorination, alkyl group size, and molecular weight have a strong effect on mixture miscibility. Although polymer/scCO2 mixtures have been modeled with some success in the past, the ability of an equation of state (EOS) to make accurate predictions has yet to be demonstrated. We have used a simple EOS to study several of these mixtures. We draw insight from the trends observed via our parameterization of pure component experimental data and discuss how the use of pure component information, alone, leads us to predictions about mixture behavior. This will ultimately aid in our understanding of what is controlling polymer miscibility in scCO2.

  13. Low-temperature data for carbon dioxide

    E-print Network

    Azreg-Aïnou, Mustapha

    2014-01-01

    We investigate the empirical data for the vapor pressure (154$ \\leq$$T$$\\leq$196 K) and heat capacity (15.52$ \\leq$$T$$\\leq$189.78 K) of the solid carbon dioxide. The approach is both theoretical and numerical, using a computer algebra system (CAS). From the latter point of view, we have adopted a cubic piecewise polynomial representation for the heat capacity and reached an excellent agreement between the available empirical data and the evaluated one. Furthermore, we have obtained values for the vapor pressure and heat of sublimation at temperatures below 195 right down to 0 K. The key prerequisites are the: 1) Determination of the heat of sublimation of 26250 J$\\cdot$mol\\textsuperscript{-1} at vanishing temperature and 2) Elaboration of a `linearized' vapor pressure equation that includes all the relevant properties of the gaseous and solid phases. It is shown that: 1) The empirical vapor pressure equation derived by Giauque & Egan remains valid below the assumed lower limit of 154 K (similar argument ...

  14. 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

  15. 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.

  16. Carbon Dioxide Exchange in Complex Topography

    NASA Astrophysics Data System (ADS)

    Reif, Matthias; Rotach, Mathias; Wohlfahrt, Georg; Gohm, Alexander

    2015-04-01

    On a global scale the budget of carbon dioxide (CO_2) bears a quite substantial uncertainty, which is commonly understood to be mainly due to land-surface exchange processes. In this project we investigate to what extent complex topography can amplify these land-surface exchange processes. The hypothesis is that, on the meso-scale, topography adds additional atmospheric mechanisms that drive the exchange of CO2 at the surface. This sensitivity model study investigates an idealized sine shaped valley with the atmospheric numerical model Weather Research and Forecasting (WRF) coupled to the community land model (CLM) to study the effect of complex topography on the CO2 budget compared to flat terrain. The experiment is designed to estimate the effect of the topography during maximum ecosystem exchange in summer using meteorological and ecosystem conditions at solstice, the 21. of June. Systematic variation of meteorological initial conditions, plant functional types and the topography creates an ensemble that unveils the fundamental factors that dominate the differences of CO2 between simulations with topography compared to plain surfaces in the model. The sign and magnitude of the difference between the CO2 exchange over topography and over a plain simulation are strongly dependent on the CLM plant functional type, the initial temperature, the initial relative humidity, the latitude and the area height distribution of the topography. However, in this model experiment the topography is, in the mean, a sink to the CO2 budget in the order of 5% per day.

  17. Carbon dioxide insufflation during colonoscopy in deeply sedated patients

    PubMed Central

    Singh, Rajvinder; Neo, Eu Nice; Nordeen, Nazree; Shanmuganathan, Ganesananthan; Ashby, Angelie; Drummond, Sharon; Nind, Garry; Murphy, Elizabeth; Luck, Andrew; Tucker, Graeme; Tam, William

