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1

Saving energy and optimizing air quality using carbon dioxide (CO)  

Microsoft Academic Search

Demand control ventilation (DCV) using carbon dioxide offers a unique opportunity for building designers and owners to resolve an age-old paradox: how to reduce energy costs while optimizing air quality. Recent innovations in gas sensor designs have considerably improved the long-term performance and cost of carbon dioxide sensing, making it one of the fastest growing segments of the HVAC control

Schell

1998-01-01

2

Climate Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Constraints  

E-print Network

Climate Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Policy Design: Interactions among Carbon Dioxide, Methane, and Urban Air Pollution Constraints by Marcus. The third case examines the benefits of increased policy coordination between air pollution constraints

de Weck, Olivier L.

3

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

Microsoft Academic Search

Carbon dioxide (CO) dioxide (CO) mixing ratio and isotopic carbon-13 dioxide δ¹³CO was measured in the air extracted form ice cores from Greenland (GISP 2, Greenland Ice Sheet Project 2) and from Antarctica (Vostok). The goals are to determine the phasing between temperature and atmospheric CO changes during periods of different climatic conditions and to gain insight into the mechanisms

Wahlen

1994-01-01

4

Carbon dioxide emissions from international air freight  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

5

Carbon dioxide assimilation from air and water by duckweed Spirodela polyrrhiza (L.) Schleid  

Microsoft Academic Search

Carbon dioxide assimilation by duckweed, S. polyrrhiza, was measured using a glass assimilation box and 14C-NaHCO3, under different pH conditions of water. S. polyrrhiza assimilates carbon dioxide from both air and water. The carbon assimilation from air is comparable to the assimilation from water under normal pH conditions.

K. Satake; S. Shimura

1983-01-01

6

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

EPA Science Inventory

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

7

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

ERIC Educational Resources Information Center

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

Jacobs, Bruce W.

8

Performance of air filters cleaned by supercritical carbon dioxide  

Microsoft Academic Search

A new technique based on the use of supercritical carbon dioxide (CO2) for cleaning HEPA filters was developed. Glass fiber filters and polytetrafluoroethylene (PTFE) membranes loaded with dioctylphthalate (DOP) droplets were cleaned with supercritical carbon dioxide under various conditions. The cleaning performance was evaluated by the weight recovery of the filter media and the recoveries of their collection efficiencies and

Takao Ito; Yoshio Otani; Hiroshi Inomata

2004-01-01

9

The Influence of Pressure on the Equilibrium between Carbon Dioxide and Air  

Microsoft Academic Search

The equilibrium between solid carbon dioxide and air has been examined at pressures from atmospheric to 200 atm and at temperatures from - 110 to - 196 degrees C. At the lower temperatures and higher pressures within this range the air was condensed to the liquid state. The concentration of carbon dioxide in the mixed phase, particularly at high pressures

T. J. Webster

1952-01-01

10

A Method for the Determination of Carbon Monoxide, Carbon Dioxide, Nitrous Oxide and Sulphur Dioxide in Air by Gas Chromatography Using an Emissive Helium Plasma Detector  

Microsoft Academic Search

A number of workers have used molecular sieves to separate carbon monoxide from air (1,2,3) and it has been shown that PORAPAK ? is suitable for the resolution of carbon dioxide and sulphur dioxide from air (3,4,5). However, the sensitive detection of such gases frequently presents problems without recourse to the use of large sample volumes.

R. M. Dagnall; D. J. Johnson; T. S. West

1973-01-01

11

An idealized assessment of the economics of air capture of carbon dioxide in mitigation policy  

E-print Network

An idealized assessment of the economics of air capture of carbon dioxide in mitigation policy is the Framework Convention on Climate Change (FCCC), negotiated in 1992, and its 1997 Kyoto Protocol. The FCCC, primarily carbon dioxide (CO2). During 2007, countries have been actively engaged in negotiating future

Colorado at Boulder, University of

12

Avoidance of 20% carbon dioxide-enriched air with humans.  

PubMed Central

Four college students were exposed to a Sidman avoidance procedure to determine if an avoidance contingency involving 20% carbon dioxide-enriched air (CO2) would produce and maintain responding. In Phase 1, two conditions (contingent and noncontingent) were conducted each day. These conditions were distinguished by the presence or absence of a blue or green box on a computer screen. In the contingent condition, CO2 presentation were delivered every 3 s unless a subject pulled a plunger. Each plunger pull postponed CO2 presentations for 10 s. In the noncontingent condition, CO2 presentations occurred on the average of every 5 min independent of responding. Following stable responding in Phase 1, condition-correlated stimuli were reversed. In both conditions, plunger response rate was high during the contingent condition and low or zero during the noncontingent condition. Furthermore, subjects avoided most CO2 presentations. However, CO2 presentations did not increase verbal reports of fear. Overall, the results from the present study suggest that CO2 can be used effectively in basic studies of aversive control and in laboratory analogues of response patterns commonly referred to as anxiety. PMID:9684345

Lejuez, C W; O'Donnell, J; Wirth, O; Zvolensky, M J; Eifert, G H

1998-01-01

13

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

SciTech Connect

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

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

1994-12-31

14

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

Microsoft Academic Search

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

M. Hasebe; Y. Suzuki

2003-01-01

15

Global Observations of Mid-Tropospheric Carbon Dioxide Using the AIRS Sounder on EOS-AQUA  

NASA Astrophysics Data System (ADS)

The Atmospheric Infrared Sounder (AIRS) has been operating continuously for more than 3 years, providing a large record of hyperspectral radiances throughout the mid-infrared. We have generated a subset of all AIRS radiances for clear, ocean fields-of-view for the purposes of validation of both the sensor and the radiative transfer algorithm used for temperature and humidity retrievals. Radiance bias comparisons between observed radiances, and those computed from both (1) radiosondes launched coincident with AIRS, and (2) ECMWF analysis/forecast fields exhibit variations with both latitude and time due to variable carbon dioxide. We present here zonally-averaged (ocean only) retrievals of mid-tropospheric carbon dioxide derived from the biases between AIRS observations and radiances computed from ECMWF. The time and latitude dependence of monthly averages of the retrieved zonal carbon dioxide amounts exhibit behavior close to the NOAA/CMDL global carbon dioxide climatologies. Long-term satellite observations of global carbon dioxide with operational hyperspectral sounders should be feasible and provide an important contribution to our understanding of carbon dioxide emissions.

Strow, L. L.; Hannon, S.

2005-12-01

16

Methane and carbon dioxide fluxes in soils evaluated by 222 Rn flux and soil air concentration profiles  

Microsoft Academic Search

Measurements of methane and carbon dioxide fluxes from diverse soils in the surroundings of Mlaga (Spain) were made. Methane and carbon dioxide fluxes were carried out by an indirect method from simultaneous measurements of 222Rn flux from the soil surface in parallel with concentration profile measurements of 222Rn, methane and carbon dioxide in the air of soil. Correlations found between

C. Dueas; M. C. Fernndez; J. Carretero; E. Liger

1999-01-01

17

Air-sea carbon dioxide exchange in the North Pacific Subtropical Gyre: Impplications for the global carbon budget  

NASA Astrophysics Data System (ADS)

The role of the ocean as a sink for anthropogenic carbon dioxide is a subject of intensive investigation and debate. Interest in this process is driven by the need to predict the rate of future increase of atmospheric carbon dioxide and subsequent global climatic change. Although estimates of the magnitude of the oceanic sink for carbon dioxide appear to be converging on a value of 2 (Gt) C yr-1 for the 1980s, a detailed understanding of the temporal and spatial variability in the rate of exchange of carbon dioxide between the ocean and the atmosphere is not available. For example, recent modeling work and direct measurements of air-sea carbon dioxide flux produce very different estimates of the air-sea flux in the northern hemisphere. As a consequence, it has been suggested that a large unidentified oceanic carbon dioxide sink may exist in the North Pacific. As a part of our time series observations in the North Pacific Subtropical Gyre, we have measured dissolved inorganic carbon and titration alkalinity over a four-year period. These measurements constitute the most extensive set of observations of carbon system parameters in the surface waters of the central Pacific Ocean. Our results show that the ocean in the vicinity of the time series site is a sink for atmospheric carbon dioxide. On the basis of these observations, we present a mechanism by which the North Pacific Subtropical Gyre can be a potential sink for 0.2 Gt C yr-1 of atmospheric carbon dioxide. Although our observations indicate that the North Pacific Subtropical Gyre is a sink for atmospheric carbon dioxide, the magnitude of this oceanic sink is relatively small. Our data and interpretations are therefore consistent with the argument for a relatively large sink during the 1980s in northern hemisphere terrestrial biomass. Another possibility is that the net release of carbon dioxide to the atmosphere owing to land use activities in tropical regions has been overestimated.

Winn, Christopher D.; MacKenzie, Fred T.; Carrillo, Christopher J.; Sabine, Christopher L.; Karl, David M.

1994-06-01

18

Electrical study of DC positive corona discharge in dry and humid air containing carbon dioxide  

Microsoft Academic Search

As most part of the industrial effluents contain carbon dioxide and water vapour, it is interesting to study from an electric point of view `basic' gas mixtures including air and various amounts of these gases, in order to precise how the corona discharge inception takes place in such mixtures. In a DC point-to-plane reactor, distinct parameters are varied, such as

S. Lachaud; J. F. Loiseau

2003-01-01

19

On the causal link between carbon dioxide and air pollution mortality  

Microsoft Academic Search

Greenhouse gases and particle soot have been linked to enhanced sea-level, snowmelt, disease, heat stress, severe weather, and ocean acidification, but the effect of carbon dioxide (CO2) on air pollution mortality has not been examined or quantified. Here, it is shown that increased water vapor and temperatures from higher CO2 separately increase ozone more with higher ozone; thus, global warming

Mark Z. Jacobson

2008-01-01

20

REGARDLESS OF WHETHER RISING ATMOSPHERIC CARBON DIOXIDE LEVELS INCREASE AIR TEMPERATURE, FLOWERING PHENOLOGY WILL BE AFFECTED  

E-print Network

factors, including atmospheric CO2, ni- trogen deposition, and precipitation, correlate with the riseREGARDLESS OF WHETHER RISING ATMOSPHERIC CARBON DIOXIDE LEVELS INCREASE AIR TEMPERATURE, FLOWERING in atmospheric CO2, which may also modify phenology. The effects of elevated CO2 and temperature on time

Reekie, Ed

21

Infrared Carbon Dioxide Sensor and its Applications in Automotive Air-Conditioning Systems  

Microsoft Academic Search

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

M. Arndt; M. Sauer

22

Carbon dioxide  

NSDL National Science Digital Library

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

Arie Melamed-Katz (None;)

2007-06-19

23

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

24

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

NASA Technical Reports Server (NTRS)

The air revitalization system of the International Space Station (ISS) operates in an open loop mode and relies on the resupply of oxygen and other consumables from earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby closing the air-loop. We have a developed a temperature-swing adsorption compressor (TSAC) for performing these tasks that is energy efficient, quiet, and has no wearing parts. This paper discusses the design features of a TSAC hardware that uses air as the cooling medium and has Space Station application.

Mulloth, Lila M.

2003-01-01

25

Patient-Controlled Room Air Insufflation Versus Automated Carbon Dioxide Delivery for CT Colonography  

Microsoft Academic Search

OBJECTIVE. Our objective was to prospectively compare colonic distention and patient comfort at screening CT colonography (CTC) with patient-controlled room air (RA) insuffla- tion versus automated carbon dioxide (CO2) delivery. SUBJECTS AND METHODS. Two hundred eight adults undergoing CTC were ran- domized to RA or CO2 (104 per method). Colonic distention was prospectively assessed by seg- ment using a 4-point

Theodore J. Shinners; Perry J. Pickhardt; Andrew J. Taylor; Debra A. Jones; Cara H. Olsen; Shinners TJ; Taylor AJ; Jones DA; Olsen CH

26

High-Performance Sorbents for Carbon Dioxide Capture from Air  

SciTech Connect

This project has focused on capture of CO2 from ambient air (air capture). If this process is technically and economically feasible, it could potentially contribute to net reduction of CO2 emissions in ways that are complementary to better developed techniques for CO2 from concentrated point sources. We focused on cyclic adsorption processes for CO2 capture from air in which the entire cycle is performed at moderate temperatures. The project involved both experimental studies of sorbent materials and process level modeling of cyclic air capture processes. In our experimental work, a series of amine-functionalized silica adsorbents were prepared and characterized to determine the impact of molecular architecture on CO2 capture. Some key findings were: Amine functionalized silicas can be prepared with high enough CO2 capacities under ambient conditions to merit consideration for use in air capture processes. Primary amines are better candidates for CO2 capture than secondary or tertiary amines, both in terms of amine efficiency for CO2 adsorption and enhanced water affinity. Mechanistic understanding of degradation of these materials can enable control of molecular architecture to significantly improve material stability. Our process modeling work provided the first publically available cost and energy estimates for cyclic adsorption processes for air capture of CO2. Some key findings were: Cycles based on diurnal ambient heating and cooling cannot yield useful purities or amounts of captured CO2. Cycles based on steam desorption at 110 oC can yield CO2 purities of ~88%. The energy requirements for cycles using steam desorption are dominated by needs for thermal input, which results in lower costs than energy input in the form of electricity. Cyclic processes with operational costs of less than $100 tCO2-net were described, and these results point to process and material improvements that could substantially reduce these costs. The most critical conclusions from our work are that (i) CO2 capture from ambient air using moderate temperature cyclic adsorption processes is technically feasible and (ii) the operational costs of realistic versions of these processes are moderate enough to encourage future development of this technology. Because of the very modest net investment that has been made in R&D associated with this approach from all sources worldwide (relative to the massive public and private investment that has been made in technologies for CO2 from concentrated point sources), our results strongly suggest that continued development of air capture is justified.

Sholl, David; Jones, Christopher

2013-03-13

27

Design and calculation of ground-to-air transmitting optical system of carbon-dioxide laser communicator  

Microsoft Academic Search

Transmitting optical sys tem was part of maneuverable type Carbon-Dioxide atmospheric Laser Communicator, which consists of Carbon-Dioxide laser, acousto-optical modulator, focusing lens, collimating lens and transmitting antenna. Ground-to-air communication distance up to 15km, error bit rate not more than 10-9. Image and speech can be transmitted separately with half duplex. Method for design major optical devices of ground-to-air laser communication

Hongtao Zhang; FuChang Yin; Qiugui Wang

2002-01-01

28

Carbon Dioxide, Particulates, and Subjective Human Responses in Office Buildings Without Histories of Indoor Air Quality Problems  

Microsoft Academic Search

Indoor air quality (IAQ) complaints have steadily increased since 1973 when the Arab oil embargo forced building owners and operators to reduce energy costs in their buildings, in part by reducing indoor\\/outdoor air exchange rates. Carbon dioxide measurements are commonly used as an indicator of the amount of fresh air that is being introduced into a building. Particulate measurements have

Bert A. Hill; Bobby F. Craft; John A. Burkart

1992-01-01

29

High accuracy standards and reference methodology for carbon dioxide in air  

SciTech Connect

This report summarizes the activities and accomplishments of a three-year NBS program for the development of standards and reference methodology for carbon dioxide (CO/sub 2/) in air that was designed to: (1) develop defined Standard Reference Materials (SRM's) for CO/sub 2/ in air at atmospheric concentrations having a total uncertainty (95% confidence level) not exceeding 0.1% relative; (2) assess the equivalency of absolute gravimetry employed by the National Bureau of Standards (NBS) and absolute manometry employed by the Scripps Institution of Oceanography (SIO) for the development of accurate standards for CO/sub 2/ in air at atmospheric concentrations; and (3) develop a state-of-the-art isotope dilution mass spectrometer (ID-MS) system and associated methodology to serve as an NBS-based reference method for absolute independent confirmation of CO/sub 2/ concentrations in CO/sub 2/ in air standards.

Zielinski, W.L. Jr.; Hughes, E.E.; Barnes, I.L; Elkins, J.W.; Rook, H.L.

1986-06-01

30

Carbon Dioxide Capture and Disposal  

NASA Astrophysics Data System (ADS)

Unless carbon dioxide from fossil fuel combustion is captured and disposed of safely and permanently, the concerns over climate change will eventually lead to the demise of fossil fuels. Because of their importance in today's energy market the phasing out of fossil fuels would likely precipitate a major energy crisis. Mineral sequestration and extraction of carbon dioxide from the air are two advanced technologies for carbon sequestration that aim at maintaining access to the vast fossil energy resources for centuries to come. While it is straightforward to dispose of carbon dioxide in limited amounts and for a limited time, permanent disposal of trillions of tons of carbon poses serious challenges. The formation of solid mineral carbonates from readily available minerals would provide safe and permanent storage. Capture of carbon dioxide from air makes it possible to sequester carbon dioxide emissions from sources other than power plants. This is important considering that even the relatively minor reductions suggested by the Kyoto Accord would have required the US to eliminate carbon dioxide emissions comparable to those of the entire 1990 coal fired power plant fleet. Capture of carbon dioxide from the air, would make it possible to close the carbon cycle in the transportation sector without phasing out liquid hydrocarbon fuels. It eliminates the need for long distance transport of carbon dioxide and allows the continued use of the existing energy infrastructure. Mineral sequestration at remote sites combined with on site carbon dioxide capture from air, would allow for long term stabilization of atmospheric carbon dioxide levels. I will outline the current state of the technology and point to advances required before these approaches are ready for large-scale implementation.

Lackner, K. S.

2002-05-01

31

Carbon Dioxide Capture and Disposal  

Microsoft Academic Search

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

K. S. Lackner

2002-01-01

32

Spatial and seasonal variability of the air-sea equilibration timescale of carbon dioxide  

NASA Astrophysics Data System (ADS)

The exchange of carbon dioxide between the ocean and the atmosphere tends to bring near-surface waters toward equilibrium by reducing the partial pressure gradient across the air-water interface. However, the equilibration process is not instantaneous; in general there is a lag between forcing and response. The timescale of air-sea equilibration depends on several factors involving the depth of the mixed layer, temperature, salinity, wind speed, and carbonate chemistry. In this work, we use a suite of observational datasets to generate climatological and seasonal composite maps of the air-sea equilibration timescale. The relaxation timescale exhibits considerable spatial and seasonal variations, which are largely set by changes in mixed layer depth and wind speed. The net effect is dominated by the mixed layer depth; the gas exchange velocity and carbonate chemistry parameters only provide partial compensation. Broadly speaking, the adjustment timescale tends to increase with latitude. We compare the observationally-derived air-sea gas exchange timescale with a model-derived surface residence time and a data-derived horizontal transport timescale, which allows us to define two non-dimensional metrics of gas exchange efficiency. These parameters highlight the Southern Ocean, equatorial Pacific, and North Atlantic as regions of inefficient air-sea equilibration where carbon anomalies are likely to form and persist. The efficiency parameters presented here can serve as simple tools for understanding regional air-sea disequilibrium in both observations and models. This work is distributed under the Creative Commons Attribution 3.0 Unported License together with an author copyright. This license does not conflict with the regulations of the Crown Copyright.

Jones, Daniel; Ito, Takamitsu; Takano, Yohei; Hsu, Wei-Ching

2014-05-01

33

Carbon dioxide power cycle  

Microsoft Academic Search

An improved direct fired power system generating and employing a combustion gas which includes carbon dioxide or a working fluid including a combustion chamber for burning a mixture which includes oxygen, carbonaceous fuel and recycled carbon dioxide working fluid at a first pressure of above 1100 PSI thereby providing a combustion gas which includes carbon dioxide and water at substantially

Osgerby

1985-01-01

34

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

Microsoft Academic Search

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

Emerson Escobar Nunez; Kyriaki Polychronopoulou; Andreas A. Polycarpou

2010-01-01

35

Is the Earth Warming? A Test of the Effect of Increased Carbon Dioxide on the Thermal Properties of Air  

NSDL National Science Digital Library

In this activity, air with increased concentrations of carbon dioxide is produced and the rate of heat loss of that air is compared to today's normal air. This is used to help demonstrate the environmental and economic effects of increased carbon dioxide (CO2) content in the atmosphere. It tests the claim that the Earth's climate is warming due to changes in the relative concentration of gases in the atmosphere. The activity involves students heating and cooling the air in a large glass vessel as a model of the atmosphere. Temperature readings are taken and plotted. This will show the rate of heat loss from "normal" air. Then, the CO2 concentration of the air will be increased and the experiment repeated. The results will demonstrate the effects of increased CO2 on the rate of heat loss from air. Students will then evaluate claims that increasing carbon dioxide will significantly increase the temperature of the atmosphere, and thus lead to climate change, in their lifetime.

Davies, David

36

Fine root responses of mature deciduous forest trees to free air carbon dioxide enrichment (FACE)  

Microsoft Academic Search

Summary 1. Elevated atmospheric carbon dioxide (CO 2 ) concentrations have often been reported to increase carbon allocation below-ground, particularly to fine root production. However, for trees these responses have primarily been studied in young expanding systems while the evidence for late successional systems that have reached steady state above- and below-ground is very limited. 2. At the Swiss Canopy

Martin Bader; Erika Hiltbrunner; Christian Krner

2009-01-01

37

The carbon dioxide cycle  

USGS Publications Warehouse

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.

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

2005-01-01

38

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

SciTech Connect

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

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

1999-05-01

39

Carbon dioxideair mixtures: mass transfer in recycling packed-bed absorption columns operating under high liquid flow rates  

Microsoft Academic Search

The absorption of carbon dioxideair mixtures in water in a packed-bed recirculating absorption column with an inner diameter of 0.08m and a length of 1.20m was investigated. A model is derived and numerically solved for recycling packed-bed absorption systems in order to determine the overall mass transfer coefficients. The relationship between the KLa values calculated in this work and the

Vural Evren; Tuncay a?atay; Ahmet R. zdural

1999-01-01

40

Role of activated carbon pellets in carbon dioxide removal  

Microsoft Academic Search

The removal of carbon dioxide from gas\\/air streams is more often becoming necessary in many industries for different purposes. In cryogenic air separation plant, air has to be free from carbon dioxide before its liquefaction otherwise blockage due to freezing of heat exchange equipment would result. Enrichment of methane in biogas to have fuel of higher calorific value can be

S. C Sarkar; A Bose

1997-01-01

41

Molecular Structure of Carbon Dioxide  

NSDL National Science Digital Library

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

2002-08-15

42

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

Microsoft Academic Search

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

L. Merlivat; P. Brault

1995-01-01

43

Tree growth in carbon dioxide enriched air and its implications for global carbon cycling and maximum levels of atmospheric CO2  

Microsoft Academic Search

In the longest carbon dioxide enrichment experiment ever conducted, well-watered and adequately fertilized sour orange tree seedlings were planted directly into the ground at Phoenix, Arizona, in July 1987 and continuously exposed, from mid-November of that year, to either ambient air or air enriched with an extra 300 ppmv of CO2 in clear-plastic-wall open-top enclosures. Only 18 months later, the

Sherwood B. Idso; Bruce A. Kimball

1993-01-01

44

Carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

The earth's climate is getting warmer because of a buildup of carbon dioxide in the atmosphere that will continue well into the next century, according to a report released October 20 by the National Research Council (NRC), the research arm of the National Academy of Sciences. As the result of a 2-year study commissioned by Congress, the NRC's Carbon Dioxide Assessment Committee predicts a global temperature rise of as much as 4.5C by the year 2100, enough to shift weather patterns, raise sea levels, and eliminate agriculture in some parts of the world. What's more, the trend seems inevitable even drastic changes in our energy use would not prevent the warmup, according to the committee's findings.CO2, the major contributor to a thermal greenhouse effect that traps re-radiated heat in the atmosphere, has risen from a concentration of 315 parts per million (ppm) to 340 ppm in one generation, largely as a result of the use of fossil fuels. Sometime in the third quarter of the next century, the report predicts, the concentration will probably be double the current level. The result will be a global warming of surface air of between 1.5 and 4.5C, with temperature rises relatively greater at the poles.

