WorldWideScience

Sample records for super-optimal co2 reduces

  1. Super-optimal CO2 reduces seed yield but not vegetative growth in wheat

    Science.gov (United States)

    Grotenhuis, T. P.; Bugbee, B.

    1997-01-01

    Although terrestrial atmospheric CO2 levels will not reach 1000 micromoles mol-1 (0.1%) for decades, CO2 levels in growth chambers and greenhouses routinely exceed that concentration. CO2 levels in life support systems in space can exceed 10000 micromoles mol-1(1%). Numerous studies have examined CO2 effects up to 1000 micromoles mol-1, but biochemical measurements indicate that the beneficial effects of CO2 can continue beyond this concentration. We studied the effects of near-optimal (approximately 1200 micromoles mol-1) and super-optimal CO2 levels (2400 micromoles mol-1) on yield of two cultivars of hydroponically grown wheat (Triticum aestivum L.) in 12 trials in growth chambers. Increasing CO2 from sub-optimal to near-optimal (350-1200 micromoles mol-1) increased vegetative growth by 25% and seed yield by 15% in both cultivars. Yield increases were primarily the result of an increased number of heads per square meter. Further elevation of CO2 to 2500 micromoles mol-1 reduced seed yield by 22% (P seeds per head by 10% and mass per seed by 11%. The toxic effect of CO2 was similar over a range of light levels from half to full sunlight. Subsequent trials revealed that super-optimal CO2 during the interval between 2 wk before and after anthesis mimicked the effect of constant super-optimal CO2. Furthermore, near-optimal CO2 during the same interval mimicked the effect of constant near-optimal CO2. Nutrient concentration of leaves and heads was not affected by CO2. These results suggest that super-optimal CO2 inhibits some process that occurs near the time of seed set resulting in decreased seed set, seed mass, and yield.

  2. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  3. Advanced technology development reducing CO2 emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sup

    2010-09-15

    Responding to Korean government policies on green growth and global energy/ environmental challenges, SK energy has been developing new technologies to reduce CO2 emissions by 1) CO2 capture and utilization, 2) efficiency improvement, and 3) Li-ion batteries. The paper introduces three advanced technologies developed by SK energy; GreenPol, ACO, and Li-ion battery. Contributing to company vision, a more energy and less CO2, the three technologies are characterized as follows. GreenPol utilizes CO2 as a feedstock for making polymer. Advanced Catalytic Olefin (ACO) reduces CO2 emission by 20% and increase olefin production by 17%. Li-ion Batteries for automotive industries improves CO2 emission.

  4. Reducing CO2 emission from bitumen upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John

    2011-07-15

    The treatment of sand oil can result in significant CO2 emission. Ceramatec Inc. has developed a technology to reduce the emission of CO2 during the upgrading of feedstocks bearing heteroatoms. This technology can be applied to kerogen derived oil (shale oil) and heavy oil as well as to bitumen from oil sands. Metallic sodium is used as the reducing and heteroatom scavenging agent. Hydrogen, methane or other hydrocarbons may be used to cap radicals formed in the process. But using methane can lead to lower material and capital costs, greater product yield, and lower CO2 emission. During the upgrading process, the aromatic constituents remain in the product, after treatment with sodium and removal of sulphur, nitrogen and metals. Aromatic saturation is not required with sodium, so less hydrogen is needed which leads to reduced CO2 emission. The reason is that CO2 is emitted in the steam methane reforming (SMR) process where hydrogen is produced. An example is introduced to demonstrate the reduction of CO2 emission from hydrogen production. Another advantage of the sodium/methane upgrading process is the incorporation of methane into the fuel. In addition, the total acid number, TAN, becomes negligible in the sodium upgrading processes. Ceramatec has also developed a process for the recovery of sodium from the sodium salts generated in the sodium/methane upgrading process.

  5. Reducing CO2 from shipping – do non-CO2 effects matter?

    Directory of Open Access Journals (Sweden)

    M. S. Eide

    2013-04-01

    Full Text Available Shipping is a growing sector in the global economy, and it contributions to global CO2 emissions are expected to increase. CO2 emissions from the world shipping fleet will likely be regulated in the near future, and studies have shown that significant emission reductions can be achieved at low cost. Regulations are being discussed for both existing ships as well as for future additions to the fleet. In this study a plausible CO2 emission reduction inventory is constructed for the cargo fleet existing in 2010, as well as for container ships, bulk ships and tankers separately. In the reduction inventories, CO2 emissions are reduced by 25–32% relative to baseline by applying 15 technical and operational emission reduction measures in accordance with a ship-type-specific cost-effectiveness criterion, and 9 other emission compounds are changed as a technical implication of reducing CO2. The overall climate and environmental effects of the changes to all 10 emission components in the reduction inventory are assessed using a chemical transport model, radiative forcing (RF models and a simple climate model. We find substantial environmental and health benefits with up to 5% reduction in surface ozone levels, 15% reductions in surface sulfate and 10% reductions in wet deposition of sulfate in certain regions exposed to heavy ship traffic. The major ship types show distinctly different contributions in specific locations. For instance, the container fleet contributes 50% of the sulfate decline on the west coast of North America. The global radiative forcing from a 1 yr emission equal to the difference between baseline and reduction inventory shows an initial strong positive forcing from non-CO2 compounds. This warming effect is due to reduced cooling by aerosols and methane. After approximately 25 yr, the non-CO2 forcing is balanced by the CO2 forcing. For the global mean temperature change, we find a shift from warming to cooling after approximately 60

  6. Reducing CO2 from shipping - do non-CO2 effects matter?

    Science.gov (United States)

    Eide, M. S.; Dalsøren, S. B.; Endresen, Ø.; Samset, B.; Myhre, G.; Fuglestvedt, J.; Berntsen, T.

    2013-04-01

    Shipping is a growing sector in the global economy, and it contributions to global CO2 emissions are expected to increase. CO2 emissions from the world shipping fleet will likely be regulated in the near future, and studies have shown that significant emission reductions can be achieved at low cost. Regulations are being discussed for both existing ships as well as for future additions to the fleet. In this study a plausible CO2 emission reduction inventory is constructed for the cargo fleet existing in 2010, as well as for container ships, bulk ships and tankers separately. In the reduction inventories, CO2 emissions are reduced by 25-32% relative to baseline by applying 15 technical and operational emission reduction measures in accordance with a ship-type-specific cost-effectiveness criterion, and 9 other emission compounds are changed as a technical implication of reducing CO2. The overall climate and environmental effects of the changes to all 10 emission components in the reduction inventory are assessed using a chemical transport model, radiative forcing (RF) models and a simple climate model. We find substantial environmental and health benefits with up to 5% reduction in surface ozone levels, 15% reductions in surface sulfate and 10% reductions in wet deposition of sulfate in certain regions exposed to heavy ship traffic. The major ship types show distinctly different contributions in specific locations. For instance, the container fleet contributes 50% of the sulfate decline on the west coast of North America. The global radiative forcing from a 1 yr emission equal to the difference between baseline and reduction inventory shows an initial strong positive forcing from non-CO2 compounds. This warming effect is due to reduced cooling by aerosols and methane. After approximately 25 yr, the non-CO2 forcing is balanced by the CO2 forcing. For the global mean temperature change, we find a shift from warming to cooling after approximately 60 yr. The major ship

  7. Reduced Brillouin backscatter in CO2 laser-target interaction

    Science.gov (United States)

    Ng, A.; Offenberger, A. A.; Karttunen, S. J.

    1981-02-01

    A substantially reduced Brillouin reflection has been found for CO2 laser-irradiated high-density gas targets. In contrast to the high reflectivity (60%) previously observed for underdense hydrogen plasma, total backscatter (stimulated plus specular) is found to peak at 30% for incident intensity 5 times 10 to the twelfth W per square centimeter and decrease thereafter to 18% at 10 to the thirteenth W per square centimeter. The ponderomotive effects are postulated to account for these observations.

  8. Applied stress reduces the CO2 sorption capacity of coal

    NARCIS (Netherlands)

    Hol, S.; Peach, C.J.; Spiers, C.J.

    2011-01-01

    Though the adsorption of CO2 by coal has been extensively studied in experiments, few systematic studies have been done on the effects of the stress state within the coal on CO2 sorption. To investigate whether or not the CO2 sorption capacity of coal is influenced by the application of an effective

  9. European Community Can Reduce CO2 Emissions by Sixty Percent : A Feasibility Study

    NARCIS (Netherlands)

    Mot, E.; Bartelds, H.; Esser, P.M.; Huurdeman, A.J.M.; Laak, P.J.A. van de; Michon, S.G.L.; Nielen, R.J.; Baar, H.J.W. de

    1993-01-01

    Carbon dioxide (CO2) emissions in the European Community (EC) can be reduced by roughly 60 percent. A great many measures need to be taken to reach this reduction, with a total annual cost of ECU 55 milliard. Fossil fuel use is the main cause of CO2 emissions into the atmosphere; CO2 emissions are t

  10. Elevating CO2 in commercial greenhouses can reduce carbon use and production cost in cool temperatures

    Science.gov (United States)

    When greenhouses are heated in the cooler months, growers attempt to minimize gaps to reduce air infiltration. Greenhouses that are well sealed can result in CO2 drawdown to the detriment of plant growth. Growers can opt to counteract the low CO2 by supplementing with CO2. However, it is unknown how...

  11. The Value of CO2-Geothermal Bulk Energy Storage to Reducing CO2 Emissions Compared to Conventional Bulk Energy Storage Technologies

    Science.gov (United States)

    Ogland-Hand, J.; Bielicki, J. M.; Buscheck, T. A.

    2016-12-01

    Sedimentary basin geothermal resources and CO2 that is captured from large point sources can be used for bulk energy storage (BES) in order to accommodate higher penetration and utilization of variable renewable energy resources. Excess energy is stored by pressurizing and injecting CO2 into deep, porous, and permeable aquifers that are ubiquitous throughout the United States. When electricity demand exceeds supply, some of the pressurized and geothermally-heated CO2 can be produced and used to generate electricity. This CO2-BES approach reduces CO2 emissions directly by storing CO2 and indirectly by using some of that CO2 to time-shift over-generation and displace CO2 emissions from fossil-fueled power plants that would have otherwise provided electricity. As such, CO2-BES may create more value to regional electricity systems than conventional pumped hydro energy storage (PHES) or compressed air energy storage (CAES) approaches that may only create value by time-shifting energy and indirectly reducing CO2 emissions. We developed and implemented a method to estimate the value that BES has to reducing CO2 emissions from regional electricity systems. The method minimizes the dispatch of electricity system components to meet exogenous demand subject to various CO2 prices, so that the value of CO2 emissions reductions can be estimated. We applied this method to estimate the performance and value of CO2-BES, PHES, and CAES within real data for electricity systems in California and Texas over the course of a full year to account for seasonal fluctuations in electricity demand and variable renewable resource availability. Our results suggest that the value of CO2-BES to reducing CO2 emissions may be as much as twice that of PHES or CAES and thus CO2-BES may be a more favorable approach to energy storage in regional electricity systems, especially those where the topography is not amenable to PHES or the subsurface is not amenable to CAES.

  12. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    Science.gov (United States)

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-01-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation. PMID:28781568

  13. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    Science.gov (United States)

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-07-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

  14. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    Energy Technology Data Exchange (ETDEWEB)

    Norby, Richard J [ORNL; Warren, Jeffrey [ORNL; Iversen, Colleen M [ORNL; Medlyn, Belinda [Macquarie University; McMurtrie, Ross [University of New South Wales; Hoffman, Forrest M [ORNL

    2008-01-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  15. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    Science.gov (United States)

    Norby, R. J.; Warren, J. M.; Iversen, C. M.; Medlyn, B. E.; McMurtrie, R. E.; Hoffman, F. M.

    2008-12-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  16. Parameter Optimization on Experimental Study to Reduce Ammonia Escape in CO2 Absorption by Ammonia Scrubbing

    Institute of Scientific and Technical Information of China (English)

    Hao Leng; Jianmin Gao; Mingyue He; Min Xie; Qian Du; Rui Sun; Shaohua Wu

    2016-01-01

    In order to research ammonia escape in CO2 absorption by ammonia scrubbing, ammonia escape was studied in CO2 absorption process using the bubbling reactor in different conditions as gas flow rate, CO2 ratio, absorbent temperature and ammonia concentration and quantity of escaped ammonia was measured by chemical titration. The results indicated that, the amount of ammonia escape can be around 20% of original amount in 90 min and the escaped amount will increase with the rise of gas flow rate, absorbent temperature, concentration of ammonia while decrease as CO2 ratio goes up. Through the analysis of the law of ammonia escape, at the same time, combined with ammonia escape and the influence of the relationship between the CO2 absorption efficiency, reducing ammonia escape working condition parameter optimization is given.

  17. Reduced Southern Hemispheric circulation response to quadrupled CO2 due to stratospheric ozone feedback

    Science.gov (United States)

    Chiodo, Gabriel; Polvani, Lorenzo M.

    2017-01-01

    Due to computational constraints, interactive stratospheric ozone chemistry is commonly neglected in most climate models participating in intercomparison projects. The impact of this simplification on the modeled response to external forcings remains unexplored. In this work, we examine the importance of including interactive stratospheric ozone chemistry on the Southern Hemispheric circulation response to an abrupt quadrupling of CO2. We find that including interactive ozone significantly reduces (by 20%) the response of the midlatitude jet to CO2, even though it does not alter the surface temperature response. The reduction of the tropospheric circulation response is due to CO2 induced ozone changes and their effects on the meridional temperature gradient near the tropopause. Our findings suggest that neglecting this stratospheric ozone feedback results in an overestimate of the circulation response to increased CO2. This has important implications for climate projections of the Southern Hemispheric circulation response to CO2.

  18. Reducing the cost of Ca-based direct air capture of CO2.

    Science.gov (United States)

    Zeman, Frank

    2014-10-07

    Direct air capture, the chemical removal of CO2 directly from the atmosphere, may play a role in mitigating future climate risk or form the basis of a sustainable transportation infrastructure. The current discussion is centered on the estimated cost of the technology and its link to "overshoot" trajectories, where atmospheric CO2 levels are actively reduced later in the century. The American Physical Society (APS) published a report, later updated, estimating the cost of a one million tonne CO2 per year air capture facility constructed today that highlights several fundamental concepts of chemical air capture. These fundamentals are viewed through the lens of a chemical process that cycles between removing CO2 from the air and releasing the absorbed CO2 in concentrated form. This work builds on the APS report to investigate the effect of modifications to the air capture system based on suggestions in the report and subsequent publications. The work shows that reduced carbon electricity and plastic packing materials (for the contactor) may have significant effects on the overall price, reducing the APS estimate from $610 to $309/tCO2 avoided. Such a reduction does not challenge postcombustion capture from point sources, estimated at $80/tCO2, but does make air capture a feasible alternative for the transportation sector and a potential negative emissions technology. Furthermore, air capture represents atmospheric reductions rather than simply avoided emissions.

  19. Reducing Power Penalty Related to PostCombustion CO2 Capture in Coal Power Plants

    Directory of Open Access Journals (Sweden)

    Ramona Mihaela Negoi

    2011-09-01

    Full Text Available Considering the important role of coal in energy security and in the same time the growing need to reduce CO2 emissions, amine-based post-combustion CO2 capture is considered as one of the most proper technologies to be implemented in coal fired power plants as well in natural gas fired plants, refinery gas, cement plants etc.. The main challenge for CO2 post-combustion is reducing the energy demand of the process, especially for solvent regeneration. In this paper, the energy reduction potential when waste heat of flue gases is integrated in the CO2 capture configuration scheme is discussed. The results are compared with a conventional coal power plant configuration when low-steam pressure is extracted from the water-steam cycle of the power plant.

  20. IGCC特点及减排CO2方法%IGCC Characteristics and Its Method for CO2 Reducing

    Institute of Scientific and Technical Information of China (English)

    廖小花

    2010-01-01

    分析了整体煤气化联合循环(IGCC)效率高、环保性能优等特点,总结了IGCC减排CO2的可行方法:燃烧后分离与回收、燃烧前分离与回收、以IGCC为基础的煤基动力化工多联产系统以及燃烧与CO2分离一体化途径.

  1. Defoliation reduces soil biota - and modifies stimulating effects of elevated CO2

    DEFF Research Database (Denmark)

    Dam, Marie; Christensen, Søren

    2015-01-01

    on microbial biomass that was not apparently affected by global change. The negative effect of defoliation cascades through to soil nematodes as dependent on CO2 and drought. At ambient CO2, drought and defoliation each reduced nematodes. In contrast, at elevated CO2, a combination of drought and defoliation......To understand the responses to external disturbance such as defoliation and possible feedback mechanisms at global change in terrestrial ecosystems, it is necessary to examine the extent and nature of effects on aboveground-belowground interactions. We studied a temperate heathland system subjected...... assessed in the rhizosphere of manually defoliated patches of Deschampsia flexuosa in June in a full-factorial FACE experiment with the treatments: increased atmospheric CO2, increased nighttime temperatures, summer droughts, and all of their combinations. We found a negative effect of defoliation...

  2. Defoliation reduces soil biota - and modifies stimulating effects of elevated CO2

    DEFF Research Database (Denmark)

    Dam, Marie; Christensen, Søren

    2015-01-01

    defoliation increased activity and biomass of soil biota and more so at elevated CO2. Based on soil biota responses, plants defoliated in active growth therefore conserve resources, whereas defoliation after termination of growth results in release of resources. This result challenges the idea that plants via...... to experimental climate and atmospheric factors based on prognoses for year 2075 and further exposed to defoliation. By defoliating plants, we were able to study how global change modifies the interactions of the plant-soil system. Shoot production, root biomass, microbial biomass, and nematode abundance were...... on microbial biomass that was not apparently affected by global change. The negative effect of defoliation cascades through to soil nematodes as dependent on CO2 and drought. At ambient CO2, drought and defoliation each reduced nematodes. In contrast, at elevated CO2, a combination of drought and defoliation...

  3. Policy options to reduce passenger car CO2 emissions after 2020

    Energy Technology Data Exchange (ETDEWEB)

    De Wilde, H.P.J.; Kroon, P. [ECN Beleidsstudies, Petten (Netherlands)

    2013-02-15

    The EU has set emission targets for new cars up to 2020 and is now preparing the post 2020 legislation. The present study aims to give insight in the design of policies to further reduce passenger car emissions after 2020. Internal combustion engine (ICE) vehicles are now expected to enable deeper and less costly CO2 emission reductions than envisioned until recently. However, even advanced ICE vehicles will not enable to meet the very stringent long term emission reduction targets for passenger cars. Therefore transport policies need not only to reduce emissions of ICE vehicles, but also ensure that electric and hydrogen vehicles are phased in timely, along with low-CO2 electricity and hydrogen. Current legislation to regulate tank-to-wheel vehicle emissions is based on CO2-limits, expressed in g CO2/km. On the short term it is important to maximize the efficiency of conventional vehicles. At the same time it is essential to foster the market introduction of electric and hydrogen vehicles, given their potential to reach eventually much deeper overall CO2-reductions. When the market share of electric and hydrogen vehicles grows it becomes increasingly important to maximize their efficiency and to minimize their upstream CO2 emissions. Maximizing both efficiency and overall CO2-performance of all vehicle types - ICE, electric, and hydrogen - will be complicated to achieve with a single CO2-based standard. At this point an efficiency-based standard is more effective, and may offer some additional benefits too. The current report provides basic directions of how such legislation could be shaped.

  4. Quasi-solid state rechargeable Na-CO2 batteries with reduced graphene oxide Na anodes.

    Science.gov (United States)

    Hu, Xiaofei; Li, Zifan; Zhao, Yaran; Sun, Jianchao; Zhao, Qing; Wang, Jianbin; Tao, Zhanliang; Chen, Jun

    2017-02-01

    Na-CO2 batteries using earth-abundant Na and greenhouse gas CO2 are promising tools for mobile and stationary energy storage, but they still pose safety risks from leakage of liquid electrolyte and instability of the Na metal anode. These issues result in extremely harsh operating conditions of Na-CO2 batteries and increase the difficulty of scaling up this technology. We report the development of quasi-solid state Na-CO2 batteries with high safety using composite polymer electrolyte (CPE) and reduced graphene oxide (rGO) Na anodes. The CPE of PVDF-HFP [poly(vinylidene fluoride-co-hexafluoropropylene)]-4% SiO2/NaClO4-TEGDME (tetraethylene glycol dimethyl ether) has high ion conductivity (1.0 mS cm(-1)), robust toughness, a nonflammable matrix, and strong electrolyte-locking ability. In addition, the rGO-Na anode presents fast and nondendritic Na(+) plating/stripping (5.7 to 16.5 mA cm(-2)). The improved kinetics and safety enable the constructed rGO-Na/CPE/CO2 batteries to successfully cycle in wide CO2 partial pressure window (5 to 100%, simulated car exhaust) and especially to run for 400 cycles at 500 mA g(-1) with a fixed capacity of 1000 mA·hour g(-1) in pure CO2. Furthermore, we scaled up the reversible capacity to 1.1 A·hour in pouch-type batteries (20 × 20 cm, 10 g, 232 Wh kg(-1)). This study makes quasi-solid state Na-CO2 batteries an attractive prospect.

  5. Quasi–solid state rechargeable Na-CO2 batteries with reduced graphene oxide Na anodes

    Science.gov (United States)

    Hu, Xiaofei; Li, Zifan; Zhao, Yaran; Sun, Jianchao; Zhao, Qing; Wang, Jianbin; Tao, Zhanliang; Chen, Jun

    2017-01-01

    Na-CO2 batteries using earth-abundant Na and greenhouse gas CO2 are promising tools for mobile and stationary energy storage, but they still pose safety risks from leakage of liquid electrolyte and instability of the Na metal anode. These issues result in extremely harsh operating conditions of Na-CO2 batteries and increase the difficulty of scaling up this technology. We report the development of quasi–solid state Na-CO2 batteries with high safety using composite polymer electrolyte (CPE) and reduced graphene oxide (rGO) Na anodes. The CPE of PVDF-HFP [poly(vinylidene fluoride-co-hexafluoropropylene)]–4% SiO2/NaClO4–TEGDME (tetraethylene glycol dimethyl ether) has high ion conductivity (1.0 mS cm−1), robust toughness, a nonflammable matrix, and strong electrolyte-locking ability. In addition, the rGO-Na anode presents fast and nondendritic Na+ plating/stripping (5.7 to 16.5 mA cm−2). The improved kinetics and safety enable the constructed rGO-Na/CPE/CO2 batteries to successfully cycle in wide CO2 partial pressure window (5 to 100%, simulated car exhaust) and especially to run for 400 cycles at 500 mA g−1 with a fixed capacity of 1000 mA·hour g−1 in pure CO2. Furthermore, we scaled up the reversible capacity to 1.1 A·hour in pouch-type batteries (20 × 20 cm, 10 g, 232 Wh kg−1). This study makes quasi–solid state Na-CO2 batteries an attractive prospect. PMID:28164158

  6. Elevated CO2 reduced floret death in wheat under warmer average temperatures and terminal drought.

    Directory of Open Access Journals (Sweden)

    Eduardo eDias de Oliveira

    2015-11-01

    Full Text Available Elevated CO2 often increases grain yield in wheat by enhancing grain number per ear, which can result from an increase in the potential number of florets or a reduction in the death of developed florets. The hypotheses that elevated CO2 reduces floret death rather than increases floret development, and that grain size in a genotype with more grains per unit area is limited by the rate of grain filling, were tested in a pair of sister lines contrasting in tillering capacity (restricted- vs free-tillering. The hypotheses were tested under elevated CO2, combined with +3 C above ambient temperature and terminal drought, using specialized field tunnel houses. Elevated CO2 increased net leaf photosynthetic rates and likely the availability of carbon assimilates, which significantly reduced the rates of floret death and increased the potential number of grains at anthesis in both sister lines by an average of 42%. The restricted-tillering line had faster grain-filling rates than the free-tillering line because the free-tillering line had more grains to fill. Furthermore, grain-filling rates were faster under elevated CO2 and +3 C above ambient. Terminal drought reduced grain yield in both lines by 19%. Elevated CO2 alone increased the potential number of grains, but a trade-off in yield components limited grain yield in the free-tillering line. This emphasizes the need for breeding cultivars with a greater potential number of florets, since this was not affected by the predicted future climate variables.

