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Sample records for carbon dioxide improves

  1. IMPROVING THE EFFICIENCY OF CARBON DIOXIDE SUPPLY ON UREA SYNTHESIS

    OpenAIRE

    Лавренченко, Г. К.; Копытин, А. В.; Афанасьев, С. В.; Рощенко, О. С.

    2011-01-01

    Aggregates of urea synthesis are reconstructed with the purpose decrease in specific expenses and increase their productivity. Supply of additional quantities of carbon dioxide and ammonia is necessary to increase production volumes of urea. In most cases there is a problem with the supply of СО2, as the equipment for its compression is not any necessary reserves. Installation for supply of carbon dioxide using a pump is considered. For liquefaction of CO2 at low pressure the cold of the liqu...

  2. Evaluation and Enhancement of Carbon Dioxide Flooding Through Sweep Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard

    2009-09-30

    Carbon dioxide displacement is a common improved recovery method applied to light oil reservoirs (30-45{degrees}API). The economic and technical success of CO{sub 2} floods is often limited by poor sweep efficiency or large CO{sub 2} utilization rates. Projected incremental recoveries for CO{sub 2} floods range from 7% to 20% of the original oil in place; however, actual incremental recoveries range from 9% to 15% of the original oil in place, indicating the potential for significant additional recoveries with improved sweep efficiency. This research program was designed to study the effectiveness of carbon dioxide flooding in a mature reservoir to identify and develop methods and strategies to improve oil recovery in carbon dioxide floods. Specifically, the project has focused on relating laboratory, theoretical and simulation studies to actual field performance in a CO{sub 2} flood in an attempt to understand and mitigate problems of areal and vertical sweep efficiency. In this work the focus has been on evaluating the status of existing swept regions of a mature CO{sub 2} flood and developing procedures to improve the design of proposed floods. The Little Creek Field, Mississippi has been studied through laboratory, theoretical, numerical and simulation studies in an attempt to relate performance predictions to historical reservoir performance to determine sweep efficiency, improve the understanding of the reservoir response to CO{sub 2} injection, and develop scaling methodologies to relate laboratory data and simulation results to predicted reservoir behavior. Existing laboratory information from Little Creek was analyzed and an extensive amount of field data was collected. This was merged with an understanding of previous work at Little Creek to generate a detailed simulation study of two portions of the field – the original pilot area and a currently active part of the field. This work was done to try to relate all of this information to an understanding

  3. Evaluation and Enhancement of Carbon Dioxide Flooding Through Sweep Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard

    2009-09-30

    Carbon dioxide displacement is a common improved recovery method applied to light oil reservoirs (30-45{degrees}API). The economic and technical success of CO{sub 2} floods is often limited by poor sweep efficiency or large CO{sub 2} utilization rates. Projected incremental recoveries for CO{sub 2} floods range from 7% to 20% of the original oil in place; however, actual incremental recoveries range from 9% to 15% of the original oil in place, indicating the potential for significant additional recoveries with improved sweep efficiency. This research program was designed to study the effectiveness of carbon dioxide flooding in a mature reservoir to identify and develop methods and strategies to improve oil recovery in carbon dioxide floods. Specifically, the project has focused on relating laboratory, theoretical and simulation studies to actual field performance in a CO{sub 2} flood in an attempt to understand and mitigate problems of areal and vertical sweep efficiency. In this work the focus has been on evaluating the status of existing swept regions of a mature CO{sub 2} flood and developing procedures to improve the design of proposed floods. The Little Creek Field, Mississippi has been studied through laboratory, theoretical, numerical and simulation studies in an attempt to relate performance predictions to historical reservoir performance to determine sweep efficiency, improve the understanding of the reservoir response to CO{sub 2} injection, and develop scaling methodologies to relate laboratory data and simulation results to predicted reservoir behavior. Existing laboratory information from Little Creek was analyzed and an extensive amount of field data was collected. This was merged with an understanding of previous work at Little Creek to generate a detailed simulation study of two portions of the field – the original pilot area and a currently active part of the field. This work was done to try to relate all of this information to an understanding

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

    Directory of Open Access Journals (Sweden)

    Charlotte J. Beurskens

    2014-01-01

    Full Text Available 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 ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen. A fixed protective ventilation protocol (6 mL/kg was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P<0.017. Results. During heliox ventilation, respiratory rate decreased (25±4 versus 23±5 breaths min−1, P=0.010. Minute volume ventilation showed a trend to decrease compared to baseline (11.1±1.9 versus 9.9±2.1 L min−1, P=0.026, while reducing PaCO2 levels (5.0±0.6 versus 4.5±0.6 kPa, P=0.011 and peak pressures (21.1±3.3 versus 19.8±3.2 cm H2O, P=0.024. Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

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

    Science.gov (United States)

    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 ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P < 0.017. Results. During heliox ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min(-1), P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min(-1), P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation. PMID:25548660

  6. Performance improvement options for the supercritical carbon dioxide brayton cycle

    International Nuclear Information System (INIS)

    The supercritical carbon dioxide (S-CO2) Brayton cycle is under development at Argonne National Laboratory as an advanced power conversion technology for Sodium-Cooled Fast Reactors (SFRs) as well as other Generation IV advanced reactors as an alternative to the traditional Rankine steam cycle. For SFRs, the S-CO2 Brayton cycle eliminates the need to consider sodium-water reactions in the licensing and safety evaluation, reduces the capital cost of the SFR plant, and increases the SFR plant efficiency. Even though the S-CO2 cycle has been under development for some time and optimal sets of operating parameters have been determined, those earlier development and optimization studies have largely been directed at applications to other systems such as gas-cooled reactors which have higher operating temperatures than SFRs. In addition, little analysis has been carried out to investigate cycle configurations deviating from the selected 'recompression' S-CO2 cycle configuration. In this work, several possible ways to improve S-CO2 cycle performance for SFR applications have been identified and analyzed. One set of options incorporates optimization approaches investigated previously, such as variations in the maximum and minimum cycle pressure and minimum cycle temperature, as well as a tradeoff between the component sizes and the cycle performance. In addition, the present investigation also covers options which have received little or no attention in the previous studies. Specific options include a 'multiple-recompression' cycle configuration, intercooling and reheating, as well as liquid-phase CO2 compression (pumping) either by CO2 condensation or by a direct transition from the supercritical to the liquid phase. Some of the options considered did not improve the cycle efficiency as could be anticipated beforehand. Those options include: a double recompression cycle, intercooling between the compressor stages, and reheating between the turbine stages. Analyses carried

  7. Improved manometric setup for the accurate determination of supercritical carbon dioxide sorption

    NARCIS (Netherlands)

    Van Hemert, P.; Bruining, H.; Rudolph, E.S.J.; Wolf, K.H.A.A.; Maas, J.G.

    2009-01-01

    An improved version of the manometric apparatus and its procedures for measuring excess sorption of supercritical carbon dioxide are presented in detail with a comprehensive error analysis. An improved manometric apparatus is necessary for accurate excess sorption measurements with supercritical car

  8. Carbon dioxide and climate

    International Nuclear Information System (INIS)

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

  9. Improvement of Microstomia in Scleroderma after Carbon Dioxide Laser Treatment.

    Science.gov (United States)

    Bennani, Imane; Lopez, Raphael; Bonnet, Delphine; Prevot, Gregoire; Constantin, Arnaud; Chauveau, Dominique; Paul, Carle; Bulai Livideanu, Cristina

    2016-01-01

    Limited mouth opening (LMO) is a frequent complication of systemic sclerosis (SS). Its management is complex and there are limited treatment options. We report four patients with SS and severe LMO [interincisal distance (IID) Handicap in Systemic Sclerosis (MHISS) scale and global evaluation by the patients. Adverse events were also reported. In all four patients, an improvement in IID occurred 3 months after the first session with a mean gain of +5 mm (range: 2-7). At 12 months, a mean gain of +8.5 mm (range: 7-10) in IID was observed. The MHISS score decreased by a mean of •14 (range: 11-17). All patients showed improvement of lip flexibility or mouth opening, allowing better phonation and mastication and easier dental care. Adverse effects were transient erythema and/or dyschromia. CO2 laser appears to be effective and well tolerated in the improvement of LMO in SS. PMID:27403126

  10. Improvement of Microstomia in Scleroderma after Carbon Dioxide Laser Treatment

    Directory of Open Access Journals (Sweden)

    Imane Bennani

    2016-05-01

    Full Text Available Limited mouth opening (LMO is a frequent complication of systemic sclerosis (SS. Its management is complex and there are limited treatment options. We report four patients with SS and severe LMO [interincisal distance (IID 2 laser. Pulsed CO2 laser treatment of the white lips was performed after all patients had signed a written informed consent in the absence of alternative treatment. Treatment was carried out under locoregional anaesthesia using a Sharplan 30C CO2 laser in the Silk Touch® resurfacing mode. One to three laser sessions were performed at intervals of 8-12 months between sessions. Assessments were performed at 3 and 12 months with measurement of the IID using a ruler, calculation of the Mouth Handicap in Systemic Sclerosis (MHISS scale and global evaluation by the patients. Adverse events were also reported. In all four patients, an improvement in IID occurred 3 months after the first session with a mean gain of +5 mm (range: 2-7. At 12 months, a mean gain of +8.5 mm (range: 7-10 in IID was observed. The MHISS score decreased by a mean of -14 (range: 11-17. All patients showed improvement of lip flexibility or mouth opening, allowing better phonation and mastication and easier dental care. Adverse effects were transient erythema and/or dyschromia. CO2 laser appears to be effective and well tolerated in the improvement of LMO in SS.

  11. Improved breath alcohol analysis with use of carbon dioxide as the tracer gas

    OpenAIRE

    Kaisdotter Andersson, Annika

    2010-01-01

    State-of-the-art breath analysers require a prolonged expiration into a mouthpiece to obtain the accuracy required for evidential testing and screening of the alcohol concentration. This requirement is unsuitable for breath analysers used as alcolock owing to their frequent use and the fact that the majority of users are sober drivers; as well as for breath testing in uncooperative persons. This thesis presents a method by which breath alcohol analysis can be improved, using carbon dioxide (C...

  12. Carbon Dioxide Fountain

    Science.gov (United States)

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

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

  13. Improving Settling Characteristics of Pure Oxygen Activated Sludge by Stripping of Carbon Dioxide.

    Science.gov (United States)

    Kundral, Somshekhar; Mudragada, Ratnaji; Coro, Ernesto; Moncholi, Manny; Mora, Nelson; Laha, Shonali; Tansel, Berrin

    2015-06-01

    Increased microbial activity at high ambient temperatures can be problematic for secondary clarifiers and gravity concentrators due to carbon dioxide (CO2) production. Production of CO2 in gravity concentrators leads to septic conditions and poor solids separation. The CO2 production can also be corrosive for the concrete surfaces. Effectiveness of CO2 stripping to improve solids settling was investigated using the sludge volume index (SVI) as the indicator parameter. Carbon dioxide was stripped by aeration from the sludge samples. Results from the study show that aeration also increased the pH values in the mixed liquor while removing CO2 and improving sludge settling. After 10 minutes of aeration at a rate of 0.37 m3 air/m3 water/min, 90% CO2 stripping was achieved. Based on the 30 min settling tests, the SVI increased by 26±1% after CO2 stripping while the pH increased by 0.8±0.1 pH units. PMID:26459818

  14. Improvement of Carbon Dioxide Sweep Efficiency by Utilization of Microbial Permeability Profile Modification to Reduce the Amount of Oil Bypassed During Carbon Dioxide Flood

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Darrel [Mississippi State Univ., Mississippi State, MS (United States); Brown, Lewis [Mississippi State Univ., Mississippi State, MS (United States); Lynch, F. Leo [Mississippi State Univ., Mississippi State, MS (United States); Kirkland, Brenda L. [Mississippi State Univ., Mississippi State, MS (United States); Collins, Krystal M. [Mississippi State Univ., Mississippi State, MS (United States); Funderburk, William K. [Mississippi State Univ., Mississippi State, MS (United States)

    2010-12-31

    The objective of this project was to couple microbial permeability profile modification (MPPM), with carbon dioxide flooding to improve oil recovery from the Upper Cretaceous Little Creek Oil Field situated in Lincoln and Pike counties, MS. This study determined that MPPM technology, which improves production by utilizing environmentally friendly nutrient solutions to simulate the growth of the indigenous microflora in the most permeable zones of the reservoir thus diverting production to less permeable, previously unswept zones, increased oil production without interfering with the carbon dioxide flooding operation. Laboratory tests determined that no microorganisms were produced in formation waters, but were present in cores. Perhaps the single most significant contribution of this study is the demonstration that microorganisms are active at a formation temperature of 115°C (239°F) by using a specially designed culturing device. Laboratory tests were employed to simulate the MPPM process by demonstrating that microorganisms could be activated with the resulting production of oil in coreflood tests performed in the presence of carbon dioxide at 66°C (the highest temperature that could be employed in the coreflood facility). Geological assessment determined significant heterogeneity in the Eutaw Formation, and documented relatively thin, variably-lithified, well-laminated sandstone interbedded with heavily-bioturbated, clay-rich sandstone and shale. Live core samples of the Upper Cretaceous Eutaw Formation from the Heidelberg Field, MS were quantitatively assessed using SEM, and showed that during MPPM permeability modification occurs ubiquitously within pore and throat spaces of 10-20 μm diameter. Testing of the MPPM procedure in the Little Creek Field showed a significant increase in production occurred in two of the five production test wells; furthermore, the decline curve in each of the production wells became noticeably less steep. This project greatly

  15. 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.

  16. 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).

  17. Carbon dioxide recycling

    Science.gov (United States)

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

  18. Improving high carbon dioxide tolerance and carbon dioxide fixation capability of Chlorella sp. by adaptive laboratory evolution.

    Science.gov (United States)

    Li, Dengjin; Wang, Liang; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

    2015-06-01

    CO2 capture by microalgae is a promising method to reduce greenhouse gas emissions. It is critical to construct a highly efficient way to obtain a microalgal strain tolerant to high CO2 concentrations with high CO2 fixation capability. In this study, two evolved Chlorella sp. strains, AE10 and AE20 were obtained after 31 cycles of adaptive laboratory evolution (ALE) under 10% and 20% CO2, respectively. Both of them grew rapidly in 30% CO2 and the maximal biomass concentration of AE10 was 3.68±0.08g/L, which was 1.22 and 2.94 times to those of AE20 and original strain, respectively. The chlorophyll contents of AE10 and AE20 were significantly higher than those of the original one under 1-30% CO2. The influences of ALE process on biochemical compositions of Chlorella cells were also investigated. This study proved that ALE was an effective approach to improve high CO2 tolerance of Chlorella sp.

  19. PERFORMANCE IMPROVEMENTS IN COMMERCIAL HEAT PUMP WATER HEATERS USING CARBON DIOXIDE

    Energy Technology Data Exchange (ETDEWEB)

    BOWERS C.D.; ELBEL S.; PETERSEN M.; HRNJAK P.S.

    2011-07-01

    Although heat pump water heaters are today widely accepted in Japan, where energy costs are high and government incentives for their use exist, acceptance of such a product in the U.S. has been slow. This trend is slowly changing with the introduction of heat pump water heaters into the residential market, but remains in the commercial sector. Barriers to heat pump water heater acceptance in the commercial market have historically been performance, reliability and first/operating costs. The use of carbon dioxide (R744) as the refrigerant in such a system can improve performance for relatively small increase in initial cost and make this technology more appealing. What makes R744 an excellent candidate for use in heat pump water heaters is not only the wide range of ambient temperatures within which it can operate, but also the excellent ability to match water to refrigerant temperatures on the high side, resulting in very high exit water temperatures of up to 82ºC (180ºF), as required by sanitary codes in the U.S.(Food Code, 2005), in a single pass, temperatures that are much more difficult to reach with other refrigerants. This can be especially attractive in applications where this water is used for the purpose of sanitation. While reliability has also been of concern historically, dramatic improvements have been made over the last several years through research done in the automotive industry and commercialization of R744 technology in residential water heating mainly in Japan. This paper presents the performance results from the development of an R744 commercial heat pump water heater of approximately 35kW and a comparison to a baseline R134a unit of the same capacity and footprint. In addition, recommendations are made for further improvements of the R744 system which could result in possible energy savings of up to 20%.

  20. NEXT GENERATION COMMERCIAL HEAT PUMPWATER HEATER USING CARBON DIOXIDE USING DIFFERENT IMPROVEMENT APPROACHES

    Energy Technology Data Exchange (ETDEWEB)

    Chad Bowers; Michael Petersen; Stefan Elbel; Pega Hrnjak

    2012-04-01

    Although heat pump water heaters are today widely accepted in Japan, where energy costs are high and government incentives for their use exist, acceptance of such a product in the U.S. has been slow. This trend is slowly changing with the introduction of heat pump water heaters into the residential market, but remains in the commercial sector. Barriers to heat pump water heater acceptance in the commercial market have historically been performance, reliability and first/operating costs. The use of carbon dioxide (R744) as the refrigerant in such a system can improve performance for relatively small increase in initial cost and make this technology more appealing. What makes R744 an excellent candidate for use in heat pump water heaters is not only the wide range of ambient temperatures within which it can operate, but also the excellent ability to match water to refrigerant temperatures on the high side, resulting in very high exit water temperatures of up to 82ºC, as required by sanitary codes in the U.S. (Food Code, 2005), in a single pass, temperatures that are much more difficult to reach with other refrigerants. This can be especially attractive in applications where this water is used for the purpose of sanitation. While reliability has also been of concern historically, dramatic improvements have been made over the last several years through research done in the automotive industry and commercialization of R744 technology in residential water heating mainly in Japan. This paper presents the performance results from the development of an R744 commercial heat pump water heater of approximately 35 kW and a comparison to a baseline R134a unit of the same capacity and footprint. In addition, recommendations are made for further improvements of the R744 system which could result in possible energy savings of up to 20 %.

  1. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  2. 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.

  3. Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh

    2006-06-01

    Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for stateof-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency.

  4. A New and Improved Carbon Dioxide Isotope Analyzer for Understanding Soil-Plant-Atmosphere Interactions

    Science.gov (United States)

    Huang, Y. W.; Berman, E. S.; Owano, T. G.; Verfaillie, J. G.; Oikawa, P. Y.; Baldocchi, D. D.; Still, C. J.; Gardner, A.; Baer, D. S.; Rastogi, B.

    2015-12-01

    Stable CO2 isotopes provide information on biogeochemical processes that occur at the soil-plant-atmosphere interface. While δ13C measurement can provide information on the sources of the CO2, be it photosynthesis, natural gas combustion, other fossil fuel sources, landfills or other sources, δ18O, and δ17O are thought to be determined by the hydrological cycling of the CO2. Though researchers have called for analytical tools for CO2 isotope measurements that are reliable and field-deployable, developing such instrument remains a challenge. The carbon dioxide isotope analyzer developed by Los Gatos Research (LGR) uses LGR's patented Off-Axis ICOS (Integrated Cavity Output Spectroscopy) technology and incorporates proprietary internal thermal control for high sensitivity and optimal instrument stability. This new and improved analyzer measures CO2 concentration as well as δ13C, δ18O, and δ17O from CO2 at natural abundance (150-2500 ppm). The laboratory precision is ±200 ppb (1σ) in CO2 at 1 s, with a long-term (2 min) precision of ±20 ppb. The 1-second precision for both δ13C and δ18O is 0.7 ‰, and for δ17O is 1.8 ‰. The long-term (2 min) precision for both δ13C and δ18O is 0.08 ‰, and for δ17O is 0.18 ‰. The instrument has improved precision, stability and user interface over previous LGR CO2 isotope instruments and can be easily programmed for periodic referencing and sampling from different sources when coupled with LGR's multiport inlet unit (MIU). We have deployed two of these instruments at two different field sites, one at Twitchell Island in Sacramento County, CA to monitor the CO2 isotopic fluxes from an alfalfa field from 6/29/2015-7/13/2015, and the other at the Wind River Experimental Forest in Washington to monitor primarily the oxygen isotopes of CO2 within the canopy from 8/4/2015 through mid-November 2015. Methodology, laboratory development and testing and field performance are presented.

  5. 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)

  6. 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

  7. Effect of hypotension and carbon dioxide changes in an improved genuine closed cranial window rat model

    DEFF Research Database (Denmark)

    Petersen, K A; Dyrby, Lone; Williamson, D;

    2005-01-01

    The genuine closed cranial window model, in which the thinned parietal bone constitutes the covering of the preparation, has contributed to a better understanding of the pathophysiological mechanisms in migraine. In its present form, only measurements of the middle meningeal artery (MMA) are...... performed. The aim of this study was, in addition, to measure pial artery/arteriole (PA) diameter and cortical cerebral blood flux in the same cranial window. The model was evaluated by studying the effects of hypotension and changes in arterial carbon dioxide pressure (PaCO2), because these parameters...... might influence the interpretation of pharmacological experiments. Out of 23 successful experiments it was possible to measure all three parameters in 19 animals. In four, PA diameter could not be measured, while MMA diameter and local cortical cerebral blood flux (LCBF(Flux)) always could. Haemorrhage...

  8. 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.

  9. Carbon dioxide sequestration by mineral carbonation

    OpenAIRE

    Huijgen, W.J.J.

    2007-01-01

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

  10. Surface Engineering of Polypropylene Membranes with Carbonic Anhydrase-Loaded Mesoporous Silica Nanoparticles for Improved Carbon Dioxide Hydration.

    Science.gov (United States)

    Yong, Joel K J; Cui, Jiwei; Cho, Kwun Lun; Stevens, Geoff W; Caruso, Frank; Kentish, Sandra E

    2015-06-01

    Carbonic anhydrase (CA) is a native enzyme that facilitates the hydration of carbon dioxide into bicarbonate ions. This study reports the fabrication of thin films of active CA enzyme onto a porous membrane substrate using layer-by-layer (LbL) assembly. Deposition of multilayer films consisting of polyelectrolytes and CA was monitored by quartz crystal microgravimetry, while the enzymatic activity was assayed according to the rates of p-nitrophenylacetate (p-NPA) hydrolysis and CO2 hydration. The fabrication of the films onto a nonporous glass substrate showed CO2 hydration rates of 0.52 ± 0.09 μmol cm(-2) min(-1) per layer of bovine CA and 2.6 ± 0.7 μmol cm(-2) min(-1) per layer of a thermostable microbial CA. The fabrication of a multilayer film containing the microbial CA on a porous polypropylene membrane increased the hydration rate to 5.3 ± 0.8 μmol cm(-2) min(-1) per layer of microbial CA. The addition of mesoporous silica nanoparticles as a film layer prior to enzyme adsorption was found to increase the activity on the polypropylene membranes even further to a rate of 19 ± 4 μmol cm(-2) min(-1) per layer of microbial CA. The LbL treatment of these membranes increased the mass transfer resistance of the membrane but decreased the likelihood of membrane pore wetting. These results have potential application in the absorption of carbon dioxide from combustion flue gases into aqueous solvents using gas-liquid membrane contactors. PMID:25984966

  11. Increased C availability at elevated carbon dioxide concentration improves N assimilation in a legume.

    Science.gov (United States)

    Rogers, Alistair; Gibon, Yves; Stitt, Mark; Morgan, Patrick B; Bernacchi, Carl J; Ort, Donald R; Long, Stephen P

    2006-08-01

    Plant growth is typically stimulated at elevated carbon dioxide concentration ([CO2]), but a sustained and maximal stimulation of growth requires acquisition of additional N in proportion to the additional C fixed at elevated [CO2]. We hypothesized that legumes would be able to avoid N limitation at elevated [CO2]. Soybean was grown without N fertilizer from germination to final senescence at elevated [CO2] over two growing seasons under fully open-air conditions, providing a model legume system. Measurements of photosynthesis and foliar carbohydrate content showed that plants growing at elevated [CO2] had a c. 25% increase in the daily integral of photosynthesis and c. 58% increase in foliar carbohydrate content, suggesting that plants at elevated [CO2] had a surplus of photosynthate. Soybeans had a low leaf N content at the beginning of the season, which was a further c. 17% lower at elevated [CO2]. In the middle of the season, ureide, total amino acid and N content increased markedly, and the effect of elevated [CO2] on leaf N content disappeared. Analysis of individual amino acid levels supported the conclusion that plants at elevated [CO2] overcame an early-season N limitation. These soybean plants showed a c. 16% increase in dry mass at final harvest and showed no significant effect of elevated [CO2] on leaf N, protein or total amino acid content in the latter part of the season. One possible explanation for these findings is that N fixation had increased, and that these plants had acclimated to the increased N demand at elevated [CO2]. PMID:16898025

  12. Recuperative supercritical carbon dioxide cycle

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Carbon Dioxide - Our Common "Enemy"

    Science.gov (United States)

    James, John T.; Macatangay, Ariel

    2009-01-01

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

  14. 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.

