WorldWideScience

Sample records for carbon dioxide concentration

  1. 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....

  2. 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....... Thus hyperkalaemia is unlikely to develop in patients with normal renal function undergoing carbon dioxide pneumoperitoneum for laparoscopic surgery....

  3. 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…

  4. Carbon dioxide concentration in Mediterranean greenhouses : how much lost production?

    NARCIS (Netherlands)

    Stanghellini, C.; Incrocci, L.; Gazquez, J.C.; Dimauro, B.

    2008-01-01

    In the absence of artificial supply of carbon dioxide in the greenhouse environment, the CO2 absorbed in the process of photosynthesis must ultimately come from the external ambient through the ventilation openings. This requires that the CO2 concentration within the house must be lower than the ext

  5. Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids.

    Science.gov (United States)

    Boullis, Antoine; Fassotte, Bérénice; Sarles, Landry; Lognay, Georges; Heuskin, Stéphanie; Vanderplanck, Maryse; Bartram, Stefan; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2017-02-01

    Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.

  6. New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

    Science.gov (United States)

    Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

    2015-12-01

    The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations.

  7. 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...... is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16...

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Luthi, D.; Bereiter, B.; Blunier, T.; Siegenthaler, U.; Kawamura, K.; Stocker, T.F. [Climate and Environm. Physics, Physics Inst., Univ. Bern, CH-3012 Bern, (Switzerland); Luthi, D.; Bereiter, B.; Blunier, T.; Siegenthaler, U.; Kawamura, K.; Stocker, T.F. [Oeschger Centre for Climate Change Research, Univ. Bern, CH-3012 Bern, (Switzerland); Le Floch, M.; Barnola, J.M.; Raynaud, D. [LGGE, CNRS-Univ. Grenoble 1, F-38402 Saint Martin d' Heres, (France); Jouzel, J. [Inst. Pierre Simon Laplace, LSCE, CEA-CNRS-Universite Versailles-Saint Quentin, CEA Saclay, F-91191 Gif sur Yvette (France); Fischer, H. [Alfred Wegener Inst. for Polar and Maine Research, D-27568 Bremerhaven, (Germany)

    2008-07-01

    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 is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16, possibly reflecting more pronounced oceanic carbon storage. We report the lowest carbon dioxide concentration measured in an ice core, which extends the pre-industrial range of carbon dioxide concentrations during the late Quaternary by about 10 p.p.m.v. to 172-300 p.p.m.v. (authors)

  10. Life support system cost study: Addendum to cost analysis of carbon dioxide concentrators

    Science.gov (United States)

    Yakut, M. M.

    1973-01-01

    New cost data are presented for the Hydrogen-Depolarized Carbon Dioxide Concentrator (HDC), based on modifying the concentrator to delete the quick disconnect valves and filters included in the system model defined in MDC-G4631. System description, cost data and a comparison between CO2 concentrator costs are presented.

  11. Selective carboxylate production by controlling hydrogen, carbon dioxide and substrate concentrations in mixed culture fermentation

    NARCIS (Netherlands)

    Arslan, D.; Steinbusch, K.J.J.; Diels, L.; Wever, de H.; Hamelers, H.V.M.; Buisman, C.J.N.

    2013-01-01

    This research demonstrated the selective production of n-butyrate from mixed culture by applying 2 bar carbon dioxide into the headspace of batch fermenters or by increasing the initial substrate concentration. The effect of increasing initial substrate concentration was investigated at 8, 13.5 and

  12. New Adsorption Cycles for Carbon Dioxide Capture and Concentration

    Energy Technology Data Exchange (ETDEWEB)

    James Ritter; Armin Ebner; Steven Reynolds Hai Du; Amal Mehrotra

    2008-07-31

    The objective of this three-year project was to study new pressure swing adsorption (PSA) cycles for CO{sub 2} capture and concentration at high temperature. The heavy reflux (HR) PSA concept and the use of a hydrotalcite like (HTlc) adsorbent that captures CO{sub 2} reversibly at high temperatures simply by changing the pressure were two key features of these new PSA cycles. Through the completion or initiation of nine tasks, a bench-scale experimental and theoretical program has been carried out to complement and extend the process simulation study that was carried out during Phase I (DE-FG26-03NT41799). This final report covers the entire project from August 1, 2005 to July 31, 2008. This program included the study of PSA cycles for CO{sub 2} capture by both rigorous numerical simulation and equilibrium theory analysis. The insight gained from these studies was invaluable toward the applicability of PSA for CO{sub 2} capture, whether done at ambient or high temperature. The rigorous numerical simulation studies showed that it is indeed possible to capture and concentrate CO{sub 2} by PSA. Over a wide range of conditions it was possible to achieve greater than 90% CO{sub 2} purity and/or greater than 90% CO{sub 2} recovery, depending on the particular heavy reflux (HR) PSA cycle under consideration. Three HR PSA cycles were identified as viable candidates for further study experimentally. The equilibrium theory analysis, which represents the upper thermodynamic limit of the performance of PSA process, further validated the use of certain HR PSA cycles for CO{sub 2} capture and concentration. A new graphical approach for complex PSA cycle scheduling was also developed during the course of this program. This new methodology involves a priori specifying the cycle steps, their sequence, and the number of beds, and then following a systematic procedure that requires filling in a 2-D grid based on a few simple rules, some heuristics and some experience. It has been

  13. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Directory of Open Access Journals (Sweden)

    Randhir K Bharti

    Full Text Available A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO. The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC, however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  14. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Science.gov (United States)

    Bharti, Randhir K; Srivastava, Shaili; Thakur, Indu Shekhar

    2014-01-01

    A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO). The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC), however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  15. Influence of the carbon dioxide concentration on the resistance to carbonation of concrete

    NARCIS (Netherlands)

    Visser, J.H.M.

    2013-01-01

    Carbonation of concrete at ambient CO2 concentration is a slow process. This makes the testing of the resistance of concrete against carbonation often too slow to be applicable for service life assessments of new structures. Raising the CO2-concentration will accelerate the test but the validity of

  16. Effects of increasing seawater carbon dioxide concentrations on chain formation of the diatom Asterionellopsis glacialis.

    Directory of Open Access Journals (Sweden)

    Joana Barcelos e Ramos

    Full Text Available Diatoms can occur as single cells or as chain-forming aggregates. These two strategies affect buoyancy, predator evasion, light absorption and nutrient uptake. Adjacent cells in chains establish connections through various processes that determine strength and flexibility of the bonds, and at distinct cellular locations defining colony structure. Chain length has been found to vary with temperature and nutrient availability as well as being positively correlated with growth rate. However, the potential effect of enhanced carbon dioxide (CO2 concentrations and consequent changes in seawater carbonate chemistry on chain formation is virtually unknown. Here we report on experiments with semi-continuous cultures of the freshly isolated diatom Asterionellopsis glacialis grown under increasing CO2 levels ranging from 320 to 3400 µatm. We show that the number of cells comprising a chain, and therefore chain length, increases with rising CO2 concentrations. We also demonstrate that while cell division rate changes with CO2 concentrations, carbon, nitrogen and phosphorus cellular quotas vary proportionally, evident by unchanged organic matter ratios. Finally, beyond the optimum CO2 concentration for growth, carbon allocation changes from cellular storage to increased exudation of dissolved organic carbon. The observed structural adjustment in colony size could enable growth at high CO2 levels, since longer, spiral-shaped chains are likely to create microclimates with higher pH during the light period. Moreover increased chain length of Asterionellopsis glacialis may influence buoyancy and, consequently, affect competitive fitness as well as sinking rates. This would potentially impact the delicate balance between the microbial loop and export of organic matter, with consequences for atmospheric carbon dioxide.

  17. Dynamic responses of atmospheric carbon dioxide concentration to global temperature changes between 1850 and 2010

    Science.gov (United States)

    Wang, Weile; Nemani, Ramakrishna

    2016-02-01

    Changes in Earth's temperature have significant impacts on the global carbon cycle that vary at different time scales, yet to quantify such impacts with a simple scheme is traditionally deemed difficult. Here, we show that, by incorporating a temperature sensitivity parameter (1.64 ppm yr-1 °C-1) into a simple linear carbon-cycle model, we can accurately characterize the dynamic responses of atmospheric carbon dioxide (CO2) concentration to anthropogenic carbon emissions and global temperature changes between 1850 and 2010 ( r 2 > 0.96 and the root-mean-square error reservoir (~12 year) approximates the long-term temperature sensitivity of global atmospheric CO2 concentration (~15 ppm °C-1), generally consistent with previous estimates based on reconstructed CO2 and climate records over the Little Ice Age. Our results suggest that recent increases in global surface temperatures, which accelerate the release of carbon from the surface reservoirs into the atmosphere, have partially offset surface carbon uptakes enhanced by the elevated atmospheric CO2 concentration and slowed the net rate of atmospheric CO2 sequestration by global land and oceans by ~30% since the 1960s. The linear modeling framework outlined in this paper thus provides a useful tool to diagnose the observed atmospheric CO2 dynamics and monitor their future changes.

  18. In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand.

    Science.gov (United States)

    Luangprasert, Maytat; Vasithamrong, Chainarin; Pongratananukul, Suphasit; Chantranuwathana, Sunhapos; Pumrin, Suree; De Silva, I P D

    2016-12-14

    It is known that in-vehicle carbon dioxide (CO2) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO2 concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied. This decay was found to follow Fickian diffusion process. The paper also provides useful operational details of the automotive HVAC system and fresh air ventilation exchange between cabin interior and exterior.

  19. A century of human-driven changes in the carbon dioxide concentration of lakes

    Science.gov (United States)

    Perga, Marie-Elodie; Maberly, Stephen C.; Jenny, Jean-Philippe; Alric, Benjamin; Pignol, Cécile; Naffrechoux, Emmanuel

    2016-02-01

    Now that evasion of carbon dioxide (CO2) from inland waters is accounted for in global carbon models, it is crucial to quantify how these fluxes have changed in the past and forecast how they may alter in the future in response to local and global change. Here we developed a sediment proxy for the concentration of summer surface dissolved CO2 concentration and used it to reconstruct changes over the past 150 years for three large lakes that have been affected by climate warming, changes in nutrient load, and detrital terrigenous supplies. Initially CO2 neutral to the atmosphere, all three lakes subsequently fluctuated between near equilibrium and supersaturation. Although catchment inputs have supplied CO2 to the lakes, internal processes and reallocation have ultimately regulated decadal changes in lake surface CO2 concentration. Nutrient concentration has been the dominant driver of CO2 variability for a century although the reproducible, nonmonotonic relationship of CO2 to nutrient concentration suggests an interplay between metabolic and chemical processes. Yet for two of these lakes, climatic control of CO2 concentrations has been important over the last 30 years, promoting higher surface CO2 concentrations, likely by decreasing hypolimnetic carbon storage. This new approach offers the unique opportunity to scale, a posteriori, the long-term impact of human activities on lake CO2.

  20. Effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root architecture and anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Lee-Ho, E.; Walton, L.J.; Reid, D.M.; Yeung, E.C.; Kurepin, L.V. [Calgary Univ., AB (Canada). Dept. of Biology

    2007-03-15

    Plant root growth is known to be influenced by higher levels of atmospheric carbon dioxide (CO{sub 2}). Roots of some species grown in hydroponics under elevated CO{sub 2} concentrations may be more competitive sinks for photosynthetic assimilates than roots grown under lower CO{sub 2} conditions. Root branching patterns may also be influenced by elevated CO{sub 2} concentrations. Studies have also shown that factors such as soil compaction, salinity and the availability of nitrate, phosphorous, oxygen and water also influence root growth, and the effects of higher CO{sub 2} on roots can be confounded by such environmental factors. This study evaluated the effects of elevated carbon dioxide and sucrose concentrations on Arabidopsis thaliana root growth, morphology, and architecture. Both ambient and elevated CO{sub 2} levels were used along with various sucrose concentrations. The study revealed that A. thaliana plants grown on a phytagar medium in small chambers with elevated CO{sub 2} had longer roots, more lateral root growth than plants grown in ambient CO{sub 2}. Roots in elevated CO{sub 2} were found to have wider root diameters, and more secondary growth. The addition of sucrose to the media closely resembled the effects of elevated CO{sub 2}. In addition, the increase in sucrose concentration had a bigger effect on root morphology under ambient, than elevated CO{sub 2}. Therefore, both elevated CO{sub 2} and increased sucrose concentrations promote root growth by increasing their number, length, and diameter. The dichotomy branching index (DBI) also dropped resulting in a more dichotomous branching pattern. 34 refs., 5 figs.

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

    Science.gov (United States)

    Kasting, J. F.

    1987-01-01

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

  2. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

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

  3. Carbon dioxide as working fluid for medium and high-temperature concentrated solar thermal systems

    Directory of Open Access Journals (Sweden)

    Van Duong

    2014-03-01

    Full Text Available This paper explores the benefits and drawbacks of using carbon dioxide in solar thermal systems at medium and high operating temperatures. For medium temperatures, application of CO2 in non-imaging-optics based compound parabolic concentrators (CPC combined with evacuated-tube collectors is studied. These collectors have been shown to obtain efficiencies higher than 40% operating at around 200℃ without the need of tracking. Validated numerical models of external compound parabolic concentrators (XCPCs are used to simulate their performance using CO2 as working fluid. For higher temperatures, a mathematical model is implemented to analyze the operating performance of a parabolic trough solar collector (PTC using CO2 at temperatures between 100℃ and 600℃.

  4. Physiological responses of Pinus sylvestris to changing carbon dioxide and ozone concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Holopainen, T. [Kuopio Univ. (Finland). Dept. of Ecology and Environmental Science; Palomaeki, V. [Joensuu Univ. (Finland). Faculty of Forestry; Helmisaari, H.S. [Finnish Forest Research Inst., Helsinki (Finland)] [and others

    1996-12-31

    The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a negative chamber effect. The elevated ozone significantly increased the chlorotic mottling and overall yellowing of second year needles as well as caused increased density of chloroplast stroma and declined photosynthesis, all these responses being often related to ozone exposures. The ozone related responses appeared at both CO{sub 2} levels indicating no clear protection due to elevated CO{sub 2}. The ozone or carbon dioxide treatments were not able to significantly change nutrient concentrations, insect herbivory or carbon allocation among the secondary compounds of needles. A tendency of increased carbon allocation to fine roots due to ozone but not so clearly to CO{sub 2} was observed

  5. Effects of carbon dioxide concentration and nutrition on photosynthetic functions of white birch seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. [Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forestry and the Forest Environment; Dang, Q.L. [Lakehead Univ., Thunder Bay, ON (Canada). Faculty of Forest and the Forest Environment; Chinese Academy of Sciences, Beijing (China). Inst. of Botany, Laboratory of Quantitative Vegetation Ecology

    2006-11-15

    Increases in atmospheric carbon dioxide (CO{sub 2}) can impact photosynthesis and dry mass production of plants. This study investigated the physiological responses of white birch seedlings to elevated carbon dioxide (CO{sub 2}) at low and high supplies of nitrogen (N), phosphorus (P) and potassium (K). A 2-way factorial experiment was carried out with birch seedlings grown for 4 months in environment-controlled greenhouses. Elevated CO{sub 2} enhanced maximal carboxylation rate and photosynthetically active radiation-saturated electron transport rates were measured after 2.5 and 3.5 months of treatment, as well as actual photochemical efficiency and photosynthetic linear electron transport to carboxylation. Net photosynthetic rate increases were observed as well as increases in photosynthetic water use efficiency (WUE); photosynthetic N efficiency and P efficiency. Stomatal conductance, transpiration rate and the fraction of total photosynthetic linear electron transport partitioned to oxygenation were reduced. Low nutrient availability decreased net photosynthetic rates, WUE, and triose phosphate utilization. However, photosynthetic linear electron transport and N use efficiency increased. There were significant interactive effects of CO{sub 2} and nutrition over time, with evidence of photosynthetic up-regulation in response to elevated CO{sub 2} in seedlings receiving high nutrition. Photosynthetic depression in response to low nutrient availability was attributed to biochemical limitation rather than stomatal limitation. Elevated CO{sub 2} reduced leaf N concentration in seedlings receiving low nutrition, but had no significant effect on leaf P or K concentrations. High nutrient availability generally increased area-based leaf N, P and K concentrations but had negligible effects on K after 2.5 months of treatment. Results suggested that increases in electron partitioning to photorespiration in response to low nutrient availability may be related to

  6. Photosynthetic responses to understory shade and elevated carbon dioxide concentration in 4 northern hardwood tree species

    Energy Technology Data Exchange (ETDEWEB)

    Sefcik, L.T.; Zak, D.R.; Ellsworth, D.S. [Michigan Univ., Ann Arbor, MI (United States). School of Natural Resources and Environment

    2006-12-15

    Stimulation of photosynthesis in response to elevated carbon dioxide (CO{sub 2}) varies among tree species and species groups. In this study, seedling responses to elevated atmospheric carbon dioxide (CO{sub 2}) concentrations and solar irradiance over 2 growing seasons were investigated for shade tolerant Acer saccharum Marsh.; Fagus grandifolia J.F. Ehrh; and shade-intolerant Prunus serotina. Seedlings were exposed to a combination of elevated and ambient concentrations of CO{sub 2} and understory shade in open-top chambers placed in a forest understory. It was observed that the elevated CO{sub 2} treatment increased mean light-saturated net photosynthetic rates by 63 per cent in the shade-tolerant species and 67 per cent in the shade-intolerant species. When measured at the elevated CO{sub 2}, long-term enhancement of photosynthesis was 10 per cent lower than the instantaneous enhancement observed in ambient-CO{sub 2}-grown plants. As the growth irradiance increased, proportional enhancement due to elevated CO{sub 2} decreased from 97 per cent for plants grown in deep shade to 47 per cent for plants grown in moderate shade. Results indicated that in nitrogen (N) limited northern temperate forests, trees grown in deep shade may display greater photosynthetic gains from a CO{sub 2} enriched atmosphere than trees growing in more moderate shade, due to greater down-regulation. It was concluded that if elevated CO{sub 2} levels promote the survival of shade-intolerant species in dim understory light, the future composition and dynamics of successional forest communities may be altered. 70 refs., 2 tabs., 3 figs.

  7. Transcriptome profiling of the microalga Chlorella pyrenoidosa in response to different carbon dioxide concentrations.

    Science.gov (United States)

    Sun, Xue; Shen, Jia; Bai, Fengwei; Xu, Nianjun

    2016-10-01

    To enrich our knowledge of carbon dioxide (CO2)-concentrating mechanism (CCM) in eukaryotic algae, we used high-throughput sequencing to investigate the transcriptome profiling of the microalga Chlorella pyrenoidosa (Chlorophyta) response to different CO2 levels. Altogether, 53.86 million (M) and 62.10M clean short reads of 100 nucleotides (nt) were generated from this microalga cultured at 4-fold air CO2 (control) and air CO2 concentrations by Illumina sequencing. A total of 32,662 unigenes were assembled from the two pooled samples. With an E-value cut-off of 1e-5, 9590, 6782, 5954, and 9092 unigenes were annotated in NR, Gene Ontology (GO), Eukaryotic Cluster of Orthologous Groups of proteins (KOG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. After screening, 51 differentially expressed unigenes were up-regulated and 8 were down-regulated in the air CO2 group, relative to the control. The transcript levels of eight differentially expressed unigenes were validated by real-time quantitative PCR, which manifested that thioredoxin-like protein, laminin subunit beta-1, and chlorophyll a/b binding protein might be associated with the utilization of inorganic carbon at low CO2 levels.

  8. Photosynthetic photon flux density, carbon dioxide concentration, and vapor pressure deficit effects on photosynthesis in cacao seedlings

    Science.gov (United States)

    Cacao (Theobroma cacao) is a shade plant, native to the under-story of the evergreen rain forest of the Amazon basin and adapted to low levels of photosynthetic photon flux density (PPFD). The influence of PPFD, leaf to air water vapor pressure deficit (VPD) and external carbon dioxide concentration...

  9. Carbon dioxide capture and nutrients removal utilizing treated sewage by concentrated microalgae cultivation in a membrane photobioreactor.

    Science.gov (United States)

    Honda, Ryo; Boonnorat, Jarungwit; Chiemchaisri, Chart; Chiemchaisri, Wilai; Yamamoto, Kazuo

    2012-12-01

    A highly efficient microalgae cultivation process was developed for carbon dioxide capture using nutrients from treated sewage. A submerged-membrane filtration system was installed in a photobioreactor to achieve high nutrient loading and to maintain a high concentration and production of microalgae. Chlorella vulgaris, Botryococcus braunii and Spirulina platensis were continuously cultivated with simulated treated sewage and 1%-CO(2) gas. The optimum hydraulic retention time (HRT) and solids retention time (SRT) were explored to achieve the maximum CO(2) capture rate, nutrient removal rate and microalgae biomass productivity. The carbon dioxide capture rate and volumetric microalgae productivity were high when the reactor was operated under 1-day (HRT) and 18-days (SRT) conditions. The independent control of HRT and SRT is effective for efficient microalgae cultivation and carbon dioxide capture using treated sewage.

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

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-02-01

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

  11. Atmospheric carbon dioxide concentrations before 2.2 billion years ago

    Science.gov (United States)

    Rye, R.; Kuo, P. H.; Holland, H. D.

    1995-01-01

    The composition of the Earth's early atmosphere is a subject of continuing debate. In particular, it has been suggested that elevated concentrations of atmospheric carbon dioxide would have been necessary to maintain normal surface temperatures in the face of lower solar luminosity in early Earth history. Fossil weathering profiles, known as palaeosols, have provided semi-quantitative constraints on atmospheric oxygen partial pressure (pO2) before 2.2 Gyr ago. Here we use the same well studied palaeosols to constrain atmospheric pCO2 between 2.75 and 2.2 Gyr ago. The observation that iron lost from the tops of these profiles was reprecipitated lower down as iron silicate minerals, rather than as iron carbonate, indicates that atmospheric pCO2 must have been less than 10(-1.4) atm--about 100 times today's level of 360 p.p.m., and at least five times lower than that required in one-dimensional climate models to compensate for lower solar luminosity at 2.75 Gyr. Our results suggest that either the Earth's early climate was much more sensitive to increases in pCO2 than has been thought, or that one or more greenhouse gases other than CO2 contributed significantly to the atmosphere's radiative balance during the late Archaean and early Proterozoic eons.

  12. Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation.

    Science.gov (United States)

    Shakun, Jeremy D; Clark, Peter U; He, Feng; Marcott, Shaun A; Mix, Alan C; Liu, Zhengyu; Otto-Bliesner, Bette; Schmittner, Andreas; Bard, Edouard

    2012-04-04

    The covariation of carbon dioxide (CO(2)) concentration and temperature in Antarctic ice-core records suggests a close link between CO(2) and climate during the Pleistocene ice ages. The role and relative importance of CO(2) in producing these climate changes remains unclear, however, in part because the ice-core deuterium record reflects local rather than global temperature. Here we construct a record of global surface temperature from 80 proxy records and show that temperature is correlated with and generally lags CO(2) during the last (that is, the most recent) deglaciation. Differences between the respective temperature changes of the Northern Hemisphere and Southern Hemisphere parallel variations in the strength of the Atlantic meridional overturning circulation recorded in marine sediments. These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO(2) concentrations is an explanation for much of the temperature change at the end of the most recent ice age.

  13. Carbon Dioxide Absorbents

    Science.gov (United States)

    1950-05-17

    carbondioxide content of the solution was then determined. A gas mixture containing 2.6% carbon dioxide and 97.4% nitrogen was prepared in the...which carbon dioxide is removed by heat0 Since this step is usually carried out by "steam stripping ", that is, contacting the solution at its boiling...required to produce the steam required for stripping the carbon dioxide from the s olution. The method ueed in this investigation for determining the

  14. CARBON DIOXIDE REDUCTION SYSTEM.

    Science.gov (United States)

    CARBON DIOXIDE , *SPACE FLIGHT, RESPIRATION, REDUCTION(CHEMISTRY), RESPIRATION, AEROSPACE MEDICINE, ELECTROLYSIS, INSTRUMENTATION, ELECTROLYTES, VOLTAGE, MANNED, YTTRIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, NICKEL.

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

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-08-01

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

  16. Air exchanges and indoor carbon dioxide concentration in Australian pig buildings: Effect of housing and management factors

    DEFF Research Database (Denmark)

    Banhazi, T. M.; Stott, P.; Rutley, D.

    2011-01-01

    factors on the concentrations of carbon dioxide (CO(2)) and air exchange rates in 160 representative Australian pig buildings. CO(2) concentrations were measured, air changes per hour (ACH) were estimated using a CO(2) balance method, and structural and management parameters were recorded. The mean CO(2......) concentration measured was 858 ppm and a mean air exchange rate of 22.8 ACH was estimated. The analysis showed that CO(2) concentrations were affected by the type of building, season, control of the wall and ridge vents, ceiling height, size of the wall vents and height of the ridge vents. Weaner buildings had...

  17. 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.)…

  18. Carbon Dioxide and Climate.

    Science.gov (United States)

    Brewer, Peter G.

    1978-01-01

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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  1. 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.

  2. Carbon dioxide sensor

    Energy Technology Data Exchange (ETDEWEB)

    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).

  3. Carbon dioxide separation using adsorption with steam regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Jeannine Elizabeth; Copeland, Robert James; Leta, Daniel P.; McCall, Patrick P.; Bai, Chuansheng; DeRites, Bruce A.

    2016-11-29

    A process for separating a carbon dioxide from a gas stream is disclosed. The process can include passing the gas stream over a sorbent that adsorbs the carbon dioxide by concentration swing adsorption and adsorptive displacement. The sorbent can be regenerated and the carbon dioxide recaptured by desorbing the carbon dioxide from the sorbent using concentration swing adsorption and desorptive displacement. A carbon dioxide separation system is also disclosed. Neither the system nor the process rely on temperature swing or pressure swing adsorption.

  4. Interglacials, Milankovitch Cycles, and Carbon Dioxide

    CERN Document Server

    Marsh, Gerald E

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Richard Sicher

    2012-01-01

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

  6. Hydrogen depolarized carbon dioxide concentrator performance improvements and cell pair structural tests. [for manned space station

    Science.gov (United States)

    Huddleston, J. D.; Aylward, J. R.

    1973-01-01

    The investigations and testing associated with the CO2 removal efficiency and voltage degradation of a hydrogen depolarized carbon oxide concentrator are reported. Also discussed is the vibration testing of a water vapor electrolysis cell pair. Performance testing of various HDC cell pairs with Cs2CO3 electrolyte provided sufficient parametric and endurance data to size a six man space station prototype CO2 removal system as having 36 HDC cell pairs, and to verify a life capability exceeding six moths. Testing also demonstrated that tetramethylammonium carbonate is an acceptable HDC electrolyte for operating over the relative humidity range of 30 to 90 percent and over a temperature range of 50 to 80 F.

  7. CARBON DIOXIDE SEPARATION BY SELECTIVE PERMEATION.

    Science.gov (United States)

    CARBON DIOXIDE , SEPARATION), (*PERMEABILITY, CARBON DIOXIDE ), POROUS MATERIALS, SILICON COMPOUNDS, RUBBER, SELECTION, ADSORPTION, TEMPERATURE, PRESSURE, POLYMERS, FILMS, PLASTICS, MEMBRANES, HUMIDITY.

  8. Carbon dioxide consumption of the microalga Scenedesmus obtusiusculus under transient inlet CO2 concentration variations.

    Science.gov (United States)

    Cabello, Juan; Morales, Marcia; Revah, Sergio

    2017-02-07

    The extensive microalgae diversity offers considerable versatility for a wide range of biotechnological applications in environmental and production processes. Microalgal cultivation is based on CO2 fixation via photosynthesis and, consequently, it is necessary to evaluate, in a short time and reliable way, the effect of the CO2 gas concentration on the consumption rate and establish the tolerance range of different strains and the amount of inorganic carbon that can be incorporated into biomass in order to establish the potential for industrial scale application. Dynamic experiments allow calculating the short-term microalgal photosynthetic activity of strains in photobioreactors. In this paper, the effect of step-changes in CO2 concentration fed to a 20L bubble column photobioreactor on the CO2 consumption rate of Scenedesmus obtusiusculus was evaluated at different operation times. The highest apparent CO2 consumption rate (336μmolm(-2)s(-1) and 5.6% of CO2) was 6530mgCO2gb(-1)d(-1) and it decreased to 222mgCO2gb(-1)d(-1) when biomass concentration increased of 0.5 to 3.1gbL(-1) and 5.6% of CO2 was fed. For low CO2 concentrations (CO2 consumption rates show that S. obtusiusculus was not limited by CO2 availability for concentrations above of 3.8%. The CO2 mass balance showed that 90% of the C-CO2 transferred was used for S. obtusiusculus growth.

  9. Photosynthetic responses to understory shade and elevated carbon dioxide concentration in four northern hardwood tree species

    Energy Technology Data Exchange (ETDEWEB)

    Sefcik, L.T.; Zak, D.R.; Ellsworth, D.S. [Michigan Univ., Ann Arbor, MI (United States). School of Natural Resources and Environment

    2006-12-15

    The stimulation of photosynthesis in response to elevated carbon dioxide (CO{sub 2}) varies among tree species and species groups and is compounded by other environmental conditions. This study investigated whether understory shade modified light-limited and light-saturated photosynthetic rates in species differing in shade tolerance grown in an elevated CO{sub 2} environment. The study aimed to validate the hypothesis that shade-intolerant species would have a greater photosynthetic response to elevated CO-2 than shade-tolerant species. To evaluate the hypothesis, various species of tree seedlings were grown in elevated and ambient CO{sub 2} in understory conditions of deep or moderate shade. Light-limited and light-saturated photosynthetic rates were measured in order to examine the physiological changes related to CO{sub 2} and light availability in Acer saccharum Marsh; Fagus grandifolia; Prunus serotina; and Betula paprifera Marsh. Results of the study showed that the elevated CO{sub 2} treatment increased mean light-saturated photosynthetic rates by 63 per cent in the shade-tolerant species, and 67 per cent in the shade-intolerant species. However, long-term enhancement of photosynthesis was 10 per cent lower when measured at the elevated CO{sub 2} than in the instantaneous enhancement noted in ambient CO{sub 2} grown plants. Growth light environment affected long-term photosynthetic enhancement by CO{sub 2}. When growth irradiance increased, proportional enhancement due to elevated CO{sub 2} decreased from 97 per cent for plants grown in deep shade to 47 per cent for plants grown in moderate shade. Results indicated that trees grown in deep shade in nitrogen-limited northern temperate forests may display greater photosynthetic gains from a CO{sub 2} enriched atmosphere than trees growing in more moderate shade. It was concluded that if photosynthetic gains by deep-shade grown plants in response to elevated CO{sub 2} translate into improved growth and

  10. Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hlaing, Nwe Ni, E-mail: nwenihlaing76@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Vignesh, K., E-mail: vignesh134@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Anano Sphere Sdn Bhd, Lorong Industri 11, Kawasan Industri Bukit Panchor, 14300 Nibong Tebal, Penang (Malaysia); Sreekantan, Srimala, E-mail: srimala@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Pung, Swee-Yong [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hinode, Hirofumi; Kurniawan, Winarto [Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Othman, Radzali [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Malacca (Malaysia); Thant, Aye Aye [Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Mohamed, Abdul Rahman [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Salim, Chris [Department of Environmental Engineering, Surya University, Tangerang 15810, Banten (Indonesia)

    2016-02-15

    Graphical abstract: Carbonation conversions of (a) CC, (b) CH-2, (c) CH-4, (d) CH-6, (e) CH-8 precursor adsorbents for 10 cycles. - Highlights: • Ca(OH){sub 2} precursor was synthesized using precipitation method. • The effect of CTAB concentration on the synthesis of Ca(OH){sub 2} was studied. • The sorbent synthesized using 0.8 M of CTAB showed good CO{sub 2} adsorption capacity. • The cyclic stability of Ca(OH){sub 2} was increased with increase of CTAB concentration. - Abstract: Calcium hydroxide (Ca(OH){sub 2}) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH){sub 2} based adsorbents for carbon dioxide (CO{sub 2}) capture. The effect of CTAB concentration (0.2–0.8 M) on the structure, morphology and CO{sub 2} adsorption performance of Ca(OH){sub 2} was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG–DTA) techniques. The phase purity, crystallite size, Brunauer–Emmett–Teller (BET) surface area and CO{sub 2} adsorption performance of Ca(OH){sub 2} precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH){sub 2} phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH){sub 2} precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

  11. Elevated atmospheric carbon dioxide concentration: effects of increased carbon input in a Lolium perenne soil on microorganisms and decomposition

    NARCIS (Netherlands)

    Ginkel, van J.H.; Gorissen, A.; Polci, D.