  7. Direct reduction process using fines and with reduced CO2 emission

    CSIR Research Space (South Africa)

    Morrison, A

    2004-08-01

    Full Text Available ferroalloy CO2 emissions from 3.0 to 2.5 Mt/year. However, the cost of biocarbon is about double that of fossil fuel. The 1997 Kyoto Protocol requires signatories to reduce CO2 emissions to 7% below 1990 levels between 2008 and 2012 and methods.... 8. ‘Gmelin handbook’, Mn-C8, Compounds, 145–147; 1982. 9. BHP Billiton/Samancor Chrome, personal communication. 10. ‘Materials technology annual report’, Sintef, 1998 (www.sintef.no). 11. Kyoto Protocol, UNFCCC, Dec. 1997, Agenda Item 5. 12...

  8. Projected near-future levels of temperature and pCO2 reduce coral fertilization success.

    Directory of Open Access Journals (Sweden)

    Rebecca Albright

    Full Text Available Increases in atmospheric carbon dioxide (pCO2 are projected to contribute to a 1.1-6.4°C rise in global average surface temperatures and a 0.14-0.35 reduction in the average pH of the global surface ocean by 2100. If realized, these changes are expected to have negative consequences for reef-building corals including increased frequency and severity of coral bleaching and reduced rates of calcification and reef accretion. Much less is known regarding the independent and combined effects of temperature and pCO2 on critical early life history processes such as fertilization. Here we show that increases in temperature (+3°C and pCO2 (+400 µatm projected for this century negatively impact fertilization success of a common Indo-Pacific coral species, Acropora tenuis. While maximum fertilization did not differ among treatments, the sperm concentration required to obtain 50% of maximum fertilization increased 6- to 8- fold with the addition of a single factor (temperature or CO2 and nearly 50- fold when both factors interact. Our results indicate that near-future changes in temperature and pCO2 narrow the range of sperm concentrations that are capable of yielding high fertilization success in A. tenuis. Increased sperm limitation, in conjunction with adult population decline, may have severe consequences for coral reproductive success. Impaired sexual reproduction will further challenge corals by inhibiting population recovery and adaptation potential.

  9. Optimizing Blendstock Composition and Ethanol Feedstock to Reduce Gasoline Well-to-Pump CO 2 Emission

    KAUST Repository

    Zhang, Bo

    2017-06-02

    Lifecycle CO2 emission of ethanol blended gasoline was simulated to investigate how fuel properties and composition affect overall emission. Fuel research octane number (RON), octane sensitivity and ethanol content (derived from sugarcane and corn) were varied in the simulations to formulate blended fuels that economically achieve target specifications. The well-to-pump (WTP) simulation results were then analyzed to understand the effects of fuel composition on emission. Elevated ethanol content displaces aromatics and olefins required in gasoline blendstock to reach a target fuel specification. The addition of greater sugarcane-based ethanol percentage in constant aromatics and olefins fuel reduces its WTP CO2 emission. Corn-based ethanol blending does not offer CO2 emission offset due to its high production emissions. The mixing of sugarcane-based with corn-based ethanol is shown to be a potentially effective method for achieving a blended fuel with a lower lifecycle CO2 emission. Besides CO2 emission, the total greenhouse gas (GHG) emission from land-use conversions (LUC), CH4, and N2O are also significant in determining the optimal fuel blend. Herein, we present preliminary results showing that total GHG emissions significantly increase when either corn or sugarcane ethanol is blended at even small percentages; detailed results will be addressed in future communications.

  10. How Much CO2 Emissions Can Be Reduced in China’s Heating Industry

    Directory of Open Access Journals (Sweden)

    Jing Lin

    2016-07-01

    Full Text Available China’s heating industry is a coal-fired industry with serious environmental issues. CO2 emissions from the heating industry accounted for an average 6.1% of China’s carbon emissions during 1985–2010. The potential for reducing emissions in China’s heating industry is evaluated by co-integration analysis and scenario analysis. The results demonstrate that there is a long-run equilibrium relationship among CO2 emissions and the influencing factors, including energy intensity, industrial scale, labor productivity, and energy productivity. Monte Carlo technique is adopted for risk analysis. It is found that the CO2 emissions reduction potential of the heating industry will be 26.7 million tons of coal equivalent (Mtce in 2020 and 64.8 Mtce in 2025 under the moderate scenario, compared with 50.6 Mtce in 2020 and 122.1 Mtce in 2025 under the advanced scenario. Policy suggestions are provided accordingly.

  11. Neither elevated nor reduced CO2 affects the photophysiological performance of the marine Antarctic diatom Chaetoceros brevis

    NARCIS (Netherlands)

    Boelen, Peter; de Poll, Willem H. van; van der Strate, Han J.; Neven, Ika A.; Beardall, John; Buma, Anita G. J.

    2011-01-01

    Enhanced or reduced pCO(2) (partial pressure of CO2) may affect the photosynthetic performance of marine microalgae since changes in pCO(2) can influence the activity of carbon concentrating mechanisms, modulate cellular RuBisCO levels or alter carbon uptake efficiency. In the present study we compa

  12. Ethylene: Response of Fruit Dehiscence to CO2 and Reduced Pressure 1

    Science.gov (United States)

    Lipe, John A.; Morgan, Page W.

    1972-01-01

    These studies were conducted to determine whether ethylene serves as a natural regulator of fruit wall dehiscence, a major visible feature of ripening in some fruits. We employed treatments to inhibit ethylene action or remove ethylene and observed their effect on fruit dehiscence. CO2 (13%), a competitive inhibitor of ethylene action in many systems, readily delayed dehiscence of detached fruits of cotton (Gossypium hirsutum L.), pecan (Carya illinoensis [Wang.] K. Koch), and okra (Hibiscus esculentus L.). The CO2 effect was duplicated by placing fruits under reduced pressure (200 millimeters mercury), to promote the escape of ethylene from the tissue. Dehiscence of detached fruits of these species as well as attached cotton fruits was delayed. The delay of dehiscence of cotton and okra by both treatments was achieved with fruit harvested at intervals from shortly after anthesis until shortly before natural dehiscence. Pecan fruits would not dehisce until approximately 1 month before natural dehiscence, and during that time, CO2 and reduced pressure delayed dehiscence. CO2 and ethylene were competitive in their effects on cotton fruit dehiscence. All of the results are compatible with a hypothetical role of ethylene as a natural regulator of dehiscence, a dominant aspect of ripening of cotton, pecan, and some other fruits. PMID:16658260

  13. Ethylene: Response of Fruit Dehiscence to CO(2) and Reduced Pressure.

    Science.gov (United States)

    Lipe, J A; Morgan, P W

    1972-12-01

    These studies were conducted to determine whether ethylene serves as a natural regulator of fruit wall dehiscence, a major visible feature of ripening in some fruits. We employed treatments to inhibit ethylene action or remove ethylene and observed their effect on fruit dehiscence. CO(2) (13%), a competitive inhibitor of ethylene action in many systems, readily delayed dehiscence of detached fruits of cotton (Gossypium hirsutum L.), pecan (Carya illinoensis [Wang.] K. Koch), and okra (Hibiscus esculentus L.). The CO(2) effect was duplicated by placing fruits under reduced pressure (200 millimeters mercury), to promote the escape of ethylene from the tissue. Dehiscence of detached fruits of these species as well as attached cotton fruits was delayed. The delay of dehiscence of cotton and okra by both treatments was achieved with fruit harvested at intervals from shortly after anthesis until shortly before natural dehiscence. Pecan fruits would not dehisce until approximately 1 month before natural dehiscence, and during that time, CO(2) and reduced pressure delayed dehiscence. CO(2) and ethylene were competitive in their effects on cotton fruit dehiscence. All of the results are compatible with a hypothetical role of ethylene as a natural regulator of dehiscence, a dominant aspect of ripening of cotton, pecan, and some other fruits.

  14. Antioxidant capacity reduced in scallions grown under elevated CO 2 independent of assayed light intensity

    Science.gov (United States)

    Levine, Lanfang H.; Paré, Paul W.

    2009-10-01

    Long-duration manned space missions mandate the development of a sustainable life support system and effective countermeasures against damaging space radiation. To mitigate the risk of inevitable exposure to space radiation, cultivation of fresh fruits and vegetables rich in antioxidants is an attractive alternative to pharmacological agents. However it has yet to be established whether antioxidant properties of crops can be preserved or enhanced in a space environment where environmental conditions differ from that which plants have acclimated to on earth. Scallion ( Allium fistulosum) rich in antioxidant vitamins C and A, and flavonoids was used as a model plant to study the impact of a range of CO 2 concentrations and light intensities that are likely encountered in a space habitat on food quality traits. Scallions were hydroponically grown in controlled environmental chambers under a combination of 3 CO 2 concentrations of 400, 1200 and 4000 μmol mol -1 and 3 light intensity levels of 150, 300, 450 μmol m -2 s -1. Total antioxidant activity (TAA) of scallion extracts was determined using a radical cation scavenging assay. Both elevated CO 2 and increasing light intensity enhanced biomass accumulation, but effects on TAA (based on dry weight) differed. TAA was reduced for plants grown under elevated CO 2, but remained unchanged with increases in light intensity. Elevated CO 2 stimulated greater biomass production than antioxidants, while an increase in photosynthetic photo flux promoted the synthesis of antioxidant compounds at a rate similar to that of biomass. Consequently light is a more effective stimulus than CO 2 for antioxidant production.

  15. Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity

    Science.gov (United States)

    Swann, Abigail L. S.; Hoffman, Forrest M.; Koven, Charles D.; Randerson, James T.

    2016-09-01

    Rising atmospheric CO2 will make Earth warmer, and many studies have inferred that this warming will cause droughts to become more widespread and severe. However, rising atmospheric CO2 also modifies stomatal conductance and plant water use, processes that are often are overlooked in impact analysis. We find that plant physiological responses to CO2 reduce predictions of future drought stress, and that this reduction is captured by using plant-centric rather than atmosphere-centric metrics from Earth system models (ESMs). The atmosphere-centric Palmer Drought Severity Index predicts future increases in drought stress for more than 70% of global land area. This area drops to 37% with the use of precipitation minus evapotranspiration (P-E), a measure that represents the water flux available to downstream ecosystems and humans. The two metrics yield consistent estimates of increasing stress in regions where precipitation decreases are more robust (southern North America, northeastern South America, and southern Europe). The metrics produce diverging estimates elsewhere, with P-E predicting decreasing stress across temperate Asia and central Africa. The differing sensitivity of drought metrics to radiative and physiological aspects of increasing CO2 partly explains the divergent estimates of future drought reported in recent studies. Further, use of ESM output in offline models may double-count plant feedbacks on relative humidity and other surface variables, leading to overestimates of future stress. The use of drought metrics that account for the response of plant transpiration to changing CO2, including direct use of P-E and soil moisture from ESMs, is needed to reduce uncertainties in future assessment.

  16. Reduced CO2 fertilization effect in temperate C3 grasslands under more extreme weather conditions

    Science.gov (United States)

    Obermeier, W. A.; Lehnert, L. W.; Kammann, C. I.; Müller, C.; Grünhage, L.; Luterbacher, J.; Erbs, M.; Moser, G.; Seibert, R.; Yuan, N.; Bendix, J.

    2016-12-01

    The increase in atmospheric greenhouse gas concentrations from anthropogenic activities is the major driver of recent global climate change. The stimulation of plant photosynthesis due to rising atmospheric carbon dioxide concentrations ([CO2]) is widely assumed to increase the net primary productivity (NPP) of C3 plants--the CO2 fertilization effect (CFE). However, the magnitude and persistence of the CFE under future climates, including more frequent weather extremes, are controversial. Here we use data from 16 years of temperate grassland grown under `free-air carbon dioxide enrichment’ conditions to show that the CFE on above-ground biomass is strongest under local average environmental conditions. The observed CFE was reduced or disappeared under wetter, drier and/or hotter conditions when the forcing variable exceeded its intermediate regime. This is in contrast to predictions of an increased CO2 fertilization effect under drier and warmer conditions. Such extreme weather conditions are projected to occur more intensely and frequently under future climate scenarios. Consequently, current biogeochemical models might overestimate the future NPP sink capacity of temperate C3 grasslands and hence underestimate future atmospheric [CO2] increase.

  17. Bubble Stripping as a Tool To Reduce High Dissolved CO2 in Coastal Marine Ecosystems.

    Science.gov (United States)

    Koweek, David A; Mucciarone, David A; Dunbar, Robert B

    2016-04-01

    High dissolved CO2 concentrations in coastal ecosystems are a common occurrence due to a combination of large ecosystem metabolism, shallow water, and long residence times. Many important coastal species may have adapted to this natural variability over time, but eutrophication and ocean acidification may be perturbing the water chemistry beyond the bounds of tolerance for these organisms. We are currently limited in our ability to deal with the geochemical changes unfolding in our coastal ocean. This study helps to address this deficit of solutions by introducing bubble stripping as a novel geochemical engineering approach to reducing high CO2 in coastal marine ecosystems. We use a process-based model to find that air/sea gas exchange rates within a bubbled system are 1-2 orders of magnitude higher than within a nonbubbled system. By coupling bubbling-enhanced ventilation to a coastal ecosystem metabolism model, we demonstrate that strategically timed bubble plumes can mitigate exposure to high CO2 under present-day conditions and that exposure mitigation is enhanced in the more acidic conditions predicted by the end of the century. We argue that shallow water CO2 bubble stripping should be considered among the growing list of engineering approaches intended to increase coastal resilience in a changing ocean.

  18. Reduced CO2 fertilization effect in temperate C3 grasslands under more extreme weather conditions

    Science.gov (United States)

    Obermeier, W. A.; Lehnert, L. W.; Kammann, C. I.; Müller, C.; Grünhage, L.; Luterbacher, J.; Erbs, M.; Moser, G.; Seibert, R.; Yuan, N.; Bendix, J.

    2017-02-01

    The increase in atmospheric greenhouse gas concentrations from anthropogenic activities is the major driver of recent global climate change. The stimulation of plant photosynthesis due to rising atmospheric carbon dioxide concentrations ([CO2]) is widely assumed to increase the net primary productivity (NPP) of C3 plants--the CO2 fertilization effect (CFE). However, the magnitude and persistence of the CFE under future climates, including more frequent weather extremes, are controversial. Here we use data from 16 years of temperate grassland grown under `free-air carbon dioxide enrichment’ conditions to show that the CFE on above-ground biomass is strongest under local average environmental conditions. The observed CFE was reduced or disappeared under wetter, drier and/or hotter conditions when the forcing variable exceeded its intermediate regime. This is in contrast to predictions of an increased CO2 fertilization effect under drier and warmer conditions. Such extreme weather conditions are projected to occur more intensely and frequently under future climate scenarios. Consequently, current biogeochemical models might overestimate the future NPP sink capacity of temperate C3 grasslands and hence underestimate future atmospheric [CO2] increase.

  19. Estimating Potential and Costs of Reducing CO2 Emissions in Lithuanian Buildings

    Directory of Open Access Journals (Sweden)

    Eglė Jaraminienė

    2012-03-01

    Full Text Available The EU is considering increasing the GHG emissions reduction target by 2020 from 20% to 30% by committing each member state to tighten up its emission reduction goals. According to the recent study such decision could cost some 2 365 million LTL to Lithuanian economy. Evaluation and comparison of CO2 abatement costs incurred by the state implementing a variety of measures in different sectors allow choosing a most cost effective policy scenario. The paper focuses on CO2 emissions related to energy use in buildings. First, this paper reviews the role of the Lithuanian building stock in overall GHG emissions. Then the paper examines the existing studies on the CO2 mitigation potential and cost in buildings. Given the limitations of existing evaluation and lack of comprehensive modelling in the existing studies, this paper proposes a framework for examining the technology options aimed to inform policy making on the options to reduce CO2 emissions in Lithuanian housing and service sectors.DOI: http://dx.doi.org/10.5755/j01.erem.59.1.680

  20. Development of air conditioning technologies to reduce CO2 emissions in the commercial sector

    Science.gov (United States)

    Yoshida, Yukiko

    2006-01-01

    Background Architectural methods that take into account global environmental conservation generally concentrate on mitigating the heat load of buildings. Here, we evaluate the reduction of carbon dioxide (CO2) emissions that can be achieved by improving heating, ventilating, and air conditioning (HVAC) technologies. Results The Climate Change Research Hall (CCRH) of the National Institute for Environmental Studies (NIES) is used as a case study. CCRH was built in line with the "Green Government Buildings" program of the Government Buildings Department at the Ministry of Land, Infrastructure and Transport in Japan. We have assessed the technology used in this building, and found that there is a possibility to reduce energy consumption in the HVAC system by 30%. Conclusion Saving energy reduces CO2 emissions in the commercial sector, although emission factors depend on the country or region. Consequently, energy savings potential may serve as a criterion in selecting HVAC technologies with respect to emission reduction targets. PMID:17062161

  1. Development of air conditioning technologies to reduce CO2 emissions in the commercial sector

    Directory of Open Access Journals (Sweden)

    Yoshida Yukiko

    2006-10-01

    Full Text Available Abstract Background Architectural methods that take into account global environmental conservation generally concentrate on mitigating the heat load of buildings. Here, we evaluate the reduction of carbon dioxide (CO2 emissions that can be achieved by improving heating, ventilating, and air conditioning (HVAC technologies. Results The Climate Change Research Hall (CCRH of the National Institute for Environmental Studies (NIES is used as a case study. CCRH was built in line with the "Green Government Buildings" program of the Government Buildings Department at the Ministry of Land, Infrastructure and Transport in Japan. We have assessed the technology used in this building, and found that there is a possibility to reduce energy consumption in the HVAC system by 30%. Conclusion Saving energy reduces CO2 emissions in the commercial sector, although emission factors depend on the country or region. Consequently, energy savings potential may serve as a criterion in selecting HVAC technologies with respect to emission reduction targets.

  2. Development of air conditioning technologies to reduce CO2 emissions in the commercial sector.

    Science.gov (United States)

    Yoshida, Yukiko

    2006-10-25

    Architectural methods that take into account global environmental conservation generally concentrate on mitigating the heat load of buildings. Here, we evaluate the reduction of carbon dioxide (CO2) emissions that can be achieved by improving heating, ventilating, and air conditioning (HVAC) technologies. The Climate Change Research Hall (CCRH) of the National Institute for Environmental Studies (NIES) is used as a case study. CCRH was built in line with the "Green Government Buildings" program of the Government Buildings Department at the Ministry of Land, Infrastructure and Transport in Japan. We have assessed the technology used in this building, and found that there is a possibility to reduce energy consumption in the HVAC system by 30%. Saving energy reduces CO2 emissions in the commercial sector, although emission factors depend on the country or region. Consequently, energy savings potential may serve as a criterion in selecting HVAC technologies with respect to emission reduction targets.

  3. Reducing CO2 Emissions in the Production of Porous Fired Clay Bricksks

    Directory of Open Access Journals (Sweden)

    Mikuláš ŠVEDA

    2017-05-01

    Full Text Available A plan to reduce CO2 emissions is a priority these days. Brick industry contributes to the increase of these emissions mainly through the use of combustible pore-forming agents such as sawdust, cellulose, and coal sludge. These agents are used to improve the thermal insulation properties of brick products, and the suppliers regularly increase the prices of these agents based on their high consumption. Therefore, in an effort to reduce raw material expenses and CO2 emissions, brick manufacturers are looking for new possibilities while maintaining the quality of their products. This article discusses the possibility of using industrially manufactured product Vuppor as an additive as a replacement for combustible pore-forming agents. The presence of this additive in the fired clay body increases the proportion of pores, especially with a size range between 0.1 and 5 µm, having a positive impact on the reduction of its thermal conductivity. With a 0.5 wt.% dose of Vuppor additive, the brick production costs and thermal conductivity can be reduced by 20 % and 12 %, respectively, while also achieving reductions in CO2 emissions over 60 %. Consequently, the combustible pore-forming agents can be used in a more environmentally friendly manner, for example in the furniture industry, the biogas production, and the like.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15103

  4. The cost of reducing CO2 emissions - methodological approach, illustrated by the Danish energy plan

    DEFF Research Database (Denmark)

    Morthorst, P.E.

    1998-01-01

    available. One of the tools available for this purpose is the construction of cost-reduction curves, relating the marginal cost of CO2 reduction and the quantity of the reduced emission to specific technology options. This paper outlines different approaches for establishing cost-reduction curves for CO2...... those technological options that have the highest reduction potential and the lowest marginal costs, and vice versa. Based on the case of the Danish energy plan, the results of the analyses show that a number of reduction options with significant reduction potentials are available at relatively low...... marginal costs. Among others can be mentioned increased use of combined heat and power (CHP), substituting conventional coal-fired CHP plants with biomass ones and the development of offshore wind turbines: (C) 1998 Elsevier Science Ltd. All rights reserved....

  5. Delay-feedback control strategy for reducing CO2 emission of traffic flow system

    Science.gov (United States)

    Zhang, Li-Dong; Zhu, Wen-Xing

    2015-06-01

    To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

  6. Long-term drainage reduces CO2 uptake and increases CO2 emission on a Siberian floodplain due to shifts in vegetation community and soil thermal characteristics

    Science.gov (United States)

    Kwon, Min Jung; Heimann, Martin; Kolle, Olaf; Luus, Kristina A.; Schuur, Edward A. G.; Zimov, Nikita; Zimov, Sergey A.; Göckede, Mathias

    2016-07-01

    With increasing air temperatures and changing precipitation patterns forecast for the Arctic over the coming decades, the thawing of ice-rich permafrost is expected to increasingly alter hydrological conditions by creating mosaics of wetter and drier areas. The objective of this study is to investigate how 10 years of lowered water table depths of wet floodplain ecosystems would affect CO2 fluxes measured using a closed chamber system, focusing on the role of long-term changes in soil thermal characteristics and vegetation community structure. Drainage diminishes the heat capacity and thermal conductivity of organic soil, leading to warmer soil temperatures in shallow layers during the daytime and colder soil temperatures in deeper layers, resulting in a reduction in thaw depths. These soil temperature changes can intensify growing-season heterotrophic respiration by up to 95 %. With decreased autotrophic respiration due to reduced gross primary production under these dry conditions, the differences in ecosystem respiration rates in the present study were 25 %. We also found that a decade-long drainage installation significantly increased shrub abundance, while decreasing Eriophorum angustifolium abundance resulted in Carex sp. dominance. These two changes had opposing influences on gross primary production during the growing season: while the increased abundance of shrubs slightly increased gross primary production, the replacement of E. angustifolium by Carex sp. significantly decreased it. With the effects of ecosystem respiration and gross primary production combined, net CO2 uptake rates varied between the two years, which can be attributed to Carex-dominated plots' sensitivity to climate. However, underlying processes showed consistent patterns: 10 years of drainage increased soil temperatures in shallow layers and replaced E. angustifolium by Carex sp., which increased CO2 emission and reduced CO2 uptake rates. During the non-growing season, drainage

  7. Reduced Brillouin scattering from multiline CO2 laser interaction with a plasma

    Science.gov (United States)

    Giles, R.; Fedosejevs, R.; Offenberger, A. A.

    1982-08-01

    Experimental verification of reduced stimulated Brillouin scattering (SBS) is reported for multiline CO2 laser radiation interacting with high-density plasma. For long-pulse (40-nsec) irradiation SBS was observed to decrease from 15% to a negligible level when the spectrum of the incident laser pulse was changed from 1 to 2 or more well-separated frequencies. Results for both long- and short-pulse multiline laser conditions are in general accord with the expected behavior for varying Δωγ0, where Δω is the frequency separation and γ0 is the homogeneous growth rate.

