WorldWideScience

Sample records for atmospheric carbon dioxide

  1. Sintering furnace with hydrogen carbon dioxide atmosphere

    International Nuclear Information System (INIS)

    A heated furnace for sintering structures of uranium oxide containing composition being introduced to the furnace is described. The furnace receives an atmosphere comprising a mixture of hydrogen and carbon dioxide as initially introduced to the furnace, and this mixture reacts in the furnace to give the presence of water vapor and carbon monoxide

  2. Global deforestation: contribution to atmospheric carbon dioxide.

    Science.gov (United States)

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

    1983-12-01

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

  3. The oxygen and carbon dioxide balance in the earth's atmosphere

    Science.gov (United States)

    Johnson, F. S.

    1975-01-01

    The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

  4. Atmospheric carbon dioxide: its role in maintaining phytoplankton standing crops

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, D.W.; Brunskill, G.J.; Emerson, S.; Broecker, W.S.; Peng, T.H.

    1972-01-01

    The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield Lake with insuffient internal sources of carbon was determined by two methods: Measuring the carbon:nitrogen:phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-/sup 222/ tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophication of any body of water receiving an adequate supply of phosphorus and nitrogen.

  5. Phase relation between global temperature and atmospheric carbon dioxide

    OpenAIRE

    Stallinga, Peter; Khmelinskii, Igor

    2013-01-01

    The primary ingredient of Anthropogenic Global Warming hypothesis is the assumption that atmospheric carbon dioxide variations are the cause for temperature variations. In this paper we discuss this assumption and analyze it on basis of bi-centenary measurements and using a relaxation model which causes phase shifts and delays.

  6. The travel-related carbon dioxide emissions of atmospheric researchers

    OpenAIRE

    A. Stohl

    2008-01-01

    Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who – like other scientists – rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of carbon dioxide (CO2). In this paper, the CO2 emis...

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

    CERN Document Server

    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...

  8. Evidence for super-exponentially accelerating atmospheric carbon dioxide growth

    CERN Document Server

    Hüsler, Andreas D

    2011-01-01

    We analyze the growth rates of atmospheric carbon dioxide and human population, by comparing the relative merits of two benchmark models, the exponential law and the finite-time-singular (FTS) power law. The later results from positive feedbacks, either direct or mediated by other dynamical variables, as shown in our presentation of a simple endogenous macroeconomic dynamical growth model. Our empirical calibrations confirm that human population has decelerated from its previous super-exponential growth until 1960 to ``just' an exponential growth, but with no sign of more deceleration. As for atmospheric CO2 content, we find that it is at least exponentially increasing and most likely characterized by an accelerating growth rate as off 2009, consistent with an unsustainable FTS power law regime announcing a drastic change of regime. The coexistence of a quasi-exponential growth of human population with a super-exponential growth of carbon dioxide content in the atmosphere is a diagnostic of insignificant impr...

  9. Time dependences of atmospheric Carbon dioxide fluxes

    CERN Document Server

    DeSalvo, Riccardo

    2014-01-01

    Understanding the lifetime of CO2 in the atmosphere is critical for predictions regarding future climate changes. A simple mass conservation analysis presented here generates tight estimations for the atmosphere's retention time constant. The analysis uses a leaky integrator model that combines the observed deficit (only less than 40% of CO2 produced from combustion of fossil fuels is actually retained in the atmosphere, while more than 60% is continuously shed) with the exponential growth of fossil fuel burning. It reveals a maximum characteristic time of less than 23 year for the transfer of atmospheric CO2 to a segregation sink. This time constant is further constrained by the rapid disappearance of 14C after the ban of atmospheric atomic bomb tests, which provides a lower limit of 18 years for this transfer. The study also generates evaluations of other CO2 fluxes, exchange time constants and volumes exchanged. Analysis of large harmonic oscillations of atmospheric CO2 concentration, often neglected in th...

  10. Mycorrhizal mediation of soil organic carbon decomposition under elevated atmospheric carbon dioxide

    Science.gov (United States)

    Significant effort in global change research has recently been directed towards assessing the potential of soil as a carbon sink under future atmospheric carbon dioxide scenarios. Attention has focused on the impact of elevated carbon dioxide on plant interactions with mycorrhizae, a symbiotic soil...

  11. Climatic response to a gradual increase of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    The transient response of a coupled ocean-atmosphere model to an increase of carbon dioxide has been the subject of several studies. The models used in these studies explicitly incorporate the effect of heat transport by ocean currents and are different from the model used by Hansen et al. Here the authors evaluate the climatic influence of increasing atmospheric carbon dioxide using a coupled model recently developed at the NOAA Geophysical Fluid Dynamics Laboratory. The model response exhibits a marked and unexpected interhemispheric asymmetry. In the circumpolar ocean of the southern hemisphere, a region of deep vertical mixing, the increase of surface air temperature is very slow. In the Northern hemisphere of the model, the rise of surface air temperature is faster and increases with latitude, with the exception of the northern North Atlantic, where it is relatively slow because of the weakening of the thermohaline circulation

  12. Atmospheric carbon dioxide and the global carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J R [ed.

    1985-12-01

    This state-of-the-art volume presents discussions on the global cycle of carbon, the dynamic balance among global atmospheric CO2 sources and sinks. Separate abstracts have been prepared for the individual papers. (ACR)

  13. Electrochemical Cell for Obtaining Oxygen from Carbon Dioxide Atmospheres

    Science.gov (United States)

    Hooker, Matthew; Rast, H. Edward; Rogers, Darren K.; Borja, Luis; Clark, Kevin; Fleming, Kimberly; Mcgurren, Michael; Oldaker, Tom; Sweet, Nanette

    1989-01-01

    To support human life on the Martian surface, an electrochemical device will be required to obtain oxygen from the carbon dioxide rich atmosphere. The electrolyte employed in such a device must be constructed from extremely thin, dense membranes to efficiently acquire the oxygen necessary to support life. A forming process used industrially in the production of multilayer capacitors and electronic substrates was adapted to form the thin membranes required. The process, known as the tape casting, involves the suspension consisting of solvents and binders. The suspension is passed under a blade, resulting in the production of ceramic membranes between 0.1 and 0.5 mm thick. Once fired, the stabilized zirconia membranes were assembled into the cell design by employing a zirconium phosphate solution as the sealing agent. The resulting ceramic-to-ceramic seals were found to be structurally sound and gas-tight. Furthermore, by using a zirconia-based solution to assemble the cell, the problem of a thermal expansion mismatch was alleviated. By adopting an industrial forming process to produce thin membranes, an electrochemical cell for obtaining oxygen from carbon dioxide was produced. The proposed cell design is unique in that it does not require a complicated manifold system for separating the various gases present in this process, nor does it require a series of complex electrical connections. Thus, the device can reliably obtain the vital oxygen supply from the toxic carbon dioxide atmosphere.

  14. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres

    OpenAIRE

    Heng, Kevin; Lyons, James R.

    2015-01-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres in hot, hydrogen-dominated atmospheres. We construct novel 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 m...

  15. Controls on the Time Scale of Carbonate Neutralization of Carbon Dioxide Released to the Atmosphere

    Science.gov (United States)

    Caldeira, K.; Cao, L.

    2007-12-01

    Once released to the atmosphere, carbon dioxide is removed on a range of time scales. On the time scale of years to centuries, carbon dioxide removal from the atmosphere is dominated by transport processes within the ocean. On the time scale of hundreds of thousands of years, carbon dioxide removal from the atmosphere is dominated by processes related to the weathering of silicate rocks on land. Between these time scales, carbon dioxide removal is dominated by interactions involving carbonate minerals both on land and in the sea. Net dissolution of carbonate minerals (on land or in the sea) increases ocean alkalinity to an extent that exceeds the amount of carbon addition; the result is a transfer of carbon from the atmosphere to the ocean and moderation of the effects of added carbon on ocean chemical parameters such as pH and carbonate mineral saturation. There has been some controversy over how fast equilibration with carbonate minerals can neutralize carbon acidity, with claims ranging from the extreme and untenable claim that this process is essentially instantaneous to more plausible claims that the equilibration time scale may approach 10 kyr. Even within the domain of informed discourse, estimates of the carbonate neutralization timescale can vary by an order-of-magnitude. Here, in an effort to understand the sources of the lack of consensus on this issue, we examine how various processes (e.g., ocean transport, sediment pore water diffusion, carbonate-mineral dissolution, and carbonate weathering on land) influence the time scale for carbonate neutralization of carbon dioxide releases to the atmosphere.

  16. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres

    Science.gov (United States)

    Heng, Kevin; Lyons, James R.

    2016-02-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres in hot, hydrogen-dominated atmospheres. We construct novel 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, 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 the metallicity is greatly enhanced, but this property is negated by temperatures above 1000 K. For hydrogen-dominated atmospheres, our generic result has the implication that retrieval studies may wish to set the subdominance of carbon dioxide as a prior of the calculation and not let its abundance completely roam free as a fitting parameter, because it directly affects the inferred value of the carbon-to-oxygen ratio and may produce unphysical conclusions. We discuss the relevance of these implications for the hot Jupiter WASP-12b and suggest that some of the previous results are chemically impossible. The relative abundance of carbon dioxide to acetylene is potentially a sensitive diagnostic of the carbon-to-oxygen ratio.

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

    Science.gov (United States)

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

    2016-01-01

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

  18. Daily Variation of Heavy Carbon Dioxide in Mars Atmosphere

    Science.gov (United States)

    Livengood, T. A.; Kostiuk, Th; Kolasinski, J.; Hewagama, T.; Henning, W. G.; Sornig, M.; Stangier, T.; Krause, P.; Sonnabend, G.

    2015-10-01

    The atmosphere of Mars is significantly enriched in C and O heavy isotopes, detected by ground based high-resolution infrared spectroscopy as well as in situ measurements by the Phoenix lander and Mars Science Laboratory Curiosity rover. Heavy isotope enrichment is consistent with the preferential loss of light isotopes in eroding Mars' primordial atmosphere. Infrared spectroscopy of Mars collected in May 2012 as well as in March and May of 2014 from the NASA IRTF resolves rovibrational transitions of normal-isotope carbon dioxide as well as singly-substituted minor isotopologues, enabling remote measurements of carbon and oxygen isotope ratios as a function of latitude and local time of day. Earlier measurements obtained in October 2007 demonstrated that the relative abundance of O-18 increased linearly with increasing surface temperature over a relatively warm early-afternoon temperature range, but did not extend far enough to inspect the effect of late-afternoon cooling. These results imply that isotopically enriched gas is sequestered overnight when surface temperature is minimum and desorbs through the course of the day as temperature increases. Current spectroscopic constants indicate that the peak isotopic enrichment could be significantly greater than what has been measured in situ, apparently due to sampling the atmosphere at different time of day and surface temperature. The observing runs in 2012 and 2014 measured O-18 enrichment at several local times in both morning and afternoon sectors as well as at the subsolar, equatorial, and anti-subsolar latitudes. The two runs in 2014 have additionally observed O-17 and C-13 transitions in the morning sector, from local dawn to noon. These observations include a limited sampling of measurements over Gale Crater, which can be compared with contemporary in situ measurements by the Curiosity rover to investigate the degree of agreement between in situ and remote methods and potentially to calibrate the

  19. Daily Variation of Isotope Ratios in Mars Atmospheric Carbon Dioxide

    Science.gov (United States)

    Livengood, Timothy A.; Kostiuk, Theodor; Kolasinski, John R.; Hewagama, Tilak; Henning, Wade G.; Sornig, Manuela; Stangier, Tobias; Krause, Pia; Sonnabend, Guido; Mahaffy, Paul R.

    2014-11-01

    The atmosphere of Mars has been shown by ground based high-resolution infrared spectroscopy and in situ measurements with the Phoenix lander and Mars Science Laboratory Curiosity rover to be enriched in C and O heavy isotopes, consistent with preferential loss of light isotopes in eroding Mars’ primordial atmosphere. The relative abundance of heavy isotopes, combined with contemporary measurements of loss rates to be obtained with MAVEN, will enable estimating the primordial atmospheric inventory on Mars. IR spectroscopy of Mars collected in May 2012 as well as in March and May of 2014 from the NASA IRTF has resolved transitions of all three singly-substituted minor isotopologues of carbon dioxide in addition to the normal isotope, enabling remote measurements of all the carbon and oxygen isotope ratios as a function of latitude, longitude, and time of day. Earlier measurements obtained in October 2007 demonstrated that the relative abundance of O-18 increased linearly with increasing surface temperature over a relatively warm early-afternoon temperature range, but did not extend far enough to inspect the effect of late-afternoon cooling. These results imply that isotopically enriched gas is sequestered overnight when surface temperature is minimum and desorbs through the course of the day as temperature increases. Current spectroscopic constants indicate that the peak isotopic enrichment could be significantly greater than what has been measured in situ, apparently due to sampling the atmosphere at different time of day and surface temperature. The observing runs in 2012 and 2014 measured O-18 enrichment at several local times in both morning and afternoon sectors as well as at the subsolar, equatorial, and anti-subsolar latitudes. The two runs in 2014 have additionally observed O-17 and C-13 transitions in the morning sector, from local dawn to noon. These observations include a limited sampling of measurements over Gale Crater, which can be compared with

  20. Monitoring of carbon 14 in atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    A purpose of this article is to present the first data of the atmospheric C-14 monitoring in CO2 form. In the Prague-Bulovka locality atmospheric CO2 have been continuously collected by absorption in 0.7 M NaOH solution. The samples were one month cumulated. Afterwards, the CO2 was extracted from the NaOH solution and benzene was synthesised. The benzene was measured by liquid scintillation counting (LSC). The monitoring results from January to July 2001 period are discussed and compared with the results from other countries. (authors)

  1. Respiration and assimilation processes reflected in the carbon isotopic composition of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    The paper presents diurnal variations of concentration and carbon isotopic composition of atmospheric carbon dioxide caused by respiration and assimilation processes. Air samples were collected during early and late summer in 1998 in unpolluted area (village Guciow located near Roztocze National Park, SE Poland) in three different environments: uncultivated field on a hill, a meadow in the Wieprz river valley and a forest. The effect is very strong during intensive vegetation growth on a sunny day and clear night. The largest diurnal variations in atmospheric CO2 concentration and its carbon isotopic composition in June above the meadow were about 480 ppm and 10 pro mille, respectively. (author)

  2. The travel-related carbon dioxide emissions of atmospheric researchers

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2008-04-01

    Full Text Available Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who – like other scientists – rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of carbon dioxide (CO2. In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc. were calculated for the years 2005–2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  3. CONSTRUCTION OF NATURAL NEUTRALIZATION FACILITIES FOR ALKALINE TUNNEL SEEPAGE USING ATMOSPHERIC CARBON DIOXIDE

    Science.gov (United States)

    Furuya, Yoshinobu; Igarashi, Toshihumi; Matsumoto, Takayuki; Okawa, Ryo

    Neutralization with liquefied carbon dioxide for alkaline tunnel seepage after construction is one of the issues to be solved by considering the costs of gas and neutralization units and management in the long run. One promising method is to neutralize it by natural processes using atmospheric carbon dioxide. In this study, the hydrological survey and dissolution experiments of atmospheric carbon dioxide in the laboratory and in situ conditions were conducted. Based on the results, natural neutralization facilities using atmospheric carbon dioxide were constructed. The pH of the effluent from the facilities was reduced by 0.13 to 0.18, indicating that the double film theory was effective in predicting the reduction of pH.

  4. Fixation of atmospheric carbon dioxide by a cadmium(II) macrocyclic complex.

    Science.gov (United States)

    Janzen, Daron E; Botros, Maikel E; VanDerveer, Donald G; Grant, Gregory J

    2007-12-01

    A crystal structure showing an unusual trinuclear Cd(II) cluster bridged in mu3 fashion by a carbonate ligand is reported. The carbonate ion is formed by fixation of atmospheric carbon dioxide from the corresponding cadmium mononuclear complex containing an aza crown ether. PMID:18271488

  5. Effect of carbon oxide and carbon dioxide atmosphere on ther rate of yttrium oxalate thermal decomposition

    International Nuclear Information System (INIS)

    The kinetics of yttrium oxalate thermal decomposition in carbon monoxide and dioxide atmosphere is studied. It is shown that yttrium oxalate pyrolysis proceeds in two stages and each stage is characterized by a certain rate and activation energy. The rate constant of the first stage of the process has higher values for CO atmosphere than for CO2 atmosphere in the whole range of investigated temperatures (400-1000 deg C). But the difference is not considerable and, thus, the effect of atmosphere composition on the rate of the first stage of the process is insignificant. Carbon dioxide atmosphere slows down the second stage of the process and increases the total time required for yttrium oxalate complete decomposition. However, the composition of the atmosphere does not affect the activation energy of the both stages of the process. The activation energy of the first stage equals 18.2 kJ/mol, and that of the second stage - 33.3 kJ/mol

  6. Antarctic Pumpdown---a New Geoengineering Concept for Capturing and Storing Atmospheric Carbon Dioxide

    Science.gov (United States)

    Beget, J. E.

    2014-12-01

    Growing concentrations of carbon dioxide in the atmosphere are increasing global temperatures. This is projected to impact human society in negative ways. Multiple geoengineering approaches have been suggested that might counteract problems created by greenhouse warming, but geoengineering itself can be problematic as some proposed methods would pose environmental risks to the oceans, atmosphere, and biosphere. I propose a new approach that would remove CO2 from the atmosphere and store it in the cryosphere. Carbon dioxide would be captured by seeding the atmosphere over a designated small region of central Antarctica with monoethanolamine (MEA), a well known compound commonly used for CO2 capture in submarines and industrial processes. Monoethanolamine captures and retains carbon dioxide until it encounters water. Because MEA crystals are stable when dry, they would fall from the atmosphere just in the local area where the seeding is done, and they would be naturally buried by snowfalls and preserved in the upper parts of the East Antarctic Ice Sheet, where thawing does not occur. The carbon dioxide removed from the atmosphere by this process could reside safely in this geologic reservoir for thousands of years, based on known flow characteristic of the ice sheet. Also, carbon dioxide stored in this way could be recovered in the future by drilling into the ice sheet to the frozen storage zone. The CO2 Antarctic Pumpdown (CAP) concept could potentially be used to stabilize or reduce the amount of carbon dioxide in the atmosphere, and then to store the carbon dioxide safely and inexpensively in a stable geologic reservoir

  7. Atmospheric carbon dioxide removal: long-term consequences and commitment

    International Nuclear Information System (INIS)

    Carbon capture from ambient air has been proposed as a mitigation strategy to counteract anthropogenic climate change. We use an Earth system model to investigate the response of the coupled climate-carbon system to an instantaneous removal of all anthropogenic CO2 from the atmosphere. In our extreme and idealized simulations, anthropogenic CO2 emissions are halted and all anthropogenic CO2 is removed from the atmosphere at year 2050 under the IPCC A2 CO2 emission scenario when the model-simulated atmospheric CO2 reaches 511 ppm and surface temperature reaches 1.8 deg. C above the pre-industrial level. In our simulations a one-time removal of all anthropogenic CO2 in the atmosphere reduces surface air temperature by 0.8 deg. C within a few years, but 1 deg. C surface warming above pre-industrial levels lasts for several centuries. In other words, a one-time removal of 100% excess CO2 from the atmosphere offsets less than 50% of the warming experienced at the time of removal. To maintain atmospheric CO2 and temperature at low levels, not only does anthropogenic CO2 in the atmosphere need to be removed, but anthropogenic CO2 stored in the ocean and land needs to be removed as well when it outgasses to the atmosphere. In our simulation to maintain atmospheric CO2 concentrations at pre-industrial levels for centuries, an additional amount of CO2 equal to the original CO2 captured would need to be removed over the subsequent 80 years.

  8. Influence of variable rates of neritic carbonate deposition on atmospheric carbon dioxide and pelagic sediments

    Science.gov (United States)

    Walker, J. C.; Opdyke, B. C.

    1995-01-01

    Short-term imbalances in the global cycle of shallow water calcium carbonate deposition and dissolution may be responsible for much of the observed Pleistocene change in atmospheric carbon dioxide content. However, any proposed changes in the alkalinity balance of the ocean must be reconciled with the sedimentary record of deep-sea carbonates. The possible magnitude of the effect of shallow water carbonate deposition on the dissolution of pelagic carbonate can be tested using numerical simulations of the global carbon cycle. Boundary conditions can be defined by using extant shallow water carbonate accumulation data and pelagic carbonate deposition/dissolution data. On timescales of thousands of years carbonate deposition versus dissolution is rarely out of equilibrium by more than 1.5 x 10(13) mole yr-1. Results indicate that the carbonate chemistry of the ocean is rarely at equilibrium on timescales less than 10 ka. This disequilibrium is probably due to sea level-induced changes in shallow water calcium carbonate deposition/dissolution, an interpretation that does not conflict with pelagic sedimentary data from the central Pacific.

  9. Canopy-scale kinetic fractionation of atmospheric carbon dioxide and water vapour isotopes

    Science.gov (United States)

    The isotopic fluxes of carbon dioxide (CO2) and water vapour (H2O) between the atmosphere and terrestrial plants provide powerful constraints on carbon sequestration on land 1-2, changes in vegetation cover 3 and the Earth’s Dole effect 4. Past studies, relying mainly on leaf-scale observations, hav...

  10. Atmospheric CO2 capture by algae: Negative carbon dioxide emission path.

    Science.gov (United States)

    Moreira, Diana; Pires, José C M

    2016-09-01

    Carbon dioxide is one of the most important greenhouse gas, which concentration increase in the atmosphere is associated to climate change and global warming. Besides CO2 capture in large emission point sources, the capture of this pollutant from atmosphere may be required due to significant contribution of diffuse sources. The technologies that remove CO2 from atmosphere (creating a negative balance of CO2) are called negative emission technologies. Bioenergy with Carbon Capture and Storage may play an important role for CO2 mitigation. It represents the combination of bioenergy production and carbon capture and storage, keeping carbon dioxide in geological reservoirs. Algae have a high potential as the source of biomass, as they present high photosynthetic efficiencies and high biomass yields. Their biomass has a wide range of applications, which can improve the economic viability of the process. Thus, this paper aims to assess the atmospheric CO2 capture by algal cultures. PMID:27005790

  11. Atmospheric Carbon Dioxide and Climate Over Phanerozoic Times

    Science.gov (United States)

    Francois, L.; Lefèbvre, V.; Goddéris, Y.; Munhoven, G.; Henrot, A.

    2006-12-01

    The atmospheric CO2 mixing ratio has fluctuated widely over the Phanerozoic, according to the estimates from available proxy records. Because atmospheric CO2 is a major greenhouse gas, these fluctuations should have led to significant climatic variations. The "classical" view is indeed that atmospheric CO2 has been the main driver of the Earth's climate history. On long-term time scales, the atmospheric CO2 level is the result of the balance between CO2 inputs from volcanoes or oxidation of old organic carbon (kerogen) in exposed rocks and outputs through silicate weathering or organic carbon deposition. Existing model reconstructions of the Phanerozoic history of atmospheric CO2 are based on such budgets. Recent data and model experiments currently challenge these models. First, the carbon cycle may be more complex than represented in the earliest models. In particular, silicate weathering depends on numerous factors, which are not obvious to model or are poorly known over the Phanerozoic. Mountain uplift is one such factor, which has been much debated in the last decade. Lithology is another example: basalts weather much more rapidly than other silicate rocks and the emplacement of large basaltic areas on the continents may trigger glaciations. Continental configuration is also more important than previously thought, as indicated by recent model experiments on super-continent fragmentation coupling geochemical and climate models. Problems of "classical" Phanerozoic CO2 models are also well illustrated by the fact that the most recent estimates of CO2 degassing show very little variation between the Cretaceous and the present, a period when large changes in CO2 have occurred, whereas degassing is the most important forcing of CO2 evolution in long-term carbon cycle models. Second, CO2 is not the only driver of climate evolution. This obvious fact has largely been forgotten in Phanerozoic studies. What the proxies tell us on paleo-atmospheric CO2 is not always in

  12. On the abundances of carbon dioxide isotopologues in the atmospheres of mars and earth

    Science.gov (United States)

    Shved, G. M.

    2016-03-01

    The isotopic composition of carbon dioxide in the Martian atmosphere from the measurements of Mars Science Laboratory have been used to estimate the relative abundances of CO2 isotopologues in the Martian atmosphere. Concurrently, this study has revealed long-standing errors in the amounts of some of low-abundance CO2 isotopologues in the Earth's atmosphere in the databases of spectroscopic parameters of gases (HITRAN, etc.).

  13. The carbon dioxide cycle

    Science.gov (United States)

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

    2005-01-01

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

  14. Short-range atmospheric dispersion of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Cortis, A.; Oldenburg, C.M.

    2009-11-01

    We present a numerical study aimed at quantifying the effects of concentration-dependent density on the spread of a seeping plume of CO{sub 2} into the atmosphere such as could arise from a leaking geologic carbon sequestration site. Results of numerical models can be used to supplement field monitoring estimates of CO{sub 2} seepage flux by modelling transport and dispersion between the source emission and concentration-measurement points. We focus on modelling CO{sub 2} seepage dispersion over relatively short distances where density effects are likely to be important. We model dense gas dispersion using the steady-state Reynolds-averaged Navier-Stokes equations with density dependence in the gravity term. Results for a two-dimensional system show that a density dependence emerges at higher fluxes than prior estimates. A universal scaling relation is derived that allows estimation of the flux from concentrations measured downwind and vice versa.

  15. Fourier Transform Spectrometer measurements of Atmospheric Carbon Dioxide and Methane

    Science.gov (United States)

    Kivi, Rigel; Heikkinen, Pauli; Chen, Huilin; Hatakka, Juha; Laurila, Tuomas

    2016-04-01

    Ground based remote sensing measurements of column CO2 and CH4 using Fourier Transform Spectrometers (FTS) within the Total Carbon Column Observing Network (TCCON) are known for high precision and accuracy. These measurements are performed at various locations globally and they have been widely used in carbon cycle studies and validation of space born measurements. The relevant satellite missions include the Orbiting Carbon Observatory-2 (OCO-2) by the National Aeronautics and Space Administration (NASA); the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) by the European Space Agency (ESA); the Greenhouse gases Observing SATellite (GOSAT) by the Japan Aerospace Exploration Agency (JAXA) and the upcoming Sentinel-5 Precursor mission, which is an ESA mission and scheduled for launch in 2016. Results of the column CO2 and CH4 measurements at Sodankylä in northern Finland (at 67.4° N, 26.6° E) are reported in this study. The measurements have been performed on regular basis since the beginning of the program in early 2009. We also present evaluation of the data quality of the ground based measurements and comparisons with the available satellite based retrievals. In case of comparisons between the GOSAT and ground based retrievals of CO2 and CH4 no significant biases were found. Sodankylä is one of the northernmost stations in the TCCON network. However, the data coverage has been relatively good thanks to the progress towards automation of the FTS measurement system. At Sodankylä the retrievals have been also compared with the balloon borne AirCore measurements at the site. AirCore sampling system is directly related to the World Meteorological Organization in situ trace gas measurement scales. The balloon platform allows sampling in both stratosphere and troposphere, which is a benefit, compared to the aircraft in situ measurements.

  16. Elevated atmospheric carbon dioxide and ozone concentrations alter LAI through changes in phenology and leaf growth

    Science.gov (United States)

    Leaves are critical for harvesting light energy, taking up carbon dioxide (CO2) and transpiring water for cooling. Changes in leaf growth, expansion or development can integrate across the plant canopy and growing season to significantly impact productivity, yield and plant-atmosphere fluxes. Althou...

  17. Highly precise atmospheric oxygen measurements as a tool to detect leaks of carbon dioxide from Carbon Capture and Storage sites

    NARCIS (Netherlands)

    van Leeuwen, Charlotte

    2015-01-01

    In Carbon Capture and Storage (CCS), carbon dioxide (CO2) from fossil fuel combustion is stored underground into a geological formation. Although the storage of CO2 is considered as safe, leakage to the atmosphere is an important concern and monitoring is necessary. Detecting and quantifying leaks o

  18. Quantifying global terrestrial carbon influx and storage as stimulated by an increase in atmospheric carbon dioxide concentration

    OpenAIRE

    Luo, Yiqi

    1997-01-01

    EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two d...

  19. Towards a stable and absolute atmospheric carbon dioxide instrument using spectroscopic null method

    Science.gov (United States)

    Xiang, B.; Nelson, D. D.; McManus, J. B.; Zahniser, M. S.; Wofsy, S. C.

    2013-07-01

    We present a novel spectral method to measure atmospheric carbon dioxide (CO2) with high precision and stability without resorting to calibration tanks during long-term operation. This spectral null method improves precision by reducing spectral proportional noise associated with laser emission instabilities. We employ sealed quartz cells with known CO2 column densities to serve as the permanent internal references in the null method, which improve the instrument's stability and accuracy. A prototype instrument - ABsolute Carbon dioxide (ABC) is developed using this new approach. The instrument has a one-second precision of 0.02 ppm, which averages down to 0.007 ppm within one minute. Long-term stability of within 0.1 ppm is achieved without any calibrations for over a one-month period. These results have the potential for eliminating the need for calibration cylinders for high accuracy field measurements of carbon dioxide.

  20. Chemical vapor deposition of high quality graphene films from carbon dioxide atmospheres.

    Science.gov (United States)

    Strudwick, Andrew James; Weber, Nils Eike; Schwab, Matthias Georg; Kettner, Michel; Weitz, R Thomas; Wünsch, Josef R; Müllen, Klaus; Sachdev, Hermann

    2015-01-27

    The realization of graphene-based, next-generation electronic applications essentially depends on a reproducible, large-scale production of graphene films via chemical vapor deposition (CVD). We demonstrate how key challenges such as uniformity and homogeneity of the copper metal substrate as well as the growth chemistry can be improved by the use of carbon dioxide and carbon dioxide enriched gas atmospheres. Our approach enables graphene film production protocols free of elemental hydrogen and provides graphene layers of superior quality compared to samples produced by conventional hydrogen/methane based CVD processes. The substrates and resulting graphene films were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Raman microscopy, sheet resistance and transport measurements. The superior quality of the as-grown graphene films on copper is indicated by Raman maps revealing average G band widths as low as 18 ± 8 cm(-1) at 514.5 nm excitation. In addition, high charge carrier mobilities of up to 1975 cm(2)/(V s) were observed for electrons in transferred films obtained from a carbon dioxide based growth protocol. The enhanced graphene film quality can be explained by the mild oxidation properties of carbon dioxide, which at high temperatures enables an uniform conditioning of the substrates by an efficient removal of pre-existing and emerging carbon impurities and a continuous suppression and in situ etching of carbon of lesser quality being co-deposited during the CVD growth. PMID:25398132

  1. Water cycle dynamic increases resilience of vegetation under higher atmospheric carbon dioxide concentration

    Science.gov (United States)

    Lemordant, L. A.; Gentine, P.; Stéfanon, M.; Drobinski, P. J.; Fatichi, S.

    2015-12-01

    Plant stomata couple the energy, water and carbon cycles. Photosynthesis requires stomata to open to take up carbon dioxide. In the process water vapor is released as transpiration. As atmospheric CO2 concentration rises, for the same amount of CO2 uptake, less water vapor is transpired, translating into higher water use efficiency. Reduced water vapor losses will increase soil water storage if the leaf area coverage remains similar. This will in turn alter the surface energy partitioning: more heat will be dissipated as sensible heat flux, resulting in possibly higher surface temperatures. In contrast with this common hypothesis, our study shows that the water saved during the growing season by increased WUE can be mobilized by the vegetation and help reduce the maximum temperature of mid-latitude heat waves. The large scale meteorological conditions of 2003 are the basis of four regional model simulations coupling an atmospheric model to a surface model. We performed two simulations with respectively 2003 (CTL) and 2100 (FUT) atmospheric CO2 applied to both the atmospheric and surface models. A third (RAD) and a fourth (FER) simulations are run with 2100 CO2 concentration applied to respectively the atmospheric model only and the surface model only. RAD investigates the impact of the radiative forcing, and FER the response to vegetation CO2 fertilization. Our results show that the water saved through higher water use efficiency during the growing season enabled by higher atmospheric carbon dioxide concentrations helps the vegetation to cope during severe heat and dryness conditions in the summer of mid-latitude climate. These results demonstrate that consideration of the vegetation carbon cycle is essential to model the seasonal water cycle dynamic and land-atmosphere interactions, and enhance the accuracy of the model outputs especially for extreme events. They also have important implications for the future of agriculture, water resources management, ecosystems

  2. Oxygen-18 Carbon Dioxide Isotope Ratio in Mars Atmosphere

    Science.gov (United States)

    Kostiuk, T.; Livengood, T. A.; Hewagama, T.; Smith, R.; Fast, K. E.; Annen, J.; Sonnabend, G.; Sornig, M.

    2012-09-01

    The determination of isotopic ratios on Mars is important to the study of atmospheric evolution [1]. The relative abundance of isotopes of CO2 provides insight into the loss of Mars' primordial atmosphere. Isotopic ratios also provide markers in the study of geochemistry of Mars meteorites and future returned samples formed in equilibrium with ambient atmosphere, and are probes of biogenic and abiotic chemistry, which differ in isotope fractionation. Due to its lesser gravity and relatively thin residual atmosphere, Mars' atmosphere should be enriched in heavy isotopes [1]. However Viking [2] results indicated an Earth-like singly substituted oxygen-18 CO2 isotopic ratio, 18OCO/OCO, with δ18O = 0±50‰ relative to Vienna Standard Mean Ocean Water (VSMOW). By comparison, isotopic ratios in Earth atmospheric CO2 are not uniquely defined due to seasonal and biotic variability, but have a range 0-41‰ relative to VSMOW [3, 4]. Phoenix lander TEGA [3] measurements found a modest enrichment of δ18O = 31.0±5.7‰. Only the Viking and Phoenix landers have carried a mass spectrometer to Mars, so far, until the arrival of Mars Science Laboratory in August 2012. Using ground-based spectroscopic techniques Krasnopolsky et al. [5] also found modest enrichment δ18O = 18±18‰. We present results from fully resolved spectroscopic measurements near 10.6 μm of both the normal and singly substituted oxygen- 18 CO2 lines, taken with the Goddard Space Flight Center Heterodyne Instrument for Planetary Winds And Composition (HIPWAC) at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii. Measurements with spectral resolving power λ/Δλ=107 were obtained in October 2007 with an instantaneous field-of-view on the planet of ~1 arcsec, at the locations shown in Fig. 1 as open squares. The solid and broken line tracks show Mars SPICAM measurements of ozone corresponding to ozone measurements also obtained with HIPWAC and shown as hatched and solid regions [6]. Figure 1

  3. The travel-related carbon dioxide emissions of atmospheric researchers

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2008-11-01

    Full Text Available Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who – like other scientists – rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of CO2. In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc. were calculated for the years 2005–2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  4. Modelling strategies of the soil plant atmosphere continuum in water limited environments and elevated atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Higher temperatures and changes in rainfall patterns have been forecasted for the future because of higher levels of carbon dioxide in the atmosphere. Warmer temperatures may cause an increase in evapotranspiration (ET) demand. A reduction in rainfall could heighten the severity and duration of drought in arid and semi-arid regions. This paper presented the water transfer scheme which includes water uptake by roots. It also described the interaction between ET and carbon dioxide enrichment. The predicted response of a plant canopy in relation to energy exchange processes was also tested for elevated atmospheric carbon dioxide level. Simulated and measured canopy conductances were reduced by about 30 per cent under elevated carbon dioxide under ideal water supply conditions. A 6 per cent reduction in both simulated and measured seasonal water use was observed under ideal conditions, while a 2 per cent reduction was observed under suboptimum irrigation. The modelling framework also included adaptation and functioning of root system of woody plant canopies. The hypothesis that water that has been relocated via hydraulic lift prevents the upper soil layers from becoming extremely dry was confirmed. Soil layers close to the surface were found to maintain soil water potential between -1.0 and -1.3 MPs during the drought period as well as under 2 different rainfall regimes. In contrast, the absence of hydraulic lift caused the soil layer close to the surface to drop to -20 MPa and -28 MPa. An additional amount of water for plant transpiration was not provided in any large amounts when water was relocated via hydraulic lift. It was concluded that carbon dioxide modelling and transpiration interactions may produce accurate estimates of canopy water use under the predicted climate change. Hydraulic lift was found to be more important for redistribution of soil moisture than for canopy transpiration

  5. Climate Sensitivity, Sea Level, and Atmospheric Carbon Dioxide

    Science.gov (United States)

    Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker

    2013-01-01

    Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3+/-1deg C for a 4 W/sq m CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4deg C for a 4 W/sq m CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.

  6. Application of Vacuum Swing Adsorption for Carbon Dioxide and Water Vapor Removal from Manned Spacecraft Atmospheres

    Science.gov (United States)

    Knox, J.; Fulda, P.; Howard, D.; Ritter, J.; Levan, M.

    2007-01-01

    The design and testing of a vacuum-swing adsorption process to remove metabolic 'water and carbon dioxide gases from NASA's Orion crew exploration vehicle atmosphere is presented. For the Orion spacecraft, the sorbent-based atmosphere revitalization (SBAR) system must remove all metabolic water, a technology approach 1Lhathas not been used in previous spacecraft life support systems. Design and testing of a prototype SBAR in sub-scale and full-scale configurations is discussed. Experimental and analytical investigations of dual-ended and single-ended vacuum desorption are presented. An experimental investigation of thermal linking between adsorbing and desorbing columns is also presented.

  7. Assessment of pre-industrial carbon dioxide content in the atmosphere using hydro-chemical data

    International Nuclear Information System (INIS)

    A hydrochemical method has been developed to calculate concentrations of carbon dioxide (CO2) in the pre-industrial atmosphere and its relationship to climatic change. The following factors affect the Earth's climate: (1) the sun with all its processes, (2) the attraction of the moon that limits the axis of inclination of the Earth, and (3) the cycle of carbon dioxide and the greenhouse effect. An imbalance in the climate system would be a major global disaster that could be detrimental for life on Earth. Recent studies and temperature measurements have shown a trend in which air temperature has increased in the troposphere in the last 100 years, affecting the normal development of natural processes. Various phenomena result from climatic change, or the gradual heating of the Earth. These include the weakening of the glacial layer that covers the Earth's surface, cycles of prolonged slowing in freeze and thaw periods of aquatic surfaces, and increased air temperature in the troposphere which can also causes abnormal fluctuations of temperature in the atmosphere, resulting in heat waves and droughts. Gradual heating of the Earth can also result in rainy periods that produce devastating floods, hurricanes and extreme winds. Changes in water temperature can influence pH levels which affect certain marine species. An increase of 5 degrees C in the global average atmospheric temperature has created changes in 420 physical processes as well as in the behavior of plants and animals. The author stated that the most drastic factor that affects the balance of the Earth's climate is the actions of man interfering with the carbon cycle, as carbon dioxide plays a vital role in the formation of the greenhouse effect. The problem results from an imbalance of the carbon dioxide cycle when CO2 emissions are increased through the combustion of fossil fuels. It was determined that before the beginning of the Industrial Revolution, carbon dioxide in the atmosphere was 256 ppm. Today

  8. Isotope aided studies of atmospheric carbon dioxide and other greenhouse gases. Phase II

    International Nuclear Information System (INIS)

    The substantial increase in atmospheric greenhouse gas concentrations and their role in global warming have become major concerns of world governments. Application of isotope techniques to label sources and sinks of CO2 and other greenhouse gases has emerged as a potentially powerful method for reducing uncertainties in the global CO2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. As with CO2 concentration measurements, meaningful integration of isotopes in global models requires careful attention to quality assurance, quality control and inter-comparability of measurements made by a number of networks and laboratories. To support improvements in isotope measurement capabilities, the IAEA began implementing Co-ordinated Research Projects (CRPs) in 1992. The first project, entitled Isotope Variations of Carbon Dioxide and other Trace Gases in the Atmosphere, was implemented from 1992 to 1994. A significant contribution was made towards a better understanding of the global carbon cycle and especially of the sources and sinks of carbon with data on the 14C and 13C content of atmospheric CO2, pointing to a better understanding of the problem of the 'missing sink' in the global carbon cycle. Important methodological developments in the field of high precision stable isotope mass spectrometry and improved data acquisition procedures emerged from work carried out within the framework of this programme. The development of pressurized gas standards and planning for an associated interlaboratory calibration were initiated. Due to the good progress and long standing nature of the required work a second CRP was initiated and implemented from 1996 to 1999. It was entitled Isotope aided Studies of Atmospheric Carbon Dioxide and Other Trace Gases - Phase II, to document the close relationship of both programmes. This publication provides an overview of the scientific outcomes of the studies conducted within Phase II of

  9. Highly precise atmospheric oxygen measurements as a tool to detect leaks of carbon dioxide from Carbon Capture and Storage sites

    OpenAIRE

    Leeuwen van, Charlotte

    2015-01-01

    In Carbon Capture and Storage (CCS), carbon dioxide (CO2) from fossil fuel combustion is stored underground into a geological formation. Although the storage of CO2 is considered as safe, leakage to the atmosphere is an important concern and monitoring is necessary. Detecting and quantifying leaks of CO2 in the atmosphere is, however, difficult due to the rapid mixing of the emitted CO2 with the surroundings and the high natural variability of the CO2 concentration. In this thesis we present ...

  10. Human population and atmospheric carbon dioxide growth dynamics: Diagnostics for the future

    Science.gov (United States)

    Hüsler, A. D.; Sornette, D.

    2014-10-01

    We analyze the growth rates of human population and of atmospheric carbon dioxide by comparing the relative merits of two benchmark models, the exponential law and the finite-time-singular (FTS) power law. The later results from positive feedbacks, either direct or mediated by other dynamical variables, as shown in our presentation of a simple endogenous macroeconomic dynamical growth model describing the growth dynamics of coupled processes involving human population (labor in economic terms), capital and technology (proxies by CO2 emissions). Human population in the context of our energy intensive economies constitutes arguably the most important underlying driving variable of the content of carbon dioxide in the atmosphere. Using some of the best databases available, we perform empirical analyses confirming that the human population on Earth has been growing super-exponentially until the mid-1960s, followed by a decelerated sub-exponential growth, with a tendency to plateau at just an exponential growth in the last decade with an average growth rate of 1.0% per year. In contrast, we find that the content of carbon dioxide in the atmosphere has continued to accelerate super-exponentially until 1990, with a transition to a progressive deceleration since then, with an average growth rate of approximately 2% per year in the last decade. To go back to CO2 atmosphere contents equal to or smaller than the level of 1990 as has been the broadly advertised goals of international treaties since 1990 requires herculean changes: from a dynamical point of view, the approximately exponential growth must not only turn to negative acceleration but also negative velocity to reverse the trend.

  11. Short and Long Term Impacts of Forest Bioenergy Production on Atmospheric Carbon Dioxide Emissions

    Science.gov (United States)

    Hudiburg, T.; Law, B. E.; Luyssaert, S.; Thornton, P. E.

    2011-12-01

    Temperate forest annual net uptake of CO2 from the atmosphere is equivalent to ~16% of the annual fossil fuel emissions in the United States. Mitigation strategies to reduce emissions of carbon dioxide have lead to investigation of alternative sources of energy including forest biomass. The prospect of forest derived bioenergy has led to implementation of new forest management strategies based on the assumption that they will reduce total CO2 emissions to the atmosphere by simultaneously reducing the risk of wildfire and substituting for fossil fuels. The benefit of managing forests for bioenergy substitution of fossil fuels versus potential carbon sequestration by reducing harvest needs to be evaluated. This study uses a combination of Federal Forest Inventory data (FIA), remote sensing, and a coupled carbon-nitrogen ecosystem process model (CLM4-CN) to predict net atmospheric CO2 emissions from forest thinning for bioenergy production in Oregon under varying future management and climate scenarios. We use life-cycle assessment (LCA) incorporating both the forest and forest product sinks and sources of carbon dioxide. Future modeled results are compared with a reduced harvest scenario to determine the potential for increased carbon sequestration in forest biomass. We find that Oregon forests are a current strong sink of 7.5 ± 1.7 Tg C yr-1 or 61 g C m-2 yr-1. (NBP; NEP minus removals from fire and harvest). In the short term, we find that carbon dynamics following harvests for fire prevention and large-scale bioenergy production lead to 2-15% higher emissions over the next 20 years compared to current management, assuming 100% effectiveness of fire prevention. Given the current sink strength, analysis of the forest sector in Oregon demonstrates that increasing harvest levels by all practices above current business-as-usual levels increases CO2 emissions to the atmosphere as long as the region's sink persists. In the long-term, we find that projected changes in

  12. Inhibition of Listeria monocytogenes on cold-smoked salmon by nisin and carbon dioxide atmosphere

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Huss, Hans Henrik; Gram, Lone

    1997-01-01

    The bacteriostatic and bacteriocidal effect of nisin in combination with carbon dioxide, NaCl and low temperature on the survival of Listeria monocytogenes was investigated in in vitro model studies and in trials with cold-smoked salmon. Addition of nisin caused various degrees of inhibition and...... most pronounced effect of nisin was found when 10(2) cfu/ml was grown in media with 5.0% NaCl and incubated in CO2 atmosphere (MBC = 30 IU/ml). The bactericidal effect of nisin was reduced in air and vacuum, and did not increase systematically with increasing NaCl concentrations. In general, nisin...

  13. Carbon dynamics in subtropical forest soil. Effects of atmospheric carbon dioxide enrichment and nitrogen addition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu X.; Zhou, Guoyi Y.; Zhang, Deqiang Q.; Duan, Honglang L.; Deng, Qi; Zhao, Liang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong H. [Griffith Univ., Nathan, Queensland (Australia). Environmental Futures Centre and School of Biomolecular and Physical Sciences

    2010-06-15

    The levels of atmospheric carbon dioxide concentration ([CO{sub 2}]) are rapidly increasing. Understanding carbon (C) dynamics in soil is important for assessing the soil C sequestration potential under elevated [CO{sub 2}]. Nitrogen (N) is often regarded as a limiting factor in the soil C sequestration under future CO{sub 2} enrichment environment. However, few studies have been carried out to examine what would happen in the subtropical or tropical areas where the ambient N deposition is high. In this study, we used open-top chambers to study the effect of elevated atmospheric [CO{sub 2}] alone and together with N addition on the soil C dynamics in the first 4 years of the treatments applied in southern China. Materials and methods Above- and below-ground C input (tree biomass) into soil, soil respiration, soil organic C, and total N as well as dissolved organic C (DOC) were measured periodically in each of the open-top chambers. Soil samples were collected randomly in each chamber from each of the soil layers (0-20, 20-40, and 40-60 cm) using a standard soil sampling tube (2.5-cm inside diameter). Soil leachates were collected at the bottom of the chamber below-ground walls in stainless steel boxes. Results and discussion The highest above- and below-ground C input into soil was found in the high CO{sub 2} and high N treatment (CN), followed by the only high N treatment (N+), the only high CO{sub 2} treatment (C+), and then the control (CK) without any CO{sub 2} enrichment or N addition. DOC in the leachates was small for all the treatments. Export of DOC played a minor role in C cycling in our experiment. Generally, soil respiration rate in the chambers followed the order: CN treatment > C + treatment > N + treatment > the control. Except for the C+ treatment, there were no significant differences in soil total N among the CN treatment, N + treatment, and the control. Overall, soil organic C (SOC) was significantly affected by the treatments (p < 0.0001). SOC

  14. Effects of patchy ocean fertilization on atmospheric carbon dioxide and biological production

    Science.gov (United States)

    Gnanadesikan, Anand; Sarmiento, Jorge L.; Slater, Richard D.

