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Last update: August 15, 2014.
1

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

2

The use of physical carbon dioxide absorbents to control pressure buildup and volume expansion of kimchi packages  

Microsoft Academic Search

CO2 absorption by zeolite and active carbon was investigated as a tool to alleviate the pressure buildup and volume expansion that results from carbon dioxide production in kimchi packages. Zeolite was more effective than active carbon in terms of CO2 absorption capacity, and could also maintain CO2 adsorption equilibrium as long as it was protected from water vapour. A plastic

Dong Sun Lee; Dong Hyuk Shin; Dong Uk Lee; Jae Cherl Kim; Hong Sik Cheigh

2001-01-01

3

Carbon dioxide adsorbent study  

NASA Technical Reports Server (NTRS)

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

Onischak, M.; Baker, B. S.

1973-01-01

4

Carbon dioxide concentrator  

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

5

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

6

Temperature VS Carbon Dioxide  

NSDL National Science Digital Library

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

7

Capturing Carbon Dioxide  

NSDL National Science Digital Library

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

Saltz, Austen

2010-01-01

8

Carbon Dioxide Emission Estimates  

NSDL National Science Digital Library

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

9

Carbon Dioxide Fountain  

ERIC Educational Resources Information Center

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

Kang, Seong-Joo; Ryu, Eun-Hee

2007-01-01

10

Carbon Dioxide and Climate.  

ERIC Educational Resources Information Center

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

Brewer, Peter G.

1978-01-01

11

Carbon Dioxide Monitoring.  

National Technical Information Service (NTIS)

The collection of luminescent microorganisms are maintained under cultivation to provide suitable biosensors for the testing program for carbon dioxide. The basic bioluminescent agar medium is currently being used for growth of the cultures. Tests of lumi...

P. S. Biernacki J. J. Kalvinskas

1973-01-01

12

Carbon dioxide (reduction).  

National Technical Information Service (NTIS)

The twin problems of global warming, caused by an increase in atmospheric carbon dioxide (CO2) concentrations, and limited fossil fuel resources have stimulated research in the utilization of CO2. These problems would be partially alleviated by the develo...

A. Fujita

2000-01-01

13

Carbon dioxide sensor  

DOEpatents

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

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

2011-11-15

14

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

15

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

16

Carbon Dioxide Exercise  

NSDL National Science Digital Library

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

Richardson, Randy; Collection, Serc -.

17

Aspects of carbon dioxide utilization  

Microsoft Academic Search

Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carboncarbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially,

Iwao Omae

2006-01-01

18

Carbon dioxide fixation.  

National Technical Information Service (NTIS)

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) conv...

E. Fujita

2000-01-01

19

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

20

Carbon Dioxide Increases  

NSDL National Science Digital Library

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

21

Efficacy and Safety of 10,600-nm Carbon Dioxide Fractional Laser on Facial Skin with Previous Volume Injections  

PubMed Central

Background: Fractionated carbon dioxide (CO2) lasers are a new treatment modality for skin resurfacing. The cosmetic rejuvenation market abounds with various injectable devices (poly-L-lactic acid, polymethyl-methacrylate, collagens, hyaluronic acids, silicone). The objective of this study is to examine the efficacy and safety of 10,600-nm CO2 fractional laser on facial skin with previous volume injections. Materials and Methods: This is a retrospective study including 14 patients treated with fractional CO2 laser and who have had previous facial volume restoration. The indication for the laser therapy, the age of the patients, previous facial volume restoration, and side effects were all recorded from their medical files. Objective assessments were made through clinical physician global assessment records and improvement scores records. Patients satisfaction rates were also recorded. Results: Review of medical records of the 14 patients show that five patients had polylactic acid injection prior to the laser session. Eight patients had hyaluronic acid injection prior to the laser session. Two patients had fat injection, two had silicone injection and one patient had facial thread lift. Side effects included pain during the laser treatment, post-treatment scaling, post-treatment erythema, hyperpigmentation which spontaneously resolved within a month. Concerning the previous facial volume restoration, no granulomatous reactions were noted, no facial shape deformation and no asymmetry were encountered whatever the facial volume product was. Conclusion: CO2 fractional laser treatments do not seem to affect facial skin which had previous facial volume restoration with polylactic acid for more than 6 years, hyaluronic acid for more than 0.5 year, silicone for more than 6 years, or fat for more than 1.4 year. Prospective larger studies focusing on many other variables (skin phototype, injected device type) are required to achieve better conclusions.

Helou, Josiane; Maatouk, Ismael; Moutran, Roy; Obeid, Grace; Stephan, Farid

2013-01-01

22

Carbon dioxide dangers demonstration model  

USGS Publications Warehouse

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

Venezky, Dina; Wessells, Stephen

2010-01-01

23

Electrochemically regenerable carbon dioxide absorber  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

24

CARBON DIOXIDE AS A FEEDSTOCK.  

SciTech Connect

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

CREUTZ,C.; FUJITA,E.

2000-12-09

25

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

26

Carbon dioxide dynamics in Kelud volcanic lake  

NASA Astrophysics Data System (ADS)

In November 2007, the extrusion of a new lava dome evaporated Kelud volcanic lake in Java, Indonesia. Four months before a detailed echo sounding survey of the volcanic lake coupled to floating accumulation chamber measurements detected abnormally high carbon dioxide emissions. It constituted the earliest sign of the volcanic unrest; well before any other monitored parameter. CO2 flux is quantified using an empirical equation based on the volume of bubbles backscattered in the water column. Its comparison with the fluxes retrieved from the floating chamber method better constrain carbon dioxide dynamics in the volcanic lake. It reveals that 70% of the carbon dioxide enters the lake in a dissolved form, while the remaining 30% is supplied to the lake on a gaseous state. Almost three-quarter of the ascending bubbles dissolve in the water column leaving the majority of the 330 Tons day-1 of carbon dioxide diffusing at the air-water interface.

Caudron, C.; Mazot, A.; Bernard, A.

2012-05-01

27

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

28

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

29

Carbon dioxide and climate  

SciTech Connect

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

Not Available

1990-10-01

30

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

31

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

32

Method for Extracting and Sequestering Carbon Dioxide  

DOEpatents

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

Rau, Gregory H.; Caldeira, Kenneth G.

2005-05-10

33

Absorption of Carbon Dioxide on Carbonic Anhydrase Containing Substrates.  

National Technical Information Service (NTIS)

Carbonic anhydrase (CA), an enzyme catalyzing carbon dioxide hydration, was evaluated for its enhancement of carbon dioxide removal when it is present in granular materials with high water content during exposure to carbon dioxide in an aerating stream. A...

J. P. Allen

1968-01-01

34

Sampling Carbon Dioxide  

NSDL National Science Digital Library

In this lab activity, student teams hypothesize which source has a greater becomes CO² concentration: their breath, auto exhaust, or air in the classroom. They test gas samples from each of these sources, plot data, and hypothesize about the respective role engine exhaust and animal respiration play in contemporary climate change. The lab procedures require Bromthymol Blue indicator solution (BTB), household ammonia, vinegar, and balloons. Links to videos supporting the investigations are provided. This activity is supported by a textbook chapter, "How is Carbon Dioxide Measured?," part of the unit, Climate Change, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

35

Carbon dioxide: atmospheric overload  

SciTech Connect

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

Not Available

1980-04-01

36

Solubility and partial molar volume of carbon dioxide and ethane in crosslinked poly(ethylene oxide) copolymer  

Microsoft Academic Search

Experimental solubility and sorptive dilation data are reported for carbon dioxide and ethane in a crosslinked poly(ethylene oxide) (XLPEO) rubbery copolymer. Five differ- ent temperatures (253 ? T (K) ? 308) were considered, with a maximum gas pressure of 2.09 MPa (20.6 atm). The polymer was prepared by photopolymerization of a solution containing 70 wt % poly(ethylene glycol) methyl ether

Cludio P. Ribeiro; Benny D. Freeman

2010-01-01

37

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

38

NASA Satellite Sees Carbon Dioxide  

NSDL National Science Digital Library

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

39

Tunable pulsed carbon dioxide laser  

NASA Technical Reports Server (NTRS)

Transverse electrically-excited-atmosphere (TEA) laser is continuously tunable over several hundred megahertz about centers of spectral lines of carbon dioxide. It is operated in single longitudinal mode (SLM) by injection of beam from continuous-wave, tunable-waveguide carbon dioxide laser, which serves as master frequency-control oscillator. Device measures absorption line of ozone; with adjustments, it is applicable to monitoring of atmospheric trace species.

Megie, G. J.; Menzies, R. T.

1981-01-01

40

THE RESPIRATORY RESPONSE TO CARBON DIOXIDE  

PubMed Central

1. A technique for determining the respiratory response to carbon dioxide on the Peabody principle is described. 2. The relation between minute volume of total pulmonary ventilation and percentage of carbon dioxide in the inspired air can be expressed by a simple mathematical formula, viz. Y = K + abz, in which Y is the ventilation rate, X is the CO2 content of the inspired air, and K, a, and b are constants characteristic for the individual. 3. The respiratory response to carbon dioxide as expressed by the total pulmonary ventilation is slightly greater at high oxygen percentages (90 per cent ) than at normal oxygen percentages in the inspired air. 4. Respiratory fatigue may consist of two elementsone nervous, manifesting itself in increased excitability of the center and a more marked response when the demand for pulmonary ventilation is small, the other muscular and involving an inability to respond when the demand for pulmonary ventilation is great.

Davies, H. Whitridge; Brow, George R.; Binger, Carl A. L.

1925-01-01

41

Drug pharmacokinetics and the carbon dioxide breath test  

Microsoft Academic Search

The interrelationship of the pharmacokinetics of a drug and the expiration of carbon dioxide formed as a metabolite have been studied. The pharmacokinetic characteristics of the drug that affect the usefulness of the carbon dioxide excretion as a measure of liver function were examined by means of computer simulations. The parent drug extraction ratio, fraction demethylated, volume of distribution, and

Ioanis Parashos

1986-01-01

42

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

43

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

44

A weekly cycle in atmospheric carbon dioxide  

Microsoft Academic Search

We present a new statistic called the Mean Symmetrized Residual (MSR) for detection and quantification of a weekly cycle in measured daily atmospheric carbon dioxide (CO2). At the Mauna Loa Observatory in Hawaii, we conclude that CO2 concentrations, on average, are significantly lower (0.022 parts per million by volume, ppmv) on weekends (SaturdaySunday) than during the rest of the week.

Randall S. Cerveny; Kevin J. Coakley

2002-01-01

45

Hydrocarbon Displacement by Carbon Dioxide Dispersions.  

National Technical Information Service (NTIS)

The US Department of Energy's (DOE) Morgantown Energy Technology Center (METC) is investigating methods to control the mobility of carbon dioxide for use in gas miscible displacements of hydrocarbons that are found in petroleum reservoirs. Carbon dioxide ...

J. R. Duda

1986-01-01

46

Process for sequestering carbon dioxide and sulfur dioxide  

DOEpatents

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

Maroto-Valer, M. Mercedes (State College, PA); Zhang, Yinzhi (State College, PA); Kuchta, Matthew E. (State College, PA); Andresen, John M. (State College, PA); Fauth, Dan J. (Pittsburgh, PA)

2009-10-20

47

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

48

Carbon Dioxide - Sources and Sinks  

NSDL National Science Digital Library

In this lab activity, students use a chemical indicator (bromothymol blue) to detect the presence of carbon dioxide in animal and plant respiration and in the burning of fossil fuels and its absence in the products of plant photosynthesis. After completing the five parts of this activity, students compare the colors of the chemical indicator in each part and interpret the results in terms of the qualitative importance of carbon sinks and sources.

Universe, Windows T.

49

RECARBONATION AND LIQUID CARBON DIOXIDE  

Microsoft Academic Search

After water has been lime-softened, it is frequently caustic; pH reduction is usually achieved by adding carbon dioxide to the watera process called recarbonation. Here is a history of recarbonation, with up-to-date information for modern installations.

Paul D. Haney; Carl L. Hamann

1969-01-01

50

Determination of the Effective Volume of an Automated Chamber System for Studying the Effect of Soil Wetting and Drying Cycles on Carbon Dioxide and Methane Soil Fluxes  

NASA Astrophysics Data System (ADS)

Measurement of terrestrial greenhouse gas (GHG) fluxes is essential for estimating and managing the effects of the human carbon footprint. This poster presentation describes a method of determining the effective volume of an automated non-steady state chamber system in order to simultaneously measure carbon dioxide (CO2) and methane (CH4) fluxes at the soil surface. Our method used a Picarro G2301-f Cavity Ring-Down Spectrometer coupled to our automated chamber system (developed by the UBC Biometeorology and Soil Physics Group) to allow for continuous, half-hourly measurements of CO2 and CH4 fluxes. The high precision of the spectrometer allowed for a relatively short 4-minute closure time of the chamber, which was sufficient for flux calculations of both CO2 and CH4. Following the closure of the 65-L chamber, ambient air was drawn into the chamber and then through the spectrometer at a flow rate of approximately 0.25 L min-1. A calibration gas (20% by volume CO2 or 0.10% by volume CH4) was injected into the chamber at a flow rate of 15 mL min-1. The chamber was fixed to an aluminum base during calibration injections, which were performed separately for CO2 and CH4. Rates of increase in chamber headspace GHG concentrations were found to be linear. The effective volume of the chamber, an essential parameter in flux calculation, was found to exceed the geometric volume of the chamber by about 8% for CO2 and 1% for CH4. Results indicated that our non-steady state system can be used to accurately measure CO2 and CH4 fluxes simultaneously and provides a novel way to approach both field and laboratory-based GHG flux assessment. Additionally, the use of the system to determine the effects of soil wetting events on CO2 and CH4 emissions will be described.

Webster, C.; Johnson, M. S.; Jassal, R. S.; Black, T. A.; Hawthorne, I.

2013-12-01

51

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

52

Mauna Loa Carbon Dioxide Record  

NSDL National Science Digital Library

The Mauna Loa atmospheric CO2 measurements constitute the longest continuous record of atmospheric CO2 concentrations available in the world. The Mauna Loa site is considered one of the most favorable locations for measuring undisturbed air because possible local influences are minimal. Methods and equipment used to obtain these measurements have remained essentially unchanged during the 47-year monitoring program. This easy to use dataset contains monthly averages of atmospheric carbon dioxide concentrations from 1958 through 2004.

Bollenbacher, A. F.; Keeling, Ralph F.; Piper, S. C.; Walker, Jeffrey S.

2010-07-05

53

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

54

Rapid determination of carbon dioxide in silicate rocks  

USGS Publications Warehouse

In the development of rapid methods for silicate rock analysis, a simpler and faster means was needed for the determination of carbon dioxide than the conventional "train" procedures. With the method presented here, which involves measurement of the volume of carbon dioxide evolved, the time required for a determination is about 5 minutes per sample. It provides a saving of 30 to 40 minutes for each determination without significant loss of accuracy.

Shapiro, L.; Brannock, W. W.

1955-01-01

55

NATIONAL PERFORMANCE AUDIT PROGRAM: 1980 PROFICIENCY SURVEY FOR SULFUR DIOXIDE, NITROGEN DIOXIDE, CARBON MONOXIDE, SULFATE, NITRATE, LEAD AND HIGH VOLUME FLOW  

EPA Science Inventory

Based on authority granted by provisions of the Clean Air Act (42 U.S.C 7410, et seq.), the Quality Assurance Division of the Environmental Monitoring Systems Laboratory, Research Triangle Park, NC administers periodic surveys of analytical proficiency for sulfur dioxide, nitroge...

56

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

57

Carbon dioxide review 1982  

SciTech Connect

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

Clark, W.C. (ed.)

1982-01-01

58

Bench-to-bedside review: Carbon dioxide  

PubMed Central

Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia remains a common - and generally underappreciated - component of many disease states, including early asthma, high-altitude pulmonary edema, and acute lung injury. Induction of hypocapnia remains a common, if controversial, practice in both adults and children with acute brain injury. In contrast, hypercapnia has traditionally been avoided in order to keep parameters normal. More recently, advances in our understanding of the role of excessive tidal volume has prompted clinicians to use ventilation strategies that result in hypercapnia. Consequently, hypercapnia has become increasingly prevalent in the critically ill patient. Hypercapnia may play a beneficial role in the pathogenesis of inflammation and tissue injury, but may hinder the host response to sepsis and reduce repair. In contrast, hypocapnia may be a pathogenic entity in the setting of critical illness. The present paper reviews the current clinical status of low and high PaCO2 in the critically ill patient, discusses the insights gained to date from studies of carbon dioxide, identifies key concerns regarding hypocapnia and hypercapnia, and considers the potential clinical implications for the management of patients with acute lung injury.

2010-01-01

59

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

60

Solubility of Carbon Dioxide in Water.  

ERIC Educational Resources Information Center

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

Bush, Pat; And Others

1992-01-01

61

Carbon dioxide equilibria and their applications  

Microsoft Academic Search

Carbon dioxide, bicarbonate ion, and carbonate ion comprise the most important acid-base system in natural waters, and the equilibria between them regulate the pH of seawater, as well as most rainwater, stream water, river water, and groundwater. Carbon Dioxide Equilibria and Their Applications provides a clear, compact presentation of this topic, which is central to geochemistry and environmental engineering. It

1992-01-01

62

Closed carbon dioxide filtration revisited.  

PubMed

There are compelling reasons why the closed carbon dioxide filtration method for inhalation anaesthesia deserves serious reconsideration. Use of the closed absorption system today can provide all the benefits recognised by those who introduced it seventy to eighty years ago. A most important benefit is the increased opportunity of learning afforded the user, which leads either neophyte or senior clinician to improvement of both concept and clinical skills. The current resurgence of interest is fully appropriate for all physicians who aspire to be true specialists in the care of patients during clinical anaesthesia. PMID:7978194

Morris, L E

1994-08-01

63

Sorption of carbon dioxide onto sodium carbonate  

SciTech Connect

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

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

2006-07-01

64

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 major objectives of the project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coal being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals, to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized below in three broad categories outlining experimentation, model development, and coal characterization. (1) Experimental Work: Our adsorption apparatus was reassembled, and all instruments were tested and calibrated. Having confirmed the viability of the experimental apparatus and procedures used, adsorption isotherms for pure methane, carbon dioxide and nitrogen on wet Fruitland coal were measured at 319.3 K (115 F) and pressures to 12.4 MPa (1800 psia). These measurements showed good agreement with our previous data and yielded an expected uncertainty of about 2%. Preparations are underway to measure adsorption isotherms for pure methane, carbon dioxide and nitrogen on two other coals. (2) Model Development: The experimental data were used to evaluate the predictive capabilities of various adsorption models, including the Langmuir/loading ratio correlation, two-dimensional cubic equations of state, and the local density model. In general, all models performed well for Type I adsorption exhibited by methane, nitrogen, and carbon dioxide up to 8.3 MPa (average deviations within 2%). However, for pressures higher than 8.3 MPa (1200 psia), carbon dioxide produced multilayer adsorption behavior similar to Type IV adsorption. Our results to date indicate that the SLD model may be a suitable choice for modeling multilayer coalbed gas adsorption. However, model improvements are required to (a) account for coal heterogeneity and structure complexity, and (b) provide for more accurate density predictions. (3) Coal Characterization: We have identified several well-characterized coals for use in our adsorption studies. The criteria for coal selection has been guided by the need for coals that (a) span the spectrum of properties encountered in coalbed methane production (such as variation in rank), and (b) originate from coalbed methane recovery sites (e.g., San Juan Basin, Black Warrior Basin, etc.). At Pennsylvania State University, we have completed calibrating our instruments using a well-characterized activated carbon. In addition, we have conducted CO{sub 2} and methane uptakes on four samples, including (a) a widely used commercial activated carbon, BPL from Calgon Carbon Corp.; (b) an Illinois No.6 bituminous coal from the Argonne Premium Coal sample bank; (c) a Fruitland Intermediate coal sample; (d) a dry Fruitland sample. The results are as expected, except for a greater sensitivity to the outgassing temperature. ''Standard'' outgassing conditions (e.g., 383.2 K, overnight), which are often used, may not be appropriate for gas storage in coalbeds. Conditions that are more representative of in-situ coal (approximately 313.2 K) may be much more appropriate. In addition, our results highlight the importance of assessing the degree of approach to adsorption equilibrium.

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

2001-06-15

65

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 false Carbon dioxide record. 24.319...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still...

2009-04-01

66

27 CFR 24.319 - Carbon dioxide record.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Carbon dioxide record. 24.319...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still...

2010-04-01

67

46 CFR 76.15-20 - Carbon dioxide storage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a)...

2013-10-01

68

Carbon Dioxide Reduction with Alkali-Metal Amalgams.  

National Technical Information Service (NTIS)

The reduction of carbon dioxide by alkali-metal amalgams was studied as a potential means for reclamation of carbon dioxide waste gas in space systems. The carbon dioxide reduction reactions were investigated at moderate temperatures and pressures - typic...

C. M. Cox R. W. Treharne

1968-01-01

69

CARBON DIOXIDE AND OUR OCEAN LEGACY  

Microsoft Academic Search

Global warming is increasing ocean tempera- tures and raising sea levels. New scientific research shows that our oceans are beginning to face yet another threat due to global warm- ing-related emissions - their basic chemistry is changing because of the uptake of carbon dioxide released by human activities. When carbon dioxide is absorbed by the oceans it reacts with seawater

Richard A. Feely; Christopher L. Sabine; Victoria J. Fabry

70

Electrochemical processing of carbon dioxide.  

PubMed

With respect to the negative role of carbon dioxide on our climate, it is clear that the time is ripe for the development of processes that convert CO(2) into useful products. The electroreduction of CO(2) is a prime candidate here, as the reaction at near-ambient conditions can yield organics such as formic acid, methanol, and methane. Recent laboratory work on the 100 A scale has shown that reduction of CO(2) to formate (HCO(2)(-)) may be carried out in a trickle-bed continuous electrochemical reactor under industrially viable conditions. Presuming the problems of cathode stability and formate crossover can be overcome, this type of reactor is proposed as the basis for a commercial operation. The viability of corresponding processes for electrosynthesis of formate salts and/or formic acid from CO(2) is examined here through conceptual flowsheets for two process options, each converting CO(2) at the rate of 100 tonnes per day. PMID:18702129

Oloman, Colin; Li, Hui

2008-01-01

71

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

72

How Is Carbon Dioxide Measured?  

NSDL National Science Digital Library

In this textbook chapter, scientists studying the concentration of becomes CO² in the atmosphere are profiled. The techniques for measuring and recording carbon dioxide concentrations at the Mauna Loa Observatory are described. A link to a video clip of an interview with NOAA scientist Dr. Pieter Tans is included. This is the fifth chapter in the unit, Climate Change, which addresses the question of how human activities are changing Earth's climate. The resource includes three classroom investigations, links to current news articles, and a suite of pre and post unit assessments. A teacher's guide supports classroom use. The resource is part of Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

73

Numerical Simulation of Extent of Carbon Dioxide Plume Injected in the Gyeongsang Basin, Korea  

NASA Astrophysics Data System (ADS)

A series of thermo-hydro-chemical numerical simulations was performed to evaluate extent of carbon dioxide plume injected in the Gyeongsang Basin, which is one of the prospective onshore sedimentary basins for geologic storage of carbon dioxide in Korea. The carbon dioxide plume extent is an important factor in estimating storage efficiency and thus storage capacity of carbon dioxide in a storage formation because it represents an actual volume of the storage formation, which is occupied by injected carbon dioxide. The carbon dioxide plume extent is also an essential component in risk analysis of geologic storage of carbon dioxide because most of thermo-hydro-mechanical-chemical responses to carbon dioxide injection occur within it. To evaluate impacts of injection scenarios (i.e., injection rate and period) of carbon dioxide and geological conditions (i.e., thickness and depth) and hydrogeochemical properties (i.e., porosity, intrinsic permeability, salt concentration in groundwater, and volume fraction of chlorite) of a storage formation on the carbon dioxide plume extent, a series of sensitivity tests was also performed. The numerical simulation results show that the carbon dioxide plume extent is significantly affected by such injection scenarios, geological conditions, and hydrogeochemical properties. The carbon dioxide plume extent increases as the injection rate (with a constant injection period) increases, and this trend does not change with time. The carbon dioxide plume extent decreases as the injection period (with a constant total injection amount) increases until about 50 years, while it is not sensitive to the injection period after about 50 years. The carbon dioxide plume extent also decreases as the thickness increases until about 100 years, while it is not sensitive to the thickness after about 100 years. In contrast, the carbon dioxide plume extent decreases as the depth increases, and this trend is intensified with time. On the other hand, the carbon dioxide plume extent increases as the porosity decreases, or the intrinsic permeability increases, and these trends do not change with time. The carbon dioxide plume extent also increases as the salt concentration in groundwater increases, or the volume fraction of chlorite decreases, and these trends emerge clearly after about 100 years and are then intensified with time. It is expected that the numerical simulation results can be utilized as reasonable and practical reference data when estimation of storage capacity of carbon dioxide and risk analysis of geologic storage of carbon dioxide in the Gyeongsang Basin are required. This work was supported by the Energy Efficiency and Resources Program funded by the Korea Institute of Energy Technology Evaluation and Planning (KETEP), Ministry of Knowledge Economy, Republic of Korea.

Kihm, J.; Park, S.; Kim, J.

2012-12-01

74

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

75

Diffusion of D-alpha-tocopherol (1); carbon dioxide (2)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) D-alpha-tocopherol; (2) carbon dioxide

Winkelmann, J.

76

Diffusion of DL-alpha-tocopherol (1); carbon dioxide (2)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) DL-alpha-tocopherol; (2) carbon dioxide

Winkelmann, J.

77

Distribution, origin and prediction of carbon dioxide in petroleum reservoirs  

Microsoft Academic Search

High concentrations of carbon dioxide (CO) in petroleum reservoirs can significantly reduce the value of the discovery, by diluting any hydrocarbons, and by increasing production costs because of the increased likelihood of corrosion and scale formation. Huge volumes of CO have been found, for example in the Indonesian Natuna d-Alpha structure (estimated 240 tcf gas, of which around 70% is

J. Thrasher; A. J. Fleet

1995-01-01

78

Diffusion of carbon dioxide (1); water (2); magnesium chloride (3)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) carbon dioxide; (2) water; (3) magnesium chloride

Winkelmann, J.