45

KEY COMPARISON: International comparison CCQM-K52: Carbon dioxide in synthetic air  

Microsoft Academic Search

The first key comparison on carbon dioxide in nitrogen dates from 1993-1994 (CCQM-K1.b). Since then, numerous national metrology institutes (NMIs) have been setting up facilities for gas analysis, and have developed claims for their Calibration and Measurement Capabilities (CMCs) for these type mixtures. In the April 2005 meeting of the CCQM Gas Analysis Working Group, a policy was proposed to

Rob M. Wessel; Adriaan M. H. van der Veen; Paul R. Ziel; Paul Steele; Ray Langenfelds; Marcel van der Schoot; Damian Smeulders; Laurie Besley; Valnei Smarao da Cunha; Zeyi Zhou; Han Qiao; Hans Joachim Heine; Beln Martin; Tatiana Mac; Prabhat K. Gupta; Elena Amico di Meane; Michela Sega; Francesca Rolle; Masaaki Maruyama; K. Kato; N. Matsumoto; Jin Seog Kim; Dong Min Moon; Jin Bok Lee; Francisco Rangel Murillo; Carlos Ramrez Nambo; Vctor M. Serrano Caballero; Manuel de Jess Avila Salas; Alejandro Prez Castorena; L. A. Konopelko; Y. A. Kustikov; A. V. Kolobova; V. V. Pankratov; O. V. Efremova; Stanislav Musil; Frantisek Chromek; Miroslava Valkova; Martin J. T. Milton; Gergely Vargha; F. Guenther; Walter R. Miller; Angelique Botha; James Tshilongo; Ipeleng S. Mokgoro; Nompumelelo Leshabane

2008-01-01

46

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

SciTech Connect

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

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

1994-10-01

47

Development of an Enthalpy and Carbon Dioxide Based Demand Control Ventilation for Indoor Air Quality and Energy Saving with Neural Network Control  

Microsoft Academic Search

An enthalpy and carbon dioxide level based demand control ventilation (EDCV) algorithm has been developed. This takes into account both the indoor occupancy level and the energy content of the fresh air and return air while controlling the fresh air supply. It has been applied under various operating conditions to ensure that the most effective control strategy was used. A

Christopher Y. H. Chao; J. S. Hu

2004-01-01

48

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

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

49

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

50

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

51

Carbon Dioxide Removal  

NSDL National Science Digital Library

In this experiment using sprigs of Elodea, learners will observe a natural process that removes carbon dioxide (CO2) from Earth's atmosphere. This process is a part of the carbon cycle and results in temperature suitable for life. Note: this experiment requires that learners make observations an hour or the next day after they set up the materials.

History, American M.

2008-01-01

52

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

NASA Technical Reports Server (NTRS)

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

Swickrath, Michael J.; Anderson, Molly

2012-01-01

53

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

NASA Astrophysics Data System (ADS)

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

Kriegler, E.; Stolaroff, J. K.

2007-12-01

54

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

PubMed

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

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

2014-05-01

55

Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

This figure, the famous Keeling Curve, shows the history of atmospheric carbon dioxide concentrations as directly measured at Mauna Loa, Hawaii. This curve is an essential piece of evidence that shows the increased greenhouse gases that cause recent increases in global temperatures.

Rohde, Robert A.; (from published NOAA data)

56

Bench Remarks: Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Bent, Henry A.

1987-01-01

57

Carbon Dioxide Laser Guidelines  

PubMed Central

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

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

2009-01-01

58

8, 73157337, 2008 Carbon dioxide  

E-print Network

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

Paris-Sud XI, Université de

59

Arnold Schwarzenegger THE CARBON DIOXIDE  

E-print Network

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

60

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

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

61

Inter-annual variation in the response of Pinus taeda tree growth to long term Free Air Carbon dioxide Enrichment (FACE)  

NASA Astrophysics Data System (ADS)

Rising carbon dioxide is predicted to increase forest productivity, though the duration of the response and how it might be altered by annual variation in rainfall and temperature are not well understood. For eight years we measured the basal area of trees exposed to Free Air Carbon-dioxide Enrichment (FACE) in a rapidly growing Pinus taeda plantation and used these measurements to estimate monthly and annual growth. We coupled these measurements with a mathematical model to estimate the start and end of growth in each year. Elevated carbon dioxide increased the basal area increment (BAI) of trees by 13 to 27 percent. Exposure to elevated carbon dioxide increased the growth rate but not the duration of the growing season in most years. With the exception of one year following an extreme drought and a severe ice storm, BAI was positively correlated with the amount of rainfall during the growing season. The inter-annual variation in the relative enhancement of BAI caused by elevated carbon dioxide was strongly related to the combination of temperature and rainfall during the growing season. There was no evidence of a systematic reduction in the stimulation of growth during the first eight years of this experiment, suggesting that hypothesized limitation of the carbon dioxide response caused by nitrogen availability has yet to occur.

Moore, D. J.; Aref, S.; Ho, R. M.; Pippen, J. S.; Hamilton, J.; de Lucia, E. H.

2005-12-01

62

Inhibition of chlorophyll synthesis by high concentrations of carbon dioxide  

Microsoft Academic Search

High concentrations of carbon dioxide inhibit the greening of etiolated plants. In the presence of 20% oxygen, concentrations of carbon dioxide of 10% and above inhibited the production of chlorophyll in etiolated leaves of barley, wheat, and dwarf French bean. On return to air, recovery from this inhibition took place rapidly. High concentrations of carbon dioxide were also inhibitory when

B. T. Steer; D. A. Walker

1964-01-01

63

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

NASA Astrophysics Data System (ADS)

Fossil energy use has benefited humankind but also threatens our environment. It has increased atmospheric carbon dioxide (CO2) levels from 280 ppm to 370 ppm, over the past century. This rise has been linked to with observed ocean acidification and global warming. Projections indicate that atmospheric CO2 could reach 540 to 970 ppm in 2100, with significant effects on our earth system. Given that fossil fuels are plentiful, cost-effective, and energy rich their use will be limited by our ability to mitigate their environmental impact. Carbon management provides potential solutions to this. Current approaches to manage carbon focus on capturing CO2 from large point sources such as power plants. They are limited because they fail to address emissions from transportation and the myriad of dispersed sources that amount to about half of all emissions. To solve this problem we have proposed and are developing direct CO2 extraction from air as a means to capture emissions from all sources [1-3]. It preserves our fuel distribution and transportation systems, and in principle could allow us to restore CO2 to pre-industrial levels. Our concept utilizes atmospheric circulation to capture CO2 directly from the dilute stream in air (370 ppm) by binding it to an adsorbent. Subsequent heating releases the bound CO2 as a pure stream suitable for permanent sequestration. For example, this cycle is favorable for Ca(OH)2 which reacts rapidly with CO2 to form CaCO3. The heat to recover CO2 from CaCO3 is 190 kJ/mole of C, less than half the heat of combustion of 500 kJ/ mole of C for coal. The scale of CO2 air-extraction plants to offset global emissions is large but could be manageable, and favorable relative to renewable sources. We report experiments on CO2 uptake by alkaline solutions as a function of pH, contact time, and mixing. Both active and passive mixing conditions are explored. Gram scale quantities of CO2 has been extracted from air by Ca(OH)2 and the product CaCO3 analyzed by X ray diffraction and thermal gravimetric analysis. We identify the atmospheric sub-laminar boundary layer and the stagnant liquid surface as potential barriers to CO2 uptake. Strategies to overcome these limits are developed. We discuss other renewable, energy efficient, and effective CO2 scrubbers with lower binding energies. High-resolution simulations are also being performed to characterize the effects of atmospheric mixing, size and geometry of extractors on the collection efficiency. Capture of CO2 from air is a promising long term strategy to sustain fossil energy use by avoiding climate change but much research and development is needed to implement it. [1] Elliott S. et al.,Compensation of atmospheric CO2 buildup through engineered chemical sinkage, Geophys. Res. Lett., 28(7), 1235-1238, 2001. [2] Dubey, M. K. et al., Extraction of carbon dioxide from the atmosphere through engineered chemical sinkage, 2002 American Chemical Society, Division of Fuel Chemistry Preprints, 47(1), 81-84, 2002. [3] Johnston, et al. Chemical Transport Modeling of Potential Atmospheric Carbon Dioxide Sinks, in press Energy Conversion & Management, 2002.

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

2002-12-01

64

Modeling Carbon Dioxide Levels  

NSDL National Science Digital Library

In this activity students will explore levels of Carbon Dioxide ( C02) in the atmosphere over time. There is concern that levels of C02 are rising; and finding a good mathematical model for CO2 levels is an important part of determining if this is attributable to human technology. Students draw a scatter plot, choose two points to create a linear model for the data, then use the model to make predictions.

2009-01-01

65

CARBON DIOXIDE FIXATION.  

SciTech Connect

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.

FUJITA,E.

2000-01-12

66

Introduction Air Quality and Nitrogen Dioxide  

E-print Network

Introduction Air Quality and Nitrogen Dioxide Air pollution can be defined as "the presence worldwide" WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulphur dioxide and motor vehicles. Nitrogen Dioxide is produced in a number of combustion processes. Nitrogen dioxide can

67

Carbon dioxide affects global ecology  

Microsoft Academic Search

Man's activities are changing the carbon dioxide and oxygen content of the entire atmosphere. These changes may, in turn, affect worldwide weather and the growth of plants. Under normal conditions, the amounts of carbon dioxide and oxygen in the atmosphere remain approximately in equilibrium on a year-to-year basis. The atmosphere today contains about 21% oxygen and about 0.032% carbon dioxide

Eugene K. Peterson

1969-01-01

68

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

SciTech Connect

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

Schilling, J.B.

1997-09-01

69

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

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

W. J. J. Huijgen; R. N. J. Comans

2007-01-01

70

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

PubMed

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

Chekov, Iu F

2009-01-01

71

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

Microsoft Academic Search

Open-Top Chambers (OTCs) are commonly used to evaluate the effect of CO,O, and other trace gases on vegetation. This study developed and tested a new technique for measuring forced air flow and net CO flux from OTCs. Experiments were performed with a 4.5-m diam. OTC with a sealed floor and a specialized air delivery system. Air flow through the chamber

Jay M. Ham; C. E. Owensby; P. I. Coyne

1993-01-01

72

Carbon Dioxide Reduction Through Urban Forestry  

E-print Network

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

Standiford, Richard B.

73

Coral reefs and carbon dioxide  

SciTech Connect

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

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

1996-03-01

74

Nondestructive natural gas hydrate recovery driven by air and carbon dioxide  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

75

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

PubMed

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

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

2014-01-01

76

Nondestructive natural gas hydrate recovery driven by air and carbon dioxide  

PubMed Central

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

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

2014-01-01

77

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

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

78

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

Microsoft Academic Search

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

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

2009-01-01

79

A hybrid process combining oxygen enriched air combustion and membrane separation for post-combustion carbon dioxide capture  

Microsoft Academic Search

For carbon dioxide capture and storage (CCS), similar to a large majority of industrial processes, the separation (i.e. capture) step dominates the costs of the technological chain. Based on a concept of minimal work of concentration, the evaluation of a tentative capture framework which combines an oxygen enrichment step before combustion and a CO2 capture step from flue gas has

Eric Favre; Roda Bounaceur; Denis Roizard

2009-01-01

80

Phenolic content and antioxidant capacity of supercritical carbon dioxide-treated and air-classified oat bran concentrate microwave-irradiated in water or ethanol at varying temperatures  

Microsoft Academic Search

Oat bran concentrate (OBC) was defatted with supercritical carbon dioxide (SCD), then microwave-irradiated (MI) at 50, 100 or 150C for 10min in water, 50% or 100% ethanol, and extract pH, soluble solids, phenolic content (PC) and antioxidant capacity (AC) were analysed. OBC was air-classified into five fractions and MI in water at 150C. OBC without SCD and microwave irradiation was

David G. Stevenson; George E. Inglett; Diejun Chen; Atanu Biswas; Fred J. Eller; Roque L. Evangelista

2008-01-01

81

Role of amine structure on carbon dioxide adsorption from ultradilute gas streams such as ambient air.  

PubMed

A fundamental study on the adsorption properties of primary, secondary, and tertiary amine materials is used to evaluate what amine type(s) are best suited for ultradilute CO(2) capture applications. A series of comparable materials comprised of primary, secondary, or tertiary amines ligated to a mesoporous silica support via a propyl linker are used to systematically assess the role of amine type. Both CO(2) and water adsorption isotherms are presented for these materials in the range relevant to CO(2) capture from ambient air and it is demonstrated that primary amines are the best candidates for CO(2) capture from air. Primary amines possess both the highest amine efficiency for CO(2) adsorption as well as enhanced water affinity compared to other amine types or the bare silica support. The results suggest that the rational design of amine adsorbents for the extraction of CO(2) from ambient air should focus on adsorbents rich in primary amines. PMID:22764080

Didas, Stephanie A; Kulkarni, Ambarish R; Sholl, David S; Jones, Christopher W

2012-10-01

82

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

SciTech Connect

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

None

2010-10-01

83

Carbon Dioxide Landscape  

NASA Technical Reports Server (NTRS)

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

2004-01-01

84

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

Microsoft Academic Search

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

M. V. Jokl

2000-01-01

85

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

Microsoft Academic Search

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

Lihua Cheng; Lin Zhang; Huanlin Chen; Congjie Gao

2006-01-01

86

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

ERIC Educational Resources Information Center

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

Keeling, Charles D.

87

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

PubMed Central

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

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

2012-01-01

88

CARBON DIOXIDE AND OUR OCEAN LEGACY  

E-print Network

of carbon dioxide from the atmosphere, or nearly half of the fossil fuel carbon emissions over this periodCARBON DIOXIDE AND OUR OCEAN LEGACY G Carbon Dioxide: Our Role The United States is the single. Every day the average American adds about 118 pounds of carbon dioxide to the atmos- phere, due largely

89

Enriched oil recovery using carbon dioxide  

Microsoft Academic Search

A single cell protein plant is operated to produce high density cell growth and a substantially pure stream of generally high pressure carbon dioxide for further use, for example, in enhanced oil recovery operations. The plant employs an air separator producing substantially pure streams of oxygen and nitrogen. The oxygen stream is used to enrich a carrier fluid and used

Hitzman

1981-01-01

90

Carbon Dioxide Separation Using Thermally Optimized Membranes  

Microsoft Academic Search

The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the

J. S. Young; B. S. Jorgensen; B. F. Espinoza; M. W. Weimer; G. D. Jarvinen; A. Greenberg; V. Khare; C. J. Orme; A. K. Wertsching; E. S. Peterson; S. D. Hopkins; J. Acquaviva

2002-01-01

91

Carbon Dioxide Emissions and Carbonation Sensors  

Microsoft Academic Search

The gases with higher heat capacities than those of O2 and N2 cause greenhouse effects. Carbon dioxide (CO2) is the main greenhouse gas associated with global climate change. At the present time, coal is responsible for 3040% of world CO2 emissions from fossil fuels. There was a higher correlation between the amount of carbon dioxide emission and percentage of carbon

A. Demirbas

2007-01-01

92

Pressurized Fuel\\/Air Operated Solid Oxide Fuel Cell Combined Carbon-Dioxide-Capturing High-Performance Power Generation System  

Microsoft Academic Search

The authors recently proposed a solid oxide fuel cell (SOFC) and closed-cycle MHD combined carbon-dioxide-capturing high-performance power generation system using pure oxygen as the oxidant. This combined system can make the best use of the merit of pure oxygen combustion, while its demerit of efficiency deterioration by large required power for oxygen generation still remains. In the present study, the

Yoshitaka Inui; Taichi Ishida; Tomohiro Matsumae

2003-01-01

93

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

Microsoft Academic Search

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

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

2008-01-01

94

Carbon Dioxide and Ocean Acidification  

NSDL National Science Digital Library

Demonstrates the affect of increased dissolved carbon dioxide on water pH using a cheap, non-toxic acid/base indicator. Students bubble breath through a straw into red cabbage juice and note the color change.

Lewis, Chris

95

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

Microsoft Academic Search

Soil respiration constitutes a major component of the global carbon cycle and is likely to be altered by climate change. However, there is an incomplete understanding of the extent to which various processes contribute to total soil respiration, especially the contributions of root and rhizosphere respiration. Here, using a stable carbon isotope tracer, the authors separate the relative contributions of

Jeffrey A. Andrews; Kevin G. Harrison; Roser Matamala; William H. Schlesinger

1999-01-01

96

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

NASA Technical Reports Server (NTRS)

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

Rosen, Micha; Mulloth, Lila; Varghese, Mini

2005-01-01

97

Carbon dioxide sequestration in concrete in different curing environments  

E-print Network

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

Wisconsin-Milwaukee, University of

98

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

E-print Network

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

99

Seventh International Carbon Dioxide Conference  

NSDL National Science Digital Library

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

100

Magnesite disposal of carbon dioxide  

SciTech Connect

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

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

1997-08-01

101

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

Microsoft Academic Search

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

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

2003-01-01

102

Carbon Dioxide - Our Common "Enemy"  

NASA Technical Reports Server (NTRS)

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 dioxide that could meet the 1000-day SMAC of 0.5%, which would apply to long-duration voyages to Mars.

James, John T.; Macatangay, Ariel

2009-01-01

103

Carbon Dioxide Absorption Heat Pump  

NASA Technical Reports Server (NTRS)

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

Jones, Jack A. (Inventor)

2002-01-01

104

Enthalpies of dissociation of clathrate hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran)  

Microsoft Academic Search

A calorimetric technique is described for measuring the enthalpy of dissociation liberated from solid hydrates. In this study, the enthalpies of dissociation were determined at T= 273.65 K andp= 0.1 MPa for simple and mixed hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran) using an isothermal microcalorimeter. The addition of tetrahydrofuran (THF)

B.-J. Ryu

2001-01-01

105

Carbon dioxide transport over complex terrain  

USGS Publications Warehouse

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.

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

2004-01-01

106

Nongovernmental valorization of carbon dioxide  

Microsoft Academic Search

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

Gene Petersen; Donn Viviani; Kim Magrini-Bair; Stephen Kelley; Luc Moens; Phil Shepherd; Dan DuBois

2005-01-01

107

Geological storage of carbon dioxide  

Microsoft Academic Search

Carbon dioxide is the main compound identified as affecting the stability of the Earth's climate. A significant reduction in the volume of greenhouse gas emissions to the atmosphere is a key mechanism for mitigating against climate change. Geological storage of CO 2, or the injection and stabilization of large volumes of CO 2 in the subsurface in saline aquifers, existing

S. J. Baines; RICHARD H. WORDEN

2004-01-01

108

2, 18491865, 2005 Carbon dioxide in  

E-print Network

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

Paris-Sud XI, Université de

109

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

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

Santos, Juan

110

SEISMIC MONITORING OF CARBON DIOXIDE FLUID FLOW  

E-print Network

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

Santos, Juan

111

7Carbon Dioxide Increases The Keeling Curve,  

E-print Network

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

112

21 CFR 184.1240 - Carbon dioxide.  

...2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and Drugs...Substances Affirmed as GRAS 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2 , CAS Reg. No....

2014-04-01

113

The air we breathe: three vital respiratory gases and the red blood cell: oxygen, nitric oxide, and carbon dioxide.  

PubMed

Three vital respiratory gases-oxygen (O(2)), nitric oxide (NO), and carbon dioxide (CO(2))-intersect at the level of the human red blood cell (RBC). In addition to hemoglobin (Hb)'s central role in O(2) transport, interaction of Hb with the Band 3 metabolon balances RBC energy flow. 2,3-Diphosphoglycerate enhances O(2) transport across the placenta and plays an important role in regulating RBC plasticity. NO is a key mediator of hypoxic vasodilation, but the precise role of RBC Hb remains controversial. In addition to established theories that depend on RBC uptake, delivery, and discharge of NO or its metabolites, an alternative hypothesis based on RBC permeability is suggested. NO depletion by free Hb may account for several clinical features seen during intravascular hemolysis or during deliberate infusion of Hb solutions used as RBC substitutes. CO(2) released by tissues triggers oxygen release through a series of well-coordinated reactions centered on the Band 3 metabolon. While RBC carbonic anhydrase and the Band 3 anion exchanger are central to this process, there is surprisingly little research on the kinetics of CO(2) clearance by transfusion. The three RBC gases are directly related to the three principal gases of Earth's atmosphere. Human fossil fuel consumption dumps 90 million metric tons of carbon into the atmosphere annually. Increasing CO(2) levels are linked to global warming, melting Arctic ice, rising sea levels, and climate instability. Just as individual cells depend on balance of the three vital gases, so too will their balance determine survival of life on Earth. PMID:21496039

Dzik, Walter H

2011-04-01

114

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles  

E-print Network

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles S.M. Liaoa) of transcritical carbon dioxide air-conditioning cycles. The analysis shows that the COP of the transcritical carbon dioxide cycle varies nonmonotonically with the heat rejection pressure; a maximum COP occurs

Zhao, Tianshou

115

Carbon Dioxide & Global Warming  

E-print Network

for the whole planet. Unfortunately, the earth's atmosphere is becoming more and more like a greenhouse our air, oceans, and climate. It only takes tem- perature increases of a few degrees to significantly the drain Because oceans absorb about 50% of the CO2 mankind produces each year, they serve as natu- ral

Miami, University of

116

The Impact of Carbon Dioxide on Climate.  

ERIC Educational Resources Information Center

Examines the relationship between climatic change and carbon dioxide from the historical perspective; details the contributions of carbon-based fuels to increasing carbon dioxide concentrations; and using global circulation models, discusses the future impact of the heavy reliance of our society on carbon-based fuels on climatic change. (BT)

MacDonald, Gordon J.