  8. Reduced graphene oxide as photocatalyst for CO2 reduction reaction(Conference Presentation)

    Science.gov (United States)

    Chang, Yu-Chung

    2016-10-01

    Photocatalytic conversion of carbon dioxide (CO2) to hydrocarbons such as methanol makes possible simultaneous solar energy harvesting and CO2 reduction. Our previous work is using graphene oxide (GO) as a promising photocatalyst for photocatalytic conversion of CO2 to methanol[1].When using graphene oxide as photocatalyst, the photocatalytic efficiency is 4-flod higher than TiO2 powder. GO has a lot of defects on the surface and those defects make sp2 carbon structure become sp3 carbon structure. The carbon structure change cause the GO has large energy gap about 2.7 eV to 3.2 eV. In order to remove the defect and reduce the energy gap of GO, Zhao et al. try to annealing GO powder in the nitrogen atmosphere at 900oC, the GO structure can be reduced to near graphene structure[2]. Zhu et al. do some low temperature annealing, it can control the structure and energy bandgap of GO by control annealing temperature. If the annealing temperature increase the bandgap of GO will be reduce[3]. So, we can using this annealing process to reduce the bandgap of the GO. In the varying temperature thermal reduction process, as the temperature increases from 130oC to 170oC, the functional groups of the graphene oxide will be reduced and band gap of graphene oxide will be narrowed at same time. The characteristic of thermal reduced graphene oxide were analyzed by SEM, XRD and Raman measurements. The band position was determined by UV/Vis. The reduction of functional groups correlates to red shift in light absorption and eventual quenching in the PL signal of RGOs. Combining hydrophobicity, light harvesting and PL quench, we get the highest yield of RGO150 (0.31 μmole g-1 -cat hr-1) is 1.7-fold higher than that of GO (0.18μmole g-1 -cat hr-1). This work investigates a modified method for using a thermal reduction process to reduce the energy gap of graphene oxide.

  9. Elevated CO2 and Phosphate Limitation Favor Micromonas pusilla through Stimulated Growth and Reduced Viral Impact

    NARCIS (Netherlands)

    Maat, Douwe S.; Crawfurd, Katherine J.; Timmermans, Klaas R.; Brussaard, Corina P. D.

    2014-01-01

    Growth and viral infection of the marine picoeukaryote Micromonas pusilla was studied under a future-ocean scenario of elevated partial CO2 (pCO(2); 750 mu atm versus the present-day 370 mu atm) and simultaneous limitation of phosphorus (P). Independent of the pCO(2) level, the ratios of M. pusilla

  10. Active measures for reducing the global climatic impacts of escalating CO 2 concentrations

    Science.gov (United States)

    Penner, S. S.; Schneider, A. M.; Kennedy, E. M.

    The buildup of CO 2 by fossil-fuel burning and associated climatic changes have become the subject of intensive investigations. Although the time scale on which significant climatic changes (e.g. mean temperature changes of several degrees, appreciable changes in global and regional rainfalls and winds, etc.) are expected to occur is long, it has been noted that the magnitude of the energy system is so vast that modifications in the primary resource mix should preferably be initiated within a decade or sooner. The notion that the most economical energy source will be replaced globally in response to longterm climate model predictions is probably false. Before policy matters of this type can be discussed reasonably, careful assessments must be made of alternative global measures that do not require curtailments of fossil-fuel applications. This study on active measures for reducing climate changes caused by escalating CO 2 concentrations deals with potentially important areas of research. We find: (a) reductions in the solar input to the Earth by reflecting sunlight directly are prohibitively costly; (b) desired changes in Earth albedo through judicious introduction of small particles can probably be accomplished at acceptable cost through the use of modified combustors on high-flying aircraft.

  11. Reducing refinery CO2 emissions through amine solvent upgrade and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Thiago V.; Valenzuela, Michelle [The Dow Chemical Company, Midland, MI (United States)

    2012-07-01

    Regional initiatives are underway to reduce and limit the emissions of greenhouse gases. With CO2 emissions making up over 80% of the greenhouse gases, cap-and-trade programs will focus on those industries that consume the most energy. Refineries are among the top energy consumers and are seeking opportunities to reduce usage. With tightening margins, energy management programs will not only help refineries meet CO{sub 2} emission regulations, but can also provide a competitive advantage. With the trend towards heavier and higher sulfur containing crudes, refineries are increasing processing capabilities, which can include capital-intensive projects and additional energy consumption. Energy conservation plans should include optimization of these processes. One area to consider includes the acid gas removal systems in refineries. Through the selection and use of optimal solvents and implementation of energy efficiency techniques, which require minimal capital investment and expenditures, refineries can reduce energy usage, overall CO{sub 2} emissions, and total cost in acid gas systems. This paper will discuss these approaches and share case studies detailing the implementation and results. (author)

  12. A reduced order model to analytically infer atmospheric CO2 concentration from stomatal and climate data

    Science.gov (United States)

    Konrad, Wilfried; Katul, Gabriel; Roth-Nebelsick, Anita; Grein, Michaela

    2017-06-01

    To address questions related to the acceleration or deceleration of the global hydrological cycle or links between the carbon and water cycles over land, reliable data for past climatic conditions based on proxies are required. In particular, the reconstruction of palaeoatmospheric CO2 content (Ca) is needed to assist the separation of natural from anthropogenic Ca variability and to explore phase relations between Ca and air temperature Ta time series. Both Ta and Ca are needed to fingerprint anthropogenic signatures in vapor pressure deficit, a major driver used to explain acceleration or deceleration phases in the global hydrological cycle. Current approaches to Ca reconstruction rely on a robust inverse correlation between measured stomatal density in leaves (ν) of many plant taxa and Ca. There are two methods that exploit this correlation: The first uses calibration curves obtained from extant species assumed to represent the fossil taxa, thereby restricting the suitable taxa to those existing today. The second is a hybrid eco-hydrological/physiological approach that determines Ca with the aid of systems of equations based on quasi-instantaneous leaf-gas exchange theories and fossil stomatal data collected along with other measured leaf anatomical traits and parameters. In this contribution, a reduced order model (ROM) is proposed that derives Ca from a single equation incorporating the aforementioned stomatal data, basic climate (e.g. temperature), estimated biochemical parameters of assimilation and isotope data. The usage of the ROM is then illustrated by applying it to isotopic and anatomical measurements from three extant species. The ROM derivation is based on a balance between the biochemical demand and atmospheric supply of CO2 that leads to an explicit expression linking stomatal conductance to internal CO2 concentration (Ci) and Ca. The resulting expression of stomatal conductance from the carbon economy of the leaf is then equated to another

  13. Reduced graphene oxide (RGO)-supported NiCo2O4 nanoparticles: an electrocatalyst for methanol oxidation

    Science.gov (United States)

    Das, Ashok Kumar; Layek, Rama K.; Kim, Nam Hoon; Jung, Daeseung; Lee, Joong Hee

    2014-08-01

    The design and development of cheap, highly active, and durable non-platinum (Pt)-based electrocatalysts for methanol electrooxidation is highly desirable, but is a challenging task. In this paper, we demonstrate the application of a hydrothermally synthesized NiCo2O4-reduced graphene oxide (RGO) composite as an electrocatalyst for the electrochemical oxidation of methanol in alkaline pH. The physicochemical properties of the NiCo2O4-RGO composite were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements. The physical characterization methods confirm the deposition of NiCo2O4 nanoparticles on the RGO surface. The TEM image shows that the NiCo2O4 nanoparticles with an average size of ~10 nm are distributed over the RGO surface. Compared to RGO and NiCo2O4 nanoparticles, the NiCo2O4-RGO-based electrode shows excellent electrocatalytic activity for the oxidation of methanol in alkaline pH. On the NiCo2O4-RGO-based electrode, the oxidation of methanol occurs at ~0.6 V with a higher catalytic current density, and the response is highly stable. The excellent electrocatalytic activity of the NiCo2O4-RGO composite is attributed to the synergistic effects between the NiCo2O4 nanoparticles and RGO. Since the NiCo2O4-RGO composite shows a highly stable response during methanol oxidation reaction, it is a very promising material to be used as an electrocatalyst in the development of high performance non-Pt based alkaline fuel cells.The design and development of cheap, highly active, and durable non-platinum (Pt)-based electrocatalysts for methanol electrooxidation is highly desirable, but is a challenging task. In this paper, we demonstrate the application of a hydrothermally synthesized NiCo2O4-reduced graphene oxide (RGO) composite as an electrocatalyst for the electrochemical

  14. Will the CO2 fertilization effect in forests be offset by reduced tree longevity?

    Science.gov (United States)

    Bugmann, Harald; Bigler, Christof

    2011-02-01

    Experimental studies suggest that tree growth is stimulated in a greenhouse atmosphere, leading to faster carbon accumulation (i.e., a higher rate of gap filling). However, higher growth may be coupled with reduced longevity, thus leading to faster carbon release (i.e., a higher rate of gap creation). The net effect of these two counteracting processes is not known. We quantify this net effect on aboveground carbon stocks using a novel combination of data sets and modeling. Data on maximum growth rate and maximum longevity of 141 temperate tree species are used to derive a relationship between growth stimulation and changes in longevity. We employ this relationship to modify the respective parameter values of tree species in a forest succession model and study aboveground biomass in a factorial design of growth stimulation × reduced maximum longevity at multiple sites along a climate gradient from the cold to the dry treeline. The results show that (1) any growth stimulation at the tree level leads to a disproportionately small increase of stand biomass due to negative feedback effects, even in the absence of reduced longevity; (2) a reduction of tree longevity tends to offset the growth-related biomass increase; at the most likely value of reduced longevity, the net effect is very close to zero in most multi- and single-species simulations; and (3) when averaging the response across all sites to mimic a "landscape-level" response, the net effect is close to zero. Thus, it is important to consider ecophysiological responses with their linkage to demographic processes in forest trees if one wishes to avoid erroneous inference at the ecosystem level. We conclude that any CO(2) fertilization effect is quite likely to be offset by an associated reduction in the longevity of forest trees, thus strongly reducing the carbon mitigation potential of temperate forests.

  15. Elevated CO2 reduces the resistance and tolerance of tomato plants to Helicoverpa armigera by suppressing the JA signaling pathway.

    Directory of Open Access Journals (Sweden)

    Huijuan Guo

    Full Text Available Both resistance and tolerance, which are two strategies that plants use to limit biotic stress, are affected by the abiotic environment including atmospheric CO(2 levels. We tested the hypothesis that elevated CO(2 would reduce resistance (i.e., the ability to prevent damage but enhance tolerance (i.e., the ability to regrow and compensate for damage after the damage has occurred of tomato plants to the cotton bollworm, Helicoverpa armigera. The results showed that elevated CO(2 reduced resistance by decreasing the jasmonic acid (JA level and activities of lipoxygenase, proteinase inhibitors, and polyphenol oxidase in wild-type (WT plants infested with H. armigera. Consequently, the activities of total protease, trypsin-like enzymes, and weak and active alkaline trypsin-like enzymes increased in the midgut of H. armigera when fed on WT plants grown under elevated CO(2. Unexpectedly, the tolerance of the WT to H. armigera (in terms of photosynthetic rate, activity of sucrose phosphate synthases, flower number, and plant biomass and height was also reduced by elevated CO(2. Under ambient CO(2, the expression of resistance and tolerance to H. armigera was much greater in wild type than in spr2 (a JA-deficient genotype plants, but elevated CO(2 reduced these differences of the resistance and tolerance between WT and spr2 plants. The results suggest that the JA signaling pathway contributes to both plant resistance and tolerance to herbivorous insects and that by suppressing the JA signaling pathway, elevated CO(2 will simultaneously reduce the resistance and tolerance of tomato plants.

  16. Mesoporous NiCo2O4-decorated reduced graphene oxide as a novel platform for electrochemical determination of rutin.

    Science.gov (United States)

    Cui, Shiqiang; Li, Li; Ding, Yaping; Zhang, Jiangjiang; Yang, Hua; Wang, Yingzi

    2017-03-01

    The glassy carbon electrode (GCE) modified with mesoporous NiCo2O4-decorated reduced graphene oxide (NiCo2O4/rGO) was first applied for the electrochemical determination of rutin. The synthesized NiCo2O4 and NiCo2O4/rGO were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) method. The sensor not only showed a satisfactory linear range (0.1-150μM) and detection limit (0.01μM) but also exhibited the good anti-interference abilities, low price, high stability, as well as favorable precision and accuracy. The present work is meaningful to expand functionalized graphene composites to sensor fields and promote the development of rutin sensors.

  17. Shade trees reduce building energy use and CO2 emissions from power plants.

    Science.gov (United States)

    Akbari, H

    2002-01-01

    Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering CO2 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5-11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10-11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25%.

  18. Elevated CO(2 modifies N acquisition of Medicago truncatula by enhancing N fixation and reducing nitrate uptake from soil.

    Directory of Open Access Journals (Sweden)

    Huijuan Guo

    Full Text Available The effects of elevated CO2 (750 ppm vs. 390 ppm were evaluated on nitrogen (N acquisition and assimilation by three Medicago truncatula genotypes, including two N-fixing-deficient mutants (dnf1-1 and dnf1-2 and their wild-type (Jemalong. The proportion of N acquisition from atmosphere and soil were quantified by (15N stable isotope, and N transportation and assimilation-related genes and enzymes were determined by qPCR and biochemical analysis. Elevated CO2 decreased nitrate uptake from soil in all three plant genotypes by down-regulating nitrate reductase (NR, nitrate transporter NRT1.1 and NR activity. Jemalong plant, however, produced more nodules, up-regulated N-fixation-related genes and enhanced percentage of N derived from fixation (%Ndf to increase foliar N concentration and N content in whole plant (Ntotal Yield to satisfy the requirement of larger biomass under elevated CO2. In contrast, both dnf1 mutants deficient in N fixation consequently decreased activity of glutamine synthetase/glutamate synthase (GS/GOGAT and N concentration under elevated CO2. Our results suggest that elevated CO2 is likely to modify N acquisition of M. truncatula by simultaneously increasing N fixation and reducing nitrate uptake from soil. We propose that elevated CO2 causes legumes to rely more on N fixation than on N uptake from soil to satisfy N requirements.

  19. TiO(OH)2 - highly effective catalysts for optimizing CO2 desorption kinetics reducing CO2 capture cost: A new pathway.

    Science.gov (United States)

    Yao, Hongbao; Toan, Sam; Huang, Liang; Fan, Maohong; Wang, Yujun; Russell, Armistead G; Luo, Guangsheng; Fei, Weiyang

    2017-06-07

    The objective is to find a new pathway for significant reduction in CO2 capture energy consumption. Specifically, nanoporous TiO(OH)2 was used to realize the objective, which was desired as a catalyst to significantly accelerate the decomposition of aqueous NaHCO3, essentially CO2 desorption - the key step of Na2CO3/NaHCO3 based CO2 capture technologies from overall CO2 energy consumption perspective. Effects of several important factors on TiO(OH)2-catalyzed NaHCO3 decomposition were investigated. The quantity of CO2 generated from 0.238 mol/L NaHCO3 at 65 °C with catalyst is ~800% of that generated without the presence of catalyst. When a 12 W vacuum pump was used for carrying the generated CO2 out of reactor, the total amount of CO2 released was improved by ~2,500% under the given experimental conditions. No significant decrease in the catalytic effect of TiO(OH)2 was observed after five cyclic CO2 activated tests. In addition, characterizations with in-situ Fourier transform infrared spectroscopy, thermal gravity analysis and Brunauer-Emmett-Teller of TiO(OH)2 indicate that TiO(OH)2 is quite stable. The discovery in this research could inspire scientists' interests in starting to focus on a new pathway instead of making huge effort or investment in designing high-capacity but expensive CO2 sorbent for developing practical or cost-effective CO2 technologies.

  20. Reduced habituation to experimental pain in migraine patients: a CO(2) laser evoked potential study.

    Science.gov (United States)

    Valeriani, M; de Tommaso, M; Restuccia, D; Le Pera, D; Guido, M; Iannetti, G D; Libro, G; Truini, A; Di Trapani, G; Puca, F; Tonali, P; Cruccu, G

    2003-09-01

    The habituation to sensory stimuli of different modalities is reduced in migraine patients. However, the habituation to pain has never been evaluated. Our aim was to assess the nociceptive pathway function and the habituation to experimental pain in patients with migraine. Scalp potentials were evoked by CO(2) laser stimulation (laser evoked potentials, LEPs) of the hand and facial skin in 24 patients with migraine without aura (MO), 19 patients with chronic tension-type headache (CTTH), and 28 control subjects (CS). The habituation was studied by measuring the changes of LEP amplitudes across three consecutive repetitions of 30 trials each (the repetitions lasted 5 min and were separated by 5-min intervals). The slope of the regression line between LEP amplitude and number of repetitions was taken as an index of habituation. The LEPs consisted of middle-latency, low-amplitude responses (N1, contralateral temporal region, and P1, frontal region) followed by a late, high-amplitude, negative-positive complex (N2/P2, vertex). The latency and amplitude of these responses were similar in both patients and controls. While CS and CTTH patients showed a significant habituation of the N2/P2 response, in MO patients this LEP component did not develop any habituation at all after face stimulation and showed a significantly lower habituation than in CS after hand stimulation. The habituation index of the vertex N2/P2 complex exceeded the normal limits in 13 out of the 24 MO patients and in none of the 19 CTTH patients (P<0.0001; Fisher's exact test). Moreover, while the N1-P1 amplitude showed a significant habituation in CS after hand stimulation, it did not change across repetitions in MO patients. In conclusion, no functional impairment of the nociceptive pathways, including the trigeminal pathways, was found in either MO or CTTH patients. But patients with migraine had a reduced habituation, which probably reflects an abnormal excitability of the cortical areas involved in

  1. Precipitating amino acid solvents for CO2 capture: opportunities to reduce costs in post combustion capture

    NARCIS (Netherlands)

    Sanchez Fernandez, E.; Heffernan, K.; Ham, L.V. van der; Linders, M.J.G.; Goetheer, E.L.V.; Vlugt, T.J.H.

    2014-01-01

    Post-combustion CO2 capture based on absorption and thermal desorption is considered a suitable technology for carbon abatement in fossil fuelled power plants. The economic viability of post-combustion capture has been widely studied. The major drawbacks of this technology are the efficiency penalti

  2. Applying Neural-Symbolic Cognitive Agents in Intelligent Transport Systems to reduce CO2 emissions

    NARCIS (Netherlands)

    Penning, L. de; Avila Garcez, A.S. d; Lamb, L.C.; Stuiver, A.; Meyer, J.J.C.

    2014-01-01

    Providing personalized feedback in Intelligent Transport Systems is a powerful tool for instigating a change in driving behaviour and the reduction of CO2 emissions. This requires a system that is capable of detecting driver characteristics from real-time vehicle data. In this paper, we apply the

  3. Precipitating amino acid solvents for CO2 capture: Opportunities to reduce costs in post combustion capture

    NARCIS (Netherlands)

    Sanchez-Fernandez, E.; Heffernan, K.; Van der Ham, L.; Linders, M.J.G.; Goetheer, E.; Vlugt, T.J.H.

    2014-01-01

    Post-combustion CO2 capture based on absorption and thermal desorption is considered a suitable technology for carbon abatement in fossil fuelled power plants. The economic viability of post-combustion capture has been widely studied. The major drawbacks of this technology are the efficiency penalti

  4. Quantifying and reducing uncertainties in estimated soil CO2 fluxes with hierarchical data-model integration

    Science.gov (United States)

    Ogle, Kiona; Ryan, Edmund; Dijkstra, Feike A.; Pendall, Elise

    2016-12-01

    Nonsteady state chambers are often employed to measure soil CO2 fluxes. CO2 concentrations (C) in the headspace are sampled at different times (t), and fluxes (f) are calculated from regressions of C versus t based on a limited number of observations. Variability in the data can lead to poor fits and unreliable f estimates; groups with too few observations or poor fits are often discarded, resulting in "missing" f values. We solve these problems by fitting linear (steady state) and nonlinear (nonsteady state, diffusion based) models of C versus t, within a hierarchical Bayesian framework. Data are from the Prairie Heating and CO2 Enrichment study that manipulated atmospheric CO2, temperature, soil moisture, and vegetation. CO2 was collected from static chambers biweekly during five growing seasons, resulting in >12,000 samples and >3100 groups and associated fluxes. We compare f estimates based on nonhierarchical and hierarchical Bayesian (B versus HB) versions of the linear and diffusion-based (L versus D) models, resulting in four different models (BL, BD, HBL, and HBD). Three models fit the data exceptionally well (R2 ≥ 0.98), but the BD model was inferior (R2 = 0.87). The nonhierarchical models (BL and BD) produced highly uncertain f estimates (wide 95% credible intervals), whereas the hierarchical models (HBL and HBD) produced very precise estimates. Of the hierarchical versions, the linear model (HBL) underestimated f by 33% relative to the nonsteady state model (HBD). The hierarchical models offer improvements upon traditional nonhierarchical approaches to estimating f, and we provide example code for the models.

  5. Combined Tin-Containing Fluoride Solution and CO2 Laser Treatment Reduces Enamel Erosion in vitro.

    Science.gov (United States)

    Esteves-Oliveira, Marcella; Witulski, Nadine; Hilgers, Ralf-Dieter; Apel, Christian; Meyer-Lueckel, Hendrik; Eduardo, Carlos de Paula

    2015-01-01

    The aim of this in vitro study was to evaluate the effect of combined CO2 laser and tin-containing fluoride treatment on the formation and progression of enamel erosive lesions. Ninety-six human enamel samples were obtained, stored in thymol solution and, after surface polishing, randomly divided into 6 different surface treatment groups (n = 16 in each group) as follows: no treatment, control (C); one CO2 laser irradiation (L1); two CO2 laser irradiations (L2); daily application of fluoride solution (F); combined daily fluoride solution + one CO2 laser irradiation (L1F), and combined daily fluoride solution + two CO2 laser irradiations (L2F). Laser irradiation was performed at 0.3 J/cm2 (5 µs/226 Hz/10.6 µm) on day 1 (L1) and day 6 (L2). The fluoride solution contained AmF/NaF (500 ppm F), and SnCl2 (800 ppm Sn) at pH 4.5. After surface treatment the samples were submitted to an erosive cycling over 10 days, including immersion in citric acid (2 min/0.05 M/pH = 2.3) 6 times daily and storage in remineralization solution (≥1 h) between erosive attacks. At the end of each cycling day, the enamel surface loss (micrometers) was measured using a 3D laser profilometer. Data were statistically analyzed by means of a 2-level mixed effects model and linear contrasts (α = 0.05). Group F (-3.3 ± 2.0 µm) showed significantly lower enamel surface loss than groups C (-27.22 ± 4.1 µm), L1 (-18.3 ± 4.4 µm) and L2 (-16.3 ± 5.3 µm) but higher than L1F (-1.0 ± 4.4 µm) and L2F (1.4 ± 3.2 µm, p surface loss, while its combination with CO2 laser irradiation at 0.3 J/cm2 hampered erosive loss almost completely. © 2015 S. Karger AG, Basel.