79

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

80

Solubility and partial molar volumes of naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene in supercritical carbon dioxide  

SciTech Connect

The effect of temperature, pressure, and supercritical fluid density on the retention and solubility in the mobile phase of solutes in supercritical fluid chromatography was investigated. New retention data for naphthalene, phenanthrene, benzoic acid, and 2-methoxynaphthalene were obtained as a function of pressure at different temperatures. Most of the data were taken near the critical region of the fluid phase where the anomalities such as enhanced solubility/selectivity and retrogate behavior are expected. These data were then used to compare two different approaches for modeling the pressure dependence of solute retention on the column. In these approaches, mobile-phase partial molar volumes of the solutes were determined either from bulk solubility data or from infinite-dilution fugacity coefficients. In both approaches, an integrated expression for the change of retention with pressure was utilized to explicitly reveal the nature of interactions between the stationary phase and the solute. The approach that utilizes the infinite-dilution fugacity coefficient predicts the pressure dependence of solute retention more accurately, especially for solutes that are substantially soluble in the mobile phase near the critical point of the mobile phase. Relationships between the pressure and temperature dependence of the solute solubility in the mobile phase and the retention of solutes on the column were also investigated.

Goenenc, Z.S.; Akman, U. [Univ. of South Florida, Tampa, FL (United States). Dept. of Chemical Engineering]|[Bogaziici Univ., Istanbul (Turkey). Dept. of Chemical Engineering; Sunol, A.K. [Univ. of South Florida, Tampa, FL (United States). Dept. of Chemical Engineering

1995-07-01

81

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

82

Adsorption of Carbon Dioxide on Chemically Modified Carbon Adsorbents  

Microsoft Academic Search

Carbon adsorbents were chemically modified to have base sites on their surfaces, and the adsorption characteristics of carbon dioxide on them were investigated. Three kinds of carbon materials were used as support materials: two activated carbons and a carbon black. Base sites were introduced by impregnating the support materials with calcium acetate solution, followed by calcination at 700C for 2

Hyun-K Song; Kun-Hing Lee

1998-01-01

83

Silver oxide sorbent for carbon dioxide  

NASA Technical Reports Server (NTRS)

Material can be regenerated at least 20 times by heating at 250 C. Sorbent is compatible with environment of high humidity; up to 20% by weight of carbon dioxide can be absorbed. Material is prepared from silver carbonate, potassium hydroxide or carbonate, and sodium silicate.

Colombo, G. V.

1974-01-01

84

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 1860 and 1980 was between 135 1015 and 228 1015 grams. Between 1.8 1015 and 4.7 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

85

LIFETIME OF EXCESS ATMOSPHERIC CARBON DIOXIDE  

EPA Science Inventory

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

86

Carbon Dioxide Absorption and Desorption by Tris with Carbonic Anhydrase.  

National Technical Information Service (NTIS)

One concept of carbon dioxide control in aerospace vehicle atmosphere regeneration and control requires an efficient gas absorber which is effective in a moist gas stream. A tris (tri(hydroxymethyl)aminomethane) solution containing the enzyme, carbonic an...

J. P. Allen

1967-01-01

87

Electrochemical Carbon Dioxide Concentrator Subsystem Development.  

National Technical Information Service (NTIS)

The fabrication of a one-person Electrochemical Depolarized Carbon Dioxide Concentrator subsystem incorporating advanced electrochemical, mechanical, and control and monitor instrumentation concepts is discussed. This subsystem included an advanced liquid...

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

1983-01-01

88

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.

William Watson

1994-08-01

89

Biochemical Capture and Removal of Carbon Dioxide.  

National Technical Information Service (NTIS)

We devised an enzyme-based facilitated transport membrane bioreactor system to selectively remove carbon dioxide (CO2) from the space station environment. We developed and expressed site-directed enzyme mutants for CO2 capture. Enzyme kinetics showed the ...

M. C. Trachtenberg

1998-01-01

90

Cost Analysis of Carbon Dioxide Concentrators.  

National Technical Information Service (NTIS)

A methodology is developed to predict the relevant contributions of the more intangible cost elements encountered in the development of flight-qualified hardware and is used to predict the costs of three carbon dioxide concentration systems. The cost and ...

M. M. Yakut

1972-01-01

91

Carbon Dioxide Catastrophes: Past and Future Menace.  

National Technical Information Service (NTIS)

Carbon dioxide is important in its role as coupler of the terrestrial biosphere to inorganic chemical processes and as the principal greenhouse gas controlling Earth's surface temperature. The hypothesis that atmospheric CO2 levels have diminished with ti...

M. E. Baur

1988-01-01

92

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

93

Buckling of block copolymer lamellae in supercritical carbon dioxide  

NASA Astrophysics Data System (ADS)

Supercritical carbon dioxide (scCO2) swells many kinds of polymers. In particular polymers containing fluorine are highly swollen. Therefore, block copolymers having fluorinated blocks are expected to be swollen selectively in scCO2 due to the higher affinity of scCO2 toward the fluorinated blocks. We studied the phase behavior of fluorinated block copolymers swollen in scCO2 and found multiple order-to-order transitions as a function of pressure. In addition, the swollen structures could be frozen by reducing temperature and subsequently carbon dioxide was removed without disturbing the swollen morphologies. As a result, the volume occupied with carbon dioxide was converted to empty space, and hence a variety of nanoporous structures were successfully formed. In particular we found that swollen lamellae in scCO2 becomes undulated lamellae with a large wavelength, which is similar to ''egg cartoon'' often observed in unbinding membranes of surfactants.

Yokoyama, Hideaki; Ito, Masateru; Sakai, Yasuhiro; Ito, Kozo; Sugiyama, Kenji

2010-03-01

94

Mitigating strategies for carbon dioxide problems  

SciTech Connect

Society can take steps to enhance our ability to adapt more easily to carbon dioxide induced changes. Given the rapidity of social and technological change in the twentieth century, facilitating adjustment is important. With the exception of data collection and analysis focused on climate, enhancing each of these functions will be to the general benefit of society, but will not be unique to carbon dioxide-induced problems. Carbon dioxide issues can provide a rationale, but more probably will be a catalyst, for pushing society to enhance its ability to adapt to and exploit change. Carbon dioxide is but one of many factors which will have an enormous impact on the economic and social institutions of the United States in the twenty-first century. If carbon dioxide-induced changes were as large as now appears possible, and if they were the only major change, then it would be worthwhile to invest in enhancing education and capital formation so that we could minimize the effects of adverse changes and take advantage of beneficial ones. Since carbon dioxide-induced changes are likely to be only one, possibly small, source of change, there is all the more reason to devote resources to making our economic and social institutions more flexible and adaptable. 7 references.

Lave, L.B.

1982-05-01

95

Mineralization strategies for carbon dioxide sequestration  

SciTech Connect

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

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

2003-01-01

96

Carbon dioxide sequestration by ex-situ mineral carbonation  

Microsoft Academic Search

The process developed for carbon dioxide sequestration utilizes a slurry of water mixed with olivine- forsterite end member (MgSiO), which is reacted with supercritical CO to produce magnesite (MgCO). Carbon dioxide is dissolved in water to form carbonic acid, which likely dissociates to H{sup +} and HCO⁻. The H{sup +} hydrolyzes the silicate mineral, freeing the cation (Mg{sup 2+}), which

W. K. OConnor; D. C. Dahlin; P. C. Turner

2000-01-01

97

Natural Methane and Carbon Dioxide Hydrates in the Earth System  

NASA Astrophysics Data System (ADS)

Both CH4 and CO2 are abundant volatiles in the earth's crust. Methane hydrates occur in permafrost regions and continental slopes of oceans. It is currently estimated that the energy stored in CH4 hydrate reserves totals more than twice the global reserves of all conventional oil, gas, and coal deposits combined. This means that methane hydrate could prove to be a very important source of energy in the future. Pressure versus temperature phase diagrams for methane and carbon dioxide define characteristic stability fields for gas, fluid and hydrates states. Sequestration of carbon dioxide in the earths crust and production of methane hydrate reservoirs are critically dependent on knowledge of the in situ elastic moduli of natural hydrates. The physical properties of simple methane and carbon dioxide hydrates are similar [1]. Our compilation of experimental data confirms high compressional wave velocities and elastic moduli for CH4 and CO2 hydrates and low compressional wave velocities for the fluid and gas phases. As methane and carbon dioxide hydrates are stable over similar pressure-temperature ranges, the two types of hydrates form in similar settings in the earth's crust. For example, temperature and pressure conditions in deepwater marine environments require both CO2 and CH4 to be in hydrate phase. However, not much is known about the origin, distribution and total volume of natural carbon dioxide hydrates stored in the earth's crust. For a number of tectonic/geological settings, CO2-rich fluids from deep crustal reservoirs must be considered: rifted margins, volcanic arcs, deepwater vents [2], mud volcanoes and mud diapirs [3]. Both methane and carbon dioxide hydrates work to cement sea floors in similar ways. Slope failure, a phenomenon usually taken as a hallmark of the presence of methane hydrate, could also be attributed to the existence of carbon dioxide hydrates. Perhaps most critically, many of the estimations of the amounts of methane hydrates are based on seismic imaging. However, since carbon dioxide hydrate can also form gas traps and subsequently bottom simulating reflections (a prime indicator of methane hydrate reserves), we speculate that some of the global estimated methane hydrate may in fact be natural carbon dioxide hydrate. References: [1] Sivaraman, R., Gas TIPS, 9, 4-7, 2003;[2] Sakai, H. et al., Science, 248, 1093-1096, 1990; [3] Mueller, C. et al., World Oil, 222, 60-67, 2001

Research Team; Milkereit, B.

2004-05-01

98

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.

99

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

100

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

101

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.

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

2014-01-01

102

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

103

Polymers for metal extractions in carbon dioxide  

DOEpatents

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

DeSimone, Joseph M. (7315 Crescent Ridge Dr., Chapel Hill, NC 27516); Tumas, William (1130 Big Rock Loop, Los Alamos, NM 87544); Powell, Kimberly R. (103 Timber Hollow Ct. Apartment 323, Chapel Hill, NC 27514); McCleskey, T. Mark (1930 Camino Mora, Los Alamos, NM 87544); Romack, Timothy J. (5810 Forest Ridge Dr., Durham, NC 27713); McClain, James B. (8530 Sommersweet La., Raleigh, NC 27612); Birnbaum, Eva R. (1930 Camino Mora, Los Alamos, NM 87544)

2001-01-01

104

Pyrethrin exraction from pyrethrum flowers using carbon dioxide  

Microsoft Academic Search

Extractions of pyrethrins from ground pyrethrum flowers, using supercritical carbon dioxide as the solvent, were carried out in a semi-batch pilot plant (extraction volume: 200 ml). Extracts were very similar to those obtained by hexane Soxhlet extraction, except that the ratio of pyrethrins I to pyrethrins II was lower (1.58 instead of 1.79), and less pigments were present. At 40C,

H. K Kiriamiti; S Camy; C Gourdon; J. S Condoret

2003-01-01

105

Dissolution of a Carbon Dioxide Bubble in a Vertical Pipe  

Microsoft Academic Search

Dissolution of single carbon dioxide (CO2) bubbles in a vertical pipe of 25 mm diameter is measured to examine the effects of the ratio lambda of the sphere-volume equivalent bubble diameter to the pipe diameter, the liquid Reynolds number and surfactants on mass transfer. The bubble diameter and liquid Reynolds number are varied from 5.0 to 26 mm (0.20 <

Satoru Abe; Hideaki Okawa; Shigeo Hosokawa; Akio Tomiyama

2008-01-01

106

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

107

Carbon Dioxide Removal System of the Regenerable Solid Adsorbent Type.  

National Technical Information Service (NTIS)

The development of a regenerable carbon dioxide removal system is discussed. The system utilizes solid zeolites to adsorb carbon dioxide and silica gel for predrying the gas stream. The system is completely regenerable, operates automatically and continuo...

G. A. Remus P. P. Nuccio R. J. Honegger

1969-01-01

108

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

109

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 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a)...

2013-10-01

110

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

111

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

112

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

113

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.

2013-10-21

114

Carbon Dioxide Research Conference: Carbon Dioxide, Science and Consensus.  

National Technical Information Service (NTIS)

The DOE program focuses on three areas each of which requires more research before the many CO sub 2 -related questions can be answered. These areas include the global carbon cycle, climate effects, and vegetation effects. Additional information is needed...

1983-01-01

115

Methanation of carbon dioxide: an overview  

Microsoft Academic Search

Although being very challenging, utilization of carbon dioxide (CO2) originating from production processes and flue gases of CO2-intensive sectors has a great environmental and industrial potential due to improving the resource efficiency of industry\\u000a as well as by contributing to the reduction of CO2 emissions. As a renewable and environmentally friendly source of carbon, catalytic approaches for CO2 fixation in

Wang Wei; Gong Jinlong

2011-01-01

116

Platinum catalyst for forming carbon dioxide  

SciTech Connect

This patent describes an improvement in a platinum wire catalytic apparatus for catalyzing the reaction of carbon monoxide and oxygen to form carbon dioxide by directly heating the catalyst to an activation temperature of about 1000{degrees} C. The improvement comprises a layer of platinum black deposited on the surface of the platinum wire to form a coating whereby the wire with the coating is directly heated to an activation temperature within the range of about 150 to 300{degrees} C.

McNeil, J.A.; Cohn, D.B.

1991-05-28

117

A Simple Model for Atmospheric Carbon Dioxide  

NSDL National Science Digital Library

In this problem set, learners will create and use a differential equation of rate-of-change of atmospheric carbon dioxide. They will refer to the "Keeling Curve" graph and information on the sources and sinks of carbon on Earth to create the equation and apply it 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.

118

Ocean uptake of carbon dioxide  

Microsoft Academic Search

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

Tsung-Hung Peng; Taro Takahashi

1993-01-01

119

Ocean uptake of carbon dioxide  

Microsoft Academic Search

Factors controlling the capacity of the ocean for taking up anthropogenic C0² include carbon chemistry, distribution of alkalinity, pCO² and total concentration of dissolved C0², sea-air pCO² difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and

Tsung-Hung Peng; Taro Takahashi

1993-01-01

120

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

121

Carbon dioxide embolism during endoscopic vein harvesting.  

PubMed

Endoscopic vein harvesting (EVH) is becoming common for the patients undergoing coronary artery bypass grafting. Using carbon dioxide insufflations during the vein harvest can produce rare but catastrophic CO(2) embolism. We report a case of massive right atrial CO(2) embolism due to femoral vein injury which occurred during the performance of a routine EVH procedure. PMID:18381362

Tamim, Muhammed; Omrani, Maher; Tash, Adel; El Watidy, Ahmed

2008-08-01

122

Ocean Acidification: The Other Carbon Dioxide Problem  

NSDL National Science Digital Library

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

Noaa; Administration, National O.

123

Carbon dioxide laser management cervical intraepithelial neoplasia  

Microsoft Academic Search

In this report we describe the use of the carbon dioxide laser for the outpatient management of cervical intraepithelial neoplasia (CIN). A comparison of treatment effectiveness for different grades of CIN is also included. Two hundred fifty-six cases were evaluated by colposcopy, cytology, and histopathology, treated by at least 5 to 6 mm of laser vaporization, and followed up for

J. H. Bellina; V. C. Wright; J. I. Voros; M. A. Riopelle; V. Hohenschutz

1981-01-01

124

Geothermal carbon dioxide for use in greenhouses  

Microsoft Academic Search

Geothermal fluids often contain carbon dioxide, which is a very effective growth stimulant for plants in greenhouses. Studies have shown that as CO concentration is increased from a normal level of 300 ppm (mmol\\/kmol) to levels of approximately 1000 ppm crop yields may increase by up to 15% (Ullmann`s Encyclopedia of Industrial Chemistry, 1989). It is suggested that geothermal greenhouse

M. G. Dunstall; G. Graeber

1997-01-01

125

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.

126

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

127

Nitrile oxide cycloadditions in supercritical carbon dioxide.  

PubMed

The regioselectivity of dipolar cycloadditions of mesitonitrile oxide to various dipolarophiles in supercritical carbon dioxide can be tuned by changes in density, the magnesium bromide-mediated cycloaddition to pent-1-en-3-ol proceeding with higher stereoselectivity than in most conventional solvents. PMID:15543310

Lee, Connie K Y; Holmes, Andrew B; Al-Duri, Bushra; Leeke, Gary A; Santos, Regina C D; Seville, Jonathan P K

2004-11-21

128

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.

129

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...

130

Spectroscopic carbon dioxide sensor for automotive applications  

Microsoft Academic Search

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

Michael Arndt; Maximilian Sauer

2004-01-01

131

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...false Still wines containing carbon dioxide. 26.222 Section...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...222 Still wines containing carbon dioxide. (a) General...not more than 0.392 gram of carbon dioxide per 100...

2010-04-01

132

27 CFR 26.222 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...false Still wines containing carbon dioxide. 26.222 Section...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...222 Still wines containing carbon dioxide. (a) General...not more than 0.392 gram of carbon dioxide per 100...

2009-04-01

133

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...false Still wines containing carbon dioxide. 26.52 Section...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...52 Still wines containing carbon dioxide. (a) General...not more than 0.392 gram of carbon dioxide per 100...

2010-04-01

134

27 CFR 26.52 - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...false Still wines containing carbon dioxide. 26.52 Section...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...52 Still wines containing carbon dioxide. (a) General...not more than 0.392 gram of carbon dioxide per 100...

2009-04-01

135

Effect of Carbon Dioxide on Multiplication of Fusarium in Soil  

Microsoft Academic Search

NUMEROUS studies have been made on the effects of carbon dioxide on fungal growth in pure culture, and on substrates other than soil. Since soil is the natural habitat of many fungi, and frequently has carbon dioxide-levels exceeding that present in normal air, it is important that effects of carbon dioxide-enriched air on fungal behaviour in soil be investigated. With

R. H. Stover; S. R. Freiberg

1958-01-01

136

Absorption of carbon dioxide in waste tanks (October 21, 1986).  

National Technical Information Service (NTIS)

The absorption of atmospheric carbon dioxide in eight waste tanks located in H-Area has been monitored for a period of six months. All of the tanks are continuously absorbing carbon dioxide. Approximately 75% of the carbon dioxide entering the waste tanks...

D. T. Hobbs

1986-01-01

137

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

138

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section...Than Class 1 and Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered...

2009-10-01

139

Estimated Carbon Dioxide Emissions in 2008: United States  

Microsoft Academic Search

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

C A Smith; A J Simon; R D Belles

2011-01-01

140

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

141

HIGH PRESSURE VAPOR LIQUID EQUILIBRIUM FOR CARBON DIOXIDE + ETHANOL + 2BUTANONE SYSTEM  

Microsoft Academic Search

Vapor-liquid equilibrium was measured for three binary systems, carbon dioxide + ethanol, carbon dioxide + 2-butanone, and ethanol + 2-butanone, and a ternary system, carbon dioxide + ethanol + 2-butanone, at 313.2K. A circulation type apparatus was used in case of the high pressure systems, carbon dioxide + ethanol, carbon dioxide + 2-butanone, and carbon dioxide + ethanol + 2-butanone,

Tomoya TSUJI; Masatoshi SAKAI; Toshihiko HIAKI

142

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

1993-06-01

143

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

144

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.

145

Ocean uptake of carbon dioxide.  

National Technical Information Service (NTIS)

Factors controlling the capacity of the ocean for taking up anthropogenic CO(sup 2) include carbon chemistry, distribution of alkalinity, pCO(sup 2) and total concentration of dissolved CO(sup 2), sea-air pCO(sup 2) difference, gas exchange rate across th...

T. H. Peng T. Takahashi

1993-01-01

146

Carbon dioxide sequestration by direct mineral carbonation with carbonic acid  

SciTech Connect

The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine and 84% conversion of olivine to the carbonate in 6 hours. The results from the current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, or some combination of the two. Future tests are intended to examine a broader pressure/temperature regime, various pretreatment options, as well as other mineral groups.

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

2000-01-01

147

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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

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

2001-01-01

148

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

149

Climate Impact of Increasing Atmospheric Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

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

1981-08-01

150

Climate Impact of Increasing Atmospheric Carbon Dioxide  

Microsoft Academic Search

The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about

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

1981-01-01

151

Solubilities of phenols in supercritical carbon dioxide  

SciTech Connect

Equilibrium solubilities of pure anthracene at 50 C, 1-naphthol at 35, 45, and 55 C, and hydroquinone at 35 and 45 C in supercritical carbon dioxide over a pressure range of about 85--300 bar have been measured using a supercritical fluid extractor coupled with an external high-pressure liquid chromatographer. The solubility results, along with those for other phenols reported in the literature, are correlated with the translated-modified Peng Robinson equation of state.

Coutsikos, P.; Magoulas, K.; Tassios, D. [National Technical Univ. of Athens (Greece)

1995-07-01

152

Carbon dioxide capture with concentrated, aqueous piperazine  

Microsoft Academic Search

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

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

2010-01-01

153

Improved immobilized carbon dioxide capture sorbents  

Microsoft Academic Search

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

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

2005-01-01

154

Polymerizations in Liquid and Supercritical Carbon Dioxide  

Microsoft Academic Search

In the past few years, remarkable progress has been made in defining the scope and limitations of carbon dioxide (CO2) as an inert polymerization medium. It has appear that CO2 represents a viable solvent choice for a variety of propagation mechanisms including both chain growth and step growth polymerizations.\\u000a When the environmental advantages of CO2 are combined with its ability

Dorian A. Canelas; Joseph M. DeSimone

155

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

156

Carbon fixation efficiency of plants influenced by sulfur dioxide.  

PubMed

In the land ecosystem, the forest can absorb the carbon dioxide (CO2) in the atmosphere and turn the CO2 into organic carbon to store it in the plant body. About 210(11) tons of CO2 changes through photosynthesis into organic matter by plant annually. In this research, ten kinds of woody plants were selected for assessing the carbon fixation ability influenced by sulfur dioxide (SO2). The tested trees were put into a fumigation chamber for 210 days in a 40-ppb SO2 environment. The results of this study showed that there was no clear symptom of tested trees under a 40-ppb SO2 environment. The tested trees could tolerate this polluted environment, but it will impact their CO2 absorption ability. The carbon fixation ability will reduce as the polluted period lengthens. The carbon fixation potential of tested trees ranged from 2.1 to 15.5 gCO2/m2d with an average of 7.7 gCO2/m2d. The changes in CO2 absorption volume for Messerschmidia argentea were more stable during the fumigation period with a variation of 102%. Among the tested trees, Diospyros morrisiana had the best carbon fixation potential of 9.19 gCO2/m2d and M. argentea had the least with 2.54 gCO2/m2d. PMID:20364315

Chung, Chung-Yi; Chung, Pei-Ling; Liao, Shao-Wei

2011-02-01

157

Carbon dioxide embolism during laparoscopic sleeve gastrectomy  

PubMed Central

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

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

2011-01-01

158

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

159

Carbon dioxide makes heat therapy work  

SciTech Connect

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

Sherman, H.

1987-01-01

160

Extraction of furfural with carbon dioxide  

SciTech Connect

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

Gamse, T.; Marr, R. [Institut fuer Thermische Verfahrenstechnik, Graz (Austria); Froeschl, F.; Siebenhofer, M. [VTU, Graz (Austria)

1997-01-01

161

Carbon dioxide reduction by the Bosch process  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

162

Carbon dioxide capture at the molecular level.  

PubMed

Carbon dioxide is recognized as a typical greenhouse gas and drastic reduction of CO2 emissions from industrial process is becoming more and more important in relation to global warming. In fact, the reaction between monoethanolamine (MEA) and CO2 in aqueous solution has been widely used for the removal from flue gases. In this study, the role of the interplay between solvent water and nitrogen (MEA)-carbon (CO2) bond formation is discussed based on the molecular theory using RISM-SCF-SEDD, which is the hybrid method of quantum chemistry of solute and statistical mechanics of solvent. PMID:19774287

Iida, Kenji; Yokogawa, Daisuke; Ikeda, Atsushi; Sato, Hirofumi; Sakaki, Shigeyoshi

2009-10-14

163

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

164

Carbon Dioxide Aquariums Greenhouse Gas Lesson  

NSDL National Science Digital Library

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

Orzali, Joe

2009-01-01

165

Reduction of carbon dioxide on modified glassy carbon electrodes  

SciTech Connect

Carbon dioxide in the atmosphere gives an important contribution to environmental pollution due to the progressive increase of its production everywhere from many sources. It is believed now that the capacity of the biosphere, due to absorption and transformation of CO{sub 2}, has been considerably exceeded and many attempts to overcome this problem by different ways, have been successful. Electrochemical reduction seems to be an appropriate route for carbon dioxide consumption and its transformation to useful compounds. Electrochemical reduction of carbon dioxide on glassy carbon (GC) was studied by applying different potential regimes and monitoring the effect of the electrode surface conditioning, as well as the nature of supporting electrolyte, upon the nature of the reaction. In the case of constant potential electrolyses, a rapid decay of the cathodic current was observed, while application of a suitable pulse program to the working electrode, in addition to the ultrasonic cleaning of the surface, allowed completion of the reaction without premature current downfall. Modification of the electrode surface, by applying potential pulses, caused a decrease of the reduction potential of CO{sub 2} on glassy carbon. High yields in carbon monoxide and methanol were obtained in these media, with the highest value obtained for methanol in sodium chloride and carbon monoxide in ammonium oxalate.

Hernandez, R.M.; Marquez, J.; Marquez, O.P.; Choy, M.; Ovalles, C.; Garcia, J.J.; Scharifker, B.

1999-11-01

166

Atmospheric Carbon Dioxide and Carbon Reservoir Changes  

Microsoft Academic Search

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

Minze Stuiver

1978-01-01

167

Sequestering Naturally Occurring Liquid Carbon Dioxide in the Deep Ocean  

NASA Astrophysics Data System (ADS)

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

Capron, M. E.

2008-12-01

168

A research needs assessment for the capture, utilization and disposal of carbon dioxide from fossil fuel-fired power plants. Volume 2, Topical reports: Final report  

SciTech Connect

This study, identifies and assesses system approaches in order to prioritize research needs for the capture and non-atmospheric sequestering of a significant portion of the carbon dioxide (CO{sub 2}) emitted from fossil fuel-fired electric power plants (US power plants presently produce about 7% of the world`s CO{sub 2} emissions). The study considers capture technologies applicable either to existing plants or to those that optimistically might be demonstrated on a commercial scale over the next twenty years. The research needs that have high priority in establishing the technical, environmental, and economic feasibility of large-scale capture and disposal of CO{sub 2} from electric power plants are:(1) survey and assess the capacity, cost, and location of potential depleted gas and oil wells that are suitable CO{sub 2} repositories (with the cooperation of the oil and gas industry); (2) conduct research on the feasibility of ocean disposal, with objectives of determining the cost, residence time, and environmental effects for different methods of CO{sub 2} injection; (3) perform an in-depth survey of knowledge concerning the feasibility of using deep, confined aquifers for disposal and, if feasible, identify potential disposal locations (with the cooperation of the oil and gas industry); (4) evaluate, on a common basis, system and design alternatives for integration of CO{sub 2} capture systems with emerging and advanced technologies for power generation; and prepare a conceptual design, an analysis of barrier issues, and a preliminary cost estimate for pipeline networks necessary to transport a significant portion of the CO{sub 2} to potentially feasible disposal locations.

