WorldWideScience

Sample records for term carbon dioxide

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

    Energy Technology Data Exchange (ETDEWEB)

    V.J. Fabry

    2007-06-30

    Predictions of increasing levels of anthropogenic carbon dioxide (CO{sub 2}) 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{sub 2} from the environment through the growth of organisms such as coccolithophorids, which are capable of sequestering CO{sub 2} relatively permanently. Calcium and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is readily oxidized and releases CO2 through microbial decomposition on land and in the sea, carbonates can sequester carbon over geologic time scales. This proposal investigates the use of coccolithophorids - single-celled, marine algae that are the major global producers of calcium carbonate - to sequester CO{sub 2} emissions from power plants. Cultivation of coccolithophorids for calcium carbonate (CaCO{sub 3}) precipitation is environmentally benign and results in a stable product with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics, it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of CO{sub 2} into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately and the amount of carbon sequestered as CaCO{sub 3} could be readily quantified. The significant advantages of this approach warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result in the maximum amount of CO{sub 2} sequestration through coccolithophorid calcite production and to evaluate the costs/benefits of using coccolithophorid cultivation ponds to abate CO{sub 2} emissions from power plants.

  2. Are long-term trends in lake carbon dioxide flux responsive to climaticvariability and change?

    Science.gov (United States)

    Golub, M.; Desai, A. R.

    2012-12-01

    Inland water bodies are major but understudied conduits of carbon in within the global land-ocean-atmosphere carbon cycle. While many researchers have shown significant 20th century trends in physical and biological lake processes driven by climatic change, there is less research on how these influence lake-atmosphere carbon dioxide flux. We investigated the effects of climatic drivers on physical features and CO2 flux in lakes. We estimated the long-term trends in ice phenology, thermal structure, and amount of carbon exchanged, using 15-25-year time series of measurements of temperature, alkalinity, pH for eleven lakes monitored by the North Temperate Lakes Long-Term Ecological Research (NTL-LTER) program. Lakes coherently responded to regional climatic warming, showing declining ice cover duration, prolonged growing season, and increasingly warmer waters. Long-term trends of CO2 trends varied among lakes, however, with the majority of lakes showing a weakening source of CO2 to atmosphere. We further compared the sensitivity of CO2 flux to climate forcing in lakes as a function of trophic states, dissolved organic carbon concentrations, and morphometric features. These results provide new insights into our understanding about the role of lakes in regional and global carbon balances, on the sensitivity of CO2 flux to climatic variability, and in improving prediction of future carbon-climate change feedbacks.

  3. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  4. Near-Term Opportunities for Carbon Dioxide Capture and Storage 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document contains the summary report of the workshop on global assessments for near-term opportunities for carbon dioxide capture and storage (CCS), which took place on 21-22 June 2007 in Oslo, Norway. It provided an opportunity for direct dialogue between concerned stakeholders in the global effort to accelerate the development and commercialisation of CCS technology. This is part of a series of three workshops on near-term opportunities for this important mitigation option that will feed into the G8 Plan of Action on Climate Change, Clean Energy and Sustainable Development. The ultimate goal of this effort is to present a report and policy recommendations to the G8 leaders at their 2008 summit meeting in Japan.

  5. Carbon Dioxide Fountain

    Science.gov (United States)

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

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

  6. Carbon dioxide as chemical feedstock

    National Research Council Canada - National Science Library

    Aresta, M

    2010-01-01

    ... Dioxide as an Inert Solvent for Chemical Syntheses 15 Alessandro Galia and Giuseppe Filardo Introduction 15 Dense Carbon Dioxide as Solvent Medium for Chemical Processes 15 Enzymatic Catalysis in Dense Carbon Dioxide 18 Other Reactions in Dense Carbon Dioxide 19 Polymer Synthesis in Supercritical Carbon Dioxide 20 Chain Polymerizations: Synt...

  7. Perspectives in the use of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Aresta Michele

    1999-01-01

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

  8. Carbon dioxide thesaurus: a comprehensive list of terms in use in the CO/sub 2/ field

    Energy Technology Data Exchange (ETDEWEB)

    Redford, J.S. (ed.)

    1981-10-01

    Standardized terms structured to allow consistent machine storage and retrieval of information pertaining to carbon dioxide and the environment are included in this thesaurus. Although terminology is based on the Energy Data Base Subject Thesaurus used by the Technical Information Center in indexing information of importance to the DOE mission, additional terms highly specific to the CO/sub 2/ literature are also included. (DMC)

  9. Carbon dioxide sensor

    Science.gov (United States)

    Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

    2011-11-15

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

  10. Carbon Dioxide Information Center thesaurus

    Energy Technology Data Exchange (ETDEWEB)

    Millemann, R.E.; Cushman, R.M.

    1986-04-01

    This thesaurus lists the keywords (including narrower, broader, and related terms, as well as forbidden terms) used by the Carbon Dioxide Information Center for the input and retrieval of records for its Bibliographic Information System (BIS), BIS is a specialized bibliographic data base on carbon dioxide and climate. It is being merged into the Department of Energy's Energy Data Base (EDB). The keywords used in the BIS Thesaurus are also used in the much larger EDB thesaurus so EDB may be searched for CO2 references using either thesaurus.

  11. Effects of Mineral Salts on Short-Term Incorporation of CarbonDioxide in Chlorella

    Energy Technology Data Exchange (ETDEWEB)

    Holm-Hansen, O.; Nishida, K.; Moses, V.; Calvin, M.

    1958-07-01

    Although the functions of the essential major elements in plant metabolism have been studied for many years, little work has been done concerning the effect of these elements during short-term incorporation of radioactive carbon dioxide. This may be of some importance as it has been the general custom during photosynthesis studies in this laboratory to suspend algae in various dilute buffer solutions or in distilled water alone assuming that the salt remaining within the cells from the time of growth in nutrient solution are sufficient in quantity for the cells not to become deficient in one or more of the essential elements during the course of the experiment. There are some indications, however, that the addition of salts to algae suspended in distilled water may have a rapid, pronounced effect on some metabolic system within the plant. Thus, Clendenning, Brown and Eyster (1956) have reported that Nostoc muscorum, if rinsed and resuspended in distilled water, loses most of its photosynthetic capacity, which can, however, be completely restored by the addition of potassium ion in concentrations no greater than a few parts per million. Also, K. Baalorud (personal communication) found that the photosynthetic rate of a marine diatom, when suspended in synthetic magnesium-free water, can be greatly increased by the addition of magnesium salts. In view of these observations it appeared worthwhile to investigate the effects of the addition of the essential elements in those photosynthesis experiments in which the cells are kept in distilled water for varying periods of time.

  12. Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

    DEFF Research Database (Denmark)

    Shaffer, G.; Olsen, S.M.; Pedersen, Jens Olaf Pepke

    2009-01-01

    Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion and assoc......Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion...... solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean. We conclude that substantial reductions in fossil-fuel use over the next...

  13. Carbon dioxide recycling

    Science.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kisholoy Goswami

    2005-10-11

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

  15. Response of soil carbon dioxide efflux to fire disturbance in a long-term grassland global change experiment

    Science.gov (United States)

    Strong, A. L.; Chiariello, N.; Tobeck, T.; Field, C. B.

    2012-12-01

    How terrestrial biosphere-atmosphere carbon dioxide exchange responds to global change is an important component to understanding global feedbacks of the carbon cycle. Soils represent a global store of organic carbon on the order of 3000 Pg C. Increased carbon dioxide release from increased respiration of soil C in response to climate warming and other direct and indirect anthropogenic factors could create a positive carbon cycle feedback to climate change. Numerous studies have demonstrated that soil respiration increases under experimental warming and elevated CO2, although the long-term, multi-year dynamics of this feedback remain poorly constrained. Punctuated disturbances, such as fire, are also likely to affect soil C responses, and understanding how fire and other global change factors interact in their influence on soil respiration is important in order to fully characterize climate-carbon cycle feedbacks. Previous studies have found that fire disturbance in semi-arid grasslands reduces soil CO2. The Jasper Ridge Global Change Experiment is a thirteen-year continuous full-factorial global change manipulation (elevated carbon dioxide, temperature, precipitation, and nitrogen deposition) located in a clay-loam soil grassland in central coastal California. In summer 2011, an additional treatment condition -- a controlled burn -- was applied to half the experimental plots to provide a fire treatment, and in the following growing season, soil carbon dioxide effluxes were measured at peak aboveground plant biomass (April 2012) and after summer senescence (June 2012) using a LiCOR-6400 soil respiration chamber and infrared gas analyzer. Across all plots and other treatments, CO2 fluxes were greater in burned grassland soils than in non-burned grassland soils (p 0.10). Neither soil temperature, nor soil moisture appeared to be correlated with soil CO2 efflux (p > 0.10). By June 2012, after senescence and dry-out, all soil CO2 effluxes were lower than in April, and

  16. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  17. Carbon dioxide disposal in solid form

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  18. Short-Term Effects of Carbon Dioxide on Carnation Callus Cell Respiration 1

    Science.gov (United States)

    Palet, Artur; Ribas-Carbó, Miquel; Argilés, Josep M.; Azcón-Bieto, Joaquim

    1991-01-01

    The addition of potassium bicarbonate to the electrode cuvette immediately stimulated the rate of dark O2 uptake of photomixotrophic and heterotrophic carnation (Dianthus caryophyllus L.) callus, of Elodea canadensis (Michx) leaves, and of other plant tissues. This phenomenon occurred at pH values lower than 7.2 to 7.8, and the stimulation depended on the concentration of gaseous CO2 in the solution. These stimulatory responses lasted several minutes and then decreased, but additional bicarbonate or gaseous CO2 again stimulated respiration, suggesting a reversible effect. Carbonic anhydrase in the solution increased the stimulatory effect of potassium bicarbonate. The CO2/bicarbonate dependent stimulation of respiration did not occur in animal tissues such as rat diaphragm and isolated hepatocytes, and was inhibited by salicylhydroxamic acid in carnation callus cells and E. canadensis leaves. This suggested that the alternative oxidase was engaged during the stimulation in plant tissues. The cytochrome pathway was severely inhibited by CO2/bicarbonate either in the absence or in the presence of the uncoupler carbonylcyanide m-chlorophenyl hydrazone. The activity of cytochrome c oxidase of callus tissue homogenates was also inhibited by CO2/bicarbonate. The results suggested that high carbon dioxide levels (mainly free CO2) partially inhibited the cytochrome pathway (apparently at the oxidase level), and this block in electron transport elicited a large transient engagement of the alternative oxidase when present uninhibited. PMID:16668209

  19. CARBON DIOXIDE AS A FEEDSTOCK.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,C.; FUJITA,E.

    2000-12-09

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

  20. Carbon Dioxide Fixation by Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Victoria H.; Calvin, Melvin

    1951-07-24

    Resting cells of eleven microorganisms were exposed to radioactive carbon dioxide for 40 minutes. The radioactive compounds formed during this time were separated and identified by paper chromatography. Resting cells of Lactobacillus casei fixed no carbon dioxide and growing cells fixed carbon dioxide primarily in malic and aspartic acids. All of the radioactive compounds formed could have become radioactive by reversal of known decarboxylation reactions.

  1. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

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

  2. Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

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

  3. Carbon Isotope Ratios Of Carbon Dioxide In The Urban Salt Lake Valley, Utah USA: Source And Long-Term Monitoring Observations

    Science.gov (United States)

    Ehleringer, J.; Lai, C.; Strong, C.; Pataki, D. E.; Bowling, D. R.; Schauer, A. J.; Bush, S.

    2011-12-01

    A high-precision, decadal record of carbon isotope ratios in atmospheric carbon dioxide has been produced for the urbanized Salt Lake Valley, Utah USA. These data complement a similar time series of atmospheric carbon dioxide concentrations for different locations in the same urban region. This isotopic record includes diurnal and nocturnal observations based on flask (IRMS-based) and continuous (TDL-based) measurement systems. These data reveal repeatable diurnal and seasonal variations in the anthropogenic and biogenic carbon sources that can be used to reconstruct different source inputs. As the Salt Lake Valley is an isolated urban region, the impacts of local anthropogenic inputs can be distinguished from regional patterns as measured by NOAA at the rural Wendover monitoring station 200 km to the west of the Salt Lake Valley. Complementary data, such as vehicle exhaust, emission from power plants and household furnaces, plant and soil organic matter, are also provided to quantify the carbon isotope ratios of the predominant anthropogenic and biogenic sources within the Salt Lake Valley. The combined source and long-term observational values will be made freely available and their utility is discussed for modeling efforts including urban metabolism modeling and atmospheric trace gas modeling.

  4. Exposure Assessment for Carbon Dioxide Gas: Full Shift Average and Short-Term Measurement Approaches.

    Science.gov (United States)

    Hill, R Jedd; Smith, Philip A

    2015-01-01

    Carbon dioxide (CO2) makes up a relatively small percentage of atmospheric gases, yet when used or produced in large quantities as a gas, a liquid, or a solid (dry ice), substantial airborne exposures may occur. Exposure to elevated CO2 concentrations may elicit toxicity, even with oxygen concentrations that are not considered dangerous per se. Full-shift sampling approaches to measure 8-hr time weighted average (TWA) CO2 exposures are used in many facilities where CO2 gas may be present. The need to assess rapidly fluctuating CO2 levels that may approach immediately dangerous to life or health (IDLH) conditions should also be a concern, and several methods for doing so using fast responding measurement tools are discussed in this paper. Colorimetric detector tubes, a non-dispersive infrared (NDIR) detector, and a portable Fourier transform infrared (FTIR) spectroscopy instrument were evaluated in a laboratory environment using a flow-through standard generation system and were found to provide suitable accuracy and precision for assessing rapid fluctuations in CO2 concentration, with a possible effect related to humidity noted only for the detector tubes. These tools were used in the field to select locations and times for grab sampling and personal full-shift sampling, which provided laboratory analysis data to confirm IDLH conditions and 8-hr TWA exposure information. Fluctuating CO2 exposures are exemplified through field work results from several workplaces. In a brewery, brief CO2 exposures above the IDLH value occurred when large volumes of CO2-containing liquid were released for disposal, but 8-hr TWA exposures were not found to exceed the permissible level. In a frozen food production facility nearly constant exposure to CO2 concentrations above the permissible 8-hr TWA value were seen, as well as brief exposures above the IDLH concentration which were associated with specific tasks where liquid CO2 was used. In a poultry processing facility the use of dry

  5. Measurement of long-term average carbon dioxide concentrations using passive diffusion sampling

    Science.gov (United States)

    Bertoni, Giuliano; Ciuchini, Carla; Tappa, Remo

    A diffusive sampling device is proposed for long-term determination of average airborne concentration of CO 2 in urban and industrial areas, as well as in indoor sites. A hydro-alcoholic barium hydroxide solution is employed as a CO 2 reagent sink. The analytical method is based on the determination of the solute barium hydroxide remained after the acid-base reaction, in which its insoluble carbonate salt precipitates. Indoor laboratory experiments show that this technique exhibits a good precision and reproducibility. A 6-week internal consistency test demonstrates that this device has a constant uptake rate, allowing us to propose it as a suitable and inexpensive tool in performing the monitoring of urban and industrial sites over long periods and in indoor-outdoor studies, like those involved in the sick-building syndrome problem.

  6. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY

    Directory of Open Access Journals (Sweden)

    O. Schneising

    2011-03-01

    Full Text Available Carbon dioxide (CO2 and methane (CH4 are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002 was the first and is now with TANSO onboard GOSAT (launch 2009 one of only two satellite instruments currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest.

    We present long-term SCIAMACHY retrievals (2003–2009 of column-averaged dry air mole fractions of both gases (denoted XCO2 and XCH4 derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2 of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4 being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics.

    The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved global annual mean XCO2 increase agrees with CarbonTracker within the error bars (1.80±0.13 ppm yr−1 compared to 1.81±0.09 ppm yr−1. The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3±0.2 ppm for the Northern Hemisphere and 1.4±0.2 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker.

    An investigation of the boreal forest carbon uptake during the

  8. Reducing carbon dioxide to products

    Science.gov (United States)

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

    2014-09-30

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

  9. Recuperative supercritical carbon dioxide cycle

    Science.gov (United States)

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

    2014-11-18

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

  10. Method for carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-12-05

    A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC-CO.sub.2) and water or bine into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation.

  11. Investigating the Fundamental Scientific Issues Affecting the Long-term Geologic Storage of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Spangler, Lee [Montana State Univ., Bozeman, MT (United States); Cunningham, Alfred [Montana State Univ., Bozeman, MT (United States); Barnhart, Elliot [Montana State Univ., Bozeman, MT (United States); Lageson, David [Montana State Univ., Bozeman, MT (United States); Nall, Anita [Montana State Univ., Bozeman, MT (United States); Dobeck, Laura [Montana State Univ., Bozeman, MT (United States); Repasky, Kevin [Montana State Univ., Bozeman, MT (United States); Shaw, Joseph [Montana State Univ., Bozeman, MT (United States); Nugent, Paul [Montana State Univ., Bozeman, MT (United States); Johnson, Jennifer [Montana State Univ., Bozeman, MT (United States); Hogan, Justin [Montana State Univ., Bozeman, MT (United States); Codd, Sarah [Montana State Univ., Bozeman, MT (United States); Bray, Joshua [Montana State Univ., Bozeman, MT (United States); Prather, Cody [Montana State Univ., Bozeman, MT (United States); McGrail, B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oldenburg, Curtis [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wagoner, Jeff [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pawar, Rajesh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-12-19

    The Zero Emissions Research and Technology (ZERT) collaborative was formed to address basic science and engineering knowledge gaps relevant to geologic carbon sequestration. The original funding round of ZERT (ZERT I) identified and addressed many of these gaps. ZERT II has focused on specific science and technology areas identified in ZERT I that showed strong promise and needed greater effort to fully develop.

  12. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site [Abstract

    Science.gov (United States)

    R. Minocha; S. Long; S. Minocha; P Marquardt; M. Kubiske

    2010-01-01

    The objective of the present study was to evaluate the long-term (10 years) effects of elevated CO2 and O3 on the carbon and nitrogen metabolism of aspen trees. The study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA).

  13. Method for carbon dioxide splitting

    Science.gov (United States)

    Miller, James E.; Diver, Jr., Richard B.; Siegel, Nathan P.

    2017-02-28

    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A.sub.xFe.sub.3-xO.sub.4, where 0.ltoreq.x.ltoreq.1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M.sub.aCe.sub.bO.sub.c, where 0gas mixture, adding carbon dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.

  14. Magnesite disposal of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

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

  15. Long-term leaf production response to elevated atmospheric carbon dioxide and tropospheric ozone

    Science.gov (United States)

    Alan F. Talhelm; Kurt S. Pregitzer; Christian P. Giardina

    2011-01-01

    Elevated concentrations of atmospheric CO2 and tropospheric O3 will profoundly influence future forest productivity, but our understanding of these influences over the long-term is poor. Leaves are key indicators of productivity and we measured the mass, area, and nitrogen concentration of leaves collected in litter traps...

  16. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    J. H. Carver

    1995-07-01

    Full Text Available A CO2-weathering model has been used to explore the possible evolution of the Earth's climate as the Sun steadily brightened throughout geologic time. The results of the model calculations can be described in terms of three, qualitatively different, "Megaclimates". Mega-climate 1 resulted from a period of rapid outgassing in the early Archean, with high, but declining, temperatures caused by the small weathering rates on a largely water-covered planet. Mega-climate 2 began about 3 Gyear ago as major continental land masses developed, increasing the weathering rate in the early Proterozoic and thereby depleting the atmospheric CO2 concentration. This process produced the first Precambrian glaciations about 2.3 Gyear ago. During Mega-climate 2, evolutionary biological processes increased the surface weatherability in incremental steps and plate tectonics modulated the CO2 outgassing rate with an estimated period of 150 Myear (approximately one-half the period for the formation and breakup of super continents. Throughout Mega-climate 2 the surface temperature was controlled by variations in the atmospheric CO2 level allowing transitions between glacial and non-glacial conditions. The results of the model for Mega-climate 2 are in agreement with the occurrence (and absence of glaciations in the geologic record. Extending the model to the future suggests that CO2 control of the Earth's temperature will no longer be able to compensate for a solar flux that continues to increase. The present level of atmospheric CO2 is so small that further reduction in CO2 cannot prevent the Earth from experiencing Mega-climate 3 with steadily increasing surface temperatures caused by the continued brightening of the Sun. During Mega-climate 3, the main danger to the biosphere would come not from an increasing temperature but from a decreasing (rather than an increasing CO2 level which could, in time, fall below 0.5 PAL, causing serious damage to the biosphere

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

    Directory of Open Access Journals (Sweden)

    J. H. Carver

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

  19. Carbon Dioxide Embolism during Laparoscopic Surgery

    Science.gov (United States)

    Park, Eun Young; Kwon, Ja-Young

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

  20. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  1. Process for sequestering carbon dioxide and sulfur dioxide

    Science.gov (United States)

    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

    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.

  2. Modelling Sublimation of Carbon Dioxide

    Science.gov (United States)

    Winkel, Brian

    2012-01-01

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

  3. Carbon Dioxide (CO2) in Blood

    Science.gov (United States)

    ... https://medlineplus.gov/labtests/carbondioxideco2inblood.html Carbon Dioxide (CO2) in Blood To use the sharing features on ... please enable JavaScript. What is a Carbon Dioxide (CO2) Blood Test? Carbon dioxide (CO2) is an odorless, ...

  4. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  5. Method for carbon dioxide splitting

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James E.; Diver, Jr., Richard B.; Siegel, Nathan P.

    2017-02-28

    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula A.sub.xFe.sub.3-xO.sub.4, where 0.ltoreq.x.ltoreq.1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula M.sub.aCe.sub.bO.sub.c, where 0carbon dioxide, and heating to a temperature less than approximately 1400 C, thereby producing carbon monoxide gas and the original metal oxide compound.

  6. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-06-15

    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

  7. GEOLOGICAL STORAGE OF CARBON DIOXIDE

    Directory of Open Access Journals (Sweden)

    Iva Kolenković

    2014-07-01

    Full Text Available Carbon dioxide geological storage represents a key segment of the carbon capture and storage system (CCS expected to significantly contribute to the reduction of its emissions, primarily in the developed countries and in those that are currently being industrialised. This approach to make use of the subsurface is entirely new meaning that several aspects are still in research phase. The paper gives a summary of the most important recent results with a short overview the possibilities in the Republic of Croatia. One option is to construct underground carbon dioxide storage facilities in deep coal seams or salt caverns. Another would be to use the CO2 in enhanced oil and gas recovery projects relying on the retention of the carbon dioxide in the deep reservoir because a portion of the injected gas is not going be produced together with hydrocarbons. Finally, the greatest potential estimated lies in depleted hydrocarbon reservoirs with significantly reduced reservoir pressure, as well as in the large regional units - layers of deep saline aquifers that extend through almost all sedimentary basins (the paper is published in Croatian.

  8. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  9. Turning carbon dioxide into fuel.

    Science.gov (United States)

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

    2010-07-28

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

  10. Sonochemical reduction of carbon dioxide.

    Science.gov (United States)

    Harada, H

    1998-06-01

    Sonolysis of carbon dioxide dissolved in water was performed from a standpoint of reducing this material in atmosphere. During one hour of sonication, the amount of CO2 decreased to about half at 5 degrees C under CO2-Ar atmosphere. The decreasing rate for CO2 followed the order Ar > He > H2 > N2 and it was down with increasing temperature in the range of 5-45 degrees C. The most favorable concentration for reducing CO2 was 0.03 (mole fraction of CO2 in gas phase). This concentration in gas phase means an equal mixture of CO2 and Ar in water, because CO2 is more soluble than Ar. Since carbon dioxide dissolved in water would be partly ionized, the roles of ions on the sonolysis were also examined. Gaseous reaction products were CO, H2 and a small amount of O2. Carbon monoxide and hydrogen might be obtained from CO2 and H2O by sonolysis, respectively. Both gases are fuel and react each other to C1 compounds such as methanol, and so on. Therefore, irradiation of ultrasonic waves should be an important technique for reducing CO2.

  11. Insufflation with Humidified and Heated Carbon Dioxide in Short-Term Laparoscopy: A Double-Blinded Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Anja Herrmann

    2015-01-01

    Full Text Available Background. We tested the hypothesis that warm-humidified carbon dioxide (CO2 insufflation would reduce postoperative pain and morphine requirement compared to cold-dry CO2 insufflation. Methods. A double-blinded, randomized, controlled trial was conducted to compare warm, humidified CO2 and cold-dry CO2. Patients with benign uterine diseases were randomized to either treatment (n=48 or control (n=49 group during laparoscopically assisted vaginal hysterectomy. Primary endpoints of the study were rest pain, movement pain, shoulder-tip pain, and cough pain at 2, 4, 6, 24, and 48 hours postoperatively, measured by visual analogue scale. Secondary outcomes were morphine consumption, rejected boli, temperature change, recovery room stay, and length of hospital stay. Results. There were no significant differences in all baseline characteristics. Shoulder-tip pain at 6 h postoperatively was significantly reduced in the intervention group. Pain at rest, movement pain, and cough pain did not differ. Total morphine consumption and rejected boli at 24 h postoperatively were significantly higher in the control group. Temperature change, recovery room stay, and length of hospital were similar. Conclusions. Warm, humidified insufflation gas significantly reduces postoperative shoulder-tip pain as well as morphine demand. This trial is registered with Clinical Trial Registration Number  DRKS00003853 (German Clinical Trials Register (DRKS.

  12. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-30

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

  13. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-10

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

  14. Carbon dioxide reducing processes; Koldioxidreducerande processer

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Fredrik

    1999-12-01

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

  15. Insights from a network of long-term measurements of biosphere-atmospheric exchanges of water vapor and carbon dioxide in a water-limited semiarid region

    Science.gov (United States)

    Scott, Russell; Biederman, Joel

    2017-04-01

    Around one-third of Earth's land surface is classified as semiarid, and carbon dioxide exchange in these regions has been shown to be an important regulator of both the trend and interannual variability of the terrestrial carbon sink. Fifteen years ago, when we began making measurements of biosphere-atmospheric exchanges of energy, water vapor, and carbon dioxide using eddy covariance in southern Arizona USA, there was paucity of semiarid observations in flux networks like AmeriFlux and EuroFlux. We started by establishing riparian sites across a woody plant encroachment gradient to quantify the productivity and consumptive plant water use along a iconic and ecologically important desert river. Soon thereafter, we added semiarid grassland, shrubland, and savanna sites that do not have access to groundwater in order to better understand how water limitation and changes in vegetation structure affect ecosystem productivity. Here, we highlight the value of multiyear, multisite flux data for addressing regional to global scale problems associated with groundwater pumping, land cover change, drought, and climate change. For the riparian sites, we find that ecosystem water availability is altered by vegetation structure such that ecosystems with more deeply rooted trees have higher productivity but at a cost of greater groundwater use. For the non-riparian sites, precipitation strongly controls ecosystem water availability and the resultant productivity, but differences in ecosystem structure impact water use efficiency due to the partitioning of evapotranspiration into its component sources. Also, the productivity at sites with more grass, and less woody, plants responds more quickly to precipitation fluctuations including long-term drought conditions. In semiarid regions, variability in water and carbon fluxes is much larger than in more mesic climes. Across our riparian and non-riparian sites, access to more stable groundwater reserves reduces variability in water and

  16. Insights from a network of long-term measurements of biosphere-atmospheric exchanges of water vapor and carbon dioxide in southern Arizona

    Science.gov (United States)

    Scott, R. L.; Barron-Gafford, G.; Biederman, J. A.

    2016-12-01

    Around one-third of Earth's land surface is classified as semiarid, and carbon dioxide exchange in these regions has been shown to be an important regulator of both the trend and interannual variability of the terrestrial carbon sink. Fifteen years ago, when we began making measurements of biosphere-atmospheric exchanges of energy, water vapor, and carbon dioxide using eddy covariance in southern Arizona USA, there was paucity of semiarid observations in flux networks like Ameriflux. We started by establishing riparian sites across a woody plant encroachment gradient to quantify the productivity and consumptive plant water use along a iconic and ecologically important desert river. Soon thereafter, we added semiarid grassland, shrubland, and savanna sites that do not have access to groundwater in order to better understand how water limitation and changes in vegetation structure affect ecosystem productivity. Here, we highlight the value of multiyear, multisite flux data for addressing regional to global scale problems associated with groundwater pumping, land cover change, drought, and climate change. For the riparian sites, we find that ecosystem water availability is altered by vegetation structure such that ecosystems with more deeply rooted trees have higher productivity but at a cost of greater groundwater use. For the non-riparian sites, precipitation strongly controls ecosystem water availability and the resultant productivity, but differences in ecosystem structure impact water use efficiency due to the partitioning of evapotranspiration into its component sources. Also, the productivity at sites with more grass, and less woody, plants responds more quickly to precipitation fluctuations including long-term drought conditions. In semiarid regions, variability in water and carbon fluxes is much larger than in more mesic climes. Across our riparian and non-riparian sites, access to more stable groundwater reserves reduces variability in water and carbon

  17. Robust optical carbon dioxide isotope analyzer Project

    Data.gov (United States)

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

  18. Carbon dioxide: making the right connection

    African Journals Online (AJOL)

    Carbon dioxide has been used in anaesthesia since the late 1920s, principally to stimulate breathing after a period of hyperventilation in the era before routine use of capnography. The authors' tertiary academic hospital still has the infrastructure for pipeline delivery of carbon dioxide. A case is reported of accidental ...

  19. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  20. Encapsulated liquid sorbents for carbon dioxide capture.

    Science.gov (United States)

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

    2015-02-05

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

  1. Validating modelled carbon-dioxide emissions against long-term eddy-covariance measurements at the urban neighborhood-scale

    Science.gov (United States)

    Christen, A.; Coops, N. C.; Crawford, B.; Heyman, E.; Kellett, R.; Liss, K.; Oke, T. R.; Olchovski, I.; Tooke, R.; van der Laan, M.; Voogt, J. A.

    2010-12-01

    It can be expected that integrative greenhouse-gas emission modeling at block or neighborhood-scales becomes an increasingly relevant part of urban planning processes in the future. A particular challenge forms the geographical distribution of emissions and a proper validation of modeled emissions at this fine scale where consumption statistics are often lacking. Direct flux measurements of GHGs using the eddy-covariance (EC) approach could be a valuable approach to validate such fine-scale urban emission inventories. In combination with micrometeorological source-area models, EC measurements provide spatial-temporal information of emissions - at scales where utility or consumption data is not available. A residential neighborhood in Vancouver, BC, Canada is used as a case study to validate modeled carbon-dioxide (CO2) emissions against direct eddy-covariance flux measurements. The model is a combination of top-down inventory and bottom-up modelling of individual objects (buildings, vegetation, traffic counts). Carbon is conceptually tracked through quantifying inputs and outputs into the modelled urban neighborhood, as well as storage changes within the neighborhood. The spatial modelling of emissions is conceptually separated into four components - buildings, transportation, human respiration and vegetation/soils. Inputs to the emission model include automated urban object classifications (buildings, trees, land cover) based on LiDAR and optical remote sensing data in combination with census data, assessment data, traffic counts and measured radiation and climate data. Based on those inputs, spatial maps of total annual CO2 emissions (or uptake) are modeled at 50 m resolution for 4 km2. The resulting maps (building, transportation, human respiration and vegetation) are then summed to create a map of integral (net-)emissions. The mapped area overlaps with the source-area of a micrometeorological flux tower location in the center of the study area. Continuous CO2

  2. Electrocatalysts for carbon dioxide conversion

    Science.gov (United States)

    Masel, Richard I; Salehi-Khojin, Amin

    2015-04-21

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

  3. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

  4. Carbon dioxide capture process with regenerable sorbents

    Science.gov (United States)

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

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

  5. High performance hydrophobic solvent, carbon dioxide capture

    Science.gov (United States)

    Nulwala, Hunaid; Luebke, David

    2017-05-09

    Methods and compositions useful, for example, for physical solvent carbon capture. A method comprising: contacting at least one first composition comprising carbon dioxide with at least one second composition to at least partially dissolve the carbon dioxide of the first composition in the second composition, wherein the second composition comprises at least one siloxane compound which is covalently modified with at least one non-siloxane group comprising at least one heteroatom. Polydimethylsiloxane (PDMS) materials and ethylene-glycol based materials have high carbon dioxide solubility but suffer from various problems. PDMS is hydrophobic but suffers from low selectivity. Ethylene-glycol based systems have good solubility and selectivity, but suffer from high affinity to water. Solvents were developed which keep the desired combinations of properties, and result in a simplified, overall process for carbon dioxide removal from a mixed gas stream.

  6. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Science.gov (United States)

    2010-04-01

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

  7. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  8. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2010-10-01

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

  10. 46 CFR 76.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

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

  11. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2010-10-01

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

  13. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  14. Reactive Capture of Carbon Dioxide Project

    Data.gov (United States)

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

  15. Carbon Dioxide Collection and Pressurization Technology Project

    Data.gov (United States)

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

  16. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  17. It is time to put carbon dioxide to work

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  18. Long-term effects of elevated carbon dioxide concentration on sour orange wood specific gravity, modulus of elasticity, and microfibril angle

    Science.gov (United States)

    David Kretschmann; James Evans; Mike Wiemann; Bruce A. Kimball; Sherwood B. Idso

    2007-01-01

    The carbon dioxide (CO2) concentration of Earth’s atmosphere continues to rise. Plants in general are responsive to changing CO2 concentrations, which suggests changes in agricultural productivity in the United States and around the world. The ability of plants to absorb CO2 during photosynthesis and then store carbon in their structure or sequester it in the soil has...