    2012-01-01

    AIM: To compare the impact of carbon dioxide (CO2) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy. METHODS: Patients referred for colonoscopy were randomized to receive either CO2 or air insufflation during the procedure. Both the colonoscopist and patient were blinded to the type of gas used. During the procedure, insertion and withdrawal times, caecal intubation rates, total sedation given and capnography readings were recorded. The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale (VAS) (0-3). Patients then graded their level of discomfort and abdominal bloating using a similar VAS. Complications during and after the procedure were recorded. RESULTS: A total of 142 patients were randomized with 72 in the air arm and 70 in the CO2 arm. Mean age between the two study groups were similar. Insertion time to the caecum was quicker in the CO2 group at 7.3 min vs 9.9 min with air (P = 0.0083). The average withdrawal times were not significantly different between the two groups. Caecal intubation rates were 94.4% and 100% in the air and CO2 groups respectively (P = 0.012). The level of discomfort assessed by the nurse was 0.69 (air) and 0.39 (CO2) (P = 0.0155) and by the patient 0.82 (air) and 0.46 (CO2) (P = 0.0228). The level of abdominal bloating was 0.97 (air) and 0.36 (CO2) (P = 0.001). Capnography readings trended to be higher in the CO2 group at the commencement, caecal intubation, and conclusion of the procedure, even though this was not significantly different when compared to readings obtained during air insufflation. There were no complications in both arms. CONCLUSION: CO2 insufflation during colonoscopy is more efficacious than air, allowing quicker and better cecal intubation rates. Abdominal discomfort and bloating were significantly less with CO2 insufflation. PMID:22783048

  18. 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.

  19. A 400 million year carbon isotope record of pedogenic carbonate: Implications for paleoatmospheric carbon dioxide

    Microsoft Academic Search

    D. D. Ekart; T. E. Cerling; I. P. Montanez; N. J. Tabor

    1999-01-01

    A 400 record of atmospheric carbon dioxide levels has been estimated by applying a COâ paleobarometer to a database of 758 analyses of paleosol (fossil soil) carbonates. This database is a compilation of new data and previously published values from the literature. Many new analyses of Mesozoic paleosols are reported, an era poorly represented in the literature. Results indicate that

  20. Impact of cement renders on airborne ozone and carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Taylor-Lange, Sarah C.; Juenger, Maria C. G.; Siegel, Jeffrey A.

    2013-05-01

    The uptake of pollutants by building surfaces can potentially improve both indoor and outdoor air quality. Cement renders provide a unique opportunity for passive pollutant removal because they can cover large surface areas. This study investigated the passive removal of carbon dioxide and ozone by cement renders having varied binder compositions and curing durations. The results from this study demonstrated shorter curing durations resulted in greater pollutant uptake. However, the use of the supplementary cementitious material, metakaolin, in the cement render increased the carbon dioxide ingress while decreasing the ozone uptake. Therefore, the adaptation of the render composition for the best effective application may result in valuable indoor air quality or carbon savings consequences.

  1. Mercury accumulation in grass and forb species as a function of atmospheric carbon dioxide concentrations and mercury exposures in air and soil

    Microsoft Academic Search

    A. G. Millhollen; D. Obrist; M. S. Gustin

    2006-01-01

    The goal of this study was to investigate the potential for atmospheric Hg° uptake by grassland species as a function of different air and soil Hg exposures, and to specifically test how increasing atmospheric CO2 concentrations may influence foliar Hg concentrations. Four common tallgrass prairie species were germinated and grown for 7 months in environmentally controlled chambers using two different

  2. Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog

    E-print Network

    Scaling up carbon dioxide capture and storage: From megatons to gigatons Howard J. Herzog MIT Global warming Carbon mitigation Low carbon energy technologies Carbon dioxide capture and storage (CCS) Carbon dioxide (CO2) capture and storage (CCS) is the only technology that can reduce CO2 emissions

  3. 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...

  4. 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.

  5. A selective and efficient electrocatalyst for carbon dioxide reduction.

    PubMed

    Lu, Qi; Rosen, Jonathan; Zhou, Yang; Hutchings, Gregory S; Kimmel, Yannick C; Chen, Jingguang G; Jiao, Feng

    2014-01-01

    Converting carbon dioxide to useful chemicals in a selective and efficient manner remains a major challenge in renewable and sustainable energy research. Silver is an interesting electrocatalyst owing to its capability of converting carbon dioxide to carbon monoxide selectively at room temperature; however, the traditional polycrystalline silver electrocatalyst requires a large overpotential. Here we report a nanoporous silver electrocatalyst that is able to electrochemically reduce carbon dioxide to carbon monoxide with approximately 92% selectivity at a rate (that is, current) over 3,000 times higher than its polycrystalline counterpart under moderate overpotentials of <0.50?V. The high activity is a result of a large electrochemical surface area (approximately 150 times larger) and intrinsically high activity (approximately 20 times higher) compared with polycrystalline silver. The intrinsically higher activity may be due to the greater stabilization of CO2?(-) intermediates on the highly curved surface, resulting in smaller overpotentials needed to overcome the thermodynamic barrier. PMID:24476921