    2003-06-01

    Increasing oceanic productivity by fertilizing nutrient-rich regions with iron has been proposed as a mechanism to offset anthropogenic emissions of carbon dioxide. Earlier studies examined the impact of large-scale fertilization of vast reaches of the ocean for long periods of time. We use an ocean general circulation model to consider more realistic scenarios involving fertilizing small regions (a few hundred kilometers on a side) for limited periods of time (of order 1 month). A century after such a fertilization event, the reduction of atmospheric carbon dioxide is between 2% and 44% of the initial pulse of organic carbon export to the abyssal ocean. The fraction depends on how rapidly the surface nutrient and carbon fields recover from the fertilization event. The modeled recovery is very sensitive to the representation of biological productivity and remineralization. Direct verification of the uptake would be nearly impossible since changes in the air-sea flux due to fertilization would be much smaller than those resulting from natural spatial variability. Because of the sensitivity of the uptake to the long-term fate of the iron and organic matter, indirect verification by measurement of the organic matter flux would require high vertical resolution and long-term monitoring. Finally, the downward displacement of the nutrient profile resulting from an iron-induced productivity spurt may paradoxically lead to a long-term reduction in biological productivity. In the worst-case scenario, removing 1 ton of carbon from the atmosphere for a century is associated with a 30-ton reduction in biological export of carbon.

  15. Carbon dioxide removal system for closed loop atmosphere revitalization, candidate sorbents screening and test results

    Science.gov (United States)

    Mattox, E. M.; Knox, J. C.; Bardot, D. M.

    2013-05-01

    Due to the difficulty and expense it costs to resupply manned-spacecraft habitats, a goal is to create a closed loop atmosphere revitalization system, in which precious commodities such as oxygen, carbon dioxide, and water are continuously recycled. Our aim is to test other sorbents for their capacity for future spacecraft missions, such as on the Orion spacecraft, or possibly lunar or Mars mission habitats to see if they would be better than the zeolite sorbents on the 4-bed molecular sieve. Some of the materials being tested are currently used for other industry applications. Studying these sorbents for their specific spacecraft application is different from that for applications on earth because in space, there are certain power, mass, and volume limitations that are not as critical on Earth. In manned-spaceflight missions, the sorbents are exposed to a much lower volume fraction of CO2 (0.6% volume CO2) than on Earth. LiLSX was tested for its CO2 capacity in an atmosphere like that of the ISS. Breakthrough tests were run to establish the capacities of these materials at a partial pressure of CO2 that is seen on the ISS. This paper discusses experimental results from benchmark materials, such as results previously obtained from tests on Grade 522, and the forementioned candidate materials for the Carbon Dioxide Removal Assembly (CDRA) system.

  16. Theoretical constraints on oxygen and carbon dioxide concentrations in the Precambrian atmosphere

    Science.gov (United States)

    Kasting, J. F.

    1987-01-01

    Simple (one-dimensional) climate models suggest that carbon dioxide concentrations during the Archean must have been at least 100-1000 times the present level to keep the Earth's surface temperature above freezing in the face of decreased solar luminosity. Such models provide only lower bounds on CO2, so it is possible that CO2 levels were substantially higher than this and that the Archean climate was much warmer than today. Periods of extensive glaciation during the early and late Proterozoic, on the other hand, indicate that the climate at these times was relatively cool. To be consistent with climate models CO2 partial pressures must have declined from approximately 0.03 to 0.3 bar around 2.5 Ga ago to between 10(-3) and 10(-2) bar at 0.8 Ga ago. This steep decrease in carbon dioxide concentrations may be inconsistent with paleosol data, which implies that pCO2 did not change appreciably during that time. Oxygen was essentially absent from the Earth's atmosphere and oceans prior to the emergence of a photosynthetic source, probably during the late Archean. During the early Proterozoic the atmosphere and surface ocean were apparently oxidizing, while the deep ocean remained reducing. An upper limit of 6 x 10(-3) bar for pO2 at this time can be derived by balancing the burial rate of organic carbon with the rate of oxidation of ferrous iron in the deep ocean. The establishment of oxidizing conditions in the deep ocean, marked by the disappearance of banded iron formations approximately 1.7 Ga ago, permitted atmospheric oxygen to climb to its present level. O2 concentrations may have remained substantially lower than today, however, until well into the Phanerozoic.

  17. Elevated atmospheric carbon dioxide concentrations amplify Alternaria alternata sporulation and total antigen production

    Science.gov (United States)

    Background: Although the association between rising levels of carbon dioxide, the principle anthropogenic greenhouse gas, and pollen production has been established, few data are available regarding the function of rising carbon dioxide on quantitative or qualitative changes in allergenic fungal sp...

  18. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept beh

  19. Carbon dioxide and climate

    International Nuclear Information System (INIS)

    Global climate change is a serious environmental concern, and the US has developed ''An Action Agenda'' to deal with it. At the heart of the US effort is the US Global Change Research Program (USGCRP), which has been developed by the Committee on Earth and Environmental Sciences (CEES) of the Federal Coordinating Council for Sciences, Engineering, and Technology (FCCSET). The USGCRP will provide the scientific basis for sound policy making on the climate-change issue. The DOE contribution to the USGCRP is the Carbon Dioxide Research Program, which now places particular emphasis on the rapid improvement of the capability to predict global and regional climate change. DOE's Carbon Dioxide Research Program has been addressing the carbon dioxide-climate change connection for more than twelve years and has provided a solid scientific foundation for the USGCRP. The expansion of the DOE effort reflects the increased attention that the Department has placed on the issue and is reflected in the National Energy Strategy (NES) that was released in 1991. This Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1991 and gives a brief overview of objectives, organization, and accomplishments. The Environmental Sciences Division of the Office of Health and Environmental Research, Office of Energy Research supports a Carbon Dioxide Research Program to determine the scientific linkage between the rise of greenhouse gases in the atmosphere, especially carbon dioxide, and climate and vegetation change. One facet is the Core CO2 Program, a pioneering program that DOE established more than 10 years ago to understand and predict the ways that fossil-fuel burning could affect atmospheric CO2 concentration, global climate, and the Earth's biosphere. Major research areas are: global carbon cycle; climate detection and models of climate change; vegetation research; resource analysis; and, information and integration

  20. Atmospheric Carbon Dioxide and the Global Carbon Cycle: The Key Uncertainties

    Science.gov (United States)

    Peng, T. H.; Post, W. M.; DeAngelis, D. L.; Dale, V. H.; Farrell, M. P.

    1987-12-01

    The biogeochemical cycling of carbon between its sources and sinks determines the rate of increase in atmospheric CO{sub 2} concentrations. The observed increase in atmospheric CO{sub 2} content is less than the estimated release from fossil fuel consumption and deforestation. This discrepancy can be explained by interactions between the atmosphere and other global carbon reservoirs such as the oceans, and the terrestrial biosphere including soils. Undoubtedly, the oceans have been the most important sinks for CO{sub 2} produced by man. But, the physical, chemical, and biological processes of oceans are complex and, therefore, credible estimates of CO{sub 2} uptake can probably only come from mathematical models. Unfortunately, one- and two-dimensional ocean models do not allow for enough CO{sub 2} uptake to accurately account for known releases. Thus, they produce higher concentrations of atmospheric CO{sub 2} than was historically the case. More complex three-dimensional models, while currently being developed, may make better use of existing tracer data than do one- and two-dimensional models and will also incorporate climate feedback effects to provide a more realistic view of ocean dynamics and CO{sub 2} fluxes. The instability of current models to estimate accurately oceanic uptake of CO{sub 2} creates one of the key uncertainties in predictions of atmospheric CO{sub 2} increases and climate responses over the next 100 to 200 years.

  1. Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

    Directory of Open Access Journals (Sweden)

    B. Xiang

    2014-08-01

    Full Text Available We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2 with high precision (0.02 ppm at 1 Hz and demonstrate high stability (within 0.1 ppm over more than 8 months, without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC is the spectral null method using an internal quartz reference cell with known CO2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermal control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level. The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA, where it has measured for eight months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of another commercially available cavity ring-down CO2 instrument (Picarro G2301 run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of calibration cylinders.

  2. The impact of Southwest Airline's contribution to atmospheric Carbon Dioxide and Nitrous Oxide totals

    Science.gov (United States)

    Wilkerson, Cody L.

    Over the last century, aviation has grown to become an economical juggernaut. The industry creates innovation, connects people, and maintains a safety goal unlike any other field. However, as the world becomes more populated with technology and individuals, a general curiosity as to how human activity effects the planet is becoming of greater interest. This study presents what one domestic airline in the United States, Southwest Airlines, contributes to the atmospheric make-up of the planet. Utilizing various sources of quantifiable data, an outcome was reached that shows the amount of Carbon Dioxide and Nitrous Oxide produced by Southwest Airlines from 2002 to 2013. This topic was chosen due to the fact that there are no real quantifiable values of emission statistics from airlines available to the public. Further investigation allowed for Southwest Airlines to be compared to the overall Carbon Dioxide and Nitrous Oxide contributions of the United States for the year 2011. The results showed that with the absence of any set standard on emissions, it is vital that one should be established. The data showed that the current ICAO standard emission values showed a higher level of emissions than when Southwest Airline's fleet was analyzed using their actual fleet mix.

  3. From Inert Carbon Dioxide to Fuel Methanol by Activation in Plasma Atmosphere

    Science.gov (United States)

    Suarez, Alejandro; Leal-Quiros, Edbertho; Gonzalez, Jorge

    2015-03-01

    The electron-molecules collisions in plasmas are fructiferous field of study, particularly in activation of inert species into extremely active chemical reactants. Several gases such as carbon dioxide, methane, nitrogen, argon, water among others are ionized or simply activated under collisions with electrons creating the complex atmosphere plasmas. Based upon the energy distribution of electrons and the cross section of molecules it is possible to stimulate molecules becoming highly active species. This research explores the assembly of methanol over a surface of Cu-O-Zr catalyst when carbon dioxide reacts with water under the plasma developed into the Electron Cyclotron Resonance device (ECR). The process was continuously monitored by a mass spectrometer and the correspondent results show the formation of methanol. The ECR operated at 10-6 torr assisted with a microwave source of 250 Watts of power; the magnetic field was developed with 300 Amp on Helmholtz coils. The mode of operation of plasma was in cusp, and the electron temperature was 6-eV reported by a single Langmuir probe. The mass spectrometry reported the presence of methanol. The catalysts characterization is reported in form of Scanning Electron Microscopy image, a Raman spectroscopy analysis, and the Electron Dispersive Spectroscopy (EDS).

  4. Controls on mangrove forest-atmosphere carbon dioxide exchanges in western Everglades National Park

    Science.gov (United States)

    Barr, Jordan G.; Engel, Vic; Fuentes, José D.; Zieman, Joseph C.; O'Halloran, Thomas L.; Smith, Thomas J.; Anderson, Gordon H.

    2010-06-01

    We report on net ecosystem production (NEP) and key environmental controls on net ecosystem exchange (NEE) of carbon dioxide (CO2) between a mangrove forest and the atmosphere in the coastal Florida Everglades. An eddy covariance system deployed above the canopy was used to determine NEE during January 2004 through August 2005. Maximum daytime NEE ranged from -20 to -25 μmol (CO2) m-2 s-1 between March and May. Respiration (Rd) was highly variable (2.81 ± 2.41 μmol (CO2) m-2 s-1), reaching peak values during the summer wet season. During the winter dry season, forest CO2 assimilation increased with the proportion of diffuse solar irradiance in response to greater radiative transfer in the forest canopy. Surface water salinity and tidal activity were also important controls on NEE. Daily light use efficiency was reduced at high (>34 parts per thousand (ppt)) compared to low (level rise and climate change.

  5. Role of Ice Sheets in Thermohaline Circulation Changes Under High Atmospheric Carbon Dioxide Concentration

    Science.gov (United States)

    Yih, H.; Oh, I. S.; Chan, W.; Motoi, T.

    2007-12-01

    Thermohaline circulation (THC) changes are considered for two experimental settings of Antarctic and Greenland ice sheets with the atmospheric carbon dioxide of 1200 ppm in GFDL atmosphere-ocean coupled model. The experimental settings are to figure out the role of the ice sheets in global climate system, in which they are present and completely removed. The coupled model consists of the atmosphere and oceans, as well as simple models of land surfaces and sea ice. Atmospheric distribution of predicted variables is represented by Rhomboidal 15 configuration and nine vertical levels. Oceanic variables in 12 vertical levels have horizontal resolution of 4.5 degree latitude and 3.75 degree longitude. Streamfunctions of zonal mean meridional circulation in model oceans are used as representing fields of the THC, which are constructed after reaching statistical equilibrium state at 3000 model years. Same restart file is used for the two runs, which is at approximately 10000 model years of integration with atmospheric carbon dioxide concentration of 300 ppm provided from GFDL/NOAA. The THC appears again, after weakening, strengthening, and rapid-increasing during the first 3000 model years. Analysis periods of the equilibrium state are from 3000 to 10000 model years. Streamfunctions of the two runs show in general similar pattern of circulation cells of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW). The cell of NADW occupies upper 2000 m mainly in north of 10 degree South, but the cell of AABW extends up to 50 degree North from the Antarctic continent in the layer below the deeper part of the NADW, while covering up to the surface in the south of 60 degree South. Difference-field of streamfunction between the two runs shows two core-regions. One core is located in the deeper part of Southern Ocean (i.e., the depth range of 2500-4000 m), and the other in the upper part, 500-2000 m depths, in the Northern Hemisphere. Latitudinal ranges of the two cores

  6. Observations of the uptake of carbonyl sulfide (COS by trees under elevated atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-02-01

    Full Text Available Global change affects ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2. We understand that carbonyl sulfide (COS, a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzmyes which are metabolizing the CO2, i.e. Ribulose-1,5-bisphosphate Carboxylase-Oxygenase (Rubisco, Phosphoenolpyruvate Carboxylase (PEP-Co and carbonic anhydrase (CA. Therefore, we discuss a physiological/biochemical adaptation of these enzymes to affect the sink strength of vegetation for COS. We investigated the adaption of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2 and determined the exchange characteristics and the content of CA after a 1–2 yr period of adaption from 350 ppm to 800 ppm CO2. We could demonstrate that the COS compensation point, the CA activity and the deposition velocities may change and cause a decrease of the COS uptake by plant ecosystems. As a consequence, the atmospheric COS level may rise leading to higher input of this trace gas into the stratosphere and causing a higher energy reflection by the stratospheric sulfur aerosol into space, thus counteracting the direct radiative forcing by the tropospheric COS.

  7. The central and eastern Arabian Sea as a perennial source of atmospheric carbon dioxide

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; George, M.D.

    Seasonal (winter monsoon, intermonsoon and southwest monsoon) and interannual (between southwest monsoon seasons of 1995 and 1996) variations in total carbon dioxide (TCO sub(2)) and partial pressure of CO sub(2) (pCO sub(2)) were studied...

  8. Carbon dioxide Information Analysis Center and World Data Center: A for Atmospheric trace gases. Annual progress report, FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Burtis, M.D. [comp.] [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.R.; Stoss, F.W. [Oak Ridge National Lab., TN (United States)

    1995-03-01

    This report summarizes the activities and accomplishments made by the Carbon Dioxide Information Analysis Center and World Data Center-A for Atmospheric Trace Gases during the fiscal year 1994. Topics discussed in this report include; organization and staff, user services, systems, communications, Collaborative efforts with China, networking, ocean data and activities of the World Data Center-A.

  9. Carbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation

    Science.gov (United States)

    Bauska, Thomas K.; Baggenstos, Daniel; Brook, Edward J.; Mix, Alan C.; Marcott, Shaun A.; Petrenko, Vasilii V.; Schaefer, Hinrich; Severinghaus, Jeffrey P.; Lee, James E.

    2016-03-01

    An understanding of the mechanisms that control CO2 change during glacial-interglacial cycles remains elusive. Here we help to constrain changing sources with a high-precision, high-resolution deglacial record of the stable isotopic composition of carbon in CO2 (δ13C-CO2) in air extracted from ice samples from Taylor Glacier, Antarctica. During the initial rise in atmospheric CO2 from 17.6 to 15.5 ka, these data demarcate a decrease in δ13C-CO2, likely due to a weakened oceanic biological pump. From 15.5 to 11.5 ka, the continued atmospheric CO2 rise of 40 ppm is associated with small changes in δ13C-CO2, consistent with a nearly equal contribution from a further weakening of the biological pump and rising ocean temperature. These two trends, related to marine sources, are punctuated at 16.3 and 12.9 ka with abrupt, century-scale perturbations in δ13C-CO2 that suggest rapid oxidation of organic land carbon or enhanced air-sea gas exchange in the Southern Ocean. Additional century-scale increases in atmospheric CO2 coincident with increases in atmospheric CH4 and Northern Hemisphere temperature at the onset of the Bølling (14.6-14.3 ka) and Holocene (11.6-11.4 ka) intervals are associated with small changes in δ13C-CO2, suggesting a combination of sources that included rising surface ocean temperature.

  10. Observations of the uptake of carbonyl sulfide (COS by trees under elevated atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-08-01

    Full Text Available Global change forces ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2. We understand that carbonyl sulfide (COS, a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzymes which are metabolizing CO2, i.e. ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, phosphoenolpyruvate carboxylase (PEP-Co and carbonic anhydrase (CA. Therefore, we discuss a physiological/biochemical acclimation of these enzymes affecting the sink strength of vegetation for COS. We investigated the acclimation of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2, and determined the exchange characteristics and the content of CA after a 1–2 yr period of acclimation from 350 ppm to 800 ppm CO2. We demonstrate that a compensation point, by definition, does not exist. Instead, we propose to discuss a point of uptake affinity (PUA. The results indicate that such a PUA, the CA activity and the deposition velocities may change and may cause a decrease of the COS uptake by plant ecosystems, at least as long as the enzyme acclimation to CO2 is not surpassed by an increase of atmospheric COS. As a consequence, the atmospheric COS level may rise causing an increase of the radiative forcing in the troposphere. However, this increase is counterbalanced by the stronger input of this trace gas into the stratosphere causing a stronger energy reflection by the stratospheric sulfur aerosol into space (Brühl et al., 2012. These data are very preliminary but may trigger a discussion on COS uptake acclimation to foster measurements with modern analytical instruments.

  11. Latitudinal distribution of the sources and sinks of atmospheric carbon dioxide derived from surface observations and an atmospheric transport model

    Science.gov (United States)

    Tans, Pieter P.; Conway, Thomas J.; Nakazawa, Takakiyo

    1989-04-01

    Determination of the present global budget of atmospheric carbon dioxide (CO2) from the small and persistent concentration gradients that exist in the atmosphere is discussed. The CO2 concentration at any site results from a combination of two factors: local sources or sinks and long-range transport. To separate these two effects, an atmospheric transport model is needed. The extensive sets of global CO2 measurements of the National Oceanic and Atmospheric Administration's (NOAA) Geophysical Monitoring for Climatic Change (GMCC) division and of the Upper Atmosphere and Space Research Laboratory of Tohoku University are combined with a two-dimensional transport model to derive, in an "inverse" calculation, the latitudinal and seasonal distributions of sources and sinks of CO2 necessary to reproduce the observed concentrations. The model transport parameters were previously derived from a three-dimensional general circulation model. It is found that the southern oceans are a sink of carbon of 0.8-1.5 Gt yr-1 (1 Gt equals 1015g) and that the equatorial areas are a source to the atmosphere of 1.4-2.8 Gt yr-1. Tropical deforestation as a major source of CO2 must be smaller than that because the oceans account for a significant part of the equatorial flux. There seems to be significant seasonality in the sources and sinks of CO2, both in the tropics and in the southern oceans. The seasonal net ecosystem production north of 25°N is found to be 6.2-8.2 Gt of carbon, but these estimates are probably somewhat too low. The source deduction problem is difficult to solve, especially for the middle and high latitudes in the northern hemisphere. This is due to a lack of observations over the continents, which occupy more than half of the global area at these latitudes and are the regions where the sources and sinks are most intense. Evidence is found in the results obtained for the GMCC and Tohoku data that the longitudinal variability of the data is large enough, even in

  12. Controls on mangrove forest-atmosphere carbon dioxide exchanges in western Everglades National Park

    Science.gov (United States)

    Barr, Jordan G.; Engel, Vic; Fuentes, Jose D.; Zieman, Joseph C.; O'Halloran, Thomas L.; Smith, Thomas J., III; Anderson, Gordon H.

    2010-01-01

    We report on net ecosystem production (NEP) and key environmental controls on net ecosystem exchange (NEE) of carbon dioxide (CO2) between a mangrove forest and the atmosphere in the coastal Florida Everglades. An eddy covariance system deployed above the canopy was used to determine NEE during January 2004 through August 2005. Maximum daytime NEE ranged from -20 to -25 μmol (CO2) m-2 s-1 between March and May. Respiration (Rd) was highly variable (2.81 ± 2.41 μmol (CO2) m-2 s-1), reaching peak values during the summer wet season. During the winter dry season, forest CO2 assimilation increased with the proportion of diffuse solar irradiance in response to greater radiative transfer in the forest canopy. Surface water salinity and tidal activity were also important controls on NEE. Daily light use efficiency was reduced at high (>34 parts per thousand (ppt)) compared to low (d by ~0.9 μmol (CO2) m-2 s-1 and nighttime Rd by ~0.5 μmol (CO2) m-2 s-1. The forest was a sink for atmospheric CO2, with an annual NEP of 1170 ± 127 g C m-2 during 2004. This unusually high NEP was attributed to year-round productivity and low ecosystem respiration which reached a maximum of only 3 g C m-2 d-1. Tidal export of dissolved inorganic carbon derived from belowground respiration likely lowered the estimates of mangrove forest respiration. These results suggest that carbon balance in mangrove coastal systems will change in response to variable salinity and inundation patterns, possibly resulting from secular sea level rise and climate change.

  13. Responses of Metabolites in Soybean Shoot Apices to Changing Atmospheric Carbon Dioxide Concentrations

    Directory of Open Access Journals (Sweden)

    Richard Sicher

    2012-01-01

    Full Text Available Soybean seedlings were grown in controlled environment chambers with CO2 partial pressures of 38 (ambient and 72 (elevated Pa. Five or six shoot apices were harvested from individual 21- to 24-day-old plants. Metabolites were analyzed by gas chromatography and, out of 21 compounds, only sucrose and fructose increased in response to CO2 enrichment. One unidentified metabolite, Unk-21.03 decreased up to 80% in soybean apices in response to elevated CO2. Levels of Unk-21.03 decreased progressively when atmospheric CO2 partial pressures were increased from 26 to 100 Pa. Reciprocal transfer experiments showed that Unk-21.03, and sucrose in soybean apices were altered slowly over several days to changes in atmospheric CO2 partial pressures. The mass spectrum of Unk-21.03 indicated that this compound likely contained both an amino and carboxyl group and was structurally related to serine and aspartate. Our findings suggested that CO2 enrichment altered a small number of specific metabolites in soybean apices. This could be an important step in understanding how plant growth and development are affected by carbon dioxide enrichment.

  14. Carbon dioxide sequestration by mineral carbonation

    OpenAIRE

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept behind mineral CO2 sequestration is the mimicking of natural weathering processes in which calcium or magnesium containing minerals react with gaseous CO2 and form solid calcium or magnesium carbonate...

  15. Physiological and morphological variation in response to elevated atmospheric carbon dioxide in two populations of Plantago lanceolata

    Energy Technology Data Exchange (ETDEWEB)

    Klus, D.J.; Kalisz, S.; Tonsor, S.J. (Michigan State Univ., Hickory Corners (United States))

    1993-06-01

    An experiment was conducted at the Duke University Phytotron to determine the nature and extent of genetic variation in response to elevated levels of atmospheric carbon dioxide in 44 families from two populations of Plantago lanceolata. 10 seedlings from each maternal family were divided equally between ambient and elevated greenhouses and were grown for 60 days. At the end of that period measurements of assimilation and transpiration were made, the plants were harvested and seven morphological traits were measured. Analysis of the data reveals that genetic variation in response to elevated carbon dioxide exists at the family level for assimilation, and at the population level for three of the morphological traits: number of vegetative shoots per plant, diameter of the vegetative shoots, and number of leaves per shoot. Thus, the potential for elevated carbon dioxide to act as an agent of natural selection exists within this plant species.

  16. Carbonate precipitation in artificial soils as a sink for atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Turnover of C in soils is the dominant flux in the global C cycle and is responsible for transporting 20 times the quantity of anthropogenic emissions each year. This paper investigates the potential for soils to be modified with Ca-rich materials (e.g. demolition waste or basic slag) to capture some of the transferred C as geologically stable CaCO3. To test this principal, artificial soil known to contain Ca-rich minerals (Ca silicates and portlandite) was analysed from two sites across NE England, UK. The results demonstrate an average C content of 30 ± 15.3 Kg C m-2 stored as CaCO3, which is three times the expected organic C content and that it has accumulated at a rate of 25 ± 12.8 t C ha-1 a-1 since 1996. Isotopic analysis of the carbonates gave values between -6.4 per mille and -27.5 per mille for δ13C and -3.92 per mille and -20.89 per mille for δ18O, respectively (against V-PDB), which suggests that a combination of carbonate formation mechanisms are operating including the hydroxylation of gaseous CO2 in solution, and the sequestration of degraded organic C with minor remobilisation/precipitation of lithogenic carbonates. This study implies that construction/development sites may be designed with a C capture function to sequester atmospheric C into the soil matrix with a maximum global potential of 290 Mt C a-1.

  17. Modelling the performance of a LIDAR system for the measurement of atmospheric carbon dioxide

    Science.gov (United States)

    Lawrence, J. P.; Leigh, R. J.; Bösch, H.; Monks, P. S.; Remedios, J. J.

    2009-04-01

    With atmospheric carbon dioxide concentrations rising steadily, investigations into locations and magnitudes of the sources, sinks and net surface fluxes are of increasing importance. Active space-borne measurement systems such as LIDAR offer one potential technique to derive global, near-surface concentrations. However, significant instrumental challenges need to be overcome for such measurements to achieve a useful degree of accuracy and precision. This poster presents the work being carried out at the University of Leicester to accurately model a spaceborne LiDAR system. The model aims at providing an insight into the performance of a differential absorption LiDAR system (DIAL) based on current and future technology in a realistic environment. This is achieved by accurately modelling the surface footprint of a laser system based on expected orbital parameters, and using atmospheric profiles, topographic information and BRDF's to simulate the laser lights interaction with the environment. The model readily simulates LiDAR systems operating at 1.57 and 2.05µm wavelengths using Voigt convolved HITRAN line centres to obtain accurate vertical sensitivity to the atmosphere as a result of spectral line broadening. This method allows any spectral line to be selected and any offset from the line centre to be applied to optimize the systems performance. It also offers the potential for investigating multi-spectral LiDAR systems and the benefits that this method has versus the standard duel wavelength DIAL systems. In order to retrieve near-surface CO2 concentrations of a few ppm the resulting instrument requirements are unquestionably demanding, but provide a benchmark for new technology development initiatives such as A-SCOPE and ASCENDS.

  18. Carbon Dioxide Extraction from the Atmosphere Through Engineered Chemical Sinkage: Enabling Energy and Environmental Security

    Science.gov (United States)

    Dubey, M. K.; Ziock, H.; Rueff, G.; Smith, W. S.; Colman, J.; Elliott, S.; Lackner, K.; Johnston, N. A.

    2002-05-01

    We present the case for carbon dioxide (CO2) extraction from air using engineered chemical sinks as a means of sustaining fossil energy use by avoiding climate change. Existing carbon sequestration strategies such as CO2 injection into geologic formations or the deep ocean and mineral carbonation, require a pure stream of concentrated CO2 to be viable. Furthermore, current emphasis on reducing the global CO2 emissions is on large centralized power plants. However, more than half of all emissions are from the transportation sector and small, distributed sources such as home heating, etc. Most solutions for dealing with these sources explicitly or implicitly entail completely overhauling the existing infrastructure. To solve these problems, Los Alamos National Laboratory has conceived a novel approach for directly extracting CO2 from the atmosphere. Direct extraction converts the dilute CO2 (370 parts per million) in the atmosphere into a pure CO2 stream ready for permanent sequestration. It provides the following advantages: (1) Preserves our existing energy use and fuel distribution systems, which represent a large investment, (2) Indirectly captures CO2 from the myriad of small, distributed, and mobile sources that otherwise are not accessible to sequestration, (3) Allows atmospheric CO2 levels to be restored to their pre-industrial age value, (4) Provides free transport of CO2 to suitable sequestration sites by using natural atmospheric circulation, and (5) Is relatively compact and therefore inexpensive when compared to renewable concepts. Our concept harnesses atmospheric circulation to transport CO2 to sites where the CO2 is extracted by binding it to an adsorbent. The bound CO2 is then recovered as pure gas by heating together with the solid adsorbent that is recycled. As a proof of concept, we show that an aqueous Ca(OH)2 solution efficiently converts CO2 to a CaCO3 solid that can be heated to obtain pure CO2 and recover the CaO. Even with recycling costs

  19. Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing.

    Science.gov (United States)

    LaRiviere, Jonathan P; Ravelo, A Christina; Crimmins, Allison; Dekens, Petra S; Ford, Heather L; Lyle, Mitch; Wara, Michael W

    2012-06-01

    Deep-time palaeoclimate studies are vitally important for developing a complete understanding of climate responses to changes in the atmospheric carbon dioxide concentration (that is, the atmospheric partial pressure of CO(2), p(co(2))). Although past studies have explored these responses during portions of the Cenozoic era (the most recent 65.5 million years (Myr) of Earth history), comparatively little is known about the climate of the late Miocene (∼12-5 Myr ago), an interval with p(co(2)) values of only 200-350 parts per million by volume but nearly ice-free conditions in the Northern Hemisphere and warmer-than-modern temperatures on the continents. Here we present quantitative geochemical sea surface temperature estimates from the Miocene mid-latitude North Pacific Ocean, and show that oceanic warmth persisted throughout the interval of low p(co(2)) ∼12-5 Myr ago. We also present new stable isotope measurements from the western equatorial Pacific that, in conjunction with previously published data, reveal a long-term trend of thermocline shoaling in the equatorial Pacific since ∼13 Myr ago. We propose that a relatively deep global thermocline, reductions in low-latitude gradients in sea surface temperature, and cloud and water vapour feedbacks may help to explain the warmth of the late Miocene. Additional shoaling of the thermocline after 5 Myr ago probably explains the stronger coupling between p(co(2)), sea surface temperatures and climate that is characteristic of the more recent Pliocene and Pleistocene epochs. PMID:22678287

  20. Empirical selection of cultivated oat in response to rising atmospheric carbon dioxide

    Science.gov (United States)

    Carbon dioxide (CO2) is a principle resource for plant growth; as such, the ongoing increase in its concentration may allow breeders to begin selecting for optimal varieties among current crop lines. However, such a selection program may not be necessary if breeders have, by empirical selection, al...

  1. Inhibition of Listeria monocytogenes on cold-smoked salmon by nisin and carbon dioxide atmosphere

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Huss, Hans Henrik; Gram, Lone

    The bacteriostatic and bacteriocidal effect of nisin in combination with carbon dioxide, NaCl and low temperature on the survival of Listeria monocytogenes was investigated in in vitro model studies and in trials with cold-smoked salmon. Addition of nisin caused various degrees of inhibition and ....... (C) 1997 Elsevier Science B.V....

  2. Effect of increased concentrations of atmospheric carbon dioxide on the global threat of zinc deficiency: a modelling study

    OpenAIRE

    Dr. Samuel S Myers, MD; K Ryan Wessells, PhD; Itai Kloog, PhD; Antonella Zanobetti, PhD; Prof. Joel Schwartz, PhD

    2015-01-01

    Background: Increasing concentrations of atmospheric carbon dioxide (CO2) lower the content of zinc and other nutrients in important food crops. Zinc deficiency is currently responsible for large burdens of disease globally, and the populations who are at highest risk of zinc deficiency also receive most of their dietary zinc from crops. By modelling dietary intake of bioavailable zinc for the populations of 188 countries under both an ambient CO2 and elevated CO2 scenario, we sought to estim...

  3. Function and composition of the soil microbial community in calcareous grassland exposed to elevated atmospheric carbon dioxide

    OpenAIRE

    Ebersberger, Diana

    2003-01-01

    Terrestrial ecosystems generally respond to rising atmospheric carbon dioxide (CO2) concentrations with increased net primary productivity and increased water use efficiency. This may change the amount and quality of organic substances entering the soil and fuelling microbial metabolism. Soil microorganisms and their activity might also be affected by increased soil moisture at elevated CO2. This thesis was designed to analyse the response of the soil microbial community in a species-rich cal...

  4. Estimating Terrestrial Wood Biomass from Observed Concentrations of Atmospheric Carbon Dioxide

    NARCIS (Netherlands)

    Schaefer, K. M.; Peters, W.; Carvalhais, N.; van der Werf, G.; Miller, J.

    2008-01-01

    We estimate terrestrial disequilibrium state and wood biomass from observed concentrations of atmospheric CO2 using the CarbonTracker system coupled to the SiBCASA biophysical model. Starting with a priori estimates of carbon flux from the land, ocean, and fossil fuels, CarbonTracker estimates net c

  5. Laboratory Measurments of the 3.7-20 cm Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide under Simulated Conditions for the Deep Atmosphere of Venus

    Science.gov (United States)

    Steffes, Paul G.; Barisich, C.

    2012-10-01

    In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA) and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho et al., JGR 71, 1966), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10-92 Bars and temperatures from 400-700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7-20 cm are now being conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Initial results from this measurement campaign conducted at 430 K and at pressures up to 92 Bars will be presented. This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

  6. Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    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. Diurnal and vertical variability of the sensible heat and carbon dioxide budgets in the atmospheric surface layer

    International Nuclear Information System (INIS)

    The diurnal and vertical variability of heat and carbon dioxide (CO2) in the atmospheric surface layer are studied by analyzing measurements from a 213 m tower in Cabauw (Netherlands). Observations of thermodynamic variables and CO2 mixing ratio as well as vertical profiles of the turbulent fluxes are used to retrieve the contribution of the budget terms in the scalar conservation equation. On the basis of the daytime evolution of turbulent fluxes, we calculate the budget terms by assuming that turbulent fluxes follow a linear profile with height. This assumption is carefully tested and the deviation from linearity is quantified. The budget calculation allows us to assess the importance of advection of heat and CO2 during day hours for three selected days. It is found that, under nonadvective conditions, the diurnal variability of temperature and CO2 is well reproduced from the flux divergence measurements. Consequently, the vertical transport due to the turbulent flux plays a major role in the daytime evolution of both scalars and the advection is a relatively small contribution. During the analyzed days with a strong contribution of advection of either heat or carbon dioxide, the flux divergence is still an important contribution to the budget. For heat, the quantification of the advection contribution is in close agreement with results from a numerical model. For carbon dioxide, we qualitatively corroborate the results with a Lagrangian transport model. Our estimation of advection is compared with traditional estimations based on the Net Ecosystem-atmosphere Exchange (NEE)

  8. Carbon dioxide level and form of soil nitrogen regulate assimilation of atmospheric ammonia in young trees

    OpenAIRE

    Lucas C. R. Silva; Alveiro Salamanca-Jimenez; Timothy A. Doane; Horwath, William R.

    2015-01-01

    The influence of carbon dioxide (CO2) and soil fertility on the physiological performance of plants has been extensively studied, but their combined effect is notoriously difficult to predict. Using Coffea arabica as a model tree species, we observed an additive effect on growth, by which aboveground productivity was highest under elevated CO2 and ammonium fertilization, while nitrate fertilization favored greater belowground biomass allocation regardless of CO2 concentration. A pulse of labe...

  9. Organic phosphorus mineralisation in a temperate grassland soil under elevated atmospheric carbon dioxide concentrations

    Science.gov (United States)

    Jarosch, Klaus A.; Andresen, Louise; Gorenflo, André D.; Müller, Christoph; Frossard, Emmanuel; Bünemann, Else K.

    2016-04-01

    Background: Phosphorus (P) is an essential nutrient for all biota and significant proportions of P in soil are present in organic form. Increased atmospheric concentrations of carbon dioxide ([CO2]) have been shown to influence plant P uptake traits, resulting in plant-mediated changes in soil P pools. However, little is known on the effect of elevated [CO2] on organic P mineralisation rates in soil. Study design & hypotheses: A 33P isotopic dilution experiment was performed with soils of the 17-year-old Giessen free air carbon dioxide enrichment (GiFACE) - trial. At the GiFACE, three plots are treated with 20 % elevated [CO2] while three control plots receive ambient air. We hypothesised that i) the observed positive effect of elevated [CO2] on plant growth translates into differences in soil organic P mineralisation rates between treated and untreated plots, resulting in ii) differences in soil organic P pools. Methods: Fresh soil (0-8 cm) was sampled from each plot, labelled with a carrier free 33P solution and incubated for 36 days at 19° C in the dark. On six time points, inorganic P and 33P in soil filtrates, soil microorganisms (by liquid fumigation) and resin extractable P were quantified. The baseline of 33P isotopic dilution was assessed from a short term batch experiment and extrapolated for 36 days. Gross organic P mineralisation rates were determined as the difference between isotopic dilution in the incubated soils (physicochemical + biological processes) minus extrapolated values (physicochemical processes only). Additionally, enzyme addition assays on alkaline soil extracts were performed to quantify different soil organic P classes, using enzymes with a known substrate specificity. Results & Discussion: Gross organic P mineralisation rates were high during the first three days (5.5 - 34.3 mg P kg‑1 d‑1), possibly due to the soil disturbance at labelling soils with 33P. However, gross organic P mineralisation decreased rapidly to rates between

  10. Organic Fuel Synthesis from Atmospheric Carbon Dioxide and Hydrogen Produced from Water by Electrolysis

    Institute of Scientific and Technical Information of China (English)

    David JOHNSTON

    2009-01-01

    Synthesis of organic fuels from cain dioxide and hydrogen is analysed, in terms of energy recovery efficiency, and the required energy input for electrolysis of water. This electrical energy is related to the thermal energy required in a power station. A method is described to recover heat from energy-producing reactions in the fuel synthesis process, which can then be used to reduce the electrical energy requirement for electrolysis. By co-locating the fuel synthesis plant with a thermal power station, primary (thermal) energy can be used to produce high temperature steam, with a lower electrical requirement for electrolytic production of hydrogen. This can make more efficient use of the primary energy than a thermodynamic engine. Comparison is made with alternative fuels, in terms of energy budget, sustainability, carbon dioxide emissions, etc. The energy security benefits of advanced fuel synthesis are also identified.

  11. Long-Term, Autonomous Measurement of Atmospheric Carbon Dioxide Using an Ormosil Nanocomposite-Based Optical Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Kisholoy Goswami

    2005-10-11

    The goal of this project is to construct a prototype carbon dioxide sensor that can be commercialized to offer a low-cost, autonomous instrument for long-term, unattended measurements. Currently, a cost-effective CO2 sensor system is not available that can perform cross-platform measurements (ground-based or airborne platforms such as balloon and unmanned aerial vehicle (UAV)) for understanding the carbon sequestration phenomenon. The CO2 sensor would support the research objectives of DOE-sponsored programs such as AmeriFlux and the North American Carbon Program (NACP). Global energy consumption is projected to rise 60% over the next 20 years and use of oil is projected to increase by approximately 40%. The combustion of coal, oil, and natural gas has increased carbon emissions globally from 1.6 billion tons in 1950 to 6.3 billion tons in 2000. This figure is expected to reach 10 billon tons by 2020. It is important to understand the fate of this excess CO2 in the global carbon cycle. The overall goal of the project is to develop an accurate and reliable optical sensor for monitoring carbon dioxide autonomously at least for one year at a point remote from the actual CO2 release site. In Phase I of this project, InnoSense LLC (ISL) demonstrated the feasibility of an ormosil-monolith based Autonomous Sensor for Atmospheric CO2 (ASAC) device. All of the Phase I objectives were successfully met.

  12. Carbon Dioxide Fountain

    Science.gov (United States)

    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. The leaching of vanadium(V) in soil due to the presence of atmospheric carbon dioxide and ammonia

    International Nuclear Information System (INIS)

    The natural leaching of vanadium(V) with CO2 from soil-water in the presence of ammonia, a known precursor to atmospheric aerosols, has been tested by bubbling carbon dioxide through soil suspension with varying amount of ammonia. It was found that the leaching of V(V) is enhanced in the presence of ammonia. From the results of the investigation, it could be concluded that atmospheric CO2 in the presence of ammonia (the only atmospheric gas that increases the pH of soil-water) could naturally leach V(V) from soil. Furthermore, it was also shown that the presence of (NH4)2CO3 in soil could enhance the leaching of toxic V(V) species thereby making it bioavailable for both plants and animals.

  14. The impact of increased atmospheric carbon dioxide on microbial community dynamics in the rhizosphere

    NARCIS (Netherlands)

    Drigo, Barbara

    2009-01-01

    Rising atmospheric CO2 levels are predicted to have major consequences upon carbon cycle feedbacks and the overall functioning of terrestrial ecosystems. Photosynthetic activity and the structure of terrestrial macrophytes is expected to change, but it remains uncertain how this will affect soil-bor

  15. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases, Fiscal Year 2002 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2003-08-28

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including atmospheric concentrations and atmospheric emissions of carbon dioxide (CO{sub 2}) and other radiatively active gases; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  16. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2000 Annual Report; ANNUAL

    International Nuclear Information System (INIS)

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO(sub 2)) 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 CO(sub 2) and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO(sub 2) on vegetation; and the vulnerability of coastal areas to rising sea levels

  17. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2000 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2001-11-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) 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 CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.

  18. Enrichment of Radon and Carbon Dioxide in the Open Atmosphere of an Australian Coal Seam Gas Field

    OpenAIRE

    Tait, Douglas R.; Santos, Isaac R.; Maher, Damien T.; Cyronak, Tyler J.; Davis, Rachael J.

    2013-01-01

    Atmospheric radon (222Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). 222Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both 222Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ∼390 ppm at the control s...

  19. Atmospheric methane and carbon dioxide from SCIAMACHY satellite data: initial comparison with chemistry and transport models

    Directory of Open Access Journals (Sweden)

    M. Buchwitz

    2004-11-01

    Full Text Available The remote sensing of the atmospheric greenhouse gases methane (CH4 and carbon dioxide (CO2 in the troposphere from instrumentation aboard satellites is a new area of research. In this manuscript, results obtained from observations of the up-welling radiation in the near-infrared by SCIAMACHY (Scanning Imaging Absorption spectroMeter for Atmospheric CHartographY, which flies on board ENVISAT, are presented. Vertical columns of CH4, CO2 and oxygen (O2 have been retrieved and the (air or O2-normalized CH4 and CO2 column amounts, the dry air column averaged mixing ratios XCH4 and XCO2 derived. In this manuscript the first results, obtained by using the version 0.4 of the Weighting Function Modified (WFM DOAS retrieval algorithm applied to SCIAMACHY data, are described and compared with global models. This is an important step in assessing the quality and information content of the data products derived from SCIAMACHY observations. This study investigates the behaviour of CO2 and CH4 in the period from January to October 2003. The SCIAMACHY greenhouse gas column amounts and their mixing ratios for cloud free scenes over land are shown to be in reasonable agreement with models. Over the ocean, as a result of the lower surface spectral reflectance and resultant low signal to noise with the exception of sun glint conditions, the accuracy of the individual data products is poorer. The measured methane column amounts agree with the model columns within a few percent. The inter-hemispheric difference of the methane mixing ratios, determined from single day cloud free measurements over land, is in the range 30–110 ppbv and in reasonable agreement with the corresponding model data (48–71 ppbv. For the set of individual measurements the standard deviations of the difference with respect to the models are in the range ~100

  20. Robust optical carbon dioxide isotope analyzer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Isotopic analysis of carbon dioxide is an important tool for characterization of the exchange and transformation of carbon between the biosphere and the atmosphere....

  1. Analysis of Carbon Dioxide Variations in the Atmosphere of Srednja Bijambarska Cave, Bosnia and Herzegovina

    Science.gov (United States)

    Milanolo, Simone; Gabrovšek, Franci

    2009-06-01

    The results of one year’s monitoring in Srednja Bijambarska Cave (Bosnia and Herzegovina) are presented and discussed. Temporal variations of the carbon dioxide (CO2) concentration are controlled by the switching between two ventilation regimes driven by outside temperature changes. A regression model with a simple perfectly mixed volume applied to a cave sector (“Music hall”) resulted in an estimate of ventilation rates between 0.02 h-1 and 0.54 h-1. Carbon dioxide input per plan surface unit is estimated by the model at around 50 × 10-6 mh-1 during the winter season and up to more than 1000 × 10-6 mh-1 during the first temperature falls at the end of summer (0.62 μmoles m-2 s-1 and 12.40 μmoles m-2 s-1 for normal conditions respectively). These values have been found to be related to the cave ventilation rate and dependent on the availability of CO2 in the surrounding environment. For airflow close to zero the values of CO2 input per plan surface have a range in the order of magnitude of a few units × 10-6 mh-1. Based on two experiments, the anthropogenic contribution from cave visitors has been calculated, at between 0.35 lCO2 min-1 person-1 and 0.45 lCO2min-1person-1.

  2. Diurnal and vertical variability of the sensible heat and carbon dioxide budgets in the atmospheric surface layer

    Science.gov (United States)

    Casso-Torralba, P.; de Arellano, J. V. -G.; Bosveld, F.; Soler, M.R.; Vermeulen, A.; Werner, C.; Moors, E.

    2008-01-01

    The diurnal and vertical variability of heat and carbon dioxide (CO2) in the atmospheric surface layer are studied by analyzing measurements from a 213 in tower in Cabauw (Netherlands). Observations of thermodynamic variables and CO2 mixing ratio as well as vertical profiles of the turbulent fluxes are used to retrieve the contribution of the budget terms in the scalar conservation equation. On the basis of the daytime evolution of turbulent fluxes, we calculate the budget terms by assuming that turbulent fluxes follow a linear profile with height. This assumption is carefully tested and the deviation ftom linearity is quantified. The budget calculation allows us to assess the importance of advection of heat and CO2 during day hours for three selected days. It is found that, under nonadvective conditions, the diurnal variability of temperature and CO2 is well reproduced from the flux divergence measurements. Consequently, the vertical transport due to the turbulent flux plays a major role in the daytime evolution of both scalars and the advection is a relatively small contribution. During the analyzed days with a strong contribution of advection of either heat or carbon dioxide, the flux divergence is still an important contribution to the budget. For heat, the quantification of the advection contribution is in close agreement with results from a numerical model. For carbon dioxide, we qualitatively corroborate the results with a Lagrangian transport model. Our estimation of advection is compared with, traditional estimations based on the Net Ecosystem-atmosphere Exchange (NEE). Copyright 2008 by the American Geophysical Union.