  15. Carbon dioxide kinetics and capnography during critical care

    OpenAIRE

    Anderson, Cynthia T; Breen, Peter H

    2000-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

  17. 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.

  18. 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…

  19. 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...

  20. The effect of oil on carbon dioxide corrosion inhibition on carbon steel - potential for improved corrosion protection

    International Nuclear Information System (INIS)

    The search for robust and cost efficient ways to prevent internal corrosion of carbon steel piping and equipment in oil and gas production and transportation has lead to the development of highly sophisticated CO2 corrosion inhibitor products. This thesis studies oil wetting and corrosion inhibitor performance on bare steel and steel with corrosion product deposits on the surface, in the presence of a refined, low aromatic hydrocarbon oil. Three surfactants were used in the experiments; two commercial inhibitor base chemicals; an oleic imidazoline salt (OI) and a phosphate ester (PE), and cetyl trimethyl ammonium bromide (CTAB), a well characterized quaternary ammonium compound. Adsorption characteristics of the inhibitors on corroding iron and FeCO3 particles were also studied. Polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) techniques were used to study the effect of the oil on the performance of the inhibitors. The performance testing was done on corroding carbon steel without any surface deposits and on carbon steel with either ferrous carbonate (FeCO3) or ferric corrosion products on the surface. The results showed that the addition of oil in the inhibitor tests had a significant, positive effect on the performance of the two commercial corrosion inhibitors; decrease in corrosion rate of about one order of magnitude compared to the rate without oil was found. Based on the EIS data it was concluded that the improved performance was caused by a modification of the inhibitor film and not the formation of a macroscopic oil film on the steel surface. Indications of oil wetting of the steel surface were only found when ferric corrosion products were present and OI was used as the inhibitor. No such effects were seen on bare steel or on FeCO3 covered surfaces. Contact angle measurements and dispersion tests were used to investigate the effect of the inhibitors on the wettability of the three types of surfaces when they were exposed to

  1. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  3. 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.

  4. Improved determination of daytime net ecosystem exchange of carbon dioxide at croplands

    Science.gov (United States)

    Zhao, P.; Lüers, J.

    2012-03-01

    The eddy-covariance technique is applied worldwide to acquire information about carbon exchange between a variety of ecosystems and atmosphere, but the data acquisition only covers, on average, two-thirds of the whole year due to system failures and data rejection. Therefore, data must be corrected and data gaps must be filled to provide seasonal or annual budgets. The gap-filing strategies, however, are still under discussion within the research community. Presently the major gap-filling methods work quite well for long-time running sites over slow-developing biosphere surfaces such as long-living evergreen forests, but difficulties appear for short-living and fast-growing croplands. In this study we developed a new Multi-Step Error Filter procedure to gain good-quality data as input for different parameterizations of the light response function of plants for two cropland sites (rice and potatoes), and we could prove that the conventional temperature binning approach is inadequate. The presented time-window scheme showed best results with a four-day time window for the potato field and an eight-day time window for the rice field. The influence of vapor pressure deficit was tested as well, but in our case it plays a minor role at both the potato and the rice fields with the exception of the early growing stage of the potatoes. Completing our research, we suggest an innovative method by introducing a Leaf Area Index factor to capture the seasonal vegetation development. With this method we are now able to fill the large gaps between observation periods when conventional methods are invalid.

  5. Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California

    Energy Technology Data Exchange (ETDEWEB)

    de la Rue du Can, Stephane; Wenzel, Tom; Price, Lynn

    2008-08-13

    Central to any study of climate change is the development of an emission inventory that identifies and quantifies the State's primary anthropogenic sources and sinks of greenhouse gas (GHG) emissions. CO2 emissions from fossil fuel combustion accounted for 80 percent of California GHG emissions (CARB, 2007a). Even though these CO2 emissions are well characterized in the existing state inventory, there still exist significant sources of uncertainties regarding their accuracy. This report evaluates the CO2 emissions accounting based on the California Energy Balance database (CALEB) developed by Lawrence Berkeley National Laboratory (LBNL), in terms of what improvements are needed and where uncertainties lie. The estimated uncertainty for total CO2 emissions ranges between -21 and +37 million metric tons (Mt), or -6percent and +11percent of total CO2 emissions. The report also identifies where improvements are needed for the upcoming updates of CALEB. However, it is worth noting that the California Air Resources Board (CARB) GHG inventory did not use CALEB data for all combustion estimates. Therefore the range in uncertainty estimated in this report does not apply to the CARB's GHG inventory. As much as possible, additional data sources used by CARB in the development of its GHG inventory are summarized in this report for consideration in future updates to CALEB.

  6. Method for carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-22

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

  7. Oxygen and carbon dioxide sensing

    Science.gov (United States)

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

    2012-01-01

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

  8. Summer Ice and Carbon Dioxide

    Science.gov (United States)

    Kukla, G.; Gavin, J.

    1981-10-01

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

  9. Corrigendum to "Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields" [J. Power Sources 268 (5 December 2014) 439-442

    Science.gov (United States)

    Majidi, Pasha; Pickup, Peter G.

    2016-09-01

    The authors regret that Equation (5) is incorrect and has resulted in errors in Fig. 4 and the efficiencies stated on p. 442. The corrected equation, figure and text are presented below. In addition, the title should be 'Sinusoidal potential cycling operation of a direct ethanol fuel cell to improve carbon dioxide yields', and the reversible cell potential quoted on p. 441 should be 1.14 V. The authors would like to apologise for any inconvenience caused.

  10. Carbon dioxide emissions from biochar in soil

    DEFF Research Database (Denmark)

    Bruun, Sander; Clauson-Kaas, Anne Sofie Kjærulff; Bobuľská, 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......-sterilized soils. It emerged that carbonate may be concentrated or form during or after biochar production, resulting in significant carbonate contents. If CO2 released from carbonates in short-term experiments is misinterpreted as mineralization of biochar, the impact of this process may be significantly over......-estimated. In addition to the CO2 released from carbonates, there appears to be a labile fraction of biochar that is oxidized quickly during the first days of incubation, probably by both abiotic and biotic processes. Later in the incubation, biotic mineralization appears to be the primary cause of CO2 evolution...

  11. 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.

  12. Use of carbon monoxide combined with carbon dioxide for modified atmosphere packaging of pre- and postrigor fresh pork sausage to improve shelf life.

    Science.gov (United States)

    Laury, Angela; Sebranek, Joseph G

    2007-04-01

    Fresh pre- and postrigor pork sausage patties were manufactured in the Iowa State University Meat Laboratory and packaged either in modified atmosphere (MAP) with 0.4% carbon monoxide (CO) and 99.6% carbon dioxide (CO2) or on foam trays overwrapped with oxygen-permeable film (OW). Packages were stored at 2 to 40C under fluorescent lights for up to 31 days. Aerobic, anaerobic, and psychrotrophic plate counts, raw and cooked color, purge, and lipid oxidation were measured during storage. Results indicated that both pork sausage products in MAP had lower aerobic and psychrotrophic counts and less lipid oxidation throughout storage (P sausage in MAP benefited more from the CO atmosphere in terms of raw color than the postrigor pork sausage in MAP. Cooked color of the prerigor pork sausage in MAP was significantly redder than cooked color of the postrigor pork sausage. Both pork sausage products in MAP were also lighter (L* value) than the OW patties for raw and cooked color. Therefore, the combination of CO and CO2 in MAP was beneficial in extending the shelf life of pre-and postrigor fresh pork sausage by reducing aerobic and psychrotrophic microbial growth and improving oxidative stability and color, compared to conventional OW packaging. However, increased purge, increased anaerobic growth, and changes in cooking behavior were also observed for the products in MAP during storage (P < 0.05).

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  14. Solubility of Carbon Dioxide in Water.

    Science.gov (United States)

    Bush, Pat; And Others

    1992-01-01

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

  15. Transformation and utilization of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

  16. 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.

  17. 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...

  18. 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.

  19. Crew Health and Performance Improvements with Reduced Carbon Dioxide Levels and the Resource Impact to Accomplish Those Reductions

    Science.gov (United States)

    James, John T.; Meyers, Valerie E.; Sipes, Walter; Scully, Robert R.; Matty, Christopher M.

    2011-01-01

    Carbon dioxide (CO2) removal is one of the primary functions of the International Space Station (ISS) atmosphere revitalization systems. Primary CO2 removal is via the ISS s two Carbon Dioxide Removal Assemblies (CDRAs) and the Russian carbon dioxide removal assembly (Vozdukh); both of these systems are regenerable, meaning that their CO2 removal capacity theoretically remains constant as long as the system is operating. Contingency CO2 removal capability is provided by lithium hydroxide (LiOH) canisters, which are consumable, meaning that their CO2 removal capability disappears once the resource is used. With the advent of 6 crew ISS operations, experience showing that CDRA failures are not uncommon, and anecdotal association of crew symptoms with CO2 values just above 4 mmHg, the question arises: How much lower do we keep CO2 levels to minimize the risk to crew health and performance, and what will the operational cost to the CDRAs be to do it? The primary crew health concerns center on the interaction of increased intracranial pressure from fluid shifts and the increased intracranial blood flow induced by CO2. Typical acute symptoms include headache, minor visual disturbances, and subtle behavioral changes. The historical database of CO2 exposures since the beginning of ISS operations has been compared to the incidence of crew symptoms reported in private medical conferences. We have used this database in an attempt to establish an association between the CO2 levels and the risk of crew symptoms. This comparison will answer the question of the level needed to protect the crew from acute effects. As for the second part of the question, operation of the ISS s regenerable CO2 removal capability reduces the limited life of constituent parts. It also consumes limited electrical power and thermal control resources. Operation of consumable CO2 removal capability (LiOH) uses finite consumable materials, which must be replenished in the long term. Therefore, increased CO

  20. 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.

  1. 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....

  2. Improved Mobility Control for Carbon Dioxide (CO{sub 2}) Enhanced Oil Recovery Using Silica-Polymer-Initiator (SPI) Gels

    Energy Technology Data Exchange (ETDEWEB)

    Oglesby, Kenneth

    2014-01-31

    SPI gels are multi-component silicate based gels for improving (areal and vertical) conformance in oilfield enhanced recovery operations, including water-floods and carbon dioxide (CO{sub 2}) floods, as well as other applications. SPI mixtures are like-water when pumped, but form light up to very thick, paste-like gels in contact with CO{sub 2}. When formed they are 3 to 10 times stronger than any gelled polyacrylamide gel now available, however, they are not as strong as cement or epoxy, allowing them to be washed / jetted out of the wellbore without drilling. This DOE funded project allowed 8 SPI field treatments to be performed in 6 wells (5 injection wells and 1 production well) in 2 different fields with different operators, in 2 different basins (Gulf Coast and Permian) and in 2 different rock types (sandstone and dolomite). Field A was in a central Mississippi sandstone that injected CO{sub 2} as an immiscible process. Field B was in the west Texas San Andres dolomite formation with a mature water-alternating-gas miscible CO{sub 2} flood. Field A treatments are now over 1 year old while Field B treatments have only 4 months data available under variable WAG conditions. Both fields had other operational events and well work occurring before/ during / after the treatments making definitive evaluation difficult. Laboratory static beaker and dynamic sand pack tests were performed with Ottawa sand and both fields’ core material, brines and crude oils to improve SPI chemistry, optimize SPI formulations, ensure SPI mix compatibility with field rocks and fluids, optimize SPI treatment field treatment volumes and methods, and ensure that strong gels set in the reservoir. Field quality control procedures were designed and utilized. Pre-treatment well (surface) injectivities ranged from 0.39 to 7.9 MMCF/psi. The SPI treatment volumes ranged from 20.7 cubic meters (m{sup 3}, 5460 gallons/ 130 bbls) to 691 m{sup 3} (182,658 gallons/ 4349 bbls). Various size and types

  3. 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...

  4. 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.

  5. 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.

  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 capture by means of cyclic organic nitrogen compounds

    OpenAIRE

    García Abuín, Alicia

    2012-01-01

    The research work included in present PhD Thesis involves the research studies to capture carbon dioxide using different cyclic nitrogen organic compounds (glucosamine (GA), chitosan (C), alkyl-pyrrolidones, pyrrolidine (PYR) and piperidine (PIP). This investigation is based on the study of three experimental systems. Each of them has characteristics potentially suitable to achieve the aim of this work, that is to say, to improve the carbon dioxide capture process, which is pre...

  8. Carbon dioxide cleaning pilot project

    International Nuclear Information System (INIS)

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

  9. Nuclear power and carbon dioxide free automobiles

    International Nuclear Information System (INIS)

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

  10. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin

    2014-03-31

    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/tCO{sub 2} in carbon utilization. By the use of self‐concentrating absorption technology, high purity CO{sub 2} can be produced at a price below $40/t. With low cost CO{sub 2} 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 CO{sub 2}/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  11. 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.

  12. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

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

    2013-07-01

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

  13. 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...

  14. 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)...

  15. 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.”...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. Silver oxide sorbent for carbon dioxide

    Science.gov (United States)

    Colombo, G. V.

    1974-01-01

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

  2. Technical Note: Improving computational efficiency in large linear inverse problems: an example from carbon dioxide flux estimation

    Directory of Open Access Journals (Sweden)

    V. Yadav

    2012-10-01

    Full Text Available Addressing a variety of questions within Earth science disciplines entails the inference of the spatio-temporal distribution of parameters of interest based on observations of related quantities. Such estimation problems often represent inverse problems that are formulated as linear optimization problems. Computational limitations arise when the number of observations and/or the size of the discretized state space become large, especially if the inverse problem is formulated in a probabilistic framework and therefore aims to assess the uncertainty associated with the estimates. This work proposes two approaches to lower the computational costs and memory requirements for large linear space-time inverse problems, taking the Bayesian approach for estimating carbon dioxide (CO2 emissions and uptake (a.k.a. fluxes as a prototypical example. The first algorithm can be used to efficiently multiply two matrices, as long as one can be expressed as a Kronecker product of two smaller matrices, a condition that is typical when multiplying a sensitivity matrix by a covariance matrix in the solution of inverse problems. The second algorithm can be used to compute a posteriori uncertainties directly at aggregated spatio-temporal scales, which are the scales of most interest in many inverse problems. Both algorithms have significantly lower memory requirements and computational complexity relative to direct computation of the same quantities (O(n2.5 vs. O(n3. For an examined benchmark problem, the two algorithms yielded a three and six order of magnitude increase in computational efficiency, respectively, relative to direct computation of the same quantities. Sample computer code is provided for assessing the computational and memory efficiency of the proposed algorithms for matrices of different dimensions.

  3. 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...

  4. 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...

  5. Supercritical carbon dioxide hop extraction

    Directory of Open Access Journals (Sweden)

    Pfaf-Šovljanski Ivana I.

    2005-01-01

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

  6. Arterialisation of transcutaneous oxygen and carbon dioxide.

    OpenAIRE

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

    1988-01-01

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

  7. Turning carbon dioxide into fuel.

    Science.gov (United States)

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

    2010-07-28

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-30

    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.

  9. 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.

  10. 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

  11. 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

  12. Carbon dioxide and methane emissions from estuaries

    OpenAIRE

    Abril, G.; Borges, Alberto

    2005-01-01

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

  13. 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

    2014-01-01

    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.

  14. Synthesis of fluoropolymers in supercritical carbon dioxide

    International Nuclear Information System (INIS)

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

  15. Global deforestation: contribution to atmospheric carbon dioxide.

    Science.gov (United States)

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

    1983-12-01

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

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

    OpenAIRE

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

    1985-01-01

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

  17. Real-World Carbon Dioxide Impacts of Traffic Congestion

    OpenAIRE

    Barth, Matthew; Boriboonsomsin, Kanok

    2010-01-01

    Transportation plays a significant role in carbon dioxide (CO2) emissions, accounting for approximately a third of the U.S. inventory. To reduce CO2 emissions in the future, transportation policy makers are planning on making vehicles more efficient and increasing the use of carbon-neutral alternative fuels. In addition, CO2 emissions can be lowered by improving traffic operations, specifically through the reduction of traffic congestion. Traffic congestion and its impact on CO2 emissions wer...

  18. Magnesian calcite sorbent for carbon dioxide capture

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  19. 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.

  20. Conductive polymers for carbon dioxide sensing

    NARCIS (Netherlands)

    Doan, T.C.D.

    2012-01-01

    Augmented levels of carbon dioxide (CO2) in greenhouses stimulate plant growth through photosynthesis. Wireless sensor networks monitoring CO2 levels in greenhouses covering large areas require preferably low power sensors to minimize energy consumption. Therefore, the main obj

  1. 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

  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. 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.

  4. 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℃.

  5. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

    .... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a byproduct of the manufacture of lime during the “burning” of limestone, from the... processing aid as defined in § 170.3(o)(24) of this chapter; and a propellant, aerating agent, and gas...

  6. Carbon dioxide in European coastal waters

    NARCIS (Netherlands)

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

    2006-01-01

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

  7. 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...

  8. 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...

  9. 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...

  10. 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;...

  11. 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...

  12. 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...

  13. 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...

  14. Ocean uptake of carbon dioxide

    International Nuclear Information System (INIS)

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

  15. The improvement by a CVD silica coating of the oxidation behaviour of a 20%Cr/25%Ni niobium stabilized stainless steel in carbon dioxide

    International Nuclear Information System (INIS)

    The improvement of the oxidation behaviour of the 20%Cr-25%Ni-Nb stabilized (20/25/Nb) austenitic stainless steel, in carbon dioxide, by a silica coating, formed by a vapour reaction upon the pre-oxidized steel surface, has been examined at 8250C. The exposure periods extended to 5975 h duration. The silica coating effectiveness increased with its thickness over the range examined, 0.5 to 27 μm. Coatings > approximately 2 μm thick reduced the extent of oxidation by at least a factor of five by providing a barrier to the diffusion of cations outwards and oxidant inwards responsible for oxide growth on the 20/25/Nb steel. In addition, they completely inhibited oxide spallation because oxidation of the steel constituents occurred primarily within the silica coating whose adherence was maintained throughout the exposure. During the prolonged heat treatment of > approximately 2 μm thick silica coated steel, the iron and nickel constituents in the precoating oxide film were reduced by solid-solid reaction with manganese and probably also chromium from the underlying steel. (author)

  16. Improving the batch-to-batch reproducibility of microbial cultures during recombinant protein production by regulation of the total carbon dioxide production.

    Science.gov (United States)

    Jenzsch, Marco; Gnoth, Stefan; Kleinschmidt, Martin; Simutis, Rimvydas; Lübbert, Andreas

    2007-03-10

    Batch-to-batch reproducibility of fermentation processes performed during the manufacturing processes of biologics can be increased by operating the cultures at feed rate profiles that are robust against typically arising disturbances. Remaining randomly appearing deviations from the desired path should be suppressed automatically by manipulating the feed rate. With respect to the cells' physiology it is best guiding the cultivations along an optimal profile of the specific biomass growth rate mu(t). However, there are two problems that speak for further investigations: Upon severe disturbances that may happen during the fermentation, the biomass concentration X may significantly deviate from its desired value, then a fixed mu-profile leads to a diminished batch-to-batch reproducibility. Second, the specific growth rate cannot easily be estimated online to a favourably high accuracy, hence it is difficult to determine the deviations in mu from the desired profile. The alternative discussed here solves both problems by keeping the process at the corresponding total cumulative carbon dioxide production-profile: it is robust against distortions in X and the controlled variable can accurately be measured online during cultivations of all relevant sizes. As compared to the fermentation practice currently used in industry, the experimental results, presented at the example of a recombinant protein production with Escherichia coli cells, show that CPR-based corrections lead to a considerably improved batch-to-batch reproducibility.

  17. 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.

  18. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Science.gov (United States)

    2010-07-01

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

  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. 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)....

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

    International Nuclear Information System (INIS)

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

  3. 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.

  4. 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.

  5. Carbon dioxide in vascular imaging and intervention

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

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

  6. Carbon dioxide in vascular imaging and intervention.

    Science.gov (United States)

    Yang, X; Manninen, H; Soimakallio, S

    1995-07-01

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

  7. Supercritical carbon dioxide decontamination of PAH contaminants

    International Nuclear Information System (INIS)

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

  8. Carbon dioxide in vascular imaging and intervention

    International Nuclear Information System (INIS)

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

  9. Improved analysis of column carbon dioxide and methane data from ground-based Miniaturized Laser Heterodyne Radiometer (Mini-LHR)

    Science.gov (United States)

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

    2014-12-01

    We present an improved data analysis for the Mini-LHR column measurements of CO2 and CH4 that includes corrections for refraction through the atmosphere and meteorological conditions. Multi-scan averaging has also been added to compensate for current shot noise limitations and improve instrument sensitivity. Data with the improved analysis will be shown for field measurements at the TCCON site at CalTech (March 2014), Calpoly during COW-Gas (March 2014), at Mauna Loa Observatory (May 2013), and Atwater, CA (February 2013). The Mini-LHR is a miniaturized version of a laser heterodyne radiometer that implements telecommunications lasers and components to produce a significantly reduced size, low-cost instrument. Laser heterodyne radiometry has been used since the 1970s to measure atmospheric gases such as ozone, water vapor, methane, ammonia, chlorine monoxide, and nitrous oxide. The Mini-LHR is passive and uses sunlight as the primary light source to measure absorption of CO2 and CH4 in the infrared. Sunlight is collected with collimation optics mounted to the AERONET sun tracker and superimposed with laser light in a single mode fiber coupler. The signals are mixed in a fast photoreceiver (InGaAs detector), and the RF (radio frequency) beat signal is extracted. Changes in concentration of the trace gas are realized through analyzing changes in the beat frequency amplitude. In addition to the complementary aerosol optical depth measurement, tandem operation with AERONET provides a clear pathway for the mini-LHR to be expanded into a global monitoring network. AERONET has more than 450 instruments worldwide and offers coverage in key arctic regions (not covered by OCO-2) where accelerated warming due to the release of CO2 and CH4 from thawing tundra and permafrost is a concern. A mini-LHR global ground network can also provide an uninterrupted data record that will both bridge gaps in data sets and offer validation for key flight missions such as OCO-2, OCO-3, and

  10. 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.

  11. 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.