  19. Apparatus for extracting and sequestering carbon dioxide

    Science.gov (United States)

    Rau, Gregory H [Castro Valley, CA; Caldeira, Kenneth G [Livermore, CA

    2010-02-02

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

  20. Inter and intra-specific variation in photosynthetic acclimation response to long term exposure of elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M. [Univ. of Essex, Colchester (United Kingdom)]|[Writtle Coll. (United Kingdom)

    1996-08-01

    The response of intra and interspecific variation in photosynthetic acclimation to growth at elevated atmospheric CO{sub 2} concentration (600{micro}mol mol-l) in six important grassland species was investigated. Plants were grown in a background sward of Lolium perenne and measurements were made after four years of growth at elevated C{sub a}. Elevated CO{sub 2} was maintained using a FACE (Free-Air Carbon Enrichment) system. Significant intra and interspecific variation in acclimation response was demonstrated. The response of adaxial and abaxial stomatal conductance to elevated CO{sub 2} was also investigated. The stomatal conductance of both the adaxial and abaxial leaf surfaces was found to be reduced by elevated C{sub a}. Significant asymmetric responses in stomatal conductance was demonstrated in D. glomerata and T. pratense. Analysis of stomatal indices and densities indicated that the observed reductions in stomatal conductance were probably the result of changes in stomatal aperture.

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

    Science.gov (United States)

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

    2014-01-07

    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.

  2. Systematic framework for carbon dioxide capture and utilization processes to reduce the global carbon dioxide emissions

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Plaza, Cristina Calvera; Gani, Rafiqul

    the two approaches that are currently being investigated, carbon capture and storage (CCS) and carbon capture and utilization (CCU) [1] to address this issue, the later approach is more promising as it reuses captured carbon dioxide, as a fuel, reactant, solvent, and others, to produce valuable products......In the year 2013, 9.5 billion metric tons of carbon dioxide gas was emitted into the air, and each year this amount is increasing [1]. Carbon dioxide emissions are of particular concern as they represent 80% of greenhouse gas emissions and therefore are a large contributor to global warming. Among....... There is not only a need for technologies for capture and utilization, via conversion, but also there are numerous questions that need to be resolved. For example, which higher value chemicals can be produced, what are their current demands and costs of production, and, how much of the captured carbon dioxide would...

  3. CARBON-DIOXIDE LASER VAPORIZATION IN EARLY GLOTTIC CARCINOMA

    NARCIS (Netherlands)

    MAHIEU, HF; PATEL, P; ANNYAS, AA

    Objective: Presently, widely employed treatment modalities for early glottic carcinoma include radiation therapy, surgical excision, and carbon dioxide laser excision. All these treatments have good oncological results, but poor or questionable functional-results in terms of quality of voice and

  4. Open nanoporous morphologies from polymeric blends by carbon dioxide foaming

    NARCIS (Netherlands)

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

    2002-01-01

    We report the formation of open nanoporous polymer films composed of homogeneous polysulfone/polyimide blends. Porosity is introduced by expansion of carbon dioxide-saturated films at elevated temperatures. To interpret details of the porous morphologies in terms of the experimental conditions

  5. Electron irradiation of carbon dioxide-carbon disulphide ice analog ...

    Indian Academy of Sciences (India)

    Upon electron irradiation the chemical composition was found to have altered and the new products from irradiation were found to be carbonyl sulphide (OCS), sulphur dioxide (SO2), ozone (O3), carbon trioxide (CO3), sulphur trioxide (SO3), carbon subsulphide (C3S2) and carbon monoxide (CO). Results obtained confirm ...

  6. Carbon dioxide removal and the futures market

    Science.gov (United States)

    Coffman, D.'Maris; Lockley, Andrew

    2017-01-01

    Futures contracts are exchange-traded financial instruments that enable parties to fix a price in advance, for later performance on a contract. Forward contracts also entail future settlement, but they are traded directly between two parties. Futures and forwards are used in commodities trading, as producers seek financial security when planning production. We discuss the potential use of futures contracts in Carbon Dioxide Removal (CDR) markets; concluding that they have one principal advantage (near-term price security to current polluters), and one principal disadvantage (a combination of high price volatility and high trade volume means contracts issued by the private sector may cause systemic economic risk). Accordingly, we note the potential for the development of futures markets in CDR, but urge caution about the prospects for market failure. In particular, we consider the use of regulated markets: to ensure contracts are more reliable, and that moral hazard is minimised. While regulation offers increased assurances, we identify major insufficiencies with this approach—finding it generally inadequate. In conclusion, we suggest that only governments can realistically support long-term CDR futures markets. We note existing long-term CDR plans by governments, and suggest the use of state-backed futures for supporting these assurances.

  7. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

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

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

    Science.gov (United States)

    1964-01-01

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

  9. Tourism Transport, Technology, and Carbon Dioxide Emissions

    NARCIS (Netherlands)

    Peeters, P.M.

    2010-01-01

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

  10. Carbon dioxide (CO2) utilizing strain database

    African Journals Online (AJOL)

    Jane

    2011-10-17

    Oct 17, 2011 ... Culling of excess carbon dioxide from our environment is one of the major challenges to scientific communities. Many physical, chemical and biological methods have been practiced to overcome this problem. The biological means of CO2 fixation using various microorganisms is gaining importance.

  11. integrated vertical photobioreactor system for carbon dioxide

    African Journals Online (AJOL)

    Astri Nugroho

    2013-07-02

    Jul 2, 2013 ... Abstract. A vertical photobioreactor containing the microalgae Scenedesmus obliquus is a highly efficient system for converting carbon dioxide (CO2) into biomass. The use of photobioreactor for CO2 mitigation has been explored using microalgae as photosynthetic microorganism. The growth rate (μ, h-1) ...

  12. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

    estuarine system, the Pearl River Estuary, China. J. Geophys. Res., 114, G03013, doi: 10.1029/2008JG000905. Hunt, C.W., J.E. Salisbury, D. Vandemark, and W. McGillis (2010). Contrasting carbon dioxide inputs and exchange in three adjacent New England...

  13. Diffusion of carbon dioxide (1); eicosane (2)

    Science.gov (United States)

    Winkelmann, J.

    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-Börnstein 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) eicosane

  14. Heat transfer coefficient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1998-01-01

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

  15. Integrated Vertical Photobioreactor System for Carbon Dioxide ...

    African Journals Online (AJOL)

    A vertical photobioreactor containing the microalgae Scenedesmus obliquus is a highly efficient system for converting carbon dioxide (CO2) into biomass. The use of photobioreactor for CO2 mitigation has been explored using microalgae as photosynthetic microorganism. The growth rate (m, h-1) were 0.03; 0.13; 0.20; 0.09 ...

  16. Carbon dioxide capture and air quality

    NARCIS (Netherlands)

    Horssen, A. van; Ramirez, C.A.; Harmelen, T. van; Koornneef, J.

    2011-01-01

    Carbon dioxide (CO2) is one of the most important greenhouse gases (GHG). The most dominant source of anthropogenic CO2 contributing to the rise in atmospheric concentration since the industrial revolution is the combustion of fossil fuels. These emissions are expected to result in global climate

  17. Carbon dioxide in European coastal waters

    NARCIS (Netherlands)

    Borges, A.V.; Schiettecatte, L.-S.; Abril, G.; Delille, B.; Gazeau, F.P.H.

    2006-01-01

    We compiled from literature annually integrated air–water fluxes of carbon dioxide (CO2) computed from field measurements, in 20 coastal European environments that were gathered into 3 main ecosystems: inner estuaries, upwelling continental shelves and non-upwelling continental shelves. The

  18. Catalyst cartridge for carbon dioxide reduction unit

    Science.gov (United States)

    Holmes, R. F. (Inventor)

    1973-01-01

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

  19. Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during ...

    African Journals Online (AJOL)

    Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during laparoscopic surgery: changes in pH, arterial partial Pressure of Carbon Dioxide (PaCo 2 ) and End Tidal Carbon Dioxide (EtCO ... EtCO2 is still a good non-invasive monitor for estimation of PaCO2 during low tidal volume ventilation during pneumoperitoneum.

  20. Studies on carbon dioxide system in central Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; Singbal, S.Y.S.

    Data on pH and total alkalinity have been utilised in the study of carbon dioxide and its species in Central Arabian Sea Total carbon dioxide and partial pressure of carbon dioxide remain fairly constant in the upper layers but increase...

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

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1...) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following special requirements: (1) All plates for tank, manway nozzle...

  2. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial...

  3. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... optimize performance. (b) Zero the carbon dioxide analyzer with either zero-grade air or zero-grade... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its...

  4. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... instrument start-up and operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction...

  5. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... performance. (b) Zero the carbon dioxide analyzer with either zero-grade air or zero-grade nitrogen. (c... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction into...

  6. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

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

    Science.gov (United States)

    2010-04-01

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

  8. 27 CFR 24.319 - Carbon dioxide record.

    Science.gov (United States)

    2010-04-01

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

  9. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

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

  10. Long term Measurements of ozone, bromine monoxide and carbon dioxide over the Frozen Arctic Ocean Surface: first data from O-Buoy Deployments

    Science.gov (United States)

    Bottenheim, J. W.; Matrai, P. A.; Netcheva, S.; Perovich, D. K.; Shepson, P. B.; Simpson, W. R.; O-Buoy Team

    2010-12-01

    We report results from the first deployments of O-Buoys in the ice of the Arctic Ocean and the Hudson Bay in 2009-2010. O-Buoys were developed to obtain long term, autonomous, atmospheric chemistry measurements in the marine boundary layer (MBL) over polar ice surfaces. It is well known that in Arctic spring the abundance of ozone (O3) in the MBL often episodically declines to very low levels, and it is assumed that halogens from sea-salt activation are responsible, especially bromine atoms which will lead to increases in bromine monoxide (BrO). Such chemical processing is hypothesized to be triggered over the frozen Arctic Ocean, and be especially effective over briny, first year ice. Even less is known about the variability of carbon dioxide (CO2) over frozen surfaces; global models largely treat the Arctic Ocean ice as an impenetrable lid between the ocean and overlying atmosphere. Clearly long term in-situ measurements are required to shed light on actually occurring processes, and start exploring their climatic implications in a changing, warming Arctic. Such measurements are impeded by serious logistical difficulties under the extreme environmental conditions of the open frozen Arctic Ocean, hence O-Buoys. After successful proof of concept in the spring of 2009 near Barrow, Alaska, we deployed the first O-Buoy in the Beaufort Sea in the fall of 2009. This O-Buoy operated successfully until contact was lost in July 2010 after 9 months of continuous operation, probably due loss of the power source after breakup of the ice. A second O-Buoy was deployed for about 40 days in the frozen Hudson Bay, while a third O-Buoy made observations in the Arctic Ocean near Borden Island for about 25 days. The results permit a unique long term look at the variations of the target chemical species at locations inaccessible by other means. Ozone depletion events (ODEs) in the spring, and concurrent BrO levels will be discussed. The data allow us to better explore the spatial and

  11. Modeling of the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X

    OpenAIRE

    Dantas,T. L. P; Luna,F. M. T; Silva Jr.,I. J.; Torres,A. E. B.; Azevedo, D. C. S.; Rodrigues,A.E.; Moreira,R.F.P.M.

    2011-01-01

    In this study, the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X was investigated. The adsorption equilibrium and breakthrough curves were determined at different temperatures - 301 - 306 K, 323 K, 373 K and 423 K. A model based on the LDF approximation for the mass transfer, considering the energy and momentum balances, was used to describe the adsorption kinetics of carbon dioxide and a carbon dioxide - nitrogen mixture. The model acceptably...

  12. The production of carbon dioxide from flue gas by membrane gas absorption

    NARCIS (Netherlands)

    Feron, P.H.M.; Jansen, A.E.

    1997-01-01

    The use of membrane gas absorption for carbon dioxide production from flue gases is discussed with special reference to the combined supply of heat and carbon dioxide to greenhouses. Novel absorption liquids are introduced which show an improved performance in terms of system stability and mass

  13. Electron irradiation of carbon dioxide-carbon disulphide ice analog ...

    Indian Academy of Sciences (India)

    Abstract. Carbon dioxide (CO2) and carbon disulphide (CS2) molecular ice mixture was prepared under low temperature (85 K) astrochemical conditions. The icy mixture irradiated with keV electrons simulates the irradiation environment experienced by icy satellites and Interstellar Icy Mantles (IIM). Upon electron irradi-.

  14. Adsorption of Carbon Dioxide, Ammonia, Formaldehyde, and Water Vapor on Regenerable Carbon Sorbents

    Science.gov (United States)

    Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is nonregenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for simultaneous carbon dioxide, ammonia, formaldehyde, and water sorption. Multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also the enhancement of formaldehyde sorption by the presence of ammonia in the gas mixture.

  15. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Science.gov (United States)

    2010-07-01

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

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

    DEFF Research Database (Denmark)

    Bjerregård, Asger; Jansen, Erik

    2012-01-01

    Measurement of the arterial carbon dioxide (P(a)CO(2)) is an established part of the monitoring of mechanically ventilated patients. Other ways to get information about carbon dioxide in the patient are measurement of end-tidal carbon dioxide (P(ET)CO(2)) and transcutaneous carbon dioxide (PTCCO2......). Carbon dioxide in the blood and cerebral tissue has great influence on vasoactivity and thereby blood volume of the brain. We have found no studies on the correlation between P(ET)CO(2) or P(TC)CO(2), and P(a)CO(2) during hyperbaric oxygen therapy (HBOT)....

  17. Energy efficient solvent regeneration process for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shaojun; Meyer, Howard S.; Li, Shiguang

    2018-02-27

    A process for removing carbon dioxide from a carbon dioxide-loaded solvent uses two stages of flash apparatus. Carbon dioxide is flashed from the solvent at a higher temperature and pressure in the first stage, and a lower temperature and pressure in the second stage, and is fed to a multi-stage compression train for high pressure liquefaction. Because some of the carbon dioxide fed to the compression train is already under pressure, less energy is required to further compress the carbon dioxide to a liquid state, compared to conventional processes.

  18. Materials for carbon dioxide separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingqing

    2014-10-01

    The CO{sub 2} adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO{sub 2} adsorption ability. Another promising class of materials for CO{sub 2} capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO{sub 3} and the relationship between physisorption and chemisorption properties of CaO-based materials.

  19. Glossary: Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    1990-08-01

    This Glossary contains definitions of selected CO{sub 2}-related terms as well as tables containing information related to CO{sub 2} and climate. Each term is defined with an emphasis on its relationship to CO{sub 2} and climate. Many of the definitions are then followed by a more detailed description of the term and its use. References to the literature from which the definitions were taken are listed at the end of the Glossary.

  20. Recycling technology of emitted carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  1. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

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

    2014-01-01

    Carbon dioxide (CO2) concentrations in arable soil profiles are influenced by autotrophic and heterotrophic respiration as well as soil physical properties that regulate gas transport. Whereas different methods have been used to assess dynamics of soil CO2 concentrations, our understanding...... on the comparability of results obtained using different methods is limited. We therefore aimed to compare the dynamics in soil CO2 concentrations obtained from an automated system (GMP343 sensors) to those from a manually operated measurement system (i.e., soil gas sampled using stainless steel needles and rods......). In a winter wheat field in Denmark, soil CO2 concentrations were measured from 29 November 2011 to 14 June 2012 at upslope and footslope positions of a short catena (25 m). Carbon dioxide was measured at 20 and 40 cm soil depths (i.e., within and below the nominal plough layer) using the two measurement...

  2. Dye solubility in supercritical carbon dioxide fluid

    Directory of Open Access Journals (Sweden)

    Yan Jun

    2015-01-01

    Full Text Available Supercritical carbon dioxide fluid is an alternative solvent for the water of the traditional dyeing. The solubility of dyestuff affects greatly the dyeing process. A theoretical model for predicting the dye solubility is proposed and verified experimentally. The paper concludes that the pressure has a greater impact on the dyestuff solubility than temperature, and an optimal dyeing condition is suggested for the highest distribution coefficient of dyestuff.

  3. Climate retainment in carbon dioxide incubators

    Directory of Open Access Journals (Sweden)

    Schuh Matthias B.

    2016-09-01

    Full Text Available Ensuring optimal climate conditions during cultivation is essential for successful and reproducible cell culture based investigation. Being the gold standard, carbon dioxide incubators fulfill this demand in various geometries and sizes to suit diverse cultivation applications. A door opening results in a climate breakdown followed by a restoration period during which optimal conditions cannot be guaranteed. The following paper investigates the influence of incubator door design to optimize climate retainment during the above mentioned event.

  4. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    Directory of Open Access Journals (Sweden)

    Amir Abu Zikry

    2011-01-01

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

  5. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-03-01

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

  6. Carbon dioxide makes heat therapy work

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, H.

    1987-01-01

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

  7. Electrocatalytic process for carbon dioxide conversion

    Energy Technology Data Exchange (ETDEWEB)

    Masel, Richard I.; Salehi-Khojin, Amin; Kutz, Robert

    2017-11-14

    An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2, and CF.sub.3COOH.

  8. Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long; Subhash Minocha; Paula Marquardt; Neil Nelson; Mark. Kubiske

    2010-01-01

    This study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA). Since 1998, 12 experimental rings planted in 1997 underwent four different treatments: control; elevated CO2 (560 ppm); elevated O3 (1.5X ambient) and elevated CO2 (560 ppm) + O...

  9. Carbon Dioxide Reduction Technology Trade Study

    Science.gov (United States)

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

    2011-01-01

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

  10. Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

    Science.gov (United States)

    Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

    2018-01-10

    An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  11. Enzymatic conversion of carbon dioxide.

    Science.gov (United States)

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

    2015-10-07

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

  12. Subsurface capture of carbon dioxide

    Science.gov (United States)

    Blount, Gerald; Siddal, Alvin A.; Falta, Ronald W.

    2014-07-22

    A process and apparatus of separating CO.sub.2 gas from industrial off-gas source in which the CO.sub.2 containing off-gas is introduced deep within an injection well. The CO.sub.2 gases are dissolved in the, liquid within the injection well while non-CO.sub.2 gases, typically being insoluble in water or brine, are returned to the surface. Once the CO.sub.2 saturated liquid is present within the injection well, the injection well may be used for long-term geologic storage of CO.sub.2 or the CO.sub.2 saturated liquid can be returned to the surface for capturing a purified CO.sub.2 gas.

  13. Carbon Storage and Carbon Dioxide Emission as Influenced by Long-term Conservation Tillage and Nitrogen Fertilization in Corn-Soybean Rotation

    Directory of Open Access Journals (Sweden)

    Rahmat Saleh

    2012-01-01

    Full Text Available Although agriculture is a victim of environmental risk due to global warming, but ironically it also contributes toglobal greenhouse gas (GHG emission. The objective of this experiment was to determine the influence of long-termconservation tillage and N fertilization on soil carbon storage and CO2 emission in corn-soybean rotation system. Afactorial experiment was arranged in a randomized completely block design with four replications. The first factorwas tillage systems namely intensive tillage (IT, minimum tillage (MT and no-tillage (NT. While the second factorwas N fertilization with rate of 0, 100 and 200 kg N ha-1 applied for corn, and 0, 25, and 50 kg N ha-1 for soybeanproduction. Samples of soil organic carbon (SOC after 23 year of cropping were taken at depths of 0-5 cm, 5-10cm and 10-20 cm, while CO2 emission measurements were taken in corn season (2009 and soybean season (2010.Analysis of variance and means test (HSD 0.05 were analyzed using the Statistical Analysis System package. At 0-5 cm depth, SOC under NT combined with 200 kg N ha-1 fertilization was 46.1% higher than that of NT with no Nfertilization, while at depth of 5-10 cm SOC under MT was 26.2% higher than NT and 13.9% higher than IT.Throughout the corn and soybean seasons, CO2-C emissions from IT were higher than those of MT and NT, whileCO2-C emissions from 200 kg N ha-1 rate were higher than those of 0 kg N ha-1 and 100 kg N ha-1 rates. With any Nrate treatments, MT and NT could reduce CO2-C emission to 65.2 %-67.6% and to 75.4%-87.6% as much of IT,respectively. While in soybean season, MT and NT could reduce CO2-C emission to 17.6%-46.7% and 42.0%-74.3% as much of IT, respectively. Prior to generative soybean growth, N fertilization with rate of 50 kg N ha-1could reduce CO2-C emission to 32.2%-37.2% as much of 0 and 25 kg N ha-1 rates.

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

    Science.gov (United States)

    2010-07-01

    ... operation. Adjust the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either zero grade air or zero grade nitrogen. (3) Calibrate on each normally used operating range with carbon... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...

  15. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either purified synthetic air or zero-grade nitrogen. (3) Calibrate on each normally used operating range with carbon... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration...

  16. Modeling of the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X

    Directory of Open Access Journals (Sweden)

    T. L. P Dantas

    2011-09-01

    Full Text Available In this study, the fixed - bed adsorption of carbon dioxide and a carbon dioxide - nitrogen mixture on zeolite 13X was investigated. The adsorption equilibrium and breakthrough curves were determined at different temperatures - 301 - 306 K, 323 K, 373 K and 423 K. A model based on the LDF approximation for the mass transfer, considering the energy and momentum balances, was used to describe the adsorption kinetics of carbon dioxide and a carbon dioxide - nitrogen mixture. The model acceptably reproduced all of the breakthrough curves and can be considered as adequate for designing a PSA cycle to separate carbon dioxidenitrogen mixtures.

  17. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  18. Measuring of carbon dioxide in water/steam cycle

    Energy Technology Data Exchange (ETDEWEB)

    Daucik, Karol

    2004-12-01

    Prevention of corrosion of the water/steam cycle caused by anionic contamination is based on control of acid conductivity. The contribution of carbon dioxide to the corrosion is very limited and yet it contributes considerably to the acid conductivity as one of the most common contaminants. Monitoring of the dangerous anionic contamination has therefore been on the agenda for many years. Commercial monitors for this purpose are based on separation of carbon dioxide from stronger acids due to its high volatility. A systematic error in these monitors comes from high volatility of other anionic contaminants, e.g. formic and acetic acid. The aim of this investigation was to show that the separation could be made on a weak base anion exchanger working on the basis of differences in the strength of acids. This simple method was expected to give reliable results with low investment and low operating costs. The results showed that the separation is indeed effective. However, reliable data are received only if the anion exchange resin is in equilibrium with the actual concentration of carbon dioxide in the sample. It may take several hours to reach this equilibrium by natural flow of the sample through the anion exchange column. Changes in the concentration of carbon dioxide in the sample will therefore temporarily give false results until a new equilibrium is achieved. The simple monitoring method can be used only in places, where verification of carbon dioxide contamination is required by long-term operation with elevated and stable acid conductivity in the steam. For future design it is suggested to install a forced achievement of the new equilibrium by conditioning of the resin by means of short-lived additions of carbon dioxide or sodium hydroxide to the sample. In these periods the output from the monitor will be suspended. Output close to the equilibrium is expected to be reached within 10 minutes. This new suggested procedure will complicate the monitoring to such a

  19. Six-fold Coordinated Carbon Dioxide VI

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-01

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

  20. Photosynthetic responses of forest understory tree species to long-term exposure to elevated carbon dioxide concentration at the Duke Forest FACE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Springer, C.J. [West Virginia Univ., Morgantown, WV (United States); Thomas, R.B. [Kansas Univ., Lawrence, KS (United States). Dept. of Ecology and Evolutionary Biology

    2007-01-15

    Tree species growing within the forest understory contribute to the overall carbon balance of forest ecosystems in addition to representing many of the species that occur in the overstory of mature ecosystems. This article described a 7 year study investigating the responses of forest understory tree species to increasing concentrations of atmospheric carbon dioxide (CO{sub 2}). The study examined the photosynthetic responses of Acer rubrum L., Carya glabra Mill., Cercis Canadensis L., and Liquidambar styraciflua L. during their seventh year of exposure to elevated CO{sub 2} at the Duke Forest Free Air Carbon Enrichment (FACE) experiment to determine whether photosynthetic down-regulation had occurred, as well as to determine whether the enhancement of photosynthesis observed during the first year of exposure to elevated CO{sub 2} was sustained. The study was conducted to test a previous hypothesis that significant photosynthetic down-regulation would be observed after 7 years of exposure to elevated CO{sub 2}. Photosynthetic CO{sub 2} response and light response curves were measured, as well as chlorophyll fluorescence, chlorophyll concentration and foliar nitrogen (N). Results showed that exposure to elevated CO{sub 2} increased photosynthesis in all species measured after 7 years of treatment. The greatest photosynthetic increase was observed near saturating irradiances. In all species, elevated CO{sub 2} increased electron transport efficiency but did not significantly alter carboxylation efficiency. Quantum yield as estimated by light curves, chlorophyll concentration, and foliar N concentrations was unaffected by elevated CO{sub 2}. It was concluded that there was scant evidence of progressive N limitation of leaf-level processes in the understory species after 7 years of exposure to elevated CO{sub 2} in the experiment. 42 refs., 2 tabs., 4 figs.

  1. Carbon dioxide absorbent and method of using the same

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Robert James; O' Brien, Michael Joseph

    2015-12-29

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

  2. Effects of Elevated Carbon Dioxide on Litter Chemistry and Decomposition

    Data.gov (United States)

    National Aeronautics and Space Administration — The results of published and unpublished experiments investigating the impacts of elevated carbon dioxide on the chemistry (nitrogen and lignin concentration) of...

  3. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

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

    1999-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

    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.

  5. A Vortex Contactor for Carbon Dioxide Separations

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

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

  6. Heat transfer coeffcient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1997-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The pipe is heated by condensing R22 outside the pipe. The heat input is supplied by an electrical heater wich evaporates the R22. With the heat flux assumed constant over...... the whole surface and with measured temperature difference between the inner surface and the evaporation temperature a mean heat transfer coefficient is calculated. The calculated heat transfer coefficient has been compared with the Chart Correlation of Shah. The Chart Correlation predicts too low heat...

  7. Capture of carbon dioxide by hybrid sorption

    Science.gov (United States)

    Srinivasachar, Srivats

    2014-09-23

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

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

    Science.gov (United States)

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

    2014-01-13

    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. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  10. Carbon dioxide fixation in green plants; Shokubutsu no tansan gas kotei ni kansuru kiso kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, S. [Kansai Electric Power Co. Inc., Osaka (Japan); Kiyota, M. [University of Osaka Prefecture, Osaka (Japan); Nishimura, M. [Kansai Tech Co., Osaka (Japan)

    1997-09-30

    Concerning the effects of carbon dioxide whose level of concentration is on the rise, the short-term effect that works on the amount of exchanged gas and the long-term effect that works on the growth of green plants are studied by use of several kinds of green plants. Changes in the carbon dioxide absorption rate (photosynthetic rate) in saplings in the wake of a rise in carbon dioxide concentration are studied, and it is found that a rise in carbon dioxide concentration results in an increase in the photosynthetic rate and that the rate rises with an increase in the intensity of light. The effect of temperature is stronger when concentration is higher, with the temperature suitable for photosynthesis moving toward the high-temperature side. Growth is investigated of seedlings of Acacia mangium two years after transplantation, and then it is found that seedlings in the 1000ppm carbon dioxide section are greater by 20% in height and by 30% in trunk diameter than those in the 350ppm carbon dioxide section. In addition, the total dry matter weight is heavier by 82%. As for dry matter accumulation, there are noticeable amounts in the branches, trunks, and roots, while there is but a 15% increase in the leaf area. Leaves fall early in the high carbon dioxide environment, and this is supposedly the cause for a slowdown in the rate of the increase of photosynthesis. 6 refs., 7 figs., 2 tabs.

  11. Combined effect of sulfur dioxide and carbon dioxide gases on mold fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kochurova, A.I.; Karpova, T.N.

    1974-01-01

    Sulfur dioxide at 0.08% killed Penicillium expansum, Stemphylium macrosporium, and Botrytis cinerea within 24 hours. At 0.2%, it killed P. citrinum, Alternaria tenuis, and Fusarium moniliforme. Sulfur dioxide (at 0.04%) and Sulfur dioxide-carbon dioxide mixtures (at 0.02 and 5% respectively) completely suppressed the growth of P. citrinum, P. expansum, P. rubrum, A. tenuis, S. macrosporium, B. cinerea, and F. moniliforme in laboratory experiments. 1 table.

  12. Cryogenic Adsorption of Nitrogen and Carbon Dioxide in Activated Carbon

    Science.gov (United States)

    Shen, Fuzhi; Liu, Huiming; Xu, Dong; Zhang, Hengcheng; Lu, Junfeng; Li, Laifeng

    2017-09-01

    Activated carbon have been used for a long time at low temperature for cryogenic applications. The knowledge of adsorption characteristics of activated carbon at cryogenic temperature is essential for some specific applications. However, such experimental data are very scare in the literature. In order to measure the adsorption characteristics of activated carbon under variable cryogenic temperatures, an adsorption measurement device was presented. The experiment system is based on the commercially available PCT-pro adsorption analyzer coupled to a two-stage Gifford McMahon refrigerator, which allows the sample to be cooled to 4.2K. Cryogenic environment can be maintained steadily without the cryogenic liquid through the cryocooler and temperature can be controlled precisely between 5K and 300K by the temperature controller. Adsorption measurements were performed in activated carbon for carbon dioxide and nitrogen and the adsorption isotherm were obtained.

  13. Carbon dioxide exchange in the Arctic

    DEFF Research Database (Denmark)

    Ravn, Nynne Marie Rand

    Low temperatures in the Arctic have through geological times caused a build-up of carbon (C) in the soil while carbon dioxide (CO2) has been removed from the atmosphere, because ecosystem respiration (ER) has been exceeded by the photosynthesis (GEP). Increasing air temperature, as occurring...... in current years, is likely to increase ER due to increased decomposition and increased substrate input e.g. due to permafrost thaw. If GEP is left unchanged and decomposition of old C from the soil is occurring this might result in an increase of the emission of CO2 to the atmosphere probably resulting...... fluxes and organic nutrient utilization between ecosystems occurring from different latitudes and dominated by different vegetation types. These aspects are important to understand the effects of climate change on the CO2 balance in the Arctic and its potential positive feedback on global climate change...

  14. Carbon Dioxide Capture Adsorbents: Chemistry and Methods.

    Science.gov (United States)

    Patel, Hasmukh A; Byun, Jeehye; Yavuz, Cafer T

    2017-04-10

    Excess carbon dioxide (CO 2 ) emissions and their inevitable consequences continue to stimulate hard debate and awareness in both academic and public spaces, despite the widespread lack of understanding on what really is needed to capture and store the unwanted CO 2 . Of the entire carbon capture and storage (CCS) operation, capture is the most costly process, consisting of nearly 70 % of the price tag. In this tutorial review, CO 2 capture science and technology based on adsorbents are described and evaluated in the context of chemistry and methods, after briefly introducing the current status of CO 2 emissions. An effective sorbent design is suggested, whereby six checkpoints are expected to be met: cost, capacity, selectivity, stability, recyclability, and fast kinetics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A miniature chemiresistor sensor for carbon dioxide.

    Science.gov (United States)

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

    2015-05-18

    A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO2 at room temperature. Good sensing performance was observed upon exposing the PEI-PANI device to 50-5000 ppm CO2 in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid-base reaction, CO2 dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO2 in air. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Cooperative redox activation for carbon dioxide conversion.

    Science.gov (United States)

    Lian, Zhong; Nielsen, Dennis U; Lindhardt, Anders T; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-16

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing 'waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

  17. Cooperative redox activation for carbon dioxide conversion

    Science.gov (United States)

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-01

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing `waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

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

    Science.gov (United States)

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

    2014-05-01

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

  19. Use of supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-09-25

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

  20. The effect of cutting on carbon dioxide absorption and carbohydrate ...

    African Journals Online (AJOL)

    grass) and Osteospermun sinuatum (Karoo-bush) plants during the flag leaf and flower bud stages respectively resulted in a sharp decline in net carbon dioxide absorption. As new photosynthetic material was produced the total carbon ...

  1. Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

    Science.gov (United States)

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

    2013-12-01

    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 μmol 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 μmol 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

  2. Promising flame retardant textile in supercritical carbon dioxide

    Science.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    Gerald E. Marsh

    2014-01-01

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

  4. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    심정은

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-. CO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1 ...

  5. Carbon Dioxide Production in Animal Houses: A literature review

    NARCIS (Netherlands)

    Pedersen, S.; Blanes-Vidal, V.; Joergensen, H.; Chwalibog, A.; Haeussermann, A.; Heetkamp, M.J.W.; Aarnink, A.J.A.

    2008-01-01

    This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from

  6. Carbon dioxide (CO 2 ) utilizing strain database | Saini | African ...

    African Journals Online (AJOL)

    The biological means of CO2 fixation using various microorganisms is gaining importance because database of their substantial role in reversing global warming. Carbon dioxide utilizing strain database (CSD) presents a comprehensive overview of microorganisms involved in biological fixation of carbon dioxide. As a part ...

  7. Carbon Dioxide and Global Warming: A Failed Experiment

    Science.gov (United States)

    Ribeiro, Carla

    2014-01-01

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

  8. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  9. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SCCO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1 ...

  10. Combined reactions and separations using ionic liquids and carbon dioxide

    NARCIS (Netherlands)

    Kroon, M.C.

    2006-01-01

    A new and general type of process for the chemical industry is presented using ionic liquids and supercritical carbon dioxide as combined reaction and separation media. In this process, the carbon dioxide pressure controls the miscibility of reactants, products, catalyst and ionic liquid, enabling

  11. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Administrator

    2011-06-15

    Jun 15, 2011 ... Full Length Research Paper. Kenaf seed oil from supercritical carbon dioxide fluid .... The cells were harvested and washed twice with phosphate- buffered saline (PBS), fixed in ice-cold 70% ethanol and ..... Extraction of coffee diterpenes and coffee oil using supercritical carbon dioxide. Food Chem.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  13. Metathesis of carbon dioxide and phenyl isocyanate catalysed by ...

    Indian Academy of Sciences (India)

    Carbodiimide metathesis is catalysed by a number of complexes leading to formation of unsymmetrical carbodiimides.1 Group 14 compounds are known to catalyse metathesis of phenyl isocyanates to give N, N′ diphenyl carbodiimides and carbon dioxide.2 The reverse reaction, metathesis of carbon dioxide with.