  6. A selective and efficient electrocatalyst for carbon dioxide reduction

    NASA Astrophysics Data System (ADS)

    Lu, Qi; Rosen, Jonathan; Zhou, Yang; Hutchings, Gregory S.; Kimmel, Yannick C.; Chen, Jingguang G.; Jiao, Feng

    2014-01-01

    Converting carbon dioxide to useful chemicals in a selective and efficient manner remains a major challenge in renewable and sustainable energy research. Silver is an interesting electrocatalyst owing to its capability of converting carbon dioxide to carbon monoxide selectively at room temperature; however, the traditional polycrystalline silver electrocatalyst requires a large overpotential. Here we report a nanoporous silver electrocatalyst that is able to electrochemically reduce carbon dioxide to carbon monoxide with approximately 92% selectivity at a rate (that is, current) over 3,000 times higher than its polycrystalline counterpart under moderate overpotentials of <0.50?V. The high activity is a result of a large electrochemical surface area (approximately 150 times larger) and intrinsically high activity (approximately 20 times higher) compared with polycrystalline silver. The intrinsically higher activity may be due to the greater stabilization of CO2?- intermediates on the highly curved surface, resulting in smaller overpotentials needed to overcome the thermodynamic barrier.

  7. Interfacial tension measurements and modelling of (carbon dioxide + n-alkane) and (carbon dioxide + water) binary mixtures at elevated pressures and temperatures

    Microsoft Academic Search

    Apostolos Georgiadis; Felix Llovell; Alexander Bismarck; Felipe J. Blas; Amparo Galindo; Geoffrey C. Maitland; J. P. Martin Trusler; George Jackson

    2010-01-01

    Supercritical carbon dioxide (CO2) is often used as a process fluid for enhanced oil recovery. The storage of carbon dioxide in underground formations is a potential way of mitigating climate change during a transition period to more sustainable energy sources. Combining injection with subsequent trapping of the non-wetting supercritical carbon dioxide phase in the pores of a depleted reservoir is

  8. It is time to put carbon dioxide to work

    SciTech Connect

    Lipinsky, E.S. [Battelle, Columbus, OH (United States)

    1993-12-31

    The need to control emissions of carbon dioxide into the atmosphere is the subject of vigorous debate at this time. There is growing evidence that rising levels of carbon dioxide increase global warming, with perhaps highly adverse impacts for the human economy. There are calls for carbon taxes and other harsh measures. Japan has established a national goal of holding carbon dioxide emissions in the year 2000 to 1990 levels. I hope that this conference will be a turning point in the United States position on this issue. The current major end uses for CO{sub 2} include refrigeration, beverage carbonation, soda ash production, fire fighting, and urea fertilizer production. They are all based on chemistry that would not surprise a good chemist of the 19th century. Consumption of carbon dioxide in synthesis of industrial chemicals is limited. Usually one explains low production of chemicals from a candidate feedstock in terms of poor availability, price, purity, or reactivity. We can eliminate the first three as the causes of the underutilization of carbon dioxide.

  9. 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 oilcontaining formations or saline aquifers. The term ?globule? refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 ?m range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 ?m or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 ?m (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized emulsions with a flow through, static mixer based apparatus under a variety

  10. 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 analysis and comparison among the technologies was made based on ESM, technology readiness level and reliability. Those technologies with potential were recommended for development.