  12. Plasma beam discharge in carbon dioxide

    International Nuclear Information System (INIS)

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

  13. 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...

  14. 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.

  15. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-03-01

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

  16. 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

  17. Increased carbon dioxide concentration improves the antioxidative properties of the Malaysian herb kacip fatimah (Labisia pumila Blume).

    Science.gov (United States)

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E

    2011-01-01

    A randomized complete randomized design (RCBD) 3 by 3 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites (total phenolics, TP; total flavonoids, TF), gluthatione (GSH), oxidized gluthatione (GSSG), soluble carbohydrate and antioxidant activities of the Malaysian medicinal herb Labisia pumila Blume under three levels of CO₂ enrichment (400, 800 and 1,200 µmol mol⁻¹) for 15 weeks. It was found that the treatment effects were solely contributed by interaction of CO₂ levels and secondary metabolites distribution in plant parts, GSH, GSHH and antioxidant activities (peroxyl radicals (ROO), superoxide radicals (O₂), hydrogen peroxide (H₂O₂) and hydroxyl radicals (OH). The records of secondary metabolites, glutahione, oxidized gluthathione and antioxidant activities in a descending manner came from the leaf enriched with 1,200 µmol/mol CO₂ > leaf 800 µmol/mol CO₂ > leaf 400 µmol/mol CO₂ > stem 1,200 µmol/mol CO₂ > stem 800 µmol/mol CO₂ > stem 400 µmol/mol CO₂ > root 1,200 µmol/mol CO₂ > root 800 µmol/mol CO₂ > root 400 µmol/mol CO₂. Correlation analyses revealed strong significant positive coefficients of antioxidant activities with total phenolics, flavonoids, GSH and GSHH indicating that an increase in antioxidative activity of L. pumila under elevated CO₂ might be up-regulated by the increase in production of total phenolics, total flavonoids, GSH, GSHH and soluble sugar. This study implied that the medicinal potential of herbal plant such as L. pumila can be enhanced under elevated CO₂, which had simultaneously improved the antioxidative activity that indicated by the high oxygen radical absorbance activity against ROO, O₂, H₂O₂, and OH radicals. PMID:21775936

  18. Increased Carbon Dioxide Concentration Improves the Antioxidative Properties of the Malaysian Herb Kacip Fatimah (Labisia pumila Blume

    Directory of Open Access Journals (Sweden)

    Mohd Hafiz Ibrahim

    2011-07-01

    Full Text Available A randomized complete randomized design (RCBD 3 by 3 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites (total phenolics, TP; total flavonoids, TF, gluthatione (GSH, oxidized gluthatione (GSSG, soluble carbohydrate and antioxidant activities of the Malaysian medicinal herb Labisia pumila Blume under three levels of CO2 enrichment (400, 800 and 1,200 µmol mol−1 for 15 weeks. It was found that the treatment effects were solely contributed by interaction of CO2 levels and secondary metabolites distribution in plant parts, GSH, GSHH and antioxidant activities (peroxyl radicals (ROO, superoxide radicals (O2, hydrogen peroxide (H2O2 and hydroxyl radicals (OH. The records of secondary metabolites, glutahione, oxidized gluthathione and antioxidant activities in a descending manner came from the leaf enriched with 1,200 µmol/mol CO2 > leaf 800 µmol/mol CO2 > leaf 400 µmol/mol CO2 > stem 1,200 µmol/mol CO2 > stem 800 µmol/mol CO2 > stem 400 µmol/mol CO2 > root 1,200 µmol/mol CO2 > root 800 µmol/mol CO2 > root 400 µmol/mol CO2. Correlation analyses revealed strong significant positive coefficients of antioxidant activities with total phenolics, flavonoids, GSH and GSHH indicating that an increase in antioxidative activity of L. pumila under elevated CO2 might be up-regulated by the increase in production of total phenolics, total flavonoids, GSH, GSHH and soluble sugar. This study implied that the medicinal potential of herbal plant such as L. pumila can be enhanced under elevated CO2, which had simultaneously improved the antioxidative activity that indicated by the high oxygen radical absorbance activity against ROO, O2, H2O2, and OH radicals.

  19. Will peak oil accelerate carbon dioxide emissions?

    Science.gov (United States)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  20. Automated carbon dioxide cleaning system

    Science.gov (United States)

    Hoppe, David T.

    1991-01-01

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

  1. Enzymatic conversion of carbon dioxide.

    Science.gov (United States)

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

    2015-10-01

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

  2. Improved ionic model of liquid uranium dioxide

    NARCIS (Netherlands)

    Gryaznov, [No Value; Iosilevski, [No Value; Yakub, E; Fortov, [No Value; Hyland, GJ; Ronchi, C

    2000-01-01

    The paper presents a model for liquid uranium dioxide, obtained by improving a simplified ionic model, previously adopted to describe the equation of state of this substance [1]. A "chemical picture" is used for liquid UO2 of stoichiometric and non-stoichiometric composition. Several ionic species a

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

    International Nuclear Information System (INIS)

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

  4. 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.

  5. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ....102-1, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1...) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon...

  6. 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.

  7. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-01

    This report describes research conducted between April 1, 2003 and June 30, 2003 on the use of dry regenerable sorbents for concentration of carbon dioxide from flue gas. Grade 1 sodium bicarbonate performed similarly to grade 5 sodium bicarbonate in fixed bed testing in that activity improved after the first carbonation cycle and did not decline over the course of 5 cycles. Thermogravimetric analysis indicated that sodium bicarbonate sorbents produced by calcination of sodium bicarbonate are superior to either soda ash or calcined trona. Energy requirements for regeneration of carbon dioxide sorbents (either wet or dry) is of primary importance in establishing the economic feasibility of carbon dioxide capture processes. Recent studies of liquid amine sorption processes were reviewed and found to incorporate conflicting assumptions of energy requirements. Dry sodium based processes have the potential to be less energy intensive and thus less expensive than oxygen inhibited amine based systems. For dry supported sorbents, maximizing the active fraction of the sorbent is of primary importance in developing an economically feasible process.

  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. Superpulsed carbon dioxide laser: an update on cutaneous surgical applications

    Science.gov (United States)

    Wheeland, Ronald G.

    1990-06-01

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

  11. 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.

  12. 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.

  13. 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....

  14. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

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

    2014-01-01

    ). 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......; however, differences may occur in response to soil spatial variability. A better coverage of spatial variability is more easily addressed using manually operated systems whereas temporal variability can be covered using the automated system. Depending on the aim of the study, the two systems may be used...

  15. Carbon dioxide detection in adult Odonata.

    Science.gov (United States)

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

    2016-04-01

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

  16. The carbon dioxide capture and geological storage

    International Nuclear Information System (INIS)

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

  17. Carbon dioxide capture and geological storage

    OpenAIRE

    2013-01-01

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

  18. 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

  19. Biomass combustion for greenhouse carbon dioxide enrichment

    International Nuclear Information System (INIS)

    Greenhouses in northern climates have a significant heat requirement that is mainly supplied by non-renewable fuels such as heating oil and natural gas. This project's goal was the development of an improved biomass furnace able to recover the heat and the CO2 available in the flue gas and use them in the greenhouse. A flue gas purification system was designed, constructed and installed on the chimney of a wood pellet furnace (SBI Caddy Alterna). The purification system consists of a rigid box air filter (MERV rating 14, 0.3 μm pores) followed by two sets of heating elements and a catalytic converter. The air filter removes the particulates present in the flue gas while the heating elements and catalysers transform the noxious gases into less harmful gases. Gas analysis was sampled at different locations in the system using a TESTO 335 flue gas analyzer. The purification system reduces CO concentrations from 1100 cm3 m−3 to less than 1 cm3 m−3 NOx from 70 to 5.5 cm3 m−3 SO2 from 19 cm3 m−3 to less than 1 cm3 m−3 and trapped particulates down to 0.3 μm with an efficiency greater than 95%. These results are satisfactory since they ensure human and plant safety after dilution into the ambient air of the greenhouse. The recuperation of the flue gas has several obvious benefits since it increases the heat usability per unit biomass and it greatly improves the CO2 recovery of biomass heating systems for the benefit of greenhouse grown plants. - Highlights: • Biomass furnace shows high potential for greenhouse carbon dioxide enrichment. • Flue gas recuperation significantly increases the thermal efficiency of a furnace. • Catalytic converter can reduce CO and NOx below humans and plants exposure limit. • Particulates control is essential to maintain the efficiency of the catalytic conversion. • CO2 recovery from biomass heating systems reduces farmer's reliance on fossil fuel

  20. 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.

  1. Carbon dioxide direct cycle modular reactor

    International Nuclear Information System (INIS)

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

  2. 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.

  3. 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.

  4. Carbon Dioxide Separation with Supported Ionic Liquid Membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-04-01

    Supported liquid membranes are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties as a direct guide in the development of a capture technology. These membranes also have the advantage of liquid phase diffusivities higher than those observed in polymeric membranes which grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high carbon dioxide solubility relative to light gases such as hydrogen, are an excellent candidate for this type of membrane since they have negligible vapor pressure and are not susceptible to evaporation. A study has been conducted evaluating the use of several ionic liquids, including 1-hexyl-3-methyl-imidazolium bis(trifuoromethylsulfonyl)imide, 1-butyl-3-methyl-imidazolium nitrate, and 1-ethyl-3-methyl-imidazolium sulfate in supported ionic liquid membranes for the capture of carbon dioxide from streams containing hydrogen. In a joint project, researchers at the University of Notre Dame lent expertise in ionic liquid synthesis and characterization, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated the resulting materials for membrane performance. Initial results have been very promising with carbon dioxide permeabilities as high as 950 barrers and significant improvements in carbon dioxide/hydrogen selectivity over conventional polymers at 37C and at elevated temperatures. Results include a comparison of the performance of several ionic liquids and a number of supports as well as a discussion of innovative fabrication techniques currently under development.

  5. The Manufacture of Polymer Nanocomposite Materials Using Supercritical Carbon Dioxide

    OpenAIRE

    Chen, Chen

    2011-01-01

    The use of supercritical carbon dioxide (scCO2) as a processing aid to help exfoliate nano-clays and improve their dispersion during melt blending in polymer matrices has been reported in the literature. One of the best processes in terms of improving the degree of nano-clay dispersion and composite mechanical properties was developed in our laboratory. This process allows the clay to be in direct contact with scCO2 and expanding the clay-CO2 mixture via rapid depressurization into a two-stag...

  6. 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.

  7. 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...

  8. 27 CFR 24.319 - Carbon dioxide record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24.319 Section 24.319 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor...

  9. Balance and forecasts of french carbon dioxide emissions

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

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

  11. 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

  12. 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…

  13. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Science.gov (United States)

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... draft ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon... occur for all inorganic nitrates- nitrites, carbon and carbon dioxide uses, as well as gas...

  14. 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.

  15. Adverse effects of the automotive industry on carbon dioxide emissions

    Directory of Open Access Journals (Sweden)

    Mpho Bosupeng

    2016-05-01

    Full Text Available This study aims to determine the effects of the automotive industry on carbon dioxide emissions for the period from 1997 to 2010 for diverse economies, as well as the relationships between carbon dioxide discharges and output. The study applies cointegration and causality tests to validate these associations. The results of the Johansen cointegration test depict long-run associations between the quantity of passenger cars and carbon dioxide emissions in France, Sweden, Spain, Hungary and Japan. In addition, significant relations were observed between output and carbon dioxide discharges in Spain, Canada, India and Japan. Changes in output had substantial impact on emissions in Germany, Canada and India. The results also show that the number of passenger cars influences the magnitude of emissions in multiple economies. In conclusion, the automotive industry has to be considered in policies that aim to reduce carbon dioxide emissions.

  16. 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

  17. Improved Ionic Model of Liquid Uranium Dioxide

    CERN Document Server

    Gryaznov, Victor; Yakub, Eugene; Fortov, Vladimir; Hyland, Gerard J; Ronchi, Claudio

    2009-01-01

    The paper presents a model for liquid uranium dioxide, obtained by improving a simplified ionic model, previously adopted to describe the equation of state of this substance [1]. A "chemical picture" is used for liquid UO2 of stoichiometric and non-stoichiometric composition. Several ionic species are considered here: U(5+), U(4+), U(3+), O(2-) and O(-). The ions are described as charged hard-spheres of different diameters. Coulomb interaction of ions is taken into account according to the modified Mean Sphere Approximation (MSA). The main result of the new model is the appearance of natural "plasma" equivalent, which, from the theory, is directly related to the definition of oxygen potential in liquid UO(2+x). The features of the model make it possible to describe non-congruent phase equilibrium (and evaporation) in uranium dioxide, as well as other relevant phenomena characterising the phase equilibrium in chemically active matter. First calculation results are discussed.

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

    International Nuclear Information System (INIS)

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

  19. Global carbon dioxide emissions from inland waters

    Science.gov (United States)

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

    2013-01-01

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

  20. Carbon dioxide emission from bamboo culms.

    Science.gov (United States)

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

    2016-05-01

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

  1. 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)

  2. Carbon dioxide: Global warning for nephrologists.

    Science.gov (United States)

    Marano, Marco; D'Amato, Anna; Cantone, Alessandra

    2016-09-01

    The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients' bloodstream every hemodialysis treatment and "acidosis by dialysate" may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle. PMID:27648406

  3. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  4. 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.

  5. 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

  6. Calcium Oxide Matrices and Carbon Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    Claudio Nicolini

    2012-05-01

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

  7. Stationary plume induced by carbon dioxide dissolution

    International Nuclear Information System (INIS)

    In this paper, laminar convection flows induced by carbon dioxide absorption are addressed from experimental, numerical and theoretical points of view. A vertical glass tube (of centimetre scale) filled with distilled water is subjected to a sudden increase in the partial pressure of carbon dioxide. As a result of the diffusion of the gas into the unsaturated solution, a thin layer of fluid located underneath the surface becomes heavier. This initial density gradient first destabilizes to form a plume, which goes downwards through the entire cell. After a first transient pulsating regime (periodic succession of such Rayleigh-Benard plumes), a stationary flow settles in the tube, which is maintained by the constant supply of gas at the surface. At late stages, this stationary regime is followed by an aperiodic regime, which lasts until the complete saturation of the solution (thermodynamic equilibrium). The present study only focuses on the stationary regime, whose characteristics appear to be almost independent of the Bond number and the aspect ratio but strongly dependent on the chemical Rayleigh number. Three decades of Rayleigh numbers are explored using particle image velocimetry measurements, which allows for a precise determination of the scaling exponents for the vertical velocity amplitude and the plume width. The assumption that gravity and a constant pressure gradient balance the viscous effects enables us to derive an analytic expression for the stationary vertical velocity on the axis, which scales as Ra2/3 (ln Ra)1/3. As a consequence, the width of the plume scales as Ra-1/6 (ln Ra)-1/3 and the mass Nusselt number as (Ra= ln Ra)1/3. These scalings are in excellent agreement with the experimental and numerical results. The multiplicative constants of these scalings can also be calculated and show a fairly good agreement if a rigid boundary condition (no-slip) is assumed at the free surface. (authors)

  8. Six-fold coordinated carbon dioxide VI

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-16

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

  9. Six-fold coordinated carbon dioxide VI.

    Science.gov (United States)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  11. 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...

  12. Design of stable catalysts for methane-carbon dioxide reforming

    NARCIS (Netherlands)

    Lercher, J.A.; Bitter, J.H.; Hally, W.; Niessen, W.; Seshan, K.

    2001-01-01

    The activity and stability of catalysts for methane-carbon dioxide reforming depend subtly upon the support and the active metal. Methane decomposes to carbon and hydrogen, forming carbon on the oxide support and the metal. Carbon on the metal is reactive and can be oxidized to CO by oxygen from dis

  13. Estimated Carbon Dioxide Emissions in 2008: United States

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-04-01

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

  14. Measurement of carbon dioxide diffusion coefficient of concrete

    OpenAIRE

    Villain, G.; PAVOINE, A; Thiery, M.

    2006-01-01

    The carbonation of concrete is a chemical reaction, which can be at the origin of the premature degradation of reinforced concrete structures. In order to predict service life of reinforced concrete structures, many models based on gas diffusion were developed. The carbon dioxide diffusion coefficient of concrete is thus a significant input datum for these models. The objective of this article is to present a simple reliable testing method to quantify the carbon dioxide diffusion coefficient ...

  15. Carbon Dioxide Sequestration and ECBM in the Powder River Basin

    Science.gov (United States)

    Colmenares, L. B.; Zoback, M. D.

    2003-12-01

    Coal seams are both a source of coal bed methane (CBM) and a potential carbon dioxide sink. For sub-bituminous coals like those in the Powder River Basin (PRB), the CO2/CH4 adsorption ratio is approximately 10:1, which indicates the significant potential for sequestering carbon dioxide. In addition, injected carbon dioxide would also enhance the production of methane from the coal seam because of its higher adsorption capacity. This means that the injection of carbon dioxide in coal beds may have the dual benefit of sequestering carbon dioxide and enhancing CBM production. Moreover, if carbon dioxide injection efficiently displaces the adsorbed methane, it may reduce the amount of water produced from CBM wells as part of the depressurization process. Our work in the Powder River Basin indicates that drilling and completion operations result in hydraulic fracturing of the coal and possibly the adjacent strata. This would result in both excess CBM water production and inefficient depressurization of coals. We have been able to collect water-enhancement tests data in coals to obtain the magnitude of the least principal stress in the coal seam. The preliminary data we have analyzed indicates that the hydrofracs are horizontal in some areas because the least principal stress corresponds to the overburden. It is interesting to speculate that one could use horizontal hydrofracs near the bottom of the coal seam for carbon dioxide injection and a horizontal hydrofrac near the upper part of the coal seam for methane production.

  16. Comparative study of solvent properties for carbon dioxide absorption

    Energy Technology Data Exchange (ETDEWEB)

    Aschenbrenner, O.; Styring, P. [University of Sheffield, Sheffield (United Kingdom)

    2010-07-01

    Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. PEG 300 was found to be the best solvent in this study and shows a high carbon dioxide solubility as well as good selectivity over nitrogen. The advantages of high stability, low solvent loss and low desorption energy of PEG 300 may outweigh its lower absorption capacity compared to the state-of-the-art solvent monoethanolamine, making it a potentially advantageous solvent for industrial carbon dioxide absorption processes.

  17. Modeling and calculation of open carbon dioxide refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • A model of open refrigeration system is developed. • The state of CO2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO2 has little relation to the state of CO2. • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

  18. 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.

  19. Carbon dioxide warming of the early Earth

    Science.gov (United States)

    Arrhenius, G.

    1997-01-01

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

  20. 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.

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

    Science.gov (United States)

    Alcamo, Joseph; De Vries, Bert

    1992-01-01

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

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

    Science.gov (United States)

    Hagedorn, Norman H. (Inventor)

    1993-01-01

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

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-01

    This report describes research conducted between January 1, 2005 and March 31, 2005 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Engineered sorbents composed of sodium carbonate on a ceramic support were tested in a laboratory fluidized bed reactor system and found to be capable of essentially complete removal of carbon dioxide at 60 C in a short residence time. Upon breakthrough the sorbents can be thermally regenerated to recover essentially all of the absorbed carbon dioxide. An optimized supported sorbent tested in a pilot-scale entrained bed absorber retained its reactivity in multicycle tests and experienced no attrition. Removal of >90% of carbon dioxide in simulated flue gas was achieved in an entrained bed reactor.

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

    OpenAIRE

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

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study o...

  6. Carbon dioxide fluid-flow modeling and injectivity calculations

    Science.gov (United States)

    Burke, Lauri

    2011-01-01

    At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-30

    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

  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. 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)

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1972-01-01

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

  12. 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...

  13. Multiphase flow of carbon dioxide and brine in dual porosity carbonates

    Science.gov (United States)

    Pentland, Christopher; Oedai, Sjaam; Ott, Holger

    2014-05-01

    only a portion of the full saturation range is investigated, corresponding to carbon dioxide entering the macro pores of the dual porosity systems. Within this pore space the relative permeability behaviour is comparable to that measured in Berea sandstone. Brooks, R. H., and A. T. Corey (1964), Hydraulic properties of porous media, Hydrology Papers 3, Civil Engineering Dept., Colorado State Univ., Fort Collins, CO. Masalmeh, S., I. Abu-Shiekah, and X. Jing (2007), Improved Characterization and Modeling of Capillary Transition Zones in Carbonate Reservoirs, SPE Reserv. Eval. Eng., 10(2), doi:10.2118/109094-PA.

  14. 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.

  15. 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.

  16. The source of carbon dioxide for gastric acid production.

    Science.gov (United States)

    Steer, Howard

    2009-01-01

    The source of carbon dioxide for the chemical reaction leading to the production of gastric acid is unknown. The decarboxylation of an amino acid releases carbon dioxide. Pepsinogens provide a rich source of the amino acid arginine. Both the source of carbon dioxide, arginine, and the consequence of arginine decarboxylation, agmatine, have been studied. The site of carbon dioxide production has been related to the survival of the parietal cell. An immunohistochemical study has been carried out on glycol methacrylate embedded gastric biopsies from the normal stomach of 38 adult patients. The sections have been stained using polyclonal antibody to pepsinogen II, polyclonal antibody to agmatine, and polyclonal antibody to Helicobacter pylori. Pepsinogen II and agmatine are found in the parietal cell canaliculi. This is consistent with the production of carbon dioxide from arginine in the parietal cell canaliculi. Evidence is presented for the decarboxylation of arginine derived from the activation segment of pepsinogen as the source of carbon dioxide for the production of gastric acid. The production of carbon dioxide by the decarboxylation of arginine in the parietal cell canaliculus enables the extracellular hydration of carbon dioxide at the known site of carbonic anhydrase activity. The extracellular production of acid in the canaliculus together with the presence of agmatine helps to explain why the parietal cells are not destroyed during the formation of gastric acid. Agmatine is found in the mucus secreting cells of the stomach and its role in acid protection of the stomach is discussed. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc. PMID:18951509

  17. 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...

  18. 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...

  19. Amazon river carbon dioxide outgassing fuelled by wetlands

    OpenAIRE

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

    2014-01-01

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

  20. Separation of carbon dioxide from flue emissions using Endex principles

    CERN Document Server

    Ball, R

    2009-01-01

    In an Endex reactor endothermic and exothermic reactions are directly thermally coupled and kinetically matched to achieve intrinsic thermal stability, efficient conversion, autothermal operation, and minimal heat losses. Applied to the problem of in-line carbon dioxide separation from flue gas, Endex principles hold out the promise of effecting a carbon dioxide capture technology of unprecedented economic viability. In this work we describe an Endex Calcium Looping reactor, in which heat released by chemisorption of carbon dioxide onto calcium oxide is used directly to drive the reverse reaction, yielding a pure stream of carbon dioxide for compression and geosequestration. In this initial study we model the proposed reactor as a continuous-flow dynamical system in the well-stirred limit, compute the steady states and analyse their stability properties over the operating parameter space, flag potential design and operational challenges, and suggest an optimum regime for effective operation.

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

    Science.gov (United States)

    Johnson, F. S.

    1975-01-01

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

  2. 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...

  3. 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...

  4. 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...

  5. 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...

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

    Science.gov (United States)

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

    2016-01-01

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

  7. 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.