1979-01-01

117

Oxygen and carbon dioxide sensing  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

118

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

NASA Astrophysics Data System (ADS)

As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and sinks of atmospheric CO 2 is necessary not only to predict the future atmospheric abundances but also their effect on future climate. Although designed for deriving high precision temperature and moisture profiles, NASA's Atmospheric InfraRed Sounder (AIRS) IR measurements include broad vertical sensitivity (between 3 and 10 km) to atmospheric CO2 variations. Coupled with AIRS' broad swath pattern and a technique referred to as "cloud-clearing" these measurements enable daily global spatial coverage. Nevertheless, AIRS' ability to determine the spatial distribution of carbon dioxide (CO2) is strongly dependent on its ability to separate the radiative effects of CO2 from temperature not to mention measurement uncertainties due to clouds and other geophysical variables such as moisture and ozone. This research presents a thorough investigation into the temporal and spatial scales that the AIRS can separate temperature (and other geophysical variables) from CO2. Through our detailed understanding of the way satellites view the Earth's atmosphere, we have developed an algorithm capable of retrieving global middle-to-upper tropospheric CO2 concentrations in all-weather conditions with total uncertainties ranging between 1 to 2 ppmv. From a radiative perspective, roughly equivalent to 30 mK to 60 mK, 1 to 2 ppmv, is an awesome feat for a space-borne sensor. Necessary for the remarkable performance of this algorithm, we developed methodologies capable of separating the radiative effect of CO2 variability from temperature, improved the fast rapid transmittance algorithm for AIRS, and derived algorithm diagnostics that provide the case-dependent skill of AIRS algorithms for temperature and all other constituents (e.g. H2O, O3, CO, CH4, and CO2) from theoretical considerations. As a result, the 1 to 2 ppmv uncertainties match extremely well with simulation experiments performed before validation experiments had collected data and the retrieval algorithm was still in its infancy.

Maddy, Eric Sean

119

Sonochemical reduction of carbon dioxide  

Microsoft Academic Search

Sonolysis of carbon dioxide dissolved in water was performed from a standpoint of reducing this material in atmosphere. During one hour of sonication, the amount of CO2 decreased to about half at 5C under CO2Ar atmosphere. The decreasing rate for CO2 followed the order Ar>He>H2>N2 and it was down with increasing temperature in the range of 545C. The most favorable

Hisashi Harada

1998-01-01

120

Interpreting recent carbon dioxide data  

NSDL National Science Digital Library

Using web-accessed climate data, students will examine the latitudinal distribution of CO2 and explain how (and why) that has changed over (recent) time. They will then work in groups of two or three to download, graph, and interpret carbon dioxide concentration data from one individual location (different groups will be assigned a different site). Each student will complete a series of questions to ensure their understanding of the concepts outlined above.

Gordon, Elizabeth

121

Carbon Dioxide Removal via Passive Thermal Approaches  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

122

Experimentally Determining the Molecular Weight of Carbon Dioxide Using a Mylar Balloon  

NASA Astrophysics Data System (ADS)

The molar mass of carbon dioxide was experimentally determined using a Mylar balloon. Mylar balloons are lightweight, have a fixed definite volume, and require minimal additional pressure for inflation. Using the Ideal Gas Equation, the number of moles of air in the balloon was calculated. The molar mass of air was calculated using the percentages of the individual gases. Having these two values, the mass of air in the balloon, also known as the buoyant force of air, was calculated. The balloon was filled with carbon dioxide and the observed mass of the carbon dioxide was added to the mass of the displaced air for the true mass of carbon dioxide. Having the number of moles the balloon holds and the mass of carbon dioxide, the molar mass of carbon dioxide was calculated.

Albers Jackson, Barbara; Crouse, David J.

1998-08-01

123

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by  

E-print Network

Thermodynamic Promotion of Carbon Dioxide Clathrate Hydrate Formation by Tetrahydrofuran, Cyclopentane)-vapour (V) equilibrium pressures for the ternary system composed of water, tetrahydrofuran (THF), and carbon and carbon dioxide. Keywords: Gas Hydrates, carbon dioxide capture, tetrahydrofuran, cyclopentane

Paris-Sud XI, Université de

124

Optimize carbon dioxide sequestration, enhance oil recovery  

E-print Network

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

125

Carbon dioxide separation from high temperature fuel cell power plants  

Microsoft Academic Search

High temperature fuel cell technologies, solid oxide fuel cells (SOFCs) and molten carbonate fuel cells (MCFCs), are considered for their potential application to carbon dioxide emission control. Both technologies feature electrochemical oxidisation of natural gas reformed fuels, avoiding the mixture of air and fuel flows and dilution with nitrogen and oxygen of the oxidised products; a preliminary analysis shows how

Stefano Campanari

2002-01-01

126

Carbon Cycle: Exchanging Carbon Dioxide between the Atmosphere and Ocean  

NSDL National Science Digital Library

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

127

Effect of Carbon Dioxide Variations on Climate  

Microsoft Academic Search

Variations in the amount of atmospheric carbon dioxide cause temperature changes sufficiently large to influence the climate. If the atmospheric carbon dioxide doubles, the surface temperature rises 3.6C if it is cut in half, the surface temperature falls 3.8C. Some of the factors that can be explained by the carbon dioxide theory are: during a single glacial epoch, the climate

Gilbert N. Plass

1956-01-01

128

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

Microsoft Academic Search

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

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

1996-01-01

129

Carbon dioxide and intergenerational choice  

SciTech Connect

Depending on ethical beliefs, different decisions emerge for resolving the carbon dioxide (CO/sup 2/) issue. It is doubtful that an international consensus can be reached on a correct ethical criterion. Perhaps the best strategy would be to delay acceptance of either a particular set of beliefs or the existing scientific evidence and wait for more-accurate and conclusive research to emerge. If the scientific evidence is accepted as valid, and all future generations that will exist are evaluated equally, then the optimal current regulatory strategy is to restrict, as much as possible, current emissions of CO/sup 2/. 17 references, 2 figure, 1 table.

D'Arge, R.C.; Schulze, W.D.; Brookshire, D.S.

1982-05-01

130

Estimated Carbon Dioxide Emissions in 2008: United States  

SciTech Connect

Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary resource consumption, electricity generation, and energy consumption within each economic sector. Flow charts of state-level energy usage and explanations of the calculations and assumptions utilized can be found at: http://flowcharts.llnl.gov. This information is translated into carbon dioxide emissions using ratios of carbon dioxide emissions to energy use calculated from national carbon dioxide emissions and national energy use quantities for each particular sector. These statistics are reported annually in the U.S. EIA's Annual Energy Review. Data for 2008 (US. EIA, 2010) was updated in August of 2010. This is the first presentation of a comprehensive state-level package of flow charts depicting carbon dioxide emissions for the United States.

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

2011-04-01

131

Ocean uptake of carbon dioxide  

SciTech Connect

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

Peng, Tsung-Hung (Oak Ridge National Lab., TN (United States)); Takahashi, Taro (Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory)

1993-01-01

132

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

Microsoft Academic Search

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel

H. Haywood; J. Eyre; H. Scholes

2001-01-01

133

The Carbon Dioxide Greenhouse: Is It Effective?  

NSDL National Science Digital Library

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

134

Carbon Dioxide Separation Using Thermally Optimized Membranes  

NASA Astrophysics Data System (ADS)

The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the recovery of hydrogen from nitrogen, carbon monoxide, and methane mixtures, and the removal of carbon dioxide from natural gas. In each of these applications, high fluxes and excellent selectivities have relied on glassy polymer membranes which separate gases based on both size and solubility differences. To date, however, this technology has focused on optimizing materials for near ambient conditions. The development of polymeric materials that achieve the important combination of high selectivity, high permeability, and mechanical stability at temperatures significantly above 25oC and pressures above 10 bar, respectively, has been largely ignored. Consequently, there is a compelling rationale for the exploration of a new realm of polymer membrane separations. Indeed, the development of high temperature polymeric-metallic composite membranes for carbon dioxide separation at temperatures of 100-450 oC and pressures of 10-150 bar would provide a pivotal contribution with both economic and environmental benefits. Progress to date includes the first ever fabrication of a polymeric-metallic membrane that is selective from room temperature to 370oC. This achievement represents the highest demonstrated operating temperature at which a polymeric based membrane has successfully functioned. Additionally, we have generated the first polybenzamidizole silicate molecular composites. Finally, we have developed a technique that has enabled the first-ever simultaneous measurements of gas permeation and membrane compaction at elevated temperatures. This technique provides a unique approach to the optimization of long-term membrane performance under challenging operating conditions.

Young, J. S.; Jorgensen, B. S.; Espinoza, B. F.; Weimer, M. W.; Jarvinen, G. D.; Greenberg, A.; Khare, V.; Orme, C. J.; Wertsching, A. K.; Peterson, E. S.; Hopkins, S. D.; Acquaviva, J.

2002-05-01

135

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

136

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

137

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2012-04-01

138

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

139

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2010-10-01

140

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2012-04-01

141

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

142

21 CFR 868.5300 - Carbon dioxide absorbent.  

...2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2014-04-01

143

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.  

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.524-78...Procedures 86.524-78 Carbon dioxide analyzer calibration. (a) Prior...and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

2014-07-01

144

21 CFR 868.5310 - Carbon dioxide absorber.  

...2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2014-04-01

145

21 CFR 868.1400 - Carbon dioxide gas analyzer.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...Diagnostic Devices 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to...

2013-04-01

146

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

147

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

2011-10-01

148

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

2012-10-01

149

46 CFR 97.37-9 - Carbon dioxide alarm.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9...Emergency Equipment, Etc. 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified:...

2011-10-01

150

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2013-04-01

151

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2013-10-01

152

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

153

46 CFR 108.431 - Carbon dioxide systems: General.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431 Section...Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems 108.431 Carbon dioxide systems: General. (a)...

2010-10-01

154

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2011-04-01

155

46 CFR 108.626 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section...and Instructions 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

156

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 76.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

157

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2012-04-01

158

46 CFR 95.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 95.15-20 Carbon dioxide storage. (a) Except as...

2012-10-01

159

21 CFR 868.5300 - Carbon dioxide absorbent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...Therapeutic Devices 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for...

2011-04-01

160

21 CFR 868.5310 - Carbon dioxide absorber.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868...Therapeutic Devices 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is...

2013-04-01

161

46 CFR 193.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193...VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details 193.15-20 Carbon dioxide storage. (a) Except as...

2011-10-01

162

46 CFR 169.565 - Fixed carbon dioxide system.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565...Firefighting Equipment 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected...

2012-10-01

163

Carbon Dioxide for pH Control  

SciTech Connect

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

Wagonner, R.C.

2001-08-16

164

A new look at atmospheric carbon dioxide  

Microsoft Academic Search

Carbon dioxide is increasing in the atmosphere and is of considerable concern in global climate change because of its greenhouse gas warming potential. The rate of increase has accelerated since measurements began at Mauna Loa Observatory in 1958 where carbon dioxide increased from less than 1 part per million per year (ppmyr?1) prior to 1970 to more than 2ppmyr?1 in

David J. Hofmann; James H. Butler; Pieter P. Tans

2009-01-01

165

Residential carbon dioxide emissions in Canada  

Microsoft Academic Search

The effect of improving house envelope, heating system and appliance efficiencies, and fuel substitution on the atmospheric emissions of carbon dioxide in the Canadian residential sector is studied based on simulation studies. The findings clearly indicate that improving appliance efficiency reduces the overall end-use energy consumption in the residential sector as well as the associated carbon dioxide emissions. However, the

V. Ismet Ugursal; Alan S. Fung

1998-01-01

166

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

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.

Marsh, Gerald E

2010-01-01

167

Interglacials, Milankovitch Cycles, and Carbon Dioxide  

E-print Network

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.

Gerald E. Marsh

2010-02-02

168

The microbial association of Greek taverna sausage stored at 4 and 10 degrees C in air, vacuum or 100% carbon dioxide, and its spoilage potential.  

PubMed

Strains of the Lactobacillus sakei/curvatus group, mainly non-slime-producing Lact. sakei, dominated the microbial flora of industrially manufactured taverna sausage, a traditional Greek cooked meat, stored at 4 degrees C and 10 degrees C in air, vacuum and 100% CO2. Atypical, arginine-positive and melibiose-negative strains of this group were isolated. The isolation frequency of Lact. sakei/curvatus from sausages stored anaerobically was as high as 92-96%, while other meat spoilage organisms were practically absent. Conversely, in air-stored sausages, leuconostocs, mainly Leuconostoc mesenteroides ssp. mesenteroides, had a considerable presence (14-21%), whereas Brochothrix thermosphacta, pseudomonads and Micrococcaceae grew, but failed to increase above 10(5) cfu g(-1) in all samples during storage. Only yeasts were able to compete against LAB and reached almost 10(7) cfu g(-1) after 30 d of aerobic storage at 10 degrees C. The great dominance (> 10(8) cfu g(-1)) of LAB caused a progressive decrease of pH and an increase of the concentration of L-lactate, D-lactate and acetate in all sausage packs. The growth of LAB and its associated chemical changes were more pronounced at 10 degrees C than 4 degrees C. At both storage temperatures, L-lactate and acetate increased more rapidly and to a higher concentration aerobically, unlike D-lactate, which formed in higher amounts anaerobically. Storage in air was the worst packaging method, resulting in greening and unpleasant off-odours associated with the high acetate content of the sausages. Carbon dioxide had no significant effect on extending shelf-life. The factors affecting the natural selection of Lact. sakei/curvatus in taverna sausage are discussed. Moreover, it was attempted to correlate the metabolic activity of this group with the physicochemical changes and the spoilage phenomena occurring in taverna sausage under the different storage conditions. PMID:10735244

Samelis, J; Georgiadou, K G

2000-01-01

169

Microfluidic studies of carbon dioxide.  

PubMed

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

Abolhasani, Milad; Gnther, Axel; Kumacheva, Eugenia

2014-07-28

170

Energy flux streamlines versus acoustic rays for modeling an acoustic lens: Energy flow inside and in the focal region for a carbon dioxide filled spherical balloon in air.  

PubMed

As an extension of recently published experimental work [Dean and Parker, "A ray model of sound focusing with a balloon lens: An experiment for high school students," J. Acoust. Soc. Am. 131, 2459-2462 (2012)], a comparison of ray acoustics and wave analysis via energy flux streamlines [Chapman, "Using streamlines to visualize acoustic energy flow across boundaries," J. Acoust. Soc. Am. 124, 48-56 (2008)] as a means of visualizing the sound field for a positive acoustic lens in the form of a carbon dioxide filled spherical balloon in air is made. The sound field is expanded in the usual Legendre polynomials and spherical Bessel functions [Anderson, "Sound scattering from a fluid sphere," J. Acoust. Soc. Am. 22, 426-431 (1950)], and the energy flux vectors at points throughout the regions of interest are calculated [Adin Mann III, et al., "Instantaneous and time-averaged energy transfer in acoustic fields," J. Acoust. Soc. Am. 82, 17-30 (1987)]. Then, energy flux streamlines are plotted using Mathematica routines for comparison with conventional acoustical rays, both inside and outside the balloon. Particular attention is paid to the focal region. PMID:25236037

Dean, Cleon E; Braselton, James P

2014-04-01

171

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

PubMed

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

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

2006-10-01

172

Carbon dioxide capture process with regenerable sorbents  

DOEpatents

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

Pennline, Henry W. (Bethel Park, PA); Hoffman, James S. (Library, PA)

2002-05-14

173

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

Microsoft Academic Search

As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and

Eric Sean Maddy

2007-01-01

174

Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recentmodelsmayhaveoverestimatedfutureyields  

Microsoft Academic Search

Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO2) concentration, (CO2), which significantly stimulates yield

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

175

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

During the present reporting period, six complementary tasks involving experimentation, model development, and coal characterization were undertaken to meet our project objectives: (1) A second adsorption apparatus, utilizing equipment donated by BP Amoco, was assembled. Having confirmed the reliability of this additional experimental apparatus and procedures, adsorption isotherms for CO{sub 2}, methane, ethane, and nitrogen on wet Fruitland coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 3%. The addition of this new facility has allowed us to essentially double our rate of data production. (2) Adsorption isotherms for pure CO{sub 2}, methane, and nitrogen on wet Illinois-6 coal and on activated carbon were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia) on our first apparatus. The activated carbon measurements showed good agreement with literature data and with measurements obtained on our second apparatus. The expected uncertainty of the data is about 3%. The Illinois-6 adsorption measurements are a new addition to the existing database. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on DESC-8 coal. (3) Adsorption from binary mixtures of methane, nitrogen and CO{sub 2} at a series of compositions was also measured on the wet Fruitland coal at 319.3 K (115 F), using our first apparatus. The nominal compositions of these mixtures are 20%/80%, 40%/60%, 60%/40%, and 80%/20%. The experiments were conducted at pressures from 100 psia to 1800 psia. The expected uncertainty for these binary mixture data varies from 2 to 9%. (4) A study was completed to address the previously-reported rise in the CO{sub 2} absolute adsorption on wet Fruitland coal at 115 F and pressures exceeding 1200 psia. Our additional adsorption measurements on Fruitland coal and on activated carbon show that: (a) the Gibbs adsorption isotherm for CO{sub 2} under study exhibits typical adsorption behavior for supercritical gas adsorption, and (b) a slight variation from Type I absolute adsorption may be observed for CO{sub 2}, but the variation is sensitive to the estimates used for adsorbed phase density. (5) The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, a two-dimensional cubic equation of state (EOS), a new two-dimensional (2-D) segment-segment interactions equation of state, and the simplified local density model (SLD). Our model development efforts have focused on developing the 2-D analog to the Park-Gasem-Robinson (PGR) EOS and an improved form of the SLD model. The new PGR EOS offers two advantages: (a) it has a more accurate repulsive term, which is important for reliable adsorption predictions, and (b) it is a segment-segment interactions model, which should more closely describe the gas-coal interactions during the adsorption process. In addition, a slit form of the SLD model was refined to account more precisely for heterogeneity of the coal surface and matrix swelling. In general, all models performed well for the Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). In comparison, the SLD model represented the adsorption behavior of all fluids considered within 5% average deviations, including the near-critical behavior of carbon dioxide beyond 8.3 MPa (1200 psia). Work is in progress to (a) derive and implement the biporous form of the SLD model, which would expand the number of structural geometries used to represent the heterogeneity of coal surface; and (b) extend the SLD model to mixture predictions. (6) Proper reduction of our adsorption data requires accurate gas-phase compressibility (Z) factors for methane, ethane, nitrogen and carbon dioxide and their mixtures to properly analyze our experimental adsorption data. A careful evaluation of t

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

2001-06-15

176

Annual carbon dioxide drawdown and the Northern Annular Mode  

Microsoft Academic Search

Yeartoyear variations in summer drawdown of Northern Hemisphere atmospheric carbon dioxide (CO2) are compared with corresponding yeartoyear variations in sealevel pressure (SLP), surface air temperature, and the productivity of land vegetation as inferred from the satellitederived normalized difference vegetation index (NDVI). Annual values of CO2 drawdown for the years 19802000 are estimated from smoothed time series derived directly from individual

Joellen L. Russell; John M. Wallace

2004-01-01

177

Air quality at Santiago, Chile: a box modeling approachI. Carbon monoxide, nitrogen oxides and sulfur dioxide  

NASA Astrophysics Data System (ADS)

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

Jorquera, Hctor

178

Photolytical Generation of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Carbon dioxide has been found by Cassini VIMS throughout the Saturnian system in locations such as Iapetus' equator where the temperature is too high for it to remain as free ice for more than a few hundred years. We suggest that the 4.26 micron absorption feature found on Iapetus and Hyperion (that has been attributed to complexed CO2) is the result of either UV photolysis or ion bombardment driving chemistry between the carbon rich layer and the water ice regolith. We conducted experiments to simulate the generation of CO2 by UV radiation under conditions similar to those on the surface of Iapetus. A simulated icy regolith was created in an argon atmosphere using flash-frozen, degassed water crushed into sub-millimeter sized particles. Isotopically labeled amorphous carbon (13C), which was ground into a fine dust, was mixed into the regolith allowing for extensive grain contact. This sample was placed in a vacuum chamber and cooled to temperatures as low at 60K. The sample was irradiated with UV light, and the products were measured using both a mass spectrometer to identify free molecules and an IR spectrometer for molecules that remained trapped on and in the simulated regolith. We report on the production and reaction rates of CO2 and CO, as well as the generation of free hydrogen and oxygen as detected by a SRS-100 mass spectrometer. We also identify residual products that either freeze on the surface or become entrained by or adsorbed onto the ice grains. We attempt to match the CO2 absorption feature found on Iapetus with that seen in our simulation, perhaps identifying a possible source of CO2 in the Saturnian system. Finally, we estimate the time required for these reactions to occur on Iapetus to see if UV photolysis would be effective.

Palmer, E. E.; Brown, R. H.

2008-12-01

179

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

SciTech Connect

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

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

1997-01-01

180

Carbon dioxide sequestration as stable carbonate minerals - environmental barriers  

NASA Astrophysics Data System (ADS)

This paper considers the major environmental impacts associated with industrial-scale carbon dioxide sequestration as stable carbonate minerals, material resulting from a study undertaken by CSMA Consultants Ltd. in 1999. The chemical bonding of carbon dioxide, through reaction of two or more products to produce magnesium or calcium carbonate has been suggested as a means to mitigate CO2 from fossil fuel power plants. The study considered six potential methods for sequestering carbon dioxide, notionally captured from fossil fuel burning power stations, as stable mineral carbonates, i.e. magnesite and limestone (calcium carbonate) and as sodium bicarbonate. Four methods were eliminated in the initial screening and two were selected for further detailed consideration. Following this stage the overall environmental costs, including environmental impacts, energy and carbon dioxide balances, meant that all the current technologies amenable to reasoned consideration had to be discarded as currently environmentally unacceptable.

Haywood, H.; Eyre, J.; Scholes, H.

2001-11-01

181

Carbon dioxide emission scenarios: limitations of the fossil fuel resource  

Microsoft Academic Search

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

Christopher Vernon; Erica Thompson; Sarah Cornell

2011-01-01

182

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere 0084-6597/09/0530-0117$20.00 Key Words climate, warming, ocean chemistry, carbon cycle Abstract CO2

Scherer, Norbert F.

183

Carbon Dioxide Emission Factors for Coal  

EIA Publications

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

1994-01-01

184

Regulating carbon dioxide capture and storage  

E-print Network

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

De Figueiredo, Mark A.