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  15. The Effect of Exports on Carbon Dioxide Emissions: Policy Implications

    Directory of Open Access Journals (Sweden)

    Bosupeng Mpho

    2016-09-01

    Full Text Available The purpose of this study is to explore long run affiliations between exports and carbon dioxide emissions. This paper examines thirty-seven countries over the period 1960 to 2010 and uses the Toda and Yamamoto causality approach to investigate the direction of causal links. The results reveal that carbon dioxide emissions Granger cause exports in the following economies: Bolivia, Canada, Costa Rica, Morocco, Austria and Ireland. Nonetheless, the reverse causality proved that exports Granger cause carbon dioxide emissions in twelve economies. Furthermore, the study registered bidirectional causal links between exports and carbon dioxide emissions in the USA and Burkina Faso. We conclude that countries should consider exports market demand, energy consumption and economic growth in their attempts to reduce carbon dioxide emissions.

  16. Carbon dioxide absorbent and method of using the same

    Science.gov (United States)

    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

    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.

  17. An open-path tunable diode laser absorption spectrometer for detection of carbon dioxide at the Bonanza Creek Long-Term Ecological Research Site near Fairbanks, Alaska

    Science.gov (United States)

    Bailey, D. Michelle; Adkins, Erin M.; Miller, J. Houston

    2017-09-01

    We have developed a low-power, open-path, near-infrared (NIR) tunable diode laser sensor for the measurement of near ground-level concentrations of greenhouse gases. Here, we report on instrument design, characterization, and initial measurements of carbon dioxide concentrations during deployment to a thermokarst collapse scar bog near Fairbanks, AK (USA). The optics "launch-box" portion of the instrument couples radiation from an NIR, distributed feedback diode laser operating near 1572 nm with a visible laser for alignment purposes. The outgoing beam is directed through a 3.2-mm hole in a parabolic mirror and the launch-box is oriented using a two axis, altitude-azimuth telescope mount such that the beam strikes a retroreflector target at a set distance downfield. The beam then retraces the path back to the launch-box where the light is collected on the surface of the parabolic mirror and focused onto a multimode fiber that transfers the radiation to an InGaAs detector. Sweeps over a 1.6 cm-1 spectral region were collected at a rate of 500 scans per second and were typically stored as 10 s sweep averages. These averaged sweeps could be individually spectrally fit for CO2 concentration or averaged into a single spectrum for fitting (after correction for slight frequency drift). Field data reported here was averaged for 2.5 min and was found to follow trends in diurnal cycles of CO2 concentration cycles reported by sensors located nearby in the field site.

  18. Impact of needle age on the response of respiration in Scots pine to long-term elevation of carbon dioxide concentration and temperature.

    Science.gov (United States)

    Zha, Tianshan; Wang, Kai-Yun; Ryyppö, Aija; Kellomäki, Seppo

    2002-12-01

    Sixteen 20-year-old Scots pine (Pinus sylvestris L.) trees growing in the field were enclosed in environment-controlled chambers that for 4 years maintained: (1) ambient conditions (CON); (2) elevated atmospheric carbon dioxide concentration [CO2] (ambient + 350 micromol mol-1; EC); (3) elevated temperature (ambient + 2-3 degrees C; ET); or (4) elevated [CO2] and temperature (EC+ET). Dark respiration rate, specific leaf area (SLA) and the concentrations of starch and soluble sugars in needles were measured in the fourth year. Respiration rates, on both an area and a mass basis, and SLA decreased in EC relative to CON, but increased in ET and EC+ET, regardless of needle age class. Starch and soluble sugar concentrations for a given needle age class increased in EC, but decreased slightly in ET and EC+ET. Respiration rates and SLA were highest in current-year needles in all treatments, whereas starch and soluble sugar concentrations were highest in 1-year-old needles. Relative to that of older needles, respiration of current-year needles was inhibited less by EC, but increased in response to ET and EC+ET. All treatments enhanced the difference in respiration between current-year and older needles relative to that in CON. Age had a greater effect on needle respiration than any of the treatments. There were no differences in carbohydrate concentration or SLA between needle age classes in response to any treatment. Relative to CON, the temperature coefficient (Q10) of respiration increased slightly in EC, regardless of age, but declined significantly in ET and EC+ET, indicating acclimation of respiration to temperature.

  19. Measurement of Near-Surface Carbon Dioxide Concentrations with an Open-Path Tunable Diode Laser Sensor and a Non-Dispersive Infrared Sensor at the Bonanza Creek Long Term Ecological Research Site near Fairbanks, Alaska

    Science.gov (United States)

    Bailey, D. M.; Caine, K. M.; Miller, J. H. H.

    2016-12-01

    Continuous collection of carbon dioxide (CO2) concentrations is imperative in understanding seasonal and inter-annual variability of carbon feedbacks above thawing permafrost. Permafrost makes up one-quarter of the Earth's terrestrial surface and has the potential to release twice the amount of carbon than is currently in the atmosphere if global temperatures continue to increase. A collaborative effort with the University of Alaska - Fairbanks, NASA Goddard Space Flight Center, and our group at George Washington University is underway to monitor these feedbacks near Fairbanks, Alaska. In June 2016, we deployed an open-path tunable diode laser sensor along with a non-dispersive infrared (NDIR) sensor at the Bonanza Creek Long Term Ecological Research Site as an exploratory study for their use in collecting near-surface CO2 concentrations above thawing permafrost. The open-path instrument (OPI) collected spatially-integrated measurements approximately 1.5 meters above the surface of a young thermokarst bog over a 15-day period whereas the NDIR sensor collected localized measurements 1 meter above the surface for 16 days. Near-continuous measurements were achieved with the NDIR sensor which was limited only by the availability of solar-produced power. The OPI measurements were further limited by maintaining laser alignment under changing environmental conditions. However, the campaign achieved a nearly 80% duty cycle for the entire test period. Here we compare both the localized and spatially-integrated carbon dioxide measurements and their observed diurnal concentration cycles, whose magnitude showed a strong dependence on daily weather at the test site.

  20. Global carbon dioxide emissions from inland waters

    Science.gov (United States)

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

    2013-01-01

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

  1. Colorimetric and refractometric measurements of carbon dioxide

    Science.gov (United States)

    Jesus Gouveia, C.; Markovics, A.; Baptista, J. M.; Kovács, B.; Jorge, P. A. S.

    2011-05-01

    In this work, a polymeric sensitive layer based on the acid-base equilibrium of phenol and of its derivative p-nitro-phenol is presented for carbon dioxide measurements. Thin films casted on glass slides were tested, using a LED source (λc at 410 nm) and an Ocean Optics USB4000 spectrometer, in the 0% to 15.25% CO2 concentrations range, showing a 40% maximum transmittance variation with a 51s response time and a 0.15% resolution. Preliminary results indicate that CO2also induces refractive index changes in the sensitive layer. Using a fiber based interferometric setup, a CO2 dependent refractive index change of ~0.045 RIU was observed, in the 0%-90% CO2 concentration range.

  2. Layered solid sorbents for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-18

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

  3. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  4. Carbon dioxide detection in adult Odonata.

    Science.gov (United States)

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

    2016-04-01

    The present paper shows, by means of single-cell recordings, responses of antennal sensory neurons of the damselfly Ischnura elegans when stimulated by air streams at different CO2 concentrations. Unlike most insects, but similarly to termites, centipedes and ticks, Odonata possess sensory neurons strongly inhibited by CO2, with the magnitude of the off-response depending upon the CO2 concentration. The Odonata antennal sensory neurons responding to CO2 are also sensitive to airborne odors; in particular, the impulse frequency is increased by isoamylamine and decreased by heptanoic and pentanoic acid. Further behavioral investigations are necessary to assign a biological role to carbon dioxide detection in Odonata. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Carbon dioxide neutral, integrated biofuel facility

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2010-12-15

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO{sub 2} from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce biodiesel, can result in an integrated, economical, large-scale process for biofuel production. Each bioreactor acts as an electrode for a coupled complete microbial fuel cell system; the integrated cultures produce electricity that is consumed as an energy source within the process. Finally, both the produced yeast and spent algae biomass can be used as added value byproducts in the feed or food industries. Using cost and revenue estimations, an IRR of up to 25% is calculated using a 5 year project lifespan. (author)

  6. Biochemical Capture and Removal of Carbon Dioxide

    Science.gov (United States)

    Trachtenberg, Michael C.

    1998-01-01

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

  7. Layered solid sorbents for carbon dioxide capture

    Science.gov (United States)

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

    2013-02-25

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

  8. Techno-economic assessment of membrane gas absorption for the production of carbon dioxide from flue gas

    NARCIS (Netherlands)

    Feron, P.H.M.; Jansen, A.E.

    1998-01-01

    Membrane gas absorption for carbon dioxide production from flue gases is discussed with special reference to the economics of the supply of carbon dioxide to greenhouses in the Netherlands. Novel absorption liquids have been introduced which show as excellent performance in terms of system stability

  9. Analysis of Supercritical Carbon Dioxide Heat Exchangers in Cooling Process

    OpenAIRE

    Chen, Yang; Lundqvist, Per

    2006-01-01

    Carbon dioxide transcritical cycles have become more and more investigated during the last decade. For all systems operating with such a cycle, there will be at least one heat exchanger to either heat or cool the supercritical carbon dioxide. Unlike in the sub-critical region, the supercritical carbon dioxide’s thermophysical properties will have sharp variations in the region close to its critical point. This variation has a significant influence on the shape of the heat exchanger’s temperat...

  10. Pysical fixation of carbon dioxide. Butsuritekina nisanka tanso no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Akai, M. (Mechanical Engineering Laboratory, Tsukuba (Japen))

    1991-10-20

    Together with the introduction of physical fixation technology of carbon dioxide, possibility and problem are to be explained of carbon dioxide fixation by utilizing the deep-sea water in the ocean. The physical fixation methods comprise, among others, the oceanic fixation method, high pressure storage method in the exhausted oil or gas field and high pressure storage method into the rock salt piles. The oceanic fixation method has recently come to be studied in Japan also as having utilizable environments therearound. The oceanographic fixation technology of carbon dioxide is of an engineeringwise developed method. Particularly among others, the fixation technology to utilize deep-sea water, deeper than several hundreds of meters, heightens the carbon dioxide in solubility by availing of a condition of low temperature by high pressure. The liquefaction pressure of carbon dioxide being approx. 70atm at ordinary temperature, the liquefied carbon dioxide is higher in density than the sea water under a higher pressure than about 3000m in head. Due to the existence of temperature lamination, the absorbed carbon dioxide hardly circulates into the atmosphere. Apart from the above two points of advantage, it is advantageous also in other points. However, there remain many problems, inclusive of those ot basic mechanism, to be elucidated. 16 refs., 3 figs.

  11. Forest management techniques for carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  12. Carbon dioxide warming of the early Earth

    Science.gov (United States)

    Arrhenius, G.

    1997-01-01

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

  13. Conversion Of Carbon Dioxide To Hydrocarbons Using Iron Nanoparticle-Carbon Nanotube Catalysts

    OpenAIRE

    Minett, Daniel

    2013-01-01

    Dealing with carbon dioxide waste is an on-going societal and technological challenge. One attractive proposition is to chemically convert waste carbon dioxide into useful chemical products. One possible route is to combine two well-known chemical processes, reverse water gas shift and Fischer-Tropsch synthesis, to make a catalyst capable of converting carbon dioxide directly intohydrocarbons. Iron nanoparticles supported on carbon nanotubes (CNT) have shown promise in the Fischer-Tropsch pro...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  15. Synthesis of dimethyl carbonate in supercritical carbon dioxide

    Directory of Open Access Journals (Sweden)

    D. Ballivet-Tkatchenko

    2006-03-01

    Full Text Available The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu3SnOCH3, n-Bu2Sn(OCH32 , and [n-Bu2(CH3OSn]2 O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO2 pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO2 pressure higher than 16 MPa. Under these conditions, CO2 acted as a reactant and a solvent.

  16. Membranes for separation of carbon dioxide

    Science.gov (United States)

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

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

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

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

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

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

  19. Air quality assessment of carbon monoxide, nitrogen dioxide and ...

    African Journals Online (AJOL)

    Air quality in urban areas is a cause of concern because of increased industrial activities that contribute to large quantities of emissions. The study assess levels and variations of carbon monoxide (CO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) in Blantyre, Malawi using a stationary environmental monitoring station ...

  20. Past explosive outbursts of entrapped carbon dioxide in salt mines provide a new perspective on the hazards of carbon dioxide

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2013-01-01

    This paper reports on a source of past carbon dioxide accidents which so far has only been sporadically mentioned in the literature. Violent and highly destructive outbursts of hundreds of tons of CO2 occurred regularly, if not routinely, in the now closed salt mines of the former DDR....... The Menzengraben mine experienced an extreme outburst in 1953, possibly involving a several thousand tons of carbon dioxide. This source of accidents fills an important gap in the available carbon dioxide accident history and may provide a unique empirical perspective on the hazards of handling very large amounts...

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

    Science.gov (United States)

    Strow, L. L.; Hannon, S.

    2005-12-01

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

  2. The causal nexus between carbon dioxide emissions and agricultural ecosystem-an econometric approach.

    Science.gov (United States)

    Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

    2017-01-01

    Achieving a long-term food security and preventing hunger include a better nutrition through sustainable systems of production, distribution, and consumption. Nonetheless, the quest for an alternative to increasing global food supply to meet the growing demand has led to the use of poor agricultural practices that promote climate change. Given the contribution of the agricultural ecosystem towards greenhouse gas (GHG) emissions, this study investigated the causal nexus between carbon dioxide emissions and agricultural ecosystem by employing a data spanning from 1961 to 2012. Evidence from long-run elasticity shows that a 1 % increase in the area of rice paddy harvested will increase carbon dioxide emissions by 1.49 %, a 1 % increase in biomass-burned crop residues will increase carbon dioxide emissions by 1.00 %, a 1 % increase in cereal production will increase carbon dioxide emissions by 1.38 %, and a 1 % increase in agricultural machinery will decrease carbon dioxide emissions by 0.09 % in the long run. There was a bidirectional causality between carbon dioxide emissions, cereal production, and biomass-burned crop residues. The Granger causality shows that the agricultural ecosystem in Ghana is sensitive to climate change vulnerability.

  3. 21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bicarbonate/carbon dioxide test system. 862.1160... Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole...

  4. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Science.gov (United States)

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with both...

  5. Gas Flaring: Carbon dioxide Contribution to Global Warming ...

    African Journals Online (AJOL)

    PROF HORSFALL

    .info and www.bioline.org.br/ja. Gas Flaring: Carbon dioxide Contribution to Global Warming. *AMAECHI ... contributor to global warming, environmental degradation, health risk and economic loss. The ... risks of climate change. Meeting ...

  6. Drying of supercritical carbon dioxide with membrane processes

    NARCIS (Netherlands)

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

    2015-01-01

    In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

  7. Elevated carbon dioxide: impacts on soil and plant water relations

    National Research Council Canada - National Science Library

    Kirkham, M. B

    2011-01-01

    .... Focusing on this critical issue, Elevated Carbon Dioxide: Impacts on Soil and Plant Water Relations presents research conducted on field-grown sorghum, winter wheat, and rangeland plants under elevated CO2...

  8. Precision remote sensor for oxygen and carbon dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes development of a passive optical sensor for simultaneous high-precision measurement of oxygen and carbon dioxide profiles within the full...

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

    Science.gov (United States)

    Johnson, F. S.

    1975-01-01

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

  10. Removing carbon dioxide from a stationary source through co ...

    African Journals Online (AJOL)

    Thomas

    . INTRODUCTION. It is estimated that the global average temperature will rise between 1.4-5.8°C by the year 2100. The contributors to greenhouse effects are carbon dioxide. (CO2), chlorofluorocarbons (CFCs), methane (CH4) and.

  11. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Hibiscus cannabinus) variety V36 extracted using supercritical carbon dioxide fluid extraction (SFE) with different combinations of pressure (bars) and temperature (°C). Extracted oils were tested on human promyelocytic HL-60, murine ...

  12. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase 1 has seen the development of a revolutionary new type of sensor for making carbon dioxide (CO2) measurements from small Unmanned Aircraft Systems (UAS) and...

  13. Miniature Carbon Dioxide Sensor for Small Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a growing need to develop improved technologies for precise airborne measurements of carbon dioxide, CO2. CO2 measurements are of great importance to many...

  14. Electrochemical Reactor for Producing Oxygen From Carbon Dioxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An electrochemical reactor is proposed by MicroCell Technologies, LLC to electrochemically reduce carbon dioxide to oxygen. In support of NASA's advanced life...

  15. ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based on...

  16. ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based...

  17. Monthly Carbon Dioxide in Troposphere (AIRS on AQUA)

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon dioxide (CO2) is an important greenhouse gas released through natural processes such as respiration and volcano eruptions and through huma activities such as...

  18. Transport Models for Radioactive Carbon Dioxide at RWMC

    Energy Technology Data Exchange (ETDEWEB)

    Hull, Laurence Charles; Hohorst, Frederick August

    2001-12-01

    Radioactive carbon dioxide (formed by oxidation of carbon-14) is a highly mobile, radioactive contaminant released from solid wastes buried at the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Radioactive CO2 is chemically active in the environment, volatile, water soluble, and subject to adsorption on solids. For this reason, its fate must be understood and controlled to meet radiological requirements (protection of the atmosphere, aquifer, vadose zones, plants and animals). In the present work, the migration of carbon-14 as dissolved bicarbonate was studied using miscible displacement experiments in water-saturated columns containing sediments from RWMC. Dissolved carbon-14 was retarded relative to the movement of water by a factor of about 3.6, which translates to a partition coefficient (Kd) of 0.8 ml/g. Two different adsorption sites were identified, with one site possibly having a nonlinear adsorption isotherm. A conservative tracer gas, sulfur hexafluoride, was used to measure the tortuosity of sedimentary material for gaseous diffusion. The tortuosity of the RWMC sediment (Spreading Area B sediment) was determined to be 3.2, which is slightly greater than predicted by the commonly used Millington-Quirk equation. In terms of affecting the migration of carbon-14 to the aquifer, the relative importance of the parameters studied is: (1) natural moisture content of the sediments, (2) sediment tortuosity to gas-phase diffusion, and (3) adsorption onto solid phases.

  19. Carbon dioxide balneotherapy and cardiovascular disease

    Science.gov (United States)

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

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  20. Carbon dioxide removal in gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Lidal, H.

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO{sub 2} in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140{sup o}C, for CO{sub 2} loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO{sub 2} into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO{sub 2} in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO{sub 2}/TEG/MEA system for estimation of CO{sub 2} partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs.

  1. Euthanasia of neonatal mice with carbon dioxide

    Science.gov (United States)

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

    2005-01-01

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

  2. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

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

    2014-01-01

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

  3. Demographic change and carbon dioxide emissions.

    Science.gov (United States)

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

    2012-07-14

    Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-01-29

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

  5. System-Level Analysis Modeling of Impacts of Operation Schemes of Geologic Carbon Dioxide Storage on Deep Groundwater and Carbon Dioxide Leakage Risk

    Science.gov (United States)

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

    2013-12-01

    The objectives of this study are to predict quantitatively groundwater and carbon dioxide flow in deep saline sandstone aquifers under various carbon dioxide injection schemes (injection rate, injection period) and to analyze integratively impacts of such carbon dioxide injection schemes on deep groundwater (brine) and carbon dioxide leakage risk through abandoned wells or faults. In order to achieve the first objective, a series of process-level prediction modeling of groundwater and carbon dioxide flow in a deep saline sandstone aquifer under several carbon dioxide injection schemes was performed using a multiphase thermo-hydrological numerical model TOUGH2 (Pruess et al., 1999). The prediction modeling results show that the extent of carbon dioxide plume is significantly affected by such carbon dioxide injection schemes. In order to achieve the second objective, a series of system-level analysis modeling of deep groundwater and carbon dioxide leakage risk through an abandoned well or a fault under several carbon dioxide injection schemes was then performed using a brine and carbon dioxide leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault increase as the carbon dioxide injection rate increases. However, the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault decrease as the carbon dioxide injection period increases. These system-level analysis modeling results for deep groundwater and carbon dioxide leakage risk can be utilized as baseline data for establishing guidelines to mitigate anticipated environmental adverse effects on shallower groundwater systems (aquifers) when deep groundwater and carbon dioxide leakage occur. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute

  6. Two case of Carbon Dioxide Laser Treatment of Oral Leukoplakia

    OpenAIRE

    中嶌, 哲; 山田, 哲男; 矢ヶ崎, 崇; 植田, 章夫; 鹿毛, 俊孝; 千野, 武廣; 長谷川, 博雅

    1987-01-01

    Recently Carbon Dioxide Laser treatment has become more available as a method for oral and maxillofacial surgeons to apply in the treatment of soft tissue lesions in the oral cavity. This paper presents two cases of leukoplakia that were treated successfully with Carbon Dioxide Laser equipment, Opelaser-01. We consider that this treatment is one of the best choices for the superficially situated soft tissue lesion, such as leukoplakia.

  7. Tethered catalysts for the hydration of carbon dioxide

    Science.gov (United States)

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

    2014-11-04

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

  8. Aesthetic Depigmentation of Gingival Smoker's Melanosis Using Carbon Dioxide Lasers

    OpenAIRE

    Luis Silva Monteiro; José Adriano Costa; Marco Infante da Câmara; Rui Albuquerque; Marco Martins; José Júlio Pacheco; Filomena Salazar; Fernando Figueira

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide ...

  9. Use of carbon dioxide in underground natural gas storage processes

    Directory of Open Access Journals (Sweden)

    Nagy Stanislaw

    2006-10-01

    Full Text Available The possibility of use of carbon dioxide in gas storage processes is presented. The model of mixing process between CO2 and methane in porous media is given. The process of injection of carbon dioxide into a lower part of storage near the water –gas contact is modeled. The example of changes in the mixing zone is presented and discussed.

  10. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin

    NARCIS (Netherlands)

    Shen, J.; Kortlever, R.; Kas, Recep; Mul, Guido; Koper, M.T.M.

    2015-01-01

    The electrochemical conversion of carbon dioxide and water into useful products is a major challenge in facilitating a closed carbon cycle. Here we report a cobalt protoporphyrin immobilized on a pyrolytic graphite electrode that reduces carbon dioxide in an aqueous acidic solution at relatively low

  11. Single and Mixed Gas Adsorption Equilibria of Carbon Dioxide/Methane on Activated Carbon

    NARCIS (Netherlands)

    van der Vaart, R.; van der Vaart, Rick; Huiskes, Cindy; Bosch, H.; Reith, T.

    2000-01-01

    Single gas adsorption isotherms of methane and carbon dioxide on micro-porous Norit RB1 activated carbon were determined in a gravimetric analyser in the temperature range of 292 to 349 K and pressures to 0.8 Mpa. Furthermore binary isotherms of carbon dioxide and methane mixtures were determined at

  12. Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydra...

  13. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward G.; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Robert G.

    2017-04-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2 consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2 and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = -0.67 and ρ = -0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  14. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Rob

    2017-01-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = −0.67 and ρ = −0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  15. Enriching blast furnace gas by removing carbon dioxide.

    Science.gov (United States)

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

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  16. Supercritical carbon dioxide for textile applications and recent developments

    Science.gov (United States)

    Eren, H. A.; Avinc, O.; Eren, S.

    2017-10-01

    In textile industry, supercritical carbon dioxide (scCO2), possessing liquid-like densities, mostly find an application on textile dyeing processes such as providing hydrophobic dyes an advantage on dissolving. Their gas-like low viscosities and diffusion properties can result in shorter dyeing periods in comparison with the conventional water dyeing process. Supercritical carbon dioxide dyeing is an anhydrous dyeing and this process comprises the usage of less energy and chemicals when compared to conventional water dyeing processes leading to a potential of up to 50% lower operation costs. The advantages of supercritical carbon dioxide dyeing method especially on synthetic fiber fabrics hearten leading textile companies to alter their dyeing method to this privileged waterless dyeing technology. Supercritical carbon dioxide (scCO2) waterless dyeing is widely known and applied green method for sustainable and eco-friendly textile industry. However, not only the dyeing but also scouring, desizing and different finishing applications take the advantage of supercritical carbon dioxide (scCO2). In this review, not only the principle, advantages and disadvantages of dyeing in supercritical carbon dioxide but also recent developments of scCO2 usage in different textile processing steps such as scouring, desizing and finishing are explained and commercial developments are stated and summed up.

  17. The role of renewable bioenergy in carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  18. Stabilization of carbon dioxide and chromium slag via carbonation.

    Science.gov (United States)

    Wu, Xingxing; Yu, Binbin; Xu, Wei; Fan, Zheng; Wu, Zucheng; Zhang, Huimin

    2017-08-01

    As the main greenhouse gas, CO2 is considered as a threat in the context of global warming. Many available technologies to reduce CO2 emission was about CO2 separation from coal combustion and geological sequestration. However, how to deal with the cost-effective storage of CO2 has become a new challenge. Moreover, chromium pollution, the treatment of which requires huge energy consumption, has attracted people's widespread attention. This study is aimed to develop the sequestration of CO2 via chromium slag. A dynamic leaching experiment of chromium slag was designed to testify the ability of CO2 adsorption onto chromium slag and to release Cr(VI) for stabilization. The results showed that the accumulative amounts of Cr(VI) were ca. 2.6 mg/g released from the chromium slag after 24 h of leaching. In addition, ca. 89 mg/g CO2 was adsorbed by using pure CO2 in the experiment at 12 h. Calcite is the only carbonate species in the post-carbonated slag analyzed by powder X-ray diffraction and thermal analysis. The approach provides the feasibility of the utilization of chromium slag and sequestration of the carbon dioxide at the same time at ordinary temperatures and pressures.

  19. Carbon dioxide laser circumcisions for children.

    Science.gov (United States)

    How, A C S W; Ong, C C P; Jacobsen, A; Joseph, V T

    2003-04-01

    The carbon dioxide laser for circumcision was introduced by our department in 1989. This study aims to review our experience with laser circumcision for children and to evaluate its cost effectiveness as compared to conventional methods. A retrospective study of 30 patients who underwent conventional circumcision in 1985 and another 30 patients who underwent laser circumcision in 1995 was undertaken. The operating times in both groups were compared. The total cost of use of the laser machine was calculated, taking into account maintenance costs, estimated life span of laser machines (10 years) and costs of disposables used during each circumcision. This was weighed against the cost savings from shorter operating times and reduced operating theatre facility charges. Also, morbidity data from 2781 laser circumcisions done between May 1997 and April 2000 was collected. There was a significant decrease of 5 minutes in operating time for the group of patients who underwent laser circumcision. Calculated cost savings per laser circumcision from the reduced operating theatre time was S dollars 31/-. Of the 2781 cases of laser circumcision performed, there was an overall complication rate of 1.15%. Twenty-nine cases (1.04%) had post circumcision bleeding, of which 10 cases (0.36%) required unplanned return to operating theatre for hemostasis. Three cases (0.11%) had wound infection, requiring admission to hospital. Laser circumcision is a simple method with reduced operative time translating into cost effectiveness. Morbidity rates of laser circumcision compare favourably to those of conventional circumcision based on reports from other institutions.

  20. Carbon Dioxide Physiological Training at NASA.

    Science.gov (United States)

    Law, Jennifer; Young, Millennia; Alexander, David; Mason, Sara S; Wear, Mary L; Méndez, Claudia M; Stanley, David; Ryder, Valerie Meyers; Van Baalen, Mary

    2017-10-01

    Astronauts undergo CO2 exposure training to recognize their symptoms that can arise acutely both on the ground and in spaceflight. This article describes acute CO2 exposure training at NASA and examines the symptoms reported by astronauts during training. In a controlled training environment, astronauts are exposed to up to 8% CO2 (60 mmHg) by a rebreathing apparatus. Symptoms are reported using a standard form. Symptom documentation forms between April 1994 and February 2012 were obtained for 130 astronauts. The number of symptoms reported per session out of the possible 24 was related to age and sex, with those older slightly more likely to report symptoms. Women reported more symptoms on average than men (men: 3.7, women: 4.7). Respiratory symptoms (90%), flushing sensation/sweating (56%), and dizziness/feeling faint/lightheadedness (43%) were the top symptoms. Only headache reached statistical significance in differences between men (13%) and women (37%) after adjustment for multiple testing. Among those with multiple training sessions, respiratory symptoms were the most consistently reported. CO2 exposure training is an important tool to educate astronauts about their potential acute CO2 symptoms. Wide interindividual and temporal variations were observed in symptoms reported during astronaut CO2 exposure training. Headache could not be relied on as a marker of acute exposure during testing since fewer than half the subjects reported it. Our results support periodic refresher training since symptoms may change over time. Further study is needed to determine the optimal interval of training to maximize symptom recognition and inform operational decisions.Law J, Young M, Alexander D, Mason SS, Wear ML, Méndez CM, Stanley D, Meyers Ryder V, Van Baalen M. Carbon dioxide physiological training at NASA. Aerosp Med Hum Perform. 2017; 88(10):897-902.

  1. Carbon-Based Regenerable Sorbents for the Combined Carbon Dioxide and Ammonia Removal for the Primary Life Support System (PLSS)

    Science.gov (United States)

    Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Manthina, Venkata; Singh, Prabhakar; Chullen, Cinda

    2014-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs). Since ammonia is the most important TC to be captured, data on TC sorption presented in this paper are limited to ammonia, with results relevant to other TCs to be reported at a later time. The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. The objective of this study was to demonstrate the feasibility of using carbon sorbents for the reversible, concurrent sorption of carbon dioxide and ammonia. Several carbon sorbents were fabricated and tested, and multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also a carbon surface conditioning technique that enhances the combined carbon dioxide and ammonia sorption without impairing sorbent regeneration.

  2. Amine reclaiming technologies in post-combustion carbon dioxide capture.

    Science.gov (United States)

    Wang, Tielin; Hovland, Jon; Jens, Klaus J

    2015-01-01

    Amine scrubbing is the most developed technology for carbon dioxide (CO2) capture. Degradation of amine solvents due to the presence of high levels of oxygen and other impurities in flue gas causes increasing costs and deterioration in long term performance, and therefore purification of the solvents is needed to overcome these problems. This review presents the reclaiming of amine solvents used for post combustion CO2 capture (PCC). Thermal reclaiming, ion exchange, and electrodialysis, although principally developed for sour gas sweetening, have also been tested for CO2 capture from flue gas. The three technologies all have their strengths and weaknesses, and further development is needed to reduce energy usage and costs. An expected future trend for amine reclamation is to focus on process integration of the current reclaiming technologies into the PCC process in order to drive down costs. Copyright © 2014. Published by Elsevier B.V.

  3. Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

    National Research Council Canada - National Science Library

    Zhang, Xiao; Li, Xueqian; Zhang, Du; Su, Neil Qiang; Yang, Weitao; Everitt, Henry O; Liu, Jie

    2017-01-01

    ... and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produce...

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

    Science.gov (United States)

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

    2014-06-03

    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.

  5. Assessing Carbon Dioxide Emissions from Energy Use at a University

    Science.gov (United States)

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

    2009-01-01

    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…

  6. High‐temperature carbon dioxide capture using metal oxides

    OpenAIRE

    Vogt, Christian

    2017-01-01

    Carbon dioxide (CO2) emissions to the atmosphere are considered a significant contributor to climate change due to the activity of the carbon dioxide molecule in the infrared spectrum. This causes solar radiation to be ‘trapped’ in the earth’s atmosphere if increased CO2 concentrations are present, leading to global warming. In order to decrease CO2 emissions from stationary sources, like fossil fuel-fired power plants, and halt global warming, carbon capture and storage is proposed as a viab...

  7. Carbon dioxide flooding as an enhanced oil recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Mungan, N. (Alberta Energy Co. Ltd., AB (Canada))

    1992-11-01

    A description is presented of the state-of-the-art on carbon dioxide flooding and how it relates to recovery of heavy oils. Carbon dioxide flooding enhances recovery due to a number of mechanisms: reduction of oil viscosity, swelling of oil, vaporization of oil, miscibility effects, reduction of interfacial tension, solution gas drive, and increases in injectivity. Three types of reservoir are particularly well suited to carbon dioxide flooding: carbonate formations which may not have a high enough injectivity to make waterflooding successful; reservoirs containing undersaturated crude oils; and certain heavy oil reservoirs. A detailed description is presented of preparation for a field test, pressure-volume-temperature data for light and heavy crude oils, and a pilot testing of CO[sub 2] flooding. To the extent that it is possible, the pilot should closely represent the formation and fluid properties and the pressures that exist in the reservoir. 7 refs., 4 figs.

  8. Sequestration of carbon dioxide with hydrogen to useful products

    Science.gov (United States)

    Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

    2017-03-07

    Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

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

    Science.gov (United States)

    Crisp, D.

    2008-01-01

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

  10. Imaging of Carbon Translocation to Fruit Using Carbon-11-Labeled Carbon Dioxide and Positron Emission Tomography

    Science.gov (United States)

    Kawachi, Naoki; Kikuchi, Kaori; Suzui, Nobuo; Ishii, Satomi; Fujimaki, Shu; Ishioka, Noriko S.; Watabe, Hiroshi

    2011-04-01

    Carbon kinetics into the fruit is an agricultural issue on the growth and development of the sink organs to be harvested. Particularly, photoassimilate translocation and distribution are important topics for understanding the mechanism. In the present work, carbon-11 (11C) labeled photoassimilate translocation into fruits of tomato has been imaged using carbon-11-labeled carbon dioxide and the positron emission tomography (PET). Dynamice PET data of gradual increasing of 11C activity and its distribution is acquired quantitatively in intact plant body. This indicates that the 3-D photoassimilate translocation into the fruits is imaged successfully and carbon kinetics is analyzable to understand the plant physiology and nutrition.