  6. REDUCING UNCERTAINTIES IN MODEL PREDICTIONS VIA HISTORY MATCHING OF CO2 MIGRATION AND REACTIVE TRANSPORT MODELING OF CO2 FATE AT THE SLEIPNER PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chen

    2015-03-31

    An important question for the Carbon Capture, Storage, and Utility program is “can we adequately predict the CO2 plume migration?” For tracking CO2 plume development, the Sleipner project in the Norwegian North Sea provides more time-lapse seismic monitoring data than any other sites, but significant uncertainties still exist for some of the reservoir parameters. In Part I, we assessed model uncertainties by applying two multi-phase compositional simulators to the Sleipner Benchmark model for the uppermost layer (Layer 9) of the Utsira Sand and calibrated our model against the time-lapsed seismic monitoring data for the site from 1999 to 2010. Approximate match with the observed plume was achieved by introducing lateral permeability anisotropy, adding CH4 into the CO2 stream, and adjusting the reservoir temperatures. Model-predicted gas saturation, CO2 accumulation thickness, and CO2 solubility in brine—none were used as calibration metrics—were all comparable with the interpretations of the seismic data in the literature. In Part II & III, we evaluated the uncertainties of predicted long-term CO2 fate up to 10,000 years, due to uncertain reaction kinetics. Under four scenarios of the kinetic rate laws, the temporal and spatial evolution of CO2 partitioning into the four trapping mechanisms (hydrodynamic/structural, solubility, residual/capillary, and mineral) was simulated with ToughReact, taking into account the CO2-brine-rock reactions and the multi-phase reactive flow and mass transport. Modeling results show that different rate laws for mineral dissolution and precipitation reactions resulted in different predicted amounts of trapped CO2 by carbonate minerals, with scenarios of the conventional linear rate law for feldspar dissolution having twice as much mineral trapping (21% of the injected CO2) as scenarios with a Burch-type or Alekseyev et al.–type rate law for feldspar dissolution (11%). So far, most reactive transport modeling (RTM) studies for

  7. Costs of solar and wind power variability for reducing CO2 emissions.

    Science.gov (United States)

    Lueken, Colleen; Cohen, Gilbert E; Apt, Jay

    2012-09-04

    We compare the power output from a year of electricity generation data from one solar thermal plant, two solar photovoltaic (PV) arrays, and twenty Electric Reliability Council of Texas (ERCOT) wind farms. The analysis shows that solar PV electricity generation is approximately one hundred times more variable at frequencies on the order of 10(-3) Hz than solar thermal electricity generation, and the variability of wind generation lies between that of solar PV and solar thermal. We calculate the cost of variability of the different solar power sources and wind by using the costs of ancillary services and the energy required to compensate for its variability and intermittency, and the cost of variability per unit of displaced CO(2) emissions. We show the costs of variability are highly dependent on both technology type and capacity factor. California emissions data were used to calculate the cost of variability per unit of displaced CO(2) emissions. Variability cost is greatest for solar PV generation at $8-11 per MWh. The cost of variability for solar thermal generation is $5 per MWh, while that of wind generation in ERCOT was found to be on average $4 per MWh. Variability adds ~$15/tonne CO(2) to the cost of abatement for solar thermal power, $25 for wind, and $33-$40 for PV.

  8. Reduced suppression of CO2-induced ventilatory stimulation by endomorphins relative to morphine.

    Science.gov (United States)

    Czapla, Marc A; Zadina, James E

    2005-10-19

    Opioids are among the most effective analgesics, but a major limitation for their therapeutic usefulness is their induction of respiratory depression. Endomorphin-1 (EM1), in contrast to several other mu opioids, exhibits a threshold for respiratory depression that is well above its threshold for analgesia. Its effect on sensitivity to CO(2), however, remains unknown. Minute ventilation (V(E)) in 2, 4, and 6% CO(2) was measured before and after systemic administration of EM1, endomorphin-2 (EM2), DAMGO, and morphine in the conscious rat. EM1 and EM2 attenuated the hypercapnic ventilatory response (HCVR) only in high doses, while DAMGO and morphine diminished the HCVR in much lower doses. The ventilatory effects of high doses of all 4 agonists were blocked by the mu-opioid antagonist naloxone (0.4 mg/kg i.v.), but not by the peripherally restricted mu-opioid antagonist, methyl-naloxone (0.4 mg/kg i.v.). It was concluded that the endomorphins attenuated the HCVR only in large doses, well beyond the analgesic threshold, and did so through a centrally mediated mu-opioid mechanism.

  9. PYR/RCAR receptors contribute to ozone-, reduced air humidity-, darkness-, and CO2-induced stomatal regulation.

    Science.gov (United States)

    Merilo, Ebe; Laanemets, Kristiina; Hu, Honghong; Xue, Shaowu; Jakobson, Liina; Tulva, Ingmar; Gonzalez-Guzman, Miguel; Rodriguez, Pedro L; Schroeder, Julian I; Broschè, Mikael; Kollist, Hannes

    2013-07-01

    Rapid stomatal closure induced by changes in the environment, such as elevation of CO2, reduction of air humidity, darkness, and pulses of the air pollutant ozone (O3), involves the SLOW ANION CHANNEL1 (SLAC1). SLAC1 is activated by OPEN STOMATA1 (OST1) and Ca(2+)-dependent protein kinases. OST1 activation is controlled through abscisic acid (ABA)-induced inhibition of type 2 protein phosphatases (PP2C) by PYRABACTIN RESISTANCE/REGULATORY COMPONENTS OF ABA RECEPTOR (PYR/RCAR) receptor proteins. To address the role of signaling through PYR/RCARs for whole-plant steady-state stomatal conductance and stomatal closure induced by environmental factors, we used a set of Arabidopsis (Arabidopsis thaliana) mutants defective in ABA metabolism/signaling. The stomatal conductance values varied severalfold among the studied mutants, indicating that basal ABA signaling through PYR/RCAR receptors plays a fundamental role in controlling whole-plant water loss through stomata. PYR/RCAR-dependent inhibition of PP2Cs was clearly required for rapid stomatal regulation in response to darkness, reduced air humidity, and O3. Furthermore, PYR/RCAR proteins seem to function in a dose-dependent manner, and there is a functional diversity among them. Although a rapid stomatal response to elevated CO2 was evident in all but slac1 and ost1 mutants, the bicarbonate-induced activation of S-type anion channels was reduced in the dominant active PP2C mutants abi1-1 and abi2-1. Further experiments with a wider range of CO2 concentrations and analyses of stomatal response kinetics suggested that the ABA signalosome partially affects the CO2-induced stomatal response. Thus, we show that PYR/RCAR receptors play an important role for the whole-plant stomatal adjustments and responses to low humidity, darkness, and O3 and are involved in responses to elevated CO2.

  10. How could the family-scale photovoltaic module help the poor farmer out of poverty and reduce CO2 emission?

    Science.gov (United States)

    Qiu, Xu; Jin, Ran

    2016-04-01

    China, the world's most populous country, is facing great opportunities and challenges. On the one hand, China's increasing economy is raising hundreds of millions of people out of poverty. On the other hand, there are still 100 million of whose daily income is less than 1 US dollar. In addition, China is the world's largest solar panel producer and also the largest emitter of greenhouse gases. Could we find a feasible way to use solar panels to help the poor and meanwhile reduce CO2 emissions? To do this, we reviewed the literature and investigated the related field sites and institutions in China. Results show that the extension of family-scale photovoltaic modules to countryside could help. The 3 kW-module is recommended for widely distribution because its technology is mature and the cost is relatively low (3500 US dollars). Besides their own use to improve their living standard, farmers can sell the excess electricity to the grid at the price of 0.17 UD/kWh. The farmer's annual income could be increased by 460-615 US dollars by selling electricity, and this is equivalent to half of their annual income in many rural regions. The photovoltaic module can be used for 25 years and the payback period is 7 years. In addition to its economic benefit, the photovoltaic module can reduce CO2 emissions by 0.93 kg/kWh. This is equivalent to annual reduction of 3000-4000 kg CO2 per family. Therefore, it is concluded that the family-scale photovoltaic module not only can help the farmers out of poverty but also can reduce CO2 emissions significantly. To promote its sustainable development, it is worthwhile to further investigations its business models as well as the effects of long-term support policies under different social and nature conditions.

  11. Subsidence and carbon loss in drained tropical peatlands: reducing uncertainty and implications for CO2 emission reduction options

    Directory of Open Access Journals (Sweden)

    A. Idris

    2011-09-01

    Full Text Available Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 years after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 years, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. Bulk density profiles indicate that consolidation contributes only 7 % to total subsidence, in the first year after drainage, and that the role of compaction is also reduced quickly and becomes negligible after 5 years. Over 18 years after drainage, 92 % of cumulative subsidence was caused by peat oxidation. The average rate of carbon loss over the first 5 years was 178 t ha−1 yr−1 CO2eq, which reduced to 73 t ha−1 yr−1 CO2eq over subsequent years, resulting in an average loss of 100 t ha−1 yr−1 CO2eq annualized over 25 years. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water table levels theoretically possible in plantations. This implies that improved water management will reduce these impacts by only 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence should be accepted as inevitable consequences of conversion of forested tropical peatlands to other land uses.

  12. An efficient methodology for utilization of K-feldspar and phosphogypsum with reduced energy consumption and CO2 emissions

    Institute of Scientific and Technical Information of China (English)

    Zhixi Gan; Zheng Cui; Hairong Yue; Siyang Tang; Changjun Liu; Chun Li; Bin Liang; Heping Xie

    2016-01-01

    The issues of reducing CO2 emissions, sustainably utilizing natural mineral resources, and dealing with industrial waste offer challenges for sustainable development in energy and the environment. We propose an efficient methodology via the co-reaction of K-feldspar and phosphogypsum for the extraction of soluble potassium salts and recovery of SO2 with reduced CO2 emission and energy consumption. The results of characterization and reactivity evaluation indicated that the partial melting of K-feldspar and phosphogypsum in the high-temperature co-reaction significantly facilitated the reduction of phosphogypsum to SO2 and the exchange of K+(K-feldspar) with Ca2+(CaSO4 in phosphogypsum). The reaction parameters were systematical y investigat-ed with the highest sulfur recovery ratio of~60%and K extraction ratio of~87.7%. This novel methodology possesses an energy consumption reduction of~28%and CO2 emission reduction of~55%comparing with the present typical commercial technologies for utilization of K-feldspar and the treatment of phosphogypsum.

  13. CO2汽提法尿素工艺降低蒸汽消耗的根本途径%The Prime Way to Reduce Steam Consumption of CO2 Stripping Urea Process

    Institute of Scientific and Technical Information of China (English)

    孙喜; 夏炎华

    2015-01-01

    CO2 stripping urea process has the maximum market share in the world, but sharp reduction of steam consumption is still not evident even through dozens of years’ development. This paper introduces the technical features of CO2 stripping urea process and addresses that adding medium pressure section is the prime way to reduce steam consumption of CO2 stripping urea process based on analysis of various factors which affect steam consumption.%CO2汽提法尿素工艺是市场占有率最大的尿素工艺,但经历数十年的发展,蒸汽消耗始终无法大幅度降低。介绍了CO2汽提法尿素工艺的技术特点,在分析了影响蒸汽消耗的各种因素的基础上,提出了增加中压段是CO2汽提法尿素工艺降低蒸汽消耗的根本途径。

  14. Antagonism between elevated CO2, nighttime warming, and summer drought reduces the robustness of PSII performance to freezing events

    DEFF Research Database (Denmark)

    Albert, Kristian Rost; Boesgaard, Kristine Stove; Ro-Poulsen, Helge

    2013-01-01

    Plant responses to warming, elevated CO2, and changes in summer precipitation patterns involve complex interactions. In this study we aim to reveal the single factor responses and their interactive effects on photosystem II (PSII) performance during an autumn-to-winter period. The study was carried...... yield in light, Fv′/Fm′, using the pulse amplitude methodology, and the total performance index, PItotal, which integrate changes of the chlorophyll-a fluorescence transient including the maximal quantum yield in darkness, Fv/Fm.Decreasing temperature during autumn linearly reduced PItotal, both...

  15. Assessment of the stoichiometry and efficiency of CO2 fixation coupled to reduced sulfur oxidation

    NARCIS (Netherlands)

    Klatt, Judith M.; Polerecky, Lubos

    2015-01-01

    Chemolithoautotrophic sulfur oxidizing bacteria (SOB) couple the oxidation of reduced sulfur compounds to the production of biomass. Their role in the cycling of carbon, sulfur, oxygen, and nitrogen is, however, difficult to quantify due to the complexity of sulfur oxidation pathways. We describe a

  16. Assessment of the stoichiometry and efficiency of CO2 fixation coupled to reduced sulfur oxidation

    NARCIS (Netherlands)

    Klatt, Judith M.; Polerecky, Lubos|info:eu-repo/dai/nl/370827929

    2015-01-01

    Chemolithoautotrophic sulfur oxidizing bacteria (SOB) couple the oxidation of reduced sulfur compounds to the production of biomass. Their role in the cycling of carbon, sulfur, oxygen, and nitrogen is, however, difficult to quantify due to the complexity of sulfur oxidation pathways. We describe a

  17. In which sectors could new illumination technology strategically reduce CO2 emissions?

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Andersen, Jan; Kjær, Tyge

    2009-01-01

    Illumination is responsible for the consumption of 19% of the total electricity consumption worldwide. Efforts to reduce the consumption of this energy fraction are, therefore, increasingly taking the attention of many governments. Denmark, as one of the leader countries in environmental actions,......, a more detailed differentiation of data shall be pursued by the electricity companies. It is suggested that detecting the right sector will give possibilities to better target actions with higher impact potential....

  18. Assessment of the stoichiometry and efficiency of CO2 fixation coupled to reduced sulfur oxidation

    Directory of Open Access Journals (Sweden)

    Judith M Klatt

    2015-05-01

    Full Text Available Chemolithoautotrophic sulfur oxidizing bacteria (SOB couple the oxidation of reduced sulfur compounds to the production of biomass. Their role in the cycling of carbon, sulfur, oxygen and nitrogen is, however, difficult to quantify due to the complexity of sulfur oxidation pathways. We describe a generic theoretical framework for linking the stoichiometry and energy conservation efficiency of autotrophic sulfur oxidation while accounting for the partitioning of the reduced sulfur pool between the energy generating and energy conserving steps as well as between the main possible products (sulfate versus elemental sulfur. Using this framework, we show that the energy conservation efficiency varies widely among SOB with no apparent relationship to their phylogeny. Aerobic SOB equipped with reverse dissimilatory sulfite reductase tend to have higher efficiency than those relying on the complete Sox pathway, whereas for anaerobic SOB the presence of membrane-bound, as opposed to periplasmic, nitrate reductase systems appears to be linked to higher efficiency. We employ the framework to also show how limited rate measurements can be used to estimate the primary productivity of SOB without the knowledge of the sulfate-to-elemental-sulfur production ratio. Finally, we discuss how the framework can help researchers gain new insights into the activity of SOB and their niches.

  19. Sustainable Development and Technological Impact on CO2 Reducing Conditions in Romania

    Directory of Open Access Journals (Sweden)

    Lucian-Ionel Cioca

    2015-02-01

    Full Text Available Climate change is a reality all over the world, and its complexity is increasing. Therefore, sustainability has become a national and international concern, ingrained in many organizational processes. The ability of organizations to respond to sustainability concerns is sometimes hindered by the complexity of integrating sustainability into business models and by the need to rethink their strategic directions. In Romania, sustainable development has become a priority for businesses, but even though companies are showing some concern, there are yet to demonstrate any full commitment (they are mainly concerned with areas such as society and the environment. This paper assesses Romania’s involvement in the adoption of actions directed toward the reduction of pollutants and greenhouse gases, namely actions focused on reducing the main causes of pollution. This analysis compares the situation in Romania with that of the European Union. The main concerns can be categorized according to four sectors, which produce the highest quantity of carbon dioxide emissions in the world: the energy sector, the transport sector, the waste sector and the industry sector. The last section of this paper deals with the carbon footprint of Romania and its implications.

  20. Crafting biochars to reduce N2O and CO2 emissions while also improving soil quality

    Science.gov (United States)

    Novak, Jeff; Ippolito, Jim; Spokas, Kurt; Sigua, Gilbert; Kammann, Claudia; Wrage-Monnig, Nicole; Borchard, Nils; Schirrmann, Michael; Estavillo, Jose Maria; Fuertes-Mendizabal, Teresa; Menendez, Sergio; Cayuela, Maria Luz

    2017-04-01

    Biochar used as an amendment has been linked to nitrous oxide (N2O) emission reductions, a decrease in nitrogen (N) leaching, and soil quality improvements (e.g., soil carbon sequestration, pH, etc.). While numerous articles will support these three facts, conversely, there are reports of no to marginal influences. One reason for the mixed biochar performance could be related to applying biochar with incorrect chemical and physical characteristics. As a means to increase biochar efficiency, we introduced the concept of crafting biochars with properties attuned to specific soil deficiencies. Implementing this concept requires a literature review to identify salient biochar characteristics that reduces N2O emissions, impacts N availability, while also improving soil quality. Thus, scientists from the USDA-ARS and through a coalition of European scientists under the FACCE-JPI umbrella have conceived the DesignChar4food (d4f) project. In this project, scientists are working collaboratively to further this concept to match the appropriate biochar for selective soil quality improvement, retain N for crops, and promote greenhouse gas reductions. This presentation will highlight results from the d4f team compromising a meta-analysis of articles on biochar:N2O dynamics, N availability, and how designer biochars can target specific soil quality improvements.

  1. Effects of reduced carbonic anhydrase activity on CO2 assimilation rates in Setaria viridis: a transgenic analysis.

    Science.gov (United States)

    Osborn, Hannah L; Alonso-Cantabrana, Hugo; Sharwood, Robert E; Covshoff, Sarah; Evans, John R; Furbank, Robert T; von Caemmerer, Susanne

    2017-01-01

    In C4 species, the major β-carbonic anhydrase (β-CA) localized in the mesophyll cytosol catalyses the hydration of CO2 to HCO3(-), which phosphoenolpyruvate carboxylase uses in the first step of C4 photosynthesis. To address the role of CA in C4 photosynthesis, we generated transgenic Setaria viridis depleted in β-CA. Independent lines were identified with as little as 13% of wild-type CA. No photosynthetic defect was observed in the transformed lines at ambient CO2 partial pressure (pCO2). At low pCO2, a strong correlation between CO2 assimilation rates and CA hydration rates was observed. C(18)O(16)O isotope discrimination was used to estimate the mesophyll conductance to CO2 diffusion from the intercellular air space to the mesophyll cytosol (gm) in control plants, which allowed us to calculate CA activities in the mesophyll cytosol (Cm). This revealed a strong relationship between the initial slope of the response of the CO2 assimilation rate to cytosolic pCO2 (ACm) and cytosolic CA activity. However, the relationship between the initial slope of the response of CO2 assimilation to intercellular pCO2 (ACi) and cytosolic CA activity was curvilinear. This indicated that in S. viridis, mesophyll conductance may be a contributing limiting factor alongside CA activity to CO2 assimilation rates at low pCO2.

  2. Characterization of growth and photosynthesis of Synechocystis sp. PCC 6803 cultures under reduced atmospheric pressures and enhanced CO2 levels

    Science.gov (United States)

    Kanervo, Eira; Lehto, Kirsi; Ståhle, Kurt; Lehto, Harry; Mäenpää, Pirkko

    2005-01-01

    Efficient life support systems are needed to maintain adequate oxygen, water and food for humans in extraterrestrial conditions. On the near-Earth missions, these are supplied by transport from the Earth, and by physical and chemical cleaning and recycling, but on long-term missions to far-away destinations, such as Mars, on-site production of the consumables may be required. Molecular oxygen and organic biomass can be most efficiently produced biologically, i.e. by photosynthesis. The conditions on Mars are distinctly harsh, and they strictly limit the growth and survival of any photosynthetic organisms to artificially maintained containments. For obtaining most economical growth conditions, minimal parameters need to be determined which still allow efficient growth of photosynthetic organisms. In this work we are testing how reduced air pressures (hypobaria) and increased CO2 concentrations, i.e. features typical for Martian conditions, affect the durability, growth and photosynthesis of laboratory strains of cyanobacteria, a group of prokaryotic organisms capable of plant-like photosynthesis. Our preliminary results show that air pressures down to 0.1 atm or CO2 concentrations up to 20% have no harmful effect on the photosynthetic oxygen production or growth rate of the cyanobacterial model species, Synechocystis sp. PCC 6803.

  3. Long-term operation of microbial electrosynthesis cell reducing CO2 to multi-carbon chemicals with a mixed culture avoiding methanogenesis.

    Science.gov (United States)

    Bajracharya, Suman; Yuliasni, Rustiana; Vanbroekhoven, Karolien; Buisman, Cees J N; Strik, David P B T B; Pant, Deepak

    2017-02-01

    In microbial electrosynthesis (MES), CO2 can be reduced preferably to multi-carbon chemicals by a biocathode-based process which uses electrochemically active bacteria as catalysts. A mixed anaerobic consortium from biological origin typically produces methane from CO2 reduction which circumvents production of multi-carbon compounds. This study aimed to develop a stable and robust CO2 reducing biocathode from a mixed culture inoculum avoiding the methane generation. An effective approach was demonstrated based on (i) an enrichment procedure involving inoculum pre-treatment and several culture transfers in H2:CO2 media, (ii) a transfer from heterotrophic to autotrophic growth and (iii) a sequential batch operation. Biomass growth and gradual acclimation to CO2 electro-reduction accomplished a maximum acetate production rate of 400mgLcatholyte(-1)d(-1) at -1V (vs. Ag/AgCl). Methane was never detected in more than 300days of operation. Accumulation of acetate up to 7-10gL(-1) was repeatedly attained by supplying (80:20) CO2:N2 mixture at -0.9 to -1V (vs. Ag/AgCl). In addition, ethanol and butyrate were also produced from CO2 reduction. Thus, a robust CO2 reducing biocathode can be developed from a mixed culture avoiding methane generation by adopting the specific culture enrichment and operation procedures without the direct addition of chemical inhibitor.

  4. Veno-venous Extracorporeal CO2 Removal: Can We Reduce Dependence on Mechanical Ventilation During En-route Care?

    Science.gov (United States)

    2010-04-01

    sec. MV (L/min), respiratory rate (RR), Hemolung blood flow (BF, L/min), CO2 removal by the Hemolung (VHemolungCO2, ml/min), PaO2 and PaCO2, plasma...Hemolung console (ALung Technologies, Inc., Pittsburgh, PA). Arterial tension of oxygen ( PaO2 , mm Hg) and carbon dioxide (PaCO2, mm Hg) were measured at...changes were not significant. PaO2 was lower at 2 hours, whereas PaCO2 was higher at 48 and 72 hours after insertion when compared to baseline values

  5. Reduced tillage and cover crops as a strategy for mitigating atmospheric CO2 increase through soil organic carbon sequestration in dry Mediterranean agroecosystems.

    Science.gov (United States)

    Almagro, María; Garcia-Franco, Noelia; de Vente, Joris; Boix-Fayos, Carolina; Díaz-Pereira, Elvira; Martínez-Mena, María

    2016-04-01

    The implementation of sustainable land management (SLM) practices in semiarid Mediterranean agroecosystems can be beneficial to maintain or enhance levels of soil organic carbon and mitigate current atmospheric CO2 increase. In this study, we assess the effects of different tillage treatments (conventional tillage (CT), reduced tillage (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil CO2 efflux, aggregation and organic carbon stabilization in two semiarid organic rainfed almond (Prunus dulcis Mill., var. Ferragnes) orchards located in SE Spain Soil CO2 efflux, temperature and moisture were measured monthly between May 2012 and December 2014 (site 1), and between February 2013 and December 2014 (site 2). In site 1, soil CO2 efflux rates were also measured immediately following winter and spring tillage operations. Aboveground biomass inputs were estimated at the end of the growing season in each tillage treatment. Soil samples (0-15 cm) were collected in the rows between the trees (n=4) in October 2012. Four aggregate size classes were distinguished by sieving (large and small macroaggregates, free microaggregates, and free silt plus clay fraction), and the microaggregates occluded within macroaggregates (SMm) were isolated. Soil CO2efflux rates in all tillage treatments varied significantly during the year, following changes during the autumn, winter and early spring, or changes in soil moisture during late spring and summer. Repeated measures analyses of variance revealed that there were no significant differences in soil CO2 efflux between tillage treatments throughout the study period at both sites. Average annual values of C lost by soil respiration were slightly but not significantly higher under RT and RTG treatments (492 g C-CO2 m-2 yr-1) than under NT treatment (405 g C-CO2 m-2 yr-1) in site 1, while slightly but not significantly lower values were observed under RT and RTG treatments (468 and 439 g C-CO2 m-2 yr-1

  6. Summer drought leads to reduced net CO2 uptake and CH4 fluxes in a New Zealand peatland

    Science.gov (United States)

    Goodrich, J. P.; Campbell, D.; Schipper, L. A.; Clearwater, M.