2007-01-01

185

Carbon Dioxide Fluxes in European Russia  

NASA Astrophysics Data System (ADS)

Measurements of carbon balance of boreal ecosystems in the southern taiga of European Russia have been conducted using eddy covariance technique starting from 1998 to the present. The method allows to continuously collect net ecosystem exchange (NEE) fluxes of water and heat between forest and atmosphere with high time resolution. Simultaneous measurements of atmospheric meteorological parameters are carried out. The studies have been conducted in the Tver Region, Russia (Central Forest Biosphere Nature Reserve, 56N, 33E) using a 29 m high tower in low-productive wet spruce forest (P. Sphagnum forest, WSF), a 44 m high tower in high- productive complex spruce forest (CSF) and under the surface of ombrotrophic bog. Eddy flux measurements during limited time intervals are supplemented by measurements of soil, leaves and trunks respiration. Observations of decomposition speed of organic material and the rating NPP are conducted as well. In general, the measurements period has captured a wide range of changes of climatic conditions. Years with extreme dry and damp vegetative seasons and years with close to average climatic conditions for this region fall into the period of observations. The results of our measurements show that unmanaged uneven-aged spruce forests can be both source and sink of carbon to the atmosphere depending on the type of forest and weather conditions. Soil respiration as a result of decomposition of the abundant dead surface- and underground biomass determines the sign and absolute mean of the carbon balance. The overall annual balance of carbon of the studied forest ecosystems differs from zero. The cumulative total of the NEE fluxes for the period of April to October depends first of all on spring temperature and precipitation with temperature being within the range of 5-10C and on the duration of this period. For the period of active vegetation, when air temperature is higher than 10C - the NEE flux depends on humidity. We found significant seasonal and interannual variability of carbon dioxide fluxes for the ombrotrophic bog. The sign and the mean of carbon dioxide fluxes between the surface of the bog and the atmosphere depend on humidity conditions during the green season. When the water balance is negative the ombotrophic bog becomes a source of carbon for the atmosphere.

Kurbatova, J.; Varlagin, A.; Vygodskaya, N.

2007-12-01

186

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

187

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

PubMed

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

Wroblewitz, Stefanie; Hther, Liane; Manderscheid, Remy; Weigel, Hans-Joachim; Wtzig, Hermann; Dnicke, Sven

2013-08-01

188

A correlation of optimal heat rejection pressures in transcritical carbon dioxide cycles  

Microsoft Academic Search

In this work, a cycle simulation model has been developed to optimize the coefficient of performance (COP) of transcritical carbon dioxide air-conditioning cycles. The analysis shows that the COP of the transcritical carbon dioxide cycle varies nonmonotonically with the heat rejection pressure; a maximum COP occurs at an optimal heat rejection pressure. It is further revealed that the values of

S. M. Liao; T. S. Zhao; A. Jakobsen

2000-01-01

189

Zinc-catalyzed copolymerization of carbon dioxide and propylene oxide  

E-print Network

The zinc-catalyzed copolymerization of carbon dioxide and propylene oxide, which is one of the promising reactions for the utilization of carbon dioxide, has been investigated from various aspects. Above all, considering that supercritical carbon...

Katsurao, Takumi

2012-06-07

190

Education, Convergence and Carbon Dioxide Growth per Capita  

E-print Network

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

Paris-Sud XI, Université de

191

Turning carbon dioxide into fuel.  

PubMed

Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide (CO2). To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. But, as populations grow and economies develop, future demands now ensure that energy will be one of the defining issues of this century. This unique set of (coupled) challenges also means that science and engineering have a unique opportunity-and a burgeoning challenge-to apply their understanding to provide sustainable energy solutions. Integrated carbon capture and subsequent sequestration is generally advanced as the most promising option to tackle greenhouse gases in the short to medium term. Here, we provide a brief overview of an alternative mid- to long-term option, namely, the capture and conversion of CO2, to produce sustainable, synthetic hydrocarbon or carbonaceous fuels, most notably for transportation purposes. Basically, the approach centres on the concept of the large-scale re-use of CO2 released by human activity to produce synthetic fuels, and how this challenging approach could assume an important role in tackling the issue of global CO2 emissions. We highlight three possible strategies involving CO2 conversion by physico-chemical approaches: sustainable (or renewable) synthetic methanol, syngas production derived from flue gases from coal-, gas- or oil-fired electric power stations, and photochemical production of synthetic fuels. The use of CO2 to synthesize commodity chemicals is covered elsewhere (Arakawa et al. 2001 Chem. Rev. 101, 953-996); this review is focused on the possibilities for the conversion of CO2 to fuels. Although these three prototypical areas differ in their ultimate applications, the underpinning thermodynamic considerations centre on the conversion-and hence the utilization-of CO2. Here, we hope to illustrate that advances in the science and engineering of materials are critical for these new energy technologies, and specific examples are given for all three examples. With sufficient advances, and institutional and political support, such scientific and technological innovations could help to regulate/stabilize the CO2 levels in the atmosphere and thereby extend the use of fossil-fuel-derived feedstocks. PMID:20566515

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

2010-07-28

192

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

E-print Network

(for water: the SPC-, SPC/E-, and TIP4P-potential models; for carbon dioxide: the EPM2 potential model. The interactions between carbon dioxide and water were estimated from the pair potentials of the pure components of intermolecular pair potentials for various substances is documented. Especially water has been the subject

193

Carbon Dioxide- Where Does it All Go?  

NSDL National Science Digital Library

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

194

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

Matsumoto, Katsumi

195

Where in the World is Carbon Dioxide?  

NSDL National Science Digital Library

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

196

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

Microsoft Academic Search

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

Norman H. Hagedorn

1991-01-01

197

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

Microsoft Academic Search

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

Norman H. Hagedorn

1993-01-01

198

Method for extracting and sequestering carbon dioxide  

DOEpatents

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

Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

2005-05-10

199

Apparatus for extracting and sequestering carbon dioxide  

DOEpatents

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

Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

2010-02-02

200

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-03-10

201

SEQUESTERING CARBON DIOXIDE IN COALBEDS  

SciTech Connect

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

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

2003-04-30

202

Carbon Dioxide Fluxes in the Global Ocean  

Microsoft Academic Search

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

Andrew J. Watson; James C. Orr

203

Global deforestation: contribution to atmospheric carbon dioxide  

Microsoft Academic Search

A study of effects of terrestrial biota on the amount of carbon dioxide in the atmosphere suggests that the global net release of carbon due to forest clearing between 1960 and 1980 was between 135 X 10¹⁵ and 228 X 10¹⁵ grams. Between 1.8 X 10¹⁵ and 4.7 X 10¹⁵ grams of carbon were released in 1980, of which nearly

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

1983-01-01

204

Designed amyloid fibers as materials for selective carbon dioxide capture  

PubMed Central

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

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

2014-01-01

205

Fundamental Aspects of the Application of Carbon Dioxide in Comfort Cooling.  

National Technical Information Service (NTIS)

This paper presents entropy generation analyses for the evaporator, compressor, gas cooler, expansion device and liquid-line suction-line heat exchanger for a transcritical carbon dioxide cycle for automotive and residential air-conditioning systems, and ...

J. S. Brown, P. A. Domanski

2003-01-01

206

Carbon dioxide hydrate and floods on Mars  

NASA Technical Reports Server (NTRS)

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

Milton, D. J.

1974-01-01

207

Carbon dioxide opacity of the Venus' atmosphere  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

208

Carbon Dioxide Fixation in Cultured Animal Cells  

E-print Network

H the activity of adenosine tri phosphatase was Increased by carbon dioxide. Also, the same investigators found that increasing the carbon dioxide concentration from 10 to 1*0 mM at constant pH stimulated the conversion of acetate into fatty acids four to six... and Cortisol were present to gether (I9li, 70 ) . Paradoxically, tryptophan and quinolinic acid increased the in vitro assayable activity of PEP-CK (259, 68). Upon extraction, the inhibition appears to dissociate from the enzyme, leaving it in a metal...

Kyner, David Smith

1969-01-01

209

Global deforestation: contribution to atmospheric carbon dioxide  

SciTech Connect

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

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

1983-12-09

210

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

Microsoft Academic Search

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

G. J. Fergusson

1958-01-01

211

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

Microsoft Academic Search

The quantities of carbon stored in the form of atmospheric carbon dioxide, CO in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates

J. Augustynski; B. Jermann; P. Kedzierzawski

1996-01-01

212

Organic syntheses employing supercritical carbon dioxide as a reaction solvent  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

213

Organic syntheses employing supercritical carbon dioxide as a reaction solvent  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

214

Gas diffusion cell removes carbon dioxide from occupied airtight enclosures  

NASA Technical Reports Server (NTRS)

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

1964-01-01

215

International Space Station Carbon Dioxide Removal Assembly Testing  

NASA Technical Reports Server (NTRS)

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

Knox, James C.

2000-01-01

216

Demonstration of a Carbon Dioxide-Based Industrial Laundry Machine  

E-print Network

Demonstration of a Carbon Dioxide- Based Industrial Laundry Machine Industrial cleaning and disinfection machine must be demonstrated with independent verification commercial supercritical-carbon dioxide textile cleaning machine to document and validate: Real

217

40 CFR 86.1524 - Carbon dioxide analyzer calibration.  

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

2014-07-01

218

Investigation of Enhancement of Carbon Dioxide Absorption by Amines with the Enzyme Carbonic Anhydrase.  

National Technical Information Service (NTIS)

Carbon dioxide absorption and desorption from an airstream with 300 ppm CO2 was evaluated in a closed air loop apparatus, and the CO2 absorption curves were recorded as ppm CO2 versus time in minutes. Low concentrations of KOH, monoethanolamine (MEA) and ...

J. P. Allen

1966-01-01

219

Euthanasia of neonatal mice with carbon dioxide  

USGS Publications Warehouse

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.

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

2005-01-01

220

Carbon dioxide dynamics in an artificial ecosystem  

NASA Astrophysics Data System (ADS)

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

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

221

The urgent need for carbon dioxide sequestration  

SciTech Connect

The danger of global warming has put in question the use of fossil fuels which constitute the most abundant and most reliable energy resource. Meeting the ever growing world demand for cheap energy, while simultaneously achieving the required drastic reduction in CO{sub 2} emissions can only be accomplished by actively preventing carbon dioxide generated in the combustion of fuels from accumulating in the atmosphere, i.e. by sequestration. Sequestration is possible and economically viable and is currently the only realistic solution to the dilemma of CO{sub 2} emissions. The authors have developed a very promising approach that disposes of carbon dioxide by chemically combining it in an exothermic reaction with readily available minerals to form carbonates. The resulting carbonates are stable solids that are known to be environmentally benign and to be stable on geological time scales. This stands in contrast to most other methods that do not appear to fully solve the long term problem.

Lackner, K.S.; Butt, D.P.; Jensen, R.; Ziock, H.

1998-09-01

222

U.S. Energy-Related Carbon Dioxide Emissions  

EIA Publications

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

2013-01-01

223

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

Microsoft Academic Search

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

Folke Bohlin

1998-01-01

224

Carbon Dioxide Production at Home  

NSDL National Science Digital Library

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

225

Carbon Dioxide Capture from Coal-Fired  

E-print Network

Carbon Dioxide Capture from Coal-Fired Power Plants: A Real Options Analysis May 2005 MIT LFEE 2005. LFEE 2005-002 Report #12;#12;i ABSTRACT Investments in three coal-fired power generation technologies environment. The technologies evaluated are pulverized coal (PC), integrated coal gasification combined cycle

226

DIETHANOLAMINE-CARBON DIOXIDE BUFFER PRODUCES ETHYLENE  

EPA Science Inventory

Carbon dioxide concentrates in containers are frequently controlled by using a diethanolamine-bicarbonate buffer. Current studies show that this buffer produces ethylene and that the production increases with increasing pH and/or time in the incubation vessel. Ethylene is not pro...

227

Recent Events: a Perspective on Carbon Dioxide  

NSDL National Science Digital Library

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

228

Carbon dioxide enhances fragility of ice crystals  

NASA Astrophysics Data System (ADS)

Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.

Qin, Zhao; Buehler, Markus J.

2012-11-01

229

Synthetic fuels, carbon dioxide and climate  

Microsoft Academic Search

The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2.Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels were

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

1982-01-01

230

Synthetic fuels, carbon dioxide and climate  

Microsoft Academic Search

The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2. Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels

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

1982-01-01

231

Atmospheric carbon dioxide record from Mauna Loa  

NSDL National Science Digital Library

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

232

World Electricity Consumption and Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will analyze a table of global electricity consumption to answer a series of questions and consider the production of carbon dioxide associated with that consumption. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

233

Acid sorption regeneration process using carbon dioxide  

DOEpatents

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

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

2001-01-01

234

Carbon dioxide hydrationand dehydration kinetics in seawater  

Microsoft Academic Search

Rate constants for the hydration and dehydration reactions of carbon dioxide with water and with hydroxyl ion were measured in seawater by a pH-stat method at salinities (X lO:l) from 3.4 to 37.06 at 25C and from 5\\

Kenneth S. Johnson

1982-01-01

235

Photobiological hydrogen production and carbon dioxide sequestration  

Microsoft Academic Search

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

Halil Berberoglu

2008-01-01

236

Carbon dioxide on the early earth  

Microsoft Academic Search

This paper uses arguments of geochemical mass balance to arrive at an estimate of the partial pressure of carbon dioxide in the terrestrial atmosphere very early in earth history. It appears that this partial pressure could have been as large as 10 bars. This large estimate depends on two key considerations. First, volatiles were driven out of the interior of

J. C. G. Walker

1985-01-01

237

The urgent need for carbon dioxide sequestration  

Microsoft Academic Search

The danger of global warming has put in question the use of fossil fuels which constitute the most abundant and most reliable energy resource. Meeting the ever growing world demand for cheap energy, while simultaneously achieving the required drastic reduction in CO emissions can only be accomplished by actively preventing carbon dioxide generated in the combustion of fuels from accumulating

K. S. Lackner; D. P. Butt; R. Jensen; H. Ziock

1998-01-01

238

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2011-07-01

239

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2010-07-01

240

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles...Procedures 86.124-78 Carbon dioxide analyzer calibration...monthly thereafter the NDIR carbon dioxide analyzer shall be...

2010-07-01

241

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration...Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines...Procedures 86.1324-84 Carbon dioxide analyzer calibration...monthly thereafter, the NDIR carbon dioxide analyzer shall be...

2011-07-01

242

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to

David W. Holladay; Gary L. Haag

1979-01-01

243

Method of immobilizing carbon dioxide from gas streams  

Microsoft Academic Search

This invention comprises a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to

D. W. Holladay; G. L. Haag

1979-01-01

244

ORNL/CDIAC-34 Carbon Dioxide Information Analysis Center and  

E-print Network

ORNL/CDIAC-34 May 1999 Carbon Dioxide Information Analysis Center and World Data Center Carbon Dioxide Information Analysis Center (423) 574-3645 Oak Ridge National Laboratory URL: http 37831-6335 FTP: cdiac.esd.ornl.gov #12;ORNL/CDIAC-34 May 1999 Carbon Dioxide Information Analysis Center

245

Chukwuemeka I. Okoye Carbon Dioxide Solubility and Absorption Rate in  

E-print Network

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

Rochelle, Gary T.

246

High Temperature Electrolysis of Steam and Carbon Dioxide  

E-print Network

High Temperature Electrolysis of Steam and Carbon Dioxide S�ren H�jgaard Jensen+,#, Jens V. T. H (ASR) #12;Electrolysis of carbon dioxide and steam CO2 + H2O H2 + CO + 3/2 O2 Interesting because of electrolysis of steam and carbon dioxide Picture taken from J. R. Rostrup, Steam Reforming and Catalysts

247

46 CFR 97.37-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

248

www.sciam.com SCIENTIFIC AMERICAN 49 Pumping carbon dioxide  

E-print Network

www.sciam.com SCIENTIFIC AMERICAN 49 CREDIT CanWe Bury GLOBAL WARMING? Pumping carbon dioxide his lungs were carbon dioxide. Each time you draw breath today, 380 mole- cules per million are carbon dioxide. That portion climbs about two mole- cules every year. No one knows the exact consequenc- es

O'Donnell, Tom

249

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.  

...2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration. 86.124-78...Procedures 86.124-78 Carbon dioxide analyzer calibration. Prior to its...and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

2014-07-01

250

46 CFR 196.37-8 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section...Equipment, etc. 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

251

46 CFR 78.47-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 78.47-11 Section...Equipment, Etc. 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

252

Irreversible climate change due to carbon dioxide emissions  

E-print Network

Irreversible climate change due to carbon dioxide emissions Susan Solomona,1 , Gian in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely

Fischlin, Andreas

253

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

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

2014-10-01

254

40 CFR 89.322 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89.322 Section...Equipment Provisions 89.322 Carbon dioxide analyzer calibration. (a) Prior...bi-monthly thereafter, the NDIR carbon dioxide analyzer shall be calibrated on...

2014-07-01

255

46 CFR 196.37-8 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

256

40 CFR 91.320 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91.320 Section...Equipment Provisions 91.320 Carbon dioxide analyzer calibration. (a) Prior...certification test, calibrate the NDIR carbon dioxide analyzer as follows: (1)...

2014-07-01

257

46 CFR 78.47-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

258

46 CFR 97.37-11 - Carbon dioxide warning signs.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Carbon dioxide warning signs. 97.37-11 Section...Equipment, Etc. 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by...

2012-10-01

259

40 CFR 90.320 - Carbon dioxide analyzer calibration.  

...2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90.320 Section...Equipment Provisions 90.320 Carbon dioxide analyzer calibration. (a) Prior...certification test, calibrate the NDIR carbon dioxide analyzer as follows: (1)...

2014-07-01

260

Catalyst cartridge for carbon dioxide reduction unit  

NASA Technical Reports Server (NTRS)

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

Holmes, R. F. (inventor)

1973-01-01

261

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

E-print Network

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

Huppert, Herbert

262

PIERS ONLINE, VOL. 5, NO. 7, 2009 637 Ventilation Efficiency and Carbon Dioxide (CO2) Concentration  

E-print Network

of the indoor air quality in indoor and enclosed environments. It serves as a measure of ventilation efficiency be reduced to below 600 ppm to eliminate most indoor air quality com- plaints [3]. The US National Institute of the suitability of outdoor air ventilation relative to indoor occupant density. Indoor carbon dioxide level must

Halgamuge, Malka N.

263

A review of carbon dioxide capture and utilization by membrane integrated microalgal cultivation processes  

Microsoft Academic Search

The capture of carbon dioxide (CO2) from the air for microalgal cultivation has received increasing interest since it allows advantages that do not only reduce the amount of CO2 already added to the air, but it is also more economical due to the accessibility of air, there are no regeneration requirements and it is a safe method that can help

Muhammad Syukri Abd Rahaman; Li-Hua Cheng; Xin-Hua Xu; Lin Zhang; Huan-Lin Chen

2011-01-01

264

Personal Carbon Dioxide Impact (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

The amount of carbon dioxide in the atmosphere has been increasing for many decades now, mostly due to the burning of fossil fuels by mankind. In this exercise, students will track their daily activities, and and estimate how much carbon dioxide they are responsible for emitting with the use of an online Personal Greenhouse Gas Calculator developed by the U.S. Environmental Protection Agency (EPA). The calculator sums the carbon dioxide produced by driving, electricity use, and waste disposal, and provides an estimate of annual carbon dioxide emissions. It also allows users to see how changes in lifestyle could reduce carbon dioxide emissions. Links to websites with additional information are also provided.

Pratte, John

265

Development and design of a high pressure carbon dioxide system for the separation of hazardous contaminants from non-hazardous debris  

Microsoft Academic Search

Under the Department of Energy (DOE)\\/United States Air Force (USAF) Memorandum of Understanding, a system is being designed that will use high pressure carbon dioxide for the separation of oils, greases, and solvents from non-hazardous solid waste. The contaminants are dissolved into the high pressure carbon dioxide and precipitated out upon depressurization. The carbon dioxide solvent can then be recycled

C. L. J. Adkins; E. M. Russick; H. M. Smith; R. B. Olson

1995-01-01

266

High Levels of Carbon Dioxide Threaten Oyster Survival  

NSDL National Science Digital Library

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

APS Communications Office (American Physiological Society Communications Office)

2010-08-04

267

Carbon dioxide transport in crustal magmatic systems  

NASA Astrophysics Data System (ADS)

The volatile chemistry of juvenile volcanic glasses has suggested that shallow-stored crustal magmas often suffer the open-system addition of a carbon-dioxide-rich fluid from below, probably from a mantle-derived basaltic source ("carbon dioxide fluxing"). However, the actual mechanism of such a fluid transport is poorly understood. To constrain the volatile transport mechanism, we formulated this phenomenon as a reactive transport process and clarified the fundamental characteristics of chemical exchange in the system. The model assumes that a carbon-dioxide-rich fluid is introduced into a water-rich rhyolitic magma column from below and ascends at a constant velocity whilst a volatile exchange takes place between the fluid and melt. Two types of exchange modes were examined. One is the equilibrium mode where the volatile exchange is instantaneously achieved at all column depths. The second is the diffusive mode where the volatile exchange is rate limited by diffusion. In the equilibrium mode, the extent of re-equilibration of the entire column is controlled solely by the mass ratio of the integrated fluid to the melt. In the diffusive mode, the extent of re-equilibration is controlled by the Damkhler number, a dimensionless parameter representing the ratio of the advection time to the diffusion time. When the Damkhler number for carbon dioxide exceeds 10, the diffusive exchange becomes indistinguishable from the equilibrium exchange. Both exchange modes produce a negative correlation between the concentrations of carbon dioxide and water in the melt, which cannot be explained by conventional degassing models without significant crystallisation. The fluid emitted from the column as a volcanic gas changes its composition from carbon dioxide rich to water rich, and the emission rate decreases monotonically during fluxing. The simulation enables us to constrain the mechanism of fluid transport. For the melt inclusion data from the Bishop Tuff (Wallace et al., 1999; Anderson et al., 2000), fluid velocity in this magma was estimated to be 10 - 6 -10 - 7 m/s. The corresponding mechanism of fluid transport may include permeable flow with a permeability of ~ 10 - 15 m 2 or a buoyant ascent of individual bubbles with a radius of 4-7 mm.

Yoshimura, Shumpei; Nakamura, Michihiko

2011-07-01

268

Carbon Dioxide: Production and Sequestration  

NSDL National Science Digital Library

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

269

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

E-print Network

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

Kaiser, Ralf I.

270

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

E-print Network

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

Wu, Jianzhong

271

Climate impact of increasing atmospheric carbon dioxide  

SciTech Connect

The global temperature rose by 0.2/sup 0/C between the middle 1960's and 1980, yielding a warming of 0.4/sup 0/C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.