    2000-01-01

    Effects of ambient and elevated atmospheric CO2 concentrations (350 and 700 μl l-1) on net carbon input into soil, the production of root-derived material and the subsequent microbial transformation were investigated. Perennial ryegrass plants (L. perenne L.) were labelled in a continuously labelled

  12. Seasonal odor, ammonia, hydrogen sulfide, and carbon dioxide concentrations and emissions from swine grower-finisher rooms.

    Science.gov (United States)

    Sun, Gang; Guo, Huiqing; Peterson, Jonathan

    2010-04-01

    Seasonal odor and gas (ammonia [NH3], hydrogen sulfide [H2S], and carbon dioxide [CO2]) concentrations and emission rates (OGCERs) from swine facilities are vital for providing accurate source emissions and reducing the uncertainty of setback distances on the basis of emission data. In this study, a repeated measurement experimental method and a split-block statistical model were used to obtain seasonal OGCER profiles from two types of swine grower-finisher rooms in Saskatchewan, Canada, over a 12-month period. The results indicate that the OGCERs were significantly affected by the sampling month and ambient temperature (P dispersion models to reduce uncertainties in setback calculations. It was also found that the seasonal OGCERs from the rooms with fully slatted floors were 6.3-40.6% higher than those with partially slatted floors. The seasonal OGCERs (except for the NH3 concentrations in October, November, and January; the CO2 concentrations in August; and the CO2 emission rates in December) between these two rooms for each measuring month did not differ significantly (P > 0.05). The measured gas concentrations were generally below the permissible exposure limits (PELs) established by the Occupational Safety and Health Administration (OSHA) throughout the year except for the NH3 concentrations in cold weather (December, January, and February).

  13. 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...

  14. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  15. Dynamics of carbon dioxide concentrations in the air and its effect on the cognitive ability of school students

    Science.gov (United States)

    Sidorin, D. I.

    2015-12-01

    The carbon dioxide (CO2) production intensity by a secondary school student is studied using a nondispersive infrared CO2 logger for different conditions: relaxation, mental stress, and physical stress. CO2 production measured for mental stress is 24% higher than that for relaxation, while CO2 production for physical stress is more than 2.5 times higher than relaxation levels. Dynamics of CO2 concentration in the classroom air is measured for a typical school building. It is shown that even when the classroom is ventilated between classes, CO2 concentration exceeds 2100 parts per million (ppm), which is significantly higher than the recommended limits defined in developed countries. The ability of seventh-grade school students to perform tasks requiring mental concentration is tested under different CO2 concentration conditions (below 1000 ppm and above 2000 ppm). Five-letter word anagrams are used as test tasks. Statistical analysis of the test results revealed a significant reduction in the number of provided correct answers and an increase in the number of errors when CO2 levels exceeded 2000 ppm.

  16. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-03-01

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

  18. Aspects of carbon dioxide utilization

    Energy Technology Data Exchange (ETDEWEB)

    Omae, Iwao [Omae Research Laboratories, 335-23 Mizuno, Sayama, Saitama 350-1317 (Japan)

    2006-06-30

    Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carbon-carbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially, the productions of formic acid, formic acid methyl ester and dimethylformamide with a ruthenium catalyst; dimethyl carbonate and urethanes with a dialkyltin catalyst; 2-pyrone with a nickel-phosphine catalyst; diphenyl carbonate with a lead phenoxide catalyst; the alternating copolymerization of carbon dioxide and epoxides with a zinc catalyst has attracted attentions as the industrial utilizations of carbon dioxide. The further development of these production processes is expected. (author)

  19. Carbon Dioxide Extraction from Air: Is It An Option?

    Energy Technology Data Exchange (ETDEWEB)

    Lackner, Klaus; Ziock, Hans-Joachim; Grimes, Patrick

    1999-02-01

    Controlling the level of carbon dioxide in the atmosphere without limiting access to fossil energy resources is only possible if carbon dioxide is collected and disposed of away from the atmosphere. While it may be cost-advantageous to collect the carbon dioxide at concentrated sources without ever letting it enter the atmosphere, this approach is not available for the many diffuse sources of carbon dioxide. Similarly, for many older plants a retrofit to collect the carbon dioxide is either impossible or prohibitively expensive. For these cases we investigate the possibility of collecting the carbon dioxide directly from the atmosphere. We conclude that there are no fundamental obstacles to this approach and that it deserves further investigation. Carbon dioxide extraction directly from atmosphere would allow carbon management without the need for a completely changed infrastructure. In addition it eliminates the need for a complex carbon dioxide transportation infrastructure, thus at least in part offsetting the higher cost of the extraction from air.

  20. NDIR Gas Sensor for Spatial Monitoring of Carbon Dioxide Concentrations in Naturally Ventilated Livestock Buildings

    Directory of Open Access Journals (Sweden)

    Luciano B. Mendes

    2015-05-01

    Full Text Available The tracer gas ratio method, using CO2 as natural tracer, has been suggested as a pragmatic option to measure emissions from naturally ventilated (NV barns without the need to directly estimate the ventilation rate. The aim of this research was to assess the performance of a low-cost Non-Dispersive Infra-Red (NDIR sensor for intensive spatial field monitoring of CO2 concentrations in a NV dairy cow house. This was achieved by comparing NDIR sensors with two commonly applied methods, a Photo-Acoustic Spectroscope (PAS Gas Monitor and an Open-Path laser (OP-laser. First, calibrations for the NDIR sensors were obtained in the laboratory. Then, the NDIR sensors were placed in a dairy cow barn for comparison with the PAS and OP-laser methods. The main conclusions were: (a in order to represent the overall barn CO2 concentration of the dairy cow barn, the number of NDIR sensors to be accounted for average concentration calculation was dependent on barn length and on barn area occupation; and (b the NDIR CO2 sensors are suitable for multi-point monitoring of CO2 concentrations in NV livestock barns, being a feasible alternative for the PAS and the OP-laser methods to monitor single-point or averaged spatial CO2 concentrations in livestock barns.

  1. Tolerance of allogromiid Foraminifera to severely elevated carbon dioxide concentrations: Implications to future ecosystem functioning and paleoceanographic interpretations

    Science.gov (United States)

    Bernhard, Joan M.; Mollo-Christensen, Elizabeth; Eisenkolb, Nadine; Starczak, Victoria R.

    2009-02-01

    Increases in the partial pressure of carbon dioxide (pCO 2) in the atmosphere will significantly affect a wide variety of terrestrial fauna and flora. Because of tight atmospheric-oceanic coupling, shallow-water marine species are also expected to be affected by increases in atmospheric carbon dioxide concentrations. One proposed way to slow increases in atmospheric pCO 2 is to sequester CO 2 in the deep sea. Thus, over the next few centuries marine species will be exposed to changing seawater chemistry caused by ocean-atmospheric exchange and/or deep-ocean sequestration. This initial case study on one allogromiid foraminiferal species ( Allogromia laticollaris) was conducted to begin to ascertain the effect of elevated pCO 2 on benthic Foraminifera, which are a major meiofaunal constituent of shallow- and deep-water marine communities. Cultures of this thecate foraminiferan protist were used for 10-14-day experiments. Experimental treatments were executed in an incubator that controlled CO 2 (15 000; 30 000; 60 000; 90 000; 200 000 ppm), temperature and humidity; atmospheric controls (i.e., ~ 375 ppm CO 2) were executed simultaneously. Although the experimental elevated pCO 2 values are far above foreseeable surface water pCO 2, they were selected to represent the spectrum of conditions expected for the benthos if deep-sea CO 2 sequestration becomes a reality. Survival was assessed in two independent ways: pseudopodial presence/absence and measurement of adenosine triphosphate (ATP), which is an indicator of cellular energy. Substantial proportions of A. laticollaris populations survived 200 000 ppm CO 2 although the mean of the median [ATP] of survivors was statistically lower for this treatment than for that of atmospheric control specimens. After individuals that had been incubated in 200 000 ppm CO 2 for 12 days were transferred to atmospheric conditions for ~ 24 h, the [ATP] of live specimens (survivors) approximated those of the comparable atmospheric

  2. Analysis of human breath with micro extraction techniques and continuous monitoring of carbon dioxide concentration.

    Science.gov (United States)

    Ma, Wei; Liu, Xinyu; Pawliszyn, Janusz

    2006-08-01

    The detection of volatile organic compounds (VOCs) in human breath can be useful for the clinical routine diagnosis of several diseases in a non-invasive manner. Traditional methods of breath analysis have some major technical problems and limitations. Membrane extraction with a sorbent interface (MESI), however, has many advantages over current methods, including good selectivity and sensitivity, and is well suited for breath analysis. The aim of this project was to develop a simple and reproducible sampling device and method based on the MESI system for breath analysis. The feasibility and validity of the MESI system was tested with real human breath samples. Internal standard calibration methods were used for the quantitative analysis of various breath samples. Calibration curves for some main components (target analytes such as acetone and pentane) were determined in the research. The optimized stripping-side and feeding-side gas velocities were determined. The use of breath CO2 as an internal standard for the analysis of breath VOCs is an effective method to solve the difficulties associated with variations in the target analyte concentrations in a sample, which are attributed to mass losses and different breathing patterns of different subjects. In this study, the concentration of breath acetone was successfully expressed normalized to CO2 as in the alveolar air. Breath acetone of healthy males and females profiled at different times of the day was plotted using the MESI system, and results were consistent with the literature. This technique can be used for monitoring breath acetone concentrations of diabetic patients and for applications with other biomarker monitoring.

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

    CERN Document Server

    Garrett, Timothy J

    2010-01-01

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

  4. Short communication: Effects of dairy calf hutch elevation on heat reduction, carbon dioxide concentration, air circulation, and respiratory rates.

    Science.gov (United States)

    Moore, D A; Duprau, J L; Wenz, J R

    2012-07-01

    Heat stress affects dairy calf welfare and can result in morbidity, mortality, and lower weight gain. The purpose of this project was to evaluate the effects of elevating the back of plastic calf hutches on measures of ventilation and heat stress. A total of 15 calves housed in individual hutches were enrolled, with each calf hutch serving as its own control. Heat, humidity, carbon dioxide, and wind speed were measured inside each hutch and the observations were compared with external measurements over two 24-h periods; 1 period without and 1 with hutch elevation. Respiratory rates were measured in the morning and afternoon as an indicator of the degree of heat stress experienced by calves with and without elevation of the hutch. When the hutch was elevated, internal hutch temperatures were cooler than external temperatures, hutch carbon dioxide levels were lower and respiratory rates were lower, particularly comparing the afternoon observation periods.

  5. Plasma variables, meat quality, and glycolytic potential in broilers stunned with different carbon dioxide concentrations.

    Science.gov (United States)

    Xu, L; Ji, F; Yue, H Y; Wu, S G; Zhang, H J; Zhang, L; Qi, G H

    2011-08-01

    This study aimed to investigate the effects of different CO(2) concentrations on blood variables, glycolytic potential (GP), and meat quality of hot-boned muscles in broilers. Thirty broilers were exposed to one of the following 5 gas mixtures for 90 s: 40% CO(2) + 30% O(2) + N(2) (control), 30% CO(2) + 21% O(2) + N(2) (G30%), 40% CO(2) + 21% O(2) + N(2) (G40%), 50% CO(2) + 21% O(2) + N(2) (G50%), and 60% CO(2) + 21% O(2) + N(2) (G60%). Samples were taken from the pectoralis major (PM), musculus iliofibularis (MI), and tibialis anterior muscles 45 min postmortem. The ultimate pH in both the PM (vs. G30% and G40%) and MI (vs. G40%) was decreased with G60% (P 0.05). In conclusion, stunning broilers with low CO(2) levels (30 and 40%) improved meat quality but had no advantage in animal welfare compared with high CO(2) levels (50 and 60%).

  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.

  7. Intercomparison study of atmospheric methane and carbon dioxide concentrations measured at the Ebre River Delta Station

    Science.gov (United States)

    Occhipinti, Paola; Morguí, Josep Anton; Àgueda, Alba; Batet, Oscar; Borràs, Sílvia; Cañas, Lídia; Curcoll, Roger; Grossi, Claudia; Nofuentes, Manel; Vazquez, Eusebi; Rodó, Xavier

    2015-04-01

    In the framework of the ClimaDat project, IC3 has established a network of eight monitoring stations across the Iberian Peninsula and the Canarian Archipelago with the aim of studying climate processes. The monitoring station at the Ebre River Delta (DEC3) is located in the Ebre River Delta Natural Park (40° 44' N; 0° 47' E) and it is characterized by the typical North-Western Mediterranean climate. Since 2013, atmospheric greenhouse gases (GHG) and 222Rn tracer gas together with the meteorological parameters are continuously measured from a 10 m a.g.l. height tower. Atmospheric GHG (CO2, CH4, CO and N2O) concentrations are determined using a Picarro analyzer G2301 (CO2 and CH4) and a modified gas chromatograph (GC) Agilent 6890N (CO2, CH4, CO and N2O). Open data access is available from the www.climadat.es website. Data collected at the DEC3 station are also submitted to the InGOS platform since this station is part of the InGOS European infrastructure project. Researchers from the Laboratory of the Atmosphere and the Oceans (LAO) at IC3 have performed an intercomparison study at the DEC3 site between three different Picarro analyzers (two Picarro G2301 and one Picarro G2301M), a Los Gatos Research (LGR) analyzer and the GC system already installed at the station. The aim of this study is to compare and assess the measuring agreement between the four optical gas analyzers and the GC. In the first part of the experiment, all instruments have been calibrated using NOAA gases as primary standards analyzing five Praxair provided targets to evaluate the precision of the measuring instruments. Max Plank Institute (MPI) gases have been used as secondary standards for the GC whereas Praxair provided tanks are used as secondary standards for the Picarro and the LGR analyzers. In the second part of the experiment, atmospheric GHG were measured from natural atmospheric air taken from a 10 m a.g.l. inlet. Daily cycles of GHG measurements were carried out using different

  8. Subalpine grassland carbon dioxide fluxes indicate substantial carbon losses under increased nitrogen deposition, but not at elevated ozone concentration

    Science.gov (United States)

    Volk, Matthias; Obrist, Daniel; Novak, Kris; Giger, Robin; Bassin, Seraina; Fuhrer, Jürg

    2010-05-01

    Ozone (O3) and nitrogen (N) deposition affect plant carbon (C) dynamics and may thus change ecosystem C-sink/-source properties. We studied effects of increased background O3 concentrations (up to ambient x 2) and increased N deposition (up to +50 kg ha-1 a-1) on mature, subalpine grassland during the third treatment year. During ten days and 13 nights, covering the vegetation period of 2006, we measured ecosystem-level CO2 exchange using a steady state cuvette. Light dependency of gross primary production (GPP) and temperature dependency of ecosystem respiration rates (Reco) were established. Soil temperature, soil water content, and solar radiation were monitored. Using Reco and GPP values, we calculated seasonal net ecosystem production (NEP), based on hourly averages of global radiation and soil temperature. Differences in NEP were compared to differences in soil organic C after five years of treatment. Under high O3 and with unchanged aboveground biomass, both mean Reco and GPP decreased throughout the season. Thus, NEP indicated an unaltered growing season CO2-C balance. Under high N treatment, with a +31% increase in aboveground productivity, mean Reco, but not GPP increased. Consequently, seasonal NEP yielded a 53.9 g C m-2 (± 22.05) C loss compared to control. Independent of treatment, we observed a negative NEP of 146.4 g C m-2 (±15.3). This C loss was likely due to a transient management effect, equivalent to a shift from pasture to hay meadow and a drought effect, specific to the 2006 summer climate. We argue that this resulted from strongly intensified soil microbial respiration, following mitigation of nutrient limitation. There was no interaction between O3 and N treatments. Thus, during the 2006 growing season, the subalpine grassland lost >2% of total topsoil organic C as respired CO2, with increased N deposition responsible for one-third of that loss.

  9. 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......). 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...

  10. Measurements of concentrations of chlorofluoromethanes (CFMs) carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems

    Science.gov (United States)

    Itoh, T.; Kubo, H.; Honda, H.; Tominaga, T.; Makide, Y.; Yakohata, A.; Sakai, H.

    1985-01-01

    Measurements of concentrations of chlorofluoromethanes (CFMs), carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems are reported. The balloon-borne grab-sampling system has been launched from Sanriku Balloon Center three times since 1981. It consists of: (1) six sampling cylinders, (2) eight motor driven values, (3) control and monitor circuits, and (4) pressurized housing. Particular consideration is paid to the problem of contamination. Strict requirements are placed on the choice of materials and components, construction methods, cleaning techniques, vacuum integrity, and sampling procedures. An aluminum pressurized housing and a 4-m long inlet line are employed to prevent the sampling air from contamination by outgassing of sampling and control devices. The sampling is performed during the descent of the system. Vertical profiles of mixing ratios of CF2Cl2, CFCl3 and CH4 are given. Mixing ratios of CF2Cl2 and CFCl3 in the stratosphere do not show the discernible effect of the increase of those in the ground level background, and decrease with altitude. Decreasing rate of CFCl3 is larger than that of CF2Cl2. CH4 mixing ratio, on the other hand, shows diffusive equilibrium, as the photodissociation cross section of CH4 is small and concentrations of OH radical and 0(sup I D) are low.

  11. Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing.

    Science.gov (United States)

    Perrier, Frédéric; Richon, Patrick

    2010-04-01

    Radon-222 and carbon dioxide concentrations have been measured during several years at several points in the atmosphere of an underground limestone quarry located at a depth of 18 m in Vincennes, near Paris, France. Both concentrations showed a seasonal cycle. Radon concentration varied from 1200 to 2000 Bq m(-3) in summer to about 800-1400 Bq m(-3) in winter, indicating winter ventilation rates varying from 0.6 to 2.5 x 10(-6) s(-1). Carbon dioxide concentration varied from 0.9 to 1.0% in summer, to about 0.1-0.3% in winter. Radon concentration can be corrected for natural ventilation using temperature measurements. The obtained model also accounts for the measured seasonal variation of carbon dioxide. After correction, radon concentrations still exhibit significant temporal variation, mostly associated with the variation of atmospheric pressure, with coupling coefficients varying from -7 to -26 Bq m(-3) hPa(-1). This variation can be accounted for using a barometric pumping model, coupled with natural ventilation in winter, and including internal mixing as well. After correction, radon concentrations exhibit residual temporal variation, poorly correlated between different points, with standard deviations varying from 3 to 6%. This study shows that temporal variation of radon concentrations in underground cavities can be understood to a satisfactory level of detail using non-linear and time-dependent modelling. It is important to understand the temporal variation of radon concentrations and the limitations in their modelling to monitor the properties of natural or artificial underground settings, and to be able to assess the existence of new processes, for example associated with the preparatory phases of volcanic eruptions or earthquakes.

  12. Reducing carbon dioxide to products

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Carbon Dioxide Flux Measurement Systems

    Data.gov (United States)

    Oak Ridge National Laboratory — The Southern Great Plains (SGP) carbon dioxide flux (CO2 flux) measurement systems provide half-hour average fluxes of CO2, H2O (latent heat), and sensible heat. The...

  14. Design and evaluation of a high temperature/pressure supercritical carbon dioxide direct tubular receiver for concentrating solar power applications

    Science.gov (United States)

    Ortega, Jesus Daniel

    This work focuses on the development of a solar power thermal receiver for a supercritical-carbon dioxide (sCO2), Brayton power-cycle to produce ~1 MWe. Closed-loop sCO2 Brayton cycles are being evaluated in combination with concentrating solar power to provide higher thermal-to-electric conversion efficiencies relative to conventional steam Rankine cycles. High temperatures (923--973 K) and pressures (20--25 MPa) are required in the solar receiver to achieve thermal efficiencies of ~50%, making concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. In this study, the CSP receiver is required to achieve an outlet temperature of 923 K at 25 MPa or 973 K at 20 MPa to meet the operating needs. To obtain compatible receiver tube material, an extensive material review was performed based the ASME Boiler and Pressure Vessel Code, ASME B31.1 and ASME B313.3 codes respectively. Subsequently, a thermal-structural model was developed using a commercial computational fluid (CFD) dynamics and structural mechanics software for designing and analyzing the tubular receiver that could provide the heat input for a ~2 MWth plant. These results were used to perform an analytical cumulative damage creep-fatigue analysis to estimate the work-life of the tubes. In sequence, an optical-thermal-fluid model was developed to evaluate the resulting thermal efficiency of the tubular receiver from the NSTTF heliostat field. The ray-tracing tool SolTrace was used to obtain the heat-flux distribution on the surfaces of the receiver. The K-ω SST turbulence model and P-1 radiation model used in Fluent were coupled with SolTrace to provide the heat flux distribution on the receiver surface. The creep-fatigue analysis displays the damage accumulated due to the cycling and the permanent deformation of the tubes. Nonetheless, they are able to support the required lifetime. The receiver surface temperatures were found to be within the safe

  15. 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.

  16. Sub-Surface Carbon Dioxide Concentration Measurement Using a Fiber Based Sensor in a Call/Return Geometry for Carbon Sequestration Site Monitoring

    Science.gov (United States)

    Wicks, G. R.; Soukup, B.; Repasky, K. S.; Carlsten, J.; Barr, J. L.; Dobeck, L.

    2010-12-01

    Geologic carbon sequestration is a means to mitigate the increasing atmospheric concentration of carbon dioxide (CO2) by capturing the CO2 at a source such as a power generation facility and storing the captured CO2 in geologic formations. Many technologic advances will need to occur for successful carbon sequestration including near surface monitoring tools and techniques to ensure site integrity and public safety. Researchers at Montana State University (MSU) are developing a scalable fiber sensor array in a call/return configuration for monitoring near sub-surface CO2 concentrations. The low cost fiber sensor array being developed at MSU for sub-surface CO2 detection for monitoring carbon sequestration sites will utilize a series of fiber probes connected to a two detectors and a 1 x N fiber switch that can direct the light to one of N fiber probes. The fiber sensor array will utilize a single tunable distributed feedback (DFB) diode laser with a center wavelength of 2.004 μm to access CO2 absorption features. The output from the DFB laser is incident on an inline fiber splitter that directs part of the light to a reference detector while the remaining light is directed to a fiber probe where the laser light interacts with the CO2. The light from the fiber probe is directed back through the switch and is incident on a transmission detector. The transmission as a function of wavelength is measured and a CO2 concentration is calculated. The fiber sensor array can easily be reconfigured by simply moving the fiber probes. Low cost is achieved by using inexpensive passive components in the fiber probes while limiting the number of the more expensive components including the DFB laser, the two detectors, and the single fiber switch. The fiber sensor was tested over a thirty day period at the Zero Emission Research Technology (ZERT) facility that was developed for testing surface and near surface carbon sequestration monitoring instrumentation using a controlled

  17. Sap flux in pure aspen and mixed aspen-birch forests exposed to elevated concentrations of carbon dioxide and ozone.

    Science.gov (United States)

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

    2008-08-01

    Elevated concentrations of atmospheric carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have the potential to affect tree physiology and structure and hence forest water use, which has implications for climate feedbacks. We investigated how a 40% increase above ambient values in [CO2] and [O3], alone and in combination, affect tree water use of pure aspen and mixed aspen-birch forests in the free air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). Measurements of sap flux and canopy leaf area index (L) were made during two growing seasons, when steady-state L had been reached after more than 6 years of exposure to elevated [CO2] and [O3]. Maximum stand-level sap flux was not significantly affected by elevated [O3], but was increased by 18% by elevated [CO2] averaged across years, communities and O(3) regimes. Treatment effects were similar in pure aspen and mixed aspen-birch communities. Increased tree water use in response to elevated [CO2] was related to positive CO2 treatment effects on tree size and L (+40%). Tree water use was not reduced by elevated [O3] despite strong negative O3 treatment effects on tree size and L (-22%). Elevated [O3] predisposed pure aspen stands to drought-induced sap flux reductions, whereas increased tree water use in response to elevated [CO2] did not result in lower soil water content in the upper soil or decreasing sap flux relative to control values during dry periods. Maintenance of soil water content in the upper soil in the elevated [CO2] treatment was at least partly a function of enhanced soil water-holding capacity, probably a result of increased organic matter content from increased litter inputs. Our findings that larger trees growing in elevated [CO2] used more water and that tree size, but not maximal water use, was negatively affected by elevated [O3] suggest that the long-term cumulative effects on stand structure may be more important than the expected primary stomatal closure responses to

  18. Gas exchange and the coagulation system of the blood during the effect on the body of high concentrations of oxygen and carbon dioxide

    Science.gov (United States)

    Palosh, L.; Agadzhanyan, N. A.; Davydov, G. A.; Rybakov, B. K.; Sergiyenko, A. S.

    1974-01-01

    Maximum permissible concentrations of oxygen and carbon dioxide in a controlled atmosphere were determined by evaluating their effects on human gas exchange, blood coagulation, and tolerances to acute hypoxia, acceleration, and physical loads. It was found that functional disturbances depend on the concentration of respiratory gases and the length of stay in an altered atmosphere. By changing the atmospheric composition and by bringing the gaseous environment into accordance with the work and rest regimen and energy expenditures, the general reactivity of the body changes favorably.

  19. Highly-resolved Modeling of Emissions and Concentrations of Carbon Monoxide, Carbon Dioxide, Nitrogen Oxides, and Fine Particulate Matter in Salt Lake City, Utah

    Science.gov (United States)

    Mendoza, D. L.; Lin, J. C.; Mitchell, L.; Ehleringer, J. R.

    2014-12-01

    Accurate, high-resolution data on air pollutant emissions and concentrations are needed to understand human exposures and for both policy and pollutant management purposes. An important step in this process is also quantification of uncertainties. We present a spatially explicit and highly resolved emissions inventory for Salt Lake County, Utah, and trace gas concentration estimates for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and fine particles (PM2.5) within Salt Lake City. We assess the validity of this approach by comparing measured concentrations against simulated values derived from combining the emissions inventory with an atmospheric model. The emissions inventory for the criteria pollutants was constructed using the 2011 National Emissions Inventory (NEI). The spatial and temporal allocation methods from the Emission Modeling Clearinghouse data set are used to downscale the NEI data from annual to hourly scales and from county-level to 500 m x 500 m resolution. Onroad mobile source emissions were estimated by combining a bottom-up emissions calculation approach for large roadway links with a top-down spatial allocation approach for other roadways. Vehicle activity data for road links were derived from automatic traffic responder data. The emissions inventory for CO2 was obtained from the Hestia emissions data product at an hourly, building, facility, and road link resolution. The AERMOD and CALPUFF dispersion models were used to transport emissions and estimate air pollutant concentrations at an hourly temporal and 500 m x 500 m spatial resolution. Modeled results were compared against measurements from a mobile lab equipped with trace gas measurement equipment traveling on pre-determined routes in the Salt Lake City area. The comparison between both approaches to concentration estimation highlights spatial locations and hours of high variability/uncertainty. Results presented here will inform understanding of variability and

  20. 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.

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

    OpenAIRE

    Marsh, Gerald E.

    2014-01-01

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

  2. Net carbon dioxide exchange rates and predicted growth patterns in Alstroemeria Jacqueline' at varying irradiances, carbon dioxide concentrations, and air temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Leonardos, E.D.; Tsujita, M.J.; Grodzinski, B. (Univ. of Guelph, Ontario (Canada). Dept. of Horticultural Science)

    1994-11-01

    The influence of irradiance, CO[sub 2] concentration, and air temperature on leaf and whole-plant net C exchange rate (NCER) of Alstroemeria Jacqueline' was studied. At ambient CO[sub 2], leaf net photosynthesis was maximum at irradiances above 600 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] photosynthetically active radiation (PAR), while whole-plant NCER required 1,200 [mu]mol[center dot]m[sup [minus]2][center dot]s[sup [minus]1] PAR to be saturated. Leaf and whole-plant NCERs were doubled under CO[sub 2] enrichment of 1,500 to 2,000 [mu]l CO[sub 2]/liter. Leaf and whole-plant NCERs declined as temperature increased from 20 to 35 C. Whereas the optimum temperature range for leaf net photosynthesis was 17 to 23 C, whole-plant NCER, even at high light and high CO[sub 2], declined above 12 C. Dark respiration of leaves and whole plants increased with a Q[sub 10] of [approx] 2 at 15 to 35 C. In an analysis of day effects, irradiance, CO[sub 2] concentration, and temperature contributed 58%, 23%, and 14%, respectively, to the total variation in NCER explained by a second-order polynomial model (R[sup 2] = 0.85). Interactions among the factors accounted for 4% of the variation in day C assimilation. The potential whole-plant growth rates during varying greenhouse day and night temperature regimes were predicted for short- and long-day scenarios. The data are discussed with the view of designing experiments to test the importance of C gain in supporting flowering and high yield during routine harvest of Alstroemeria plants under commercial greenhouse conditions.

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

    Directory of Open Access Journals (Sweden)

    GholamReza Roshan

    2012-12-01

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

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

    Science.gov (United States)

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

    2015-07-01

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

  5. 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.

  6. 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.

  7. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

  8. Carbon Dioxide Detection and Indoor Air Quality Control.

    Science.gov (United States)

    Bonino, Steve

    2016-04-01

    When building ventilation is reduced, energy is saved because it is not necessary to heat or cool as much outside air. Reduced ventilation can result in higher levels of carbon dioxide, which may cause building occupants to experience symptoms. Heating or cooling for ventilation air can be enhanced by a DCV system, which can save energy while providing a comfortable environment. Carbon dioxide concentrations within a building are often used to indicate whether adequate fresh air is being supplied to the building. These DCV systems use carbon dioxide sensors in each space or in the return air and adjust the ventilation based on carbon dioxide concentration; the higher the concentration, the more people occupy the space relative to the ventilation rate. With a carbon dioxide sensor DCV system, the fresh air ventilation rate varies based on the number ofpeople in the space, saving energy while maintaining a safe and comfortable environment.

  9. Kinetics of absorption of carbon dioxide in aqueous piperazine solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Kleingeld, T.; van Aken, C.; Hogendoorn, J. A.; Versteeg, G. F.