  11. Generation, capture, and utilization of industrial carbon dioxide.

    Science.gov (United States)

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

    2010-03-22

    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

  12. Direct carbon dioxide emissions from civil aircraft

    Science.gov (United States)

    Grote, Matt; Williams, Ian; Preston, John

    2014-10-01

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

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

    Science.gov (United States)

    Totani, Nagao; Inoue, Ryota; Yawata, Miho

    2016-06-01

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

  14. Helium enrichment during convective carbon dioxide dissolution

    Science.gov (United States)

    Larson, T.; Hesse, M. A.

    2013-12-01

    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 δ13C 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 δ13C value of equilibrated headspace CO2 was within 0.25‰ of its starting δ13C 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

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

    OpenAIRE

    Tsuji, Yasushi; Fujihara, Tetsuaki

    2012-01-01

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

  16. Ammonia and Carbon Dioxide Heat Pumps for Heat Recovery in Industry

    DEFF Research Database (Denmark)

    Brix, Wiebke; Christensen, Stefan W.; Markussen, Michael M.

    2012-01-01

    . Calculations of cycle performances are performed using a reference cycle for both ammonia and carbon dioxide as refrigerant. For each cycle a thorough sensitivity analysis reveals that the forward and return temperatures of the heat sink (condenser or gas cooler) of the heat pump are most important......This paper presents a generic, numerical study of high temperature heat pumps for waste heat recovery in industry using ammonia and carbon dioxide as refrigerants. A study of compressors available on the market today, gives a possible application range of the heat pumps in terms of temperatures...

  17. Structural change and the environment : a case study of China's production recipe and carbon dioxide emissions

    NARCIS (Netherlands)

    Lan, J.; Lenzen, M.; Dietzenbacher, Erik; Moran, D.; Kanemoto, K.; Murray, J.; Geschke, A.

    We use the input-output tables in constant prices extended with carbon dioxide (CO2) emissions for examining the development of China, a country undergoing rapid growth. We undertake this empirical analysis in terms of a new and therefore rarely applied methodology: instead of average coefficients

  18. Photosynthesis in tropical cover crop legumes influenced by irradiance, external carbon dioxide concentration and temperature

    Science.gov (United States)

    In plantation crops perennial tropical legumes are grown as understory plants, receive limited irradiance, and are subjected to elevated levels of CO2 and temperature. Independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration [CO2] and temper...

  19. Video-assisted thoracoscopic thymectomy using 5-mm ports and carbon dioxide insufflation

    DEFF Research Database (Denmark)

    Petersen, René Horsleben

    2016-01-01

    The continuous development and refinement of minimally invasive approaches to thymectomy over the last two decades has potential benefits for patients in terms of better cosmesis, less postoperative pain, shorter length of stay, earlier return to daily activities, less bleeding and fewer complica......, carbon dioxide (CO2) insufflation and bipolar electrocoagulation (LigaSure)....

  20. Sources and delivery of carbon dioxide for enhanced oil recovery. Final report, October 1977--December 1978

    Energy Technology Data Exchange (ETDEWEB)

    Hare, M.; Perlich, H.; Robinson, R.; Shah, M.; Zimmerman, F.

    1978-12-01

    Results are presented from a comprehensive study by Pullman Kellogg, with assistance from Gulf Universities Research Consortium (GURC) and National Cryo-Chemics Incorporated (NCI), of the carbon dioxide supply situation for miscible flooding operations to enhance oil recovery. A survey of carbon dioxide sources within the geographic areas of potential EOR are shown on four regional maps with the tabular data for each region to describe the sources in terms of quantity and quality. Evaluation of all the costs, such as purchase, production, processing, and transportation, associated with delivering the carbon dioxide from its source to its destination are presented. Specific cases to illustrate the use of the maps and cost charts generated in this study have been examined.

  1. Aesthetic Depigmentation of Gingival Smoker's Melanosis Using Carbon Dioxide Lasers.

    Science.gov (United States)

    Monteiro, Luis Silva; Costa, José Adriano; da Câmara, Marco Infante; Albuquerque, Rui; Martins, Marco; Pacheco, José Júlio; Salazar, Filomena; Figueira, Fernando

    2015-01-01

    Melanic pigmentation results from melanin produced by the melanocytes present in the basal layer of the oral epithelium. One of the most common causes of oral pigmentation is smoker melanosis, a condition associated with the melanocyte stimulation caused by cigarette smoke. This paper aims to illustrate the use of a carbon dioxide laser in the removal of the gingival melanic pigmentation for aesthetic reasons in a 27-year-old female patient with history of a smoking habit. The carbon dioxide laser vaporisation was performed on the gingival mucosa with effective and quick results and without any complications or significant symptoms after the treatment. We conclude that a carbon dioxide laser could be a useful, effective, and safe instrument to treat the aesthetic complications caused by oral smoker melanosis.

  2. Using LMDI approach to analyze changes in carbon dioxide emissions of China’s logistics industry

    OpenAIRE

    Ying Dai; Jing Zhu; Han Song

    2015-01-01

    Purpose: China is confronting with tremendous pressure in carbon emission reduction. While logistics industry seriously relies on fossil fuel, and emits greenhouse gas, especially carbon dioxide. The aim of this article is to estimate the carbon dioxide emission in China’s logistics sector, and analyze the causes for the change of carbon dioxide emission, and identify the critical factors which mainly drive the change in carbon dioxide emissions of China’s logistics industry. Design/methodolo...

  3. Short-term variability of surface carbon dioxide and sea-air CO2 fluxes in the shelf waters of the Galician coastal upwelling system

    Directory of Open Access Journals (Sweden)

    Alba Marina Cobo-Viveros

    2013-01-01

    Full Text Available Using data collected during the DYBAGA and ECO cruises, remote sensing chlorophyll-a estimations and the averaged upwelling index of the previous fortnight (Iw’, we studied the variability of the sea surface CO2 fugacity (fCO2 over the Galician continental shelf during three seasonal cycles. Sea surface salinity (SSS distribution controlled fCO2 mainly in spring, while sea surface temperature (SST did so during periods of intense cooling in November and warming in June. The uptake of carbon by photosynthetic activity, which was more intense during spring and autumn, masked the surface increase in the dissolved inorganic carbon concentration during upwelling events, especially during spring. A significant low correlation between fCO2 and Iw’ was found during spring and summer when upwelling events were observed, whereas no relationship was observed during the downwelling period. High fCO2 exceeding atmospheric values was only found during the summer stratification breakdown. Although sea-air CO2 fluxes showed a marked inter-annual variability, surface waters off the Galician coast were net sinks for atmospheric CO2 in every seasonal cycle, showing a lower CO2 uptake (~65% compared to previously published values. Marked inter-annual changes in the sea-air CO2 fluxes seem to be influenced by fresh water inputs on the continental shelf under different meteorological scenarios.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    Experimental and theoretical studies on the interaction of carbon dioxide with pseudomorphic and rough copper layers deposited on a platinum (111) single crystal are reported. Evidence for carbon dioxide dissociation and carbonate formation is presented and the relevance to methanol synthesis......) reveals a broad high temperature desorption state for CO2 with peak maximum around 450 K. X-ray photoelectron spectroscopy (XPS) shows that approximately one third of the oxygen accumulated on the surface upon CO2 exposure remains after TPD, indicative of carbonate formation via CO2 dissociation supplying...... O-ads and then facile CO2 + O-ads association, as well as subsequent decomposition at higher temperatures. Density functional theory studies of stepped Cu and Cu/Pt slabs reproduce vibrational frequencies of the carbonate, suggesting a nearly flat tridentate configuration at steps/defect sites....

  5. Visual and reversible carbon dioxide sensing enabled by doctor blade coated macroporous photonic crystals.

    Science.gov (United States)

    Lin, Yi-Han; Suen, Shing-Yi; Yang, Hongta

    2017-11-15

    With significant impacts of carbon dioxide on global climate change, carbon dioxide sensing is of great importance. However, most of the existing sensing technologies are prone to interferences from carbon monoxide, or suffer from the use of sophisticated instruments. This research reports the development of reproducible carbon dioxide sensor using roll-to-roll compatible doctor blade coated three-dimensional macroporous photonic crystals. The pores are functionalized with amine groups to allow the reaction with carbon dioxide in the presence of humidity. The adsorption of carbon dioxide leads to red-shift and amplitude reduction of the optical stop bands, resulting in carbon dioxide detection with visible readout. The dependences of the diffraction wavelength on carbon dioxide partial pressure for various amine-functionalized photonic crystals and different humidities in the environment are systematically investigated. In addition, the reproducibility of carbon dioxide sensing has also been demonstrated in this research. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Science.gov (United States)

    2010-05-26

    ...] [FR Doc No: 2010-12591] ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0434; FRL-8826-6] Inorganic... ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon and carbon... inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas cartridge uses of sulfur. The...

  7. Supercritical carbon dioxide drying of methanol-Zinc borate mixtures

    OpenAIRE

    Gönen, Mehmet; Balköse, Devrim; Gupta, Ram B.; Ülkü, Semra

    2009-01-01

    Supercritical carbon dioxide (CO 2) drying of zinc borate species was investigated to evaluate possible chemical alterations in the product during the drying. Methanol-wetted zinc borates produced either from borax decahydrate and zinc nitrate hexahydrate (2ZnO · 3B 2O 3 ·7H 2O) or from zinc oxide and boric acid (2ZnO · 3B 2O 3 ·3H 2O) were dried by both conventional and supercritical carbon dioxide drying methods. Zinc borate samples dried by both techniques were characterized using analytic...

  8. Supercritical carbon dioxide-based sterilization of decellularized heart valves.

    Science.gov (United States)

    Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

    2017-02-01

    The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe

  9. Carbon dioxide capture and storage : hindrances for implementation in Norway

    OpenAIRE

    Houm, Marius

    2007-01-01

    This paper is an actor-network theory-based analysis of the hindrances for implementation of carbon dioxide capture, transport and storage, CCS, as a climate mitigation initiative in Norway. It uses the Norwegian projects Kårstø, Mongstad, Tjeldbergodden/Halten/Draugen, Sleipner and Snøhvit as the basis for a discussion of the relevant technologies, obstacles, policies, rhetoric and realities. CCS is a possible way to reduce emissions of carbon dioxide. We need an emission reduction of th...

  10. Solubility of anthracene and anthraquinone in cyclohexanone + carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.J. (National Chung-Hsing Univ., Taichung (Taiwan, Province of China). Dept. of Chemical Engineering)

    1994-10-01

    In the processing of an anthracene oil fraction from coal tar, a mixture of anthracene and anthraquinone is required to be separated to obtain products of high purity. The solubilities of anthracene and anthraquinone were measured in cyclohexanone + carbon dioxide as a function of the temperature and pressure of carbon dioxide at 291, 300, and 313 K and from 1.8--12.4 MPa. Average equilibrium solubilities and recoveries of both solids increased with increasing normalized concentration and pressure. The average separation factor of anthracene to anthraquinone, due to the effect of the mixed solvent, was 2.88 [+-] 1.91.

  11. The anaesthesia of fish by high carbon-dioxide concentrations

    Science.gov (United States)

    1942-01-01

    A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

  12. Kinetic study of coals gasification into carbon dioxide atmosphere

    Directory of Open Access Journals (Sweden)

    Korotkikh A.G.

    2015-01-01

    Full Text Available The solid fuel gasification process was investigated to define chemical reactions rate and activation energy for a gas-generator designing and regime optimizing. An experimental procedure includes coal char samples of Kuznetskiy and Kansko-Achinskiy deposits consequent argon pyrolysis into argon and oxidating into carbon dioxide with different temperatures. The thermogravimetric analysis data of coal char gasification into carbon dioxide was obtained in the temperature range 900–1200 ºC. The mass loss and gasification time dependencies from temperature were defined to calculate chemical reaction frequency factor and activation energy. Two coal char gasification physico-mathematical models were proposed and recommendations for them were formed.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...... the performance in this setting. Glass substrates were used for model studies with an active area of 100cm2 and flexible substrates based on polyethyleneterphthalate (PET), polyethylenenaphtalate (PEN) and polyethylene (PE) with a similar area for prototypes of photocatalytic converters. The results from this new...

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

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, M P [ed.

    1987-03-01

    Four State of the Art (SOA) reports, ''Atmospheric Carbon Dioxide and the Global Carbon Cycle,'' ''Direct Effects of Increasing Carbon Dioxide on Vegetation,'' ''Detecting the Climatic Effects of Increasing Carbon Dioxide,'' and ''Projecting the Climatic Effects of Increasing Carbon Dioxide,'' and two companion reports, ''Characterization of Information Requirements for Studies of CO/sub 2/ Effects: Water Resources, Agriculture, Fisheries, Forests and Human Health'' and ''Glaciers, Ice Sheets, and Sea Level: Effect of a CO/sub 2/-Induced Climatic Change,'' were published by the US Department of Energy's Carbon Dioxide Research Division. Considerable information on atmospheric carbon dioxide and its possible effects on world climate is summarized in these six volumes. Each volume has its own index, but to make the information that is distributed throughout the six volumes more accessible and usable, comprehensive citation and subject indexes have been compiled. The subject indexes of the individual volumes have been edited to provide a uniformity from volume to volume and also to draw distinctions not needed in the separate volumes' indexes. Also, the comprehensive subject index has been formatted in a matrix arrangement to graphically show the distribution of subject treatment from volume to volume. Other aids include cross references between the scientific and common names of the animals and plants referred to, a glossary of special terms used, tables of data and conversion factors related to the data, and explanations of the acronyms and initialisms used in the texts of the six volumes. The executive summaries of the six volumes are collected and reproduced to allow the readers interested in the contents of one volume to rapidly gain information on the contents of the other volumes.

  15. Short- and long-term consequences of larval stage exposure to constantly and ephemerally elevated carbon dioxide for marine bivalve populations

    Directory of Open Access Journals (Sweden)

    C. J. Gobler

    2013-04-01

    Full Text Available While larval bivalves are highly sensitive to ocean acidification, the basis for this sensitivity and the longer-term implications of this sensitivity are unclear. Experiments were performed to assess the short-term (days and long-term (months consequences of larval stage exposure to varying CO2 concentrations for calcifying bivalves. Higher CO2 concentrations depressed both calcification rates assessed using 45Ca uptake and RNA : DNA ratios in Mercenaria mercenaria and Argopecten irradians larvae with RNA : DNA ratios being highly correlated with larval growth rates (r2>0.9. These findings suggested that high CO2 has a cascading negative physiological impact on bivalve larvae stemming in part from lower calcification rates. Exposure to elevated CO2 during the first four days of larval development significantly depressed A. irradians larval survival rates, while a 10-day exposure later in larval development did not, demonstrating the extreme CO2 sensitivity of bivalve larvae during first days of development. Short- (weeks and long-term (10 month experiments revealed that individuals surviving exposure to high CO2 during larval development grew faster when exposed to normal CO2 as juveniles compared to individuals reared under ambient CO2 as larvae. These increased growth rates could not, however, overcome size differences established during larval development, as size deficits of individuals exposed to even moderate levels of CO2 as larvae were evident even after 10 months of growth under normal CO2 concentrations. This "legacy effect" emphasizes the central role larval stage CO2 exposure can play in shaping the success of modern-day bivalve populations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, L E [ed.

    1980-12-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased CO2; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO2; social responses to the CO2 problem; a scenario for atmospheric CO2 to 2025; marine photosynthesis and the global carbon cycle; and the role of tropical forests in the carbon balance of the world. Separate abstracts of nine papers have been prepared for inclusion in the Energy Data Base. (RJC)

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

    Science.gov (United States)

    Miyauchi, Takuya; Kamata, Masahiro

    2012-01-01

    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…

  18. Adsorption of chlorine dioxide gas on activated carbons.

    Science.gov (United States)

    Wood, Joseph P; Ryan, Shawn P; Snyder, Emily Gibb; Serre, Shannon D; Touati, Abderrahmane; Clayton, Matthew J

    2010-08-01

    Research and field experience with chlorine dioxide (ClO2) gas to decontaminate structures contaminated with Bacillus anthracis spores and other microorganisms have demonstrated the effectiveness of this sterilant technology. However, because of its hazardous properties, the unreacted ClO2, gas must be contained and captured during fumigation events. Although activated carbon has been used during some decontamination events to capture the ClO2 gas, no data are available to quantify the performance of the activated carbon in terms of adsorption capacity and other sorbent property operational features. Laboratory experiments were conducted to determine and compare the ClO2 adsorption capacities of five different types of activated carbon as a function of the challenge ClO2 concentration. Tests were also conducted to investigate other sorbent properties, including screening tests to determine gaseous species desorbed from the saturated sorbent upon warming (to provide an indication of how immobile the ClO2 gas and related compounds are once captured on the sorbent). In the adsorption tests, ClO2 gas was measured continuously using a photometric-based instrument, and these measurements were verified with a noncontinuous method utilizing wet chemistry analysis. The results show that the simple activated carbons (not impregnated or containing other activated sorbent materials) were the most effective, with maximum adsorption capacities of approximately 110 mg/g. In the desorption tests, there was minimal release of ClO(2) from all sorbents tested, but desorption levels of chlorine (Cl2) gas (detected as chloride) varied, with a maximum release of nearly 15% of the mass of ClO2 adsorbed.

  19. Energy Saving High-Capacity Moderate Pressure Carbon Dioxide Storage System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our approach to high-pressure carbon dioxide storage will directly address the challenges associated with storage of compressed carbon dioxide - the need to reduce...

  20. Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report is the authoritative reference for carbon dioxide (CO2) emissions,...

  1. Accuracy of Transcutaneous Carbon Dioxide Tension Measurements during Cardiopulmonary Exercise Testing

    National Research Council Canada - National Science Library

    Stege, Gerben; van den Elshout, Frank J.J; Heijdra, Yvonne F; van de Ven, Marjo J.T; Dekhuijzen, P.N. Richard; Vos, Petra J.E

    2009-01-01

    Background: Measurements of transcutaneous carbon dioxide tension (PtcCO ) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO...

  2. Microbial carbon dioxide fixation: new tricks for an old game.

    Science.gov (United States)

    Branduardi, Paola; Sauer, Michael

    2017-12-06

    The exploitation of petroleum as energy and material source opened unprecedented possibilities for the development of our human societies, but only now we realize that the use of fossil resources comes at devastatingly high environmental costs. Consequently, our efforts to tap other carbon sources are steadily increasing. Industrial microbiology has the potential to use carbon dioxide directly as carbon source, thereby converting a foe into a friend. This thematic issue of FEMS Microbiology Letters sheds some light on recent developments for the understanding of microbial pathways for carbon dioxide fixation and on strategies for their industrial exploitation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

    Meisinger, Philipp; Wittlich, Christian

    2014-05-01

    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. 10°C, 20°C, 40°C). 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

  4. Erosion of organic carbon in the Arctic as a geological carbon dioxide sink.

    Science.gov (United States)

    Hilton, Robert G; Galy, Valier; Gaillardet, Jérôme; Dellinger, Mathieu; Bryant, Charlotte; O'Regan, Matt; Gröcke, Darren R; Coxall, Helen; Bouchez, Julien; Calmels, Damien

    2015-08-06

    Soils of the northern high latitudes store carbon over millennial timescales (thousands of years) and contain approximately double the carbon stock of the atmosphere. Warming and associated permafrost thaw can expose soil organic carbon and result in mineralization and carbon dioxide (CO2) release. However, some of this soil organic carbon may be eroded and transferred to rivers. If it escapes degradation during river transport and is buried in marine sediments, then it can contribute to a longer-term (more than ten thousand years), geological CO2 sink. Despite this recognition, the erosional flux and fate of particulate organic carbon (POC) in large rivers at high latitudes remains poorly constrained. Here, we quantify the source of POC in the Mackenzie River, the main sediment supplier to the Arctic Ocean, and assess its flux and fate. We combine measurements of radiocarbon, stable carbon isotopes and element ratios to correct for rock-derived POC. Our samples reveal that the eroded biospheric POC has resided in the basin for millennia, with a mean radiocarbon age of 5,800 ± 800 years, much older than the POC in large tropical rivers. From the measured biospheric POC content and variability in annual sediment yield, we calculate a biospheric POC flux of 2.2(+1.3)(-0.9) teragrams of carbon per year from the Mackenzie River, which is three times the CO2 drawdown by silicate weathering in this basin. Offshore, we find evidence for efficient terrestrial organic carbon burial over the Holocene period, suggesting that erosion of organic carbon-rich, high-latitude soils may result in an important geological CO2 sink.

  5. Oceanic crustal carbon cycle drives 26-million-year atmospheric carbon dioxide periodicities.

    Science.gov (United States)

    Müller, R Dietmar; Dutkiewicz, Adriana

    2018-02-01

    Atmospheric carbon dioxide (CO 2 ) data for the last 420 million years (My) show long-term fluctuations related to supercontinent cycles as well as shorter cycles at 26 to 32 My whose origin is unknown. Periodicities of 26 to 30 My occur in diverse geological phenomena including mass extinctions, flood basalt volcanism, ocean anoxic events, deposition of massive evaporites, sequence boundaries, and orogenic events and have previously been linked to an extraterrestrial mechanism. The vast oceanic crustal carbon reservoir is an alternative potential driving force of climate fluctuations at these time scales, with hydrothermal crustal carbon uptake occurring mostly in young crust with a strong dependence on ocean bottom water temperature. We combine a global plate model and oceanic paleo-age grids with estimates of paleo-ocean bottom water temperatures to track the evolution of the oceanic crustal carbon reservoir over the past 230 My. We show that seafloor spreading rates as well as the storage, subduction, and emission of oceanic crustal and mantle CO 2 fluctuate with a period of 26 My. A connection with seafloor spreading rates and equivalent cycles in subduction zone rollback suggests that these periodicities are driven by the dynamics of subduction zone migration. The oceanic crust-mantle carbon cycle is thus a previously overlooked mechanism that connects plate tectonic pulsing with fluctuations in atmospheric carbon and surface environments.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-01-01

    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.

  7. Optimization through Response Surface Methodology of a Reactor Producing Methanol by the Hydrogenation of Carbon Dioxide

    OpenAIRE

    Grazia Leonzio

    2017-01-01

    Carbon dioxide conversion and utilization is gaining significant attention worldwide, not only because carbon dioxide has an impact on global climate change, but also because it provides a source for potential fuels and chemicals. Methanol is an important fuel that can be obtained by the hydrogenation of carbon dioxide. In this research, the modeling of a reactor to produce methanol using carbon dioxide and hydrogen is carried out by way of an ANOVA and a central composite design. Reaction te...

  8. Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Thomas O. Nelson; Brian S. Turk; Paul D. Box; Raghubir P. Gupta

    2006-03-31

    This report describes research conducted between January 1, 2006, and March 31, 2006, on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from coal combustion flue gas. An integrated system composed of a downflow co-current contact absorber and two hollow screw conveyors (regenerator and cooler) was assembled, instrumented, debugged, and calibrated. A new batch of supported sorbent containing 15% sodium carbonate was prepared and subjected to surface area and compact bulk density determination.

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

    Science.gov (United States)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co

  10. Carbon Dioxide Absorption in a Membrane Contactor with Color Change

    Science.gov (United States)

    Pantaleao, Ines; Portugal, Ana F.; Mendes, Adelio; Gabriel, Joaquim

    2010-01-01

    A pedagogical experiment is described to examine the physical absorption of gases, in this case carbon dioxide, in a hollow fiber membrane contactor (HFMC) where the absorption concentration profile can be followed by a color change. The HFMC is used to teach important concepts and can be used in interesting applications for students, such as…

  11. Design of Stable Catalysts for Methane-Carbon Dioxide Reforming

    NARCIS (Netherlands)

    Seshan, K.; Bitter, J.H.; Lercher, J.A.

    1998-01-01

    PtZrO2 is an active and stable catalyst for methane- carbon dioxide reforming reaction. The reaction between CO2 and CH4 to yield synthesis gas might proceed vie two different pethways. At high temperatures (>1075K) CO2 can be dissociated on Pt to CO and absorbed oxygen. Methane can be dissociated

  12. Electrochemical carbon dioxide reduction on rough copper surfaces

    NARCIS (Netherlands)

    Kas, Recep

    2016-01-01

    Sustainable development and climate change is considered to be one of the top challenges of humanity. Electrochemical carbon dioxide (CO2) reduction to fuels or fuel precursor using renewable electricity is a very promising way to recycle CO2 and store the electricity. This would also provide

  13. Carbon dioxide detection with polyethylenimine blended with polyelectrolytes

    NARCIS (Netherlands)

    Doan, T.C.D.; Baggerman, J.; Ramaneti, R.; Tong, H.D.; Marcelis, A.T.M.; Rijn, van C.J.M.

    2014-01-01

    Branched polyethylenimine (PEI) is studied for use as a chemiresistor for detection of carbon dioxide(CO2) at room temperature. The DC and AC measurements of drop-coated PEI films on interdigitated electrodes revealed a noticeable decrease in conductivity upon exposure to CO2 (400–2000 ppm)

  14. Risk mitigation strategies and policy implications for carbon dioxide ...

    African Journals Online (AJOL)

    USER

    Risk mitigation strategies and policy implications for carbon dioxide (CO2) emission in ... 1National Centre for Technology Management (NACETEM), Federal Ministry of Science and Technology,. Obafemi Awolowo University ..... needs assessment report under project: climate change enabling activity (Phase II). Republic of ...

  15. Solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Kazemi, Somayeh; Belandria, Veronica; Janssen, Nico

    2012-01-01

    In this work, the solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide (scCO2) were measured using an analytical method in a quasi-flow apparatus. High-performance liquid chromatography was applied through an online sampling procedure to determine the concentration...

  16. Extraction of Coal-tar Pitch by Supercritical Carbon Dioxide ...

    African Journals Online (AJOL)

    Several extractions of coal-tar pitch were performed using supercritical fluid carbon dioxide. The relationships between extraction yield during supercritical fluid extraction (SFE) and the variables temperature, pressure and extraction time were investigated. For qualitative and quantitative identification of organic compounds, ...

  17. Quantitative aspects of oxygen and carbon dioxide exchange ...

    African Journals Online (AJOL)

    Quantitative aspects of oxygen and carbon dioxide exchange through the lungs in Ocypode ceratophthalmus (Crustacea: Decapoda) during rest and exercise in water ... The percent accumulated 14-CO2 in exhaled air, plotted against time, intersects zero time on the x-axis, indicating rapid gas exchange at the lung surface.

  18. Regulation of carbon dioxide fixation in the chemoautotroph Xanthobacter flavus

    NARCIS (Netherlands)

    Keulen, Geertje van

    2000-01-01

    Autotrophic bacteria and plants are able to convert the greenhouse gas carbon dioxide, CO2, into cell material. Although there are a number of metabolic pathways supporting autotrophic growth, the Calvin cycle is the most widely distributed of these. CO2 fixation requires a large amount of energy

  19. Carbon Dioxide Emissions Reduction Estimates: Potential Use of ...

    African Journals Online (AJOL)

    User

    UNIVERSITY OF MAURITIUS RESEARCH JOURNAL – Volume 16 – 2010. University of Mauritius, Réduit, Mauritius. Research Week 2009/2010. 512. Carbon Dioxide Emissions Reduction. Estimates: Potential Use of Biofuels in. Mauritian Transport Sector for Cars and Dual. Cars. D Surroop *. Faculty of Engineering,.

  20. Carbon dioxide, water vapour and energy fluxes over a semi ...

    Indian Academy of Sciences (India)

    42

    Key words: Eddy covariance; semi-evergreen forest; surface energy balance; Carbon dioxide. 25 flux; Indian .... following forest types and biomes (Champion and Seth 1968), namely Eastern wet alluvial. 86 grasslands ..... Turbulence characteristics of the site were analyzed (table 2 a-b)during whole period. 197 and four ...

  1. Reducing Carbon Dioxide Emissions: Using the Mole Concept.

    Science.gov (United States)

    Myers, Alan

    2002-01-01

    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)

  2. SCATTERING OF CARBON-DIOXIDE MOLECULES FROM PD(111) SURFACES

    NARCIS (Netherlands)

    SCHLATHOLTER, T; HEILAND, W; Schlathölter, Thomas

    1995-01-01

    Carbon dioxide positive ions and neutral molecules are subject to different charge exchange processes when scattered off clean or potassium-covered Pd(111) surfaces under grazing incidence. The time-of-flight method is a suitable tool to investigate these processes with respect to dissociation and

  3. 9 CFR 313.5 - Chemical; carbon dioxide.

    Science.gov (United States)

    2010-01-01

    ... the species of animals being anesthetized. They shall be free from pain-producing restraining devices... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chemical; carbon dioxide. 313.5 Section 313.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE...

  4. Gas flaring: Carbon dioxide contribution to global warming ...

    African Journals Online (AJOL)

    Flaring been a source of anthropogenic carbon dioxide, is a concern to skeptics and local oil producing communities as a significant contributor to global warming, environmental degradation, health risk and economic loss. The purpose of the study was to ascertain the impacts of gas flaring on global warming and the local ...

  5. Serpentine dissolution in hydrochloric acid for carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Amankwah, R.K.; Pickles, C.A. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mining Engineering

    2008-07-01

    Increased carbon dioxide concentrations in the atmosphere can be attributed to industrialization and the associated combustion of large amounts of fossil fuels. The release of carbon dioxide into the atmosphere causes greenhouse gases, which is expected to have a destabilizing effect on the climate. Several methods have been investigated to reduce the amount of greenhouse gases in the atmosphere, such as improved energy efficiency and conservation programs; utilization of alternative energy sources; and carbon dioxide sequestration. This paper discussed the sequestration of carbon dioxide by minerals as a potential method for reducing the greenhouse gas concentration in the atmosphere. The paper presented a study that involved the dissolution of lizardite, a serpentine mineral, in hydrochloric acid at high pressures in an autoclave. The thermodynamics of the system were examined and experimental data were presented. The solubility of the mineral was shown to be strongly dependent on processing time, acid concentration and pulp density but not strongly affected by stirring or temperature. The paper also discussed the characterization of the reacted samples by thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The reacted samples were compared to the as-received material. It was concluded that the equilibrium calculations, the kinetic experiments and the characterization of the processed samples indicated that a silica-rich layer formed on the lizardite as the magnesium dissolved, and that this layer hindered further dissolution. 13 refs., 1 tab., 8 figs.

  6. Integrated biofuel facility, with carbon dioxide consumption and power generation

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering

    2009-07-01

    This presentation provided details of an economical design for a large-scale integrated biofuel facility for coupled production of bioethanol and biodiesel, with carbon dioxide capture and power generation. Several designs were suggested for both batch and continuous culture operations, taking into account all costs and revenues associated with the complete plant integration. The microalgae species Chlorella vulgaris was cultivated in a novel photobioreactor (PBR) in order to consume industrial carbon dioxide (CO{sub 2}). This photosynthetic culture can also act as a biocathode in a microbial fuel cell (MFC), which when coupled to a typical yeast anodic half cell, results in a complete biological MFC. The photosynthetic MFC produces electricity as well as valuable biomass and by-products. The use of this novel photosynthetic microalgae cathodic half cell in an integrated biofuel facility was discussed. A series of novel PBRs for continuous operation can be integrated into a large-scale bioethanol facility, where the PBRs serve as cathodic half cells and are coupled to the existing yeast fermentation tanks which act as anodic half cells. These coupled MFCs generate electricity for use within the biofuel facility. The microalgae growth provides oil for biodiesel production, in addition to the bioethanol from the yeast fermentation. The photosynthetic cultivation in the cathodic PBR also requires carbon dioxide, resulting in consumption of carbon dioxide from bioethanol production. The paper also discussed the effect of plant design on net present worth and internal rate of return. tabs., figs.

  7. Carbon dioxide uptake by a temperate tidal sea

    NARCIS (Netherlands)

    Klaassen, Wim

    2007-01-01

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

  8. Use of carbon dioxide laser in oral soft tissue procedures

    Science.gov (United States)

    Garg, Nimit; Verma, Sunil; Chadha, Minni; Rastogi, Pavitra

    2015-01-01

    Lasers have been introduced in dentistry as an alternative to conventional knife surgery. The advantage to the operator includes a clean dry field that enhances visibility and reduces the procedure time. The patient benefits by minimal postoperative pain and swelling. The paper discusses use of carbon dioxide laser in five conditions commonly encountered in oral cavity. PMID:26668460

  9. A Discovery Experiment: Carbon Dioxide Soap Bubble Dynamics.

    Science.gov (United States)

    Millikan, Roger C.

    1978-01-01

    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)

  10. Binary mixtures of carbon dioxide and dimethyl ether as alternative ...

    African Journals Online (AJOL)

    Vapor-liquid equilibrium (VLE) data were predicted for the binary mixture of carbon dioxide (CO2) and dimethyl ether (DME) at ten temperatures ranging from 273.15 to 386.56 K and pressure upto 7.9 MPa to observe this mixture's potential of COP enhancement and capacity modulation as a working fluid in a refrigeration ...

  11. Solubilities of sub- and supercritical carbon dioxide in polyester resins

    NARCIS (Netherlands)

    Nalawade, SP; Picchioni, F; Janssen, LPBM; Patil, VE; Keurentjes, JTF; Staudt, R; Nalawade, Sameer P.; Patil, Vishal E.; Keurentjes, Jos T.F.

    In supercritical carbon dioxide (CO2) assisted polymer processes the solubility of CO2 in a polymer plays a vital role. The higher the amount of CO2 dissolved in a polymer the higher is the viscosity reduction of the polymer. Solubilities Of CO2 in polyester resins based on propoxylated bisphenol

  12. Removing carbon dioxide from a stationary source through co ...

    African Journals Online (AJOL)

    Except temperature of solvent, all study variables showed strong relation with the amount of carbon dioxide absorbed (with a P-value < 0.05). Uniquely, this study has evaluated the potential for sodium bicarbonate production from the CO2 absorbed using gravimetric analysis. It is also possible to recover over 28% crystal ...