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

1981-08-28

272

Heterogeneous catalytic reactions of carbon dioxide  

NASA Astrophysics Data System (ADS)

The most important classes of heterogeneous catalytic reactions involving CO2 are examined: the incorporation of CO2 in the C-C, C-H, and C-N bonds with formation of carbonyl- and carboxyl-containing compounds and oxidation of other compounds by CO2. Reactions of the second class are more promising from the standpoint of the utilisation of carbon dioxide as a chemical raw material and from the standpoint of the solution of the ecological problems involving its utilisation from the gaseous waste discharged into the atmosphere. The reactions involving the oxidation of C1-C7 hydrocarbons and C1-C2 alcohols by carbon dioxide, which have been investigated by the authors of this review, are examined in detail. Catalysts based on manganese oxides are most effective in these reactions. The bibliography includes 231 references.

Krylov, Oleg V.; Mamedov, A. Kh

1995-09-01

273

The direct carbon dioxide effect on plants  

Microsoft Academic Search

Carbon dioxide may affect plants by changing the climate, but it can have another more subtle and quite separate influence,\\u000a through its direct effects on plant physiology. Since CO2 is fundamental to photosynthesis, it makes sense that increasing the amount of CO2 in the atmosphere will tend to allow plants to photosynthesize faster. This then is one-half of the direct

Jonathan Adams

274

Carbon dioxide separation from hydrogen and nitrogen  

Microsoft Academic Search

CO2-selective membranes that obtain high CO2 permeabilities accompanied with high CO2\\/H2 and CO2\\/N2 separation factors at industrial temperatures and pressures are applicable to fuel cell operations and flue gas purification. This paper describes the separation of carbon dioxide from a mixed gas stream of hydrogen and nitrogen by a chitosan membrane containing 40wt% sodium arginate. Continuous membrane separations were done

Louei A. El-Azzami; Eric A. Grulke

2009-01-01

275

Carbon dioxide balneotherapy and cardiovascular disease  

Microsoft Academic Search

Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However,\\u000a its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We\\u000a performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded

Efstathios D. Pagourelias; Paraskevi G. Zorou; Miltiadis Tsaligopoulos; Vasilis G. Athyros; Asterios Karagiannis; Georgios K. Efthimiadis

276

Carbon dioxide sequestration: how much and when?  

Microsoft Academic Search

Carbon dioxide (CO2) sequestration has been proposed as a key component in technological portfolios for managing anthropogenic climate change,\\u000a since it may provide a faster and cheaper route to significant reductions in atmospheric CO2 concentrations than abating CO2 production. However, CO2 sequestration is not a perfect substitute for CO2 abatement because CO2 may leak back into the atmosphere (thus imposing

Klaus Keller; David McInerney; David F. Bradford

2008-01-01

277

Electrochemical carbon dioxide concentrator: Math model  

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

278

Transport of Carbon Dioxide and Radioactive Waste  

Microsoft Academic Search

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

Daro R. Gmez; Michael Tyacke

279

Elevated atmospheric carbon dioxide increases soil carbon  

SciTech Connect

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

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

2005-01-01

280

Carbon dioxide in Arctic and subarctic regions  

SciTech Connect

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.

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

1981-03-01

281

Carbon dioxide sensitivity of zeolitic imidazolate frameworks.  

PubMed

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

Mottillo, Cristina; Fri?i?, Tomislav

2014-07-14

282

Carbon dioxide disposal in carbonate minerals  

Microsoft Academic Search

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

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

1995-01-01

283

Predicted shift in the C-13\\/C-12 ratio of atmospheric carbon dioxide  

Microsoft Academic Search

Knowledge of recent global changes in the rare isotopic species (C-13)O2 in atmospheric carbon dioxide does not now distinguish whether the land biosphere is a source or sink for fossil fuel carbon dioxide. The question is critically dependent on isotopic fractionation between the atmosphere and ocean water; if the isotopic fractionation factor for CO2 uptake at the air-ocean boundary, alpha(am),

C. D. Keeling; R. B. Bacastow; P. P. Tans

1980-01-01

284

Direct carbon dioxide emissions from civil aircraft  

NASA Astrophysics Data System (ADS)

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

Grote, Matt; Williams, Ian; Preston, John

2014-10-01

285

Carbon dioxide solubility and carbon isotope fractionation in basaltic melt  

SciTech Connect

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

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

1991-11-01

286

Using panicogenic inhalations of carbon dioxide enriched air to induce attentional bias for threat: Implications for the development of anxiety disorders.  

PubMed

The tendency for anxious individuals to selectively attend to threatening information is believed to cause and exacerbate anxious emotional responding in a self-perpetuating cycle. The present study sought to examine the relation between differential interoceptive conditioning (IC) using carbon dioxide inhalation as a panicogenic unconditioned stimulus (US) and the development of Stroop colour-naming interference to various non-word conditioned stimuli (CSs). Healthy university students (N = 27) underwent the assessment of colour-naming interference to reinforced CS+ and non-reinforced CS- non-words prior to and following differential fear conditioning. Participants showed greater magnitude electrodermal and verbal-evaluative responses to the CS+ over the CS- non-word following IC, and demonstrated the expected slower colour-naming latencies to the CS+ compared to the CS- non-word from baseline to post-conditioning. We discuss the relation between fear learning and the emergence of attentional bias for threat to further understand the maintenance of anxiety disorders. PMID:24499115

Valdivia-Salas, Sonsoles; Forsyth, John P; Berghoff, Christopher R; Ritzert, Timothy R

2014-12-01

287

Carbon dioxide power plant for total emission control and enhanced oil recovery. [Removal, storage, and use of CO  

Microsoft Academic Search

The design of a compact environmentally acceptable carbon dioxide diluted coal-oxygen fired power plant is described. The plant releases no combustion products to the atmosphere. The oxygen for combustion is separated in an air liquefaction plant and the effluent nitrogen is available for use in oil well production. Recycle carbon dioxide mixed with oxygen replaces the nitrogen for the combustion

F. L. Horn; M. Steinberg

1981-01-01

288

Tribological Studies on Scuffing Due to the Influence of Carbon Dioxide Used as a Refrigerant in Compressors  

Microsoft Academic Search

Because hydrofluorocarbon (HFC) refrigerants in air-conditioning systems are known to have a negative effect on the environment, carbon dioxide (CO2) is a candidate as a replacement refrigerant. Research work related to CO2 as a refrigerant has been focused primarily on its thermodynamic performance, whereas work in the area of tribology related to carbon dioxide is absent. In this study, the

NICHOLAOS G. DEMAS; ANDREAS A. POLYCARPOU; THOMAS F. CONRY

2005-01-01

289

Photoacoustic spectrometer for accurate, continuous measurements of atmospheric carbon dioxide concentration  

NASA Astrophysics Data System (ADS)

We have developed a portable photoacoustic spectrometer that offers routine, precise and accurate measurements of the molar concentration of atmospheric carbon. The temperature-controlled spectrometer continuously samples dried atmospheric air and employs an intensity-modulated distributed feedback laser and fiber amplifier operating near 1.57 m. For measurements of carbon dioxide in air, we demonstrate a measurement precision (60-s averaging time) of 0.15 mol mol-1 and achieve a standard uncertainty of 0.8 mol mol-1 by calibrating the analyzer response in terms of certified gas mixtures. We also investigate how water vapor affects the photoacoustic signal by promoting collisional relaxation of the carbon dioxide.

Reed, Zachary D.; Sperling, Brent; van Zee, Roger D.; Whetstone, James R.; Gillis, Keith A.; Hodges, Joseph T.

2014-06-01

290

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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.

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

2001-07-01

291

Chemical Recycling of Carbon Dioxide to Methanol and Dimethyl Ether: From Greenhouse Gas to Renewable, Environmentally Carbon Neutral Fuels and Synthetic Hydrocarbons  

Microsoft Academic Search

Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to

George A. Olah; Alain Goeppert; G. K. Surya Prakash

2009-01-01

292

Robust carbon dioxide reduction on molybdenum disulphide edges.  

PubMed

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

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

2014-01-01

293

Enriching blast furnace gas by removing carbon dioxide.  

PubMed

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

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

2013-12-01

294

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

Microsoft Academic Search

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

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

1997-01-01

295

Experimentally Determining the Molecular Weight of Carbon Dioxide Using a Mylar Balloon  

Microsoft Academic Search

The molar mass of carbon dioxide was experimentally determined using a Mylar balloon. Mylar balloons are lightweight, have a fixed definite volume, and require minimal additional pressure for inflation. Using the Ideal Gas Equation, the number of moles of air in the balloon was calculated. The molar mass of air was calculated using the percentages of the individual gases. Having

Barbara Albers Jackson; David J. Crouse

1998-01-01

296

Carbon dioxide emissions from estuaries of northern and northeastern Brazil  

NASA Astrophysics Data System (ADS)

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

Noriega, Carlos; Araujo, Moacyr

2014-08-01

297

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

ERIC Educational Resources Information Center

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

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

298

Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere  

E-print Network

interaction with infrared · Basic model and some results #12;#12;#12;Earth's emitted spectrum Ozone Carbon #12;Fine structure of carbon dioxide absorption spectrum near 15 micron wavelength #12Thermal Infrared Radiation and Carbon Dioxide in the Atmosphere Bill Satzer 3M Company #12;Outline

Olver, Peter

299

Carbon Dioxide Production in the Oxidation of Organic  

E-print Network

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

Steinbock, Oliver

300

Thermochemical generation of hydrogen and carbon dioxide  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

301

Research Spotlight: Rain modifies ocean-atmosphere carbon dioxide exchange  

NASA Astrophysics Data System (ADS)

Exchanges of carbon dioxide (CO2) between the atmosphere and the oceans play an important role in the global carbon cycle and in determining how much CO2 is stored in the atmosphere and how much is stored in the ocean. A new study shows that rain can be an important, though often overlooked, factor in this exchange. Rain can contribute to the air-sea carbon exchange in several ways. Rain dilutes the CO2 in the surface layer of the ocean, increases the speed at which gas is transferred between the atmosphere and ocean, and deposits carbon from the atmosphere into the ocean. To determine the effects of rain on the air-sea carbon flux in the western equatorial Pacific, Turk et al. analyzed rain measurements from a buoy at 0, 156E during 2002 as well as a dilution model based on observational ocean studies and output from an ocean carbon cycle model. (Geophysical Research Letters, doi:10.1029/2010GL045520, 2010)

Tretkoff, Ernie

2011-01-01

302

Optical Sensors for Carbon Dioxide and Their Applications  

Microsoft Academic Search

There are few analytes in the world as significant as carbon dioxide, the basic chemical feedstock of life. Through green\\u000a plant photosynthesis, carbon dioxide is converted to the fuel and food necessary for the continued existence of most known\\u000a forms of life. In addition carbon dioxide is an indicator of the existence of life and a measure of health via

Andrew Mills

303

Carbon dioxide resistance of fiberglass oil field pipe  

SciTech Connect

Unlined aromatic amine-cured epoxy fiberglass piping systems have been successfully used to handle oil field services requiring resistance to carbon dioxide. Fiberglass pipe made from vinyl ester and premium isophthalic polyester resins have also been proposed for use in this type of service. This paper presents test data comparing the carbon dioxide resistance of fiberglass pipe made from these three resins. Test data for fiberglass pipe exposed to carbon dioxide containing 5% hydrogen sulfide are also presented.

Oswald, K.J.

1988-08-01

304

Supercritical carbon dioxide: a solvent like no other  

PubMed Central

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

Peach, Jocelyn

2014-01-01

305

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

Federal Register 2010, 2011, 2012, 2013

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

2013-05-14

306

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

PubMed

An off-limb scan of Callisto was conducted by the Galileo near-infrared mapping spectrometer to search for a carbon dioxide atmosphere. Airglow in the carbon dioxide nu3 band was observed up to 100 kilometers above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10(-12) bar and a temperature of about 150 kelvin, close to the surface temperature. A lifetime on the order of 4 years is suggested, based on photoionization and magnetospheric sweeping. Either the atmosphere is transient and was formed recently or some process is currently supplying carbon dioxide to the atmosphere. PMID:9933159

Carlson, R W

1999-02-01

307

Toward solar fuels: photocatalytic conversion of carbon dioxide to hydrocarbons.  

PubMed

The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle carbon dioxide into readily transportable hydrocarbon fuel (i.e., a solar fuel) would help reduce atmospheric CO2 levels and partly fulfill energy demands within the present hydrocarbon based fuel infrastructure. We review the present status of carbon dioxide conversion techniques, with particular attention to a recently developed photocatalytic process to convert carbon dioxide and water vapor into hydrocarbon fuels using sunlight. PMID:20141175

Roy, Somnath C; Varghese, Oomman K; Paulose, Maggie; Grimes, Craig A

2010-03-23

308

Production of precipitated calcium carbonate from calcium silicates and carbon dioxide  

Microsoft Academic Search

The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating

Sebastian Teir; Sanni Eloneva; Ron Zevenhoven

2005-01-01

309

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

E-print Network

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

Barthelat, Francois

310

A photoelectrochemical approach to splitting carbon dioxide for a manned mission to Mars  

Microsoft Academic Search

A photoelectrochemical system for splitting carbon dioxide to carbon monoxide and oxygen is discussed. The Martian atmosphere consists of 95% carbon dioxide. Splitting carbon dioxide would provide both oxygen to support life and carbon monoxide, which can be used as a substitute for hydrogen fuel. The photoelectrochemical system involves a cathodic compartment where reduction of carbon dioxide to carbon monoxide

Brian K Breedlove; Gregory M Ferrence; John Washington; Clifford P Kubiak

2001-01-01

311

Asthma, sulfur dioxide, and the Clean Air Act  

Microsoft Academic Search

Laboratory findings on the effects of sulfur dioxide in patients with asthma are related to theories about the mechanisms of bronchial hyperreactivity, an abnormality that may be fundamental to the pathogenesis of asthma and then to questions of national policy on air quality. Work has shown that people with asthma are abnormally sensitive to inhalation of sulfur dioxide and that

Boushey

1982-01-01

312

Air Pollution XVI 247 Emissions of Nitrogen Dioxide from Modern  

E-print Network

Air Pollution XVI 247 Emissions of Nitrogen Dioxide from Modern Diesel Vehicles G.A. Bishop and D;Air Pollution XVI 248 The DPF is an extremely effective means to achieve particle reduction goals increase, are of concern to air pollution photochemistry because NO2 leads directly, through solar

Denver, University of

313

Searching for clues to ancient carbon dioxide  

SciTech Connect

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

Appenzeller, T.

1993-02-12

314

A Conductivity Device for Measuring Sulfur Dioxide in the Air  

ERIC Educational Resources Information Center

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

Craig, James C.

1972-01-01

315

Asthma, sulfur dioxide, and the Clean Air Act  

SciTech Connect

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

Boushey, H.

1982-02-01

316

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

EPA Science Inventory

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

317

Absorption of Carbon Dioxide in Aqueous Piperazine/Methyldiethanolamine  

E-print Network

Absorption of Carbon Dioxide in Aqueous Piperazine/Methyldiethanolamine Sanjay Bishnoi and Gary T dioxide absorption in 0.6 M piperazine PZ r4 M methyldiethanolamine ( )MDEA was measured in a wetted wall dioxide from synthesis gas in ammonia plants and hydrogenrcarbon Z .monoxide plants Wammes et al., 1994

Rochelle, Gary T.

318

Total column carbon dioxide and methane measurements at Sodankyl  

NASA Astrophysics Data System (ADS)

Carbon dioxide and methane are the two most important anthropogenic greenhouse gases. Total column measurements of these gases have been performed at various Total Carbon Column Observing Network (TCCON) sites using solar Fourier Transform Spectrometers (FTS), operating in the near infrared spectral region. Sodankyl in northern Finland (at 67.4 N, 26.6 E) is one of the sites of the TCCON network. At Sodankyl we have performed FTS measurements since early 2009. Here we present a description of the instrumentation at Sodankyl and analysis of five years of reprocessed TCCON retrievals at the site. Relevant to the FTS measurements, in September 2013 we have started with balloon borne AirCore profile measurements of CO2, CH4 and CO at Sodankyl. The aim is to continue with year around activities, thus adding available column information for the winter period. The AirCore measurements are expected to provide improved profile and total column estimates for the FTS retrieval system. A total gas column measured by an AirCore sampling system is directly related to the World Meteorological Organization in situ trace gas measurement scales. Secondly, an AirCore measurement has the benefit of reaching higher altitudes compared to the aircraft in situ measurements. Therefore AirCore data could be used to validate and improve the accuracy of the FTS total column CO2 and CH4 retrievals at the site.

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

2014-05-01

319

The lifetime of excess atmospheric carbon dioxide  

SciTech Connect

Since the beginning of the industrial revolution human activity has significantly altered biogeochemical cycling on a global scale. The uncertainties of future climate change rests partly on issues of physical-climate system dynamics and their representation in general circulation models. However understanding the carbon cycle is a key to comprehending the changing terrestrial biosphere and to developing a reasonable range of future concentrations of greenhouse gases. The authors look at correction of model uncertainties in the examination of the lifetime of carbon dioxide. The two difficulties analysed are as follows: (1) most model-derived estimates of the relaxation of the concentration of CO2 reveal a function which is not always well approximated by weighted sums of exponentials; (2) the function c(t) is quite sensitive to assumptions about the terrestrial biosphere and the relaxation experiment. 51 refs., 15 figs., 7 tabs.

Moore, B. III; Braswell, B.H. (Univ. of New Hampshire, Durham, NH (United States))

1994-03-01

320

Carbon dioxide research plan. A summary  

SciTech Connect

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

Not Available

1983-11-01

321

Modeling flow of mineralized carbon dioxide slurry  

SciTech Connect

Direct mineral carbonation was investigated at Albany Research Center (US DOE) as a means to sequester carbon dioxide into stable mineral matrices. Although previous work focused on treating Mg-containing minerals in conventional autoclaves, recent work has been done using pipeline-reactor technology for the high-temperature, high-pressure (HTHP) reaction of the minerals in aqueous/CO2 media. Sequestration of CO2 using above-ground reactors may be uneconomical, but the technology may also be applicable in geological sequestration of CO2. Progress is described in using a prototype HTHP flow-loop reactor to model flow in the dynamic three-phase system to help determine the pumping-energy requirements to optimize reactivity.

Penner, Larry R.; Dahlin, David C.; Gerdemann, Stephen J.; Saha, K.K. (Mechanical and Aerospace Engineering Dept., Computational Fluid Dynamics Laboratory, Arizona State University)

2005-04-01

322

Chinese carbon dioxide observation satellite (TanSat) project  

NASA Astrophysics Data System (ADS)

The Chinese carbon dioxide observation satellite project is one of the national high technology research and development programs. It is funded and supported by the ministry of science and technology of the people's republic of China and the Chinese Academy of Sciences. The TanSat - Chinese carbon dioxide observation satellite (Tan-carbon in Chinese) will be launched in 2015, which is going to monitor the carbon dioxide in Sun-Synchronous orbit. Two instruments will be onboard the TanSat, the main instrument is a high resolution grating spectrometer that measure reflected sunlight with the 0.76 ?m O2 A-band and two CO2 bands at 1.61 and 2.06 ?m. The second instrument is the Cloud and Aerosol Imager, which is a wide field of view moderate resolution imaging spectrometer, it include 0.38, 0.67, 0.87, 1.38 and 1.61?m channels in ultraviolet, visible, and near infrared bands, with two polarization channels in 0.67?m. Soundings recorded from main instrument will be used to retrieve the column-averaged CO2 dry air mole fraction (XCO2), while data from Cloud and Aerosol Imager will be used to correct cloud and aerosol interference. A full physical optimal estimation method will be developed as a retrieval method of XCO2, while other sensitive parameters will be inversed at the same time. Ground based observation network system will be established around China to validate satellite CO2 observation results. The final object is to monitor XCO2 from space with precision of 1%. Global CO2 source and sink will be studied by using XCO2 observation results.

Liu, Y.; Yin, Z.; Yang, Z.; Zheng, Y.; Yan, C.; Yang, D.

2011-12-01

323

Titrimetric Determination of Carbon Dioxide in a Heterogeneous Sample  

Microsoft Academic Search

A traditional exercise in quantitative analysis is the titration of mixtures of sodium hydroxide, sodium carbonate, and sodium bicarbonate. Often, consumer products are studied. A procedure to analyze the total volume of carbon dioxide bubbles in the candy \\

Craig M. Davis; Matthew C. Mauck

2003-01-01

324

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

325

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

Federal Register 2010, 2011, 2012, 2013

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

2011-09-09

326

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

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

2014-10-01

327

Modeling Infinite Dilution and Fickian Diffusion Coefficients of Carbon Dioxide in Water  

E-print Network

Modeling Infinite Dilution and Fickian Diffusion Coefficients of Carbon Dioxide in Water J. Wambui infinite dilution diffusion coefficients for carbon dioxide and water mixtures. The model takes, carbon dioxide, classical thermodynamics Introduction The increase in atmospheric concentrations of CO2

Firoozabadi, Abbas

328

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

E-print Network

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

Santiago, Juan G.

329

49 CFR 175.900 - Handling requirements for carbon dioxide, solid (dry ice).  

...2014-10-01 false Handling requirements for carbon dioxide, solid (dry ice). 175.900 Section...175.900 Handling requirements for carbon dioxide, solid (dry ice). Carbon dioxide, solid (dry ice) when shipped...

2014-10-01

330

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters  

NASA Astrophysics Data System (ADS)

Intensive research has been undertaken on carbon dioxide efflux from lakes, estuaries and oceans, but much less attention has been given to rivers and streams, especially lower order streams. River systems are often over-saturated with carbon dioxide and so tend to act as sources of carbon dioxide to the atmosphere. It has been thought that rivers act as pipes carrying this terrestrial carbon to the oceans. However, recent studies have shown that a significant amount of the carbon is reprocessed within the system in a series of transformations and losses. Fluvial evasion of carbon dioxide is now recognised to be a significant component of carbon cycles, however the factors controlling carbon dioxide efflux and its magnitude remain poorly understood and quantified. This research aims to quantify, and better understand the controls on, freshwater carbon dioxide evasion. Data are presented here from field measurements that commenced in Sept 2013 in two contrasting Scottish rivers: the River Kelvin which has a large (335 km.sq) part-urban catchment with predominantly non-peat soils and Drumtee Water, a small (9.6 km.sq) rural catchment of peat soils and agricultural land. Using a floating chamber with the headspace connected to an infrared gas analyser to measure changes in carbon dioxide concentration, efflux rates from 0.22 - 47.4 ?mol CO2/m.sq/sec were measured, these close to the middle of the range of previously reported values. At one site on the River Kelvin in May 2013 an influx of -0.61 - -3.53 ?mol CO2/m.sq/sec was recorded. Whereas previous research finds carbon dioxide efflux to increase with decreasing river size and a more organic-rich soil catchment, here the controls on carbon dioxide evasion are similar across the contrasting catchments. Carbon dioxide evasion shows seasonality, with maximum fluxes in the summer months being up to twice as high as the winter maxima. Linear regression demonstrates that evasion increases with increased flow velocity, water surface disturbance indicated by Froude number, and turbulent mixing indicated by Reynolds number. Similar relationships with season, flow velocity and turbulence have been reported previously, but there is little known about the mechanisms involved. When comparing spot carbon dioxide efflux measurements to river stage time series data, carbon dioxide efflux is more sensitive to an increase in stage at more turbulent measurement points. Further investigation of the mechanisms will be obtained by measurement of DIC concentration and isotopic composition to assess the controls of carbon source versus degassing, and the analysis of the interactions between hydraulic and seasonal controls and carbon dioxide fluxes extended.