Not Available

1993-07-01

169

Irreversible climate change due to carbon dioxide emissions  

PubMed Central

The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases 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 compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the dust bowl era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.41.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.61.9 m for peak CO2 concentrations exceeding ?1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer.

Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

2009-01-01

170

Irreversible climate change due to carbon dioxide emissions.  

PubMed

The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases 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 compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the "dust bowl" era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4-1.0 m if 21st century CO(2) concentrations exceed 600 ppmv and 0.6-1.9 m for peak CO(2) concentrations exceeding approximately 1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

2009-02-10

171

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

172

Automated carbon dioxide cleaning system  

NASA Technical Reports Server (NTRS)

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

Hoppe, David T.

1991-01-01

173

Carbon Dioxide Transport through Membranes*  

PubMed Central

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

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

2008-01-01

174

Carbon dioxide: A substitute for phosgene  

SciTech Connect

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

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

1997-03-01

175

Carbon dioxide sensor. [partial pressure measurement using monochromators  

NASA Technical Reports Server (NTRS)

Analytical techniques for measuring CO2 were evaluated and rated for use with the advanced extravehicular mobility unit. An infrared absorption concept using a dual-wavelength monochromator was selected for investigation. A breadboard carbon dioxide sensor (CDS) was assembled and tested. The CDS performance showed the capability of measuring CO2 over the range of 0 to 4.0 kPa (0 to 30 mmHg) P sub (CO2). The volume and weight of a flight configured CDS should be acceptable. It is recommended that development continue to complete the design of a flight prototype.

1975-01-01

176

Carbon dioxide and water vapor high temperature electrolysis  

NASA Technical Reports Server (NTRS)

The design, fabrication, breadboard testing, and the data base obtained for solid oxide electrolysis systems that have applications for planetary manned missions and habitats are reviewed. The breadboard tested contains sixteen tubular cells in a closely packed bundle for the electrolysis of carbon dioxide and water vapor. The discussion covers energy requirements, volume, weight, and operational characteristics related to the measurement of the reactant and product gas compositions, temperature distribution along the electrolyzer tubular cells and through the bundle, and thermal energy losses. The reliability of individual cell performance in the bundle configuration is assessed.

Isenberg, Arnold O.; Verostko, Charles E.

1989-01-01

177

The nature of carbon dioxide waters in Snaefellsnes, western Iceland  

USGS Publications Warehouse

Over 20 occurrences of thermal and non-thermal waters rich in carbon dioxide are known in the Snaefellsnes Peninsula of western Iceland. On the basis of the thermal, chemical and isotopic characteristics of these waters, and hydrological considerations, it is concluded that they represent meteoric waters which have seeped to variable depths into the bedrock. Ascending carbon dioxide gas originating from intrusions or the mantle mixes with the meteoric waters to produce carbon dioxide waters: at considerable depth in the case of the thermal carbon dioxide waters but close to the surface in the case of cold carbon dioxide waters. The occurrence of carbon dioxide waters cannot be regarded as evidence for underground geothermal reservoirs. ?? 1983.

Arnorsson, S.; Barnes, I.

1983-01-01

178

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

Microsoft Academic Search

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,

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

2005-01-01

179

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

180

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

181

Atmospheric carbon dioxide and carbon reservoir changes.  

PubMed

The net release of CO(2) from the biosphere to the atmosphere between 1850 and 1950 is estimated to amount to 1.2 x 10(9) tons of carbon per year. During this interval, changes in land use reduced the total terrestrial biomass by 7 percent. There has been a smaller reduction in biomass over the last few decades. In the middle 19th century the air had a CO(2) content of approximately 268 parts per millon, and the total increase in atmospheric CO(2) content since 1850 has been 18 percent. Major sinks for fossil fuel CO(2) are the thermocline regions of large oceanic gyres. About 34 percent of the excess CO(2) generated so far is stored in surface and thermocline gyre waters, and 13 percent has been advected into the deep sea. This leaves an airborne fraction of 53 percent. PMID:17759647

Stuiver, M

1978-01-20

182

Hemodynamic effects of carbon dioxide insufflation during endoscopic vein harvesting  

Microsoft Academic Search

Background. A prospective study was performed assessing the hemodynamic effects of carbon dioxide (CO2) insufflation during endoscopic vein harvesting (EVH) using the Guidant Vasoview Uniport system.Methods. Five hemodynamic and respiratory parameters (end-tidal carbon dioxide, arterial partial pressure of carbon dioxide, mean arterial pressure, mean pulmonary arterial pressure, and cardiac output), were measured in 100 consecutive patients undergoing EVH with CO2

Richard M Vitali; Ramachandra C Reddy; Peter J Molinaro; Mario F Sabado; Israel J Jacobowitz

2000-01-01

183

Sequestering carbon dioxide in industrial polymers: Building materials for the 21st century  

SciTech Connect

This study was undertaken to determine the possibility of developing beneficial uses for carbon dioxide as a key component for a large-volume building product. Such a use may provide an alternative to storing the gas in oceanic sinks or clathrates as a way to slow the rate of global warming. The authors investigated the concept that carbon dioxide might be used with other chemicals to make carbon-dioxide-based polymers which would be lightweight, strong, and economical alternatives to some types of wood and silica-based building materials. As a construction-grade material, carbon dioxide would be fixed in a solid, useful form where it would not contribute to global warming. With the probable imposition of a fuel carbon tax in industrialized countries, this alternative would allow beneficial use of the carbon dioxide and could remove it from the tax basis if legislation were structured appropriately. Hence, there would be an economic driver towards the use of carbon-dioxide-based polymers which would enhance their future applications. Information was obtained through literature searches and personal contacts on carbon dioxide polymers which showed that the concept (1) is technically feasible, (2) is economically defensible, and (3) has an existing industrial infrastructure which could logically develop it. The technology exists for production of building materials which are strong enough for use by industry and which contain up to 90% by weight of carbon dioxide, both chemically and physically bound. A significant side-benefit of using this material would be that it is self-extinguishing in case of fire. This report is the first stage in the investigation. Further work being proposed will provide details on costs, specific applications and volumes, and potential impacts of this technology.

Molton, P.M.; Nelson, D.A.

1993-06-01

184

Preparation of perlite-based carbon dioxide absorbent.  

PubMed

A new highly efficient carbon dioxide absorbent consisting of sodium hydroxide, expanded perlite and acid-base indicator was prepared. The absorption efficiency, absorption capacity, flow resistance and color indication for the absorbent were tested and compared with some commercial products. The absorbent can reduce the carbon dioxide content in gases to 3.3 ppb (v/v) and absorbs not less than 35% of its weight of carbon dioxide. Besides its large capacity and sharp color indication, the absorbent has an outstanding advantage of small flow resistance in comparison with other commercial carbon dioxide absorbents. Applications in gas analysis and purification were also investigated. PMID:18965919

He, H; Wu, L; Zhu, J; Yu, B

1994-02-01

185

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

186

A tenuous carbon dioxide atmosphere on Jupiter's moon Callisto  

NASA Technical Reports Server (NTRS)

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.

Carlson, R. W.

1999-01-01

187

High-pressure vapor-liquid equilibria of two binary systems: Carbon dioxide + cyclohexanol and carbon dioxide + cyclohexanone  

SciTech Connect

Vapor-liquid equilibria for carbon dioxide + cyclohexanol and carbon dioxide + cyclohexanone were measured using an apparatus based on a static-analytic method with in situ samplings. P, T, x, y measurements were made at pressures up to 22 MPa. The carbon dioxide + cyclohexanol system was studied at 433 and 473 K, and carbon dioxide + cyclohexanone, at 433 and 473 K. The results are correlated by the Redlich-Kwong-Soave and Peng and Robinson equations and several mixing rules. The best fittings are obtained with the Peng-Robinson equation of state and a two-parameter mixing rule, i.e., within 1.1% for both pressures and vapor mole fractions on the carbon dioxide + cyclohexanone system and within 1.9% for pressures and 2.9% for vapor mole fractions on the carbon dioxide + cyclohexanol system. More recent equations by Patel and Teja and Salim and Trebble show no significant advantages.

Laugier, S. [Ecole Nationale Superieure de Chimie et Physique de Bordeaux, Talence (France)] [Ecole Nationale Superieure de Chimie et Physique de Bordeaux, Talence (France); Richon, D. [Ecole Nationale Superieure des Mines de Paris, Fontainebleau (France)] [Ecole Nationale Superieure des Mines de Paris, Fontainebleau (France)

1997-01-01

188

Phase equilibria from PVT measurements for carbon dioxide, water, and n-decane  

SciTech Connect

Phase equilibrium properties for the carbon dioxide - water - n-decane system were determined from pressure-temperature-volume (PVT) measurements. PVT properties were also obtained for pure carbon dioxide and water, and the binary mixtures of carbon dioxide - water and carbon dioxide - n-decane. The experiments were conducted at temperatures of 313.17, 353.15 and 393.15 Kelvin, and at pressures from 37 to 416 bar. Measurements for the mixtures were terminated when complete miscibility was observed. The Perturbed-Hard-Chain (PHC) equation of state developed by Gmehling et al (1979) was chosen to correlate the measured data because of its ability to handle the complexity of the molecular interactions in the mixtures. Binary interaction parameters were regressed for the carbon dioxide - water and carbon dioxide - n-decane mixtures while those of water - n-decane were obtained from ternary data. A fiber-optic scope was used to observe the number of phases present and qualitatively measure the equilibrium liquid phase volumes. The measured data were then compared to predictions from the model. Ternary diagrams are presented showing predicted coexisting equilibrium phases for the three isotherms and several pressures.

Okafor, M.N.

1987-01-01

189

Development of a prototype regenerable carbon dioxide absorber  

NASA Technical Reports Server (NTRS)

Design information was obtained for a new, regenerable carbon dioxide control system for extravehicular activity life support systems. Solid potassium carbonate was supported in a thin porous sheet form and fabricated into carbon dioxide absorber units. Carbon dioxide and water in the life support system atmosphere react with the potassium carbonate and form potassium bicarbonate. The bicarbonate easily reverts to the carbonate by heating to 150 deg C. The methods of effectively packing the sorbent material into EVA-sized units and the effects of inlet concentrations, flowrate, and temperature upon performance were investigated. The cycle life of the sorbent upon the repeated thermal regenerations was demonstrated through 90 cycles.

Onischak, M.

1976-01-01

190

Cost analysis of carbon dioxide concentrators  

NASA Technical Reports Server (NTRS)

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

Yakut, M. M.

1972-01-01

191

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

192

Electrochemical carbon dioxide concentrator subsystem development  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

193

Carbon dioxide measurements in the stratosphere  

NASA Technical Reports Server (NTRS)

A mass spectrometer experiment for the analysis of minor constituents in the stratosphere has been flown successfully four times from Palestine, Texas on board a balloon gondola. The carbon dioxide mixing ratio, which shows unexpectedly large variations in the stratosphere, reached 400 ppm in one particular night flight. This is about 20% higher than the ground value. Evidence is presented that the experiment performed well during each of the balloon flights. The isotopic ratio C-12/C-13 was measured and found in good agreement with previous air analyses showing a depletion of C-13.

Mauersberger, K.; Finstad, R.

1980-01-01

194

Carbon dioxide capture and use: organic synthesis using carbon dioxide from exhaust gas.  

PubMed

A carbon capture and use (CCU) strategy was applied to organic synthesis. Carbon dioxide (CO2) captured directly from exhaust gas was used for organic transformations as efficiently as hyper-pure CO2 gas from a commercial source, even for highly air- and moisture-sensitive reactions. The CO2 capturing aqueous ethanolamine solution could be recycled continuously without any diminished reaction efficiency. PMID:24307628

Kim, Seung Hyo; Kim, Kwang Hee; Hong, Soon Hyeok

2014-01-13

195

Vapor-liquid phase coexistence of alkane-carbon dioxide and perfluoroalkane-carbon dioxide mixtures  

Microsoft Academic Search

Both government and industry are seeking benign substitutes for the many organic solvents used in industry. Solvents are used as media for cleaning, for chemical reactions, and for chemical separation, and most of the solvents used are hazardous to health, safety, and the environment. Supercritical carbon dioxide (SC-CO) is often considered as an ideal solvent substitute, but several important classes

S. T. Cui; H. D. Cochran; P. T. Cummings

1999-01-01

196

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

Code of Federal Regulations, 2013 CFR

...dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers. (b) The use of linearizing circuits is permitted. (c) The minimum water rejection...

2013-07-01

197

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

198

Carbon Cycle Data from the Carbon Dioxide Information Analysis Center (CDIAC)  

DOE Data Explorer

CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, models, etc. and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to carbon cycle includes: Terrestrial Carbon Sequestration Data Sets Area and Carbon Content of Sphagnum Since Last Glacial Maximum (2002) (Trends Online) Carbon Dioxide Emissions from Fossil-Fuel Consumption and Cement Manufacture, (2002) (Trends Online) Estimates of Monthly CO2 Emissions and Associated 13C/12C Values from Fossil-Fuel Consumption in the U.S.A., (2004) (Trends Online) Estimates of Annual Fossil-Fuel CO2 Emitted for Each State in the U.S.A. and the District of Columbia for Each Year from 1960 through 2001 (Trends Online) Global, Regional, and National Annual CO2 Emissions from Fossil-Fuel Burning, Cement Production, and Gas Flaring: 1751-1999 (updated 2002) Geographic Patterns of Carbon Dioxide Emissions from Fossil-Fuel Burning, Hydraulic Cement Production, and Gas Flaring on a One Degree by One Degree Grid Cell Basis: 1950 to 1990 (1997) Carbon Dioxide Emission Estimates from Fossil-Fuel Burning, Hydraulic Cement Production, and Gas Flaring for 1995 on a One Degree Grid Cell Basis (1998) AmeriFlux - Terrestrial Carbon Dioxide, Water Vapor, and Energy Balance Measurements Intergovernmental Panel on Climate Change (IPCC), Working Group 1, 1994: Modelling Results Relating Future Atmospheric CO2 Concentrations to Industrial Emissions (1995) Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) (2003) Global Patterns of Carbon Dioxide emissions from Soils on a 0.5 Degree Grid Cell Basis (1996) Carbon Flux to the Atmosphere from Land-use Changes: 1850 to 1990 (2001) Northern Hemisphere Biome- and Process-Specific Changes in Forest Area and Gross Merchantable Volume: 1890-1990 (1997) Historic Land Use and Carbon Estimates for South and Southeast Asia: 1880-1980 (1994) Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Forests: A Database (2001) Tropical Africa: Land Use, Biomass, and Carbon Estimates for 1980 (1996) Worldwide Organic Soil Carbon and Nitrogen Data (1986) A Global 1 Degree by 1 Degree Distribution of Atmospheric - Soil CO2 Consumption by Continental Weathering and of Riverine HCO3 Yield (1995) Goddard Institute for Space Studies (GISS) 3-Dimensional (3-D) Global Tracer Transport Model (1993) (Specialized Interface)

199

Carbon dioxide enrichment inhibits nitrate assimilation in wheat and Arabidopsis.  

PubMed

The concentration of carbon dioxide in Earth's atmosphere may double by the end of the 21st century. The response of higher plants to a carbon dioxide doubling often includes a decline in their nitrogen status, but the reasons for this decline have been uncertain. We used five independent methods with wheat and Arabidopsis to show that atmospheric carbon dioxide enrichment inhibited the assimilation of nitrate into organic nitrogen compounds. This inhibition may be largely responsible for carbon dioxide acclimation, the decrease in photosynthesis and growth of plants conducting C(3) carbon fixation after long exposures (days to years) to carbon dioxide enrichment. These results suggest that the relative availability of soil ammonium and nitrate to most plants will become increasingly important in determining their productivity as well as their quality as food. PMID:20466933

Bloom, Arnold J; Burger, Martin; Rubio Asensio, Jose Salvador; Cousins, Asaph B

2010-05-14

200

The effect of elevated carbon dioxide on the growth and yield of wheat in the Australian Grains Free Air Carbon dioxide Enrichment (AGFACE) experiment  

Microsoft Academic Search

Current predictions indicate that Australia is likely to be particularly challenged by the impacts of rising atmospheric carbon dioxide and the consequent perturbations in climate. The Australian Grains Free Air Carbon dioxide Enrichment (AGFACE) project in Horsham, Victoria was designed to simulate predicted atmospheric carbon dioxide levels in the year 2050. The experiment measures the interacting effects of carbon dioxide

Rob Norton; Glenn Fitzgerald; Chris Korte

201

Chemical Reactions in Supercritical Carbon Dioxide  

NASA Astrophysics Data System (ADS)

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

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

1998-12-01

202

Six-fold coordinated carbon dioxide VI  

NASA Astrophysics Data System (ADS)

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

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

2007-01-01

203

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.

204

Reactions of Carbon Dioxide with Silicates under High Pressures.  

National Technical Information Service (NTIS)

Reactions of carbon dioxide with molten glass under high pressures were studied. Two special types of apparatus were employed. The results supported the existence of equilibria between silicates and carbonates. No evidence was found for the existence of e...

W. Weyl

1975-01-01

205

66 FR 66994 - Controlling Corrosion on Hazardous Liquid and Carbon Dioxide Pipelines  

Federal Register 2010, 2011, 2012, 2013

...195 Controlling Corrosion on Hazardous Liquid and Carbon Dioxide Pipelines; Final Rule...2137-AD24 Controlling Corrosion on Hazardous Liquid and Carbon Dioxide Pipelines AGENCY...corrosion control standards for hazardous liquid and carbon dioxide pipelines. The...

2001-12-27

206

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.  

Code of Federal Regulations, 2013 CFR

... false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storageT/ALL....

2013-10-01

207

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

208

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

209

Foaming agents for carbon dioxide and steam floods  

Microsoft Academic Search

This patent describes improvement in a steam flood or carbon dioxide flood in an underground hydrocarbon formation. The improvement comprises: injecting into an injection well above 0.05% to about 5% by weight aqueous surfactant solution which will foam and reduce the permeability of swept zones, forcing steam or carbon dioxide into unswept areas of the formation, the aqueous surfactant solution

Naae

1991-01-01

210

Solid amine compounds as sorbents for carbon dioxide: A concept  

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

211

Absorption of Carbon Dioxide in Waste Tanks (September 3, 1987).  

National Technical Information Service (NTIS)

Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefo...

D. T. Hobbs

1987-01-01

212

An Electrochemical Technic for Measuring Carbon Dioxide Content of Blood.  

National Technical Information Service (NTIS)

An electrochemical technic for measuring carbon dioxide content in whole blood has been devised and evaluated. This technic has been extended to measure the Bunsen solubility coefficient of carbon dioxide. The method requires a membrane-covered pH electro...

R. J. Reyes J. R. Neville

1967-01-01

213

The acid rain\\/carbon dioxide threat Control strategies  

Microsoft Academic Search

Many of the world's most troublesome problems are closely interrelated. A case in point is the acid rain\\/carbon dioxide threat. Acid rain is the commonly used synonym for the major ingredients in the ongoing regional forest dieback, and carbon dioxide is a major influencing factor in the man-induced global geophysical experiment which is feared to lead to unacceptable climatic changes.

Wilfrid Bach

1985-01-01

214

Carbon dioxide and climate: Summaries of research in FY 1988  

SciTech Connect

Detailed worldwide measurements indicate that the amount of carbon dioxide in the earth's atmosphere has increased about 25 percent during the past 188 years, primarily because of fossil-fuel combustion and deforestation. Carbon dioxide is one of several trace gases that can modify the earth's heat balance by absorbing outgoing radiation from the earth's surface, thereby increasing the amount of heat retained by the atmosphere--the so-called greenhouse effect. Scientific analyses suggest that this increase could substantially affect climate, agriculture, and other human endeavors. The Carbon Dioxide Research Program is aimed at improving the scientific knowledge base to enable researchers to project future atmospheric concentrations of carbon dioxide, to estimate carbon dioxide-induced global and regional climate changes, and to assess the responses of vegetation to higher concentrations of carbon dioxide and changing climate. The Department of Energy is the lead federal agency for research related to atmospheric carbon dioxide. Its responsibility is to sponsor a program of directed research and to coordinate this research with relevant activities of other federal agencies, private concerns, and international institutions. This Program Summary documents the activities and products of the Carbon Dioxide Research (CDR) Program in Fiscal Year 1988. The Summary provides descriptions of all projects funded during the year and a brief overview of the CDR Program's goals, objectives, and organization. 1 fig., 3 tabs.

Not Available

1988-10-01

215

Carbon Dioxide Changes During the Last 400,000 years  

NSDL National Science Digital Library

In this problem set, learners will analyze a graph of carbon dioxide concentration in the last 400,000 years and consider the rise in carbon dioxide of the last 150 years. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

216

Flexible substrates as basis for photocatalytic reduction of carbon dioxide  

Microsoft Academic Search

A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized the performance in this setting. Glass substrates were used for model studies with an active area of 100cm2

Jacob Jensen; Mette Mikkelsen; Frederik C. Krebs

2011-01-01

217

Ocean Acidification Consequences of Stabilization of Atmospheric Carbon Dioxide  

Microsoft Academic Search

We investigate ocean chemistry changes that would result from the stabilization of atmospheric carbon dioxide concentrations at different levels. To determine the fate of ocean chemistry after atmospheric carbon dioxide is stabilized, we perform a suite of simulations using the UVic Earth system model in which atmospheric CO2 is stabilized at levels ranging from 280 ppm to 5000 ppm. Atmospheric

L. Cao; K. Caldeira

2007-01-01

218

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.

219

Herbivore responses to plants grown in enriched carbon dioxide atmospheres  

Microsoft Academic Search

Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient

Lincoln

1990-01-01

220

A Tenuous Carbon Dioxide Atmosphere on Jupiter's Moon Callisto  

Microsoft Academic Search

An off-limb scan of Callisto was conducted by the Galileo Near Infrared Mapping Spectrometer to search for a carbon dioxide atmosphere. Airglow in the CO, v,, band was observed up to 100 km above the surface and indicates the presence of a tenuous carbon dioxide atmosphere with surface pressure of 7.5 x 10\\

Robert W. Carlson

1999-01-01

221

Carbon dioxide sequestration by ex-situ mineral carbonation  

SciTech Connect

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

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

2000-01-01

222

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

223

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

USGS Publications Warehouse

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

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

224

Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.  

PubMed

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

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

2014-01-01

225

Carbon dioxide hydrogenation on Ni(110).  

PubMed

We demonstrate that the key step for the reaction of CO 2 with hydrogen on Ni(110) is a change of the activated molecule coordination to the metal surface. At 90 K, CO 2 is negatively charged and chemically bonded via the carbon atom. When the temperature is increased and H approaches, the H-CO 2 complex flips and binds to the surface through the two oxygen atoms, while H binds to the carbon atom, thus yielding formate. We provide the atomic-level description of this process by means of conventional ultrahigh vacuum surface science techniques combined with density functional theory calculations and corroborated by high pressure reactivity tests. Knowledge about the details of the mechanisms involved in this reaction can yield a deeper comprehension of heterogeneous catalytic organic synthesis processes involving carbon dioxide as a reactant. We show why on Ni the CO 2 hydrogenation barrier is remarkably smaller than that on the common Cu metal-based catalyst. Our results provide a possible interpretation of the observed high catalytic activity of NiCu alloys. PMID:18665600

Vesselli, Erik; De Rogatis, Loredana; Ding, Xunlei; Baraldi, Alessandro; Savio, Letizia; Vattuone, Luca; Rocca, Mario; Fornasiero, Paolo; Peressi, Maria; Baldereschi, Alfonso; Rosei, Renzo; Comelli, Giovanni

2008-08-27

226

Global carbon dioxide emissions from inland waters.  

PubMed

Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8(+0.25)(-0.25)? petagrams of carbon (Pg?C) per year from streams and rivers and 0.32(+0.52)(-0.26)? Pg?C?yr(-1) from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1?Pg?C?yr(-1) is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally. PMID:24256802

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

2013-11-21

227

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.

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

2012-01-01

228

Thermodynamical effects during carbon dioxide release  

NASA Astrophysics Data System (ADS)

Pruess [1] investigated the risk of carbon dioxide leakage from shallow storage sites by modeling scenarios. Such a fluid release is associated with mechanical work performed by formation fluid against expansion without taking heat from ambient environment. Understanding of heat related to mechanical work is essential to predict the temperature at the leak. According to the first law of thermodynamics, internal energy of working fluid decreases with an amount which is equivalent to this work hence, working fluid lost its own heat. Such kind of heat loss depends strongly on whether the expansion process is adiabatic or isothermal. Isothermal expansion allows the working fluid to interact thermally with the solid matrix. Adiabatic expansion is an isenthalpic process that takes heat from the working fluid and the ambient environment remains unchanged. This work is part of the CLEAN research project [6]. In this study, thermodynamic effects of mechanical work during eventual carbon dioxide leakage are investigated numerically. In particular, we are interested to detect the temperature at leakage scenarios and its deviation with different thermodynamic processes. Finite element simulation is conducted with a two-dimensional rectangular geometry representing a shallow storage site which bottom was located at -300m below the land surface. A fully saturated porous medium is assumed where the pore space is filled completely with carbon dioxide. Carbon dioxide accumulated in the secondary trap at 30 Bar and 24 C is allowed to leak from top right point of rectangle with atmospheric pressure. With (i) adiabatic and (ii) isothermal compressibility factors, temperature around leakage area has been calculated which show a significant difference. With some simplification, this study detects leak temperature which is very close with [1]. Temporal evaluation at the leaky area shows that the working fluid temperature can be reduced to -20 C when the leakage scenario is performed under isothermal expansion. Under adiabatic expansion, further reduction in the working fluid temperature can be expected. The governing equations from mass and energy balance laws of porous media mechanics are used for problem description. Pressure and fluid phase temperature are chosen as the primary variables. Extended ideal gas law is used with super compressibility factor (SCF) to predict real gas density for large range of pressure and temperature [2]. Cubic equation based on Peng-Robinson equation of state was solved analytically for SCF [3]. Real fluid properties, such as dynamic viscosity, thermal conductivity and specific heat capacity used in this study are density and temperature dependent. Analytical expression for the derivatives of SCF with respect to temperature and pressure are used. Subsequently, these derivatives are utilized to define isothermal compressibility, adiabatic compressibility and thermal expansion coefficient for the real gas. These parameters can influence heat loss due to thermodynamic effects significantly. The governing equations are discretized spatially within the Galerkin approach, whereas for the temporal discretization, we adopt generalized single step method [5]. The coupled system of governing equations is solved in a monolithic way with variable time stepping. The numerical module has been implemented within the open source object-oriented finite element code OpenGeoSys [4].