    2006-01-01

    In the present work the absorption of carbon dioxide into aqueous piperazine (PZ) solutions has been studied in a stirred cell, at low to moderate temperatures, piperazine concentrations ranging from 0.6 to 1.5 kmol m- 3, and carbon dioxide pressures up to 500 mbar, respectively. The obtained experi

  10. 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…

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

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

    2013-07-01

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

  17. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-04-01

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

  18. Erosion-corrosion in carbon dioxide saturated systems in presence of sand, inhibitor, oil, and high concentration of salt

    Science.gov (United States)

    Hassani, Shokrollah

    Oil and gas production is usually accompanied by formation water which typically contains high levels of chloride. Some effects of chloride concentration on corrosion are not widely known in the literature, and this can result in misleading conclusions. One goal of this research was to contribute to a better understanding of the effects of chloride concentration in CO2 corrosion. Experimental and theoretical studies conducted in the present work have shown that increasing the NaCl concentration in solution has three important effects on corrosion results. First, standard pH meter readings in high NaCl concentration solutions require corrections. Second, increasing the NaCl concentration decreases the CO2 concentration in solution and therefore contributes to a decrease in the corrosion rate. Third, increasing the NaCl concentration increases the solubility of FeCO3 and therefore reduces the likelihood of forming an iron carbonate scale. High NaCl concentration also decreases the sand erosion rate of the metal slightly by increasing the density and viscosity of the liquid. There are two main contributions of this research. The first contribution is the experimental characterization of inhibited erosion-corrosion behavior of mild steel under CO2-saturated conditions with a high salt concentration. Chemical inhibition is one the most important techniques for controlling erosion-corrosion in offshore mild steel pipelines, tubing and pipe fittings in oil and gas industry. The second contribution is the introduction of a new approach for predicting inhibited erosion-corrosion in mild steel pipes including the effects of flow and environmental conditions, sand production, and an oil phase. Sand erosion can decrease the efficiency of corrosion protection systems including iron-carbonate scale formation and chemical inhibition. The need to be able to predict inhibitor performance under sand production conditions is particularly acute when the wells are deep or off

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    In spite of the agricultural importance of potato (Solanum tuberosum L.), most plant physiology studies have not accounted for the effect of the interaction between elevated carbon dioxide concentration ([CO2]) and other consequences of climate change on WUE. In 2010, a first controlled environment...... photosynthetic water use efficiency (pWUE) by stimulation in net photosynthesis rate (62 and 43% increase of An) with coincident decline in both stomatal conductance (21 and 43% decrease of gs) and leaf transpiration rate (19 and 40% decrease of E) resulting in pWUE increments of 89 and 147%. Furthermore...... stomatal conductance (25%) with a simultaneous drop in transpiration rate although not significant. The ratio Ci/Ca was in contrast to the first experiment significantly higher in plants grown at elevated [CO2]. Despite this photosynthetic acclimation, concurrent stimulation of aboveground and belowground...

  20. Carbon Dioxide Removal via Passive Thermal Approaches

    Science.gov (United States)

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

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  1. The fixation of carbon dioxide in inorganic and organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Aresta, M. (Universita degli Studi, Bari (Italy). Dispartimento di Chemica e Centro CNR-MISO)

    1993-01-01

    The recovery of carbon dioxide from concentrated sources is currently under evaluation as a technology for the control of the emission into the atmosphere. In order for this option to be operative it is necessary to define the fate of recovered carbon dioxide. Two ways forward are open: disposal in natural fields (oceans, aquifers, deep geological cavities); - utilisation (technological use or chemical conversion). The fixation in chemicals can contribute both to reduce the use of fossil carbon and to cut the emission of carbon dioxide into the atmosphere. 6 refs., 1 fig., 5 tabs.

  2. 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.

  3. 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.

  4. Controlling Foam Morphology of Poly(methyl methacrylate via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

    Directory of Open Access Journals (Sweden)

    Deniz Rende

    2013-01-01

    Full Text Available Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2 nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume. In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate, PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight. The supercritical CO2 foaming was performed at four different temperatures (40, 65, 75, and 85°C and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from 9.62±5.22 to 1.06±0.32 μm, whereas, the cell density was increased from 7.5±0.5×108 to 4.8±0.3×1011 cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology.

  5. 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....

  6. 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.

  7. Predicting residential indoor concentrations of nitrogen dioxide, fine particulate matter, and elemental carbon using questionnaire and geographic information system based data

    Science.gov (United States)

    Baxter, Lisa K.; Clougherty, Jane E.; Paciorek, Christopher J.; Wright, Rosalind J.; Levy, Jonathan I.

    Previous studies have identified associations between traffic-related air pollution and adverse health effects. Most have used measurements from a few central ambient monitors and/or some measure of traffic as indicators of exposure, disregarding spatial variability and factors influencing personal exposure-ambient concentration relationships. This study seeks to utilize publicly available data (i.e., central site monitors, geographic information system, and property assessment data) and questionnaire responses to predict residential indoor concentrations of traffic-related air pollutants for lower socioeconomic status (SES) urban households. As part of a prospective birth cohort study in urban Boston, we collected indoor and outdoor 3-4 day samples of nitrogen dioxide (NO 2) and fine particulate matter (PM 2.5) in 43 low SES residences across multiple seasons from 2003 to 2005. Elemental carbon (EC) concentrations were determined via reflectance analysis. Multiple traffic indicators were derived using Massachusetts Highway Department data and traffic counts collected outside sampling homes. Home characteristics and occupant behaviors were collected via a standardized questionnaire. Additional housing information was collected through property tax records, and ambient concentrations were collected from a centrally located ambient monitor. The contributions of ambient concentrations, local traffic and indoor sources to indoor concentrations were quantified with regression analyses. PM 2.5 was influenced less by local traffic but had significant indoor sources, while EC was associated with traffic and NO 2 with both traffic and indoor sources. Comparing models based on covariate selection using p-values or a Bayesian approach yielded similar results, with traffic density within a 50 m buffer of a home and distance from a truck route as important contributors to indoor levels of NO 2 and EC, respectively. The Bayesian approach also highlighted the uncertanity in the

  8. Volcanic versus anthropogenic carbon dioxide

    Science.gov (United States)

    Gerlach, T.

    2011-01-01

    Which emits more carbon dioxide (CO2): Earth's volcanoes or human activities? Research findings indicate unequivocally that the answer to this frequently asked question is human activities. However, most people, including some Earth scientists working in fields outside volcanology, are surprised by this answer. The climate change debate has revived and reinforced the belief, widespread among climate skeptics, that volcanoes emit more CO2 than human activities [Gerlach, 2010; Plimer, 2009]. In fact, present-day volcanoes emit relatively modest amounts of CO2, about as much annually as states like Florida, Michigan, and Ohio.

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

    Institute of Scientific and Technical Information of China (English)

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

    2002-01-01

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

  10. Photosynthesis acclimation, leaf nitrogen concentration, and growth of four tree species over 3 years in response to elevated carbon dioxide and nitrogen treatment in subtropical China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juxiu; Zhou, Guoyi; Duan, Honglang; Li, Yuelin; Zhang, Deqiang [Chinese Academy of Sciences, Guangzhou (China). South China Botanical Garden; Xu, Zhihong [Griffith Univ., Nathan, Brisbane (Australia). Centre for Forestry and Horticultural Research

    2011-10-15

    Up to date, most studies about the plant photosynthetic acclimation responses to elevated carbon dioxide (CO{sub 2}) concentration have been performed in temperate areas, which are often N limited under natural conditions and with low ambient N deposition. It is unclear whether photosynthetic downregulation is alleviated with increased N availability, for example, from increased N deposition due to fossil fuel combustion in the tropics and subtropics. Awareness of plant photosynthetic responses to elevated CO{sub 2} concentration will contribute to the better understanding and prediction of future forest productivity under global change. Four tree species, Schima superba Gardn. et Champ., Ormosia pinnata (Lour.) Merr, Castanopsis hystrix AC. DC., and Acmena acuminatissima (Blume) Merr. et Perry were exposed to a factorial combination of atmospheric CO{sub 2} concentration (ambient and elevated CO{sub 2} concentration at ca. 700 {mu}mol CO{sub 2} mol{sup -1}) and N deposition (ambient and ambient + 100 kg N ha{sup -1} year{sup -1}) in open-top chambers in southern China for 3 years since March 2005. Light-saturated net photosynthetic rate, leaf N concentration, and tree growth of all species were measured. The CO{sub 2} treatments did not affect light-saturated net photosynthetic rate of all species grown with the high N treatment. However, S. superba grown with the low N treatment (ambient) had 23% and 47% greater net photosynthesis in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for December 2006 and November 2007 (20 and 31 months after the treatments were applied), respectively, and A. acuminatissima grown with the low N treatment had 173%, 26%, and 121% greater net photosynthesis in trees grown in the ambient CO{sub 2} concentration than those in the elevated CO{sub 2} concentration for July 2006 (16 months after the treatments), December 2006 (20 months), and November 2007 (31 months), respectively, whereas

  11. 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.

  12. 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....

  13. Carbon dioxide heat pump for dual-temperature drinking fountain

    Institute of Scientific and Technical Information of China (English)

    杨大章; 吕静; 何哲彬; 黄秀芝

    2009-01-01

    Carbon dioxide trans-critical heat pump system for heating and cooling water was designed,and its thermodynamic steady-state concentration model was established. Based on the steady-state model,parameters of the carbon dioxide trans-critical heat pump were calculated by computer programming. According to these parameters,the effects and application prospect of the heat pump system were analyzed for dual-temperature drinking fountains.

  14. Seawater pH and Anthropogenic Carbon Dioxide

    CERN Document Server

    Marsh, Gerald E

    2008-01-01

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

  15. The impact of enhanced atmospheric carbon dioxide on yield, proximate composition, elemental concentration, fatty acid and vitamin C contents of tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Khan, Ikhtiar; Azam, Andaleeb; Mahmood, Abid

    2013-01-01

    The global average temperature has witnessed a steady increase during the second half of the twentieth century and the trend is continuing. Carbon dioxide, a major green house gas is piling up in the atmosphere and besides causing global warming, is expected to alter the physico-chemical composition of plants. The objective of this work was to evaluate the hypothesis that increased CO(2) in the air is causing undesirable changes in the nutritional composition of tomato fruits. Two varieties of tomato (Lycopersicon esculentum) were grown in ambient (400 μmol mol(-1)) and elevated (1,000 μmol mol(-1)) concentration of CO(2) under controlled conditions. The fruits were harvested at premature and fully matured stages and analyzed for yield, proximate composition, elemental concentration, fatty acid, and vitamin C contents. The amount of carbohydrates increased significantly under the enhanced CO(2) conditions. The amount of crude protein and vitamin C, two important nutritional parameters, decreased substantially. Fatty acid content showed a mild decrease with a slight increase in crude fiber. Understandably, the effect of enhanced atmospheric CO(2) was more pronounced at the fully matured stage. Mineral contents of the fruit samples changed in an irregular fashion. Tomato fruit has been traditionally a source of vitamin C, under the experimental conditions, a negative impact of enhanced CO(2) on this source of vitamin C was observed. The nutritional quality of both varieties of tomato has altered under the CO(2) enriched atmosphere.

  16. Atmospheric carbon dioxide, irrigation, and fertilization effects on phenolic and nitrogen concentrations in loblolly pine (Pinus taeda) needles.

    Science.gov (United States)

    Booker, F L; Maier, C A

    2001-06-01

    Concentrations of total soluble phenolics, catechin, proanthocyanidins (PA), lignin and nitrogen (N) were measured in loblolly pine (Pinus taeda L.) needles exposed to either ambient CO(2) concentration ([CO(2)]), ambient plus 175 or ambient plus 350 micromol CO(2) mol(-1) in branch chambers for 2 years. The CO(2) treatments were superimposed on a 2 x 2 factorial combination of irrigation and fertilization treatments. In addition, we compared the effects of branch chambers and open-top chambers on needle chemistry. Proanthocyanidin and N concentrations were measured in needles from branch chambers and from trees in open-top chambers exposed concurrently for two years to either ambient [CO(2)] or ambient plus 200 micromol CO(2) mol(-1) in combination with a fertilization treatment. In the branch chambers, concentrations of total soluble phenolics in needles generally increased with needle age. Concentrations of total soluble phenolics, catechin and PA in needle extracts increased about 11% in response to the elevated [CO(2)] treatments. There were no significant treatment effects on foliar lignin concentrations. Nitrogen concentrations were about 10% lower in needles from the elevated [CO(2)] treatments than in needles from the ambient [CO(2)] treatments. Soluble phenolic and PA concentrations were higher in the control and irrigated soil treatments in about half of the comparisons; otherwise, differences were not statistically significant. Needle N concentrations increased 23% in response to fertilization. Treatment effects on PA and N concentrations were similar between branch and open-top chambers, although in this part of the study N concentrations were not significantly affected by the CO(2) treatments in either the branch or open-top chambers. We conclude that elevated [CO(2)] and low N availability affected foliar chemical composition, which could in turn affect plant-pathogen interactions, decomposition rates and mineral nutrient cycling.

  17. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Pennathur, Sumita; Kristensen, Jesper; Crumrine, Andrew

    2011-01-01

    conductance for low salt concentrations, we identify a minimum conductance value before saturation at a value independent of salt concentration in the dilute limit. Our model self-consistently couples chemical equilibrium models of the silica wall and the electrolyte bulk, and is parameterized by only...

  18. Hydronium-dominated ion transport in carbon-dioxide-saturated electrolytes at low salt concentrations in nanochannels

    DEFF Research Database (Denmark)

    Lund Jensen, Kristian; Kristensen, Jesper Toft; Crumrine, Andrew Michael

    2011-01-01

    the nanochannel conductance at low salt concentrations and identify a conductance minimum before saturation at a value independent of salt concentration in the dilute limit. Via the Poisson-Boltzmann equation, our model self-consistently couples chemical-equilibrium dissociation models of the silica wall...

  19. Carbon dioxide emission from bamboo culms.

    Science.gov (United States)

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

    2016-05-01

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

  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. Carbon Dioxide Mitigation by Microalgal Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mijeong Lee; Gillis, James M.; Hwang, Jiann Yang [Michigan Technological University, Houghton (United States)

    2003-12-15

    Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 μg CO{sub 2}/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

  2. Effects of pulses of elevated carbon dioxide concentration on stomatal conductance and photosynthesis in wheat and rice.

    Science.gov (United States)

    Bunce, James A

    2013-10-01

    Systems for exposing plants to elevated concentrations of CO₂ may expose plants to pulses of CO₂ concentrations considerably above the control set point. The importance of such pulses to plant function is unknown. Single leaves of wheat (Triticum aestivum cv Choptank) and rice (Oryza sativa cv Akitakomachi) were exposed for 30 minutes to pulses of elevated CO₂ similar to the frequency, duration and magnitude of pulses observed in free-air CO₂ enrichment systems. Stomatal conductance decreased within a few minutes of exposure to once per minute pulses of high CO₂ of all the durations tested, in both species. Both species had 20-35% lower stomatal conductance for at least 30 min after the termination of the pulses. After the pulses had stopped, in all cases photosynthesis was below the values expected for the observed substomatal CO₂ concentration, which suggests that either patchy stomatal closure occurred or that photosynthesis was directly inhibited. It was also found that a single, 2 s pulse of elevated CO₂ concentration reaching a maximum of 1000 µmol mol⁻¹ decreased stomatal conductance in both species. On the basis of these results, it is probable that plants in many CO₂ enrichment systems have lower photosynthesis and stomatal conductance than would plants exposed to the same mean CO₂ concentration but without pulses of higher concentration.

  3. Measurement of carbon dioxide concentration by fiber-loop ring-down spectroscopy for continuous remote measurement

    Science.gov (United States)

    Shimizu, Hiromasa; Noriyasu, Hiroshi

    2014-11-01

    We report on the continuous remote measurement of CO2 concentration using a fiber-loop ring-down spectroscopy system at a wavelength of 1572.334 nm. In fiber-loop ring-down spectroscopy, the effective propagation distance through the CO2 atmosphere determines the minimum detectable CO2 concentration. The effective propagation distance is determined by the signal-to-noise ratio in the fiber loop, including the gain of an Er-doped optical fiber amplifier (EDFA), and the loss in the single-mode fiber, coupling losses, and losses in optical devices. We examined the influence of noise due to the EDFA in the system. A noise figure for the EDFA was measured, and the maximum effective propagation distance through the CO2 atmosphere was 350 m. Using the obtained EDFA gain and the optical loss in the system, we simulated the ring-down time for a CO2 concentration range of 0 to 0.5%. We set up the fiber-loop ring-down spectroscopy system and measured the ring-down waveforms with a CO2 concentration range of 0 to 0.5%. In this CO2 concentration range, the measurement resolution was 0.05%, showing good agreement with the calculated results.

  4. Improved biomass productivity in algal biofilms through synergistic interactions between photon flux density and carbon dioxide concentration.

    Science.gov (United States)

    Schnurr, Peter J; Molenda, Olivia; Edwards, Elizabeth; Espie, George S; Allen, D Grant

    2016-11-01

    Algal biofilms were grown to investigate the interaction effects of bulk medium CO2 concentration and photon flux density (PFD) on biomass productivities. When increasing the CO2 concentration from 0.04% to 2%, while maintaining a PFD of 100μmol/m(2)/s, biomass productivities increased from ∼0.5 to 2.0g/m(2)/d; however, the productivities plateaued when CO2 concentrations were incrementally increased above 2-12%. Statistical analysis demonstrates that there is a significant interaction between PFD and CO2 concentrations on biomass productivities. By simultaneously increasing PFD and CO2 concentrations, biomass productivities were significantly increased to 4.0 and 4.1g/m(2)/d in the experimental and modeled data, respectively. The second order model predicted increases in biomass productivities as both PFD and CO2 simultaneously increased yielding an optimum at 440μmol/m(2)/s and 7.1%; however, when conditions were extended to the highest end of their respective ranges, the conditions were detrimental to growth and productivities decreased.

  5. Legume presence increases photosynthesis and N concentrations of co-occurring non-fixers but does not modulate their responsiveness to carbon dioxide enrichment.

    Science.gov (United States)

    Lee, Tali D; Reich, Peter B; Tjoelker, Mark G

    2003-09-01

    Legumes, with the ability to fix atmospheric nitrogen (N), may help alleviate the N limitations thought to constrain plant community response to elevated concentrations of atmospheric carbon dioxide (CO(2)). To address this issue we assessed: (1) the effects of the presence of the perennial grassland N(2 )fixer, Lupinus perennis, on biomass accumulation and plant N concentrations of nine-species plots of differing plant composition; (2) leaf-level physiology of co-occurring non-fixing species (Achillea millefolium, Agropyron repens, Koeleria cristata) in these assemblages with and without Lupinus; (3) the effects of elevated CO(2) on Lupinus growth and symbiotic N(2) fixation in both monoculture and the nine-species assemblages; and (4) whether assemblages containing Lupinus exhibit larger physiological and growth responses to elevated CO(2 )than those without. This study was part of a long-term grassland field experiment (BioCON) that controls atmospheric CO(2) at current ambient and elevated (560 micromol mol(-1)) concentrations using free-air CO(2) enrichment. Nine-species plots with Lupinus had 32% higher whole plot plant N concentrations and 26% higher total plant N pools than those without Lupinus, based on both above and below ground measurements. Co-occurring non-fixer leaf N concentrations increased 22% and mass-based net photosynthetic rates increased 41% in plots containing Lupinus compared to those without. With CO(2) enrichment, Lupinus monocultures accumulated 32% more biomass and increased the proportion of N derived from fixation from 44% to 57%. In nine-species assemblages, Lupinus N derived from fixation increased similarly from 43% to 54%. Although Lupinus presence enhanced photosynthetic rates and leaf N concentrations of co-occurring non-fixers, and increased overall plant N pools, Lupinus presence did not facilitate stronger photosynthetic responses of non-fixing species or larger growth responses of overall plant communities to elevated CO(2

  6. Electrocatalysts for carbon dioxide conversion

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Carbon Dioxide Photodissociation on Iapetus

    Science.gov (United States)

    Palmer, Eric; Brown, R. H.

    2009-09-01

    Carbon dioxide has been detected on Iapetus (Buratti et al., 2005) and is correlated with the dark material, mostly at mid-latitudes on the leading face of Iapetus (Palmer and Brown, in preparation). The average absorption feature of CO2 in the dark region is 24.7%; if it were a thin veneer of CO2 ice, it would be 14 um thick. Estimating the surface area of dark material and extrapolating gives a total CO2 budget of 8 x 107 kg on the surface of Iapetus. Volatile studies indicate that the surface of Iapetus is too hot to have CO2 ice remain on the surface for more than a few hundred years (Palmer and Brown, 2008). It has been suggested that complexing of volatiles, such as in clathrates, fluid or gas inclusions, or adsorption, would increase the stability on the Jovian and Saturnian satellites, increasing their residence times (McCord; et al., 1998; Hibbitts et al., 2001, 2002, 2007). While complexing would increase carbon dioxide's thermal stability, the resident time of CO2 on Iapetus would remain short due to the effect of UV radiation. We calculated the photodissociation rate for CO2 and found that the entire budget of CO2 on Iapetus would be destroyed in less than one Earth year. If we assume a steady-state system on Iapetus (photodissociation equal to photo-generation) approx. 108 kg will be destroyed and produced every Earth year. Unless the complexing mechanism provides some shielding from UV radiation while still allowing the detection of the 4.26-micron CO2 band, then a source of CO2 is required. We suggest that the source of CO2 is photolytic production from water ice and carbonaceous material.

  8. Carbon dioxide concentration and nitrogen input affect the C and N storage pools in Amanita muscaria-Picea abies mycorrhizae.

    Science.gov (United States)

    Turnau, K; Berger, A; Loewe, A; Einig, W; Hampp, R; Chalot, M; Dizengremel, P; Kottke, I

    2001-02-01

    We studied the influence of elevated atmospheric CO2 concentration ([CO2]) on the vacuolar storage pool of nitrogen-containing compounds and on the glycogen pool in the hyphal sheath of Amanita muscaria (L. ex Fr.) Hooker-Picea abies L. Karst. mycorrhizae grown with two concentrations of ammonium in the substrate. Mycorrhizal seedlings were grown in petri dishes on agar containing 5.3 or 53 mg N l(-1) and exposed to 350 or 700 microl CO2 l(-1) for 5 or 7 weeks, respectively. Numbers and area of nitrogen-containing bodies in the vacuoles of the mycorrhizal fungus were determined by light microscopy linked to an image analysis system. The relative concentration of nitrogen in the vacuolar bodies was measured by electron energy loss spectroscopy (EELS). Glycogen stored in the cytosol was determined at the ultrastructural level by image analysis after staining the sections (PATAg test). Shoot dry weight, net photosynthesis and relative amounts of N in vacuolar bodies were greater at the higher N and CO2 concentrations. The numbers and areas of vacuolar N-containing bodies were significantly greater at the higher N concentration only at ambient [CO2]. In the same treatment the percentage of hyphae containing glycogen declined to nearly zero. We conclude that, in the high N/low [CO2] treatment, the mycorrhizal fungus had an insufficient carbohydrate supply, partly because of increased amino acid synthesis by the non-mycorrhizal rootlets. When [CO2] was increased, the equilibrium between storage of glycogen and N-containing compounds was reestablished.

  9. Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish.

    Science.gov (United States)

    Talmage, Stephanie C; Gobler, Christopher J

    2010-10-01

    The combustion of fossil fuels has enriched levels of CO(2) in the world's oceans and decreased ocean pH. Although the continuation of these processes may alter the growth, survival, and diversity of marine organisms that synthesize CaCO(3) shells, the effects of ocean acidification since the dawn of the industrial revolution are not clear. Here we present experiments that examined the effects of the ocean's past, present, and future (21st and 22nd centuries) CO(2) concentrations on the growth, survival, and condition of larvae of two species of commercially and ecologically valuable bivalve shellfish (Mercenaria mercenaria and Argopecten irradians). Larvae grown under near preindustrial CO(2) concentrations (250 ppm) displayed significantly faster growth and metamorphosis as well as higher survival and lipid accumulation rates compared with individuals reared under modern day CO(2) levels. Bivalves grown under near preindustrial CO(2) levels displayed thicker, more robust shells than individuals grown at present CO(2) concentrations, whereas bivalves exposed to CO(2) levels expected later this century had shells that were malformed and eroded. These results suggest that the ocean acidification that has occurred during the past two centuries may be inhibiting the development and survival of larval shellfish and contributing to global declines of some bivalve populations.

  10. Responses of calcification of massive and encrusting corals to past, present, and near-future ocean carbon dioxide concentrations.

    Science.gov (United States)

    Iguchi, Akira; Kumagai, Naoki H; Nakamura, Takashi; Suzuki, Atsushi; Sakai, Kazuhiko; Nojiri, Yukihiro

    2014-12-15

    In this study, we report the acidification impact mimicking the pre-industrial, the present, and near-future oceans on calcification of two coral species (Porites australiensis, Isopora palifera) by using precise pCO2 control system which can produce acidified seawater under stable pCO2 values with low variations. In the analyses, we performed Bayesian modeling approaches incorporating the variations of pCO2 and compared the results between our modeling approach and classical statistical one. The results showed highest calcification rates in pre-industrial pCO2 level and gradual decreases of calcification in the near-future ocean acidification level, which suggests that ongoing and near-future ocean acidification would negatively impact coral calcification. In addition, it was expected that the variations of parameters of carbon chemistry may affect the inference of the best model on calcification responses to these parameters between Bayesian modeling approach and classical statistical one even under stable pCO2 values with low variations.

  11. Indoor carbon dioxide concentrations and sick building syndrome symptoms in the BASE study revisited: Analyses of the 100 building dataset

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, Christine A.; Steiner, Kate C.; Apte, Michael G.

    2002-02-01

    In previously published analyses of the 41-building 1994-1996 USEPA Building Assessment Survey and Evaluation (BASE) dataset, higher workday time-averaged indoor minus outdoor CO{sub 2} concentrations (dCO{sub 2}) were associated with increased prevalence of certain mucous membrane and lower respiratory sick building syndrome (SBS) symptoms, even at peak dCO{sub 2} concentrations below 1,000 ppm. For this paper, similar analyses were performed using the larger 100-building 1994-1998 BASE dataset. Multivariate logistic regression analyses quantified the associations between dCO{sub 2} and the SBS symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. Adjusted dCO{sub 2} prevalence odds ratios for sore throat and wheeze were 1.17 and 1.20 per 100-ppm increase in dCO{sub 2} (p <0.05), respectively. These new analyses generally support our prior findings. Regional differences in climate, building design, and operation may account for some of the differences observed in analyses of the two datasets.

  12. Carbon Dioxide Fluxes and Concentrations in a Cotton Field in Northwestern China: Effects of Plastic Mulching and Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Guo; ZHANG Run-Hua; WANG Xiu-Jun; WANG Jie-Ping; ZHANG Cui-Ping; TIAN Chang-Yan

    2011-01-01

    In northwestern China, there has been a change from traditional cultivation system (TC) with no mulching and flood irrigation to a more modern cultivation system (MC) using plastic film mulching with drip irrigation. A field study was conducted to compare soil CO2 concentrations and soil surface CO2 fluxes between TC and MC systems during a cotton growing season. CO2 concentrations in the soil profile were higher in the MC system (3 107-9212 μL L-1) than in the TC system (1 275-8994 μL L-1) but the rate of CO2 flux was lower in the MC system. Possible reasons for this included decreased gas diffusion and higher soil moisture due to the mulching cover in the MC system, and the consumption of soil CO2 by weathering reactions. Over the whole cotton growing season,accumulated rates of CO2 flux were 300 and 394 g C m-2 for the MC and TC systems, respectively. When agricultural practices were converted from traditional cultivation to a plastic film mulching system, soil CO2 emissions could be reduced by approximately 100 g C m-2 year-1 in agricultural lands in arid and/or semi-arid areas of northern and northwestern China.

  13. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration.

    Science.gov (United States)

    McGrath, Justin M; Karnosky, David F; Ainsworth, Elizabeth A

    2010-04-01

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO(2)]) and elevated ozone concentration ([O(3)]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO(2)] and [O(3)] predicted for approximately 2050. The responses of two clones were compared during the first month of spring leaf out when CO(2) fumigation had begun, but O(3) fumigation had not. Trees in elevated [CO(2)] plots showed a stimulation of leaf area index (36%), while trees in elevated [O(3)] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO(2)], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO(2)]; however, the two clones responded differently to long-term growth at elevated [O(3)]. The O(3)-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O(3)] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O(3)] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O(3)], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions.

  14. Growth at elevated ozone or elevated carbon dioxide concentration alters antioxidant capacity and response to acute oxidative stress in soybean (Glycine max)

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, K.M.; Rogers, A.; Ainsworth, E. A.

    2011-01-31

    Soybeans (Glycine max Merr.) were grown at elevated carbon dioxide concentration ([CO{sub 2}]) or chronic elevated ozone concentration ([O{sub 3}]; 90 ppb), and then exposed to an acute O{sub 3} stress (200 ppb for 4 h) in order to test the hypothesis that the atmospheric environment alters the total antioxidant capacity of plants, and their capacity to respond to an acute oxidative stress. Total antioxidant metabolism, antioxidant enzyme activity, and antioxidant transcript abundance were characterized before, immediately after, and during recovery from the acute O{sub 3} treatment. Growth at chronic elevated [O{sub 3}] increased the total antioxidant capacity of plants, while growth at elevated [CO{sub 2}] decreased the total antioxidant capacity. Changes in total antioxidant capacity were matched by changes in ascorbate content, but not phenolic content. The growth environment significantly altered the pattern of antioxidant transcript and enzyme response to the acute O{sub 3} stress. Following the acute oxidative stress, there was an immediate transcriptional reprogramming that allowed for maintained or increased antioxidant enzyme activities in plants grown at elevated [O{sub 3}]. Growth at elevated [CO{sub 2}] appeared to increase the response of antioxidant enzymes to acute oxidative stress, but dampened and delayed the transcriptional response. These results provide evidence that the growth environment alters the antioxidant system, the immediate response to an acute oxidative stress, and the timing over which plants return to initial antioxidant levels. The results also indicate that future elevated [CO{sub 2}] and [O{sub 3}] will differentially affect the antioxidant system.

  15. 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...

  16. Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Wheeler, R. M.; Lowery, W.; Sager, J. C.

    1990-01-01

    Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area.

  17. Action of gibberellins on growth and metabolism of Arabidopsis plants associated with high concentration of carbon dioxide.

    Science.gov (United States)

    Ribeiro, Dimas M; Araújo, Wagner L; Fernie, Alisdair R; Schippers, Jos H M; Mueller-Roeber, Bernd

    2012-12-01

    Although the positive effect of elevated CO(2) concentration [CO(2)] on plant growth is well known, it remains unclear whether global climate change will positively or negatively affect crop yields. In particular, relatively little is known about the role of hormone pathways in controlling the growth responses to elevated [CO(2)]. Here, we studied the impact of elevated [CO(2)] on plant biomass and metabolism in Arabidopsis (Arabidopsis thaliana) in relation to the availability of gibberellins (GAs). Inhibition of growth by the GA biosynthesis inhibitor paclobutrazol (PAC) at ambient [CO(2)] (350 µmol CO(2) mol(-1)) was reverted by elevated [CO(2)] (750 µmol CO(2) mol(-1)). Thus, we investigated the metabolic adjustment and modulation of gene expression in response to changes in growth of plants imposed by varying the GA regime in ambient and elevated [CO(2)]. In the presence of PAC (low-GA regime), the activities of enzymes involved in photosynthesis and inorganic nitrogen assimilation were markedly increased at elevated [CO(2)], whereas the activities of enzymes of organic acid metabolism were decreased. Under ambient [CO(2)], nitrate, amino acids, and protein accumulated upon PAC treatment; however, this was not the case when plants were grown at elevated [CO(2)]. These results suggest that only under ambient [CO(2)] is GA required for the integration of carbohydrate and nitrogen metabolism underlying optimal biomass determination. Our results have implications concerning the action of the Green Revolution genes in future environmental conditions.

  18. Carbon Dioxide/Methane Separation by Adsorption on Sepiolite

    Institute of Scientific and Technical Information of China (English)

    José A.Delgado; María A.Uguina; José L.Sotelo; Beatriz Ruíz; Marcio Rosário

    2007-01-01

    In this work,the use of sepiolite for the removal of carbon dioxide from a carbon dioxide/methane mixture by a pressure swing adsorption (PSA) process has been researched.Adsorption equilibrium and kinetics have been measured in a fixed-bed.and the adsorption equilibrium parameters of carbon dioxide and methane on sepiolite have been obtained.A model based on the LDF approximation has been employed to simulate the fixed-bed kinetics.using the Langmuir equation to describe the adsotption equilibrium isotherm.The functioning of a PSA cycle for separating carbon dioxide/methane mixtures using sepiolite as adsorbent has also been studied.The experimental results were compared with the ones predicted by the model adapted to a PSA system.Methane with purity higher than 97% can be obtained from feeds containing carbon dioxide with concentrations ranging from 34% to 56% with the proposed PSA cycle.These results suggest that sepiolite is an adsorbent with good properties for its employment in a PSA cycle for carbon dioxide removal from landfill gases.