  3. Atmospheric methane and carbon dioxide from SCIAMACHY satellite data: initial comparison with chemistry and transport models

    Directory of Open Access Journals (Sweden)

    M. Buchwitz

    2005-01-01

    Full Text Available The remote sensing of the atmospheric greenhouse gases methane (CH4 and carbon dioxide (CO2 in the troposphere from instrumentation aboard satellites is a new area of research. In this manuscript, results obtained from observations of the up-welling radiation in the near-infrared by SCIAMACHY on board ENVISAT are presented. Vertical columns of CH4, CO2 and oxygen (O2 have been retrieved and the (air or O2-normalised CH4 and CO2 column amounts, the dry air column averaged mixing ratios XCH4 and XCO2 derived. In this manuscript the first results, obtained by using the version 0.4 of the Weighting Function Modified (WFM DOAS retrieval algorithm applied to SCIAMACHY data, are described and compared with global models. For the set of individual cloud free measurements over land the standard deviation of the difference with respect to the models is in the range ~100–200 ppbv (5–10% for XCH4 and ~14–32 ppmv (4–9% for XCO2. The inter-hemispheric difference of the methane mixing ratio, as determined from single day data, is in the range 30–110 ppbv and in reasonable agreement with the corresponding model data (48–71 ppbv. The weak inter-hemispheric difference of the CO2 mixing ratio can also be detected with single day data. The spatiotemporal pattern of the measured and the modelled XCO2 are in reasonable agreement. However, the amplitude of the difference between the maximum and the minimum for SCIAMACHY XCO2 is about ±20 ppmv which is about a factor of four larger than the variability of the model data which is about ±5 ppmv. More studies are needed to explain the observed differences. The XCO2 model field shows low CO2 concentrations beginning of January 2003 over a spatially extended CO2 sink region located in southern tropical/sub-tropical Africa. The SCIAMACHY data also show low CO2 mixing ratios over this area. According to the model the sink region becomes a source region about six months later and exhibits higher mixing ratios

  4. Causes and Implications of Persistent Atmospheric Carbon Dioxide Biases in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Forrest M [ORNL; Randerson, James T. [University of California, Irvine; Arora, Vivek K. [Canadian Centre for Climate Modelling and Analysis, Meteorological Service of Canada; Bao, Qing [State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics; Cadule, Patricia [Institut Pierre Simon Laplace, Laboratoire des Sciences du Climat et de l' Environment; Ji, Duoying [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing; Jones, Chris D. [Hadley Centre, U.K. Met Office; Kawamiya, Michio [Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Khatiwala, Samar [Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY; Lindsay, Keith [National Center for Atmospheric Research (NCAR); Obata, Atsushi [Meteorological Research Institute, Japan; Shevliakova, Elena [Princeton University; Six, Katharina D. [Max Planck Institute for Meteorology, Hamburg, Germany; Tjiputra, Jerry F. [Uni Climate, Uni Research; Volodin, Evgeny M. [Institute of Numerical Mathematics, Russian Academy of Science, Moscow; Wu, Tongwen [China Meteorological Administration (CMA), Beijing

    2014-01-01

    The strength of feedbacks between a changing climate and future CO2 concentrations are uncertain and difficult to predict using Earth System Models (ESMs). We analyzed emission-driven simulations--in which atmospheric CO2 levels were computed prognostically--for historical (1850-2005) and future periods (RCP 8.5 for 2006-2100) produced by 15 ESMs for the Fifth Phase of the Coupled Model Intercomparison Project (CMIP5). Comparison of ESM prognostic atmospheric CO2 over the historical period with observations indicated that ESMs, on average, had a small positive bias in predictions of contemporary atmospheric CO2. Weak ocean carbon uptake in many ESMs contributed to this bias, based on comparisons with observations of ocean and atmospheric anthropogenic carbon inventories. We found a significant linear relationship between contemporary atmospheric CO2 biases and future CO2 levels for the multi-model ensemble. We used this relationship to create a contemporary CO2 tuned model (CCTM) estimate of the atmospheric CO2 trajectory for the 21st century. The CCTM yielded CO2 estimates of 600 {plus minus} 14 ppm at 2060 and 947 {plus minus} 35 ppm at 2100, which were 21 ppm and 32 ppm below the multi-model mean during these two time periods. Using this emergent constraint approach, the likely ranges of future atmospheric CO2, CO2-induced radiative forcing, and CO2-induced temperature increases for the RCP 8.5 scenario were considerably narrowed compared to estimates from the full ESM ensemble. Our analysis provided evidence that much of the model-to-model variation in projected CO2 during the 21st century was tied to biases that existed during the observational era, and that model differences in the representation of concentration-carbon feedbacks and other slowly changing carbon cycle processes appear to be the primary driver of this variability. By improving models to more closely match the long-term time series of CO2 from Mauna Loa, our analysis suggests uncertainties in

  5. Plants, Weathering, and the Evolution of Atmospheric Carbon Dioxide and Oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Robert A

    2008-02-05

    Over the past six years we have published 24 papers that can be divided into three sections: (1) Study of plants and weathering, (2) modeling the evolution of atmospheric CO2 over Phanerozoic time (past 550 million years). (3) Modeling of atmospheric O2 over Phanerozoic time. References to papers published acknowledging this grant can be found at the end of this report and almost all are supplied in pdf form. (1) In the temperate forests of the Cascade Mountains, USA, calcium and magnesium meet vastly different fates beneath angiosperms vs gymnosperms. Calcium is leached beneath both groves of trees, but leached 20-40% more beneath the angiosperms. Magnesium is retained in the forest system beneath the angiosperms and leached from beneath the gymnosperms. (2) We have shown that climate and CO2, based on both carbon cycle modeling and hundreds of independent proxies for paleo-CO2, correlate very well over the past 550 million year. In a recent paper we use this correlation to deduce the sensitivity of global mean temperature to a doubling of atmospheric CO2, and results are in excellent agreement with the results of climatologists based on the historical record and on theoretical climate models (GCM’s).(3) We have shown that concentrations of atmospheric oxygen, calculated by a combined carbon-sulfur cycle model, over the past 550 million years have varied with and influenced biological evolution.

  6. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  7. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  8. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described

  9. Carbon dioxide increase in the atmosphere and oceans and possible effects on climate

    Science.gov (United States)

    Chen, C.-T. A.; Drake, E. T.

    Current knowledge on the problem of increasing CO2 in the atmosphere is reviewed, the carbonate system in the oceans is discussed, and recent findings on the CO2 increase in the oceans are reported. Consideration is also given to the possible consequences of the rising atmospheric CO2 content and to the feasibility of tactics that might delay the 'greenhouse' warming. The continued used to fossil fuels together with the large-scale deforestation necessary to provide land for cultivation of food are the two factors which emerge as the crux of the CO2 problem. It is shown that the preindustrial CO2 level has been rising since the middle of the nineteenth century; if the present trends continue, a global warming of a few degrees Celsius could result by the middle of the next century.

  10. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: FY 1993 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Stoss, F.W. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment, and Resources Center

    1994-01-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provide technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC (including World Data Center-A for Atmospheric Trace Gases) during the period October 1, 1992, to September 30, 1993. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of NDPS, CMPS, technical reports, newsletters, fact sheets, specialty publications, and reprints are provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also presented.

  11. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: FY 1993 activities

    International Nuclear Information System (INIS)

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provide technical responses to specific inquiries related to carbon dioxide (CO2), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC (including World Data Center-A for Atmospheric Trace Gases) during the period October 1, 1992, to September 30, 1993. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of NDPS, CMPS, technical reports, newsletters, fact sheets, specialty publications, and reprints are provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also presented

  12. Carbon Dioxide Removal via Passive Thermal Approaches

    Science.gov (United States)

    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.

  13. Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

    Science.gov (United States)

    Frankenberg, Christian; Kulawik, Susan S.; Wofsy, Steven C.; Chevallier, Frédéric; Daube, Bruce; Kort, Eric A.; O'Dell, Christopher; Olsen, Edward T.; Osterman, Gregory

    2016-06-01

    In recent years, space-borne observations of atmospheric carbon dioxide (CO2) have been increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column-averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network (TCCON). Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) flights from 01/2009 through 09/2011 to validate CO2 measurements from satellites (Greenhouse Gases Observing Satellite - GOSAT, Thermal Emission Sounder - TES, Atmospheric Infrared Sounder - AIRS) and atmospheric inversion models (CarbonTracker CT2013B, Monitoring Atmospheric Composition and Climate (MACC) v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, in particular at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of -0.06 ppm, and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm, and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm, and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20, and 50 atmospheric soundings have been averaged for GOSAT, TES, and AIRS

  14. Characteristic of coal combustion in oxygen/carbon dioxide atmosphere and nitric oxide release during this process

    International Nuclear Information System (INIS)

    Combustion characteristic of a bituminous coal and an anthracite coal in oxygen/carbon dioxide (O2/CO2) atmosphere is investigated in a thermogravimetric (TG) analyzer. The characteristic parameters, which are deduced from the TG-DTG (differential thermogravimetric) curves, show that the coal combustion process is basically kept consistent in O2/CO2 and O2/N2 atmosphere at the O2 concentration of 20%. The Coats-Redfern method with the reaction order of 1.25 could perfectly describe the combustion process in these two different atmospheres through the calculation of the kinetic parameters for the two coals. Nitric oxide (NO) release is concentrated in a narrower time period in O2/CO2 atmosphere compared with the one in O2/N2 atmosphere during the coal combustion process. Though the high value of the NO release rate peak, the total conversion of the fuel-N to NO is strongly depressed in O2/CO2 atmosphere, and at 1473 K, the conversion is reduced by 28.99% for the bituminous coal and 22.54% for the anthracite coal, respectively. When O2 concentration is increased from 20% to 40% in O2/CO2 atmosphere, the coal combustion property is obviously improved with the shift of the whole process into the lower temperature zone and the more intensive of the reaction occurrence in a narrower temperature range. However, the total fuel-N to NO conversion is increased accordingly. For bituminous coal the increase is 17.22% at 1073 K and 20.51% at 1173 K, and for anthracite coal the increase is 15.73% at 1073 K and 16.19% at 1173 K.

  15. Carbon dioxide recycling

    Science.gov (United States)

    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 ...

  16. Enhancement of enterotoxin production by carbon dioxide in Vibrio cholerae.

    OpenAIRE

    Shimamura, T; Watanabe, S; Sasaki, S.

    1985-01-01

    We found that Vibrio cholerae 569B produced much more cholera enterotoxin in the presence of added carbon dioxide than in its absence. An atmosphere of 10% carbon dioxide was optimal for maximal enterotoxin production.

  17. Carbon Dioxide - Our Common "Enemy"

    Science.gov (United States)

    James, John T.; Macatangay, Ariel

    2009-01-01

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

  18. CARBON DIOXIDE AS A FEEDSTOCK.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,C.; FUJITA,E.

    2000-12-09

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

  19. Plant Responses to Rising Carbon Dioxide and Nitrogen Relations

    OpenAIRE

    Bloom, Arnold J.

    2009-01-01

    The responses of higher plants to rising carbon dioxide concentration in the atmosphere are strongly dependent on their ability to acquire mineral nitrogen, ammonium and nitrate. Elevated atmospheric carbon dioxide limits both sources and sinks of plant mineral nitrogen. With regard to sources, elevated carbon dioxide stimulates microbial immobilization and inhibits nitrogen fixation. With regard to sinks, elevated carbon dioxide inhibits nitrate assimilation into amino acids within the shoo...

  20. Solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon, and carbon monoxide in 1-butyl-3-methylimidazolium tetrafluoroborate between temperatures 283 K and 343 K and at pressures close to atmospheric

    OpenAIRE

    Jacquemin, J.; Costa Gomes, M.F.; Husson, P.; Majer, V.

    2006-01-01

    Experimental values for the solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon and carbon monoxide in 1-butyl-3- methylimidazolium tetrafluoroborate, [bmim][BF4] - a room temperature ionic liquid - are reported as a function of temperature between 283 K and 343 K and at pressures close to atmospheric. Carbon dioxide is the most soluble gas with mole fraction solubilities of the order of 10-2. Ethane and methane are one order of magnitude more soluble than the oth...

  1. Assessment of the possible future climatic impact of carbon dioxide increases based on a coupled one-dimensional atmospheric-oceanic model

    International Nuclear Information System (INIS)

    A radiative-convective equilibrium model of the atmosphere has been coupled with a mixed layer model of the ocean to investigate the response of this one-dimensional system to increasing carbon dioxide amounts in the atmosphere. For global mean conditions a surface temperature rise of about 20 K was obtained for a doubling of the carbon dioxide amount, in reasonable agreement with the commonly accepted results of Manabe and Wetherald. This temperature rise was essentially invariant with season and indicates that including a shallow (300 m) ocean slab in this problem does not basically alter previous assessments. While the mixed layer depth of the ocean was only very slightly changed by the temperature increase, which extended throughout the depth of the mixed layer, the impact of this increase on the overall behavior of the ocean warrants further study. A calculation was also made of the temporal variation of the sea surface temperature for three possible carbon dioxide growth rates starting from an initial carbon dioxide content of 300 ppm. This indicated that the thermal inertia of the slab ocean provides a time lag of 8 years in the sea surface temperature response compared to a land situation. This is not considered to be of great significance as regards the likely future climatic impact of carbon dioxide increase

  2. Fiscal Year 1998 Annual Report, Carbon Dioxide Information Analysis Center, World Data Center -- A for Atmospheric Trace Gases

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.; Boden, T.A.; Hook, L.A.; Jones, S.B.; Kaiser, D.P.; Nelson, T.R.

    1999-03-01

    Once again, the most recent fiscal year was a productive one for the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL), as well as a year for change. The FY 1998 in Review section in this report summarizes quite a few new and updated data and information products, and the ''What's Coming in FY 1999'' section describes our plans for this new fiscal year. During FY 1998, CDIAC began a data-management system for AmeriFlux, a long-term study of carbon fluxes between the terrestrial biosphere of the Western Hemisphere and the atmosphere. The specific objectives of AmeriFlux are to establish an infrastructure for guiding, collecting, synthesizing, and disseminating long-term measurements of CO{sub 2}, water, and energy exchange from a variety of ecosystems; collect critical new information to help define the current global CO{sub 2} budget; enable improved predictions of future concentrations of atmospheric CO{sub 2}; and enhance understanding of carbon fluxes. Net Ecosystem Production (NEP), and carbon sequestration in the terrestrial biosphere. The data-management system, available from CDIAC'S AmeriFlux home page (http://cdiac.esd.ornl.gov/programs/ameriflux/ ) is intended to provide consistent, quality-assured, and documented data across all AmeriFlux sites in the US, Canada, Costa Rica, and Brazil. It is being developed by Antoinette Brenkert and Tom Boden, with assistance from Susan Holladay (who joined CDIAC specifically to support the AmeriFlux data-management effort).

  3. Tropical forests and the global carbon cycle: impacts of atmospheric carbon dioxide, climate change and rate of deforestation.

    OpenAIRE

    Cramer, Wolfgang; Bondeau, Alberte; Schaphoff, Sibyll; Lucht, Wolfgang; Smith, Benjamin; Sitch, Stephen

    2004-01-01

    The remaining carbon stocks in wet tropical forests are currently at risk because of anthropogenic deforestation, but also because of the possibility of release driven by climate change. To identify the relative roles of CO2 increase, changing temperature and rainfall, and deforestation in the future, and the magnitude of their impact on atmospheric CO2 concentrations, we have applied a dynamic global vegetation model, using multiple scenarios of tropical deforestation (extrapolated from two ...

  4. Deposition of carbon dioxide

    International Nuclear Information System (INIS)

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  5. Response of tundra ecosystems to elevated atmospheric carbon dioxide. [Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Oechel, W.C.; Grulke, N.E.

    1988-12-31

    Our past research shows that arctic tussock tundra responds to elevated atmospheric CO{sub 2} with marked increases in net ecosystem carbon flux and photosynthetic rates. However, at ambient temperatures and nutrient availabilities, homeostatic adjustments result in net ecosystem flux rates dropping to those found a contemporary CO{sub 2} levels within three years. Evidence for ecosystem-level acclimation in the first season of elevated CO{sub 2} exposure was found in 1987. Photosynthetic rates of Eriophorum vaginatum, the dominant species, adjusts to elevated CO{sub 2} within three weeks. Past research also indicates other changes potentially important to ecosystem structure and function. Elevated CO{sub 2} treatment apparently delays senescence and increases the period of positive photosynthetic activity. Recent results from the 1987 field season verify the results obtained in the 1983--1986 field seasons: Elevated CO{sub 2} resulted in increased ecosystem-level flux rates. Regressions fitted to the seasonal flux rates indicate an apparent 10 d extension of positive CO{sub 2} uptake reflecting a delay of the onset of plant dormancy. This delay in senescence could increase the frost sensitivity of the system. Major end points proposed for this research include the effects of elevated CO{sub 2} and the interaction of elevated atmospheric CO{sub 2} with elevated soil temperature and increased nutrient availability on: (1) Net ecosystem CO{sub 2} flux; (2) Net photosynthetic rates; (3) Patterns and resource controls on homeostatic adjustment in the above processes to elevated CO{sub 2}; (4) Plant-nutrient status, litter quality, and forage quality; (5) Soil-nutrient status; (6) Plant-growth pattern and shoot demography.

  6. Whitings as a Potential Mechanism for Controlling Atmospheric Carbon Dioxide Concentrations – Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Brady D. Lee; William A. Apel; Michelle R. Walton

    2006-03-01

    Species of cyanobacteria in the genera Synechococcus and Synechocystis are known to be the catalysts of a phenomenon called "whitings", which is the formation and precipitation of fine-grained CaCO3 particles. Whitings occur when the cyanobacteria fix atmospheric CO2 through the formation of CaCO3 on their cell surfaces which leads to precipitation to the ocean floor and subsequent entombment in mud. Whitings represent one potential mechanism for CO2 sequestration. Research was performed to determine the ability of various strains of Synechocystis and Synechococcus to calcify when grown in microcosms amended with 2.5 mM HCO3- and 3.4 mM Ca2+. Results indicated that while all strains tested have the ability to calcify, only two, Synechococcus species, strains PCC 8806 and PCC 8807, were able to calcify to the extent that CaCO3 was precipitated. Enumeration of the cyanobacterial cultures during testing indicated that cell density did not appear to have an effect on calcification. Factors that had the greatest effect on calcification were CO2 removal and subsequent generation of alkaline pH. As CO2 was removed, growth medium pH increased and soluble Ca2+ was removed from solution. The largest increases in growth medium pH occurred when CO2 levels dropped below 400 ppmv. Precipitation of CaCO3 catalyzed by the growth and physiology of cyanobacteria in the Genus Synechococcus represents a potential mechanism for sequestration of atmospheric CO2 produced during the burning of coal for power generation. Synechococcus sp. strain PCC 8806 and Synechococcus sp. strain PCC 8807 were tested in microcosm experiments for their ability to calcify when exposed to a fixed calcium concentration of 3.4 mM and dissolved inorganic carbon concentrations of 0.5, 1.25 and 2.5 mM. Synechococcus sp. strain PCC 8806 removed calcium continuously over the duration of the experiment producing approximately 18.6 mg of solid-phase calcium. Calcium removal occurred over a two-day time period when

  7. Carbon dioxide disposal in solid form

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Modeling caspian sea water level oscilLations Under Diffrent Scenarioes of Increasing Atmospheric Carbon Dioxide Concentrations

    Directory of Open Access Journals (Sweden)

    GholamReza Roshan

    2012-12-01

    Full Text Available The rapid rise of Caspian Sea water level (about 2.25 meters since 1978 has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in thecoastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was stimulated. Variations in environmentalparameters such as temperature, precipitation, evaporation, tmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for bothpast (1951-2006 and future (2025-2100 time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software(version 5.3. The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site has increased by ca. 0.17ºC per decade under the impacts of atmospheric carbon dioxide changes (r=0.21. The Caspian Sea water level has increasedby ca. +36 mm per decade (r=0.82 between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64ºC and precipitation will decrease by ca. 10% (182 mm over the Caspian Sea, whilst in the Volga river basin,temperatures are projected to increase by ca. 4.78ºC and precipitation increase by ca. 12% (58 mm by the year 2100. Finally, statistical modeling of the Caspian Sea water levels projectfuture water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

  9. Carbon dioxide laser guidelines

    Directory of Open Access Journals (Sweden)

    Krupa Shankar D

    2009-01-01

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

  10. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 2001 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2002-10-15

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) 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 CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on climate and vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Director) of DOE's Office of Biological and Environmental Research. CDIAC represents DOE in the multi-agency Global Change Data and Information System (GCDIS). Wanda Ferrell is DOE's Program Manager with overall responsibility for CDIAC. Roger Dahlman is responsible for CDIAC's AmeriFlux tasks, and Anna Palmisano for CDIAC's Ocean Data tasks. CDIAC is made

  11. Carbon Dioxide Information Analysis Center and World Data Center for Atmospheric Trace Gases Fiscal Year 1999 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.

    2000-03-31

    The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global-change data and information analysis center of the Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has--since its inception in 1982--enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) 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 CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea level. CDIAC is located within the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. CDIAC is co-located with ESD researchers investigating global-change topics, such as the global carbon cycle and the effects of carbon dioxide on vegetation. CDIAC staff are also connected with current ORNL research on related topics, such as renewable energy and supercomputing technologies. CDIAC is supported by the Environmental Sciences Division (Jerry Elwood, Acting Director) of DOE's Office of Biological and Environmental Research. CDIAC's FY 1999 budget was 2.2M dollars. CDIAC represents the DOE in the multi-agency Global Change Data and Information System. Bobbi Parra, and Wanda Ferrell on an interim basis, is DOE's Program Manager with responsibility for CDIAC. CDIAC comprises three groups, Global Change Data, Computer Systems, and

  12. Temporal and zonal variability and of mid-tropospheric carbon dioxide from the Atmospheric Infrared Sounder compared to surface measurements

    Science.gov (United States)

    Pagano, T. S.; Olsen, E. T.; Nguyen, H. M.; Jiang, X.

    2012-12-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 um spectral region with spectral resolution of better than 1200, and spatial resolution of 13.5 km with global daily coverage. The AIRS was designed to measure temperature and water vapor profiles for improvement in weather forecast and improved parameterization of climate processes. Currently the AIRS Level 1B Radiance Products are assimilated by NWP centers worldwide and have shown considerable forecast improvement. AIRS L1 and L2 products are widely used for studying critical climate processes related to water vapor feedback, atmospheric transport and cloud properties. AIRS trace gas products include ozone profiles, carbon monoxide, and the first global maps of mid-tropospheric carbon dioxide. The global daily coverage of AIRS allows scientists to follow the transport of these gases to aid in validation of chemical/weather transport models. AIRS mid-tropospheric carbon dioxide has a peak sensitivity of about 450 mb and a width of about 500 mb. This broad mid-tropospheric sensitivity is useful for identifying global circulation patterns including ENSO (Jiang et al., 2010) and MJO (Li et al., 2010). Climatologies were developed that represent averages of AIRS Monthly L3 CO2 data detrended and averaged over the individual months for 12 maps on 2.0 x 2.5 degree grid scale (Pagano, 2011). The climatologies show a persistent low in the CO2 in the South Atlantic due to a constant downward flux from the Walker Circulation. The significantly reduced noise level in the climatologies also reveal that the horizontal variability in the AIRS CO2 measurements is not entirely driven by global circulation, but also the underlying global vegetation cycle. Further investigation into the seasonal behavior of the zonal averages of AIRS CO2, AIRS mid-troposphere and surface temperature data, MODIS derived GPP, and other ground

  13. Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

    Science.gov (United States)

    Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

    2013-04-01

    Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields. PMID:23444905

  14. Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2013-01-01

    Full Text Available Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2, have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in Kongsfjorden on the west coast of Spitsbergen (Norway, in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a, peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured as high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2-related shifts in nutrient flow into different phytoplankton groups (mainly dinoflagellates, prasinophytes and haptophytes could have consequences for future organic matter flow to higher trophic levels and export production, with consequences

  15. Temporal biomass dynamics of an Arctic plankton bloom in response to increasing levels of atmospheric carbon dioxide

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2012-09-01

    Full Text Available Ocean acidification and carbonation, driven by anthropogenic emissions of carbon dioxide (CO2, have been shown to affect a variety of marine organisms and are likely to change ecosystem functioning. High latitudes, especially the Arctic, will be the first to encounter profound changes in carbonate chemistry speciation at a large scale, namely the under-saturation of surface waters with respect to aragonite, a calcium carbonate polymorph produced by several organisms in this region. During a CO2 perturbation study in 2010, in the framework of the EU-funded project EPOCA, the temporal dynamics of a plankton bloom was followed in nine mesocosms, manipulated for CO2 levels ranging initially from about 185 to 1420 μatm. Dissolved inorganic nutrients were added halfway through the experiment. Autotrophic biomass, as identified by chlorophyll a standing stocks (Chl a, peaked three times in all mesocosms. However, while absolute Chl a concentrations were similar in all mesocosms during the first phase of the experiment, higher autotrophic biomass was measured at high in comparison to low CO2 during the second phase, right after dissolved inorganic nutrient addition. This trend then reversed in the third phase. There were several statistically significant CO2 effects on a variety of parameters measured in certain phases, such as nutrient utilization, standing stocks of particulate organic matter, and phytoplankton species composition. Interestingly, CO2 effects developed slowly but steadily, becoming more and more statistically significant with time. The observed CO2 related shifts in nutrient flow into different phytoplankton groups (mainly diatoms, dinoflagellates, prasinophytes and haptophytes could have consequences for future organic matter flow to higher trophic levels and export production, with consequences for ecosystem productivity and atmospheric

  16. Continuous measurements of atmospheric oxygen and carbon dioxide on a North Sea gas platform

    OpenAIRE

    van der Laan-Luijkx, I. T.; R. E. M. Neubert; S. Van der Laan; Meijer, H. A. J.; D. Toohey

    2010-01-01

    A new atmospheric measurement station has been established on the North Sea oil and gas production platform F3, 200 km north off the Dutch coast (54 degrees 51' N, 4 degrees 44' E). Atmospheric concentrations of O(2) and CO(2) are continuously measured using fuel cell technology and compact infrared absorption instruments, respectively. Furthermore, the station includes an automated air flask sampler for laboratory analysis of the atmospheric concentrations of CO(2), CH(4), CO and O(2) and is...

  17. Summer Ice and Carbon Dioxide

    Science.gov (United States)

    Kukla, G.; Gavin, J.

    1981-10-01

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

  18. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    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.

  19. Experimental drought in a tropical rain forest increases soil carbon dioxide losses to the atmosphere

    Science.gov (United States)

    Cleveland, Cory C.; Wieder, William R.; Reed, Sasha C.; Townsend, Alan R.

    2010-01-01

    Climate models predict precipitation changes for much of the humid tropics, yet few studies have investigated the potential consequences of drought on soil carbon (C) cycling in this important biome. In wet tropical forests, drought could stimulate soil respiration via overall reductions in soil anoxia, but previous research suggests that litter decomposition is positively correlated with high rainfall fluxes that move large quantities of dissolved organic matter (DOM) from the litter layer to the soil surface. Thus, reduced rainfall could also limit C delivery to the soil surface, reducing respiration rates. We conducted a throughfall manipulation experiment to investigate how 25% and 50% reductions in rainfall altered both C movement into soils and the effects of those DOM fluxes on soil respiration rates. In response to the experimental drought, soil respiration rates increased in both the -25% and -50% treatments. Throughfall fluxes were reduced by 26% and 55% in the -25% and -50% treatments, respectively. However, total DOM fluxes leached from the litter did not vary between treatments, because the concentrations of leached DOM reaching the soil surface increased in response to the simulated drought. Annual DOM concentrations averaged 7.7 ± 0.8, 11.2 ± 0.9, and 15.8 ± 1.2 mg C/L in the control, -25%, and -50% plots, respectively, and DOM concentrations were positively correlated with soil respiration rates. A laboratory incubation experiment confirmed the potential importance of DOM concentration on soil respiration rates, suggesting that this mechanism could contribute to the increase in CO2 fluxes observed in the reduced rainfall plots. Across all plots, the data suggested that soil CO2 fluxes were partially regulated by the magnitude and concentration of soluble C delivered to the soil, but also by soil moisture and soil oxygen availability. Together, our data suggest that declines in precipitation in tropical rain forests could drive higher CO2 fluxes

  20. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. PPDF-based method to account for atmospheric light scattering in observations of carbon dioxide from space

    Science.gov (United States)

    Oshchepkov, Sergey; Bril, Andrey; Yokota, Tatsuya

    2008-12-01

    We present an original method that accounts for thin clouds in carbon dioxide retrievals from space-based reflected sunlight observations in near-infrared regions. This approach involves a reasonable, simple parameterization of effective transmittance using a set of parameters that describe the path-length modification caused by clouds. The complete retrieval scheme included the following: estimation of cloud parameters from the 0.76-μm O2 A-band and from the H2O-saturated absorption area of the 2.0-μm band; a necessary correction to utilize these parameters at the target CO2 1.58-μm band using estimated ground surface albedo outside of gas absorption lines in this band; and retrieval of CO2 amount at the 1.58-μm band using a maximum a posteriori method of inversion. The primary retrieved parameters refer to the CO2 volume mixing ratio vertical profile that is then transformed to an averaged-column amount under a pre-defined increment of pressure. A set of numerical simulations with synthetic radiance spectra particular to Greenhouse Gases Observing Satellite (GOSAT) observations showed that the proposed method provides acceptably accurate CO2 retrievals from an atmosphere that includes thin cirrus clouds. Efficiency of the aerosol and cloud corrections was demonstrated by comparing it with a modified iterative maximum a posteriori-DOAS (IMAP-DOAS) that neglects path length modifications due to the scattering effects.

  2. Tedlar bag sampling technique for vertical profiling of carbon dioxide through the atmospheric boundary layer with high precision and accuracy.

    Science.gov (United States)

    Schulz, Kristen; Jensen, Michael L; Balsley, Ben B; Davis, Kenneth; Birks, John W

    2004-07-01

    Carbon dioxide is the most important greenhouse gas other than water vapor, and its modulation by the biosphere is of fundamental importance to our understanding of global climate change. We have developed a new technique for vertical profiling of CO2 and meteorological parameters through the atmospheric boundary layer and well into the free troposphere. Vertical profiling of CO2 mixing ratios allows estimates of landscape-scale fluxes characteristic of approximately100 km2 of an ecosystem. The method makes use of a powered parachute as a platform and a new Tedlar bag air sampling technique. Air samples are returned to the ground where measurements of CO2 mixing ratios are made with high precision (< or =0.1%) and accuracy (< or =0.1%) using a conventional nondispersive infrared analyzer. Laboratory studies are described that characterize the accuracy and precision of the bag sampling technique and that measure the diffusion coefficient of CO2 through the Tedlar bag wall. The technique has been applied in field studies in the proximity of two AmeriFlux sites, and results are compared with tower measurements of CO2. PMID:15296321

  3. High-oxygen and high-carbon dioxide containing atmospheres inhibit growth of food associated moulds

    NARCIS (Netherlands)

    Hoogerwerf, S W; Kets, E P W; Dijksterhuis, J

    2002-01-01

    AIMS: The objective of this study was to determine the relationship between the growth of three foodborne fungi and high-oxygen modified atmosphere. METHODS AND RESULTS: Petri dishes were incubated in a series of connected flasks, which were placed in a climatized room and flushed continuously with

  4. Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations

    NARCIS (Netherlands)

    Peters, W.; Krol, M.C.; Werf, van der G.R.; Houweling, S.; Jones, C.D.; Hughes, J.; Schaefer, K.; Masarie, K.A.

    2010-01-01

    We present an estimate of net ecosystem exchange (NEE) of CO2 in Europe for the years 2001–2007. It is derived with a data assimilation that uses a large set of atmospheric CO2 mole fraction observations (~70 000) to guide relatively simple descriptions of terrestrial and oceanic net exchange, while

  5. Testing of a Two-Micron Double-Pulse IPDA Lidar Instrument for Airborne Atmospheric Carbon Dioxide Measurement

    Science.gov (United States)

    Yu, J.; Petros, M.; Refaat, T. F.; Remus, R.; Singh, U. N.

    2015-12-01

    Utilizing a tunable two-micron double-pulse laser transmitter, an airborne IPDA lidar system has been developed at NASA Langley Research Center for atmospheric carbon dioxide column measurements. The instrument comprises a receiver with 0.4 m telescope and InGaAs pin detectors coupled to 12-bit, 200 MS/s waveform digitizers. For on-site ground testing, the 2-μm CO2 IPDA lidar was installed inside a trailer located where meteorological data and CO2 mixing ratio profiles were obtained from CAPABLE and LiCoR in-suite sampling, respectively. IPDA horizontal ground testing with 860 m target distance indicated CO2 sensitivity of 2.24 ppm with -0.43 ppm offset, while operating at 3 GHz on-line position from the R30 line center. Then, the IPDA lidar was integrated inside the NASA B-200 aircraft, with supporting instrumentation, for airborne testing and validation. Supporting instruments included in-situ LiCoR sensor, GPS and video recorder for target identification. Besides, aircraft built-in sensors provided altitude, pressure, temperature and relative humidity sampling during flights. The 2-mm CO2 IPDA lidar airborne testing was conducted through ten daytime flights (27 hours flight time). Airborne testing included different operating and environmental conditions for flight altitude up to 7 km, different ground target conditions such as vegetation, soil, ocean, snow and sand and different cloud conditions. Some flights targeted power plant incinerators for investigating IPDA sensitivity to CO2 plums. Relying on independent CO2 in-situ sampling, conducted through NOAA, airborne IPDA CO2 sensitivity of 4.15 ppm with 1.14 ppm offset were observed at 6 km altitude and 4 GHz on-line offset frequency. This validates the 2-μm double-pulse IPDA lidar for atmospheric CO2 measurement.

  6. Weak response of the Atlantic thermohaline circulation to an increase of atmospheric carbon dioxide in IAP/LASG Climate System Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tianjun; YU Rucong; LIU Xiying; GUO Yufu; YU Yongqiang; ZHANG Xuehong

    2005-01-01

    Response of the Atlantic thermohaline circula- tion (THC) to global warming is examined by using the climate system model developed at IAP/LASG. The evidence indicates that the gradually warming climate associated with the increased atmospheric carbon dioxide leads to a warmer and fresher sea surface water at the high latitudes of the North Atlantic Ocean, which prevents the down-welling of the surface water. The succedent reduction of the pole-to- equator meridional potential density gradient finally results in the decrease of the THC in intensity. When the atmospheric carbon dioxide is doubled, the maximum value of the Atlantic THC decreases approximately by 8%. The associated poleward oceanic heat transport also becomes weaker. This kind of THC weakening centralizes mainly in the northern part of the North Atlantic basin, indicating briefly a local scale adjustment rather than a loop oscillation with the whole Atlantic "conveyor belt" decelerating.

  7. Carbon Dioxide Information Analysis Center and World Data Center-A for atmospheric trace gases: Fiscal year 1995 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Burtis, M.D. [comp.; Cushman, R.M.; Boden, T.A.; Jones, S.B.; Nelson, T.; Stoss, F.W.

    1996-01-01

    Fiscal year 1995 was both a very productive year for the Carbon Dioxide Information Analysis Center and a year of significant change. This document presents information about the most notable accomplishments made during the year. Topics include: high-lights; statistics; future plans; publications, presentations, and awards; and change in organization and staff.

  8. Differential response of cultivated and weedy (red) rice to recent and projected increases in atmospheric carbon dioxide

    Science.gov (United States)

    Carbon dioxide (CO2) is a principle resource for plant growth; as such, the ongoing increase in its concentration may differentially affect the growth of cultivated and wild types of the same species. Red rice in the U.S. is a weedy relative of cultivated rice that represents a major production con...

  9. Biotic enhancement of weathering, atmospheric oxygen and carbon dioxide in the Neoproterozoic

    Science.gov (United States)

    Lenton, Timothy M.; Watson, Andrew J.

    2004-03-01

    It has been suggested that biological colonization of the land surface began in the Neoproterozoic 1000-544 million years ago (Ma). We hypothesize that this colonization involved selective weathering of P from rocks, as well as an amplification of overall weathering rates. We show that two recent models, despite differences in the feedback mechanisms represented, predict that an increase in the weathering flux of P to the ocean would have caused a rise in atmospheric O2 in the Neoproterozoic. This in turn may have provided a necessary condition for the evolution of animals with hard skeletons seen in the 'Cambrian explosion'. Increased weathering of silicate rocks would also have caused a decline in atmospheric CO2, which could have been a causal factor in the Neoproterozoic glaciations.

  10. Sugarcane Bagasse Pyrolysis in a Carbon Dioxide Atmosphere with Conventional and Microwave-Assisted Heating

    OpenAIRE

    Lin, Bo-Jhih; Chen, Wei-Hsin

    2015-01-01

    Pyrolysis is an important thermochemical method to convert biomass into bio-oil. In this study, the pyrolysis of sugarcane bagasse in a CO2 atmosphere under conventional and microwave-assisted heating is investigated to achieve CO2 utilization. In the microwave pyrolysis, charcoal is used as the microwave absorber to aid in pyrolysis reactions. The results indicate that the yields of pyrolysis products are greatly influenced by the heating modes. In the conventional heating, the prime product...

  11. Sugarcane bagasse pyrolysis in a carbon dioxide atmosphere with conventional and microwave-assisted heating

    OpenAIRE

    Bo-Jhih eLin; Wei-Hsin eChen

    2015-01-01

    Pyrolysis is an important thermochemical method to convert biomass into bio-oil. In this study, the pyrolysis of sugarcane bagasse in a CO2 atmosphere under conventional and microwave-assisted heating is investigated to achieve CO2 utilization. In the microwave pyrolysis, charcoal is used as the microwave absorber to aid in pyrolysis reactions. The results indicate that the yields of pyrolysis products are greatly influenced by the heating modes. In the conventional heating, the prime product...

  12. Rising atmospheric carbon dioxide concentration and the future of C4 crops for food and fuel

    OpenAIRE

    Leakey, Andrew D.B.

    2009-01-01

    Crops with the C4 photosynthetic pathway are vital to global food supply, particularly in the tropical regions where human well-being and agricultural productivity are most closely linked. While rising atmospheric [CO2] is the driving force behind the greater temperatures and water stress, which threaten to reduce future crop yields, it also has the potential to directly benefit crop physiology. The nature of C4 plant responses to elevated [CO2] has been controversial. Recent evidence from fr...

  13. Continuous measurements of atmospheric oxygen and carbon dioxide on a North Sea gas platform

    Directory of Open Access Journals (Sweden)

    I. T. Luijkx

    2009-07-01

    Full Text Available A new atmospheric measurement station has been established on the North Sea oil and gas production platform F3, 200 km north off the Dutch coast (54°51' N, 4°44' E. Atmospheric mixing ratios of O2 and CO2 are continuously measured using fuel cell technology and compact infrared absorption instruments, respectively. Furthermore, the station includes an automated air flask sampler for laboratory analysis of the atmospheric mixing ratios of CO2, CH4, CO and O2 and isotope measurements of δ13C, δ18O and Δ14C from CO2. This station is – to our knowledge – the first fixed sea based station with on-site continuous O2 and CO2 measurements and therefore yields valuable additional information about the CO2 uptake in coastal marine regions, specifically the North Sea. This paper presents the measurement station and the used methodologies in detail. Additionally, the first data is presented showing the seasonal cycle as expected during August 2008 through June 2009. In comparison to land-based stations, the data show low day-to-day variability, as they are practically free of nightly inversions. Therefore, the data set collected at this measurement station serves directly as background data for the coastal northwest European region. Additionally, some short-term O2 and CO2 signals are presented, including very large (over 200 per meg and fast negative atmospheric O2 excursions.

  14. The role of atmospheric heat transport in the seasonal carbon dioxide cycle

    Science.gov (United States)

    Pollack, James B.; Haberle, R. M.; Murphy, James R.; Schaeffer, J.

    1993-01-01

    We have carried out numerical experiments with a general circulations model (GCM) and energy balance model of the martian atmosphere to define the importance of heat transported to the polar regions in determining the amount of CO2 condensed on the surface during the fall and winter seasons and the amount sublimated during the spring and summer seasons. In so doing, we performed both sensitivity experiments, in which the dust opacity was varied over the full range of its observed values, and annual simulations, in which the dust opacity varied continuously with seasonal data, in accord with measurements taken at the Viking landers. Dust opacity represents the key variable for determining the contribution of atmospheric heat advection to the energy budget in the polar regions. The amount of heat advected to the winter polar regions increases monotonically as the dust opacity at low and middle latitudes increases. However, the increase is sharpest between optical depths of 0 and 1 tends to level off at still higher optical depths. Heat advection is more important at times of CO2 condensation than CO2 sublimation, since the temperature gradients are much steeper in the winter hemisphere than in the summer hemisphere. Because dust opacity is much higher during northern winter than during southern winter, atmospheric heat advection reduces the amount of CO2 that condenses in the north by a much larger factor than it does in the south.

  15. Concentration and delta13C variation of atmospheric carbon dioxide near car traffic routes

    International Nuclear Information System (INIS)

    Results of CO2 concentration and delta13C measurements in the atmospheric air sampled in Cracow and neighbourhood at the points of different influence of automobil exhaust gases are presented. Observed maximum the CO2 concentration at heavy traffic cross-road reached value 419 ppm while delta13C = -9.2%o. The CO2 concentration and delta13C values show correlation for either four sampling points. In the case of domination natural daily fluctuation of CO2 simple mixing model fits very well. Fluctuations determined by anthropogenic CO2 cannot be described by this model indicating different type of correlation. (author)

  16. Atmospheric carbon dioxide and the long-term control of the Earth's climate

    Directory of Open Access Journals (Sweden)

    J. H. Carver

    Full Text Available A CO2-weathering model has been used to explore the possible evolution of the Earth's climate as the Sun steadily brightened throughout geologic time. The results of the model calculations can be described in terms of three, qualitatively different, "Megaclimates". Mega-climate 1 resulted from a period of rapid outgassing in the early Archean, with high, but declining, temperatures caused by the small weathering rates on a largely water-covered planet. Mega-climate 2 began about 3 Gyear ago as major continental land masses developed, increasing the weathering rate in the early Proterozoic and thereby depleting the atmospheric CO2 concentration. This process produced the first Precambrian glaciations about 2.3 Gyear ago. During Mega-climate 2, evolutionary biological processes increased the surface weatherability in incremental steps and plate tectonics modulated the CO2 outgassing rate with an estimated period of 150 Myear (approximately one-half the period for the formation and breakup of super continents. Throughout Mega-climate 2 the surface temperature was controlled by variations in the atmospheric CO2 level allowing transitions between glacial and non-glacial conditions. The results of the model for Mega-climate 2 are in agreement with the occurrence (and absence of glaciations in the geologic record. Extending the model to the future suggests that CO2 control of the Earth's temperature will no longer be able to compensate for a solar flux that continues to increase. The present level of atmospheric CO2 is so small that further reduction in CO2 cannot prevent the Earth from experiencing Mega-climate 3 with steadily increasing surface temperatures caused by the continued brightening of the Sun. During Mega-climate 3, the main danger to the biosphere would come not from an increasing temperature but from a decreasing (rather than an increasing CO2

  17. Field Testing of a Two-Micron DIAL System for Profiling Atmospheric Carbon Dioxide

    Science.gov (United States)

    Refaat, Tamer F.; Ismail, Syed; Koch, Grady J.; Diaz, Liza; Davis, Ken; Rubio, Manuel

    2010-01-01

    A 2-m DIAL system has been developed at NASA Langley Research Center through the NASA Instrument Incubator Program. The system utilizes a tunable 2-m pulsed laser and an IR phototransistor for the transmitter and the receiver, respectively. The system targets the CO2 absorption line R22 in the 2.05-m band. Field experiments were conducted at West Branch, Iowa, for evaluating the system for CO2 measurement by comparison with in-situ sensors. The CO2 in-situ sensors were located on the NOAA's WBI tower at 31, 99 and 379 m altitudes, besides the NOAA s aircraft was sampling at higher altitudes. Preliminary results demonstrated the capabilities of the DIAL system in profiling atmospheric CO2 using the 2-m wavelength. Results of these experiments will be presented and discussed.

  18. Projections of the pace of warming following an abrupt increase in atmospheric carbon dioxide concentration

    International Nuclear Information System (INIS)

    The temperature response of atmosphere–ocean climate models is analyzed based on atmospheric CO2 step-function-change simulations submitted to phase 5 of the Coupled Model Intercomparison Project (CMIP5). From these simulations and a control simulation, we estimate adjusted radiative forcing, the climate feedback parameter, and effective climate system thermal inertia, and we show that these results can be used to predict the temperature response to time-varying CO2 concentrations. We evaluate several kinds of simple mathematical models for the CMIP5 simulation results, including single- and multiple-exponential models and a one-dimensional ocean-diffusion model. All of these functional forms, except the single-exponential model, can produce curves that fit most CMIP5 results quite well for both continuous and step-function CO2-change pathways. Choice of model for any particular application would include consideration of factors such as the number of free parameters to be constrained and the conception of the underlying mechanistic model. Smooth curve fits to the CMIP5 simulation results realize approximately half (range 38%–61%) of equilibrium warming within the first decade after a CO2 concentration increase, but approximately one quarter (range 14%–40%) of equilibrium warming occurs more than a century after the CO2 increase. Following an instantaneous quadrupling of atmospheric CO2, fits to four of the 20 simulation results reach 4 ° C of warming within the first decade, but fits to three of the 20 simulation results require more than a century to reach 4 ° C. These results indicate the need to reduce uncertainty in the temporal response of climate models and to consider this uncertainty when evaluating the risks posed by climate change. (letter)

  19. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

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

    2013-07-01

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

  20. Addressing the Grand Challenge of atmospheric carbon dioxide: geologic sequestration vs. biological recycling

    Directory of Open Access Journals (Sweden)

    Stuart Ben J

    2011-11-01

    Full Text Available Abstract On February 15, 2008, the National Academy of Engineering unveiled their list of 14 Grand Challenges for Engineering. Building off of tremendous advancements in the past century, these challenges were selected for their role in assuring a sustainable existence for the rapidly increasing global community. It is no accident that the first five Challenges on the list involve the development of sustainable energy sources and management of environmental resources. While the focus of this review is to address the single Grand Challenge of "develop carbon sequestration methods", is will soon be clear that several other Challenges are intrinsically tied to it through the principles of sustainability. How does the realm of biological engineering play a role in addressing these Grand Challenges?

  1. Conversion of carbon dioxide to value-added chemicals in atmospheric pressure dielectric barrier discharges

    International Nuclear Information System (INIS)

    The aim of this work consists of the evaluation of atmospheric pressure dielectric barrier discharges for the conversion of greenhouse gases into useful compounds. Therefore, pure CO2 feed flows are administered to the discharge zone at varying discharge frequency, power input, gas temperature and feed flow rates, aiming at the formation of CO and O2. The discharge obtained in CO2 is characterized as a filamentary mode with a microdischarge zone in each half cycle of the applied voltage. It is shown that the most important parameter affecting the CO2-conversion levels is the gas flow rate. At low flow rates, both the conversion and the CO-yield are significantly higher. In addition, also an increase in the gas temperature and the power input give rise to higher conversion levels, although the effect on the CO-yield is limited. The optimum discharge frequency depends on the power input level and it cannot be unambiguously stated that higher frequencies give rise to increased conversion levels. A maximum CO2 conversion of 30% is achieved at a flow rate of 0.05 L min-1, a power density of 14.75 W cm-3 and a frequency of 60 kHz. The most energy efficient conversions are achieved at a flow rate of 0.2 L min-1, a power density of 11 W cm-3 and a discharge frequency of 30 kHz.

  2. On the coupled evolution of inflation, wealth and atmospheric concentrations of carbon dioxide

    CERN Document Server

    Garrett, Timothy J

    2010-01-01

    In a prior study (Garrett, 2009), a thermodynamically-based economic growth model was introduced that was based on the finding that the rate of consumption of energy by civilization has been related to its historical accumulation of inflation-adjusted Gross World Product (GWP), or its ``wealth'', through a constant value {\\lambda} of 9.7 {\\pm} 0.3 milliwatts per 1990 US dollar. Here, this simple model is extended to describe, first, a thermodynamically-based theory for economic inflation and, second, a prognostic model for the coupled multi-decadal evolution of CO2 concentrations and GWP. Multi-decadal hindcasts of GWP and CO2 concentrations made with this model are shown to be accurate. Applied to coming decades, the model implies that, like a long-term natural disaster, future greenhouse warming will accelerate economic inflation. Such inflation will slow growth of not just inflation-adjusted economic wealth, but also CO2 emission rates because the two are coupled through {\\lambda}. Maintaining atmospheric ...