Singh, A. K.; Bttcher, N.; Grke, U.-J.; Kolditz, O.

2012-04-01

229

Calcium oxide matrices and carbon dioxide sensors.  

PubMed

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 (CO(2)) via a nanogravimetric method by performing the experiments inside an atmosphere-controlled chamber filled with CO(2). Furthermore, the composite material showed a linear absorption of CO(2) 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 CO(2). PMID:22778620

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

2012-01-01

230

Carbon dioxide-in-water microemulsions.  

PubMed

Liquid and supercritical carbon dioxide swell potassium carboxylate perfluoropolyether (PFPE-K) cylindrical micelles in water to produce novel CO(2)-in-water (C/W) microemulsions. The swelling elongates the micelles significantly from 20 to 80 nm as the molar ratio of CO(2) in the micelles to surfactant (R(CO2)) reaches approximately 8. As the micelles swell to form microemulsions, the solubility of pyrene increases by a factor of ca. 10. Fluorescence spectra suggest that pyrene resides primarily in the low-polarity micelle core rather than in the palisade region. The results illustrate the ability of C/W microemulsions to solubilize both lipophilic and fluorophilic substances simultaneously. PMID:12617686

Lee, C Ted; Ryoo, Won; Smith, P Griffin; Arellano, Jose; Mitchell, Daniel R; Lagow, Richard J; Webber, Stephen E; Johnston, Keith P

2003-03-12

231

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

232

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

233

Coiled tubing drilling with supercritical carbon dioxide  

DOEpatents

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

Kolle , Jack J. (Seattle, WA)

2002-01-01

234

Six-fold coordinated carbon dioxide VI.  

PubMed

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

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

2007-01-01

235

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

236

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

237

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

238

Carbon Dioxide in the Gulf of Trieste  

NASA Astrophysics Data System (ADS)

Coastal marine regions such as the Gulf of Trieste (GOT) in the Northern Adriatic Sea serve as the link between carbon cycling on land and the ocean interior and potentially contribute large uncertainties in the estimate of anthropogenic CO2 uptake. This system may be either a sink or a source for atmospheric CO2. Understanding the sources and sinks as a result of biological and physical controls for air-sea carbon dioxide fluxes in coastal waters may substantially alter the current view of the global carbon budget for unique terrestrial and ocean regions such as the GOT. GOT is a semi-enclosed Mediterranean basin situated in the northern part of Adriatic Sea. It is one of the most productive regions in the Mediterranean and is affected by extreme fresh river input, phytoplankton blooms, and large changes of air-sea exchange during Bora high wind events. The unique combination of these environmental processes and relatively small size of the area makes the region an excellent study site for investigations of air-sea interaction, and changes in biology and carbon chemistry. Here we investigate biological (phytoplankton blooms) and physical (freshwater input and winds) controls on the temporal variability of pCO2 in the GOT. The aqueous CO2 was measured at the Coastal Oceanographic buoy VIDA, Slovenia using the SAMI CO2 sensor. Our results indicate that: 1) The GOT was a sink for atmospheric CO2 in late spring of 2007; 2) Aqueous pCO2 was influenced by fresh water input from rivers entering the GOT and biological production associated with high nutrient input; 3) Surface water pCO2 showed a strong correlation with SST when river plumes where not present at the buoy location, and reasonable correlation with SSS during the presence of the plume.

Turk, D.; Malacic, V.; Degrandpre, M. D.; McGillis, W. R.

2009-04-01

239

Diffusion of 2-methyl-1,4-naphthoquinone (1); carbon dioxide (2)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) 2-methyl-1,4-naphthoquinone; (2) carbon dioxide

Winkelmann, J.

240

Diffusion of 2-methyl-1,4-naphthoquinone (1); carbon dioxide (2); hexane (3)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) 2-methyl-1,4-naphthoquinone; (2) carbon dioxide; (3) hexane

Winkelmann, J.

241

UNDERSTANDING AND MANAGING RISKS POSED BY BRINES CONTAINING DISSOLVED CARBON DIOXIDE  

EPA Science Inventory

Geologic disposal of supercritical carbon dioxide in saline aquifers and depleted oil and gas fields will cause large volumes of brine to become saturated with dissolved CO2 at concentrations of 50 g/l or more. As CO2 dissolves in brine, the brine de...

242

Diffusion of carbon dioxide (1); water (2); sodium chloride (3); magnesium chloride (4)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) carbon dioxide; (2) water; (3) sodium chloride; (4) magnesium chloride

Winkelmann, J.

243

Diffusion of carbon dioxide (1); water (2); magnesium chloride (3); sodium sulphate (4)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Brnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of (1) carbon dioxide; (2) water; (3) magnesium chloride; (4) sodium sulphate

Winkelmann, J.

244

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

NASA Technical Reports Server (NTRS)

An alkali metal, such as lithium, is the anodic reactant; carbon dioxide or a mixture of carbon dioxide and carbon monoxide is the cathodic reactant; and carbonate of the alkali metal is the electrolyte in an electrochemical cell for the storage and delivery of electrical energy. Additionally, alkali metal-carbon dioxide battery systems include a plurality of such electrochemical cells. Gold is a preferred catalyst for reducing the carbon dioxide at the cathode. The fuel cell of the invention produces electrochemical energy through the use of an anodic reactant which is extremely energetic and light, and a cathodic reactant which can be extracted from its environment and therefore exacts no transportation penalty. The invention is, therefore, especially useful in extraterrestrial environments.

Hagedorn, Norman H. (inventor)

1993-01-01

245

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

DOEpatents

A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

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

2010-11-09

246

Atmospheric Trace Gases, Carbon Isotopes, Radionuclides, and Aerosols: Atmospheric Carbon Dioxide Data from the Carbon Dioxide Information Analysis Center (CDIAC)  

DOE Data Explorer

CDIAC products include numeric data packages, publications, trend data, atlases, models, etc. and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication titled Trends Online: A Compendium of Global Change Data. Most datasets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to atmospheric carbon dioxide data includes: Atmospheric Carbon Dioxide and Carbon Isotopes Atmospheric carbon dioxide records from Mauna Loa, Hawaii Monthly atmospheric CO2 mixing ratios and other data from the NOAA/CMDL continuous monitoring network Data from the CSIRO GASLAB Flask Sampling Network Atmospheric CO2 records from continuous measurements at Jubany Station, Antarctica and from 10 sites in the SIO air sampling network Historical data from the extended Vostok ice core (2003) and the Siple Station ice core (1997) Historical records from the Law Dome DE08, DE08-2, and DSS ice cores (1998) AmeriFlux Carbon Dioxide, Water Vapor, and Energy Balance Measurements Data from the Canadian Background Air Pollution Monitoring Network Flask Samples from at U.S.S.R.-Operated Sites (1991) The CISIRO (Australia) Monitoring Program from Aircraft for 1972-1981 CO2 Concentrations in Surface Water and the Atmosphere during 1986-1989 NOAA/PMEL Cruises in the Pacific and Indian Oceans Surface Water and Atmospheric CO2 and Nitrous Oxide Observations by Shipboard Automated Gas Chromatography: Results from Expeditions Between 1977 and 1990 (1992) IPCC Working Group 1, 1994: Modeling Results Relating Future Atmospheric CO2 Concentrations to Industrial Emissions (1995). New datasets are added when available to the category of atmospheric carbon dioxide.

247

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

248

REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE  

EPA Science Inventory

The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

249

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

250

Allowable Exposure Limits for Carbon Dioxide during Extravehicular Activity.  

National Technical Information Service (NTIS)

The intent was to review the research pertaining to human exposure to carbon dioxide (CO2) and to recommend allowable exposure limits for extravehicular activity (EVA). Respiratory, renal, and gastrointestinal systems may be adversely affected by chronic ...

A. J. Seter

1993-01-01

251

Hiilidioksiditoimikunnan mietintoe. (Report of the carbon dioxide commission).  

National Technical Information Service (NTIS)

The Commission was entrusted with investigating alternative strategies and measures for limiting and reducing the emissions of carbon dioxide and other greenhouse gases. It was to study both technical and structural means of reducing these emissions. The ...

J. Routti

1991-01-01

252

Plants Can't Do without Carbon Dioxide.  

ERIC Educational Resources Information Center

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

Hershey, David R.

1992-01-01

253

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

254

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 animal used. The unanaesthetized restrained birds were...

H. S. Weiss L. W. Torley

1975-01-01

255

Numerical analysis of a carbon dioxide SFUR laser.  

National Technical Information Service (NTIS)

Within the framework of the ENEA (Italian Commission for Alternative Energy Sources) project on optical and electro-optical technologies, a TEA carbon dioxide laser was developed based upon a Self Filtering Unstable Resonator (SFUR). It delivers high ener...

R. Barbini, F. Colao, A. Petri

1989-01-01

256

Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures  

DOEpatents

A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

Aines, Roger D.; Bourcier, William L.; Viani, Brian

2013-01-29

257

Effect of helium in helium headspace carbon dioxide cylinders on packed-column supercritical fluid chromatography.  

PubMed

Supercritical fluid chromatography of PAHs was performed with pure carbon dioxide and helium headspace carbon dioxide at various cylinder fill levels. The retention times of the PAHs increased when helium headspace carbon dioxide was used as a carrier fluid relative to pure carbon dioxide. The increased retention times were affected by the level of the liquid phase present in the helium headspace carbon dioxide cylinder. As more liquid phase was removed from the cylinder, the effect of helium on the solvating power of CO(2) was reduced because the relative amount of helium dissolved in the liquid phase decreased. Furthermore, the effect of helium headspace carbon dioxide was investigated with methanol-modified carbon dioxide mobile phases for the analysis of steroids. We observed that the relative solubility of helium in carbon dioxide resulted in longer retention times when compared to pure carbon dioxide as the liquid level of carbon dioxide decreased. PMID:21619186

Leichter, E; Strode, J T; Taylor, L T; Schweighardt, F K

1996-03-01

258

Decorating catalytic palladium nanoparticles on carbon nanotubes in supercritical carbon dioxide  

SciTech Connect

Hydrogen reduction of a Pd(II)-b-diketone precursor in supercritical carbon dioxide produces palladium nanoparticles on multi-walled carbon nanotubes that exhibit promising catalytic properties for hydrogenation of olefins in carbon dioxide as well as electro-reduction of oxygen in fuel cell applications.

Ye, Xiang-Rong; Lin, Yuehe; Wai, C M.

2003-02-25

259

Effect of carbon dioxide on fuel stability under storage conditions  

Microsoft Academic Search

1.Carbon dioxide, when used as an inert gas medium for filling the free space in tanks and reservoirs, limits the sediment formation, wards off the formation of oxidation products and existent gum, and stabilizes the acid number and cloud point of the fuel.2.The favorable stabilizing effect of carbon dioxide on fuel oxidation in storage is retained at gas-phase CO2 concentrations

V. N. Zrelov; V. M. Shagin; N. V. Avdeev; T. S. Merzlova; N. A. Afanas'eva; V. V. Bulavin

1973-01-01

260

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

261

Precipitation of food protein using high pressure carbon dioxide  

Microsoft Academic Search

High pressure carbon dioxide has been applied to precipitate soy protein. The method is suitable for effective precipitation of soy proteins and prevents local pH overshoot, which usually occurs in case of using mineral acids for the precipitation processes. It was possible to achieve 68.3wt% of soy protein precipitate using 30bars of pressurized carbon dioxide, at pH of 5.60 and

Nawal Khorshid; M. M. Farid

2007-01-01

262

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

263

Supercritical carbon dioxide extraction and deacidification of rice bran oil  

Microsoft Academic Search

This study examined pilot-scale extraction and lab-scale deacidification of rice bran oil by using supercritical carbon dioxide (SC-CO2). Two purest gamma-oryzanols (?-oryzanols) (>98wt%) were initially obtained by preparative reverse-phase high-performance liquid chromatography. Supercritical carbon dioxide extraction at 300bar and 313K from 1.03kg powdered rice bran indicated a total yield of oil of 15.7% with a free fatty acids content of

Chao-Rui Chen; Chih-Hung Wang; Ling-Ya Wang; Zih-Hao Hong; Shuo-Hsiu Chen; Wai-Jane Ho; Chieh-Ming J. Chang

2008-01-01

264

Feasibility of Metalworking Fluids Delivered in Supercritical Carbon Dioxide  

Microsoft Academic Search

This paper presents a new method to lubricate, cool, and evacuate chips in metalworking operations using supercritical carbon dioxide (scCO2). Water-based and straight oil metalworking fluids (MWFs) are currently being used to perform these functions even though they are characterized by high economic, occupational health, and environmental costs. Carbon dioxide above its critical temperature and pressure is a finely tunable

Andres F. Clarens; Kim F. Hayes; Steven J. Skerlos

2006-01-01

265

Methanolysis of seed oils in flowing supercritical carbon dioxide  

Microsoft Academic Search

The direct methanolysis of triglycerides in flowing supercritical carbon dioxide by an immobilized lipase is described. The\\u000a reaction system consists of two syringe pumps for substrate addition and another two syringe pumps for delivering CO2 at 24.1 MPa. Corn oil is pumped into the carbon dioxide stream at a rate of 4 ?L\\/min, and methanol is pumped at 5 ?L\\/min

Michael A. Jackson; Jerry W. King

1996-01-01

266

Carbon dioxide sequestration by direct mineral carbonation with carbonic acid  

Microsoft Academic Search

The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation,

William K. OConnor; David C. Dahlin; David N. Nilsen; Richard P. Walters; Paul C. Turner

2000-01-01

267

Acute carbon dioxide avoidance in Caenorhabditis elegans.  

PubMed

Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm. PMID:18524955

Hallem, Elissa A; Sternberg, Paul W

2008-06-10

268

Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors  

NASA Technical Reports Server (NTRS)

A miniaturized electrochemical carbon dioxide (CO2) sensor using Na3Z r2Si2PO12 (NASICON) as a solid electrolyte has been fabricated and de monstrated. Microfabrication techniques were used for sensor fabricat ion to yield a sensing area around 1.0 mm x 1.1 mm. The NASICON solid electrolyte and the Na2CO3/BaCO3 (1:1.7 molar ratio) auxiliary elect rolyte were deposited by sputtering in between and on top of the inte rdigitated finger-shaped platinum electrodes. This structure maximize s the length of the three-phase boundary (electrode, solid electrolyt e, and auxiliary electrolyte), which is critical for gas sensing. The robust CO2 sensor operated up to 600 C in an amperometric mode and a ttempts were made to optimize sensor operating parameters. Concentrat ions of CO2 between 0.02% and 4% were detected and the overall sensor performance was evaluated. Linear response of sensor current output to ln[CO2 concentration] ranging from 0.02% to 1% was achieved.

Hunter, G. W.; Xu, J. C.; Liu, C. C.; Hammond, J. W.; Ward, B.; Lukco, D.; Lampard, P.; Artale, M.; Androjna, D.

2006-01-01

269

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

270

Rat aversion to isoflurane versus carbon dioxide  

PubMed Central

Some experts suggest that sedation of laboratory rodents with isoflurane before euthanasia with carbon dioxide (CO2) is a humane alternative to euthanasia with CO2 alone, but little research has compared aversion with these agents. Albino rats were tested in a lightdark box where they had the choice between remaining in a dark compartment filling with isoflurane or CO2, or escaping to a lit compartment. Experiment 1 validated the procedure by confirming that rats responded to agent and light intensity. In experiment 2, 9/16 and 0/16 rats remained in the dark compartment until recumbent when initially exposed to isoflurane and CO2, respectively. In experiment 3, more rats remained in the dark compartment until recumbent during initial (10/16) versus re-exposure (1/16) to isoflurane. These results indicate that initial exposure to CO2 is more aversive than isoflurane, and that re-exposure to isoflurane is more aversive than initial exposure. We conclude that sedation with isoflurane is a refinement over euthanasia with CO2 alone for rats that have not been previously exposed to inhalant anaesthetics.

Wong, Devina; Makowska, I. Joanna; Weary, Daniel M.

2013-01-01

271

Zenker's Diverticulum: Carbon Dioxide Laser Endoscopic Surgery  

PubMed Central

Nowadays endoscopic diverticulotomy is the surgical approach of the first choice in treatment of Zenker's diverticulum. We report our experience with this procedure and try to sum up recent recommendations for management of surgery and postoperative care. Data of 34 patients with Zenker's diverticulum, treated by endoscopic carbon dioxide laser diverticulotomy at the Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine, Charles University, University Hospital Motol, Prague, Czech Republic, were prospectively stored and followed in relatively short period from May 2009 to December 2013. The average length of diverticulum was 32?mm. The average duration of surgery was 32?min. The patients were fed via feeding tube for 6.1 days and antibiotics were administered for 7 days. Mean hospitalization time was 7.4 days. We observed one transient recurrent laryngeal nerve paralysis and no other serious complications. Recurrence rate was 3%. We recommend complete transection of the diverticular septum in one procedure, systemic antibiotic treatment and exclusion of transoral intake for minimally 5 days, and contrast oesophagogram before resumption of oral intake to exclude fistula. Open diverticulectomy should be reserved for cases with inadequate endoscopic exposure and for revision surgery for multiple recurrences from endoscopic diverticulotomies.

Plzak, Jan; Zabrodsky, Michal; Lukes, Petr

2014-01-01

272

Carbon dioxide sequestration by direct aqueous mineral carbonation  

SciTech Connect

Carbon dioxide sequestration by an ex-situ, direct aqueous mineral carbonation process has been investigated over the past two years. This process was conceived to minimize the steps in the conversion of gaseous CO2 to a stable solid. This meant combining two separate reactions, mineral dissolution and carbonate precipitation, into a single unit operation. It was recognized that the conditions favorable for one of these reactions could be detrimental to the other. However, the benefits for a combined aqueous process, in process efficiency and ultimately economics, justified the investigation. The process utilizes a slurry of water, dissolved CO2, and a magnesium silicate mineral, such as olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. These minerals were selected as the reactants of choice for two reasons: (1) significant abundance in nature; and (2) high molar ratio of the alkaline earth oxides (CaO, MgO) within the minerals. Because it is the alkaline earth oxide that combines with CO2 to form the solid carbonate, those minerals with the highest ratio of these oxides are most favored. Optimum results have been achieved using heat pretreated serpentine feed material, sodium bicarbonate and sodium chloride additions to the solution, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Future studies are intended to investigate various mineral pretreatment options, the carbonation solution characteristics, alternative reactants, scale-up to a continuous process, geochemical modeling, and process economics.

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

2000-01-01

273

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

NSDL National Science Digital Library

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

274

Carbon dioxide fluxes from an urban area in Beijing  

NASA Astrophysics Data System (ADS)

A better understanding of urban carbon dioxide (CO 2) emissions is important for quantifying urban contributions to the global carbon budget. From January to December 2008, CO 2 fluxes were measured, by eddy covariance at 47 m above ground on a meteorological tower in a high-density residential area in Beijing. The results showed that the urban surface was a net source of CO 2 in the atmosphere. Diurnal flux patterns were similar to those previously observed in other cities and were largely influenced by traffic volume. Carbon uptake by both urban vegetation during the growing season and the reduction of fuel consumption for domestic heating resulted in less-positive daily fluxes in the summer. The average daily flux measured in the summer was 0.48 mg m - 2 s - 1 , which was 82%, 35% and 36% lower than those in the winter, spring and autumn, respectively. The reduction of vehicles on the road during the 29th Olympic and Paralympic Games had a significant impact on CO 2 flux. The flux of 0.40 mg m - 2 s - 1 for September 2008 was approximately 0.17 mg m - 2 s - 1 lower than the flux for September 2007. Annual CO 2 emissions from the study site were estimated at 20.6 kg CO 2 m - 2 y - 1 , considerably higher than yearly emissions obtained from other urban and suburban landscapes.

Song, Tao; Wang, Yuesi

2012-03-01

275

Fixation and activation of carbon dioxide on aluminum porphyrin. Catalytic formation of carbamic ester from carbon dioxide, amine, and epoxide  

SciTech Connect

Carbon dioxide is trapped by (5,10,15,20-tetraphenylporphinato) aluminum acetate in the presence of a secondary amine in the form of an aluminum carbamate on the opposite side to the acetate group with respect to the porphyrin plane. Carbon dioxide thus trapped by aluminum porphyrin is activated enough to undergo a catalytic reaction involving secondary amine and epoxide to afford dialkylcarbamic ester under atmospheric pressure at room temperature. 15 references, 2 figures, 2 tables.

Kojima, F.; Aida, T.; Inoue, S.

1986-02-05

276

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS  

SciTech Connect

This report describes research conducted between April 1, 2004 and June 30, 2004 on the preparation and use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Support materials and supported sorbents were prepared by spray drying. Sorbents consisting of 20 to 50% sodium carbonate on a ceramic support were prepared by spray drying in batches of approximately 300 grams. The supported sorbents exhibited greater carbon dioxide capture rates than unsupported calcined sodium bicarbonate in laboratory tests. Preliminary process design and cost estimation for a retrofit application suggested that costs of a dry regenerable sodium carbonate-based process could be lower than those of a monoethanolamine absorption system. In both cases, the greatest part of the process costs come from power plant output reductions due to parasitic consumption of steam for recovery of carbon dioxide from the capture medium.

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

2004-07-01

277

Calculation of hydrocarbon-in-place in gas and gas-condensate reservoirs - Carbon dioxide sequestration  

USGS Publications Warehouse

The Energy Independence and Security Act of 2007 (Public Law 110-140) authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2), requiring estimation of hydrocarbon-in-place volumes and formation volume factors for all the oil, gas, and gas-condensate reservoirs within the U.S. sedimentary basins. The procedures to calculate in-place volumes for oil and gas reservoirs have already been presented by Verma and Bird (2005) to help with the USGS assessment of the undiscovered resources in the National Petroleum Reserve, Alaska, but there is no straightforward procedure available for calculating in-place volumes for gas-condensate reservoirs for the carbon sequestration project. The objective of the present study is to propose a simple procedure for calculating the hydrocarbon-in-place volume of a condensate reservoir to help estimate the hydrocarbon pore volume for potential CO2 sequestration.

Verma, Mahendra K.

2012-01-01

278

Urban carbon dioxide in Portland, Oregon  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

279

The Headache of Carbon Dioxide Exposures  

NASA Technical Reports Server (NTRS)

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

James, John T.

2007-01-01

280

Carbon dioxide catastrophes: Past and future menace  

NASA Technical Reports Server (NTRS)

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

Baur, Mario E.

1988-01-01

281

Development of Carbon Dioxide Removal Systems for Advanced Exploration Systems  

NASA Technical Reports Server (NTRS)

"NASA's Advanced Exploration Systems (AES) program is pioneering new approaches for rapidly developing prototype systems, demonstrating key capabilities, and validating operational concepts for future human missions beyond Earth orbit" (NASA 2012). These forays beyond the confines of earth's gravity will place unprecedented demands on launch systems. They must not only blast out of earth's gravity well as during the Apollo moon missions, but also launch the supplies needed to sustain a crew over longer periods for exploration missions beyond earth's moon. Thus all spacecraft systems, including those for the separation of metabolic carbon dioxide and water from a crewed vehicle, must be minimized with respect to mass, power, and volume. Emphasis is also placed on system robustness both to minimize replacement parts and ensure crew safety when a quick return to earth is not possible. Current efforts are focused on improving the current state-of-the-art systems utilizing fixed beds of sorbent pellets by seeking more robust pelletized sorbents, evaluating structured sorbents, and examining alternate bed configurations to improve system efficiency and reliability. These development efforts combine testing of sub-scale systems and multi-physics computer simulations to evaluate candidate approaches, select the best performing options, and optimize the configuration of the selected approach, which is then implemented in a full-scale integrated atmosphere revitalization test. This paper describes the carbon dioxide (CO2) removal hardware design and sorbent screening and characterization effort in support of the Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project within the AES program. A companion paper discusses development of atmosphere revitalization models and simulations for this project.

Knox, James C.; Trinh, Diep; Gostowski, Rudy; King, Eric; Mattox, Emily M.; Watson, David; Thomas, John

2012-01-01

282

Removal of organic impurities from liquid carbon dioxide  

NASA Astrophysics Data System (ADS)

The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

Zito, Richard R.

2002-09-01

283

Generation, capture, and utilization of industrial carbon dioxide.  

PubMed

As a carbon-based life form living in a predominantly carbon-based environment, it is not surprising that we have created a carbon-based consumer society. Our principle sources of energy are carbon-based (coal, oil, and gas) and many of our consumer goods are derived from organic (i.e., carbon-based) chemicals (including plastics, fabrics and materials, personal care and cleaning products, dyes, and coatings). Even our large-volume inorganic-chemicals-based industries, including fertilizers and construction materials, rely on the consumption of carbon, notably in the form of large amounts of energy. The environmental problems which we now face and of which we are becoming increasingly aware result from a human-induced disturbance in the natural carbon cycle of the Earth caused by transferring large quantities of terrestrial carbon (coal, oil, and gas) to the atmosphere, mostly in the form of carbon dioxide. Carbon is by no means the only element whose natural cycle we have disturbed: we are transferring significant quantities of elements including phosphorus, sulfur, copper, and platinum from natural sinks or ores built up over millions of years to unnatural fates in the form of what we refer to as waste or pollution. However, our complete dependence on the carbon cycle means that its disturbance deserves special attention, as is now manifest in indicators such as climate change and escalating public concern over global warming. As with all disturbances in materials balances, we can seek to alleviate the problem by (1) dematerialization: a reduction in consumption; (2) rematerialization: a change in what we consume; or (3) transmaterialization: changing our attitude towards resources and waste. The "low-carbon" mantra that is popularly cited by organizations ranging from nongovernmental organizations to multinational companies and from local authorities to national governments is based on a combination of (1) and (2) (reducing carbon consumption though greater efficiency and lower per capita consumption, and replacing fossil energy sources with sources such as wind, wave, and solar, respectively). "Low carbon" is of inherently less value to the chemical and plastics industries at least in terms of raw materials although a version of (2), the use of biomass, does apply, especially if we use carbon sources that are renewable on a human timescale. There is however, another renewable, natural source of carbon that is widely available and for which greater utilization would help restore material balance and the natural cycle for carbon in terms of resource and waste. CO(2), perhaps the most widely discussed and feared chemical in modern society, is as fundamental to our survival as water, and like water we need to better understand the human as well as natural production and consumption of CO(2) so that we can attempt to get these into a sustainable balance. Current utilization of this valuable resource by the chemical industry is only 90 megatonne per year, compared to the 26.3 gigatonne CO(2) generated annually by combustion of fossil fuels for energy generation, as such significant opportunities exist for increased utilization of CO(2) generated from industrial processes. It is also essential that renewable energy is used if CO(2) is to be utilized as a C1 building block. PMID:20049768

Hunt, Andrew J; Sin, Emily H K; Marriott, Ray; Clark, James H

2010-03-22

284

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

285

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

DOE Data Explorer

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

286

Assessing Carbon Dioxide Emissions from Energy Use at a University  

ERIC Educational Resources Information Center

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

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

2009-01-01

287

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

288

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

289

Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide  

DOEpatents

A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

Rathke, J.W.; Klingler, R.J.