  13. Kinetics of absorption of carbon dioxide in aqueous ammonia solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Versteeg, G. F.

    2009-01-01

    In the present work the absorption of carbon dioxide into aqueous ammonia solutions has been studied in a stirred cell reactor, at low temperatures and ammonia concentrations ranging from 0.1 to about 7 kmol m-3. The absorption experiments were carried out at conditions where the so-called pseudo

  14. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    NARCIS (Netherlands)

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical

  15. Intertidal zones as carbon dioxide sources to coastal oceans

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; Rajagopal, M.D.

    To understand the factors controlling carbon dioxide (CO sub(2)) exchanges near land-sea boundary diurnal observations have been made twice on CO sub(2) in the air and water in a coastal region. The results suggest that CO sub(2) enrichment...

  16. Kenaf seed oil from supercritical carbon dioxide fluid extraction ...

    African Journals Online (AJOL)

    Kenaf seed oil from supercritical carbon dioxide fluid extraction shows cytotoxic effects towards various cancer cell lines. ... African Journal of Biotechnology ... Even though kenaf seed oil from both varieties were cytotoxic to all the cancer cells, kenaf seed oil variety V36 extracted by SFE at 600 bars 40°C (V600/40) was the ...

  17. Trade, production fragmentation, and China's carbon dioxide emissions

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Pei, Jiansuo; Yang, Cuihong

    An input-output framework is adopted to estimate China's carbon dioxide (CO2) emissions as generated by its exports in 2002. More than one half of China's exports are related to international production fragmentation. These processing exports generate relatively little value added but also

  18. Classroom Carbon Dioxide Concentration, School Attendance, and Educational Attainment

    Science.gov (United States)

    Gaihre, Santosh; Semple, Sean; Miller, Janice; Fielding, Shona; Turner, Steve

    2014-01-01

    Background: We tested the hypothesis that classroom carbon dioxide (CO[subscript 2]) concentration is inversely related to child school attendance and educational attainment. Methods: Concentrations of CO[subscript 2] were measured over a 3-5?day period in 60 naturally ventilated classrooms of primary school children in Scotland. Concentrations of…

  19. A new manometric method for measuring carbon dioxide production ...

    African Journals Online (AJOL)

    This paper describe a technique for carbon dioxide (CO2) measurement based on the displacement of acidifying liquid in burette at constant pressure. It was adapted to allow the growth of ... The CO2 production rate was higher with the parental strain (6.5 mM/ h) than with the variants. The amount of CO2 produced was ...

  20. TWO-PHASE EJECTOR of CARBON DIOXIDE HEAT PUMP CALCULUS

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2010-12-01

    Full Text Available It is presented the calculus of the two-phase ejector for carbon dioxide heat pump. The method of calculus is based on the method elaborated by S.M. Kandil, W.E. Lear, S.A. Sherif, and is modified taking into account entrainment ratio as the input for the calculus.

  1. Metathesis of carbon dioxide and phenyl isocyanate catalysed by ...

    Indian Academy of Sciences (India)

    The insertion reactions of zirconium(IV) -butoxide and titanium(IV) -butoxide with a heterocumulene like carbodiimide, carbon dioxide or phenyl isocyanate are compared. Both give an intermediate which carries out metathesis at elevated temperatures by inserting a second heterocumulene in a head-to-head fashion.

  2. Carbon dioxide and water vapour characteristics on the west coast ...

    Indian Academy of Sciences (India)

    Carbon dioxide and water vapour in the atmo- sphere are considered as the green-house gases and responsible for the global warming, hence much attention has been given to its measurement and analysis (Jones et al. 1978; Jones and Smith 1977;. Leuning et al. 1982; Ohtaki and Matsui 1982;. Ohtaki 1985).

  3. Characterization of potassium glycinate for carbon dioxide absorption purposes

    NARCIS (Netherlands)

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

    2007-01-01

    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 3 M, were determined at temperatures from 293 to 313 K. Diffusivity of CO2 in solution was estimated applying the

  4. Solubility of carbon dioxide in aqueous piperazine solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Dijkstra, H. B. S.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    In the present work, new experimental data are presented on the solubility of carbon dioxide in aqueous piperazine solutions, for concentrations of 0.2 and 0.6 molar piperazine and temperatures of 25, 40, and 70°C respectively. The present data, and other data available in the literature, were

  5. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    An increase in carbon dioxide (CO2) concentrations in the atmosphere due to anthropogenic activities is responsible for global warming and hence in recent years, CO2 measurement network has expanded globally. In the monsoon season (July–September) of year 2011, we carried out measurements of CO2 and water ...

  6. Intravenous carbon dioxide as an echocardiographic contrast agent

    NARCIS (Netherlands)

    R.S. Meltzer (Richard); P.W.J.C. Serruys (Patrick); P.G. Hugenholtz (Paul); J.R.T.C. Roelandt (Jos)

    1981-01-01

    textabstractIntravenous carbon dioxide (CO2) was employed to cause echocardiographic contrast in 40 patients. One to 3 cc of medically pure CO2 were agitated with 5 to 8 cc of 5% dextrose in water and rapidly injected into an upper extremity vein. Contrast was obtained in all patients. In 33

  7. Carbon dioxide inhibition of yeast growth in biomass production.

    Science.gov (United States)

    Chen, S L; Gutmains, F

    1976-10-01

    Saccharomyces cerevisiae was grown under aerobic and substrate-limiting conditions for efficient biomass production. Under these conditions, where the sugar substrate was fed incrementally, the growth pattern of the yeast cells was found to be uniform, as indicated by a constant respiratory quotient during the entire growing period. The effect of carbon dioxide was investigated by replacing portions of the nitrogen in the air stream with carbon dioxide, while maintaining the oxygen content at the normal 20% level, so that identical oxygen transfer rate and atmospheric pressure were maintained for all experiments with different partial pressures of carbon dioxide. Inhibition of yeast growth was negligible below 20% CO2 in the aeration mixture. Slight inhibition was noted at the 40% CO2 level and significant inhibition was noted above the 50% CO2 level, corresponding to 1.6 X 10(-2)M of dissolved CO2 in the fermentor broth. High carbon dioxide content in the gas phase also inhibited the fermentation activity of baker's yeast.

  8. Transferable force field for carbon dioxide adsorption in zeolites

    NARCIS (Netherlands)

    García-Sánchez, A.; Ania, C.O.; Parra, J.B.; Dubbeldam, D.; Vlugt, T.J.H.; Krishna, R.; Calero, S.

    2009-01-01

    We have developed a complete force field that accurately reproduces the adsorption properties of carbon dioxide in a variety of zeolites with different topologies and compositions. The force field parameters were obtained by fitting to our own experimental data and validated with available data

  9. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    DEFF Research Database (Denmark)

    Andres, R.J.; Gregg, Jay Sterling; Losey, L.

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950–2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80...

  10. The chemical fixation of carbon dioxide by tetramethylguanidine and ...

    African Journals Online (AJOL)

    ... with TMG and TBD at normal conditions of temperature and pressure. Finally it was also proposed that, the method used could be useful for the uptake and release of atmospheric CO2. Keywords: Carbon dioxide, Chemical fixation, Heteronuclear Multiple-Bond Correlation Tetramethylguanidine, Triazabicyclo decene ...

  11. Supercritical carbon dioxide extraction of oil from Clanis bilineata ...

    African Journals Online (AJOL)

    Oil was extracted from the dry meat of Clanis bilineata (Lepidoptera) using supercritical carbon dioxide in a continuous flow extractor. The following optimum extraction conditions were investigated: temperature, 35°C; pressure, 25 MPa; supercritical CO2 flow rate, 20 L/min and time, 60 min. Under these extraction ...

  12. Dynamics of Carbon-dioxide production and its economic importance

    African Journals Online (AJOL)

    Dynamics of Carbon-dioxide production and its economic importance. I A Musa. Abstract. No Abstract. GJPAS Vol. 13 (4) 2007: pp.517-521. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Article Metrics. No metrics found. Metrics powered by PLOS ALM

  13. Dry-cleaning with high-pressure carbon dioxide

    NARCIS (Netherlands)

    Van Roosmalen, M.J.E.

    2003-01-01

    Dry-cleaning is a process for removing soils and stains from fabrics and garments which uses a non-aqueous solvent with detergent added. The currently most used dry-cleaning solvent is perchloroethylene (PER), which is toxic, environmentally harmful and suspected to be carcinogenic. Carbon dioxide

  14. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Chen, Y.H.; Chikindas, M.L.

    2000-01-01

    for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic membrane...

  15. Measurements and interpretation of oxygen isotopes in stratospheric carbon dioxide

    NARCIS (Netherlands)

    Mrozek, D.J.

    2017-01-01

    Carbon dioxide (CO2) is an important natural and anthropogenic greenhouse gas in Earth's atmosphere. Its atmospheric mole fraction has increased from about 280 ppm (parts per million) in the pre-industrial atmosphere to more than 400 ppm at present. Investigation of the stable isotopic composition

  16. Supercritical carbon dioxide cycle control analysis.

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-04-11

    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

  17. Photosynthesis in Rhodospirillum rubrum. II. Photoheterotrophic carbon dioxide fixation.

    Science.gov (United States)

    Anderson, L; Fuller, R C

    1967-04-01

    The contribution of the reductive pentose phosphate cycle to the photometabolism of carbon dioxide and to carbon metabolism in Rhodospirillum rubrum grown photoheterotrophically with l-malate as the carbon source is nil, unlike autotrophically grown R. rubrum. Glycolic acid appears to be the first stable product of CO(2) fixation in R. rubrum cultured photoheterotrophically on l-malate. The results obtained in (14)CO(2) fixation experiments suggest that the photometabolism of CO(2) through glycolate into malate is a major pathway of CO(2) fixation in such cells. However, l-malate was a much more efficient precursor of phosphate esters, and of glutamic acid, than was carbon dioxide; l-malate is therefore, in this case, a far more important source of cell carbon than is carbon dioxide. The products of the light-dependent incorporation of CO(2) and of acetate were investigated in R. rubrum grown photoheterotrophically on acetate. Carboxylation reactions and the reductive pentose phosphate cycle are apparently of greater significance in the photometabolism of acetate heterotrophs than in malate heterotrophs; the photometabolism of the acetate photoheterotrophs seems to be intermediate between the photoheterotrophy of malate heterotrophs and strict autotrophy.

  18. Photosynthesis in Rhodospirillum rubrum. II. Photoheterotrophic Carbon Dioxide Fixation 1

    Science.gov (United States)

    Anderson, Louise; Fuller, R. C.

    1967-01-01

    The contribution of the reductive pentose phosphate cycle to the photometabolism of carbon dioxide and to carbon metabolism in Rhodospirillum rubrum grown photoheterotrophically with l-malate as the carbon source is nil, unlike autotrophically grown R. rubrum. Glycolic acid appears to be the first stable product of CO2 fixation in R. rubrum cultured photoheterotrophically on l-malate. The results obtained in 14CO2 fixation experiments suggest that the photometabolism of CO2 through glycolate into malate is a major pathway of CO2 fixation in such cells. However, l-malate was a much more efficient precursor of phosphate esters, and of glutamic acid, than was carbon dioxide; l-malate is therefore, in this case, a far more important source of cell carbon than is carbon dioxide. The products of the light-dependent incorporation of CO2 and of acetate were investigated in R. rubrum grown photoheterotrophically on acetate. Carboxylation reactions and the reductive pentose phosphate cycle are apparently of greater significance in the photometabolism of acetate heterotrophs than in malate heterotrophs; the photometabolism of the acetate photoheterotrophs seems to be intermediate between the photoheterotrophy of malate heterotrophs and strict autotrophy. PMID:6042358

  19. The impact of carbon dioxide in stored-product insect treatment with ...

    African Journals Online (AJOL)

    In laboratory experiments, toxicity of carbon dioxide and carbon dioxide - phosphine mixture was investigated against 4 species of stored-product insects. In empty-space trials, estimates of the median lethal doses of carbon dioxide against adults of Oryzaephilus surinamensis (L.), Lasioderma serricorne (F.) and eggs of ...

  20. Microporous metal-organic framework with potential for carbon dioxide capture at ambient conditions

    NARCIS (Netherlands)

    Xiang, S.C.; He, Y.; Zhang, Z.; Wu, H.; Zhou, W.; Krishna, R.; Chen, B.

    2012-01-01

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve

  1. Carbon dioxide euthanasia in rats: Oxygen supplementation minimizes signs of agitation and asphyxia

    NARCIS (Netherlands)

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

    1995-01-01

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

  2. 27 CFR 27.42a - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... carbon dioxide. 27.42a Section 27.42a Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... On Imported Distilled Spirits, Wines, and Beer Wines § 27.42a Still wines containing carbon dioxide. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except...

  3. Depleted Oil Reservoirs: A Carbon Dioxide Sequestration Option

    Science.gov (United States)

    Pawar, R. J.; Zhang, D.

    2001-05-01

    Safe, long-term sequestration of carbon dioxide (CO2) is fast becoming a need because of the environmental impact of increased amounts of greenhouse gases in the atmosphere. A number of alternatives are currently being studied to permanently remove CO2 from the atmosphere. These can be divided in three main categories, ocean, terrestrial and geologic disposal. Multiple geologic settings can be used for geologic disposal including depleted oil and gas reservoirs, deep aquifers, coal beds and natural serpentinites/ultramafics caverns, etc. Injection of CO2 in depleted oil and gas reservoirs is one of the options where technology already exists because CO2 is routinely used in enhanced oil recovery operations. Even with the technological advances and the long history of CO2 enhanced oil recovery, a number of unknowns exist. These include coupled physicochemical processes involving CO2, water, oil and reservoir rock, capacity of reservoir for long-term sequestration and long-term fate of injected CO2. In addition, precise and accurate monitoring technologies for determining presence and location of injected CO2 are also lacking. All of these issues need to be addressed before this alternative can be used as a sequestration option. In this paper we used a depleted oil reservoir to study some of the above mentioned issues. We explored the total capacity of the reservoir for long-term sequestration. Attempts were made to take into account various interactions between injected CO2 and reservoir oil, water as well as rock. Thermodynamic interactions between CO2 and reservoir oil and gas were taken into account. Effect of reservoir heterogeneity on the extent of CO2 plume and its migration was studied. Long term fate of injected CO2 and the host reservoir was also studied.

  4. Methane and Carbon Dioxide Emissions from Different Composting Periods

    Directory of Open Access Journals (Sweden)

    Cheng-Hsiung Chang

    2009-01-01

    Full Text Available To investigate green house gas emissions from compost preparations, methane and carbon dioxide concentrations and emission rates at different accumulative times and composting periods were determined. While the accumulative time was less than 10 min with a closed acrylic chamber, meth ane and carbon dioxide emissions in creased slightly but with high fluntuation in the sampling e ror, and these values decreased significantly when the accumulative time was more than 20 min. During the 8 weeks of composting, the methane emission rate reaches its peak near the end of the second week and the carbon dioxide emission rate does the same near the end of third week. Meth ane and carbon dioxide emissions had high val ues at the first stage of com post ing and then de creased grad u ally for the ma tu rity of com post. Carbon dioxide emission (y was significantly related to temperature (x1, moisture content (x2, and total or ganiccarbon (x3; and there gression equation is: y = 3.11907x1 + 6.19236x2 - 6.63081x3 - 50.62498. The re gres sion equa tion be tween meth ane emis sion (y? and mois ture con tent (x2, pH (x4, C/N ra tio (x5, and ash con tent (x6 is: y?= 0.13225x2 - 0.97046x4 - 1.10599x5 - 0.55220x6 + 50.77057 in the ini tial com post ing stage (weeks 1 to 3; while, the equa tion is: y?= 0.02824x2 - 0.0037x4 - 0.1499x5 - 0.07013x6 + 4.13589 in the later compost ing stage (weeks 4 to 8. Dif ferent stage composts have significant variation of properties and greenhouse gas emissions. Moreover, the emissions may be reduced by manipulating the proper factors.

  5. Synthesis of Chiral Cyclic Carbonates via Kinetic Resolution of Racemic Epoxides and Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Xiao Wu

    2016-01-01

    Full Text Available The catalytic synthesis of cyclic carbonates using carbon dioxide as a C1-building block is a highly active area of research. Here, we review the catalytic production of enantiomerically enriched cyclic carbonates via kinetic resolution of racemic epoxides catalysed by metal-containing catalyst systems.

  6. Kinetics of absorption of carbon dioxide in aqueous MDEA solutions with carbonic anhydrase at 298 K

    NARCIS (Netherlands)

    Penders-van Elk, Nathalie J. M. C.; Derks, Peter W. J.; Fradette, Sylvie; Versteeg, Geert F.

    In present work the absorption of carbon dioxide in aqueous N-methyldiethanolamine (MDEA) solutions with and without the enzyme carbonic anhydrase has been studied in a stirred cell at 298 K, with MDEA concentrations ranging from 0.5 to 4 kmol m(-3) and carbonic anhydrase concentrations ranging from

  7. Mineralization of Carbon Dioxide: Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, V; Soong, Y; Carney, C; Rush, G; Nielsen, B; O' Connor, W

    2015-01-01

    CCS research has been focused on CO2 storage in geologic formations, with many potential risks. An alternative to conventional geologic storage is carbon mineralization, where CO2 is reacted with metal cations to form carbonate minerals. Mineralization methods can be broadly divided into two categories: in situ and ex situ. In situ mineralization, or mineral trapping, is a component of underground geologic sequestration, in which a portion of the injected CO2 reacts with alkaline rock present in the target formation to form solid carbonate species. In ex situ mineralization, the carbonation reaction occurs above ground, within a separate reactor or industrial process. This literature review is meant to provide an update on the current status of research on CO2 mineralization. 2

  8. Carbon dioxide: A new material for energy storage

    Directory of Open Access Journals (Sweden)

    Jacques Amouroux

    2014-08-01

    Full Text Available Though carbon dioxide is the main green house gas due to burning of fossil resource or miscellaneous chemical processes, we propose here that carbon dioxide be a new material for energy storage. Since it can be the key to find the solution for three critical issues facing the world: food ecosystems, the greenhouse issue and energy storage. We propose to identify the carbon recovery through a circular industrial revolution in the first part, and in the second part we present the starting way of three business plants to do that from industrial examples. By pointing out all the economic constraints and the hidden competitions between energy, water and food, we try to qualify the phrase “sustainable development” and open the way of a huge circular economy.

  9. Carbon Dioxide Sealing Capacity: Textural or Compositional Controls?

    Energy Technology Data Exchange (ETDEWEB)

    Cranganu, Constantin; Soleymani, Hamidreza; Sadiqua, Soleymani; Watson, Kieva

    2013-11-30

    This research project is aiming to assess the carbon dioxide sealing capacity of most common seal-rocks, such as shales and non-fractured limestones, by analyzing the role of textural and compositional parameters of those rocks. We hypothesize that sealing capacity is controlled by textural and/or compositional pa-rameters of caprocks. In this research, we seek to evaluate the importance of textural and compositional parameters affecting the sealing capacity of caprocks. The conceptu-al framework involves two testable end-member hypotheses concerning the sealing ca-pacity of carbon dioxide reservoir caprocks. Better understanding of the elements controlling sealing quality will advance our knowledge regarding the sealing capacity of shales and carbonates. Due to relatively low permeability, shale and non-fractured carbonate units are considered relatively imper-meable formations which can retard reservoir fluid flow by forming high capillary pres-sure. Similarly, these unites can constitute reliable seals for carbon dioxide capture and sequestration purposes. This project is a part of the comprehensive project with the final aim of studying the caprock sealing properties and the relationship between microscopic and macroscopic characteristics of seal rocks in depleted gas fields of Oklahoma Pan-handle. Through this study we examined various seal rock characteristics to infer about their respective effects on sealing capacity in special case of replacing reservoir fluid with super critical carbon dioxide (scCO{sub 2}). To assess the effect of textural and compositional properties on scCO{sub 2} maximum reten-tion column height we collected 30 representative core samples in caprock formations in three counties (Cimarron, Texas, Beaver) in Oklahoma Panhandle. Core samples were collected from various seal formations (e.g., Cherokee, Keys, Morrowan) at different depths. We studied the compositional and textural properties of the core samples using several techniques

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

    Science.gov (United States)

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

    1981-01-01

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

  11. CARBON DIOXIDE MITIGATION THROUGH CONTROLLED PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2000-10-01

    This research was undertaken to meet the need for a robust portfolio of carbon management options to ensure continued use of coal in electrical power generation. In response to this need, the Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO{sub 2} from fossil-fired power plants by growing organisms capable of converting CO{sub 2} to complex sugars through the process of photosynthesis. Once harvested, the organisms could be used in the production of fertilizer, as a biomass fuel, or fermented to produce alcohols. In this work, a mesophilic organism, Nostoc 86-3, was examined with respect to the use of thermophilic algae to recycle CO{sub 2} from scrubbed stack gases. The organisms were grown on stationary surfaces to facilitate algal stability and promote light distribution. The testing done throughout the year examined properties of CO{sub 2} concentration, temperature, light intensity, and light duration on process viability and the growth of the Nostoc. The results indicate that the Nostoc species is suitable only in a temperature range below 125 F, which may be practical given flue gas cooling. Further, results indicate that high lighting levels are not suitable for this organism, as bleaching occurs and growth rates are inhibited. Similarly, the organisms do not respond well to extended lighting durations, requiring a significant (greater than eight hour) dark cycle on a consistent basis. Other results indicate a relative insensitivity to CO{sub 2} levels between 7-12% and CO levels as high as 800 ppm. Other significant results alluded to previously, relate to the development of the overall process. Two processes developed during the year offer tremendous potential to enhance process viability. First, integration of solar collection and distribution technology from Oak Ridge laboratories could provide a significant space savings and enhanced use of solar energy. Second, the use of translating slug flow

  12. Atmospheric carbon dioxide levels over phanerozoic time.

    Science.gov (United States)

    Berner, R A

    1990-09-21

    A new model has been constructed for calculating the level of atmospheric CO(2) during the past 570 million years. A series of successive steady states for CO(2) is used in order to calculate CO(2) level from a feedback function for the weathering of silicate minerals. Processes considered are: sedimentary burial of organic matter and carbonates; continental weathering of silicates, carbonates, and organic matter; and volcanic and metamorphic degassing of CO(2). Sediment burial rates are calculated with the use of an isotope mass-balance model and carbon isotopic data on ancient seawater. Weathering rates are calculated from estimates of past changes in continental land area, mean elevation, and river runoff combined with estimates of the effects of the evolution of vascular land plants. Past degassing rates are estimated from changes in the rate of generation of sea floor and the shift of carbonate deposition from platforms to the deep sea. The model results indicate that CO(2) levels were high during the Mesozoic and early Paleozoic and low during the Permo-Carboniferous and late Cenozoic. These results correspond to independently deduced Phanerozoic paleoclimates and support the notion that the atmospheric CO(2) greenhouse mechanism is a major control on climate over very long time scales.

  13. Weathering approaches to carbon dioxide sequestration

    NARCIS (Netherlands)

    Schuiling, R.D.

    2012-01-01

    The aim of enhanced weathering is to capture CO2 by the carbonation of silicates, or by dissolution of these silicates during which the greenhouse gas CO2 is converted to bicarbonate in solution. Research in this field is still focused on increasing the rate of reaction, but the required

  14. Carbon dioxide adsorption in graphene sheets

    Science.gov (United States)

    Mishra, Ashish Kumar; Ramaprabhu, Sundara

    2011-09-01

    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 unique surface morphology. In the present work, we have demonstrated the CO2 adsorption capacity of graphene, prepared via hydrogen induced exfoliation of graphitic oxide at moderate temperatures. The CO2 adsorption study was performed using high pressure Sieverts apparatus and capacity was calculated by gas equation using van der Waals corrections. Physical adsorption of CO2 molecules in graphene was confirmed by FTIR study. Synthesis of graphene sheets via hydrogen exfoliation is possible at large scale and lower cost and higher adsorption capacity of as prepared graphene compared to other carbon nanostructures suggests its possible use as CO2 adsorbent for industrial application. Maximum adsorption capacity of 21.6 mmole/g was observed at 11 bar pressure and room temperature (25 °C).

  15. Carbon dioxide adsorption in graphene sheets

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Mishra

    2011-09-01

    Full Text Available 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 unique surface morphology. In the present work, we have demonstrated the CO2 adsorption capacity of graphene, prepared via hydrogen induced exfoliation of graphitic oxide at moderate temperatures. The CO2 adsorption study was performed using high pressure Sieverts apparatus and capacity was calculated by gas equation using van der Waals corrections. Physical adsorption of CO2 molecules in graphene was confirmed by FTIR study. Synthesis of graphene sheets via hydrogen exfoliation is possible at large scale and lower cost and higher adsorption capacity of as prepared graphene compared to other carbon nanostructures suggests its possible use as CO2 adsorbent for industrial application. Maximum adsorption capacity of 21.6 mmole/g was observed at 11 bar pressure and room temperature (25 ºC.

  16. Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Mogensen, Mogens Bjerg

    2009-01-01

    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 and 0.44 mV h−1 when operated in mixtures of CO2/CO = 70/30 or CO2/CO = 98/02 (industrial grade) at 850 °C and current densities between −0.25 and −0.50 A cm−2. The passivation rate was independent...... in the gas stream, most likely sulphur, adsorbing on some specific nickel sites in the cathode of the SOEC. Activation can be carried out by hydrogen reacting with adsorbed sulphur to form the volatile compound H2S. Because adsorption of sulphur is site specific, only a part of the nickel sites were...

  17. Supply of carbon dioxide for enhanced oil recovery. Final report, October 15, 1976--September 1, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Rump, W.M.; Hare, M.; Porter, R.E.

    1977-09-01

    Results are presented from a study of the carbon dioxide supply situation for miscible flooding operations to enhance oil recovery. Candidate oil reservoirs were identified, and the carbon dioxide requirements and the potential recoverable oil for some of these were estimated. A survey of carbon dioxide sources has been conducted within the geographic areas where candidate oil reservoirs exist. Sources considered were both high and low quality gases from combustion vents, chemical process stacks, and naturally occurring gas deposits. The survey shows more than enough carbon dioxide is available from above-ground sources alone to meet expected demands. Systems to purify and deliver the carbon dioxide were designed and the costs of the delivered carbon dioxide estimated. Lowest cost is carbon dioxide from natural source with credit for by-product methane. A more comprehensive survey of above-ground and natural sources is recommended.

  18. Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO{sub 2}) in a polar environment

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Brant M.; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawai' i at Manoa, Honolulu, HI 96822 (United States); Strazzulla, Giovanni, E-mail: brantmj@hawaii.edu [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy)

    2014-06-20

    Carbon dioxide (CO{sub 2}) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν{sub 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 CO{sub 2} 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 (H{sub 2}O)-carbon dioxide (CO{sub 2}) (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 ν{sub 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.

  19. The Economics of Carbon Dioxide Removal: The Case against Free Disposal

    Science.gov (United States)

    Keller, D. P.; Rickels, W.; Quaas, M.; Oschlies, A.; Reith, F.

    2016-12-01

    Facing the challenge to keep the average global temperature increase below 2°C and to limit long-term climate change, removing carbon dioxide from the atmosphere (Carbon Dioxide Removal, CDR) and disposing of it in non-atmospheric carbon reservoirs is becoming increasingly necessary. The social cost of removing carbon into the terrestrial biosphere (e.g. by afforestation) or the ocean (e.g. by spreading olivine in coastal areas) arises from carbon-cycle feedbacks and saturation effects. Yet they are ignored in existing economic studies on CDR. Neglecting non-atmospheric social cost results in inconsistent estimates with regard to the share and timing of CDR measures in climate policy. Here, we use an intermediate-complexity earth system model, the University of Victoria (UVic) model, to calibrate a dynamic economic model, capturing the temperature feedback and saturation effect of terrestrial carbon uptake and the saturation effect of oceanic carbon uptake to obtain an improved understanding of the net social carbon value of terrestrial and oceanic CDR. We show that planning horizons beyond the year 2100 are required to properly reflect long-term scarcity issues of non-atmospheric carbon reservoirs in current carbon prices and that neglecting non-atmospheric social cost results in too low abatement efforts and in turn in too large and earlier application of CDR measures than if applied optimally. The figure shows the carbon prices for the different carbon reservoirs in the year 2100 in dependence of the planning horizon (for a climate policy aiming to limit global mean temperature increase to 2°C). The difference between the atmospheric and the non-atmospheric carbon prices indicates the benefits of the different CDR options.

  20. Effects of tropospheric ozone on methane and carbon dioxide fluxes from peatland mesocosms

    Science.gov (United States)

    Toet, Sylvia; Oliver, Vikki; Helgason, Thorunn; Peacock, Simon; Barnes, Jeremy; Ineson, Phil; Ashmore, Mike

    2010-05-01

    Tropospheric ozone is currently the third most important greenhouse gas, and also the most important gaseous air pollutant globally in terms of effects on vegetation world-wide. At present levels it poses a significant threat to crop yield and forest productivity of sensitive species, while background ozone concentrations are expected to increase further during the next decades. The potential importance of ozone in reducing carbon assimilation, and consequently in increasing atmospheric carbon dioxide concentrations, has been recognised. However, regional modelling studies are based on the impact of ozone on photosynthetic rates and above-ground growth, and do not consider effects of ozone on belowground carbon fluxes. The limited experimental data on the long-term effects of ozone on belowground carbon processes, mainly from arable crop and forest systems, are a major constraint to understanding the impacts of ozone on global carbon fluxes. Very little attention has been paid to ozone effects on peatland carbon dynamics, though northern peatlands store a third of the global soil organic carbon pool and are an important source of atmospheric methane. The aims of this study were to assess the long-term effects of elevated ozone on carbon dioxide and methane fluxes in temperate peatland mesocosms and to identify underlying plant, soil and microbial processes. Mesocosms from a wet heath (Isle of Skye, UK) with vegetation dominated by the peat moss Sphagnum papillosum and the sedge Schoenus nigricans have been exposed to ambient (control) and three elevated levels of ozone in open-top chambers from May 2008. Methane emission, carbon dioxide fluxes and relevant plant and soil variables were measured every 6 weeks (growing season) or 8 weeks (winter). Methane emissions were significantly reduced by elevated ozone over the first 18 months of the experiment. Ecosystem respiration only showed a significant increase in response to ozone in the second growing season, while

  1. Warming reduces carbon losses from grassland exposed to elevated atmospheric carbon dioxide.

    Directory of Open Access Journals (Sweden)

    Elise Pendall

    Full Text Available The flux of carbon dioxide (CO2 between terrestrial ecosystems and the atmosphere may ameliorate or exacerbate climate change, depending on the relative responses of ecosystem photosynthesis and respiration to warming temperatures, rising atmospheric CO2, and altered precipitation. The combined effect of these global change factors is especially uncertain because of their potential for interactions and indirectly mediated conditions such as soil moisture. Here, we present observations of CO2 fluxes from a multi-factor experiment in semi-arid grassland that suggests a potentially strong climate - carbon cycle feedback under combined elevated [CO2] and warming. Elevated [CO2] alone, and in combination with warming, enhanced ecosystem respiration to a greater extent than photosynthesis, resulting in net C loss over four years. The effect of warming was to reduce respiration especially during years of below-average precipitation, by partially offsetting the effect of elevated [CO2] on soil moisture and C cycling. Carbon losses were explained partly by stimulated decomposition of soil organic matter with elevated [CO2]. The climate - carbon cycle feedback observed in this semiarid grassland was mediated by soil water content, which was reduced by warming and increased by elevated [CO2]. Ecosystem models should incorporate direct and indirect effects of climate change on soil water content in order to accurately predict terrestrial feedbacks and long-term storage of C in soil.

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

    Science.gov (United States)

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

    2009-10-01

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

  3. Measuring the human contribution to atmospheric carbon dioxide

    Science.gov (United States)

    Schultz, Colin

    2012-05-01

    Although it is well established that humans are responsible for the modern increase in atmospheric carbon dioxide concentrations, the precise emission rates of carbon dioxide and other environmentally important gases are less well known. Traditionally, the reported usages of coal, oil, and other commodities are used to estimate emission rates. Though this economics-based approach is thought to work well at global and national scales, uncertainties increase for smaller regional scales or time scales shorter than a year. Drawing on 6 years of gas concentration measurements taken every 2 weeks from an airplane at two sites over the northeastern United States, Miller et al. developed a system to measure the anthropogenic contribution to atmospheric gas concentrations that is independent of accounting-based approaches.

  4. Carbon Dioxide Snow Storms During the Polar Night on Mars

    Science.gov (United States)

    Toon, Owen B.; Colaprete, Anthony

    2001-01-01

    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.

  5. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    Science.gov (United States)

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

    2014-09-16

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

  6. Hydrogen Storage in the Carbon Dioxide - Formic Acid Cycle.

    Science.gov (United States)

    Fink, Cornel; Montandon-Clerc, Mickael; Laurenczy, Gabor

    2015-01-01

    This year Mankind will release about 39 Gt carbon dioxide into the earth's atmosphere, where it acts as a greenhouse gas. The chemical transformation of carbon dioxide into useful products becomes increasingly important, as the CO(2) concentration in the atmosphere has reached 400 ppm. One approach to contribute to the decrease of this hazardous emission is to recycle CO(2), for example reducing it to formic acid. The hydrogenation of CO(2) can be achieved with a series of catalysts under basic and acidic conditions, in wide variety of solvents. To realize a hydrogen-based charge-discharge device ('hydrogen battery'), one also needs efficient catalysts for the reverse reaction, the dehydrogenation of formic acid. Despite of the fact that the overwhelming majority of these reactions are carried out using precious metals-based catalysts (mainly Ru), we review here developments for catalytic hydrogen evolution from formic acid with iron-based complexes.