  8. Carbon dioxide removal in gas treating processes

    International Nuclear Information System (INIS)

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO2 in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140oC, for CO2 loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO2 into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO2 in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO2/TEG/MEA system for estimation of CO2 partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs

  9. Effects of carbon dioxide on laryngeal receptors

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.W.; Sant' Ambrogio, F.B.; Orani, G.P.; Sant' Ambrogio, G.; Mathew, O.P. (Univ. of Texas, Galveston (United States))

    1990-02-26

    Carbon dioxide (CO{sub 2}) either stimulates or inhibits laryngeal receptors in the cat. The aim of this study was to correlate the CO{sub 2} response of laryngeal receptors with their response to other known stimuli (i.e. pressure, movement, cold, water and smoke). Single unit action potentials were recorded from fibers in the superior laryngeal nerve of 5 anesthetized, spontaneously breathing dogs together with CO{sub 2} concentration, esophageal and subglottic pressure. Constant streams of warm, humidified air or 10% CO{sub 2} in O{sub 2} were passed through the functionally isolated upper airway for 60 s. Eight of 13 randomly firing or silent receptors were stimulated by CO{sub 2} (from 0.4{plus minus}0.1 to 1.8{plus minus}0.4 imp.s). These non-respiratory-modulated receptors were more strongly stimulated by solutions lacking Cl{sup {minus}} and/or cigarette smoke. Six of 21 respiratory modulated receptors (responding to pressure and/or laryngeal motion) were either inhibited or stimulated by CO{sub 2}. Our results show that no laryngeal receptor responds only to CO{sub 2}. Silent or randomly active receptors were stimulated most often by CO{sub 2} consistent with the reflex effect of CO{sub 2} in the larynx.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Zenker's Diverticulum: Carbon Dioxide Laser Endoscopic Surgery

    Directory of Open Access Journals (Sweden)

    Jan Plzák

    2014-01-01

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

  15. Carbon Dioxide Angiography: Scientific Principles and Practice.

    Science.gov (United States)

    Cho, Kyung Jae

    2015-09-01

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

  16. 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.

  17. 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

    2016-01-01

    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. PMID:27572662

  18. 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.

  19. 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.

  20. 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.

  1. A simple, disposable end-tidal carbon dioxide detector.

    OpenAIRE

    Rosenberg, M; Block, C. S.

    1991-01-01

    Detection of expired carbon dioxide is one of the most reliable methods of avoiding accidental esophageal intubation. Although capnography has become a standard monitoring technique in the hospital operating room, it is rarely available in the office setting or other arenas where emergency endotracheal intubation may be required. A new and inexpensive device, however, has been developed for assessing end-tidal carbon dioxide. This semi-quantitative detector fits between the endotracheal tube ...

  2. Economic Growth, Carbon Dioxide Emissions, Renewable Energy and Globalization

    OpenAIRE

    Nuno Carlos LEITÃO

    2014-01-01

    This article investigates the correlation between economic growth, carbon dioxide emissions, renewable energy and globalization for the period 1970-2010, using time series (OLS,GMM, unit root test, VEC model, and Granger causality) to Portuguese economy. OLS estimator and GMM model demonstrate that carbon dioxide emissions and renewable energy are positively correlated with economic growth. The econometric models also show that the overall index of globalization has a positive effect...

  3. 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...

  4. 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.

  5. 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.

  6. Ecological Limits to Terrestrial Biological Carbon Dioxide Removal

    Science.gov (United States)

    Torn, M. S.; Smith, L. J.; Mishra, U.; Sanchez, D.; Williams, J.

    2014-12-01

    Many climate change mitigation scenarios include terrestrial atmospheric carbon dioxide removal (BCDR) or carbon neutral bioenergy production through bioenergy with carbon capture and storage (BECS) or afforestation/reforestation. Very high sequestration potentials for these strategies have been reported, and we evaluate the potential ecological limits (e.g., land and resource requirements) to implementation at the 1 Pg C y-1 scale relevant to climate change mitigation for U.S. and global scenarios. We estimate that removing 1 Pg C y-1 via tropical afforestation would require at least 7×106 ha y-1 of land, 0.09 Tg y-1 of nitrogen, and 0.2 Tg y-1 of phosphorous, and would increase evapotranspiration from those lands by almost 50%. Because of improved carbon capture technologies, we are updating (and reducing) our previous estimates for switchgrass BECS (previous estimate was 2×108 ha land and 20 Tg y-1 of nitrogen (20 % of global fertilizer nitrogen production)). Miscanthus could meet the same biomass production with much lower N demand. Moreover, transitioning the U.S land currently under corn- ethanol production to no-till perennial grasses for bioenergy would meet U.S. needs and have additional environmental benefits (such as improved wildlife habitat and soil restoration). Thus, there are both signficant ecological limits to BCDR as well as potential ecological benefits, depending on implementation.

  7. 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).

  8. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  10. 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.

  11. Simulation study to determine the feasibility of injecting hydrogen sulfide, carbon dioxide and nitrogen gas injection to improve gas and oil recovery oil-rim reservoir

    Science.gov (United States)

    Eid, Mohamed El Gohary

    This study is combining two important and complicated processes; Enhanced Oil Recovery, EOR, from the oil rim and Enhanced Gas Recovery, EGR from the gas cap using nonhydrocarbon injection gases. EOR is proven technology that is continuously evolving to meet increased demand and oil production and desire to augment oil reserves. On the other hand, the rapid growth of the industrial and urban development has generated an unprecedented power demand, particularly during summer months. The required gas supplies to meet this demand are being stretched. To free up gas supply, alternative injectants to hydrocarbon gas are being reviewed to support reservoir pressure and maximize oil and gas recovery in oil rim reservoirs. In this study, a multi layered heterogeneous gas reservoir with an oil rim was selected to identify the most optimized development plan for maximum oil and gas recovery. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked. The development scheme is identified, in which the pattern and completion of the wells are optimized to best adapt to the heterogeneity of the reservoir. Lateral and maximum block contact holes will be investigated. The non-hydrocarbon gases considered for this study are hydrogen sulphide, carbon dioxide and nitrogen, utilized to investigate miscible and immiscible EOR processes. In November 2010, re-vaporization study, was completed successfully, the first in the UAE, with an ultimate objective is to examine the gas and condensate production in gas reservoir using non hydrocarbon gases. Field development options and proces schemes as well as reservoir management and long term business plans including phases of implementation will be identified and assured. The development option that maximizes the ultimate recovery factor will be evaluated and selected. The study achieved satisfactory results in integrating gas and oil

  12. 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.

  13. Uranium Dioxide Powder Flow ability Improvement Using Sol-Gel

    International Nuclear Information System (INIS)

    The improvement of flow ability characteristics of uranium dioxide powder has been done using sol-gel process. To anticipate a pellet mass production with uniform pellet dimension, the uranium dioxide powder must be have a spherical form. Uranium dioxide spherical powder has been diluted in acid transformed into sol colloidal solution. To obtain uranium dioxide spherical form, the uranium sol-colloidal solution has been dropped in a hot paraffin ( at the temperature of 900C) to form gelatinous colloid and then dried at 8000C, and sintered at the temperature of 17000C. The flow ability of spherical uranium dioxide powder has been examined by using Flowmeter Hall (ASTM. B. 213-46T). The measurement result reveals that the spherical uranium dioxide powder has a flow ability twice than that of unprocessed uranium dioxide powder

  14. Surface chemistry of polymers. The adsorption of carbon dioxide and sulfur dioxide on polyvinylidene chloride

    OpenAIRE

    Stoeckli, Fritz

    2007-01-01

    Isotherms for the adsorption of nitrogen (77 K), carbon dioxide (195-247 K) and sulfur dioxide (254-293 K) on polyvinylidene chloride have been measured volumetrically. The B.E.T. cross-sectional areas of 18 Å2 (CO2) and 24 Å2 (SO2) are comparable to liquid density values. The isosteric heat of adsorption of CO2 is constant for 0.2

  15. Coping with carbon: a near-term strategy to limit carbon dioxide emissions from power stations.

    Science.gov (United States)

    Breeze, Paul

    2008-11-13

    Burning coal to generate electricity is one of the key sources of atmospheric carbon dioxide emissions; so, targeting coal-fired power plants offers one of the easiest ways of reducing global carbon emissions. Given that the world's largest economies all rely heavily on coal for electricity production, eliminating coal combustion is not an option. Indeed, coal consumption is likely to increase over the next 20-30 years. However, the introduction of more efficient steam cycles will improve the emission performance of these plants over the short term. To achieve a reduction in carbon emissions from coal-fired plant, however, it will be necessary to develop and introduce carbon capture and sequestration technologies. Given adequate investment, these technologies should be capable of commercial development by ca 2020. PMID:18757277

  16. Meridional carbon dioxide transport in the northern North Atlantic

    NARCIS (Netherlands)

    Stoll, M.H.C.; Aken, H.M. van; Baar, H.J.W. de; Boer, C.J. de

    1996-01-01

    Combination of estimated water transport and accurate measurements of total carbon dioxide (TCO2) on a hydrographic section at 58°N allows the assessment of meridional inorganic carbon transport in the northern North Atlantic Ocean. The transport has been decomposed into contributions from the large

  17. 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.

  18. 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...

  19. 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.

  20. 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…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-10-01

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

  2. Heterogeneously Catalysed Chemical Reactions in Carbon Dioxide Medium

    DEFF Research Database (Denmark)

    Musko, Nikolai E.

    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...... useful for the phase behaviour investigations. The direct synthesis of dimethyl carbonate from methanol and CO2 has been investigated for quite a long time, however hardly any sufficiently active catalysts have been found so far. Nevertheless, optimisation of the phase equilibria of the reaction mixture...... 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...

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

    Directory of Open Access Journals (Sweden)

    B. Xiang

    2013-07-01

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

  4. 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.

  5. 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.

  6. 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

  7. Carbon dioxide, the feedstock for using renewable energy

    International Nuclear Information System (INIS)

    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.

  8. 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.

  9. 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.

  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. Measures for carbon dioxide problem and utilization of energy

    International Nuclear Information System (INIS)

    As global environment problems, there are water, expansion of deserts, weather, tropical forests, wild animals, ocean pollution, nuclear waste contamination, acid rain, ozone layer and so on, and population, foods, energy, and resources are the problems surrounding them. It is clear that these origins are attributed to the development and consumption largely dependent on the intention of developed countries and the population problem of developing countries. In this report, the discharge of carbon dioxide that causes greenhouse effect and its relation with energy are discussed. The increase of carbon dioxide concentration, its release from fossil fuel, the destruction of forests, the balance of carbon on the earth, the development of new energy such as solar energy, the transport of new energy, secondary energy system and the role of carbon dioxide, the transfer to low carbon fuel and the carbon reduction treatment of fuel, the utilization of unused energy and energy price, the efficiency of energy utilization, the heightening of efficiency of energy conversion, energy conservation and the breakaway from energy wasteful use culture, and the recovery, preservation and use of discharged carbon dioxide are described. (K.I.)

  12. Oxidative Treatment to Improve Coating and Electrochemical Stability of Carbon Fiber Paper with Niobium Doped Titanium Dioxide Sols for Potential Applications in Fuel Cells

    International Nuclear Information System (INIS)

    Highlights: • Solution coating of metal oxide layer directly onto carbon paper. • Most uniform Metal oxide coating on functionalized carbon paper. • Highest electrochemical stability for metal oxide coated functionalized carbon paper. - Abstract: Regular hydrophobized carbon paper cannot be used for unitized regenerative fuel cell applications as it corrodes at high potentials on the oxygen electrode side. Reported here are the oxidative treatment and dip-coating of carbon paper (Spectracarb™ 2050A-0850) with Nb-doped TiO2 sols (anatase phase) to increase the corrosion resistance of the carbon paper at the interface between catalyst layer and gas diffusion backing layer. Coating of carbon paper with Nb-doped TiO2 sols generates a reasonably uniform layer of TiO2 and covers the individual carbon fibers well only if the carbon paper is oxidatively functionalized prior to coating. This can be reasoned with a better wetting of the functionalized carbon paper by the sol-gel and the formation of covalent bonds between Ti and the large number of functional groups on the surface of oxidized carbon paper, which is in good agreement with previous observation for carbon nanotubes. The resistance towards oxidation of coated and uncoated samples of untreated and functionalized carbon paper was probed by cyclic voltammetry in 0.5 M aqueous H2SO4 at 1.2 V versus Ag/AgCl for up to 72 hours to mimic the conditions in a unitized regenerative fuel cell. Among these four cases studied here, functionalized carbon paper coated with a layer of Nb-doped TiO2 shows the highest stability towards electrochemical oxidation while uncoated functionalized carbon paper is the least stable due to the large number of available oxidation sites. These results clearly demonstrate that a coating of carbon fibers with TiO2 generates a lasting protection against oxidation under conditions encountered at the oxygen electrode side of unitized regenerative fuel cells

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  14. 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...

  15. 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.

  16. 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.

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

    OpenAIRE

    Tsuji, Yasushi; Fujihara, Tetsuaki

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-04-01

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

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

    International Nuclear Information System (INIS)

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

  20. Properties of equilibrium carbon dioxide hydrate in porous medium

    Science.gov (United States)

    Voronov, V. P.; Gorodetskii, E. E.; Podnek, V. E.; Grigoriev, B. A.

    2016-09-01

    Specific heat capacity, dissociation heat and hydration number of carbon dioxide hydrate in porous medium are determined by adiabatic calorimetry method. The measurements were carried out in the temperature range 250-290 K and in pressure range 1-5 MPa. The measured specific heat of the hydrate is approximately 2.7 J/(g K), which is significantly larger than the specific heat of methane hydrate. In particular, at heating, larger value of the specific heat of carbon dioxide hydrate is a result of gas emission from the hydrate. The hydration number at the hydrate-gas coexistence changes from 6.2 to 6.9. The dissociation heat of carbon dioxide hydrate varies from the 55 kJ/mol near the upper quadruple point to the 57 kJ/mol near the lower quadruple point.

  1. Polyureas from diamines and carbon dioxide: synthesis, structures and properties.

    Science.gov (United States)

    Wu, Chaoyong; Wang, Jinyao; Chang, Pingjing; Cheng, Haiyang; Yu, Yancun; Wu, Zhijian; Dong, Dewen; Zhao, Fengyu

    2012-01-14

    Polyureas were synthesized from diamines and carbon dioxide in the absence of any catalyst or solvent, analogous to the synthesis of urea from condensation of ammonia with carbon dioxide. The method used carbon dioxide as a carbonyl source to substitute highly toxic isocyanates for the synthesis of polyureas. FTIR and DFT calculations confirmed that strong bidentate hydrogen bonds were formed between urea motifs, and XRD patterns showed that the PUas were highly crystalline and formed a network structure through hydrogen bonds, which served as physical cross-links. The long chain PUas presented a microphase separated morphology as characterized by SAXS and showed a high melting temperature above 200 °C. The PUas showed high resistance to solvents and excellent thermal stability, which benefitted from their special network structures. The PUas synthesized by this method are a new kind of functional material and could serve some areas where their analogues with similar functional groups could not be applied. PMID:22120724

  2. Pre-Combustion Carbon Dioxide Capture by a New Dual Phase Ceramic-Carbonate Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry

    2014-09-30

    This report documents synthesis, characterization and carbon dioxide permeation and separation properties of a new group of ceramic-carbonate dual-phase membranes and results of a laboratory study on their application for water gas shift reaction with carbon dioxide separation. A series of ceramic-carbonate dual phase membranes with various oxygen ionic or mixed ionic and electronic conducting metal oxide materials in disk, tube, symmetric, and asymmetric geometric configurations was developed. These membranes, with the thickness of 10 μm to 1.5 mm, show CO2 permeance in the range of 0.5-5×10-7 mol·m-2·s-1·Pa-1 in 500-900oC and measured CO2/N2 selectivity of up to 3000. CO2 permeation mechanism and factors that affect CO2 permeation through the dual-phase membranes have been identified. A reliable CO2 permeation model was developed. A robust method was established for the optimization of the microstructures of ceramic-carbonate membranes. The ceramic-carbonate membranes exhibit high stability for high temperature CO2 separations and water gas shift reaction. Water gas shift reaction in the dual-phase membrane reactors was studied by both modeling and experiments. It is found that high temperature syngas water gas shift reaction in tubular ceramic-carbonate dual phase membrane reactor is feasible even without catalyst. The membrane reactor exhibits good CO2 permeation flux, high thermal and chemical stability and high thermal shock resistance. Reaction and separation conditions in the membrane reactor to produce hydrogen of 93% purity and CO2 stream of >95% purity, with 90% CO2 capture have been identified. Integration of the ceramic-carbonate dual-phase membrane reactor with IGCC process for carbon dioxide capture was analyzed. A methodology was developed to identify optimum operation conditions for a membrane tube of given dimensions that would treat coal syngas with targeted performance. The calculation results show that the dual-phase membrane reactor could

  3. Improvement of a monitoring tape for nitrogen dioxide in air

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, Kunio [Faculty of Engineering, Kogakuin University, 2665-1, Nakanocho, Hachioji-shi, Tokyo (Japan); Nakano, Nobuo [Riken Keiki Co., Ltd., 2-7-6, Azusawa, Itabashi-ku, Tokyo (Japan)

    1999-06-14

    A porous cellulose tape containing a silica gel that was previously impregnated with a processing solution containing p-toluenesulfonic acid, sulfanilic acid, N-1-naphthyl ethylene diamine dihydrochloride, ethylene glycol and methanol has been developed to provide a highly sensitive detection of nitrogen dioxide in air. When the sample including nitrogen dioxide was passed through the tape, the color of tape changed to red, and the degree of color change could be recorded by measuring the intensity of reflecting light (555 nm). The calibration graph was linear up to =0.10 ppm. The detection limit was 0.5 ppb for nitrogen dioxide with a sampling time of 8 min and a flow rate of 60 ml min{sup -1}. No interferences were observed from ammonia (40 ppm), sulfur dioxide (51 ppm), carbon dioxide (21%), ozone (0.75 ppm), hydrogen sulfide (27 ppm) or nitrogen monoxide (99 ppm)

  4. Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO2) in a polar environment

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H2O)-carbon dioxide (CO2) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν3 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.

  5. Economic Evaluations for the Carbon Dioxide-involved Production of High-value Chemicals

    International Nuclear Information System (INIS)

    Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this CO2 carbonation technology is an cost-effective technology option for the reduction of greenhouse gas

  6. Economic Evaluations for the Carbon Dioxide-involved Production of High-value Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Hyun; Lee, Dong Woog; Jang, Se Gyu; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo [KEPCO Research Institute, Daejon (Korea, Republic of); Choi, Jong Shin [Korea East-West Power Co. LTD, Seoul (Korea, Republic of)

    2014-06-15

    Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this CO2 carbonation technology is an cost-effective technology option for the reduction of greenhouse gas.

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

    Energy Technology Data Exchange (ETDEWEB)

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson; Santosh Gangwal; Ya Liang; Tyler Moore; Margaret Williams; Douglas P. Harrison

    2004-09-30

    sodium carbonate in these tests is initially very rapid and high degrees of removal are possible. The exothermic nature of the carbonation reaction resulted in a rise in bed temperature and subsequent decline in removal rate. Good temperature control, possibly through addition of supplemental water and evaporative cooling, appears to be the key to getting consistent carbon dioxide removal in a full-scale reactor system. The tendency of the alkali carbonate sorbents to cake on contact with liquid water complicates laboratory investigations as well as the design of larger scale systems. Also their low attrition resistance appears unsuitable for their use in dilute-phase transport reactor systems. Sodium and potassium carbonate have been incorporated in ceramic supports to obtain greater surface area and attrition resistance, using a laboratory spray dryer. The caking tendency is reduced and attrition resistance increased by supporting the sorbent. Supported sorbents with loading of up to 40 wt% sodium and potassium carbonate have been prepared and tested. These materials may improve the feasibility of large-scale CO{sub 2} capture systems based on short residence time dilute-phase transport reactor systems.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-11-01

    sodium carbonate in these tests is initially very rapid and high degrees of removal are possible. The exothermic nature of the carbonation reaction resulted in a rise in bed temperature and subsequent decline in removal rate. Good temperature control, possibly through addition of supplemental water and evaporative cooling, appears to be the key to getting consistent carbon dioxide removal in a full-scale reactor system. The tendency of the alkali carbonate sorbents to cake on contact with liquid water complicates laboratory investigations as well as the design of larger scale systems. Also their low attrition resistance appears unsuitable for their use in dilute-phase transport reactor systems. Sodium and potassium carbonate have been incorporated in ceramic supports to obtain greater surface area and attrition resistance, using a laboratory spray dryer. The caking tendency is reduced and attrition resistance increased by supporting the sorbent. Supported sorbents with loading of up to 40 wt% sodium and potassium carbonate have been prepared and tested. These materials may improve the feasibility of large-scale CO{sub 2} capture systems based on short residence time dilute-phase transport reactor systems.

  9. Highly selective plasma-activated copper catalysts for carbon dioxide reduction to ethylene

    Science.gov (United States)

    Mistry, Hemma; Varela, Ana Sofia; Bonifacio, Cecile S.; Zegkinoglou, Ioannis; Sinev, Ilya; Choi, Yong-Wook; Kisslinger, Kim; Stach, Eric A.; Yang, Judith C.; Strasser, Peter; Cuenya, Beatriz Roldan

    2016-06-01

    There is an urgent need to develop technologies that use renewable energy to convert waste products such as carbon dioxide into hydrocarbon fuels. Carbon dioxide can be electrochemically reduced to hydrocarbons over copper catalysts, although higher efficiency is required. We have developed oxidized copper catalysts displaying lower overpotentials for carbon dioxide electroreduction and record selectivity towards ethylene (60%) through facile and tunable plasma treatments. Herein we provide insight into the improved performance of these catalysts by combining electrochemical measurements with microscopic and spectroscopic characterization techniques. Operando X-ray absorption spectroscopy and cross-sectional scanning transmission electron microscopy show that copper oxides are surprisingly resistant to reduction and copper+ species remain on the surface during the reaction. Our results demonstrate that the roughness of oxide-derived copper catalysts plays only a partial role in determining the catalytic performance, while the presence of copper+ is key for lowering the onset potential and enhancing ethylene selectivity.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  12. ACTUAL PROBLEMS OF MANUFACTURING AND USING OF CARBON DIOXIDE

    OpenAIRE

    Лавренченко, Г. К.

    2015-01-01

    The Ukrainian Association of Manufacturers of Industrial Gases «UA-SIGMA» on May, 18-22, 2009 in Odessa had been carried out the third international seminar «СО2-2009». The questions considered at seminar have been incorporated by an actual problem of increase of efficiency and ecologically-technological safety of manufacture and use of carbon dioxide. In this problem was interested not only the manufacturers of СО2 and urea but also those who releases the various carbon dioxide equipment. Th...

  13. Fluxes of carbon dioxide at Thetford Forest

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The Thetford Project (1968–1976 was a keystone project for the newly established Institute of Hydrology. Its primary objective was to elucidate the processes underlying evaporation of transpired water and intercepted rainfall from plantation forest, so as to explain hydrological observations that more water was apparently returned to the atmosphere from plantations than from grassland and heathland. The primary approach was to determine the fluxes of water vapour from a stand of Scots pine, situated within a larger area of plantations of Scots and Corsican pine, in Thetford Forest, East Anglia, UK, using the Bowen ratio approach. In 1976, advantage was taken of the methodology developed to add measurement of profiles of carbon dioxide concentration so as to enable the fluxes of CO2 also to be calculated. A team from Aberdeen and Edinburgh Universities collected 914 hours of 8-point CO2 concentration profiles, largely between dawn and dusk, on days from March to October, and the data from an "elite" data set of 710 hours have been analysed. In conditions of moderate temperature (−1 with high solar irradiance (>500 W m−2, CO2 uptake reached relatively high rates for pine of up to 20 µmol m−2 s−1 in the middle of the day. This rate of CO2 uptake is higher than has been recently found for four Scots pine forests in continental Europe during July 1997. However, the year of 1976 was exceptionally hot and dry, with air temperatures reaching 30°C and the water deficit in the top 3 m of soil at the site of 152 mm by August. Air temperatures of over 25°C led to large specific humidity deficits, approaching 20 g kg−1, and associated severe reductions in CO2 uptake, as well as in evaporation. However, when specific humidity deficits dropped below c. 15 g kg−1 on succeeding days, generally as a result of lower air temperatures rather than lower solar irradiance, there was rapid recovery in both uptake and evaporation, thus indicating that

  14. 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)

  15. 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…

  16. 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.