1993-03-30

290

Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide  

DOEpatents

A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

Rathke, Jerome W. (Lockport, IL); Klingler, Robert J. (Westmount, IL)

1993-01-01

291

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

292

Capturing carbon dioxide as a polymer from natural gas.  

PubMed

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

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

2014-01-01

293

Supercritical Carbon Dioxide Regeneration of Activated Carbon Loaded with Contaminants from Rocky Mountain Arsenal Well Water.  

National Technical Information Service (NTIS)

The method of supercritical carbon dioxide (SCF CO2) regeneration of granular activated carbon (GAC) loaded with DIMP (diisopropyl methylphosphonate) from Rocky Mountain Arsenal Well (NO. 23-120) water was investigated. A laboratory-based adsorption/regen...

R. M. O'Brien R. P. de Filippi C. E. Smith D. G. Hager

1982-01-01

294

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

295

What Are the Human-Caused Sources of Carbon Dioxide?  

NSDL National Science Digital Library

This activity presents a digital interactive where students identify anthropogenic sources of carbon dioxide and their relative contribution to carbon enrichment of the atmosphere. Students then obtain a photograph pair of a scene in their community, and identify sources of atmospheric carbon dioxide that did not exist in the earlier photograph. Alternatively, they can interview community members to obtain the same information. This activity is supported by a textbook chapter, How is the Atmosphere Changing?, part of the unit, Climate Change, in Global Systems Science (GSS), an interdisciplinary course for high school students that emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact.

296

Environmental and Societal Consequences of a Possible CO sub 2 -Induced Climate Change. Volume II, Part 14. Research Needed to Determine the Present Carbon Balance of Northern Ecosystems and the Potential Effect of Carbon-Dioxide-Induced Climate Change.  

National Technical Information Service (NTIS)

Given the potential significance of northern ecosystems to the global carbon budget it is critical to estimate the current carbon balance of these ecosystems as precisely as possible, to improve estimates of the future carbon balance if world climates cha...

P. C. Miller

1982-01-01

297

Economic Effects of Using Carbon Taxes to Reduce Carbon Dioxide Emissions in Major OECD Countries.  

National Technical Information Service (NTIS)

A tax on fossil fuels designed to obtain a 20 percent reduction in emissions of carbon dioxide by the year 2020 would lower output among major OECD nations by 1 to 3 1/2 percent. The tax required to achieve a 20% reduction in emissions of carbon dioxide b...

1992-01-01

298

Hedging Carbon Risk: Protecting Customers and Shareholders from the Financial Risk Associated with Carbon Dioxide Emissions  

SciTech Connect

Utilities and regulators are recognizing the imprudence of assuming that carbon dioxide emissions will not cost anything over the long lifetime of new investments. Several utilities have begun to protect their customers and shareholders from this financial risk by integrating an estimated cost of carbon dioxide emissions into their evaluation of resource options, and selecting the overall least-cost portfolio of resources.

Bokenkamp, Karl; LaFlash, Hal; Singh, Virinder; Bachrach Wang, Devra

2005-07-01

299

SCORR - supercritical carbon dioxide resist removal.  

SciTech Connect

SCORR, short for supercritical carbon dioxide resist removal, is a new technology that could continue to enable the technological development of photolithography processes in industry. SCORR is based upon the physical properties of supercritical fluids (SCFs). These special properties enable SCFs to remove coatings, residues, and particles froin high-aspect-ratio structures in integrated circuits (ICs). SCORR also eliminates rinsing and drying steps presently used in IC manufacture, thereby eliminating the generation of millions of gallons of water per fab per day. Fabricating integrated circuits relies heavily on photolithography to define the shape and pattern of individual components. Once a single stage of a silicon wafer's topography has been completed, the hardened resist must be removed. Conventional processes generates more waste than any single step in the IC manufacturing process, and the production of a complete IC can involve many photolithography iterations. The cost associated with the treatment and disposal of this waste, as well as employee health and safety considerations, are driving a search for a1 ternative, environmentally benign, cost-effective solutions. In addition, photoresist stripping is confronting finer architectures and higher aspect ratios, as well as new low-k materials that are highly sensitive to post-etch residue. Low-k dielectrics and low-resistivity conductors such as copper are necessary for meeting industry's need for faster and smaller chips. Further, each low-k choice requires different plasma-etching processes, or chemistries, to etch structures into the low-k material; therefore, the nature of the residues can be different. No one product can meet all copper/low-k applications, and existing chemistries are not tunable - or even desirable - for the new processes. We have developed a new process - known as SCORR - that removes photoresist and post-ash, -etch, and -CMP (particulate) residue from semiconductor wafers. As IC feature sizes become smaller, the need for ensuring particle removal will increase. With feature sizes of less than 0.18{micro}m, it will become imperative that all particles greater than about 0.1 micron be removed from the semiconductor wafer. Existing cleaning technologies (such as liquid or high-pressure jet scrubbing) cannot remove particles on the order of 0.1 micron because of surface boundary layer constraints. Because of the low viscosities of supercritical fluids (SCFs), these constraints are virtually eliminated.

Jacobson, G. B. (Gunilla B.); Williams, L. L. (Laurie L.); Hollis, W. K. (William K.); Barton, Jerome C.; Taylor, C. M. (Craig M.)

2002-01-01

300

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

301

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

Microsoft Academic Search

A global carbon cycle model is used to reconstruct the carbon budget, balancing emissions from fossil fuel and land use with carbon uptake by the oceans, and the terrestrial biosphere. We apply Bayesian statistics to estimate uncertainty of carbon uptake by the oceans and the terrestrial biosphere based on carbon dioxide and carbon isotope records, and prior information on model

Haroon S. Kheshgi; Atul K. Jain; Donald J. Wuebbles

1999-01-01

302

Helium enrichment during convective carbon dioxide dissolution  

NASA Astrophysics Data System (ADS)

Motivated by observed variations of the CO2/He ratios in natural carbon dioxide (CO2) reservoirs, such as the Bravo Dome field in northeastern New Mexico, we have performed laboratory experiments equilibrating gas mixtures containing Helium (He) and CO2 with water, at close to ambient conditions in a closed system. The experimental design allows for continuous measurement of headspace pressure as well as timed interval measurements of the CO2/He ratios and the ?13C value of CO2 in the headspace. Results from three dissolution experiments are reported: 1) pure Helium system, 2) 98% CO2 + 2% Nitrogen system, and 3) 97% CO2 and 3% Helium. Final equilibrated experimental results are compared to theoretical results obtained using Henry's Law relationships. The evolution of the amount of dissolved CO2 computed from gas pressure and gas compositions are in good agreement with Henry's Law relationships. For example, the CO2 + N2 system was initially pressurized with pure CO2 to 1323 mbar and after six days it equilibrated to a measured headspace pressure of 596 mbar. This compares very well with a calculated equilibrium headspace pressure of 592 mbar for this system. The CO2 + He system was pressurized to 1398 mbar CO2 and after six days equilibrated to a measured headspace pressure of 397 mbar. This measured pressure is slightly higher than the predicted equilibrated headspace pressure of 341 mbar, indicating a possible leak in the system during this particular experiment. In both experiments the initial pH of the water was 9.3 and the final equilibrated pH was 5.4. The ?13C value of equilibrated headspace CO2 was within 0.25 of its starting ?13C value, demonstrating insignificant carbon isotope fractionation at low pH. Measured Helium/ CO2 ratios throughout the CO2+Helium experiment preserve a non-linear trend of increasing He/ CO2 ratios through time that correlate very well with the measured pressure drop from CO2 dissolution. This indicates that gas composition, in particular the He/ CO2-ratio, can be used to infer the amount of dissolved CO2 in the field where pressure evolution is not available. Our experiments show that the rate of dissolution is determined by convective mass transfer in the brine. Convective transport is driven by the increase of water density with increasing CO2 saturation. However, unlike previous experiments with analog systems we do not observe a constant dissolution rate. This is due to the continued drop in gas pressure that continuously reduces the equilibrium aqueous CO2 concentration and with it the driving force for convection. This feed back may significantly reduce the magnitude of solubility trapping that can be expected during geological CO2 storage.

Larson, T.; Hesse, M. A.

2013-12-01

303

A study of nitrogen and carbon dioxide chemisorption on platinum black  

Microsoft Academic Search

The relationship between sites responsible for nitrogen chemisorption and sites responsible for stronger adsorption of carbon dioxide on platinum black is reported. A 2 to 1 ratio has been found between molecules of more strongly adsorbed carbon dioxide and molecules of nitrogen chemisorbed on individual samples. This relationship has allowed us to deduce the structure of chemisorbed carbon dioxide. Carbon

E. F. Rissmann; J. M. Parry

1992-01-01

304

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

Microsoft Academic Search

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon

John Colt; Barnaby Watten; Michael Rust

2009-01-01

305

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

306

Carbonic Acid as a Reserve of Carbon Dioxide on Icy Moons: The Formation of Carbon Dioxide (CO2) in a Polar Environment  

NASA Astrophysics Data System (ADS)

Carbon dioxide (CO2) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ?3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H2O)-carbon dioxide (CO2) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ?3 band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni

2014-06-01

307

Atmospheric carbon dioxide record from flask measurements at Lampedusa Island  

NSDL National Science Digital Library

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

Chamard, Paolo.; Ciattaglia, Luigi.; Di Sarra, Alcide.; Monteleone, Francesco.

2001-01-01

308

Exposures to carbon dioxide in the poultry processing industry  

SciTech Connect

The use of dry ice has increased dramatically in poultry processing plants because of changes in the fast food industry. Concentrations of carbon dioxide in four such plants were measured and were found to exceed the Immediately Dangerous to Life and Health Level (50,000 ppm) inside holding coolers where ventilation is poor. In other areas, where dry ice is delivered to poultry packages, time-weighted average exposures can exceed the threshold limit value of 5000 ppm by substantial margins, even if local exhaust ventilation systems are present. Reports of adverse health effects from carbon dioxide exposure and various control measures are reviewed. Recommendations regarding sampling and analytical techniques also are presented. Operators of poultry plants where dry ice is used need to recognize the occupational hazards of exposure to carbon dioxide.

Jacobs, D.E.; Smith, M.S.

1988-12-01

309

Cleaning of ITO glass with carbon dioxide snow jet spray  

NASA Astrophysics Data System (ADS)

ITO glass cleaning is LCD, OLED and other flat panel display industry's key technologies. At present, the usual wet cleaning technology consumes large amount of water and chemicals, and produces a large amount of contaminant venting. CO2 snow jet spray cleaning has been successfully applied to cleaning the surface of semiconductor chip, vacuum devices and space telescopes. Surface cleaning of indium tin oxide (ITO) film was carried out with carbon dioxide snow jet treatment .Based on the measurements of the contact angles, X-ray photoelectron spectroscopy and scanning electron microscopy (SEM) ,the influence of carbon dioxide snow jet treatment on surface cleaning of indium tin Oxide film was investigated and compared with the samples of low frequency immersion ultrasonic cleaning. Experimental data show that the carbon dioxide snow jet treatment effectively removes particulate and hydrocarbon on ITO surface.

Li, Jun-jian; Qi, Tong; Li, Shu-lin; Zhao, Guang

2007-12-01

310

Comparative Assessment of Status and Opportunities for Carbon Dioxide Capture and Storage and Radioactive Waste Disposal in North America  

Microsoft Academic Search

\\u000a Aside from the target storage regions being underground, geologic carbon sequestration (GCS) and radioactive waste disposal\\u000a (RWD) share little in common in North America. The large volume of carbon dioxide (CO2) needed to be sequestered along with its relatively benign health effects present a sharp contrast to the limited volumes\\u000a and hazardous nature of high-level radioactive waste (RW). There is

Curtis M. Oldenburg; Jens T. Birkholzer

2011-01-01

311

Modelling interactions of carbon dioxide, forests, and climate  

SciTech Connect

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

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

1994-09-01

312

Electricity Load and Carbon Dioxide Emissions: Effects of a Carbon Price in the Short Term  

Microsoft Academic Search

Stabilizing atmospheric carbon dioxide levels at acceptable levels will require a dramatic de-carbonization of the electric generation sector in the U.S. One increasingly discussed way to meet this policy goal is to put an explicit price on carbon emissions, either through a tax or a trading scheme. Increasing demand response has also been discussed as a way to reduce carbon

Adam Newcomer; Seth Blumsack; Jay Apt; Lester B. Lave; M. Granger Morgan

2008-01-01

313

42 CFR 84.97 - Test for carbon dioxide in inspired gas; open- and closed-circuit apparatus; maximum allowable...  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Test for carbon dioxide in inspired gas; open- and...Apparatus § 84.97 Test for carbon dioxide in inspired gas; open- and... (1) The concentration of carbon dioxide in inspired gas in...

2010-10-01

314

42 CFR 84.97 - Test for carbon dioxide in inspired gas; open- and closed-circuit apparatus; maximum allowable...  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Test for carbon dioxide in inspired gas; open- and...Apparatus § 84.97 Test for carbon dioxide in inspired gas; open- and... (1) The concentration of carbon dioxide in inspired gas in...

2009-10-01

315

Environmental and societal consequences of a possible CO-induced climate change. Volume II, Part 14. Research needed to determine the present carbon balance of northern ecosystems and the potential effect of carbon-dioxide-induced climate change  

Microsoft Academic Search

Given the potential significance of northern ecosystems to the global carbon budget it is critical to estimate the current carbon balance of these ecosystems as precisely as possible, to improve estimates of the future carbon balance if world climates change, and to assess the range of certainty associated with these estimates. As a first step toward quantifying some of the

1982-01-01

316

Cerebrovascular reactivity to carbon dioxide in Alzheimer's disease. A review  

PubMed Central

There is growing evidence that cerebrovascular reactivity to carbon dioxide (CVRCO2) is impaired in Alzheimers disease (AD). Preclinical and animal studies suggest chronic hypercontractility in brain vessels in AD. We review (a) preclinical studies of mechanisms for impaired CVRCO2 in AD; (b) clinical studies of cerebrovascular function in subjects with AD dementia, mild cognitive impairment (MCI), and normal cognition. Although results of clinical studies are inconclusive, an increasing number of reports reveal an impairment of vascular reactivity to carbon dioxide in subjects with AD, and possibly also in MCI. Thus, CVRCO2 may be an attractive means to detect an early vascular dysfunction in subjects at risk.

Glodzik, Lidia; Randall, Catherine; Rusinek, Henry; de Leon, Mony J.

2013-01-01

317

Experimental Comparison of Nitrogen and Carbon Dioxide Oil Displacement in Carbonate Cores  

Microsoft Academic Search

The feasibility of nitrogen and carbon dioxide flooding is being investigated experimentally as possible enhanced oil recovery processes in Iranian carbonate oil fields. Laboratory tests were conducted on a tight permeability sample of an Iranian oil field. Three flooding tests were conducted at back pressures of 1,000, 2,000, and 2,500 psi for both nitrogen and carbon dioxide separately. All tests

M. Ghasemi; S. R. Shadizadeh

2011-01-01

318

Carbon nanotube-coated surface acoustic wave sensor for carbon dioxide sensing  

Microsoft Academic Search

Carbon dioxide gas sensors have been fabricated by self-assembling single-wall nanotube films on a surface acoustic wave delay line operating at 286MHz. Polymer functionalization was used to enhance the sensitivity of the carbon nanotubes to carbon dioxide. A pulse radar-type interrogation system was used to monitor the conductivity of the nanotube film by measuring the attenuation of the surface acoustic

S. Sivaramakrishnan; R. Rajamani; C. S. Smith; K. A. McGee; K. R. Mann; N. Yamashita

2008-01-01

319

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

320

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

321

Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity  

NASA Technical Reports Server (NTRS)

Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

2010-01-01

322

Carbon dioxide adsorption in graphene sheets  

Microsoft Academic Search

Control over the CO2 emission via automobiles and industrial exhaust in atmosphere, is one of the major concerns to render environmental friendly milieu. Adsorption can be considered to be one of the more promising methods, offering potential energy savings compared to absorbent systems. Different carbon nanostructures (activated carbon and carbon nanotubes) have attracted attention as CO2 adsorbents due to their

Ashish Kumar Mishra; Sundara Ramaprabhu

2011-01-01

323

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

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Carbon dioxide; exemption from...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD...Tolerances § 180.1049 Carbon dioxide; exemption...

2010-07-01

324

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

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Carbon dioxide; exemption from...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD...Tolerances § 180.1049 Carbon dioxide; exemption...

2009-07-01

325

27 CFR 27.42a - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Still wines containing carbon dioxide. 27.42a Section 27...and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE...27.42a Still wines containing carbon dioxide. Still wines may...

2010-04-01

326

27 CFR 27.42a - Still wines containing carbon dioxide.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Still wines containing carbon dioxide. 27.42a Section 27...and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE...27.42a Still wines containing carbon dioxide. Still wines may...

2009-04-01

327

46 CFR 169.732 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2013 CFR

... false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms....

2013-10-01

328

Electrochemical Carbon Dioxide Reduction - Oxygen Generation System Having Only Liquid Waste Products.  

National Technical Information Service (NTIS)

The electrochemical reduction of carbon dioxide has been investigated as a means of simplifying the disposal of carbon dioxide and hydrogen from a submarine atmospheric regeneration unit. Ejection of these materials as organic liquid wastes is preferable ...

F. H. Meller

1968-01-01

329

21 CFR 179.43 - Carbon dioxide laser for etching food.  

Code of Federal Regulations, 2013 CFR

...THE PRODUCTION, PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.43 Carbon dioxide laser for etching...food under the following conditions: (a) The radiation source consists of a carbon dioxide laser...

2013-04-01

330

Eco-Materials Made From Industrial By-Products and Carbon Dioxide  

NASA Astrophysics Data System (ADS)

The eco-materials made from steel-making slag and carbon dioxide are introduced. Steel-making slag is one of industrial by-products and it has been wanted to be used in more beneficial way. Carbon dioxide is also wanted to be decreased the emission for green house effects. The materials made with steel-making slag by carbonation have very high strength and very high durability for hydration and abrasion. Mechanisms of carbonation reaction is discussed, in which the effects of water content, temperature, porosity of compacts, gas content and pressure, etc. are discussed. The compressive strength was obtained about 100 MPa at a porosity of 10 volume %these carbonated blocks have higher abrasion resistance than hydrated cement pastes. The most benefit in this process is no energy is required for the reaction except that of grinding, handling and/or transportation of materials. The exhaust gas from plant will be available for the source of carbon dioxide. Lastly, Marine block, matrix of glass fiber reinforced concrete, and artificial aggregate are introduced as application examples.

Goto, S.

2007-03-01

331

A miniaturized carbon dioxide gas sensor based on infrared absorption  

NASA Astrophysics Data System (ADS)

A miniaturized sensor for measuring carbon dioxide (CO 2) gas concentration is developed based on infrared absorption. A novel space-double-beam optical probe is designed, which consists of an infrared source, an air chamber, an infrared receiving device, and two sapphire windows. The air chamber is modified by incorporating a parabolic-shaped receiving-light cone to effectively improve the signal-to-noise ratio of the sensor. Four rectangle holes are arranged around the air chamber, and diffusive sampling is adopted to collect gas into the air chamber. The infrared source works between ON and OFF states. The interference of background light is eliminated by subtracting the measured value in the ON state from the OFF state. The measurement model of the sensor is established based on the Lambert-Beer law and the working principle of the sensor. The partial least squares method is applied to calibrate the measurement model. The sensor has a volume of 80 mm ( L)78 mm ( W)35 mm ( H), a weight of 200 g, a power consumption of 1.5 W, and a response time of 2.5 s. The experimental results show that the measurement accuracy of the sensor is 0.026% with a measurement range of 0-3% for CO 2 gas concentration.

Zhang, Guangjun; Li, Yaping; Li, Qingbo

2010-12-01

332

Acute toxicity of high concentrations of carbon dioxide in rats.  

PubMed

Subterranean storage of carbon dioxide (CO2) has been proposed to diminish atmospheric increases of this greenhouse gas. To contribute to risk assessment of accidental release associated with handling, transport and storage, rats were exposed to high concentrations (targets 40, 43 and 50volume %) of CO2. The oxygen concentrations dropped as a result, but were not supplemented. For each concentration, pairs of animals were exposed for different exposure durations to derive an exposure concentration-duration relation in which mortality is described as a function of C(n)t (probit relation). A very high "n" value for the probit function could be derived from the data obtained at 40% and 43% CO2, which indicates that for exposure durations longer than 30min the LC50 decreases hardly with increasing exposure duration. Below 30min the LC50 seemed to increase with decreasing exposure durations. The variability in the data of 43% and 50% CO2, however, did not allow to derive a meaningful value of "n". PMID:24713210

Muijser, H; van Triel, J J; Duistermaat, E; Bos, P M J

2014-07-01

333

ARTICLES: Vapor-Liquid Equilibrium Data of Carbon Dioxide+Methyl Propionate and Carbon Dioxide+Propyl Propionate Systems  

NASA Astrophysics Data System (ADS)

High-pressure vapor-liquid equilibrium data for the binary systems of methyl propionate+carbon dioxide and propyl propionate+carbon dioxide were measured at pressure from 1.00 MPa to 12.00 MPa and temperature in the range from 313 K to 373 K. Experimental results were correlated with the Peng-Robinson equation of state with the two-parameter van der Waals mixing rule. At the same time, the Henry's coefficient, partial molar enthalpy change and partial molar entropy change of CO2 during dissolution at different temperature were also calculated.

Xu, Wei; Xie, Chuan-xin; Li, Hong-ling; Tian, Yi-ling

2010-06-01

334

Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum  

SciTech Connect

The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

Ho, C.S.; Smith, M.D.

1986-01-01

335

Effect of carbon dioxide concentration on the bioleaching of a pyrite-arsenopyrite ore concentrate  

SciTech Connect

The effect of carbon dioxide concentration on the bacterial leaching of a pyrite-arsenopyrite ore concentrate was studied in continuous-flow reactors. Steady-state operation with two feed slurry densities, 6 wt% and 16wt% solids, were tested for the effect of carbon dioxide concentration. Bacterial growth rates were estimated via the measurement of carbon dioxide consumption rates. Aqueous-phase carbon dioxide concentrations in excess of 10 mg/L were found to be inhibitory to bacterial growth.

Nagpal, S.; Dahlstrom, D. (Univ. of Utah, Salt Lake City (United States)); Oolman, T. (Radian Corp., Austin, TX (United States))

1993-02-20

336

Effect of carbon dioxide concentration on the bioleaching of a pyrite-arsenopyrite ore concentrate  

Microsoft Academic Search

The effect of carbon dioxide concentration on the bacterial leaching of a pyrite-arsenopyrite ore concentrate was studied in continuous-flow reactors. Steady-state operation with two feed slurry densities, 6 wt% and 16wt% solids, were tested for the effect of carbon dioxide concentration. Bacterial growth rates were estimated via the measurement of carbon dioxide consumption rates. Aqueous-phase carbon dioxide concentrations in excess

Soumitro Nagpal; Donald Dahlstrom; Timothy Oolman

1993-01-01

337

Somewhere beyond the sea? The oceanic - carbon dioxide - reactions  

NASA Astrophysics Data System (ADS)

In correlation to climate change and CO2 emission different campaigns highlight the importance of forests and trees to regulate the concentration of carbon dioxide in the earths' atmosphere. Seeing millions of square miles of rainforest cut down every day, this is truly a valid point. Nevertheless, we often tend to forget what scientists like Spokes try to raise awareness for: The oceans - and foremost deep sea sections - resemble the second biggest deposit of carbon dioxide. Here carbon is mainly found in form of carbonate and hydrogen carbonate. The carbonates are needed by corals and other sea organisms to maintain their skeletal structure and thereby to remain vital. To raise awareness for the protection of this fragile ecosystem in schools is part of our approach. Awareness is achieved best through understanding. Therefore, our approach is a hands-on activity that aims at showing students how the carbon dioxide absorption changes in relation to the water temperature - in times of global warming a truly sensitive topic. The students use standard syringes filled with water (25 ml) at different temperatures (i.e. 10C, 20C, 40C). Through a connector students inject carbon dioxide (25ml) into the different samples. After a fixed period of time, students can read of the remaining amount of carbon dioxide in relation to the given water temperature. Just as with every scientific project, students need to closely monitor their experiments and alter their setups (e.g. water temperature or acidity) according to their initial planning. A digital template (Excel-based) supports the analysis of students' experiments. Overview: What: hands-on, minds -on activity using standard syringes to exemplify carbon dioxide absorption in relation to the water temperature (Le Chatelier's principle) For whom: adjustable from German form 11-13 (age: 16-19 years) Time: depending on the prior knowledge 45-60 min. Sources (extract): Spokes, L.: Wie Ozeane CO2 aufnehmen. Environmental Sciences. University of East Anglia, Norwich 2007. Von Borstel, G. und Bhm, A.: Le Chatelier einmal anders, Gleichgewichtsverschiebungen am Kontext Sprudelwasser. Naturwissenschaft im Unterricht Chemie 6 (2006) H. 96, S. 34-37

Meisinger, Philipp; Wittlich, Christian

2014-05-01

338

Thermodynamics of the carbon dioxide system in the oceans  

Microsoft Academic Search

In the next ten years, a number of studies on the carbonate system are planned as part of the JGOFS\\/WOCE programs. The carbon dioxide system will be studied by measuring at least two of the controlling parameters; pH, total alkalinity (TA), total inorganic CO2 (TCO2), and the fugacity of CO2 (fCO2). The other parameters can be calculated using thermodynamic relations.