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

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for the synthesis of all components of cell

  8. Using LMDI approach to analyze changes in carbon dioxide emissions of China’s logistics industry

    Directory of Open Access Journals (Sweden)

    Ying Dai

    2015-05-01

    Full Text Available Purpose: China is confronting with tremendous pressure in carbon emission reduction. While logistics industry seriously relies on fossil fuel, and emits greenhouse gas, especially carbon dioxide. The aim of this article is to estimate the carbon dioxide emission in China’s logistics sector, and analyze the causes for the change of carbon dioxide emission, and identify the critical factors which mainly drive the change in carbon dioxide emissions of China’s logistics industry. Design/methodology/approach: The logarithmic mean Divisia index (LMDI method has often been used to analyze decomposition of energy consumption and carbon emission due to its theoretical foundation, adaptability, ease of use and result interpretation. So we use the LMDI method to analyze the changes in carbon dioxide emission in China’s logistics industry in this paper. Findings: By analyzing carbon dioxide emission of China’s logistics, the results show that the carbon dioxide emission of logistics in China has increased by 21.5 times, from 45.1 million tons to 1014.1 million tons in the research period. The highway transport is the main contributor to carbon dioxide emission in logistics industry. The energy intensity and carbon dioxide emission factors were contributing to the reduction of carbon dioxide emission in China’s logistics industry in overall study period. Originality/value: Although there are a lot of literature analyzed carbon dioxide emission in many industry sectors, for example manufacturing, iron and steel , pulp and paper, cement, glass industry, and so on. However, few scholars researched on carbon dioxide emission in logistics industry. This the first study is in the context of carbon dioxide emission of China’s logistics industry.

  9. Carbon dioxide emission from brickfields around Bangladesh

    Directory of Open Access Journals (Sweden)

    M.A. Imran

    2014-12-01

    Full Text Available The study was undertaken at six divisions of Bangladesh to investigate the CO2 emission from brickfields. to explore the rate of carbon emission over the last 10 years, based on existing technology for brick production. The finding reveals that there were more than 45,000 Brick kilns in Bangladesh which together account for about 95% of operating kilns including Bull's Trench Kiln, Fixed Chimney Kiln, Zigzag Kiln and Hoffman Kiln. These kilns were the most carbon emitting source but it varies on fuel type, kiln type and also for location. It has been found that, maximum carbon emission area was Chittagong, which was 93.150 with percentage of last 10 years and 9.310 per cent per year. Whereas Sylhet was lower carbon emission area indicating percentage 17.172 of last 10 years and 4.218 percent per year. It has been found that total annual amount of CO2 emission for 4 types brick kilns from Dhaka, Chittagong, Rajshahi, Khulana, Sylhet and Barisal were 8.862 Mt yr-1, 10.048 Mt yr-1, 12.783 Mt yr-1, 15.250 Mt yr-1, in the year of 2002, 2005, 2007 and 2010 respectively. In Mymensingh district, the maximum CO2 emission and coal consumption was obtained in Chamak brick field, which was 1882 tons and 950 tons, respectively and minimum was obtained in Zhalak brick field, which was 1039.5 tons and 525.0 tons, respectively during the year of 2013. The percentage in last 10 years of CO2 emission was 72.784 and per cent per year 7.970, which is very alarming for us. The estimates obtained from surveys and on-site investigations indicate that these kilns consume an average of 240 tons of coal to produce 1 million bricks. This type of coal has a measured calorific value of 6,400 KJ, heating value of coal is 20.93 GJ t-1 and it produces 94.61 TJ t-1 and 56.1 TJ t-1 CO2 from coal and natural gas, respectively.

  10. Optimization of carbon dioxide fixation and starch accumulation by ...

    African Journals Online (AJOL)

    The effects of the initial biomass concentration (0.13, 0.8, 1.8, 2.8 and 3.47 g L-1), the gas flow rate (0.03, 0.1, 0.2, 0.3 and 0.37 V V-1 m-1) and different carbon dioxide concentrations (1.63, 5, 10, 15 and 18.37%) were considered using a central composite design. By using response surface methodology and the desirability ...

  11. Spontaneous oxygen isotope exchange between carbon dioxide and\

    Czech Academy of Sciences Publication Activity Database

    Knížek, Antonín; Zukalová, Markéta; Kavan, Ladislav; Zukal, Arnošt; Kubelík, Petr; Rojík, P.; Skřehot, P.; Ferus, Martin; Civiš, Svatopluk

    2017-01-01

    Roč. 137, MAR 2017 (2017), s. 6-10 ISSN 0169-1317 R&D Projects: GA MŠk LD14115; GA ČR(CZ) GA14-12010S; GA ČR GA13-07724S; GA MŠk(CZ) LM2015073 Institutional support: RVO:61388955 Keywords : clay * carbon dioxide * FTIR spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.101, year: 2016

  12. Effect Of Geothermal Heat Pump On Carbon Dioxide Emissions

    Directory of Open Access Journals (Sweden)

    Ahmed F. Atwan

    2015-08-01

    Full Text Available In this research the calculations of carbon dioxide emissions CO2 in summer May to September 150 day and winter seasons December to February 90 day were performed by using the coefficient of performance for each air and ground source heat pump. The place of study case take relative to solar path in to account and the study case was three halls men women and surgery halls in Al-Musayyib hospital in Babylon.

  13. Efficiency of Carbon Dioxide Fractional Laser in Skin Resurfacing

    Directory of Open Access Journals (Sweden)

    Andrej Petrov

    2016-05-01

    CONCLUSION: Multifunctional fractional carbon dioxide laser used in treatment of patients with acne and pigmentation from acne, as well as in the treatment of scars from different backgrounds, is an effective and safe method that causes statistically significant better effect of the treatment, greater patients’ satisfaction, minimal side effects and statistically better response to the therapy, according to assessments by the patient and the therapist.

  14. Temperature measurements via narrow line laser absorption of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, M.S. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

    1996-12-31

    Theoretical development for temperature measurements via narrow line, infrared absorption of carbon dioxide (CO{sub 2}) is presented. The proposed technique is based on rapid-scanning of two adjacent absorption line shapes. Spectroscopic considerations for sensitivity to temperature measurements are discussed. Several line pairs are evaluated, and the R(58) and R(60) transitions of the (00{sup 0}1){l_arrow}(00{sup 0}0) band are suggested for use in high temperature measurements for combustion systems.

  15. Fractional Carbon Dioxide Laser in Treatment of Acne Scars

    OpenAIRE

    Petrov, Andrej

    2016-01-01

    BACKGROUND: Scars appear as a result of skin damage during the process of the skin healing. There are two types of acne scars, depending on whether there is a loss or accumulation of collagen: atrophic and hypertrophic. In 80-90% it comes to scars with loss of collagen compared to smaller number of hypertrophic scars and keloids. AIM: The aim of the study was to determine efficiency and safety of fractional carbon dioxide laser in the treatment of acne scars. MATERIAL AN...

  16. Titanium dioxide, single-walled carbon nanotube composites

    Science.gov (United States)

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

    2015-07-14

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

  17. Extraction of olive oil with supercritical carbon dioxide / Ilana Geerdts

    OpenAIRE

    Geerdts, Ilana

    2005-01-01

    The principal objective of this study was to extract olive oil from the fruit of Olea europaea by means of supercritical carbon dioxide (sc-C02) as an alternative to traditional methods. Extractions were performed on a laboratory scale supercritical fluid extractor of the latest design, featuring three mutually independent flow systems and extremely high flow rates. A number of extraction runs based on a statistical design was performed to establish the conditions (time, pressu...

  18. The effect of carbon dioxide therapy on composite graft survival

    OpenAIRE

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino Júnior, Ruy de Souza; Sousa,João Batista de

    2013-01-01

    PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, h...

  19. Study on carbon dioxide conversion by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hyun; Park, Geun Il; Cho, Il Hoon; Choi, Sang Do; Hong, Kwang Hee; Lee, Chang Woo

    1999-09-01

    This study was carried out to investigate the synergistic effects on the CO{sub 2} conversion by the application of semiconductor in the field of gamma-ray. Gamma-ray irradiation was performed to examine the effects of semiconductor application on CO{sub 2} conversion in water and the formation of organic material from carbonate solution. From experimental results it is clear that the supplication of semiconductor in the field of gamma-ray increases the efficiency for CO{sub 2} conversion to organic matter. Based on the obtained experimental results it is obvious that the synergistic effects of semiconductor materials in the gamma-ray field leads to increase of the CO{sub 2} conversion yield to organic matter up to 50 percent compared to the gamma-ray irradiation. The way of achieving higher activity is due to thecatalytic action of semiconductor by gamma-ray irradiation. Zr-doped TiO{sub 2} catalyst prepared by sol-gel method exhibits the higher efficiency for CO{sub 2} conversion in aqueous solution and carbonate containing solution. This effect of Zr-doping can be explained by the formation of additional defects in surface of TiO{sub 2} film. (author)

  20. Irreversible climate change due to carbon dioxide emissions.

    Science.gov (United States)

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

    2009-02-10

    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.

  1. [Thoracoscopic thymectomy with carbon dioxide insufflation in the mediastinum].

    Science.gov (United States)

    Ferrero-Coloma, C; Navarro-Martinez, J; Bolufer, S; Rivera-Cogollos, M J; Alonso-García, F J; Tarí-Bas, M I

    2015-02-01

    The case is presented of a 71 year-old male, diagnosed with a thymoma. A thoracoscopic thymectomy was performed using the carbon dioxide insufflation technique in the mediastinum. During the procedure, while performing one-lung ventilation, the patient's respiration worsened. The contralateral lung had collapsed, as carbon dioxide was travelling from the mediastinum to the thorax through the opened pleura. Two-lung ventilation was decided upon, which clearly improved oxygenation in the arterial gases and airway pressures. Both pH and pCO2 stabilized. The surgical approach and the carbon dioxide technique were continued because 2-lung ventilation did not affect the surgical procedure. This technique has many serious complications and it should always be performed using 2-lung ventilation. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo

    2010-03-15

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  3. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  4. Fluid phase equilibria during propylene carbonate synthesis from propylene oxide in carbon dioxide medium

    DEFF Research Database (Denmark)

    Gharnati, Loubna; Musko, Nikolai; Jensen, Anker Degn

    2013-01-01

    In the present study the influence of the amount of carbon dioxide on the catalytic performance during the propylene carbonate synthesis from propylene oxide and CO2 was investigated. The reaction was performed in high-pressure batch autoclaves using immobilized 1-hydroxyethyl-9-propyl...

  5. Carbon dioxide emissions of Antarctic tourism

    NARCIS (Netherlands)

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

    2011-01-01

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

  6. The lifetime of excess atmospheric carbon dioxide

    Science.gov (United States)

    Moore, Berrien; Braswell, B. H.

    1994-03-01

    We explore the effects of a changing terrestrial biosphere on the atmospheric residence time of CO2 using three simple ocean carbon cycle models and a model of global terrestrial carbon cycling. We find differences in model behavior associated with the assumption of an active terrestrial biosphere (forest regrowth) and significant differences if we assume a donor-dependent flux from the atmosphere to the terrestrial component (e.g., a hypothetical terrestrial fertilization flux). To avoid numerical difficulties associated with treating the atmospheric CO2 decay (relaxation) curve as being well approximated by a weighted sum of exponential functions, we define the single half-life as the time it takes for a model atmosphere to relax from its present-day value half way to its equilibrium pCO2 value. This scenario-based approach also avoids the use of unit pulse (Dirac Delta) functions which can prove troublesome or unrealistic in the context of a terrestrial fertilization assumption. We also discuss some of the numerical problems associated with a conventional lifetime calculation which is based on an exponential model. We connect our analysis of the residence time of CO2 and the concept of single half-life to the residence time calculations which are based on using weighted sums of exponentials. We note that the single half-life concept focuses upon the early decline of CO2 under a cutoff/decay scenario. If one assumes a terrestrial biosphere with a fertilization flux, then our best estimate is that the single half-life for excess CO2 lies within the range of 19 to 49 years, with a reasonable average being 31 years. If we assume only regrowth, then the average value for the single half-life for excess CO2 increases to 72 years, and if we remove the terrestrial component completely, then it increases further to 92 years.

  7. Electrocatalytic reduction of carbon dioxide under plasma DBD process

    Science.gov (United States)

    Amouroux, Jacques; Cavadias, Simeon

    2017-11-01

    Carbon dioxide can be converted, by reaction with hydrogen, into fine chemicals and liquid fuels such as methanol and DME. Methane production by the Sabatier reaction opens the way of carbon recycling for a circular economy of carbon resources. The catalytic process of methanation of carbon dioxide produces two molecules of water as a by-product. A current limitation in the CO2 methanation is the ageing of catalysts, mainly due to water adsorption during the process. To avoid this adsorption, the process is operated at high temperature (300 °C–400 °C), leading to carbon deposition on the catalyst and its deactivation. To overcome this problem, a methanation plasma-catalytic process has been developed, which achieves high CO2 conversion rate (80%), and a selectivity close to 100%, working from room temperature to 150 °C, instead of 300 °C–400 °C for the thermal catalytic process. The main characteristics of this process are high-voltage pulses of few nanoseconds duration, activating the adsorption of CO2 in bent configuration and the polarization of the catalyst. The key step in this process is the desorption of water from the polarized catalyst. The high CO2 conversion at low temperature could be explained by the creation of a plasma inside the nanopores of the catalyst.

  8. Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production

    Science.gov (United States)

    Liebermeister, C.

    1978-01-01

    Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

  9. End-tidal carbon dioxide (ETCO2) can replace methods for measuring partial pressure of carbon dioxide (PCO2) in pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2017-01-01

    We compared end-tidal carbon dioxide (ETCO2) with partial pressure of carbon dioxide (PCO2) in domestic pigs anesthetized for neuroscience. There was good agreement between ETCO2 and PCO2 under both hypocapnia, normocapnia, and hypercapnia conditions. ETCO2 saves time by continually providing...

  10. Kinetic of formation for single carbon dioxide and mixed carbon dioxide and tetrahydrofuran hydrates in water and sodium chloride aqueous solution

    NARCIS (Netherlands)

    Sabil, K.M.; Duarte, A.R.C.; Zevenbergen, J.F.; Ahmad, M.M.; Yusup, S.; Omar, A.A.; Peters, C.J.

    2010-01-01

    A laboratory-scale reactor system is built and operated to measure the kinetic of formation for single and mixed carbon dioxide-tetrahydrofuran hydrates. The T-cycle method, which is used to collect the kinetic data, is briefly discussed. For single carbon dioxide hydrate, the induction time

  11. Carbon Dioxide Fixation by Lupin Root Nodules

    Science.gov (United States)

    Laing, William A.; Christeller, John T.; Sutton, William D.

    1979-01-01

    Labeling studies using detached lupin (Lupinus angustifolius) nodules showed that over times of less than 3 minutes, label from [3,4-14C]glucose was incorporated into amino acids, predominantly aspartic acid, to a much greater extent than into organic acids. Only a slight preferential incorporation was observed with [1-14C]- and [6-14C]glucose, while with [U-14C]-glucose more label was incorporated into organic acids than into amino acids at all labeling times. These results are consistent with a scheme whereby the “carbon skeletons” for amino acid synthesis are provided by the phosphoenolpyruvate carboxylase reaction. A comparison of 14CO2 release from nodules supplied with [1-14C]- and [6-14C]glucose indicated that the oxidative pentose phosphate pathway accounted for less than 6% of glucose metabolism. Several enzymes of the oxidative pentose phosphate and glycolytic pathways were assayed in vitro using the 12,000g supernatant fraction from nodule homogenates. In all cases, the specific activities were adequate to account for the calculated in vivo fluxes. Three out of four diverse treatments that inhibited nodule nitrogen fixation also inhibited nodule CO2 fixation, and in the case of the fourth treatment, replacement of N2 with He, it was shown that the normal entry of label from exogenous 14CO2 into the nodule amino acid pool was strongly inhibited. PMID:16660746

  12. Carbon dioxide free production of hydrogen

    Science.gov (United States)

    Stoppel, L.; Fehling, T.; Geißler, T.; Baake, E.; Wetzel, T.

    2017-07-01

    The present report summarizes the theoretical modelling and experimental investigation results of the study on the direct thermal methane cracking. This work is a part of the LIMTECH-Project (Liquid Metal Technologies) funded of Helmholtz Alliance and was carried out from 2012 to 2017. The Project-part B5 “CO2-free production of hydrogen” focused on experimental testing and particularly on modelling the novel methane cracking method based on liquid metal technology. The new method uses a bubble column reactor, filled with liquid metal, where both the chemical reaction of methane decomposition and the separation of gas fraction from solid carbon occur. Such reactor system was designed and built in the liquid metal laboratory (KALLA) at KIT. The influences of liquid metal temperature distribution in reactor and feed gas flow rate on methane conversion ratio were investigated experimentally at the temperature range from 930°C to 1175 °C and methane flow rate at the reactor inlet from 50 to 200 mLn/min. In parallel with experimental investigations, a thermochemical model, giving insight in the influence of the above mentioned parameters has been developed at KIT and a CFD model was developed at LUH to get an overview about the bubble dynamics in the reaction system. The influence of different bubble sizes and shapes, multi-inlet coalescence effects as well as the potential of electromagnetic stirring have been investigated.

  13. Growth enhancement by soil derived carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Grodzinski, B.; Wallis, M.; O' Sullivan, J. (Univ. of Guelph, Ontario (Canada))

    1989-04-01

    The objective of this study was to investigate the role which naturally evolved CO{sub 2} from the soil can play in the early growth and establishment of vegetable transplants in the field. Two planting dates were utilized to examine the effects of the time of tunnel placement on development of a crop of bell peppers, Capsicum annuum L. Ambient CO{sub 2} levels were 340 {plus minus} 4 ppm. In the first 3 weeks of spring (May) CO levels 2 to 3 cm above the soil surface were 420 to 480 ppm. Inside plastic tunnels the upward flux of CO{sub 2} evolved from the soil was restricted effectively raising the tunnel atmosphere to over 3000 ppm even at midday. Data from parallel field and controlled environment chamber experiments support the view that 25-40% of the increase in seedling growth in the field tunnels in the spring was due to enhanced photosynthesis and carbon partitioning into both sugars and starch not merely the elevated temperatures associated with protected structures.

  14. Social acceptance of carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

    Huijts, Nicole M.A.; Midden, Cees J.H.; Meijnders, Anneloes L. [Department of Technology Management, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2007-05-15

    This article discusses public acceptance of carbon capture and storage (CCS). Responses by citizens are described in relation to responses by professionally involved actors. Interviews with members of the government, industry and environmental NGOs showed that these professional actors are interested in starting up storage projects, based on thorough evaluation processes, including discussions on multi-actor working groups. As appeared from a survey among citizens living near a potential storage site (N=103), public attitudes in general were slightly positive, but attitudes towards storage nearby were slightly negative. The general public appeared to have little knowledge about CO{sub 2}-storage, and have little desire for more information. Under these circumstances, trust in the professional actors is particularly important. NGOs were found to be trusted most, and industry least by the general public. Trust in each of the three actors appeared to depend on perceived competence and intentions, which in turn were found to be related to perceived similarity of goals and thinking between trustee and trustor. Implications for communication about CCS are discussed. (author)

  15. A molecular-based approach to the thermodynamics of aqueous solutions: binary mixture of water and carbon dioxide

    Science.gov (United States)

    Jirsák, J.; Škvor, J.

    2015-05-01

    A simple model and theory of molecular fluids is applied to a binary mixture of water and carbon dioxide. An approach based on the perturbation theory is followed using a reference system of so-called pseudo-hard bodies for water and hard triatomics for carbon dioxide. Pseudo-hard bodies bear the traits of the non-additive nature of association supplementing the common excluded volume effect. The reference term is parametrized using Monte Carlo simulation data on the compressibility factor. After adding a simple mean-field term to the reference equation, fluid phase equilibria are qualitatively reproduced.

  16. Effects of pre-cracks on both initiation and propagation of re-bar corrosion in pure carbon dioxide

    OpenAIRE

    L’Hostis Valérie; Hiep Dang Vu; François Raoul

    2013-01-01

    This paper deals with effects of pre-cracks on both initiation and propagation of reinforcement steel corrosion due to carbonation. The ring shaped mortar samples with 8 mm steel bar inside were cracked with different crack widths ranging from 12 micrometers to 600 micrometers and then subjected to carbon dioxide environment for different terms to assess the carbonation profile in cracks and along the interface between steel and concrete, damaged by the internal pressure applied to the ring s...

  17. Application of a systematic methodology for sustainable carbon dioxide utilization process design

    DEFF Research Database (Denmark)

    Plaza, Cristina Calvera; Frauzem, Rebecca; Gani, Rafiqul

    there are two methods of reducing carbon dioxide emissions, carbon capture and storage (CCS) and carbon capture and utilization (CCU), CCU is considered promising as it makes further use of the carbon dioxide as a solvent, raw material, and reagent to produce valuable products [1]. Using such utilization...... processes, the emissions can be reduced as they are being utilized and profit can be obtained, or the cost of operation for the carbon dioxide treatment can be returned, through this utilization process. In order to systematically reduce such emissions, carbon capture and utilization is considered rather...... than carbon capture and storage. To achieve this a methodology is developed to design sustainable carbon dioxide utilization processes. First, the information on the possible utilization alternatives is collected, including the economic potential of the process and the carbon dioxide emissions...

  18. Optical carbon dioxide sensor based on the colorimetric change of α-naphtholphthalein and internal reference fluorescent CIS/ZnS QDs

    Science.gov (United States)

    Chu, Cheng-Shane; Hsieh, Meng-Wei

    2017-04-01

    A new optical carbon dioxide sensor based on the colormetric change of pH indicator α-naphtholphthalein with the internal reference fluorescent CIS/ZnS quantum dots (QDs) was developed. The luminescence intensity of CIS/ZnS QDs increased with increasing carbon dioxide concentration. The sensing films consisting of α-naphtholphthalein in polyIBM and CIS/ZnS QDs in polystyrene layer. The sensitivity of optical carbon dioxide sensor is quantified in terms of the ration I100/I0, where I100 and I0 represent the detected luminescence intensities in pure carbon dioxide and pure nitrogen environments, respectively. The experimental result reveals that the new optical carbon dioxide sensor has sensitivity of I100/I0=13.4.

  19. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  20. Hydrogen storage and delivery: the carbon dioxide - formic acid couple.

    Science.gov (United States)

    Laurenczy, Gábor

    2011-01-01

    Carbon dioxide and the carbonates, the available natural C1 sources, can be easily hydrogenated into formic acid and formates in water; the rate of this reduction strongly depends on the pH of the solution. This reaction is catalysed by ruthenium(II) pre-catalyst complexes with a large variety of water-soluble phosphine ligands; high conversions and turnover numbers have been realised. Although ruthenium(II) is predominant in these reactions, the iron(II) - tris[(2-diphenylphosphino)-ethyl]phosphine (PP3) complex is also active, showing a new perspective to use abundant and inexpensive iron-based compounds in the CO2 reduction. In the catalytic hydrogenation cycles the in situ formed metal hydride complexes play a key role, their structures with several other intermediates have been proven by multinuclear NMR spectroscopy. In the other hand safe and convenient hydrogen storage and supply is the fundamental question for the further development of the hydrogen economy; and carbon dioxide has been recognised to be a viable H2 vector. Formic acid--containing 4.4 weight % of H2, that is 53 g hydrogen per litre--is suitable for H2 storage; we have shown that in aqueous solutions it can be selectively decomposed into CO-free (CO carbonate solution, opening the way to use cheap, non-noble metal based catalysts for this reaction, too.

  1. Carbon Dioxide Leaser For The Treatment Of Keloids

    Directory of Open Access Journals (Sweden)

    Verma Kaushal K

    2002-01-01

    Full Text Available Keloids are difficult to treat medically or surgically. Carbon dioxide (CO2 laser is considered to be a better therapeutic option due to less chances of recurrence with this modality. Fourteen patients, 4 males and 10 females, between 9 and 36 years of age having keloids for 1 to 10 years were included in this study. The lesions were present on chest, ear lobes, nape of neck, forearm, arm and shoulder. CO2 laser with a power setting of 10 to 20 watts was used in continuous mode to vaporize/excise the lesions. The patients were followed up at the end of last week, 2nd week and then every 4 weeks for 3 months to evaluate the response to treatment. Twelve patients followed up regularly and completed this study. Six patients with keliods on chest had 50 to 70% response. Remaining 6 patients with keliods on chest had 50 to 70% response. Remaining 6 patients with lesions on the ear lobes (3, showed 50 to 90% response. Nape of neck (1, shoulder, arm and forearm (2 lesions had 50 to 90% response. In all, except one patient the healing started by 4 weeks and complete healing of the treatment area occurred within 8 weeks. Four patients with poor response to CO2 laser alone were given in addition intralesional triaminolone acetonide 40mg/ml, which resulted in a better response in these patients. One patient had depigmentation of the treated area. There were no side effects in other patients. We therefore conclude that CO2 laser is a good therapeutic modality for the treatment of keloids: however recurrence on long term follow up needs to be observed.

  2. Study on the Seepage and Stability of Carbon Dioxide Geological Storage in Scrap Metal Mine: A Finite Difference Analysis

    Directory of Open Access Journals (Sweden)

    Qingwen Li

    2015-01-01

    Full Text Available The carbon dioxide geological storage is one of the most effective ways to slow down the earth's climate warming. The ideal location for storage is in the deep scrap mines. Because of the characteristics of the deep underground condition, the long-term mechanical stability must have close relationship with the geostress fields and permeability, whose development can determine and reflect the mechanical behaviors of carbon dioxide geological storage. The permeability of host rock is affected by existing joints and discontinuity surfaces. Furthermore, as the liquid carbon dioxide is injected into the geological storage, the injection pressure and buoyancy force will change the state of geostress obviously. In this paper, based on mechanical properties of the host rock (granite, coupled brittle shear constitutive model was adopted and the analysis module was implemented in software FLAC3D. Then, with the in situ survey of joints in the host rock and the monitoring of in situ geostress, the permeability characteristics and geostress inverse analysis were input in FLAC3D. At last, fluid-solid coupled model was used to analyze the seepage characteristics of each phase after the injection and long-term storage of liquid carbon dioxide. Therefore, the systematic analysis of the storage stability of carbon dioxide geological could be carried out.

  3. Carbon dioxide degassing in fresh and saline water I: Degassing performance of a cascade column

    DEFF Research Database (Denmark)

    Moran, Damian

    2010-01-01

    A study was undertaken to measure carbon dioxide degassing in a cascade column operating with both fresh (0‰) and saline water (35‰ NaCl) at 15 °C. The cascade column contained bio-block type packing material, was 1.7 m long in each dimension, and was tested both with and without countercurrent a...... to differences in the ionization fractions of inorganic carbon species in the effluent water. The results indicate that CO2 removal will be more problematic for saline or seawater recirculating systems compared to freshwater systems.......A study was undertaken to measure carbon dioxide degassing in a cascade column operating with both fresh (0‰) and saline water (35‰ NaCl) at 15 °C. The cascade column contained bio-block type packing material, was 1.7 m long in each dimension, and was tested both with and without countercurrent air...... exchange. The CO2 concentration of the influent and effluent water was measured using submersible infrared CO2 probes over an influent range of 10-60 mg L−1 CO2. Carbon dioxide degassing was quantified in terms of the mass transfer coefficient (kLa, log concentration driving force divided by packing height...

  4. Sequestration of carbon dioxide (CO2) using red mud.

    Science.gov (United States)

    Yadav, Vishwajeet S; Prasad, Murari; Khan, Jeeshan; Amritphale, S S; Singh, M; Raju, C B

    2010-04-15

    Red mud, an aluminium industry hazardous waste, has been reported to be an inexpensive and effective adsorbent. In the present work applicability of red mud for the sequestration of green house gases with reference to carbon dioxide has been studied. Red mud sample was separated into three different size fractions (RM I, RM II, RM III) of varying densities (1.5-2.2 g cm(-3)). Carbonation of each fraction of red mud was carried out separately at room temperature using a stainless steel reaction chamber at a fixed pressure of 3.5 bar. Effects of reaction time (0.5-12 h) and liquid to solid ratio (0.2-0.6) were studied for carbonation of red mud. Different instrumental techniques such as X-ray diffraction, FTIR and scanning electron microscope (SEM) were used to ascertain the different mineral phases before and after carbonation of each fraction of red mud. Characterization studies revealed the presence of boehmite, cancrinite, chantalite, hematite, gibbsite, anatase, rutile and quartz. Calcium bearing mineral phases (cancrinite and chantalite) were found responsible for carbonation of red mud. Maximum carbonation was observed for the fraction RM II having higher concentration of cancrinite. The carbonation capacity is evaluated to be 5.3 g of CO(2)/100 g of RM II. 2009 Elsevier B.V. All rights reserved.

  5. Apparatus and method for removing solvent from carbon dioxide in resin recycling system

    Science.gov (United States)

    Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

    2009-01-06

    A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

  6. Atmospheric carbon dioxide and the global carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J R [ed.

    1985-12-01

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

  7. Adding value to carbon dioxide from ethanol fermentations.

    Science.gov (United States)

    Xu, Yixiang; Isom, Loren; Hanna, Milford A

    2010-05-01

    Carbon dioxide (CO(2)) from ethanol production facilities is increasing as more ethanol is produced for alternative transportation fuels. CO(2) produced from ethanol fermentation processes is of high purity and is nearly a saturated gas. Such highly-concentrated source of CO(2) is a potential candidate for capture and utilization by the CO(2) industry. Quantity, quality and capture of CO(2) from ethanol fermentations are discussed in this review. The established and emerging value-added opportunities and markets for CO(2) from ethanol plants also are reviewed. The majority of CO(2) applications are dedicated to serving carbonated beverage and food processing and preservation markets. Beyond traditional merchant markets, the potential for exploring some fresh and profitable markets are discussed including carbon sources in chemical industries for the following: enhanced oil recovery; production of chemicals, fuels, and polymers; and production of algae-based biofuels through CO(2) fixation by microalgae. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. Life cycle study. Carbon dioxide emissions lower in electric heating than in oil heating

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, A.; Jaervinen, P.; Nikula, A.

    1996-11-01

    A primary objective of energy conservation is to cut carbon dioxide emissions. A comparative study on the various heating forms, based on the life cycle approach, showed that the carbon dioxide emissions resulting form heating are appreciably lower now that electric heating has become more common. The level of carbon dioxide emissions in Finland would have been millions of tonnes higher had oil heating been chosen instead of electric heating. (orig.)

  9. Solid carbon dioxide to promote the extraction of extra-virgin olive oil

    OpenAIRE

    Zinnai, A.; Venturi, F; Quartacci, M.F.; Sanmartin, C.; Favati, F.; Andrich, G.

    2016-01-01

    The use of solid carbon dioxide (dry ice) as a cryogen is widespread in the food industry to produce high quality wines, rich in color and perfumes. The direct addition of carbon dioxide to olives in the solid state before milling represents a fundamental step which characterizes this innovative extraction system. At room temperature conditions solid carbon dioxide evolves directly into the air phase (sublimation), and the direct contact between the cryogen and the olives induces a partial so...

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

    Science.gov (United States)

    Bennett, Chris J; Jamieson, Corey S; Kaiser, Ralf I

    2009-06-07

    Binary ice mixtures of two carbon monoxide isotopomers, (13)C(16)O and (12)C(18)O, were subjected at 10 K to energetic electrons to investigate the interaction of ionizing radiation with extraterrestrial, carbon monoxide bearing ices. The chemical modifications were monitored on line and in situ via absorption-reflection-absorption Fourier transform infrared spectroscopy as well as in the gas-phase via a quadrupole mass spectrometer. Detected products include two newly formed carbon monoxide isotopomers ((12)C(16)O and (13)C(18)O), carbon dioxide ((12)C(16)O(2), (12)C(18)O(16)O, (12)C(18)O(2), (13)C(16)O(2), (13)C(18)O(16)O, and (13)C(18)O(2)), and dicarbon monoxide ((12)C(13)C(16)O and (13)C(13)C(16)O). Kinetic profiles of carbon monoxide and of carbon dioxide were extracted and fit to derive reaction mechanisms and information on the decomposition of carbon monoxide and on the formation of carbon dioxide in extraterrestrial ice analog samples.

  11. Carbon Dioxide and Nitrogen Infused Compressed Air Foam for Depopulation of Caged Laying Hens

    Science.gov (United States)

    Gurung, Shailesh; White, Dima; Archer, Gregory; Styles, Darrel; Zhao, Dan; Farnell, Yuhua; Byrd, James; Farnell, Morgan

    2018-01-01

    Simple Summary Compressed air, detergent, and water make up compressed air foam. Our laboratory has previously reported that compressed air foam may be an effective method for mass depopulation of caged layer hens. Gases, such as carbon dioxide and nitrogen, have also been used for poultry euthanasia and depopulation. The objective of this study was to produce compressed air foam infused with carbon dioxide or nitrogen to compare its efficacy against foam with air and gas inhalation methods (carbon dioxide or nitrogen) for depopulation of caged laying hens. The study showed that a carbon dioxide-air mixture or 100% nitrogen can replace air to make compressed air foam. However, the foam with carbon dioxide had poor foam quality compared to the foam with air or nitrogen. The physiological stress response of hens subjected to foam treatments with and without gas infusion did not differ significantly. Hens exposed to foam with nitrogen died earlier as compared to methods such as foam with air and carbon dioxide. The authors conclude that infusion of nitrogen into compressed air foam results in better foam quality and shortened time to death as compared to the addition of carbon dioxide. Abstract Depopulation of infected poultry flocks is a key strategy to control and contain reportable diseases. Water-based foam, carbon dioxide inhalation, and ventilation shutdown are depopulation methods available to the poultry industry. Unfortunately, these methods have limited usage in caged layer hen operations. Personnel safety and welfare of birds are equally important factors to consider during emergency depopulation procedures. We have previously reported that compressed air foam (CAF) is an alternative method for depopulation of caged layer hens. We hypothesized that infusion of gases, such as carbon dioxide (CO2) and nitrogen (N2), into the CAF would reduce physiological stress and shorten time to cessation of movement. The study had six treatments, namely a negative control

  12. Metal-organic frameworks for electrocatalytic reduction of carbon dioxide.

    Science.gov (United States)

    Kornienko, Nikolay; Zhao, Yingbo; Kley, Christopher S; Zhu, Chenhui; Kim, Dohyung; Lin, Song; Chang, Christopher J; Yaghi, Omar M; Yang, Peidong

    2015-11-11

    A key challenge in the field of electrochemical carbon dioxide reduction is the design of catalytic materials featuring high product selectivity, stability, and a composition of earth-abundant elements. In this work, we introduce thin films of nanosized metal-organic frameworks (MOFs) as atomically defined and nanoscopic materials that function as catalysts for the efficient and selective reduction of carbon dioxide to carbon monoxide in aqueous electrolytes. Detailed examination of a cobalt-porphyrin MOF, Al2(OH)2TCPP-Co (TCPP-H2 = 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoate) revealed a selectivity for CO production in excess of 76% and stability over 7 h with a per-site turnover number (TON) of 1400. In situ spectroelectrochemical measurements provided insights into the cobalt oxidation state during the course of reaction and showed that the majority of catalytic centers in this MOF are redox-accessible where Co(II) is reduced to Co(I) during catalysis.