    2013-12-01

    Global climate change is likely to influence the frequency and severity of drought events in many regions. This has implications for changing carbon (C) storage in peatland ecosystems, which provide an important global sink for atmospheric C. However, the relative impacts on ecosystem respiration (ER), gross primary productivity (GPP), and CH4 efflux are not well understood and may alter the C balance differently depending on peatland type, vegetation, and timing of drought. We measured CO2 and CH4 fluxes using eddy covariance in a New Zealand peatland during two contrasting years capturing the impact of an historically extreme drought on these two major components of the net ecosystem C balance. Kopuatai bog is a 96 km2 ombrotrophic raised bog dominated by the endemic peat-forming rush species, Empodisma robustum. The drought impacted the growing season period from January to May, 2013. Net ecosystem exchange of CO2 (NEE) during the drought was approximately half that of the previous relatively wet summer. From January 1 to May 1, cumulative NEE was -133.3 gC m-2 in 2012 and -66.7 gC m-2 in 2013. Increases in ER during the drought were responsible for up to 88% of the difference in NEE, while differences in GPP were comparatively small. For April, mean daily CH4 fluxes during the drought (25 mgCH4 m-2 day-1) reduced to approximately one third of the mean flux measured in April 2012 (80 mgCH4 m-2 day-1). CH4 fluxes remained low for several months following water table recharge, suggesting a substantial lag in the recovery of the methanogenic population. Despite the magnitude of respiration enhancement, the relatively consistent GPP and reduced CH4 flux led to net storage of C during drought, albeit significantly smaller than the previous wet year.

  7. Solid Fuel - Oxygen Fired Combustion for Production of Nodular Reduced Iron to Reduce CO2 Emissions and Improve Energy Efficiencies

    Energy Technology Data Exchange (ETDEWEB)

    Donald R. Fosnacht; Richard F. Kiesel; David W. Hendrickson; David J. Englund; Iwao Iwasaki; Rodney L. Bleifuss; Mathew A. Mlinar

    2011-12-22

    The current trend in the steel industry is an increase in iron and steel produced in electric arc furnaces (EAF) and a gradual decline in conventional steelmaking from taconite pellets in blast furnaces. In order to expand the opportunities for the existing iron ore mines beyond their blast furnace customer base, a new material is needed to satisfy the market demands of the emerging steel industry while utilizing the existing infrastructure and materials handling capabilities. This demand creates opportunity to convert iron ore or other iron bearing materials to Nodular Reduced Iron (NRI) in a recently designed Linear Hearth Furnace (LHF). NRI is a metallized iron product containing 98.5 to 96.0% iron and 2.5 to 4% C. It is essentially a scrap substitute with little impurity that can be utilized in a variety of steelmaking processes, especially the electric arc furnace. The objective of this project was to focus on reducing the greenhouse gas emissions (GHG) through reducing the energy intensity using specialized combustion systems, increasing production and the use of biomass derived carbon sources in this process. This research examined the use of a solid fuel-oxygen fired combustion system and compared the results from this system with both oxygen-fuel and air-fuel combustion systems. The solid pulverized fuels tested included various coals and a bio-coal produced from woody biomass in a specially constructed pilot scale torrefaction reactor at the Coleraine Minerals Research Laboratory (CMRL). In addition to combustion, the application of bio-coal was also tested as a means to produce a reducing atmosphere during key points in the fusion process, and as a reducing agent for ore conversion to metallic iron to capture the advantage of its inherent reduced carbon footprint. The results from this study indicate that the approaches taken can reduce both greenhouse gas emissions and the associated energy intensity with the Linear Hearth Furnace process for converting

  8. Partially reduced iridium oxide clusters dispersed on titania as efficient catalysts for facile synthesis of dimethylformamide from CO2, H2 and dimethylamine.

    Science.gov (United States)

    Bi, Qing-Yuan; Lin, Jian-Dong; Liu, Yong-Mei; Xie, Song-Hai; He, He-Yong; Cao, Yong

    2014-08-21

    A novel bifunctional catalyst based on partially reduced iridium oxide supported on TiO2 was found to be exceedingly efficient for the organic-solvent-free synthesis of dimethylformamide from CO2, H2 and dimethylamine.

  9. Novel CuCo2O4/graphitic carbon nitride nanohybrids: Highly effective catalysts for reducing CO generation and fire hazards of thermoplastic polyurethane nanocomposites.

    Science.gov (United States)

    Shi, Yongqian; Yu, Bin; Zhou, Keqing; Yuen, Richard K K; Gui, Zhou; Hu, Yuan; Jiang, Saihua

    2015-08-15

    Novel spinel copper cobaltate (CuCo2O4)/graphitic carbon nitride (g-C3N4) (named C-CuCo2O4) nanohybrids with different weight ratios of g-C3N4 to CuCo2O4 were successfully synthesized via a facile hydrothermal method. Then the nanohybrids were added into the thermoplastic polyurethane (TPU) matrix to prepare TPU nanocomposites using a master batch-melt compounding approach. Morphological analysis indicated that CuCo2O4 nanoparticles were uniformly distributed on g-C3N4 nanosheets. Thermal analysis revealed that C-CuCo2O4-7 (proportion of g-C3N4 to CuCo2O4 of 93/7) was an optimal nanohybrid for the properties improvement of TPU. Incorporation of C-CuCo2O4-7 into TPU led to significant improvements in the onset decomposition temperature, temperature at maximal mass loss rate and char yields. The heat release rate and total heat release of TPU/C-CuCo2O4-7 decreased by 37% and 31.3%, respectively, compared with those of pure TPU. Furthermore, the amounts of pyrolysis gaseous products, including combustible volatiles and carbon monoxide (CO), were remarkably reduced, whereas, non-flammable gas (carbon dioxide) increased. Excellent dispersion of C-CuCo2O4-7 in TPU host was achieved, due to the synergistic effect between g-C3N4 and CuCo2O4. Enhancements in the thermal stability and flame retardancy were attributed to the explanations that g-C3N4 nanosheets showed the physical barrier effect and catalytic nitrogen monoxide (NO) decomposition, and that CuCo2O4 catalyzes the reaction of CO with NO and increased char residues. Copyright © 2015. Published by Elsevier B.V.

  10. CO2 exposure at pressure impacts metabolism and stress responses in the model sulfate-reducing bacterium Desulfovibrio vulgaris strain Hildenborough

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Hoyt, David W.; Marshall, Matthew J.; Alderson, Paul A.; Plymale, Andrew E.; Markillie, Lye Meng; Tucker, Abigail E.; Walter, Eric D.; Linggi, Bryan E.; Dohnalkova, Alice; Taylor, Ronald C.

    2014-09-01

    Geologic carbon dioxide (CO2) sequestration drives physical and geochemical changes in deep subsurface environments that impact indigenous microbial activities. The combined effects of pressurized CO2 on a model sulfate-reducing microorganism, Desulfovibrio vulgaris, have been assessed using a suite of genomic and kinetic measurements. Novel high-pressure NMR time-series measurements using 13C-lactate were used to track D. vulgaris metabolism. We identified cessation of respiration at CO2 pressures of 10 bar, 25 bar, 50 bar, and 80 bar. Concurrent experiments using N2 as the pressurizing phase had no negative effect on microbial respiration, as inferred from reduction of sulfate to sulfide. Complementary pressurized batch incubations and fluorescence microscopy measurements supported NMR observations, and indicated that non-respiring cells were mostly viable at 50 bar CO2 for at least four hours, and at 80 bar CO2 for two hours. The fraction of dead cells increased rapidly after four hours at 80 bar CO2. Transcriptomic (RNA-Seq) measurements on mRNA transcripts from CO2-incubated biomass indicated that cells up-regulated the production of certain amino acids (leucine, isoleucine) following CO2 exposure at elevated pressures, likely as part of a general stress response. Evidence for other poorly understood stress responses were also identified within RNA-Seq data, suggesting that while pressurized CO2 severely limits the growth and respiration of D. vulgaris cells, biomass retains intact cell membranes at pressures up to 80 bar CO2. Together, these data show that geologic sequestration of CO2 may have significant impacts on rates of sulfate reduction in many deep subsurface environments where this metabolism is a key respiratory process.

  11. CO2 exposure at pressure impacts metabolism and stress responses in the model sulfate-reducing bacterium Desulfovibrio vulgaris strain Hildenborough

    Directory of Open Access Journals (Sweden)

    Michael J Wilkins

    2014-09-01

    Full Text Available Geologic carbon dioxide (CO2 sequestration drives physical and geochemical changes in deep subsurface environments that impact indigenous microbial activities. The combined effects of pressurized CO2 on a model sulfate-reducing microorganism, Desulfovibrio vulgaris, have been assessed using a suite of genomic and kinetic measurements. Novel high-pressure NMR time-series measurements using 13C-lactate were used to track D. vulgaris metabolism. We identified cessation of respiration at CO2 pressures of 10 bar, 25 bar, 50 bar, and 80 bar. Concurrent experiments using N2 as the pressurizing phase had no negative effect on microbial respiration, as inferred from reduction of sulfate to sulfide. Complementary pressurized batch incubations and fluorescence microscopy measurements supported NMR observations, and indicated that non-respiring cells were mostly viable at 50 bar CO2 for at least four hours, and at 80 bar CO2 for two hours. The fraction of dead cells increased rapidly after four hours at 80 bar CO2. Transcriptomic (RNA-Seq measurements on mRNA transcripts from CO2-incubated biomass indicated that cells up-regulated the production of certain amino acids (leucine, isoleucine following CO2 exposure at elevated pressures, likely as part of a general stress response. Evidence for other poorly understood stress responses were also identified within RNA-Seq data, suggesting that while pressurized CO2 severely limits the growth and respiration of D. vulgaris cells, biomass retains intact cell membranes at pressures up to 80 bar CO2. Together, these data show that geologic sequestration of CO2 may have significant impacts on rates of sulfate reduction in many deep subsurface environments where this metabolism is a key respiratory process.

  12. Hynol: An economic process for methanol production from biomass and natural gas with reduced CO2 emission

    Science.gov (United States)

    Steinberg, M.; Dong, Yuanji

    1993-10-01

    The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (1) hydrogasification of biomass, (2) steam reforming of the produced gas with additional natural gas feedstock, and (3) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps. The H2-rich gas remaining after methanol synthesis is recycled to gasify the biomass in an energy neutral reactor so that there is no need for an expensive oxygen plant as required by commercial steam gasifiers. Recycling gas allows the methanol synthesis reactor to perform at a relatively lower pressure than conventional while the plant still maintains high methanol yield. Energy recovery designed into the process minimizes heat loss and increases the process thermal efficiency. If the Hynol methanol is used as an alternative and more efficient automotive fuel, an overall 41% reduction in CO2 emission can be achieved compared to the use of conventional gasoline fuel. A preliminary economic estimate shows that the total capital investment for a Hynol plant is 40% lower than that for a conventional biomass gasification plant. The methanol production cost is $0.43/gal for a 1085 million gal/yr Hynol plant which is competitive with current U.S. methanol and equivalent gasoline prices. Process flowsheet and simulation data using biomass and natural gas as cofeedstocks are presented. The Hynol process can convert any condensed carbonaceous material, especially municipal solid waste (MSW), to produce methanol.

  13. Reduced respiratory neural activity elicits a long-lasting decrease in the CO2 threshold for apnea in anesthetized rats.

    Science.gov (United States)

    Baertsch, N A; Baker, T L

    2017-01-01

    Two critical parameters that influence breathing stability are the levels of arterial pCO2 at which breathing ceases and subsequently resumes - termed the apneic and recruitment thresholds (AT and RT, respectively). Reduced respiratory neural activity elicits a chemoreflex-independent, long-lasting increase in phrenic burst amplitude, a form of plasticity known as inactivity-induced phrenic motor facilitation (iPMF). The physiological significance of iPMF is unknown. To determine if iPMF and neural apnea have long-lasting physiological effects on breathing, we tested the hypothesis that patterns of neural apnea that induce iPMF also elicit changes in the AT and RT. Phrenic nerve activity and end-tidal CO2 were recorded in urethane-anesthetized, ventilated rats to quantify phrenic nerve burst amplitude and the AT and RT before and after three patterns of neural apnea that differed in their duration and ability to elicit iPMF: brief intermittent neural apneas, a single brief "massed" neural apnea, or a prolonged neural apnea. Consistent with our hypothesis, we found that patterns of neural apnea that elicited iPMF also resulted in changes in the AT and RT. Specifically, intermittent neural apneas progressively decreased the AT with each subsequent neural apnea, which persisted for at least 60min. Similarly, a prolonged neural apnea elicited a long-lasting decrease in the AT. In both cases, the magnitude of the AT decrease was proportional to iPMF. In contrast, the RT was transiently decreased following prolonged neural apnea, and was not proportional to iPMF. No changes in the AT or RT were observed following a single brief neural apnea. Our results indicate that the AT and RT are differentially altered by neural apnea and suggest that specific patterns of neural apnea that elicit plasticity may stabilize breathing via a decrease in the AT.

  14. Two-Stage, Integrated, Geothermal-CO2 Storage Reservoirs: An Approach for Sustainable Energy Production, CO2-Sequestration Security, and Reduced Environmental Risk

    Energy Technology Data Exchange (ETDEWEB)

    Buscheck, T A; Chen, M; Sun, Y; Hao, Y; Elliot, T R

    2012-02-02

    We introduce a hybrid two-stage energy-recovery approach to sequester CO{sub 2} and produce geothermal energy at low environmental risk and low cost by integrating geothermal production with CO{sub 2} capture and sequestration (CCS) in saline, sedimentary formations. Our approach combines the benefits of the approach proposed by Buscheck et al. (2011b), which uses brine as the working fluid, with those of the approach first suggested by Brown (2000) and analyzed by Pruess (2006), using CO{sub 2} as the working fluid, and then extended to saline-formation CCS by Randolph and Saar (2011a). During stage one of our hybrid approach, formation brine, which is extracted to provide pressure relief for CO{sub 2} injection, is the working fluid for energy recovery. Produced brine is applied to a consumptive beneficial use: feedstock for fresh water production through desalination, saline cooling water, or make-up water to be injected into a neighboring reservoir operation, such as in Enhanced Geothermal Systems (EGS), where there is often a shortage of a working fluid. For stage one, it is important to find economically feasible disposition options to reduce the volume of brine requiring reinjection in the integrated geothermal-CCS reservoir (Buscheck et al. 2012a). During stage two, which begins as CO{sub 2} reaches the production wells; coproduced brine and CO{sub 2} are the working fluids. We present preliminary reservoir engineering analyses of this approach, using a simple conceptual model of a homogeneous, permeable CO{sub 2} storage formation/geothermal reservoir, bounded by relatively impermeable sealing units. We assess both the CO{sub 2} sequestration capacity and geothermal energy production potential as a function of well spacing between CO{sub 2} injectors and brine/CO{sub 2} producers for various well patterns and for a range of subsurface conditions.

  15. Two-Stage, Integrated, Geothermal-CO2 Storage Reservoirs: An Approach for Sustainable Energy Production, CO2-Sequestration Security, and Reduced Environmental Risk

    Energy Technology Data Exchange (ETDEWEB)

    Buscheck, T A; Chen, M; Sun, Y; Hao, Y; Elliot, T R

    2012-02-02

    We introduce a hybrid two-stage energy-recovery approach to sequester CO{sub 2} and produce geothermal energy at low environmental risk and low cost by integrating geothermal production with CO{sub 2} capture and sequestration (CCS) in saline, sedimentary formations. Our approach combines the benefits of the approach proposed by Buscheck et al. (2011b), which uses brine as the working fluid, with those of the approach first suggested by Brown (2000) and analyzed by Pruess (2006), using CO{sub 2} as the working fluid, and then extended to saline-formation CCS by Randolph and Saar (2011a). During stage one of our hybrid approach, formation brine, which is extracted to provide pressure relief for CO{sub 2} injection, is the working fluid for energy recovery. Produced brine is applied to a consumptive beneficial use: feedstock for fresh water production through desalination, saline cooling water, or make-up water to be injected into a neighboring reservoir operation, such as in Enhanced Geothermal Systems (EGS), where there is often a shortage of a working fluid. For stage one, it is important to find economically feasible disposition options to reduce the volume of brine requiring reinjection in the integrated geothermal-CCS reservoir (Buscheck et al. 2012a). During stage two, which begins as CO{sub 2} reaches the production wells; coproduced brine and CO{sub 2} are the working fluids. We present preliminary reservoir engineering analyses of this approach, using a simple conceptual model of a homogeneous, permeable CO{sub 2} storage formation/geothermal reservoir, bounded by relatively impermeable sealing units. We assess both the CO{sub 2} sequestration capacity and geothermal energy production potential as a function of well spacing between CO{sub 2} injectors and brine/CO{sub 2} producers for various well patterns and for a range of subsurface conditions.

  16. Rising CO2 from historical concentrations enhances the physiological performance of Brassica napus seedlings under optimal water supply but not under reduced water availability.

    Science.gov (United States)

    Faralli, Michele; Grove, Ivan G; Hare, Martin C; Kettlewell, Peter S; Fiorani, Fabio

    2017-02-01

    The productivity of many important crops is significantly threatened by water shortage, and the elevated atmospheric CO2 can significantly interact with physiological processes and crop responses to drought. We examined the effects of three different CO2 concentrations (historical ~300 ppm, ambient ~400 ppm and elevated ~700 ppm) on physiological traits of oilseed rape (Brassica napus L.) seedlings subjected to well-watered and reduced water availability. Our data show (1) that, as expected, increasing CO2 level positively modulates leaf photosynthetic traits, leaf water-use efficiency and growth under non-stressed conditions, although a pronounced acclimation of photosynthesis to elevated CO2 occurred; (2) that the predicted elevated CO2 concentration does not reduce total evapotranspiration under drought when compared with present (400 ppm) and historical (300 ppm) concentrations because of a larger leaf area that does not buffer transpiration; and (3) that accordingly, the physiological traits analysed decreased similarly under stress for all CO2 concentrations. Our data support the hypothesis that increasing CO2 concentrations may not significantly counteract the negative effect of increasing drought intensity on Brassica napus performance.

  17. Reducing CO2 emissions from drained peatlands : The Kyoto Protocol as a solution? The Republic of Belarus as a case

    NARCIS (Netherlands)

    Volders, Evelien

    2008-01-01

    The drainage of peatlands leads to the oxidation of the upper peat layer. As a result, green-house gas carbon dioxide (CO2) is emitted into the atmosphere. Worldwide the drainage of peatlands results in the release of 800 million tons of CO2 per year, thu

  18. CO2 dissociation activated through electron attachment on reduced rutile TiO2(110)-1x1 surface

    CERN Document Server

    Tan, Shijing; Zhao, Jin; Wang, Zhuo; Ma, Chuanxu; Zhao, Aidi; Wang, Bing; Luo, Yi; Yang, Jinlong; Hou, Jianguo

    2011-01-01

    Converting CO$_2$ to useful compounds through the solar photocatalytic reduction has been one of the most promising strategies for artificial carbon recycling. The highly relevant photocatalytic substrate for CO$_2$ conversion has been the popular TiO$_2$ surfaces. However, the lack of accurate fundamental parameters that determine the CO$_2$ reduction on TiO$_2$ has limited our ability to control these complicated photocatalysis processes. We have systematically studied the reduction of CO2 at specific sites of the rutile TiO$_2$(110)-1x1 surface using scanning tunneling microscopy at 80 K. The dissociation of CO2 molecules is found to be activated by one electron attachment process and its energy threshold, corresponding to the CO$_2^{\\dot-}$/CO$_2$ redox potential, is unambiguously determined to be 2.3 eV higher than the onset of the TiO$_2$ conduction band. The dissociation rate as a function of electron injection energy is also provided. Such information can be used as practical guidelines for the design...

  19. Determination of feasibility and advantages of using additional turbines to reduce energy consumption and CO2 emission of a distillation column

    Directory of Open Access Journals (Sweden)

    Svang-Ariyaskul Apichit

    2014-01-01

    Full Text Available Distillation is a process that consumes an extensive amount of energy and emits an enormous amount of CO2. It is attractive to reduce the energy consumption and CO2 emission for distillation. A new design of distillation is proposed by adding turbines in the vapor process streams before the condenser and after a reboiler to produce domestic electricity. As a result, this new design helps in reducing energy consumption and CO2 emission. The key variables are the distillate to feed ratio and the reflux ratio because they are the direct factors that control the vapor flowrates supplying the turbines. The distillation of an alkane mixture of C4 - C8 commonly found in a petroleum refinery was used as a test model to prove the process feasibility. The energy consumption and CO2 emission of the new process are reduced to 0.93 - 0.96 and 0.89 - 0.90 of the conventional process, respectively. This new design increases process efficiency in terms of second law efficiency by reducing the entropy generation from the conventional distillation at low distillate to feed ratios and reflux ratios. The distillation with additional turbines is promising to reduce energy consumption and CO2 emission and to increase process efficiency.

  20. Localized CO2 laser treatment and post-heating process to reduce the growth coefficient of fused silica surface damage

    Institute of Scientific and Technical Information of China (English)

    Shizhen Xu; Xiaotao Zu; Xiaodong Yuan

    2011-01-01

    The lifetime of optical components in high-fluence ultraviolet (UV) laser applications is typically limited by laser-initiated damage and its subsequent growth. Using 10.6-μm CO2 laser pulses, we successfully mitigate 355-nm laser induced damage sites on fused silica surface with dimensions less than 200 μm.The damage threshold increases and the damage growth mitigates. However, the growth coefficients of new damage on the CO2 laser processed area are higher than those of the original sample. The damage grows with crack propagation for residual stress after CO2 laser irradiation. Furthermore, post-heating is beneficial to the release of residual stress and slows down the damage growth.%@@ The lifetime of optical components in high-fluence ultraviolet (UV) laser applications is typically limited by laser-initiated damage and its subsequent growth.Using 10.6-μm CO2 laser pulses, we successfully mitigate 355-nm laser induced damage sites on fused silica surface with dimensions less than 200 μm.The damage threshold increases and the damage growth mitigates.However, the growth coefficients of new damage on the CO2 laser processed area are higher than those of the original sample.The damage grows with crack propagation for residual stress after CO2 laser irradiation.Furthermore, post-heating is beneficial to the release of residual stress and slows down the damage growth.

  1. Satellite based estimates of reduced CO and CO2 emissions due to traffic restrictions during the 2008 Beijing Olympics

    Science.gov (United States)

    Worden, H. M.; Cheng, Y.; Pfister, G.; Carmichael, G. R.; Zhang, Q.; Streets, D. G.; Deeter, M. N.; Edwards, D. P.; Gille, J. C.; Worden, J.

    2012-12-01

    We present estimates of the reductions in CO and CO2 emissions resulting from the control measures on the Beijing transportation sector taken during the 2008 Beijing Olympics. This study used MOPITT (Measurements Of Pollution In The Troposphere) multispectral satellite measurements of near surface CO along with WRF Chem (Weather Research and Forecasting model with Chemistry) simulations for Beijing during August, 2007 and 2008 to estimate changes in CO due to meteorology and emissions. Using fractional changes in the emissions inventory transportation sector along with a reported CO/CO2 emission ratio for Beijing vehicles, we find the corresponding reduction in CO2 emissions. We then compare this reduction to target CO2 emissions in the RCP (representative concentration pathway) scenarios being considered for the IPCC AR5 (Intergovernmental Panel on Climate Change, 5th Assessment Report). Our result suggests that urban traffic reductions could play a significant role in meeting target cuts for global CO2 emissions, even for the most aggressive control scenario (RCP2.6).