Frank J. Millero

1995-01-01

339

Carbon dioxide fluxes over bermudagrass, native prairie, and sorghum  

Microsoft Academic Search

The Bowen ratio\\/energy balance (BREB) method was used to measure 30min water vapor and carbon dioxide (CO2) fluxes over three fields dominated by different C4 grasses (bermudagrass, tallgrass native prairie, and sorghum) at the Blackland Research Center, Temple, TX. Fluxes were related to biotic and abiotic phenomena. Carbon accumulation rates calculated from BREB measurements were compared with those determined from

W. A Dugas; M. L Heuer; H. S Mayeux

1999-01-01

340

The Concentration of Atmospheric Carbon Dioxide in Hawaii  

Microsoft Academic Search

The concentration of atmospheric carbon dioxide at and near Mauna Loa Ob- servatory, Hawaii, is reported for the first six years (1958-1963) of a long-term program to document the effects of the combustion of coal and petroleum on the distribution of COs gas in the atmosphere and in the world's oceans. The majority of the measurements reported here were obtained

Jack C. Pales; Charles D. Keeling

1965-01-01

341

Reduction of Carbon Dioxide Embolism for Endoscopic Saphenous Vein Harvesting  

Microsoft Academic Search

Background. The endoscopic saphenous vein harvest- ing (EVH) introduced in coronary artery bypass surgery (CABG) is associated with less wound complication and postoperative pain. Carbon dioxide (CO2) insufflation is used during EVH to facilitate the procedure. The purpose of this study was to determine whether the incidence of CO2 embolism during EVH with CO2 insufflation could be reduced with lower

Kuan-Ming Chiu; Tzu-Yu Lin; Ming-Jiuh Wang; Shu-Hsun Chu

2006-01-01

342

Endoscopic vein harvesting with the aid of carbon dioxide insufflation  

Microsoft Academic Search

Endoscopic harvesting of the long saphenous vein has been introduced to decrease the morbidity of obtaining venous conduit for coronary artery bypass grafting. Herein is described an endoscopic method using carbon dioxide insufflation into the tissues around the vein. This has several advantages; improved vision, no physical retraction required, easier development of tissue planes, and improved hemostasis.

Malcolm J. R Dalrymple-Hay; Aiman Alzetani; Robert Costa; Sunil K Ohri

2001-01-01

343

Negative results - Coronary Carbon dioxide embolism during endoscopic vein harvesting  

Microsoft Academic Search

Endoscopic vein harvesting (EVH) is becoming common for the patients undergoing coronary artery bypass grafting. Using carbon dioxide insufflations during the vein harvest can produce rare but catastrophic CO embolism. We report a case of massive right atrial CO embolism 2 2 due to femoral vein injury which occurred during the performance of a routine EVH procedure. 2008 Published by

Muhammed Tamim; Maher Omrani; Adel Tash; Ahmed El Watidy

2010-01-01

344

Optimization of supercritical carbon dioxide extraction of Passiflora seed oil  

Microsoft Academic Search

This study investigates extraction of Passiflora seed oil by using supercritical carbon dioxide. Artificial neural network (ANN) and response surface methodology (RSM) were applied for modeling and the prediction of the oil extraction yield. Moreover, process optimization were carried out by using both methods to predict the best operating conditions, which resulted in the maximum extraction yield of the Passiflora

Gholamreza Zahedi; Abbas Azarpour

2011-01-01

345

New analytical technique for carbon dioxide absorption solvents  

Microsoft Academic Search

The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO, water + MDEA + CO, and water + MEA + MDEA) used for carbon dioxide (CO) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO absorption at temperatures from

Fatemeh Pouryousefi; Raphael O. Idem

2008-01-01

346

Biodiversity and biological impact of ocean disposal of carbon dioxide  

SciTech Connect

Five major characteristics of deep-sea organisms that are relevant to the carbon dioxide ocean sequestration are pointed out. They are (1) low biological activities, (2) long life span, (3) high sensitivity to the environmental disturbance, (4) high species diversity, and (5) low density. These characteristics suggest the deep-sea species are sensitive to the environmental disturbance, and once they are damaged, they may easily become extinct or it might take a long time to recover. To get public acceptance for ocean sequestration of carbon dioxide, the authors need a reliable assessment of its affects on the deep-sea ecosystem based on an accurate model. For a better modeling, data regarding the long-term (chronic) effect of slightly increased concentration of carbon dioxide on the deep-sea organisms are prerequisite. Precise data regarding such biological characteristics can be obtained only from in-situ experiments. To develop a system for ecophysiological in-situ experiments of deep-sea organisms is thus as important as solving the technological problems related to the ocean sequestration of carbon dioxide.

Shirayama, Yoshihisa [Univ. of Tokyo (Japan)] [Univ. of Tokyo (Japan)

1998-07-01

347

Ethanol as Fuel: Energy, Carbon Dioxide Balances, and Ecological Footprint  

Microsoft Academic Search

The major amtrihtitor to global wanning is considered to he the high levels of greenhouse gas emissions, especially carbon dioxide (COJ, caused by the burtiing of fossil fuel. Thus, to mitigate CO^ emissions, renewable energy sources such as ethanol have been seen as a promising alternative to fossil fuel consumption. Brazil was the world's first nation to run a large-scale

MARCELO E. DIAS DE OLIVEIRA; BURTON E. VAUGHAN; EDWARD J. RYKIEL JR

2005-01-01

348

Raising the Level of Carbon Dioxide in Your Blood  

NSDL National Science Digital Library

In this activity (on page 146 of the PDF), learners will explore the effects of increased carbon dioxide in the bloodstream. This activity can be enhanced by sharing the "Astronaut's Sleep" Podcast with learners (see related resource link). This resource guide includes background information and sample evaluation questions. Note: learners with respiratory ailments should not participate as subjects.

Macleish, Marlene Y.; Mclean, Bernice R.

2013-05-15

349

Synthesis of epoxy ferrite nanocomposites in supercritical carbon dioxide  

Microsoft Academic Search

A series of epoxy ferrite nanocomposites (EFNCs) was synthesised through dispersing ferrite nanoparticles (5.0 phr, parts per hundred of resin) into diglycidylether of bisphenol A (0.1 mol) in supercritical carbon dioxide at 85 1C, 1600 psi over 1 h followed by curing with triethylene tetramine (15 phr) at 40 1C. For this purpose, ferrite nanoparticles were synthesised through

M. G. H. Zaidi; P. L. Sah; S. Alam; A. K. Rai

2009-01-01

350

A Discovery Experiment: Carbon Dioxide Soap Bubble Dynamics.  

ERIC Educational Resources Information Center

The observation of soap bubbles in a beaker of carbon dioxide gas helps students to feel the pleasure that comes from understanding nature, from applying that understanding to real problems, and from making unexpected discoveries that yield to analysis. (Author/BB)

Millikan, Roger C.

1978-01-01

351

Carbon Dioxide Measurement from Breath Gas Using Blind Source Separation  

Microsoft Academic Search

There are many approaches which use breath gas to diagnose disease such as lung cancer, breast cancer and diabetes. But, it has not been used in medical field because of low accuracy by low concentration of target component (ppt, ppb level). According to previous study, end-tidal concentrations of volatile organic component (VOC) correlated with carbon dioxide (CO2) levels. So, we

Jongyoun Lee; Jing Bai; Inyoung Kim

2008-01-01

352

Regression analysis study on the carbon dioxide capture process  

Microsoft Academic Search

Research on amine-based carbon dioxide (CO) capture has mainly focused on improving the effectiveness and efficiency of the CO capture process. The objective of our work is to explore relationships among key parameters that affect the CO production rate. From a survey of relevant literature, we observed that the significant parameters influencing the CO production rate include the reboiler heat

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

2008-01-01

353

End-tidal carbon dioxide monitoring in the prehospital setting  

Microsoft Academic Search

End-tidal carbon dioxide (ETCO2) monitoring is an exciting technology and has the potential to become a very useful tool in the prehospital setting. It can be useful in verifying endotracheal tube position and during cardiopulmonary resuscitation in the field. Recent reports of misplaced endotracheal tubes in the prehospital setting make it important to ensure that paramedics learn correct techniques of

Mananda S. Bhende; David C. LaCovey

2001-01-01

354

Extraction of ginger flavor with liquid or supercritical carbon dioxide  

Microsoft Academic Search

Ginger flavor, containing both aromatic and pungent components, was extracted by high pressure carbon dioxide from the rhizome of dried ginger (Zingiber officinale Roscoe). However, the effects of extraction conditions on yield and quality of the ginger flavor have not yet been elucidated. In this study, the extract yield and the composition of the extract were studied using a semi-batch

Chiaki Yokoyama; H HINATA; R YOSHIDA; Y SHIMIZU

1995-01-01

355

Energy requirements of ammoniacarbon dioxide forward osmosis desalination  

Microsoft Academic Search

The energy requirements of ammoniacarbon dioxide forward osmosis (FO) desalination are predicted by the use of chemical process modeling software (HYSYS). The FO process is modeled using single or multiple distillation columns to separate draw solution solutes from the product water for solute recycling within the FO system. Thermal and electrical energy requirements of the process are calculated, as well

Robert L. McGinnis; Menachem Elimelech

2007-01-01

356

Carbon dioxide supersaturation in the surface waters of lakes  

Microsoft Academic Search

Data on the partial pressure of carbon dioxide (CO) in the surface waters from a large number of lakes (1835) with a worldwide distribution show that only a small proportion of the 4665 samples analyzed (less than 10 percent) were within {+-}20 percent of equilibrium with the atmosphere and that most samples (87 percent) were supersaturated. The mean partial pressure

J. J. Cole; N. F. Caraco; G. W. Kling; T. K. Kratz

1994-01-01

357

Electrochemical Approaches to the Reduction of Carbon Dioxide.  

National Technical Information Service (NTIS)

Carbon dioxide reduction requires the input of energy or a high energy reductant to drive the reaction. Two possible energy sources which can be used in this capacity are electro-chemical potential and light. Approaches ot CO2 reduction by direct and indi...

C. O'Connell R. Eisenberg S. I. Hommeltoft

1986-01-01

358

Reducing Carbon Dioxide Emissions: Using the Mole Concept.  

ERIC Educational Resources Information Center

Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)

Myers, Alan

2002-01-01

359

Environmental Challenges: Radon and Carbon Dioxide in School Buildings.  

ERIC Educational Resources Information Center

Many school buildings with high radon levels also exhibit high carbon dioxide levels that starve the minds of students for oxygen. Administrators must realize that the world's best educator cannot teach minds made dysfunctional by their environment. This article describes Environmental Protection Agency testing results and offers radon monitoring

Krueger, James

1991-01-01

360

Carbon dioxide laser oral safety parameters for teeth  

Microsoft Academic Search

The carbon dioxide laser is used in the oral cavity for a variety of procedures. Although the procedures may not involve the teeth directly, precaution should be exercised to preserve their integrity. The results of this study indicate that the most limiting parameter for oral use of the CO laser is damage to the enamel surface, which could be inflicted

G. Lynn Powell; Brian K. Whisenant; Thomas H. Morton

1990-01-01

361

SELECTIVE OXIDATION IN SUPERCRITICAL CARBON DIOXIDE USING CLEAN OXIDANTS  

EPA Science Inventory

We have systematically investigated heterogeneous catalytic oxidation of different substrates in supercritical carbon dioxide (SC-CO2). Three types of catagysts: a metal complex, 0.5% platinum g-alumina and 0.5% palladium g-alumina were used at a pressure of 200 bar, temperatures...

362

Transporting carbon dioxide recovered from fossil-energy cycles.  

National Technical Information Service (NTIS)

Transportation of carbon dioxide (CO(sub 2)) for enhanced oil recovery is a mature technology, with operating experience dating from the mid-1980s. Because of this maturity, recent sequestration studies for the US Department of Energy's National Energy Te...

R. Doctor J. Molburg J. Brockmeier

2000-01-01

363

Adsorption of carbon dioxide on the chemically modified silica adsorbents  

Microsoft Academic Search

Silica adsorbents were chemically modified to have base sites on their surfaces and the adsorption characteristics of carbon dioxide on them were investigated. Base sites were introduced either by impregnation of silica gels with calcium acetate salt or by synthesizing silica xerogels using a solgel method from alcoholic solution of TEOS and calcium acetate salt. The salt in gels was

Hyun-Kon Song; Kil Won Cho; Kun-Hong Lee

1998-01-01

364

CARBON DIOXIDE WITHIN CONTROLLED ENVIRONMENTS; THE COMMONLY NEGLECTED VARIABLE  

Microsoft Academic Search

The option to measure and control carbon dioxide levels within controlled environment chambers has been commercially available for over a decade. Despite this fact, relatively few controlled environment users choose to purchase or even utilise this option when it is available on their equipment. Routine measurements taken at the McGill University Phytotron have shown pronounced fluctuations and significant variability of

Mark Romer

365

Complications of carbon dioxide laser resurfacing and their prevention  

Microsoft Academic Search

Carbon dioxide laser resurfacing has gained widespread acceptance. Although advances in laser technology have greatly improved this technique and minimized operator error, adverse outcomes and complications still occur. Many of these complications can be readily avoided. In our series of 1925 patients, undesirable outcomes occurred mainly in the early stages of our experience and could be attributed to poor preoperative

Cynthia Weinstein; Jason N. Pozner; Oscar M. Ramirez

1997-01-01

366

Global Warming: Carbon Dioxide and the Greenhouse Effect  

NSDL National Science Digital Library

This video segment demonstrates carbon dioxide's role in the greenhouse effect and explains how increasing concentrations of C02 in the atmosphere may be contributing to global warming. Video includes an unusual demonstration of C02's heat-absorbing properties, using infrared film, a researcher's face, and a stream of C02 between them.

Frontline/nova; Foundation, Wgbh E.; Domain, Teachers'

367

27 CFR 24.245 - Use of carbon dioxide in still wine.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Use of carbon dioxide in still wine. 24...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...Wine § 24.245 Use of carbon dioxide in still wine. The addition of carbon dioxide to (and...

2009-04-01

368

27 CFR 24.245 - Use of carbon dioxide in still wine.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Use of carbon dioxide in still wine. 24...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...Wine § 24.245 Use of carbon dioxide in still wine. The addition of carbon dioxide to (and...

2010-04-01

369

46 CFR 108.627 - Carbon dioxide and clean agent alarms.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627...OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT... § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm...

2013-10-01

370

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.  

Code of Federal Regulations, 2013 CFR

...Carbon dioxide and clean agent alarms-T/ALL. 35.40-7 Section 35.40-7 Shipping... Posting and Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarmsT/ALL. Each carbon dioxide or clean...

2013-10-01

371

A carbon dioxide monitor that does not show the waveform is worthless  

Microsoft Academic Search

The author suggests that the carbon dioxide waveform should be displayed, as are the electrocardiogram and arterial pressure waveforms. He argues that a carbon dioxide analyzer that does not provide a waveform is not of value, as subtle changes in the carbon dioxide waveform can reflect impending problems. Only when a plateau is present in the capnogram can one be

Frank E. Block; J Clin Monit

1987-01-01

372

A study of the oxygen and carbon dioxide requirements of thermophilic campylobacters  

Microsoft Academic Search

The oxygen and carbon dioxide requirements of different biotypes of thermophilic campylobacters were investigated by means of (a) quantitative studies, and (b) total growth studies. Oxygen tolerance of the five test organisms differed markedly and varied with the carbon dioxide concentration. At most carbon dioxide concentrations tested, Campylobacter jejuni strains NCTC 11168 and NCTC 11392 tolerated 21% oxygen (growth reduced),

F J Bolton; D Coates

1983-01-01

373

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N)  

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News: TES News ... Level: L2 Platform: TES/Aura L2 Carbon Dioxide Spatial Coverage: 5.2 x 8.5 km nadir ... Data: TES Order Tool Parameters: Carbon Dioxide Order Data: Reverb: Order Data ...

2014-02-12

374

TES/Aura L2 Carbon Dioxide (CO2) Lite Nadir (TL2CO2LN)  

TES/Aura L2 Carbon Dioxide (CO2) Lite Nadir (TL2CO2LN) News: TES ... Level: L2 Instrument: TES/Aura L2 Carbon Dioxide Spatial Coverage: 5.3 km nadir ... Data: TES Order Tool Parameters: Carbon Dioxide Order Data: Reverb: Order Data ...

2013-11-06

375

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS)  

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS) News: TES News ... Level: L2 Platform: TES/Aura L2 Carbon Dioxide Spatial Coverage: 5.3 x 8.5 km nadir ... Data: TES Order Tool Parameters: Carbon Dioxide Order Data: Reverb: Order Data ...

2013-12-18

376

Heat rejection pressure optimization for a carbon dioxide split system: An experimental study  

Microsoft Academic Search

Recent studies indicate carbon dioxide (R744) as a valid alternative to classical substances such as HFCs used in vapour compression plants. However a transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually near the ambient temperature. Consequently the carbon dioxide refrigerator performances are significantly influenced by the heat rejection pressure. In this paper an experimental

Ciro Aprea; Angelo Maiorino

2009-01-01

377

High-resolution mapping of motor vehicle carbon dioxide emissions  

NASA Astrophysics Data System (ADS)

fuel-based inventory for vehicle emissions is presented for carbon dioxide (CO2) and mapped at various spatial resolutions (10 km, 4 km, 1 km, and 500 m) using fuel sales and traffic count data. The mapping is done separately for gasoline-powered vehicles and heavy-duty diesel trucks. Emission estimates from this study are compared with the Emissions Database for Global Atmospheric Research (EDGAR) and VULCAN. All three inventories agree at the national level within 5%. EDGAR uses road density as a surrogate to apportion vehicle emissions, which leads to 20-80% overestimates of on-road CO2 emissions in the largest U.S. cities. High-resolution emission maps are presented for Los Angeles, New York City, San Francisco-San Jose, Houston, and Dallas-Fort Worth. Sharp emission gradients that exist near major highways are not apparent when emissions are mapped at 10 km resolution. High CO2 emission fluxes over highways become apparent at grid resolutions of 1 km and finer. Temporal variations in vehicle emissions are characterized using extensive day- and time-specific traffic count data and are described over diurnal, day of week, and seasonal time scales. Clear differences are observed when comparing light- and heavy-duty vehicle traffic patterns and comparing urban and rural areas. Decadal emission trends were analyzed from 2000 to 2007 when traffic volumes were increasing and a more recent period (2007-2010) when traffic volumes declined due to recession. We found large nonuniform changes in on-road CO2 emissions over a period of ~5 years, highlighting the importance of timely updates to motor vehicle emission inventories.

McDonald, Brian C.; McBride, Zoe C.; Martin, Elliot W.; Harley, Robert A.

2014-05-01

378

Environmental and societal consequences of a possible CO/sub 2/-induced climate change. Volume II, Part 14. Research needed to determine the present carbon balance of northern ecosystems and the potential effect of carbon-dioxide-induced climate change  

SciTech Connect

Given the potential significance of northern ecosystems to the global carbon budget it is critical to estimate the current carbon balance of these ecosystems as precisely as possible, to improve estimates of the future carbon balance if world climates change, and to assess the range of certainty associated with these estimates. As a first step toward quantifying some of the potential changes, a workshop with tundra and taiga ecologists and soil scientists was held in San Diego in March 1980. The first part of this report summarizes the conclusions of this workshop with regard to the estimate of the current areal extent and carbon content of the circumpolar arctic and the taiga, current rates of carbon accumulation in the peat in the arctic and the taiga, and predicted future carbon accumulation rates based on the present understanding of controlling processes and on the understanding of past climates and vegetation. This report presents a finer resolution of areal extents, standing crops, and production rates than was possible previously because of recent syntheses of data from the International Biological Program and current studies in the northern ecosystems, some of which have not yet been published. This recent information changes most of the earlier estimates of carbon content and affects predictions of the effect of climate change. The second part of this report outlines research needed to fill major gaps in the understanding of the role of northern ecosystems in global climate change.

Miller, P.C.

1982-10-01

379

Supercritical carbon dioxide cycle control analysis.  

SciTech Connect

This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined. In particular, the peak heat removal capacity of the shutdown heat removal loop may be specified to be 1.1 % of the nominal reactor power. An investigation of the oscillating cycle behavior calculated by the ANL Plant Dynamics Code under specific conditions has been carried out. It has been found that the calculation of unstable operation of the cycle during power reduction to 0 % may be attributed to the modeling of main compressor operation. The most probable reason for such instabilities is the limit of applicability of the currently used one-dimensional compressor performance subroutines which are based on empirical loss coefficients. A development of more detailed compressor design and performance models is required and is recommended for future work in order to better investigate and possibly eliminate the calculated instabilities. Also, as part of such model development, more reliable surge criteria should be developed for compressor operation close to the critical point. It is expected that more detailed compressor models will be developed as a part of validation of the Plant Dynamics Code through model comparison with the experiment data generated in the small S-CO{sub 2} loops being constructed at Barber-Nichols Inc. and Sandia National Laboratories (SNL). Although such a comparison activity had been planned to be initiated in FY 2008, data from the SNL compression loop currently in operation at Barber Nichols Inc. has not yet become available by the due date of this report. To enable the transient S-CO{sub 2} cycle investigations to be carried out, the ANL Plant Dynamics Code for the S-CO{sub 2} Brayton cycle was further developed and improved. The improvements include further optimization and tuning of the control mechanisms as well as an adaptation of the code for reactor systems other than the Lead-Cooled Fast Reactor (LFR). Since the focus of the ANL work on S-CO{sub 2} cycle development for the majority of the current year has been on the applicability of the cycle to SFRs, work has started on modification of the ANL Plant Dynamics Code to allow

Moisseytsev, A.; Sienicki, J. J. (Nuclear Engineering Division)

2011-04-11

380

Tropical deforestation and atmospheric carbon dioxide  

Microsoft Academic Search

Recent estimates of the net release of carbon to the atmosphere from deforestation in the tropics have ranged between 0.4 and 2.5 1015 g yr-1. Two things have happened to require a revision of these estimates. First, refinements of the methods used to estimate the stocks of carbon in the vegetation of tropical forests have produced new estimates that

R. A. Houghton

1991-01-01

381

Measurement of the P V T relationship for carbon dioxide+ n-butane and carbon dioxide+ i-butane in the vicinity of the critical point  

Microsoft Academic Search

The PVT relationship of three systems, pure carbon dioxide (CO2) and the two binaries CO2+n-butane (n-C4H10) and CO2+i-butane (i-C4H10), were measured with a constant volume method. The experimental temperatures were set to be 304.65, 310.93 and 320.00K for pure CO2 and 310.93K for the two binary mixtures. The range of pressures was from 0.5 to 10.5MPa. For the mixtures, the

Tomoya Tsuji; Satoko Honda; Toshihiko Hiaki; Masaru Hongo

1998-01-01

382

ADSORPTION AND DESORPTION OF M-XYLENE FROM SUPERCRITICAL CARBON DIOXIDE ON ACTIVATED CARBON  

Microsoft Academic Search

The equilibrium loadings of m-xylene from supercritical carbon dioxide on activated carbon are reported. The experimental data were obtained by measuring the outlet concentration of m-xylene eluted from a column packed with activated carbon until the effluent reached the input concentration. The Freundlich isotherm expression was found to correlate the experimental data satisfactorily. In a second step, the regeneration by

Jamal Benkhedda; Jean-Nol Jaubert; Danielle Barth; Carsten Zetzl; Gerd Brunner

2001-01-01

383

Application of carbon nanotube in wireless sensor network to monitor carbon dioxide  

Microsoft Academic Search

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Over the years, new discoveries have led to new applications, often taking advantage of their unique electrical properties, extraordinary strength and efficiency in heat conduction. Since industrialisation, human activities have resulted in steadily increasing concentrations of the greenhouse gases. Excess amount of carbon dioxide (CO2) in living environment is

Othman Sidek; S. A. Quadri; Shahid Kabir; Muhammad Hassan Bin Afzal

2012-01-01

384

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

SciTech Connect

A 400 record of atmospheric carbon dioxide levels has been estimated by applying a CO{sub 2} 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 large fluctuations in atmospheric carbon dioxide levels have occurred over the study interval, ranging from the current level up to ten times the current level. Declining pCO{sub 2} levels through the middle Paleozoic culminate in low levels in the Early Permian. An abrupt increase in pCO{sub 2} in the Early Permian is followed by a decrease prior to the Permo-Triassic boundary. Carbon dioxide levels increase through the Triassic to approx. 3,000 ppmV, a level maintained through the Jurassic period. Levels lowered through the Cretaceous, dropping to less than 1,000 ppmV prior to the Cretaceous-Tertiary boundary. Relatively low levels persisted throughout the Cenozoic, with some evidence of higher levels in the Eocene and Oligocene.

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

1999-12-01

385

High-pressure phase equilibria for the carbon dioxide + 3-pentanol and carbon dioxide + 3-pentanol + water systems  

SciTech Connect

High-pressure vapor-liquid equilibria for the binary carbon dioxide + 3-pentanol system were measured at 313.2 K. The phase equilibrium apparatus used in this work was of the circulation type in which the coexisting phases were recirculated, on-line sampled, and analyzed. The critical pressure and corresponding mole fraction of carbon dioxide at 313.2 K were found to be 8.22 MPa and 0.974, respectively, for this binary system. The phase equilibria for the ternary carbon dioxide + 3-pentanol + water system were also measured at 313.2 K and pressures of 2.00, 4.00, 6.00, 8.00, and 8.25 MPa. This ternary system showed the liquid-liquid-vapor (LLV) phase behavior over the range of pressure up to the critical pressure of 8.25 MPa. The binary equilibrium data were all reasonably well-correlated with the Redlich-Kwong, Soave-Redlich-Kwong, Peng-Robinson, and Patel-Teja equations of state incorporated with the eight different mixing rules: the van der Waals, Panagiotopoulos-Reic, and six modified Huron-Vidal mixing rules with UNIQUAC parameters. For the prediction of high-pressure phase equilibria for the systems containing carbon dioxide and alcohols, the SRK-MHV2 might reproduce many features of the measured behavior although further tests are needed with other systems.