  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 systematic errors in the CO2 density measurements. Under conditions of high positive or negative sensible heat flux, air-temperature fluctuations are correlated with fluctuations of the vertical wind component and can lead to significant biases in the CO2 flux estimates. This study demonstrates that sonically derived fast-response air temperature in the optical sensing path of an OP gas analyzer can replace the slow-response measurements from the temperature sensor as a scaling parameter in the calibration model to correct for these air temperature-induced spectroscopic effects. Our approach is evaluated by comparison between different OP and CP gas analyzer-based eddy-covariance systems in ecosystems with low CO2 uptake under a range of sensible heat flux regimes and varying meteorological parameters. We show that ignoring high-frequency spectroscopic effects can lead to false interpretations of net ecosystem CO2 exchange for specific site and environmental conditions.

  12. Development of Chinese Carbon Dioxide Satellite (TanSat)

    NASA Astrophysics Data System (ADS)

    Yi, Liu; Cai, Zhaonan; Yang, Dongxu; Duan, Minzheng; Lv, Daren; Yin, Zengshan; Zhang, Yonghe; Yang, Zhongdong; Zhang, Xingying; Zheng, Yuquan; Yan, Changxiang

    2013-04-01

    The Chinese carbon dioxide observation satellite (TanSat) project is the national high technology research and development program. It is funded by the ministry of science and technology of the people's republic of China and the Chinese Academy of Sciences. The TanSat is going to monitor the carbon dioxide in Sun-Synchronous orbit with XCO2 precision of 1~4ppm over regional scale. Two detectors are under design, the main instrument is a high resolution grating spectrometer that measure reflected sunlight with the 0.76 ?m O2 A-band and two CO2 bands at 1.61 and 2.06 ?m, the second one is the Cloud and Aerosol Polarization Imager (CAPI), which is a wide field of view moderate resolution imaging spectrometer, it include 0.38, 0.67, 0.87, 1.375 and 1.64?m channels, with two polarization channels in 0.67?m and 1.64?m. A full physical optimal estimation method has being developed to retrieve the column-averaged CO2 dry air mole fraction (XCO2), and the data from CAPI will be used to correct cloud and aerosol interference. Global and regional surface CO2 flux will be derived from XCO2 observations with inverse modeling. Ground based validation network are being established around China. The CO2 observation consist of 3 Bruker IFS125 and 3 Optical Spectrum Analyzer over Beijing, Shenzhen, Shangdong, Inner Mongol, and Hainan Island, etc. Currently, we are passing through the preliminary design review and will finish critical design review at the end of 2014, satellite readiness review and launching will be scheduled from Dec. 2014 to June 2015.

  13. Urban Evapotranspiration and Carbon Dioxide Flux in Miami - Dade, Florida

    NASA Astrophysics Data System (ADS)

    Bernier, T.; Hopper, W.

    2010-12-01

    Atmospheric Carbon Dioxide (CO2) concentrations are leading indicators of secular climate change. With increasing awareness of the consequences of climate change, methods for monitoring this change are becoming more important daily. Of particular interest is the carbon dioxide exchange between natural and urban landscapes and the correlation of atmospheric CO2 concentrations. Monitoring Evapotranspiration (ET) is important for assessments of water availability for growing populations. ET is surprisingly understudied in the hydrologic cycle considering ET removes as much as 80 to over 100% of precipitation back into the atmosphere as water vapor. Lack of understanding in spatial and temporal ET estimates can limit the credibility of hydrologic water budgets designed to promote sustainable water use and resolve water-use conflicts. Eddy covariance (EC) methods are commonly used to estimate ET and CO2 fluxes. The EC platform consist of a (CSAT) 3-D Sonic Anemometer and a Li-Cor Open Path CO2/ H2O Analyzer. Measurements collected at 10 Hz create a very large data sets. A EC flux tower located in the Snapper Creek Well Field as part of a study to estimate ET for the Miami Dade County Water and Sewer project. Data has been collected from December 17, 2009 to August 30, 2010. QA/QC is performed with the EdiRe data processing software according to Ameri-flux protocols. ET estimates along with other data--latent-heat flux, sensible-heat flux, rainfall, air temperature, wind speed and direction, solar irradiance, net radiation, soil-heat flux and relative humidity--can be used to aid in the development of water management policies and regulations. Currently, many financial institutions have adopted an understanding about baseline environmental monitoring. The “Equator Principle” is an example of a voluntary standard for managing social and environmental risk in project financing and has changed the way in which projects are financed.