  3. Sugarcane bagasse pyrolysis in a carbon dioxide atmosphere with conventional and microwave-assisted heating

    Directory of Open Access Journals (Sweden)

    Bo-Jhih eLin

    2015-02-01

    Full Text Available Pyrolysis is an important thermochemical method to convert biomass into bio-oil. In this study, the pyrolysis of sugarcane bagasse in a CO2 atmosphere under conventional and microwave-assisted heating is investigated to achieve CO2 utilization. In the microwave pyrolysis, charcoal is used as the microwave absorber to aid in pyrolysis reactions. The results indicate that the yields of pyrolysis products are greatly influenced by the heating modes. In the conventional heating, the prime product is bio-oil and its yield is in the range of 51-54 wt%, whereas biochar is the major product in microwave-assisted heating and its yield ranges from 61 to 84 wt%. Two different absorber blending ratios of 0.1 and 0.3 are considered in the microwave pyrolysis. The solid yield decreases when the absorber blending ratio decreases from 0.3 to 0.1, while the gas and liquid yields increase. This is attributed to more energy consumed for bagasse pyrolysis at the lower blending ratio. Hydrogen is produced under the microwave pyrolysis and its concentration is between 2 and 12 vol%. This arises from the fact that the secondary cracking of vapors and the secondary decomposition of biochar in an environment with microwave irradiation is easier than those with conventional heating.

  4. Can enhanced weathering remove carbon dioxide from the atmosphere to prevent climate change? (Invited)

    Science.gov (United States)

    Renforth, P.; Pogge von Strandmann, P.; Henderson, G. M.

    2013-12-01

    On long timescales, silicate weathering provides the ultimate sink for CO2 released by volcanic degassing and, because the rate of such weathering is temperature dependant, this sink is thought to respond to climate change to provide a strong negative feedback stabilising Earth's climate. An increase of global weathering rates is expected in response to anthropogenic warming and this increased weathering will ultimately (on the timescale of hundreds of thousands of years) serve to remove additional CO2 and return the climate system to lower temperatures. Some have proposed that accelerating this natural process by adding ground minerals to the land surface may help to prevent climate change. However, a major challenge in assessing such a proposal is the lack of experimental kinetic data for minerals added to the environment. Here we will present results from an experiment in which a forsterite rich olivine (Mg2SiO4) was added to the top of a soil column extracted from an agricultural field. A solution was passed through the columns over a period of 5 months and the drainage waters were collected and analysed. The greater flux of Mg measured eluting from the treated soil can be used to constrain the weathering rate of the olivine. A weathering rate can be determined by normalising the rate of magnesium flux to the surface area of olivine in the soil. By combining this information with a simple shrinking core model, we can estimate that an average particle size less than 1 μm would be required in order for the olivine to completely dissolve in a year. Therefore, the energy requirements for enhanced weathering are large >2 GJ(electrical) per net tonne of CO2 sequestered, but it is at least comparable to direct air capture technologies. These preliminary results suggest limited carbon capture potential for enhanced weathering in temperate agricultural soils. However, some environments may be better suited (e.g. humid tropical agricultural soils) and additional

  5. Carbon Dioxide (CO2) Retrievals from Atmospheric Chemistry Experiment (ACE) Solar Occultation Measurements

    Science.gov (United States)

    Rinsland, Curtis P.; Chiou, Linda; Boone, Chris; Bernath, Peter

    2010-01-01

    The Atmospheric Chemistry Experiment ACE satellite (SCISAT-1) was launched into an inclined orbit on 12 August 2003 and is now recording high signal-to-noise 0.02 per centimeter resolution solar absorption spectra covering 750-4400 per centimeter (2.3-13 micrometers). A procedure has been developed for retrieving average dry air CO2 mole fractions (X(sub CO2)) in the altitude range 7-10 kilometers from the SCISAT-1 spectra. Using the N2 continuum absorption in a window region near 2500 per centimeter, altitude shifts are applied to the tangent heights retrieved in version 2.2 SCISAT-1 processing, while cloudy or aerosol-impacted measurements are eliminated. Monthly-mean XCO2 covering 60 S to 60 N latitude for February 2004 to March 2008 has been analyzed with consistent trends inferred in both hemispheres. The ACE XCO2 time series have been compared with previously-reported surface network measurements, predictions based on upper tropospheric aircraft measurements, and space-based measurements. The retrieved X(sub CO2) from the ACE-FTS spectra are higher on average by a factor of 1.07 plus or minus 0.025 in the northern hemisphere and by a factor of 1.09 plus or minus 0.019 on average in the southern hemisphere compared to surface station measurements covering the same time span. The ACE derived trend is approximately 0.2% per year higher than measured at surface stations during the same observation period.

  6. Conversion of carbon dioxide to value-added chemicals in atmospheric pressure dielectric barrier discharges

    Energy Technology Data Exchange (ETDEWEB)

    Paulussen, Sabine; Verheyde, Bert [VITO, Vlaamse Instelling voor Technologisch Onderzoek, Materials Technology, Mol (Belgium); Tu Xin; Sels, Bert [Center for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Heverlee (Belgium); De Bie, Christophe; Martens, Tom; Petrovic, Dragana; Bogaerts, Annemie, E-mail: sabine.paulussen@vito.b [University of Antwerp, Research Group PLASMANT, Wilrijk (Belgium)

    2010-06-15

    The aim of this work consists of the evaluation of atmospheric pressure dielectric barrier discharges for the conversion of greenhouse gases into useful compounds. Therefore, pure CO{sub 2} feed flows are administered to the discharge zone at varying discharge frequency, power input, gas temperature and feed flow rates, aiming at the formation of CO and O{sub 2}. The discharge obtained in CO{sub 2} is characterized as a filamentary mode with a microdischarge zone in each half cycle of the applied voltage. It is shown that the most important parameter affecting the CO{sub 2}-conversion levels is the gas flow rate. At low flow rates, both the conversion and the CO-yield are significantly higher. In addition, also an increase in the gas temperature and the power input give rise to higher conversion levels, although the effect on the CO-yield is limited. The optimum discharge frequency depends on the power input level and it cannot be unambiguously stated that higher frequencies give rise to increased conversion levels. A maximum CO{sub 2} conversion of 30% is achieved at a flow rate of 0.05 L min{sup -1}, a power density of 14.75 W cm{sup -3} and a frequency of 60 kHz. The most energy efficient conversions are achieved at a flow rate of 0.2 L min{sup -1}, a power density of 11 W cm{sup -3} and a discharge frequency of 30 kHz.

  7. Analysis and interpretation of satellite measurements in the near-infrared spectral region: Atmospheric carbon dioxide and methane

    OpenAIRE

    Schneising, Oliver

    2008-01-01

    Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases. SCIAMACHY on ENVISAT is the first satellite instrument whose measurements are sensitive to concentration changes of the two gases at all altitude levels down to the Earth's surface where the source/sink signals are largest. Three years (2003-2005) of SCIAMACHY near-infrared nadir measurements have been processed to simultaneously retrieve vertical columns of CO2, CH4, and oxygen using the scienti...

  8. Growth, radiation use efficiency, and canopy reflectance of wheat and corn grown under elevated ozone and carbon dioxide atmosphere

    International Nuclear Information System (INIS)

    Estimates of increases in future agricultural production in response to increases in carbon dioxide (CO2) concentrations in the atmosphere are often based on the beneficial physiological effect of CO2 enrichment on plant growth, especially in Ca plants. However, these estimates fail to consider the negative impact of ozone (O3) air pollution on crop production. Increases in tropospheric concentrations of both gases, CO2 and O3, have been observed over the past century, and both are predicted to continue to increase at even higher rates in the near future to levels when they may have a significant impact on agricultural production. Field studies with wheat (Friticum aestivum L.) in 1991 and 1992, and corn (Zea mays L.) in 1991 were conducted using open-top chambers to mimic atmospheric concentrations of CO2 (~ 500 μL-1 CO2) and Oa (- 40 nL L-1 O3 above ambient air [O3] during 7 h day- 1, 5 days week-1) that are predicted to occur at the Earth's surface during the first half of the 21st century. Wheat and corn (C3 vs. C4) produced clearly different responses to CO2 enrichment, but similar responses to O3 exposure. In wheat, O3 exposure led to reduced grain yield, biomass, and radiation use efficiency (RUE, phytomass production per unit of energy received); in both years; but reduction in accumulated absorbed photosynthetically active radiation (AAPAR) was observed only in 1991. Conversely, CO2 enrichment produced greater grain yield, dry biomass, and RUE. With CO2 enrichment, the Oa-induced stress to wheat plants was apparently ameliorated since responses were equivalent to the control group (low O3 and ambient CO2) for all variables. In contrast, corn demonstrated no benefit to CO2 enrichment for measured variables, and corn grain yield was the only parameter negatively influenced by O3 exposure that is attributed to O3-induced damage during the flowering process. Additionally, no treatment differences were observed for leaf area index (LAI) as determined

  9. Double-pulse 2-μm integrated path differential absorption lidar airborne validation for atmospheric carbon dioxide measurement.

    Science.gov (United States)

    Refaat, Tamer F; Singh, Upendra N; Yu, Jirong; Petros, Mulugeta; Remus, Ruben; Ismail, Syed

    2016-05-20

    Field experiments were conducted to test and evaluate the initial atmospheric carbon dioxide (CO2) measurement capability of airborne, high-energy, double-pulsed, 2-μm integrated path differential absorption (IPDA) lidar. This IPDA was designed, integrated, and operated at the NASA Langley Research Center on-board the NASA B-200 aircraft. The IPDA was tuned to the CO2 strong absorption line at 2050.9670 nm, which is the optimum for lower tropospheric weighted column measurements. Flights were conducted over land and ocean under different conditions. The first validation experiments of the IPDA for atmospheric CO2 remote sensing, focusing on low surface reflectivity oceanic surface returns during full day background conditions, are presented. In these experiments, the IPDA measurements were validated by comparison to airborne flask air-sampling measurements conducted by the NOAA Earth System Research Laboratory. IPDA performance modeling was conducted to evaluate measurement sensitivity and bias errors. The IPDA signals and their variation with altitude compare well with predicted model results. In addition, off-off-line testing was conducted, with fixed instrument settings, to evaluate the IPDA systematic and random errors. Analysis shows an altitude-independent differential optical depth offset of 0.0769. Optical depth measurement uncertainty of 0.0918 compares well with the predicted value of 0.0761. IPDA CO2 column measurement compares well with model-driven, near-simultaneous air-sampling measurements from the NOAA aircraft at different altitudes. With a 10-s shot average, CO2 differential optical depth measurement of 1.0054±0.0103 was retrieved from a 6-km altitude and a 4-GHz on-line operation. As compared to CO2 weighted-average column dry-air volume mixing ratio of 404.08 ppm, derived from air sampling, IPDA measurement resulted in a value of 405.22±4.15  ppm with 1.02% uncertainty and 0.28% additional bias. Sensitivity analysis of environmental

  10. A multi-scale approach to monitor urban carbon-dioxide emissions in the atmosphere over Vancouver, Canada

    Science.gov (United States)

    Christen, A.; Crawford, B.; Ketler, R.; Lee, J. K.; McKendry, I. G.; Nesic, Z.; Caitlin, S.

    2015-12-01

    Measurements of long-lived greenhouse gases in the urban atmosphere are potentially useful to constrain and validate urban emission inventories, or space-borne remote-sensing products. We summarize and compare three different approaches, operating at different scales, that directly or indirectly identify, attribute and quantify emissions (and uptake) of carbon dioxide (CO2) in urban environments. All three approaches are illustrated using in-situ measurements in the atmosphere in and over Vancouver, Canada. Mobile sensing may be a promising way to quantify and map CO2 mixing ratios at fine scales across heterogenous and complex urban environments. We developed a system for monitoring CO2 mixing ratios at street level using a network of mobile CO2 sensors deployable on vehicles and bikes. A total of 5 prototype sensors were built and simultaneously used in a measurement campaign across a range of urban land use types and densities within a short time frame (3 hours). The dataset is used to aid in fine scale emission mapping in combination with simultaneous tower-based flux measurements. Overall, calculated CO2 emissions are realistic when compared against a spatially disaggregated scale emission inventory. The second approach is based on mass flux measurements of CO2 using a tower-based eddy covariance (EC) system. We present a continuous 7-year long dataset of CO2 fluxes measured by EC at the 28m tall flux tower 'Vancouver-Sunset'. We show how this dataset can be combined with turbulent source area models to quantify and partition different emission processes at the neighborhood-scale. The long-term EC measurements are within 10% of a spatially disaggregated scale emission inventory. Thirdly, at the urban scale, we present a dataset of CO2 mixing ratios measured using a tethered balloon system in the urban boundary layer above Vancouver. Using a simple box model, net city-scale CO2 emissions can be determined using measured rate of change of CO2 mixing ratios

  11. Evaluation of submarine atmospheres: effects of carbon monoxide, carbon dioxide and oxygen on general toxicology, neurobehavioral performance, reproduction and development in rats. I. Subacute exposures.

    Science.gov (United States)

    Hardt, Daniel J; James, R Arden; Gut, Chester P; McInturf, Shawn M; Sweeney, Lisa M; Erickson, Richard P; Gargas, Michael L

    2015-02-01

    The inhalation toxicity of submarine contaminants is of concern to ensure the health of men and women aboard submarines during operational deployments. Due to a lack of adequate prior studies, potential general, neurobehavioral, reproductive and developmental toxicity was evaluated in male and female rats exposed to mixtures of three critical submarine atmospheric components: carbon monoxide (CO) and carbon dioxide (CO2; levels elevated above ambient), and oxygen (O2; levels decreased below ambient). In a 14-day, 23 h/day, whole-body inhalation study of exposure to clean air (0.4 ppm CO, 0.1% CO2 and 20.6% O2), low-dose, mid-dose and high-dose gas mixtures (high dose of 88.4 ppm CO, 2.5% CO2 and 15.0% O2), no adverse effects on survival, body weight or histopathology were observed. Reproductive, developmental and neurobehavioral performance were evaluated after a 28-day exposure in similar atmospheres. No adverse effects on estrus phase, mating, gestation or parturition were observed. No developmental or functional deficits were observed in either exposed parents or offspring related to motor activity, exploratory behavior or higher-level cognitive functions (learning and memory). Only minimal effects were discovered in parent-offspring emotionality tests. While statistically significant increases in hematological parameters were observed in the offspring of exposed parents compared to controls, these parameters remained within normal clinical ranges for blood cells and components and were not considered adverse. In summary, subacute exposures to elevated concentrations of the submarine atmosphere gases did not affect the ability of rats to reproduce and did not appear to have any significant adverse health effects. PMID:25600219

  12. Evaluation of submarine atmospheres: effects of carbon monoxide, carbon dioxide and oxygen on general toxicology, neurobehavioral performance, reproduction and development in rats. II. Ninety-day study.

    Science.gov (United States)

    Hardt, Daniel J; James, R Arden; Gut, Chester P; McInturf, Shawn M; Sweeney, Lisa M; Erickson, Richard P; Gargas, Michael L

    2015-02-01

    Carbon monoxide (CO), carbon dioxide (CO2) and low-level oxygen (O2) (hypoxia) are submarine atmosphere components of highest concern because of a lack of toxicological data available to address the potential effects from long-duration, combined exposures on female reproductive and developmental health. In this study, subchronic toxicity of mixed atmospheres of these three submarine air components was evaluated in rats. Male and female rats were exposed via inhalation to clean air (0.4 ppm CO; 0.13% CO2; 20.6% O2) (control), a low-dose (5.0 ppm CO; 0.41% CO2; 17.1% O2), a mid-dose (13.9 ppm CO; 1.19 or 1.20% CO2; 16.1% O2) and a high-dose (89.9 ppm CO; 2.5% CO2; 15.0% O2) gas mixture for 23 h per day for 70 d premating and a 14-d mating period. Impregnated dams continued exposure to gestation day 19. Adverse reproductive effects were not identified in exposed parents (P0) or first (F1) and second generation (F2) offspring during mating, gestation or parturition. No adverse changes to the estrous cycle or in reproductive hormone concentrations were identified. The exposure-related effects were reduced weight gains and adaptive up-regulation of erythropoiesis in male rats from the high-dose group. No adverse, dose-related health effects on clinical data or physiological data were observed. Neurobehavioral tests identified no apparent developmental deficits at the tested levels of exposure. In summary, subchronic exposures to the submarine atmosphere gases did not affect the ability of the exposed rats or their offspring to reproduce and did not appear to have any significant adverse health effects. PMID:25687554

  13. Carbon dioxide and methane emissions from estuaries

    OpenAIRE

    Abril, G.; Borges, Alberto

    2005-01-01

    Carbon dioxide and methane emissions from estuaries are reviewed in relationwith biogeochemical processes and carbon cycling. In estuaries, carbondioxide and methane emissions show a large spatial and temporalvariability, which results from a complex interaction of river carbon inputs,sedimentation and resuspension processes, microbial processes in watersand sediments, tidal exchanges with marshes and flats and gas exchangewith the atmosphere. The net mineralization of land-derived organic ca...

  14. Measurement of forest ecosystem-atmosphere exchange of delta-carbon-13--carbon dioxide using Fourier transform infrared spectroscopy and disjunct eddy covariance

    Science.gov (United States)

    Cambaliza, Maria Obiminda L.

    The measurement of the stable isotopic content and isotopic flux of atmospheric carbon dioxide is important for understanding the carbon budget on ecosystem, regional, and global spatial scales. Conventional measurements of the isotopic composition of atmospheric CO2 involve laboratory mass spectrometry analysis of grab samples from the field, which limits the location, collection frequency and throughput of samples. More technologically advanced methods (e.g. tunable diode laser spectroscopy) suffer from interferences with other chemical species. We have developed a new measurement method based on Fourier-transform infrared spectroscopy (FTIR) and disjunct eddy covariance (DEC) for fast, continuous, real-time measurement of the carbon isotopic composition of atmospheric CO2. Molecular absorption is measured in the 2100 to 2500 cm -1 spectral region of the 13CO2 and 12CO2 vibration-rotation bands with concentrations of both isotopologues used to determine delta13C. We demonstrate the capability of this new technique in a managed poplar forest near Boardman, Oregon with measurements during the summers of 2005 and 2006 from a 22-meter tower in a 16-m forest canopy. Long-term calibration using reference gas cylinders yielded field accuracy and precision for the forest measurements of 0.5‰ and 0.8‰, respectively, for the 45-second cycle time between samples. The signature of ecosystem respiration derived from the nighttime vertical profile measurements of CO2-delta13C was --26.6‰, about 2‰ more enriched than the isotopic composition of measured bulk leaf samples from the forest. Ecosystem respired CO 2 was ˜1.6‰ more enriched than soil-respired CO2. A comparison of the FTIR -- DEC total CO2 fluxes against standard eddy covariance measurements showed excellent (10%) agreement. FTIR-DEC measurement of the CO2 isoflux enabled the estimation of the mean carbon isotope ratio of the photosynthetic flux (deltaP). The average deltaP (-24.9‰) was 13C

  15. The exchange of carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Directory of Open Access Journals (Sweden)

    L. Kutzbach

    2007-06-01

    Full Text Available The exchange fluxes of carbon dioxide between wet arctic polygonal tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was situated in the centre of the Lena River Delta in Northern Siberia (72°22' N, 126°30' E. The study region is characterized by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The soils at the site are characterized by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The micrometeorological campaigns were performed during the periods July–October 2003 and May–July 2004 which included the period of snow and soil thaw as well as the beginning of soil refreeze. The main CO2 exchange processes, the gross photosynthesis and the ecosystem respiration, were found to be of a generally low intensity. The gross photosynthesis accumulated to –432 g m−2 over the photosynthetically active period (June–September. The contribution of mosses to the gross photosynthesis was estimated to be about 40%. The diurnal trend of the gross photosynthesis was mainly controlled by the incoming photosynthetically active radiation. During midday the photosynthetic apparatus of the canopy was frequently near saturation and represented the limiting factor on gross photosynthesis. The synoptic weather conditions strongly affected the exchange fluxes of CO2 by changes in cloudiness, precipitation and pronounced changes of air temperature. The ecosystem respiration accumulated to +327 g m−2 over the photosynthetically active period, which corresponds to 76% of the CO2 uptake by photosynthesis. However, the ecosystem respiration continued at substantial rates during autumn when photosynthesis had ceased and the soils

  16. Latitudinal and Altitudinal Distribution of Carbon Dioxide, Halocarbons, Nitrous Oxide, Methane, Carbon Monoxide and Hydroxyl in the Atmosphere

    OpenAIRE

    Kroeze, C.

    1992-01-01

    Due to human activities, atmospheric concentrations of several gases have been increasing during the past century. Some of these gases are so-called greenhouse gases and play an important role in the earth's climate. Increasing concentrations of greenhouse gases may ultimately result in global climate change. In order to investigate regional effects of the enhanced greenhouse effect, 1- to 3-dimensional computer simulation models are being developed. For the calculation of radiative transfer ...

  17. Effects of Syn-Pandemic Reforestation on Atmospheric Carbon Dioxide From 1500 to 1700 A.D.

    Science.gov (United States)

    Nevle, R. J.; Bird, D. K.

    2005-12-01

    Recent analysis of paleoclimate proxies suggests that biomass burning by humans during the past eight millennia produced quantities of CO2 sufficient to counteract the effects of decreasing insolation driven by orbital variations and thus prevented ice sheet expansion. Correlation between periods of declining population and biomass burning, such as implied by the synchroneity of the American pandemics and decreasing atmospheric CO2 concentration during the 16th-18th centuries, provides an important test of the extent to which pre-industrial anthropogenic activity affected the atmospheric greenhouse gas budget. Numerous studies have attributed the ~5 ppm decline of atmospheric CO2 concentration, as well as the synchronous ~0.1 per mil increase of the δ13C of atmospheric CO2 between 1500 and 1700 A.D., to the effects of Little Ice Age cooling. However, this interpretation is not supported by recent multiproxy-based surface temperature reconstructions, which demonstrate a diminutive global temperature anomaly of ~0.1 C that was unlikely to have independently produced the distinct effect observed in atmospheric CO2 concentration. Alternatively, it is possible that a decline in CO2 concentration driven by massive reforestation produced cooling as a by-product. The timing and magnitude of changes in both the concentration and carbon-isotope composition of atmospheric CO2 recorded by globally distributed climate proxies from the tropics (sponges), temperate latitudes (tree rings), and polar regions (ice cores) are compatible with fixation of >10 Gt C due to reforestation. Reforestation, which explains pre-industrial atmospheric CO2 variations between 1500 and 1700 A.D. in a manner more consistent with the global surface temperature record than explanations requiring substantial cooling, presumably occurred on lands that were cultivated and seasonally burned, then subsequently abandoned, by indigenous Americans who perished in pandemics during European conquest. The

  18. Carbon Dioxide Embolism during Laparoscopic Surgery

    OpenAIRE

    Park, Eun Young; Kwon, Ja-Young; Kim, Ki Jun

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ra...

  19. Carbon Dioxide and Global Warming: A Failed Experiment

    Science.gov (United States)

    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…

  20. Carbon dioxide emission during forest fires ignited by lightning

    OpenAIRE

    Pelc, Magdalena; Osuch, Radoslaw

    2009-01-01

    In this paper we developed the model for the carbon dioxide emission from forest fire. The master equation for the spreading of the carbon dioxide to atmosphere is the hyperbolic diffusion equation. In the paper we study forest fire ignited by lightning. In that case the fores fire has the well defined front which propagates with finite velocity.

  1. Interglacials, Milankovitch Cycles, Solar Activity, and Carbon Dioxide

    OpenAIRE

    Marsh, Gerald E.

    2014-01-01

    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.

  2. Enhanced research program on the long-range climatic effects of increased atmospheric carbon dioxide and sulfate aerosols. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Washington, W.M.; Meehl, G.A.

    1997-04-01

    Consistent with the objectives to extract as much as possible from existing models on the role of the oceans in the greenhouse effect and to improve various aspects of the coupled system, the authors made significant progress in three areas. (1) In a series of manuscripts, they documented how the El Nino-Southern Oscillation operates in the model and how it is enhanced with increased carbon dioxide. (2) In studies with collaborators Branstator, Karoly, and Karl, they explored the possible carbon dioxide ``fingerprint`` in zonal mean temperatures, the effects of changes in extratropical teleconnections, and the regional effects of low-frequency variability and climate change. (3) They experimented with an advanced version of the NCAR community climate model (CCM0) that also includes the Ramanathan and Collins cirrus albedo feedback mechanism. This model was run with a mixed layer and was tested with the 1{degree} 20-level Semtner and Chervin ocean model. The latter includes the Arctic Ocean and dynamic sea ice, both showing realistic results. The authors completed the coupling of the advanced models. The dynamic ocean model was a 1{degree}x1{degree} version of the Semtner-Chervin 1/2{degree}x1/2{degree} ocean model with 20 vertical levels. The 1{degree}x1{degree} version of the Semtner-Chervin model used in this research explicitly resolved some aspects of the mesoscale eddies as did the parent model. The new coupled model system for greenhouse gas simulations on climate change was tested on multidecadal runs.

  3. Solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon, and carbon monoxide in 1-butyl-3-methylimidazolium tetrafluoroborate between temperatures 283 K and 343 K and at pressures close to atmospheric

    International Nuclear Information System (INIS)

    Experimental values for the solubility of carbon dioxide, ethane, methane, oxygen, nitrogen, hydrogen, argon and carbon monoxide in 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4] - a room temperature ionic liquid - are reported as a function of temperature between 283 K and 343 K and at pressures close to atmospheric. Carbon dioxide is the most soluble gas with mole fraction solubilities of the order of 10-2. Ethane and methane are one order of magnitude more soluble than the other five gases that have mole fraction solubilities of the order of 10-4. Hydrogen is the less soluble of the gaseous solutes studied. From the variation of solubility, expressed as Henry's law constants, with temperature, the partial molar thermodynamic functions of solvation such as the standard Gibbs energy, the enthalpy, and the entropy are calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations is of 1%

  4. Reconciliation of Carbon Dioxide Flux Estimates from Atmospheric Inversions and Inventories in the Mid-Continent Intensive

    Science.gov (United States)

    Breidt, F. J.; Cooley, D. S.; Thurier, Q.; Wang, Y.; Schuh, A. E.; Denning, A.; Davis, K. J.; West, T. O.; Ogle, S. M.

    2009-12-01

    Atmospheric inversions and inventories provide two distinct data sources for describing regional carbon budgets in the Mid-Continent Intensive (MCI) study of the North American Carbon Program (NACP). Inversions rely on temporally rich CO2 concentration measurements to infer fluxes between the terrestrial surface and atmosphere. Since towers from which concentration measurements are obtained are sparsely distributed on the landscape, inversion data tend to be temporally rich and spatially poor. Inventories are typically conducted using models for which the inputs are driving variables that influence uptake and release of CO2 from the terrestrial surface, and the outputs are predicted changes in C pools, or CO2 fluxes directly. In contrast to inversions, the inventory data tend to be spatially rich and temporally poor. A statistical methodology based on a state-space model and the Kalman recursions is proposed to combine the inversion and inventory data for optimal estimation of CO2 fluxes. The methodology trades off the strengths and weaknesses of the two data streams. This synthesis activity provides the most rigorous estimates of CO2 flux for the MCI, along with estimated uncertainties. In particular, it identifies portions of the region and time series, as well as sources and C pools, with the largest uncertainties.

  5. Quantifying biological and atmospheric processes with in-situ measurements of carbon dioxide and water vapor isotopes (Invited)

    Science.gov (United States)

    Lee, X.

    2010-12-01

    The ability to make real-time, high-frequency measurements of CO2 and H2O isotopes in the atmosphere opens a new channel of scientific pursuit. The objectives of this paper are (1) to examine practical issues on using these measurements in biospheric and atmospheric research, and (2) to compare two different perspectives on isotopic surface-air fluxes. From the user’s perspective, three issues should be resolved in order to further realize the power of these in-situ measurements. The first one is related to instrument calibration. By their nature, isotopologue measurements by optical methods are prone to biases from nonlinear concentration dependence. Overcoming the nonlinear effect via calibration is important for the measurement of the isotopic abundance of CO2 or H2O and even more so for the measurement of the isotopic signal of their fluxes. Further, a portable calibration system is essential for deployment in remote sites. The second challenge that researchers face is instrument cost. We envision the development of a new flux network with real-time observations of isotopic fluxes of CO2 and H2O to help diagnose changes in atmospheric and biospheric processes. This can become a realistic goal if the instrument cost is brought down to a level comparable to that of broadband infrared analyzers. Third, speed of detection also deserves attention. In-situ measurements of CO2 and H2O isotope ratios in ambient air, especially if made on a long-term basis and calibrated precisely, can aid atmospheric inverse analysis of land carbon sink and the tracking of water transport in the atmosphere. Ambient monitoring alone is however not very useful in ecological studies. To measure the source/sink signature properly, one should interface the isotopic analyzer with a plant or soil chamber, deploy it in the gradient-diffusion mode either over a plant canopy or over the soil surface inside the canopy, or combine it with a sonic anemometer for direct eddy covariance measurement

  6. Seawater pH and Anthropogenic Carbon Dioxide

    CERN Document Server

    Marsh, Gerald E

    2008-01-01

    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.

  7. The effect of atmospheric carbon dioxide concentrations on the performance of the mangrove Avicennia germinans over a range of salinities.

    Science.gov (United States)

    Reef, Ruth; Winter, Klaus; Morales, Jorge; Adame, Maria Fernanda; Reef, Dana L; Lovelock, Catherine E

    2015-07-01

    By increasing water use efficiency and carbon assimilation, increasing atmospheric CO2 concentrations could potentially improve plant productivity and growth at high salinities. To assess the effect of elevated CO2 on the salinity response of a woody halophyte, we grew seedlings of the mangrove Avicennia germinans under a combination of five salinity treatments [from 5 to 65 parts per thousand (ppt)] and three CO2 concentrations (280, 400 and 800 ppm). We measured survivorship, growth rate, photosynthetic gas exchange, root architecture and foliar nutrient and ion concentrations. The salinity optima for growth shifted higher with increasing concentrations of CO2 , from 0 ppt at 280 ppm to 35 ppt at 800 ppm. At optimal salinity conditions, carbon assimilation rates were significantly higher under elevated CO2 concentrations. However, at salinities above the salinity optima, salinity had an expected negative effect on mangrove growth and carbon assimilation, which was not alleviated by elevated CO2 , despite a significant improvement in photosynthetic water use efficiency. This is likely due to non-stomatal limitations to growth at high salinities, as indicated by our measurements of foliar ion concentrations that show a displacement of K(+) by Na(+) at elevated salinities that is not affected by CO2 . The observed shift in the optimal salinity for growth with increasing CO2 concentrations changes the fundamental niche of this species and could have significant effects on future mangrove distribution patterns and interspecific interactions. PMID:25263409

  8. Active carbon-pools in rhizosphere of wheat (Triticum aestivum L.) grown under elevated atmospheric carbon dioxide concentration in a Typic Haplustept in sub-tropical India

    International Nuclear Information System (INIS)

    Study on active and labile carbon-pools can serve as a clue for soil organic carbon dynamics on exposure to elevated level of CO2. Therefore, an experimental study was conducted in a Typic Haplustept in sub-tropical semi-arid India with wheat grown in open top chambers at ambient (370 μmol mol-1) and elevated (600 μmol mol-1) concentrations of atmospheric CO2. Elevated atmospheric CO2 caused increase in yield and carbon uptake by all plant parts, and their preferential partitioning to root. Increases in fresh root weight, volume and length have also been observed. Relative contribution of medium-sized root to total root length increased at the expense of very fine roots at elevated CO2 level. All active carbon-fractions gained due to elevated atmospheric CO2 concentration, and the order followed their relative labilities. All the C-pools have recorded a significant increase over initial status, and are expected to impart short-to-medium-term effect on soil carbon sequestration. - The elevation in atmospheric CO2 concentration can potentially increase the active carbon-pools in wheat rhizosphere in the semi-arid India

  9. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-03-01

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

  10. Carbon dioxide transport over complex terrain

    OpenAIRE

    Sun, RC

    2004-01-01

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

  11. Perspectives in the use of carbon dioxide

    OpenAIRE

    1999-01-01

    The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the...

  12. Modelling Sublimation of Carbon Dioxide

    Science.gov (United States)

    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…

  13. A high resolution record of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the glacial inception

    Directory of Open Access Journals (Sweden)

    R. Schneider

    2013-04-01

    Full Text Available The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (δ13Catm, as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a highly resolved record of δ13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 yr BP. The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC and the Talos Dome ice cores in East Antarctica. We find an 0.4‰ offset between the mean δ13Catm level in the Penultimate (~140 000 yr BP and Last Glacial Maximum (~22 000 yr BP, which can be explained by either (i changes in the isotopic composition or (ii intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 yr, but with different phasing and magnitudes. Furthermore, a 5000 yr lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS 5.5 (120 000 yr BP. Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

  14. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  15. A reconstruction of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the last glacial inception

    Directory of Open Access Journals (Sweden)

    R. Schneider

    2013-11-01

    δ13Catm level in the Penultimate (~ 140 000 yr BP and Last Glacial Maximum (~ 22 000 yr BP, which can be explained by either (i changes in the isotopic composition or (ii intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 yr, but with different phasing and magnitudes. Furthermore, a 5000 yr lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS5.5 (120 000 yr BP. Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

  16. New technology for carbon dioxide at high pressure

    International Nuclear Information System (INIS)

    Carbon dioxide has long been the nemesis of environmentalists because of its role in global warming, but under just the right conditions-namely, high pressure and high temperature its one of nature's best and most environmentally benign solvents. Decaf-coffee lovers, for instance, benefit from its ability to remove caffeine from coffee beans.During the last few years, carbon dioxide has also made inroads in the dry-cleaning industry, providing a safe cleaning alternative to the chemical perchloroethylene. But it's on the high-tech front that carbon dioxide may make its biggest impact. There are huge opportunities. Scientists have known for more than a century that at 75 times atmospheric pressure and 31 degree centigrade, carbon dioxide goes into and odd state that chemists called supercritical. What's interesting to industry is that supercritical carbon dioxide may be an enabling technology for going to smaller dimensions.(Author)

  17. The oxygen and carbon dioxide compensation points of C3 plants: possible role in regulating atmospheric oxygen.

    Science.gov (United States)

    Tolbert, N E; Benker, C; Beck, E

    1995-11-21

    The O2 and CO2 compensation points (O2 and CO2) of plants in a closed system depend on the ratio of CO2 and O2 concentrations in air and in the chloroplast and the specificities of ribulose bisphosphate carboxylase/oxygenase (Rubisco). The photosynthetic O2 is defined as the atmospheric O2 level, with a given CO2 level and temperature, at which net O2 exchange is zero. In experiments with C3 plants, the O2 with 220 ppm CO2 is 23% O2; O2 increases to 27% with 350 ppm CO2 and to 35% O2 with 700 ppm CO2. At O2 levels below the O2, CO2 uptake and reduction are accompanied by net O2 evolution. At O2 levels above the O2, net O2 uptake occurs with a reduced rate of CO2 fixation, more carbohydrates are oxidized by photorespiration to products of the C2 oxidative photosynthetic carbon cycle, and plants senesce prematurely. The CO2 increases from 50 ppm CO2 with 21% O2 to 220 ppm with 100% O2. At a low CO2/high O2 ratio that inhibits the carboxylase activity of Rubisco, much malate accumulates, which suggests that the oxygen-insensitive phosphoenolpyruvate carboxylase becomes a significant component of the lower CO2 fixation rate. Because of low global levels of CO2 and a Rubisco specificity that favors the carboxylase activity, relatively rapid changes in the atmospheric CO2 level should control the permissive O2 that could lead to slow changes in the immense O2 pool. PMID:11607591

  18. Turning carbon dioxide into fuel.

    Science.gov (United States)

    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

  19. Reproducing early Martian atmospheric carbon dioxide partial pressure by modeling the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops on Mars

    Science.gov (United States)

    Berk, Wolfgang; Fu, Yunjiao; Ilger, Jan-Michael

    2012-10-01

    The well defined composition of the Comanche rock's carbonate (Magnesite0.62Siderite0.25Calcite0.11Rhodochrosite0.02) and its host rock's composition, dominated by Mg-rich olivine, enable us to reproduce the atmospheric CO2partial pressure that may have triggered the formation of these carbonates. Hydrogeochemical one-dimensional transport modeling reveals that similar aqueous rock alteration conditions (including CO2partial pressure) may have led to the formation of Mg-Fe-Ca carbonate identified in the Comanche rock outcrops (Gusev Crater) and also in the ultramafic rocks exposed in the Nili Fossae region. Hydrogeochemical conditions enabling the formation of Mg-rich solid solution carbonate result from equilibrium species distributions involving (1) ultramafic rocks (ca. 32 wt% olivine; Fo0.72Fa0.28), (2) pure water, and (3) CO2partial pressures of ca. 0.5 to 2.0 bar at water-to-rock ratios of ca. 500 molH2O mol-1rock and ca. 5°C (278 K). Our modeled carbonate composition (Magnesite0.64Siderite0.28Calcite0.08) matches the measured composition of carbonates preserved in the Comanche rocks. Considerably different carbonate compositions are achieved at (1) higher temperature (85°C), (2) water-to-rock ratios considerably higher and lower than 500 mol mol-1 and (3) CO2partial pressures differing from 1.0 bar in the model set up. The Comanche rocks, hosting the carbonate, may have been subjected to long-lasting (>104 to 105 years) aqueous alteration processes triggered by atmospheric CO2partial pressures of ca. 1.0 bar at low temperature. Their outcrop may represent a fragment of the upper layers of an altered olivine-rich rock column, which is characterized by newly formed Mg-Fe-Ca solid solution carbonate, and phyllosilicate-rich alteration assemblages within deeper (unexposed) units.

  20. Six-year record of atmospheric carbon dioxide and methane at a high-altitude mountain site in Poland

    International Nuclear Information System (INIS)

    Carbon dioxide and methane observations from the continental mountain station Kasprowy Wierch in the Tatra Mountains, southern Poland, are presented. They cover a six-year period from 1994 to 2000. Significant year-to-year variability of CO2 concentration was observed. The seasonal cycles 1996-1997 were similar, with a peak-to-peak amplitude of the selected and smoothed CO2 record of approximately 20 ppm and no significant increase of the annual mean values. For 1998 and 1999 large increases of the annual mean values by 3.3 and 4.0 ppm per year, respectively, were observed. This increase was accompanied by a reduction of the seasonal amplitude of the smoothed record to approximately 15 ppm in 1998 and 16 ppm in 1999. In 2000 the seasonal amplitude increased again to a value similar as in 1996/1997, whereas the mean annual value remained close to that recorded for 1999. Similar features can also be traced in the selected and smoothed CO2 record for Schauinsland station, Germany, located ca. 1000 km west of Kasprowy Wierch. These similarities strongly suggest that both stations are capturing the same large-scale European phenomena, most probably related to a disturbance of the CO2 cycle by the recent El Nino event. The mean CH4 mixing ratio at Kasprowy Wierch for the period 1996-1999 was about 30 ppb higher than over the Atlantic Ocean, confirming previous observations that the European continent is a net source of methane throughout the year. No significant seasonal cycle of methane has been observed at Kasprowy Wierch. The short-term changes of CO2 and CH4 are strongly correlated during winter months: the average monthly mean slope of the linear relationship between CH4 and CO2 was 10.7 ± 0.3 ppbCH4 per ppmCO2. During summer months this strong correlation breaks down. Diurnal changes of CO2 and CH4 mixing ratios observed at Kasprowy Wierch are typical for continental mountain sites, with a distinct minimum of CO2 during afternoon hours in summer and maximum during

  1. Recycling technology of emitted carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hironori [National Inst. of Materials and Chemical Research (NIMC), Ibaraki (Japan)

    1993-12-31

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

  2. Sequestering ADM ethanol plant carbon dioxide

    Science.gov (United States)

    Finley, R.J.; Riddle, D.

    2008-01-01

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

  3. Perspectives in the use of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Aresta Michele

    1999-01-01

    Full Text Available The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

  4. Soil-atmosphere exchange of nitrous oxide, methane and carbon dioxide in a gradient of elevation in the coastal Brazilian Atlantic forest

    Science.gov (United States)

    Sousa Neto, E.; Carmo, J. B.; Keller, M.; Martins, S. C.; Alves, L. F.; Vieira, S. A.; Piccolo, M. C.; Camargo, P.; Couto, H. T. Z.; Joly, C. A.; Martinelli, L. A.

    2011-03-01

    Soils of tropical forests are important to the global budgets of greenhouse gases. The Brazilian Atlantic Forest is the second largest tropical moist forest area of South America, after the vast Amazonian domain. This study aimed to investigate the emissions of nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) fluxes along an altitudinal transect and the relation between these fluxes and other climatic, edaphic and biological variables (temperature, fine roots, litterfall, and soil moisture). Annual means of N2O flux were 3.9 (± 0.4), 1.0 (± 0.1), and 0.9 (± 0.2) ng N cm-2 h-1 at altitudes 100, 400, and 1000 m, respectively. On an annual basis, soils consumed CH4 at all altitudes with annual means of -1.0 (± 0.2), -1.8 (± 0.3), and -1.6 (± 0.1) mg m-2 d-1 at 100 m, 400 m and 1000 m, respectively. Estimated mean annual fluxes of CO2 were 3.5, 3.6, and 3.4 μmol m-2 s-1 at altitudes 100, 400 and 1000 m, respectively. N2O fluxes were significantly influenced by soil moisture and temperature. Soil-atmosphere exchange of CH4 responded to changes in soil moisture. Carbon dioxide emissions were strongly influenced by soil temperature. While the temperature gradient observed at our sites is only an imperfect proxy for climatic warming, our results suggest that an increase in air and soil temperatures may result in increases in decomposition rates and gross inorganic nitrogen fluxes that could support consequent increases in soil N2O and CO2 emissions and soil CH4 consumption.

  5. Inter-annual variability of the atmospheric carbon dioxide concentrations as simulated with global terrestrial biosphere models and an atmospheric transport model

    International Nuclear Information System (INIS)

    Seasonal and inter-annual variations of atmospheric CO2 for the period from 1961 to 1997 have been simulated using a global tracer transport model driven by a new version of the Biome BioGeochemical Cycle model (Biome-BGC). Biome-BGC was forced by daily temperature and precipitation from the NCEP reanalysis dataset, and the calculated monthly-averaged CO2 fluxes were used as input to the global transport model. Results from an inter-comparison with the Carnegie-Ames-Stanford Approach model (CASA) and the Simulation model of Carbon CYCLE in Land Ecosystems (Sim-CYCLE) model are also reported. The phase of the seasonal cycle in the Northern Hemisphere was reproduced generally well by Biome-BGC, although the amplitude was smaller compared to the observations and to the other biosphere models. The CO2 time series simulated by Biome-BGC were compared to the global CO2 concentration anomalies from the observations at Mauna Loa and the South Pole. The modeled concentration anomalies matched the phase of the inter-annual variations in the atmospheric CO2 observations; however, the modeled amplitude was lower than the observed value in several cases. The result suggests that a significant part of the inter-annual variability in the global carbon cycle can be accounted for by the terrestrial biosphere models. Simulations performed with another climate-based model, Sim-CYCLE, produced a larger amplitude of inter-annual variability in atmospheric CO2, making the amplitude closer to the observed range, but with a more visible phase mismatch in a number of time periods. This may indicate the need to increase the Biome-BGC model sensitivity to seasonal and inter-annual changes in temperature and precipitation

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

    Science.gov (United States)

    Pagano, Thomas S.; Olsen, Edward T.

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Simultaneous and Independent Measurement of Atmospheric Water Vapor and Carbon Dioxide using a Triple-Pulsed, 2-micron Airborne IPDA Lidar - A Feasibility Study

    Science.gov (United States)

    Singh, U. N.; Refaat, T. F.; Yu, J.; Petros, M.

    2013-12-01

    Water vapor (H2O) and carbon dioxide (CO2) are dominant greenhouse gases that are critical for Earth's radiation budget and global warming through the eco-system and the carbon cycle. NASA Langley Research Center (LaRC) has a strong heritage in atmospheric remote sensing of both gases using several instruments adopting various DIAL techniques. This communication presents a feasibility study for measuring both H2O and CO2 simultaneously and independently using a single instrument. This instrument utilizes the Integrated Path Differential Absorption (IPDA) lidar technique to measure the weighted-average column dry-air mixing ratios of CO2 (XCO2) and H2O (XH2O) independently and simultaneously from an airborne platform. The key component of this instrument is a tunable triple-pulse 2-micron laser. The three laser pulses are transmitted sequentially within a short time interval of 200 microsec. The wavelength of each of the laser pulses can be tuned separately. The IPDA receiver design is based on low-risk, commercially available components, including 300-micron diameter InGaAs 2-micron pin detector, a low-noise, high speed trans-impedance amplifier (TIA) and 12-bit 400 MHz digitizer.

  9. Amazon river carbon dioxide outgassing fuelled by wetlands

    OpenAIRE

    Abril, G.; Martinez, J M; Artigas, L.F.; Moreira-Turcq, P.; Benedetti, M. F.; Vidal, L.; Meziane, T.; Kim, J. -H.; Bernardes, M. C.; Savoye, N.; Deborde, J; Souza, E.L.; Alberic, P; de Souza, M.F.L.; Roland, F.

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle(1). A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems(2). It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream ...

  10. Energy and carbon dioxide implications of building construction

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, A.H. (Canterbury Univ., Christchurch (New Zealand)); Honey, B.G. (Canterbury Univ., Christchurch (New Zealand))

    1994-01-01

    This paper investigates the amount of energy required to construct buildings, and the resulting carbon dioxide emissions to the atmosphere from the fossil fuel components of that energy. Energy requirements and carbon dioxide emissions are compared for typical commercial, industrial and residential buildings, using New Zealand as an example. A modest change from concrete and steel to more wood construction could lead to a substantial reduction in energy requirements and carbon dioxide emissions, but the sustainability of such a change has significant forestry implications. (orig.)

  11. Pan-Arctic land–atmospheric fluxes of methane and carbon dioxide in response to climate change over the 21st century

    International Nuclear Information System (INIS)

    Future changes of pan-Arctic land–atmospheric methane (CH4) and carbon dioxide (CO2) depend on how terrestrial ecosystems respond to warming climate. Here, we used a coupled hydrology–biogeochemistry model to make our estimates of these carbon exchanges with two contrasting climate change scenarios (no-policy versus policy) over the 21st century, by considering (1) a detailed water table dynamics and (2) a permafrost-thawing effect. Our simulations indicate that, under present climate conditions, pan-Arctic terrestrial ecosystems act as a net greenhouse gas (GHG) sink of −0.2 Pg CO2-eq. yr−1, as a result of a CH4 source (53 Tg CH4 yr−1) and a CO2 sink (−0.4 Pg C yr−1). In response to warming climate, both CH4 emissions and CO2 uptakes are projected to increase over the century, but the increasing rates largely depend on the climate change scenario. Under the non-policy scenario, the CH4 source and CO2 sink are projected to increase by 60% and 75% by 2100, respectively, while the GHG sink does not show a significant trend. Thawing permafrost has a small effect on GHG sink under the policy scenario; however, under the no-policy scenario, about two thirds of the accumulated GHG sink over the 21st century has been offset by the carbon losses as CH4 and CO2 from thawing permafrost. Over the century, nearly all CO2-induced GHG sink through photosynthesis has been undone by CH4-induced GHG source. This study indicates that increasing active layer depth significantly affects soil carbon decomposition in response to future climate change. The methane emissions considering more detailed water table dynamics continuously play an important role in affecting regional radiative forcing in the pan-Arctic. (letter)

  12. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

    Florio, J.T.; Mackenzie, D.A.R.; McKenzie, R.S. [ARE Physiological Laboratory, Gosport (United Kingdom)

    1998-04-01

    This report summarises the work carried out at the ARE Physiological Laboratory (ARE(PL)) between July 1978 and December 1983. The work was intended to examine the proposition that some divers have a low ventilatory response to carbon dioxide; that this results in a low ventilatory response to exercise with consequent hypercapnia; and that these characteristics put the diver at a greater-than-normal risk by increasing the individual`s susceptibility to oxygen toxicity and to other hazards associated with diving (e.g. nitrogen narcosis, decompression sickness and hypothermia). The specific aims of the project can be summarised as follows: (a) to demonstrate the existence of divers who exhibit the tendency to `retain carbon dioxide` when working in hyperbaric conditions; (b) to define the circumstances under which such individuals are at risk; (c) to assess the magnitude of the risk; and (d) to recommend ways to eliminate or to reduce the risk. (author)

  13. Method for carbon dioxide sequestration

    Science.gov (United States)

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

    2015-09-22

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

  14. Oxygen and carbon dioxide sensing

    Science.gov (United States)

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

    2012-01-01

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

  15. The contribution of terrestrial sources and sinks to trends in the seasonal cycle of atmospheric carbon dioxide

    OpenAIRE

    Randerson, JT; Thompson, MV; Conway, TJ; Fung, IY; Field, CB

    1997-01-01

    © 1997 by the American Geophysical Union. We characterized decadal changes in the amplitude and shape of the seasonal cycle of atmospheric CO2 with three kinds of analysis. First, we calculated the trends in the seasonal cycle of measured atmospheric CO2 at observation stations in the National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostic Laboratory network. Second, we assessed the impact of terrestrial ecosystems in various localities on the mean seasonal cycle of ...