  2. Satellite-based estimates of reduced CO and CO2 emissions due to traffic restrictions during the 2008 Beijing Olympics

    Science.gov (United States)

    Worden, Helen M.; Cheng, Yafang; Pfister, Gabriele; Carmichael, Gregory R.; Zhang, Qiang; Streets, David G.; Deeter, Merritt; Edwards, David P.; Gille, John C.; Worden, John R.

    2012-07-01

    During the 2008 Olympics, the Chinese government made a significant effort to improve air quality in Beijing, including restrictions on traffic. Here we estimate the reductions in carbon monoxide (CO) and carbon dioxide (CO2) emissions resulting from the control measures on Beijing transportation. Using MOPITT (Measurements Of Pollution In The Troposphere) multispectral satellite observations of near-surface CO along with WRF-Chem (Weather Research and Forecasting model with Chemistry) simulations for Beijing during August, 2007 and 2008, we estimate changes in CO due to meteorology and transportation sector emissions. Applying a reported CO/CO2 emission ratio for fossil fuels, we find the corresponding reduction in CO2, 60 ± 36 Gg[CO2]/day. As compared to emission scenarios being considered for the IPCC AR5 (Intergovernmental Panel on Climate Change, 5th Assessment Report), this result suggests that urban traffic controls on the Beijing Olympics scale could play a significant role in meeting target reductions for global CO2 emissions.

  3. "EFFECTIVENESS OF ABDOMINAL WALL ELEVATOR IN REDUCING INTRA-ABDOMINAL PRESSURE AND CO2 VOLUME DURING LAPAROSCOPIC CHOLECYSTECTOMY"

    Directory of Open Access Journals (Sweden)

    A. Yaghoobi Notash

    2004-06-01

    Full Text Available Since CO2 pneumoperitoneum is the dominant method of laparoscopic exposure due to facility and good view, its physiologic effects are most relevant to the surgeons. CO2 pneumoperitoneum may affects hemodynamics by increased intra-abdominal pressure (IAP and the physiologic effects of absorbed CO2. The adverse effects of both mechanisms relate directly to the duration of the pneumoperitoneum and the elevation of IAP. Gasless laparoscopy involves obtaining exposure for laparoscopy by placing an internal retracting device through a small incision and lifting the anterior abdominal wall. We designed and made a mechanical wall elevator and used it in 24 patients, compared with a control group (52 cases using a conventional laparoscopic cholecystectomy. A prospective trial was undertaken in Sina Hospital, Tehran University of Medical Sciences from 1998 to 2000. The patients were assigned randomly to two groups. There was a significant decrease in IAP and CO2 consumption in the group using mechanical wall elevator as compared to conventional laparoscopic cholecystectomy, (mean IAP of 3.5 mmHg compared to 11.4 mmHg in the control group, mean CO2 volume 17 liters compared to 73 liters in the control group. We recommend this semigasless method in laparoscopy due to safety in performance and significant reduction in IAP through the surgery. This method provides a satisfactory view and easy performance without any increase in time or complications. The hospital stay and costs did not increase.

  4. Physiological and Growth Responses of C3 and C4 Plants to Reduced Temperature When Grown at Low CO2 of the Last Ice Age

    Institute of Scientific and Technical Information of China (English)

    Joy K. Ward; David A. Myers; Richard B. Thomas

    2008-01-01

    During the last Ice age, CO2 concentration ([CO2]) was 180-200 μmol/mol compared with the modern value of 380 μmol/mol,and global temperatures were ~8 ℃ cooler. Relatively little is known about the responses of C3 and C4 species to longterm exposure to glacial conditions. Here Abutilon theophrasti Medik. (C3) and Amaranthus retroflexus L. (C4) were grown at 200 μmol/mol CO2 with current (30/24 ℃) and glacial (22/16 ℃) temperatures for 22 d. Overall, the C4 species exhibited a large growth advantage over the C3 species at low [CO2]. However, this advantage was reduced at low temperature, where the C4 species produced 5× the total mass of the C3 species versus 14× at the high temperature.This difference was due to a reduction In C4 growth at low temperature, since the C3 species exhibited similar growth between temperatures. Physiological differences between temperatures were not detected for either species, although photorespirationlnet photosynthesis was reduced in the C3 species grown at low temperature, suggesting evidence of improved carbon balance at this treatment. This system suggests that C4 species had a growth advantage over C3 species during low [CO2] of the last ice age, although concurrent reductions in temperatures may have reduced this advantage.

  5. Electronic Band Structure of BaCo_{2}As_{2}: A Fully Doped Ferropnictide Analog with Reduced Electronic Correlations

    Directory of Open Access Journals (Sweden)

    N. Xu

    2013-01-01

    Full Text Available We report an investigation with angle-resolved photoemission spectroscopy of the Fermi surface and electronic band structure of BaCo_{2}As_{2}. Although its quasinesting-free Fermi surface differs drastically from that of its Fe-pnictide cousins, we show that the BaCo_{2}As_{2} system can be used as an approximation to the bare unoccupied band structure of the related BaFe_{2-x}Co_{x}As_{2} and Ba_{1-x}K_{x}Fe_{2}As_{2} compounds. However, our experimental results, in agreement with dynamical-mean-field-theory calculations, indicate that electronic correlations are much less important in BaCo_{2}As_{2} than in the ferropnictides. Our findings suggest that this effect is due to the increased filling of the electronic 3d shell in the presence of significant Hund’s exchange coupling.

  6. Low-flow CO2 removal integrated into a renal-replacement circuit can reduce acidosis and decrease vasopressor requirements

    Science.gov (United States)

    2013-01-01

    Introduction Lung-protective ventilation in patients with ARDS and multiorgan failure, including renal failure, is often paralleled with a combined respiratory and metabolic acidosis. We assessed the effectiveness of a hollow-fiber gas exchanger integrated into a conventional renal-replacement circuit on CO2 removal, acidosis, and hemodynamics. Methods In ten ventilated critically ill patients with ARDS and AKI undergoing renal- and respiratory-replacement therapy, effects of low-flow CO2 removal on respiratory acidosis compensation were tested by using a hollow-fiber gas exchanger added to the renal-replacement circuit. This was an observational study on safety, CO2-removal capacity, effects on pH, ventilator settings, and hemodynamics. Results CO2 elimination in the low-flow circuit was safe and was well tolerated by all patients. After 4 hours of treatment, a mean reduction of 17.3 mm Hg (−28.1%) pCO2 was observed, in line with an increase in pH. In hemodynamically instable patients, low-flow CO2 elimination was paralleled by hemodynamic improvement, with an average reduction of vasopressors of 65% in five of six catecholamine-dependent patients during the first 24 hours. Conclusions Because no further catheters are needed, besides those for renal replacement, the implementation of a hollow-fiber gas exchanger in a renal circuit could be an attractive therapeutic tool with only a little additional trauma for patients with mild to moderate ARDS undergoing invasive ventilation with concomitant respiratory acidosis, as long as no severe oxygenation defects indicate ECMO therapy. PMID:23883472

  7. Use of a microsecond Er:YAG laser in laryngeal surgery reduces collateral thermal injury in comparison to superpulsed CO2 laser.

    Science.gov (United States)

    Böttcher, Arne; Jowett, Nathan; Kucher, Stanislav; Reimer, Rudolph; Schumacher, Udo; Knecht, Rainald; Wöllmer, Wolfgang; Münscher, Adrian; Dalchow, Carsten V

    2014-05-01

    Despite causing significant thermocoagulative insult, use of the carbon dioxide (CO2) laser is considered gold standard in surgery for early stage larynx carcinoma. Limited attention has been paid to the use of the erbium:yttrium-aluminium-garnet (Er:YAG) laser in laryngeal surgery as a means to reduce thermal tissue injury. The objective of this study is to compare the extent of thermal injury and precision of vocal fold incisions made using microsecond Er:YAG and superpulsed CO2 lasers. In the optics laboratory ex vivo porcine vocal folds were incised using Er:YAG and CO2 lasers. Lateral epithelial and subepithelial thermal damage zones and cutting gap widths were histologically determined. Environmental scanning electron microscopy (ESEM) images were examined for signs of carbonization. Temperature rise during Er:YAG laser incisions was determined using infrared thermography (IRT). In comparison to the CO2 laser, Er:YAG laser incisions showed significantly decreased epithelial (236.44 μm) and subepithelial (72.91 μm) damage zones (p CO2 (878.72 μm) compared to Er:YAG (1090.78 μm; p = 0.027) laser. ESEM revealed intact collagen fibres along Er:YAG laser cutting edges without obvious carbonization, in comparison to diffuse carbonization and tissue melting seen for CO2 laser incisions. IRT demonstrated absolute temperature rise below 70 °C for Er:YAG laser incisions. This study has demonstrated significantly reduced lateral thermal damage zones with wider basal cutting gaps for vocal fold incisions made using Er:YAG laser in comparison to those made using CO2 laser.

  8. Field study of a Brownian Demister Unit to reduce aerosol based emission from a Post Combustion CO2 Capture plant

    NARCIS (Netherlands)

    Khakharia, P.M.; Kvamsdal, H.M.; Da Silva, E.F.; Vlugt, T.J.H.; Goetheer, E.L.V.

    2014-01-01

    Emission of solvent and its degradation products from a typical absorption-desorption based Post Combustion CO2 Capture (PCCC) process is inevitable and thus, an area of growing concern. Recently, it has been pointed out that emissions can also occur by means of aerosol droplets. Conventional counte

  9. Impact on air quality of measures to reduce CO2 emissions from road traffic in Basel, Rotterdam, Xi'an and Suzhou

    NARCIS (Netherlands)

    Keuken, M.P.; Jonkers, S.; Verhagen, H.L.M.; Perez, L.; Truëb, S.; Okkerse, W.J.; Liu, J.; Pan, X.C.; Zheng, L.; Wang, H.; Xu, R.; Sabel, C.E.

    2014-01-01

    Two traffic scenarios to reduce CO2 emissions from road traffic in two European cities (Basel and Rotterdam) and two Chinese cities (Xi'an and Suzhou) were evaluated in terms of their impact on air quality. The two scenarios, one modelling a reduction of private vehicle kilometres driven by 10% on u

  10. Impact on air quality of measures to reduce CO2 emissions from road traffic in Basel, Rotterdam, Xi'an and Suzhou

    NARCIS (Netherlands)

    Keuken, M.P.; Jonkers, S.; Verhagen, H.L.M.; Perez, L.; Truëb, S.; Okkerse, W.J.; Liu, J.; Pan, X.C.; Zheng, L.; Wang, H.; Xu, R.; Sabel, C.E.

    2014-01-01

    Two traffic scenarios to reduce CO2 emissions from road traffic in two European cities (Basel and Rotterdam) and two Chinese cities (Xi'an and Suzhou) were evaluated in terms of their impact on air quality. The two scenarios, one modelling a reduction of private vehicle kilometres driven by 10% on

  11. Reduced N cycling in response to elevated CO2, warming, and drought in a Danish heathland: Synthesizing results of the CLIMAITE project after two years of treatments

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Andresen, Louise C.; Beier, Claus

    2011-01-01

    Field-scale experiments simulating realistic future climate scenarios are important tools for investigating the effects of current and future climate changes on ecosystem functioning and biogeochemical cycling. We exposed a seminatural Danish heathland ecosystem to elevated atmospheric carbon...... dioxide (CO2), warming, and extended summer drought in all combinations. Here, we report on the short-term responses of the nitrogen (N) cycle after 2 years of treatments. Elevated CO2 significantly affected aboveground stoichiometry by increasing the carbon to nitrogen (C/N) ratios in the leaves of both...... co-dominant species (Calluna vulgaris and Deschampsia flexuosa), as well as the C/N ratios of Calluna flowers and by reducing the N concentration of Deschampsia litter. Belowground, elevated CO2 had only minor effects, whereas warming increased N turnover, as indicated by increased rates of microbial...

  12. Reducing Soil CO2 Emission and Improving Upland Rice Yield with no-Tillage, Straw Mulch and Nitrogen Fertilization in Northern Benin

    Science.gov (United States)

    Dossou-Yovo, E.; Brueggemann, N.; Naab, J.; Huat, J.; Ampofo, E.; Ago, E.; Agbossou, E.

    2015-12-01

    To explore effective ways to decrease soil CO2 emission and increase grain yield, field experiments were conducted on two upland rice soils (Lixisols and Gleyic Luvisols) in northern Benin in West Africa. The treatments were two tillage systems (no-tillage, and manual tillage), two rice straw managements (no rice straw, and rice straw mulch at 3 Mg ha-1) and three nitrogen fertilizers levels (no nitrogen, recommended level of nitrogen: 60 kg ha-1, and high level of nitrogen: 120 kg ha-1). Potassium and phosphorus fertilizers were applied to be non-limiting at 40 kg K2O ha-1 and 40 kg P2O5 ha-1. Four replications of the twelve treatment combinations were arranged in a randomized complete block design. Soil CO2 emission, soil moisture and soil temperature were measured at 5 cm depth in 6 to 10 days intervals during the rainy season and every two weeks during the dry season. Soil moisture was the main factor explaining the seasonal variability of soil CO2 emission. Much larger soil CO2 emissions were found in rainy than dry season. No-tillage planting significantly reduced soil CO2 emissions compared with manual tillage. Higher soil CO2 emissions were recorded in the mulched treatments. Soil CO2 emissions were higher in fertilized treatments compared with non fertilized treatments. Rice biomass and yield were not significantly different as a function of tillage systems. On the contrary, rice biomass and yield significantly increased with application of rice straw mulch and nitrogen fertilizer. The highest response of rice yield to nitrogen fertilizer addition was obtained for 60 kg N ha-1 in combination with 3 Mg ha-1 of rice straw for the two tillage systems. Soil CO2 emission per unit grain yield was lower under no-tillage, rice straw mulch and nitrogen fertilizer treatments. No-tillage combined with rice straw mulch and 60 kg N ha-1 could be used by smallholder farmers to achieve higher grain yield and lower soil CO2 emission in upland rice fields in northern Benin.

  13. Development of reducing CO_2 emission technologies of blast furnace ironmaking%降低高炉炼铁碳排放技术的发展

    Institute of Scientific and Technical Information of China (English)

    曾先喜; 郭豪

    2011-01-01

    Based on blast furnace operating conditions,the reducting agent consumption for an "ideal" blast furnace was calculated by Rist Operating Line model.Considering the calculation results and the potential of reducing CO2 emission in China,it is proposed that decreasing blast furnace fuel ratio is the main measure to reduce CO2 emission.In integrated iron and steel enterprises,there are many ways to reduce the fuel consumption of blast furnace,however,the energy balance of the whole enterprise should be considered.In this sense,some new technologies,such as Oxygen BF,top gas circulation,plastic injection and using prereduction burden,etc.may be adopted to reduce the CO2 emission of blast furnace ironmaking with high efficiency and good environment.%以生产高炉为基础,通过Rist操作线模型计算了"理想"高炉的还原剂消耗。针对"理想"高炉的计算和我国目前高炉碳排放潜能的分析,提出了在我国现有条件下,降低高炉燃料比是减排高炉碳排放的主要措施,然而考虑到整个钢铁厂的能量平衡,应该选择最佳的方法减少CO2排放量。氧气高炉、炉顶煤气循环、高炉喷吹废旧塑料以及使用预还原炉料都可以依靠流程的系统优化不同程度地减少CO2排放量,并保持系统的高效环保。

  14. Feasible study of international cooperation on the long-term scenario for reducing CO2. DNE-21 simulation database; CO2 sakugen ni kakawaru choki scenario ni kansuru kokusai kyoryoku kanosei chosa. DNE21 simulation database

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report describes calculation codes of DNE-21 which can simulate the optimization model for reducing CO2. The DNE-21 was modified from the former NE-21. The term was set between 2000 and 2100. Optimization can be conducted across the different time. Non-conventional petroleum was removed from the primary energy. Capacity of nuclear power generation facilities was taken in the model for the optimization. Decision making analysis can be done by considering the uncertainty. The DNE-21 has eleven input files including the model operation, technical property related data, cost related data, data of tax, subsidy and customs, and scenario data of future energy demand and supply, GNP, population and nuclear power. The DNE-21 has fifteen output files including the optimization calculation results for the world, Oceania, the Middle East, North Africa, Central America, South America, former USSR, and OECD countries. 2 figs.

  15. Green heterogeneous small-cell networks: Toward reducing the CO2 emissions of mobile communications industry using uplink power adaptation

    KAUST Repository

    Shakir, Muhammad Zeeshan

    2013-06-01

    Heterogeneous small cell networks, or Het- SNets, are considered as a standard part of future mobile networks in which multiple lowpower low-cost user deployed base stations complement the existing macrocell infrastructure. This article proposes an energy-efficient deployment of the cells where the small cell base stations are arranged around the edge of the reference macrocell, and the deployment is referred to as cell-on-edge (COE) deployment. The proposed deployment ensures an increase in the network spectral and energy efficiency by facilitating cell edge mobile users with small cells. Moreover, COE deployment guarantees reduction of the carbon footprint of mobile operations by employing adaptive uplink power control. In order to calibrate the reduction in CO2 emissions, this article quantifies the ecological and associated economical impacts of energy savings in the proposed deployment. Simulation results quantify the improvements in CO2 emissions and spectral and energy gains of the proposed COE deployment compared to macro-only networks and typical small cell deployment strategies where small cells are randomly deployed within a given macrocell. © 2013 IEEE.

  16. A Multi-Objective Unit Commitment Model for Setting Carbon Tax to Reduce CO2 Emission: Thailand's Electricity Generation Case

    Directory of Open Access Journals (Sweden)

    Nuchjarin Intalar

    2015-07-01

    Full Text Available Carbon tax policy is a cost-effective instrument for emission reduction. However, setting the carbon tax is one of the challenging task for policy makers as it will lead to higher price of emission-intensive sources especially the utility price. In a large-scale power generation system, minimizing the operational cost and the environmental impact are conflicting objectives and it is difficult to find the compromise solution. This paper proposes a methodology of finding a feasible carbon tax rate on strategic level using the operational unit commitment model. We present a multi-objective mixed integer linear programming model to solve the unit commitment problem and consider the environmental impacts. The methodology of analyzing of the effect of carbon tax rates on the power generation, operating cost, and CO2 emission is also provided. The trade-off relationship between total operating cost and total CO2 emission is presented in the Pareto-optimal curve to analyze the feasible carbon tax rate that is influencing on electricity operating cost. The significant outcome of this paper is a modeling framework for the policy makers to determine the possible carbon tax that can be imposed on the electricity generation.

  17. PYR/RCAR Receptors Contribute to Ozone-, Reduced Air Humidity-, Darkness-, and CO2-Induced Stomatal Regulation1[C][W][OA

    Science.gov (United States)

    Merilo, Ebe; Laanemets, Kristiina; Hu, Honghong; Xue, Shaowu; Jakobson, Liina; Tulva, Ingmar; Gonzalez-Guzman, Miguel; Rodriguez, Pedro L.; Schroeder, Julian I.; Broschè, Mikael; Kollist, Hannes

    2013-01-01

    Rapid stomatal closure induced by changes in the environment, such as elevation of CO2, reduction of air humidity, darkness, and pulses of the air pollutant ozone (O3), involves the SLOW ANION CHANNEL1 (SLAC1). SLAC1 is activated by OPEN STOMATA1 (OST1) and Ca2+-dependent protein kinases. OST1 activation is controlled through abscisic acid (ABA)-induced inhibition of type 2 protein phosphatases (PP2C) by PYRABACTIN RESISTANCE/REGULATORY COMPONENTS OF ABA RECEPTOR (PYR/RCAR) receptor proteins. To address the role of signaling through PYR/RCARs for whole-plant steady-state stomatal conductance and stomatal closure induced by environmental factors, we used a set of Arabidopsis (Arabidopsis thaliana) mutants defective in ABA metabolism/signaling. The stomatal conductance values varied severalfold among the studied mutants, indicating that basal ABA signaling through PYR/RCAR receptors plays a fundamental role in controlling whole-plant water loss through stomata. PYR/RCAR-dependent inhibition of PP2Cs was clearly required for rapid stomatal regulation in response to darkness, reduced air humidity, and O3. Furthermore, PYR/RCAR proteins seem to function in a dose-dependent manner, and there is a functional diversity among them. Although a rapid stomatal response to elevated CO2 was evident in all but slac1 and ost1 mutants, the bicarbonate-induced activation of S-type anion channels was reduced in the dominant active PP2C mutants abi1-1 and abi2-1. Further experiments with a wider range of CO2 concentrations and analyses of stomatal response kinetics suggested that the ABA signalosome partially affects the CO2-induced stomatal response. Thus, we show that PYR/RCAR receptors play an important role for the whole-plant stomatal adjustments and responses to low humidity, darkness, and O3 and are involved in responses to elevated CO2. PMID:23703845

  18. Ionic liquid-assisted electrochemical determination of pyrimethanil using reduced graphene oxide conjugated to flower-like NiCo2O4.

    Science.gov (United States)

    Yang, Lijun; Hu, Yandong; Wang, Qiong; Dong, Yuanyuan; Zhang, Lei

    2016-09-07

    The novel hierarchical flower-like superstructure NiCo2O4/reduced graphene oxide (rGO) hybrids have been successfully synthesized with a facile one-step hydrothermal process for the determination of fungicide pyrimethanil (PMT). For comparison, various structures of NiCo2O4/rGO including hexagonal nanoplates and nanorods were also synthesized. Among them, three-dimensional (3D) flower-like NiCo2O4/rGO exhibited the highest electrocatalytic activity for the oxidation of PMT. With the synergistic effect of [OMIM]PF6 ionic liquid (IL), the electrochemical sensor film (NiCo2O4/rGO/IL) further facilitated interfacial electron transfer and enhanced electrocatalytic activity for the oxidation of PMT. Under the optimum conditions, the electrochemical sensor exhibited two linear ranges of 0.1-10.0 μmol/L and 20.0-140 μmol/L for PMT with a low detection concentration of 11.0 nmol/L. Besides, the interference, repeatability, reproducibility and stability measurements were also evaluated. The proposed method was successfully applied to the detection of PMT in water, seawater, fruits and vegetables with good recovery ranging from 93% to 105%, and possessed potential applications in the analysis of real samples.

  19. Self-consistent modeling for estimation of the reduced electric field in a DC excited diffusion controlled CW CO2 laser

    Science.gov (United States)

    Kumar, Manoj; Bhagat, M. S.; Biswas, A. K.; Rana, L. B.; Pakhare, Jagdish; Rawat, B. S.; Kukreja, L. M.

    2016-07-01

    The results of a numerical simulation method that estimate various discharge parameters in the positive column of a DC glow discharge controlled by ambipolar diffusion are presented. The parameters like reduced electric field (E/N), electron temperature, ionization rates, ambipolar diffusion losses and the average gas temperature were numerically evaluated for several mixtures of CO2, N2 and He in low pressure regime. The estimated E/N value which is a primary governing parameter of positive column was verified experimentally using a double probe in diffusion controlled CW CO2 laser for a variety of CO2, N2 and He mixtures. The role of auxiliary ionization source like pulser used for pre-ionization and its effect on the steady state E/N value was also studied. A reasonably good agreement was found between the theoretical and the experimental results. Based on the results of this simulation a zigzag folded, diffusion-cooled, 500 W CW CO2 laser has been designed and developed for research in gas phase nanoparticle synthesis.

  20. Large fractions of CO2-fixing microorganisms in pristine limestone aquifers appear to be involved in the oxidation of reduced sulfur and nitrogen compounds

    Science.gov (United States)

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe; Küsel, Kirsten

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricellaand Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds.

  1. Hierarchical Nanocomposite by Integrating Reduced Graphene Oxide and Amorphous Carbon with Ultrafine MgO Nanocrystallites for Enhanced CO2 Capture.