  19. 46 CFR 193.15-20 - Carbon dioxide storage.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  20. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  1. 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...

  2. 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.”...

  3. 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...

  4. 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)...

  5. 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...

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  10. 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...

  11. 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).

  12. Branch growth and gas exchange in 13-year-old loblolly pine (Pinus taeda) trees in response to elevated carbon dioxide concentration and fertilization.

    Science.gov (United States)

    Maier, Chris A; Johnsen, Kurt H; Butnor, John; Kress, Lance W; Anderson, Peter H

    2002-11-01

    We used whole-tree, open-top chambers to expose 13-year-old loblolly pine (Pinus taeda L.) trees, growing in soil with high or low nutrient availability, to either ambient or elevated (ambient + 200 micromol mol-1) carbon dioxide concentration ([CO2]) for 28 months. Branch growth and morphology, foliar chemistry and gas exchange characteristics were measured periodically in the upper, middle and lower crown during the 2 years of exposure. Fertilization and elevated [CO2] increased branch leaf area by 38 and 13%, respectively, and the combined effects were additive. Fertilization and elevated [CO2] differentially altered needle lengths, number of fascicles and flush length such that flush density (leaf area/flush length) increased with improved nutrition but decreased in response to elevated [CO2]. These results suggest that changes in nitrogen availability and atmospheric [CO2] may alter canopy structure, resulting in greater foliage retention and deeper crowns in loblolly pine forests. Fertilization increased foliar nitrogen concentration (N(M)), but had no consistent effect on foliar leaf mass (W(A)) or light-saturated net photosynthesis (A(sat)). However, the correlation between A(sat) and leaf nitrogen per unit area (N(A) = W(A)N(M)) ranged from strong to weak depending on the time of year, possibly reflecting seasonal shifts in the form and pools of leaf nitrogen. Elevated [CO2] had no effect on W(A), N(M) or N(A), but increased A(sat) on average by 82%. Elevated [CO2] also increased photosynthetic quantum efficiency and lowered the light compensation point, but had no effect on the photosynthetic response to intercellular [CO2], hence there was no acclimation to elevated [CO2]. Daily photosynthetic photon flux density at the upper, middle and lower canopy position was 60, 54 and 33%, respectively, of full sun incident to the top of the canopy. Despite the relatively high light penetration, W(A), N(A), A(sat) and R(d) decreased with crown depth. Although

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

    Science.gov (United States)

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

    2012-12-01

    A series of thermo-hydro-chemical numerical simulations was performed to evaluate extent of carbon dioxide plume injected in the Gyeongsang Basin, which is one of the prospective onshore sedimentary basins for geologic storage of carbon dioxide in Korea. The carbon dioxide plume extent is an important factor in estimating storage efficiency and thus storage capacity of carbon dioxide in a storage formation because it represents an actual volume of the storage formation, which is occupied by injected carbon dioxide. The carbon dioxide plume extent is also an essential component in risk analysis of geologic storage of carbon dioxide because most of thermo-hydro-mechanical-chemical responses to carbon dioxide injection occur within it. To evaluate impacts of injection scenarios (i.e., injection rate and period) of carbon dioxide and geological conditions (i.e., thickness and depth) and hydrogeochemical properties (i.e., porosity, intrinsic permeability, salt concentration in groundwater, and volume fraction of chlorite) of a storage formation on the carbon dioxide plume extent, a series of sensitivity tests was also performed. The numerical simulation results show that the carbon dioxide plume extent is significantly affected by such injection scenarios, geological conditions, and hydrogeochemical properties. The carbon dioxide plume extent increases as the injection rate (with a constant injection period) increases, and this trend does not change with time. The carbon dioxide plume extent decreases as the injection period (with a constant total injection amount) increases until about 50 years, while it is not sensitive to the injection period after about 50 years. The carbon dioxide plume extent also decreases as the thickness increases until about 100 years, while it is not sensitive to the thickness after about 100 years. In contrast, the carbon dioxide plume extent decreases as the depth increases, and this trend is intensified with time. On the other hand, the

  14. 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.

  15. Experimental studies on removal of carbon dioxide by aqueous ammonia fine spray

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Experimental studies on carbon dioxide capture in a spray scrubber were carried out.Fine spray of aqueous ammonia was used as CO2 absorbent.Effects of different operating and design parameters on CO2 removal efficiency including concentration of aqueous ammonia,liquid flow rate,total gas flow rate,initial temperature and concentration of carbon dioxide were investigated.

  16. Carbon dioxide emissions from biochar in soil

    DEFF Research Database (Denmark)

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

    2014-01-01

    The stability of biochar in soil is of importance if it is to be used for carbon sequestration and long-term improvement of soil properties. It is well known that a significant fraction of biochar is highly stable in soil, but carbon dioxide (CO2) is also released immediately after application...

  17. Method for Extracting and Sequestering Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

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

  18. 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 corr

  19. 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…

  20. 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...

  1. Distribution of carbon dioxide produced by people in a room:

    DEFF Research Database (Denmark)

    Baránková, Petra; Naydenov, Kiril Georgiev; Melikov, Arsen Krikor

    2004-01-01

    Carbon dioxide produced by occupants can be used as a natural tracer gas for analysing air change rates in dwellings. However, a high level of concentration uniformity is necessary for tracer gas measurements. Therefore, mixing fans are usually used. The use of such fans in occupied homes...

  2. 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

  3. 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

  4. Photobiological hydrogen production and carbon dioxide sequestration

    Science.gov (United States)

    Berberoglu, Halil

    Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

  5. 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.

  6. 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

    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...... 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....... 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...

  7. Carbon dioxide utilisation in the chemical industry

    Energy Technology Data Exchange (ETDEWEB)

    Aresta, M.; Tommasi, I. [Universita di Bari (Italy). Centro METEA e Dipartimento di Chimica

    1997-12-31

    The amount of carbon dioxide available for industrial utilisation may expand to unprecedented levels if the recovery of carbon dioxide from energy plants flue gases is implemented. The potential of each of the three possible uses (technological, chemical, and biological) is far from being clearly defined. The chemical utilisation option, that has intrinsic thermodynamic and kinetic constraints, may raise controversial positions, depending on the criteria used for the analysis. The estimate of its real potential demands a thorough comparative analysis, using the Life Cycle Assessment methodology, of existing processes/products with the new ones based on CO{sub 2}, in order to establish whether, or not, the latter avoid carbon dioxide (either directly or indirectly) and their economics. The rejection/consideration assessment methodology will produce reliable results only if an exhaustive number of parameters is used. The analysis cannot be limited to practiced industrial processes, but must be extended to an exhaustive inventory of cases. (Author)

  8. 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.

  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. Carbon Concentration of Austenite

    Directory of Open Access Journals (Sweden)

    Z. Ławrynowicz

    2007-07-01

    Full Text Available The investigation was carried out to examine the influence of temperature and times of austempering process on the maximum extend towhich the bainite reaction can proceed and the carbon content in retained austenite. It should be noted that a small percentage change in theaustenite carbon content can have a significant effect on the subsequent austempering reaction changing the volume fraction of the phasespresent and hence, the resulting mechanical properties. Specimens were prepared from an unalloyed ductile cast iron, austenitised at 950oCfor 60 minutes and austempered by the conventional single-step austempering process at four temperatures between BS and MS, eg., 250,300, 350 and 400oC. The samples were austempered at these temperatures for 15, 30, 60, 120 and 240 minutes and finally quenched toambient temperature. Volume fractions of retained austenite and carbon concentration in the residual austenite have been observed byusing X-ray diffraction. Additionally, carbon concentration in the residual austenite was calculated using volume fraction data of austeniteand a model developed by Bhadeshia based on the McLellan and Dunn quasi-chemical thermodynamic model. The comparison ofexperimental data with the T0, T0' and Ae3' phase boundaries suggests the likely mechanism of bainite reaction in cast iron is displacive rather than diffusional. The carbon concentration in retained austenite demonstrates that at the end of bainite reaction the microstructure must consist of not only ausferrite but additionally precipitated carbides.

  11. Carbon dioxide elimination and regeneration of resources in a microwave plasma torch.

    Science.gov (United States)

    Uhm, Han S; Kwak, Hyoung S; Hong, Yong C

    2016-04-01

    Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials.

  12. Indirect methods for characterization of carbon dioxide levels in fermentation broth.

    Science.gov (United States)

    Frick, R; Junker, B

    1999-01-01

    Various factors which influence dissolved carbon dioxide levels were indirectly evaluated in pilot scale and laboratory studies. For pilot scale studies, off-gas carbon dioxide (percentage in exit air) was measured using a mass spectrometer and then its potential impact on dissolved carbon dioxide concentrations qualitatively examined. Greater volumetric air flowrates reduced off-gas carbon dioxide levels more effectively at lower airflow ranges and thus lowered expected dissolved carbon dioxide levels through gas stripping. Lower broth pH values decreased off-gas carbon dioxide levels but increased expected dissolved carbon dioxide levels due to the pH-dependence of the gas/liquid carbon dioxide equilibrium. While back-pressure increases had an insignificant effect on off-gas carbon dioxide levels, they directly affected expected dissolved carbon dioxide levels according to Henry's law. Laboratory studies, conducted using both uninoculated and inoculated fermentation media, quantified the response of the media to pH changes with bicarbonate addition, specifically its buffering capacity. This effect then was related qualitatively to expected dissolved carbon dioxide levels. Higher dissolved carbon dioxide levels, as demonstrated by reduced pH changes with bicarbonate addition, thus would be expected for salt solutions of increased ionic strength and higher protein content media. In addition, pH changes with greater bicarbonate additions declined for fermentation samples taken over the course of a one week cultivation, most likely due to the higher protein content associated with biomass growth. The presence of weak acids/bases initially in the media or formed as metabolic by products, as well as the concentration of buffering ions such as phosphate, also were believed to be important contributing elements to the buffering capacity of the solution.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-04-01

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

  14. Effect of Solid Loading on Carbon Dioxide Absorptionin Bubble Column

    Directory of Open Access Journals (Sweden)

    Alyaa Khadhier Mageed

    2011-01-01

    Full Text Available In the present work experiments were conducted to study the effect of solid loading (1,5 and 9 vol.% on the enhancement of carbon dioxide absorption in bubble column at various volumetric gas flow rate (0.75, 1 and 1.5 m3/h and absorbent concentration (caustic soda( 0.1,0.5 and 1 M . Activated carbon and alumina oxide (Al2O3 are used as solid particles. The Danckwerts method was used to calculate interfacial area and individual mass transfer coefficients during absorption of carbon dioxide in a bubble column. The results show that the absorption rate was increased with increasing volumetric gas flow rate, caustic soda concentration and solid loading. Mass transfer coefficient and interfacial area were increased with increasing volumetric gas flow rate, and solid loading.

  15. 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.

  16. 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...

  17. Diiodination of Alkynes in supercritical Carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    李金恒; 谢叶香; 尹笃林; 江焕峰

    2003-01-01

    A general,green and efficient method for the synthesis of transdiiodoalkenes in CO2(sc) has been developed.Trans-diiodoalkenes were obtained stereospecifically in quantitative yields via diiodination of both electron-rich and electron-deficient alkynes in the presence of KI,Ce(SO4)2 and water in supercritical carbon dioxide [CO2(sc)]at 40℃.

  18. Immobilized Ruthenium Catalyst for Carbon Dioxide Hydrogenation

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  19. Cooperative redox activation for carbon dioxide conversion

    DEFF Research Database (Denmark)

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.

    2016-01-01

    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...

  20. 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...

  1. Carbon dioxide sensing with sulfonated polyaniline

    NARCIS (Netherlands)

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

    2012-01-01

    The use of polyaniline and especially sulfonated polyaniline (SPAN) is explored for sensing carbon dioxide (CO2) at room temperature. Frequency-dependent AC measurements were carried out to detect changes in impedance of the polymer, drop casted on interdigitated electrodes, when exposed to CO2 gas.

  2. Carbon dioxide foaming of glassy polymers

    NARCIS (Netherlands)

    Wessling, M.; Borneman, Z.; Boomgaard, van den Th.; Smolders, C.A.

    1994-01-01

    The mechanism of foaming a glassy polymer using sorbed carbon dioxide is studied in detail. A glassy polymer supersaturated with nitrogen forms a microcellular foam, if the polymer is quickly heated above its glass transition temperature. A glassy polymer supersaturated with CO2 forms this foam-like

  3. Electrocatalytic carbon dioxide reduction - a mechanistic study

    NARCIS (Netherlands)

    Schouten, Klaas Jan Schouten

    2013-01-01

    This thesis presents new insights into the reduction of carbon dioxide to methane and ethylene on copper electrodes. This electrochemical process has great potential for the storage of surplus renewable electrical energy in the form of hydrocarbons. The research described in this thesis focuses on t

  4. Tourism Transport, Technology, and Carbon Dioxide Emissions

    NARCIS (Netherlands)

    Peeters, P.M.

    2010-01-01

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

  5. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  6. 9 CFR 313.5 - Chemical; carbon dioxide.

    Science.gov (United States)

    2010-01-01

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

  7. 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...

  8. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 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... carbon dioxide analyzer as follows: (1) Follow good engineering practices for instrument start-up...

  9. 46 CFR 108.431 - Carbon dioxide systems: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  10. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 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... carbon dioxide analyzer shall be calibrated on all normally used instrument ranges. New...

  11. 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...

  12. 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;...

  13. 21 CFR 868.5310 - Carbon dioxide absorber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  14. 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...

  15. RESEARCH ON ELECTRIC ARC REDUCTION OF CARBON DIOXIDE,

    Science.gov (United States)

    CARBON DIOXIDE , REDUCTION(CHEMISTRY), ELECTRIC ARCS, CHEMICAL REACTIONS, HEAT OF REACTION, GAS FLOW, OXYGEN, CARBON COMPOUNDS, MONOXIDES, ELECTRODES, LABORATORY EQUIPMENT, HIGH TEMPERATURE, PLASMAS(PHYSICS), ENERGY.

  16. The carbon dioxide content in ice cores - climatic curves of carbon dioxide. Zu den CO sub 2 -Klimakurven aus Eisbohrkernen

    Energy Technology Data Exchange (ETDEWEB)

    Heyke, H.E.

    1992-05-01

    The 'greenhouse effect', which implies a temperature of 15 deg C as against -18 deg C, owes its effect to 80% from water (clouds and gaseous phase) and to 10% from carbon dioxide, besides other components. Whereas water is largely unaccounted for, carbon dioxide has been postulated as the main cause of anticipated climatic catastrophe. The carbon dioxide concentration in the atmosphere has risen presently to such levels that all previous figures seem to have been left far behind. The reference point is the concentration of carbon dioxide in the air bubbles trapped in ice cores of Antartic and Greenland ice dated 160 000 years ago, which show much lower values than at present. A review of the most relevant publications indicates that many basic laws of chemistry seem to have been left largely unconsidered and experimental errors have made the results rather doubtful. Appropriate arguments have been presented. The investigations considered should be repeated under improved and more careful conditions. (orig.).

  17. 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)....

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  19. Adsorption of Carbon Dioxide on Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    Bo Guo; Liping Chang; Kechang Xie

    2006-01-01

    The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Freundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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.

  6. Effect of temperature on carbon dioxide absorption in monoethanolamine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rocio Maceira; Estrella Alvarez; M. Angeles Cancela [University of Vigo, Vigo (Spain). Chemical Engineering Department

    2008-05-01

    The effect of temperature on volumetric mass transfer coefficient was studied during the absorption process of carbon dioxide in monoethanolamine aqueous solutions, using a square bubble column. Our studies provide an empirical correlation type Boltzmann to estimate the temperature operated, at different amine concentrations and gas flow rates. An excellent agreement has been shown between predicted and experimental data (r{sup 2} {gt} 0.991).

  7. Sequestering ADM ethanol plant carbon dioxide

    Science.gov (United States)

    Finley, R.J.; Riddle, D.

    2008-01-01

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

  8. 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.

  9. 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.

  10. Pulsed discharge plasmas in supercritical carbon dioxide

    OpenAIRE

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

    2005-01-01

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

  11. Water in supercritical carbon dioxide dyeing

    Directory of Open Access Journals (Sweden)

    Zheng Lai-Jiu

    2015-01-01

    Full Text Available This paper investigates the effect of water serving as entrainer on the dyeing of wool fabrics in supercritical carbon dioxide. Compared with previous supercritical dyeing methods, addition of water makes the dyeing process more effective under low temperature and low pressure. During dyeing process, dyestuff can be uniformly distributed on fabrics’s surface due to water interaction, as a result coloration is enhanced while color difference is decreased.

  12. Acute carbon dioxide avoidance in Caenorhabditis elegans

    OpenAIRE

    Hallem, Elissa A.; Sternberg, Paul W.

    2008-01-01

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement....

  13. 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.

  14. Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems

    Science.gov (United States)

    Watten, Barnaby J.; Rust, Michael; Colt, John

    2009-01-01

    In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

  15. Elevated carbon dioxide alters the relative fitness of Taraxacum officinale genotypes

    Science.gov (United States)

    I tested whether elevated carbon dioxide concentration differentially affected which genotypes of the apomictic species dandelion produced the largest number of viable seeds in two different field experiments, and identified morphological and physiological traits associated with fitness at elevated ...

  16. 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

  17. 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.

  18. Carbon dioxide: A substitute for phosgene

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  19. Evidence for Carbonate Surface Complexation during Forsterite Carbonation in Wet Supercritical Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Loring, John S.; Chen, Jeffrey; Benezeth Ep Gisquet, Pascale; Qafoku, Odeta; Ilton, Eugene S.; Washton, Nancy M.; Thompson, Christopher J.; Martin, Paul F.; McGrail, B. Peter; Rosso, Kevin M.; Felmy, Andrew R.; Schaef, Herbert T.

    2015-07-14

    Continental flood basalts are attractive formations for geologic sequestration of carbon dioxide because of their reactive divalent-cation containing silicates, such as forsterite (Mg2SiO4), suitable for long-term trapping of CO2 mineralized as metal carbonates. The goal of this study was to investigate at a molecular level the carbonation products formed during the reaction of forsterite with supercritical CO2 (scCO2) as a function of the concentration of H2O adsorbed to the forsterite surface. Experiments were performed at 50 °C and 90 bar using an in situ IR titration capability, and post-reaction samples were examined by ex situ techniques, including SEM, XPS, FIB-TEM, TGA-MS, and MAS-NMR. Carbonation products and reaction extents varied greatly with adsorbed H2O. We show for the first time evidence of Mg-carbonate surface complexation under wet scCO2 conditions. Carbonate is found to be coordinated to Mg at the forsterite surface in a predominately bidentate fashion at adsorbed H2O concentrations below 27 µmol/m2. Above this concentration and up to 76 µmol/m2, monodentate coordinated complexes become dominant. Beyond a threshold adsorbed H2O concentration of 76 µmol/m2, crystalline carbonates continuously precipitate as magnesite, and the particles that form are hundreds of times larger than the estimated thicknesses of the adsorbed water films of about 7 to 15 Å. At an applied level, these results suggest that mineral carbonation in scCO2 dominated fluids near the wellbore and adjacent to caprocks will be insignificant and limited to surface complexation, unless adsorbed H2O concentrations are high enough to promote crystalline carbonate formation. At a fundamental level, the surface complexes and their dependence on adsorbed H2O concentration give insights regarding forsterite dissolution processes and magnesite nucleation and growth.

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

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, A.G.; Ho, C.S.

    1988-06-20

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

  1. 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...

  2. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service, and monthly thereafter, or within one month prior to the certification test, calibrate the NDIR carbon...

  3. Hydrogenation of carbon dioxide by hybrid catalysts, direct synthesis of aromatic from carbon dioxide and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kuei Chikung; Lee Mindar (National Taiwan Univ., Taipei (Taiwan))

    1991-02-01

    To improve climatic conditions and to solve the carbon resource problem, it is desirable to develop techniques whereby carbon dioxide can be converted to valuable liquid hydrocarbons which can be used either as fuels or industrial raw materials. Direct synthesis of aromatics from carbon dioxide hydrogenation was investigated in a single stage reactor using hybrid catalysts composed of iron catalysts and HZSM-5 zeolite. Carbon dioxide was first converted to CO by the reverse water gas shift reaction, followed by the hydrogenation of CO to hydrocarbons on iron catalyst, and finally the hydrocarbons were converted to aromatics in HZSM-5. Under the operating conditions of 350{degree}C, 2100 kilopascals and CO{sub 2}/H{sub 2}={1/2} the maximum aromatic selectivity obtained was 22% with a CO{sub 2} conversion of 38% using fused iron catalyst combined with the zeolite. Together with the kinetic studies, thermodynamic analysis of the CO{sub 2} hydrogenation was also conducted. It was found that unlike Fischer Tropsch synthesis, the formation of hydrocarbons from CO{sub 2} may not be thermodynamically favored at higher temperature. However, the sufficiently high yields of aromatics possible with this process provides a route for the direct synthesis of high-octane gasoline from carbon dioxide. 24 refs., 9 figs., 5 tabs.

  4. Membrane loop process for separating carbon dioxide for use in gaseous form from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Wijmans, Johannes G; Baker, Richard W; Merkel, Timothy C

    2016-09-06

    The invention is a process involving membrane-based gas separation for separating and recovering carbon dioxide emissions from combustion processes in partially concentrated form, and then transporting the carbon dioxide and using or storing it in a confined manner without concentrating it to high purity. The process of the invention involves building up the concentration of carbon dioxide in a gas flow loop between the combustion step and a membrane separation step. A portion of the carbon dioxide-enriched gas can then be withdrawn from this loop and transported, without the need to liquefy the gas or otherwise create a high-purity stream, to a destination where it is used or confined, preferably in an environmentally benign manner.

  5. Effect of hydrogen and carbon dioxide on carboxylic acids patterns in mixed culture fermentation.

    Science.gov (United States)

    Arslan, D; Steinbusch, K J J; Diels, L; De Wever, H; Buisman, C J N; Hamelers, H V M

    2012-08-01

    This study investigated the carboxylate spectrum from mixed culture fermentation of three organic waste streams after supplying 2 bar hydrogen and carbon dioxide or a mixture of these two gases to the headspace. Under any modified headspace, propionate production was ceased and butyrate, caproate and the total carboxylate concentrations were higher than in the reactors with N(2) headspace (control). Production of one major compound was achieved under hydrogen and carbon dioxide mixed headspace after 4 weeks of incubation. Both the highest acetate concentration (17.4 g COD/l) and the highest fraction (87%) were observed in reactors with mixed hydrogen and carbon dioxide headspace independent of the substrate used. In the control reactor, acetate made up maximum 67% of the total products. For other products, the highest concentration and fraction were seldom observed together. Selective butyrate production reaching a 75% fraction was found under the carbon dioxide headspace on the carbohydrate rich waste.

  6. Carbon dioxide utilization in the chemical industry

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  7. Supercritical carbon dioxide: a solvent like no other

    Directory of Open Access Journals (Sweden)

    Jocelyn Peach

    2014-08-01

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

  8. Dissolved carbon dioxide and oxygen concentrations in purge of vacuum-packaged pork chops and the relationship to shelf life and models for estimating microbial populations.

    Science.gov (United States)

    Adams, K R; Niebuhr, S E; Dickson, J S

    2015-12-01

    The objectives of this study were to determine the dissolved CO2 and O2 concentrations in the purge of vacuum-packaged pork chops over a 60 day storage period, and to elucidate the relationship of dissolved CO2 and O2 to the microbial populations and shelf life. As the populations of spoilage bacteria increased, the dissolved CO2 increased and the dissolved O2 decreased in the purge. Lactic acid bacteria dominated the spoilage microflora, followed by Enterobacteriaceae and Brochothrix thermosphacta. The surface pH decreased to 5.4 due to carbonic acid and lactic acid production before rising to 5.7 due to ammonia production. A mathematical model was developed which estimated microbial populations based on dissolved CO2 concentrations. Scanning electron microscope images were also taken of the packaging film to observe the biofilm development. The SEM images revealed a two-layer biofilm on the packaging film that was the result of the tri-phase growth environment.

  9. 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.

  10. Carbon dioxide absorbent and method of using the same

    Science.gov (United States)

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

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

  11. Preparation of perlite-based carbon dioxide absorbent.

    Science.gov (United States)

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

    1994-02-01

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

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

    Science.gov (United States)

    Carlson, R. W.

    1999-01-01

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

  13. Evidence for Carbonate Surface Complexation during Forsterite Carbonation in Wet Supercritical Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Loring, John S.; Chen, Jeffrey; Benezeth, Pascale; Qafoku, Odeta; Ilton, Eugene S.; Washton, Nancy M.; Thompson, Christopher J.; Martin, Paul F.; McGrail, B. Peter; Rosso, Kevin M.; Felmy, Andrew R.; Schaef, Herbert T.

    2015-06-16

    Continental flood basalts are attractive formations for geologic sequestration of carbon dioxide because of their reactive divalent-cation containing silicates, such as forsterite (Mg2SiO4), suitable for long-term trapping of CO2 mineralized as metal carbonates. The goal of this study was to investigate at a molecular level the carbonation products formed during the reaction of forsterite with supercritical CO2 (scCO2) as a function of the concentration of H2O adsorbed to the forsterite surface. Experiments were performed at 50 °C and 90 bar using an in situ IR titration capability, and post-reaction samples were examined by ex situ techniques, including SEM, XPS, FIB-TEM, TGA-MS, and MAS-NMR. Carbonation products and reaction extents varied greatly with adsorbed H2O. We show for the first time evidence of Mg-carbonate surface complexation under wet scCO2 conditions. Carbonate is found to be coordinated to Mg at the forsterite surface in a predominately bidentate fashion at adsorbed H2O concentrations below 27 µmol/m2. Above this concentration and up to 76 µmol/m2, monodentate coordinated complexes become dominant. Beyond a threshold adsorbed H2O concentration of 76 µmol/m2, crystalline carbonates continuously precipitate as magnesite, and the particles that form are hundreds of times larger than the estimated thicknesses of the adsorbed water films of about 7 to 15 Å. At an applied level, the implication of these results is that mineral trapping in scCO2 dominated fluids will be insignificant and limited to surface complexation unless adsorbed H2O concentrations are high enough to promote crystalline carbonate formation. At a fundamental level, the surface complexes and their dependence on adsorbed H2O concentration give insights regarding forsterite dissolution processes and magnesite nucleation and growth.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Evidence for atmospheric carbon dioxide variability over the Gulf Stream

    Science.gov (United States)

    Bufton, J. L.

    1984-01-01

    Two airborne surveys of atmospheric carbon dioxide concentration have been conducted over the Gulf Stream off the east coast of Virginia and North Carolina on September 7-8, 1983. In situ CO2 data were acquired at an aircraft altitude of 300 m on trajectories that transcected the Gulf Stream near 36 deg N 73 deg W. Data show evidence of a CO2 concentration increase by 4 ppm to 15 ppm above the nominal atmospheric background value of 345 ppm. These enhanced values were associated with the physical location of the Gulf Stream prior to the passage of a weak cold front.

  16. 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.

  17. 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.

  18. 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.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  20. Transcriptome-Wide Changes in Chlamydomonas reinhardtii Gene Expression Regulated by Carbon Dioxide and the CO2-Concentrating Mechanism Regulator CIA5/CCM1[W][OA

    Science.gov (United States)

    Fang, Wei; Si, Yaqing; Douglass, Stephen; Casero, David; Merchant, Sabeeha S.; Pellegrini, Matteo; Ladunga, Istvan; Liu, Peng; Spalding, Martin H.

    2012-01-01

    We used RNA sequencing to query the Chlamydomonas reinhardtii transcriptome for regulation by CO2 and by the transcription regulator CIA5 (CCM1). Both CO2 and CIA5 are known to play roles in acclimation to low CO2 and in induction of an essential CO2-concentrating mechanism (CCM), but less is known about their interaction and impact on the whole transcriptome. Our comparison of the transcriptome of a wild type versus a cia5 mutant strain under three different CO2 conditions, high CO2 (5%), low CO2 (0.03 to 0.05%), and very low CO2 (<0.02%), provided an entry into global changes in the gene expression patterns occurring in response to the interaction between CO2 and CIA5. We observed a massive impact of CIA5 and CO2 on the transcriptome, affecting almost 25% of all Chlamydomonas genes, and we discovered an array of gene clusters with distinctive expression patterns that provide insight into the regulatory interaction between CIA5 and CO2. Several individual clusters respond primarily to either CIA5 or CO2, providing access to genes regulated by one factor but decoupled from the other. Three distinct clusters clearly associated with CCM-related genes may represent a rich source of candidates for new CCM components, including a small cluster of genes encoding putative inorganic carbon transporters. PMID:22634760

  1. Transcriptome-Wide Changes in Chlamydomonas reinhardtii Gene Expression Regulated by Carbon Dioxide and the CO2-Concentrating Mechanism Regulator CIA5/CCM1

    Energy Technology Data Exchange (ETDEWEB)

    Fang, W; Si, YQ; Douglass, S; Casero, D; Merchant, SS; Pellegrini, M; Ladunga, I; Liu, P; Spalding, MH

    2012-06-26

    We used RNA sequencing to query the Chlamydomonas reinhardtii transcriptome for regulation by CO2 and by the transcription regulator CIA5 (CCM1). Both CO2 and CIA5 are known to play roles in acclimation to low CO2 and in induction of an essential CO2-concentrating mechanism (CCM), but less is known about their interaction and impact on the whole transcriptome. Our comparison of the transcriptome of a wild type versus a cia5 mutant strain under three different CO2 conditions, high CO2 (5%), low CO2 (0.03 to 0.05%), and very low CO2 (< 0.02%), provided an entry into global changes in the gene expression patterns occurring in response to the interaction between CO2 and CIA5. We observed a massive impact of CIA5 and CO2 on the transcriptome, affecting almost 25% of all Chlamydomonas genes, and we discovered an array of gene clusters with distinctive expression patterns that provide insight into the regulatory interaction between CIA5 and CO2. Several individual clusters respond primarily to either CIA5 or CO2, providing access to genes regulated by one factor but decoupled from the other. Three distinct clusters clearly associated with CCM-related genes may represent a rich source of candidates for new CCM components, including a small cluster of genes encoding putative inorganic carbon transporters.

  2. Using broadband absorption spectroscopy to measure concentration of sulfur dioxide

    Science.gov (United States)

    Wang, H. S.; Zhang, Y. G.; Wu, S. H.; Lou, X. T.; Zhang, Z. G.; Qin, Y. K.

    2010-09-01

    A linear relationship between concentration of sulfur dioxide (SO2) and optical parameter (OP) is established using the Beer-Lambert law. The SO2 measuring system is set up to measure the concentration of sulfur dioxide in the wavelength range 275-315 nm. Experimental results indicate that the detection limit of the sulfur dioxide measuring system is below 0.2 ppm per meter of path length, and the measurement precision is better than ±1%. The proposed SO2 measuring method features limited interference from other gases and dust, and high stability and short response time.

  3. The extreme carbon dioxide outburst at the Menzengraben potash mine 7 July 1953

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2012-01-01

    PHAST. Output from the model is inconsistent with the asphyxiation harm observed. The high-momentum release is predicted to disperse safely and never reach the ground. Carbon dioxide capture and storage (CCS) schemes will involve handling and transportation of unprecedented quantities of CO2. Case......Carbon dioxide is an asphyxiant and an irritant gas. An extreme outburst of carbon dioxide took place 7 July 1953 in a potash mine in the former East Germany. During 25 min, a large amount of CO2 was blown out of the mine shaft with great force. It was wind still and concentrated CO2 accumulated...... in a valley leading to multiple asphyxiation casualties. Based on a review of concentration–response relationships, the location of victims, and other information, it is concluded that concentrations of 10–30% carbon dioxide may have occurred 450 m from the point of release for at least 45 min...