  14. Carbon Dioxide Carbonates in the Earth;s Mantle: Implications to the Deep Carbon Cycle

    SciTech Connect

    Yoo, Choong-Shik; Sengupta, Amartya; Kim, Minseob (Princeton); (WSU)

    2012-05-22

    An increase in the ionic character in C-O bonds at high pressures and temperatures is shown by the chemical/phase transformation diagram of CO{sub 2}. The presence of carbonate carbon dioxide (i-CO{sub 2}) near the Earth's core-mantle boundary condition provides insights into both the deep carbon cycle and the transport of atmospheric CO{sub 2} to anhydrous silicates in the mantle and iron core.

  15. 14 April 2001 tmospheric carbon dioxide

    E-print Network

    Teskey, Robert O.

    emissions is through increased carbon sequestration into forests. In a large-scale assessment, Birdsey- ing carbon sequestration in southern forests. Carbon sequestration via southern pine forests may policy commitments. Keywords: carbon sequestration; southern pine forests ABSTRACT MEETING GLOBAL POLICY

  16. Ionic Liquid Membranes for Carbon Dioxide Separation

    SciTech Connect

    Myers, C.R.; Ilconich, J.B.; Luebke, D.R.; Pennline, H.W.

    2008-07-12

    Recent scientific studies are rapidly advancing novel technological improvements and engineering developments that demonstrate the ability to minimize, eliminate, or facilitate the removal of various contaminants and green house gas emissions in power generation. The Integrated Gasification Combined Cycle (IGCC) shows promise for carbon dioxide mitigation not only because of its higher efficiency as compared to conventional coal firing plants, but also due to a higher driving force in the form of high partial pressure. One of the novel technological concepts currently being developed and investigated is membranes for carbon dioxide (CO2) separation, due to simplicity and ease of scaling. A challenge in using membranes for CO2 capture in IGCC is the possibility of failure at elevated temperatures or pressures. Our earlier research studies examined the use of ionic liquids on various supports for CO2 separation over the temperature range, 37°C-300°C. The ionic liquid, 1-hexyl-3methylimidazolium Bis(trifluoromethylsulfonyl)imide, ([hmim][Tf2N]), was chosen for our initial studies with the following supports: polysulfone (PSF), poly(ether sulfone) (PES), and cross-linked nylon. The PSF and PES supports had similar performance at room temperature, but increasing temperature caused the supported membranes to fail. The ionic liquid with the PES support greatly affected the glass transition temperature, while with the PSF, the glass transition temperature was only slightly depressed. The cross-linked nylon support maintained performance without degradation over the temperature range 37-300°C with respect to its permeability and selectivity. However, while the cross-linked nylon support was able to withstand temperatures, the permeability continued to increase and the selectivity decreased with increasing temperature. Our studies indicated that further testing should examine the use of other ionic liquids, including those that form chemical complexes with CO2 based on amine interactions. The hypothesis is that the performance at the elevated temperatures could be improved by allowing a facilitated transport mechanism to become dominant. Several amine-based ionic liquids were tested on the cross-linked nylon support. It was found that using the amine-based ionic liquid did improve selectivity and permeability at higher temperature. The hypothesis was confirmed, and it was determined that the type of amine used also played a role in facilitated transport. Given the appropriate aminated ionic liquid with the cross-linked nylon support, it is possible to have a membrane capable of separating CO2 at IGCC conditions. With this being the case, the research has expanded to include separation of other constituents besides CO2 (CO, H2S, etc.) and if they play a role in membrane poisoning or degradation. This communication will discuss the operation of the recently fabricated ionic liquid membranes and the impact of gaseous components other than CO2 on their performance and stability.

  17. Carbon dioxide exchange in a peatland ecosystem

    NASA Astrophysics Data System (ADS)

    Shurpali, N. J.; Verma, S. B.; Kim, J.; Arkebauer, T. J.