  17. 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...

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

    Science.gov (United States)

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

    2015-01-27

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

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

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

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

    International Nuclear Information System (INIS)

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

  2. 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.

  3. Improving Carbon Fixation Pathways

    OpenAIRE

    Ducat, Daniel C.; Silver, Pamela A

    2012-01-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing...

  4. Study on Permeability Change Rule of Different Rank Coals by Injecting Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Guo Hui

    2015-01-01

    Full Text Available This paper provides an experimental support for increasing the flow conductivity of coal reservoir by identifying permeability change rule caused by reactions with different minerals in coal after injecting carbon dioxide. Based on measurement of nitrogen adsorption, mineral composition and permeability of medium-high rank coal in Tunlan mine and Sihe mine, it is used to investigate the permeability change rule caused by reactions with different minerals in coal and its improving effect after injecting carbon dioxide. A permeability change model was established by making a nonlinear regression analysis of the initial permeability, the reaction time and the improved permeability. The results showed that as a result of CO2-water-rock interaction, permeability of medium-high rank coal increases at first and then decreases with time going by after injecting carbon dioxide. The permeability of Sihe coal samples reaches maximum value earlier than that of Tunlan coal samples. Improving effect of permeability of Sihe coal samples is better than that of Tunlan coal samples. The initial permeability which is too large or too small is insensitive to the change of permeability, while the medium permeability within 0.1--0.2×10-3μm2 is more favorable. The reliability of the mathematical model is verified by the experiment. The results can also provide a theoretical basis for the analysis of permeability change after injecting carbon dioxide.

  5. Carbon Dioxide, Energy Taxes and Household Income

    OpenAIRE

    Cathal O'Donoghue

    1997-01-01

    This paper examines the impact of a carbon tax on the income distribution in Ireland using the 1987 Household Budget Survey. Previous studies have focused on the direct impact of the carbon tax on expenditures on domestic fuels. This study however, drawing on previous work expands the analysis to cover the indirect impact of carbon taxes on other household purchases> A direct and indirect tax would have a less regressive effect on the income distribution than a simple direct tax on household ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-20

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

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

    OpenAIRE

    Voyame, Patrick

    2016-01-01

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

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

    Science.gov (United States)

    Millikan, Roger C.

    1978-01-01

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

  9. 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

  10. Measurements of atmospheric carbon dioxide concentration above the ocean

    Energy Technology Data Exchange (ETDEWEB)

    Voskresenskii, A.I.; Kamenogradskii, N.E.

    1984-01-01

    Changes in the composition of the atmosphere can have a destabilizing effect on the climate. One change is related to an increase in the concentration of carbon dioxide as a result of the combustion of organic fuels. The most effective procedures for monitoring the atmospheric carbon dioxide concentration are discussed, taking into account suitable analytic methods and the most appropriate locations for the conduction of the measurements. It is found that polar and oceanic regions are best suited for the performance of the considered measurements. The analytic procedure selected is based on a spectroscopic approach utilizing the absorption of solar radiation by carbon dioxide at a wavelength of 2.06 microns. A description is given of measurements conducted on Soviet expeditions to the Antarctic during the time from 1979 to 1981. The concentration of atmospheric carbon dioxide as a function of geographic latitude is shown in graphs, taking into account data for January, February, March, and April. Water vapor concentrations are also shown. 11 references.

  11. Intertidal zones as carbon dioxide sources to coastal oceans

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  12. Self-Assembled Monolayers deposition in Supercritical Carbon Dioxide

    OpenAIRE

    Rabbia, Laurent; Perrut, Vincent; Pons, Patrick; Lellouchi, Djemel

    2009-01-01

    Self-Assembled Monolayers of organic molecules have been successfully deposited onto wafer surface in supercritical carbon dioxide. Deposition method and apparatus are described. The layers are characterized by AFM and water droplet contact angle. Interest of this technique compared to liquid and vapor phase is discussed and studied for surface conversion from hydrophilic to hydrophobic for different materials.

  13. 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.

  14. 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

  15. Hydrological restoration of Indonesian peatlands to mitigate carbon dioxide emissions

    NARCIS (Netherlands)

    Wösten, H.; Jaenicke, J.; Budiman, A.; Siegert, F.

    2010-01-01

    Delta Session DS 9: The lowland deltas of Indonesia. Hydrological restoration of Indonesian peatlands to mitigate carbon dioxide emissions, Henk Wösten (2010). Presented at the international conference Deltas in Times of Climate Change, 29 September - 1 October, Rotterdam, the Netherlands.

  16. 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...

  17. 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.

  18. 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

  19. Phase relation between global temperature and atmospheric carbon dioxide

    OpenAIRE

    Stallinga, Peter; Khmelinskii, Igor

    2013-01-01

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

  20. Using the 5E Learning Cycle Sequence with Carbon Dioxide

    Science.gov (United States)

    Schlenker, Richard M.; Blanke, Regina; Mecca, Peter

    2007-01-01

    The authors used the 5E learning cycle (engage, explore, explain, extend, and evaluate) and a pulmonary carbon dioxide mystery to introduce eighth grade students to the study of chemistry. The activity engages students in measurement, data collection, data analysis, media and internet research, research design, and report writing as they search…

  1. 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…

  2. Electrochemical carbon dioxide reduction on rough copper surfaces

    NARCIS (Netherlands)

    Kas, R.

    2016-01-01

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

  3. 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

  4. 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.

  5. 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…

  6. 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…

  7. CARBON-DIOXIDE LASER VAPORIZATION IN EARLY GLOTTIC CARCINOMA

    NARCIS (Netherlands)

    MAHIEU, HF; PATEL, P; ANNYAS, AA

    1994-01-01

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

  8. 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

  9. 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...

  10. 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...

  11. 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.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Carbonated hydrocarbons for improved gas well fracturing results

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, N. G.; Anderson, H. A.

    1996-10-01

    A process for hydraulic fracturing gas reservoirs has been developed which used the reservoir gas as a drive mechanism and a specially designed fluid slug to achieve miscible recovery of the treating fluid. The slug combines carbon dioxide with certain hydrocarbons, causing the hydrocarbons to achieve high viscosity, which in turn results in low friction and good sand carrying capability. The carbon dioxide in solution creates a miscible bank of enriched carbon dioxide between the fracturing fluid and the reservoir gas, which then permits recovery of virtually all of the fracturing fluid. The resulting high permeability leads to improved well productivity. Field results to verify the applicability of this process were presented. It was found that miscibility between the reservoir fluid, the enriched carbon dioxide bank, and the fracturing fluid must be present to achieve optimum recovery. 30 refs., 5 tabs., 14 figs.

  17. PERFECTION OF COMPRESSORS OF HIGH AND AVERAGE PRODUCTIVITY WITH GREASING AND WITHOUT GREASING FOR COMPRESSION OF CARBON DIOXIDE

    OpenAIRE

    Ворошилов, И. В.; Барко, А. В.

    2015-01-01

    Carbon dioxide are finds the wide application in three kinds: liquid high and low pressure, dry ice. For its manufacture in such kind it is necessary to use the piston compressors with three or four steps of compression. Dry condensation are applied to improvement of quality made carbon dioxide in compressors in vapors of cylinder–piston and rod–gasket. Mechanisms of compressors’ movement have system of greasing with limited oil supply. Compressors are created for work with the increased numb...

  18. 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.

  19. The thermodynamics of direct air capture of carbon dioxide

    International Nuclear Information System (INIS)

    An analysis of thermodynamic constraints shows that the low concentration of carbon dioxide in ambient air does not pose stringent limits on air capture economics. The thermodynamic energy requirement is small even using an irreversible sorbent-based process. A comparison to flue gas scrubbing suggests that the additional energy requirement is small and can be supplied with low-cost energy. In general, the free energy expended in the regeneration of a sorbent will exceed the free energy of mixing, as absorption is usually not reversible. The irreversibility, which grows with the depth of scrubbing, tends to affect flue gas scrubbing more than air capture which can successfully operate while extracting only a small fraction of the carbon dioxide available in air. This is reflected in a significantly lower theoretical thermodynamic efficiency for a single stage flue gas scrubber than for an air capture device, but low carbon dioxide concentration in air still results in a larger energy demand for air capture. The energy required for capturing carbon dioxide from air could be delivered in various ways. I analyze a thermal swing and also a previously described moisture swing which is driven by the evaporation of water. While the total amount of heat supplied for sorbent regeneration in a thermal swing, in accordance with Carnot's principle, exceeds the total free energy requirement, the additional free energy required as one moves from flue gas scrubbing to air capture can be paid with an amount of additional low grade heat that equals the additional free energy requirement. Carnot's principle remains satisfied because the entire heat supplied, not just the additional amount, must be delivered at a slightly higher temperature. Whether the system is driven by water evaporation or by low grade heat, the cost of the thermodynamically-required energy can be as small as $1 to $2 per metric ton of carbon dioxide. Thermodynamics does not pose a practical constraint on the

  20. Effects of carbon dioxide and nitrogen on adhesive growth and expressions of E-cadherin and VEGF of human colon cancer cell CCL-228

    Institute of Scientific and Technical Information of China (English)

    Kai-Lin Cai; Guo-Bing Wang; Li-Juan Xiong

    2003-01-01

    AIM: To study the effects of carbon dioxide on the metastatic capability of cancer cells, and to compare them with that of nitrogen.METHODS: The colon cancer cell CCL-228 was treated with 100 % carbon dioxide or nitrogen at different time points and then cultured under normal condition. Twelve hours after the treatment, the survival rates of suspension cells and the expressions of e-cadherin and VEGF were examined.RESULTS: After 60 min of carbon dioxide and longer time of nitrogen treatment, the suspended cells increased and the expression of e-cadherin decreased while the expression of VEGF was enhanced significantly. And the effects of nitrogen were similar to, but weaker than, those of carbon dioxide.CONCLUSION: Carbon dioxide may improve the metastatic capability of cancer cells and its effects are significantly stronger than that of nitrogen. A sequential use of carbon dioxide and nitrogen in pneumoperitoneum may take the advantage of both gases.

  1. 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...

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

    NARCIS (Netherlands)

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

    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

  3. 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

  4. 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... HAZARDOUS SHIPS' STORES Stowage and Other Special Requirements for Particular Materials § 147.65 Carbon dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of...

  5. 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...

  6. 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.

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

    Science.gov (United States)

    Graves, Christopher Ronald

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

  8. 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.

  9. 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

  10. Electropolymerized carbonic anhydrase immobilization for carbon dioxide capture.

    Science.gov (United States)

    Merle, Geraldine; Fradette, Sylvie; Madore, Eric; Barralet, Jake E

    2014-06-17

    Biomimetic carbonation carried out with carbonic anhydrase (CA) in CO2-absorbing solutions, such as methyldiethanolamine (MDEA), is one approach that has been developed to accelerate the capture of CO2. However, there are several practical issues, such as high cost and limited enzyme stability, that need to be overcome. In this study, the capacity of CA immobilization on a porous solid support was studied to improve the instability in the tertiary amine solvent. We have shown that a 63% porosity macroporous carbon foam support makes separation and reuse facile and allows for an efficient supply and presentation of CO2 to an aqueous solvent and the enzyme catalytic center. These enzymatic supports conserved 40% of their initial activity after 42 days at 70 °C in an amine solvent, whereas the free enzyme shows no activity after 1 h in the same conditions. In this work, we have overcome the technical barrier associated with the recovery of the biocatalyst after operation, and most of all, these electropolymerized enzymatic supports have shown a remarkable increase of thermal stability in an amine-based CO2 sequestration solvent. PMID:24856780

  11. 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.

  12. Carbon dioxide effects research and assessment program

    International Nuclear Information System (INIS)

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

  13. Carbon Dioxide Separation from Flue Gas by Phase Enhanced Absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tim Fout

    2007-06-30

    A new process, phase enhanced absorption, was invented. The method is carried out in an absorber, where a liquid carrier (aqueous solution), an organic mixture (or organic compound), and a gas mixture containing a gas to be absorbed are introduced from an inlet. Since the organic mixture is immiscible or at least partially immiscible with the liquid carrier, the organic mixture forms a layer or small parcels between the liquid carrier and the gas mixture. The organic mixture in the absorber improves mass transfer efficiency of the system and increases the absorption rate of the gas. The organic mixture serves as a transportation media. The gas is finally accumulated in the liquid carrier as in a conventional gas-liquid absorption system. The presence of the organic layer does not hinder the regeneration of the liquid carrier or recovery of the gas because the organic layer is removed by a settler after the absorption process is completed. In another aspect, the system exhibited increased gas-liquid separation efficiency, thereby reducing the costs of operation and maintenance. Our study focused on the search of the organic layer or transportation layer to enhance the absorption rate of carbon dioxide. The following systems were studied, (1) CO{sub 2}-water system and CO{sub 2}-water-organic layer system; (2) CO{sub 2}-Potassium Carbonate aqueous solution system and CO{sub 2}-Potassium Carbonate aqueous solution-organic layer system. CO{sub 2}-water and CO{sub 2}-Potassium Carbonate systems are the traditional gas-liquid absorption processes. The CO{sub 2}-water-organic layer and CO{sub 2}-Potassium Carbonate-organic layer systems are the novel absorption processes, phase enhanced absorption. As we mentioned early, organic layer is used for the increase of absorption rate, and plays the role of transportation of CO{sub 2}. Our study showed that the absorption rate can be increased by adding the organic layer. However, the enhanced factor is highly depended on the

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

    Science.gov (United States)

    Moreira, Diana; Pires, José C M

    2016-09-01

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

  15. 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.

  16. 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.

  17. 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.

  18. Executive order no. 659 of 4. July 2000. Executive order on the agreement on energy efficiency improvement and on state subsidies for covering the expenses of taxation on carbon dioxide paid by certain companies. (Executive order on energy agreement)

    International Nuclear Information System (INIS)

    The Danish executive order no. 659 of July 4, 2000. Pursuant to paragraph 1 - section 4, paragraph 2 - section 1, paragraph 4 and paragraph 7 - section 2, of the law on state subsidies for coverage of expenses related to taxation on carbon dioxide in cases of certain companies that consume a large amount of energy, refer to executive order no. 946 of November 17, 1997. Executive order no. 659, of July 4, 2000, contains regulations on conditions on which agreements are to be reached relevant to obtaining subsidies, on energy surveys, on leaders of energy auditing within individual firms, on plans of management, on agreement on the plan of management for energy conservation with in a firm or company, on special rules for agreements and plans of management within branches of industry, on verification etc., on assurance of the payment of subsidies, on withdrawal of assurance and on repay of subsidies, on accounting, subsidies to energy efficiency improvement activities and other legislation on authorization and inspection, on a board to be set up to receive complaints and on penalties. The executive order will come into force on August 1, 2000. (EHS)

  19. 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...... reproduces monthly patterns in the data and the global monthly pattern of emissions is relatively insensitive to the exact proxy assignments used. The data and results presented here should lead to a better understanding of global and regional carbon cycles, especially when the mass data are combined...... with the stable carbon isotope data in atmospheric transport models....

  20. Using the second law first: Improving the thermodynamic efficiency of carbon dioxide separation from gas streams in an Endex calcium looping system

    International Nuclear Information System (INIS)

    The most costly step in carbon capture from flue gas streams is regeneration of the pure CO2 stream from the sorbent, because of the high temperatures required by conventional systems. This work presents an entropy generation analysis of the new Endex calcium looping method, in which regeneration is driven directly by the heat of carbonation and pressure-swing is used to reduce the temperature of calcination. Entropy generation rates for the important subprocesses in the control volume are computed and visualised over the expedient parameter space. The performance of the system is optimised in two ways: by minimising the total entropy generation rate per mole of CO2 captured, and by maximising the capture efficiency. The tradeoff between these two objectives is highlighted. - Highlights: • Entropy generation analysis is applied to a model Endex CO2 scrubbing system. • Entropy generation rates are computed for all of the important subprocesses. • The specific entropy generation rate and the CO2 capture efficiency are optimised. • Reducing the temperatures and pressures can reduce the second law efficiency. • Irreversibility from even a very small sorbent replacement flow is significant

  1. Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone.

    Science.gov (United States)

    Karberg, N J; Pregitzer, K S; King, J S; Friend, A L; Wood, J R

    2005-01-01

    Global emissions of atmospheric CO(2) and tropospheric O(3) are rising and expected to impact large areas of the Earth's forests. While CO(2) stimulates net primary production, O(3) reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects of multiple air pollutants can alter belowground C allocation, leading to changes in the partial pressure of CO(2) (pCO(2)) in the soil , chemistry of dissolved inorganic carbonate (DIC) and the rate of mineral weathering. As this system represents a linkage between the long- and short-term C cycles and sequestration of atmospheric CO(2), changes in atmospheric chemistry that affect net primary production may alter the fate of C in these ecosystems. To date, little is known about the combined effects of elevated CO(2) and O(3) on the inorganic C cycle in forest systems. Free air CO(2) and O(3) enrichment (FACE) technology was used at the Aspen FACE project in Rhinelander, Wisconsin to understand how elevated atmospheric CO(2) and O(3) interact to alter pCO(2) and DIC concentrations in the soil. Ambient and elevated CO(2) levels were 360+/-16 and 542+/-81 microl l(-1), respectively; ambient and elevated O(3) levels were 33+/-14 and 49+/-24 nl l(-1), respectively. Measured concentrations of soil CO(2) and calculated concentrations of DIC increased over the growing season by 14 and 22%, respectively, under elevated atmospheric CO(2) and were unaffected by elevated tropospheric O(3). The increased concentration of DIC altered inorganic carbonate chemistry by increasing system total alkalinity by 210%, likely due to enhanced chemical weathering. The study also demonstrated the close coupling between the seasonal delta(13)C of soil pCO(2) and DIC, as a mixing model showed that new atmospheric CO(2) accounted for approximately 90% of the C leaving the system as DIC. This study illustrates the potential of using stable isotopic techniques and FACE technology to examine long- and short

  2. 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.

    estuaries. The mean pCO sub(2) and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO sub(2) fluxes from...

  3. Molecular transport: Catch the carbon dioxide

    Science.gov (United States)

    Kirchner, Barbara; Intemann, Barbara

    2016-05-01

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

  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. 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...

  6. 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.

  7. Carbon Dioxide Separation from Flue Gas by Phase Enhanced Absorption

    Energy Technology Data Exchange (ETDEWEB)

    Liang Hu

    2006-06-30

    A new process, phase enhanced absorption, was invented. The method is carried out in an absorber, where a liquid carrier (aqueous solution), an organic mixture (or organic compound), and a gas mixture containing a gas to be absorbed are introduced from an inlet. Since the organic mixture is immiscible or at least partially immiscible with the liquid carrier, the organic mixture forms a layer or small parcels between the liquid carrier and the gas mixture. The organic mixture in the absorber improves mass transfer efficiency of the system and increases the absorption rate of the gas. The organic mixture serves as a transportation media. The gas is finally accumulated in the liquid carrier as in a conventional gas-liquid absorption system. The presence of the organic layer does not hinder the regeneration of the liquid carrier or recovery of the gas because the organic layer is removed by a settler after the absorption process is completed. In another aspect, the system exhibited increased gas-liquid separation efficiency, thereby reducing the costs of operation and maintenance. Our study focused on the search of the organic layer or transportation layer to enhance the absorption rate of carbon dioxide. The following systems were studied, (1) CO{sub 2}-water system and CO{sub 2}-water-organic layer system; (2) CO{sub 2}-Potassium Carbonate aqueous solution system and CO{sub 2}-Potassium Carbonate aqueous solution-organic layer system. CO{sub 2}-water and CO{sub 2}-Potassium Carbonate systems are the traditional gas-liquid absorption processes. The CO{sub 2}-water-organic layer and CO{sub 2}-Potassium Carbonate-organic layer systems are the novel absorption processes, phase enhanced absorption. As we mentioned early, organic layer (transportation layer phase) is used for the increase of absorption rate. Our study showed that the absorption rate can be increased by adding the organic layer. However, the enhanced factor is highly depended on the liquid mass transfer

  8. 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.

  9. Carbon dioxide emissions embodied in international trade in Central Europe between 1995 and 2008

    Directory of Open Access Journals (Sweden)

    Vlčková Jana

    2015-12-01

    Full Text Available Climate change and environmental policies are widely discussed, but much less is known about emissions embodied in goods traded internationally, and the distinction between emission producers and consumers. The carbon dioxide emissions embodied in international trade in Central European countries are subject to examination in this paper. As a result of industrial restructuring and environmental legislation, air pollution has improved significantly in Central European countries since the 1989 transition. On the other hand, economic growth has been accompanied by a rise in consumerism. Despite the increasing role of exports, the Visegrad group countries have become net importers of carbon dioxide emissions between 1995 and 2008. This seems to be the ‘standard trajectory’ of a country’s transition toward a more developed and consumption-oriented economy. The global patterns of carbon dioxide emissions embodied in manufacturing exports are also mapped, using network analysis and constructing ‘product space’. The analysis confirms that industrial re-structuring played an important role in lowering the production of carbon dioxide emissions in the Visegrad countries.

  10. Carbon dioxide digital subtraction angiography manifestations of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Yan-hao; HE Xiao-feng; CHEN Yong; ZENG Qing-le; XU Xiao-li

    2002-01-01

    Objective: To investigate the imaging features and clinical significance of carbon dioxide digital subtraction angiography (CO2-DSA) in the diagnosis and treatment of hepatocellular carcinoma (HCC).Methods: Both CO2-DSA and conventional DSA were performed in all 47 patients with HCC, and the angiographic manifestations of CO2-DSA were compared with those of conventional DSA in the same patients.Results: Peripheral arterial and capillary imaging by CO2-DSA was inferior to that by conventional DSA, although blood pools were well visualized with CO2. Improved visualization of arterioportal shunting (APS)was obtained with CO2-DSA compared with that by conventional angiography. APS was observed in 33 cases by CO2-DSA and in 12 cases by conventional angiography (P<0. 001). Retrograde visualization of the portal vein (PV) trunk and its large branches was demonstrated in 16 cases by CO2-DSA and in 1 case by conventional DSA (P<0. 001). The manifestation of lipiodol retention in the tumors was consistent with CO2-DSA images after TAE in 38 cases, and with those of conventional DSA in 23 cases (P<0. 01). Conclusion: CO2-DSA was superior to conventional DSA in the detection of APS and retrograde visualization of PV system,and the former can provide usefulness information for the treatment planning (chemoembolization) and patient prognosis. Demonstration of APS by CO2-DSA may suggest the presence of intrahepatic metastases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

    The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. Testing conducted previously confirmed that the reaction rate and achievable CO{sub 2} capacity of sodium carbonate decreased with increasing temperature, and that the global rate of reaction of sodium carbonate to sodium bicarbonate increased with an increase in both CO{sub 2} and H{sub 2}O concentrations. Energy balance calculations indicated that the rate of heat removal from the particle surface may determine the reaction rate for a particular particle system. This quarter, thermogravimetric analyses (TGA) were conducted which indicated that calcination of sodium bicarbonate at temperatures as high as 200 C did not cause a significant decrease in activity in subsequent carbonation testing. When sodium bicarbonate was subjected to a five cycle calcination/carbonation test, activity declined slightly over the first two cycles but was constant thereafter. TGA tests were also conducted with two other potential sorbents. Potassium carbonate was found to be less active than sodium carbonate, at conditions of interest in preliminary TGA tests. Sodium carbonate monohydrate showed negligible activity. Testing was also conducted in a 2-inch internal diameter quartz fluidized-bed reactor system. A five cycle test demonstrated that initial removals of 10 to 15 percent of the carbon dioxide in a simulated flue gas could be achieved. The carbonation reaction proceeded at temperatures as low as 41 C. Future work by TGA and in fixed

  12. 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

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

    Science.gov (United States)

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

    2009-10-01

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

  14. 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.).