  4. The kinetics of binding carbon dioxide in magnesium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M. [Los Alamos National Lab., NM (United States); Nomura, Koji [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.]|[Chichibu Onada Cement Co., Tokyo (Japan)

    1998-08-01

    Humans currently consume about 6 Gigatons of carbon annually as fossil fuel. In some sense, the coal industry has a unique advantage over many other anthropogenic and natural emitters of CO{sub 2} in that it owns large point sources of CO{sub 2} from which this gas could be isolated and disposed of. If the increased energy demands of a growing world population are to be satisfied from coal, the implementation of sequestration technologies will likely be unavoidable. The authors` method of sequestration involves binding carbon dioxide as magnesium carbonate, a thermodynamically stable solid, for safe and permanent disposal, with minimal environmental impact. The technology is based on extracting magnesium hydroxide from common ultramafic rock for thermal carbonation and subsequent disposition. The economics of the method appear to be promising, however, many details of the proposed process have yet to be optimized. Realization of a cost effective method requires development of optimal technologies for efficient extraction and thermal carbonation.

  5. Carbon dioxide research plan. A summary

    Energy Technology Data Exchange (ETDEWEB)

    Trivelpiece, Alvin W.; Koomanoff, F. A.; Suomi, Verner E.

    1983-11-01

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

  6. 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.

  7. Carbon Dioxide Capture Adsorbents: Chemistry and Methods.

    Science.gov (United States)

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

    2016-12-21

    Excess carbon dioxide (CO2 ) 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 CO2 . 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, CO2 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 CO2 emissions. An effective sorbent design is suggested, whereby six checkpoints are expected to be met: cost, capacity, selectivity, stability, recyclability, and fast kinetics.

  8. Electrocatalytic process for carbon dioxide conversion

    Energy Technology Data Exchange (ETDEWEB)

    Masel, Richard I.; Salehi-Khojin, Amin

    2017-01-31

    An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and Helper Catalyst 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 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.

  9. Pharmaceutical applications of supercritical carbon dioxide.

    Science.gov (United States)

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

    2001-12-01

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

  10. 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.

  11. 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

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  13. 40 CFR 86.1524 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration. 86.1524 Section 86.1524 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Test Procedures § 86.1524 Carbon dioxide analyzer calibration. (a) The calibration requirements for...

  14. 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...

  15. 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…

  16. 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...

  17. 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...

  18. 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 f

  19. Activation of Carbon Dioxide and Synthesis of Propylene Carbonate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  20. 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.

  1. 21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

    Science.gov (United States)

    2010-04-01

    ... relative changes in a hemodynamically stable patient's cutaneous carbon dioxide tension as an adjunct to arterial carbon dioxide tension measurement. (b) Classification. Class II (special controls). The...

  2. 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.

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

    Science.gov (United States)

    Heck, Vera; Donges, Jonathan; Lucht, Wolfgang

    2015-04-01

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

  4. Effects of Carbon Dioxide on Astringency Removal in Mopanshi Persimmon

    Institute of Scientific and Technical Information of China (English)

    LENG Ping; LI Bao; ZHANG Wen; JIA Ke-gong

    2003-01-01

    Fruits of persimmon (Diospyros kaki cv. Mopanshi) were used to investigate the effects of different concentrations of carbon dioxide (CO2) gas on removing astringency after harvest. Treatment of 95 % concentration of CO2 gas gave the best results; fruits turned non-astringent after 20 h, and kept the fruit firm for 7 d at room temperature. Fruits, treated with 85 and 90 % concentration of CO2 gas, turned non-astringent after 24 - 28 h, and the firmness-keeping stage was 5 - 6 d at room temperature. While the CO2 gas was at 80, 70 and 60%, the de-astringency period was 48, 72 and 96 h, and the corresponding firmness-keeping stage was 3, 2 and 1 d, respectively. Fruits, treated with 50 % concentration of CO2 gas,remained astringent.

  5. 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.

  6. Effect of carbon dioxide and temperature on passive film parametersof superduplex stainless steel

    Directory of Open Access Journals (Sweden)

    Emandro Vieira da Costa

    2013-01-01

    Full Text Available Superduplex stainless steel has been frequently employed in new sites of Brazilian Pre-Salt. In these environments, chloride concentration, temperature and carbon dioxide are normally present in higher levels than those at sea water at room temperature. In these conditions, it is expected that the passive films of stainless steel also show modifications. To better understand such modifications, samples of superduplex stainless steel UNS S32750 were submitted to electrochemical impedance measurements in brine media, at two temperatures and under presence/absence of carbon dioxide. The electrochemical impedance results were initially tested using the Kramers-Kronig transform and subsequently fitted by equivalent circuit employing constant phase elements - CPE. Moreover, to quantify the effect of each factor (temperature, chloride, carbon dioxide and microstructure on the equivalent circuit, their parameters were tested applying statistical analysis. Significant effect of carbon dioxide and temperature was found on related parameters of passive film for heat-treated samples.

  7. Climatic consequences of very high carbon dioxide levels in the earth's early atmosphere

    Science.gov (United States)

    Kasting, James F.; Ackerman, Thomas P.

    1986-01-01

    The possible consequences of very high carbon dioxide concentrations in the earth's early atmosphere have been investigated with a radiative-convective climate model. The early atmosphere would apparently have been stable against the onset of a runaway greenhouse (that is, the complete evaporation of the oceans) for carbon dioxide pressures up to at least 100 bars. A 10- to 20-bar carbon dioxide atmosphere, such as may have existed during the first several hundred million years of the earth's history, would have had a surface temperature of approximately 85 to 110 C. The early stratosphere should have been dry, thereby precluding the possibility of an oxygenic prebiotic atmosphere caused by photodissociation of water vapor followed by escape of hydrogen to space. Earth's present atmosphere also appears to be stable against a carbon dioxide-induced runaway greenhouse.

  8. 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)

  9. Oxygen and carbon dioxide monitoring during sleep.

    Science.gov (United States)

    Amaddeo, Alessandro; Fauroux, Brigitte

    2016-09-01

    Monitoring of oxygen and carbon dioxide (CO2) is of crucial importance during sleep-disordered breathing in order to assess the consequences of respiratory events on gas exchange. Pulse oximetry (SpO2) is a simple and cheap method that is used routinely for the recording of oxygen levels and the diagnosis of hypoxemia. CO2 recording is necessary for the diagnosis of alveolar hypoventilation and can be performed by means of the end-tidal (PetCO2) or transcutaneous CO2 (PtcCO2). However, the monitoring of CO2 is not performed on a routine basis due to the lack of simple, cheap and reliable CO2 monitors. This short review summarizes some technical aspects of gas exchange recording during sleep in children before discussing the different definitions of alveolar hypoventilation and the importance of CO2 recording.

  10. 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.

  11. 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.

  12. Thermodynamical effects during carbon dioxide release

    Science.gov (United States)

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

    2012-04-01

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

  13. 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.

  14. Carbon dioxide absorbents for rebreather diving.

    Science.gov (United States)

    Pennefather, John

    2016-09-01

    Firstly I would like to thank SPUMS members for making me a Life Member of SPUMS; I was surprised and greatly honoured by the award. I also want to confirm and expand on the findings on carbon dioxide absorbents reported by David Harvey et al. For about 35 years, I was the main player in deciding which absorbent went into Australian Navy and Army diving sets. On several occasions, suppliers of absorbents to the anaesthesia market tried to supply the Australian military market. On no occasion did they provide absorbent that came close to the minimum absorbent capacity required, generally being 30-40% less efficient than diving-grade absorbents. Because I regard lives as being more important than any likely dollar saving, the best absorbent was always selected unless two suppliers provided samples with the same absorbent capacity. On almost every occasion, there was a clear winner and cost was never considered. I suggest the same argument for the best absorbent should be used by members and their friends who dive using rebreather sets. I make this point because of my findings on a set that was brought to me after the death of its owner. The absorbent was not the type or grain size recommended by the manufacturer of the set and did not resemble any of the diving grade absorbents I knew of. I suspected by its appearance that it was anaesthetic grade absorbent. When I tested the set, the absorbent system failed very quickly so it is likely that carbon dioxide toxicity contributed to his death. The death was not the subject of an inquest and I have no knowledge of how the man obtained the absorbent. Possibly there was someone from an operating theatre staff who unintentionally caused their friend's death by supplying him with 'borrowed absorbent'. I make this point as I would like to discourage members from making a similar error.

  15. Epoxide-functionalization of polyethyleneimine for synthesis of stable carbon dioxide adsorbent in temperature swing adsorption

    Science.gov (United States)

    Choi, Woosung; Min, Kyungmin; Kim, Chaehoon; Ko, Young Soo; Jeon, Jae Wan; Seo, Hwimin; Park, Yong-Ki; Choi, Minkee

    2016-08-01

    Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g-1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation.

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

    CERN Document Server

    Cardoso, Silvana S S

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-08-01

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

  18. Evidence for Carbonate Surface Complexation during Forsterite Carbonation in Wet Supercritical Carbon Dioxide.

    Science.gov (United States)

    Loring, John S; Chen, Jeffrey; Bénézeth, Pascale; Qafoku, Odeta; Ilton, Eugene S; Washton, Nancy M; Thompson, Christopher J; Martin, Paul F; McGrail, B Peter; Rosso, Kevin M; Felmy, Andrew R; Schaef, Herbert T

    2015-07-14

    Continental flood basalts are attractive formations for geologic sequestration of carbon dioxide because of their reactive divalent-cation containing silicates, such as forsterite (Mg2SiO4), suitable for long-term trapping of CO2 mineralized as metal carbonates. The goal of this study was to investigate at a molecular level the carbonation products formed during the reaction of forsterite with supercritical CO2 (scCO2) as a function of the concentration of H2O adsorbed to the forsterite surface. Experiments were performed at 50 °C and 90 bar using an in situ IR titration capability, and postreaction samples were examined by ex situ techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), focused ion beam transmission electron microscopy (FIB-TEM), thermal gravimetric analysis mass spectrometry (TGA-MS), and magic angle spinning nuclear magnetic resonance (MAS NMR). Carbonation products and reaction extents varied greatly with adsorbed H2O. We show for the first time evidence of Mg-carbonate surface complexation under wet scCO2 conditions. Carbonate is found to be coordinated to Mg at the forsterite surface in a predominately bidentate fashion at adsorbed H2O concentrations below 27 μmol/m(2). Above this concentration and up to 76 μmol/m(2), monodentate coordinated complexes become dominant. Beyond a threshold adsorbed H2O concentration of 76 μmol/m(2), crystalline carbonates continuously precipitate as magnesite, and the particles that form are hundreds of times larger than the estimated thicknesses of the adsorbed water films of about 7 to 15 Å. At an applied level, these results suggest that mineral carbonation in scCO2 dominated fluids near the wellbore and adjacent to caprocks will be insignificant and limited to surface complexation, unless adsorbed H2O concentrations are high enough to promote crystalline carbonate formation. At a fundamental level, the surface complexes and their dependence on adsorbed H2O

  19. The Formation of Ethane from Carbon Dioxide under Cold Plasma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane,carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

  20. Microbial community dynamics and methane, carbon dioxide, oxygen, and nitrous oxide concentrations in upland forest and riparian soils across a seasonal gradient of fully saturated soils to completely dried soils

    Science.gov (United States)

    Jones, R. T.; McGlynn, B. L.; McDermott, T.; Dore, J. E.

    2015-12-01

    Gas concentrations (CH4, CO2, N2O, and O2), soil properties (soil water content and pH), and microbial community composition were measured from soils at 32 sites across the Stringer Creek Watershed in the Tenderfoot Creek Experimental Forest 7 times between June 3, 2013 and September 20, 2013. Soils were fully saturated during the initial sampling period and dried down over the course of the summer. Soils and gas were sampled from 5cm and 20cm at each site and also at 50cm at eight riparian sites. In total, 496 individual soil samples were collected. Soil moisture ranged from 3.7% to fully saturated; soil pH ranged from 3.60 to 6.68. Methane concentrations in soils ranged from 0.426 ppm to 218 ppm; Carbon dioxide concentrations ranged from 550 ppm to 42,990 ppm; Nitrous oxide concentrations ranged from 0.220 ppm to 2.111 ppm; Oxygen concentrations ranged from 10.2% to 21.5%. Soil microbial communities were characterized by DNA sequences covering the V4 region of the 16S rRNA gene. DNA sequences were generated (~30,000,000 sequences) from the 496 soil samples using the Illumina MiSeq platform. Operational Taxonomic Units were generated using USEARCH, and representative sequences were taxonomically classified according the Ribosomal Database Project's taxonomy scheme. Analysis of similarity revealed that microbial communities found within a landscape type (high upland forest, low upland forest, riparian) were more similar than among landscape types (R = 0.600; p<0.001). Similarly, communities from unique site x depths were similar across the 7 collection periods (R = 0.646; p<0.001) despite changes in soil moisture. Euclidean distances of soil properties and gas concentrations were compared to Bray-Curtis community dissimilarity matrices using Mantel tests to determine how community structure co-varies with the soil environment and gas concentrations. All variables measured significantly co-varied with microbial community membership (pH: R = 0.712, p < 0.001; CO2: R

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  2. Histidine-catalyzed synthesis of cyclic carbonates in supercritical carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The coupling reaction of carbon dioxide with epoxides was investigated using naturally occurring α-amino acids as the catalyst in supercritical carbon dioxide and it was found that L-histidine is the most active catalyst.In the presence of 0.8 mol% of L-histidine at 130°C under 8 MPa of CO2,the reaction of carbon dioxide with epoxides proceeded smoothly,affording corresponding cyclic carbonates in good to excellent yields.

  3. 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.

  4. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

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

    2000-01-01

    This paper examines the synergistic action of carbon dioxide and nisin on Listeria monocytogenes Scott A wild-type and nisin-resistant (Nis(r)) cells grown in broth at 4 degrees C. Carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree...... 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...

  5. Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers

    Energy Technology Data Exchange (ETDEWEB)

    Mayorga, E; Aufdenkampe, A K; Masiello, C A; Krusche, A V; Hedges, J I; Quay, P D; Richey, J E; Brown, T A

    2005-06-23

    Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition ({sup 13}C and {sup 14}C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than 5 years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in mid-size to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  7. Solving corrosion problems at the NEA Bellingham Massachusetts carbon dioxide recovery plant

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, T.R. [Duke/Fluor Daniel, Charlotte, NC (United States); Hansen, D.A. [Fluor Daniel Inc., Houston, TX (United States); Mariz, C.L. [Fluor Daniel Inc., Irvine, CA (United States); McCullough, J.G. [Proton Technology Ltd., Hawthorne, NY (United States)

    1999-11-01

    The Northeast Energy Associates (NEA) carbon dioxide recovery plant at Bellingham, MA utilizes a 30 wt % monoethanol amine (MEA) solution with a proprietary additive to inhibit the corrosion of carbon steel. This plant was the first application of this technology to gas turbine flue gas, which has high concentrations of oxygen (typically 13 vol. %) and low concentrations of carbon dioxide (typically 3 vol. %). Prior to the operation of the Bellingham plant, the technology had been applied to boiler flue gas streams, which typically contain more than 8 vol. % carbon dioxide and 2--4 vol. % oxygen. In this first application of the technology to gas turbine flue gas, unexpected corrosion occurred in both the absorber and stripper towers. The causes of the corrosion and its successful elimination are the subject of this paper.

  8. 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.

  9. Microbial Response to Carbon Dioxide Injection in a Shallow Aquifer

    Science.gov (United States)

    Rook, A.; Faehndrich, D.; O'Mullan, G.; Mailloux, B.; Matter, J.; Stute, M.; Goldberg, D.

    2007-12-01

    Extensive research is underway to investigate the geophysical and geochemical dynamics of subsurface carbon sequestration, but there has been only theoretical consideration of the microbial response. Microbial dynamics are capable of altering the range and rates of geochemical reactions in the subsurface. The goal of this field experiment is to link geochemical changes due to CO2 injection to alterations in the microbial community and to provide an initial characterization of the microbial response. A seven week push-pull experiment was conducted at the Lamont-Doherty Earth Observatory Test Well. 200L of groundwater was extracted, bubbled with carbon dioxide, augmented with a bromide tracer, and injected to 230m depth below ground surface. The hydraulically isolated injection zone marked the contact area between dolerite sill and sedimentary rock. Samples were taken on a weekly basis. Geochemically, a drop in pH from 9.4 to 4.5 at injection was coupled with a release of Fe2+ from the formation. As neutralization and mixing caused pH to return toward background levels, Fe2+ concentrations decreased. The aquifer remained anoxic throughout the experiment. DNA was successfully extracted and the gene encoding 16S ribosomal RNA was amplified from all samples with the exception of the injection fluid. Sequencing from clone libraries and tRFLP analyses were used to characterize microbial dynamics during the seven week study. Whereas the number of microbial groups detected remained relatively constant over the course of the experiment, changes were observed in both the dominant microbes phylogenetic identity and relative abundance. Methane concentrations increased from background levels (below 50 nM) to 4.2 nM after injection, but initial attempts to amplify archaeal and methanogen-specific genes were unsuccessful, bringing into question the presence of a significant methanogenic population. These results confirm that there is a microbial response to carbon dioxide

  10. Simultaneous effect of nitrate (NO3- concentration, carbon dioxide (CO2 supply and nitrogen limitation on biomass, lipids, carbohydrates and proteins accumulation in Nannochloropsis oculata

    Directory of Open Access Journals (Sweden)

    Aarón Millán-Oropeza

    2015-03-01

    Full Text Available Biodiesel from microalgae is a promising technology. Nutrient limitation and the addition of CO2 are two strategies to increase lipid content in microalgae. There are two different types of nitrogen limitation, progressive and abrupt limitation. In this work, the simultaneous effect of initial nitrate concentration, addition of CO2, and nitrogen limitation on biomass, lipid, protein and carbohydrates accumulation were analyzed. An experimental design was established in which initial nitrogen concentration, culture time and CO2 aeration as independent numerical variables with three levels were considered. Nitrogen limitation was taken into account as a categorical independent variable. For the experimental design, all the experiments were performed with progressive nitrogen limitation. The dependent response variables were biomass, lipid production, carbohydrates and proteins. Subsequently, comparison of both types of limitation i.e. progressive and abrupt limitation, was performed. Nitrogen limitation in a progressive mode exerted a greater effect on lipid accumulation. Culture time, nitrogen limitation and the interaction of initial nitrate concentration with nitrogen limitation had higher influences on lipids and biomass production. The highest lipid production and productivity were at 582 mgL-1 (49.7 % lipid, dry weight basis and 41.5 mgL-1d-1, respectively; under the following conditions: 250 mgL-1 of initial nitrate concentration, CO2 supply of 4% (v/v, 12 d of culturing and 2 d in state of nitrogen starvation induced by progressive limitation. This work presents a novel way to perform simultaneous analysis of the effect of the initial concentration of nitrate, nitrogen limitation, and CO2 supply on growth and lipid production of Nannochloropsis oculata, with the aim to produce potential biofuels feedstock.

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

    CERN Document Server

    Heng, Kevin

    2015-01-01

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

  12. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

    2016-12-01

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  13. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates.

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N; Vajtai, Robert; Yu, Aaron Z; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J A; Ajayan, Pulickel M

    2016-12-13

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

  14. Synthesis pf dimethyl carbonate in supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ballivet-Tkatchenko, D.; Plasseraud, L. [Universite de Bourgogne-UFR Sciences et Techniques, Dijon (France). Lab. de Synthese et Electrosynthese Organometalliques]. E-mail: ballivet@u-bourgogne.fr; Ligabue, R.A. [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Dept. de Quimica Pura

    2006-01-15

    The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu{sub 3}SnOCH{sub 3}, n-Bu{sub 2}Sn(OCH{sub 3}){sub 2}, and [n-Bu{sub 2}(CH{sub 3}O)Sn]{sub 2}O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO{sub 2} 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 CO{sub 2} pressure higher than 16 MPa. Under these conditions, CO{sub 2} acted as a reactant and a solvent. (author)

  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. Clean Hydrogen Production. Carbon Dioxide Free Alternatives. Project Phisico2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Fierro, J. L.; Gonzalez, C.; Serrano, D.; Penelas, G.; Romero, M.; Marcos, M. J.; Rodriguez, C.

    2006-07-01

    The main goal of the PHISICO2 project, funded and promoted by Comunidad de Madrid, is the evaluation and optimisation of three different processes for the clean hydrogen production without carbon dioxide emission. Solar energy and associated Technologies are proposed to be jointly employed with the aim of improving the process efficiency and reducing the production costs. As a transition to the non-fossil fuel hydrogen economy, the thermocatalytic CO2-free production of hydrogen from natural gas will be considered. One of the most promising alternatives of this process is to develop a cheap and stable carbon-based catalyst able to efficiently decompose methane into a CO2-free hydrogen stream and solid carbon. Thus, not only pure hydrogen can be obtained through but also carbon with specific properties and commercial value can be produced. Another option to be explored is the splitting of water by means of solar light by means of two different approaches: (i) photodissociation promoted by semiconductor catalysts and (ii) thermochemical cycles in which a specific mixed oxide is first thermally reduced by sunlight and then reoxidized by steam in a second step with the parallel production of hydrogen. Indeed, option (i) implies necessarily the development of semiconductors with appropriate band-gap able to decompose water into hydrogen and oxygen in an efficient manner. Another critical issue will be the development of a strategy/concept that allows efficient separation of hydrogen and oxygen within the cell. In option (ii), the development of stable ferrites which act as the redox element of the cycle is also an important challenge. Finally, a 5 kW prototype solar engine water splitting, based on the mentioned thermochemical cycle, will developed and tested using concentrated solar light as an energy source. Moreover, thermodynamic and kinetic studies, reactor design, process optimisation, economical studies and comparison with conventional hydrogen production systems

  17. 75 FR 75059 - Mandatory Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide

    Science.gov (United States)

    2010-12-01

    ... Sequestration of Carbon Dioxide; Final Rule #0;#0;Federal Register / Vol. 75 , No. 230 / Wednesday, December 1... sequestration of carbon dioxide and all other facilities that conduct injection of carbon dioxide. This rule... may determine''). These regulations will affect owners or operators of carbon dioxide (CO...

  18. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  19. 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...

  20. Membranes for separation of carbon dioxide

    Science.gov (United States)

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Ramaswamy, Vidya; Willson, Patrick Daniel; Gao, Yan

    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.

  1. 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...

  2. 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.

  3. 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...

  4. Heterogeneously Catalysed Chemical Reactions in Carbon Dioxide Medium

    DEFF Research Database (Denmark)

    Musko, Nikolai E.

    studies of catalytic chemical reactions in dense and supercritical carbon dioxide have been complemented by the theoretical calculations of phase equilibria using advanced thermodynamic models. In the recent years, the use of compressed carbon dioxide as innovative, non-toxic and non-flammable, cheap...... is discussed more extensively. Heterogeneously catalysed hydrogenation reactions are considered to be quite well studied and established. However, the catalyst performance can alter significantly when the reaction is performed in carbon dioxide medium. This effect was studied with the example of the selective...... the selective hydrogenation of unsaturated aldehydes in carbon dioxide medium. It was found that supported tungstosilicic acid catalysts and acidic resin Amberlyst-15 are very effective for performing aldol reactions. The positive influence of temperature and CO2-content on catalyst activity was studied...

  5. 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...

  6. Comment on "An optimized potential for carbon dioxide"

    OpenAIRE

    Merker, T.; Vrabec, J.; Hasse, H.

    2009-01-01

    A molecular model for carbon dioxide is assessed regarding vapor-liquid equilibrium properties. Large deviations, being above 15 %, are found for vapor pressure and saturated vapor density in the entire temperature range.

  7. Carbon dioxide and nitrous oxide in the North Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; Naqvi, S.W.A.; Jayakumar, D.A.; George, M.D.; Narvekar, P.V.; DeSousa, S.N.

    The understanding of biogeochemical cycling of carbon dioxide and nitrous oxide in the oceans is essential for predicting the fate of anthropogenically emitted components. The North Indian Ocean, with its diverse regimes, provides us with a natural...

  8. 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...

  9. 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...

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Precision remote sensor for oxygen and carbon dioxide Project

    Data.gov (United States)

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

  12. Carbon dioxide laser treatment of balanitis xerotica obliterans.

    Science.gov (United States)

    Ratz, J L

    1984-05-01

    A case of balanitis xerotica obliterans unresponsive to topical therapy is presented. The condition was successfully corrected following epithelial vaporization with the carbon dioxide laser, the patient remaining free of recurrence for 21 months postoperatively.

  13. Factors affecting ethylene and carbon dioxide concentrations during ripening: Incidence on final dry matter, total soluble solids content and acidity of mango fruit.

    Science.gov (United States)

    Nordey, Thibault; Léchaudel, Mathieu; Génard, Michel; Joas, Jacques

    2016-06-01

    Ripening of climacteric fruits is associated with pronounced changes in fruit gas composition caused by a concomitant rise in respiration and ethylene production. There is a discrepancy in the literature since some authors reported that changes in fruit gas compositions differ in attached and detached fruits. This study presents for the first time an overview of pre- and post-harvest factors that lead to variations in the climacteric respiration and ethylene production, and attempts to determine their impacts on fruit composition, i.e., dry matter, total soluble solids content and acidity. The impact of growing conditions such as the fruit position in the canopy and the fruit carbon supply; fruit detachment from the tree, including the maturity stage at harvest; and storage conditions after harvest, i.e., relative humidity and temperature were considered as well as changes in fruit skin resistance to gas diffusion during fruit growth and storage. Results showed that fruit gas composition vary with all pre and post-harvest factors studied. Although all mangoes underwent a respiratory climacteric and an autocatalytic ethylene production, whatever pre and post-harvest factors studied, large differences in ethylene production, climacteric respiration and fruit quality were measured. Results suggested that the ripening capacity is not related to the fruit ability to produce great amount of ethylene. In agreement with precedent studies, this work provided several lines of evidence that gas composition of fruit is related to its water balance. Our measurements indicated that skin resistance to gas diffusion increased after the harvest and during storage. It was so suggested that the faster ripening of detached fruit may be explained in part by changes in fruit water balance and skin resistance to gas diffusion caused by fruit detachment.

  14. Kinetic study of coals gasification into carbon dioxide atmosphere

    OpenAIRE

    Korotkikh A.G.; Slyusarskiy K.V.

    2015-01-01

    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 ...

  15. Carbon Dioxide Effects under Conditions of Raised Environmental Pressure

    Science.gov (United States)

    1974-12-26

    the inspiratory muscles might have contributed to the elevated carbon dioxide tensions in the trained underwater swimmer because it was shown that...alveolar carbon dioxide tensions increase linearly with the work- load on the inspiratory muscles (Milic- Emili & Tyler 1962). Lanphier (1963...Submarine Escape Training Tank, U.S. Naval Submarine Base New London, in dives to 90 ft (3.7 ATA) (Sehaefer 1955; Schaefer & Carey 1962). During

  16. Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats

    Institute of Scientific and Technical Information of China (English)

    Gui-Sen Xu; He-Nian Liu; Jun Li; Xiao-Ling Wu; Xue-Mei Dai; Ying-Hai Liu

    2009-01-01

    AIM: To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism. METHODS: Thi r ty heal thy male SD rats were randomly divided into control group (n = 10), 0 h experimental group (n = 10) and 1 h experimental group (n = 10) after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver tissue were observed with hematoxylineosin staining. Liver function was assayed with an automatic biochemical analyzer. Concentration of malonyldialdehyde (MDA) and activity of superoxide dismutase (SOD) were assayed by colorimetry. Activity of adenine nucleotide translocator in liver tissue was detected with the atractyloside-inhibitor stop technique. Expression of hypoxia inducible factor-1 (HIF-1) mRNA in liver tissue was detected with in situ hybridization. RESULTS: Carbon dioxide pneumoperitoneum for 60 min could induce liver injury in rats. Alanine aminotransferase and aspartate aminotransferase were 95.7 ± 7.8 U/L and 86.8 ± 6.9 U/L in 0 h experimental group, and 101.4 ± 9.3 U/L and 106.6 ± 8.7 U/L in 1 h experimental group. However, no significant difference was found in total billirubin, albumin, and pre-albumin in the three groups. In 0 h experimental group, the concentration of MDA was 9.83 ± 2.53 μmol/g in liver homogenate and 7.64 ± 2.19 μmol/g in serum respectively, the activity of SOD was 67.58 ± 9.75 nu/mg in liver and 64.47 ± 10.23 nu/mg in serum respectively. In 1 h experimental group, the concentration of MDA was 16.57 ± 3.45 μmol/g in liver tissue and 12.49 ± 4.21 μmol/g in serum respectively, the activity of SOD was 54.29 ± 7.96 nu/mg in liver tissue and 56.31 ± 9.85 nu/mg in serum, respectively. The activity of ANT in liver tissue was 9.52 ± 1.56 in control group, 6.37 ± 1.33 in 0 h experimental group and 7.28 ± 1.45 (10-9 mol/min per gram protein) in 1 h experimental group, respectively. The expression of HIF-1 mRNA in liver tissue was not detected in

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

    Science.gov (United States)

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

  18. 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...

  19. Carbon dioxide grows as recovery tool

    Energy Technology Data Exchange (ETDEWEB)

    Byars, C.

    1972-08-07

    Two more companies, Shell Oil Co. and Atlantic Richfield Co., are starting up COD2U injection projects in W. Texas. Miscible recovery projects using carbon dioxide are being started in Crossett Field and Wasson Field. Announcement of similar projects in North Cowden and Slaughter-Leveland fields to be conducted by Amoco Production Co. is expected. Shell, which is supplying some of the gas from its deep wells in the JM and East Brown Bassett fields, is taking 20 MMcfd of the COD2U as the line goes through the North Cross unit on its way to Sacroc. The North Cross project expects to recover an additional 8,851,000 bbl of oil. Original oil-in-place is estimated at 51 million bbl. Cumulative production has been 6.9 million bbl and current output is 1,600 bpd from 18 wells. Atlantic Richfield Co. (ARCO) will start injecting COD2U in mid-September at their project in the Willard unit of Wasson Field in Yoakum County. The project area has produced about 85.8 million bbl of 33$ gravi regenerated scrubbing solution to ste (10 claims)

  20. Vibrations of the carbon dioxide dimer

    Science.gov (United States)

    Chen, Hua; Light, J. C.

    2000-03-01

    Fully coupled four-dimensional quantum-mechanical calculations are presented for intermolecular vibrational states of rigid carbon dioxide dimer for J=0. The Hamiltonian operator is given in collision coordinates. The Hamiltonian matrix elements are evaluated using symmetrized products of spherical harmonics for angles and a potential optimized discrete variable representation (PO-DVR) for the intermolecular distance. The lowest ten or so states of each symmetry are reported for the potential energy surface (PES) given by Bukowski et al. [J. Chem. Phys. 110, 3785 (1999)]. Due to symmetries, there is no interconversion tunneling splitting for the ground state. Our calculations show that there is no tunneling shift of the ground state within our computation precision (0.01 cm-1). Analysis of the wave functions shows that only the ground states of each symmetry are nearly harmonic. The van der Waals frequencies and symmetry adapted force constants are found and compared to available experimental values. Strong coupling between the stretching coordinates and the bending coordinates are found for vibrationally excited states. The interconversion tunneling shifts are discussed for the vibrationally excited states.

  1. 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.