Lee, H.S.; Mun, S.Y.; Lee, H. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Chemical Engineering] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Chemical Engineering

1999-05-01

386

Carbon dioxide postcombustion capture: a novel screening study of the carbon dioxide absorption performance of 76 amines  

Microsoft Academic Search

The significant and rapid reduction of greenhouse gas emissions is recognized as necessary to mitigate the potential climate effects from global warming. The postcombustion capture (PCC) and storage of carbon dioxide (CO) produced from the use of fossil fuels for electricity generation is a key technology needed to achieve these reductions. The most mature technology for CO capture is reversible

Graeme Puxty; Robert Rowland; Andrew Allport; Qi Yang; Mark Bown; Robert Burns; Marcel Maeder; Moetaz Attalla

2009-01-01

387

Biomineralization of Hydromagnesite and its Application in Carbon Dioxide Sequestration  

NASA Astrophysics Data System (ADS)

A collection of highly alkaline wetlands, which exist as part of the hydromagnesite playas near Atlin, British Columbia, contain extensive microbial mats associated with carbonate deposition. X-ray diffraction and scanning electron microscopy has demonstrated that cyanobacteria catalyze the precipitation of hydromagnesite from magnesium-rich waters in this system. In addition, hydromagnesite was also precipitated in laboratory experiments using cyanobacterial enrichments from this field site and filter-sterilized natural waters. Within biofilms dominated by filamentous cyanobacteria, rosettes and flakey globular aggregates of hydromagnesite were precipitated while abiotic controls produced less carbonate in the form of nesquehonite. This precipitation experiment is analogous to the magnesium carbonates that precipitate within the hydromagnesite wetland. Carbonate crusts that form on the water surface are composed primarily of nesquehonite and form due to evaporation. In contrast, the microbial mats that cover the wetland floor are mostly composed of hydromagnesite. The experimental evidence conclusively demonstrates that cyanobacteria precipitate hydromagnesite and have played a significant role in the development of this natural environment. Consequently, Atlin provides a natural model for developing a passive carbon dioxide sequestration process by which ultramafic rock is weathered and re-precipitated as magnesium carbonates with the aid of cyanobacteria in a wetland environment. This biogeochemical process represents an important link between the biosphere and the inorganic carbon pool within the global carbon dioxide budget.

Power, I.; Wilson, S.; Dipple, G.; Southam, G.

2005-12-01

388

CARBON DIOXIDE SEQUESTRATION IN TERRESTRIAL ECOSYSTEMS  

EPA Science Inventory

The terrestrial biosphere plays a prominent role in the global carbon (C) cycle. errestrial ecosystems are currently accumulating C and it appears feasible to manage existing terrestrial (forest, agronomic, desert) ecosystems to maintain or increase C storage. orest ecosystems ca...

389

The preparation of liposomes using compressed carbon dioxide: strategies, important considerations and comparison with conventional techniques.  

PubMed

Numerous strategies are currently available for preparing liposomes, although no single method is ideal in every respect. Two methods for producing liposomes using compressed carbon dioxide in either its liquid or supercritical state were therefore investigated as possible alternatives to the conventional techniques currently used. The first technique used modified compressed carbon dioxide as a solvent system. The way in which changes in pressure, temperature, apparatus geometry and solvent flow rate affected the size distributions of the formulations was examined. In general, liposomes in the nano-size range with an average diameter of 200 nm could be produced, although some micron-sized vesicles were also present. Liposomes were characterized according to their hydrophobic drug-loading capacity and encapsulated aqueous volumes. The latter were found to be higher than in conventional techniques such as high-pressure homogenization. The second method used compressed carbon dioxide as an anti-solvent to promote uniform precipitation of phospholipids from concentrated ethanolic solutions. Finely divided solvent-free phospholipid powders of saturated lipids could be prepared that were subsequently hydrated to produce liposomes with mean volume diameters of around 5 microm. PMID:16734979

Bridson, R H; Santos, R C D; Al-Duri, B; McAllister, S M; Robertson, J; Alpar, H O

2006-06-01

390

Phase equilibria in carbon dioxide expanded solvents: Experiments and molecular simulations.  

PubMed

We present complementary molecular simulations and experimental results of phase equilibria for carbon dioxide expanded acetonitrile, methanol, ethanol, acetone, acetic acid, toluene, and 1-octene. The volume expansion measurements were done using a high-pressure Jerguson view cell. Molecular simulations were performed using the Gibbs ensemble Monte Carlo method. Calculations in the canonical ensemble (NVT) were performed to determine the coexistence curve of the pure solvent systems. Binary mixtures were simulated in the isobaric-isothermal distribution (NPT). Predictions of vapor-liquid equilibria of the pure components agree well with experimental data. The simulations accurately reproduced experimental data on saturated liquid and vapor densities for carbon dioxide, methanol, ethanol, acetone, acetic acid, toluene, and 1-octene. In all carbon dioxide expanded liquids (CXL's) studied, the molecular simulation results for the volume expansion of these binary mixtures were found to be as good as, and in many cases superior to, predictions based on the Peng-Robinson equation of state, demonstrating the utility of molecular simulation in the prediction of CXL phase equilibria. PMID:16805632

Houndonougbo, Yao; Jin, Hong; Rajagopalan, Bhuma; Wong, Kean; Kuczera, Krzysztof; Subramaniam, Bala; Laird, Brian

2006-07-01

391

A preliminary cost and engineering estimate for desalinating produced formation water associated with carbon dioxide capture and storage  

Microsoft Academic Search

The risk associated with storage of carbon dioxide in the subsurface can be reduced by removal of a comparable volume of existing brines (e.g. Buscheck et al., 2011). In order to avoid high costs for disposal, the brines should be processed into useful forms such as fresh and low-hardness water. We have carried out a cost analysis of treatment of

W. L. Bourcier; T. J. Wolery; T. Wolfe; C. Haussmann; T. A. Buscheck; R. D. Aines

2011-01-01

392

Carbon dioxide in the atmosphere. [and other research projects  

NASA Technical Reports Server (NTRS)

Research projects for the period ending September 15, 1973 are reported as follows: (1) the abundances of carbon dioxide in the atmosphere, and the processes by which it is released from carbonate deposits in the earth and then transferred to organic material by photosynthesis; the pathways for movement of carbon and oxygen through the atmosphere; (2) space science computation assistance by PDP computer; the performance characteristics and user instances; (3) OGO-6 data analysis studies of the variations of nighttime ion temperature in the upper atmosphere.

Johnson, F. S.

1974-01-01

393

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs  

USGS Publications Warehouse

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Kleypas, J. A.; Buddemeier, R. W.; Archer, D.; Gattuso, J. -P.; Langdon, C.; Opdyke, B. N.

1999-01-01

394

Current views on the regulation of autotrophic carbon dioxide fixation via the Calvin cycle in bacteria  

Microsoft Academic Search

The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates\\u000a of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for\\u000a the synthesis of all components of cell material. Autotrophic carbon dioxide fixation is energetically expensive and it is\\u000a therefore not surprising that

L. Dijkhuizen; W. Harder

1984-01-01

395

Experimental measurement of gas diffusivity in bitumen: Results for carbon dioxide  

SciTech Connect

A new technique is developed to measure the diffusivity of gas in bitumen as a function of composition. Results are presented for a carbon dioxide-bitumen system, which is of considerable industrial relevance. The technique employs transient pressure data obtained from a nonintrusive pressure decay experiment at constant temperature and volume. The underlying theory is presented along with a computational algorithm to calculate diffusivity. Using experimental pressure decay data in the range 25--90 C at 4 MPa, the diffusivity of carbon dioxide in bitumen is calculated. The results are compared with the limited data available in the literature. The approach is straightforward and can be easily applied to other nonvolatile liquid systems.

Upreti, S.R.; Mehrotra, A.K.

2000-04-01

396

Structural and thermodynamic properties of fluid carbon dioxide from a new ab initio potential energy surface  

NASA Astrophysics Data System (ADS)

An intermolecular potential energy surface for the carbon dioxide dimer is calculated fully ab initio using a large basis set and including electron correlation. From this potential the dimer structure and the second virial coefficients are determined. In addition, it is applied in molecular dynamics simulations to obtain the fluid structure, the pressure, the internal energy, the thermal pressure coefficient, and the molar heat at constant volume. The results are compared with those from simulations with a previous ab initio potential. In this way we gain information regarding the sensitivity of each property to the quality of the quantum chemically obtained potential. Equilibration of carbon dioxide simulations must be done with great care due to the very slow energy transfer between the intramolecular vibrations and the other degrees of freedom. This point is addressed in some detail.

Steinebrunner, Gerold; Dyson, Anthony J.; Kirchner, Barbara; Huber, Hanspeter

1998-08-01

397

Air pollution: sensitive detection of ten pollutant gases by carbon monoxide and carbon dioxide lasers.  

PubMed

Detection sensitivities of a few parts per billion for ten gaseous pollutants have been evaluated by measuring the strength of the absorption of infrared radiation from carbon monoxide and carbon dioxide lasers. Ethylene concentrations as small as 5 parts per billion have been detected in air. The measured absorption strengths indicate that in mixtures of pollutants, such as nitrogen dioxide and water vapor, the sensitivity is reduced by overlapping absorption bands. However, calculations indicate that it should be possible to detect nitrogen dioxide concentrations of 0.01 part per million in the presence of water vapor concentrations of 105 parts per million. PMID:5035485

Kreuzer, L B; Kenyon, N D; Patel, C K

1972-07-28

398

Carbon dioxide laser trabeculostomy for the treatment of neovascular glaucoma.  

PubMed Central

During the past 18 months, 23 cases of advanced neovascular glaucoma, unresponsive to medical therapy, have been treated by a trabeculostomy procedure using a carbon dioxide laser. This procedure entails surgical entry into the anterior chamber from beneath either a conjunctival or a scleral flap in such a way as to completely cauterize any neovascular tissue in the iridocorneal angle and to permit adequate drainage of the aqueous fluid from the anterior chamber to the periocular space. The average intraocular pressure, prior to carbon dioxide laser trabeculostomy was 54 mm Hg and these pressures were lowered below 18 mm Hg in over 57% of the cases followed for longer than six months post-laser therapy. Treatment was considered a failure in 26% of the cases where the intraocular pressure was not lowered substantially, and 17% of the treated eyes sustained a pressure decrease to within the 25 to 35 mm Hg range. Carbon dioxide laser trabeculostomy or trabeculo-sclerostomy provides a new method of lowering the intraocular pressure in severe cases of neovascular glaucoma without the hazard of intraocular hemorrhage, common with other filtration procedures. These procedures have proved satisfactory in alleviating the high pressures of neovascular glaucoma in a relatively large proportion of the patients treated. If the eye is grossly hyperemic and irritated because of the high intraocular pressure and the deteriorated condition of the eye, it is suggested that the carbon dioxide laser trabeculostomy procedure with a scleral flap be performed with an implanted seton as the procedure of choice. If the eye is relatively quiet and has some visual reserve but an exceedingly high and intractable intraocular pressure, it is advisable to use either the carbon dioxide laser trabeculostomy procedure or the carbon dioxide laser trabeculo-sclerostomy operation as described. These procedures are being further refined, but the results of this investigation suggest that these procedures can be utilized judiciously, and should prove useful, particularly in those eyes with advanced neovascular glaucoma with useful vision still remaining. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 A FIGURE 11 B

L'Esperance, F A; Mittl, R N

1982-01-01

399

Atmospheric carbon dioxide concentrations over the past 60 million years.  

PubMed

Knowledge of the evolution of atmospheric carbon dioxide concentrations throughout the Earth's history is important for a reconstruction of the links between climate and radiative forcing of the Earth's surface temperatures. Although atmospheric carbon dioxide concentrations in the early Cenozoic era (about 60 Myr ago) are widely believed to have been higher than at present, there is disagreement regarding the exact carbon dioxide levels, the timing of the decline and the mechanisms that are most important for the control of CO2 concentrations over geological timescales. Here we use the boron-isotope ratios of ancient planktonic foraminifer shells to estimate the pH of surface-layer sea water throughout the past 60 million years, which can be used to reconstruct atmospheric CO2 concentrations. We estimate CO2 concentrations of more than 2,000 p.p.m. for the late Palaeocene and earliest Eocene periods (from about 60 to 52 Myr ago), and find an erratic decline between 55 and 40 Myr ago that may have been caused by reduced CO2 outgassing from ocean ridges, volcanoes and metamorphic belts and increased carbon burial. Since the early Miocene (about 24 Myr ago), atmospheric CO2 concentrations appear to have remained below 500 p.p.m. and were more stable than before, although transient intervals of CO2 reduction may have occurred during periods of rapid cooling approximately 15 and 3 Myr ago. PMID:10963587

Pearson, P N; Palmer, M R

2000-08-17

400

Carbon dioxide sequestration in cement kiln dust through mineral carbonation  

Microsoft Academic Search

Carbon sequestration through the formation of carbonates is a potential means to reduce CO emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation. The degree of mineral carbonation achievable in cement kiln dust (CKD) under ambient temperatures and pressures was examined through

Deborah N. Huntzinger; John S. Gierke; S. Komar Kawatra; Timothy C. Eisele; Lawrence L. Sutter

2009-01-01

401

Reduction of carbon dioxide to petrochemical intermediates  

Microsoft Academic Search

The electrochemical reduction of CO at the Cu electrode was investigated in methanol-based electrolyte using various cesium supporting salts as the ionophore at an extremely low temperature (243 K). Cesium acetate, chloride, bromide, iodide, and thiocyanate were used as the ionophore. The main products from CO by electrochemical reduction were methane, ethylene, ethane, carbon monoxide, and formic acid. In the

S. Kaneco; K. Iiba; K. Ohta; T. Mizuno

2000-01-01

402

Synthesis of titanium dioxides in water-in-carbon dioxide microemulsion and their photocatalytic activity  

Microsoft Academic Search

Titania nanoparticles were prepared by controlled hydrolysis of titanium tetraisopropoxide (TTIP) in water-in-carbon dioxide microemulsion using ammonium carboxylate perfluoropolyether (PFPE-NH4) as a surfactant. The physical properties were examined by thermogravimetric-differential thermal analysis (TGA-DTA), X-ray diffraction (XRD) and transmission electron microscope (TEM). In addition, the photocatalytic decomposition of p-nitrophenol was also investigated using batch reactor in the presence of UV light.

Seong-Soo Hong; Man Sig Lee; Gun-Dae Lee; Kwon Taek Lim; Bae-Jin Ha

2003-01-01

403

Deactivation of carbon electrode for elimination of carbon dioxide evolution from rechargeable lithium-oxygen cells.  

PubMed

Carbon has unfaired advantages in material properties to be used as electrodes. It offers a low cost, light weight cathode that minimizes the loss in specific energy of lithium-oxygen batteries as well. To date, however, carbon dioxide evolution has been an unavoidable event during the operation of non-aqueous lithium-oxygen batteries with carbon electrodes, due to the reactivity of carbon against self-decomposition and catalytic decomposition of electrolyte. Here we report a simple but potent approach to eliminate carbon dioxide evolution by using an ionic solvate of dimethoxyethane and lithium nitrate. We show that the solvate leads to deactivation of the carbon against parasitic reactions by electrochemical doping of nitrogen into carbon. This work demonstrates that one could take full advantage of carbon by mitigating the undesired activity. PMID:24849589

Kang, Seok Ju; Mori, Takashi; Narizuka, Satoru; Wilcke, Winfried; Kim, Ho-Cheol

2014-01-01

404

Equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride  

SciTech Connect

Natural gas components such as hydrogen sulfide, carbon dioxide, and ethane form gas hydrates of structure I under suitable temperature and pressure conditions. Information on such conditions is vital to the oil and gas industry in order to design and operate processing equipment and pipelines so that hydrate formation is avoided. Incipient equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride were experimentally obtained in the temperature range 264--290 K and the pressure range 0.23--3.18 MPa. A variable-volume sapphire cell was used for the measurements.

Majumdar, A.; Mahmoodaghdam, E.; Bishnoi, P.R.

2000-02-01

405

Assessing the Thermodynamic Feasibility of the Conversion of Methane Hydrate into Carbon Dioxide Hydrate in Porous Media  

Microsoft Academic Search

Concerns about the potential effects of rising carbon dioxide levels in the atmosphere have stimulated interest in a number of carbon dioxide sequestration studies. One suggestion is the sequestration of carbon dioxide as clathrate hydrates by injection of carbon dioxide into methane hydrate. Energy-supply research estimates indicate that natural gas hydrates in arctic and sub-seafloor formations contain more energy than

Duane H. Smith; Kal Seshadri; Joseph W. Wilder

406

Preparation of titania\\/silica mesoporous composites with activated carbon template in supercritical carbon dioxide  

Microsoft Academic Search

Titania\\/silica mesoporous composites have been prepared with nanoscale casting process using activated carbon as template in supercritical carbon dioxide (SC CO2). The composite precursor of tetrabutyl titanate and tetraethyl orthosilicate (TEOS) were dissolved in supercritical CO2, and then coated on activated carbon in the desired supercritical condition. After removal of activated carbon template by calcinations in air at 600C, TiO2\\/SiO2

Qun Xu; Haijuan Fan; Yiqun Guo; Yanxia Cao

2006-01-01

407

Nanoporous ferric oxide prepared with activated carbon template in supercritical carbon dioxide  

Microsoft Academic Search

Nanoporous ferric oxide has been prepared with nanoscale casting process using activated carbon template in supercritical carbon dioxide. The precursors with the cosolvent of acetone were dissolved in supercritical CO2, and then attached to activated carbon in the supercritical condition. After removal of the activated carbon template by calcinations in air at 873K, the nanoporous Fe2O3 was obtained. Four factors

Haijuan Fan; Qun Xu; Yiqun Guo; Qi Peng; Zhenzhong Hou

2006-01-01

408

Noninvasive monitoring of carbon dioxide: A comparison of the partial pressure of transcutaneous and end-tidal carbon dioxide with the partial pressure of arterial carbon dioxide  

Microsoft Academic Search

This study compares two noninvasive techniques for monitoring the partial pressure of carbon dioxide (Pco2) in 24 anesthetized\\u000a adult patients. End-tidal PCO2 (PETCO2) and transcutaneous Pco2 (PtcCO2) were simultaneously monitored and compared with arterial Pco2 (PaCO2) determined by intermittent analysis of arterial blood samples. PETCO2 and PtcCO2 values were compared with PaCO2 values corrected to patient body temperature (PaC02T) and

Can Q. Phan; Kevin K. Tremper; Steven E. Lee; Steven J. Barker

1987-01-01

409

Adsorption of methane, ethane, ethylene, and carbon dioxide on high silica pentasil zeolites and zeolite like materials using gas chromatography pulse technique  

SciTech Connect

Adsorption of methane, ethane, ethylene, and carbon dioxide in H-ZSM-5, Na-ZSM-5, H-ZSM-8, Na-ZSM-8, Silicalite, and ALPO-5 at 303-473 K has been investigated using a gas chromatography pulse technique. The zeolites have been compared for the heat of adsorption of the adsorbates at near zero adsorbate loading and also for the specific retention volume (or thermodynamic adsorption equilibrium constant) of ethane, ethylene, and carbon dioxide relative to that of methane. Among the zeolites, ALPO-5 has a high potential for the separation of methane, ethane, ethylene, and carbon dioxide from their mixture. 21 refs., 4 figs., 4 tabs.

Choudhary, V.R.; Mayadevi, S. (National Chemical Lab., Pune (India))

1993-10-01

410

Assessing Effects of Rising Carbon Dioxide Levels on Ocean Ecosystems  

NASA Astrophysics Data System (ADS)

Carbon Productivity Responses to Increased Dissolved Inorganic Carbon Concentrations in Surface Ocean: Exploring the Feasibility of an in Situ Mesoscale Carbon Addition Experiment; Palisades, New York, 23-24 March 2009; To assess the effects of future elevated carbon dioxide (CO2) levels on ocean biogeochemistry and ecosystems, it is desirable to mimic such an environment in nature. A workshop to explore an in situ open ocean mesoscale CO2 perturbation experiment that would simulate the oceanic conditions expected toward the end of this century was held at Lamont-Doherty Earth Observatory at Columbia University (LDEO). The objectives were to evaluate the current understanding of the potential effects on open ocean ecosystems and biogeochemical cycling resulting from carbon chemistry and pH changes in response to increased atmospheric partial pressure of carbon dioxide (pCO2) and to examine the scientific justification and logistical feasibility of an in situ open ocean mesoscale CO2/pH perturbation experiment. The 15 participants represented fields of modeling and physical, geochemical, and biological oceanography.

Lance, Veronica P.

2009-07-01

411

An optimal centralized carbon dioxide repository for Florida, USA.  

PubMed

For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida's electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels), from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s) is also presented. PMID:21695024

Poiencot, Brandon; Brown, Christopher

2011-04-01

412

Kinetics of the reaction between carbon dioxide and tertiary amines  

SciTech Connect

The reaction between carbon dioxide and amines is of great technical importance and has been the subject of many investigations. The authors have shown that the reaction for secondary amines in anhydrous ethanol and in aqueous solution is exclusively second-order in amine and that the zwitterion intermediate postulated by Danckwerts is probably of negligible significance in the mechanism. The reaction with tertiary amines has also been studied, but the data are less controversial. In order to complete their studies of the reactions of carbon dioxide with amines, using their conductimetric stopped-flow apparatus, they have studied this reaction for MDEA (methyldiethanolamine, IUPAC name N-methyl-2,2{prime}-iminodiethanol) and TEA (triethanolamine, IUPAC name 2,2{prime},2{double prime}-nitrilotris(ethanol)).

Crooks, J.E.; Donnellan, J.P. (King's Coll., London (England))

1990-02-16

413

Carbon Dioxide Snow Storms During the Polar Night on Mars  

NASA Technical Reports Server (NTRS)

The Mars Orbiter Laser Altimeter (MOLA) detected clouds associated with topographic features during the polar night on Mars. While uplift generated from flow over mountains initiates clouds on both Earth and Mars, we suggest that the Martian clouds differ greatly from terrestrial mountain wave clouds. Terrestrial wave clouds are generally compact features with sharp edges due to the relatively small particles in them. However, we find that the large mass of condensible carbon dioxide on Mars leads to clouds with snow tails that may extend many kilometers down wind from the mountain and even reach the surface. Both the observations and the simulations suggest substantial carbon dioxide snow precipitation in association with the underlying topography. This precipitation deposits CO2, dust and water ice to the polar caps, and may lead to propagating geologic features in the Martian polar regions.

Toon, Owen B.; Colaprete, Anthony

2001-01-01

414

Effect of carbon monoxide and nitrogen dioxide on ICR mice  

NASA Technical Reports Server (NTRS)

Times to incapacitation and death and LC(50) values were determined for male ICR mice exposed to different concentration of carbon monoxide for 30 min and of nitrogen dioxide for 10 min in a 4.2 liter hemispherical chamber. The data indicate that ICR mice are more resistant to these two toxicants than Swiss albino mice. The carbon monoxide LC(50) for a 30-min exposure was about 8,000 ppm for ICR mice compared to 3,570 ppm for Swiss albino mice. The nitrogen dioxide LC(50) for a 10-min exposure was above 2,000 ppm for ICR mice compared to about 1,000 ppm for Swiss albino mice.

Hilado, C. J.; Cumming, H. J.

1977-01-01

415

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

416

Carbon Dioxide Observational Platform System (CO-OPS), feasibility study  

NASA Technical Reports Server (NTRS)

The Carbon Dioxide Observational Platform System (CO-OPS) is a near-space, geostationary, multi-user, unmanned microwave powered monitoring platform system. This systems engineering feasibility study addressed identified existing requirements such as: carbon dioxide observational data requirements, communications requirements, and eye-in-the-sky requirements of other groups like the Defense Department, the Forestry Service, and the Coast Guard. In addition, potential applications in: earth system science, space system sciences, and test and verification (satellite sensors and data management techniques) were considered. The eleven month effort is summarized. Past work and methods of gathering the required observational data were assessed and rough-order-of magnitude cost estimates have shown the CO-OPS system to be most cost effective (less than $30 million within a 10 year lifetime). It was also concluded that there are no technical, schedule, or obstacles that would prevent achieving the objectives of the total 5-year CO-OPS program.

Bouquet, D. L.; Hall, D. W.; Mcelveen, R. P.

1987-01-01

417

Supercritical carbon dioxide extraction of solvent from micromachined structures  

SciTech Connect

We have demonstrated that supercritical carbon dioxide extraction can be used for solvent removal to successfully release compliant surface micromachined structures on silicon wafers developed at Sandia National Laboratories. Structures that have been successfully extracted and released include single gear microengines, bridge and cantilever beams, pressure transducers, and experimental comb drive actuators. Since the supercritical fluid has negligible surface tension, it has virtually unabated access to solvent residing in capillary-like spaces as narrow as 1--3 {mu}m under the micromachined features. While conventional drying techniques have been plagued with the collapse and sticking of micromachined structures due to surface tension effects, supercritical carbon dioxide has been shown to reproducibly dry components and test structures, including bridge and cantilever beams approaching 1000 {mu}m in length, without collapsing. The equipment and the extraction process are described, and photographs of supercritically dried test structures and components are presented.

Russick, E.M.; Adkins, C.L.J.; Dyck, C.W.

1995-12-31

418

Superpulsed carbon dioxide laser: an update on cutaneous surgical applications  

NASA Astrophysics Data System (ADS)

Superpulsing the carbon dioxide laser allows delivery of high energy pulses separated by short pauses during which tissue cooling can occur.1 This new technology can provide several important advantages in cutaneous surgery over similar procedures performed with conventional continuous discharge carbon dioxide laser systems. In the excisional mode, there is a two-thirds reduction in thermal necrosis of the wound edge.2 This should translate into more rapid healing3 and increased rate of gain in tensile strength. In the vaporizational mode, precise, superficial and bloodless ablation of multiple benign appendigeal tumors is possible with less thermal damage yielding excellent cosmetic results. The establishment through additional research of accurate laser parameters, pulse duration, peak energy levels, and frequency of pulses, will help improve the specificity of the laser-tissue interaction to provide even better surgical results.

Wheeland, Ronald G.