  16. Ocean uptake of carbon dioxide

    International Nuclear Information System (INIS)

    Factors controlling the capacity of the ocean for taking up anthropogenic C02 include carbon chemistry, distribution of alkalinity, pCO2 and total concentration of dissolved C02, sea-air pCO2 difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C02 uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C02 from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C02 fertilization is a potential candidate for such missing carbon sinks

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

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Thomas Nelson; Brian S. Turk; Paul Box; Weijiong Li; Raghubir P. Gupta

    2005-07-01

    This report describes research conducted between April 1, 2005 and June 30, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas from coal combustion and synthesis gas from coal gasification. Supported sodium carbonate sorbents removed up to 76% of the carbon dioxide from simulated flue gas in a downflow cocurrent flow reactor system, with an approximate 15 second gas-solid contact time. This reaction proceeds at temperatures as low as 25 C. Lithium silicate sorbents remove carbon dioxide from high temperature simulated flue gas and simulated synthesis gas. Both sorbent types can be thermally regenerated and reused. The lithium silicate sorbent was tested in a thermogravimetric analyzer and in a 1-in quartz reactor at atmospheric pressure; tests were also conducted at elevated pressure in a 2-in diameter high temperature high pressure reactor system. The lithium sorbent reacts rapidly with carbon dioxide in flue gas at 350-500 C to absorb about 10% of the sorbent weight, then continues to react at a lower rate. The sorbent can be essentially completely regenerated at temperatures above 600 C and reused. In atmospheric pressure tests with synthesis gas of 10% initial carbon dioxide content, the sorbent removed over 90% of the carbon dioxide. An economic analysis of a downflow absorption process for removal of carbon dioxide from flue gas with a supported sodium carbonate sorbent suggests that a 90% efficient carbon dioxide capture system installed at a 500 MW{sub e} generating plant would have an incremental capital cost of $35 million ($91/kWe, assuming 20 percent for contingencies) and an operating cost of $0.0046/kWh. Assuming capital costs of $1,000/kW for a 500 MWe plant the capital cost of the down flow absorption process represents a less than 10% increase, thus meeting DOE goals as set forth in its Carbon Sequestration Technology Roadmap and Program Plan.

  18. Carbon dioxide and the radiation budget

    International Nuclear Information System (INIS)

    This chapter addresses the radiative forcing of the Earth-atmosphere system caused by an increase in carbon dioxide (CO2) levels that can lead to climate change. The importance of the Earth's radiation budget is described, and the radiative properties of CO2 and other radiatively important gases are presented. Methods of computing gaseous absorption and their accuracy are discussed. Components of the radiation budget (solar and longwave) are described along with the effect of variations in CO2 concentration. Because aerosols and clouds also have important radiative properties, the effects of changes in aerosol and cloud amounts are also discussed. The purpose of this chapter is to provide an overview of the radiative effects of CO2 and other atmospheric constituents that are important in determining the potential climatic effects of changes in atmospheric composition

  19. The carbon dioxide capture and geological storage

    International Nuclear Information System (INIS)

    This road-map proposes by the Group Total aims to inform the public on the carbon dioxide capture and geological storage. One possible means of climate change mitigation consists of storing the CO2 generated by the greenhouse gases emission in order to stabilize atmospheric concentrations. This sheet presents the CO2 capture from lage fossil-fueled combustion installations, the three capture techniques and the CO2 transport options, the geological storage of the CO2 and Total commitments in the domain. (A.L.B.)

  20. Nuclear energy significantly reduces carbon dioxide emissions

    International Nuclear Information System (INIS)

    This article is devoted to nuclear energy, to its acceptability, compatibility and sustainability. Nuclear energy is non-dispensable part of energy sources with vast innovation potential. The safety of nuclear energy, radioactive waste deposition, and prevention of risk from misuse of nuclear material have to be very seriously adjudged and solved. Nuclear energy is one of the ways how to decrease the contamination of atmosphere with carbon dioxide and it solves partially also the problem of global increase of temperature and climate changes. Given are the main factors responsible for the renaissance of nuclear energy. (author)

  1. A preliminary assessment of carbon dioxide mitigation options

    International Nuclear Information System (INIS)

    The purpose of this paper is to place the potential needs to control global carbon dioxide emissions in perspective. In order to limit carbon dioxide levels in the earth's atmosphere to no more than twice pre- anthropogenic levels, it will be necessary to limit carbon emissions to approximately 10 gigatons per year by 2050. The implications of such a constraint to the developed countries, developing countries, and international community are assessed. It is clear that international priorities must be established and specific approaches developed in the first quarter of the 21st century to define the necessary, minimum- cost mitigation strategies. Because of the complexity of establishing a meaningful policy approach, imposition of an arbitrary carbon tax is unlikely to provide the constraints necessary to achieve a satisfactory earth atmosphere - carbon dioxide equilibrium state

  2. Trends in carbon isotope fractionation in atmospheric carbon dioxide constrain water use efficiency of northern ecosystems from the 1980s to 2010

    Science.gov (United States)

    Welp, L. R.; Piper, S. C.; Graven, H. D.; Bollenbacher, A.; Meijer, H. A.; Keeling, R. F.

    2013-12-01

    Atmospheric CO2 concentrations have increased by approximately 120 ppm since preindustrial times and have reached levels higher than any other time during the last three to five million years ago with uncertain consequences for the modern terrestrial biosphere. When plants take up CO2 for photosynthesis from the atmosphere through stomata openings in their leaves, water escapes due to the gradient in water vapor pressure from the leaf interior to the atmospheric boundary layer. The amount of carbon assimilated by photosynthesis per water lost determines the water use efficiency (WUE) of the plant. The extra CO2 in the atmosphere has been shown to increase WUE in growth chamber studies, allowing plants to take up the same or more CO2 with reduced stomatal conductance, thereby reducing water loss. Carbon isotope fractionation by plants is related to the CO2 concentration gradient from inside the leaf (Ci) to that in the atmosphere (Ca) (e.g. Farquhar model). Therefore intrinsic water use efficiency (iWUE) of the biosphere, defined as the amount of net photosynthesis divided by the stomatal conductance, leaves an imprint on the record of δ13C in atmospheric CO2. We will present estimates of the biological carbon isotope fractionation of atmospheric CO2 from the Scripps Institution of Oceanography flask network from the 1980s to 2010 and discuss the constraints it provides on trends in iWUE over this period. Using the seasonal co-variation of 13C and CO2, we calculate effective fractionation. This data can be used to test hypothetical trends in iWUE and Ci. The conventional wisdom in the field has been that the ratio of Ci/Ca would remain approximately constant as CO2 rises, which would result in no change in fractionation but a modest increase in iWUE. Keenan et al. (2013) recently published an analysis of FluxNet eddy covariance measurements suggesting that Ci has stayed nearly constant since the mid-1990s, translating to a large ~3% yr-1 increase in i

  3. Climate response to changes in atmospheric carbon dioxide and solar irradiance on the time scale of days to weeks

    International Nuclear Information System (INIS)

    Recent studies show that fast climate response on time scales of less than a month can have important implications for long-term climate change. In this study, we investigate climate response on the time scale of days to weeks to a step-function quadrupling of atmospheric CO2 and contrast this with the response to a 4% increase in solar irradiance. Our simulations show that significant climate effects occur within days of a stepwise increase in both atmospheric CO2 content and solar irradiance. Over ocean, increased atmospheric CO2 warms the lower troposphere more than the surface, increasing atmospheric stability, moistening the boundary layer, and suppressing evaporation and precipitation. In contrast, over ocean, increased solar irradiance warms the lower troposphere to a much lesser extent, causing a much smaller change in evaporation and precipitation. Over land, both increased CO2 and increased solar irradiance cause rapid surface warming that tends to increase both evaporation and precipitation. However, the physiological effect of increased atmospheric CO2 on plant stomata reduces plant transpiration, drying the boundary layer and decreasing precipitation. This effect does not occur with increased solar irradiance. Therefore, differences in climatic effects from CO2 versus solar forcing are manifested within days after the forcing is imposed. (letter)

  4. Climate response to changes in atmospheric carbon dioxide and solar irradiance on the time scale of days to weeks

    Science.gov (United States)

    Cao, Long; Bala, Govindasamy; Caldeira, Ken

    2012-09-01

    Recent studies show that fast climate response on time scales of less than a month can have important implications for long-term climate change. In this study, we investigate climate response on the time scale of days to weeks to a step-function quadrupling of atmospheric CO2 and contrast this with the response to a 4% increase in solar irradiance. Our simulations show that significant climate effects occur within days of a stepwise increase in both atmospheric CO2 content and solar irradiance. Over ocean, increased atmospheric CO2 warms the lower troposphere more than the surface, increasing atmospheric stability, moistening the boundary layer, and suppressing evaporation and precipitation. In contrast, over ocean, increased solar irradiance warms the lower troposphere to a much lesser extent, causing a much smaller change in evaporation and precipitation. Over land, both increased CO2 and increased solar irradiance cause rapid surface warming that tends to increase both evaporation and precipitation. However, the physiological effect of increased atmospheric CO2 on plant stomata reduces plant transpiration, drying the boundary layer and decreasing precipitation. This effect does not occur with increased solar irradiance. Therefore, differences in climatic effects from CO2 versus solar forcing are manifested within days after the forcing is imposed.

  5. Absorption of carbon dioxide in waste tanks

    International Nuclear Information System (INIS)

    Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

  6. Uncertainty analysis for the miniaturized laser heterodyne radiometer (mini-LHR) for the measurement of carbon dioxide in the atmospheric column

    International Nuclear Information System (INIS)

    Presented here is a sensitivity analysis for the miniaturized laser heterodyne radiometer. This passive, ground-based instrument measures carbon dioxide (CO2) in the atmospheric column and has been under development at NASA/GSFC since 2009. The goal of this development is to produce a low-cost, easily-deployable instrument that can extend current ground measurement networks in order to (1) validate column satellite observations, (2) provide coverage in regions of limited satellite observations, (3) target regions of interest such as thawing permafrost, and (4) support the continuity of a long-term climate record. In this paper an uncertainty analysis of the instrument performance is presented and compared with results from three sets of field measurements. The signal-to-noise ratio (SNR) and corresponding maximum uncertainty for a single scan are calculated to be 329.4 ± 1.3 by deploying error propagation through the equation governing the SNR. Reported is an absorbance noise of 0.0024 for six averaged scans of field data, for an instrument precision of 0.14 ppmv for CO2. (paper)

  7. Reconstructing sea surface temperature, sea surface salinity and partial pressure of carbon dioxide in atmosphere in the Okinawa Trough during the Holocene and their paleoclimatic implications

    Institute of Scientific and Technical Information of China (English)

    MENGXianwei; LIUYanguang; LlUZhenxia; DUDewen; HUANGQiyu; Y.Saito

    2003-01-01

    The sediment core DGKS9603 collected from the Okinawa Trough was used as research target. By use of unsaturated index U37k of long-chain alkenone, δ13C of POC and of planktonic foraminifera (G sacculifer), the evolutions of sea surface temperature and partial pressure of carbon dioxide in the atmosphere during the Holocene were reconstructed in the Okinawa Trough. And in combination of δ18O of planktonic foraminifera, the relative difference of sea surface salinity during the Holocene was also reconstructed.Consequently, three cooling events (E1-E3) were identified,each of which occurred at 1.7-1.6, 5.1-4.8 and 8.1-7.4kaBP (cal), respectively. Of the three events, E2 and E3 are globally comparable, their occurrence mechanism would be that the main stream of the Kuroshio Current shifted eastward due to the enhanced circulation of the northeastern Pacific Ocean, which was driven in turn by amplified intensity of sunshine and subsequent enhancement of subtropical high pressure; E1 corresponds to the Small Ice-Age Event occurring between 1550 and 1850AD in China. In the Okinawa Trough, E1 might be also related to the eastward shift of main stream of the Kuroshio current driven by powerful Asia winter monsoon.

  8. Transformation and utilization of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Bhanage, Bhalchandra M. [Institute of Chemical Technology, Mumbai (India). Dept. of Chemistry; Arai, Masahiko (ed.) [Hokkaido Univ., Sapporo (Japan). Division of Chemical Process Engineering

    2014-04-01

    This book shows the various organic, polymeric and inorganic compounds which result from the transformation of carbon dioxide through chemical, photocatalytic, electrochemical, inorganic and biological processes. The book consists of twelve chapters demonstrating interesting examples of these reactions, depending on the types of reaction and catalyst. It also includes two chapters dealing with the utilization of carbon dioxide as a reaction promoter and presents a wide range of examples of chemistry and chemical engineering with carbon dioxide.

  9. Carbon Dioxide Production Responsibility on the Basis of comparing in Situ and mean CO2 Atmosphere Concentration Data

    CERN Document Server

    Mavrodiev, S Cht; Vachev, B

    2008-01-01

    The method is proposed for estimation of regional CO2 and other greenhouses and pollutants production responcibility. The comparison of CO2 local emissions reduction data with world CO2 atmosphere data will permit easy to judge for overall effect in curbing not only global warming but also chemical polution.

  10. Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; Ambus, Per; Michelsen, Anders;

    2011-01-01

    Carbon dioxide (CO2) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO2 concentration from c. 380 μmol...

  11. Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

    DEFF Research Database (Denmark)

    Selsted, M.B.; Ambus, P.; Michelsen, A.;

    2011-01-01

    Carbon dioxide (CO(2)) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO(2) concentration from c. 380 mu...

  12. The role of renewable bioenergy in carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, C.M. [Hawaii Natural Energy Inst., Honolulu, HI (United States)

    1993-12-31

    The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

  13. Soil-atmosphere exchange of nitrous oxide, methane and carbon dioxide in a gradient of elevation in the coastal Brazilian Atlantic forest

    Directory of Open Access Journals (Sweden)

    E. Sousa Neto

    2010-07-01

    Full Text Available Soils of tropical forests are important to the global budgets of greenhouse gases. The Brazilian Atlantic Forest is the second largest tropical moist forest area of South America, after the vast Amazonian domain. This study aimed to investigate the emissions of Nitrous Oxide (N2O and Carbon Dioxide (CO2 as well as methane (CH4 emissions and consumptions along an altitudinal transect and the relation between these fluxes and other climatic, edaphic and biological variables (temperature, fine roots, litterfall, and soil moisture. Annual means of N2O flux were 2.6 (±0.5, 0.9 (±0.1, and 0.7 (±0.2 ng N cm−2 h−1 at altitudes 100, 400, and 1000 m, respectively. On an annual basis, soils consumed CH4 at all altitudes with annual means of −1.0 (±0.2, −1.8 (±0.1, and −1.6 (±0.3 mg m−2 d−1 at 100 m, 400 m and 1000 m, respectively. Although not sampled in the hottest and wettest portion of the year because of instrument malfunctions, mean fluxes of CO2 averaged 3.6 (±0.2, 3.5 (±0.3, and 3.1 (±0.3 μmol m−2 s−1 at altitudes 100, 400 and 1000 m, respectively. N2O fluxes were significantly influenced by soil moisture and temperature. Soil-atmosphere exchange of methane responded to changes in soil moisture. Carbon dioxide emissions were strongly influenced by soil temperature. While the temperature gradient observed at our sites is only an imperfect proxy for climate warming, our results suggest that increasing temperatures will result in increased in microbial activity with a consequent increase in soil N2O and CO2 emissions and soil CH4 consumption.

  14. Soil-atmosphere exchange of nitrous oxide, methane and carbon dioxide in a gradient of elevation in the coastal Brazilian Atlantic forest

    Directory of Open Access Journals (Sweden)

    E. Sousa Neto

    2011-03-01

    Full Text Available Soils of tropical forests are important to the global budgets of greenhouse gases. The Brazilian Atlantic Forest is the second largest tropical moist forest area of South America, after the vast Amazonian domain. This study aimed to investigate the emissions of nitrous oxide (N2O, carbon dioxide (CO2 and methane (CH4 fluxes along an altitudinal transect and the relation between these fluxes and other climatic, edaphic and biological variables (temperature, fine roots, litterfall, and soil moisture. Annual means of N2O flux were 3.9 (± 0.4, 1.0 (± 0.1, and 0.9 (± 0.2 ng N cm−2 h−1 at altitudes 100, 400, and 1000 m, respectively. On an annual basis, soils consumed CH4 at all altitudes with annual means of −1.0 (± 0.2, −1.8 (± 0.3, and −1.6 (± 0.1 mg m−2 d−1 at 100 m, 400 m and 1000 m, respectively. Estimated mean annual fluxes of CO2 were 3.5, 3.6, and 3.4 μmol m−2 s−1 at altitudes 100, 400 and 1000 m, respectively. N2O fluxes were significantly influenced by soil moisture and temperature. Soil-atmosphere exchange of CH4 responded to changes in soil moisture. Carbon dioxide emissions were strongly influenced by soil temperature. While the temperature gradient observed at our sites is only an imperfect proxy for climatic warming, our results suggest that an increase in air and soil temperatures may result in increases in decomposition rates and gross inorganic nitrogen fluxes that could support consequent increases in soil N2O and CO2 emissions and soil CH4 consumption.

  15. Carbon dioxide-guided angioplasty

    International Nuclear Information System (INIS)

    Revascularization procedures are frequently necessary in patients with severe peripheral vascular disease and renal insufficiency (often coexistent with diabetes mellitus). This paper examines the use of carbon dioxide as the contrast agent in percutaneous revascularization procedures (balloon angioplasty). Over the past 10 months, our protocol has used CO2 as the contrast agent for balloon angioplasty in a select group of patients (n = 12) with peripheral vascular disease and renal insufficiency. Some had coexistent diabetes mellitus. With digital subtraction angiography, CO2 was the only contrast agent used during revascularization. Pressure gradients were obtained in appropriate patients

  16. Nuclear power and carbon dioxide free automobiles

    International Nuclear Information System (INIS)

    Nuclear energy has been developed as a major source of electric power in Canada. Electricity from nuclear energy already avoids the emission of about 100 million tonnes of carbon dioxide to the atmosphere in Canada. This is a significant fraction of the 619 million tonnes of Canadian greenhouse gas emissions in 1995. However, the current scope of application of electricity to end use energy needs in Canada limits the contribution nuclear energy can make to carbon dioxide emission reduction. Nuclear energy can also contribute to carbon dioxide emissions reduction through expansion of the use of electricity to less traditional applications. Transportation, in particular contributed 165 million tonnes of carbon dioxide to the Canadian atmosphere in 1995. Canada's fleet of personal vehicles consisted of 16.9 million cars and light trucks. These vehicles were driven on average 21,000 km/year and generated 91 million tonnes of greenhouse gases expressed as a C02 equivalent. Technology to improve the efficiency of cars is under development which is expected to increase the energy efficiency from the 1995 level of about 10 litres/100 km of gasoline to under 3 litres/100km expressed as an equivalent referenced to the energy content of gasoline. The development of this technology, which may ultimately lead to the practical implementation of hydrogen as a portable source of energy for transportation is reviewed. Fuel supply life cycle greenhouse gas releases for several personal vehicle energy supply systems are then estimated. Very substantial reductions of greenhouse gas emissions are possible due to efficiency improvements and changing to less carbon intensive fuels such as natural gas. C02 emissions from on board natural gas fueled versions of hybrid electric cars would be decreased to approximately 25 million t/year from the current 91 million tonnes/year. The ultimate reduction identified is through the use of hydrogen fuel produced via electricity from CANDU power

  17. Photocatalytic and Electrocatalytic Reduction of Carbon Dioxide in Pressurized Systems

    OpenAIRE

    Voyame, Patrick

    2016-01-01

    The depletion of carbon-based fossil fuels and the rise in atmospheric carbon dioxide concentration will force an inevitable change in the future global energy landscape. CO2 reduction presents the advantages of decreasing its atmospheric concentration and storing energy in chemical form in CO2 reduction products. With a predicted conversion to renewable energy such as solar or wind energy, energy storage will become a key process in the near future for buffering the fluctuating energy produc...

  18. Atmosphere, water, sun, carbon dioxide, weather, climate, living - some fundamental terms; Atmosphaere, Wasser, Sonne, Kohlenstoffdioxid, Wetter, Klima, Leben - einige Grundbegriffe

    Energy Technology Data Exchange (ETDEWEB)

    Hopp, Vollrath

    2012-07-01

    The author of the book under consideration explains the physical, chemical and meteorological principles. The knowledge of these fundamentals is necessary in order to understand the weather in its manifold manifestations. Solar energy, atmosphere, oceans and continents are interrelated. Large amounts of energy are exchanged at their interfaces causing high temperature differences and strong materials flows. A historical review shows that the climatic change is determined by changes in solar activity, cosmic radiation, inclination of the earth's axis (from about 24.5 to 22.5 ) in periods of up to 41,000 years, the Earth's magnetic field, the gravitation and by large volcanic eruptions.

  19. Carbon dioxide reducing processes; Koldioxidreducerande processer

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Fredrik

    1999-12-01

    This thesis discusses different technologies to reduce or eliminate the carbon dioxide emissions, when a fossil fuel is used for energy production. Emission reduction can be accomplished by separating the carbon dioxide for storage or reuse. There are three different ways of doing the separation. The carbon dioxide can be separated before the combustion, the process can be designed so that the carbon dioxide can be separated without any energy consumption and costly systems or the carbon dioxide can be separated from the flue gas stream. Two different concepts of separating the carbon dioxide from a combined cycle are compared, from the performance and the economical point of view, with a standard natural gas fired combined cycle where no attempts are made to reduce the carbon dioxide emissions. One concept is to use absorption technologies to separate the carbon dioxide from the flue gas stream. The other concept is based on a semi-closed gas turbine cycle using carbon dioxide as working fluid and combustion with pure oxygen, generated in an air-separating unit. The calculations show that the efficiency (power) drop is smaller for the first concept than for the second, 8.7 % points compared to 13.7 % points, when power is produced. When both heat and power are produced, the relation concerning the efficiency (power) remains. Regarding the overall efficiency (heat and power) the opposite relation is present. A possible carbon dioxide tax must exceed 0.21 SEK/kg CO{sub 2} for it to be profitable to separate carbon dioxide with any of these technologies.

  20. A multiresolution spatial parametrization for the estimation of fossil-fuel carbon dioxide emissions via atmospheric inversions.

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Jaideep; Lee, Jina; Lefantzi, Sophia; Yadav, Vineet [Carnegie Institution for Science, Stanford, CA; Michalak, Anna M. [Carnegie Institution for Science, Stanford, CA; van Bloemen Waanders, Bart Gustaaf [Sandia National Laboratories, Albuquerque, NM; McKenna, Sean Andrew [IBM Research, Mulhuddart, Dublin 15, Ireland

    2013-04-01

    The estimation of fossil-fuel CO2 emissions (ffCO2) from limited ground-based and satellite measurements of CO2 concentrations will form a key component of the monitoring of treaties aimed at the abatement of greenhouse gas emissions. To that end, we construct a multiresolution spatial parametrization for fossil-fuel CO2 emissions (ffCO2), to be used in atmospheric inversions. Such a parametrization does not currently exist. The parametrization uses wavelets to accurately capture the multiscale, nonstationary nature of ffCO2 emissions and employs proxies of human habitation, e.g., images of lights at night and maps of built-up areas to reduce the dimensionality of the multiresolution parametrization. The parametrization is used in a synthetic data inversion to test its suitability for use in atmospheric inverse problem. This linear inverse problem is predicated on observations of ffCO2 concentrations collected at measurement towers. We adapt a convex optimization technique, commonly used in the reconstruction of compressively sensed images, to perform sparse reconstruction of the time-variant ffCO2 emission field. We also borrow concepts from compressive sensing to impose boundary conditions i.e., to limit ffCO2 emissions within an irregularly shaped region (the United States, in our case). We find that the optimization algorithm performs a data-driven sparsification of the spatial parametrization and retains only of those wavelets whose weights could be estimated from the observations. Further, our method for the imposition of boundary conditions leads to a 10computational saving over conventional means of doing so. We conclude with a discussion of the accuracy of the estimated emissions and the suitability of the spatial parametrization for use in inverse problems with a significant degree of regularization.

  1. Snowpack-atmosphere gas exchanges of carbon dioxide, ozone, and nitrogen oxides at a hardwood forest site in northern Michigan

    Directory of Open Access Journals (Sweden)

    Brian Seok

    2015-03-01

    Full Text Available Abstract Snowpack-atmosphere gas exchanges of CO2, O3, and NOx (NO + NO2 were investigated at the University of Michigan Biological Station (UMBS, a mid-latitude, low elevation hardwood forest site, during the 2007–2008 winter season. An automated trace gas sampling system was used to determine trace gas concentrations in the snowpack at multiple depths continuously throughout the snow-covered period from two adjacent plots. One natural plot and one with the soil covered by a Tedlar sheet were setup for investigating whether the primary source of measured trace gases was biogenic (i.e., from the soil or non-biogenic (i.e., from the snowpack. The results were compared with the “White on Green” study conducted at the Niwot Ridge (NWT Long Term Ecological Research site in Colorado. The average winter CO2 flux ± s.e. from the soil at UMBS was 0.54 ± 0.037 µmol m-2 s-1 using the gradient diffusion method and 0.71 ± 0.012 µmol m-2 s-1 using the eddy covariance method, and in a similar range as found for NWT. Observed snowpack-O3 exchange was also similar to NWT. However, nitrogen oxides (NOx fluxes from snow at UMBS were 10 times smaller than those at NWT, and fluxes were bi-directional with the direction of the flux dependent on NOx concentrations in ambient air. The compensation point for the change in the direction of NOx flux was estimated to be 0.92 nmol mol-1. NOx in snow also showed diurnal dependency on incident radiation. These NOx dynamics in the snow at UMBS were notably different compared to NWT, and primarily determined by snow-atmosphere interactions rather than by soil NOx emissions.

  2. Forest management techniques for carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

    Fujimori, Takao [Forestry and Forest Products Research Inst., Tsukuba, Ibaraki (Japan)

    1993-12-31

    In the global ecosystem concerning carbon dioxide content in the atmosphere, the forest ecosystem plays an important role. In effect, the ratio of forest biomass to total terrestrial biomass is about 90%, and the ratio of carbon stored in the forest biomass to that in the atmosphere is two thirds. When soils and detritus of forests are added, there is more C stored in forests than in the atmosphere, about 1.3 times or more. Thus, forests can be regarded as the great holder of C on earth. If the area of forest land on the earth is constantly maintained and forests are in the climax stage, the uptake of C and the release of C by and from the forests will balance. In this case, forests are neither sinks nor sources of CO{sub 2} although they store a large amount of C. However, when forests are deforested, they become a source of C; through human activities, forests have become a source of C. According to a report by the IPCC, 1.6{+-}1.2 PgC is annually added to the atmosphere by deforestation. According to the FAO (1992), the area of land deforested annually in the tropics from 1981 to 1990 was 16.9 x 10{sup 6} ha. This value is nearly half the area of Japanese land. The most important thing for the CO{sub 2} environment concerning forests is therefore how to reduce deforestation and to successfully implement a forestation or reforestation.

  3. Carbon dioxide problems. Countermeasures to the carbon dioxide problem in hydrocarbon-fired plants

    International Nuclear Information System (INIS)

    Among the environmental problems discussed in this paper, global warming and the restriction of CFC are primarily thermal engineering issues. In particular, global warming, likely to be caused by an increase in the atmospheric carbon dioxide concentration, is one of the most essential and urgent environmental problems. In recent international conferences, held for example by UNEP, a proposal was made that carbon dioxide concentration be controlled under its 1898 level. However, this proposal may not be so forceful, since it is not clear whether the control is to be imposed on each country separately or on the developed countries as a whole. The vague content of the proposal may be attributed to the existing international situation, whereby the energy resources available to each country differ substantially

  4. Effect of the permafrost thawing on the organic carbon and microbial activity in thermokarst lakes of Western Siberia: important source of carbon dioxide in the atmosphere

    Science.gov (United States)

    Shirokova, L. S.; Pokrovsky, O. S.; Kirpotin, S. N.; Dupre, B.

    2008-12-01

    Ongoing processes of the permafrost thawing in Western Siberia are likely to increase the surface of water reservoirs via forming so-called thermokarst lakes, mobilizing the organic carbon (OC) from the soil pool to the rivers and, finally, to the ocean, and thus modifying the fluxes of methane and CO2 to the atmosphere. In order to understand the mechanisms of carbon mobilization and biodegradation during permafrost thawing and to establish the link between the OC and microbial activity in forming thermokarstic lakes, we performed a comparative multidisciplinary study on the biogeochemistry of OC and metals in lakes located in the northern part of Western Siberia. About 10 lakes and small ponds of various size and age were sampled for dissolved and colloidal organic carbon and metals and total bacterial cell number. There is a systematic evolution of DOC, pH, trace elements and biological activity during successions of thermokarst lakes encountered in the present study. At the beginning of permafrost thawing at the scale of several meter size ponds, fast lixiviation of unaltered peat yields significant amount of OC, major and trace elements; the pH of these waters is between 3.5 and 4.0 and the conductivity is 20-30 μS. The intermediate stage of lake formation still preserve low pHs, high DOC and conductivity, even in relatively large, up to 1 km diameter but fast growing lakes. At these stages, there is no any productivity as phytoplankton cannot live in these acidic waters and bacterial mineralization intensity is around 0.3 mg C/L/day both in the surface and bottom horizons. Once the lake border is stabilized, there are no new "unaltered peat" sources and the biological processes start to consume the OC and nutrients. At this stage, there is still no production in the water column (begging of permafrost thawing to oligotrophic/mesotrophic at the final "khasyrey" stage (80 CFU/mL). Two main conclusions can be drawn from this work: 1) At all stages of lake

  5. Forward Modeling of Atmospheric Carbon Dioxide in GEOS-5: Uncertainties Related to Surface Fluxes and Sub-Grid Transport

    Science.gov (United States)

    Pawson, Steven; Ott, Lesley E.; Zhu, Zhengxin; Bowman, Kevin; Brix, Holger; Collatz, G. James; Dutkiewicz, Stephanie; Fisher, Joshua B.; Gregg, Watson W.; Hill, Chris; Menemenlis, DImiris; Potter, Christopher S.; Gunson, Michael R.; Jucks, Kenneth W.

    2011-01-01

    Forward GEOS-5 AGCM simulations of CO2, with transport constrained by analyzed meteorology for 2009-2010, are examined. The CO2 distributions are evaluated using AIRS upper tropospheric CO2 and ACOS-GOSAT total column CO2 observations. Different combinations of surface C02 fluxes are used to generate ensembles of runs that span some uncertainty in surface emissions and uptake. The fluxes are specified in GEOS-5 from different inventories (fossil and biofuel), different data-constrained estimates of land biological emissions, and different data-constrained ocean-biology estimates. One set of fluxes is based on the established "Transcom" database and others are constructed using contemporary satellite observations to constrain land and ocean process models. Likewise, different approximations to sub-grid transport are employed, to construct an ensemble of CO2 distributions related to transport variability. This work is part of NASA's "Carbon Monitoring System Flux Pilot Project,"

  6. Effects of Syn-pandemic Fire Reduction and Reforestation in the Tropical Americas on Atmospheric Carbon Dioxide During European Conquest

    Science.gov (United States)

    Nevle, R. J.; Bird, D. K.

    2008-12-01

    2000 BP correlate with expanding indigenous population, agriculture, and fire use in the tropical Americas. The rise in inter-site variability in charcoal accumulation after 2000 BP is consistent with a demographic shift toward sedentary agrarian communities and localized increases in charcoal accumulation in densely populated centers. Declines in regional charcoal accumulation and inter-site variability after 500 BP suggest a correlative cause related to reduction in anthropogenic biomass burning resulting from pandemic-driven population collapse. Published reconstructions of Pre-Columbian demography indicate that during European conquest, pandemics killed ~90% of the indigenous American population (~60 million), estimated to represent ~20% of the 16th century global population. Our predictive calculations suggest that fire reduction in the tropical Americas is associated with massive forest regeneration on ~5 x 105 km2 of land and sequestration of 5-10 Gt C into the terrestrial biosphere, which can account for 13- 50% of the ~2% global reduction in atmospheric CO2 levels and the 0.1‰ increase in δ13C of atmospheric CO2 from 1500 to 1700 CE recorded in Antarctic ice cores and tropical sponges. New archeological discoveries revealing extensive networks of geoglyphs and urban polities in Pre-Columbian Amazonia suggest that our estimates of reforestation, and consequent effects on atmospheric CO2, may be conservative.

  7. Quantification of carbon dioxide, methane, nitrous oxide, and chloroform emissions over Ireland from atmospheric observations at Mace Head

    International Nuclear Information System (INIS)

    Flux estimates of CO2, CH4, N2O and CHCl3 over Ireland are inferred from continuous atmospheric records of these species. We use radon-222 (222Rn) as a reference compound to estimate unknown sources of other species. The correlation between each species and 222Rn is calculated for a suite of diurnal events that have been selected in the Mace Head record over the period 1995-1997 to represent air masses exposed to sources over Ireland. We established data selection criteria based on 222Rn and 212Pb concentrations. We estimated flux densities of 12x103 kg CH4/km2/yr, 680 kg N2O/km2/yr and 20 kg CHCl3/km2/yr for CH4, N2O and CHCl3, respectively. We also inferred flux densities of 250x103 kg C/km2/yr for CO2 during wintertime, and of 760x103 kg C/km2/yr for CO2 during summer night-time. Our CH4 inferred flux compare well with the CORINAIR90 and CORNAIR94 inventories for Ireland. The N2O emission flux we inferred is close to the inventory value by CORINAIR90, but twice the inventory value by CORINAIR94 and EDGAR 2.0. This discrepancy may have been caused by the use of the revised 1996 IPCC guidelines for national greenhouse gas inventories in 1994, which include a new methodology for N2O emissions from agriculture. We carried out the first estimation of CHCl3 emission fluxes over Ireland. This estimation is 4 times larger than the CHCl3 emission fluxes measured close to the Mace Head station over peatlands. Our CHCl3 emission fluxes estimate is consistent with the interpretation of the same data by Ryall (personal communication, 2000), who obtained, using a Lagrangian atmospheric transport model, CHCl3 fluxes of 24±7 kg CHCl3/km2/yr. Our estimates of CO2 emission fluxes during summer night-time and wintertime are close to those estimated from inventories and to one biogeochemical model of heterotrophic respiration

  8. Carbon compounds in the atmosphere and their chemical reactions

    OpenAIRE

    Martišová, Petra

    2013-01-01

    The essay dissert on compounds of carbon in the atmosphere and its reaction. The most important are carbon dioxide, carbon monoxide and methane. Included among important compounds of carbon are volatile organic substances, polycyclic aromatic hydrocarbon and dioxin. Carbon dioxide and methane representing greenhouse gases have also indispensable meaning. As they, together with water vapour, nitrogen monoxide and other gases are causing the major part of greenhouse effect. Primarily because of...

  9. The exchange of energy, water and carbon dioxide between wet arctic tundra and the atmosphere at the Lena River Delta, Northern Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Kutzbach, L.

    2006-07-01

    The ecosystem-scale exchange fluxes of energy, water and carbon dioxide between wet arctic tundra and the atmosphere were investigated by the micrometeorological eddy covariance method. The investigation site was the centre of the Lena River Delta in Northern Siberia characterised by a polar and distinctly continental climate, very cold and ice-rich permafrost and its position at the interface between the Eurasian continent and the Arctic Ocean. The measurements were performed on the surface of a Holocene river terrace characterised by wet polygonal tundra. The soils at the site are characterised by high organic matter content, low nutrient availability and pronounced water logging. The vegetation is dominated by sedges and mosses. The fluctuations of the H{sub 2}O and CO{sub 2} concentrations were measured with a closed-path infrared gas analyser. The fast-response eddy covariance measurements were supplemented by a set of slow-response meteorological and soil-meteorological measurements. The combined datasets of the two campaigns 2003 and 2004 were used to characterise the seasonal course of the energy, water and CO{sub 2} fluxes and the underlying processes for the synthetic measurement period May 28..October 21 2004/2003 including the period of snow and soil thawing as well as the beginning of refreezing. The synthetic measurement period 2004/2003 was characterised by a long snow ablation period and a late start of the growing season. On the other hand, the growing season ended also late due to high temperatures and snow-free conditions in September. The cumulative summer energy partitioning was characterised by low net radiation, large ground heat flux, low latent heat flux and very low sensible heat flux compared to other tundra sites. These findings point out the major importance of the very cold permafrost for the summer energy budget of the tundra in Northern Siberia. (orig./SR)

  10. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.;

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o......C) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass...

  11. Encapsulated liquid sorbents for carbon dioxide capture

    Science.gov (United States)

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

    2015-02-01

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

  12. Estimates of regional surface carbon dioxide exchange and carbon and oxygen isotope discrimination during photosynthesis from concentration profiles in the atmospheric boundary layer

    International Nuclear Information System (INIS)

    The integrating properties of the atmospheric boundary layer allow the influence of surface exchange processes on the atmosphere to be quantified and estimates of large-scale fluxes of trace gases and plant isotopic discrimination to be made. Five flights were undertaken over two days in and above the convective boundary layer (CBL) in a vegetated region in central Siberia. Vertical profiles of CO2 and H2O concentrations, temperature and pressure were obtained during each flight. Air flask samples were taken at various heights for carbon and oxygen isotopic analysis of CO2. Two CBL budget methods were compared to estimate regional surface fluxes of CO2 and plant isotopic discrimination against 13CO2 and C18O16O. Flux estimates were compared to ground-based eddy covariance measurements. The fluxes obtained for CO2 using the first method agreed to within 10% of fluxes measured in the forest at the study site by eddy covariance. Those obtained from the second method agreed to within 35% when a correction was applied for air loss out of the integrating column and for subsidence. The values for 13C discrimination were within the range expected from knowledge of C3 plant discriminations during photosynthesis, while the inferred 18O discrimination varied considerably over the two-day period. This variation may in part be explained by the enrichment of chloroplast water during the day due to evaporation from an initial signature in the morning close to source water. Additional potential complications arising from the heterogeneous nature of the landscape are discussed

  13. Six-fold Coordinated Carbon Dioxide VI

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

    孙艳朋; 聂勇; 吴昂山; 姬登祥; 于凤文; 计建炳

    2012-01-01

    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.

  15. Carbon dioxide cleaning pilot project

    International Nuclear Information System (INIS)

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

  16. Modelling interactions of carbon dioxide, forests, and climate

    Energy Technology Data Exchange (ETDEWEB)

    Luxmoore, R.J. [Oak Ridge National Lab., TN (United States); Baldocchi, D.D. [National Oceanic and Atmospheric Administration, Oak Ridge, TN (United States)

    1994-09-01

    Atmospheric carbon dioxide is rising and forests and climate is changing! This combination of fact and premise may be evaluated at a range of temporal and spatial scales with the aid of computer simulators describing the interrelationships between forest vegetation, litter and soil characteristics, and appropriate meteorological variables. Some insights on the effects of climate on the transfers of carbon and the converse effect of carbon transfer on climate are discussed as a basis for assessing the significance of feedbacks between vegetation and climate under conditions of rising atmospheric carbon dioxide. Three main classes of forest models are reviewed. These are physiologically-based models, forest succession simulators based on the JABOWA model, and ecosystem-carbon budget models that use compartment transfer rates with empirically estimated coefficients. Some regression modeling approaches are also outlined. Energy budget models applied to forests and grasslands are also reviewed. This review presents examples of forest models; a comprehensive discussion of all available models is not undertaken.

  17. Carbon dioxide warming of the early Earth

    Science.gov (United States)

    Arrhenius, G.

    1997-01-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

  18. Carbon neutron star atmospheres

    CERN Document Server

    Suleimanov, V F; Pavlov, G G; Werner, K

    2013-01-01

    The accuracy of measuring the basic parameters of neutron stars is limited in particular by uncertainties in chemical composition of their atmospheres. For example, atmospheres of thermally - emitting neutron stars in supernova remnants might have exotic chemical compositions, and for one of them, the neutron star in CasA, a pure carbon atmosphere has recently been suggested by Ho & Heinke (2009). To test such a composition for other similar sources, a publicly available detailed grid of carbon model atmosphere spectra is needed. We have computed such a grid using the standard LTE approximation and assuming that the magnetic field does not exceed 10^8 G. The opacities and pressure ionization effects are calculated using the Opacity Project approach. We describe the properties of our models and investigate the impact of the adopted assumptions and approximations on the emergent spectra.

  19. Carbon dioxide research conference: carbon dioxide, science and consensus

    International Nuclear Information System (INIS)

    The DOE program focuses on three areas each of which requires more research before the many CO2-related questions can be answered. These areas include the global carbon cycle, climate effects, and vegetation effects. Additional information is needed to understand the sources and sinks of CO2. Research efforts include an attempt to estimate regional and global changes in temperature and precipitation. Increased atmospheric CO2 may be a potential benefit to vegetation and crops because it is an essential element required for plant growth. Eight separate papers are included

  20. Carbon dioxide uptake by a temperate tidal sea

    NARCIS (Netherlands)

    Klaassen, Wim

    2007-01-01

    Carbon dioxide (CO2) exchange between the atmosphere and the Wadden Sea, a shallow coastal region along the northern Netherlands, has been measured from April 2006 onwards on a tidal flat and over open water. Tidal flat measurements were done using a flux chamber, and ship borne measurements using a

  1. It is time to put carbon dioxide to work

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. High-resolution carbon dioxide concentration record 650,000-800,000 years before present

    DEFF Research Database (Denmark)

    Lüthi, Dieter; Le Floch, Martine; Bereiter, Bernhard;

    2008-01-01

    Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650...... is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16......,000 years. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data and the present work, we find that atmospheric carbon dioxide...

  3. Soil-Atmosphere Exchange of Nitrous Oxide, Nitric Oxide, Methane, and Carbon Dioxide in Logged and Undisturbed Forest in the Tapajos National Forest, Brazil

    Science.gov (United States)

    Keller, M.; Varner, R. K.; Dias, J. D.; Silva, H.; Crill, P. M.; de Oliveira, R. C.; Asner, G. P.

    2004-12-01

    Selective logging is an extensive land use in the Brazilian Amazon region. We studied the soil-atmosphere fluxes of nitrous oxide (N2O), nitric oxide (NO), methane (CH4), and carbon dioxide (CO2) on two soil types (clay Oxisol and sandy loam Ultisol) over two years (2000-2001) in both undisturbed forest and forest recently logged using reduced impact forest management in the Tapajos National Forest, near Santarem, Para, Brazil. In undisturbed forest, annual soil-atmosphere fluxes of N2O (mean +/- standard error) were 7.9 +/- 0.7 and 7.0 +/- 0.6 ng N cm-2 h-1 for the Oxisol and 1.7 +/- 0.1 and 1.6 +/- 0.3 ng N cm-2 h-1 for the Ultisol for 2000 and 2001 respectively. The annual fluxes of NO from undisturbed forest soil in 2001 was 9.0 +/- 2.8 ng N cm-2 h-1 for the Oxisol and 8.8 +/- 5.0 ng N cm-2 h-1 for the Ultisol. Consumption of CH4 from the atmosphere dominated over production on undisturbed forest soils. Fluxes averaged -0.3 +/- 0.2 and -0.1 +/- 0.9 mg CH4 m-2 d-1 on the Oxisol and -1.0 +/- 0.2 and -0.9 +/- 0.3 mg CH4 m-2 d-1 on the Ultisol for years 2000 and 2001. For CO2 in 2001, the annual fluxes averaged 3.6 +/- 0.4 μ mol m-2 d-1 on the Oxisol and 4.9 +/- 1.1 μ mol m-2 d-1 on the Ultisol. We measured fluxes over one year each from two recently logged forests on the Oxisol in 2000 and on the Ultisol in 2001. Sampling in logged areas was stratified from greatest to least ground disturbance covering log decks, skid trails, tree-fall gaps, and forest matrix. Areas of strong soil compaction, especially the skid trails and logging decks were prone to significantly greater emissions of N2O, NO, and especially CH4. In the case of CH4, estimated annual emissions from decks reached extremely high rates of 531 +/- 419 and 98 +/- 41 mg CH4 m-2 d-1, for Oxisol and Ultisol respectively, comparable to wetland emissions in the region. We calculated excess fluxes from logged areas by subtraction of a background forest flux and adjusted these fluxes for the proportional

  4. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Fain, D.E. [Oak Ridge National Laboratory, TN (United States)

    1993-12-31

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

  5. The Fluid Mechanics of Carbon Dioxide Sequestration

    Science.gov (United States)

    Huppert, Herbert E.; Neufeld, Jerome A.

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, L E [ed.

    1980-12-01

    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 CO2; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO2; social responses to the CO2 problem; a scenario for atmospheric CO2 to 2025; marine photosynthesis and the global carbon cycle; and the role of tropical forests in the carbon balance of the world. Separate abstracts of nine papers have been prepared for inclusion in the Energy Data Base. (RJC)

  7. Monitoring carbon dioxide in mechanically ventilated patients during hyperbaric treatment

    DEFF Research Database (Denmark)

    Bjerregård, Asger; Jansen, Erik

    2012-01-01

    Measurement of the arterial carbon dioxide (P(a)CO(2)) is an established part of the monitoring of mechanically ventilated patients. Other ways to get information about carbon dioxide in the patient are measurement of end-tidal carbon dioxide (P(ET)CO(2)) and transcutaneous carbon dioxide (PTCCO2...

  8. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2010-10-01

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

  10. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  11. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  12. 46 CFR 95.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

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

  13. 46 CFR 76.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

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

  14. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  15. Reactive Capture of Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase I SBIR, Reactive Innovations, LLC (RIL) proposes to develop a compact and lightweight electrochemical to capture carbon dioxide in the martian...

  16. Carbon Dioxide Collection and Pressurization Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reactive Innovations, LLC, proposes a Phase I SBIR program to develop a compact and lightweight electrochemical reactor to separate and pressurize carbon dioxide...

  17. Supercritical carbon dioxide hop extraction

    Directory of Open Access Journals (Sweden)

    Pfaf-Šovljanski Ivana I.

    2005-01-01

    Full Text Available The hop of Magnum cultivar was extracted using supercritical carbon dioxide (SFE-as extractant. Extraction was carried out in the two steps: the first one being carried out at 150 bar and 40°C for 2.5 h (Extract A, and the second was the extraction of the same hop sample at 300 bar and 40°C for 2.5 h (Extract B. Extraction kinetics of the system hop-SFE-CO2 was investigated. Two of four most common compounds of hop aroma (α-humulene and β-caryophyllene were detected in Extract A. Isomerised α-acids and β-acids were detected too. a-Acid content in Extract B was high (that means it is a bitter variety of hop. Mathematical modeling using empirical model characteristic time model and simple single sphere model has been performed on Magnum cultivar extraction experimental results. Characteristic time model equations, best fitted experimental results. Empirical model equation, fitted results well, while simple single sphere model equation poorly approximated the results.