  2. Some Organic Reactions in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    JIANG Huan-feng; YANG Xiao-yue; LI Guo-ping; ZOU Gang

    2004-01-01

    Organic reactions in supercritical carbon dioxide (scCO2) have facilitated great progress in recent years 1. ScCO2, as an environmentally friendly reaction medium, may be a substitute for volatile and toxic organic solvents and show some special advantages. Firstly, CO2 is inexpensive,nonflammable, nontoxic and chemical inert under many conditions. Secondly, scCO2 possesses hybrid properties of both liquid and gas, to the advantage of some reactions involving gaseous reagents. Control of the solvent density by variation of the temperature and pressure enables the solvent properties to be "tuned" to reactants. Finally, separating of CO2 from the reaction mixture is energy-efficient and simple. Here we disclose our new work on some organic reactions involving small molecules in scCO2.The results showed that the upper reactions in scCO2 could be carried out smoothly and thepressure of CO2 had a remarkable effect on the conversion and selectivity.

  3. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

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

  4. 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.

  5. 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.

  6. Methane and carbon dioxide ratio in excreted air for quantification of the methane production from ruminants

    DEFF Research Database (Denmark)

    Madsen, Jørgen; Bjerg, Bjarne Schmidt; Hvelplund, Torben

    2010-01-01

    This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake of metab......This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH4) production from animals by using the CH4 and carbon dioxide (CO2) concentrations in air near the animals combined with an estimation of the total CO2 production from information on intake...

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

    Institute of Scientific and Technical Information of China (English)

    孙艳朋; 聂勇; 吴昂山; 姬登祥; 于凤文; 计建炳

    2012-01-01

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

  8. Associations of indoor carbon dioxide concentrations and environmental susceptibilities with mucous membrane and lower respiratory building related symptoms in the BASE study: Analyses of the 100 building dataset

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, Christine A.; Apte, Michael G.

    2003-09-01

    Using the US EPA 100 office-building BASE Study dataset, they conducted multivariate logistic regression analyses to quantify the relationship between indoor CO{sub 2} concentrations (dCO{sub 2}) and mucous membrane (MM) and lower respiratory system (LResp) building related symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. In addition, they tested the hypothesis that certain environmentally-mediated health conditions (e.g., allergies and asthma) confer increased susceptibility to building related symptoms within office buildings. Adjusted odds ratios (ORs) for statistically significant, dose-dependent associations (p < 0.05) for dry eyes, sore throat, nose/sinus congestion, and wheeze symptoms with 100 ppm increases in dCO{sub 2} ranged from 1.1 to 1.2. These results suggest that increases in the ventilation rates per person among typical office buildings will, on average, reduce the prevalence of several building related symptoms by up to 70%, even when these buildings meet the existing ASHRAE ventilation standards for office buildings. Building occupants with certain environmentally-mediated health conditions are more likely to experience building related symptoms than those without these conditions (statistically significant ORs ranged from 2 to 11).

  9. Growth parameters and resistance against Drechslera teres of spring barley (Hordeum vulgare L. cv. Scarlett) grown at elevated ozone and carbon dioxide concentrations.

    Science.gov (United States)

    Plessl, M; Heller, W; Payer, H-D; Elstner, E F; Habermeyer, J; Heiser, I

    2005-11-01

    Spring barley ( Hordeum vulgare L. cv. Scarlett) was grown at two CO2 levels (400 vs. 700 ppm) combined with two ozone regimes (ambient vs. double ambient) in climate chambers for four weeks, beginning at seedling emergence. Elevated CO2 concentration significantly increased aboveground biomass, root biomass, and tiller number, whereas double ambient ozone significantly decreased these parameters. These ozone-induced reductions in growth parameters were strongly overridden by 700 ppm CO2. The elevated CO2 level increased C : N ratio of the leaf tissue and leaf starch content but decreased leaf protein levels. Exposure to double ambient ozone did not affect protein content and C : N ratio but dramatically increased leaf starch levels at 700 ppm CO2. Resistance against Drechslera teres (Sacc.) Shoemaker was increased in leaves grown at double ambient ozone but was less obvious at 700 ppm than at 400 ppm CO2. Constitutive activities of beta-1,3-glucanase and chitinase were significantly higher in leaves grown at double ambient ozone compared to ambient ozone levels. The sum of methanol-soluble and alkali-released cell wall-bound aromatic metabolites (i.e., C-glycosylflavones and several structurally unidentified metabolites) and lignin contents did not show any treatment-dependent differences.

  10. Effect of forage-to-concentrate ratio in dairy cow diets on emission of methane, carbon dioxide, and ammonia, lactation performance, and manure excretion.

    Science.gov (United States)

    Aguerre, M J; Wattiaux, M A; Powell, J M; Broderick, G A; Arndt, C

    2011-06-01

    Holstein cows housed in a modified tie-stall barn were used to determine the effect of feeding diets with different forage-to-concentrate ratios (F:C) on performance and emission of CH(4), CO(2) and manure NH(3)-N. Eight multiparous cows (means ± standard deviation): 620 ± 68 kg of body weight; 52 ± 34 d in milk and 8 primiparous cows (546 ± 38 kg of body weight; 93 ± 39 d in milk) were randomly assigned to 1 of 4 air-flow controlled chambers, constructed to fit 4 cows each. Chambers were assigned to dietary treatment sequences in a single 4 × 4 Latin square design. Dietary treatments, fed as 16.2% crude protein total mixed rations included the following F:C ratio: 47:53, 54:46, 61:39, and 68:32 [diet dry matter (DM) basis]. Forage consisted of alfalfa silage and corn silage in a 1:1 ratio. Cow performance and emission data were measured on the last 7 d and the last 4 d, respectively of each 21-d period. Air samples entering and exiting each chamber were analyzed with a photo-acoustic field gas monitor. In a companion study, fermentation pattern was studied in 8 rumen-cannulated cows. Increasing F:C ratio in the diet had no effect on DM intake (21.1 ± 1.5 kg/d), energy-corrected milk (ECM, 37.4 ± 2.2 kg/d), ECM/DM intake (1.81 ± 0.18), yield of milk fat, and manure excretion and composition; however, it increased milk fat content linearly by 7% and decreased linearly true protein, lactose, and solids-not-fat content (by 4, 1, and 2%, respectively) and yield (by 10, 6, and 6%, respectively), and milk N-to-N intake ratio. On average 93% of the N consumed by the cows in the chambers was accounted for as milk N, manure N, or emitted NH(3)-N. Increasing the F:C ratio also increased ruminal pH linearly and affected concentrations of butyrate and isovalerate quadratically. Increasing the F:C ratio from 47:53 to 68:32 increased CH(4) emission from 538 to 648 g/cow per day, but had no effect on manure NH(3)-N emission (14.1 ± 3.9 g/cow per day) and CO(2) emission

  11. Carbon dioxide sequestration by direct aqueous mineral carbonation

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-01-01

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

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  14. Distribution of Nitrogen Dioxide Concentration in Kaunas 2003–2007

    Directory of Open Access Journals (Sweden)

    Dovilė LAURINAVIČIENĖ

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The aim of the present study was to assess distribution of nitrogen dioxide concentration in Kaunas. A passive sampling method was used. Sampling was carried out in 62 measurements points of Kaunas city during four different seasons in 2003-2007. According to the measured concentration average seasonal and annual concentration of nitrogen dioxide was calculated. The study results showed that mean nitrogen dioxide concentration in Kaunas was 18.1 µgm-3. The highest mean seasonal concentration was found during spring (20.1 µgm-3, the lowest - during winter (16.5 µgm-3. The highest nitrogen dioxide concentration was in Centras district (26.3 µgm-3, the lowest in Rokai - 11.4 µgm-3. Using Arc GIS program, maps of nitrogen dioxide concentration distribution were plotted. Nitrogen dioxide concentration interpoliation results revealed that the highest pollution was in Centras, Žaliakalnis, Dainava districts, the lowest was found in the areas with lower traffic flows and more green places.

  15. 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.

  16. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2)...

  17. Recent Progress in the Synthesis of Polymers Based on Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    H. Sugimoto; S. Inoue

    2005-01-01

    @@ 1Introduction Carbon dioxide is the most fundamental carbon resource indispensable for all living systems including human being via photosynthesis by green plants. On the other hand, chemical utilization of carbon dioxide has been rather limited.

  18. Oxygen Atom Recombination in Carbon Dioxide Atmospheres

    Science.gov (United States)

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

    2009-09-01

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

  19. Climate Change, Carbon Dioxide, and Pest Biology: Monitor, Mitigate, Manage.

    Science.gov (United States)

    Ziska, Lewis H; McConnell, Laura L

    2016-01-13

    Rising concentrations of atmospheric carbon dioxide ([CO2]) and subsequent changes in climate, including temperature and precipitation extremes, are very likely to alter pest pressures in both managed and unmanaged plant communities. Such changes in pest pressures can be positive (migration from a region) or negative (new introductions), but are likely to be accompanied by significant economic and environmental consequences. Recent studies indicate the range of invasive weeds such as kudzu and insects such as mountain pine beetle have already expanded to more northern regions as temperatures have risen. To reduce these consequences, a better understanding of the link between CO2/climate and pest biology is needed in the context of existing and new strategies for pest management. This paper provides an overview of the probable biological links and the vulnerabilities of existing pest management (especially chemical control) and provides a preliminary synthesis of research needs that could potentially improve the ability to monitor, mitigate, and manage pest impacts.

  20. Extraction of Genistein from Sophora flavescens with Supercritical Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chang-Nam; Kang, Choon-Hyoung [Chonnam National University, Gwangju (Korea, Republic of)

    2015-08-15

    This study was directed to finding an optimum extraction condition of genistein from the S. flavescens with supercritical carbon dioxide as a solvent. In this effort, effects of the extraction conditions including pressure, temperature and a co-solvent on the extraction efficiency were investigated. The aqueous ethanol and methanol solutions were used as co-solvents while the tested operating pressure and temperature ranges were from 200 bar to 300 bar and from 308.15 K to 323.15 K, respectively. The concentration of genistein was determined by means of HPLC equipped with a UV detector. From the results, it was observed that an increase in pressure led to the higher extraction efficiency. Further, methanol showed better performance as a co-solvent than ethanol. The DPPH radical scavenging activities were measured to compare antioxidant activities of S. flavescens extracts.

  1. Mapping the Mineral Resource Base for Mineral Carbon-Dioxide Sequestration in the Conterminous United States

    Science.gov (United States)

    Krevor, S.C.; Graves, C.R.; Van Gosen, B. S.; McCafferty, A.E.

    2009-01-01

    This database provides information on the occurrence of ultramafic rocks in the conterminous United States that are suitable for sequestering captured carbon dioxide in mineral form, also known as mineral carbon-dioxide sequestration. Mineral carbon-dioxide sequestration is a proposed greenhouse gas mitigation technology whereby carbon dioxide (CO2) is disposed of by reacting it with calcium or magnesium silicate minerals to form a solid magnesium or calcium carbonate product. The technology offers a large capacity to permanently store CO2 in an environmentally benign form via a process that takes little effort to verify or monitor after disposal. These characteristics are unique among its peers in greenhouse gas disposal technologies. The 2005 Intergovernmental Panel on Climate Change report on Carbon Dioxide Capture and Storage suggested that a major gap in mineral CO2 sequestration is locating the magnesium-silicate bedrock available to sequester the carbon dioxide. It is generally known that silicate minerals with high concentrations of magnesium are suitable for mineral carbonation. However, no assessment has been made in the United States that details their geographical distribution and extent, nor has anyone evaluated their potential for use in mineral carbonation. Researchers at Columbia University and the U.S. Geological Survey have developed a digital geologic database of ultramafic rocks in the conterminous United States. Data were compiled from varied-scale geologic maps of magnesium-silicate ultramafic rocks. The focus of our national-scale map is entirely on ultramafic rock types, which typically consist primarily of olivine- and serpentine-rich rocks. These rock types are potentially suitable as source material for mineral CO2 sequestration.

  2. 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…

  3. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    Science.gov (United States)

    Rathke, Jerome W.; Klingler, Robert J.

    1993-01-01

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

  4. Entrainment process of carbon dioxide in the atmospheric boundary layer

    NARCIS (Netherlands)

    Vilà-Guerau de Arellano, J.; Gioli, B.; Miglietta, F.; Jonker, H.J.J.; Klein Baltink, H.; Hutjes, R.W.A.; Holtslag, A.A.M.

    2004-01-01

    Aircraft and surface measurements of turbulent thermodynamic variables and carbon dioxide (CO2) were taken above a grassland in a convective atmospheric boundary layer. The observations were analyzed to assess the importance of the entrainment process for the distribution and evolution of carbon dio

  5. 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.

  6. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  7. Regeneration of oxygen from carbon dioxide and water.

    Science.gov (United States)

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

    1972-01-01

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

  8. Molecular Simulation of Carbon Dioxide Adsorbed in a Slit Carbon Pore

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both the grand canonical Monte Carlo and molecular dynamics simulation methods are used to investigate the adsorption and diffusion of carbon dioxide confined in a 1.86 nm slit carbon pore at 4 temperatures from subcritical (120 K) to supercritical (313 K) conditions. Layering transition, capillary condensation and adsorption hysteresis are found at 120 K. The microstructure of carbon dioxide fluid in the slit carbon pore is analyzed. The diffusion coefficients of carbon dioxide parallel to the slit wall are significantly larger than those normal to the slit wall.

  9. Sequestration of carbon dioxide with hydrogen to useful products

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Monte-Carlo simulations of methane/carbon dioxide and ethane/carbon dioxide mixture adsorption in zeolites and comparison with matrix treatment of statistical mechanical lattice model

    Science.gov (United States)

    Dunne, Lawrence J.; Furgani, Akrem; Jalili, Sayed; Manos, George

    2009-05-01

    Adsorption isotherms have been computed by Monte-Carlo simulation for methane/carbon dioxide and ethane/carbon dioxide mixtures adsorbed in the zeolite silicalite. These isotherms show remarkable differences with the ethane/carbon dioxide mixtures displaying strong adsorption preference reversal at high coverage. To explain the differences in the Monte-Carlo mixture isotherms an exact matrix calculation of the statistical mechanics of a lattice model of mixture adsorption in zeolites has been made. The lattice model reproduces the essential features of the Monte-Carlo isotherms, enabling us to understand the differing adsorption behaviour of methane/carbon dioxide and ethane/carbon dioxide mixtures in zeolites.

  11. Electrochemical response of carbon paste electrode modified with mixture of titanium dioxide/zirconium dioxide in the detection of heavy metals: lead and cadmium.

    Science.gov (United States)

    Nguyen, Phuong Khanh Quoc; Lunsford, Suzanne K

    2012-11-15

    A novel carbon modified electrode was developed by incorporating titanium dioxide/zirconium dioxide into the graphite carbon paste electrode to detect heavy metals-cadmium and lead. In this work, the development of the novel titanium dioxide/zirconium dioxide modified carbon paste electrode was studied to determine the optimum synthesis conditions related to the temperature, heating duration, amount and ratio of titanium dioxide/zirconium dioxide, and amount of surfactant, to create the most reproducible results. Using cyclic voltammetric (CV) analysis, this study has proven that the novel titanium dioxide/zirconium dioxide can be utilized to detect heavy metals-lead and cadmium, at relatively low concentrations (7.6×10(-6) M and 1.1×10(-5) M for Pb and Cd, respectively) at optimum pH value (pH=3). From analyzing CV data the optimal electrodes surface area was estimated to be 0.028 (±0.003) cm(2). Also, under the specific experimental conditions, electron transfer coefficients were estimated to be 0.44 and 0.33 along with the heterogeneous electron transfer rate constants of 5.64×10(-3) and 2.42×10(-3) (cm/s) for Pb and Cd, respectively.

  12. Carbon dioxide as a potential danger to medical rescue teams at work - A case study.

    Science.gov (United States)

    Podlewski, Roland; Płotek, Włodzimierz; Grześkowiak, Małgorzata; Małkiewicz, Tomasz; Frydrysiak, Krystyna; Żaba, Zbigniew

    2017-02-28

    Medical rescue teams might be exposed to the risk of accidental poisoning while performing rescue procedures. Exposure to the risk of lethal carbon dioxide (CO2) concentrations is a rare situation. This case study describes rescuing a patient who suffered from sudden cardiac arrest due to accidental CO2 poisoning. The victim was finally evacuated and resuscitated, but the circumstances of the rescue operation point to the need to equip ambulances with carbon dioxide detectors and hermetic oxygen masks. Med Pr 2017;68(1):135-138.

  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. Carbon dioxide, the feedstock for using renewable energy

    Science.gov (United States)

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

    2011-03-01

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

  15. Carbon dioxide, the feedstock for using renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K; Kato, Z [Tohoku Institute of Technology, Sendai, 982-8577 (Japan); Kumagai, N; Izumiya, K, E-mail: koji@imr.tohku.ac.jp [Daiki Ataka Engineering Co. Ltd. Kashiwa, 277-8515 (Japan)

    2011-03-15

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

  16. Predator-induced reduction of freshwater carbon dioxide emissions

    Science.gov (United States)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  17. Effects of dissolved carbon dioxide on energy metabolism and stress responses in European seabass (Dicentrarchus labrax)

    NARCIS (Netherlands)

    Santos, G.A.; Schrama, J.W.; Capelle, J.; Rombout, J.H.W.M.; Verreth, J.A.J.

    2013-01-01

    Elevated carbon dioxide concentrations reduce feed intake and growth in several fish species and induce stress responses. In this study, the effects of moderately elevated CO2 levels on performance, energy partitioning, swimming activity and stress response in European seabass were assessed. Europea

  18. The role of climate change and increasing atmospheric carbon dioxide on weed management: Herbicide Efficacy

    Science.gov (United States)

    Rising concentrations of carbon dioxide [CO2] and a changing climate will almost certainly affect weed biology and demographics with consequences for crop productivity. The extent of such consequences could be minimal if weed management, particularly the widespread and effective use of herbicides, m...

  19. Kinetics of absorption of carbon dioxide into aqueous potassium salt of proline

    DEFF Research Database (Denmark)

    Paul, Subham; Thomsen, Kaj

    2012-01-01

    The absorption of carbon dioxide (CO2) into aqueous solution of potassium prolinate (KPr) are studied at 303, 313, and 323K within the salt concentration range of 0.5–3.0kmolm−3 using a wetted wall column absorber. The experimental results are used to interpret the kinetics of the reaction of CO2...

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

    Science.gov (United States)

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

    2010-01-01

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

  1. Carbon dioxide conversion by means of coplanar dielectric barrier discharges

    Science.gov (United States)

    Schiorlin, Milko; Klink, Rouven; Brandenburg, Ronny

    2016-08-01

    To face the worldwide problem of anthropogenic carbon dioxide (CO2) emission new techniques have to be developed. One approach for carbon capture utilization (CCU) is the conversion of CO2 to more valuable chemicals, e.g., carbon monoxide (CO) by means of non-thermal plasma generated at ambient conditions and supplied by excess energy from renewable sources. This paper reports about the effect of the admixture of inert gases, namely nitrogen or argon to CO2 in a coplanar dielectric barrier discharge (DBD). Systematic experiments were conducted to investigate the effects of applied voltage, frequency, flowrate and CO2 concentration in the influent. The composition of products, energy efficiency and yield were determined. Within the investigated parameter ranges, the maximum conversion of CO2 to CO efficiency of 1% was achieved when the specific input energy was 190 J L-1, whereas the maximum CO yield of 0.7% was achieved when the specific input energy was 210 J L-1. In conclusion, the energy efficiency can be significantly increased by operating the plasma in a diluted CO2 gas. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  2. 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

  3. Metal corrosion in a supercritical carbon dioxide - liquid sodium power cycle.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert Charles; Conboy, Thomas M.

    2012-02-01

    A liquid sodium cooled fast reactor coupled to a supercritical carbon dioxide Brayton power cycle is a promising combination for the next generation nuclear power production process. For optimum efficiency, a microchannel heat exchanger, constructed by diffusion bonding, can be used for heat transfer from the liquid sodium reactor coolant to the supercritical carbon dioxide. In this work, we have reviewed the literature on corrosion of metals in liquid sodium and carbon dioxide. The main conclusions are (1) pure, dry CO{sub 2} is virtually inert but can be highly corrosive in the presence of even ppm concentrations of water, (2) carburization and decarburization are very significant mechanism for corrosion in liquid sodium especially at high temperature and the mechanism is not well understood, and (3) very little information could be located on corrosion of diffusion bonded metals. Significantly more research is needed in all of these areas.

  4. Carbon dioxide production during cardiopulmonary bypass: pathophysiology, measure and clinical relevance.

    Science.gov (United States)

    Ranucci, Marco; Carboni, Giovanni; Cotza, Mauro; de Somer, Filip

    2017-01-01

    Carbon dioxide production during cardiopulmonary bypass derives from both the aerobic metabolism and the buffering of lactic acid produced by tissues under anaerobic conditions. Therefore, carbon dioxide removal monitoring is an important measure of the adequacy of perfusion and oxygen delivery. However, routine monitoring of carbon dioxide removal is not widely applied. The present article reviews the main physiological and pathophysiological sources of carbon dioxide, the available techniques to assess carbon dioxide production and removal and the clinically relevant applications of carbon dioxide-related variables as markers of the adequacy of perfusion during cardiopulmonary bypass.

  5. Water and Carbon Dioxide Adsorption at Olivine Surfaces

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-14

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

  6. INFLUENCE OF ELEVATED OZONE AND CARBON DIOXIDE ON INSECT DENSITIES.

    Energy Technology Data Exchange (ETDEWEB)

    DELUCIA, E.; DERMODY, O.; O' NEILL, B.; ALDEA, M.; HAMILTON, J.; ZANGERL, A.; ROGER, A.; BERENBAUM, M.

    2005-01-05

    The combustion of fossil fuels is profoundly altering the chemical composition of the atmosphere. Beginning with the Industrial Revolution, the concentration of carbon dioxide in the atmosphere has increased from approximately 280 to 370 {micro}l l{sup -1} in 2004, and it is expected to exceed 550 {micro}l l{sup -1} by 2050. Tropospheric ozone has risen even more rapidly than CO{sub 2} and average summer concentrations in the Northern Hemisphere are expected to continue to increase by 0.5-2.5% per year over the next 30 years. Although elevated CO{sub 2} stimulates photosynthesis and productivity of terrestrial ecosystems, ozone (O{sub 3}) is deleterious. In addition to directly affecting the physiology and productivity of crops, increased concentrations of tropospheric CO{sub 2} and O{sub 3} are predicted to lower the nutritional quality of leaves, which has the potential to increase herbivory as insects eat more to meet their nutritional demands. We tested the hypothesis that changes in tropospheric chemistry affect the relationship between plants and insect herbivores by changing leaf quality. The susceptibility to herbivory of soybean grown in elevated CO{sub 2} or O{sub 3} was examined using free air gas concentration enrichment (SoyFACE). FACE technology has the advantage that plants are cultivated under realistic field conditions with no unwanted alteration of microclimate or artificial constraints on the insect community.

  7. Chemoselective Alternating Copolymerization of Limonene Dioxide and Carbon Dioxide: A New Highly Functional Aliphatic Epoxy Polycarbonate.

    Science.gov (United States)

    Li, Chunliang; Sablong, Rafaël J; Koning, Cor E

    2016-09-12

    The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2 ) catalyzed by a zinc β-diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg ) up to 135 °C. These polycarbonates can be efficiently modified by thiols or carboxylic acids in combination with lithium hydroxide or tetrabutylphosphonium bromide as catalysts, respectively, without destruction of the main chain. Moreover, polycarbonates bearing pendent cyclic carbonates can be quantitatively prepared by CO2 insertion catalyzed by lithium bromide.

  8. Carbon Dioxide As a Raw Material for Biodegradable Plastics

    Institute of Scientific and Technical Information of China (English)

    WANG Xianhong; QIN Yusheng; WANG Fosong

    2011-01-01

    @@ Carbon dioxide is the main greenhouse gas, but it is also a renewable and abundant source of carbon.It has not onlv shown various phvsicai utilization in the manufacturing of food, beverage and other industry areas, but been chemically fixed into urea, salicylic acid, organic and inorganic carbonates (Mikkelsen, Jorgensen & Krebs, 2010).However, developing a high value-added fixation route to CO is badly needed.

  9. 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.

  10. [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.

  11. 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

    2006-09-30

    This report describes research conducted between July 1, 2006 and September 30, 2006 on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from coal combustion flue gas. Modifications to the integrated absorber/ sorbent regenerator/ sorbent cooler system were made to improve sorbent flow consistency and measurement reliability. Operation of the screw conveyor regenerator to achieve a sorbent temperature of at least 120 C at the regenerator outlet is necessary for satisfactory carbon dioxide capture efficiencies in succeeding absorption cycles. Carbon dioxide capture economics in new power plants can be improved by incorporating increased capacity boilers, efficient flue gas desulfurization systems and provisions for withdrawal of sorbent regeneration steam in the design.

  12. Novel carbon dioxide gas sensor based on infrared absorption

    Science.gov (United States)

    Zhang, Guangjun; Lui, Junfang; Yuan, Mei

    2000-08-01

    The feasibility of sensing carbon dioxide with a IR single- beam optical structure is studied, and a novel carbon dioxide gas sensor based on IR absorption is achieved. Applying the Lambert-Beer law and some key techniques such as current stabilization for IR source, using a high-quality IR detector, and data compensation for the influences of ambience temperature and atmosphere total pressure, the sensor can measure carbon dioxide with high precision and efficiency. The mathematical models for providing temperature and pressure compensation for the sensor are established. Moreover the solutions to the models are proposed. Both the models and the solutions to the models are verified via experiments. The sensor possesses the advantages of small volume, light weight, low power consumption, and high reliability. Therefore it can be used in many associated fields, such as environmental protection, processing control, chemical analysis, medical diagnosis, and space environmental and control systems.

  13. Carbon dioxide enrichment alters plant community structure and accelerates shrub growth in the shortgrass steppe

    OpenAIRE

    Jack A Morgan; Milchunas, Daniel G.; LeCain, Daniel R.; West, Mark; MOSIER, ARVIN R.

    2007-01-01

    A hypothesis has been advanced that the incursion of woody plants into world grasslands over the past two centuries has been driven in part by increasing carbon dioxide concentration, [CO2], in Earth's atmosphere. Unlike the warm season forage grasses they are displacing, woody plants have a photosynthetic metabolism and carbon allocation patterns that are responsive to CO2, and many have tap roots that are more effective than grasses for reaching deep soil water stores that can be enhanced u...

  14. 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.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    performance of the process to the L/G ratio to the absorber, CO2 lean solvent loadings, and striper pressure are presented in this paper. Based on the sensitivity analysis process optimization problems have been defined and solved and, a preliminary control structure selection has been made.......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...

  16. Potential of the technological and chemical utilisation of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Aresta, M. [Univ. Bari (Italy). Dip. di Chimica e Centro METEA

    1998-10-01

    The carbon dioxide mitigation has been agreed at international level. Besides the efficiency technologies, the recovery of CO{sub 2} from power-plants flue gases is a most innovative approach. This would make available large amounts of CO{sub 2}, either for disposal or for utilisation. The technological and chemical utilisation of carbon dioxide are options whose potential is under evaluation. The Life Cycle Analysis (LCA) study seems to be the most effective tool for their assessment. The two options are considered in this paper and the synthetic methodologies that appear as most likely to be implemented are analysed.

  17. Carbon dioxide capture capacity of sodium hydroxide aqueous solution.

    Science.gov (United States)

    Yoo, Miran; Han, Sang-Jun; Wee, Jung-Ho

    2013-01-15

    The present paper investigates the various features of NaOH aqueous solution when applied as an absorbent to capture carbon dioxide (CO(2)) emitted with relatively high concentration in the flue gas. The overall CO(2) absorption reaction was carried out according to consecutive reaction steps that are generated in the order of Na(2)CO(3) and NaHCO(3). The reaction rate and capture efficiency were strongly dependent on the NaOH concentration in the Na(2)CO(3) production range, but were constant in the NaHCO(3) production step, irrespective of the NaOH concentration. The amount of CO(2) absorbed in the solution was slightly less than the theoretical value, which was ascribed to the low trona production during the reaction and the consequent decrease in CO(2) absorption in the NaOH solution. The mass ratio of absorbed CO(2) that participated in the Na(2)CO(3), NaHCO(3), and trona production reactions was calculated to be 20:17:1, respectively.

  18. Carbon Dioxide Capture from Flue Gas Using Dry Regenerable Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Nelson; David Green; Paul Box; Raghubir Gupta; Gennar Henningsen

    2007-06-30

    Regenerable sorbents based on sodium carbonate (Na{sub 2}CO{sub 3}) can be used to separate carbon dioxide (CO{sub 2}) from coal-fired power plant flue gas. Upon thermal regeneration and condensation of water vapor, CO{sub 2} is released in a concentrated form that is suitable for reuse or sequestration. During the research project described in this report, the technical feasibility and economic viability of a thermal-swing CO{sub 2} separation process based on dry, regenerable, carbonate sorbents was confirmed. This process was designated as RTI's Dry Carbonate Process. RTI tested the Dry Carbonate Process through various research phases including thermogravimetric analysis (TGA); bench-scale fixed-bed, bench-scale fluidized-bed, bench-scale co-current downflow reactor testing; pilot-scale entrained-bed testing; and bench-scale demonstration testing with actual coal-fired flue gas. All phases of testing showed the feasibility of the process to capture greater than 90% of the CO{sub 2} present in coal-fired flue gas. Attrition-resistant sorbents were developed, and these sorbents were found to retain their CO{sub 2} removal activity through multiple cycles of adsorption and regeneration. The sodium carbonate-based sorbents developed by RTI react with CO{sub 2} and water vapor at temperatures below 80 C to form sodium bicarbonate (NaHCO3) and/or Wegscheider's salt. This reaction is reversed at temperatures greater than 120 C to release an equimolar mixture of CO{sub 2} and water vapor. After condensation of the water, a pure CO{sub 2} stream can be obtained. TGA testing showed that the Na{sub 2}CO3 sorbents react irreversibly with sulfur dioxide (SO{sub 2}) and hydrogen chloride (HCl) (at the operating conditions for this process). Trace levels of these contaminants are expected to be present in desulfurized flue gas. The sorbents did not collect detectable quantities of mercury (Hg). A process was designed for the Na{sub 2}CO{sub 3}-based sorbent that

  19. 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…

  20. 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)

  1. 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,...

  2. 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...

  3. Immunosensor based on carbon nanotube/manganese dioxide electrochemical tags.

    Science.gov (United States)

    Tu, Meng-Che; Chen, Han-Yi; Wang, Yuxi; Moochhala, Shabbir M; Alagappan, Palaniappan; Liedberg, Bo

    2015-01-01

    This article reports on carbon nanotube/manganese dioxide (CNT-MnO2) composites as electrochemical tags for non-enzymatic signal amplification in immunosensing. The synthesized CNT-MnO2 composites showed good electrochemical activity, electrical conductivity and stability. The electrochemical signal of CNT-MnO2 composites coated glassy carbon electrode (GCE) increased by nearly two orders of magnitude compared to bare GCE in hydrogen peroxide (H2O2) environment. CNT-MnO2 composite was subsequently validated as electrochemical tags for sensitive detection of α-fetoprotein (AFP), a tumor marker for diagnosing hepatocellular carcinoma. The electrochemical immunosensor demonstrated a linear response on a log-scale for AFP concentrations ranging from 0.2 to 100 ng mL(-1). The limit of detection (LOD) was estimated to be 40 pg mL(-1) (S/N=3) in PBS buffer. Further measurements using AFP spiked plasma samples revealed the applicability of fabricated CNT-MnO2 composites for clinical and diagnostic applications.

  4. Preparation of calcium carbonate particles coated with titanium dioxide

    Institute of Scientific and Technical Information of China (English)

    Hai Lin; Ying-bo Dong; Le-yong Jiang

    2009-01-01

    The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was stud-ied. The mechanism of the preparation process was proposed. The new mineral composite material was made by the mechanochemi-eal method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5:3.5. The mass ratios of two different types of titanium dioxide (anatase to rutile) and grinding media to grinded materials were 8:2 and 4:1 respec-tively, and the modified density was 60%. Under this condition, the new material was capable of forming after 120-min modification.The hiding power and oil absorption of this new material were 29.12 g/m~2 and 23.30%, respectively. The results show that the modi-fication is based on surface hydroxylation. After coating with titanium dioxide, the hiding power of calcium carbonate can be im-proved greatly. The new mineral composite materials can be used as the substitute for titanium dioxide.