Long, H. E.; Waldron, S.; Hoey, T.; Newton, J.; Quemin, S.

2013-12-01

331

CARBON DIOXIDE STANDARD EMISSIVITY BY MIXED GRAY-GASES MODEL  

Microsoft Academic Search

Conventional fossil fuels are of carbon-hydrogen composition. A number of alternative fuels, e.g., coal, lignite, are carbon-based fuels. The high temperature combustion of such fuels would generate carbon dioxide, and if hydrogen is present, water vapor. The knowledge of the emissivities of carbon dioxide and water vapor is very important in burner design and thermal efficiency calculations. The present work

IHAB H. FARAG; T. A. ALLAM

1982-01-01

332

Sources and sinks of carbon dioxide in the Arctic regions  

SciTech Connect

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

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

1982-01-01

333

Carbon dioxide emission during forest fires ignited by lightning  

E-print Network

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.

Pelc, Magdalena

2009-01-01

334

Carbon Dioxide Capture DOI: 10.1002/anie.201000431  

E-print Network

gas and phasing in the use of renewable energy resources (e.g., solar energy, wind, and biomassCarbon Dioxide Capture DOI: 10.1002/anie.201000431 Carbon Dioxide Capture: Prospects for New The prospect of a worsening climatic situation due to global warming is a subject of widespread public concern

335

Method and apparatus for producing food grade carbon dioxide  

Microsoft Academic Search

A method is disclosed of producing food grade carbon dioxide from an impure carbon dioxide source stream containing contaminants which may include light and heavy hydrocarbons (at least C to C) and light sulfur compounds such as hydrogen sulfide and carbonyl sulfide as well as heavier sulfur constituents in the nature of mercaptans (RSH) and\\/or organic mono and disulfides (RSR

J. E. Nobles; L. K. Swenson

1984-01-01

336

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

337

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

338

Recovery of carbon dioxide from fuel cell exhaust  

Microsoft Academic Search

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

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

1988-01-01

339

Carbon Dioxide Reforming of Methane to Syngas by Thermal Plasma  

Microsoft Academic Search

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

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

2012-01-01

340

Options for the collection and disposal of carbon dioxide  

Microsoft Academic Search

If society should ever decide that unacceptable changes in climate are imminent because of the accumulation of carbon dioxide in the atmosphere from the use of fossil fuels, it may be necessary to collect and dispose of carbon dioxide. At present it appears that such disposal would consume a large fraction of the energy derived from the fossil fuel. To

C. F. Jr. Baes; S. E. Beall; D. W. Lee; G. Marland

1980-01-01

341

Response of the oceans to increasing atmospheric carbon dioxide  

Microsoft Academic Search

The rate at which the oceans take up excess atmospheric carbon dioxide from the burning of fossil fuels is an important factor in determining the rate of increase in the atmospheric concentration of carbon dioxide and the maximum value it will reach. In this review are considered the relevant physical and chemical features of the ocean, the observational evidence of

Baes; C. F. Jr

1981-01-01

342

Measurements of atmospheric carbon dioxide concentration above the ocean  

Microsoft Academic Search

Changes in the composition of the atmosphere can have a destabilizing effect on the climate. One change is related to an increase in the concentration of carbon dioxide as a result of the combustion of organic fuels. The most effective procedures for monitoring the atmospheric carbon dioxide concentration are discussed, taking into account suitable analytic methods and the most appropriate

A. I. Voskresenskii; N. E. Kamenogradskii; V. P. Ustinov

1984-01-01

343

Isothermal and isobaric desorption of carbon dioxide by purge  

Microsoft Academic Search

Adsorption and desorption constitute the two most basic steps in all pressure swing adsorption (PSA) processes for gas separation. The desorption steps are the primary energy-consuming steps in the PSA process. They also dictate the overall separation efficiency. Isothermal and isobaric desorption of carbon dioxide was experimentally evaluated by purging adsorbent columns saturated with pure carbon dioxide with pure hydrogen,

Shivaji Sircar; Timothy C. Golden

1995-01-01

344

The Greenness of Cities: Carbon Dioxide Emissions and Urban Development  

Microsoft Academic Search

Carbon dioxide emissions may create significant social harm because of global warming, yet American urban development tends to be in low density areas with very hot summers. In this paper, we attempt to quantify the carbon dioxide emissions associated with new construction in different locations across the country. We look at emissions from driving, public transit, home heating, and household

Edward L. Glaeser; Matthew E. Kahn

2008-01-01

345

The greenness of cities: Carbon dioxide emissions and urban development  

Microsoft Academic Search

Carbon dioxide emissions may create significant social harm because of global warming, yet American urban development tends to be in low density areas with very hot summers. In this paper, we attempt to quantify the carbon dioxide emissions associated with new construction in different locations across the country. We look at emissions from driving, public transit, home heating, and household

Edward L. Glaeser; Matthew E. Kahn

2010-01-01

346

Criteria for Intermediate Storage of Carbon Dioxide in Geological Formations  

Microsoft Academic Search

The greenhouse gas (GHG) making the largest contribution to atmospheric emissions from human activities is carbon dioxide (CO 2) and released dominantly by burning fossil fuels such as coal, oil, and natural gas. Increased emissions of GHG, causes global warming thus steps should be taken that aim in the stabilization of greenhouse gas concentrations in the atmosphere. Carbon dioxide capture

Semere Solomon

347

Uptake of carbon dioxide from flue gas by microalgae  

Microsoft Academic Search

The technology under development seeks to provide affordable, and efficient methods for reducing carbon dioxide and other emissions from coal-fired electricity generation based on biological assimilation. Photosynthetic microorganisms such as microalgae, when grown in large outdoor ponds could use carbon dioxide from flue gas directly injected into the culture. This process requires land, water, sunlight and other nutrients. Currently, commercial

Lewis M. Brown

1996-01-01

348

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

ERIC Educational Resources Information Center

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

Jadrich, James; Bruxvoort, Crystal

2010-01-01

349

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

Microsoft Academic Search

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

James Jadrich; Crystal Bruxvoort

2010-01-01

350

Process Based Belowground Carbon Dioxide Modeling in a Desert Ecosystem  

Microsoft Academic Search

We describe a study to integrate and assess biological and physical processes that govern belowground carbon dioxide levels at a semi-arid grassland near Canyonlands National Park. Carbon dioxide concentrations were measured every 30 minutes at 5 and 15 cm depth within the rooting zones of the two dominant grass species, Stipa hymenoides and Hilaria jamesii, as well as the interspace

J. M. Zobitz; D. R. Bowling

2003-01-01

351

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

NSDL National Science Digital Library

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

Nutshell, Planet; Network, Utah E.

352

Carbon dioxide emission during forest fires ignited by lightning  

E-print Network

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.

Magdalena Pelc; Radoslaw Osuch

2009-03-31

353

Carbon Dioxide Sequestration Capacity of the Mt Simon Formation  

NASA Astrophysics Data System (ADS)

A technique has been developed to better predict the quantity of carbon dioxide that can be sequestered in a formation through solubility or free phase trapping. The technique is being improved to incorporate the potential for carbonate mineral precipitation. The current study evaluates the extent to which the Mt. Simon formation can serve as a trapping reservoir. The Mt. Simon formation was selected for this study because it meets many of the criteria required for sequestration. To determine the capacity of the Mt. Simon formation to trap carbon dioxide as a soluble component, an experiment was conducted in natural Mt. Simon formation brine. The experiment was conducted at 55 degrees Celsius and pressures from 50 to 350 bars, conditions that fall within the range expected for the entire formation. The data collected compare well to existing models that only account for carbon dioxide solubility. Thus, the solubility model can be reliably used to predict dissolved carbon dioxide concentrations for the range of temperatures and pressures expected to be encountered. The capacity of the Mt. Simon formation to sequester dissolved carbon dioxide was calculated using results of the solubility model, estimation of the density of carbon dioxide saturated brine, estimation of the formation porosity, and geographic information system data on the extent of the formation. Results indicate that the Mt. Simon formation can sequester as much as 26 Gt of dissolved carbon dioxide or 255 Gt of free phase carbon dioxide depending on the efficiency of the system. The current estimated annual production of carbon dioxide from power plant emissions of IL, IA and MI is 0.24 Gt. This indicates that the basin could accept the annual emissions of these power plants for approximately 100 years or more if current carbon dioxide production does not increase.

Allen, D. E.; Dilmore, B.; Hedges, S.; Soong, Y.

2008-12-01

354

Carbon dioxide absorbent and method of using the same  

DOEpatents

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

Perry, Robert James (Niskayuna, NY); Lewis, Larry Neil (Scotia, NY); O'Brien, Michael Joseph (Clifton Park, NY); Soloveichik, Grigorii Lev (Latham, NY); Kniajanski, Sergei (Clifton Park, NY); Lam, Tunchiao Hubert (Clifton Park, NY); Lee, Julia Lam (Niskayuna, NY); Rubinsztajn, Malgorzata Iwona (Ballston Spa, NY)

2011-10-04

355

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

356

Grasland Stable Isotope Flux Measurements: Three Isotopomers of Carbon Dioxide Measured by QCL Spectroscopy  

NASA Astrophysics Data System (ADS)

To improve our understanding of greenhouse gas dynamics of managed ecosystems such as grasslands, we not only need to investigate the effects of management (e.g., grass cuts) and weather events (e.g., rainy days) on carbon dioxide fluxes, but also need to increase the time resolution of our measurements. Thus, for the first time, we assessed respiration and assimilation fluxes with high time resolution (5Hz) stable isotope measurements at an intensively managed farmland in Switzerland (Chamau, 400m ASL). Two different methods were used to quantify fluxes of carbon dioxide and associated fluxes of stable carbon isotopes: (1) the flux gradient method, and (2) the eddy covariance method. During a week long intensive measurement campaign, we (1) measured mixing ratios of carbon dioxide isotopomers (12C16O2, 12C16O18O, 13C16O2) with a Quantum Cascade Laser (QCL, Aerodyne Inc.) spectroscope and (2) collected air samples for isotope analyses (13C/12C) and (18O/16O) of carbon dioxide by Isotope Ratio Mass Spectrometry (IRMS, Finnigan) every two hours, concurrently along a height profile (z = 0.05; 0.10; 0.31; 2.15m). In the following week, the QCL setup was used for closed-path eddy covariance flux measurement of the carbon dioxide isotopomers, with the air inlet located next to an open-path Infra Red Gas Analyzers (IRGA, LiCor 7500) used simultaneously for carbon dioxide measurements. During this second week, an area of grass inside the footprint was cut and harvested after several days. The first results of in-field continuous QCL measurements of carbon dioxide mixing ratios and their stable isotopic ratios show good agreement with IRGA measurements and isotope analysis of flask samples by IRMS. Thus, QCL spectroscopy is a very promising tool for stable isotope flux investigations.

Zeeman, M. J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Buchmann, N.; Emmenegger, L.

2007-12-01

357

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

Microsoft Academic Search

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

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

2011-01-01

358

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

SciTech Connect

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

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

1999-08-01

359

Dissociation-excitation reactions of argon metastables with carbon dioxide.  

NASA Technical Reports Server (NTRS)

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

Starr, W. L.

1971-01-01

360

Miniaturized remission sensor for carbon dioxide detection  

NASA Astrophysics Data System (ADS)

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.

Martan, T.; Will, M.

2010-02-01

361

Calcium Oxide Matrices and Carbon Dioxide Sensors  

PubMed Central

Homogeneous matrices of calcium oxide (CaO) were prepared by mixing this material with polyethylene glycol (PEG) acting as malleable inert support in order to obtain processable composites. Preliminary tests were carried out to assess the best concentration of CaO in the composite, individuated in the CaO/PEG weight ratio of 1/4. Experimental data highlighted that the composite was able to selectively detect carbon dioxide (CO2) via a nanogravimetric method by performing the experiments inside an atmosphere-controlled chamber filled with CO2. Furthermore, the composite material showed a linear absorption of CO2 as a function of the gas concentration inside the atmosphere-controlled chamber, thus paving the way for the possible use of these matrices for applications in the field of sensor devices for long-term evaluation of accumulated environmental CO2. PMID:22778620

Terencio, Tercio Bezerra Correia; Bavastrello, Valter; Nicolini, Claudio

2012-01-01

362

Demographic change and carbon dioxide emissions.  

PubMed

Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. PMID:22784534

O'Neill, Brian C; Liddle, Brant; Jiang, Leiwen; Smith, Kirk R; Pachauri, Shonali; Dalton, Michael; Fuchs, Regina

2012-07-14

363

Pulsed-discharge carbon dioxide lasers  

NASA Technical Reports Server (NTRS)

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

Willetts, David V.

1990-01-01

364

The Fluid Mechanics of Carbon Dioxide Sequestration  

NASA Astrophysics Data System (ADS)

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.

Huppert, Herbert E.; Neufeld, Jerome A.

2014-01-01

365

The vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of kerosene  

NASA Astrophysics Data System (ADS)

In ground tests of hypersonic scramjet, the high-enthalpy airstream produced by burning hydrocarbon fuels often contains contaminants of water vapor and carbon dioxide. The contaminants may change the ignition characteristics of fuels between ground tests and real flights. In order to properly assess the influence of the contaminants on ignition characteristics of hydrocarbon fuels, the effect of water vapor and carbon dioxide on the ignition delay times of China RP-3 kerosene was studied behind reflected shock waves in a preheated shock tube. Experiments were conducted over a wider temperature range of 800-1 500K, at a pressure of 0.3 MPa, equivalence ratios of 0.5 and 1, and oxygen concentration of 20%. Ignition delay times were determined from the onset of the excited radical OH emission together with the pressure profile. Ignition delay times were measured for four cases: (1) clean gas, (2) gas vitiated with 10% and 20% water vapor in mole, (3) gas vitiated with 10% carbon dioxide in mole, and (4) gas vitiated with 10% water vapor and 10% carbon dioxide, 20% water vapor and 10% carbon dioxide in mole. The results show that carbon dioxide produces an inhibiting effect at temperatures below 1 300 K when ? = 0.5, whereas water vapor appears to accelerate the ignition process below a critical temperature of about 1 000 K when ? = 0.5. When both water vapor and carbon dioxide exist together, a minor inhibiting effect is observed at ? = 0.5, while no effect is found at ? = 1.0. The results are also discussed preliminary by considering both the combustion reaction mechanism and the thermophysics properties of the fuel mixtures. The current measurements demonstrate vitiation effects of water vapor and carbon dioxide on the autoignition characteristics of China RP-3 kerosene at air-like O2 concentration. It is important to account for such effects when data are extrapolated from ground testing to real flight conditions.

Liang, Jin-Hu; Wang, Su; Zhang, Sheng-Tao; Yue, Lian-Jie; Fan, Bing-Cheng; Zhang, Xin-Yu; Cui, Ji-Ping

2014-08-01

366

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates, through reaction with carbon dioxide and

David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

2002-01-01

367

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple and inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates through reaction with carbon dioxide and

David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Ya Liang; Douglas P. Harrison

2002-01-01

368

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

SciTech Connect

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

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

2008-11-15

369

Does carbon dioxide pool or stream in the subsurface?  

E-print Network

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...

Cardoso, Silvana S S

2014-01-01

370

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between October 1, 2004 and December 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Two supported sorbents were tested in a bench scale fluidized bed reactor system. The sorbents were prepared by impregnation of sodium carbonate on to an inert support at a commercial catalyst manufacturing facility. One sorbent, tested through five cycles of carbon dioxide sorption in an atmosphere of 3% water vapor and 0.8 to 3% carbon dioxide showed consistent reactivity with sodium carbonate utilization of 7 to 14%. A second, similarly prepared material, showed comparable reactivity in one cycle of testing. Batches of 5 other materials were prepared in laboratory scale quantities (primarily by spray drying). These materials generally have significantly greater surface areas than calcined sodium bicarbonate. Small scale testing showed no significant adsorption of mercury on representative carbon dioxide sorbent materials under expected flue gas conditions.

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

2005-01-01

371

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

PubMed Central

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

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

2005-01-01

372

Testing a Regenerative Carbon Dioxide and Moisture Removal Technology  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were per-formed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic sim-ulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey; Curley, Suzanne

373

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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.

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

2005-07-01

374

Carbon dioxide warming of the early Earth  

NASA Technical Reports Server (NTRS)

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.

Arrhenius, G.

1997-01-01

375

Carbon dioxide warming of the early Earth.  

PubMed

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure. PMID:11541253

Arrhenius, G

1997-02-01

376

Can the carbon dioxide problem be resolved  

SciTech Connect

The combustion of fossil fuels increases atmospheric levels of carbon dioxide (CO/sub 2/). This may cause a long-term warming of the atmosphere. Solutions to the CO/sub 2/ problem are particularly difficult because adverse effects will be felt by future generations, but remedial action and sacrifices must be made by present generations. Decisions regarding the problem which affect both the immediate and long-range future must be made deliberately or by default in perhaps only 15 to 20 years, before we are reasonably confident of our knowledge of the problem and before we know whether atmospheric warming will, in fact, occur. Empirical and evaluative data do not seem compelling to decision makers. First, remedial actions require present generations to conserve fossil fuels for the benefit of posterity, and there is no consensus that an ethical obligation to posterity exists. Second, actions must be based upon uncertain projections of future energy use and uncertain scientific knowledge of the carbon cycle and the environment. Third, economic and social factors may preclude resolution of the problem. Fourth, speculation from moral psychology suggests that mankind may be psychologically incapable of caring enough for posterity to make serious sacrifices. Therefore, public policy regarding sacrifice by present generations for the benefit of posterity is not likely to be forthcoming from policy makers or suported by the public. 120 references.

Lemons, J.

1984-01-01

377

Multiphase Fluid Equilibria between Supercritical Carbon Dioxide and Brine: Potential for Widespread Relevance in Geochemical Systems  

Microsoft Academic Search

The potential significance of two fluid phases (excluding air and hydrocarbons) has been established for a limited number of geochemical processes. Of note are phase equilibria in metacarbonate rocks for low to moderate prograde metamophism, flow and transport in metamorphic rocks, and fluid inclusions. However, the reactive properties of a supercritical carbon dioxide phase that may coexist at relatively low

D. R. Janecky; J. P. Kaszuba; M. G. Snow

2002-01-01

378

Performance of a hypersonic hot fuselage structure with a carbon dioxide frost projected, nonintegral cryogenic tank  

Microsoft Academic Search

A model which consisted of a hot structure and a nonintegral tank protected by a carbon dioxide frost thermal protection system was tested under the following conditions: (1) room temperature loading and (2) heating and loading corresponding to the Mach 8 flight of an air-breathing launch vehicle. In the simulated flight tests, liquid nitrogen inside the tank was withdrawn at

E. L. Sharpe; L. R. Jackson

1975-01-01

379

High-resolution carbon dioxide concentration record 650,000800,000 years before present  

E-print Network

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 Project for Ice Coring in Antarctica (EPICA). The drillings at both sites, one located in the Dronning

Laughlin, Robert B.

380

The Effect of Atmospheric Carbon Dioxide Elevation on Plant Growth in Freshwater Ecosystems  

Microsoft Academic Search

We developed a dynamic model to investigate the effect of atmospheric carbon dioxide (CO 2) increase on plant growth in freshwater ecosystems. Steady-state simulations were performed to analyze the response of phytoplankton and submerged macrophytes to atmospheric CO 2 elevation from 350 to 700 ppm. We studied various conditions that may affect this response, such as alkalinity, the airwater exchange

Peter Schippers; Jan E. Vermaat; Jeroen de Klein; Wolf M. Mooij

2004-01-01

381

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

Microsoft Academic Search

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

Xueliang Guo; Guoguang Zheng; Dezhen Jin

2006-01-01

382

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

E-print Network

of carbon dioxide by the burning of fossil fuels ( 6 billion tons of carbon per year). Possible shiftsModel-based estimation of the global carbon budget and its uncertainty from carbon dioxide, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial

Jain, Atul K.

383

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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.

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

2005-04-01

384

Low Energy, Low Emissions: Sulfur Dioxide; Nitrogen Oxides, and Carbon Dioxide in Western Europe.  

ERIC Educational Resources Information Center

Links proposed low-energy scenarios for different Western European countries with the amount of pollutants that may result from these scenarios. Sulfur dioxide, nitrogen oxide, and carbon dioxide emissions are calculated for the 10 countries for which low-energy scenarios are available, resulting in reductions of 54%, 37%, and 40%, respectively.

Alcamo, Joseph; De Vries, Bert

1992-01-01

385

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU  

NASA Technical Reports Server (NTRS)

The atmosphere of Mars has many resources that can be processed to produce things such as oxygen, fuel, buffer gas, and water for support of human exploration missions. Successful manipulation of these resources is crucial for safe, cost-effective, and self-sufficient long-term human exploration of Mars. In our research, we are developing enabling technologies that require fundamental knowledge of adsorptive gas storage and separation processes. In particular, we are designing and constructing an innovative, low mass, low power separation device to recover carbon dioxide and carbon monoxide for Mars ISRU (in-situ resource utilization). The technology has broad implications for gas storage and separations for gas-solid systems that are ideally suited for reduced gravitational environments. This paper describes our separation process design and experimental procedures and reports results for the separation of CO2 and CO by a four-step adsorption cycle.

Walton, Krista S.; LeVan, M. Douglas

2004-01-01

386

The use of air-bottoming cycle as a heat source for the carbon dioxide capture installation of a coal-fired power unit  

NASA Astrophysics Data System (ADS)

The installations of CO2 capture from flue gases using chemical absorption require a supply of large amounts of heat into the system. The most common heating medium is steam extracted from the cycle, which results in a decrease in the power unit efficiency. The use of heat needed for the desorption process from another source could be an option for this configuration. The paper presents an application of gas-air systems for the generation of extra amounts of energy and heat. Gas-air systems, referred to as the air bottoming cycle (ABC), are composed of a gas turbine powered by natural gas, air compressor and air turbine coupled to the system by means of a heat exchanger. Example configurations of gas-air systems are presented. The efficiency and power values, as well as heat fluxes of the systems under consideration are determined. For comparison purposes, the results of modelling a system consisting of a gas turbine and a regenerative exchanger are presented.