  15. 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.

  16. 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.

  17. 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.

  18. The underground storages of carbon dioxide. Juridical aspects

    International Nuclear Information System (INIS)

    In the framework of the reduction of the carbon dioxide emissions in the air, the underground storage of the CO2 is studied. Some experimentation are already realized in the world and envisaged in France. This document aims to study the juridical aspects of these first works in France. After a presentation of the realization conditions and some recalls on the carbon dioxide its capture and storage, the natural CO2 underground storages and the first artificial storages are discussed. The CO2 waste qualification, in the framework of the environmental legislation is then detailed with a special task on the Lacq region. The problem of the sea underground storages is also presented. (A.L.B.)

  19. Detecting Climate Change due to Increasing Carbon Dioxide.

    Science.gov (United States)

    Madden, R A; Ramanathan, V

    1980-08-15

    The observed interannual variability of temperature at 60 degrees N has been investigated. The results indicate that the surface warming due to increased carbon dioxide which is predicted by three-dimensional climate models should be detectable now. It is not, possibly because the predicted warming is being delayed more than a decade by ocean thermal inertia, or because there is a compensating cooling due to other factors. Further consideration of the uncertainties in model predictions and of the likely delays introduced by ocean thermal inertia extends the range of time for the detection of warming, if it occurs, to the year 2000. The effects of increasing carbon dioxide should be looked for in several variables simultaneously in order to minimize the ambiguities that could result from unrecognized compensating cooling. PMID:17753291

  20. 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...

  1. Crop soil air carbon dioxide concentration and sludge

    Energy Technology Data Exchange (ETDEWEB)

    Guiresse, M.; Gers, C.; Dourel, L.; Kaemmerer, M.; Revel, J.C. [Institut National Polytechnique de Toulouse, Toulouse (France). Ecole Nationale Superieure Agronomique de Toulouse

    1995-12-31

    The introduction of organic compounds into the soil may increase carbon dioxide emission and thus change the composition of the soil air and microfauna. These factors were studied in a field experiment in luvi-redoxisoils in the South West of France. The untreated liquid sludge from the wastewater treatment plant of Toulouse was tested. The first field plot was an unploughed plot, without any fertilizer and any sludge; the second was a control plot sown with Zea mays and a standard mineral fertilizer without any sludge; the third plot was sown with Zea mays and a normal amount of sludge; and the last plot was sown with Zea mays and a large amount of sludge. In these plots soil air dioxide carbon concentration during all the maize cultivation was measured using the Draeger field method twice a week. The results showed that burying degradable organic compounds increases soil air CO{sub 2}. 8 refs., 6 figs.

  2. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-16

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

  3. Carbon monoxide poisoning in a patient with carbon dioxide retention: a therapeutic challenge

    OpenAIRE

    Lane, Tristan RA; Williamson, Wilby J; Brostoff, Joshua M

    2008-01-01

    We present the case of a 70 year-old man with carbon monoxide poisoning following a house fire. A significant smoking history and likely underlying chronic lung pathology complicated treatment, as due to symptomatic retention of carbon dioxide we were unable to use high-flow oxygen to facilitate the elimination of carbon monoxide. We suggest that patients with risk factors for obstructive lung disease be monitored extremely carefully during treatment for carbon monoxide toxicity.

  4. Titanium dioxide, single-walled carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-14

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

  5. 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.

  6. Carbon dioxide based nephroscopy: a trick for laparoscopic pyelolithotomy.

    Science.gov (United States)

    Mason, Barry Michael; Hoenig, David

    2008-12-01

    For certain selected cases, laparoscopic pyelolithotomy is a practical and effective method to manage renal stone disease. One such case is that of an ectopically located pelvic kidney with a large stone burden. Here, we describe our technique and provide what we feel is a trick to performing a key part of this procedure--flexible nephroscopy while using carbon dioxide gas to "inflate" the collecting system. PMID:19099514

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

    OpenAIRE

    A. Stohl

    2008-01-01

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

  8. High-energy, short-pulse, carbon-dioxide lasers

    International Nuclear Information System (INIS)

    Lasers for fusion application represent a special class of short-pulse generators; not only must they generate extremely short temporal pulses of high quality, but they must do this at ultra-high powers and satisfy other stringent requirements by this application. This paper presents the status of the research and development of carbon-dioxide laser systems at the Los Alamos Scientific Laboratory, vis-a-vis the fusion requirements

  9. Inhibition of Weld Corrosion in Flowing Brines Containing Carbon Dioxide

    OpenAIRE

    Alawadhi, Khaled

    2009-01-01

    The aim of this research was to study the effectiveness of a typical oilfield corrosion inhibitor, which is considered to be a green inhibitor (non toxic to the environment) in controlling internal corrosion of welded X65 pipeline steel in brines saturated with carbon dioxide at one bar pressure, under dynamic flowing conditions, over a range of temperatures. Several experimental configurations were used ranging from a simple flat plate design to a novel rotating cylinder electrode, to all...

  10. Bacterial inactivation by using near- and supercritical carbon dioxide

    OpenAIRE

    Dillow, Angela K.; Dehghani, Fariba; Hrkach, Jeffrey S.; Foster, Neil R.; Langer, Robert

    1999-01-01

    The three most common methods of sterilization in use today are ethylene oxide exposure, γ-irradiation, and steam sterilization. Each of these methods has serious limitations for the sterilization of some materials used in medicine, especially thermally and hydrolytically sensitive polymers by themselves and in combination with proteins. In this work, we demonstrate a potential new method of sterilization by using supercritical fluid carbon dioxide. Using this method we achieve complete inact...

  11. 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.

  12. Revealing the Origin of Activity in Nitrogen-Doped Nanocarbons towards Electrocatalytic Reduction of Carbon Dioxide

    DEFF Research Database (Denmark)

    Xu, Junyuan; Kan, Yuhe; Huang, Rui;

    2016-01-01

    Carbon nanotubes (CNTs) are functionalized with nitrogen atoms for reduction of carbon dioxide (CO2). The investigation explores the origin of the catalyst’s activity and the role of nitrogen chemical states therein. The catalysts show excellent performances, with about 90% current efficiency...... for CO formation and stability over 60 hours. The Tafel analyses and density functional theory calculations suggest that the reduction of CO2 proceeds through an initial rate-determining transfer of one electron to CO2, which leads to the formation of carbon dioxide radical anion (CO2C). The initial...... reduction barrier is too high on pristine CNTs, resulting in a very high overpotentials at which the hydrogen evolution reaction dominates over CO2 reduction.The doped nitrogen atoms stabilize the radical anion,thereby lowering the initial reduction barrier and improving the intrinsic activity. The most...

  13. 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)

  14. Study on carbon dioxide conversion by radiation

    International Nuclear Information System (INIS)

    This study was carried out to investigate the synergistic effects on the CO2 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 CO2 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 CO2 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 CO2 conversion yield to organic matter up to 50 percent compared to the gamma-ray irradiation. The way of achieving higher activity is due to the catalytic action of semiconductor by gamma-ray irradiation. Zr-doped TiO2 catalyst prepared by sol-gel method exhibits the higher efficiency for CO2 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 TiO2 film. (author)

  15. Minimizing emission of carbon dioxide in the coconut processing

    International Nuclear Information System (INIS)

    About 90% of the world's coconut production is made into copra. There are 2-3 million smoke kilns which are used by the coconut farmers for making copra. It is estimated that these kilns emit carbon dioxide from 247 to 366 gram of carbon per kg of copra produced. From the world copra production of 10 M tons, the total carbon released in copra making range is 2-3 Tg(telegram=1012grams) or 2-3M tons of carbon per year. To minimize carbon dioxide emission in copra making, kilns with better combustion characteristics and heat utilization efficiencies must be used. One of the most promising alternative dryers is a direct-fired, natural draft dryer known as the Los Banos (Lozada) Dryer. Developed at the University of the Philippines Los Banos, the dryer consist of a simple burner, a heat distributor and a drying bin. The burner combust coconut shell, corn cob, and wood pieces with extremely high efficiency thus minimizing fuel consumption and dramatically reducing the release of airborne pollutants. The resulting copra is practically smoke free. Tests have shown that carbon dioxide emissions from the Los Banos (Lozada) Dryer are about half of that released by the traditional smoke kilns. Furthermore, the dryer emits lower concentrations of CO (50 ppm vs 2000-3000 ppm), of NOx(5 ppm vs 400 ppm), and SOx(5 ppm vs 400 ppm). When used widely, significant reductions in the emissions of greenhouse and acid rain gases from biomass combustion will be attained. (About 500 units of the Los Banos (Lozada) Dryer are now in use in the Philippines and Papua New Guinea). (Author)

  16. Electrochemical Cell for Obtaining Oxygen from Carbon Dioxide Atmospheres

    Science.gov (United States)

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

    1989-01-01

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

  17. 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.

  18. Regional carbon dioxide implications of forest bioenergy production

    OpenAIRE

    Hudiburg, Tara W.; Law, Beverly E.; Wirth, Christian; Luyssaert, Sebastiaan

    2011-01-01

    International audience Strategies for reducing carbon dioxide emissions include substitution of fossil fuel with bioenergy from forests1, where carbon emitted is expected to be recaptured in the growth of new biomass to achieve zero net emissions2, and forest thinning to reduce wildfire emissions3. Here, we use forest inventory data to show that fire prevention measures and large-scale bioenergy harvest in US West Coast forests lead to 2-14% (46-405 Tg C) higher emissions compared with cur...

  19. 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.

  20. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  1. Carbon Dioxide Sequestration, Weathering Approaches to

    Science.gov (United States)

    Schuiling, R. D.

    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 technologies add considerably to the cost of the process. In this entry, the focus is on the optimization of the weathering conditions, by selecting the most reactive abundantly available minerals, grinding them, and spreading the grains over land. Thereafter nature takes its course. Since its formulation in the late 1990s, more and more people realize that this simple and natural approach may well turn out to be one of the most promising and environmentally friendliest ways to counteract climate change and ocean acidification

  2. Measurement and Modeling of Carbon Dioxide Solubility in Polar and Nonpolar Solvent

    OpenAIRE

    Hojatollah Ahmadi

    2012-01-01

    The solubility of gases is an important issue in the industries. Carbon Dioxide Through gas transmission line exists as sour gas therefore it is eliminated by solvent in industry. Carbone Dioxide is nonpolar molecule that has lower solubility in liquid solvent. In this study the solubility of carbon dioxide in some polar and nonpolar solvents (include Acetone, Acetic Acid, Benzene, Carbon Tetra Chloride, Chlorobenzene, Chloroform, Cyclo-hexane, Di-Methyl Formamid, Ethanol, Ethyl acetate, Meth...

  3. 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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-01

    This report describes research conducted between January 1, 2004 and March 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. RTI has produced laboratory scale batches (approximately 300 grams) of supported sorbents (composed of 20 to 40% sodium carbonate) with high surface area and acceptable activity. Initial rates of weight gain of the supported sorbents when exposed to a simulated flue gas exceeded that of 100% calcined sodium bicarbonate. One of these sorbents was tested through six cycles of carbonation/calcination by thermogravimetric analysis and found to have consistent carbonation activity. Kinetic modeling of the regeneration cycle on the basis of diffusion resistance at the particle surface is impractical, because the evolving gases have an identical composition to those assumed for the bulk fluidization gas. A kinetic model of the reaction has been developed on the basis of bulk motion of water and carbon dioxide at the particle surface (as opposed to control by gas diffusion). The model will be used to define the operating conditions in future laboratory- and pilot-scale testing.

  6. Advances in Raman Lidar Measurements of Water Vapor, Cirrus Clouds and Carbon Dioxide

    Science.gov (United States)

    Whiteman, David N.; Potter, John R.; Tola, Rebecca; Rush, Kurt; Veselovskii, Igor; Cadirola, Martin; Comer, Joseph

    2006-01-01

    Narrow-band interference filters with improved transmission in the ultraviolet have been developed under NASA-funded research and used in the Raman Airborne Spectroscopic Lidar (RASL) in ground- based, upward-looking tests. RASL is an airborne Raman Lidar system designed to measure water vapor mixing ratio, and aerosol backscatter/extinction/depolarization. It also possesses the capability to make experimental measurements of cloud liquid water and carbon dioxide. It is being prepared for first flight tests during the summer of 2006. With the newly developed filters installed in RASL, measurements were made of atmospheric water vapor, cirrus cloud optical properties and carbon dioxide that improve upon any previously demonstrated using Raman lidar. Daytime boundary layer profiling of water vapor mixing ratio is performed with less than 5% random error using temporal and spatial resolution of 2-minutes and 60 - 210, respectively. Daytime cirrus cloud optical depth and extinction- to-backscatter ratio measurements are made using 1-minute average. Sufficient signal strength is demonstrated to permit the simultaneous profiling of carbon dioxide and water vapor mixing ratio into the free troposphere during the nighttime. Downward-looking from an airborne RASL should possess the same measurement statistics with approximately a factor of 5 - 10 decrease in averaging time. A description of the technology improvements are provided followed by examples of the improved Raman lidar measurements.

  7. SOFT SENSOR FOR BETTER CONTROL OF CARBON DIOXIDE REMOVAL PROCESS IN ETHYLENE GLYCOL PLANT

    Directory of Open Access Journals (Sweden)

    NADEEM M. KHALFE

    2011-03-01

    Full Text Available Low carbon dioxide in cycle gas loop of ethylene glycol (EG plant improves catalyst selectivity and overall economics of the plant. Carbon dioxide produced as a byproduct in ethylene oxide reactor is removed by the Benfield process. In this process, the carbonate and bicarbonate ratio in lean carbonate solution is considered as an important quality control (QC variable as the efficiency of carbon dioxide removal largely depends on it. In the event of a process malfunction or operating under suboptimal condition, the CO2 content in the cycle gas loop will continue to rise until corrective action is taken after obtaining lab results for carbonate and bicarbonate ratio. This time consuming sampling process can be overcome by implementing a technological solution in form of an accurate and robust mathematical model capable of real time QC variable prediction. For well understood processes, the structure of the correlation for QC variables as well as the choice of the inputs may be well known in advance. However, the Benfield process is too complex and the appropriate form of the correlation and choice of input variables are not obvious. Here, knowledge of the processes, operating experience and statistical methods were applied in developing the soft sensor. This paper describes a systematic approach to the development of inferential measurements of carbonate and bi¬carbonate ratio using Support Vector Regression (SVR analysis. Given histo¬rical process data, a simple SVR-based soft sensor model is found capable of identifying and capturing the cause and effect relationship between operating variables (model inputs and QC variables (model outputs. Special care was taken to choose input variables, so that the final correlation and regression coefficient make senses from process engineering point of view. The developed soft sensor was implemented in commercial ethylene glycol plant in an Exa¬quantum interface and was found to satisfactorily predict

  8. Oxygen Generation from Carbon Dioxide for Advanced Life Support

    Science.gov (United States)

    Bishop, Sean; Duncan, Keith; Hagelin-Weaver, Helena; Neal, Luke; Sanchez, Jose; Paul, Heather L.; Wachsman, Eric

    2007-01-01

    The partial electrochemical reduction of carbon dioxide (CO2) using ceramic oxygen generators (COGs) is well known and widely studied. However, complete reduction of metabolically produced CO2 (into carbon and oxygen) has the potential of reducing oxygen storage weight for life support if the oxygen can be recovered. Recently, the University of Florida devel- oped novel ceramic oxygen generators employing a bilayer elec- trolyte of gadolinia-doped ceria and erbia-stabilized bismuth ox- ide (ESB) for NASA's future exploration of Mars. The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. The strategy discussed here for advanced life support systems employs a catalytic layer com- bined with a COG cell so that CO2 is reduced all the way to solid carbon and oxygen without carbon buildup on the COG cell and subsequent deactivation.

  9. Amazon River carbon dioxide outgassing fuelled by wetlands

    Science.gov (United States)

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

    2014-01-01

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

  10. 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.

  11. Carbon dioxide enrichment of greenhouse crops

    Energy Technology Data Exchange (ETDEWEB)

    Enoch, H.Z.; Kimball, B.A.

    1986-01-01

    This volume contains the following on these major topics of physiology, yield and economics: Fixation of Inorganic Carbon in Plant Cells. Effects of CO/sub 2/ Enrichment on Photosynthesis of C/sub 3/ Plants. Effects of CO/sub 2/ Concentration on Photosynthesis and Respiration of C/sub 4/ and CAM Plants. Effects of CO/sub 2/ Concentration on Composition, Anatomy, and Morphology of Plants. Stimulation of Growth and Yield Under Environmental Restraints. Woody Plant Reactions to CO/sub 2/ Enrichment. Influence of the CO/sub 2/ Content of the Ambient Air on Stomatal Conductance and CO/sub 2/ Concentration in Leaves. Influence of Elevated CO/sub 2/ on Crop Yield. Fertilization of Carnations and Some Other Flower Crops. CO/sub 2/ Enrichment for Greenhouse Rose Production. CO/sub 2/ Enrichment of Tomato Crops. CO/sub 2/ Enrichment Duration and Heating Credit as Determined by Climate. Economics of CO/sub 2/ Enrichment in Greenhouses. Units Conversion. Currency Exchange Rates.

  12. Precise Measurement of Carbon Dioxide Column by Passive Ground Based Sensor

    Science.gov (United States)

    Heaps, William S.; Wilson, Emily L.; Georgieva, Elena

    2007-01-01

    Over the past four years we have developed a family of differential radiometers based upon the Fabry-Perot interferometers that exhibit very great sensitivity to changes in the atmospheric column of carbon dioxide, oxygen, and water vapor. Our instruments employ a solid Fabry-Perot etalon that is tuned to the proper wavelength by changing its temperature. The thickness of the etalon has been selected so that its multiple pass bands align with regularly space absorption features of the molecule under investigation. Using multiple absorption features improves the optical throughput of the instrument and improves the stability of the instrument response with respect to environmental changes. We are presently working to extend this technique to the carbon 13 isotope of carbon dioxide and to methane. Our instruments are intrinsically rugged and can be fabricated in a small package at relatively low cost.. As such they hold promise for widespread use in ground based networks for calibration and validation of satellite instruments such as OCO and GOSAT. Results will be presented for long term ground based operations of these systems. The effects of atmospheric scattering, pointing errors, pressure broadening and temperature effects will be discussed with regard to achieving precision better than .5% required for validation of carbon dioxide column measured from space. Finally we will outline the approach for extension of this methodology to additional molecular species of interest.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-01

    The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates or intermediate salts through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that high calcination temperatures decrease the activity of sodium bicarbonate Grade 1 (SBC No.1) during subsequent carbonation cycles, but there is little or no progressive decrease in activity in successive cycles. SBC No.1 appears to be more active than SBC No.3. As expected, the presence of SO{sub 2} in simulated flue gas results in a progressive loss of sorbent capacity with increasing cycles. This is most likely due to an irreversible reaction to produce Na{sub 2}SO{sub 3}. This compound appears to be stable at calcination temperatures as high as 200 C. Tests of 40% supported potassium carbonate sorbent and plain support material suggest that some of the activity observed in tests of the supported sorbent may be due to adsorption by the support material rather than to carbonation of the sorbent.

  14. Development of NaY zeolite derived from biomass and environmental assessment of carbon dioxide reduction

    OpenAIRE

    Worathanakul Patcharin; Tobarameekul Patchaya

    2016-01-01

    Carbon dioxide is one of greenhouse gases. The carbon dioxide caused by the industry activities and impact to the global warming. The objectives of this research were to synthesize NaY zeolite from bagasse ash as silica source and loaded with different weight percentage of Cu(II) for carbon dioxide reduction. The carbon footprint of Cu/Y zeolite for carbon dioxide reduction was calculated. The synthesized NaY zeolite from bagasse ash can be easily formed at Si/Al ratio of 0.75 with the additi...

  15. The potential of clear-sky carbon dioxide satellite retrievals

    Directory of Open Access Journals (Sweden)

    R. R. Nelson

    2015-12-01

    Full Text Available Since the launch of the Greenhouse Gases Observing Satellite (GOSAT in 2009, retrieval algorithms designed to infer the column-averaged dry-air mole fraction of carbon dioxide (XCO2 from hyperspectral near-infrared observations of reflected sunlight have been greatly improved. They now generally include the scattering effects of clouds and aerosols, as early work found that absorption-only retrievals, which neglected these effects, often incurred unacceptably large errors, even for scenes with optically thin cloud or aerosol layers. However, these "full-physics" retrievals tend to be computationally expensive and may incur biases from trying to deduce the properties of clouds and aerosols when there are none present. Additionally, algorithms are now available that can quickly and effectively identify and remove most scenes in which cloud or aerosol scattering plays a significant role. In this work, we test the hypothesis that non-scattering, or "clear-sky", retrievals may perform as well as full-physics retrievals for sufficiently clear scenes. Clear-sky retrievals could potentially avoid errors and biases brought about by trying to infer properties of clouds and aerosols when none are present. Clear-sky retrievals are also desirable because they are orders of magnitude faster than full-physics retrievals. Here we use a simplified version of the Atmospheric Carbon Observations from Space (ACOS XCO2 retrieval algorithm that does not include the scattering and absorption effects of clouds or aerosols. It was found that for simulated Orbiting Carbon Observatory-2 (OCO-2 measurements, the clear-sky retrieval had errors comparable to those of the full-physics retrieval. For real GOSAT data, the clear-sky retrieval had nearly indistinguishable error characteristics over land, but roughly 30–60 % larger errors over ocean, depending on filtration level, compared to the full-physics retrieval. In general, the clear-sky retrieval had XCO2 root

  16. Carbon dioxide sequestration in cement kiln dust through mineral carbonation.

    Science.gov (United States)

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

    2009-03-15

    Carbon sequestration through the formation of carbonates is a potential means to reduce CO2 emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation The degree of mineral carbonation achievable in cement kiln dust (CKD) underambienttemperatures and pressures was examined through a series of batch and column experiments. The overall extent and potential mechanisms and rate behavior of the carbonation process were assessed through a complementary set of analytical and empirical methods, including mass change, thermal analysis, and X-ray diffraction. The carbonation reactions were carried out primarily through the reaction of CO2 with Ca(OH)2, and CaCO3 was observed as the predominant carbonation product. A sequestration extent of over 60% was observed within 8 h of reaction without any modifications to the waste. Sequestration appears to follow unreacted core model theory where reaction kinetics are controlled by a first-order rate constant at early times; however, as carbonation progresses, the kinetics of the reaction are attenuated by the extent of the reaction due to diffusion control, with the extent of conversion never reaching completion. PMID:19368202

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-05-01

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

  18. Repigmentation of hypopigmented scars using combination of fractionated carbon dioxide laser with topical latanoprost vs. fractionated carbon dioxide laser alone

    Directory of Open Access Journals (Sweden)

    Amir Hossein Siadat

    2015-01-01

    Full Text Available Background: Fractionated carbon dioxide (CO 2 can treat hypopigmented scars. Latanoprost is a prostaglandin analog used to treat glaucoma. It can cause adverse effects, such as periocular hyperpigmentation. The aim of this study was to assess the efficacy and safety of latanoprost plus CO 2 laser on the repigmentation of hypopigmented scars. Patients and Methods: 28 patients with hypopigmented scars were divided randomly into two groups. The patients in group A were treated in six sessions (1-month intervals with 10600-nm fractional CO 2 laser plus latanoprost 0.005% and those of group B fractionated CO 2 laser plus placebo (distilled water. Digital photographs were taken at baseline and 3 months after the last treatment session. The blinded dermatologist compared the photographs and evaluated the efficacy of treatment in the hypopigmented scars using a 4-scale point (grade 1-4. Patient satisfaction was scored from 0 to 10 on a visual analog scale. Results: Follow-up results 12 weeks after the last treatment session demonstrated that 11 of the 14 patients in group A had more than 50% improvement in hypopigmentation The difference in improvement of the two groups was statistically significant (P = 0.027. The mean of the VAS scores of patients in group A was 6.50 ± 1.45 and in group B 4.57 ± 1.6. The difference in mean satisfaction of the two groups was statistically significant (P = 0.003. Side effects were mild and resolved within 1 to 5 days. Conclusion: The fractional CO 2 laser resurfacing plus topical latanoprost can be used as a safe and efficacious method to treat hypopigmented scars.