    1995-07-01

    Micrometeorological measurements of carbon dioxide exchange were made in an open peatland in north central Minnesota during two growing seasons (1991 and 1992). The vegetation at the site was dominated by Sphagnum papillosum, Scheuchzeria palustris, and Chamaedaphne calyculata. The objective of the study was to examine the diurnal and seasonal variations in canopy photosynthesis (P) and develop information on the net ecosystem CO2 exchange. The two seasons provided contrasting microclimatic conditions: as compared with 1991, the 1992 season was significantly wetter and cooler. Canopy photosynthesis was sensitive to changes in light, temperature, and moisture stress (as indicated by water table depth and atmospheric vapor pressure deficit). Under moderate conditions (temperature 18-28°C, vapor pressure deficit 0.7-1.5 kPa, and water table near the surface) during the peak growth period, midday (averaged between 1000-1400 hours) P values ranged from 0.15 to 0.24 mg m-2 s-1. Under high-temperature (30°-34°C) and moisture stress (water table 0.16-0.23 m below the surface and vapor pressure deficit 2.2-3.0 kPa) conditions, midday P was reduced to about 0.03-0.06 mg m-2 s-1. There was a high degree of consistency in the values of P under similar conditions in the two seasons. Seasonally integrated values of the daily net ecosystem CO2 exchange indicated that the study site was a source of atmospheric CO2, releasing about 71 g C m-2 over a 145-day period (May-October) in 1991. Over a similar period in 1992, however, this ecosystem was a sink for atmospheric CO2 with a net accumulation of about 32 g C m-2. These results are consistent with previous investigations on CO2 exchange in other northern wetland sites during wet and dry periods.

  18. 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; Ya Liang; Douglas P. Harrison

    2002-10-01

    The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that higher temperature calcination of trona leds to reduced carbonation activity in subsequent cycles, but that calcination in dry carbon dioxide did not result in decreased activity relative to calcination in helium. Following higher temperature calcination, sodium bicarbonate (SBC) No.3 has greater activity than either coarse or fine grades of trona. Fixed bed testing of calcined SBC No.3 at 70 C confirmed that high rates of carbon dioxide absorption are possible and that the resulting product is a mixture of Wegscheider's salt and sodium carbonate. In fluidized bed testing of supported potassium carbonate, very rapid carbonation rates were observed. Activity of the support material complicated the data analysis. A milled, spherical grade of SBC appeared to be similar in attrition and abrasion characteristics to an unmilled, less regularly shaped SBC. The calcination behavior, at 107 C, for the milled and unmilled materials was also similar.

  19. Capturing carbon dioxide as a polymer from natural gas.

    PubMed

    Hwang, Chih-Chau; Tour, Josiah J; Kittrell, Carter; Espinal, Laura; Alemany, Lawrence B; Tour, James M

    2014-01-01

    Natural gas is considered the cleanest and recently the most abundant fossil fuel source, yet when it is extracted from wells, it often contains 10-20 mol% carbon dioxide (20-40 wt%), which is generally vented to the atmosphere. Efforts are underway to contain this carbon dioxide at the well-head using inexpensive and non-corrosive methods. Here we report nucleophilic porous carbons are synthesized from simple and inexpensive carbon-sulphur and carbon-nitrogen precursors. Infrared, Raman and (13)C nuclear magnetic resonance signatures substantiate carbon dioxide fixation by polymerization in the carbon channels to form poly(CO2) under much lower pressures than previously required. This growing chemisorbed sulphur- or nitrogen-atom-initiated poly(CO2) chain further displaces physisorbed hydrocarbon, providing a continuous carbon dioxide selectivity. Once returned to ambient conditions, the poly(CO2) spontaneously depolymerizes, leading to a sorbent that can be easily regenerated without the thermal energy input that is required for traditional sorbents. PMID:24892923

  20. II. Greenhouse gas markets, carbon dioxide credits and biofuels17

    E-print Network

    15 II. Greenhouse gas markets, carbon dioxide credits and biofuels17 The previous chapter analysed biofuels production. GHG policies18 that create a carbon price either through an emissions trading system or directly by taxing GHG emissions also generate increased demand for biofuels. They do so by raising