    Science.gov (United States)

    Li, Ping; Zeng, Hua Chun

    2017-10-04

    Exploring efficient and low-cost solid sorbents is essential for carbon capture and storage. Herein, a novel class of high-performance CO2 adsorbent (rGO@MgO/C) is engineered based on controllable integration of reduced graphene oxide (rGO), amorphous carbon and MgO nanocrystallites. The optimized rGO@MgO/C nanocomposite exhibits remarkable CO2 capture capacity (up to 31.5 wt% at 27 °C, 1 bar CO2 and 22.5 wt% under the simulated flue gas), fast sorption rate and strong process durability. The enhanced capture capability of CO2 is the best among all the MgO-based sorbents reported so far. The high performance of this adsorbent can be ascribed to the hierarchical architecture and special physicochemical features, including the sheet-on-sheet sandwich-like structure, ultrathin nanosheets with abundant nanopores, large surface area, highly dispersed ultrafine MgO nanocrystallites (ca. 3 nm in size), together with the rGO sheet and in-situ generated amorphous carbon which serve as a dual carbon support and protectant to prevent MgO nanocrystallites from agglomeration. In addition, the CO2 uptake capacity at intermediate temperature (e.g., 350 °C) can be further improved by >3 times through alkali metal salt promotion treatment. This work provides a facile and effective strategy to engineer advanced graphene-based functional nanocomposites with rationally designed compositions and architectures for potential applications in the field of gas storage and separation.

  2. Large Fractions of CO2-Fixing Microorganisms in Pristine Limestone Aquifers Appear To Be Involved in the Oxidation of Reduced Sulfur and Nitrogen Compounds

    Science.gov (United States)

    Herrmann, Martina; Rusznyák, Anna; Akob, Denise M.; Schulze, Isabel; Opitz, Sebastian; Totsche, Kai Uwe

    2015-01-01

    The traditional view of the dependency of subsurface environments on surface-derived allochthonous carbon inputs is challenged by increasing evidence for the role of lithoautotrophy in aquifer carbon flow. We linked information on autotrophy (Calvin-Benson-Bassham cycle) with that from total microbial community analysis in groundwater at two superimposed—upper and lower—limestone groundwater reservoirs (aquifers). Quantitative PCR revealed that up to 17% of the microbial population had the genetic potential to fix CO2 via the Calvin cycle, with abundances of cbbM and cbbL genes, encoding RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) forms I and II, ranging from 1.14 × 103 to 6 × 106 genes liter−1 over a 2-year period. The structure of the active microbial communities based on 16S rRNA transcripts differed between the two aquifers, with a larger fraction of heterotrophic, facultative anaerobic, soil-related groups in the oxygen-deficient upper aquifer. Most identified CO2-assimilating phylogenetic groups appeared to be involved in the oxidation of sulfur or nitrogen compounds and harbored both RubisCO forms I and II, allowing efficient CO2 fixation in environments with strong oxygen and CO2 fluctuations. The genera Sulfuricella and Nitrosomonas were represented by read fractions of up to 78 and 33%, respectively, within the cbbM and cbbL transcript pool and accounted for 5.6 and 3.8% of 16S rRNA sequence reads, respectively, in the lower aquifer. Our results indicate that a large fraction of bacteria in pristine limestone aquifers has the genetic potential for autotrophic CO2 fixation, with energy most likely provided by the oxidation of reduced sulfur and nitrogen compounds. PMID:25616797

  3. Impact on air quality of measures to reduce CO2 emissions from road traffic in Basel, Rotterdam, Xi'an and Suzhou

    DEFF Research Database (Denmark)

    Keuken, Menno; Jonkers, Sander; Verhagen, Henk

    2014-01-01

    . The urban background follows this regional trend, while near busy road traffic, air pollution will remain elevated due to the considerable growth in traffic volume. A major constraint for modelling air quality in China is access to the input data required and lack of measurements at ground level....... Traffic related CO2 emissions may be reduced by up to 5% and 25%, respectively using the first and second scenarios. Air pollution in the Chinese cities is a factor 3 to 5 higher than in the European cities in 2010 and 2020-BAU. The impact of both CO2 reduction scenarios on air quality in 2020-BAU...... is limited. In Europe, due to implementation of stringent emission standards in all sectors, air quality is expected to improve at both the urban background and near busy road traffic. In China, the regional background is expected to improve for EC, stabilize for PM2.5 and PM10, and decrease for NO2...

  4. Synthesis of mesoporous NiCo2S4 deposited on reduced graphite oxide assistant by co-polymer Pluronic F127 for high-performance supercapacitor

    Science.gov (United States)

    Qin, Huiya; Yang, Shuo; Zhao, Wenliang; Yang, Zhengchun; Li, Xuan; Li, Huijun; Yao, Pei

    2017-10-01

    Mesoporous NiCo2S4 particles deposited on reduced graphite oxide (RGO) sheets using the co-polymer Pluronic F127 as a structure-directing agent have been successfully prepared as a supercapacitor electrode. The formation of F127 micelles alleviated the aggregation of the RGO sheets and generated NiCo2S4 nanoparticles through hydrophilic affinity of ethylene oxide (EO) ends to produce porous channels during the hydrothermal process. This resulted in a large specific area of the prepared material, and superior electrochemical performance in terms of outstanding rate capability of 85.6% (from 1 A g-1 to 20 A g-1) and cycling stability (92.7% retention after 6500 cycles), features that are crucial for supercapacitors in practical application.

  5. Impact on air quality of measures to reduce CO2 emissions from road traffic in Basel, Rotterdam, Xi'an and Suzhou

    Science.gov (United States)

    Keuken, M. P.; Jonkers, S.; Verhagen, H. L. M.; Perez, L.; Trüeb, S.; Okkerse, W.-J.; Liu, J.; Pan, X. C.; Zheng, L.; Wang, H.; Xu, R.; Sabel, C. E.

    2014-12-01

    Two traffic scenarios to reduce CO2 emissions from road traffic in two European cities (Basel and Rotterdam) and two Chinese cities (Xi'an and Suzhou) were evaluated in terms of their impact on air quality. The two scenarios, one modelling a reduction of private vehicle kilometres driven by 10% on urban streets and the other modelling the introduction of 50% electric-powered private vehicle kilometres on urban streets, were both compared to a scenario following “business-as-usual”: 2020-BAU. The annual average concentrations of NO2, PM2.5, PM10 and elemental carbon (EC) were modelled separately in busy street canyons, near urban motorways and in the remainder of the urban area. It was concluded that traffic-related CO2 emissions in 2020-BAU could be expected to remain at the levels of 2010 in Basel and Rotterdam, while in Xi'an and Suzhou to increase 30-50% due to growth in the traffic volume. Traffic-related CO2 emissions may be reduced by up to 5% and 25%, respectively using the first and second scenarios. Air pollution in the Chinese cities is a factor 3 to 5 higher than in the European cities in 2010 and 2020-BAU. The impact of both CO2 reduction scenarios on air quality in 2020-BAU is limited. In Europe, due to implementation of stringent emission standards in all sectors, air quality is expected to improve at both the urban background and near busy road traffic. In China, the regional background is expected to improve for EC, stabilize for PM2.5 and PM10, and decrease for NO2. The urban background follows this regional trend, while near busy road traffic, air pollution will remain elevated due to the considerable growth in traffic volume. A major constraint for modelling air quality in China is access to the input data required and lack of measurements at ground level for validation.

  6. Research on Mechanism of Deformation Reduced by CO2 Gas Shielded Arc Welding%CO2气体保护焊降低焊接变形机理研究

    Institute of Scientific and Technical Information of China (English)

    李汉文; 宗培; 杨铁磊

    2011-01-01

    为了研究CO2气体保护焊强制对流对焊接变形的影响,通过分析多种换热边界条件,分别确定了适用于自然对流和有强制对流效果的气体保护焊的对流辐射边界条件计算公式,计算得出综合换热系数.在此基础上对手工焊和CO2焊焊接应力应变进行计算分析.结果表明,CO2焊保护气体形成的强制对流而形成的冷却环境是其降低焊接变形的重要因素.%The influences of forced convection on the welding deformation of CO2 gas shielded arc welding were investigated. The formula of the combined coefficient, including convection coefficient and radiation coefficient, was obtained by analyzing two convection boundary conditions, which considers natrual convection and force convection, seperately. Based on these two conditions, the deformation of butt welding plate with 3 mm was simulated. The stimulation results show that compared with manual welding, the force convection boundary condition of CO2 gas shielded arc welding is a critical factor to form less deformation.

  7. Forecasting global atmospheric CO2

    Directory of Open Access Journals (Sweden)

    A. Agustí-Panareda

    2014-05-01

    become available in near-real time. In this way, the accumulation of errors in the atmospheric CO2 forecast will be reduced. Improvements in the CO2 forecast are also expected with the continuous developments in the operational IFS.

  8. Electrosynthesis of acetate from CO2 by a highly structured biofilm assembled with reduced graphene oxide–tetraethylene pentamine

    DEFF Research Database (Denmark)

    Chen, Leifeng; Tremblay, Pier-Luc; Mohanty, Soumyaranjan

    2016-01-01

    transfer from the cathode to microbes. Here, carbon cloth cathodes modified with reduced graphene oxide functionalized with tetraethylene pentamine (rGO-TEPA) were readily self-assembled in the cathodic chamber of a MES reactor. Electroactive biofilms with unique spatial arrangement were subsequently...

  9. A reduced fraction of plant N derived from atmospheric N (%Ndfa) and reduced rhizobial nifH gene numbers indicate a lower capacity for nitrogen fixation in nodules of white clover exposed to long-term CO2 enrichment

    Science.gov (United States)

    Watanabe, T.; Bowatte, S.; Newton, P. C. D.

    2013-12-01

    Using the δ15N natural abundance method, we found that the fraction of nitrogen derived from atmospheric N (%Ndfa) in field-grown white clover (Trifolium repens L.) plants was significantly lower (72.0% vs. 89.8%, p = 0.047 in a grassland exposed to elevated CO2 for 13 yr using free air carbon dioxide enrichment (FACE). Twelve months later we conducted an experiment to investigate the reasons behind the reduced N fixation. We took cuttings from white clover plants growing in the FACE and established individual plants in a glasshouse using soil from the appropriate ambient or elevated CO2 treatments. The established plants were then transplanted back into their "rings of origin" and sampled over a 6-week period. We used molecular ecological analyses targeting nifH genes and transcripts of rhizobia in symbiosis with white clover (Trifolium repens L.) to understand the potential mechanisms. Shoot biomass was significantly lower in eCO2, but there was no difference in nodule number or mass per plant. The numbers of nifH genes and gene transcripts per nodule were significantly reduced under eCO2, but the ratio of gene to transcript number and the strains of rhizobia present were the same in both treatments. We conclude that the capacity for biological nitrogen fixation was reduced by eCO2 in white clover and was related to the reduced rhizobia numbers in nodules. We discuss the finding of reduced gene number in relation to factors controlling bacteroid DNA amount, which may imply an influence of nitrogen as well as phosphorus.

  10. Changing Arctic Ecosystems: Updated forecast: Reducing carbon dioxide (CO2) emissions required to improve polar bear outlook

    Science.gov (United States)

    Oakley, Karen L.; Atwood, Todd C.; Mugel, Douglas N.; Rode, Karyn D.; Whalen, Mary E.

    2015-01-01

    The Arctic is warming faster than other regions of the world due to the loss of snow and ice, which increases the amount of solar energy absorbed by the region. The most visible consequence has been the rapid decline in sea ice over the last 3 decades-a decline projected to bring long ice-free summers if greenhouse gas (GHG) emissions are not significantly reduced. The polar bear (Ursus maritimus) depends on sea ice over the biologically productive continental shelves of the Arctic Ocean as a platform for hunting seals. In 2008, the U.S. Fish and Wildlife Service listed the polar bear as threatened under the Endangered Species Act (ESA) due to the threat posed by sea ice loss. The polar bear was the first species to be listed due to forecasted population declines from climate change.

  11. Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees.

    Science.gov (United States)

    Ziska, Lewis H; Pettis, Jeffery S; Edwards, Joan; Hancock, Jillian E; Tomecek, Martha B; Clark, Andrew; Dukes, Jeffrey S; Loladze, Irakli; Polley, H Wayne

    2016-04-13

    At present, there is substantive evidence that the nutritional content of agriculturally important food crops will decrease in response to rising levels of atmospheric carbon dioxide, Ca However, whether Ca-induced declines in nutritional quality are also occurring for pollinator food sources is unknown. Flowering late in the season, goldenrod (Solidago spp.) pollen is a widely available autumnal food source commonly acknowledged by apiarists to be essential to native bee (e.g. Bombus spp.) and honeybee (Apis mellifera) health and winter survival. Using floral collections obtained from the Smithsonian Natural History Museum, we quantified Ca-induced temporal changes in pollen protein concentration of Canada goldenrod (Solidago canadensis), the most wide spread Solidago taxon, from hundreds of samples collected throughout the USA and southern Canada over the period 1842-2014 (i.e. a Ca from approx. 280 to 398 ppm). In addition, we conducted a 2 year in situtrial of S. Canadensis populations grown along a continuous Ca gradient from approximately 280 to 500 ppm. The historical data indicated a strong significant correlation between recent increases in Ca and reductions in pollen protein concentration (r(2)= 0.81). Experimental data confirmed this decrease in pollen protein concentration, and indicated that it would be ongoing as Ca continues to rise in the near term, i.e. to 500 ppm (r(2)= 0.88). While additional data are needed to quantify the subsequent effects of reduced protein concentration for Canada goldenrod on bee health and population stability, these results are the first to indicate that increasing Ca can reduce protein content of a floral pollen source widely used by North American bees.

  12. Facile synthesis of highly active reduced graphene oxide-CuI catalyst through a simple combustion method for photocatalytic reduction of CO2 to methanol

    Science.gov (United States)

    Zhang, Wenjun; Li, Yingjie; Zhang, Xiaoxiong; Li, Cuiluo

    2017-09-01

    We report a facile combustion method synthesis of reduced graphene oxide/CuI composites as a photocatalyst, in which CuI nanoparticles were homogeneously distributed on the surface of reduced graphene oxide (rGO), showing a good visible light response. The rGO-supported and unsupported CuI hybrids were tested over the photocatalytic reduction of CO2 for methanol evolution in visible light. In the current study rGO-CuI composites have shown excellent yields (19.91 μmol g-cat-1). rGO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the CuI nanoparticles.

  13. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.

    2016-01-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  14. CO2-Neutral Fuels

    Science.gov (United States)

    Goede, Adelbert; van de Sanden, Richard

    2016-06-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.

  15. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.

    2016-01-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  16. Synthesis of three-dimensional reduced graphene oxide layer supported cobalt nanocrystals and their high catalytic activity in F-T CO2 hydrogenation.

    Science.gov (United States)

    He, Fei; Niu, Na; Qu, Fengyu; Wei, Shuquan; Chen, Yujin; Gai, Shili; Gao, Peng; Wang, Yan; Yang, Piaoping

    2013-09-21

    The reduced graphene oxide (rGO) supported cobalt nanocrystals have been synthesized through an in situ crystal growth method using Co(acac)2 under solvothermal conditions by using DMF as the solvent. By carefully controlling the reaction temperature, the phase transition of the cobalt nanocrystals from the cubic phase to the hexagonal phase has been achieved. Moreover, the microscopic structure and morphology as well as the reduction process of the composite have been investigated in detail. It is found that oxygen-containing functional groups on the graphene oxide (GO) can greatly influence the formation process of the Co nanocrystals by binding the Co(2+) cations dissociated from the Co(acac)2 in the initial reaction solution at 220 °C, leading to the 3D reticular structure of the composite. Furthermore, this is the first attempt to use a Co/rGO composite as the catalyst in the F-T CO2 hydrogenation process. The catalysis testing results reveal that the as-synthesized 3D structured composite exhibits ideal catalytic activity and good stability, which may greatly extend the scope of applications for this kind of graphene-based metal hybrid material.

  17. AISI/DOE Technology Roadmap Program: Development of an O2-Enriched Furnace System for Reduced CO2 and NOx Emissions For the Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    Edward W. Grandmaison; David J. Poirier; Eric Boyd

    2003-01-20

    An oxygen-enriched furnace system for reduced CO2 and NOx emission has been developed. The furnace geometry, with a sidewall-mounted burner, was similar to configurations commonly encountered in a steel reheat furnace. The effect of stack oxygen concentration, oxygen enrichment level and air infiltration on fuel savings/CO2 reduction, NOx emissions and scale formation were investigated. The firing rate required to maintain the furnace temperature at 1100 C decreased linearly with increasing oxygen enrichment. At full oxygen enrichment a reduction of 40-45% in the firing rate was required to maintain furnace temperature. NOx emissions were relatively constant at oxygen enrichment levels below 60% and decreased concentration at all oxygen enrichment levels. Air infiltration also had an effect on NOx levels leading to emissions similar to those observed with no air infiltration but with similar stack oxygen concentrations. At high oxygen enrichment levels, there was a larger variation in the refractory surface-temperature on the roof and blind sidewall of the furnace. Scale habit, intactness, adhesion and oxidation rates were examined for five grades of steel over a range of stack oxygen concentrations and oxygen enrichment levels at 1100 degree C. The steel grade had the largest effect on scaling properties examined in this work. The stack oxygen concentration and the oxygen enrichment level had much smaller effects on the scaling properties.

  18. Porous NiCo2O4 nanosheets/reduced graphene oxide composite: facile synthesis and excellent capacitive performance for supercapacitors.

    Science.gov (United States)

    Ma, Lianbo; Shen, Xiaoping; Ji, Zhenyuan; Cai, Xiaoqing; Zhu, Guoxing; Chen, Kangmin

    2015-02-15

    A composite with porous NiCo2O4 nanosheets attached on reduced graphene oxide (RGO) sheets is synthesized through a facile solution-based method combined with a simple thermal annealing process. The capacitive performances of the as-prepared NiCo2O4/RGO (NCG) composites as electrode materials are investigated. It is found that the NCG composites exhibit a high specific capacitance up to 1186.3 F g(-1) at the current density of 0.5 A g(-1), and superior cycling stability with about 97% of the initial capacitance after 100 cycles. The greatly enhanced capacitive performance of the NCG electrode can be attributed to the existence of RGO support, which serves as both conductive channels and active interface. The approach used in the synthesis provides a facile route for preparing graphene-binary metal oxide electrode materials. The remarkable capacitive performance of NCG composites will undoubtedly make them be attractive for high performance energy storage applications.

  19. Porous CuCo2O4 nanocubes wrapped by reduced graphene oxide as high-performance lithium-ion battery anodes.

    Science.gov (United States)

    Kang, Wenpei; Tang, Yongbing; Li, Wenyue; Li, Zhangpeng; Yang, Xia; Xu, Jun; Lee, Chun-Sing

    2014-06-21

    A composite of porous CuCo2O4 nanocubes well wrapped by reduced graphene oxide (rGO) sheets has been synthesized by a facile microwave-assisted solvothermal reaction and applied as anode in lithium ion batteries (LIBs). The porous structure of the CuCo2O4 nanocubes not only provides a high surface area for contact with the electrolyte, but also assists by accommodating volume change upon charging-discharging. Impedance measurements and transmission electron microscopy show that incorporation of rGO further decreases the charge transfer resistance and improves the structural stability of the composite. As an anode material for a LIB, the composite exhibits a high stable capacity of ∼ 570 mA h g(-1) at a current density of 1000 mA g(-1) after 350 cycles. With a high specific surface area and a low charge transfer resistance, the composite anode shows impressive performance especially at high current density. The LIB shows a high capacity of ∼ 450 mA h g(-1) even at a high current density of 5000 mA g(-1), demonstrating the composite's potential for applications in LIBs with long cycling life and high power density.

  20. Modelling sewer sediment deposition, erosion, and transport processes to predict acute influent and reduce combined sewer overflows and CO(2) emissions.

    Science.gov (United States)

    Mouri, Goro; Oki, Taikan

    2010-01-01

    Understanding of solids deposition, erosion, and transport processes in sewer systems has improved considerably in the past decade. This has provided guidance for controlling sewer solids and associated acute pollutants to protect the environment and improve the operation of wastewater systems. Although measures to decrease combined sewer overflow (CSO) events have reduced the amount of discharged pollution, overflows continue to occur during rainy weather in combined sewer systems. The solution lies in the amount of water allotted to various processes in an effluent treatment system, in impact evaluation of water quality and prediction technology, and in stressing the importance of developing a control technology. Extremely contaminated inflow has been a serious research subject, especially in connection with the influence of rainy weather on nitrogen and organic matter removal efficiency in wastewater treatment plants (WWTP). An intensive investigation of an extremely polluted inflow load to WWTP during rainy weather was conducted in the city of Matsuyama, the region used for the present research on total suspended solid (TSS) concentration. Since the inflow during rainy weather can be as much as 400 times that in dry weather, almost all sewers are unsettled and overflowing when a rain event is more than moderate. Another concern is the energy consumed by wastewater treatment; this problem has become important from the viewpoint of reducing CO(2) emissions and overall costs. Therefore, while establishing a prediction technology for the inflow water quality characteristics of a sewage disposal plant is an important priority, the development of a management/control method for an effluent treatment system that minimises energy consumption and CO(2) emissions due to water disposal is also a pressing research topic with regards to the quality of treated water. The procedure to improve water quality must make use of not only water quality and biotic criteria, but also

  1. CO2 -Responsive polymers.

    Science.gov (United States)

    Lin, Shaojian; Theato, Patrick

    2013-07-25

    This Review focuses on the recent progress in the area of CO2 -responsive polymers and provides detailed descriptions of these existing examples. CO2 -responsive polymers can be categorized into three types based on their CO2 -responsive groups: amidine, amine, and carboxyl groups. Compared with traditional temperature, pH, or light stimuli-responsive polymers, CO2 -responsive polymers provide the advantage to use CO2 as a "green" trigger as well as to capture CO2 directly from air. In addition, the current challenges of CO2 -responsive polymers are discussed and the different solution methods are compared. Noteworthy, CO2 -responsive polymers are considered to have a prosperous future in various scientific areas.

  2. CO2 laser modeling

    Science.gov (United States)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  3. Sedation or Inhalant Anesthesia before Euthanasia with CO2 Does Not Reduce Behavioral or Physiologic Signs of Pain and Stress in Mice

    Science.gov (United States)

    Valentine, Helen; Williams, Wendy O; Maurer, Kirk J

    2012-01-01

    CO2 administration is a common euthanasia method for research mice, yet questions remain regarding whether CO2 euthanasia is associated with pain and stress. Here we assessed whether premedication with acepromazine, midazolam, or anesthetic induction with isoflurane altered behavioral and physiologic parameters that may reflect pain or stress during CO2 euthanasia. Mice were assigned to 1 of 6 euthanasia groups: CO2 only at a flow rate of 1.2 L/min which displaces 20% of the cage volume per minute (V/min; control group); premedication with acepromazine (5 mg/kg), midazolam (5 mg/kg), or saline followed by 20% V/min CO2; induction with 5% isoflurane followed by greater than 100% V/min CO2 (>6L/min); and 100% V/min CO2 only (6 L/min). Measures included ultrasonic sound recordings, behavioral analysis of video recordings, plasma ACTH and corticosterone levels immediately after euthanasia, and quantification of c-fos from brain tissue. Compared with 20% V/min CO2 alone, premedication with acepromazine or midazolam did not significantly alter behavior but did induce significantly higher c-fos expression in the brain. Furthermore, the use of isoflurane induction prior to CO2 euthanasia significantly increased both behavioral and neuromolecular signs of stress. The data indicate that compared with other modalities, 20% V/min CO2 alone resulted in the least evidence of stress in mice and therefore was the most humane euthanasia method identified in the current study. PMID:22330868

  4. Reduced-order modeling with sparse polynomial chaos expansion and dimension reduction for evaluating the impact of CO2 and brine leakage on groundwater

    Science.gov (United States)

    Liu, Y.; Zheng, L.; Pau, G. S. H.