  19. 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

  20. Permeability variation characteristics of coal after injecting carbon dioxide into a coal seam

    Institute of Scientific and Technical Information of China (English)

    Ni Xiaoming; Li Quanzhong; Wang Yanbin; Gao Shasha

    2015-01-01

    A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal (mainly including montmorillonite, illite and kaolinite) exhibit expansion as a result of ion exchange with the H+in acid solution, which has a negative effect on the per-meability of the coal. The permeability of coal samples increased at first and then decreased with immer-sion time, and when the soaking time is 2–3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 mD, the effect on the permeabil-ity is low;when the permeability of the coal is in the range 0.2–2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox-ide injection under different reservoir permeability conditions and subsequent drainage.

  1. Advanced Supercritical Carbon Dioxide Brayton Cycle Development

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark [Univ. of Wisconsin, Madison, WI (United States); Sienicki, James [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, Anton [Argonne National Lab. (ANL), Argonne, IL (United States); Nellis, Gregory [Univ. of Wisconsin, Madison, WI (United States); Klein, Sanford [Univ. of Wisconsin, Madison, WI (United States)

    2015-10-21

    Fluids operating in the supercritical state have promising characteristics for future high efficiency power cycles. In order to develop power cycles using supercritical fluids, it is necessary to understand the flow characteristics of fluids under both supercritical and two-phase conditions. In this study, a Computational Fluid Dynamic (CFD) methodology was developed for supercritical fluids flowing through complex geometries. A real fluid property module was implemented to provide properties for different supercritical fluids. However, in each simulation case, there is only one species of fluid. As a result, the fluid property module provides properties for either supercritical CO2 (S-CO2) or supercritical water (SCW). The Homogeneous Equilibrium Model (HEM) was employed to model the two-phase flow. HEM assumes two phases have same velocity, pressure, and temperature, making it only applicable for the dilute dispersed two-phase flow situation. Three example geometries, including orifices, labyrinth seals, and valves, were used to validate this methodology with experimental data. For the first geometry, S-CO2 and SCW flowing through orifices were simulated and compared with experimental data. The maximum difference between the mass flow rate predictions and experimental measurements is less than 5%. This is a significant improvement as previous works can only guarantee 10% error. In this research, several efforts were made to help this improvement. First, an accurate real fluid module was used to provide properties. Second, the upstream condition was determined by pressure and density, which determines supercritical states more precise than using pressure and temperature. For the second geometry, the flow through labyrinth seals was studied. After a successful validation, parametric studies were performed to study geometric effects on the leakage rate. Based on these parametric studies, an optimum design strategy for the see

  2. 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.

  3. Microchannel Heat Exchangers with Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Ohadi, M.M.; Radermacher, R.

    2001-09-15

    The objective of the present study was to determine the performance of CO{sub 2} microchannel evaporators and gas coolers in operational conditions representing those of residential heat pumps. A set of breadboard prototype microchannel evaporators and gas coolers was developed and tested. The refrigerant in the heat exchangers followed a counter cross-flow path with respect to the airflow direction. The test conditions corresponded to the typical operating conditions of residential heat pumps. In addition, a second set of commercial microchannel evaporators and gas coolers was tested for a less comprehensive range of operating conditions. The test results were reduced and a comprehensive data analysis, including comparison with the previous studies in this field, was performed. Capacity and pressure drop of the evaporator and gas cooler for the range of parameters studied were analyzed and are documented in this report. A gas cooler performance prediction model based on non-dimensional parameters was also developed and results are discussed as well. In addition, in the present study, experiments were conducted to evaluate capacities and pressure drops for sub-critical CO{sub 2} flow boiling and transcritical CO{sub 2} gas cooling in microchannel heat exchangers. An extensive review of the literature failed to indicate any previous systematic study in this area, suggesting a lack of fundamental understanding of the phenomena and a lack of comprehensive data that would quantify the performance potential of CO{sub 2} microchannel heat exchangers for the application at hand. All experimental tests were successfully conducted with an energy balance within {+-}3%. The only exceptions to this were experiments at very low saturation temperatures (-23 C), where energy balances were as high as 10%. In the case of evaporators, it was found that a lower saturation temperature (especially when moisture condensation occurs) improves the overall heat transfer coefficient

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

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

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

  5. Research of fiber carbon dioxide sensing system based laser absorption spectrum

    Science.gov (United States)

    Wei, Yubin; Zhang, Tingting; Li, Yanfang; Zhao, Yanjie; Wang, Chang; Liu, Tongyu

    2012-02-01

    Carbon dioxide is one of the important gas need to be detected in coal mine safety. In the mine limited ventilation environment, Concentration of carbon dioxide directly affects the health of coal miners. Carbon dioxide is also one of important signature Gas in spontaneous combustion forecasting of coal goaf area, it is important to accurately detect concentration of carbon dioxide in coal goaf area. This paper proposed a fiber carbon dioxide online sensing system based on tunable diode laser spectroscopy. The system used laser absorption spectroscopy and optical fiber sensors combined, and a near-infrared wavelength 1608nm fiber-coupled distributed feedback laser (DFB) as a light source and a 7cm length gas cell, to achieve a high sensitivity concentration detection of carbon dioxide gas. The technical specifications of sensing system can basically meet the need of mine safety.

  6. 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. PMID:20036053

  7. Self-Assembled Enzyme Nanoparticles for Carbon Dioxide Capture.

    Science.gov (United States)

    Shanbhag, Bhuvana Kamath; Liu, Boyin; Fu, Jing; Haritos, Victoria S; He, Lizhong

    2016-05-11

    Enzyme-based processes have shown promise as a sustainable alternative to amine-based processes for carbon dioxide capture. In this work, we have engineered carbonic anhydrase nanoparticles that retain 98% of hydratase activity in comparison to their free counterparts. Carbonic anhydrase was fused with a self-assembling peptide that facilitates the noncovalent assembly of the particle and together were recombinantly expressed from a single gene construct in Escherichia coli. The purified enzymes, when subjected to a reduced pH, form 50-200 nm nanoparticles. The CO2 capture capability of enzyme nanoparticles was demonstrated at ambient (22 ± 2 °C) and higher (50 °C) temperatures, under which the nanoparticles maintain their assembled state. The carrier-free enzymatic nanoparticles demonstrated here offer a new approach to stabilize and reuse enzymes in a simple and cost-effective manner.

  8. Energy efficiency and carbon dioxide emissions reduction opportunities in the U.S. cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Nathan; Worrell, Ernst; Price, Lynn

    1999-08-01

    This paper reports on an in-depth analysis of the U.S. cement industry, identifying cost-effective energy efficiency measures and potentials. The authors assess this industry at the aggregate level (Standard Industrial Classification 324), which includes establishments engaged in manufacturing hydraulic cements, including Portland, natural, masonry, and pozzolana when reviewing industry trends and when making international comparisons. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Between 1970 and 1997, primary physical energy intensity for cement production (SIC 324) dropped 30%,from 7.9 GJ/t to 5.6 GJ/t, while carbon dioxide intensity due to fuel consumption (carbon dioxide emissions expressed in tons of carbon per ton cement) dropped 25%, from 0.16 tC/ton to 0.12 tC/ton. Carbon dioxide intensity due to fuel consumption and clinker calcination dropped 17%, from 0.29 tC/ton to 0.24 tC/ton. They examined 30 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. They constructed an energy conservation supply curve for U.S. cement industry which found a total cost-effective reduction of 0.6 GJ/ton of cement consisting of measures having a simple payback period of 3 years or less. This is equivalent to potential energy savings of 11% of 1994 energy use for cement making and a savings of 5% of total 1994 carbon dioxide emissions by the U.S. cement industry. Assuming the increased production of blended cement in the U.S., as is common in many parts of the world, the technical potential for energy efficiency improvement would not change considerably. However, the cost-effective potential, would increase to 1.1 GJ/ton cement or 18% of total energy use, and carbon dioxide emissions would be reduced by 16%.

  9. Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

    Science.gov (United States)

    Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

    2016-01-01

    Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50% because half of the hydrogen used in the Sabatier reactor is lost as methane which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon, is capable of recovering all the oxygen from carbon dioxide, and it is a promising alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon, and the resulting carbon buildup eventually fouls the catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

  10. Atmospheric carbon dioxide and the global carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J R [ed.

    1985-12-01

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

  11. Life cycle study. Carbon dioxide emissions lower in electric heating than in oil heating

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, A.; Jaervinen, P.; Nikula, A.

    1996-11-01

    A primary objective of energy conservation is to cut carbon dioxide emissions. A comparative study on the various heating forms, based on the life cycle approach, showed that the carbon dioxide emissions resulting form heating are appreciably lower now that electric heating has become more common. The level of carbon dioxide emissions in Finland would have been millions of tonnes higher had oil heating been chosen instead of electric heating. (orig.)

  12. New equipment to prevent carbon dioxide rebreathing during eye surgery under retrobulbar anaesthesia

    OpenAIRE

    Schlager, A.; Staud, H.

    1999-01-01

    BACKGROUND—Carbon dioxide concentration under ophthalmic drapes increases during eye surgery under local anaesthesia. A new prototype has been designed which combines continuous suction of carbon dioxide enriched air and continuous oxygen insufflation under ophthalmic drapes to prevent carbon dioxide accumulation in spontaneously breathing patients undergoing cataract surgery.
METHODS—In a prospective randomised single blind study the effectiveness of this new prototype was examined in 50 unp...

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

    OpenAIRE

    Bolton, F J; Coates, D.

    1983-01-01

    The oxygen and carbon dioxide requirements of different biotypes of thermophilic campylobacters were investigated by means of (a) quantitative studies, and (b) total growth studies. Oxygen tolerance of the five test organisms differed markedly and varied with the carbon dioxide concentration. At most carbon dioxide concentrations tested, Campylobacter jejuni strains NCTC 11168 and NCTC 11392 tolerated 21% oxygen (growth reduced), C coli NCTC 11353 tolerated 15% oxygen (growth reduced), and C ...

  14. 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. PMID:16232479

  15. Research on urban road congestion pricing strategy considering carbon dioxide emissions

    OpenAIRE

    Yitian Wang; Zixuan Peng; Keming Wang; Xiaolin Song; Baozhen Yao; Tao Feng

    2015-01-01

    Congestion pricing strategy has been recognized as an effective countermeasure in the practical field of urban traffic congestion mitigation. In this paper, a bi-level programming model considering carbon dioxide emission is proposed to mitigate traffic congestion and reduce carbon dioxide emissions. The objective function of the upper level model is to minimize the sum of travel costs and the carbon dioxide emissions costs. The lower level is a multi-modal transportation network equilibrium ...

  16. Determinants of Chronic Carbon Dioxide Retention and Its Correction in Humans

    OpenAIRE

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

    1980-01-01

    17 patients with chronic ventilatory failure (including 14 with chronic obstructive pulmonary disease) were studied to determine the causes of carbon dioxide retention and the chronic effect of medroxyprogesterone acetate on ventilatory drive and acid-base status. Carbon dioxide retention in patients with high mechanical loads occurred concomitantly with a higher than normal inspiratory effort (mouth occlusion pressure) and normal minute ventilation to carbon dioxide production ratio (V̇e/V̇c...

  17. Automobiles and global warming: Alternative fuels and other options for carbon dioxide emissions reduction

    International Nuclear Information System (INIS)

    Automobiles are a source of considerable pollution at the global level, including a significant fraction of the total greenhouse gas emissions. Alternative fuels have received some attention as potential options to curtail the carbon dioxide emissions from motor vehicles. This article discusses the feasibility and desirability (from a technical as well as a broader environmental perspective) of the large-scale production and use of alternative fuels as a strategy to mitigate automotive carbon dioxide emissions. Other options such as improving vehicle efficiency and switching to more efficient modes of passenger transportation are also discussed. These latter options offer an effective and immediate way to tackle the greenhouse and other pollutant emission from automobiles, especially as the limitations of currently available alternative fuels and the technological and other constraints for potential future alternatives are revealed

  18. 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%.

  19. Low energy decomposition of carbon dioxide and other molecules

    Science.gov (United States)

    Pamfiloff, Eugene

    2013-05-01

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

  20. COCAP - A compact carbon dioxide analyser for airborne platforms

    Science.gov (United States)

    Kunz, Martin; Lavrič, Jošt V.; Jeschag, Wieland; Bryzgalov, Maksym; Hök, Bertil; Heimann, Martin

    2014-05-01

    Airborne platforms are a valuable tool for atmospheric trace gas measurements due to their capability of movement in three dimensions, covering spatial scales from metres to thousands of kilometres. Although crewed research aircraft are flexible in payload and range, their use is limited by high initial and operating costs. Small unmanned aerial vehicles (UAV) have the potential for substantial cost reduction, but require lightweight, miniaturized and energy-efficient scientific equipment. We are developing a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). It contains a non-dispersive infrared CO2sensor with a nominal full scale of 3000 μmol/mol. Sampled air is dried with magnesium perchlorate before it enters the sensor. This enables measurement of the dry air mole fraction of CO2, as recommended by the World Meteorological Organization. During post-processing, the CO2 measurement is corrected for temperature and pressure variations in the gas line. Allan variance analysis shows that we achieve a precision of better than 0.4 μmol/mol for 10 s averaging time. We plan to monitor the analyser's stability during flight by measuring reference air from a miniature gas tank in regular intervals. Besides CO2, COCAP measures relative humidity, temperature and pressure of ambient air. An on-board GPS receiver delivers accurate timestamps and allows georeferencing. Data is both stored on a microSD card and simultaneously transferred over a wireless serial interface to a ground station for real-time review. The target weight for COCAP is less than 1 kg. We deploy COCAP on a commercially available fixed-wing UAV (Bormatec Explorer) with a wingspan of 2.2 metres. The UAV has high payload capacity (2.5 kg) as well as sufficient space in the fuselage (80x80x600 mm3). It is built from a shock-resistant foam material, which allows quick repair of minor damages in the field. In case of severe damage spare parts are readily available. Calculations suggest that the

  1. Fractional Carbon Dioxide Laser in Treatment of Acne Scars

    OpenAIRE

    Andrej Petrov; Vesna Pljakovska

    2015-01-01

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

  2. Enhanced photocatalytic activity of titanium dioxide by nut shell carbon

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xiaoliang, E-mail: sxl@whut.edu.cn [School of Mechanical and Electronic Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 (China); State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 (China); Wang Sheng; Dong Xuebin [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 (China); Zhang Qiaoxin [School of Mechanical and Electronic Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 (China); State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 (China)

    2009-08-15

    Nut shell carbon (NSC)-nanotitanium dioxide (TiO{sub 2}) composites were prepared by sol-gel method. Photocatalytic activity on degradation of dye Rhodamine B was studied. X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmett-Teller surface area, pore size distribution, ultraviolet-vis light absorption spectrum, and photoluminescence spectrum were carried out to characterize the composite catalyst. The results indicated that the photocatalytic activity of NSC-nano-TiO{sub 2} composites was much higher than P25 (Degussa). NSC could greatly absorb the organic substance and oxygen of solution because of its large surface area.

  3. Dissolution rate measurements for resist processing in supercritical carbon dioxide

    Science.gov (United States)

    Pham, Victor Q.; Weibel, Gina L.; Rao, Nagesh G.; Ober, Christopher K.

    2002-07-01

    A dissolution rate monitor (DRM) was successfully constructed to study the behavior of thin photoresist films undergoing the dissolution process in supercritical carbon dioxide (SCCO2). The DRM is based on the principles of interferometry but requires special modifications to the processing vessel to allow for the passage of transmitted and reflected He-Ne laser light. Dissolution rates obtained agree well with independent profilometric measurements of film thickness loss. We found that for block and random copolymers of THPMA-F7MA, dissolution rates vary with film thickness, slowing down considerably towards the silicon surface. This behavior was also observed in TBMA-F7MA random copolymers.

  4. New and future developments in catalysis activation of carbon dioxide

    CERN Document Server

    Suib, Steven L

    2013-01-01

    New and Future Developments in Catalysis is a package of books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes. This volume presents a complete picture of all carbon dioxide (CO2) sources, outlines the environmental concerns regarding CO2, and critica

  5. 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.

  6. A Review of Carbon Dioxide Selective Membranes: A Topical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dushyant Shekhawat; David R. Luebke; Henry W. Pennline

    2003-12-01

    Carbon dioxide selective membranes provide a viable energy-saving alternative for CO2 separation, since membranes do not require any phase transformation. This review examines various CO2 selective membranes for the separation of CO2 and N2, CO2 and CH4, and CO2 and H2 from flue or fuel gas. This review attempts to summarize recent significant advances reported in the literature about various CO2 selective membranes, their stability, the effect of different parameters on the performance of the membrane, the structure and permeation properties relationships, and the transport mechanism applied in different CO2 selective membranes.

  7. 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.

  8. Persistent colonization of carbon dioxide incubators with Candida parapsilosis.

    Science.gov (United States)

    Schär, G; Grehn, M; von Graevenitz, A

    1990-10-01

    Recurrent contamination of bacteriological specimens with Candida parapsilosis led to epidemiological investigations which indicated persistent colonization of carbon dioxide incubators as the most likely source. Changes in the technical arrangements and institution of a meticulous cleansing protocol eliminated contamination of specimens but not colonization of the incubators. Tests for tolerance of 17% NaCl and survival at 50 degrees C, and SDS-PAGE analysis of crude cell extracts allowed discrimination between epidemic and non-epidemic isolates, while enzyme profile analysis and susceptibility studies failed as typing methods.

  9. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2).

  10. Carbon dioxide and methane fluxes from arctic mudboils

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, K.S.; Humphreys, E.R.

    2010-08-15

    Carbon-rich ecosystems in the Arctic have large stores of soil carbon. However, small changes in climate have the potential to change the carbon (C) balance. This study examined how changes in ecosystem structure relate to differences in the exchange of greenhouse gases, notably carbon dioxide (CO{sub 2}) and methane (CH{sub 4}), between the atmosphere and soil. In particular, it examined low-center mudboils to determine the influence that this distinct form of patterned ground in the Arctic may have on the overall C balance of Tundra ecosystems. The net ecosystem exchange of carbon dioxide (NEE) was measured along with methane efflux along a 35-m transect intersecting two mudboils in a wet sedge fen in Canada's Southern Arctic during the summer of 2008. Mudboil features revealed significant variations in vegetation, soil temperature and thaw depth, and soil organic matter content along this transect. Variations in NEE were attributed to changes in the amount of vascular vegetation, but CO{sub 2} and CH{sub 4} effluxes were similar among the two mudboil and the sedge fen sampling areas. The study showed that vegetation played a key role in limiting temporal variations in CH{sub 4} effluxes through plant mediated transport in both mudboil and sedge fen sampling areas. The negligible vascular plant colonization in one of the mudboils was likely due to more active frost heave processes. Growth and decomposition of cryptogamic organisms along with inflow of dissolved organic C and warmer soil temperatures may have been the cause of the rather high CO{sub 2} and CH{sub 4} efflux in this mudboil area.

  11. Synthesis and Characterization of Cobalt-Carbon Core-Shell Microspheres in Supercritical Carbon Dioxide System

    Institute of Scientific and Technical Information of China (English)

    Jun-song Yang; Qian-wang Chen

    2008-01-01

    The synthesis of cobalt-carbon core-shell microspheres in supercritical carbon dioxide system was investigated. Cobalt-carbon core-shell microspheres with diameter of about 1μm were prepared at 350℃ for 12 h in a closed vessel containing an appropriate amount of bis(cyclopentadienyl)cobalt powder and dry ice.Characterization by a variety of techniques,including X-ray powder diffraction,X-ray photoelectron spectroscopy,Transmission electron microscope,Fourier transform infrared spectrum and Raman spectroscopy analysis reveals that each cobalt-carbon core-shell microsphere is made up of an amorphous cobalt core with diameter less than 1 μm and an amorphous carbon shell with thickness of about 200 nm.The possible growth mechanism of cobalt-carbon core-shell microspheres is discussed,based on the pyrolysis of bis(cyclopentadienyl)cobalt in supercritical carbon dioxide and the deposition of carbon or carbon clusters with odd electrons on the surface of magnetic cobalt cores due to magnetic attraction.Magnetic measurements show 141.41 emu/g of saturation magnetization of a typical sample,which is lower than the 168 emu/g of the corresponding metal cobalt bulk material.This is attributed to the considerable mass of the carbon shell and amorphous nature of the magnetic core.Control of magnetism in the cobalt-carbon core-shell microspheres was achieved by annealing treatments.

  12. A gaseous measurement system for carbon-14 dioxide and carbon-14 methane: An analytical methodology to be applied in the evaluation of the carbon-14 dioxide and carbon-14 methane produced via microbial activity in volcanic tuff

    International Nuclear Information System (INIS)

    The objectives of this study were to develop a gaseous measurement system for the carbon-14 dioxide and carbon-14 methane produced via microbial activity or geochemical action on leachate in tuff; to determine the trapping efficiency of the system for carbon-14 dioxide; to determine the trapping efficiency of the system for carbon-14 methane; to apply the experimentally determined factors regarding the system's trapping efficiency for carbon-14 dioxide and carbon-14 methane to a trapping algorithm to determine the activity of the carbon-14 dioxide and carbon-14 methane in a mixed sample; to determine the minimum detectable activity of the measurement process in picocuries per liter; and to determine the lower limit or detection of the measurement process in counts per minute

  13. Development of a new gas sensor for binary mixtures based on the permselectivity of polymeric membranes. Application to carbon dioxide/methane and carbon dioxide/helium mixtures

    OpenAIRE

    Rosa Rego; Nídia Caetano; Adélio Mendes

    2004-01-01

    Membrane-based gas sensors were developed and used for determining the composition on bi-component mixtures in the 0100% range, such as oxygen/nitrogen and carbon dioxide/methane (biogas). These sensors are low cost and are aimed at a low/medium precision market.The paper describes the use of this sensor for two gas mixtures: carbon dioxide/methane and carbon dioxide/helium. The membranes used are poly(dimethylsiloxane) (PDMS) and Teflon-AF hollow fibers. The response curves for both sensors ...