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

    Science.gov (United States)

    Noriega, Carlos; Araujo, Moacyr

    2014-01-01

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

  14. Lidar detection of carbon dioxide in volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Maio, Giovanni; Del Franco, Mario; Aiuppa, Alessandro

    2015-06-01

    Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high spatial and temporal resolution. Two differential absorption lidar instruments will be presented in this paper: BILLI (BrIdge voLcanic LIdar), based on injection seeded Nd:YAG laser, double grating dye laser, difference frequency mixing (DFM) and optical parametric amplifier (OPA), and VULLI (VULcamed Lidar), based on injection seeded Nd:YAG laser and optical parametric oscillator (OPO). The first one is funded by the ERC (European Research Council) project BRIDGE and the second one by the ERDF (European Regional Development Fund) project VULCAMED. While VULLI has not yet been tested in a volcanic site, BILLI scanned the gas emitted by Pozzuoli Solfatara (Campi Flegrei volcanic area, Naples, Italy) during a field campaign carried out from 13 to 17 October 2014. Carbon dioxide concentration maps were retrieved remotely in few minutes in the crater area. Lidar measurements were in good agreement with well-established techniques, based on different operating principles. To our knowledge, it is the first time that carbon dioxide in a volcanic plume is retrieved by lidar, representing the first direct measurement of this kind ever performed on an active volcano and showing the high potential of laser remote sensing in geophysical research.

  15. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Response of Agronomic and Forest Species to Elevated Atmospheric Carbon Dioxide

    Science.gov (United States)

    Rogers, Hugo H.; Thomas, Judith F.; Bingham, Gail E.

    1983-04-01

    The effects of atmospheric carbon dioxide on corn, soybeans, loblolly pine, and sweetgum were studied in the field during a growing season. The plants were exposed to a range of concentrations of carbon dioxide day and night in open-topped, flow-through chambers. At a mean daytime carbon dioxide concentration of 910 parts per million, increases in total biomass ranged from 157 to 186 percent of the control values. Seed yield and wood volume increased and there were changes in plant anatomy and form. Net photosynthesis increased with increasing carbon dioxide concentration in soybeans and sweetgum, but was unaffected in corn. Water use efficiency also increased in corn, soybeans, and sweetgum.

  17. Relationship between Sampling Distance and Carbon Dioxide Emission under Oil Palm Plantation

    Directory of Open Access Journals (Sweden)

    Ai Dariah

    2013-05-01

    Full Text Available A carbon dioxide emission on peatland under oil palm plantation was highly varied due to many factors involved. The objectives of the research were to evaluate the effect of sampling distance from center of oil palm tree on Carbon dioxide flux, and to study the factors that cause variability of carbon dioxide flux on peatland under oil palm plantation. The study was conducted on peatland at Arang-Arang Village, Kumpek Ulu Sub-District, Muaro Jambi District, Jambi Province, on six-years old oil palm plantation. The study was conducted in the form of observational exploratory. Emission measurements were performed on 5 selected oil palm trees at points within 100, 150, 200, 250, 300, 350, and 400 cm from the center of trunk. Carbon dioxide flux was measured using (IRGA, Li-COR 820. The results showed that there was significant correlation between the distance of sampling from center of oil palm tree and Carbon dioxide flux. The farther distance from the tree, the more decreased of Carbon dioxide flux . Before applying fertilizer, variability of soil fertility was not significantly correlated with the flux of Carbon dioxide, so the difference of Carbon dioxide flux based on distance sampling can be caused by root distribution factor. After fertilizer application, variability of Carbon dioxide flux under the oil palm tree were not only affected by differences in root distribution but also greatly influenced by fertilization.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650......,000 years. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data and the present work, we find that atmospheric carbon dioxide...

  19. Extraction of heavy oil by supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Rudyk, Svetlana Nikolayevna; Spirov, Pavel; Søgaard, Erik Gydesen

    2010-01-01

    The present study deals with the extraction of heavy oil by supercritical carbon dioxide at the pressure values changing from 16 to 56 MPa at the fixed value of temperature: 60oC. The amount of the recovered liquid phase of oil was calculated as a percentage of the extracted amount to the initial...... to apply it for the efficient displacement of oil through CO2 injection. A much higher recovery rate of 48% for liquid phase and 27% for the gas phase was observed at the pressure of 56 MPa. That shows that supercritical CO2 can provide high recovery rates when applied to heavy oil, facilitating...

  20. Drivers of seasonality in Arctic carbon dioxide fluxes

    DEFF Research Database (Denmark)

    Mbufong, Herbert Njuabe

    and the potential for widespread feedbacks with global consequences. In this thesis, I present and discuss the findings of an investigation of comparable drivers of the seasonality in carbon dioxide (CO2) fluxes across heterogeneous Arctic tundra ecosystems. Due to the remoteness and the harsh climatic conditions...... that monitoring, modelling and manipulation experiments of drivers of greenhouse gas fluxes be intensified across the globe. The Arctic tundra represents an important biome in the context of global climate change. This is because of the highly sensitive nature of the Arctic tundra to climatic perturbations...

  1. Chemical looping integration with a carbon dioxide gas purification unit

    Science.gov (United States)

    Andrus, Jr., Herbert E.; Jukkola, Glen D.; Thibeault, Paul R.; Liljedahl, Gregory N.

    2017-01-24

    A chemical looping system that contains an oxidizer and a reducer is in fluid communication with a gas purification unit. The gas purification unit has at least one compressor, at least one dryer; and at least one distillation purification system; where the gas purification unit is operative to separate carbon dioxide from other contaminants present in the flue gas stream; and where the gas purification unit is operative to recycle the contaminants to the chemical looping system in the form of a vent gas that provides lift for reactants in the reducer.

  2. Distribution of Carbon Dioxide Produced by People in a Room:

    DEFF Research Database (Denmark)

    Naydenov, Kiril Georgiev; Baránková, Petra; Sundell, Jan

    2004-01-01

    Carbon dioxide exhaled by people can be used as a tracer gas for air change measurements in homes. Good mixing of tracer gas with room air is a necessary condition to obtain accurate results. However, the use of fans to ensure mixing is inconvenient. The natural room distribution of metabolic CO2...... was detected in both studies when constant CO2 emission was obtained. Several critical points of insufficient mixing were identified. If such locations are avoided, additional mixing may not be necessary when using CO2 as a tracer gas in decay and constant emission methods....

  3. Office workers' sick building syndrome and indoor carbon dioxide concentrations.

    Science.gov (United States)

    Tsai, Dai-Hua; Lin, Jia-Shiang; Chan, Chang-Chuan

    2012-01-01

    This study attempted to determine whether any association exists between sick building syndrome (SBS) and indoor carbon dioxide (CO(2)) concentrations. We evaluated SBS among 111 office workers in August and November 2003. The environmental conditions in the office, including CO(2) concentrations, temperature, relative humidity, and fine particulate matter (PM(2.5)), were continuously monitored. The most prevalent symptoms of the five SBS groups were eye irritation and nonspecific and upper respiratory symptoms. The generalized estimating equation (GEE) models show that workers exposed to indoor CO(2) levels greater than 800 ppm were likely to report more eye irritation or upper respiratory symptoms.

  4. New and future developments in catalysis activation of carbon dioxide

    CERN Document Server

    Suib, Steven L

    2013-01-01

    New and Future Developments in Catalysis is a package of books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes. This volume presents a complete picture of all carbon dioxide (CO2) sources, outlines the environmental concerns regarding CO2, and critica

  5. TIR-1 carbon dioxide laser system for fusion

    Science.gov (United States)

    Adamovich, V. A.; Anisimov, V. N.; Afonin, E. A.; Baranov, V. Iu.; Borzenko, V. L.; Kozochkin, S. M.; Maliuta, D. D.; Satov, Iu. A.; Sebrant, A. Iu.; Smakovski, Iu. B.

    1980-03-01

    The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system consists of an oscillator-preamplifier that produces about 1-nsec laser pulse with an energy contrast ratio of 1 million, a large triple-pass amplifier, and a target chamber with diagnostic equipment.

  6. A Review of Carbon Dioxide Selective Membranes: A Topical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dushyant Shekhawat; David R. Luebke; Henry W. Pennline

    2003-12-01

    Carbon dioxide selective membranes provide a viable energy-saving alternative for CO2 separation, since membranes do not require any phase transformation. This review examines various CO2 selective membranes for the separation of CO2 and N2, CO2 and CH4, and CO2 and H2 from flue or fuel gas. This review attempts to summarize recent significant advances reported in the literature about various CO2 selective membranes, their stability, the effect of different parameters on the performance of the membrane, the structure and permeation properties relationships, and the transport mechanism applied in different CO2 selective membranes.

  7. Carbon dioxide stripping in aquaculture -- part III: model verification

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

    Based on conventional mass transfer models developed for oxygen, the use of the non-linear ASCE method, 2-point method, and one parameter linear-regression method were evaluated for carbon dioxide stripping data. For values of KLaCO2 enrichment remains to be determined. The one-parameter linear regression model was used to vary the C*CO2 over the test, but it did not result in a better fit to the experimental data when compared to the ASCE or fixed C*CO2 assumptions.

  8. Supercritical carbon dioxide: the art of technology in art conservation

    Directory of Open Access Journals (Sweden)

    Ana Aguiar-Ricardo

    2007-01-01

    Full Text Available Herein we present a survey of reported work covering specific applications of liquid and supercritical carbon dioxide (scCO2 in art conservation. CO2 has been tested and applied in a wide range of materials, as well as in various steps of a conservation / restoration operation, such as cleaning, protection and consolidation, and it has been demonstrated that CO2 has a great potential in replacing current conventional conservation processes. In this paper we will present some of the main results published in literature, concerning CO2 applications for the conservation and restoration of paper, wood, waterlogged, ethnographic materials, stone and textiles.

  9. Fractional Carbon Dioxide Laser in Treatment of Acne Scars

    OpenAIRE

    Andrej Petrov; Vesna Pljakovska

    2015-01-01

    BACKGROUND: Scars appear as a result of skin damage during the process of the skin healing. There are two types of acne scars, depending on whether there is a loss or accumulation of collagen: atrophic and hypertrophic. In 80-90% it comes to scars with loss of collagen compared to smaller number of hypertrophic scars and keloids. AIM: The aim of the study was to determine efficiency and safety of fractional carbon dioxide laser in the treatment of acne scars. MATERIAL AND METHODS: The...

  10. Synthesis and characterization of zwitterionic carbon dioxide fixing reagents

    DEFF Research Database (Denmark)

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

    2010-01-01

    The synthesis of three amine-based carbon dioxide fixing reagents is presented. The reagents were designed so that they would be able to bind CO2 reversibly through the formation of the well known carbamates that was stabilized through forming a zwitterion. CO2 fixing experiments were performed...... with 13CO2 labeling and medium pressure NMR. The experiments showed that two of the three reagents were able to form carbamates and thus bind CO2. In addition we investigated this particular class of molecules for the possible formation of neutrally charged spiro compounds and we show that these did...

  11. Extraction of bixin from annatto seeds using supercritical carbon dioxide

    OpenAIRE

    Silva,G. F.; Gamarra,Felix M. C.; Oliveira,A. L.; Cabral,F. A.

    2008-01-01

    The solubility of 93% pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present in annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50ºC and pressure between 10 and 35 MPa and for the pure bixin, at 40ºC from 10 to 35 MPa. The main pigments of annatto seeds are bixin and norbixin, but the extracts only showed the presence of cis and trans-bixin, indicating that norbixin is not soluble in SC-CO2. The a...

  12. A Novel Airborne Carbon Isotope Analyzer for Methane and Carbon Dioxide Source Fingerprinting

    Science.gov (United States)

    Berman, E. S.; Huang, Y. W.; Owano, T. G.; Leifer, I.

    2014-12-01

    Recent field studies on major sources of the important greenhouse gas methane (CH4) indicate significant underestimation of methane release from fossil fuel industrial (FFI) and animal husbandry sources, among others. In addition, uncertainties still exist with respect to carbon dioxide (CO2) measurements, especially source fingerprinting. CO2 isotopic analysis provides a valuable in situ measurement approach to fingerprint CH4 and CO2as associated with combustion sources, leakage from geologic reservoirs, or biogenic sources. As a result, these measurements can characterize strong combustion source plumes, such as power plant emissions, and discriminate these emissions from other sources. As part of the COMEX (CO2 and MEthane eXperiment) campaign, a novel CO2 isotopic analyzer was installed and collected data aboard the CIRPAS Twin Otter aircraft. Developing methods to derive CH4 and CO2 budgets from remote sensing data is the goal of the summer 2014 COMEX campaign, which combines hyperspectral imaging (HSI) and non-imaging spectroscopy (NIS) with in situ airborne and surface data. COMEX leverages the synergy between high spatial resolution HSI and moderate spatial resolution NIS. The carbon dioxide isotope analyzer developed by Los Gatos Research (LGR) uses LGR's patented Off-Axis ICOS (Integrated Cavity Output Spectroscopy) technology and incorporates proprietary internal thermal control for high sensitivity and optimal instrument stability. This analyzer measures CO2 concentration as well as δ13C, δ18O, and δ17O from CO2 at natural abundance (100-3000 ppm). The laboratory accuracy is ±1.2 ppm (1σ) in CO2 from 370-1000 ppm, with a long-term (1000 s) precision of ±0.012 ppm. The long-term precision for both δ13C and δ18O is 0.04 ‰, and for δ17O is 0.06 ‰. The analyzer was field-tested as part of the COWGAS campaign, a pre-cursor campaign to COMEX in March 2014, where it successfully discriminated plumes related to combustion processes associated with

  13. Optimizing the Process Parameters for Electrochemical Reduction of Carbon Dioxide

    Science.gov (United States)

    Mudunur, Santosh shekar

    One the major problems of this modern industrialized world is its dependence on fossil fuels for its energy needs. Burning of fossils fuels generates green-house gases which have adverse effects on global climate contributing to global warming. According to Environmental Protection Agency (EPA), carbon dioxide makes up 80 percent of green-house gases emitted in USA. Electrochemical reduction of carbon dioxide is an approach which uses CO2 emissions to produce other useful hydrocarbons which can be used in many ways. In this study, primary focus was on optimizing the operating conditions, determining the better catalyst material, and analyzing the reaction products for the process of electrochemical reduction of carbon dioxide (ERC). Membrane electrode assemblies (MEA's) are developed by air bushing the metal particles with a spray gun on to Nafion-212 which is a solid polymer based electrolyte (SPE), to support the electrodes in the electrochemical reactor gas diffusion layers (GDL) are developed using porous carbon paper. Anode was always made using the same material which is platinum but cathode material was changed as it is the working electrode. The membrane electrode assembly (MEA) is then placed into the electrochemical reactor along with gas diffusion layer (GDL) to assess the performance of the catalyst material by techniques like linear sweep voltammetry and chronoamperometry. Performance of MEA was analyzed at 4 different potentials, 2 different temperatures and for 2 different cathode catalyst materials. The reaction products of the process are analyzed using gas chromatography (GC) which has thermal conductivity detector (TCD) used for detecting hydrogen (H2), carbon monoxide (CO) and flame ionization detector (FID) used for detecting hydrocarbons. The experiments performed at 40° C gave the better results when compared with the experiments performed at ambient temperature. Also results suggested that copper oxide cathode catalyst has better durability

  14. Carbon dioxide adsorption in chemically activated carbon from sewage sludge.

    Science.gov (United States)

    de Andrés, Juan Manuel; Orjales, Luis; Narros, Adolfo; de la Fuente, María del Mar; Encarnación Rodríguez, María

    2013-05-01

    In this work, sewage sludge was used as precursor in the production of activated carbon by means of chemical activation with KOH and NaOH. The sludge-based activated carbons were investigated for their gaseous adsorption characteristics using CO2 as adsorbate. Although both chemicals were effective in the development of the adsorption capacity, the best results were obtained with solid NaOH (SBA(T16)). Adsorption results were modeled according to the Langmuir and Freundlich models, with resulting CO2 adsorption capacities about 56 mg/g. The SBA(T16) was characterized for its surface and pore characteristics using continuous volumetric nitrogen gas adsorption and mercury porosimetry. The results informed about the mesoporous character of the SBA(T16) (average pore diameter of 56.5 angstroms). The Brunauer-Emmett-Teller (BET) surface area of the SBA(T16) was low (179 m2/g) in comparison with a commercial activated carbon (Airpel 10; 1020 m2/g) and was mainly composed of mesopores and macropores. On the other hand, the SBA(T16) adsorption capacity was higher than that of Airpel 10, which can be explained by the formation of basic surface sites in the SBA(T16) where CO2 experienced chemisorption. According to these results, it can be concluded that the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2. Adsorption methods are one of the current ways to reduce CO2 emissions. Taking this into account, sewage-sludge-based activated carbons were produced to study their CO2 adsorption capacity. Specifically, chemical activation with KOH and NaOH of previously pyrolyzed sewage sludge was carried out. The results obtained show that even with a low BET surface area, the adsorption capacity of these materials was comparable to that of a commercial activated carbon. As a consequence, the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2 and an interesting application for this waste.

  15. Sulfur dioxide leaching of spent zinc-carbon-battery scrap

    Science.gov (United States)

    Avraamides, J.; Senanayake, G.; Clegg, R.

    Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2 M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25 °C. Alkaline leaching with 6 M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30 min at 30 °C using 0.1-1.0 M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1 M to 2 M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide.

  16. The Carbon-Nitrogen Balance of the Nodule and Its Regulation under Elevated Carbon Dioxide Concentration

    Directory of Open Access Journals (Sweden)

    Marc Libault

    2014-01-01

    Full Text Available Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2. In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

  17. The carbon-nitrogen balance of the nodule and its regulation under elevated carbon dioxide concentration.

    Science.gov (United States)

    Libault, Marc

    2014-01-01

    Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

  18. The Carbon-Nitrogen Balance of the Nodule and Its Regulation under Elevated Carbon Dioxide Concentration

    Science.gov (United States)

    2014-01-01

    Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency. PMID:24987690

  19. Evaluation and Enhancement of Carbon Dioxide Flooding Through Sweep Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard

    2009-09-30

    Carbon dioxide displacement is a common improved recovery method applied to light oil reservoirs (30-45{degrees}API). The economic and technical success of CO{sub 2} floods is often limited by poor sweep efficiency or large CO{sub 2} utilization rates. Projected incremental recoveries for CO{sub 2} floods range from 7% to 20% of the original oil in place; however, actual incremental recoveries range from 9% to 15% of the original oil in place, indicating the potential for significant additional recoveries with improved sweep efficiency. This research program was designed to study the effectiveness of carbon dioxide flooding in a mature reservoir to identify and develop methods and strategies to improve oil recovery in carbon dioxide floods. Specifically, the project has focused on relating laboratory, theoretical and simulation studies to actual field performance in a CO{sub 2} flood in an attempt to understand and mitigate problems of areal and vertical sweep efficiency. In this work the focus has been on evaluating the status of existing swept regions of a mature CO{sub 2} flood and developing procedures to improve the design of proposed floods. The Little Creek Field, Mississippi has been studied through laboratory, theoretical, numerical and simulation studies in an attempt to relate performance predictions to historical reservoir performance to determine sweep efficiency, improve the understanding of the reservoir response to CO{sub 2} injection, and develop scaling methodologies to relate laboratory data and simulation results to predicted reservoir behavior. Existing laboratory information from Little Creek was analyzed and an extensive amount of field data was collected. This was merged with an understanding of previous work at Little Creek to generate a detailed simulation study of two portions of the field – the original pilot area and a currently active part of the field. This work was done to try to relate all of this information to an understanding

  20. In situ infrared spectroscopic study of brucite carbonation in dry to water-saturated supercritical carbon dioxide.

    Science.gov (United States)

    Loring, John S; Thompson, Christopher J; Zhang, Changyong; Wang, Zheming; Schaef, Herbert T; Rosso, Kevin M

    2012-05-17

    In geologic carbon sequestration, whereas part of the injected carbon dioxide will dissolve into host brine, some will remain as neat to water saturated supercritical CO(2) (scCO(2)) near the well bore and at the caprock, especially in the short term life cycle of the sequestration site. Little is known about the reactivity of minerals with scCO(2) containing variable concentrations of water. In this study, we used high-pressure infrared spectroscopy to examine the carbonation of brucite (Mg(OH)(2)) in situ over a 24 h reaction period with scCO(2) containing water concentrations between 0% and 100% saturation, at temperatures of 35, 50, and 70 °C, and at a pressure of 100 bar. Little or no detectable carbonation was observed when brucite was reacted with neat scCO(2). Higher water concentrations and higher temperatures led to greater brucite carbonation rates and larger extents of conversion to magnesium carbonate products. The only observed carbonation product at 35 °C was nesquehonite (MgCO(3)·3H(2)O). Mixtures of nesquehonite and magnesite (MgCO(3)) were detected at 50 °C, but magnesite was more prevalent with increasing water concentration. Both an amorphous hydrated magnesium carbonate solid and magnesite were detected at 70 °C, but magnesite predominated with increasing water concentration. The identity of the magnesium carbonate products appears strongly linked to magnesium water exchange kinetics through temperature and water availability effects.

  1. Poly(urethane–carbonate)s from Carbon Dioxide

    KAUST Repository

    Chen, Zuliang

    2017-03-09

    A one-pot, two-step protocol for the direct synthesis of polyurethanes containing few carbonate linkages through polycondensation of diamines, dihalides, and CO2 in the presence of Cs2CO3 and tetrabutylammonium bromide is described. The conditions were optimized by studying the polycondensation of CO2 with 1,6-hexanediamine and 1,4-dibromobutane as model monomers. Then, various diamines and dihalides were tested under optimal conditions. Miscellaneous samples of such carbonate-containing polyurethanes exhibiting molar masses from 6000 to 22 000 g/mol (GPC) and yields higher than 85% were obtained. The thermal properties of such polyurethanes were unveiled by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA): they were found very similar to those of traditional polyurethanes obtained by diisocyanates + diols polycondensation.

  2. The Carbon Dioxide System in the Baltic Sea Surface Waters

    Energy Technology Data Exchange (ETDEWEB)

    Wesslander, Karin

    2011-05-15

    The concentration of carbon dioxide (CO{sub 2}) in the atmosphere is steadily increasing because of human activities such as fossil fuel burning. To understand how this is affecting the planet, several pieces of knowledge of the CO{sub 2} system have to be investigated. One piece is how the coastal seas, which are used by people and influenced by industrialization, are functioning. In this thesis, the CO{sub 2} system in the Baltic Sea surface water has been investigated using observations from the last century to the present. The Baltic Sea is characterized of a restricted water exchange with the open ocean and a large inflow of river water. The CO{sub 2} system, including parameters such as pH and partial pressure of CO{sub 2} (pCO{sub 2}), has large seasonal and inter-annual variability in the Baltic Sea. These parameters are affected by several processes, such as air-sea gas exchange, physical mixing, and biological processes. Inorganic carbon is assimilated in the primary production and pCO{sub 2} declines to approx150 muatm in summer. In winter, pCO{sub 2} levels increase because of prevailing mineralization and mixing processes. The wind-mixed surface layer deepens to the halocline (approx60 m) and brings CO{sub 2}- enriched water to the surface. Winter pCO{sub 2} may be as high as 600 muatm in the surface water. The CO{sub 2} system is also exposed to short-term variations caused by the daily biological cycle and physical events such as upwelling. A cruise was made in the central Baltic Sea to make synoptic measurements of oceanographic, chemical, and meteorological parameters with high temporal resolution. Large short-term variations were found in pCO{sub 2} and oxygen (O{sub 2}), which were highly correlated. The diurnal variation of pCO{sub 2} was up to 40 muatm. The CO{sub 2} system in the Baltic Sea changed as the industrialization increased around 1950, which was demonstrated using a coupled physical-biogeochemical model of the CO{sub 2} system

  3. Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

    Science.gov (United States)

    Zhang, Xiao; Li, Xueqian; Zhang, Du; Su, Neil Qiang; Yang, Weitao; Everitt, Henry O.; Liu, Jie

    2017-01-01

    Photocatalysis has not found widespread industrial adoption, in spite of decades of active research, because the challenges associated with catalyst illumination and turnover outweigh the touted advantages of replacing heat with light. A demonstration that light can control product selectivity in complex chemical reactions could prove to be transformative. Here, we show how the recently demonstrated plasmonic behaviour of rhodium nanoparticles profoundly improves their already excellent catalytic properties by simultaneously reducing the activation energy and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produced without illumination. The reduced activation energy and super-linear dependence on light intensity cause the unheated photocatalytic methane production rate to exceed the thermocatalytic rate at 350 °C. PMID:28230100

  4. Carbon dioxide capture using resin-wafer electrodeionization

    Science.gov (United States)

    Lin, YuPo J.; Snyder, Seth W.; Trachtenberg, Michael S.; Cowan, Robert M.; Datta, Saurav

    2015-09-08

    The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium. A pH suitable for exchange of CO.sub.2 is electrochemically maintained within the basic and acidic ion exchange wafers by applying an electric potential across the cathode and anode.

  5. Catalytic conversion of methane: Carbon dioxide reforming and oxidative coupling

    KAUST Repository

    Takanabe, Kazuhiro

    2012-01-01

    Natural gas conversion remains one of the essential technologies for current energy needs. This review focuses on the mechanistic aspects of the development of efficient and durable catalysts for two reactions, carbon dioxide reforming and the oxidative coupling of methane. These two reactions have tremendous technological significance for practical application in industry. An understanding of the fundamental aspects and reaction mechanisms of the catalytic reactions reviewed in this study would support the design of industrial catalysts. CO 2 reforming of methane utilizes CO 2, which is often stored in large quantities, to convert as a reactant. Strategies to eliminate carbon deposition, which is the major problem associated with this reaction, are discussed. The oxidative coupling of methane directly produces ethylene in one reactor through a slightly exothermic reaction, potentially minimizing the capital cost of the natural gas conversion process. The focus of discussion in this review will be on the attainable yield of C 2 products by rigorous kinetic analyses.

  6. Application of end-tidal carbon dioxide monitoring via distal gas samples in ventilated neonates.

    Science.gov (United States)

    Jin, Ziying; Yang, Maoying; Lin, Ru; Huang, Wenfang; Wang, Jiangmei; Hu, Zhiyong; Shu, Qiang

    2017-08-01

    Previous research has suggested correlations between the end-tidal partial pressure of carbon dioxide (PETCO2) and the partial pressure of arterial carbon dioxide (PaCO2) in mechanically ventilated patients, but both the relationship between PETCO2 and PaCO2 and whether PETCO2 accurately reflects PaCO2 in neonates and infants are still controversial. This study evaluated remote sampling of PETCO2 via an epidural catheter within an endotracheal tube to determine the procedure's clinical safety and efficacy in the perioperative management of neonates. Abdominal surgery was performed under general anesthesia in 86 full-term newborns (age 1-30 days, weight 2.55-4.0 kg, American Society of Anesthesiologists class I or II). The infants were divided into 2 groups (n = 43 each), and carbon dioxide (CO2) gas samples were collected either from the conventional position (the proximal end) or a modified position (the distal end) of the epidural catheter. The PETCO2 measured with the new method was significantly higher than that measured with the traditional method, and the difference between PETCO2 and PaCO2 was also reduced. The accuracy of PETCO2 measured increased from 78.7% to 91.5% when the modified sampling method was used. The moderate correlation between PETCO2 and PaCO2 by traditional measurement was 0.596, which significantly increased to 0.960 in the modified sampling group. Thus, the PETCO2 value was closer to that of PaCO2. PETCO2 detected via modified carbon dioxide monitoring had a better accuracy and correlation with PaCO2 in neonates. Copyright © 2017. Published by Elsevier B.V.

  7. Carbon dioxide content in the atmospheric thickness over central Eurasia (Issyk Kul Monitoring Station)

    Science.gov (United States)

    Kashin, F. V.; Aref'ev, V. N.; Kamenogradskii, N. E.; Semenov, V. K.; Sinyakov, V. P.

    2007-08-01

    The refined data obtained from the spectroscopic measurements of carbon dioxide in the column of the continental atmosphere over the Issyk Kul Monitoring Station during the period 1980-2006 and the results of their comparison with the data obtained from the measurements of carbon dioxide in air samples and with the mean zonal empirical model of the Climate Monitoring and Diagnostics Laboratory (CMDL) are given. Seasonal variations and a long-term trend of carbon dioxide concentration in the atmospheric thickness over a 25-year period of measurements are analyzed. The monthly mean concentration of CO2 is increased by ˜40.5 ppm, and the linear-trend index is 1.62 ppm per year. The results of the aircraft measurements of CO2 concentration in air samples are, on the average, in agreement with the data obtained from the spectroscopic measurements of carbon dioxide concentration in the atmospheric column. The CO2 concentration in the surface air varies from day to day, and only its minimum values coincide with the CO2 concentration in the atmospheric thickness. The results of measurements of CO2 concentration in the atmospheric thickness and in the atmospheric surface layer over the KZD and KZM stations nearest to each other are, on the whole, in disagreement; moreover, the KZD and KZM data are inconsistent. The CO2 concentration in the atmospheric thickness is, on the average, 1-2% higher than that obtained with the CMDL model for 42.6° N latitude. The coefficient of correlation between the measurement results and model data is high ( r= 0.95).

  8. Carbonate fuel cell system with integrated carbon dioxide/thermal management

    Energy Technology Data Exchange (ETDEWEB)

    Paetsch, L.

    1995-08-01

    The objective of the present work is to define the stack design and system requirements for a commercial-scale carbonate fuel cell with an integrated carbon dioxide management system. Significant simplification and cost reduction of the system is achieved by direct transfer of the fuel exhaust to the oxidant inlet of the fuel cell, thereby eliminating the anode exhaust converter and high temperature piping utilized in conventional system designs.

  9. Reactions of Vanadocene-Carbyls with Carbon Monoxide, Xylylisocyanide and Carbon Dioxide

    NARCIS (Netherlands)

    Nieman, J.; Teuben, J.H.

    1985-01-01

    Vanadocene-allyl Cp2V(η1-C3H5) (1a) reacts with strong π-acceptor substrate ligands such as carbon monoxide, carbon dioxide and isonitriles. No reactions are observed with poorer π-acceptor substrates such as alkynes and nitriles. Reaction of 1a with CO gives Cp[η4-C5H5(C3H5)]V(CO)2, showing that

  10. Effects of Carbonization Parameters of Moso-Bamboo-Based Porous Charcoal on Capturing Carbon Dioxide

    OpenAIRE

    Pei-Hsing Huang; Jhih-Wei Jhan; Yi-Ming Cheng; Hau-Hsein Cheng

    2014-01-01

    This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis-) based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET) surface area, iodine number, pore volume, a...

  11. Optical carbon dioxide sensor based on fluorescent capillary array

    Directory of Open Access Journals (Sweden)

    Jian Wang

    Full Text Available A novel carbon dioxide (CO2 gas sensor based on capillary array is presented. The capillary array is composed of 51 capillaries and modified by fluorescent dye 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS, PTS− and tetraoctylammonium cation (TOA+ doped porous ethyl cellulose. A Y-fiber is used to transmit exciting light and fluorescence. A fiber optic pigtail-contained spectrophotometer is used to collect and deal with optical signals. Due to its structural features, each capillary has the two rolling-up layers of inner and outer sensing films, which make the 2 cm long capillary array has large sensing area about 12.81 cm2 and the fluorescence signal easily be collected. The sensing probe has advantages such as small volume, compact structure and large sensing area. The results demonstrate that the sensor has a linear response in the CO2 volume ratio range from 0 to 10%. Keywords: Carbon dioxide chemical sensor, Fluorescence sensor, Capillary array

  12. Performance of carbon dioxide vent for direct methanol fuel cells

    Science.gov (United States)

    Prakash, Shruti; Kohl, Paul A.

    Direct methanol fuel cells have potentially high energy density if the balance of plant and fuel losses can be kept to a minimum. CO 2 accumulation in the fuel tank can lower the efficiency and performance of closed-tank methanol fuel cells. This report discusses the implementation of a passive CO 2 vent fabricated with poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane. The performance of the membrane as a selective vent for carbon dioxide in the presence of methanol has been studied at various operating conditions. First, the selectivity of the vent membrane improved with temperature. Second, the activation energy for permeation through the polymer membrane corresponded to diffusion controlled transport of CO 2 and sorption controlled transport for methanol vapor. The activation energy for CO 2 transport through the poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane membrane was less than that for a pure poly(1-trimethyl silyl propyne) membrane. Finally, the polymer had a high selectivity for carbon dioxide compared to both liquid and vapor phase methanol.