  18. Extraction of Uranium Using Nitrogen Dioxide and Carbon Dioxide for Spent Fuel Reprocessing

    International Nuclear Information System (INIS)

    For the reprocessing of spent nuclear fuels, a new method to extract actinides from spent fuel using highly compressed gases, nitrogen dioxide and carbon dioxide was proposed. Uranium extraction from broken pieces, whose average grain size was 5 mm, of uranium dioxide pellet with nitrogen dioxide and carbon dioxide was demonstrated in the present study. (authors)

  19. The carbon dioxide problem - a challenge to environmental protection

    International Nuclear Information System (INIS)

    Over the last century, man's activities on earth have sent off trace gases into the planet's atmosphere that have been concentrating to a level posing a threat to the global climate. Since scientists particularly spotted carbon dioxide as the main contributor to what we now call the greenhouse effect, there is urgent need for measures reducing carbon dioxide emission worldwide, may be on the basis of a global convention to be signed by both the industrialised and the developing countries. The industrialised countries, which certainly are the main pollutors, also will have the technological and financial resources to respond to the challenge of global warning more directly and faster than the developing countries. The power industry's management in the FRG is taking the problem seriously and has already come out with strategies for curbing carbon dioxide emissions from fossil-fuel power plant. (orig.)

  20. Bench-to-bedside review: Carbon dioxide

    OpenAIRE

    Curley, Gerard; Laffey, John G; Kavanagh, Brian P.

    2010-01-01

    Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia remains a common - and generally underappreciated - component of many disease states, including early asthma, high-altitude pulmonary edema, and acute lung injury. Induction of hypocapnia remains a common, if controversial, practice in both adults and children with acute brain injury. In contrast, hypercap...

  1. Arterialisation of transcutaneous oxygen and carbon dioxide.

    OpenAIRE

    Broadhurst, E; Helms, P; Vyas, H; Cheriyan, G

    1988-01-01

    We compared previously calculated global correction factors for oxygen and carbon dioxide arterial/transcutaneous ratios with individual in vivo calibrations from the first arterial sample. In infants beyond the neonatal period and older children in vivo calibration confers little benefit over the use of a global calibration correction factor for transcutaneous carbon dioxide, and may reduce the precision with which arterial oxygen can be estimated from transcutaneous oxygen.

  2. Carbon dioxide emission from bamboo culms.

    Science.gov (United States)

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

    2016-05-01

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

  3. Global carbon dioxide emissions from inland waters

    Science.gov (United States)

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

    2013-01-01

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

  4. Carbon dioxide catastrophes: Past and future menace

    Science.gov (United States)

    Baur, Mario E.

    1988-01-01

    Carbon dioxide is important in its role as coupler of the terrestrial biosphere to inorganic chemical processes and as the principal greenhouse gas controlling Earth's surface temperature. The hypothesis that atmospheric CO2 levels have diminished with time, with the resulting cooling effect offsetting an increase in the solar constant, seems firmly established, and it is shown that feedback mechanisms exist which can maintain the terrestrial surface in a relatively narrow temperature range over geological time. Of the factors involved in such CO2 variation, the oceanic reservoir appears the most important. Surface waters are probably in approximate equilibrium with regard to CO2 exchange with the ambient atmosphere in most regions, but data from deep-ocean water sampling indicates that such waters are somewhat undersaturated in the sense that they would tend to absorb CO2 from the atmosphere if brought to the surface without change in composition or temperature. If major impacts into the ocean can result in loss of a substantial portion of the atmospheric CO2 reservoir, then any such future event could imperil the continuation of most higher forms of life on Earth. The most likely candidate for an inverse Nyos global event in previous Earth history is the Cretaceous-Tertiary terminal extinction event. The Cretaceous was characterized by warm, equable temperatures presumably indicative of relatively high CO2 levels and an intense greenhouse heating. Cooling of the oceans in absence of massive transfer of CO2 to the oceanic reservoir in itself would promote a condition of CO2 undersaturation in abyssal waters, and this is made even more extreme by the pattern of ocean water circulation. It is possible to envision a situation in which deep ocean waters were at least occasionally profoundly undersaturated with regard to CO2. Turnover of a major fraction of such an ocean would then remove, on a very short time scale, as much as 90 percent of the atmospheric CO2

  5. Photoassisted carbon dioxide reduction and formation of twoand three-carbon compounds. [prebiological photosynthesis

    Science.gov (United States)

    Halmann, M.; Aurian-Blajeni, B.; Bloch, S.

    1981-01-01

    The photoassisted reduction of aqueous carbon dioxide in the presence of naturally occurring minerals is investigated as a possible abiotic precursor of photosynthesis. Aqueous carbon dioxide saturated suspensions or surfaces of the minerals nontronite, bentonite, anatase, wolframite, molybdenite, minium, cinnabar and hematite were irradiated with high-pressure mercury lamps or sunlight. Chemical analyses reveal the production of formic acid, formaldehyde, methanol and methane, and the two and three-carbon compounds glyoxal (CHOCHO) and malonaldehyde (CH2(CHO)2). It is suggested that such photosynthetic reactions with visible light in the presence of semiconducting minerals may provide models for prebiological carbon and nitrogen fixation in both oxidized and reduced atmospheres.

  6. Understanding how individuals perceive carbon dioxide. Implications for acceptance of carbon dioxide capture and storage

    Energy Technology Data Exchange (ETDEWEB)

    Itaoka, K.; Saito, A. [Mizuho Information and Research Institute, Tokyo (Japan); Paukovic, M.; De Best-Waldhober, M. [ECN Policy Studies, Petten (Netherlands); Dowd, A.M.; Jeanneret, T.; Ashworth, P.; James, M. [The Global CCS Institute, Canberra (Australia)

    2012-06-15

    Carbon dioxide capture and storage (CCS) presents one potential technological solution for mitigating the atmospheric emission of carbon dioxide sources. However, CCS is a relatively new technology with associated uncertainties and perceived risks. For this reason, a growing body of research now focuses on public perceptions and potential for societal acceptance of CCS technology. Almost all explanations of CCS technology make reference to carbon dioxide, with an assumption that the general public understands CO2. It has become apparent that the general public’s knowledge and understanding of CO2’s properties influences how they engage with CO2 emitting industries and CCS technologies. However, surprisingly little research has investigated public perceptions, knowledge, and understanding of CO2. This investigation attempts to fill that gap. This report describes an investigation of how citizens of three countries (Japan, Australia, and the Netherlands) perceive CO2. Furthermore, it attempts to relate individual perceptions of CO2 to perceptions of CCS, and to determine how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards low carbon energy options, particularly CCS. In brief, the research had four ultimate aims. It aimed to: Explore the public’s knowledge and understanding of the properties of CO2; Examine the influence of that knowledge on their perceptions of CO2 and CCS; Investigate how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards CCS; and Identify if any differences between countries exist in relation to values and beliefs, knowledge of CO2’s properties, and CCS perceptions.

  7. Graphite suspension in carbon dioxide

    International Nuclear Information System (INIS)

    Since 1963 the Atomic Division of SNECMA has been conducting, under a contract with the CEA, an experimental work with a two-component fluid comprised of carbon dioxide and small graphite particles. The primary purpose was the determination of basic engineering information pertaining to the stability and the flowability of the suspension. The final form of the experimental loop consists mainly of the following items: a light-phase compressor, a heavy-phase pump, an electrical-resistance type heater section, a cooling heat exchanger, a hairpin loop, a transparent test section and a separator. During the course of the testing, it was observed that the fluid could be circulated quite easily in a broad range of variation of the suspension density and velocity - density from 30 to 170 kg/m3 and velocity from 2 to 24 m/s. The system could be restarted and circulation maintained without any difficulty, even with the heavy-phase pump alone. The graphite did not have a tendency to pack or agglomerate during operation. No graphite deposition was observed on the wall of the tubing. A long period run (250 hours) has shown the evolution of the particle dimensions. Starting with graphite of surface area around 20 m2/g (graphite particles about 1 μ), the powder surface area reaches an asymptotic value of 300 m2/g (all the particles less than 0.3 μ). Moisture effect on flow stability, flow distribution between two parallel channels, pressure drop in straight tubes, recompression ratio in diffusers were also investigated. (author)

  8. Six-fold coordinated carbon dioxide VI

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Six-fold coordinated carbon dioxide VI.

    Science.gov (United States)

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

    2007-01-01

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

  10. Using a Regional Cluster of AmeriFlux Sites in Central California to Advance Our Knowledge on Decadal-Scale Ecosystem-Atmosphere Carbon Dioxide Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Baldocchi, Dennis [Univ. of California, Berkeley, CA (United States)

    2015-03-24

    Continuous eddy convariance measurements of carbon dioxide, water vapor and heat were measured continuously between an oak savanna and an annual grassland in California over a 4 year period. These systems serve as representative sites for biomes in Mediterranean climates and experience much seasonal and inter-annual variability in temperature and precipitation. These sites hence serve as natural laboratories for how whole ecosystem will respond to warmer and drier conditions. The savanna proved to be a moderate sink of carbon, taking up about 150 gC m-2y-1 compared to the annual grassland, which tended to be carbon neutral and often a source during drier years. But this carbon sink by the savanna came at a cost. This ecosystem used about 100 mm more water per year than the grassland. And because the savanna was darker and rougher its air temperature was about 0.5 C warmer. In addition to our flux measurements, we collected vast amounts of ancillary data to interpret the site and fluxes, making this site a key site for model validation and parameterization. Datasets consist of terrestrial and airborne lidar for determining canopy structure, ground penetrating radar data on root distribution, phenology cameras monitoring leaf area index and its seasonality, predawn water potential, soil moisture, stem diameter and physiological capacity of photosynthesis.

  11. Carbon dioxide and global change: Earth in transition

    International Nuclear Information System (INIS)

    The volume covers the pros and cons of all issues related to the risk in atmospheric carbon dioxide. The first half of the book presents a critical review of the status of current climatic enrichment of the Earth with carbon dioxide. A number of recent developments in the empirical approach to climate change are discussed. This half concludes with a review of current research efforts directed to detecting the first signs of the predicted climate catastrophe. The second half of the book is biologically oriented. It includes a comprehensive review of known effects of atmospheric carbon dioxide enrichment on plant physiological processes and the potential modification of a number of environmental constraints. The effects of carbon dioxide on animals and a comprehensive analysis of where the world may be headed as a result of this process is included. The text is thoroughly documented to encourage the reader to form his own opinions. Included are over 2,000 literature citations, a 3,500 entry subject index, and a list of more than 2,700 authors. It is a valuable source for learning about a perplexing situation facing mankind

  12. Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Annual technical report

    Energy Technology Data Exchange (ETDEWEB)

    Oechel, W.C.

    1992-04-01

    Northern ecosystems contain up to 455 Gt of C in the soil active layer and upper permafrost. The soil carbon in these layers is equivalent to approximately 60% of the carbon currently in the atmosphere as CO{sub 2}. Much of this carbon is stored in the soil as dead organic matter. Its fate is subject to the net effects of global change on the plant and soil systems of northern ecosystems. The arctic alone contains about 60 Gt C, 90% of which is present in the soil active layer and upper permafrost. The arctic is assumed to have been a sink for CO{sub 2} during the historic and recent geologic past. The arctic has the potential to be a very large, long-term source or sink of CO{sub 2} with respect to the atmosphere. In situ experimental manipulations of atmospheric CO{sub 2}, indicated that there is little effect of elevated atmospheric CO{sub 2} on leaf level photosynthesis or whole-ecosystem CO{sub 2} flux over the course of weeks to years, respectively. However, there may be longer- term ecosystem responses to elevated CO{sub 2} that could ultimately affect ecosystem CO{sub 2} balance. In addition to atmospheric CO{sub 2}, climate may affect net ecosystem carbon balance. Recent results indicate that the arctic has become a source of CO{sub 2} to the atmosphere. This change coincides with recent climatic variation in the arctic, and suggests a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. The research proposed in this application has four principal aspects: (A) Long-term response of arctic plants and ecosystems to elevated atmospheric CO{sub 2}; (B) Circumpolar patterns of net ecosystem CO{sub 2} flux; (C) In situ controls by temperature and moisture on net ecosystem CO{sub 2} flux; (D) Scaling of CO{sub 2} flux from plot, to landscape, to regional scales (In conjunction with research proposed for NSF support).

  13. Improved model calculation of atmospheric CO2 increment in affecting carbon stock of tropical mangrove forest

    OpenAIRE

    Jana, Tapan Kumar; Ray, Raghab; Chowdhury, Chumki; Majumder, Natasha; Dutta, Manab Kumar; Mukhopadhyay, Sandip Kumar

    2013-01-01

    Because of the difficulties in setting up arrangements in the intertidal zone for free-air carbon dioxide enrichment experimentation, the responses to increasing atmospheric carbon dioxide in mangrove forests are poorly studied. This study applied box model to overcome this limitation, and the relative changes in present level of reservoirs organic carbon contents in response to the future increase of atmospheric carbon dioxide were examined in the Avicennia-dominated mangrove forest at the l...

  14. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    This paper presents an attempt to develop a new system for fixing carbon dioxide from the atmosphere. The proposed molecular system has been designed to have the capacity to spontaneously bind CO2 from the atmosphere with high affinity. The molecular system is furthermore designed to have the...... ability to liberate CO2 at a later stage in the process, i.e., in a separate compartment. The liberated CO2 presents a carbon neutral way of obtaining pure CO2. The proposed molecular system is based on a small stable organic molecule that potentially have two forms: one without bound CO2 and one with...

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

    International Nuclear Information System (INIS)

    Electrobalance studies of calcination and carbonation of sodium bicarbonate materials were conducted at Louisiana State University. Calcination in an inert atmosphere was rapid and complete at 120 C. Carbonation was temperature dependent, and both the initial rate and the extent of reaction were found to decrease as temperature was increased between 60 and 80 C. A fluidization test apparatus was constructed at RTI and two sodium bicarbonate materials were fluidized in dry nitrogen at 22 C. The bed was completely fluidized at between 9 and 11 in. of water pressure drop. Kinetic rate expression derivations and thermodynamic calculations were conducted at RTI. Based on literature data, a simple reaction rate expression, which is zero order in carbon dioxide and water, was found to provide the best fit against reciprocal temperature. Simulations based on process thermodynamics suggested that approximately 26 percent of the carbon dioxide in flue gas could be recovered using waste heat available at 240 C

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

    Electrobalance studies of calcination and carbonation of sodium bicarbonate materials were conducted at Louisiana State University. Calcination in an inert atmosphere was rapid and complete at 120 C. Carbonation was temperature dependent, and both the initial rate and the extent of reaction were found to decrease as temperature was increased between 60 and 80 C. A fluidization test apparatus was constructed at RTI and two sodium bicarbonate materials were fluidized in dry nitrogen at 22 C. The bed was completely fluidized at between 9 and 11 in. of water pressure drop. Kinetic rate expression derivations and thermodynamic calculations were conducted at RTI. Based on literature data, a simple reaction rate expression, which is zero order in carbon dioxide and water, was found to provide the best fit against reciprocal temperature. Simulations based on process thermodynamics suggested that approximately 26 percent of the carbon dioxide in flue gas could be recovered using waste heat available at 240 C.

  17. Method for Extracting and Sequestering Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

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

  18. Comment on "The phase relation between atmospheric carbon dioxide and global temperature" Humlum et al. [Glob. Planet. Change 100: 51-69.]: Isotopes ignored

    Science.gov (United States)

    Kern, Zoltán; Leuenberger, Markus

    2013-10-01

    A recent study relying purely on statistical analysis of relatively short time series suggested substantial re-thinking of the traditional view about causality explaining the detected rising trend of atmospheric CO2 (atmCO2) concentrations. If these results are well-justified then they should surely compel a fundamental scientific shift in paradigms regarding both atmospheric greenhouse warming mechanism and global carbon cycle. However, the presented work suffers from serious logical deficiencies such as, 1) what could be the sink for fossil fuel CO2 emissions, if neither the atmosphere nor the ocean - as suggested by the authors - plays a role? 2) What is the alternative explanation for ocean acidification if the ocean is a net source of CO2 to the atmosphere? Probably the most provocative point of the commented study is that anthropogenic emissions have little influence on atmCO2 concentrations. The authors have obviously ignored the reconstructed and directly measured carbon isotopic trends of atmCO2 (both δ13C, and radiocarbon dilution) and the declining O2/N2 ratio, although these parameters provide solid evidence that fossil fuel combustion is the major source of atmCO2 increase throughout the Industrial Era.

  19. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-30

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

  20. Thermodynamical effects during carbon dioxide release

    Science.gov (United States)

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

    2012-04-01

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

  1. Gas-exchange, water use efficiency and yield responses of elite potato (Solanum tuberosum L.) cultivars to changes in atmospheric carbon dioxide concentration, temperature and relative humidity

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sørensen, Kirsten Kørup; Nielsen, Kåre Lehmann;

    2014-01-01

    decreased stomatal conductance (25%) with a simultaneous drop in transpiration rate although not significant. The ratio Ci/Ca was in contrast to the first experiment significantly higher in plants grown at elevated [CO2]. Despite this photosynthetic acclimation, concurrent stimulation of aboveground and......In spite of the agricultural importance of potato (Solanum tuberosum L.), most plant physiology studies have not accounted for the effect of the interaction between elevated carbon dioxide concentration ([CO2]) and other consequences of climate change on WUE. In 2010, a first controlled environment...... chamber experiment (E1) was performed with two treatments: one control at a [CO2] exposure level of 380 ppm and the other at elevated [CO2] first to 700 ppm and subsequently to 1000 ppm. Plants grown at elevated [CO2] levels of 700 and 1000 ppm showed a consistent significant increase in leaf level...

  2. 2-Micron Triple-Pulse Integrated Path Differential Absorption Lidar Development for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

    Science.gov (United States)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong

    2016-01-01

    For more than 15 years, NASA Langley Research Center (LaRC) has contributed in developing several 2-micron carbon dioxide active remote sensors using the DIAL technique. Currently, an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development at NASA LaRC. This paper focuses on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of wavelength control, packaging and lidar integration. In addition, receiver development updates will also be presented, including telescope integration, detection systems and data acquisition electronics. Future plan for IPDA lidar system for ground integration, testing and flight validation will be presented.

  3. Development of an Airborne Triple-Pulse 2-Micron Integrated Path Differential Absorption Lidar (IPDA) for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

    Science.gov (United States)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Remus, Ruben

    2016-01-01

    This presentation will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar being developed at NASA Langley Research Center with support from NASA ESTO Instrument Incubator Program. The development of this active optical remote sensing IPDA instrument is targeted for measuring both atmospheric carbon dioxide and water vapor in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plan for IPDA lidar system for ground integration, testing and flight validation will also be presented.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-04-01

    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 CO/sub 2/ and environmental control technology for CO/sub 2/ are also discussed. Lists of research projects and reports and publications of the Carbon Dioxide and Climate Research Program are included. An expanded CO/sub 2/ monitoring network is providing increased coverage for interpretation of patterns of sources and sinks seasonal variability, and documentation of the global growth of CO/sub 2/. Modeling studies emphasized that knowledge of the transport and mixing of surface ocean waters is important in understanding deep oceanic circulation. Initial studies in the equatorial Pacific are helping quantify estimates of the amount of outgassing CO/sub 2/ from tropical waters. During fiscal year 1979, there was a substantial increase in appreciation of the role of the ocean in controlling not only atmospheric CO/sub 2/ concentrations but also the climatic response to changes in concentration. Model simulations of the effect of doubled CO/sub 2/ concentration carried out with fixed ocean temperatures a situation that is possible during perhaps the next 20 years, showed relatively small summer heating over land areas. On the other hand, simulations in which the oceanic temperatures could come into instantaneous equilibrium with atmospheric conditions continued to show global temperature increases of 3 +- 1.5/sup 0/C, accentuated at high latitudes. To improve understanding of possible regional climate changes, there were increased efforts to reconstruct regional climatic patterns prevailing during past warm periods that might serve as analogs of future climatic conditions. Particular attention was directed to the climates of the United States and other countries bordering the North Atlantic Ocean during the warm period 5000 to 7000 years ago.

  5. Carbon dioxide sequestration by mineral carbonation. Literature Review

    International Nuclear Information System (INIS)

    In order to prevent CO2 concentrations in the atmosphere rising to unacceptable levels, carbon dioxide can be separated from the flue gas of, for example, a power plant and subsequently sequestrated. Various technologies for carbon dioxide sequestration have been proposed, such as storage in depleted gas fields, oceans and aquifers. An alternative sequestration route is the so-called 'mineral CO2 sequestration' route in which CO2 is chemically stored in solid carbonates by the carbonation of minerals. As mineral feedstock, rocks that are rich in alkaline earth silicates can be used. Examples are olivine (MgSiO4) and wollastonite (CaSiO3). Mineral CO2 sequestration has some fundamental advantages compared to other sequestration routes. The formed products are thermodynamically stable and therefore the sequestration of CO2 is permanent and safe. Furthermore, the sequestration capacity is large because large suitable feedstock deposits are available worldwide. Finally, the carbonation reactions are exothermic and occur spontaneously in nature. The reaction rates of the process at atmospheric conditions, however, are much too slow for an industrial process. Therefore, research focuses on increasing the reaction rate in order to obtain an industrial viable process. Optimisation of the process conditions is constrained by the thermodynamics of the process. Increasing the temperature and CO2 pressure accelerates the reaction rate, but gaseous CO2 is favoured over mineral carbonates at high temperatures. Using water or another solvent to extract the reactive component from the matrix accelerates the process. Pre-treatment of the mineral by size reduction and thermal or mechanical activation and optimisation of the solution chemistry result in major improvements of the reaction rate. During recent years, laboratory-scale experiments have shown major improvements of the conversion rates by developing various process routes and optimising process conditions. The most

  6. Carbon Dioxide Management on the International Space Station

    Science.gov (United States)

    Burlingame, Katie

    2016-01-01

    The International Space Station (ISS) is a manned laboratory operating in orbit around the Earth that was built and is currently operated by several countries across the world. The ISS is a platform for novel scientific research as well as a testbed for technologies that will be required for the next step in space exploration. In order for astronauts to live on ISS for an extended period of time, it is vital that on board systems consistently provide a clean atmosphere. One contaminant that must be removed from the atmosphere is carbon dioxide (CO2). CO2 levels on ISS are higher than those on Earth and can cause crew members to experience symptoms such as headaches, lethargy and mental slowness. A variety of systems exist on ISS to remove carbon dioxide, including adsorbent technologies which can be reused and testbed technologies for future space vehicles.

  7. [Pharmaceutical applications of supercritical carbon dioxide].

    Science.gov (United States)

    Delattre, L

    2007-01-01

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

  8. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    Carbon and nitrogen are the most abundant elements in plants, together making up around 40-50% and 2-6% of dry matter respectively. Elevated atmospheric CO2 levels are predicted to double by the end of this century, increasing carbon fixation by C3 plants like Arabidopsis and, hence, their carbon...... cues and adjusting it to the plant internal status. The two major types of GS include cytosolic GS1 (five isoforms in Arabidopsis, GLN1;1 to GLN1;5) and a single chloroplastic GS2. GS draws its substrates from carbon skeletons to synthesize amino acids. Thus, carbon and nitrogen metabolisms are closely...... nitrogen species (ammonium and nitrate) and availability. Arabidopsis gln1;2 knock-out and gln2 (reduced GS2 activity by 50%) mutants were studied in response to elevated CO2 (800 ppm) when provided with moderate and high levels of ammonium or nitrate alone, or in combination. Elevated CO2 promoted plant...

  9. n-Nonane Nucleation in the Presence of Carbon Dioxide

    Czech Academy of Sciences Publication Activity Database

    Labetski, D.G.; Hrubý, Jan; Dongen, M. E. H.

    Vienna : Springer Netherlands , 2007, s. 78-82. ISBN 978-1-4020-6474-6. [Nucleation and Atmospheric Aerosols International Conference /17./. Galway (IE), 13.08.2007-17.08.2007] R&D Projects: GA ČR GA101/05/2214 Institutional research plan: CEZ:AV0Z20760514 Keywords : nucleation * natural gas * carbon dioxide Subject RIV: BJ - Thermodynamics http://www.springerlink.com/content/r278044g8244v561/

  10. Enzymatic conversion of carbon dioxide.

    Science.gov (United States)

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

    2015-10-01

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

  11. Synthesis of fluoropolymers in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Fluoropolymers are used in many technologically demanding applications because of their balance of high-performance properties. A significant impediment to the synthesis of variants of commercially available amorphous fluoropolymers is their general insolubility in most solvents except chlorofluorocarbons (CFCs). The environmental concerns about CFCs can be circumvented by preparing these technologically important materials in supercritical fluids. The homogeneous solution polymerization of highly fluorinated acrylic monomers can be achieved in supercritical carbon dioxide by using free radical methods. In addition, detailed decomposition rates and efficiency factors were measured for azobisisobutyronitrile in supercritical carbon dioxide and were compared to those obtained with conventional liquid solvents

  12. Sensitivity Analysis of Atmospheric Carbon Dioxide Retrieval Parameters Based on RTTOV%基于RTTOV模式的大气二氧化碳反演参数敏感性分析

    Institute of Scientific and Technical Information of China (English)

    李镜尧; 施润和; 殷瑞娟

    2014-01-01

    As one of the main greenhouse gases, global atmospheric carbon dioxide has increased one third over the past one hundred years, becoming the focus of global warming research. Using satellite remote sensing tech-nology and radiative transfer model to retrieve atmospheric carbon dioxide has become the most important means to obtain the global carbon dioxide concentration data. However, the input parameters of radiative transfer model inevitably carry some errors, which will influence the retrieval accuracy more or less, so this influence must be quantified and considered in the retrieval algorithm. In this paper, the radiances of 17 infrared carbon di-oxide retrieval channels located in 15μm wave band of the Aqua/AIRS infrared detection instrument are simulat-ed by the fast radiative transfer model RTTOV10. The temperature profile, ozone profile, water vapor profile, surface temperature and emissivity are considered as the influence factors. And the sensitivities of the outgoing radiance to the errors of these input parameters are calculated. Then the comparison between these sensitivities and that to 0.5%change of atmospheric carbon dioxide concentration is made. Analysis shows that:temperature profile errors have the biggest influence on carbon dioxide retrieval, and these errors should be less than 0.5k. The total sensitivity of all channels to ozone profile errors are about one third of that to carbon dioxide, making ozone profile errors take the second place. The sensitivities to errors of water vapor profile and surface tempera-ture show the same trend which is only high at channel 738.1 cm-1 and 738.4 cm-1. Errors of surface emissivity are negligible at all channels, because the sensitivities due to them are far less than that to carbon dioxide. Final-ly, for each channel, these parameters are divided into three classes which are high sensitive parameters, low sen-sitive parameters and non-sensitive parameters, providing a reference for carbon dioxide

  13. Carbon Dioxide Angiography: Scientific Principles and Practice.

    Science.gov (United States)

    Cho, Kyung Jae

    2015-09-01

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

  14. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M;

    1999-01-01

    to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically...

  15. Magnesian calcite sorbent for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    Mabry, J.C.; Mondal, K. [Southern Illinois University, Carbondale, IL (United States)

    2011-07-01

    Magnesian calcite with controlled properties was synthesized for the removal of carbon dioxide. The results from characterization, reactivity and CO{sub 2} capture capacity for different synthesis conditions are reported. The magnesian calcite samples (CaCO{sub 3}:MgCO{sub 3}) were synthesized by the coprecipitation of specific amounts of commercially available CaO and MgO by carbon dioxide. Characterization was done with BET, SEM/EDS, particle size analysis and XRD. The capacity was measured using TGA cycles at 800 {sup o}C and compared for different preparation conditions. The effects of CaO, MgO and surfactant loading on the physical properties and carbonation activity were studied to determine the optimal synthesis condition. A long-term carbonation-calcination cycling test was conducted on the optimal sample. It was observed that the sample maintained its capacity to 86% of its original uptake even after 50 cycles.

  16. Removal of Carbon Dioxide Gas From the Exhaust Gases Generated at the Takoradi Thermal Power Station

    Directory of Open Access Journals (Sweden)

    M. Charles

    2010-10-01

    Full Text Available Takoradi Thermal Power Station (TTPS generates electricity by burning fossil-fuel and hence it also generates greenhouse gases especially carbon dioxide, which is vented into the atmosphere. These greenhouse gases are pollutants known to cause global warming. A method for the removal of carbon dioxide gas from the exhaust gases generated at TTPS is proposed in this research. It aims at reducing the plant’s carbon dioxide emission into the atmosphere and hence reducing the plant’s rate of pollution into the atmosphere. The method employed is a modification of a method known as the Fluor Daniel ECONAMINE FG process. This method removes carbon dioxide from exhaust gas by using an amine solution which comes into “contact” with the exhaust gas in a counter-current manner. This method has been applied by 23 companies which produce CO2 on a large scale. However, before TTPS apply this method a cost feasibility study is recommended.

  17. Immobilized Ruthenium Catalyst for Carbon Dioxide Hydrogenation

    Institute of Scientific and Technical Information of China (English)

    Ying Min YU; Jin Hua FEI; Yi Ping ZHANG; Xiao Ming ZHENG

    2006-01-01

    Three kinds of cross linked polystyrene resin (PS) supported ruthenium complexes were developed as catalysts for the synthesis of formic acid from carbon dioxide hydrogenation. Many factors, such as the functionalized supports, solvents and ligands, could influence their activities and reuse performances greatly. These immobilized catalysts also offer the industrial advantages such as easy separation.

  18. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Plauborg, Finn; Heckrath, Goswin Johann;

    2014-01-01

    Carbon dioxide (CO2) concentrations in arable soil profiles are influenced by autotrophic and heterotrophic respiration as well as soil physical properties that regulate gas transport. Whereas different methods have been used to assess dynamics of soil CO2 concentrations, our understanding on the...

  19. Tourism Transport, Technology, and Carbon Dioxide Emissions

    NARCIS (Netherlands)

    Peeters, P.M.

    2010-01-01

    Technological development from horse-drawn carriages to the new Airbus A380 has led to a remarkable increase in both the capacity and speed of tourist travel. This development has an endogenous systemic cause and will continue to increase carbon dioxide emissions/energy consumption if left unchecked

  20. Heat transfer coefficient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1998-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The calculated heat transfer coeeficient has been compared with the Chart correlation of Shah. The Chart Correlation predits too low heat transfer coefficient but the ratio...

  1. Heat transfer coeffcient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1997-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The pipe is heated by condensing R22 outside the pipe. The heat input is supplied by an electrical heater wich evaporates the R22. With the heat flux assumed constant over...

  2. Recovery of carbon dioxide from fuel cell exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Healy, H.C.; Kolodney, M.; Levy, A.H.; Trocciola, P.

    1988-06-14

    An acid fuel cell power plant system operable to produce carbon dioxide as a by-product is described comprising: (a) fuel cell stack means having anode means, cathode means, and fuel cell cooling means, the cooling means using a water coolant; (b) means for delivering a hydrogen-rich fuel gas which contains carbon dioxide to the anode means for consumption of hydrogen by the anode means in an electrochemical reaction in the stack; (c) carbon dioxide absorber means including an absorbent for stripping carbon dioxide from gaseous mixtures thereof; (d) means for delivering hydrogen-depleted exhaust gas containing carbon dioxide from the anode means to the carbon dioxide absorber means for absorption of carbon dioxide from the exhaust gas; (e) an absorbent regenerator; (f) means for delivering carbon dioxide-enriched absorbent from the absorber means to the regenerator for separation of carbon dioxide from the absorbent; (g) means for exhausting carbon dioxide from the regenerator, the means for exhausting further including means for cooling and compressing carbon dioxide exhausted from the regenerator; and (h) means for removing the compressed carbon dioxide from the power plant.

  3. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

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

  4. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  5. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  6. 9 CFR 313.5 - Chemical; carbon dioxide.

    Science.gov (United States)

    2010-01-01

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

  7. 27 CFR 24.319 - Carbon dioxide record.

    Science.gov (United States)

    2010-04-01

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

  8. Designing and Demonstrating a Master Student Project to Explore Carbon Dioxide Capture Technology

    Science.gov (United States)

    Asherman, Florine; Cabot, Gilles; Crua, Cyril; Estel, Lionel; Gagnepain, Charlotte; Lecerf, Thibault; Ledoux, Alain; Leveneur, Sebastien; Lucereau, Marie; Maucorps, Sarah; Ragot, Melanie; Syrykh, Julie; Vige, Manon

    2016-01-01

    The rise in carbon dioxide (CO[subscript 2]) concentration in the Earth's atmosphere, and the associated strengthening of the greenhouse effect, requires the development of low carbon technologies. New carbon capture processes are being developed to remove CO[subscript 2] that would otherwise be emitted from industrial processes and fossil fuel…

  9. Systemic effects of geoengineering by terrestrial carbon dioxide removal on carbon related planetary boundaries

    Science.gov (United States)

    Heck, Vera; Donges, Jonathan; Lucht, Wolfgang

    2015-04-01

    The planetary boundaries framework as proposed by Rockström et al. (2009) provides guidelines for ecological boundaries, the transgression of which is likely to result in a shift of Earth system functioning away from the relatively stable Holocene state. As the climate change boundary is already close to be transgressed, several geoengineering (GE) methods are discussed, aiming at a reduction of atmospheric carbon concentrations to control the Earth's energy balance. One of the proposed GE methods is carbon extraction from the atmosphere via biological carbon sequestration. In case mitigation efforts fail to substantially reduce greenhouse gas emissions, this form of GE could act as potential measure to reduce atmospheric carbon dioxide concentrations. We here study the possible influences of human interactions in the Earth system on carbon related planetary boundaries in the form of geoengineering (terrestrial carbon dioxide removal). We use a conceptual model specifically designed to investigate fundamental carbon feedbacks between land, ocean and atmosphere (Anderies et al., 2013) and modify it to include an additional geoengineering component. With that we analyze the existence and stability of a safe operating space for humanity, which is here conceptualized in three of the 9 proposed dimensions, namely climate change, ocean acidification and land-use. References: J. M. Anderies et al., The topology of non-linear global carbon dynamics: from tipping points to planetary boundaries. Environ. Res. Lett., 8(4):044048 (2013) J. Rockström et al., A safe operating space for humanity. Nature 461 (7263), 472-475 (2009)

  10. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Science.gov (United States)

    2010-07-01

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

  11. Modelling interactions of carbon dioxide, forests, and climate

    International Nuclear Information System (INIS)

    Atmospheric carbon dioxide is rising and forests and climate is changing exclamation point This combination of fact and premise may be evaluated at a range of temporal and spatial scales with the aid of computer simulators describing the interrelationships between forest vegetation, litter and soil characteristics, and appropriate meteorological variables. Some insights on the effects of climate on the transfers of carbon and the converse effect of carbon transfer on climate are discussed as a basis for assessing the significance of feedbacks between vegetation and climate under conditions of rising atmospheric carbon dioxide. Three main classes of forest models are reviewed. These are physiologically-based models, forest succession simulators based on the JABOWA model, and ecosystem-carbon budget models that use compartment transfer rates with empirically estimated coefficients. Some regression modeling approaches are also outlined. Energy budget models applied to forests and grasslands are also reviewed. This review presents examples of forest models; a comprehensive discussion of all available models is not undertaken

  12. Carbon dioxide flux measurements from a coastal Douglas-fir forest floor

    International Nuclear Information System (INIS)

    This thesis examined the process that affects the exchange of carbon between the soil and the atmosphere with particular attention to the large amounts of carbon stored in soils in the form of decaying organic matter. This forest floor measuring study was conducted in 2000 at a micro-meteorological tower flux site in a coastal temperature Douglas-fir forest. The measuring study involved half hourly measurements of both carbon dioxide and below-ground carbon dioxide storage. Measurements were taken at 6 locations between April and December to include a large portion of the growing season. Eddy covariance (EC) measurements of carbon dioxide flux above the forest floor over a two month period in the summer and the autumn were compared with forest floor measurements. Below-ground carbon dioxide mixing ratios of soil air were measured at 6 depths between 0.02 to 1 m using gas diffusion probes and a syringe sampling method. Maximum carbon dioxide fluxes measured by the soil chambers varied by a factor of 3 and a high spatial variability in soil carbon dioxide flux was noted. Forest floor carbon dioxide fluxes measured by each of the chambers indicated different sensitivities to soil temperature. Hysteresis in the flux temperature relationship over the year was evident. Reliable below-canopy EC measurements of the forest floor carbon dioxide flux were difficult to obtain because of the every low wind speeds below the forest canopy. The amount of carbon dioxde present in the soil increased rapidly with depth near the surface but less rapidly deeper in the soil. It was suggested that approximately half of the carbon dioxide produced below-ground comes from between the soil surface and the first 0.15 m of depth. Carbon dioxide fluxes from the floor of a Douglas-fir forest were found to be large compared to other, less productive ecosystems

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (carbon dioxide removal.

  14. Materials for carbon dioxide separation

    International Nuclear Information System (INIS)

    The CO2 adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO2 adsorption ability. Another promising class of materials for CO2 capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO3 and the relationship between physisorption and chemisorption properties of CaO-based materials.

  15. Carbon Dioxide Reduction Technology Trade Study

    Science.gov (United States)

    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

  16. Biofixation of Carbon dioxide by Chlamydomonas sp. in a Tubular Photobioreactor

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-02-01

    Full Text Available The biogas production from anaerobic digestion is a potential fuel for power generators application, if biogas can be upgraded to the same standards as fossil natural gas by CO2, H2S, and other non-combustible component removal. Microalgae Chlamydomonas sp. has potency to biofix the carbon dioxide and can be used as an additional food ingredient. The variations of flow rate and carbon dioxide concentration in the process resulting different value of biomass production and carbon dioxide biofixation. Biomass production at 40% carbon dioxide concentration obtained 5.685 gr/dm3 at 10% carbon dioxide concentration obtained 4.892 gr/dm3. The greatest value of carbon dioxide absorption occurs at a 40% concentration amounting to 12.09%. The rate of growth and productivity of microalgae tend to rise in 10% and 20% (%v carbon dioxide concentration, but began started a constant at 30% and 40% (%v carbon dioxide concentration. Biomass production tends to increase in light conditions while a constant in dark conditions. This study used Chlamydomonas sp. as media culture and performed on bubble column and tubular reactor with 6 litres of culture medium at a temperature of 28oC and atmospheric pressure.

  17. Biofixation of Carbon dioxide by Chlamydomonas sp. in a Tubular Photobioreactor

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-04-01

    Full Text Available The biogas production from anaerobic digestion is a potential fuel for power generators application, if biogas can be upgraded to the same standards as fossil natural gas by CO2, H2S, and other non-combustible component removal. Microalgae Chlamydomonas sp. has potency to biofix the carbon dioxide and can be used as an additional food ingredient. The variations of flow rate and carbon dioxide concentration in the process resulting different value of biomass production and carbon dioxide biofixation. Biomass production at 40% carbon dioxide concentration obtained 5.685 gr/dm3 at 10% carbon dioxide concentration obtained 4.892 gr/dm3. The greatest value of carbon dioxide absorption occurs at a 40% concentration amounting to 12.09%. The rate of growth and productivity of microalgae tend to rise in 10% and 20% (%v carbon dioxide concentration, but began started a constant at 30% and 40% (%v carbon dioxide concentration. Biomass production tends to increase in light conditions while a constant in dark conditions. This study used Chlamydomonas sp. as media culture and performed on bubble column and tubular reactor with 6 litres of culture medium at a temperature of 28oC and atmospheric pressure.

  18. Carbon Dioxide Mitigation Benefit of High-Speed Railway in Terms of Carbon Tax

    OpenAIRE

    Fu Yanbing; Zhang Sufen; Xie Meiquan; Li Shuping; Huang Zelin

    2013-01-01

    This paper calculates the carbon dioxide mitigation benefit of high-speed railway based on the carbon dioxide tax policy. We define the carbon dioxide emission system boundary for high-speed railway in its whole life cycle and estimate the life cycle carbon dioxide inventories during its construction, application, and recovery stages. And then we establish a theoretical model to calculate the life cycle carbon dioxide mitigation quantity for high-speed railway when compared with road transpor...

  19. Urban carbon dioxide in Portland, Oregon

    Science.gov (United States)

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

    2010-12-01

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

  20. Carbon dioxide emissions from biochar in soil

    DEFF Research Database (Denmark)

    Bruun, S; Clauson-Kaas, S; Bobul'ská, L;

    2014-01-01

    -sterilized soils. It emerged that carbonate may be concentrated or form during or after biochar production, resulting in significant carbonate contents. If CO2 released from carbonates in short-term experiments is misinterpreted as mineralization of biochar, the impact of this process may be significantly over...... evolution. Finally, we found that both production temperature and clay content affect biochar mineralization. As protective mechanisms hypothesized to prevent degradation of organic matter in soil usually implicate clay, we conclude that biochar is likely to be protected from mineralization during the early......The stability of biochar in soil is of importance if it is to be used for carbon sequestration and long-term improvement of soil properties. It is well known that a significant fraction of biochar is highly stable in soil, but carbon dioxide (CO2) is also released immediately after application...

  1. Efficient Fixation of Carbon Dioxide by Electrolysis - Facile Synthesis of Useful Carboxylic Acids -

    Institute of Scientific and Technical Information of China (English)

    Masao Tokuda

    2006-01-01

    Electrochemical fixation of atmospheric pressure of carbon dioxide to organic compounds is a useful and attractive method for synthesizing of various carboxylic acids. Electrochemical fixation of carbon dioxide, electrochemical carboxylation, organic halides, organic triflates, alkenes, aromatic compounds, and carbonyl compounds can readily occur in the presence of an atmospheric pressure of carbon dioxide to form the corresponding carboxylic acids with high yields, when a sacrificial anode such as magnesium or aluminum is used in the electrolysis. The electrochemical carboxylation of vinyl bromides was successfully applied for the synthesis of the precursor of nonsteroidal anti-inflammatory agents such as ibuprofen and naproxen. On the other hand, supercritical carbon dioxide (scCO2) has significant potential as an environmentally benign solvent in organic synthesis and it could be used both as a solvent and as a reagent in these electrochemical carboxylations by using a small amount of cosolvent.

  2. The study on density change of carbon dioxide seawater solution at high pressure and low temperature

    International Nuclear Information System (INIS)

    It has been widely considered that the global warming, induced by the increasing concentration of carbon dioxide and other greenhouse gases in the atmosphere, is an environmental task affecting the world economic development. In order to mitigate the concentration of CO2 in the atmosphere, the sequestration of carbon dioxide into the ocean had been investigated theoretically and experimentally over the last 10 years. In addition to ocean dynamics, ocean geological, and biological information on large space and long time scales, the physical-chemistry properties of seawater-carbon dioxide system at high pressure (P>5.0 MPa) and lower temperature (274.15 K3, which is approximately same with that of carbon dioxide freshwater solution, the slope of which is 0.275 g/cm3

  3. Carbon dioxide in vascular imaging and intervention

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xiaoming [Dept. of Clinical Radiology, Univ. Hospital, Kuopio (Finland); Manninen, H. [Dept. of Clinical Radiology, Univ. Hospital, Kuopio (Finland); Soimakallio, S. [Dept. of Clinical Radiology, Univ. Hospital, Kuopio (Finland)

    1995-07-01

    Angiography with iodinated contrast agents is bound up with the risks of contrast-induced nephrotoxicity and hypersensitivity, which led to the idea of using carbon dioxide (CO{sub 2}) gas as a negative contrast medium to eliminate these drawbacks. During the last decade, refinements and experiences have proved carbon dioxide digital subtraction angiography (CO{sub 2}-DSA) to be an accurate, safe, and clinically promising vascular imaging modality, with the advantages of no hypersensitivity and no nephrotoxicity as well as minimal patient discomfort. In this article, we have reviewed the history, physical and chemical aspects, techniques, and pathophysiologic changes with the use of CO{sub 2}-DSA as well as some clinical trials. Applications of CO{sub 2} gas in vascular interventions and other imagings, and the advantages and limitations of using CO{sub 2} gas in DSA are also discussed. (orig.).

  4. Carbon dioxide in vascular imaging and intervention.

    Science.gov (United States)

    Yang, X; Manninen, H; Soimakallio, S

    1995-07-01

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

  5. Supercritical carbon dioxide decontamination of PAH contaminants

    International Nuclear Information System (INIS)

    Before the 1940's, more than 2,000 manufactured gas plant sites existed across North America for the production of a low Btu gas for heating and lighting. These sites, now abandoned, are contaminated with polycyclic aromatic hydrocarbons (PAHs), a coal gasification byproduct that was dumped on-site into unlined pits. The potential for ground water contamination of PAHs has made these sites an environmental concern. The remediation of PAH contaminated sites is difficult to achieve by conventional cleaning methods. In this work, supercritical carbon dioxide extraction has been investigated on a town gas soil containing 3.37 wt% contamination. The soil has been remediated in a 300 cm3 semi-continuous extraction vessel and the effects of solvent temperature, pressure, and density will be discussed. Supercritical carbon dioxide extraction is an emerging technology that can extract compounds that are difficult or impossible by conventional processes

  6. Carbon dioxide in vascular imaging and intervention

    International Nuclear Information System (INIS)

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

  7. Carbon dioxide methanation for intensified reactors

    OpenAIRE

    Coronado Martín, Irene

    2015-01-01

    The present work is related to the development of sustainable energy systems based on the Power-to-Gas concept. The main objective is to utilise renewable hydrogen and carbon dioxide to produce methane for storage in the natural gas infrastructure. Multitubular fixed-bed reactors are established at industrial scale for CO2 methanation. Catalytic pellets commonly loaded in this type of reactor involve poor heat transfer and high pressure drop that lead to inefficient processes. Today, reac...

  8. Plasma beam discharge in carbon dioxide

    International Nuclear Information System (INIS)

    The paper deals with the dissociation of carbon dioxide in nonequilibrium plasma of a stationary plasma-beam discharge. Experimental results of spectroscopic and probe measurements of plasma parameters are given. Moreover, a mass-spectrometric analysis of gaseous products of the chemical reactions is presented. In addition the measurement of the deposition rate of solid products by means of a quartz oscillator is described. The results show that plasma beam discharge is an effective tool for inducing plasma-chemical reactions. (author)

  9. Pulsed discharge plasmas in supercritical carbon dioxide

    OpenAIRE

    Kiyan, Tsuyoshi; Uemura, A.; Tanaka, K.; Zhang, C. H.; Namihira, Takao; Sakugawa, Takashi; Katsuki, Sunao; Akiyama, Hidenori; Roy, B.C; Sasaki, M.; Goto, M; キヤン, ツヨシ; ナミヒラ, タカオ; サクガワ, タカシ; カツキ, スナオ

    2005-01-01

    In recent years, several studies about electrical discharge plasma in supercritical carbon dioxide (CO2) have been carried out. One of the unique characteristics of supercritical fluid is a large density fluctuation near the critical point that can result in marked dramatic changes of thermal conductivity. Therefore, the electrical discharge plasma produced in supercritical fluid has unique features and reactions unlike those of normal plasma produced in gas phase. In our experiments, two typ...

  10. CIVIL AVIATION CARBON DIOXIDE EMISSIONS IN CHINA

    OpenAIRE

    Chen, Sainan

    2013-01-01

    With the social and economic development, the civil aviation industry of China is experiencing rapid growth. This growth will lead to more CO2 emissions. Carbon dioxide emissions and greenhouse effect are already serious problems especially in China, but also all over the world. Civil aviation has brought environmental pollution in the context of improving social activity and economic growth. Because of civil aviation, the rapid increase of the total amount of air pollutants are also in...