  5. A Molecular Dynamics Study on the Confinement of Carbon Dioxide Molecules in Carbon Nanotubes

    Science.gov (United States)

    Lazor, Meagan; Rende, Deniz; Baysal, Nihat; Ozisik, Rahmi

    2012-02-01

    The influence of atmospheric carbon dioxide (CO2) concentration on global warming is considered as one of the primary environmental issues of the past two decades. The main source of CO2 emission is human activity, such as the use of fossil fuels in transportation and industrial plants. Following the release of Kyoto Protocol in 1997, effective ways of controlling CO2 emissions received much attention. As a result, various materials such as activated carbon, zeolites, and carbon nanotubes (CNTs) were investigated for their CO2 adsorbing properties. CNTs were reported to have CO2 adsorption capability twice that of activated carbon, hence they received the most attention. In the current study, single walled carbon nanotubes (SWNTs) were used as one dimensional nanoporous materials and their CO2 adsorption capacity was analyzed with Molecular Dynamics simulations. Results indicated that SWNTs are excellent CO2 adsorbers and their effectiveness increase at low CO2 concentrations. In addition, we showed that by varying temperature, CO2 can be removed from the SWNTs, providing a simple method to reuse SWNTs.

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

    Science.gov (United States)

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

    2010-06-01

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

  7. 78 FR 23524 - Approval and Promulgation of Implementation Plans; North Carolina: Deferral of Carbon Dioxide (CO2

    Science.gov (United States)

    2013-04-19

    ... Carbon Dioxide (CO 2 ) Emissions From Prevention of Significant Deterioration (PSD) Requirements for... applicability to biogenic carbon dioxide (CO 2 ) emissions from bioenergy and other biogenic stationary...

  8. 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.

  9. 不同玉米象感染度的小麦储存环境中二氧化碳浓度变化研究%RESEARCH ON CONCENTRATION CHANGE OF CARBON DIOXIDE IN STORED WHEAT INFESTED BY SITOPHILUS ZEAMAIS MOTSCHULSKY

    Institute of Scientific and Technical Information of China (English)

    王殿轩; 徐威; 陆群

    2012-01-01

    在模拟储存环境中研究了小麦感染不同玉米象Sitophilus zeamais Motschulsky后不同时间的二氧化碳浓度变化,试验环境温度分别为20℃和25℃,试验中设置的玉米象成虫密度分别为0头/kg、2头/kg、5头/kg、10头/kg.主要结果为:初始成虫密度为0头/kg的小麦样品中,20℃4个月内二氧化碳浓度从0.046%增长到了0.752%,25℃时二氧化碳浓度从0.44%增加到0.820%;2头/kg的样品中,20 ℃二氧化碳浓度增长到5.638%,25℃浓度增加到7.505%;5头/kg成虫密度的样品中,20C二氧化碳浓度增长到8.702%,25℃时浓度增加到10.474%;害虫密度为10头/kg的样品中,20℃二氧化碳浓度增长到17.381%,25℃时浓度增加到18.244%.主要结果显示:对于感染害虫的粮食环境,二氧化碳的累积浓度明显随时间增加而上升,且同比条件下,温度为25℃的环境中二氧化碳浓度显著大于20℃时的环境.密闭无害虫感染的粮食中,粮食及微生物也能使二氧化碳浓度有很小变化.当小麦中有害虫感染后,密闭10 d后即可检测到明显的二氧化碳浓度增加,且增加速率与害虫密度、环境温度和储存时间呈正相关.试验结果表明,在密闭的储粮环境中,二氧化碳浓度变化可在一定程度上反映储粮害虫的发生状态.%In this paper, we studied the concentration change of carbon dioxide in simulated storage environment of wheat which was infested by Sitophilus zeamais Motschulsky adults for different periods, wherein the environment temperature was set to 20 ℃ and 25 ℃ ,and three samples with 0,2,5 and 10 adults per kilogram wheat were selected in the experiment. The results showed that: in the sample without adults,the concentration of carbon dioxide increased from 0.046% to 0.752% at 20 ℃ in four months,and increased from 0.44% to 0.820% at 25 ℃ in four months; in the sample with 2 adults per kilogram wheat, the concentration of carbon dioxide

  10. Carbon dioxide fluxes from Tifway bermudagrass: early results

    Science.gov (United States)

    Cotten, David L.; Zhang, G.; Leclerc, M. Y.; Raymer, P.; Steketee, C. J.

    2016-06-01

    This paper reports for the first time preliminary data on carbon uptake of warm-season turfgrass at a well-managed sod farm in south central Georgia. It examines the changes in carbon uptake from one of the most widely used warm-season turfgrass cultivars in the world, Tifway Bermudagrass. It elucidates the role of canopy density and light avalaibility on the net carbon uptake using the eddy-covariance technique. Preliminary evidence suggests that turfgrass is effective at sequestering carbon dioxide during the summer months even when the canopy is being reestablished following a grass harvest.

  11. Palladium-Catalyzed Addition of Carbon Monoxide and Carbon Tetrachloride to 1-Octene in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    张群健; 孙均华; 江焕峰; 欧阳小月; 程金生

    2003-01-01

    The Pd-catalyzed addition of carbon monoxide and carbon tetrachloride to 1-octene gave coadduct [alkyl 2-( 2, 2, 2-trichloroethyl)octanoate] as the major product in supercritical carbon dioxide by using pyridine as the base. It was found that the selectivity and the yield of coadduct were greatly affected by the pressure of carbon dioxide, the reaction temperature and the amounts of alcohol and base used.

  12. Carbon dioxide capture and storage: a win-win option? (the economic case)

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, G. [Future Energy Solutions, Didcot (United Kingdom)

    2003-07-01

    The UK currently derived 90% of its primary energy and generates over 70% of its electricity from fossil fuels. Moreover, it has access to substantial carbon dioxide storage capacity. In particular there is potential for storage combined with Enhance Oil Recovery (EOR) in the oil fields of the central and northern North Sea areas, while the gas fields of the southern North Sea offer a large near shore resource for storage. In the longer term saline aquifers offer an even large storage capacity. Consequently carbon dioxide capture and storage needs to be assessed as an important potential option for greenhouse gas abatement for the UK. This scoping study has examined the implementation, operation, economics and barriers to undertaking carbon dioxide capture and storage in the UK. It has concentrated on carbon dioxide capture from fossil fuel power stations; large 'point sources' of the gas that would need to be tackled in order to deliver significant levels of greenhouse gas abatement. Options for gas capture considered are retrofitting equipment to existing coal and natural gas fired plant as well as the construction of new coal (IGCC) and gas (GTCC) technology. Economic assessments have been made with 'present day' costs, and do not consider future improvements through technical innovation and; learning by doing', the potential of which is considerable for the mature carbon capture technologies.

  13. Carbonate effects on hexavalent uranium removal from water by nanocrystalline titanium dioxide.

    Science.gov (United States)

    Wazne, Mahmoud; Meng, Xiaoguang; Korfiatis, George P; Christodoulatos, Christos

    2006-08-10

    A novel nanocrystalline titanium dioxide was used to treat depleted uranium (DU)-contaminated water under neutral and alkaline conditions. The novel material had a total surface area of 329 m(2)/g, total surface site density of 11.0 sites/nm(2), total pore volume of 0.415 cm(3)/g and crystallite size of 6.0 nm. It was used in batch tests to remove U(VI) from synthetic solutions and contaminated water. However, the capacity of the nanocrystalline titanium dioxide to remove U(VI) from water decreased in the presence of inorganic carbonate at pH > 6.0. Adsorption isotherms, Fourier transform infrared (FTIR) spectroscopy, and surface charge measurements were used to investigate the causes of the reduced capacity. The surface charge and the FTIR measurements suggested that the adsorbed U(VI) species was not complexed with carbonate at neutral pH values. The decreased capacity of titanium dioxide to remove U(VI) from water in the presence of carbonate at neutral to alkaline pH values was attributed to the aqueous complexation of U(VI) by inorganic carbonate. The nanocrystalline titanium dioxide had four times the capacity of commercially available titanium dixoide (Degussa P-25) to adsorb U(VI) from water at pH 6 and total inorganic carbonate concentration of 0.01 M. Consequently, the novel material was used to treat DU-contaminated water at a Department of Defense (DOD) site.

  14. CHEMICAL FIXATION OF CARBON DIOXIDE USING SOLVENT EXTRACTION

    OpenAIRE

    SASAMOTO, Naoki; MASHIMO, Miki; MATSUMOTO, Shigeno; Yamamoto, Hideki; SHIBATA, Junji

    1996-01-01

    Investigations were carried out to create a chemical fixation process,where carbon dioxide and sodium chloride solution are converted to sodium hydrogen carbonate and hydrochloric acid. Because the reaction has a large and positive free energy change,it does not proceed unless a suitable condition is established.The reaction is able to proceed if hydrochloric acid,which is one of the reaction products,is removed from the reaction system by extraction with amine.Stripping of hydrochloric acid ...

  15. Photodissociation of carbon dioxide in the Mars upper atmosphere

    Science.gov (United States)

    Barth, C. A.

    1974-01-01

    Calculation of the intensity of two of the emissions produced during the dissociative excitation of carbon dioxide in the upper atmosphere of Mars by solar ultraviolet radiation. The calculation tangential column emission rates of the atomic oxygen 2972-A line and the carbon monoxide Cameron bands produced by the photodissociative mechanism are found to be factors of 3 and 10, respectively, smaller than the emission rates observed by Mariner ultraviolet spectrometers.

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

    Science.gov (United States)

    Moreira, Diana; Pires, José C M

    2016-09-01

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

  17. Synthesis of fatty acid starch esters in supercritical carbon dioxide

    NARCIS (Netherlands)

    Muljana, Henky; van der Knoop, Sjoerd; Keijzer, Danielle; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2010-01-01

    This manuscript describes an exploratory study on the synthesis of fatty acid/potato starch esters using supercritical carbon dioxide (scCO(2)) as the solvent. The effects of process variables such as pressure (6-25 MPa), temperature (120-150 degrees C) and various basic catalysts and fatty acid der

  18. 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...

  19. 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...

  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...

  1. 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...

  2. Aerobic Oxidation of Methyl Vinyl Ketone in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    OUYANG,Xiao-Yue(欧阳小月); JIANG,Huan-Feng(江焕峰); CHENG,Jin-Sheng(程金生); ZHANG,Qun-Jian(张群健)

    2002-01-01

    Aerobic oxidation of methyl vinyl ketone to acetal in supercritical carbon dioxide are achieved in high conversion and high selectivity when oxygen pressure reaches 0.5MPa. The effects of cocatalysts,additive, pressure and temperature of the reaction are studied in detail.

  3. Fluxes of Methane and Carbon Dioxide from a Subarctic Lake

    DEFF Research Database (Denmark)

    Jammet, Mathilde Manon

    ) and carbon dioxide (CO2) with the atmosphere. Yet uncertainties in the magnitude and drivers of these fluxes remain, partly due to a lack of direct observations covering all seasons of the year, but also because of the diversity in measurement methods that often miss components of the transport processes...

  4. 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...

  5. How Can We Use Carbon Dioxide as a Solvent?

    Science.gov (United States)

    Mohamed, Azmi; Eastoe, Julian

    2011-01-01

    This article describes the work being undertaken to make more use of supercritical carbon dioxide as a green solvent. It discusses how the use of surfactants can address the limitations of supercritical CO[subscript 2] in dissolving solutes that are polar and of higher molecular weight. The design of appropriate hydrocarbon CO[subscript 2]-philic…

  6. 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.

  7. 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...

  8. Cryotherapy gas--to use nitrous oxide or carbon dioxide?

    Science.gov (United States)

    Maiti, H; Cheyne, M F; Hobbs, G; Jeraj, H A

    1999-02-01

    Cryotherapy is regularly used in our clinic for treating genital warts. Nitrous oxide was used as the cryogenic gas. Following a health and safety review it was decided to monitor the nitrous oxide levels in the treatment room under different conditions. The Occupational Exposure Standard for nitrous oxide is 100 parts per million (PPM) (8-h time weighted average) and an indicative short-term exposure limit of 300 PPM (15-min reference period). High levels of gas were detected, especially when the exhaust was not vented to the outside. Venting of the gas to the outside could also present a hazard to adjacent areas. The situation was considered to be unacceptable and carbon dioxide was proposed as an alternative. The Occupational Exposure Standard for carbon dioxide is 5000 PPM (8-h time weighted average) and a short-term limit of 15,000 PPM (15-min reference period). Carbon dioxide levels were found to be within the Occupational Exposure Standard. There is no noticeable difference in the cryogenic efficacy of the 2 gases. Carbon dioxide is, therefore, a safer alternative. It also offers significant savings when compared with nitrous oxide.

  9. 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.

    2006-01-01

    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 (P

  10. Carbon dioxide uptake by a temperate tidal sea

    NARCIS (Netherlands)

    Klaassen, Wim

    2007-01-01

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

  11. Drying of supercritical carbon dioxide with membrane processes

    NARCIS (Netherlands)

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata T.; Benes, N.E.; 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 water-l

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

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Pei, Jiansuo; Yang, Cuihong

    2012-01-01

    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 relativel

  13. Green dyeing of cotton fabrics by supercritical carbon dioxide

    Directory of Open Access Journals (Sweden)

    Zhang Juan

    2015-01-01

    Full Text Available Green dyeing process with zero waste water emission is a hot topic recently. This paper reveals that supercritical carbon dioxide is the best candidate for this purpose. Effects of thermodynamic parameters, such as enthalpy and entropy of activation, on dyeing process are studied experimentally.

  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 ven

  15. Supercritical carbon dioxide process for pasteurization of fruit juices

    Science.gov (United States)

    Supercritical carbon dioxide (SCCO2) nonthermal processing inactivates microorganisms in juices using non-toxic and non-reactive CO2. However, data is lacking on the inactivation of E. coli K12 and L. plantarum in apple cider using pilot plant scale SCCO2 equipment. For this study, pasteurized pres...

  16. Glaciers as indicators of the carbon dioxide warming

    NARCIS (Netherlands)

    Oerlemans, J.

    1986-01-01

    During the past 150 years, mountain glaciers have shown a worldwide retreat. It has been argued that this is related to the warming which is predicted to result from increased carbon dioxide levels in the atmosphere; however, this warming has not been detected in a statistically significant way from

  17. 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.

  18. Phase relation between global temperature and atmospheric carbon dioxide

    CERN Document Server

    Stallinga, Peter

    2013-01-01

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

  19. Continuous wave carbon dioxide treatment of balanitis xerotica obliterans.

    Science.gov (United States)

    Rosemberg, S K; Jacobs, H

    1982-05-01

    Herein is presented the first case of balanitis xerotica obliterans treated successfully by carbon dioxide-continuous wave (CW-CO2) laser vaporization. This method appears to be a safe addition to other well-known treatment modalities, offering minimal postoperative discomfort, preservation of anatomic landmarks and function, and excellent cosmetic results.

  20. 21 CFR 201.161 - Carbon dioxide and certain other gases.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use...

  1. 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;...

  2. 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

  3. 76 FR 25236 - Carbon Dioxide; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-05-04

    ... AGENCY 40 CFR Part 180 Carbon Dioxide; Exemption From the Requirement of a Tolerance AGENCY... from the requirement of a tolerance for residues of carbon dioxide (CAS Reg. No. 124-38-9) when used as... permissible level for residues of carbon dioxide. DATES: This regulation is effective May 4, 2011....

  4. 46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph...

  5. 40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Carbon dioxide; exemption from the... Exemptions From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the requirement of a tolerance when used after harvest in...

  6. 76 FR 48073 - Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide...

    Science.gov (United States)

    2011-08-08

    ... Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities AGENCY... Conservation and Recovery Act (RCRA) to conditionally exclude carbon dioxide (CO 2 ) streams that are hazardous... of carbon dioxide streams that would otherwise be regulated as hazardous wastes under the...

  7. 76 FR 55846 - Hazardous Waste Management System: Identification and Listing of Hazardous Waste: Carbon Dioxide...

    Science.gov (United States)

    2011-09-09

    ... Listing of Hazardous Waste: Carbon Dioxide (CO2) Streams in Geologic Sequestration Activities AGENCY...) to conditionally exclude carbon dioxide (CO 2 ) streams that are hazardous from the definition of... Recovery Act (RCRA) to conditionally exclude carbon dioxide (CO 2 ) streams that are hazardous from...

  8. 75 FR 8431 - Carbon Dioxide Fire Suppression Systems on Commercial Vessels

    Science.gov (United States)

    2010-02-24

    ... Homeland Security Coast Guard 46 Parts 25, 27, 28, et al. Carbon Dioxide Fire Suppression Systems on..., 182, 185, 189, 190, 193, 194, and 196 RIN 1625-AB44 Carbon Dioxide Fire Suppression Systems on... vessels. The amendments would clarify that approved alternatives to carbon dioxide systems may be used...

  9. 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..., nose, and throat microsurgical carbon dioxide laser. (a) Identification. An ear, nose, and throat microsurgical carbon dioxide laser is a device intended for the surgical excision of tissue from the ear,...

  10. 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 s

  11. Performance of a new carbon dioxide absorbent, Yabashi lime® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs

    OpenAIRE

    KONDOH, Kei; ATIBA, Ayman; NAGASE, Kiyoshi; Ogawa, Shizuko; Miwa, Takashi; KATSUMATA, Teruya; Ueno, Hiroshi; UZUKA, Yuji

    2015-01-01

    In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime® with a conventional CO2 absorbent, Sodasorb® as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime® with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carb...

  12. Production and detection of carbon dioxide on Iapetus

    Science.gov (United States)

    Palmer, Eric E.; Brown, Robert H.

    2011-04-01

    Cassini VIMS detected carbon dioxide on the surface of Iapetus during its insertion orbit. We evaluated the CO 2 distribution on Iapetus and determined that it is concentrated almost exclusively on Iapetus' dark material. VIMS spectra show a 4.27-μm feature with an absorption depth of 24%, which, if it were in the form of free ice, requires a layer 31 nm thick. Extrapolating for all dark material on Iapetus, the total observable CO 2 would be 2.3 × 10 8 kg. Previous studies note that free CO 2 is unstable at 10 AU over geologic timescales. Carbon dioxide could, however, be stable if trapped or complexed, such as in inclusions or clathrates. While complexed CO 2 has a lower thermal volatility, loss due to photodissociation by UV radiation and gravitational escape would occur at a rate of 2.6 × 10 7 kg year -1. Thus, Iapetus' entire inventory of surface CO 2 could be lost within a few decades. The high loss/destruction rate of CO 2 requires an active source. We conducted experiments that generated CO 2 by UV radiation of simulated icy regolith under Iapetus-like conditions. The simulated regolith was created by flash-freezing degassed water, crushing it into sub-millimeter sized particles, and then mixing it with isotopically labeled amorphous carbon ( 13C) dust. These samples were placed in a vacuum chamber and cooled to temperatures between 50 K and 160 K. The samples were irradiated with UV light, and the products were measured using a mass spectrometer, from which we measured 13CO 2 production at a rate of 2.0 × 10 12 mol s -1. Extrapolating to Iapetus and adjusting for the solar UV intensity and Iapetus' surface area, we calculated that CO 2 production for the entire surface would be 1.1 × 10 7 kg year -1, which is only a factor of two less than the loss rate. As such, UV photochemical generation of CO 2 is a plausible source of the detected CO 2.

  13. Ecological Limits to Terrestrial Carbon Dioxide Removal Strategies

    Science.gov (United States)

    Smith, L. J.; Torn, M. S.; Jones, A. D.

    2011-12-01

    Carbon dioxide removal from the atmosphere through terrestrial carbon sequestration and bioenergy (biological CDR) is a proposed climate change mitigation strategy. Biological CDR increases the carbon storage capacity of soils and biomass through changes in land cover and use, including reforestation, afforestation, conversion of land to agriculture for biofuels, conversion of degraded land to grassland, and alternative management practices such as conservation tillage. While biological CDR may play a valuable role in future climate change mitigation, many of its proponents fail to account for the full range of biological, biophysical, hydrologic, and economic complexities associated with proposed land use changes. In this analysis, we identify and discuss a set of ecological limits and impacts associated with terrestrial CDR. The capacity of biofuels, soils, and other living biomass to sequester carbon may be constrained by nutrient and water availability, soil dynamics, and local climate effects, all of which can change spatially and temporally in unpredictable ways. Even if CDR is effective at sequestering CO2, its associated land use and land cover changes may negatively impact ecological resources by compromising water quality and availability, degrading soils, reducing biodiversity, displacing agriculture, and altering local climate through albedo and evapotranspiration changes. Measures taken to overcome ecological limitations, such as fertilizer addition and irrigation, may exacerbate these impacts even further. The ecological considerations and quantitative analyses that we present highlight uncertainties introduced by ecological complexity, disagreements between models, perverse economic incentives, and changing environmental factors. We do not reject CDR as a potentially valuable strategy for climate change mitigation; ecosystem protection, restoration, and improved management practices could enhance soil fertility and protect biodiversity while reducing

  14. 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 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......) and the CO2 stripping efficiency (the difference in CO2 concentration between the influent water and the effluent water that has re-established chemical equilibria approximately 1 min after exiting the column). Mass transfer coefficients were similar between fresh and saline water. Countercurrent air flow...

  15. Pyruvate inhibition of the carbon dioxide fixation of the strict chemolithotroph Thiobacillus thiooxidans.

    Science.gov (United States)

    Butler, R G

    1975-12-01

    A flow-through dialysis system used to decrease the concentrations of toxic organic materials excreted by Thiobacillus thiooxidans permitted an improved efficiency of carbon dioxide fixation when compared with cells taken from the usual shaken culture. The additions of various concentrations of pyruvic acid and succinic acid inhibited growth significantly. Pyruvate at a concentration of 5 X 10(-3) M completely inhibited the respiration of resting cells oxidizing sulfur. The toxicity of pyruvic acid was found to be permanent as evidenced by the inability to obtain satisfactory oxidation rates after washing the exposed cells twice in buffer. Both pyruvate (10(-3) M) and succinate (10(-3) M) inhibited carbon dioxide fixation by 84%.

  16. Carbon dioxide reduction in a tubular solid oxide electrolysis cell for a carbon recycling energy system

    Energy Technology Data Exchange (ETDEWEB)

    Dipu, Arnoldus Lambertus, E-mail: dipu.a.aa@m.titech.ac.jp [Department of Nuclear Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Ujisawa, Yutaka [Nippon Steel and Sumitomo Metal Corporation, 16-1, Sunayama, Kamisu, Ibaraki 314-0255 (Japan); Ryu, Junichi; Kato, Yukitaka [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1-N1-22, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2014-05-01

    A new energy transformation system based on carbon recycling is proposed called the active carbon recycling energy system (ACRES). A high-temperature gas reactor was used as the main energy source for ACRES. An experimental study based on the ACRES concept of carbon monoxide (CO) regeneration via high-temperature reduction of carbon dioxide (CO{sub 2}) was carried out using a tubular solid oxide electrolysis cell employing Ni-LSM cermet|YSZ|YSZ-LSM as the cathode|electrolyte|anode. The current density increased with increasing CO{sub 2} concentration at the cathode, which was attributed to a decrease in cathode activation and concentration overpotential. Current density, as well as the CO and oxygen (O{sub 2}) production rates, increased with increasing operating temperature. The highest CO and O{sub 2} production rates of 1.24 and 0.64 μmol/min cm{sup 2}, respectively, were measured at 900 °C. Based on the electrolytic characteristics of the cell, the scale of a combined ACRES CO{sub 2} electrolysis/iron production facility was estimated.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-05-01

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

  19. Carbon Dioxide Sequestration by Direct Mineral Carbonation: Results from Recent Studies and Current Status

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

    Direct mineral carbonation has been investigated as a process to convert gaseous CO2 into a geologically stable, solid final form. The process utilizes a solution of sodium bicarbonate (NaHCO3), sodium chloride (NaCl), and water, mixed with a mineral reactant, such as olivine (Mg2SiO4) or serpentine [Mg3Si2O5(OH)4]. Carbon dioxide is dissolved into this slurry, by diffusion through the surface and gas dispersion within the aqueous phase. The process includes dissolution of the mineral and precipitation of magnesium carbonate (MgCO3) in a single unit operation. Optimum results have been achieved using heat pretreated serpentine feed material, with a surface area of roughly 19 m2 per gram, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% stoichiometric conversion of the silicate to the carbonate was achieved in 30 minutes. Studies suggest that the mineral dissolution rate is primarily surface controlled, while the carbonate precipitation rate is primarily dependent on the bicarbonate concentration of the slurry. Current studies include further examination of the reaction pathways, and an evaluation of the resource potential for the magnesium silicate reactant, particularly olivine. Additional studies include the examination of various pretreatment options, the development of a continuous flow reactor, and an evaluation of the economic feasibility of the process.

  20. 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.

  1. 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

  2. In Situ Infrared Spectroscopic Study of Brucite Carbonation in Dry to Water-Saturated Supercritical Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Loring, John S.; Thompson, Christopher J.; Zhang, Changyong; Wang, Zheming; Schaef, Herbert T.; Rosso, Kevin M.

    2012-04-25

    In geologic carbon sequestration, while part of the injected carbon dioxide will dissolve into host brine, some will remain as neat to water saturated super critical CO2 (scCO2) 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 scCO2 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 hr reaction period with scCO2 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 scCO2. 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 (MgCO3 • 3H2O). Mixtures of nesquehonite and magnesite (MgCO3) 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.

  3. 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.

  4. 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

  5. Determination of Critical Parameters of Carbon Dioxide+ Butyraldehyde System with Different Compositions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-chang; GAO Xi-xin; CAO Wei-liang

    2005-01-01

    Supercritical carbon dioxide( SC-CO2 ) is considered in green chemistry as a substitute for conventional solvents in chemical reactions due to its environmentally benign character. Recently we have reported the homogeneous hydroformylation of propylene in supercritical carbon dioxide( SC-CO2 ), which is an example of this kind of application of carbon dioxide. The determination for the critical parameters of carbon dioxide + butyraldehyde mixtures is necessary for this reaction design which is the focus of the present paper. The critical parameters of the binary systems were determined via the static visual method at a constant volume with the molar fraction of butyraldehyde ranging from 1.0%to 2. 2% and the pressure ranging from 5 to 10 MPa. The experimental results show that the critical pressure and temperature increased with increasing the molar fraction of butyraldehyde. The bubble(dew) temperatures and the bubble (dew) pressures for the binary systems were also determined experimentally. The p-T Figures at different compositions of the binary systems were described. In addition, the critical compressibility factors Zc of the binary systems at different concentrations of n-butyraldehyde were calculated. It was found that the critical compressibility factor values of the binary systems decreased with increasing the molar fraction of n-butyraldehyde in the experimental range.

  6. Radiocarbon evidence for a smaller oceanic carbon dioxide sink than previously believed

    Energy Technology Data Exchange (ETDEWEB)

    Hesshaimer, Vago; Levin, Ingeborg (Heidelberg Univ. (Germany). Inst. fuer Umweltphysik); Heimann, Martin (Max-Planck-Institut fuer Meteorologie, Hamburg (Germany))

    1994-07-21

    Radiocarbon produced naturally in the upper atmosphere or artificially during nuclear weapons testing is the main tracer used to validate models of oceanic carbon cycling, in particular the exchange of carbon dioxide with the atmosphere and the mixing parameters within the ocean itself. Here we test the overall consistency of exchange fluxes between all relevant compartments in a simple model of the global carbon cycle, using measurements of the long-term tropospheric CO[sub 2] concentration and radiocarbon composition, the bomb [sup 14]C inventory in the stratosphere and a compilation of bomb detonation dates and strengths. (author).

  7. Carbon dioxide fixation and respiration relationships observed during closure experiments in Biosphere 2

    Science.gov (United States)

    Nelson, Mark; Dempster, William; Allen, John P.

    Biosphere 2 enclosed several ecosystems - ones analogous to rainforest, tropical savannah, thornscrub, desert, marsh and coral reef - and a diverse agro-ecology, with dozens of food crops, in virtual material isolation from Earth's environment. This permits a detailed examination of fixation and respiration from the continuous record of carbon dioxide concentration from sensors inside the facility. Unlike the Earth, all the ecosystems were active during sunlight hours, while phyto and soil respiration dominated nighttime hours. This resulted in fluctuations of as much as 600-700 ppm CO2 daily during days of high sunlight input. We examine the relationships between daytime fixation as driven by photosynthesis to nighttime respiration and also fixation and respiration as related to carbon dioxide concentration. Since carbon dioxide concentrations varied from near Earth ambient levels to over 3000 ppm (during low-light winter months), the response of the plant communities and impact on phytorespiration and soil respiration may be of relevance to the global climate change research community. An investigation of these dynamics will also allow the testing of models predicting the response of community metabolism to variations in sunlight and degree of previous net carbon fixation.

  8. Carbon Dioxide Separation with Novel Microporous Metal Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Richard Willis; Annabelle Benin; John Low; Ganesh Venimadhavan; Syed Faheem; David Lesch; Adam Matzger; Randy Snurr

    2008-02-04

    The goal of this program was to develop a low cost novel sorbent to remove carbon dioxide from flue gas and gasification streams in electric utilities. Porous materials named metal-organic frameworks (MOFs) were found to have good capacity and selectivity for the capture of carbon dioxide. Several materials from the initial set of reference MOFs showed extremely high CO{sub 2} adsorption capacities and very desirable linear isotherm shapes. Sample preparation occurred at a high level, with a new family of materials suitable for intellectual property protection prepared and characterized. Raman spectroscopy was shown to be useful for the facile characterization of MOF materials during adsorption and especially, desorption. Further, the development of a Raman spectroscopic-based method of determining binary adsorption isotherms was initiated. It was discovered that a stronger base functionality will need to be added to MOF linkers in order to enhance CO{sub 2} selectivity over other gases via a chemisorption mechanism. A concentrated effort was expended on being able to accurately predict CO{sub 2} selectivities and on the calculation of predicted MOF surface area values from first principles. A method of modeling hydrolysis on MOF materials that correlates with experimental data was developed and refined. Complimentary experimental data were recorded via utilization of a combinatorial chemistry heat treatment unit and high-throughput X-ray diffractometer. The three main Deliverables for the project, namely (a) a MOF for pre-combustion (e.g., IGCC) CO{sub 2} capture, (b) a MOF for post-combustion (flue gas) CO{sub 2} capture, and (c) an assessment of commercial potential for a MOF in the IGCC application, were completed. The key properties for MOFs to work in this application - high CO{sub 2} capacity, good adsorption/desorption rates, high adsorption selectivity for CO{sub 2} over other gases such as methane and nitrogen, high stability to contaminants, namely

  9. Applying Econometrics to the Carbon Dioxide “Control Knob”

    Directory of Open Access Journals (Sweden)

    Timothy Curtin

    2012-01-01

    Full Text Available This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]. However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010.

  10. Applying Econometrics to the Carbon Dioxide “Control Knob”

    Science.gov (United States)

    Curtin, Timothy

    2012-01-01

    This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG) effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]). However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010). PMID:22629196

  11. Applying econometrics to the carbon dioxide "control knob".

    Science.gov (United States)

    Curtin, Timothy

    2012-01-01

    This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG) effect, that effect is merely a "feedback" from rising temperatures initially resulting only from "non-condensing" GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H(2)O]). However, this paper shows that "initial radiative forcing" is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H(2)O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective "control knob" as claimed by Lacis et al. (2010).

  12. 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-cyclic gua......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...

  13. 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.