Chmielniak, Tadeusz; Lepszy, Sebastian; Czaja, Daniel

2011-12-01

387

Study of the interactions of molten sodium nitrate-potassium nitrate 50 mol % mixture with water vapor and carbon dioxide in air. Final report, June 2, 1980June 30, 1981  

Microsoft Academic Search

The interactions of aerial components such as water, carbon dioxide, and oxygen with the binary 50 mol % mixture of sodium nitrate and potassium nitrate have been studied in the temperature range 300 to 600°C using electrochemical methods. In addition, the behavior of nitrite ions in this melt was investigated electrochemically. By judicious choice of techniques, in situ electroanalysis was

S. H. White; U. M. Twardoch

1981-01-01

388

Membranes for separation of carbon dioxide  

DOEpatents

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.

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

389

Carbon dioxide euthanasia in rats: oxygen supplementation minimizes signs of agitation and asphyxia  

Microsoft Academic Search

Summary This paper records the effects of carbon dioxide when used for euthanasia, on behaviour, electrical brain activity and heart rate in rats. Four different methods were used. Animals were placed in a box (a) that was completely filled with carbon dioxide; (b) into which carbon dioxide was streamed at a high flow rate; leiinto which carbon dioxide was streamed

A. M. L. Coenen; W. H. I. M. Drinkenburgl; R. Hoenderken; E. L. J. M. van Luijtelaar

1995-01-01

390

2008 Nature Publishing Group Atmospheric carbon dioxide linked  

E-print Network

atmosphere reaching back over 200 Myr, by using a new method based on the strong dependency of carbon-isotope concentrations from a combination of carbon-isotope analyses of non-vascular plant (bryophyte) fossils© 2008 Nature Publishing Group LETTERS Atmospheric carbon dioxide linked with Mesozoic and early

Cai, Long

391

Pretreatment for cellulose hydrolysis by carbon dioxide explosion  

SciTech Connect

Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 C for a controlled time period. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose. An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment. This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50%. Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol. As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

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

1998-11-01

392

Fixed-bed performance for production of oxygen-enriched carbon dioxide stream by perovskite-type ceramic sorbent  

Microsoft Academic Search

This paper reports on an experimental study on production of oxygen-enriched carbon dioxide stream by a fixed-bed packed with a perovskite-type ceramic sorbent La0.1Sr0.9Co0.5Fe0.5O3??, which can adsorb oxygen from air. Oxygen-enriched carbon dioxide stream is produced by passing carbon dioxide into the fixed-bed saturated with oxygen. Fixed-bed experiments were performed to study the oxygen separation performance of this sorbent. The

Qing Yang; Jerry Y. S. Lin

2006-01-01

393

Synthesis of Amides and Lactams in Supercritical Carbon Dioxide  

E-print Network

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

Mak, Xiao Yin

394

Control strategies for supercritical carbon dioxide power conversion systems  

E-print Network

The supercritical carbon dioxide (S-C02) recompression cycle is a promising advanced power conversion cycle which couples well to numerous advanced nuclear reactor designs. This thesis investigates the dynamic simulation ...

Carstens, Nathan, 1978-

2007-01-01

395

Mechanism of oxidative carbon dioxide production during Renilla reniformis bioluminescence.  

PubMed

The oxidation of luciferin catalyzed by sea pansy luciferase results in the emission of light. Molecular oxygen is required and carbon dioxide is produced. When the reaction occurs in the presence of H(2) (18)O, both of the oxygens of the carbon dioxide are labeled. One of the oxygens arises from the nonenzymic exchange of the ketone group of the substrate; the other oxygen is incorporated during the enzymic oxidation of the luciferin. When the reaction is carried out in the presence of (18)O(2), neither of the oxygens of the carbon dioxide is labeled. Thus the source of oxygen in the carbon dioxide is water. A mechanism for the oxidative reaction is proposed. PMID:4397765

DeLuca, M; Dempsey, M E; Hori, K; Wampler, J E; Cormier, M J

1971-07-01

396

Electrochemically-mediated amine regeneration for carbon dioxide separations  

E-print Network

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

Stern, Michael C. (Michael Craig)

2014-01-01

397

World energy consumption and carbon dioxide emissions : 1950-2050  

E-print Network

Emissions of carbon dioxide form combustion of fossil fuels, which may contribute to long-term climate change, are projected through 2050 using reduced form models estimated with national-level panel data for the period ...

Schmalensee, Richard

1995-01-01

398

World energy consumption and carbon dioxide emissions : 1950-2050  

E-print Network

Emissions of carbon dioxide from combustion of fossil fuels, which may contribute to long-term climate change, are projected through 2050 using reduced form models estimated with national-level panel data for the period ...

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

399

Atmospheric concentrations of carbon dioxide, methane and nitrous oxide  

NSDL National Science Digital Library

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

IPCC (Intergovernmental Panel of Climate Change)

400

Role of Carbon Dioxide in Inert Gas Narcosis.  

National Technical Information Service (NTIS)

The role of carbon dioxide and oxygen in high pressure narcosis was studied by exposing animals to hyperbaric conditions while maintaining them normoxic and normocapnic. Chickens were the experimental animals. Heated, humidified gas entered the lung via a...

H. S. Weiss

1977-01-01

401

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

NASA Technical Reports Server (NTRS)

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.

Johnson, F. S.

1975-01-01

402

Permanent storage of carbon dioxide in geological reservoirs by mineral carbonation  

Microsoft Academic Search

Anthropogenic greenhouse-gas emissions continue to increase rapidly despite efforts aimed at curbing the release of such gases. One potentially long-term solution for offsetting these emissions is the capture and storage of carbon dioxide. In principle, fluid or gaseous carbon dioxide can be injected into the Earth's crust and locked up as carbonate minerals through chemical reactions with calcium and magnesium

Peter B. Kelemen; Jrg M. Matter

2009-01-01

403

Determination of tropospheric mean carbon dioxide concentration from satellite high spectral resolution IR-sounder data  

Microsoft Academic Search

In view of the importance of studying a global carbon cycle and inadequacy of a ground-based network of observations of the\\u000a atmospheric carbon dioxide (CO2) concentrations and its fluxes, the feasibility of remote sensing of the atmospheric CO2 concentration obtained from the satellite high-spectral resolution IR-sounder data is studied. In reference to the AIRS infrared-sounder\\u000a measurements (the EOS Aqua satellite)

A. V. Kukharskii; A. B. Uspenskii

2009-01-01

404

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

Microsoft Academic Search

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

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

1979-01-01

405

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

Microsoft Academic Search

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

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

2006-01-01

406

Endoscopic Carbon Dioxide Laser Photocoagulation Of Bleeding Canine Gastric Ulcers  

NASA Astrophysics Data System (ADS)

This is the first report which describes carbon dioxide laser photocoagulation of upper gastrointestinal bleeding via a flexible endoscope, using an infrared transmitting siver nalide fiber. Various laser parameters were checked to determine the optimal conditions for hemostasis. Both the acute effects of laser irradiation on tissue and the chronic effects on healing process were examined. Preliminary results indicate that carbon dioxide laser beam can successfully photocoagulate moderately bleeding ulcers.

Gal, Dov; Ron, Nimrod; Orgad, Uri; Katzir, Abraham

1987-04-01

407

Testing a Regenerative Carbon Dioxide and Moisture Removal Technology  

Microsoft Academic Search

The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed

Daniel J. Barta; Amy Button; Jeffrey Sweterlitsch; Suzanne Curley

2010-01-01

408

Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE  

Microsoft Academic Search

All of the technical goals of the World Ocean Circulation Experiment (WOCE) field program which were supported under the Department of Energy research grant ''Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' (DE-FG03-90ER60981) have been met. This has included the measurement of the partial pressures of carbon dioxide (C0) and nitrous oxide (NO) in both the surface ocean

1998-01-01

409

Carbon dioxide in the ocean surface: The homogeneous buffer factor  

USGS Publications Warehouse

The amount of carbon dioxide that can be dissolved in surface seawater depends at least partially on the homogeneous buffer factor, which is a mathematical function of the chemical equilibrium conditions among the various dissolved inorganic species. Because these equilibria are well known, the homogeneous buffer factor is well known. Natural spatial variations depend very systematically on sea surface temperatures, and do not contribute significantly to uncertainties in the present or future carbon dioxide budget. Copyright ?? 1979 AAAS.

Sundquist, E. T.; Plummer, L. N.; Wigley, T. M. L.

1979-01-01

410

Seawater pH and Anthropogenic Carbon Dioxide  

E-print Network

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.

Gerald E. Marsh

2008-10-20

411

Suppressing bullfrog larvae with carbon dioxide  

USGS Publications Warehouse

Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert

2014-01-01

412

Carbon dioxide balneotherapy and cardiovascular disease  

NASA Astrophysics Data System (ADS)

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.

Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

2011-09-01

413

Synthetic fuels, carbon dioxide and climate  

NASA Astrophysics Data System (ADS)

The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2. Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels were used instead of petroleum. The use of synthetic fuels derivved from biomass would make no net addition to atmospheric CO2 provided no fossil fuels are used in biomass production and/or conversion. Assuming that synthetic liquid fuels would gradually replace petroleum and that they would supply all of the worldwide liquid fuel demand by the year 2060, we calculated that the atmospheric CO2 concentration would increase from the current 335 parts per million on a volume basis (ppmv) to 778 ppmv in 2060. However, even if the liquid fuel demand were met by petroleum alone, the CO2 level would be 715 ppmv in that year. Furthermore, we estimated that as a result of these increases in the CO2 level, the globally averaged earth's surface temperature in the year 2060 will have risen by 2.6 K with the use of synthetic liquids and 2.2 K without their use.

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

1982-05-01

414

Low-temperature data for carbon dioxide  

E-print Network

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 ...

Azreg-Anou, Mustapha

2014-01-01

415

Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction  

NASA Astrophysics Data System (ADS)

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.

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

416

Quantitative aspects of oxygen and carbon dioxide exchange through the lungs in Ocypode ceratophthalmus (Crustacea: Decapoda) during rest and exercise in water and air  

Microsoft Academic Search

Ghost crabs Ocypode ceratophthalmus were exercised in air and water to measure CO2 and O2 exchange rates using the method of instantaneous measurements of oxygen consumption rate (MO2) where applicable. Average heart rate increased from 100 to nearly 400 pulses per minute after five minutes of exercise on a treadmill at a run rate of 0.133 m s. It took

WJ van Aardt

2010-01-01

417

40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2013 CFR

...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

2013-07-01

418

40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2012 CFR

...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection...National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...

2012-07-01

419

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

Microsoft Academic Search

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

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

1999-01-01

420

Carbon Dioxide Reduction Technology Trade Study  

NASA Technical Reports Server (NTRS)

For long-term human missions, a closed-loop atmosphere revitalization system (ARS) is essential to minimize consumables. A carbon dioxide (CO2) reduction technology is used to reclaim oxygen (O2) from metabolic CO2 and is vital to reduce the delivery mass of metabolic O2. A key step in closing the loop for ARS will include a proper CO2 reduction subsystem that is reliable and with low equivalent system mass (ESM). Sabatier and Bosch CO2 reduction are two traditional CO2 reduction subsystems (CRS). Although a Sabatier CRS has been delivered to International Space Station (ISS) and is an important step toward closing the ISS ARS loop, it recovers only 50% of the available O2 in CO2. A Bosch CRS is able to reclaim all O2 in CO2. However, due to continuous carbon deposition on the catalyst surface, the penalties of replacing spent catalysts and reactors and crew time in a Bosch CRS are significant. Recently, technologies have been developed for recovering hydrogen (H2) from Sabatier-product methane (CH4). These include methane pyrolysis using a microwave plasma, catalytic thermal pyrolysis of CH4 and thermal pyrolysis of CH4. Further, development in Sabatier reactor designs based on microchannel and microlith technology could open up opportunities in reducing system mass and enhancing system control. Improvements in Bosch CRS conversion have also been reported. In addition, co-electrolysis of steam and CO2 is a new technology that integrates oxygen generation and CO2 reduction functions in a single system. A co-electrolysis unit followed by either a Sabatier or a carbon formation reactor based on Bosch chemistry could improve the overall competitiveness of an integrated O2 generation and CO2 reduction subsystem. This study evaluates all these CO2 reduction technologies, conducts water mass balances for required external supply of water for 1-, 5- and 10-yr missions, evaluates mass, volume, power, cooling and resupply requirements of various technologies. A system analysis and comparison among the technologies was made based on ESM, technology readiness level and reliability. Those technologies with potential were recommended for development.

Jeng, Frank F.; Anderson, Molly S.; Abney, Morgan B.

2011-01-01

421

14 April 2001 tmospheric carbon dioxide  

E-print Network

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

Teskey, Robert O.

422

Ionic Liquid Membranes for Carbon Dioxide Separation  

SciTech Connect

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

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

2008-07-12

423

Carbon dioxide exchange in a peatland ecosystem  

NASA Astrophysics Data System (ADS)

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

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

1995-07-01

424

Oxygen Atom Recombination in Carbon Dioxide Atmospheres  

NASA Astrophysics Data System (ADS)

Understanding processes involving atomic oxygen is crucial for the study and modeling of composition, energy transfer, airglow, and transport dynamics in planetary atmospheres. Significant gaps and uncertainties exist in our understanding of the above processes, and often the relevant input from laboratory measurements is missing or outdated. We are conducting experiments to measure the rate coefficients for O + O + CO2 and O + O2 + CO2 recombination and investigate the O2 excited states produced following O-atom recombination. These laboratory measurements are key input for a quantitative understanding and reliable modeling of the atmospheres of the CO2 planets and their airglow. An ArF excimer laser with 193-nm pulsed output radiation is employed to partially photodissociate carbon dioxide. In an ambient-pressure (760 Torr) background of CO2, the O atoms produced recombine in a time scale of a few milliseconds. Detection of laser-induced fluorescence at 845 nm following two-photon excitation near 226 nm monitors the decay of the oxygen atom population. From the temporal evolution of the signal we can extract the rate coefficients for recombination of O + O and O + O2 in the presence of CO2. We also use fluorescence and resonance-enhanced multi-photon ionization techniques to detect the products of the O-atom recombination and subsequent relaxation in CO2. This work is supported by the US National Science Foundation's (NSF) Planetary Astronomy Program. Rosanne Garcia's participation was funded by the NSF Research Experiences for Undergraduates (REU) Program.

Jamieson, Corey; Garcia, R. M.; Pejakovic, D. A.; Kalogerakis, K. S.

2009-09-01

425

Impact of cement renders on airborne ozone and carbon dioxide concentrations  

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

426

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

Microsoft Academic Search

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

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

2010-01-01

427

Development of Chinese Carbon Dioxide Satellite (TanSat)  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

428

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

E-print Network

Mar., 1955 GASIFICATIONOF CARBONRODSWITH CARBONDIOXIDE 241 GASIFICATION OF CARBON RODS WITH CARBON commercial carbons and their gasification rates with carbon dioxide at a series of temperatures between 900. No general correlation between these properties and the carbon gasification rates was found. Introduction

429

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

The supercritical state is currently viewed as uniform and homogeneous on the pressure-temperature phase diagram in terms of physical properties. Here, we study structural properties of the supercritical carbon dioxide, and discover the existence of persistent medium-range order correlations which make supercritical carbon dioxide non-uniform and heterogeneous on an intermediate length scale, a result not hitherto anticipated. We report on the carbon dioxide heterogeneity shell structure where, in the first shell, both carbon and oxygen atoms experience gas-like type inter- actions with short range order correlations, while within the second shell oxygen atoms essentially exhibit liquid-like type of interactions with medium range order correlations due to localisation of transverse-like phonon packets. We show that the local order heterogeneity remains in the three phase-like equilibrium within very wide temperature range. Importantly, we highlight a catalytic role of atoms inside the nearest neighbor heterogeneity shell in providing a mechanism for diffusion in the supercritical carbon dioxide on an intermediate length scale. Finally, we discuss important implications for answering the intriguing question whether Venus may have had carbon dioxide oceans and urge for an experimental detection of this persistent local order heterogeneity.

Dima Bolmatov; D. Zav'yalov; M. Gao; M. Zhernenkov

2014-06-06

430

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

SciTech Connect

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.

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

1980-04-01

431

A role for nickel-iron cofactors in biological carbon monoxide and carbon dioxide utilization  

E-print Network

NiFe containing enzymes are involved in the biological utilization of carbon monoxide, carbon dioxide, and hydrogen. Interest in these enzymes has increased in recent years due to hydrogen fuel initiatives and concerns ...

Kung, Yan

432

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

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

David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P.Gupta; William J. McMichael; Ya Liang; Douglas P. Harrison

2002-10-01

433

Enhanced carbon dioxide uptake by the world's oceans  

Microsoft Academic Search

The growth of phytoplankton over much of the ocean is limited by the availability of nitrogen in the upper sunlit region of the ocean. It is through photosynthesis that upper ocean carbon is exported to the deep ocean and replaced with carbon dioxide fluxed by physical processes from the atmosphere. The addition of nitrogen to the ocean surface waters has

Ian S. F. Jones

1996-01-01

434

Mechanisms of Neutralization of Bauxite Residue by Carbon Dioxide  

Microsoft Academic Search

Bauxite residue red mud, an alkaline slurry from alumina refining, is produced in large volumes and disposed of in large surface impoundments. The objectives of this study were to measure the extent of neutralization of bauxite residue by carbon dioxide as a function of CO2 partial pressure and to determine the geochemical reactions responsible for carbon sequestration. Bauxite residue was

Sameer Khaitan; David A. Dzombak

2009-01-01

435

II. Greenhouse gas markets, carbon dioxide credits and biofuels17  

E-print Network

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

436

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

SciTech Connect

The quantities of carbon stored in the form of atmospheric carbon dioxide, CO{sub 2} in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates and polycarbonates. However, the situation is expected to change in the future, if effective catalytic systems allowing to activate carbon dioxide will become available. In this connection, the electrochemical reduction of CO{sub 2}, requiring only an additional input of water and electrical energy, appears as an attractive possibility. For more than 100 years formic acid and formates of alkali metals were considered as the only significant products of the electroreduction of carbon dioxide in aqueous solutions. The highest current efficiencies, exceeding 90 %, were obtained either with mercury or with amalgam electrodes. The only comprehensive study regarding kinetics of CO{sub 2} reduction in aqueous solution has been performed by Eyring et al. using a mercury cathode. This paper describes electrolysis studies.

Augustynski, J.; Jermann, B.; Kedzierzawski, P. [Univ. of Geneva (Switzerland)

1996-12-31

437

Assessing carbon dioxide emissions from energy use at a university  

Microsoft Academic Search

Purpose The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design\\/methodology\\/approach First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated with consumption of a single unit was

William Riddell; Krishan Kumar Bhatia; Matthew Parisi; Jessica Foote; John Imperatore III

2009-01-01

438

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, or ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate

David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

2002-01-01

439

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

The objective of this project is to develop a simple, inexpensive process to separate CO as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is

David A. Green; Brian S. Turk; Raghubir P. Gupta; Douglas P. Harrison; Ya Liang

2001-01-01

440

Capturing carbon dioxide as a polymer from natural gas  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

441

Distribution of and changes in industrial carbon dioxide production  

Microsoft Academic Search

The burning of fossils fuels is believed to be the major source responsible for an observed increase in the concentration of carbon dioxide in the atmosphere now measured at many locations around the world. This paper revises earlier published data on the annual amounts of carbon released to the atmosphere during the period 1950--1978 and updates the record through 1980.

Ralph M. Rotty

1983-01-01

442

Regeneration of oxygen from carbon dioxide and water.  

NASA Technical Reports Server (NTRS)

In a closed ecological system it is necessary to reclaim most of the oxygen required for breathing from respired carbon dioxide and the remainder from waste water. One of the advanced physicochemical systems being developed for generating oxygen in manned spacecraft is the solid electrolyte-electrolysis system. The solid electrolyte system consists of two basic units, an electrolyzer and a carbon monoxide disproportionator. The electrolyzer can reclaim oxygen from both carbon dioxide and water. Electrolyzer preparation and assembly are discussed together with questions of reactor design and electrolyzer performance data.

Weissbart, J.; Smart, W. H.; Wydeven, T.

1972-01-01

443

Persistent local order heterogeneity in the supercritical carbon dioxide  

E-print Network

The supercritical state is currently viewed as uniform and homogeneous on the pressure-temperature phase diagram in terms of physical properties. Here, we study structural properties of the supercritical carbon dioxide, and discover the existence of persistent medium-range order correlations which make supercritical carbon dioxide non-uniform and heterogeneous on an intermediate length scale, a result not hitherto anticipated. We report on the carbon dioxide heterogeneity shell structure where, in the first shell, both carbon and oxygen atoms experience gas-like type inter- actions with short range order correlations, while within the second shell oxygen atoms essentially exhibit liquid-like type of interactions with medium range order correlations due to localisation of transverse-like phonon packets. We show that the local order heterogeneity remains in the three phase-like equilibrium within very wide temperature range. Importantly, we highlight a catalytic role of atoms inside the nearest neighbor heterog...

Bolmatov, Dima; Gao, M; Zhernenkov, M

2014-01-01

444

Carbon dioxide effects on crop energy balance: Testing ecosys with a free-air CO{sub 2} enrichment (FACE) experiment  

SciTech Connect

Elevated CO{sub 2} concentrations (C{sub e}) have been observed to decrease short-term plant water use under controlled conditions by increasing stomatal resistance. The extent to which this decrease occurs over a growing season in the field is uncertain, however, because stomatal resistance is only one of many mechanisms that control water use. In this study, we tested the ecosystem simulation model ecosys, which reproduces an hourly energy balance through soil-vegetation systems under defined atmospheric boundary conditions, using energy exchange data measured as part of the Free-Air CO{sub 2} Enrichment (FACE) experiment at C{sub e}=550 vs. 370 {mu}mol mol{sup -1}. The model reproduced reductions in measured upward latent heat fluxes that varied from -10 to +40 W m{sup -2}, depending on atmospheric conditions. In the model, the primary effect of elevated C{sub e} on latent heat fluxes was through canopy stomatal conductance. This effect was largely offset by secondary effects through canopy temperature that enabled the model to reproduce measured changes in sensible heat fluxes. The total effect simulated by ecosys of C{sub e}=550 vs. 370 {mu}mol mol{sup -1} on evapotranspiration during the entire FACE experiment was a reduction of 7%. This reduction compares with one of 11% estimated from accumulated daily measurements of latent heat flux. In the model, the different effects of C{sub e} on plant water use depend on atmosphere and soil boundary conditions, and are highly dynamic. Consequently the simulated C{sub e}-water use relationship is likely to be site-specific. The use of models such as ecosys allows site-specific boundary conditions to be considered in the study of C{sub e} effects on plant growth and water use. 51 refs., 7 figs., 2 tabs.