  11. Production of lightweight aggregate from industrial waste and carbon dioxide.

    Science.gov (United States)

    Gunning, Peter J; Hills, Colin D; Carey, Paula J

    2009-10-01

    The concomitant recycling of waste and carbon dioxide emissions is the subject of developing technology designed to close the industrial process loop and facilitate the bulk-re-use of waste in, for example, construction. The present work discusses a treatment step that employs accelerated carbonation to convert gaseous carbon dioxide into solid calcium carbonate through a reaction with industrial thermal residues. Treatment by accelerated carbonation enabled a synthetic aggregate to be made from thermal residues and waste quarry fines. The aggregates produced had a bulk density below 1000 kg/m(3) and a high water absorption capacity. Aggregate crushing strengths were between 30% and 90% stronger than the proprietary lightweight expanded clay aggregate available in the UK. Cast concrete blocks containing the carbonated aggregate achieve compressive strengths of 24 MPa, making them suitable for use with concrete exposed to non-aggressive service environments. The energy intensive firing and sintering processes traditionally required to produce lightweight aggregates can now be augmented by a cold-bonding, low energy method that contributes to the reduction of green house gases to the atmosphere. PMID:19577916

  12. Conversion of carbon dioxide to valuable petrochemicals:An approach to clean development mechanism

    Institute of Scientific and Technical Information of China (English)

    Farnaz Tahriri Zangeneh; Saeed Sahebdelfar; Maryam Takht Ravanchi

    2011-01-01

    The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea.The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases,modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts.

  13. As carbon dioxide rises, food quality will decline without careful nitrogen management

    OpenAIRE

    Bloom, Arnold J.

    2009-01-01

    Rising atmospheric concentrations of carbon dioxide could dramatically influence the performance of crops, but experimental results to date have been highly variable. For example, when C3 plants are grown under carbon dioxide enrichment, productivity increases dramatically at first. But over time, organic nitrogen in the plants decreases and productivity diminishes in soils where nitrate is an important source of this nutrient. We have discovered a phenomenon that provides a relatively simple...

  14. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    Directory of Open Access Journals (Sweden)

    Amir Abu Zikry

    2011-01-01

    Full Text Available Bariatric restrictive and malabsorptive operations are being carried out in most countries laparoscopically. Carbon dioxide or gas embolism has never been reported in obese patients undergoing bariatric surgery. We report a case of carbon dioxide embolism during laparoscopic sleeve gastrectomy (LSG in a young super obese female patient. Early diagnosis and successful management of this complication are discussed. An 18-year-old super obese female patient with enlarged fatty liver underwent LSG under general anesthesia. During initial intra-peritoneal insufflation with CO 2 at high flows through upper left quadrant of the abdomen, she had precipitous fall of end-tidal CO 2 and SaO 2 % accompanied with tachycardia. Early suspicion led to stoppage of further insufflation. Clinical parameters were stabilized after almost 30 min, while the blood gas analysis was restored to normal levels after 1 h. The area of gas entrainment on the damaged liver was recognized by the surgeon and sealed and the surgery was successfully carried out uneventfully. Like any other laparoscopic surgery, carbon dioxide embolism can occur during bariatric laparoscopic surgery also. Caution should be exercised when Veress needle is inserted through upper left quadrant of the abdomen in patients with enlarged liver. A high degree of suspicion and prompt collaboration between the surgeon and anesthetist can lead to complete recovery from this potentially fatal complication.

  15. Amazon River carbon dioxide outgassing fuelled by wetlands

    Science.gov (United States)

    Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L. Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F.; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C.; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F.; Roland, Fabio

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

  16. Carbon-14 measurement using carbon dioxide absorption method - Our experience

    International Nuclear Information System (INIS)

    Carbon-C14 measurement using absorption technique consists of direct absorption of sample carbon dioxide into an absorber - scintillator mixture. This technique is a simple, fast, less expensive and less hazardous technique compared to benzene synthesis or any other technique. This techniques enable us in preparing six/seven samples in a day while benzene synthesis technique takes two days for the preparation of one sample. It is useful for radiocarbon age up to about 38,000 a BP (∼1 pMC), which is adequate for most of the hydrological investigations. All the total dissolved inorganic carbon (TDIC) is precipitated as barium carbonate from the ∼60 to 70 liters of water at the site. In the laboratory, it is reacted with orthophosphoric acid to give carbon dioxide (CO2). This carbon dioxide is transferred into 0.5 L capacity cylinder. The reaction and collection of gas is done under vacuum using a glass vacuum line. Carbon dioxide is directly absorbed in 11.5 ml of carbasorb + 11 ml of Permaflour V (commercially not available) or its equivalent scintillator in the specially made absorption apparatus. Since, absorption process is exothermic, temperature of the medium is maintained at about 220 deg. C, it results in the absorption of ∼7 m moles of carbon dioxide per mL of cabasorb. As reaction progresses, bubbles can be seen rising slowly. The end point is marked by rapid rise in the solution level. Carbon dioxide obtained from oxalic acid (Standard) and background carbon dioxide are also absorbed in the same quantity of absorber and scintillator mixture. Samples, standard and background are transferred in 22 mL teflon vials and counted in low level liquid scintillation counter (LKB Wallac 1220 Quantulus) for 1000 minutes. The counting efficiency at best factor of merit (AON/ON/√B) is ∼60 % where AON is normalized net count rate of standard and B is the background count rate. The mean count rate of last fifteen background samples is 0.64 ± .0005 cpm with an

  17. Carbon dioxide, temperature, salinity, and atmospheric pressure from surface underway survey in the North Pacific from January 1998 to January 2004 (NODC Accession 0045502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface pCO2, sea surface temperature, sea surface salinity, and atmospheric pressure measurements collected in the North Pacific as part of the NOAA Office of...

  18. Field results from 3 campaigns to validate the performance of the Miniaturized Laser Heterodyne Radiometer (mini-LHR) for measuring carbon dioxide and methane in the atmospheric column

    Science.gov (United States)

    Wilson, E. L.; Clarke, G. B.; Melroy, H.; Miller, J. H.; Allan, G. R.; McLinden, M. L.; Ott, L.; Holben, B. N.

    2013-12-01

    We present mini-LHR measurements of column CO2 and CH4 from our recent field campaign at Mauna Loa Observatory (MLO), HI in May 2013 as well as column CO2 measurements from Castle Airport in Merced, CA during the ASCENDS DC-8 campaign in February 2013, and column CO2 measurements made at the NOAA LEF/TCCON (Total Column Carbon Observing Network) site in Park Falls, WI in September 2012. The mini-LHR was completely automated at the MLO location and operates in tandem with an AERONET sun photometer and measures CO2 and CH4 every 15 minutes during daylight hours in clear sky conditions. Laser heterodyne radiometry has been an established receiver technique since the 1970s and has been used to measure a range of atmospheric gases such as ozone, water vapor, methane, ammonia, chlorine monoxide, and nitrous oxide. The mini-LHR is a passive variation on this technique that uses sunlight as the light source to measure absorption of CO2 and CH4 in the infrared. In this instrument, sunlight is collected with collimation optics mounted to the AERONET sun tracker and superimposed with laser light in a single mode fiber coupler. The signals are mixed in a fast photoreceiver (InGaAs detector), and the RF (radio frequency) beat signal is extracted. Changes in concentration of the trace gas are realized through analyzing changes in the beat frequency amplitude. Miniaturization was made possible through the use of smaller distributive feedback (DFB) lasers and related fiber optic components that have recently become commercially available and inexpensive through progress in the telecommunications industry. In addition to the complementary aerosol optical depth measurement, tandem operation with AERONET provides a clear pathway for the mini-LHR to be expanded into a global monitoring network. AERONET has more than 450 instruments worldwide and offers coverage in key arctic regions (not covered by OCO-2) where accelerated warming due to the release of CO2 and CH4 from thawing tundra

  19. High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suite Gas Processing System (GPS) Carbon Dioxide Scrubber

    Science.gov (United States)

    Hoffman, Christopher; Munoz, Bruno; Gundersen, Cynthia; Thomas, Walter, III; Stephenson, Timothy

    2008-01-01

    In support of the GPS for the SAM instrument suite built by NASA/GSFC, a life test facility was developed to test the suitability of 80Ni-20Cr alloy wire, 0.0142 cm diameter, for use as a heater element for the carbon dioxide scrubber. The element would be required to operate at 1000 C in order to attain the 800 C required for regeneration of the getter. The element also would need to operate in the Mars atmosphere, which consists mostly of CO2 at pressures between 4 and 12 torr. Data on the high temperature degradation mechanism of 80Ni- 20Cr in low pressure CO2, coupled with the effects of thermal cycling, were unknown. In addition, the influence of work hardening of the wire during assembly and the potential for catastrophic grain growth also were unknown. Verification of the element reliability as defined by the mission goals required the construction of a test facility that would accurately simulate the duty cycles in a simulated Mars atmosphere. The experimental set-up, along with the test protocol and results will be described.

  20. Perspectives of nuclear power and carbon dioxide abatement

    International Nuclear Information System (INIS)

    The papers presented at the conference particularly look at reactor safety aspects and nuclear power programmes worldwide, which are discussed in connection with the demand for ensuring power supplies in the future, and reducing atmospheric pollution by carbon dioxide. The CO2 problem as it is encountered at present and strategies for CO2 abatement are explained in some papers, whereas other papers are concerned with nuclear power reactors and the related major aspects of safety engineering, nuclear fuel supply and radioactive waste management, and further development of nuclear installations, comparing the technical details and pro and cons of LWR, HTR, and breeder reactor programmes. (DG)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

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

  3. The carbon dioxide thermometer and the cause of global warming

    International Nuclear Information System (INIS)

    Carbon dioxide in the air may be increasing because the world is warming. This possibility, which contradicts the hypothesis of an enhanced greenhouse warming driven by manmade emissions, is here pursued in two ways. First, increments in carbon dioxide are treated as readings of a natural thermometer that tracks global and hemispheric temperature deviations, as gauged by meteorologists' thermometers. Calibration of the carbon dioxide thermometer to conventional temperatures then leads to a history of carbon dioxide since 1856 that diverges from the ice-core record. Secondly, the increments of carbon dioxide can also be accounted for, without reference to temperature, by the combined effects of cosmic rays, El Nino and volcanoes. The most durable effect is due to cosmic rays. A solar wind history, used as a long-term proxy for the cosmic rays, gives a carbon dioxide history similar to that inferred from the global temperature deviations. (author)

  4. Carbon dioxide stripping in aquaculture -- part II: development of gas transfer models

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    The basic mass transfer equation for gases such as oxygen and carbon dioxide can be derived from integration of the driving force equation. Because of the physical characteristics of the gas transfer processes, slightly different models are used for aerators tested under the non steady-state procedures, than for packed columns, or weirs. It is suggested that the standard condition for carbon dioxide should be 20 °C, 1 atm, CCO2=20 mg/kg, and XCO2=0.000285. The selection of the standard condition for carbon dioxide based on a fixed mole fraction ensures that standardized carbon dioxide transfer rates will be comparable even though the value of C*CO2 in the atmosphere is increasing with time. The computation of mass transfer for carbon dioxide is complicated by the impact of water depth and gas phase enrichment on the saturation concentration within the unit, although the importance of either factor depends strongly on the specific type of aerator. For some types of aerators, the most accurate gas phase model remains to be determined for carbon dioxide. The assumption that carbon dioxide can be treated as a non-reactive gas in packed columns may apply for cold acidic waters but not for warm alkaline waters.

  5. Interaction of carbon dioxide with Cu overlayers on Pt(111)

    DEFF Research Database (Denmark)

    Schumacher, N.; Andersson, Klas Jerker; Grabow, L.C.;

    2008-01-01

    Experimental and theoretical studies on the interaction of carbon dioxide with pseudomorphic and rough copper layers deposited on a platinum (111) single crystal are reported. Evidence for carbon dioxide dissociation and carbonate formation is presented and the relevance to methanol synthesis is...

  6. SOIL CARBON DIOXIDE EFFLUX IN RESPONSE TO FERTILIZATION AND MULCHING TREATMENTS IN A TWO-YEAR-OLD LOBLOLLY PINE (Pinus taeda L.) PLANTATION IN THE VIRGINIA PIEDMONT

    OpenAIRE

    Pangle, Robert E

    2000-01-01

    Due to concern over the increasing concentration of carbon dioxide in the atmosphere, forest researchers and managers are currently studying the effects of varying silvicultural and harvesting practices on the carbon dynamics of intensely managed forest ecosystems. Soil carbon dioxide efflux resulting from soil microbial activity and root respiration is one of the major components of the total carbon flux in forested ecosystems. In an effort to examine the response of soil carbon dioxide ...

  7. Robust direct effect of carbon dioxide on tropical circulation and regional precipitation

    Science.gov (United States)

    Bony, Sandrine; Bellon, Gilles; Klocke, Daniel; Sherwood, Steven; Fermepin, Solange; Denvil, Sébastien

    2013-06-01

    Predicting the response of tropical rainfall to climate change remains a challenge. Rising concentrations of carbon dioxide are expected to affect the hydrological cycle through increases in global mean temperature and the water vapour content of the atmosphere. However, regional precipitation changes also closely depend on the atmospheric circulation, which is expected to weaken in a warmer world. Here, we assess the effect of a rise in atmospheric carbon dioxide concentrations on tropical circulation and precipitation by analysing results from a suite of simulations from multiple state-of-the-art climate models, and an operational numerical weather prediction model. In a scenario in which humans continue to use fossil fuels unabated, about half the tropical circulation change projected by the end of the twenty-first century, and consequently a large fraction of the regional precipitation change, is independent of global surface warming. Instead, these robust circulation and precipitation changes are a consequence of the weaker net radiative cooling of the atmosphere associated with higher atmospheric carbon dioxide levels, which affects the strength of atmospheric vertical motions. This implies that geo-engineering schemes aimed at reducing global warming without removing carbon dioxide from the atmosphere would fail to fully mitigate precipitation changes in the tropics. Strategies that may help constrain rainfall projections are suggested.

  8. PREPARATION OF MESOPOROUS CARBON BY CARBON DIOXIDE ACTIVATION WITH CATALYST

    Institute of Scientific and Technical Information of China (English)

    W.Z.Shen; A.H.Lu; J.T.Zheng

    2002-01-01

    A mesoporous activated carbon (AC) can be successfully prepared by catalytic activa-tion with carbon dioxide. For iron oxide as catalyst, there were two regions of mesoporesize distribution, i.e. 2-5nm and 30-70nm. When copper oxide or magnesium oxidecoexisted with iron oxide as composite catalyst, the content of pores with sizes of 2-5nm was decreased, while the pores with 30 70nm were increased significantly. Forcomparison, AC reactivated by carbon dioxide directly was also investigated. It wasshown that the size of mesopores of the resulting AC concentrated in 2-5nm with lessvolume. The adsorption of Congo red was tested to evaluate the property of the result-ing AC. Furthermore, the factors affecting pore size distribution and the possibility ofmesopore formation were discussed.

  9. Supercritical carbon dioxide: a solvent like no other

    Directory of Open Access Journals (Sweden)

    Jocelyn Peach

    2014-08-01

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

  10. Supercritical carbon dioxide: a solvent like no other

    OpenAIRE

    Jocelyn Peach; Julian Eastoe

    2014-01-01

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

  11. Carbon dioxide kinetics and capnography during critical care

    OpenAIRE

    Anderson, Cynthia T; Breen, Peter H

    2000-01-01

    Greater understanding of the pathophysiology of carbon dioxide kinetics during steady and nonsteady state should improve, we believe, clinical care during intensive care treatment. Capnography and the measurement of end-tidal partial pressure of carbon dioxide (PETCO2) will gradually be augmented by relatively new measurement methodology, including the volume of carbon dioxide exhaled per breath (VCO2,br) and average alveolar expired PCO2 (PA̅E̅CO2). Future directions include the study of oxy...

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

    OpenAIRE

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

    2013-01-01

    New and improved materials capable of binding carbon dioxide are essential to addressing the global threat of accelerating climate change. The presently used industrial methods for carbon dioxide capture have severe drawbacks, including toxicity and energy inefficiency. Newer porous materials are so far less effective in water, invariably a component of combustion gases. Here, we present a material for carbon dioxide capture. This material, amyloid fibers in powdered form, selectively capture...

  13. The transient response of global-mean precipitation to increasing carbon dioxide levels

    International Nuclear Information System (INIS)

    The transient response of global-mean precipitation to an increase in atmospheric carbon dioxide levels of 1% yr-1 is investigated in 13 fully coupled atmosphere-ocean general circulation models (AOGCMs) and compared to a period of stabilization. During the period of stabilization, when carbon dioxide levels are held constant at twice their unperturbed level and the climate left to warm, precipitation increases at a rate of ∼ 2.4% per unit of global-mean surface-air-temperature change in the AOGCMs. However, when carbon dioxide levels are increasing, precipitation increases at a smaller rate of ∼ 1.5% per unit of global-mean surface-air-temperature change. This difference can be understood by decomposing the precipitation response into an increase from the response to the global surface-temperature increase (and the climate feedbacks it induces), and a fast atmospheric response to the carbon dioxide radiative forcing that acts to decrease precipitation. According to the multi-model mean, stabilizing atmospheric levels of carbon dioxide would lead to a greater rate of precipitation change per unit of global surface-temperature change.

  14. Leakage and atmospheric dispersion of CO2 associated with carbon capture and storage projects

    OpenAIRE

    Mazzoldi, Alberto

    2009-01-01

    Climate change is affecting planet Earth. The main cause is anthropogenic emissions of greenhouse gases, the principal one being carbon dioxide, released in the atmosphere as a by-product of the combustion of hydrocarbons for the generation of energy. Carbon capture and storage (CCS) is a technology that would prevent carbon dioxide from being emitted into the atmosphere by safely sequestering it underground. For so doing, CO2 must be captured at large emission points and transported at high ...

  15. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M;

    1999-01-01

    Hyperkalaemia with ECG changes had been noted during prolonged carbon dioxide pneumoperitoneum in pigs. We have compared plasma potassium concentrations during surgery in 11 patients allocated randomly to undergo either laparoscopic or open appendectomy and in another 17 patients allocated randomly...... to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically...... insignificant. Thus hyperkalaemia is unlikely to develop in patients with normal renal function undergoing carbon dioxide pneumoperitoneum for laparoscopic surgery....

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

    Science.gov (United States)

    Imshenetskiĭ, A A; Murzakov, B G

    1978-01-01

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

  17. Carbon Dioxide Mitigation by Microalgal Photosynthesis

    International Nuclear Information System (INIS)

    Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 μg CO2/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8

  18. Carbon dioxide capture and geological storage

    OpenAIRE

    2013-01-01

    Sustainable Carbon dioxide Capture and Storage, or CCS, can be achieved using geological means, an approach that differs in many ways from CO2 capture and storage in vegetation. Firstly, it differs because this latter approach enables CO2 to be stored only temporarily – for less than one year in annual plants or for several centuries in tree phytomass. Secondly, CO2 capture is associated with bioconversion of the sun’s energy which is then stored in biochemical form in the phytomass. As the t...

  19. Carbon dioxide detection in adult Odonata.

    Science.gov (United States)

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

    2016-04-01

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

  20. Carbon in Atmospheric Particulate Matter

    International Nuclear Information System (INIS)

    Carbon compounds account for a large fraction of airborne particulate matter ('carbonaceous aerosols'). Their presence raises a number of scientific questions dealing with climate issues and possible effects on human health. This review describes the current state of knowledge with respect to the ambient concentrations levels (elemental carbon, organic carbon and organic matter) and the various emission sources, and summarizes the role of atmospheric carbon in the various environmental issues. The report finishes by identifying the actual gaps in knowledge and gives (related) suggestions for future research

  1. Killing wild geese with carbon dioxide or a mixture of carbon dioxide and argon

    NARCIS (Netherlands)

    Gerritzen, M.A.; Reimert, H.G.M.; Lourens, A.; Bracke, M.B.M.; Verhoeven, M.T.W.

    2013-01-01

    The killing of animals is the subject of societal and political debate. Wild geese are caught and killed on a regular basis for fauna conservation and damage control. Killing geese with carbon dioxide (CO2) is commonly practiced, but not listed in legislation on the protection of flora and fauna, an

  2. Molecular transport: Catch the carbon dioxide

    Science.gov (United States)

    Kirchner, Barbara; Intemann, Barbara

    2016-05-01

    Understanding the minute details of CO2 transport is key to finding new technologies that reduce the hazardous levels of CO2 in our atmosphere. Now, the observation that the transport of CO2 in molten calcium carbonate occurs faster than standard molecular diffusion brings us one step closer.

  3. Effect of increased carbon dioxide concentrations on stratospheric ozone

    International Nuclear Information System (INIS)

    During the past several years, much attention has been focused on the destruction of ozone by anthropogenic pollutants such as the nitrogen oxides and chlorofluoromethane. Little or no attention has been given to the influence on ozone of an increased carbon dioxide concentration for which a measurable growth has been observed. Increased carbon dioxide can directly affect ozone by perturbing atmospheric temperatures, which will alter ozone production, whose rate displays a fairly strong temperature dependence. This paper presents one-dimensional model results for the steady state ozone behavior when the CO2 concentration is twice its ambient level which account for coupling between chemistry and temperature. When the CO2 level doubled, the total ozone burden increased in relation to the ambient burden by 1.2--2.5%, depending on the vertical diffusion coefficient used. Above 30 km. In this region the relation variations were insensitive to the choice of diffusion coefficient. Below 30 km, ozone concentrations were smaller than the unperturbed values and were sensitive to the vertical diffusion profile in this region (10--30 km). Ozone decreases in the lower stratosphere because of a reduction in ozone-producing solar radiation, which results in smaller downward ozone fluxes from the region at 25--30 km relative to the flux values for the ambient atmosphere. These offsetting changes occurring in the upper and lower stratosphere act to minimize the variation in total ozone

  4. Soil fertility controls soil-atmosphere carbon dioxide and methane fluxes in a tropical landscape converted from lowland forest to rubber and oil palm plantations

    Science.gov (United States)

    Hassler, E.; Corre, M. D.; Tjoa, A.; Damris, M.; Utami, S. R.; Veldkamp, E.

    2015-10-01

    Expansion of palm oil and rubber production, for which global demand is increasing, causes rapid deforestation in Sumatra, Indonesia, and is expected to continue in the next decades. Our study aimed to (1) quantify changes in soil CO2 and CH4 fluxes with land-use change and (2) determine their controlling factors. In Jambi Province, Sumatra, we selected two landscapes on heavily weathered soils that differ mainly in texture: loam and clay Acrisol soils. In each landscape, we investigated the reference land-use types (forest and secondary forest with regenerating rubber) and the converted land-use types (rubber, 7-17 years old, and oil palm plantations, 9-16 years old). We measured soil CO2 and CH4 fluxes monthly from December 2012 to December 2013. Annual soil CO2 fluxes from the reference land-use types were correlated with soil fertility: low extractable phosphorus (P) coincided with high annual CO2 fluxes from the loam Acrisol soil that had lower fertility than the clay Acrisol soil (P < 0.05). Soil CO2 fluxes from the oil palm (107.2 to 115.7 mg C m-2 h-1) decreased compared to the other land-use types (between 178.7 and 195.9 mg C m-2 h-1; P < 0.01). Across land-use types, annual CO2 fluxes were positively correlated with soil organic carbon (C) and negatively correlated with 15N signatures, extractable P and base saturation. This suggests that the reduced soil CO2 fluxes from oil palm were the result of strongly decomposed soil organic matter and reduced soil C stocks due to reduced litter input as well as being due to a possible reduction in C allocation to roots due to improved soil fertility from liming and P fertilization in these plantations. Soil CH4 uptake in the reference land-use types was negatively correlated with net nitrogen (N) mineralization and soil mineral N, suggesting N limitation of CH4 uptake, and positively correlated with exchangeable aluminum (Al), indicating a decrease in methanotrophic activity at high Al saturation. Reduction in

  5. Pharmaceutical applications of supercritical carbon dioxide.

    Science.gov (United States)

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

    2001-12-01

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

  6. Carbon dioxide direct cycle modular reactor

    International Nuclear Information System (INIS)

    Recently, as the micro gas-turbine power generation is clean for environment and has high convenience, it is focused as a small size dispersion electric source for super markets, hospitals, factories, and so on. And, a modular high temperature gas reactor (PBMR) adopting the gas turbine is also focused recently, and is progressed on its construction in South Africa and reported on construction plan of the Exelon Inc. in U.S.A. PBMR has specific safety for a small size and pebble-bed reactor and also has some characters on low construction cost similar to that of LWR due to simplification and small size module adoption of its plant. The PBMR uses helium for its coolants, of which exit temperature is set for at 900degC to get higher thermal efficiency. This is because of its adoption of Brayton cycle to fast reduce the efficiency with falling temperature. However, as helium is a costly and easy-emission vapor, it is desired to alternate to cheaper and more difficult-emission vapor. Here were introduced on carbon dioxide (CO2) direct cycle using carbon dioxide with extremely higher thermal efficiency than helium and its applicability to nuclear reactors. (G.K.)

  7. Adaptation to carbon dioxide tax in shipping

    International Nuclear Information System (INIS)

    This note discusses the consequences for the sea transport sector between Norway and continental Europe of levying a carbon dioxide tax on international bunker. The influence of such a tax on the operational costs of various types of ship and various transport routes is calculated. The profit obtainable from the following ways of adapting to an increased tax level is assessed: (1) Reducing the speed, (2) Rebuilding the engine to decrease fuel consumption, (3) Changing the design speed for new ships. It is found that a carbon dioxide tax of NOK 200 per tonne of CO2 will increase the transport costs by 3 - 15 percent. In the long run much of this may be transferred to the freight rates since so much of the sea transport are in segments in which the demand for the service is not sensitive to the prices. Even if the freight rates are not changed, a tax this size will not make it necessary to reduce the speed of the existing fleet. The income lost by taking fewer trips will exceed the costs saved in reducing the speed. However, the optimum design speed for new ships may be somewhat reduced (0.5 knots). Rebuilding engines to reduce the fuel consumption would pay off were it not for the fact that the remaining life of the present fleet is probably too short for this to be interesting

  8. Use of supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Masayuki (Niigata Univ., Faculty of Engineering, Niigata, (Japan))

    1989-09-25

    Supercritical fluid extraction is a novel diffusion and separation technique which exploits simultaneously the increase of vapor pressure and the difference of chemical affinities of fluids near the critical point. A solvent which is used as the supercritical fluid has the following features: the critical point exists in the position of relatively ease of handling, the solvent is applicable to the extraction of a physiological active substance of thermal instability. Carbon dioxide as the solvent is non-flammable, non-corrosive, non-toxic, cheap, and readily available of high purity. The results of studies on the use of supercritical carbon dioxide (SC-CO{sub 2}) as a solvent for natural products in the fermentation and food industries, were collected. SC-CO{sub 2} extraction are used in many fields, examples for the application are as follows: removal of organic solvents from antibiotics; extraction of vegetable oils contained in wheat germ oil, high quality mustard seeds, rice bran and so on; brewing of sake using rice and rice-koji; use as a non-aqueous medium for the synthesis of precursors of the Aspartame; and use in sterilization. 66 refs., 17 figs., 21 tabs.

  9. Elevated pressure of carbon dioxide affects growth of thermophilic Petrotoga sp.

    Science.gov (United States)

    Rakoczy, Jana; Gniese, Claudia; Schippers, Axel; Schlömann, Michael; Krüger, Martin

    2014-05-01

    Carbon capture and storage (CCS) is considered a promising new technology which reduces carbon dioxide emissions into the atmosphere and thereby decelerates global warming. During CCS, carbon dioxide is captured from emission sources (e.g. fossil fuel power plants or other industries), pressurised, and finally stored in deep geological formations, such as former gas or oil reservoirs as well as saline aquifers. However, with CCS being a very young technology, there are a number of unknown factors that need to be investigated before declaring CCS as being safe. Our research investigates the effect of high carbon dioxide concentrations and pressures on an indigenous microorganism that colonises a potential storage site. Growth experiments were conducted using the thermophilic thiosulphate-reducing bacterium Petrotoga sp., isolated from formation water of the gas reservoir Schneeren (Lower Saxony, Germany), situated in the Northern German Plain. Growth (OD600) was monitored over one growth cycle (10 days) at different carbon dioxide concentrations (50%, 100%, and 150% in the gas phase), and was compared to control cultures grown with 20% carbon dioxide. An additional growth experiment was performed over a period of 145 days with repeated subcultivation steps in order to detect long-term effects of carbon dioxide. Cultivation over 10 days at 50% and 100% carbon dioxide slightly reduced cell growth. In contrast, long-term cultivation at 150% carbon dioxide reduced cell growth and finally led to cell death. This suggested a more pronounced effect of carbon dioxide at prolonged cultivation and stresses the need for a closer consideration of long-term effects. Experiments with supercritical carbon dioxide at 100 bar completely inhibited growth of freshly inoculated cultures and also caused a rapid decrease of growth of a pre-grown culture. This demonstrated that supercritical carbon dioxide had a sterilising effect on cells. This effect was not observed in control cultures

  10. Carbon dioxide effects research and assessment program

    International Nuclear Information System (INIS)

    Information about the past and present concentrations of CO2 in the atmosphere and variations in climate can be obtained from measurements of stable isotopes in tree rings; specifically carbon-13, oxygen-18 and deuterium. The analysis of these stable isotopes in tree rings is a relatively new and rapidly developing field. This proceedings volume contains most of the papers presented at the meeting. The first paper gives an overview of the status of carbon-13 research. Papers relating to carbon-13 are in section I and grouped separately from the contributions on carbon-14. Although the meeting was primarily concerned with stable isotopes, all carbon isotopic analysis may be helpful in understanding the carbon-13 record in tree rings. The papers on hydrogen and oxygen isotope studies are in sections II and III respectively. The remaining sections contain papers that consider more than one isotope at a time, general topics related to isotopes, atmospheric changes and tree growth, and methods of isotopic analysis

  11. Chemistry Of Atmospheric Brown Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-05-27

    Organic carbon (OC) accounts for a large fraction of atmospheric aerosol and has profound effects on air quality, atmospheric chemistry and climate forcing. Molecular composition of the OC and its evolution during common processes of atmospheric aging have been a subject of extensive research over the last decade (see reviews of Ervens et al.,1 Hallquist et al.,2 Herckes et al.,3 Carlton et al.,4 Kroll and Seinfeld,5 Rudich et al.,6 and Kanakidou et al.7). Even though many fundamental advances have been reported in these studies, our understanding of the climate-related properties of atmospheric OC is still incomplete and the specific ways in which OC impacts atmospheric environment and climate forcing are just beginning to be understood. This review covers one topic of particular interest in this area –environmental chemistry of light-absorbing aerosol OC and its impact on radiative forcing.

  12. Low energy decomposition of carbon dioxide and other molecules

    Science.gov (United States)

    Pamfiloff, Eugene

    2013-05-01

    Since the observation of elevating quantities of atmospheric greenhouse gases, finding a practical method other than the capture-and-sequestration scheme for the reduction and disposal of carbon dioxide (CO2) has been an important objective. Recently, an efficient low-energy process has been developed allowing the selective molecular decomposition of CO2, CO, and other molecules. Thus, CO2 can be broken down into C + O + O. This permits the O2 molecules to be stored or released while the clean carbon atoms can be bagged and utilized in various industries. For the control of carbon dioxide or other gas emissions at their source, it can be scaled up for power plants or down for smaller facilities. The process also allows the production of a beam of exclusively positive ions or exclusively negative ions and contrary to other devices, excludes the probability of beam contamination by plasma or neutral particles, making it ideal for electronic thin-films manufacturing and spectroscopy systems. Because the system allows the simultaneous production of ion beams containing selectable ratios of positive to negative ions, it simplifies construction of favored or complex molecules through varied ionic bonds. Also discussed are several methods to apply the new technology as an upgrade to spectrometers and other devices. For further information contact the author: epamfiloff@mattertech.com.

  13. Sintering uranium oxide in the reaction product of hydrogen-carbon dioxide mixtures

    International Nuclear Information System (INIS)

    Compacted pellets of uranium oxide alone or containing one or more additives such as plutonium dioxide, gadolinium oxide, titanium dioxide, silica, and alumina are heated to 900 to 15990C in the presence of a mixture of hydrogen and carbon dioxide, either alone or with an inert carrier gas and held at the desired temperature in this atmosphere to sinter the pellets. The sintered pellets are then cooled in an atmosphere having an oxygen partial pressure of 10-4 to 10-18 atm of oxygen such as dry hydrogen, wet hydrogen, dry carbon monoxide, wet carbon monoxide, inert gases such as nitrogen, argon, helium, and neon and mixtures of ayny of the foregoing including a mixture of hydrogen and carbon dioxide. The ratio of hydrogen to carbon dioxide in the gas mixture fed to the furnace is controlled to give a ratio of oxygen to uranium atoms in the sintered particles within the range of 1.98:1 to about 2.10:1. The water vapor present in the reaction products in the furnace atmosphere acts as a hydrolysis agent to aid removal of fluoride should such impurity be present in the uranium oxide. (U.S.)

  14. Validation of HITEMP-2010 for carbon dioxide and water vapour at high temperatures and atmospheric pressures in 450-7600cm-1 spectral range

    DEFF Research Database (Denmark)

    Alberti, Michael; Weber, Roman; Mancini, Marco;

    2015-01-01

    The objective of the work is validation of HITEMP-2010 at atmospheric pressures and temperatures reaching 1770K. To this end, spectral transmissivities at 1cm-1 resolution and excellent signal-to-noise-ratio have been measured for 22 CO2/H2O/N2 mixtures. In this paper we consider the 450cm-1-7600cm...

  15. Porous Carbon Based Solid Adsorbents for Carbon Dioxide Capture

    OpenAIRE

    Travis, W.

    2015-01-01

    The aim of this project is the design, synthesis and characterisation of porous carbon structures capable of the selective capture of carbon dioxide (CO2) from the exhaust gases of coal and gas post-combustion power stations. In such systems, the fossil fuel is burnt in an air environment producing CO2 as just one of a multi-component flue gas. This flue gas is expected to contain nitrogen and water among other constituents. It is at ambient pressures and temperatures of ≥323 K. Successful ca...

  16. Activation of Carbon Dioxide and Synthesis of Propylene Carbonate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cycloaddition of carbon dioxide and propylene oxide to propylene carbonate catalyzed by tetra-tert-butyl metal phthalocyanine in the presence of tributylamine (TBA) shows higher yield than catalyzed by unsubstituted metal phthalocyanine. Comparing different catalysts of diverse metals, (t-Bu)4PcMg is more active than (t-Bu)4PcFe. But (t-Bu)4PcCo and (t-Bu)4PcNi only have low catalytic activities towards the reaction. Moreover, the yield will increase as the temperature increases.

  17. Carbon Dioxide, a Solvent and Synthon for Green Chemistry

    OpenAIRE

    Ballivet-Tkatchenko, D.; Camy, Séverine; Condoret, Jean-Stéphane

    2005-01-01

    Carbon dioxide is a renewable resource of carbon when we consider the reuse of existing CO2 as a carbon source for producing chemicals. The development of new applications is of major interest from the point of view of carbon dioxide sequestration and within the scope of green chemistry. For example, using CO2 instead of CO or COCl2 for chemical synthesis constitutes an attractive alternative avoiding hazardous and toxic reactants. However, it has the lowest chemical reactivity, which i...

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

    Science.gov (United States)

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

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

  19. Carbon dioxide capture processes: Simulation, design and sensitivity analysis

    DEFF Research Database (Denmark)

    Zaman, Muhammad; Lee, Jay Hyung; Gani, Rafiqul

    Carbon dioxide is the main greenhouse gas and its major source is combustion of fossil fuels for power generation. The objective of this study is to carry out the steady-state sensitivity analysis for chemical absorption of carbon dioxide capture from flue gas using monoethanolamine solvent. First...

  20. Flexible substrates as basis for photocatalytic reduction of carbon dioxide

    DEFF Research Database (Denmark)

    Jensen, Jacob; Mikkelsen, Mette; Krebs, Frederik C

    2011-01-01

    A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...

  1. Balance and forecasts of french carbon dioxide emissions

    International Nuclear Information System (INIS)

    This paper strikes the balance of carbon dioxide emissions in France between 1986 and 1991 and gives forecasts till 2010. Since 1986, France has reduced its efforts for energy conservation and air pollution by carbon dioxide begins to growth again in connection with consumption growth in transport area, development of computer and simulation needs

  2. Carbon dioxide capture processes: Simulation, design and sensitivity analysis

    DEFF Research Database (Denmark)

    Zaman, Muhammad; Lee, Jay Hyung; Gani, Rafiqul

    2012-01-01

    Carbon dioxide is the main greenhouse gas and its major source is combustion of fossil fuels for power generation. The objective of this study is to carry out the steady-state sensitivity analysis for chemical absorption of carbon dioxide capture from flue gas using monoethanolamine solvent. First...

  3. High-brightness all semiconductor laser at 1.57 µm for space-borne lidar measurements of atmospheric carbon dioxide: device design and analysis of requirements

    OpenAIRE

    Esquivias Moscardo, Ignacio; Consoli Barone, Antonio; Krakowski, M.; Faugeron, M.; Kochem, G.; Traub, M.; Barbero, J.; Fiadino, P.; Ai, Xiao; Rarity, John; Quatrevalet, Mathieu; Ehret, Gerhard

    2014-01-01

    The availability of suitable laser sources is one of the main challenges in future space missions for accurate measurement of atmospheric CO2. The main objective of the European project BRITESPACE is to demonstrate the feasibility of an all-semiconductor laser source to be used as a space-borne laser transmitter in an Integrated Path Differential Absorption (IPDA) lidar system. We present here the proposed transmitter and system architectures, the initial device design and the results of t...

  4. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Science.gov (United States)

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... draft ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon... occur for all inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas...

  5. Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers

    Energy Technology Data Exchange (ETDEWEB)

    Mayorga, E; Aufdenkampe, A K; Masiello, C A; Krusche, A V; Hedges, J I; Quay, P D; Richey, J E; Brown, T A

    2005-06-23

    Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition ({sup 13}C and {sup 14}C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than 5 years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in mid-size to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.

  6. Investigations during fiscal 1995 on capability of oceans to absorb and fix carbon dioxide; 1995 nendo kaiyo no nisanka tanso kyushu kotei noryoku no chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Investigations were given on capability of oceans to absorb and fix carbon dioxide as part of measures to prevent global warming. Carbon dioxide absorption and fixation in oceans relate to biological and chemical processes, whereas parameter dependence of each process was investigated. In relation to dissolution and dissociation of carbon dioxide into oceans, the parameter that governs exchange of carbon dioxide between atmosphere and ocean is partial pressure of carbon dioxide in surface sea water. This partial pressure is largely affected by water temperature, total carbonic acid and alkalinity. Particle-shaped organic carbon (detritus) is formed mainly by withering of photoplanktons. Formation of calcium carbonate due to activities of living organisms increases the carbon dioxide partial pressure. Fluxes of detritus are predominant among the whole precipitation flux in carbon circulation, which are more than two times the precipitation flux of photoplanktons. Particles are turned into inorganics by bacteria during the precipitation process. 29 refs., 21 figs., 6 tabs.

  7. Adverse effects of the automotive industry on carbon dioxide emissions

    Directory of Open Access Journals (Sweden)

    Mpho Bosupeng

    2016-05-01

    Full Text Available This study aims to determine the effects of the automotive industry on carbon dioxide emissions for the period from 1997 to 2010 for diverse economies, as well as the relationships between carbon dioxide discharges and output. The study applies cointegration and causality tests to validate these associations. The results of the Johansen cointegration test depict long-run associations between the quantity of passenger cars and carbon dioxide emissions in France, Sweden, Spain, Hungary and Japan. In addition, significant relations were observed between output and carbon dioxide discharges in Spain, Canada, India and Japan. Changes in output had substantial impact on emissions in Germany, Canada and India. The results also show that the number of passenger cars influences the magnitude of emissions in multiple economies. In conclusion, the automotive industry has to be considered in policies that aim to reduce carbon dioxide emissions.

  8. Photobiological hydrogen production and carbon dioxide sequestration

    Science.gov (United States)

    Berberoglu, Halil

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

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

    Science.gov (United States)

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

    2014-01-01

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

  10. Carbon dioxide, argon, nitrogen and methane clathrate hydrates: Thermodynamic modelling, investigation of their stability in Martian atmospheric conditions and variability of methane trapping

    OpenAIRE

    Herri, Jean-Michel; Chassefière, Eric

    2012-01-01

    This paper deals with the stability of clahtrate hydrates at low temperature and low pressure in the conditions prevailing in the atmosphere and at the surface of Mars. We fit the classical van der Waals model to compare deviation from experimental results published in the literature. It appears to be acceptable and allows to simulating a Martian gas, CO2 dominated (95.3%) plus nitrogen (2.7%) and argon (2%). The hydrate is a CO2-based hydrate which is unstable during Mars' summer and stable ...

  11. A modelling approach for simulation of water and carbon dioxide exchange between multi-species tropical rain forest and the atmosphere

    DEFF Research Database (Denmark)

    Olchev, A.; Ibrom, Andreas; Ross, T.;

    2008-01-01

    of the physical and biological processes on the leaf, tree (plant) and stand levels that allows to apply this model for prediction of atmospheric fluxes for the different vegetation types from grasslands and agricultural crops to vertically structured mono-specific and mixed forest stands represented by one...... and that there are no differences in biophysical properties between the same tree species. Mixfor-SVAT was applied to a natural tropical rainforest in Central Sulawesi, Indonesia. The modelled H2O and CO2 fluxes were compared with results of eddy covariance flux measurements above the forest canopy for the period from October 2003...

  12. Carbon Dioxide Exchange Between the Atmosphere and an Alpine Shrubland Meadow During the Growing Season on the Qinghai-Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    Liang ZHAO; Ying-Nian LI; Song GU; Xing-Quan ZHAO; Shi-Xiao XU; Gui-Rui YU

    2005-01-01

    In the present study, we used the eddy covariance method to measure CO2 exchange between the atmosphere and an alpine shrubland meadow ecosystem (37°36′ N, 101o18′ E; 3 250 m a.s.l.) on the Qinghai-Tibetan Plateau, China, during the growing season in 2003, from 20 April to 30 September. This meadow is dominated by formations ofPotentillafruticosa L. The soil is Mol-Cryic Cambisols. During the study period, the meadow was not grazed. The maximum rates of CO2 uptake and release derived from the latitudes. Daily CO2 uptake during the measurement period indicated that the alpine shrubland meadow ecosystem may behave as a sink of atmospheric CO2 during the growing season. The daytime CO2 uptake was correlated exponentially or linearly with the daily photosynthetic photon flux density each month. The daytime average water use efficiency of the ecosystem was 6.47 mg CO2/g H2O. The efficiency of the ecosystem increased with a decrease in vapor pressure deficit.

  13. Where do fossil fuel carbon dioxide emissions from California go? An analysis based on radiocarbon observations and an atmospheric transport model

    Energy Technology Data Exchange (ETDEWEB)

    Riley, W.J.; Hsueh, D.Y.; Randerson, J.T.; Fischer, M.L.; Hatch, J.G.; Pataki, D.E.; Wang, W.; Goulden, M.L.

    2008-05-01

    Characterizing flow patterns and mixing of fossil fuel-derived CO{sub 2} is important for effectively using atmospheric measurements to constrain emissions inventories. Here we used measurements and a model of atmospheric radiocarbon ({sup 14}C) to investigate the distribution and fluxes of atmospheric fossil fuel CO{sub 2} across the state of California. We sampled {sup 14}C in annual C{sub 3} grasses at 128 sites and used these measurements to test a regional model that simulated anthropogenic and ecosystem CO{sub 2} fluxes, transport in the atmosphere, and the resulting {sup 14}C of annual grasses ({Delta}{sub g}). Average measured {Delta}{sub g} in Los Angeles, San Francisco, the Central Valley, and the North Coast were 27.7 {+-} 20.0, 44.0 {+-} 10.9, 48.7 {+-} 1.9, and 59.9 {+-} 2.5{per_thousand}, respectively, during the 2004-2005 growing season. Model predictions reproduced regional patterns reasonably well, with estimates of 27.6 {+-} 2.4, 39.4 {+-} 3.9, 46.8 {+-} 3.0, and 59.3 {+-} 0.2{per_thousand} for these same regions and corresponding to fossil fuel CO{sub 2} mixing ratios (Cf) of 13.7, 6.1, 4.8, and 0.3 ppm. {Delta}{sub g} spatial heterogeneity in Los Angeles and San Francisco was higher in the measurements than in the predictions, probably from insufficient spatial resolution in the fossil fuel inventories (e.g., freeways are not explicitly included) and transport (e.g., within valleys). We used the model to predict monthly and annual transport patterns of fossil fuel-derived CO{sub 2} within and out of California. Fossil fuel CO{sub 2} emitted in Los Angeles and San Francisco was predicted to move into the Central Valley, raising Cf above that expected from local emissions alone. Annually, about 21, 39, 35, and 5% of fossil fuel emissions leave the California airspace to the north, east, south, and west, respectively, with large seasonal variations in the proportions. Positive correlations between westward fluxes and Santa Ana wind conditions were

  14. Miniaturized remission sensor for carbon dioxide detection

    International Nuclear Information System (INIS)

    Recently, optical sensors for detection of carbon dioxide (CO2) have been explored for variety of applications in chemistry, industry, and medicine. This paper deals with the development of a planar optical remission sensor employing a dye immobilized in a polymer layer designed for gaseous CO2 detection. The principle of CO2 detection was based on colour changes of Tetraethylammonium Cresol red immobilized in a special composed polymer layer that was irradiated by LED diodes. Absorption properties of the dye were changed due to its chemical reaction with CO2 and corresponding colour changes were detected by PIN diodes. These changes were analyzed by using a PC-controlled board connected by USB. The sensitivity, response time, and the detection limit of the remission sensor were characterized.

  15. Carbon dioxide neutral, integrated biofuel facility

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2010-12-15

    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 CO{sub 2} 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 biodiesel, can result in an integrated, economical, large-scale process for biofuel production. Each bioreactor acts as an electrode for a coupled complete microbial fuel cell system; the integrated cultures produce electricity that is consumed as an energy source within the process. Finally, both the produced yeast and spent algae biomass can be used as added value byproducts in the feed or food industries. Using cost and revenue estimations, an IRR of up to 25% is calculated using a 5 year project lifespan. (author)

  16. Carbon dioxide (CO2) angiography in children

    International Nuclear Information System (INIS)

    Background. When iodinated contrast material is contraindicated, carbon dioxide (CO2) gas can be injected intravascularly to produce high-quality digital subtraction angiograms. Objective. CO2 angiography, although previously described in adults, has never before been reported in children. Materials and methods. We present three children with renal transplants who required renal angiography. Because of elevated creatinine levels, iodinated contrast was not used to search for possible renal artery stenosis. Instead, CO2 angiography was used to evaluate the renal artery anastomosis. Results. In all three cases, the renal artery anastomosis was clearly visualized using CO2 angiography and showed no evidence of renal artery stenosis. Conclusion. Digital CO2 angiography is an effective method for pediatric renal angiography. The technique can easily be adapted for virtually any angiographic laboratory capable of digital subtraction imaging. Digital CO2 angiography also lacks the risks of a conventional iodinated contrast medium, namely nephrotoxicity, allergic reaction and volume overload. (orig.). With 1 fig

  17. Biochemical Capture and Removal of Carbon Dioxide

    Science.gov (United States)

    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.

  18. Carbon dioxide and methane fluxes from arctic mudboils

    International Nuclear Information System (INIS)

    Carbon-rich ecosystems in the Arctic have large stores of soil carbon. However, small changes in climate have the potential to change the carbon (C) balance. This study examined how changes in ecosystem structure relate to differences in the exchange of greenhouse gases, notably carbon dioxide (CO2) and methane (CH4), between the atmosphere and soil. In particular, it examined low-center mudboils to determine the influence that this distinct form of patterned ground in the Arctic may have on the overall C balance of Tundra ecosystems. The net ecosystem exchange of carbon dioxide (NEE) was measured along with methane efflux along a 35-m transect intersecting two mudboils in a wet sedge fen in Canada's Southern Arctic during the summer of 2008. Mudboil features revealed significant variations in vegetation, soil temperature and thaw depth, and soil organic matter content along this transect. Variations in NEE were attributed to changes in the amount of vascular vegetation, but CO2 and CH4 effluxes were similar among the two mudboil and the sedge fen sampling areas. The study showed that vegetation played a key role in limiting temporal variations in CH4 effluxes through plant mediated transport in both mudboil and sedge fen sampling areas. The negligible vascular plant colonization in one of the mudboils was likely due to more active frost heave processes. Growth and decomposition of cryptogamic organisms along with inflow of dissolved organic C and warmer soil temperatures may have been the cause of the rather high CO2 and CH4 efflux in this mudboil area.