  14. Carbon dioxide fixation by microalgae cultivated in open bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Centeno da Rosa, Ana Priscila; Fernandes Carvalho, Lisiane; Goldbeck, Luzia [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil); Vieira Costa, Jorge Alberto, E-mail: dqmjorge@furg.br [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil)

    2011-08-15

    Highlights: {yields} We studied the growth and CO{sub 2} fixation by Spirulina LEB18 and Chlorella kessleri. {yields} The maximum dailyfixation was obtained for Spirulina with an injection of 6% of CO{sub 2}. {yields} The microalgae presented growth during the 20 d of culture with up to 18% of CO{sub 2}. {yields} The use of CO{sub 2} from industrial generation decreases the cost of producing biomass. - Abstract: The biofixation of carbon dioxide (CO{sub 2}) by microalgae has been proven to be an efficient and economical method, mainly due to the photosynthetic ability of these microorganisms to use this gas as a source of nutrients for their development. The aim of this work was to study the growth of Spirulina LEB18 and Chlorella kessleri microalgae, exposed to controlled and non-controlled conditions, with the injection of different concentrations of CO{sub 2}. The cultures was carried out in 6 L open raceway ponds, under controlled conditions at 30 {sup o}C and 39 {mu}E m{sup -2} s{sup -1} and under non-controlled conditions, protected by a tunnel of transparent film. The experiments were subjected to CO{sub 2} injections at concentrations of 0.038, 6, 12 and 18% (v/v). The highest concentration of biomass (4.95 g L{sup -1}) and maximum daily fixation (0.21 g g{sup -1} d{sup -1}) were obtained for Spirulina LEB18 in culture that was prepared in non-controlled conditions with an injection of 6% (v/v) of CO{sub 2}. C. kessleri had maximum (p < 0.0008) specific growth rate (0.84 d{sup -1}) when grown with 18% (v/v) of CO{sub 2} in non-controlled conditions of cultivation.

  15. 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.

  16. Carbon dioxide capture using polyethylenimine-loaded mesoporous carbons

    Institute of Scientific and Technical Information of China (English)

    Jitong Wang; Huichao Chen; Huanhuan Zhou; Xiaojun Liu; Wenming Qiao; Donghui Long; Licheng Ling

    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℃,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℃,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.

  17. 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.

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

    DEFF Research Database (Denmark)

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

    gases are carbon dioxide, methane and nitrous oxide, of which carbon dioxide is the highest constituent at 82%. Furthermore, the amount of carbon dioxide emissions is growing with time. These trends make it evident that there is a need for methods to reduce these greenhouse gases emissions. While...... 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...

  19. Chemical technologies for exploiting and recycling carbon dioxide into the value chain.

    Science.gov (United States)

    Peters, Martina; Köhler, Burkhard; Kuckshinrichs, Wilhelm; Leitner, Walter; Markewitz, Peter; Müller, Thomas E

    2011-09-19

    While experts in various fields discuss the potential of carbon capture and storage (CCS) technologies, the utilization of carbon dioxide as chemical feedstock is also attracting renewed and rapidly growing interest. These approaches do not compete; rather, they are complementary: CCS aims to capture and store huge quantities of carbon dioxide, while the chemical exploitation of carbon dioxide aims to generate value and develop better and more-efficient processes from a limited part of the waste stream. Provided that the overall carbon footprint for the carbon dioxide-based process chain is competitive with conventional chemical production and that the reaction with the carbon dioxide molecule is enabled by the use of appropriate catalysts, carbon dioxide can be a promising carbon source with practically unlimited availability for a range of industrially relevant products. In addition, it can be used as a versatile processing fluid based on its remarkable physicochemical properties.

  20. In-vehicle nitrogen dioxide concentrations in road tunnels

    Science.gov (United States)

    Martin, Ashley N.; Boulter, Paul G.; Roddis, Damon; McDonough, Liza; Patterson, Michael; Rodriguez del Barco, Marina; Mattes, Andrew; Knibbs, Luke D.

    2016-11-01

    There is a lack of knowledge regarding in-vehicle concentrations of nitrogen dioxide (NO2) during transit through road tunnels in urban environments. Furthermore, previous studies have tended to involve a single vehicle and the range of in-vehicle NO2 concentrations that vehicle occupants may be exposed to is not well defined. This study describes simultaneous measurements of in-vehicle and outside-vehicle NO2 concentrations on a route through Sydney, Australia that included several major tunnels, minor tunnels and busy surface roads. Tests were conducted on nine passenger vehicles to assess how vehicle characteristics and ventilation settings affected in-vehicle NO2 concentrations and the in-vehicle-to-outside vehicle (I/O) concentration ratio. NO2 was measured directly using a cavity attenuated phase shift (CAPS) technique that gave a high temporal and spatial resolution. In the major tunnels, transit-average in-vehicle NO2 concentrations were lower than outside-vehicle concentrations for all vehicles with cabin air recirculation either on or off. However, markedly lower I/O ratios were obtained with recirculation on (0.08-0.36), suggesting that vehicle occupants can significantly lower their exposure to NO2 in tunnels by switching recirculation on. The highest mean I/O ratios for NO2 were measured in older vehicles (0.35-0.36), which is attributed to older vehicles having higher air exchange rates. The results from this study can be used to inform the design and operation of future road tunnels and modelling of personal exposure to NO2.

  1. 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.

  2. Magmatic carbon dioxide emissions at Mammoth Mountain, California

    Science.gov (United States)

    Farrar, Christopher D.; Neil, John M.; Howle, James F.

    1999-01-01

    Carbon dioxide (CO2) of magmatic origin is seeping out of the ground in unusual quantities at several locations around the flanks of Mammoth Mountain, a dormant volcano in Eastern California. The most recent volcanic activity on Mammoth Mountain was steam eruptions about 600 years ago, but seismic swarms and long-period earthquakes over the past decade are evidence of an active magmatic system at depth. The CO2 emission probably began in 1990 but was not recognized until 1994. Seismic swarms and minor ground deformation during 1989, believed to be results of a shallow intrusion of magma beneath Mammoth Mountain, probably triggered the release of CO2, which persists in 1998. The CO2 gas is at ambient temperatures and emanates diffusely from the soil surface rather than flowing from distinct vents. The CO2 has collected in the soil by displacing air in the pore spaces and reaches concentrations of greater than 95 percent by volume in places. The total area affected by high CO2 concentrations and high CO2 flux from the soil surface was estimated at 60 hectares in 1997. Coniferous forest covering about 40 hectares has been killed by high CO2 concentrations in the root zone. In more than 300 soil-gas samples collected from depths of 0.5 to 2 m in 1995, CO2 concentrations ranged from background levels (less than 1 percent) to greater than 95 percent by volume. At 250 locations, CO2 flux was measured using a closed chamber in 1996; values, in grams per square meter per day, ranged from background (less than 25) to more than 30,000. On the basis of these data, the total emission of magmatic CO2 in 1996 is estimated to be about 530 megagrams per day. Concentrations of CO2 exceeding Occupational Safety and Health Administration standards have been measured in pits dug in soil and snow, in poorly ventilated buildings, and in below-ground valve-boxes around Mammoth Mountain. CO2 concentrations greater than 10 percent in poorly ventilated spaces are not uncommon on some parts

  3. 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.

  4. 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 additional

  5. 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.

    , H. Matsueda, and Y. Sawa. (2011). Carbon balance of South Asia constrained by passenger aircraft CO2 measurements. Atmos. Chem. Phys. Discuss, 11, 5379-5405. Ram, A.S.P., S. Nair, D. Chandramohan, (2003). Seasonal shift in net ecosystem production...

  6. 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.

  7. Radon, carbon dioxide and fault displacements in central Europe related to the Tōhoku Earthquake.

    Science.gov (United States)

    Briestenský, M; Thinová, L; Praksová, R; Stemberk, J; Rowberry, M D; Knejflová, Z

    2014-07-01

    Tectonic instability may be measured directly using extensometers installed across active faults or it may be indicated by anomalous natural gas concentrations in the vicinity of active faults. This paper presents the results of fault displacement monitoring at two sites in the Bohemian Massif and Western Carpathians. These data have been supplemented by radon monitoring in the Mladeč Caves and by carbon dioxide monitoring in the Zbrašov Aragonite Caves. A significant period of tectonic instability is indicated by changes in the fault displacement trends and by anomalous radon and carbon dioxide concentrations. This was recorded around the time of the catastrophic MW=9.0 Tōhoku Earthquake, which hit eastern Japan on 11 March 2011. It is tentatively suggested that the Tōhoku Earthquake in the Pacific Ocean and the unusual geodynamic activity recorded in the Bohemian Massif and Western Carpathians both reflect contemporaneous global tectonic changes.

  8. Storage and recycling of water and carbon dioxide in the earth

    Science.gov (United States)

    Wood, Bernard J.

    1994-01-01

    The stabilities and properties of water- and carbon-bearing phases in the earth have been determined from phase equilibrium measurements, combined with new data on the equations of state of water, carbon dioxide, carbonates and hydrates. The data have then been used to predict the fate of calcite and hydrous phases in subducting oceanic lithosphere. From the compositions of MORB's one can estimate concentrations of water and carbon of around 200 ppm and 80 ppm respectively in the upper mantle. Lower mantle estimates are very uncertain, but 1900 ppm water and 2000 ppm C are plausible concentrations. Measurements of the density of supercritical water to 3 GPa demonstrate that this phase is less compressible than anticipated from the equations of state of Haar et al. or Saul and Wagner and is closer to predictions based on molecular dynamics simulations. Conversely, fugacity measurements on carbon dioxide to 7 GPa show that this fluid is more compressible than predicted from the MRK equation of state. The results imply that hydrates are relatively more stable and carbonates less stable at pressures greater than 5 GPa than would be predicted from simple extrapolation of the low pressure data. Nevertheless, carbonates remain extremely refractory phases within both the upper and lower mantle.

  9. Spring leaf flush in aspen (Populus tremuloides) clones is altered by growth at elevated carbon dioxide and elevated ozone

    Science.gov (United States)

    Early spring leaf out is important to the success of trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how elevated carbon dioxide concentration and elevated ozone concentration altered leaf area index development in a clos...

  10. Carbon dioxide effects research and assessment program. A comprehensive plan. Part I. The global carbon cycle and climatic effects of increasing carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Slade, David H.

    1980-08-01

    Initial plans for research of the carbon dioxide (CO/sub 2/) and climate issue were prepared in 1978 and were reviewed extensively at that time by federal agencies and members of the scientific community. Since then the plans have been used to guide early phases of the Department of Energy's and the nation's efforts related to this issue. This document represents a revision of the 1978 plan to (a) reflect recent ideas and strategies for carbon cycle research, and (b) expand the scope of research on climatic responses to increasing atmospheric concentrations of CO/sub 2/. The revised plan takes into account a number of investigations already being supported by various agencies, and it attempts to build on or add to existing research where there is a crucial need for information directly related to the CO/sub 2/ issue. It should be recognized that this document is the first section of a comprehensive plan on the overall consequences of increasing concentrations of CO/sub 2/, and includes guidelines for research on the Global Carbon Cycle and Climatic Effects of Increasing CO/sub 2/.

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

    CERN Document Server

    Hüsler, Andreas D

    2011-01-01

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

  12. Salinity Effect on Ocean Surface Carbon Dioxide Fugacity

    Science.gov (United States)

    Xie, X.; Liu, W. T.

    2015-12-01

    Sea surface salinity (SSS) measured by Aquarius and the Soil Moisture Ocean Salinity (SMOS) over global ocean is used to characterize the change of the partial pressure of carbon dioxide at sea (pCO2sea). A statistical model on satellite retrieval of pCO2sea is used to examine the relation between the two parameters over two selected regions. One is the tropical western Atlantic, where hydrological forcing by Amazon River discharge causes major changes, and the other is the equatorial eastern Pacific, where ocean thermodynamics is more important. In both regions, pCO2sea tracks SSS closely in seasonal and year-to-year changes. In the Pacific, tropical instability wave is a major factor in the high frequency changes of both parameters. The manifestations of this relation in ocean-atmosphere carbon dioxide exchange and ocean acidification are explored.

  13. An intercomparison exercise for oceanic carbon dioxide measurements

    Science.gov (United States)

    Dickson, Andrew G.

    The Joint Scientific Committee on Oceanic Research (SCOR)/United Nations Educational, Scientific, and Cultural Organization (UNESCO/International Council for the Exploration of the Sea (ICES)/International Association for Physical Sciences of the Ocean (IAPSO) Panel on Oceanographic Tables and Standards (JPOTS) recently established a Sub-Panel on Standards for Carbon Dioxide Measurements. The terms of reference for this subpanel are coordination and assessment of work done toward preparing carbon dioxide standards for oceanographic measurements, and development of recommendations for the production and use of such standards. Members are A. G. Dickson (Scripps Institution of Oceanography, La Jolla, Calif.), chairman; F. Culkin (Institute of Oceanographic Sciences, Wormley, U.K.), A. Poisson (Universite Pierre et Marie Curie, Paris), C. S. Wong (Institute of Ocean Sciences, Sidney, Canada), and F. J. Millero (University of Miami, Miami, Fla.).

  14. Carbon Dioxide Management on the International Space Station

    Science.gov (United States)

    Burlingame, Katie

    2016-01-01

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

  15. Syneresis of Vitreous by Carbon Dioxide Laser Radiation

    Science.gov (United States)

    Bridges, T. J.; Patel, C. K. N.; Strnad, A. R.; Wood, O. R.; Brewer, E. S.; Karlin, D. B.

    1983-03-01

    In carbon dioxide laser surgery of the vitreous a process of vaporization has been advocated. In this report syneresis, a thermal liquefaction of gel, is shown to be over ten times more efficient on an energy basis than vaporization. Syneresis of vitreous is experimentally shown to be a first-order kinetic process with an activation energy of 41 ± 0.5 kilocalories per mole. A theory of laser surgery in which this figure is used agrees closely with results from laser experiments on human eye-bank vitreous. The syneresis of vitreous by carbon dioxide laser radiation could lead to a more delicate form of ocular microsurgery, and application to other biological systems may be possible.

  16. Simulation of the interaction of methane, carbon dioxide and coal

    Institute of Scientific and Technical Information of China (English)

    Nie Baisheng; Wang Longkang; Li Xiangchun; Wang Chao; Li Li

    2013-01-01

    Gas adsorption has an important influence on gas flow in a coal body. Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal. In this paper, the interaction between methane, carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method. Adsorption energy and adsorption configurations of different quantities of gas mole-cules absorbed on the coal surface were calculated. The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration. Gas molecules are more easily adsorbed in the hydroxyl-containing side chain, while it is difficult for them to be adsorbed at the position of the benzene ring. Besides, carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules. The findings have an important signifi-cance in revealing the nature of gas adsorption in coal.

  17. Schwannoma of tongue base treated with transoral carbon dioxide laser.

    Science.gov (United States)

    Mehrzad, H; Persaud, R; Papadimitriou, N; Kaniyur, S; Mochloulis, G

    2006-12-01

    Schwannomas are benign slow growing solitary tumours of nerve sheath origin and can arise from any myelinated nerve. They have been reported to occur in most parts of the body with the highest incidence (25%) in the head and neck region, although tongue base lesions are rare. The tumour is resistant to radiotherapy, and therefore, the treatment of choice is surgery. We present a case of a tongue base schwannoma which was completely extirpated with a carbon dioxide laser via the transoral approach. The patient experienced virtually no morbidity from the use of the laser. Whilst tongue base schwannoma has been documented, we could not find an earlier report in the English literature describing our method of treatment. We conclude that transoral carbon dioxide laser can be added to the surgical armamentarium for the management of other similar cases in the future.

  18. Uso de dióxido de carbono na agricultura Use of carbon dioxide in agriculture

    Directory of Open Access Journals (Sweden)

    José Maria Pinto

    2000-10-01

    Full Text Available O ciclo do carbono na biosfera tem sido significativamente alterado pela atividade do homem nos últimos 150 anos. O CO2 emitido pela atividade humana é da ordem de 8,5 bilhões de toneladas anuais, como conseqüência a concentração de CO2 atmosférico está aumentando. Estudos relacionando os efeitos do aumento artificial da concentração de CO2 nas plantas para obtenção de produtos em maior quantidade e melhor qualidade permitem conhecer a capacidade das plantas de adaptarem-se a esses ambientes. No entanto, fatores relacionados à aplicação de dióxido de carbono necessitam de estudos ecofisiológicos mais detalhados referentes às trocas de CO2.The carbon cycle in the biosphere has been significantly altered by man's activities in the last 150 years. The CO2 emitted by human activity is approximately 8.5 billion of tons yearly, as a consequence, the carbon dioxide concentration is increasing. Studies related to the artificial increase effects of CO2 concentration on plants used for obtaining products in greater quantity and with a better quality permit us to know the capacity of the plants to adapt in this environment. Therefore, factors related to the application of carbon dioxide need more accurate studies concerning to carbon dioxide changes.

  19. 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.

  20. 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...

  1. Oxygen isotopic composition of carbon dioxide in the middle atmosphere

    OpenAIRE

    Liang, Mao-Chang; Blake, Geoffrey A.; Lewis, Brenton R.; Yung, Yuk L.

    2007-01-01

    The isotopic composition of long-lived trace molecules provides a window into atmospheric transport and chemistry. Carbon dioxide is a particularly powerful tracer, because its abundance remains >100 parts per million by volume (ppmv) in the mesosphere. Here, we successfully reproduce the isotopic composition of CO2 in the middle atmosphere, which has not been previously reported. The mass-independent fractionation of oxygen in CO2 can be satisfactorily explained by the exchange reaction with...

  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. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lincoln, D.E.

    1995-10-01

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

  5. 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 decreas

  6. Sustainable catalyst supports for carbon dioxide gas adsorbent

    Science.gov (United States)

    Mazlee, M. N.

    2016-07-01

    The adsorption of carbon dioxide (CO2) become the prime attention nowadays due to the fact that increasing CO2 emissions has been identified as a contributor to global climate change. Major sources of CO2 emissions are thermoelectric power plants and industrial plants which account for approximately 45% of global CO2 emissions. Therefore, it is an urgent need to develop an efficient CO2 reduction technology such as carbon capture and storage (CCS) that can reduce CO2 emissions particularly from the energy sector. A lot of sustainable catalyst supports have been developed particularly for CO2 gas adsorbent applications.

  7. 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)

  8. Innovative Ration Preservation via Supercritical Carbon Dioxide

    Science.gov (United States)

    2012-07-01

    As a result, SC fluids have been used in applications that range from decaffeinating coffee to the sterilization of medical instruments. CO2...the cell (Damar 2006). It should be noted that SCCO2 is a powerful extraction solvent, and has been used to extract everything from caffeine to...further understand the diffusing power of the SCCO2, polypropelene Falcon tubes were filled with different concentrations of agar (0.25-1.0%) and 2

  9. Examples of the effects of different averaging methods on carbon dioxide fluxes calculated using the eddy correlation method

    Directory of Open Access Journals (Sweden)

    A. D. Culf

    2000-01-01

    Full Text Available Three hours of high frequency vertical windspeed and carbon dioxide concentration data recorded over tropical forest in Brazil are presented and discussed in relation to various detrending techniques used in eddy correlation analysis. Running means with time constants 100, 1000 and 1875s and a 30 minute linear detrend, as commonly used to determine fluxes, have been calculated for each case study and are presented. It is shown that, for different trends in the background concentration of carbon dioxide, the different methods can lead to the calculation of radically different fluxes over an hourly period. The examples emphasise the need for caution when interpreting eddy correlation derived fluxes especially for short term process studies. Keywords: Eddy covariance; detrending; running mean; carbon dioxide; tropical forest

  10. Volcanic carbon dioxide vents show ecosystem effects of ocean acidification.

    Science.gov (United States)

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

    2008-07-01

    The atmospheric partial pressure of carbon dioxide (p(CO(2))) will almost certainly be double that of pre-industrial levels by 2100 and will be considerably higher than at any time during the past few million years. The oceans are a principal sink for anthropogenic CO(2) where it is estimated to have caused a 30% increase in the concentration of H(+) in ocean surface waters since the early 1900s and may lead to a drop in seawater pH of up to 0.5 units by 2100 (refs 2, 3). Our understanding of how increased ocean acidity may affect marine ecosystems is at present very limited as almost all studies have been in vitro, short-term, rapid perturbation experiments on isolated elements of the ecosystem. Here we show the effects of acidification on benthic ecosystems at shallow coastal sites where volcanic CO(2) vents lower the pH of the water column. Along gradients of normal pH (8.1-8.2) to lowered pH (mean 7.8-7.9, minimum 7.4-7.5), typical rocky shore communities with abundant calcareous organisms shifted to communities lacking scleractinian corals with significant reductions in sea urchin and coralline algal abundance. To our knowledge, this is the first ecosystem-scale validation of predictions that these important groups of organisms are susceptible to elevated amounts of p(CO(2)). Sea-grass production was highest in an area at mean pH 7.6 (1,827 (mu)atm p(CO(2))) where coralline algal biomass was significantly reduced and gastropod shells were dissolving due to periods of carbonate sub-saturation. The species populating the vent sites comprise a suite of organisms that are resilient to naturally high concentrations of p(CO(2)) and indicate that ocean acidification may benefit highly invasive non-native algal species. Our results provide the first in situ insights into how shallow water marine communities might change when susceptible organisms are removed owing to ocean acidification.

  11. Atmospheric Lifetime of Fossil Fuel Carbon Dioxide

    Science.gov (United States)

    Archer, David; Eby, Michael; Brovkin, Victor; Ridgwell, Andy; Cao, Long; Mikolajewicz, Uwe; Caldeira, Ken; Matsumoto, Katsumi; Munhoven, Guy; Montenegro, Alvaro; Tokos, Kathy

    2009-05-01

    CO2 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere, the ocean, and the terrestrial biosphere on timescales of a few centuries. However, a sizeable fraction of the CO2 remains in the atmosphere, awaiting a return to the solid earth by much slower weathering processes and deposition of CaCO3. Common measures of the atmospheric lifetime of CO2, including the e-folding time scale, disregard the long tail. Its neglect in the calculation of global warming potentials leads many to underestimate the longevity of anthropogenic global warming. Here, we review the past literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial results from a model intercomparison project on this topic. The models agree that 20-35% of the CO2 remains in the atmosphere after equilibration with the ocean (2-20 centuries). Neutralization by CaCO3 draws the airborne fraction down further on timescales of 3 to 7 kyr.

  12. Surface chemistry of carbon dioxide revisited

    Science.gov (United States)

    Taifan, William; Boily, Jean-François; Baltrusaitis, Jonas

    2016-12-01

    This review discusses modern developments in CO2 surface chemistry by focusing on the work published since the original review by H.J. Freund and M.W. Roberts two decades ago (Surface Science Reports 25 (1996) 225-273). It includes relevant fundamentals pertaining to the topics covered in that earlier review, such as conventional metal and metal oxide surfaces and CO2 interactions thereon. While UHV spectroscopy has routinely been applied for CO2 gas-solid interface analysis, the present work goes further by describing surface-CO2 interactions under elevated CO2 pressure on non-oxide surfaces, such as zeolites, sulfides, carbides and nitrides. Furthermore, it describes additional salient in situ techniques relevant to the resolution of the interfacial chemistry of CO2, notably infrared spectroscopy and state-of-the-art theoretical methods, currently used in the resolution of solid and soluble carbonate species in liquid-water vapor, liquid-solid and liquid-liquid interfaces. These techniques are directly relevant to fundamental, natural and technological settings, such as heterogeneous and environmental catalysis and CO2 sequestration.

  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. Prospects for the utilization of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Aresta, M.; Quaranta, E.; Tommasi, I. (Universita degli Studi, Bari (Italy). Dipatimento di Chimica)

    1992-01-01

    The paper discusses the recovery and fixation of CO{sub 2}. Industrial applications of CO{sub 2} can be divided as follows:- non-synthetic industrial uses such as waste water treatment and food additives; utilization in the synthesis of organic chemicals; and the synthesis of intermediates and specialty chemicals such as urea and pharmaceuticals. The evaluation criteria for CO{sub 2} utilization pathways are:- the added value of the products; the energy requirements of the product; the rate of CO{sub 2} conversion; and the lifetime of the product. The conversion of CO{sub 2} into fuels raises three main questions: the amount of CO{sub 2} used, the source of energy from CO{sub 2} reduction and the rate of conversion of CO{sub 2}. The fixation of CO{sub 2} in organic materials such as carbonates may be of great relevance to the permanent fixation of CO{sub 2}. 5 refs., 3 figs., 6 tabs.

  15. Carbon dioxide and methane emission dynamics in central London (UK)

    Science.gov (United States)

    Helfter, Carole; Nemitz, Eiko; Barlow, Janet F.; Wood, Curtis R.

    2013-04-01

    London, with a population of 8.2 million, is the largest city in Europe. It is heavily built-up (typically 8% vegetation cover within the central boroughs) and boasts some of the busiest arteries in Europe despite efforts to reduce traffic in the city centre with the introduction of a congestion charging scheme in 2007. We report on two substantial pollution monitoring efforts in the heart of London between October 2006 and present. Fluxes of carbon dioxide (CO2) and water (H2O) were measured continuously by eddy-covariance in central London from October 2006 until May 2008 from a 190 m telecommunication tower (BT tower; 51° 31' 17.4'' N 0° 8' 20.04'' W). The eddy-covariance system consisted of a Gill R3-50 ultrasonic anemometer operated at 20 Hz and a LI-COR 6262 infrared gas analyser. Air was sampled 0.3 m below the sensor head of the ultrasonic anemometer - which was itself mounted on a 3 m mast to the top of a 15 m lattice tower situated on the roof of the tower (instrument head at 190 m above street level) - and pulled down 45 m of 12.7 mm OD Teflon tubing. In addition, meteorological variables (temperature, relative humidity, pressure, precipitation, wind speed and direction) were also measured with a multi-sensor (Weather Transmitter WXT510, Vaisala). Eddy-covariance measurements at the BT tower location were reinstated in July 2011 and include methane (CH4), CO2 and H2O concentrations measured by a Picarro fast methane analyser (G2301-f). CO2 emissions were found to be mainly controlled by fossil fuel combustion (e.g. traffic, commercial and domestic heating). Diurnal averages of CO2 fluxes were found to be highly correlated to traffic. However changes in heating-related natural gas consumption and, to a lesser extent, photosynthetic activity in two large city centre green spaces (Hyde Park and Regent's Park) explained the seasonal variability. Annual estimates of net exchange of CO2 obtained by eddy-covariance agreed well with up-scaled data from the UK

  16. Eco-Friendly Disperse Dyeing and Functional Finishing of Nylon 6 Using Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Tarek Abou Elmaaty

    2015-08-01

    Full Text Available In this work, a supercritical carbon dioxide assembly was successfully constructed for dyeing Nylon6 fabric. Primary experiments were carried out to confirm the possibility of bringing the dyeing up to factory scale. A series of disperse azo dyes with potential antibacterial activity were applied to dye the fabric under our study in supercritical carbon dioxide (scCO2. The factors affecting the dyeing conditions (i.e., dye concentration, time, temperature and pressure and functional properties were discussed and compared with those in aqueous dyeing. The comparison revealed that elimination of auxiliary chemicals such as salt, carrier or dispersing agent has no diverse effect on dyeing. The color strength of the dyed fabric evaluated by using K/S measurements increased by increasing dye concentration from 2% to 6% owf. (on weight of fabric. The nylon6 fabrics dyed in supercritical carbon dioxide have good fastness properties, and especially light fastness compared with conventional exhaustion dyeing. Antibacterial activity of the dyed samples under supercritical conditions was evaluated and the results showed excellent antibacterial efficiency.

  17. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    Science.gov (United States)

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus.

  18. Global warming and carbon dioxide through sciences.

    Science.gov (United States)

    Florides, Georgios A; Christodoulides, Paul

    2009-02-01

    Increased atmospheric CO(2)-concentration is widely being considered as the main driving factor that causes the phenomenon of global warming. This paper attempts to shed more light on the role of atmospheric CO(2) in relation to temperature-increase and, more generally, in relation to Earth's life through the geological aeons, based on a review-assessment of existing related studies. It is pointed out that there has been a debate on the accuracy of temperature reconstructions as well as on the exact impact that CO(2) has on global warming. Moreover, using three independent sets of data (collected from ice-cores and chemistry) we perform a specific regression analysis which concludes that forecasts about the correlation between CO(2)-concentration and temperature rely heavily on the choice of data used, and one cannot be positive that indeed such a correlation exists (for chemistry data) or even, if existing (for ice-cores data), whether it leads to a "severe" or a "gentle" global warming. A very recent development on the greenhouse phenomenon is a validated adiabatic model, based on laws of physics, forecasting a maximum temperature-increase of 0.01-0.03 degrees C for a value doubling the present concentration of atmospheric CO(2). Through a further review of related studies and facts from disciplines like biology and geology, where CO(2)-change is viewed from a different perspective, it is suggested that CO(2)-change is not necessarily always a negative factor for the environment. In fact it is shown that CO(2)-increase has stimulated the growth of plants, while the CO(2)-change history has altered the physiology of plants. Moreover, data from palaeoclimatology show that the CO(2)-content in the atmosphere is at a minimum in this geological aeon. Finally it is stressed that the understanding of the functioning of Earth's complex climate system (especially for water, solar radiation and so forth) is still poor and, hence, scientific knowledge is not at a level to

  19. The need of research for developing the carbon dioxide disposal and utilization options

    Energy Technology Data Exchange (ETDEWEB)

    Aresta, M. [Univ. di Bari (Italy). METEA Research Center

    1996-12-31

    The idea of global warming correlating to the increasing atmospheric level of greenhouse gases is controversial. Assessing CO{sub 2}-mitigation technologies and a better knowledge of global effects of increasing atmospheric CO{sub 2} level, will contribute to avoiding a non return point. Mitigation technologies can be categorized as follows: Efficiency technologies; energy saving; alternative energy sources; enhanced atmospheric carbon dioxide fixation; recovery of carbon dioxide from concentrated sources (power plants or industries). The latter has a good potentiality for avoiding major amounts of atmospheric carbon dioxide, supposing that the questions about the fate of recovered CO{sub 2} (disposal or utilization) find a sound answer. Possible sites for disposal of CO{sub 2} are: depleted oil and gas fields, oceans, aquifers, deep geological cavities, and soil. The utilization of CO{sub 2} as solvent and reagent is beneficial for the environment: a non-toxic solvent is made available and a way to recycling carbon, with the double benefit of developing new benign syntheses and saving energy sources. This paper will discuss the research needed for implementing the CO{sub 2} recovery option.

  20. Carbon dioxide-based supercritical fluids as IC manufacturing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Sivils, L.D.; Pierce, T.; Tiefert, K.

    1999-05-11

    The production of integrated circuits (IC's) involves a number of discrete steps which utilize hazardous or regulated solvents and generate large waste streams. ES&H considerations associated with these chemicals have prompted a search for alternative, more environmentally benign solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Research work, conducted at Los Alamos in conjunction with the Hewlett-Packard Company, has lead to the development of a CO{sub 2}-based supercritical fluid treatment system for the stripping of hard-baked photoresists. This treatment system, known as Supercritical CO{sub 2} Resist Remover, or CORR, uses a two-component solvent composed of a nonhazardous, non-regulated compound, dissolved in supercritical CO{sub 2}. The solvent/treatment system has been successfully tested on metallized Si wafers coated with negative and positive photoresist, the latter both before and after ion-implantation. A description of the experimental data will be presented. Based on the initial laboratory results, the project has progressed to the design and construction of prototype, single-wafer photoresist-stripping equipment. The integrated system involves a closed-loop, recirculating cycle which continuously cleans and regenerates the CO{sub 2}, recycles the dissolved solvent, and separates and concentrates the spent resist. The status of the current design and implementation strategy of a treatment system to existing IC fabrication facilities will be discussed. Additional remarks will be made on the use of a SCORR-type system for the cleaning of wafers prior to processing.