Grant, R.F. [Univ. of Alberta, Edmonton (Canada); Kimball, B.A.; Pinter, P.J. [Water Conservation Lab., Phoenix, AZ (United States)

1995-05-01

445

Coupling automated radon and carbon dioxide measurements in coastal waters.  

PubMed

Groundwater discharge could be a major, but as yet poorly constrained, source of carbon dioxide to lakes, wetlands, rivers, estuaries, and coastal waters. We demonstrate how coupled radon ((222)Rn, a natural groundwater tracer) and pCO(2) measurements in water can be easily performed using commercially available gas analysers. Portable, automated radon and pCO(2) gas analysers were connected in series and a closed air loop was established with gas equilibration devices (GED). We experimentally assessed the advantages and disadvantages of six GED. Response times shorter than 30 min for (222)Rn and 5 min for pCO(2) were achieved. Field trials revealed significant positive correlations between (222)Rn and pCO(2) in estuarine waterways and in a mangrove tidal creek, implying that submarine groundwater discharge was a source of CO(2) to surface water. The described system can provide high resolution, high precision concentrations of both radon and pCO(2) with nearly no additional effort compared to measuring only one of these gases. Coupling automated (222)Rn and pCO(2) measurements can provide new insights into how groundwater seepage contributes to aquatic carbon budgets. PMID:22694256

Santos, Isaac R; Maher, Damien T; Eyre, Bradley D

2012-07-17

446

Membrane processes for gas separations: Part I. Removal of carbon dioxide and hydrogen sulfide from low-quality natural gas. Part II. Enrichment of krypton in air  

NASA Astrophysics Data System (ADS)

I. The objective of this study was to determine the process design characteristics and economics of membrane separation processes for reducing the concentrations of H2S and CO2 in low-quality natural gas containing substantial amounts of the two acid gases to pipeline specifications ( ? 2 mole-% CO2 and ? 4 ppm H2S). The new processes considered the simultaneous use of two different types of polymer membranes for the above application, namely, one with higher CO2/CH4 selectivity and the other with higher H2S/CH4 selectivity. The performance and economics of membrane process configurations comprising one, two, and three permeation stages, with and without recycle streams, were examined and optimized via extensive computer simulations. Most computations assumed as a "base-case", the processing of a medium-size natural gas stream of 35 MMSCFD at 800 psia. The natural gas was taken to contain ? 10 mole-% H2S and ? 40 mole-% CO2. The most economical process configuration was two permeation stages in series, with H2S-selective membranes in the first stage and CO2-selective membranes in the second stage. The most economical process configurations for upgrading natural gas containing either only substantial amounts of H2S or of CO2 were also determined. The sensitivity of the process economics to feed flow rate, feed pressure, membrane module cost, and wellhead cost of natural gas was studied. A comparison of the processing cost of membrane processes with that of conventional gas absorption processes utilizing diethanolamine as solvent was also investigated. II. A membrane process for enrichment of Kr in air was studied experimentally as a technique of improving the accuracy of Kr analysis. "Asymmetric" silicone rubber membranes were found to be most suitable for this application. The study was investigated with a feed gas mixture containing 0.99 mole-% Kr, 20.70 mole-% O2, and 78.30 mole-% N2. The Kr concentration could be increased from 0.99 to 2.23 mole-% in a single membrane stage and further raised to 3.73 mole-% in two stages in cascade. Computer simulations of "cross-flow" model yielded results in general agreement with experimental data.

Hao, Jibin

447

Carbon dioxide, the feedstock for using renewable energy  

NASA Astrophysics Data System (ADS)

Extrapolation of world energy consumption between 1990 and 2007 to the future reveals the complete exhaustion of petroleum, natural gas, uranium and coal reserves on Earth in 2040, 2044, 2049 and 2054, respectively. We are proposing global carbon dioxide recycling to use renewable energy so that all people in the whole world can survive. The electricity will be generated by solar cell in deserts and used to produce hydrogen by seawater electrolysis at t nearby desert coasts. Hydrogen, for which no infrastructures of transportation and combustion exist, will be converted to methane at desert coasts by the reaction with carbon dioxide captured by energy consumers. Among systems in global carbon dioxide recycling, seawater electrolysis and carbon dioxide methanation have not been performed industrially. We created energy-saving cathodes for hydrogen production and anodes for oxygen evolution without chlorine formation in seawater electrolysis, and ideal catalysts for methane formation by the reaction of carbon dioxide with hydrogen. Prototype plant and industrial scale pilot plant have been built.

Hashimoto, K.; Kumagai, N.; Izumiya, K.; Kato, Z.

2011-03-01

448

Carbon dioxide as a carbon source in organic transformation: carbon-carbon bond forming reactions by transition-metal catalysts.  

PubMed

Recent carbon-carbon bond forming reactions of carbon dioxide with alkenes, alkynes, dienes, aryl zinc compounds, aryl boronic esters, aryl halides, and arenes having acidic C-H bonds are reviewed in which transition-metal catalysts play an important role. PMID:22859266

Tsuji, Yasushi; Fujihara, Tetsuaki

2012-10-14

449

Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes  

USGS Publications Warehouse

Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.

Gerlach, Terrence

1990-01-01

450

A regional and global analysis of carbon dioxide physiological forcing and its impact on climate  

NASA Astrophysics Data System (ADS)

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.

Andrews, Timothy; Doutriaux-Boucher, Marie; Boucher, Olivier; Forster, Piers M.

2011-02-01

451

Water and Carbon Dioxide Adsorption at Olivine Surfaces  

SciTech Connect

Plane-wave density functional theory (DFT) calculations were performed to simulate water and carbon dioxide adsorption at the (010) surface of five olivine minerals, namely, forsterite (Mg2SiO4), calcio-olivine (Ca2SiO4), tephroite (Mn2SiO4), fayalite (Fe2SiO4), and Co-olivine (Co2SiO4). Adsorption energies per water molecule obtained from energy minimizations varied from -78 kJ mol-1 for fayalite to -128 kJ mol-1 for calcio-olivine at sub-monolayer coverage and became less exothermic as coverage increased. In contrast, carbon dioxide adsorption energies at sub-monolayer coverage ranged from -20 kJ mol-1 for fayalite to -59 kJ mol-1 for calcio-olivine. Therefore, the DFT calculations show a strong driving force for carbon dioxide displacement by water at the surface of all olivine minerals in a competitive adsorption scenario. Additionally, adsorption energies for both water and carbon dioxide were found to be more exothermic for the alkaline-earth (AE) olivines than for the transition-metal (TM) olivines and to not correlate with the solvation enthalpies of the corresponding divalent cations. However, a correlation was obtained with the charge of the surface divalent cation indicating that the more ionic character of the AE cations in the olivine structure relative to the TM cations leads to greater interactions with adsorbed water and carbon dioxide molecules at the surface and thus more exothermic adsorption energies for the AE olivines. For calcio-olivine, which exhibits the highest divalent cation charge of the five olivines, ab initio molecular dynamics simulations showed that this effect leads both water and carbon dioxide to react with the surface and form hydroxyl groups and a carbonate-like species, respectively.

Kerisit, Sebastien N.; Bylaska, Eric J.; Felmy, Andrew R.

2013-11-14

452

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates, through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests conducted at LSU indicated that exposure of sorbent to water vapor prior to contact with carbonation gas does not significantly increase the reaction rate. Calcined fine mesh trona has a greater initial carbonation rate than calcined sodium bicarbonate, but appears to be more susceptible to loss of reactivity under severe calcination conditions. The Davison attrition indices for Grade 5 sodium bicarbonate, commercial grade sodium carbonate and extra fine granular potassium carbonate were, as tested, outside of the range suitable for entrained bed reactor testing. Fluidized bed testing at RTI indicated that in the initial stages of reaction potassium carbonate removed 35% of the carbon dioxide in simulated flue gas, and is reactive at higher temperatures than sodium carbonate. Removals declined to 6% when 54% of the capacity of the sorbent was exhausted. Carbonation data from electrobalance testing was correlated using a shrinking core reaction model. The activation energy of the reaction of sodium carbonate with carbon dioxide and water vapor was determined from nonisothermal thermogravimetry.

David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

2002-04-01

453

Master/Diploma project Degradation of carbon dioxide by micro organisms  

E-print Network

or storage of produced carbon dioxide. Unfortunately, applications based on fossil fuels cannot be improved for carbon dioxide neutral fuel, their efficiency for the above described industrial applications is to lowMaster/Diploma project Degradation of carbon dioxide by micro organisms The accumulation of carbon

Rostock, Universität

454

Carbon Dioxide Measurement and Tracking We are combining our expertise in remote sensing, measurement,  

E-print Network

Carbon Dioxide Measurement and Tracking We are combining our expertise in remote sensing, measurement, experimentation, and modeling to track and quantify CO2. 7 08 FACT SHEET Carbon Dioxide." Among the proposed solutions are carbon sequestration (storing carbon dioxide emissions in geologic

455

OPERATIONAL NOTE A SIMPLIFIED TRIPOD SUPPORT FOR USE WITH CARBON DIOXIDE  

E-print Network

OPERATIONAL NOTE A SIMPLIFIED TRIPOD SUPPORT FOR USE WITH CARBON DIOXIDE­ BAITED VECTOR surveillance trap support was designed as a tripod of polyvinyl chloride pipes to suspend carbon dioxide, vector surveillance, hanging traps, carbon dioxide, mosquito trap Carbon dioxide (CO2) emission is common

456

of carbon dioxide containing 12 but the low concentration of 14  

E-print Network

of carbon dioxide containing 12 C and 13 C, but the low concentration of 14 C has made its measurement in carbon dioxide extremely difficult. Using an ultrasensitive technique called saturated carbon at values well below radiocarbon's natural abundance in carbon dioxide. In their technique

Zare, Richard N.

457

Supercritical fluid carbon dioxide cleaning of plutonium parts  

SciTech Connect

Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.

Hale, S.J.

1991-12-31

458

Heavy oil recovery process using cyclic carbon dioxide steam stimulation  

SciTech Connect

This patent describes a method of recovering oil from a subterranean formation containing viscous quality oil that is penetrated by at least one well in fluid communication with a substantial portion of the formation. The method consists of two principal component operations. The first operation is characterized in the patent in detail and consists of injecting a mixture of carbon dioxide and steam into the formation through the well. The ratio of carbon dioxide to steam in this infused mixture must be from 200-300 SCF carbon dioxide per barrel of steam (cold water equivalent) to produce the desired effect. The last operation described in the detailing of the method of recovery is the recovering of fluids, including oil, from the formation through the well.

Pebdani, F.N.; Shu, W.R.

1986-01-21

459

Fate of Fossil Fuel Carbon Dioxide and the Global Carbon Budget  

Microsoft Academic Search

The fate of fossil fuel carbon dioxide released into the atmosphere depends on the exchange rates of carbon between the atmosphere and three major carbon reservoirs, namely, the oceans, shallow-water sediments, and the terrestrial biosphere. Various assumptions and models used to estimate the global carbon budget for the last 20 years are reviewed and evaluated. Several versions of recent atmosphere-ocean

W. S. Broecker; T. Takahashi; H. J. Simpson; T.-H. Peng

1979-01-01

460

Regulation of Carbonic Anhydrase Expression by Zinc, Cobalt, and Carbon Dioxide in the Marine Diatom  

E-print Network

Regulation of Carbonic Anhydrase Expression by Zinc, Cobalt, and Carbon Dioxide in the Marine of carbonic anhydrase (CA) in the marine diatom Thalassiosira weissflogii. We have examined the roles for Zn in a CA. Our data also support the conclusion that TWCA1 plays a central role in carbon

Morel, François M. M.

461

Fate of fossil fuel carbon dioxide and the global carbon budget  

Microsoft Academic Search

The fate of fossil fuel carbon dioxide released into the atmosphere depends on the exchange rates of carbon between the atmosphere and three major carbon reservoirs, namely, the oceans, shallow-water sediments, and the terrestrial biosphere. Various assumptions and models used to estimate the global carbon budget for the last 20 years are reviewed and evaluated. Several versions of recent atmosphere-ocean

W. S. Broecker; T. Takahashi; H. J. Simpson; T.-H. Peng

1979-01-01

462

The travel-related carbon dioxide emissions of atmospheric researchers  

NASA Astrophysics Data System (ADS)

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.

Stohl, A.

2008-04-01

463

Reconciling glacial cycle atmospheric radiocarbon and carbon dioxide signatures  

NASA Astrophysics Data System (ADS)

The mechanisms causing the glacial-interglacial range of ~90ppmv are still not fully understood. The deep Pacific is a potential isolated storage reservoir of respired carbon related to reduced ocean ventilation at this time. During the initial deglaciation (18-14kyr BP), atmospheric carbon dioxide concentrations increased by ~40ppmv. Corresponding records of atmospheric radiocarbon concentration display a massive decrease of 190, which also suggest the sudden release of a large store of carbon that has been isolated from the atmosphere for a significant period of time. In this study we have used an Earth system model of intermediate complexity, GENIE (Grid ENabled Integrated Earth) to investigate the influence of plausible physical changes in ocean circulation on deep Pacific storage of carbon, and the impact on atmospheric carbon dioxide and distribution of carbon isotopes. We perform transient simulations of the last glacial cycle (120kyr) to examine the sensitivity of Pacific carbon storage to prescribed ocean circulations and sea-ice cover, including freshwater hosing to simulate Heinrich events. In particular we present modelled changes in carbon dioxide and radiocarbon, which produce deglacial changes consistent with available palaeo-records in terms of time scale and magnitude.

Felton, Michelle; Singarayer, Joy

2010-05-01

464

Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons  

NASA Astrophysics Data System (ADS)

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 helium balloons. An investigation into the details of this phenomenon provides students with an excellent opportunity to apply the kinetic theory of gases and the ideal gas law, and it can also be exploited for a dramatic in-class demonstration of diffusion and the second law of thermodynamics.

Jadrich, James; Bruxvoort, Crystal

2010-09-01

465

Carbon dioxidenitrogen separation through adsorption on activated carbon in a fixed bed  

Microsoft Academic Search

The reduction of carbon dioxide emissions from flue gases can be achieved using post-combustion capture technologies such as adsorption. In this paper, we report experimental data for the fixed-bed adsorption of carbon dioxide and nitrogen on activated carbon. The breakthrough curves were obtained at different temperatures 301306, 323, 373 and 423K using CO2\\/N2 mixtures. XPS and FTIR measurements

Tirzh L. P. Dantas; Francisco Murilo T. Luna; Ivanildo J. Silva Jr.; Diana C. S. de Azevedo; Carlos A. Grande; Alrio E. Rodrigues; Regina F. P. M. Moreira

2011-01-01

466

Effects of Carbon Dioxide Inhalation on Psychomotor and Mental Performance During Exercise and Recovery  

Microsoft Academic Search

On separate days, 6 highly trained participants performed psychomotor tests while breathing for 60 min 3 carbon dioxide (CO2) mixtures (room air, 3% CO2, or 4% CO2) prior to, between, and following two 15- min treadmill exercise bouts (70% VO2max). Each individual was extensively practiced (at least 4 days) before testing began, and both gas conditions and order of tasks

Max Vercruyssen; Eliazor Kamon; Peter A. Hancock

467

Effects of elevated growth temperature and carbon dioxide levels on some physicochemical properties of wheat starch  

Microsoft Academic Search

Crops of winter wheat (cv. Hereward) were grown in the field under double-skinned polyethylene tunnels in two consecutive seasons (199192 and 199293). Air containing ambient (350 ppm) or elevated (700 ppm) concentrations of carbon dioxide was circulated through the tunnels, and temperature gradients, typically from 1C below ambient to 47C above ambient, were maintained within each tunnel. Despite a shorter

R. F. Tester; W. R. Morrison; R. H. Ellis; J. R. Piggo; G. R. Batts; T. R. Wheeler; J. I. L. Morison; P. Hadley; D. A. Ledward

1995-01-01

468

Carbon dioxide build-up within a suburban canopy layer in winter night  

Microsoft Academic Search

This study concerns the build-up of carbon dioxide, hereafter CO2, within a suburban canopy under nocturnal stably stratified conditions. The results were derived from wintertime field measurements of the vertical profiles of CO2, air temperature and turbulent exchange processes, in a residential area with a mean canopy height of 7.3m in Tokyo, Japan. In the daytime, especially under very windy

Ryo Moriwaki; Manabu Kanda; Harumi Nitta

2006-01-01

469

Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water  

NASA Astrophysics Data System (ADS)

Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis of CO2 and H2O to produce syngas (CO/H2 mixture) is identified as a promising method. High temperature electrolysis makes very efficient use of electricity and heat (near-100% electricity-to-syngas efficiency), provides high reaction rates, and the syngas produced can be catalytically converted to hydrocarbons in well-known fuel synthesis reactors (e.g. Fischer-Tropsch). The experimental studies of high temperature electrolysis are made at different scales -- at the cell level, electrode level, and in materials and microstructure development. The results include cell performance and durability, insight into electrode reaction mechanisms, and new high-performance electrode materials. The experimental studies make extensive use of electrochemical impedance spectroscopy and systematic variation of test conditions to examine the electrochemical phenomena. Variation of the material composition itself within families of related materials was an additional parameter used in the electrode level and materials studies that revealed more information than studying a single material would have. Using full cells, the performance and durability of a solid oxide cell applied for co-electrolysis of CO2 and H2O was investigated. High initial performance was observed but the long-term durability needs to be improved. Based on these results, an analysis of the energy balance and economics of an electrolysis-based synthetic fuel production process, including CO2 air capture and Fischer-Tropsch fuel synthesis, determined that the system can feasibly operate at 70% electricity-to-liquid fuel efficiency (higher heating value basis) and that the price of electricity needed to produce competitive synthetic gasoline (at USD2/gal, or 0.53/L, wholesale) is 2-3 U.S. cents per kWh. For 3/gal (0.78/L) gasoline, 4-5 cents per kWh is needed. Fuel production may already be economical in some regions that have inexpensive renewable electricity, such as Iceland. The dominant costs of the process are the electricity cost and the capital cost of the electrolyzer, and this capital cost is si

Graves, Christopher Ronald

470

Classroom Demonstration: Combustion of Diamond to Carbon Dioxide Followed by Reduction to Graphite  

ERIC Educational Resources Information Center

An educational demonstration shows the combustion of carbon to carbon dioxide and then the reduction of carbon dioxide to carbon. A melee diamond is the source of the carbon and the reaction is carried out in a closed flask. The demonstration helps students to realize that diamonds are made of carbon and that atoms do not change or vanish in

Miyauchi, Takuya; Kamata, Masahiro

2012-01-01

471

Electrochemical cell for obtaining oxygen from carbon dioxide atmospheres  

NASA Technical Reports Server (NTRS)

For manned missions to Mars to become a reality, an efficient and reliable means of obtaining oxygen from the carbon dioxide-rich atmosphere will be required. Otherwise, the high cost of transporting the oxygen needed to sustain the astronauts will severely restrict the expedition to the martian surface. Recently, the use of electrochemical devices has been explored as a means of obtaining oxygen from the carbon dioxide-rich atmosphere. In these devices, oxygen ions diffuse through solid oxide membranes, thus, separating oxygen from the other gases presented. This phenomenon has only recently been explored as a means of obtaining large quantities of oxygen from toxic atmospheres, although first observed by Walter nernst in 1899. Nernst observed that stabilized zirconia will conduct oxygen ions when an electrical potential is applied across metallic electrodes applied to the ceramic membrane. Diatomic oxygen molecules are dissociated at the positive electrode/electrolyte interface. The oxygen ions enter the ceramic body due to the ion density gradient which is produced by the electrical potential across the electrolytic membrane. Once the ions have diffused through the membrane, they reform diatomic oxygen molecules at the anode. The separation of oxygen from carbon dioxide is achieved by the combination of thermal and electrochemical processes. The thermal decomposition of carbon dioxide (at 1000 C) results in the production of carbon monoxide and oxygen by the reaction.

Hooker, M. W.; Rast, H. E.; Rogers, D. K.

1989-01-01

472

Evaluation of a transportable capnometer for monitoring end-tidal carbon dioxide.  

PubMed

We compared a small and transportable Capnometer (EMMA) with a reference capnometer, the Siesta i TS Anaesthesia. During air-breathing through a facemask, both the EMMA (nine modules) and reference capnometer sampled expired gas simultaneously. A wide range of end-tidal carbon dioxide values were obtained during inhalation of carbon dioxide and voluntary hyperventilation. The median IQR [range] difference between all sets of carbon dioxide values (EMMA - reference) was -0.3 (-0.6 to 0.0 [-1.7 to 1.6] kPa; n = 297) using new batteries, which was statistically significant (p = 0.04) and located to two of the nine EMMAs tested. Using batteries with reduced voltage did not influence the measurements. The 95% CI of the medians of the differences were -0.4 to -0.2. We conclude that the EMMA can slightly under-read the end-tidal carbon dioxide but is generally comparable with a free-standing monitor. The precision of the EMMAs was similar whether new batteries or batteries with reduced voltage were used. PMID:21198468

Hildebrandt, T; Espelund, M; Olsen, K S

2010-10-01

473

21 CFR 201.161 - Carbon dioxide and certain other gases.  

Code of Federal Regulations, 2010 CFR

...Other Exemptions 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are exempted from the requirements of 201.100(b) (2), (3),...

2010-04-01

474

Continual production of glycerol from carbon dioxide by Dunaliella tertiolecta.  

PubMed

Microalgae have high photosynthetic efficiencies and produce many valuable compounds from carbon dioxide. The Dunaliella genus accumulates glycerol, yet no commercial process currently exists for glycerol production from this microalga. Here it was found that in addition to intracellular accumulation, Dunaliella tertiolecta also releases glycerol into the external medium continuously, forming a large and stable carbon pool. The process is not affected by nutrient starvation or onset of cell death. Carbon dioxide was fixed at a constant rate, the bulk of it being channelled to extracellular glycerol (82%), resulting in enhanced photosynthetic carbon assimilation of 5 times that used for biomass production. The final extracellular glycerol concentration was 34 times the maximum concentration of intracellular glycerol; the latter declined further during cell death. Findings from this work will assist in the development of a bioconversion process to produce glycerol using D. tertiolecta without the need for cell harvest or disruption. PMID:23567730

Chow, Yvonne Y S; Goh, Serena J M; Su, Ziheng; Ng, Daphne H P; Lim, Chan Yuen; Lim, Natalie Y N; Lin, Huixin; Fang, Lei; Lee, Yuan Kun

2013-05-01

475

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

Electrobalance studies of calcination and carbonation of sodium bicarbonate materials