  13. Experimental performance of carbon dioxide compressor with parallel compression

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Bachir; Kaemmer, Norbert [Emerson Climate Technologies GmbH, Aachen (Germany)

    2011-07-01

    Carbon dioxide (CO2) was proposed in the recent years as a natural fluid to replace the HFCs in refrigeration applications. Its implementation in refrigeration, first in subcritical and recently in transcritical systems is becoming a technology of increasing importance. Trans-critical CO2 system presents lower COP compared to HFCs systems when the ambient temperature is high. Reciprocating compressors with two compression stages having a vapor injection port (VI) have been proposed for parallel compression to improve the efficiency of the system. Many publications have been presented to explain the application advantage but experimental data are lacking to support the theoretical analysis. The work presented here highlight the advantage of the parallel compresion and explains the experimental tests carried-out on a reciprocating prototype with carbon dioxide working with two compression stages (parallel compression) and finally discusses the experimental results. The compressor is a semi-hermetic four cylinders compressor with one compression chamber (cylinder) dedicated to the parallel compression. The tests was performed on hot gas by-pass cycle at -10 C evaporating temperature varying the intermediate and discharge pressures. The experimental result shows the performance at different operating conditions varying the intermediate pressure. It highlights the influence of the intermediate pressure on the efficiency of the compressor and the system. The intermediate pressure influences the volumetric efficiency of the compressor and consequently the COP of the system. Finally, a system efficiency comparison between this configuration and dedicated compressor for parallel compression have been evaluated.

  14. Electrochemical device for converting carbon dioxide to a reaction product

    Science.gov (United States)

    Masel, Richard I.; Chen, Qingmei; Liu, Zengcai; Kutz, Robert

    2016-11-01

    An electrochemical device converts carbon dioxide to a reaction product. The device includes an anode and a cathode, each comprising a quantity of catalyst. The anode and cathode each has reactant introduced thereto. A polymer electrolyte membrane is interposed between the anode and the cathode. At least a portion of the cathode catalyst is directly exposed to gaseous carbon dioxide during electrolysis. The average current density at the membrane is at least 20 mA/cm.sup.2, measured as the area of the cathode gas diffusion layer that is covered by catalyst, and CO selectivity is at least 50% at a cell potential of 3.0 V. In some embodiments, the polymer electrolyte membrane comprises a polymer in which a constituent monomer is (p-vinylbenzyl)-R, where R is selected from the group consisting of imidazoliums, pyridiniums and phosphoniums. In some embodiments, the polymer electrolyte membrane is a Helper Membrane comprising a polymer containing an imidazolium ligand, a pyridinium ligand, or a phosphonium ligand.

  15. Carbon Dioxide Information Analysis Center: FY 1992 activities

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  16. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also described.

  17. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  18. Carbon Dioxide Shuttling Thermochemical Storage Using Strontium Carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Renwei [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical and Aerospace Engineering

    2015-06-15

    Phase I concludes with significant progress made towards the SunShot ELEMENTS goals of high energy density, high power density, and high temperature by virtue of a SrO/SrCO3 based material. A detailed exploration of sintering inhibitors has been conducted and relatively stable materials supported by YSZ or SrZO3 have been identified as the leading candidates. In 15 cycle runs using a 3 hour carbonation duration, several materials demonstrated energy densities of roughly 1500 MJ/m3 or greater. The peak power density for the most productive materials consistently exceeded 40 MW/m3—an order of magnitude greater than the SOPO milestone. The team currently has a material demonstrating nearly 1000 MJ/m3 after 100 abbreviated (1 hour carbonation) cycles. A subsequent 8 hour carbonation after the 100 cycle test exhibited over 1500 MJ/m3, which is evidence that the material still has capacity for high storage albeit with slower kinetics. Kinetic carbonation experiments have shown three distinct periods: induction, kinetically-controlled, and finally a diffusion-controlled period. In contrast to thermodynamic equilibrium prediction, higher carbonation temperatures lead to greater conversions over a 1 hour periods, as diffusion of CO2 is more rapid at higher temperatures. A polynomial expression was fit to describe the temperature dependence of the linear kinetically-controlled regime, which does not obey a traditional Arrhenius relationship. Temperature and CO2 partial pressure effects on the induction period were also investigated. The CO2 partial pressure has a strong effect on the reaction progress at high temperatures but is insignificant at temperatures under 900°C. Tomography data for porous SrO/SrCO3 structures at initial stage and after multiple carbonation/decomposition cycles have been obtained. Both 2D slices and 3D reconstructed representations have

  19. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons.

    Science.gov (United States)

    Wang, Jitong; Chen, Huichao; Zhou, Huanhuan; Liu, Xiaojun; Qiao, Wenming; Long, Donghui; Ling, Licheng

    2013-01-01

    A high efficiency sorbent for CO2 capture was developed by loading polyethylenimine (PEI) on mesoporous carbons which possessed well-developed mesoporous structures and large pore volume. The physicochemical properties of the sorbent were characterized by N2 adsorption/desorption, scanning electron microscopy (SEM), thermal gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR) techniques followed by testing for CO2 capture. Factors that affected the sorption capacity of the sorbent were studied. The sorbent exhibited extraordinary capture capacity with CO2 concentration ranging from 5% to 80%. The optimal PEI loading was determined to be 65 wt.% with a CO2 sorption capacity of 4.82 mmol-CO2/g-sorbent in 15% CO2/N2 at 75 degrees C, owing to low mass-transfer resistance and a high utilization ratio of the amine compound (63%). Moisture had a promoting effect on the sorption separation of CO2. In addition, the developed sorbent could be regenerated easily at 100 degrees C, and it exhibited excellent regenerability and stability. These results indicate that this PEI-loaded mesoporous carbon sorbent should have a good potential for CO2 capture in the future.

  20. Method of carbon dioxide-free hydrogen production from hydrocarbon decomposition over metal salts

    Energy Technology Data Exchange (ETDEWEB)

    Erlebacher, Jonah; Gaskey, Bernard

    2017-10-03

    A process to decompose methane into carbon (graphitic powder) and hydrogen (H.sub.2 gas) without secondary production of carbon dioxide, employing a cycle in which a secondary chemical is recycled and reused, is disclosed.

  1. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Science.gov (United States)

    A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

  2. Soil carbon dioxide (CO2) efflux of two shrubs in response to plant ...

    African Journals Online (AJOL)

    Jane

    2010-10-11

    , Institute of Soil and Water ... Although plant density should affect soil carbon dioxide (CO2) efflux and carbon cycling in semi-arid regions, the effects ...... root and microbial contributions to soil respiration in Leymus chinensis ...

  3. Assessing the Health and Performance Risks of Carbon Dioxide Exposures

    Science.gov (United States)

    James, John T.; Meyers, V. E.; Alexander, D.

    2010-01-01

    Carbon dioxide (CO2) is an anthropogenic gas that accumulates in spacecraft to much higher levels than earth-normal levels. Controlling concentrations of this gas to acceptable levels to ensure crew health and optimal performance demands major commitment of resources. NASA has many decades of experience monitoring and controlling CO2, yet we are uncertain of the levels at which subtle performance decrements develop. There is limited evidence from ground-based studies that visual disturbances can occur during brief exposures and visual changes have been noted in spaceflight crews. These changes may be due to CO2 alone or in combination with other known spaceflight factors such as increased intracranial pressure due to fluid shifts. Discerning the comparative contribution of each to performance decrements is an urgent issue if we hope to optimize astronaut performance aboard the ISS. Long-term, we must know the appropriate control levels for exploration-class missions to ensure that crewmembers can remain cooperative and productive in a highly stressful environment. Furthermore, we must know the magnitude of interindividual variability in susceptibility to the adverse effects of CO2 so that the most tolerant crewmembers can be identified. Ground-based studies have been conducted for many years to set exposure limits for submariners; however, these studies are typically limited and incompletely reported. Nonetheless, NASA, in cooperation with the National Research Council, has set exposure limits for astronauts using this limited database. These studies do not consider the interactions of spaceflight-induced fluid shifts and CO2 exposures. In an attempt to discern whether CO2 levels affect the incidence of headache and visual disturbances in astronauts we performed a retrospective study comparing average CO2 levels and the prevalence of headache and visual disturbances. Our goal is to narrow gaps in the risk profile for in-flight CO2 exposures. Such studies can

  4. GOSAT observations of anthropogenic emission of carbon dioxide and methane

    Science.gov (United States)

    Janardanan, Rajesh; Maksyutov, Shamil; Oda, Tomohiro; Saito, Makoto; Ito, Akihiko; Kaiser, Johannes W.; Ganshin, Alexander; Yoshida, Yukio; Yokota, Tatsuya; Matsunaga, Tsuneo

    2017-04-01

    Carbon dioxide (CO2) and methane (CH4) are the most important greenhouse gases in terms of radiative forcing. Human activities such as combustion of fossil fuel (for CO2), and gas leakage, animal agriculture, rice cultivation and landfill emissions (for CH4), are considered to be major sources of their emissions. Global emissions datasets usually depend on emission estimates reported by countries, which are seldom evaluated in an objective way. Here we present a method for delineating anthropogenic contributions to global atmospheric CO2 and CH4 (2009-2014) concentration fields using GOSAT observations of column-average dry air mole fractions (XCO2 and XCH4) and atmospheric transport model simulations using high-resolution emissions datasets (ODIAC for CO2 and EDGAR for CH4). The XCO2 and XCH4 concentration enhancements due to anthropogenic emissions are estimated at all GOSAT observation locations using the transport model simulation. We calculated threshold values to classify GOSAT observations into two categories: (1) data influenced by the anthropogenic sources and (2) those not influenced. We defined a clean background (averaged concentrations of GOSAT data that are free from contamination) in 10˚ ×10˚ regions over the globe and subtracted the background values from individual GOSAT observations. The anomalies (GOSAT observed values minus background values) were binned and compared to model-based anomalies over continental regions and selected countries. For CO2, we have found global and regional linear relationships between model and observed anomalies especially for Eurasia and North America. The analysis for East Asian region showed a systematic bias that is somewhat comparable in magnitude to the uncertainties in emission inventories in that region, which were reported by recent studies. In the case of CH4, we found a good match between inventory-based estimates and GOSAT observations for continental regions and large countries. The inventory

  5. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    Carbon dioxide (CO2) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO2 concentration from c. 380 μmol...... concentration, and the flux also decreased in FACE plots, to 0.79 times that at low concentration. Similar SR in control plots was decreased 0.94 times in control plots and 0.88 times in FACE plots. We found that a useful method to achieve stable and reproducible chamber headspace and soil CO2 concentration...... prior to commencement of flux measurements was to turn off the FACE system at least 10 min in advance. Within 10 min a new equilibrium was established between the soil and atmosphere, apparently due to CO2 degassing from the top soil. The observed increase in SR in response to increased CO2 persisted...

  7. Natural land carbon dioxide exchanges in the ECMWF integrated forecasting system: Implementation and offline validation

    NARCIS (Netherlands)

    Boussetta, S.; Balsamo, G.; Beljaars, A.C.M.; Panareda, A.A.; Calvet, J.C.; Jacobs, C.M.J.; Hurk, van den B.J.J.M.; Viterbo, P.; Lafont, S.; Dutra, E.

    2013-01-01

    The European Centre for Medium-Range Weather Forecasts land surface model has been extended to include a carbon dioxide module. This relates photosynthesis to radiation, atmospheric carbon dioxide (CO2) concentration, soil moisture, and temperature. Furthermore, it has the option of deriving a

  8. Uncertainities in carbon dioxide radiative forcing in atmospheric general circulation models

    Energy Technology Data Exchange (ETDEWEB)

    Cess, R.D.; Zhang, M.H. (State Univ. of New York, Stony Brook, NY (United States)); Potter, G.L.; Gates, W.L.; Taylor, K.E. (Lawrence Livermore National Laboratory, CA (United States)); Colman, R.A.; Fraser, J.R.; McAvaney, B.J. (Bureau of Meterorology Research Centre, Victoria (Australia)); Dazlich, D.A.; Randall, D.A. (Colorado State Univ., Fort Collins, CO (United States)); Del Genio, A.D.; Lacis, A.A. (Goddard Institute for Space Studies, New York, NY (United States)); Esch, M.; Roeckner, E. (Max Planck Institute for Meteorology, Hamburg (Germany)); Galin, V. (Russian Academy of Sciences, Moscow (Russian Federation)); Hack, J.J.; Kiehl, J.T. (National Center for Atmospheric Research, Boulder, CO (United States)); Ingram, W.J. (Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)); Le Treut, H.; Lli, Z.X. (Laboratoire de Meteorologie Dynamique, Paris (France)); Liang, X.Z.; Wang, W.C. (State Univ. of New York, Albany, NY (United States)); Mahfouf,

    1993-11-19

    Global warming, caused by an increase in the concentrations of greenhouse gases, is the direct result of greenhouse gas-induced radiative forcing. When a doubling of atmospheric carbon dioxide is considered, this forcing differed substantially among 15 atmospheric general circulation models. Although there are several potential causes, the largest contributor was the carbon dioxide radiation parameterizations of the models.

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

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-02-01

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

  10. Evaluation of a membrane based carbon dioxide absorber for spacecraft ECLS applications

    NARCIS (Netherlands)

    Feron, P.H.M.; Eckhard, F.; Witt, J.

    1996-01-01

    In an on-going harmonized ESA/NIVR project, performed by Stork Comprimo and TNO-MEP, the removal of the carbon dioxide with membranes is studied. The use of membrane gas absorption for carbon dioxide removal is currently hampered by the fact that the commonly used alkanolamines result in leakage

  11. 46 CFR 167.45-1 - Steam, carbon dioxide, and halon fire extinguishing systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steam, carbon dioxide, and halon fire extinguishing....45-1 Steam, carbon dioxide, and halon fire extinguishing systems. (a) General requirements. (1...-extinguishing system. On such vessels contracted for prior to January 1, 1962, a steam smothering system may be...

  12. The polity and politics of carbon-dioxide taxation in small European states

    DEFF Research Database (Denmark)

    Andersen, Mikael Skou

    The most recent smaller country to adopt a carbon dioxide tax is Portugal (2014), but also Iceland (2013), Ireland (2010), Switzerland (2008), Croatia (2007), Estonia (2000) and Slovenia (1997) have managed to find ways to put into place taxes on carbon dioxide. France (2014) remains the exception...

  13. 21 CFR 874.4500 - Ear, nose, and throat microsurgical carbon dioxide laser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear, nose, and throat microsurgical carbon dioxide laser. 874.4500 Section 874.4500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND..., nose, and throat microsurgical carbon dioxide laser. (a) Identification. An ear, nose, and throat...

  14. 75 FR 8431 - Carbon Dioxide Fire Suppression Systems on Commercial Vessels

    Science.gov (United States)

    2010-02-24

    ...--Marine engineering, vital 62.25-20. systems automation. 71, 76, 78--Subchapter H 71.20-20, 71.25-20, 71... tested and marked, and all flexible connections on fixed carbon dioxide systems must be tested or renewed... Homeland Security Coast Guard 46 Parts 25, 27, 28, et al. Carbon Dioxide Fire Suppression Systems on...

  15. The importance of groundwater-derived carbon dioxide in the restoration of small Sphagnum bogs

    NARCIS (Netherlands)

    Patberg, Wouter; Baaijens, Gert Jan; Smolders, Alfons J. P.; Grootjans, Ab P.; Elzenga, J. Theo M.

    Essential for successful bog restoration is the reestablishment of Sphagnum mosses. High carbon dioxide availability has been shown to be of great importance for the growth of Sphagnum mosses. In well-developed Sphagnum bogs large amounts of carbon dioxide are produced by (an)aerobic decomposition

  16. Environmental controls on the seasonal carbon dioxide fluxes in the northeastern Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Maya, M.V.; Shetye, S.; PrasannaKumar, S.; Fernandes, V.; Paul, J.; Ramaiah, N.

    Total carbon dioxide (TCO sub(2)) and computations of partial pressure of carbon dioxide (pCO sub(2)) had been examined in Northerneastern region of Indian Ocean. It exhibit seasonal and spatial variability. North-south gradients in the pCO sub(2...

  17. Two-Dimensional Covalent Organic Frameworks for Carbon Dioxide Capture through Channel-Wall Functionalization

    NARCIS (Netherlands)

    Huang, N.; Chen, X.; Krishna, R.; Jiang, D.

    2015-01-01

    Ordered open channels found in two-dimensional covalent organic frameworks (2D COFs) could enable them to adsorb carbon dioxide. However, the frameworks' dense layer architecture results in low porosity that has thus far restricted their potential for carbon dioxide adsorption. Here we report a

  18. Emission of carbon dioxide from a tropical estuarine system, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; Manerikar, M.

    Carbon dioxide species were studied in Mandovi-Zuari system, a tropical estuarine complex influenced by strong monsoonal run-off, with implications to build up and air-water exchange of CO sub(2) . Total carbon dioxide (TOC sub(2)) behaved...

  19. A study of the carbon dioxide system in the northern Indian Ocean during premonsoon

    Digital Repository Service at National Institute of Oceanography (India)

    George, M.D.; DileepKumar, M.; Naqvi, S.W.A.; Banerjee, S.; Narvekar, P.V.; DeSousa, S.N.; Jayakumar, D.A.

    Extensive data sets on the carbon dioxide system in the northern Indian Ocean have been obtained during the premonsoon season. A marked increase (~50 ~kM) in the total carbon dioxide (TCO@d2@@) content is observedin deep (~. 1 km) waters...

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

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-04-01

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

  1. Accuracy of transcutaneous carbon dioxide tension measurements during cardiopulmonary exercise testing.

    NARCIS (Netherlands)

    Stege, G.; Elshout, F.J.J. van den; Heijdra, Y.F.; Ven, M.J.T. van de; Dekhuijzen, P.N.R.; Vos, P.J.E.

    2009-01-01

    BACKGROUND: Measurements of transcutaneous carbon dioxide tension (PtcCO(2)) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO(2)) in several settings but not during cardiopulmonary exercise testing (CPET).

  2. DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

    Energy Technology Data Exchange (ETDEWEB)

    OGDEN DM; KIRCH NW

    2007-10-31

    This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

  3. Estimating diesel fuel consumption and carbon dioxide emissions from forest road construction

    Science.gov (United States)

    Dan Loeffler; Greg Jones; Nikolaus Vonessen; Sean Healey; Woodam Chung

    2009-01-01

    Forest access road construction is a necessary component of many on-the-ground forest vegetation treatment projects. However, the fuel energy requirements and associated carbon dioxide emissions from forest road construction are unknown. We present a method for estimating diesel fuel consumed and related carbon dioxide emissions from constructing forest roads using...

  4. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480...CO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive heated sensor and a pH-sensitive glass electrode placed on a patient's skin, which is intended to monitor...

  5. Carbon Dioxide Absorbers: An Engaging Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Ticich, Thomas M.

    2011-01-01

    A simple and direct method for measuring the absorption of carbon dioxide by two different substances is described. Lithium hydroxide has been used for decades to remove the gas from enclosed living spaces, such as spacecraft and submarines. The ratio of the mass of carbon dioxide absorbed to the mass of lithium hydroxide used obtained from this…

  6. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Science.gov (United States)

    2010-04-01

    ... still wine. 24.245 Section 24.245 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.245 Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine...

  7. Analysis of carbon dioxide, water vapour and energy fluxes over an ...

    Indian Academy of Sciences (India)

    temperate grassland ecosystem; Bound.-Layer Meteorol. 52 135–149. Mahrt L and Dean V 2002 Relationship of area-averaged carbon dioxide and water vapour fluxes to atmospheric variables; Agric. For. Meteor. 112 195–202. Ohtaki E 1984 Application of an infrared carbon dioxide and humidity instrument to studies of ...

  8. Measuring the impact of global tropospheric ozone, carbon dioxide and sulfur dioxide concentrations on biodiversity loss.

    Science.gov (United States)

    Ahmed Bhuiyan, Miraj; Rashid Khan, Haroon Ur; Zaman, Khalid; Hishan, Sanil S

    2018-01-01

    The aim of this study is to examine the impact of air pollutants, including mono-nitrogen oxides (NOx), nitrous oxide (N2O), sulfur dioxide (SO2), carbon dioxide emissions (CO2), and greenhouse gas (GHG) emissions on ecological footprint, habitat area, food supply, and biodiversity in a panel of thirty-four developed and developing countries, over the period of 1995-2014. The results reveal that NOx and SO2 emissions both have a negative relationship with ecological footprints, while N2O emission and real GDP per capita have a direct relationship with ecological footprints. NOx has a positive relationship with forest area, per capita food supply and biological diversity while CO2 emission and GHG emission have a negative impact on food production. N2O has a positive impact on forest area and biodiversity, while SO2 emissions have a negative relationship with them. SO2 emission has a direct relationship with per capita food production, while GDP per capita significantly affected per capita food production and food supply variability across countries. The overall results reveal that SO2, CO2, and GHG emissions affected potential habitat area, while SO2 and GHG emissions affected the biodiversity index. Trade liberalization policies considerably affected the potential habitat area and biological diversity in a panel of countries. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Electrocatalytic Transformation of Carbon Dioxide into Low Carbon Compounds on Conducting Polymers Derived from Multimetallic Porphyrins.

    Science.gov (United States)

    Dreyse, Paulina; Honores, Jessica; Quezada, Diego; Isaacs, Mauricio

    2015-11-01

    The electrochemical reduction of carbon dioxide is studied herein by using conducting polymers based on metallotetraruthenated porphyrins (MTRPs). The polymers on glassy carbon electrodes were obtained by electropolymerization processes of the monomeric MTRP. The linear sweep voltammetry technique resulted in polymeric films that showed electrocatalytic activity toward carbon dioxide reduction with an onset potential of -0.70 V. The reduction products obtained were hydrogen, formic acid, formaldehyde, and methanol, with a tendency for a high production of methanol with a maximum value of turnover frequency equal to 15.07 when using a zinc(II) polymeric surface. Studies of the morphology (AFM) and electrochemical impedance spectroscopy results provide an adequate background to explain that the electrochemical reduction is governed by the roughness of the polymer, for which the possible mechanism involves a series of one-electron reduction reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Anthropogenic And Biogenic Carbon Dioxide Fluxes in Urban Houston

    Science.gov (United States)

    Werner, N. D.; Schade, G. W.; Savage, J.; Hale, M.

    2011-12-01

    Approximately 5% of North American land cover is characterized as urban, representing a large source of anthropogenic carbon to the atmosphere but also an unknown sink in urban vegetation and its management. We present measurements of energy and trace gas fluxes from a unique urban research site in Houston, Texas, with a focus on evaluating the anthropogenic and biogenic contributions to the measured net CO2 exchange at this site. Eddy covariance carbon dioxide flux measurements, and CO2 and NOx flux gradient measurements have been operated (with a one-year gap) since mid 2007 from a commercial communications tower north of downtown Houston. In addition, leaf-level and soil CO2 efflux measurements were carried out in the tower's footprint region in 2011. Bottom-up estimates were developed for anthropogenic CO2 fluxes through correlation with CO, traffic count and natural gas use data, and for biogenic CO2 fluxes through modeling soil and plant respiration, and photosynthesis. CO, NO¬x, and CO2 data were strongly correlated during the morning rush hours, and were used to extrapolate CO2 emissions from traffic using measured biweekly to monthly CO (NOx) flux averages. CO emissions from natural gas use were extrapolated from monthly gas consumption data. The results will be compared to a top-down flux estimate that uses quadrant analysis of CO2 fluxes with simultaneously acquired heat and water vapor fluxes to distinguish biogenic (high q'C' correlation) from anthropogenic (high T'C' correlation) carbon flux contributions. First results from both bottom-up and top-down flux estimates will be presented. The successful implementation of this new analysis may allow us to better judge the importance of constantly growing urban areas in the North American carbon cycle. It addresses identified gaps in carbon cycle knowledge and can help in validating inventories and improving estimates of carbon cycling.

  11. Permeability, diffusivity and solubility of carbon dioxide in fluoropolymers: An experimental and modeling study

    DEFF Research Database (Denmark)

    Neela, Vasu; von Solms, Nicolas

    2014-01-01

    Carbon dioxide has successfully been used as an alternative refrigerant in many applications, replacing chlorofluoro- and hydrofluorocarbons (CFCs and HFCs), due to its negligible ozone depletion and significantly lower global warming potential. However, the use of carbon dioxide as a refrigerant....... Using a high-pressure permeation cell, the permeability and diffusivity of carbon dioxide were measured in several polymers used as packing and sealing materials. These were the fluoropolymers PTFE, FKM and TFM, both pure and containing glass, graphite, Ekonol and polysulfone as additives....... The solubility coefficient of carbon dioxide in these polymers was then obtained as the ratio of the measured permeability and diffusivity data. Measurements were carried out over a pressure range of 45-50 bar and a temperature range of 40-80 °C. The solubility of carbon dioxide in the polymers is then modeled...

  12. Process systems engineering issues and applications towards reducing carbon dioxide emissions through conversion technologies

    DEFF Research Database (Denmark)

    Roh, Kosan; Frauzem, Rebecca; Gani, Rafiqul

    2016-01-01

    This paper reviews issues and applications for design of sustainable carbon dioxide conversion processes, specifically through chemical conversion, and the integration of the conversion processes with other systems from a process systems engineering (PSE) view-point. Systematic and computer......-aided methods and tools for reaction network generation, processing route generation, process design/optimization, and sustainability analysis are reviewed with respect to carbon dioxide conversion. Also, the relevant gaps and opportunities are highlighted. In addition, the integration of carbon dioxide...... conversion processes with other systems including coexisting infrastructure and carbon dioxide sources is described.Then, the importance of PSE based studies for such application is discussed. Finally, some perspectives on the status and future directions of carbon dioxide conversion technology...

  13. Numerical Simulations of Glaciogenic Cloud Seeding with Dry Ice Pellets and Liquid Carbon Dioxide under Simplified Conditions

    National Research Council Canada - National Science Library

    Hashimoto, Akihiro; Murakami, Masataka

    2016-01-01

    Dry ice (DI, solid carbon dioxide) and liquid carbon dioxide (LC) are both used in airborne glaciogenic cloud seeding, but no studies have objectively compared the efficacies of those two seeding agents...

  14. Carbon Dioxide and Nisin Act Synergistically on Listeria monocytogenes

    Science.gov (United States)

    Nilsson, Lilian; Chen, Yuhuan; Chikindas, Michael L.; Huss, Hans Henrik; Gram, Lone; Montville, Thomas J.

    2000-01-01

    This paper examines the synergistic action of carbon dioxide and nisin on Listeria monocytogenes Scott A wild-type and nisin-resistant (Nisr) cells grown in broth at 4°C. Carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree in the Nisr cells. Wild-type cells grown in 100% CO2 were two to five times longer than cells grown in air. Nisin (2.5 μg/ml) did not decrease the viability of Nisr cells but for wild-type cells caused an immediate 2-log reduction of viability when they were grown in air and a 4-log reduction when they were grown in 100% CO2. There was a quantifiable synergistic action between nisin and CO2 in the wild-type strain. The MIC of nisin for the wild-type strain grown in the presence of 2.5 μg of nisin per ml increased from 3.1 to 12.5 μg/ml over 35 days, but this increase was markedly delayed for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic membrane. Liposomes made from cells grown in a CO2 atmosphere were even more sensitive to nisin action. Liposomes made from cells grown at 4°C were dramatically more nisin sensitive than were liposomes derived from cells grown at 30°C. Cells grown in the presence of 100% CO2 and those grown at 4°C had a greater proportion of short-chain fatty acids. The synergistic action of nisin and CO2 is consistent with a model where membrane fluidity plays a role in the efficiency of nisin action. PMID:10653749

  15. Selection and characterization of new absorbents for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

    Ma' mun, Sholeh

    2005-09-01

    Removal of acidic gases, in particular CO2, is an important industrial operation. Carbon dioxide is produced in large quantities by fossil-fuel-fired power plants, steel production, the production of petrochemicals, cement production, and natural gas purification. The global climate change, where CO2 is found to be a major contributor, is one of the most important and challenging environmental issues facing the world community. This has motivated intensive research on CO2 capture and storage. Carbon dioxide capture by an absorption process is one of the most common industrial technologies today. Recent economic studies indicate that the process will also remain competitive in the future. One of the key improvements under development is new, faster and more energy-efficient absorbents. A chemical to be used as a commercial absorbent must have high net cyclic capacity, high absorption rate for CO2 and good chemical stability. Alkanolamines are the most commonly used chemical absorbents for the removal of acidic gases today. In the first part of this thesis, an experimental screening of new absorbents for CO2 capture was performed by absorption of CO2 into both single absorbents and absorbent mixtures for amine-based and non-amine-based systems at 40 deg. Celsius From testing of approx. 30 systems, it was found that an aqueous 30 mass % AEEA (2-(2-aminoethyl-amino)ethanol) solution seems to be a potentially good absorbent for capturing CO2 from atmospheric flue gases. It offers high absorption rate combined with high absorption capacity. In addition toAEEA, MMEA (2-(methylamino)ethanol) also needs to be considered. It could have a good potential when used in contactors where the two phases are separated, like in membrane contactors, whereas indications from the study showed foaming tendencies that will make it difficult to use in ordinary towers. AEEA as the selected absorbent obtained from the screening tests was further investigated to determine its vapor

  16. The alkenone-CO2 proxy and ancient atmospheric carbon dioxide.

    Science.gov (United States)

    Pagani, Mark

    2002-04-15

    Cenozoic climates have varied across a variety of time-scales, including slow, unidirectional change over tens of millions of years, as well as severe, geologically abrupt shifts in Earth's climatic state. Establishing the history of atmospheric carbon dioxide is critical in prioritizing the factors responsible for past climatic events, and integral in positioning future climate change within a geological context. One approach in this pursuit uses the stable carbon isotopic composition of marine organic molecules known as alkenones. The following report represents a summary of the factors affecting alkenone carbon isotopic compositions, the underlying assumptions and accuracy of short- and long-term CO(2) records established from these sedimentary molecules, and their implications for the controls on the evolution of Cenozoic climates.

  17. Sustainable chemical processing and energy-carbon dioxide management: review of challenges and opportunities

    DEFF Research Database (Denmark)

    Vooradi, Ramsagar; Bertran, Maria-Ona; Frauzem, Rebecca

    2017-01-01

    This paper presents a brief review of the available energy sources for consumption, their effects in terms of CO2-emission and its management, and sustainable chemical processing where energy-consumption, CO2-emission, as well as economics and environmental impacts are considered. Not all availab...... are presented. These examples highlight issues of energy sustainable design, energy-CO2 neutral design, energy-retrofit design,and energy-process intensification. Finally, some perspectives on the status and future directions of carbon dioxide management are given....

  18. Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide

    Science.gov (United States)

    Juliá-Hernández, Francisco; Moragas, Toni; Cornella, Josep; Martin, Ruben

    2017-05-01

    Catalytic carbon-carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules. It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites. Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly.

  19. Phase-Change Aminopyridines as Carbon Dioxide Capture Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Malhotra, Deepika [Energy Processes and Materials; Page, Jordan P. [Energy Processes and Materials; Bowden, Mark E. [Energy Processes and Materials; Karkamkar, Abhijeet [Energy Processes and Materials; Heldebrant, David J. [Energy Processes and Materials; Glezakou, Vassiliki-Alexandra [Energy Processes and Materials; Rousseau, Roger [Energy Processes and Materials; Koech, Phillip K. [Energy Processes and Materials

    2017-06-22

    Carbon dioxide is the main atmospheric greenhouse gas released from industrial point sources. In order to mitigate adverse environmental effects of these emissions, carbon capture, storage and utilization is required. To this end, several CO2 capture technologies are being developed for application in carbon capture, which include aqueous amines and water-lean solvents. Herein we report new aminopyridine solvents with the potential for CO2 capture from coal-fired power plants. These four solvents 2-picolylamine, 3-picolylamine, 4-picolylamine and N’-(pyridin-4-ylmethyl)ethane-1,2-diamine are liquids that rapidly bind CO2 to form crystalline solids at standard room temperature and pressure. These solvents have displayed high CO2 capture capacity (11 - 20 wt%) and can be regenerated at temperatures in the range of 120 - 150 C. The advantage of these primary aminopyridine solvents is that crystalline salt product can be separated, making it possible to regenerate only the CO2-rich solid ultimately resulting in reduced energy penalty.

  20. Endogenous gas formation of carbon dioxide used for wound flooding--an experimental study with implications regarding gas microembolism during cardiopulmonary bypass.

    Science.gov (United States)

    Lindholm, L; Engström, K G

    2014-05-01

    Gas microembolisation is an identified risk in cardiac surgery. Flooding the wound with carbon dioxide is a method proposed to reduce this problem. The high solubility of carbon dioxide is beneficial, but may also cause problems. The gas solubility diminishes at warming and endogenous bubbles are formed when cold blood saturated with carbon dioxide is returned by cardiotomy suction. The release of endogenous gas was measured at high resolution in an experimental digital model. A medium (water or blood) was incubated and equilibrated with gas (100% carbon dioxide or air) at a low temperature (10 °C or 23 °C). The temperature was increased to 37 °C and the gas release was measured, at rest and at fluid motion. The amount of carbon dioxide released at warming was substantial for both water and blood (both p=0.005). The effect was more pronounced when the temperature differential increased (p=0.005). However, blood and water differed in these terms: with water, the release of carbon-dioxide started instantly at warming; with blood, carbon dioxide remained dissolved and was released at fluid motion. When blood was warmed from 10 °C to 37 °C, the gas release corresponded to 44.4% (40.6/46.5) of the medium volume (median with quartile range). Gas dissolved in a medium becomes released at warming, as confirmed here. Blood exposed to carbon dioxide became heavily oversaturated at warming, with the gas instantly released at fluid motion. The amount of contained gas increased with a higher temperature differential. Our study has relevance to wound flushing, using carbon dioxide, in cardiac surgery. The clinical consequences of these findings remain to be answered.