  14. The Carbon-Nitrogen Balance of the Nodule and Its Regulation under Elevated Carbon Dioxide Concentration

    Directory of Open Access Journals (Sweden)

    Marc Libault

    2014-01-01

    Full Text Available Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2. In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-30

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

  16. Hydrophilic polymer composites synthesized by electrospinning under dense carbon dioxide

    Science.gov (United States)

    Wahyudiono, Okamoto, Koichi; Machmudah, Siti; Kanda, Hideki; Goto, Motonobu

    2015-12-01

    Electrospinning technique is feasible in some applications, it has attracted more attention in recent years. Various polymers have been successfully electrospun into ultrafine fibers in solvent solution and some in melt form. In this work, polyvinylpyrrolidone (PVP) as a hydrophilic polymer would be synthesized by electrospinning under dense carbon dioxide (CO2). The experiments were performed at 40 °C and ˜ 5 MPa. During the electrospinning process, the applied voltage was 10-17 kV and the distance of nozzle and collector was 8 cm. The concentration of PVP solution as a major component was 4 wt%. The results showed that the fibers surface morphology from PVP which blended with poly L-lactide acid (PLLA) were smooth with hollow core fibers at 5 MPa. At the same conditions, PVP-carbon nanotube was also successfully generated into electrospun fiber products with diameter ˜ 2 μm.

  17. Ocean Surface Carbon Dioxide Fugacity Observed from Space

    Science.gov (United States)

    Liu, W. Timothy; Xie, Xiaosu

    2014-01-01

    We have developed and validated a statistical model to estimate the fugacity (or partial pressure) of carbon dioxide (CO2) at sea surface (pCO2sea) from space-based observations of sea surface temperature (SST), chlorophyll, and salinity. More than a quarter million in situ measurements coincident with satellite data were compiled to train and validate the model. We have produced and made accessible 9 years (2002-2010) of the pCO2sea at 0.5 degree resolutions daily over the global ocean. The results help to identify uncertainties in current JPL Carbon Monitoring System (CMS) model-based and bottom-up estimates over the ocean. The utility of the data to reveal multi-year and regional variability of the fugacity in relation to prevalent oceanic parameters is demonstrated.

  18. Catalytic conversion of methane: Carbon dioxide reforming and oxidative coupling

    KAUST Repository

    Takanabe, Kazuhiro

    2012-01-01

    Natural gas conversion remains one of the essential technologies for current energy needs. This review focuses on the mechanistic aspects of the development of efficient and durable catalysts for two reactions, carbon dioxide reforming and the oxidative coupling of methane. These two reactions have tremendous technological significance for practical application in industry. An understanding of the fundamental aspects and reaction mechanisms of the catalytic reactions reviewed in this study would support the design of industrial catalysts. CO 2 reforming of methane utilizes CO 2, which is often stored in large quantities, to convert as a reactant. Strategies to eliminate carbon deposition, which is the major problem associated with this reaction, are discussed. The oxidative coupling of methane directly produces ethylene in one reactor through a slightly exothermic reaction, potentially minimizing the capital cost of the natural gas conversion process. The focus of discussion in this review will be on the attainable yield of C 2 products by rigorous kinetic analyses.

  19. 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...... of the current density and irreversible when operated at conditions that would oxidise carbon. This clearly shows that the passivation was not caused by coke formation. On the other hand, the passivation was partly reversible when introducing hydrogen. The passivation may be a consequence of impurities...... in the gas stream, most likely sulphur, adsorbing on some specific nickel sites in the cathode of the SOEC. Activation can be carried out by hydrogen reacting with adsorbed sulphur to form the volatile compound H2S. Because adsorption of sulphur is site specific, only a part of the nickel sites were...

  20. Carbon Dioxide Emissions: 17 Years and Still Talking

    International Nuclear Information System (INIS)

    This paper, written in French and in English, examines how the figures have changed from Kyoto base year 1990 up to 2007, before looking at certain countries' proposals for the future of their carbon dioxide emissions. Statistics are given concerning the emissions changes in various countries (or groups of countries) but also their developments in regards to the economy and energy use. Changes in CO2 emissions, changes in the gross domestic product of a country, its CO2 emissions per capita, its energy intensity (the ratio of energy use to the monetary value of GDP) and its carbon intensity of energy use as well as population change, are presented. The main countries considered are: United States, European Union, China, Japan, India, Brazil, South Africa and Russia

  1. Catalytic Formation of Propylene Carbonate from Supercritical Carbon Dioxide/Propylene Oxide Mixture

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Propylene carbonate was synthesized from supercritical carbon dioxide (SC-CO2)/ propylene oxide mixture with phthalocyaninatoaluminium chloride (ClAlPc)/ tetrabutylammon-ium bromide (n-Bu4NBr) as catalyst. The high rate of reaction was attributed to rapid diffusion and the high miscibility of propylene oxide in SC-CO2 under employed conditions. Various reaction periods present different formation rate of propylene carbonate, mainly due to the existence of phase change during the reaction. The experimental results demonstrate that SC-CO2 could be used as not only an environmentally benign solvent but also a carbon precursor in synthesis.

  2. Regional carbon dioxide implications of forest bioenergy production

    Science.gov (United States)

    Hudiburg, Tara W.; Law, Beverly E.; Wirth, Christian; Luyssaert, Sebastiaan

    2011-11-01

    Strategies for reducing carbon dioxide emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be recaptured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here, we use forest inventory data to show that fire prevention measures and large-scale bioenergy harvest in US West Coast forests lead to 2-14% (46-405TgC) higher emissions compared with current management practices over the next 20 years. We studied 80 forest types in 19 ecoregions, and found that the current carbon sink in 16 of these ecoregions is sufficiently strong that it cannot be matched or exceeded through substitution of fossil fuels by forest bioenergy. If the sink in these ecoregions weakens below its current level by 30-60gCm-2yr-1 owing to insect infestations, increased fire emissions or reduced primary production, management schemes including bioenergy production may succeed in jointly reducing fire risk and carbon emissions. In the remaining three ecoregions, immediate implementation of fire prevention and biofuel policies may yield net emission savings. Hence, forest policy should consider current forest carbon balance, local forest conditions and ecosystem sustainability in establishing how to decrease emissions.

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

    International Nuclear Information System (INIS)

    The objective of this project is to develop a simple, inexpensive process to separate CO(sub 2) as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, or ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO(sub 2) stream after condensation of water vapor. This quarter, five cycle thermogravimetric tests were conducted at the Louisiana State University (LSU) with sodium bicarbonate Grade 3 (SBC(numbersign)3) which showed that carbonation activity declined slightly over 5 cycles following severe calcination conditions of 200 C in pure CO(sub 2). Three different sets of calcination conditions were tested. Initial carbonation activity (as measured by extent of reaction in the first 25 minutes) was greatest subsequent to calcination at 120 C in He, slightly less subsequent to calcination in 80% CO(sub 2)/20% H(sub 2)O, and lowest subsequent to calcination in pure CO(sub 2) at 200 C. Differences in the extent of reaction after 150 minutes of carbonation, subsequent to calcination under the same conditions followed the same trend but were less significant. The differences between fractional carbonation under the three calcination conditions declined with increasing cycles. A preliminary fixed bed reactor test was also conducted at LSU. Following calcination, the sorbent removed approximately 19% of the CO(sub 2) in the simulated flue gas. CO(sub 2) evolved during subsequent calcination was consistent with an extent of carbonation of approximately 49%. Following successful testing of SBC(numbersign)3 sorbent at RTI reported in the last quarter, a two cycle fluidized bed reactor test was conducted with trona as the sorbent precursor, which was calcined to sodium carbonate. In the first carbonation cycle, CO

  4. 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

  5. Measurement of Carbon Dioxide Column via Space Borne Laser Absorption

    Science.gov (United States)

    Heaps, WIlliam S.

    2007-01-01

    In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an analysis of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics Several systems for meeting these requirements that are under investigation at various institutions in the US as well as Europe will be discussed.

  6. Carbon Dioxide Information Analysis Center: FY 1992 activities

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  7. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  8. Carbon Dioxide Information Analysis Center: FY 1991 activities

    Energy Technology Data Exchange (ETDEWEB)

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also described.

  9. Accuracy of Transcutaneous Carbon Dioxide Measurement in Premature Infants.

    Science.gov (United States)

    Janaillac, Marie; Labarinas, Sonia; Pfister, Riccardo E; Karam, Oliver

    2016-01-01

    Background. In premature infants, maintaining blood partial pressure of carbon dioxide (pCO2) value within a narrow range is important to avoid cerebral lesions. The aim of this study was to assess the accuracy of a noninvasive transcutaneous method (TcpCO2), compared to blood partial pressure of carbon dioxide (pCO2). Methods. Retrospective observational study in a tertiary neonatal intensive care unit. We analyzed the correlation between blood pCO2 and transcutaneous values and the accuracy between the trends of blood pCO2 and TcpCO2 in all consecutive premature infants born at weight: 1250 g), providing 1365 pairs of TcpCO2 and blood pCO2 values. Pearson's R correlation between these values was 0.58. The mean bias was -0.93 kPa with a 95% confidence limit of agreement of -4.05 to +2.16 kPa. Correlation between the trends of TcpCO2 and blood pCO2 values was good in only 39.6%. Conclusions. In premature infants, TcpCO2 was poorly correlated to blood pCO2, with a wide limit of agreement. Furthermore, concordance between trends was equally low. We warn about clinical decision-making on TcpCO2 alone when used as continuous monitoring. PMID:27375901

  10. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    Science.gov (United States)

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

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

  11. Effect of increased carbon dioxide concentrations on stratospheric ozone

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  13. Carbonate fuel cell system with integrated carbon dioxide/thermal management

    Energy Technology Data Exchange (ETDEWEB)

    Paetsch, L.

    1995-08-01

    The objective of the present work is to define the stack design and system requirements for a commercial-scale carbonate fuel cell with an integrated carbon dioxide management system. Significant simplification and cost reduction of the system is achieved by direct transfer of the fuel exhaust to the oxidant inlet of the fuel cell, thereby eliminating the anode exhaust converter and high temperature piping utilized in conventional system designs.

  14. Understanding Geochemical Impacts of Carbon Dioxide Leakage from Carbon Capture and Sequestration

    Science.gov (United States)

    US EPA held a technical Geochemical Impact Workshop in Washington, DC on July 10 and 11, 2007 to discuss geological considerations and Area of Review (AoR) issues related to geologic sequestration (GS) of Carbon Dioxide (CO2). Seventy=one (71) representatives of the electric uti...

  15. The Path of Carbon in Photosynthesis X. Carbon Dioxide Assimilation in Plants

    Science.gov (United States)

    Calvin, M.; Bassham, J. A.; Benson, A. A.; Lynch, V.; Ouellet, C.; Schou, L.; Stepka, W.; Tolbert, N. E.

    1950-04-01

    The conclusions which have been drawn from the results of C{sup 14}O{sub 2} fixation experiments with a variety of plants are developed in this paper. The evidence for thermochemical reduction of carbon dioxide fixation intermediates is presented and the results are interpreted from such a viewpoint.

  16. A modelling on estimation of the carbon dioxide emission from vehicles using logistic equation

    Science.gov (United States)

    Chandra, E. W.; Andry, A.; Afra, F.; Sumarti, N.

    2016-04-01

    In this paper, the logistic differential equation is used in developing a model on carbon dioxide traces which potentially releases from a particular area. The improvement to a higher scale or scope is straightforward by considering the larger observed data or larger number of the potential CO2 sources. Let G(t) the total amount of the carbon dioxide emission from motorcycles and cars used by the resident of the area. G (t )=P (t )(r1(t )η (t )+r2(t )ξ (t )) where P(t) is the number of the resident of the observed area (population of Bandung Institute of Technology) at year t, r1(t) and r2(t) are the portion of the population who use motorcycles and cars respectively, η(t) and ξ(t) are the approximated total emission of the carbon dioxide from the related vehicles respectively. The number of resident is modeled by the logistic equation so the future number can be estimated. The model is implemented in a campus of Institut Teknologi Bandung (ITB) at Ganesha street, Indonesia. The results show that the amount of CO2 produced from the transport in Ganesha campus will reach the carrying capacity of the campus in the next 3 years, which will be at around 2.1 billion kilotons of CO2. Therefore, the need of reducing the usage of motorcycles and cars is inevitable in the near future.

  17. Carbon dioxide emission standards for U.S. power plants. An efficiency analysis perspective

    Energy Technology Data Exchange (ETDEWEB)

    Hampf, Benjamin [Technische Univ. Darmstadt (Germany). Fachbereich Rechts- und Wirtschaftswissenschaften; Roedseth, Kenneth Loevold [Institute of Transport Economics, Oslo (Norway). Dept. of Economics and Logistics

    2013-07-01

    On June 25, 2013, President Obama announced his plan to introduce carbon dioxide emission standards for electricity generation. This paper proposes an efficiency analysis approach that addresses which mission rates (and standards) would be feasible if the existing generating units adopt best practices. A new efficiency measure is introduced and further decomposed to identify different sources' contributions to emission rate improvements. Estimating two Data Envelopment Analysis (DEA) models - the well-known joint production model and the new materials balance model - on a dataset consisting of 160 bituminous-fired generating units, we find that the average generating unit's electricity-to-carbon dioxide ratio is 15.3 percent below the corresponding best-practice ratio. Further examinations reveal that this discrepancy can largely be attributed to non-discretionary factors and not to managerial inefficiency. Moreover, even if the best practice ratios could be implemented, the generating units would not be able to comply with the EPA's recently proposed carbon dioxide standard.

  18. Design and experimental analysis of a carbon dioxide transcritical chiller for commercial refrigeration

    International Nuclear Information System (INIS)

    Carbon dioxide is an interesting solution for commercial refrigeration and in perspective for air-conditioning systems. In this paper a newly developed carbon dioxide transcritical air cooled chiller for refrigerating propylene glycol down to -8 oC supply temperature is described. The aim of the project was at optimising the cycle energy efficiency while assuring reliable operation and simple management of the unit. The carbon dioxide optimal pressure issue is addressed with an innovate system architecture and control logic. Using a flash tanks and two electronic valves, the optimal cycle upper pressure was maintained in transcritical operation mode. The managing of the valves allows the refrigeration machine efficiency improvement when the gas cooler inlet air allows subcritical working conditions. A simulation model of the chiller was developed and its results validated with experimental data. A measurement campaign was carried out, testing the chiller at external temperatures ranging from 18 to 35 oC, the unit energy efficiency ranging from 3.1 to 2.0.

  19. Continuous Process for the Etching, Rinsing and Drying of MEMS Using Supercritical Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Min, Seon Ki; Han, Gap Su; You, Seong-sik [Korea University of Technology and Education, Cheonan (Korea, Republic of)

    2015-10-15

    The previous etching, rinsing and drying processes of wafers for MEMS (microelectromechanical system) using SC-CO{sub 2} (supercritical-CO{sub 2}) consists of two steps. Firstly, MEMS-wafers are etched by organic solvent in a separate etching equipment from the high pressure dryer and then moved to the high pressure dryer to rinse and dry them using SC-CO{sub 2}. We found that the previous two step process could be applied to etch and dry wafers for MEMS but could not confirm the reproducibility through several experiments. We thought the cause of that was the stiction of structures occurring due to vaporization of the etching solvent during moving MEMS wafer to high pressure dryer after etching it outside. In order to improve the structure stiction problem, we designed a continuous process for etching, rinsing and drying MEMS-wafers using SC-CO{sub 2} without moving them. And we also wanted to know relations of states of carbon dioxide (gas, liquid, supercritical fluid) to the structure stiction problem. In the case of using gas carbon dioxide (3 MPa, 25 .deg. C) as an etching solvent, we could obtain well-treated MEMS-wafers without stiction and confirm the reproducibility of experimental results. The quantity of rinsing solvent used could be also reduced compared with the previous technology. In the case of using liquid carbon dioxide (3 MPa, 5 .deg. C), we could not obtain well-treated MEMS-wafers without stiction due to the phase separation of between liquid carbon dioxide and etching co-solvent(acetone). In the case of using SC-CO{sub 2} (7.5 Mpa, 40 .deg. C), we had as good results as those of the case using gas-CO{sub 2}. Besides the processing time was shortened compared with that of the case of using gas-CO{sub 2}.

  20. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

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

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  1. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Science.gov (United States)

    A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

  2. Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio Enrique

    2003-12-18

    Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO{sub 2} will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO{sub 2} and NaCl has been conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO{sub 2}-H{sub 2}O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO{sub 2}. The basic problem of CO{sub 2} injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO{sub 2} injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO{sub 2} injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO{sub 2}. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous

  3. 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.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    B. Xiang

    2013-02-01

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

  6. Influence of pre-treatment on enzymatic degumming of apocynum venetum bast fibers in supercritical carbon dioxide

    Directory of Open Access Journals (Sweden)

    Gao Shi-Hui

    2015-01-01

    Full Text Available Pre-treatment of apocynum venetum bast fibers in supercritical carbon dioxide can improve the efficiency of enzymatic degumming of apocynum venetum bast fiber. This paper studies experimentally effect of pressure and degumming time on degradation rate, the results can be used for optimal design of degumming.

  7. Carbon dioxide, ground air and carbon cycling in Gibraltar karst

    Science.gov (United States)

    Mattey, D. P.; Atkinson, T. C.; Barker, J. A.; Fisher, R.; Latin, J.-P.; Durrell, R.; Ainsworth, M.

    2016-07-01

    We put forward a general conceptual model of CO2 behaviour in the vadose zone of karst aquifers, based on physical principles of air flow through porous media and caves, combined with a geochemical interpretation of cave monitoring data. This 'Gibraltar model' links fluxes of water, air and carbon through the soil with the porosity of the vadose zone, the circulation of ground air and the ventilation of caves. Gibraltar hosts many natural caves whose locations span the full length and vertical range of the Rock. We report results of an 8-year monitoring study of carbon in soil organic matter and bedrock carbonate, dissolved inorganic carbon in vadose waters, and gaseous CO2 in soil, cave and ground air. Results show that the regime of cave air CO2 results from the interaction of cave ventilation with a reservoir of CO2-enriched ground air held within the smaller voids of the bedrock. The pCO2 of ground air, and of vadose waters that have been in close contact with it, are determined by multiple factors that include recharge patterns, vegetation productivity and root respiration, and conversion of organic matter to CO2 within the soil, the epikarst and the whole vadose zone. Mathematical modelling and field observations show that ground air is subject to a density-driven circulation that reverses seasonally, as the difference between surface and underground temperatures reverses in sign. The Gibraltar model suggests that cave air pCO2 is not directly related to CO2 generated in the soil or the epikarstic zone, as is often assumed. Ground air CO2 formed by the decay of organic matter (OM) washed down into the deeper unsaturated zone is an important additional source of pCO2. In Gibraltar the addition of OM-derived CO2 is the dominant control on the pCO2 of ground air and the Ca-hardness of waters within the deep vadose zone. The seasonal regime of CO2 in cave air depends on the position of a cave in relation to the density-driven ground air circulation pattern which

  8. Taking the Headaches out of Anesthetizing "Drosophila": A Cheap & Easy Method of Constructing Carbon Dioxide Staging

    Science.gov (United States)

    Artiss, Thomas; Hughes, Bobby

    2007-01-01

    Carbon dioxide is an excellent alternative to conventional methods of anesthetizing fruit flies as it is non-flammable and odorless. We have devised a method of constructing carbon dioxide stages used to keep "Drosophila" immobilized cheaply and easily using empty micropipette tip containers. (Contains 6 figures.)

  9. 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.

  10. Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation

    Science.gov (United States)

    Airlifts simplify recirculating aquaculture systems and can potentially reduce capital costs and minimize maintenance issues. Airlifts have the ability to move and aerate water as well as degass the water of any carbon dioxide. This study evaluated the oxygen transfer and carbon dioxide removal abil...

  11. DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

    Energy Technology Data Exchange (ETDEWEB)

    OGDEN DM; KIRCH NW

    2007-10-31

    This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

  12. Varmeovergang og trykfald ved fordampning af kuldioxid (Heat Transfer and Pressure Drop for Boiling Carbon Dioxide)

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    1999-01-01

    Heat transfer and pressure drop for carbon dioxide, pure and mixed with oil, has the been measured for flow in pipe. The measured heat transfer coefficient for pure carbon dioxide is much higher than the value calculated with the Shah correlation. With oil even higher heat transfer coefficient ha...

  13. Accuracy of transcutaneous carbon dioxide tension measurements during cardiopulmonary exercise testing.

    NARCIS (Netherlands)

    Stege, G.; Elshout, F.J.J. van den; Heijdra, Y.F.; Ven, M.J.T. van de; Dekhuijzen, P.N.R.; Vos, P.J.E.

    2009-01-01

    BACKGROUND: Measurements of transcutaneous carbon dioxide tension (PtcCO(2)) with current devices are proven to provide clinically acceptable agreement with measurements of partial arterial carbon dioxide tension (PaCO(2)) in several settings but not during cardiopulmonary exercise testing (CPET). O

  14. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Science.gov (United States)

    2010-04-01

    ... still wine. 24.245 Section 24.245 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.245 Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still...

  15. Permeability, diffusivity and solubility of carbon dioxide in fluoropolymers: An experimental and modeling study

    DEFF Research Database (Denmark)

    Neela, Vasu; von Solms, Nicolas

    2014-01-01

    Carbon dioxide has successfully been used as an alternative refrigerant in many applications, replacing chlorofluoro- and hydrofluorocarbons (CFCs and HFCs), due to its negligible ozone depletion and significantly lower global warming potential. However, the use of carbon dioxide as a refrigerant...

  16. 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.

  17. Carbon Dioxide Absorbers: An Engaging Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Ticich, Thomas M.

    2011-01-01

    A simple and direct method for measuring the absorption of carbon dioxide by two different substances is described. Lithium hydroxide has been used for decades to remove the gas from enclosed living spaces, such as spacecraft and submarines. The ratio of the mass of carbon dioxide absorbed to the mass of lithium hydroxide used obtained from this…

  18. 21 CFR 874.4500 - Ear, nose, and throat microsurgical carbon dioxide laser.

    Science.gov (United States)

    2010-04-01

    ... laser. 874.4500 Section 874.4500 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND..., nose, and throat microsurgical carbon dioxide laser. (a) Identification. An ear, nose, and throat microsurgical carbon dioxide laser is a device intended for the surgical excision of tissue from the ear,...

  19. Metal Ions Extraction with Glucose Derivatives as Chelating Reagents in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    Guo Chen YANG; Hai Jian YANG

    2006-01-01

    A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-1-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr2+ and Pb2+ extraction in supercritical carbon dioxide.

  20. Palladium-Catalyzed Carbonylation of Primary Amines in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    李金恒; 江焕峰; 陈鸣才

    2001-01-01

    The chemoselectity of the palladimm-catalyzed carbonylation of amines was affected by the addition of MeOH in supercritical carbon dioxide. The results show different selectivity in supercritical carbon dioxide CO2(sc) from that in alcohol.Methyl carbamate and its derivatives were obtained in high yields in CO2(sc).