  19. A regional and global analysis of carbon dioxide physiological forcing and its impact on climate

    Science.gov (United States)

    Andrews, Timothy; Doutriaux-Boucher, Marie; Boucher, Olivier; Forster, Piers M.

    2011-02-01

    An increase in atmospheric carbon dioxide concentration has both a radiative (greenhouse) effect and a physiological effect on climate. The physiological effect forces climate as plant stomata do not open as wide under enhanced CO2 levels and this alters the surface energy balance by reducing the evapotranspiration flux to the atmosphere, a process referred to as `carbon dioxide physiological forcing'. Here the climate impact of the carbon dioxide physiological forcing is isolated using an ensemble of twelve 5-year experiments with the Met Office Hadley Centre HadCM3LC fully coupled atmosphere-ocean model where atmospheric carbon dioxide levels are instantaneously quadrupled and thereafter held constant. Fast responses (within a few months) to carbon dioxide physiological forcing are analyzed at a global and regional scale. Results show a strong influence of the physiological forcing on the land surface energy budget, hydrological cycle and near surface climate. For example, global precipitation rate reduces by ~3% with significant decreases over most land-regions, mainly from reductions to convective rainfall. This fast hydrological response is still evident after 5 years of model integration. Decreased evapotranspiration over land also leads to land surface warming and a drying of near surface air, both of which lead to significant reductions in near surface relative humidity (~6%) and cloud fraction (~3%). Patterns of fast responses consistently show that results are largest in the Amazon and central African forest, and to a lesser extent in the boreal and temperate forest. Carbon dioxide physiological forcing could be a source of uncertainty in many model predicted quantities, such as climate sensitivity, transient climate response and the hydrological sensitivity. These results highlight the importance of including biological components of the Earth system in climate change studies.

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

    Science.gov (United States)

    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.

  1. Stationary plume induced by carbon dioxide dissolution

    International Nuclear Information System (INIS)

    In this paper, laminar convection flows induced by carbon dioxide absorption are addressed from experimental, numerical and theoretical points of view. A vertical glass tube (of centimetre scale) filled with distilled water is subjected to a sudden increase in the partial pressure of carbon dioxide. As a result of the diffusion of the gas into the unsaturated solution, a thin layer of fluid located underneath the surface becomes heavier. This initial density gradient first destabilizes to form a plume, which goes downwards through the entire cell. After a first transient pulsating regime (periodic succession of such Rayleigh-Benard plumes), a stationary flow settles in the tube, which is maintained by the constant supply of gas at the surface. At late stages, this stationary regime is followed by an aperiodic regime, which lasts until the complete saturation of the solution (thermodynamic equilibrium). The present study only focuses on the stationary regime, whose characteristics appear to be almost independent of the Bond number and the aspect ratio but strongly dependent on the chemical Rayleigh number. Three decades of Rayleigh numbers are explored using particle image velocimetry measurements, which allows for a precise determination of the scaling exponents for the vertical velocity amplitude and the plume width. The assumption that gravity and a constant pressure gradient balance the viscous effects enables us to derive an analytic expression for the stationary vertical velocity on the axis, which scales as Ra2/3 (ln Ra)1/3. As a consequence, the width of the plume scales as Ra-1/6 (ln Ra)-1/3 and the mass Nusselt number as (Ra= ln Ra)1/3. These scalings are in excellent agreement with the experimental and numerical results. The multiplicative constants of these scalings can also be calculated and show a fairly good agreement if a rigid boundary condition (no-slip) is assumed at the free surface. (authors)

  2. Reduction of Carbon Dioxide by a Molybdenum-Containing Formate Dehydrogenase: A Kinetic and Mechanistic Study.

    Science.gov (United States)

    Maia, Luisa B; Fonseca, Luis; Moura, Isabel; Moura, José J G

    2016-07-20

    Carbon dioxide accumulation is a major concern for the ecosystems, but its abundance and low cost make it an interesting source for the production of chemical feedstocks and fuels. However, the thermodynamic and kinetic stability of the carbon dioxide molecule makes its activation a challenging task. Studying the chemistry used by nature to functionalize carbon dioxide should be helpful for the development of new efficient (bio)catalysts for atmospheric carbon dioxide utilization. In this work, the ability of Desulfovibrio desulfuricans formate dehydrogenase (Dd FDH) to reduce carbon dioxide was kinetically and mechanistically characterized. The Dd FDH is suggested to be purified in an inactive form that has to be activated through a reduction-dependent mechanism. A kinetic model of a hysteretic enzyme is proposed to interpret and predict the progress curves of the Dd FDH-catalyzed reactions (initial lag phase and subsequent faster phase). Once activated, Dd FDH is able to efficiently catalyze, not only the formate oxidation (kcat of 543 s(-1), Km of 57.1 μM), but also the carbon dioxide reduction (kcat of 46.6 s(-1), Km of 15.7 μM), in an overall reaction that is thermodynamically and kinetically reversible. Noteworthy, both Dd FDH-catalyzed formate oxidation and carbon dioxide reduction are completely inactivated by cyanide. Current FDH reaction mechanistic proposals are discussed and a different mechanism is here suggested: formate oxidation and carbon dioxide reduction are proposed to proceed through hydride transfer and the sulfo group of the oxidized and reduced molybdenum center, Mo(6+)═S and Mo(4+)-SH, are suggested to be the direct hydride acceptor and donor, respectively. PMID:27348246

  3. Measurement of Carbon Dioxide Column via Space Borne Laser Absorption

    Science.gov (United States)

    Heaps, WIlliam S.

    2007-01-01

    In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an analysis of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics Several systems for meeting these requirements that are under investigation at various institutions in the US as well as Europe will be discussed.

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

    CERN Document Server

    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...

  5. Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms

    Science.gov (United States)

    Buth, Jeffrey M.

    2016-01-01

    Ocean acidification refers to the process by which seawater absorbs carbon dioxide from the atmosphere, producing aqueous carbonic acid. Acidic conditions increase the solubility of calcium carbonate, threatening corals and other calcareous organisms that depend on it for protective structures. The global nature of ocean acidification and the…

  6. Effects of doubled carbon dioxide on rainfall responses to radiative processes of water clouds

    Science.gov (United States)

    Li, Xiaofan; Li, Tingting; Lou, Lingyun

    2014-12-01

    The effects of doubled carbon dioxide on rainfall responses to radiative processes of water clouds are investigated in this study. Two groups of two-dimensional cloud-resolving model sensitivity experiments with regard to pre-summer heavy rainfall around the summer solstice and tropical rainfall around the winter solstice are conducted and their five-day averages over the model domain are analyzed. In the presence of radiative effects of ice clouds, doubled carbon dioxide changes pre-summer rainfall from the decrease associated with the enhanced atmospheric cooling to the increase associated with the enhanced infrared cooling as a result of the exclusion of radiative effects of water clouds. Doubled carbon dioxide leads to the reduction in tropical rainfall, caused by the removal of radiative effects of water clouds through the suppressed infrared cooling. In the absence of radiative effects of ice clouds, doubled carbon dioxide changes pre-summer rainfall from the increase associated with the strengthened atmospheric warming to the decrease associated with the weakened release of latent heat caused by the elimination of radiative effects of water clouds. The exclusion of radiative effects of water clouds increases tropical rainfall through the strengthened infrared cooling, which is insensitive to the change in carbon dioxide.

  7. Influence of Flow Parameters on Capture of Carbon Dioxide Gas by a Wet Scrubber

    Directory of Open Access Journals (Sweden)

    Hiram Ndiritu

    2013-01-01

    Full Text Available Increase in atmospheric temperature has been found to cause a rise in sea level, melting of snow in ice capped mountains,prolonged drought among others. This is due to increase in energy demand for economic growth which in turn has caused emission of carbon dioxide at a rate of 6 billion tonnes annually. Analysis has shown that carbon dioxide forms between 13 to 15% of the combustion exhaust gases that are released directly into the atmosphere. Such concentrations areeectively reduced using wet scrubbing. This is a capturing mechanism that involves interaction of a liquid and the gas phase in a counter ow conguration. In this paper the performance of such a system based on variation in flow properties is presented. Results have shown that an increase in liquid and gas flow rate causes a 19% rise in absorption of carbon dioxide. This was as a result of proper mixing of gas and liquid phases within the absorber facilitated by the packed bed surface. Heating of the carbon dioxide gas caused an increase in absorption of more than 10% for varying liquid flow rate and by 14% for varying gas flow rate. This was attributed to an increase in heat energy for reaction of carbon dioxide and water.

  8. Effect of carbon dioxide on the rate of iodine vapor absorption by aqueous solution of sodium hydroxide

    International Nuclear Information System (INIS)

    There is always carbon dioxide in the atmosphere as an impurity. Since this is an acid gas similar to iodine, each absorption rate seems to be affected by the other due to the coexistence of these two. Experiments have been conducted to clarify the absorption rate and absorption mechanism of iodine in the simultaneous absorption of iodine and carbon dioxide. Carbon dioxide coexisting with gas phases as an impurity decreases the absorption rate of iodine in the removal by washing with water of iodine mixed in the air. The first cause of this is that the diffusion coefficient of iodine in gas phase decreases with the carbon dioxide content in the gas phase. The second cause is that coexistent carbon dioxide is an acid gas, dissociates by dissolving into the absorbing solution, increases hydrogen ion concentration together with the formation of negative ions of bicarbonate and carbonate, and reduces hydroxyl ion concentration as a result. It is more important that existence of iodine has a catalytic effect to the rate of basic catalytic hydrolysis of carbon dioxide simultaneously dissolved in water phase, and accelerates this reaction rate. The mechanism of catalytic effect of iodine for the hydrolysis of carbon dioxide can not be clarified in detail only by this experiment, but the simultaneous absorption rate of iodine and carbon dioxide can be explained satisfactorily. (Wakatsuki, Y

  9. Estimated Carbon Dioxide Emissions in 2008: United States

    Energy Technology Data Exchange (ETDEWEB)

    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

  10. Measurement of carbon dioxide diffusion coefficient of concrete

    OpenAIRE

    Villain, G.; PAVOINE, A; Thiery, M.

    2006-01-01

    The carbonation of concrete is a chemical reaction, which can be at the origin of the premature degradation of reinforced concrete structures. In order to predict service life of reinforced concrete structures, many models based on gas diffusion were developed. The carbon dioxide diffusion coefficient of concrete is thus a significant input datum for these models. The objective of this article is to present a simple reliable testing method to quantify the carbon dioxide diffusion coefficient ...

  11. Effects of Induced High Carbon Dioxide and Desiccated Atmospheres on the Water Loss and Survival of Subterranean and Invading Drywood Termites.

    Science.gov (United States)

    Choi, Baek Yong; Yoshimura, Tsuyoshi

    2016-04-01

    Termites have evolved a variety of morphological, physiological, and behavioral adaptations that together increase the chances of survival in unfavorable environments. Morphological advantages (i.e., a relatively large body size, a large mass of reserves that are metabolized by reducing body water mass, a mass of cuticular lipids, and cuticular hydrocarbons) increase the cuticular resistance to water loss under desiccating conditions. However, termites are incapacitated when exposed to high levels of CO2 and can be eradicated at sufficiently high levels. Based on the results of this study, in an artificially induced high CO2 atmosphere, the loss of body water from drywood termites increased, which generally led to increased rates of mortality. Although the mechanism for the increased loss of body water under high CO2 conditions was not determined, for practical application, the time required for fumigation can be reduced because of the increase in the rate of body water loss from drywood termites in high CO2 conditions. PMID:26612892

  12. Future climate trends from a first-difference atmospheric carbon dioxide regression model involving emissions scenarios for business as usual and for peak fossil fuel

    CERN Document Server

    Leggett, L M W

    2014-01-01

    This paper investigates the implications of the future continuation of the demonstrated past (1960-2012) strong correlation between first-difference atmospheric CO2 and global surface temperature. It does this, for the period from the present to 2050, for a comprehensive range of future global fossil fuel energy use scenarios. The results show that even for a business-as-usual (the mid-level IPCC) fossil fuel use estimate, global surface temperature will rise at a slower rate than for the recent period 1960-2000. Concerning peak fossil fuel, for the most common scenario the currently observed (1998-2013)temperature plateau will turn into a decrease. The observed trend to date for temperature is compared with that for global climate disasters: these peaked in 2005 and are notably decreasing. The temperature and disaster results taken together are consistent with either a reduced business-as-usual fossil fuel use scenario into the future, or a peak fossil fuel scenario, but not with the standard business-as-usu...

  13. Dynamics of Water Yield From China's Terrestrial Ecosystems in the 20th Century: Impact of Climate Change, Atmospheric Carbon Dioxide, Tropospheric Ozone, and Land- Use

    Science.gov (United States)

    Liu, M.; Tian, H.; Zhang, C.; Ren, W.; Liu, J.

    2006-05-01

    The availability of freshwater resources is critical to China's economic development and human's health. Water yield, the runoff from the drainage basin, is one important index of ecosystem service that directly controls the total freshwater availability and rain erosity. The monsoon climate system and the complexity of natural geography in China lead to substantially spatial and temporal variability in water resources. It has been argued that intensively human activity and air pollution have altered the terrestrial water cycle in the last century. However, little is known about the magnitude and historical trend of water yield across China as well as underlying mechanisms. This study used a process-based Dynamic Land Ecosystem Model (DLEM) to address the effects of multiple stressors on water yield nationwide during 1900 to 2000. These multiple stressors include changes in climate, atmospheric CO2 concentration, tropospheric ozone, and land-use (including cropland expansion, cropland abandonment, urbanization, and irrigation). By using optimal fingerprinting statistical techniques and factorial simulation experiments, we determined the relative contribution of these multiple stressors to water yield for the study period. The simulated results were evaluated against river's runoff records and watershed observations. Our simulated results suggest that the land-use change and precipitation appear to be two primary factors controlling water yield in China.

  14. NOAA carbon dioxide measurements at Mauna Loa Observatory, 1974-1976

    International Nuclear Information System (INIS)

    The Geophysical Monitoring for Climatic Change program of NOAA's Environmental Research Laboratories has measured atmospheric carbon dioxide concentrations at Mauna Loa Observatory, Hawaii, continuously since June 1974. The measurements through 1976 have been analyzed for recent secular concentration changes and show a continuing increase of about 0.9 ppm/year

  15. Seasonal and interannual variability of carbon dioxide and water balances of a grassland

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Holtslag, A.A.M.

    2007-01-01

    There is great international concern over the increase of atmospheric carbon dioxide and its effect on vegetation and climate, and vice versa. Many studies on this issue are based on climate model calculations or indirect satellite observations. In contrast we present a 12-year study (1994¿2005) on

  16. Carbon dioxide control in an open system that measures canopy gas exchanges

    Science.gov (United States)

    Atmospheric carbon dioxide concentration ([CO2]) effects both C3 net assimilation (A) as well as crop water use. Methods for measuring whole canopy gas exchange responses under [CO2] enrichment are needed for breeding programs aiming to develop crop cultivars resistant to stresses like drought in a...

  17. Rising carbon dioxide as a selection factor in rice/red rice competition

    Science.gov (United States)

    Carbon dioxide (CO2), along with sunlight, water, and nutrients constitutes one of the four resources needed for plants to grow. As such, the sudden increase in its concentration in the atmosphere (up 22% since 1960) could be exploited in order to boost crop yields. However, the rise in CO2 is indi...

  18. Genotypic Variation in Soybean Molecular Responses to Elevated Carbon Dioxide Concentration

    Science.gov (United States)

    A critical step in maximizing crop yield in a future of elevated atmospheric carbon dioxide concentration ([CO2]) is identifying genotypic variability in response to elevated [CO2] and understanding the molecular basis for the variation. We compared photosynthesis, leaf metabolites and global gene e...

  19. Gas enhanced magnetic resonance angiography of the cerebrum using carbon dioxide and oxygen - preliminary results

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Hansen, Kristoffer Lindskov; Ohlhues, Anders;

    meninges may obscure the signal from the arteries of interest. It is known that oxygen enhances the T1-weighted signal and that carbon dioxide increases the arterial blood flow. This paper presents preliminary results of gas enhanced MRA using combinations of atmospheric air, O2 and CO2. Subjects and...

  20. Coping with carbon: a near-term strategy to limit carbon dioxide emissions from power stations.

    Science.gov (United States)

    Breeze, Paul

    2008-11-13

    Burning coal to generate electricity is one of the key sources of atmospheric carbon dioxide emissions; so, targeting coal-fired power plants offers one of the easiest ways of reducing global carbon emissions. Given that the world's largest economies all rely heavily on coal for electricity production, eliminating coal combustion is not an option. Indeed, coal consumption is likely to increase over the next 20-30 years. However, the introduction of more efficient steam cycles will improve the emission performance of these plants over the short term. To achieve a reduction in carbon emissions from coal-fired plant, however, it will be necessary to develop and introduce carbon capture and sequestration technologies. Given adequate investment, these technologies should be capable of commercial development by ca 2020. PMID:18757277

  1. Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU-Concepts

    Science.gov (United States)

    LeVan, M. Douglas; Finn, John E.; Sridhar, K. R.

    2000-01-01

    Solid oxide electrolyzers, such as electrolysis cells utilizing yttria-stabilized zirconia, can produce oxygen from Mars atmospheric carbon dioxide and reject carbon monoxide and unreacted carbon dioxide in a separate stream. The oxygen-production process has been shown to be far more efficient if the high-pressure, unreacted carbon dioxide can be separated and recycled back into the feed stream. Additionally, the mass of the adsorption compressor can be reduced. Also, the carbon monoxide by-product is a valuable fuel for space exploration and habitation, with applications from fuel cells to production of hydrocarbons and plastics. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU. Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, respectively. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU, Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, Research needs for the design shown are as follows: (1) The best adsorbent

  2. Comparative study of solvent properties for carbon dioxide absorption

    Energy Technology Data Exchange (ETDEWEB)

    Aschenbrenner, O.; Styring, P. [University of Sheffield, Sheffield (United Kingdom)

    2010-07-01

    Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. PEG 300 was found to be the best solvent in this study and shows a high carbon dioxide solubility as well as good selectivity over nitrogen. The advantages of high stability, low solvent loss and low desorption energy of PEG 300 may outweigh its lower absorption capacity compared to the state-of-the-art solvent monoethanolamine, making it a potentially advantageous solvent for industrial carbon dioxide absorption processes.

  3. Modeling and calculation of open carbon dioxide refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • A model of open refrigeration system is developed. • The state of CO2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO2 has little relation to the state of CO2. • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

  4. The Formation of Ethane from Carbon Dioxide under Cold Plasma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane,carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

  5. Atmospheric exchange of carbon dioxide and methane of a small water body and a floating mat in the Luther Marsh peatland, Ontario, Canada

    Science.gov (United States)

    Burger, Magdalena; Berger, Sina; Blodau, Christian

    2015-04-01

    Recent investigations have suggested that small water bodies cover larger areas in northern peatlands than previously assumed. Their role in the carbon cycle and gas exchange rates are poorly constrained so far. To address this issue we measured CO2 and CH4 fluxes on a small water body (ca. 700 m2) and the surrounding floating mat in the Luther Marsh peatland in Ontario, Canada from July to September 2014. To this end we used closed chambers combined with a portable Los Gatos high-resolution trace gas analyzer at different water depths and distances from the shore on the pond and with different dominating plant types on the floating mat surrounding the pond. In addition, CO2 concentrations were recorded in high temporal resolution using an infrared sensor system during selected periods. Air and water temperature, humidity and temperature of the floating mat, wind speed and direction, photosynthetically active radiation, air pressure and relative humidity were also recorded as auxiliary data at the study site. The results show that pond and floating mat were sources of methane throughout the whole measuring period. Methane emissions via the ebullition pathway occurred predominantly near the shore and on the floating mat. During the daytime measurements the floating mat acted as a net sink and the pond as a net source of CO2. The dynamics of CO2 exchange was also strongly time dependent, as CO2 emissions from the pond strongly increased after mid-August. This suggests that photosynthesis was more affected by seasonal decline than respiration process in the pond and that the allochthonous component of the CO2 flux increased in relative importance towards fall.

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

    Science.gov (United States)

    Hagedorn, Norman H. (Inventor)

    1993-01-01

    An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

  7. Soil fertility controls soil–atmosphere carbon dioxide and methane fluxes in a tropical landscape converted from lowland forest to rubber and oil palm plantations

    Directory of Open Access Journals (Sweden)

    E. Hassler

    2015-06-01

    Full Text Available Expansion of palm oil and rubber production, for which global demand is increasing, causes rapid deforestation in Sumatra, Indonesia and is expected to continue in the next decades. Our study aimed to (1 quantify changes in soil CO2 and CH4 fluxes with land-use change, and (2 determine their controlling factors. In Jambi Province, Sumatra, we selected two landscapes on heavily weathered soils that differ mainly in texture: loam and clay Acrisol soils. At each landscape, we investigated the reference land uses: forest and secondary forest with regenerating rubber, and the converted land uses: rubber (7–17 years old and oil palm plantations (9–16 years old. We measured soil CO2 and CH4 fluxes monthly from December 2012 to December 2013. Annual soil CO2 fluxes from the reference land uses were correlated with soil fertility: low extractable phosphorus (P coincided with high annual CO2 fluxes from the loam Acrisol soil that had lower fertility than the clay Acrisol soil (P 2 fluxes from the oil palm decreased compared to the other land uses (P 2 fluxes were positively correlated with soil organic carbon (C and negatively correlated with 15N signatures, extractable P and base saturation. This suggests that the reduced soil CO2 fluxes from oil palm was a result of strongly decomposed soil organic matter due to reduced litter input, and possible reduction in C allocation to roots due to improved soil fertility from liming and P fertilization in these plantations. Soil CH4 uptake in the reference land uses was negatively correlated with net nitrogen (N mineralization and soil mineral N, suggesting N limitation of CH4 uptake, and positively correlated with exchangeable aluminum (Al, indicating decrease in methanotrophic activity at high Al saturation. Reduction in soil CH4 uptake in the converted land uses compared to the reference land uses (P 2 and CH4 in a tropical landscape, a mechanism that we were able to detect by conducting this study at the

  8. Histidine-catalyzed synthesis of cyclic carbonates in supercritical carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The coupling reaction of carbon dioxide with epoxides was investigated using naturally occurring α-amino acids as the catalyst in supercritical carbon dioxide and it was found that L-histidine is the most active catalyst.In the presence of 0.8 mol% of L-histidine at 130°C under 8 MPa of CO2,the reaction of carbon dioxide with epoxides proceeded smoothly,affording corresponding cyclic carbonates in good to excellent yields.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Ecological Limits to Terrestrial Biological Carbon Dioxide Removal

    Science.gov (United States)

    Torn, M. S.; Smith, L. J.; Mishra, U.; Sanchez, D.; Williams, J.

    2014-12-01

    Many climate change mitigation scenarios include terrestrial atmospheric carbon dioxide removal (BCDR) or carbon neutral bioenergy production through bioenergy with carbon capture and storage (BECS) or afforestation/reforestation. Very high sequestration potentials for these strategies have been reported, and we evaluate the potential ecological limits (e.g., land and resource requirements) to implementation at the 1 Pg C y-1 scale relevant to climate change mitigation for U.S. and global scenarios. We estimate that removing 1 Pg C y-1 via tropical afforestation would require at least 7×106 ha y-1 of land, 0.09 Tg y-1 of nitrogen, and 0.2 Tg y-1 of phosphorous, and would increase evapotranspiration from those lands by almost 50%. Because of improved carbon capture technologies, we are updating (and reducing) our previous estimates for switchgrass BECS (previous estimate was 2×108 ha land and 20 Tg y-1 of nitrogen (20 % of global fertilizer nitrogen production)). Miscanthus could meet the same biomass production with much lower N demand. Moreover, transitioning the U.S land currently under corn- ethanol production to no-till perennial grasses for bioenergy would meet U.S. needs and have additional environmental benefits (such as improved wildlife habitat and soil restoration). Thus, there are both signficant ecological limits to BCDR as well as potential ecological benefits, depending on implementation.

  11. Atmospheric corrosion of carbon steel in the prairie regions

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, W.J. [Calgary Univ., AB (Canada). Dept. of Mechanical and Manufacturing Engineering; Andersson, J.I. [Husky Oil Operations Ltd., Calgary, AB (Canada)

    2010-07-01

    A study of atmospheric corrosion and carbon steel located in the prairie regions of Canada was presented. The study considered corrosion behaviour as well as the standards currently used to establish and predict corrosion in atmospheric conditions. The aim of the study was to develop an accurate predictive method of establishing corrosion amounts over time. The controlling parameters for atmospheric corrosion included acidic rainfall; temperature and humidity; time of wetness; and the presence of major contaminants such as sulfur dioxide (SO{sub 2}). The predictive approach involved the study of a protective film of magnetite iron oxide that establishes itself on carbon steel over time. The presence of the film provides increased atmospheric corrosion resistance. An analysis of the atmospheric corrosion of steel tanks at the Hardisty terminal was used to demonstrate the method. 22 refs., 5 tabs., 7 figs.

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

    OpenAIRE

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

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study o...

  13. Production and emission of methane and carbon dioxide by ruminants

    International Nuclear Information System (INIS)

    Animal digestion is responsible for the production of both carbon dioxide and methane, while breathing produces only carbon dioxide. The author described the digestion mechanism of ruminants, explaining that they produce higher levels of methane and carbon dioxide than other animals. Fermentation stoichiometry of ruminants was also discussed along with the influence that diet has on methane production. It was noted that methane production can be decreased by increasing animal productivity, or by using ionophore antibiotics and long chain fatty acids. Test results from each of these methods have revealed side effects and none appears to be applicable for the time being. 10 refs., 1 tab., 1 fig

  14. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Chen, Y.H.; Chikindas, M.L.;

    2000-01-01

    This paper examines the synergistic action of carbon dioxide and nisin on Listeria monocytogenes Scott A wild-type and nisin-resistant (Nis(r)) cells grown in broth at 4 degrees C. Carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree...... delayed for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic...

  15. Carbon dioxide fluid-flow modeling and injectivity calculations

    Science.gov (United States)

    Burke, Lauri

    2011-01-01

    At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.

  16. Carbon dioxide removal from coal-fired power plants

    International Nuclear Information System (INIS)

    To diminish the threat of a rapidly changing climate, emissions of CO2 should be reduced. One way to reduce these emissions is CO2 removal -the recovery of carbon dioxide from energy conversion processes and storage outside the atmosphere. This book gives an extensive description of three methods of capturing CO2 from flue gases of a conventional coal-fired power plant using amines, polymer membranes; and low temperature distillation, and two methods that are based on the modification of an integrated coal gasifier combined cycle plant, one using a shift reactor and a scrubber, the other using membrane separation and a CO2 gas turbine. The present state of the technology is described and optimized recovery designs are presented. Energy use is calculated in detail and elaborate cost calculations are given. In the last chapter, global storage potentials and costs of CO2 in aquifers, empty natural gas, and oil fields, are discussed. 170 refs

  17. Climate Change, Carbon Dioxide, and Pest Biology: Monitor, Mitigate, Manage.

    Science.gov (United States)

    Ziska, Lewis H; McConnell, Laura L

    2016-01-13

    Rising concentrations of atmospheric carbon dioxide ([CO2]) and subsequent changes in climate, including temperature and precipitation extremes, are very likely to alter pest pressures in both managed and unmanaged plant communities. Such changes in pest pressures can be positive (migration from a region) or negative (new introductions), but are likely to be accompanied by significant economic and environmental consequences. Recent studies indicate the range of invasive weeds such as kudzu and insects such as mountain pine beetle have already expanded to more northern regions as temperatures have risen. To reduce these consequences, a better understanding of the link between CO2/climate and pest biology is needed in the context of existing and new strategies for pest management. This paper provides an overview of the probable biological links and the vulnerabilities of existing pest management (especially chemical control) and provides a preliminary synthesis of research needs that could potentially improve the ability to monitor, mitigate, and manage pest impacts. PMID:25671793

  18. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    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

  19. Radiocarbon evidence for a smaller oceanic carbon dioxide sink than previously believed

    International Nuclear Information System (INIS)

    Radiocarbon produced naturally in the upper atmosphere or artificially during nuclear weapons testing is the main tracer used to validate models of oceanic carbon cycling, in particular the exchange of carbon dioxide with the atmosphere and the mixing parameters within the ocean itself. Here we test the overall consistency of exchange fluxes between all relevant compartments in a simple model of the global carbon cycle, using measurements of the long-term tropospheric CO2 concentration and radiocarbon composition, the bomb 14C inventory in the stratosphere and a compilation of bomb detonation dates and strengths. (author)

  20. Synthesis of dimethyl carbonate in supercritical carbon dioxide

    Directory of Open Access Journals (Sweden)

    D. Ballivet-Tkatchenko

    2006-03-01

    Full Text Available The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu3SnOCH3, n-Bu2Sn(OCH32 , and [n-Bu2(CH3OSn]2 O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO2 pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO2 pressure higher than 16 MPa. Under these conditions, CO2 acted as a reactant and a solvent.

  1. Membranes for separation of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

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

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, M P [ed.

    1987-03-01

    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 CO/sub 2/ Effects: Water Resources, Agriculture, Fisheries, Forests and Human Health'' and ''Glaciers, Ice Sheets, and Sea Level: Effect of a CO/sub 2/-Induced Climatic Change,'' were published by the US Department of Energy's Carbon Dioxide Research Division. Considerable information on atmospheric carbon dioxide and its possible effects on world climate is summarized in these six volumes. Each volume has its own index, but to make the information that is distributed throughout the six volumes more accessible and usable, comprehensive citation and subject indexes have been compiled. The subject indexes of the individual volumes have been edited to provide a uniformity from volume to volume and also to draw distinctions not needed in the separate volumes' indexes. Also, the comprehensive subject index has been formatted in a matrix arrangement to graphically show the distribution of subject treatment from volume to volume. Other aids include cross references between the scientific and common names of the animals and plants referred to, a glossary of special terms used, tables of data and conversion factors related to the data, and explanations of the acronyms and initialisms used in the texts of the six volumes. The executive summaries of the six volumes are collected and reproduced to allow the readers interested in the contents of one volume to rapidly gain information on the contents of the other volumes.

  5. Past explosive outbursts of entrapped carbon dioxide in salt mines provide a new perspective on the hazards of carbon dioxide

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2013-01-01

    This paper reports on a source of past carbon dioxide accidents which so far has only been sporadically mentioned in the literature. Violent and highly destructive outbursts of hundreds of tons of CO2 occurred regularly, if not routinely, in the now closed salt mines of the former DDR. The...... Menzengraben mine experienced an extreme outburst in 1953, possibly involving a several thousand tons of carbon dioxide. This source of accidents fills an important gap in the available carbon dioxide accident history and may provide a unique empirical perspective on the hazards of handling very large amounts...

  6. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Science.gov (United States)

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  7. 75 FR 75059 - Mandatory Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide

    Science.gov (United States)

    2010-12-01

    ... Sequestration of Carbon Dioxide; Final Rule #0;#0;Federal Register / Vol. 75 , No. 230 / Wednesday, December 1... sequestration of carbon dioxide and all other facilities that conduct injection of carbon dioxide. This rule... may determine''). These regulations will affect owners or operators of carbon dioxide (CO...

  8. Carbon dioxide sorption/ desorption characteristics of coals in Taiwan

    Science.gov (United States)

    Chien-Hung, Hsiao; Loung-Yie, Tsai

    2013-04-01

    Geological sequestration of CO2 into depleted oil reservoir, saline aquifer or unmineable coal seam is now being actively investigated for the purpose of reducing greenhouse gas in the atmosphere. Understanding the physical, chemical, and thermodynamic phenomena occurred with CO2 injection is very important in marking a reliable prediction of sequestration. This study examined the feasibility of carbon dioxide sequestration into unmineable coal seams in Taiwan. A total of 20 Miocene-aged coal samples from Western Foothill Belt, NW Taiwan, were collected. The stratigraphy include Mushan, Shihti, and Nanchuang Formation from bottom up. Proximate and petrographic analyses include maceral composition, Vitrinite reflectance were also measured. Carbon dioxide adsorption isotherms were analyzed at 35 degrees Celsius and up to 800 psi, by using a gravimetric ad/desorption apparatus. Isotherms were then fitted with a modified Langmuir Isotherm model by using Langmuir Pressure and Langmuir Volume so the model can be applied to supercritical conditions. According to the result of adsorption experiment, the pressure and temperature were quite significant. The gas storage capacity of CO2 was about 400 600 scf/ton at pressure up to 800 psi. Comparing the results of adsorption capacity with Proximate analysis and vitrinite reflectance, the Langmuir Volume shows a strong positive correlation with fixed carbon and vitrinite content. Furthermore, Adsorption capacity is closely related to micropores which were also rank and maceral dependent. It is noticed that the observed coal pore structures were affected by rank, and then exhibit have different diffusion rate of CO2.Finally, images under SEM were evaluated to understand the pathways of gas sorption.

  9. A Simple Thousand-Year Prognosis for Oceanic and Atmospheric Carbon Change

    Science.gov (United States)

    Fowler, A. C.

    2015-01-01

    A simple carbon-cycle box model allows for very simple quantitative insight into the evolution of climate over the next millennium. While melting ice sheets, rising sea levels, and ocean acidification are well recognised, we show that a further consequence of the repartitioning of ocean carbon is a dramatic rise in atmospheric carbon dioxide on a millennial time scale.

  10. Electrochemical Reactor for Producing Oxygen From Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An electrochemical reactor is proposed by MicroCell Technologies, LLC to electrochemically reduce carbon dioxide to oxygen. In support of NASA's advanced life...

  11. Precision remote sensor for oxygen and carbon dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes development of a passive optical sensor for simultaneous high-precision measurement of oxygen and carbon dioxide profiles within the full...

  12. Monthly Carbon Dioxide in Troposphere (AIRS on AQUA)

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon dioxide (CO2) is an important greenhouse gas released through natural processes such as respiration and volcano eruptions and through huma activities such as...

  13. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a growing need to develop improved technologies for precise airborne measurements of carbon dioxide, CO2. CO2 measurements are of great importance to many...

  14. Carbon dioxide and nitrous oxide in the North Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; Naqvi, S.W.A.; Jayakumar, D.A.; George, M.D.; Narvekar, P.V.; DeSousa, S.N.

    The understanding of biogeochemical cycling of carbon dioxide and nitrous oxide in the oceans is essential for predicting the fate of anthropogenically emitted components. The North Indian Ocean, with its diverse regimes, provides us with a natural...

  15. Energy costs of carbon dioxide concentrating mechanisms in aquatic organisms

    Czech Academy of Sciences Publication Activity Database

    Raven, John A.; Beardall, J.; Giordano, Mario

    2014-01-01

    Roč. 121, 2-3 (2014), s. 111-124. ISSN 0166-8595 Institutional support: RVO:61388971 Keywords : carbon dioxide * environmental change * radiation Subject RIV: EE - Microbiology, Virology Impact factor: 3.502, year: 2014

  16. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase 1 has seen the development of a revolutionary new type of sensor for making carbon dioxide (CO2) measurements from small Unmanned Aircraft Systems (UAS) and...

  17. Separation of carbon dioxide from flue emissions using Endex principles

    CERN Document Server

    Ball, R

    2009-01-01

    In an Endex reactor endothermic and exothermic reactions are directly thermally coupled and kinetically matched to achieve intrinsic thermal stability, efficient conversion, autothermal operation, and minimal heat losses. Applied to the problem of in-line carbon dioxide separation from flue gas, Endex principles hold out the promise of effecting a carbon dioxide capture technology of unprecedented economic viability. In this work we describe an Endex Calcium Looping reactor, in which heat released by chemisorption of carbon dioxide onto calcium oxide is used directly to drive the reverse reaction, yielding a pure stream of carbon dioxide for compression and geosequestration. In this initial study we model the proposed reactor as a continuous-flow dynamical system in the well-stirred limit, compute the steady states and analyse their stability properties over the operating parameter space, flag potential design and operational challenges, and suggest an optimum regime for effective operation.

  18. Applying Econometrics to the Carbon Dioxide “Control Knob”

    Directory of Open Access Journals (Sweden)

    Timothy Curtin

    2012-01-01

    Full Text Available This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]. However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010.

  19. Effects of carbon dioxide on laryngeal receptors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Carbon dioxide removal in gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Lidal, H.

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO{sub 2} in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140{sup o}C, for CO{sub 2} loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO{sub 2} into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO{sub 2} in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO{sub 2}/TEG/MEA system for estimation of CO{sub 2} partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs.

  1. Carbon dioxide removal in gas treating processes

    International Nuclear Information System (INIS)

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO2 in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140oC, for CO2 loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO2 into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO2 in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO2/TEG/MEA system for estimation of CO2 partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs

  2. Low-temperature data for carbon dioxide

    CERN Document Server

    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 ...

  3. Euthanasia of neonatal mice with carbon dioxide

    Science.gov (United States)

    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.

  4. Carbon dioxide balneotherapy and cardiovascular disease

    Science.gov (United States)

    Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  5. Modelling of cyclopentane promoted gas hydrate systems for carbon dioxide capture processes

    DEFF Research Database (Denmark)

    Herslund, Peter Jørgensen; Thomsen, Kaj; Abildskov, Jens;

    2014-01-01

    A thermodynamic model based on the Cubic-Plus-Association equation of state and the van der Waals-Platteeuw hydrate model is applied to perform a thermodynamic evaluation of gas hydrate forming systems relevant for post-combustion carbon dioxide capture.A modelling study of both fluid phase...... first stage is estimated to be 24.9. MPa. Applying three consecutive hydrate formation/dissociation stages (three-stage capture process), a carbon dioxide-rich product (97. mol%) may be delivered at a temperature of 280. K and a pressure of 3.65. MPa.A second capture process, where cyclopentane is...... study suggests the hydrate-based separation technology to be unsuitable for the specific case of post-combustion carbon dioxide capture from power station flue gases, where operating pressures should preferably remain close to atmospheric. Even though the hydrate structure becomes available at low...

  6. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Science.gov (United States)

    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.

  7. Atmospheric carbon dioxide and the climate record

    International Nuclear Information System (INIS)

    This paper is an attempt to provide a summary review of conclusions from previous studies on this subject. Subject headings include: conceptualization of the greenhouse effect, the climatic effect of doubled CO2, interpretation of the climatic record, diagnosis of apparent and possible model deficiencies, and the palaeoclimatic record

  8. Atmospheric carbon dioxide and the climate record

    Energy Technology Data Exchange (ETDEWEB)

    Ellsaesser, H.W.

    1989-04-01

    This paper is an attempt to provide a summary review of conclusions from previous studies on this subject. Subject headings include: conceptualization of the greenhouse effect, the climatic effect of doubled CO/sub 2/, interpretation of the climatic record, diagnosis of apparent and possible model deficiencies, and the palaeoclimatic record.

  9. Economic Growth, Carbon Dioxide Emissions, Renewable Energy and Globalization

    OpenAIRE

    Nuno Carlos LEITÃO

    2014-01-01

    This article investigates the correlation between economic growth, carbon dioxide emissions, renewable energy and globalization for the period 1970-2010, using time series (OLS,GMM, unit root test, VEC model, and Granger causality) to Portuguese economy. OLS estimator and GMM model demonstrate that carbon dioxide emissions and renewable energy are positively correlated with economic growth. The econometric models also show that the overall index of globalization has a positive effect...

  10. A simple, disposable end-tidal carbon dioxide detector.

    OpenAIRE

    Rosenberg, M; Block, C. S.

    1991-01-01

    Detection of expired carbon dioxide is one of the most reliable methods of avoiding accidental esophageal intubation. Although capnography has become a standard monitoring technique in the hospital operating room, it is rarely available in the office setting or other arenas where emergency endotracheal intubation may be required. A new and inexpensive device, however, has been developed for assessing end-tidal carbon dioxide. This semi-quantitative detector fits between the endotracheal tube ...

  11. Carbon dioxide capture by means of cyclic organic nitrogen compounds

    OpenAIRE

    García Abuín, Alicia

    2012-01-01

    The research work included in present PhD Thesis involves the research studies to capture carbon dioxide using different cyclic nitrogen organic compounds (glucosamine (GA), chitosan (C), alkyl-pyrrolidones, pyrrolidine (PYR) and piperidine (PIP). This investigation is based on the study of three experimental systems. Each of them has characteristics potentially suitable to achieve the aim of this work, that is to say, to improve the carbon dioxide capture process, which is pre...

  12. Carbon dioxide heat pump for dual-temperature drinking fountain

    Institute of Scientific and Technical Information of China (English)

    杨大章; 吕静; 何哲彬; 黄秀芝

    2009-01-01

    Carbon dioxide trans-critical heat pump system for heating and cooling water was designed,and its thermodynamic steady-state concentration model was established. Based on the steady-state model,parameters of the carbon dioxide trans-critical heat pump were calculated by computer programming. According to these parameters,the effects and application prospect of the heat pump system were analyzed for dual-temperature drinking fountains.

  13. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  14. Phase equilibrium condition of marine carbon dioxide hydrate

    International Nuclear Information System (INIS)

    Highlights: ► CO2 hydrate phase equilibrium was studied in simulated marine sediments. ► CO2 hydrate equilibrium temperature in NaCl and submarine pore water was depressed. ► Coarse-grained silica sand does not affect CO2 hydrate phase equilibrium. ► The relationship between equilibrium temperature and freezing point was discussed. - Abstract: The phase equilibrium of ocean carbon dioxide hydrate should be understood for ocean storage of carbon dioxide. In this paper, the isochoric multi-step heating dissociation method was employed to investigate the phase equilibrium of carbon dioxide hydrate in a variety of systems (NaCl solution, submarine pore water, silica sand + NaCl solution mixture). The experimental results show that the depression in the phase equilibrium temperature of carbon dioxide hydrate in NaCl solution is caused mainly by Cl− ion. The relationship between the equilibrium temperature and freezing point in NaCl solution was discussed. The phase equilibrium temperature of carbon dioxide hydrate in submarine pore water is shifted by −1.1 K to lower temperature region than that in pure water. However, the phase equilibrium temperature of carbon dioxide hydrate in mixture samples of coarsed-grained silica sand and NaCl solution is in agreement with that in NaCl solution with corresponding concentrations. The relationship between the equilibrium temperature and freezing point in mixture samples was also discussed.

  15. Carbon Dioxide/Methane Separation by Adsorption on Sepiolite

    Institute of Scientific and Technical Information of China (English)

    José A.Delgado; María A.Uguina; José L.Sotelo; Beatriz Ruíz; Marcio Rosário

    2007-01-01

    In this work,the use of sepiolite for the removal of carbon dioxide from a carbon dioxide/methane mixture by a pressure swing adsorption (PSA) process has been researched.Adsorption equilibrium and kinetics have been measured in a fixed-bed.and the adsorption equilibrium parameters of carbon dioxide and methane on sepiolite have been obtained.A model based on the LDF approximation has been employed to simulate the fixed-bed kinetics.using the Langmuir equation to describe the adsotption equilibrium isotherm.The functioning of a PSA cycle for separating carbon dioxide/methane mixtures using sepiolite as adsorbent has also been studied.The experimental results were compared with the ones predicted by the model adapted to a PSA system.Methane with purity higher than 97% can be obtained from feeds containing carbon dioxide with concentrations ranging from 34% to 56% with the proposed PSA cycle.These results suggest that sepiolite is an adsorbent with good properties for its employment in a PSA cycle for carbon dioxide removal from landfill gases.

  16. Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction

    Science.gov (United States)

    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.

  17. Atmospheric sulphur dioxide pollution in Malta : a preliminary study

    OpenAIRE

    Vella, Alfred J.; Caruana, S.; Demanuele, J.

    1993-01-01

    The results of a preliminary survey of the air quality in Malta during May-December 1990 with respect to sulphur dioxide are presented. One-hour-average S02 concentrations as high as 320 ug m-3 have been measured from areas proximate to the Marsa power station. The concentration of S02 in ambient air was found to be strongly dependent on atmospheric conditions and especially on wind direction. At Paola, measured concentrations varied from below the detection limit of 25 ug m-3 to about 160 ug...

  18. Nuclear power and the carbon dioxide problem

    International Nuclear Information System (INIS)

    This study deals with the question, which contribution can be delivered by nuclear power to the redution of the emission of carbon dioxide (CO2) from the power supply. The emphasis lays upon the following aspects: the emissions of CO2 which occur in the nuclear-power cycle (the so-called indirect emission of CO2 power plants); the amount of uranium stocks; the change of CO2 emission caused by replacement of fossil fuels, in particular coal, by nuclear power. First an energy-analysis of the nuclear power cycle is presented. On the base of this analysis the CO2 uranium can be calculated. The role of nuclear power in the reduction of CO2 emission depends on the development of the final power demand. Therefore in this study two scenarios derived from the 'IIASA-low' scenario; 'low-energy'-scenario in which the world-energy consumption remains at about the same level. In the calculations the indirect emissions of CO2, also dependent on the ore richness and the technology used, have always been taken into account. In the calculations two uranium-reserve variants of resp. 5.7 and 30 mln. tons have been assumed. From the results of the calculations it can be concluded that whether or not taking account of the indirect emissions of CO2 in the nuclear power cycle, has only limited effect on the calculated contribution of nuclear power to the solution of the greenhouse effect. The uranium reserves turn out to be determining for the potential contribution of nuclear power. By putting on the surely available reserve of 5.7 mln. tons, or the speculative reserve of 30 mln. tons, with the actual technology, an emission of resp. 130-140 billion and 880 billion tons CO2 can be avoided in replacing coal. With maximal employment of improved conversion techniques these contributions may be doubled. (H.W.). 40 refs.; 13 figs.; 10 tabs

  19. Photopromoted carbonylation of olefins with carbon dioxide and labelling studies with 13CO2 and 13CH3OH

    Institute of Scientific and Technical Information of China (English)

    YIN Jingmei; GAO Dabin; HU Jiehan; ZHOU Guangyun; JIA Yingping; WANG Xiangsheng

    2003-01-01

    Photopromoted carbonylation of olefins with carbon dioxide can be completed in ambient conditions (room temperatures and atmospheric pressure) by Co(OAc)2 catalysis. It was found that in carbonyl carbons of methyl ester of aliphatic acid 50% is from CO2 and the other 50% from CH3OH by labelling experimental with 13CO2 and 13CH3OH.

  20. Continuous flow isotope ratio mass spectrometry of carbon dioxide trapped as strontium carbonate

    International Nuclear Information System (INIS)

    The isotopic signal provided by differential discrimination against atmospheric carbon dioxide (13CO2) by C3 and C4 plant photosynthetic pathways is being widely used to study the processes of carbon (C) fixation, soil organic matter formation, and mineralization in nature. These studies have been facilitated by the availability of automated C and nitrogen (N) combustion analyzers (ANCA) combined with continuous flow isotope ratio mass spectrometers (CFIRMS). Analysis of 13CO2 in these instruments requires consistent sample mass for best precision, a requirement that is easily satisfied for soil and tissue samples by adjusting sample weight. Consistent CO2 sample size is much more difficult to achieve using gas handling systems for samples of headspace gases when CO2 concentrations vary widely. Long storage of gaseous samples also is difficult. Extended respiration studies are most easily conducted by trapping CO2 in alkali and conversion to an insoluble carbonate. Thermal decomposition of the carbonate in an on-line ANCA allows consistent and optimal CO2 sample mass to be obtained. The use of precipitated carbonates also facilitates storage of samples and enables full automation of sample analysis using an ANCA interfaced to a CFIRMS. Calcium (Ca), strontium (Sr), and barium (Ba) carbonates were tested. Strontium carbonate (SrCO3) with the addition of vanadium pentoxide (V2O5) as a combustion catalyst was found most suitable