1990-06-01

419

Determinants of Chronic Carbon Dioxide Retention and Its Correction in Humans  

PubMed Central

17 patients with chronic ventilatory failure (including 14 with chronic obstructive pulmonary disease) were studied to determine the causes of carbon dioxide retention and the chronic effect of medroxyprogesterone acetate on ventilatory drive and acid-base status. Carbon dioxide retention in patients with high mechanical loads occurred concomitantly with a higher than normal inspiratory effort (mouth occlusion pressure) and normal minute ventilation to carbon dioxide production ratio (V?e/V?co2); but with shortened inspiratory time (1.30.1 vs. 1.83 s), increased breathing frequency (171 vs. 141 breaths/min), low tidal volume (0.570.03 vs. 0.880.04 L), and high dead space to tidal volume ratio (0.630.02 vs. 0.390.07). Using a randomized application of treatment and placebo conditions, it was shown that 4 wk of medroxyprogesterone acetate caused significant reductions in Paco2 (from 511 to 421 mm Hg) in 10 of 17 patients. This correction of Paco2 in these patients was associated with increases in mouth occlusion pressure (14%), tidal volume (11%), and alveolar ventilation (15%) compared to placebo, although inspiratory time remained shortened. Arterial and lumbar cerebrospinal fluid pH was alkaline compared to placebo in patients who corrected Paco2. No change was noted in lung mechanics or core temperature. Common prerequisites for correction of Paco2 with medroxyprogesterone acetate treatment were the ability to significantly lower Paco2 upon acute voluntary hyperventilation and to increase tidal volume rather than breathing frequency in response to the drug. We attribute chronic CO2 retention in these patients to alterations in respiratory cycle timing and to a neuromuscular inspiratory effort which is adequate for the level of tissue CO2 production, but inadequate in the presence of mechanical and ventilation-perfusion abnormalities to normalize arterial blood gases.

Skatrud, James B.; Dempsey, Jerome A.; Bhansali, Praful; Irvin, Charles

1980-01-01

420

The carbon dioxide system in the Arabian Sea  

Microsoft Academic Search

In 1995 the WHOI (C. Goyet) and MIAMI (F.J. Millero) groups participated on a number of research cruises in the Arabian Sea as part of the U.S. Joint Global Ocean Flux Study (JGOFS) sponsored by the National Science Foundation (NSF). This paper gives the results of our total inorganic carbon dioxide (TCO2), total alkalinity (TA) and potentiometric pH measurements made

Frank J. Millero; Elizabeth A. Degler; Daniel W. OSullivan; Catherine Goyet; Greg Eischeid

1998-01-01

421

Compatibility of FBR structural materials with supercritical carbon dioxide  

Microsoft Academic Search

A key problem in the application of a supercritical carbon dioxide (CO2) turbine cycle to a fast breeder reactor is the corrosion of structural materials brought about by supercritical CO2 at high temperatures. In this study, long-term (8000h) compatibility tests on candidate materials, two high-chromium martensitic steels (12Cr- and 9Cr-steels) and an austenitic stainless steel (316FR), were performed at 400600C

T. Furukawa; Y. Inagaki; M. Aritomi

2011-01-01

422

Supercritical carbon dioxide extraction of cuphea seed oil  

Microsoft Academic Search

Cuphea seed oil (CSO) is a potential domestic source of medium chain fatty acids. Although CSO has been obtained using solvent extraction and screw pressing, both methods suffer from disadvantages. Supercritical carbon dioxide (SC-CO2) extraction is a promising alternative extraction technology. It is a very effective means to extract vegetable oils, non-toxic, non-flammable, easy to separate from extracts (i.e., no

F. J. Eller; S. C. Cermak; S. L. Taylor

2011-01-01

423

Serotonergic neurons as carbon dioxide sensors that maintain ph homeostasis  

Microsoft Academic Search

Serotonergic neurons in the medulla have recently been shown to be sensors of carbon dioxide and pH. There is compelling evidence that the co-release of serotonin, substance P and thyrotropin-releasing hormone from these neurons stimulates the neural network that controls breathing at numerous sites using many different mechanisms. Serotonergic neurons in the midbrain are also chemosensitive, and might mediate non-respiratory

George B. Richerson

2004-01-01

424

Carbon Dioxide in the Atmosphere and in Atlantic Ocean Water  

Microsoft Academic Search

An investigation of carbon dioxide partial pressures in the atmosphere and surface ocean conducted as part of a cooperative study under the general sponsorship of the International Geophysical Year is summarized. Results are given for about 470 hours of air analyses and 200 individual surface ocean water measurements made from 1957 to 1959 between 60N and 58S. Over the Atlantic

Taro Takahashi

1961-01-01

425

Effects of carbon dioxide on preoptic thermosensitive neurons in vitro  

Microsoft Academic Search

Effects of carbon dioxide (CO2) on the firing rates of preoptic thermosensitive neurons were examined in rat brain slice preparations. The perfusing medium was saturated with gas mixtures consisting of 90% O2 and one of various concentrations (5%, 6.3%, 7.5%, and 10%) of CO2 balanced with N2. The medium containing 5% CO2 was used as control. Most preoptic neurons were

K. Matsumura; T. Nakayama; T. Kaminaga

1987-01-01

426

Fiber-optic fluorescence carbon dioxide sensor for environmental monitoring  

Microsoft Academic Search

Fiber-optic sensors were developed for monitoring dissolved carbon dioxide in water samples in the 0 to 900 ppm concentration range. A pH-sensitive fluorescent dye (HPTS) was reacted with a cationic quaternary ammonium salt to form an ion pair which was electrostatically bound to the surface of particles of aminocellulose which then were dispersed into a gas-permeable silicone polymer. The green

Otto S. Wolfbeis; Barna Kovcs; Kisholoy Goswami; Stanley M. Klainer

1998-01-01

427

The thermal conductivity of argon, carbon dioxide and nitrous oxide  

Microsoft Academic Search

The paper presents new, absolute measurements of the thermal conductivity of three gases: argon (Ar), carbon dioxide (CO2) and nitrous oxide (N2O). The measurements have been carried out with a transient hot-wire instrument in the temperature range 308 to 430 K and at pressures up to 11 MPa. For most of the range of thermodynamic states covered by the measurements

J. Millat; M. Mustafa; M. Ross; W. A. Wakeham; M. Zalaf

1987-01-01

428

ELECTRODISPERSION OF FINE AQUEOUS DROPLETS IN SUPERCRITICAL CARBON DIOXIDE  

Microsoft Academic Search

This first study of electrospraying of a liquid into a dense, supercritical fluid has demonstrated a new method for dispersing aqueous liquid into supercritical carbon dioxide (SC-CO2) using pulsed high-voltage electric fields. The electrodispersion cell (EDC) was equipped with a laser light scattering system to determine the dependence of mean droplet size on operating variables such as field strength, pulse

K. D. Heath; H. D. Cochran

2001-01-01

429

Response surfaces of hazelnut oil yield in supercritical carbon dioxide  

Microsoft Academic Search

Response Surface Methodology was used to determine the effects of solvent flow rate (1, 3 and 5g\\/min), pressure (300, 375 and 450bar) and temperature (40, 50 and 60C) on hazelnut oil yield in supercritical carbon dioxide (SC-CO 2). Oil yield was represented by a second order response surface equation (R 2=0.997) using Box-Bhenken design of experiments. Oil yield increased with

S. G. zkal; M. E. Yener; U. Salg?n; . Mehmeto?lu

2005-01-01

430

Supercritical carbon dioxide extraction of triglycerides from Aquilaria crassna seeds  

Microsoft Academic Search

This study examines the effects of pressure, temperature and solvent to solid ratio (SSR) on extraction efficiency of triglycerides from powdered Aquilaria crassna seeds by using supercritical carbon dioxide (SC-CO2) extraction. Supercritical extractions were designed for pressures ranging from 250 to 350bar, temperatures ranging from 313 to 333K and SSR values ranging from 60:1 to 120:1. All values were selected

Wei-Heng Chen; Ching-Hung Chen; Chieh-Ming J. Chang; Bing-Chung Liau; Daina Hsiang

2010-01-01

431

Upconverting nanoparticle based optical sensor for carbon dioxide  

Microsoft Academic Search

We demonstrate a novel optical sensor for carbon dioxide in concentrations between 0 and 3%. The sensing scheme is based on the optical interrogation of a 12-?m polystyrene (PS) film containing upconverting nanoparticles (UCNPs; 40100nm in size) of the type NaYF4:Yb,Er, and the longwave absorption pH probe bromothymol blue (BTB) in its anionic (blue) form. PS is chosen as a

Reham Ali; Sayed M. Saleh; Robert J. Meier; Hassan A. Azab; Ibraheim I. Abdelgawad; Otto S. Wolfbeis

2010-01-01

432

Degradation of aqueous piperazine in carbon dioxide capture  

Microsoft Academic Search

Concentrated, aqueous piperazine (PZ) is a novel solvent for carbon dioxide (CO2) capture by absorption\\/stripping. One of the major advantages of PZ is its resistance to thermal degradation and oxidation.At 135 and 150C, 8m PZ is up to two orders of magnitude more resistant to thermal degradation than 7m monoethanolamine (MEA). After 18 weeks at 150C, only 6.3% of the

Stephanie A. Freeman; Jason Davis; Gary T. Rochelle

2010-01-01

433

Carbon dioxide gas sensor using a graphene sheet  

Microsoft Academic Search

In this article, we report on a high-performance graphene carbon dioxide (CO2) gas sensor fabricated by mechanical cleavage. Unlike other solid-state gas sensors, the graphene sensor can be operated under ambient conditions and at room temperature. Changes in the device conductance are measured for various concentrations of CO2 gas adsorbed on the surface of graphene. The conductance of the graphene

Hyeun Joong Yoon; Do Han Jun; Jin Ho Yang; Zhixian Zhou; Sang Sik Yang; Mark Ming-Cheng Cheng

2011-01-01

434

Intravascular carbon dioxide monitoring using micro-flow colorimetry  

Microsoft Academic Search

An intravascular carbon dioxide sensor is investigated which employs continuous perfusion of micro-quantities of reagent through silicone membrane tubing in contact with blood. Blood is sampled from a vessel by periodic withdrawal-reinfusion through a catheter and passes by the sensor membrane tubing integrated into the catheter system. Blood CO2 equilibrates across the silicone membrane causing a color change in the

Christopher G. Cooney; Bruce C. Towe

1997-01-01

435

Intraoperative events diagnosed by expired carbon dioxide monitoring in children  

Microsoft Academic Search

Expired carbon dioxide measurements (PECO2) were used (1) to assess the adequacy of initial alveolar ventilation, and (2) to document intraoperative airway events and\\u000a metabolic trends. Three hundred and thirty-one children were studied. Thirty-five intraoperative events were diagnosed by\\u000a continuous PeCO2 monitoring; 20 were potentially life-threatening problems (malignant hyperthermia, circuit disconnection or leak, equipment\\u000a failure, accidental extubation, endobronchial intubation, or

Charles J. Cot; Letty M. P. Liu; Stanislaw K. Szyfelbein; Susan Firestone; Nishan G. Goudsouzian; James P. Welch; Alfred L. Daniels

1986-01-01

436

Transcutaneous oxygen and carbon dioxide monitoring in intensive care  

Microsoft Academic Search

Transcutaneous oxygen (TcPo2) and carbon dioxide (TcPco2) tensions were compared with arterial values in 23 children aged 4 months to 14 years, all requiring some form of respiratory support, but not in shock. Electrodes were placed on the upper chest and were heated to 45 degrees C. For TcPo2 and arterial oxygen (Pao2) a tight linear correlation over the range

D Marsden; M C Chiu; F Paky; P Helms

1985-01-01

437

Growth rates of carbon dioxide emission in India  

Microsoft Academic Search

SummaryEstimates have been made of the carbon dioxide (CO2) emission into the atmosphere through the combustion of non-fossil and fossil fuels in India for the period 19501982. Results show that 6.5 1015 g C has been added to the earth's atmosphere. Of this, the individual contributions have been 69.2% by fire-wood, 23.7% by coal, 6.2% by petroleum products, 0.3%

L. S. Hingane; Bh. V. Ramana Murty

1984-01-01

438

Characterization of potassium glycinate for carbon dioxide absorption purposes  

Microsoft Academic Search

Aqueous solutions of potassium glycinate were characterized for carbon dioxide absorption purposes. Density and viscosity of these solutions, with concentrations ranging from 0.1 to 3M, were determined at temperatures from 293 to 313K. Diffusivity of CO2 in solution was estimated applying the modified StokesEinstein relation. Solubilities of N2O at the same temperatures and concentrations were measured and the ion specific

A. F. Portugal; P. W. J. Derks; G. F. Versteeg; F. D. Magalhes; A. Mendes

2007-01-01

439

Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells  

Microsoft Academic Search

Carbon dioxide electrolysis was studied in Ni\\/YSZ electrode supported Solid Oxide Electrolysis Cells (SOECs) consisting of a Ni-YSZ support, a Ni-YSZ electrode layer, a YSZ electrolyte, and a LSM-YSZ O2 electrode (YSZ=Yttria Stabilized Zirconia). The results of this study show that long term CO2 electrolysis is possible in SOECs with nickel electrodes.The passivation rate of the SOEC was between 0.22

Sune Dalgaard Ebbesen; Mogens Mogensen

2009-01-01

440

Volcanic carbon dioxide vents show ecosystem effects of ocean acidification  

Microsoft Academic Search

The atmospheric partial pressure of carbon dioxide (pCO2) will almost certainly be double that of pre-industrial levels by 2100 and will be considerably higher than at any time during the past few million years. The oceans are a principal sink for anthropogenic CO2 where it is estimated to have caused a 30% increase in the concentration of H+ in ocean

Jason M. Hall-Spencer; Riccardo Rodolfo-Metalpa; Sophie Martin; Emma Ransome; Maoz Fine; Suzanne M. Turner; Sonia J. Rowley; Dario Tedesco; Maria-Cristina Buia

2008-01-01

441

Deacidification of olive oils by supercritical carbon dioxide  

Microsoft Academic Search

An investigation of the application of supercritical carbon dioxide (SC-CO2) extraction to the deacidification of olive oils has been made to verify that the nutritional properties of the oil remain\\u000a unchanged when this technique is applied.\\u000a \\u000a Preliminary runs at 20 and 30 MPa in the temperature range of 3560C were performed on fatty acids and triglycerides as pure\\u000a compounds or

L. Brunetti; A. Daghetta; E. Fedell; I. Kikic; L. Zanderighi

1989-01-01

442

First Results From the Maljamar Carbon Dioxide Pilot  

Microsoft Academic Search

Continuous carbon dioxide injection in the Grayburg\\/San Andres formations of the MCA unit has been completed; follow-up brine injection began in December 1983. Incremental oil production began in mid-1983 from the Grayburg zone and six months later from the San Andres. Special features of the inverted five-spot pilot include separate completions in the Grayburg and San Andres zones; fiberglass-cased logging

P. J. Lingane; R. E. McWilliams; K. R. Pittaway

1984-01-01

443

Purification of Waste Cooking Oils via Supercritical Carbon Dioxide Extraction  

Microsoft Academic Search

Purification of waste cooking oils (palm oil and soybean oil) using supercritical carbon dioxide (scCO2) extraction has been investigated. The purified oils were characterized by their acid value, conjugated diene value, total polar compound measurements, and high-performance size exclusion chromatography. Using optimal extractions conditions of 353.15K, 20MPa, and CO2 flow rate of 40g\\/min, 80% of the oil was recovered and

Seung-Ah Hong; Jaehoon Kim; Jae-Duck Kim; Jeong Won Kang; Youn-Woo Lee

2010-01-01

444

Adsorption of Carbon Dioxide onto EDA-CP-MS41  

Microsoft Academic Search

Carbon dioxide was adsorbed onto mesoporous adsorbent of ethylene diamine immobilized CP-MCM41 (EDA-CP-MS41), which was synthesized by chloropropyl functionalized MCM-41 (CP-MS41) with ethylene diamine, in a laboratory-scale packed-bed. The adsorber was operated batchwise with the charge of adsorbent in the range of 13g to obtain the breakthrough curves of CO2. Experiments were carried out at different adsorption temperatures (3050C) and

Kyu-Suk Hwang; Young-Sik Son; Sang-Wook Park; Dae-Won Park; Kwang-Joong Oh; Seong-Soo Kim

2009-01-01

445

THE ROLES OF CARBON DIOXIDE IN METHANOL SYNTHESIS  

Microsoft Academic Search

The roles played by carbon dioxide in the chemistry of methanol synthesis over CuO\\/ZnO\\/A12O3 catalysts have been experimentally investigated. It was concluded based on reaction rate measurements and thermodynamic considerations, that the two reactions that best describe the chemical system of methanol synthesis are the CO2-hydrogenation and water-gas shift reactions. It was also found experimentally that the presence of CO2

Sunggyu Lee; Vetkav R. Parameswaran; Irving Wender; Conrad J. Kulik

1989-01-01

446

Interfacial tension in high-pressure carbon dioxide mixtures  

Microsoft Academic Search

High-pressure interfacial- and surface-tension phenomena govern the migration and recovery of oil and gas from hydrocarbon reservoirs. The phenomena are of particular relevance to phase separation and mass transfer in light hydrocarbon fractionation plants and in propane deasphalting in lubricating oil refining. Interfacial tensions of carbon dioxide-water-alcohol mixtures were measured at temperatures in the range 5--71 C and pressures 0.1--18.6

Byung-Soo Chun; Gordon T. Wilkinson

1995-01-01

447

Supercritical carbon dioxide extraction of CLA-ethyl ester  

Microsoft Academic Search

Supercritical carbon dioxide (SC-CO2) extraction of Conjugated linoleic acid (CLA) ethyl ester was investigated at pressures in the range of 9 to 10.5 MPa and\\u000a temperature gradients ranging from 0C to 21C. The content of CLA-ethyl ester in the fraction was analyzed with gas chromatography\\u000a (GC). The experimental results indicated that the rate of extraction would rise with the increase

Yingdi Chen; Peng Xu; Jian Cheng

2011-01-01

448

Colored polymer microparticles through carbon dioxide-assisted dyeing  

Microsoft Academic Search

A new procedure is described for dyeing polymer beads using liquid carbon dioxide as a plasticizer to facilitate transport of dye into the particle phase. Aqueous latexes consisting of monodisperse polystyrene particles with surface-grafted poly(N-vinylpyrrolidone) were dyed with Sudan Red 7B using CO at 25 C and 310 bar. Adding CO to the headspace above the latex resulted in some

M. Z. Yates; E. R. Birnbaum; T. M. McCleskey

2000-01-01

449

Gasification combined cycle: Carbon dioxide recovery, transport, and disposal  

Microsoft Academic Search

Initiatives to limit carbon dioxide (CO[sub 2]) emissions have drawn considerable interest to integrated gasification combined-cycle (IGCC) power generation. This process can reduce C0[sub 2] production because of its higher efficiency, and it is amenable to C0[sub 2] capture, because C0[sub 2] can be removed before combustion and the associated dilution with atmospheric nitrogen. This paper presents a process-design baseline

R. D; J. C. Molburg; P. Thimmapuram; G. F. Berry; C. D. Livengood; R. A. Johnson

1993-01-01

450

Adding value to carbon dioxide from ethanol fermentations  

Microsoft Academic Search

Carbon dioxide (CO2) from ethanol production facilities is increasing as more ethanol is produced for alternative transportation fuels. CO2 produced from ethanol fermentation processes is of high purity and is nearly a saturated gas. Such highly-concentrated source of CO2 is a potential candidate for capture and utilization by the CO2 industry. Quantity, quality and capture of CO2 from ethanol fermentations

Yixiang Xu; Loren Isom; Milford A. Hanna

2010-01-01

451

Electrochemical carbon dioxide concentrator advanced technology tasks  

NASA Technical Reports Server (NTRS)

Technology advancement studies are reported on the basic electrochemical CO2 removal process to provide a basis for the design of the next generation cell, module and subsystem hardware. An Advanced Electrochemical Depolarized Concentrator Module (AEDCM) is developed that has the characteristics of low weight, low volume, high CO2, removal, good electrical performance and low process air pressure drop. Component weight and noise reduction for the hardware of a six man capacity CO2 collection subsystem was developed for the air revitalization group of the Space Station Prototype (SSP).

Schneider, J. J.; Schubert, F. H.; Hallick, T. M.; Woods, R. R.

1975-01-01

452

Combined carbon dioxide/water solid oxide electrolysis  

NASA Astrophysics Data System (ADS)

Solid oxide electrolysis of a mixture of water and carbon dioxide has many applications in space exploration. It can be implemented in propellant production systems that use Martian resources or in closed-loop life support systems to cleanse the atmosphere of facilities in extraterrestrial bases and of cabin spacecrafts. This work endeavors to quantify the performance of combined water and carbon dioxide electrolysis, referred to as "combined electrolysis", and to understand how it works so that the technology can be best applied. First, to thoroughly motivate the research, system modeling is presented that demonstrates the competitiveness of the technology in terms of electrolysis power requirements and consequential system mass savings. Second, to demonstrate and quantify the performance of the technology, experimental results are presented. Electrolysis cells were constructed with 8% by mol yttria-stabilized zirconia electrolytes, 50/50 by weight platinum/yttria-stabilized zirconia electrodes and chromium-alloy or alumina manifolds and tubing. Performance and gas chromatograph data from electrolysis of many different gas mixtures, including water, carbon dioxide, and a combined mixture of both, are presented. Third, to explain observations made during experiments and theorize about the phenomena governing combined electrolysis, data analyses and thermodynamic modeling are applied. Conclusions are presented regarding the transient response of combined electrolysis, the relative performance of it to that of other mixtures, how its performance depends on the water to carbon dioxide ratio, its effect on cell health, and its preference to water versus carbon dioxide. Procedures are also derived for predicting the composition of combined electrolysis exhaust for a given oxygen production rate, humidity content, and inlet flow rate. The influence of the two cell materials proves to be significant. However, in both cases it is proven that combined electrolysis does not encourage carbon deposition and the makeup of its products is governed by the water gas shift reaction. It is shown that the chromium-alloy system achieves water gas shift reaction equilibrium whereas the alumina system does not. Experimental observations support the argument that chromium oxide inside the chromium alloy cell forces its water gas shift reaction to equilibrium during electrolysis, influencing combined electrolysis performance.

Iacomini, Christine Schroeder

453

Atlas of high resolution infrared spectra of carbon dioxide  

NASA Technical Reports Server (NTRS)

An atlas of long-path room-temperature absorption spectra of carbon dioxide is presented for the spectral intervals 1830-2100 cm, 2395-2680 cm, and 3140-3235 cm. The spectral data were recorded at high signal to noise with the 0.01 cm resolution Fourier transform interferometer. The spectra were obtained with pressures between 1 and 10 Torr of CO2 and with total paths between 24 and 384 meters. A compilation of the measured line positions and the assignments derived from the analysis are presented. Of the 3336 lines in the atlas, 94 percent were identified as CO2 lines or as residual lines H2O and CO. Calculated positions are presented for the carbon dioxide lines; a total of 52 bands of C-12O2-16, C-13O2-16, C-12O-16O-18, C-12O-16O-17, and C-13O-16O18 were identified. The weakest carbon dioxide lines marked in the atlas have intensities of approximately 0.5 x 10 to the negative 26th power cm/molecule at room temperature.

Rinsland, C. P.; Benner, D. C.; Devi, V. M.; Ferry, P. S.; Sutton, C. H.; Richardson, D. J.

1984-01-01

454

Electrochemical cell for obtaining oxygen from carbon dioxide atmospheres  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

455

Removal of carbon dioxide from gas mixtures by wollastonite  

NASA Astrophysics Data System (ADS)

Wollastonite synthesis and decomposition were analyzed from the viewpoint of thermodynamics (using the TERRA software). It is shown that wollastonite synthesis from limestone and silica takes place at a minimum content of nitrogen (10-5 N2) with a release of carbon dioxide. The synthesis temperature is T ? 560 K. Wollastonite is decomposed in the presence of flue gas (4N2) with limestone and silica formation and burial of carbon dioxide in the form of CaCO3(c). Wollastonite decomposition temperature is T ? 420 K. The cyclic reciprocating process for complete removal of carbon dioxide by wollastonite is suggested. Four strokes of the reciprocating system with the fixed temperatures of wollastonite decomposition (T=300 K) and wollastonite synthesis (T=560 K) are presented. Total energy consumption (T = 560 K) is ? I ? 130 kJ/mole, 30 % of energy is spent for heating and 70 % of energy is spent for chemical reaction. This is comparable with the heat of CO2 solution in ethanolamin.

Engelsht, V. S.; Muratalieva, V. Zh.

2013-09-01

456

[Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Final report  

SciTech Connect

This program investigated how host plant responses to elevated atmospheric carbon dioxide may be transmitted to other trophic levels, especially leaf eating insects, and alter consumption of leaves and impare their function. Study results included the following findings: increased carbon dioxide to plants alters feeding by insect herbivores; leaves produced under higher carbon conditions contain proportionally less nitrogen; insect herbivores may have decreased reproduction under elevated carbon dioxide.

Lincoln, D.E.

1995-10-01

457

Atmospheric carbon dioxide levels for the last 500 million years  

PubMed Central

The last 500 million years of the strontium-isotope record are shown to correlate significantly with the concurrent record of isotopic fractionation between inorganic and organic carbon after the effects of recycled sediment are removed from the strontium signal. The correlation is shown to result from the common dependence of both signals on weathering and magmatic processes. Because the long-term evolution of carbon dioxide levels depends similarly on weathering and magmatism, the relative fluctuations of CO2 levels are inferred from the shared fluctuations of the isotopic records. The resulting CO2 signal exhibits no systematic correspondence with the geologic record of climatic variations at tectonic time scales.

Rothman, Daniel H.

2002-01-01

458

Synthesis of cyclic carbonate from carbon dioxide and diols over metal acetates  

Microsoft Academic Search

Different metallic acetates were used as the catalysts to synthesize cyclic carbonates from carbon dioxide and diols in the presence of acetonitrile. In the course of reaction, acetonitrile acted as not only the solvent but also the dehydrating reagent to eliminate the effect of the water produced from the reaction. Thus, the thermodynamic equilibrium was shifted and the yield of

Shi-yong HUANG; Shui-gang LIU; Jun-ping LI; Ning ZHAO; Wei WEI; Yu-han SUN

2007-01-01

459

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2001-01-01

460

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2002-01-01

461

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2004-01-01

462

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2005-01-01

463

Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2006-01-01

464

Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2005-01-01

465

Calcium Carbonate Produced by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2007-01-01

466

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2003-01-01

467

CALCIUM CARBONATE PRODUCTION BY COCCOLITHOPHORID ALGAE IN LONG TERM, CARBON DIOXIDE SEQUESTRATION  

Microsoft Academic Search

Predictions of increasing levels of anthropogenic carbon dioxide (CO) and the specter of global warming have intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered, including bioprocessing methods to promote and accelerate biosequestration of CO from the environment through the growth of organisms such as coccolithophorids, which are capable of

V. J. Fabry

2003-01-01