    2016-12-01

    A careful assessment of the risk associated with geologic CO2 storage is critical to the deployment of large-scale storage projects. While numerical modeling is an indispensable tool for risk assessment, there has been increasing need in considering and addressing uncertainties in the numerical models. However, uncertainty analyses have been significantly hindered by the computational complexity of the model. As a remedy, reduced-order models (ROM), which serve as computationally efficient surrogates for high-fidelity models (HFM), have been employed. The ROM is constructed at the expense of an initial set of HFM simulations, and afterwards can be relied upon to predict the model output values at minimal cost. The ROM presented here is part of National Risk Assessment Program (NRAP) and intends to predict the water quality change in groundwater in response to hypothetical CO2 and brine leakage. The HFM based on which the ROM is derived is a multiphase flow and reactive transport model, with 3-D heterogeneous flow field and complex chemical reactions including aqueous complexation, mineral dissolution/precipitation, adsorption/desorption via surface complexation and cation exchange. Reduced-order modeling techniques based on polynomial basis expansion, such as polynomial chaos expansion (PCE), are widely used in the literature. However, the accuracy of such ROMs can be affected by the sparse structure of the coefficients of the expansion. Failing to identify vanishing polynomial coefficients introduces unnecessary sampling errors, the accumulation of which deteriorates the accuracy of the ROMs. To address this issue, we treat the PCE as a sparse Bayesian learning (SBL) problem, and the sparsity is obtained by detecting and including only the non-zero PCE coefficients one at a time by iteratively selecting the most contributing coefficients. The computational complexity due to predicting the entire 3-D concentration fields is further mitigated by a dimension

  5. Selecting CO2 Sources for CO2 Utilization by Environmental-Merit-Order Curves.

    Science.gov (United States)

    von der Assen, Niklas; Müller, Leonard J; Steingrube, Annette; Voll, Philip; Bardow, André

    2016-02-01

    Capture and utilization of CO2 as alternative carbon feedstock for fuels, chemicals, and materials aims at reducing greenhouse gas emissions and fossil resource use. For capture of CO2, a large variety of CO2 sources exists. Since they emit much more CO2 than the expected demand for CO2 utilization, the environmentally most favorable CO2 sources should be selected. For this purpose, we introduce the environmental-merit-order (EMO) curve to rank CO2 sources according to their environmental impacts over the available CO2 supply. To determine the environmental impacts of CO2 capture, compression and transport, we conducted a comprehensive literature study for the energy demands of CO2 supply, and constructed a database for CO2 sources in Europe. Mapping these CO2 sources reveals that CO2 transport distances are usually small. Thus, neglecting transport in a first step, we find that environmental impacts are minimized by capturing CO2 first from chemical plants and natural gas processing, then from paper mills, power plants, and iron and steel plants. In a second step, we computed regional EMO curves considering transport and country-specific impacts for energy supply. Building upon regional EMO curves, we identify favorable locations for CO2 utilization with lowest environmental impacts of CO2 supply, so-called CO2 oases.

  6. Direct Observation by Rapid-Scan FT-IR Spectroscopy of Two-Electron-Reduced Intermediate of Tetraaza Catalyst [Co(II)N4H(MeCN)](2+) Converting CO2 to CO.

    Science.gov (United States)

    Sheng, Hua; Frei, Heinz

    2016-08-10

    In the search for the two-electron-reduced intermediate of the tetraaza catalyst [Co(II)N4H(MeCN)](2+) (N4H = 2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene) for CO2 reduction and elementary steps that result in the formation of CO product, rapid-scan FT-IR spectroscopy of the visible-light-sensitized catalysis, using Ir(ppy)3 in wet acetonitrile (CD3CN) solution, led to the observation of two sequential intermediates. The initially formed one-electron-reduced [Co(I)N4H](+)-CO2 adduct was converted by the second electron to a transient [Co(I)N4H](+)-CO2(-) complex that spontaneously converted CO2 to CO in a rate-limiting step on the second time scale in the dark under regeneration of the catalyst (room temperature). The macrocycle IR spectra of the [Co(I)N4H](+)-CO2(-) complex and the preceding one-electron [Co(I)N4H](+)-CO2 intermediate show close similarity but distinct differences in the carboxylate modes, indicating that the second electron resides mainly on the CO2 ligand. Vibrational assignments are corroborated by (13)C isotopic labeling. The structure and stability of the two-electron-reduced intermediate derived from the time-resolved IR study are in good agreement with recent predictions by DFT electronic structure calculations. This is the first observation of an intermediate of a molecular catalyst for CO2 reduction during the bond-breaking step producing CO. The reaction pathway for the Co tetraaza catalyst uncovered here suggests that the competition between CO2 reduction and proton reduction of a macrocyclic multi-electron catalyst is steered toward CO2 activation if the second electron is directly captured by an adduct of CO2 and the one-electron-reduced catalyst intermediate.

  7. MnCo2O4 nanowires anchored on reduced graphene oxide sheets as effective bifunctional catalysts for Li-O2 battery cathodes.

    Science.gov (United States)

    Kim, Jong Guk; Kim, Youngmin; Noh, Yuseong; Kim, Won Bae

    2015-05-22

    A hybrid composite system of MnCo2 O4 nanowires (MCO NWs) anchored on reduced graphene oxide (RGO) nanosheets was prepared as the bifunctional catalyst of a Li-O2 battery cathode. The catalysts can be obtained from the hybridization of one-dimensional MCO NWs and two-dimensional RGO nanosheets. As O2 -cathode catalysts for Li-O2 cells, the MCO@RGO composites showed a high initial discharge capacity (ca. 11092.1 mAh gcarbon (-1) ) with a high rate performance. The Li-O2 cells could run for more than 35 cycles with high reversibility under a limited specific capacity of 1000 mAh gcarbon (-1) with a low potential polarization of 1.36 V, as compared with those of pure Ketjenblack and MCO NWs. The high cycling stability, low potential polarization, and rate capability suggest that the MCO@RGO composites prepared here are promising catalyst candidates for highly reversible Li-O2 battery cathodes.

  8. Energyless CO2 Absorption, Generation, and Fixation Using Atmospheric CO2.

    Science.gov (United States)

    Inagaki, Fuyuhiko; Okada, Yasuhiko; Matsumoto, Chiaki; Yamada, Masayuki; Nakazawa, Kenta; Mukai, Chisato

    2016-01-01

    From an economic and ecological perspective, the efficient utilization of atmospheric CO2 as a carbon resource should be a much more important goal than reducing CO2 emissions. However, no strategy to harvest CO2 using atmospheric CO2 at room temperature currently exists, which is presumably due to the extremely low concentration of CO2 in ambient air (approximately 400 ppm=0.04 vol%). We discovered that monoethanolamine (MEA) and its derivatives efficiently absorbed atmospheric CO2 without requiring an energy source. We also found that the absorbed CO2 could be easily liberated with acid. Furthermore, a novel CO2 generator enabled us to synthesize a high value-added material (i.e., 2-oxazolidinone derivatives based on the metal catalyzed CO2-fixation at room temperature) from atmospheric CO2.

  9. 全球气候变化与CO_2减排方案的探讨%On exploration for global climate changes and carbon dioxide emission-reducing scheme

    Institute of Scientific and Technical Information of China (English)

    赵洁

    2012-01-01

    The study points out the greenhouse gas mainly with carbon dioxide is the major driving factor for the global climate changes,explores the emission-reducing scheme of the carbon dioxide from the population,the Per Capita GDP,unit energy consumption and the energy carbon content,which play the role in the emission of the carbon dioxide,and considers the geological sequestration including the oil deposits,the gas layer and the deep aquifer can increase the carbon content,and indicates the reduction of the man-made carbon dioxide is the most potential way to reduce the emission of carbon dioxide.%指出以CO2为主的温室气体是全球气候变化的最主要的驱动因素,就影响CO2排放量的入口、人均GDP、单位耗能量和能源含碳量以及碳汇量等进行CO2减排方案的探讨,并认为油田、煤气层和深部含水层等地质处置方法能够有效增加CO2的碳汇量,降低CO2的人为排放量,是当前最有潜力的CO2减排途径。

  10. CO2NNIE

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2015-01-01

    We propose a system for calculating the personalized annual fuel consumption and CO2 emissions from transportation. The system, named CO2NNIE, estimates the fuel consumption on the fastest route between the frequent destinations of the user. The travel time and fuel consumption estimated are based......% of the actual fuel consumption (4.6% deviation on average). We conclude, that the system provides new detailed information on CO2 emissions and fuel consumption for any make and model....

  11. Wearable CO2 sensor

    OpenAIRE

    Radu, Tanja; Fay, Cormac; Lau, King-Tong; Waite, Rhys; Diamond, Dermot

    2009-01-01

    High concentrations of CO2 may develop particularly in the closed spaces during fires and can endanger the health of emergency personnel by causing serious physiological effects. The proposed prototype provides real-time continuous monitoring of CO2 in a wearable configuration sensing platform. A commercially available electrochemical CO2 sensor was selected due to its selectivity, sensitivity and low power demand. This was integrated onto an electronics platform that performed signal capture...

  12. CO2 blood test

    Science.gov (United States)

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum ... Many medicines can interfere with blood test results. Your health care provider will tell you if you need to stop taking any medicines before you have this test. DO ...

  13. CO2 laser resurfacing.

    Science.gov (United States)

    Fitzpatrick, R E

    2001-07-01

    The CO2 Laser offers a variety of unique features in resurfacing facial photodamage and acne scarring. These include hemostasis, efficient removal of the epidermis in a single pass, thermally induced tissue tightening, and safe, predictable tissue interaction. Knowledge of these mechanisms will result in the capability of using the CO2 laser effectively and safely whether the goal is superficial or deep treatment.

  14. Influence of copper content on structural features and performance of pre-reduced LaMn_(1-x)Cu_xO_3 (0≤x<1) catalysts for methanol synthesis from CO_2/H_2

    Institute of Scientific and Technical Information of China (English)

    贾立山; 高敬; 方维平; 李清彪

    2010-01-01

    A series of pre-reduced LaMn1-xCuxO3 (0≤x<1) catalysts for methanol synthesis from CO2 hydrogenation were prepared by a sol-gel method. The catalytic performances were strongly dependent on the copper content. XRD investigation revealed that the single perovskite structure could be preserved after being reduced, when the substitution for Mn by Cu was less than 50%. The Cu-doped (x=0.5) LaMnO3 was much more active than the other catalysts for reaction, showing CO2 conversion up to 11.33% and methanol selecti...

  15. 全球二氧化碳减排不应是CCS,应是CCU%CCU:A More Feasible and Economic Strategy than CCS for Reducing CO2 Emissions

    Institute of Scientific and Technical Information of China (English)

    谢和平; 谢凌志; 王昱飞; 朱家骅; 梁斌; 鞠杨

    2012-01-01

    A new and promising strategy of C02 capture and utilization (CCU) based on analysis of the costs and potential geological risks of application of CCS technique was presented. It is believed that, in addition to enormous energy expenditure and costs, applica- tion of CCS faces a few geological risks such as leakage of C02, destruction of saline, ground upheaval and triggering earthquake. CCU, meaning that CO2 being captured and used as raw material to produce high-value chemical products (or related by-products), thereby reducing CO2 emissions with low energy expenditure and costs, is more attractive than CCS as the besl currently available technology. This study, for the first time, shows several promising methods to mineralize CO2 and simultaneously produce valuable products, such as employing MgC12 ~ 6H2 0 to mineralize CO2 and to recover hydrochloric acid and magnesium carbom,te, and using phosphogypsum to mineralize CO2 and produce Sulphur-based compound fertilizer and calcium carbonate as well. It is shown that within the scope of hu- man use ( about 5 km underground), if 1% of calcium and magnesium ions of the total amount of the earth' s crust were used for miner- alization of CO2 with a conversion rate of 50%, it could theoretically sequestrate 2.56 -06 billion tons of CO2. According to a report by the International Energy Agency, global CO2 emission in 2010 was expected to reach 50.06 billion tons. P~tentially, ill theme', tile natural sources couhl mineralize as much as 85 thousand years of global CO_, emissions. Besides, if the magnesium ions of approximate 50 million tons of phosphogypsum wastes annually produced in China were used for mineralization, it could theoretically sequestrate 12. 5 million tons of CO2 per year. By producing value-added product compensating the costs of handling CO2, the proposed CCU strategy provides a feasible and economic way to fulfill commercial application of techniques for reducing global CO2 emission.%

  16. Outsourcing CO2 Emissions

    Science.gov (United States)

    Davis, S. J.; Caldeira, K. G.

    2009-12-01

    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

  17. Students' Understanding of the Greenhouse Effect, the Societal Consequences of Reducing CO2 Emissions and the Problem of Ozone Layer Depletion.

    Science.gov (United States)

    Andersson, Bjorn; Wallin, Anita

    2000-01-01

    Contributes to the growing body of knowledge about students' conceptions and views of environmental and natural resource issues. Questions 9th and 12th grade Swedish students' understandings of the greenhouse effect, reduction of CO2 emissions, and the depletion of the ozone layer. Observes five models of the greenhouse effect that appear among…

  18. Students' Understanding of the Greenhouse Effect, the Societal Consequences of Reducing CO2 Emissions and the Problem of Ozone Layer Depletion.

    Science.gov (United States)

    Andersson, Bjorn; Wallin, Anita

    2000-01-01

    Contributes to the growing body of knowledge about students' conceptions and views of environmental and natural resource issues. Questions 9th and 12th grade Swedish students' understandings of the greenhouse effect, reduction of CO2 emissions, and the depletion of the ozone layer. Observes five models of the greenhouse effect that appear among…

  19. Cleaner fuels to reduce emissions of CO2, NOx and PM10 by container ships: A solution or a box of Pandora?

    NARCIS (Netherlands)

    Vleugel, J.M.; Bal, F.

    2015-01-01

    Transport vehicles contribute to the on going rise in emissions of CO2 worldwide and emit large amounts of NOx and PM10. The growing demand for container transport is only sustainable if transport becomes ‘greener’. There are innovations, which unite economic and environmental interests. One example

  20. Elevated CO2 plus chronic warming reduces nitrogen uptake and levels or activities of nitrogen -uptake and -assimilatory proteins in tomato roots

    Science.gov (United States)

    Atmospheric CO2 enrichment is expected to often benefit plant growth, despite causing global warming and nitrogen (N) dilution in plants. Most plants primarily procure N as inorganic nitrate (NO3-) or ammonium (NH4+), using membrane-localized transport proteins in roots, which are key targets for im...

  1. Amine scrubbing for CO2 capture.

    Science.gov (United States)

    Rochelle, Gary T

    2009-09-25

    Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas and hydrogen since 1930. It is a robust technology and is ready to be tested and used on a larger scale for CO2 capture from coal-fired power plants. The minimum work requirement to separate CO2 from coal-fired flue gas and compress CO2 to 150 bar is 0.11 megawatt-hours per metric ton of CO2. Process and solvent improvements should reduce the energy consumption to 0.2 megawatt-hour per ton of CO2. Other advanced technologies will not provide energy-efficient or timely solutions to CO2 emission from conventional coal-fired power plants.

  2. Experimental Ion Mobility measurements in Ne-CO$_2$ and CO$_2$-N$_2$ mixtures

    CERN Document Server

    Encarnação, P.M.C.C.; Veenhof, R.; Neves, P.N.B.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.

    2016-01-01

    In this paper we present the experimental results for the mobility, K0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N2) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm2V−1s−1 in the 10%-99% interval of CO2, and from 4.61 ± 0.19 to 3.00 ± 0.09 cm2V−1s−1 for the second peak observed (10%–25% of CO2). For the CO2-N2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+(CO2), with a second peak appearing for CO2 concentrations below 10%. This secon...

  3. The CO2nnect activities

    Science.gov (United States)

    Eugenia, Marcu

    2014-05-01

    Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

  4. CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites.

    Science.gov (United States)

    Dai, Zhenxue; Viswanathan, Hari; Middleton, Richard; Pan, Feng; Ampomah, William; Yang, Changbing; Jia, Wei; Xiao, Ting; Lee, Si-Yong; McPherson, Brian; Balch, Robert; Grigg, Reid; White, Mark

    2016-07-19

    Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.

  5. Improved Criteria for Increasing CO2 Storage Potential with CO2 Enhanced Oil Recovery

    Science.gov (United States)

    Bauman, J.; Pawar, R.

    2013-12-01

    In recent years it has been found that deployment of CO2 capture and storage technology at large scales will be difficult without significant incentives. One of the technologies that has been a focus in recent years is CO2 enhanced oil/gas recovery, where additional hydrocarbon recovery provides an economic incentive for deployment. The way CO2 EOR is currently deployed, maximization of additional oil production does not necessarily lead to maximization of stored CO2, though significant amounts of CO2 are stored regardless of the objective. To determine the potential of large-scale CO2 storage through CO2 EOR, it is necessary to determine the feasibility of deploying this technology over a wide range of oil/gas field characteristics. In addition it is also necessary to accurately estimate the ultimate CO2 storage potential and develop approaches that optimize oil recovery along with long-term CO2 storage. This study uses compositional reservoir simulations to further develop technical screening criteria that not only improve oil recovery, but maximize CO2 storage during enhanced oil recovery operations. Minimum miscibility pressure, maximum oil/ CO2 contact without the need of significant waterflooding, and CO2 breakthrough prevention are a few key parameters specific to the technical aspects of CO2 enhanced oil recovery that maximize CO2 storage. We have developed reduced order models based on simulation results to determine the ultimate oil recovery and CO2 storage potential in these formations. Our goal is to develop and demonstrate a methodology that can be used to determine feasibility and long-term CO2 storage potential of CO2 EOR technology.

  6. CO2-strategier

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2008-01-01

    I 2007 henvendte Lyngby-Taarbæk kommunens Agenda 21 koordinator sig til Videnskabsbutikken og spurgte om der var interesse for at samarbejde om CO2-strategier. Da Videnskabsbutikken DTU er en åben dør til DTU for borgerne og deres organisationer, foreslog Videnskabsbutikken DTU at Danmarks...... Naturfredningsforening’s lokalkomité for Lyngby blev en del af samarbejdet for at få borgerne i kommunen involveret i arbejdet med at udvikle strategier for reduktion af CO2. Siden sommeren 2007 har Videnskabsbutikken DTU, Lyngby-Taarbæk kommune og Danmarks Naturfredningsforening i Lyngby-Taarbæk samarbejdet om analyse...... og innovation i forhold til CO2-strategier....

  7. Biochar from sugarcane filtercake reduces soil CO2 emissions relative to raw residue and improves water retention and nutrient availability in a highly-weathered tropical soil.

    Directory of Open Access Journals (Sweden)

    Angela Joy Eykelbosh

    Full Text Available In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w. were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w. raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w. in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions.

  8. Biochar from Sugarcane Filtercake Reduces Soil CO2 Emissions Relative to Raw Residue and Improves Water Retention and Nutrient Availability in a Highly-Weathered Tropical Soil

    Science.gov (United States)

    Eykelbosh, Angela Joy; Johnson, Mark S.; Santos de Queiroz, Edmar; Dalmagro, Higo José; Guimarães Couto, Eduardo

    2014-01-01

    In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions. PMID:24897522

  9. Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged

    Science.gov (United States)

    Wertin, Timothy M.; Belnap, Jayne; Reed, Sasha C.

    2016-01-01

    1.Drylands represent our planet's largest terrestrial biome and, due to their extensive area, maintain large stocks of carbon (C). Accordingly, understanding how dryland C cycling will respond to climate change is imperative for accurately forecasting global C cycling and future climate. However, it remains difficult to predict how increased temperature will affect dryland C cycling, as substantial uncertainties surround the potential responses of the two main C fluxes: plant photosynthesis and soil CO2 efflux. In addition to a need for an improved understanding of climate effects on individual dryland C fluxes, there is also notable uncertainty regarding how climate change may influence the relationship between these fluxes.

  10. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-05-01

    Carbon dioxide (CO2) has long been regarded as the major greenhouse gas, which leads to numerous negative effects on global environment. The capture and separation of CO2 by selective adsorption using porous materials proves to be an effective way to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs with high CO2 adsorption capacities and CO2/N2 selectivities for post-combustion effluent (e.g. flue gas) treatment. We will also exploit the correlation between the CO2 capture performance of POPs and their textual properties/functionalities. Chapters Two focuses on the study of a group of porous phenolic-aldehyde polymers (PPAPs) synthesized by a catalyst-free method, the CO2 capture capacities of these PPAPs exceed 2.0 mmol/g at 298 K and 1 bar, while keeping CO2/N2 selectivity of more than 30 at the same time. Chapter Three reports the gas adsorption results of different hyper-cross-linked polymers (HCPs), which indicate that heterocyclo aromatic monomers can greatly enhance polymers’ CO2/N2 selectivities, and the N-H bond is proved to the active CO2 adsorption center in the N-contained (e.g. pyrrole) HCPs, which possess the highest selectivities of more than 40 at 273 K when compared with other HCPs. Chapter Four emphasizes on the chemical modification of a new designed polymer of intrinsic microporosity (PIM) with high CO2/N2 selectivity (50 at 273 K), whose experimental repeatability and chemical stability prove excellent. In Chapter Five, we demonstrate an improvement of both CO2 capture capacity and CO2/N2 selectivity by doping alkali metal ions into azo-polymers, which leads a promising method to the design of new porous organic polymers.

  11. CO2 capture research in the Netherlands

    NARCIS (Netherlands)

    Meerman, J.C.; Kuramochi, T.; Egmond, S. van

    2008-01-01

    The global climate is changing due to human activities. This human‑induced climate change is mainly caused by global emissions of carbon dioxide (CO2) into the atmosphere. Most scientists agree that in order to mitigate climate change, by 2050, global CO2 emissions must be reduced by at least 50% co

  12. CO2 capture, transport, storage and utilisation

    NARCIS (Netherlands)

    Brouwer, J.H.

    2013-01-01

    Reducing CO2 emissions requires an integrated CO2 management approach. The dependency between the different industry sectors is higher than commonly acknowledged and covers all areas; capture, transport, storage and utilisation. TNO is one of Europe’s largest independent research organisations and p

  13. Opportunity for offshore wind to reduce future demand for coal-fired power plants in China with consequent savings in emissions of CO2.

    Science.gov (United States)

    Lu, Xi; McElroy, Michael B; Chen, Xinyu; Kang, Chongqing

    2014-12-16

    Although capacity credits for wind power have been embodied in power systems in the U.S. and Europe, the current planning framework for electricity in China continues to treat wind power as a nondispatchable source with zero contribution to firm capacity. This study adopts a rigorous reliability model for the electric power system evaluating capacity credits that should be recognized for offshore wind resources supplying power demands for Jiangsu, China. Jiangsu is an economic hub located in the Yangtze River delta accounting for 10% of the total electricity consumed in China. Demand for electricity in Jiangsu is projected to increase from 331 TWh in 2009 to 800 TWh by 2030. Given a wind penetration level of 60% for the future additional Jiangsu power supply, wind resources distributed along the offshore region of five coastal provinces in China (Shandong, Jiangsu, Shanghai, Zhejiang, and Fujian) should merit a capacity credit of 12.9%, the fraction of installed wind capacity that should be recognized to displace coal-fired systems without violating the reliability standard. In the high-coal-price scenario, with 60% wind penetration, reductions in CO2 emissions relative to a business as usual reference could be as large as 200.2 million tons of CO2 or 51.8% of the potential addition, with a cost for emissions avoided of $29.0 per ton.

  14. CO2-neutral fuels

    Science.gov (United States)

    Goede, A. P. H.

    2015-08-01

    The need for storage of renewable energy (RE) generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G) scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel cycle is

  15. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

    Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

  16. CO2 deserts: implications of existing CO2 supply limitations for carbon management.

    Science.gov (United States)

    Middleton, Richard S; Clarens, Andres F; Liu, Xiaowei; Bielicki, Jeffrey M; Levine, Jonathan S

    2014-10-01

    Efforts to mitigate the impacts of climate change will require deep reductions in anthropogenic CO2 emissions on the scale of gigatonnes per year. CO2 capture and utilization and/or storage technologies are a class of approaches that can substantially reduce CO2 emissions. Even though examples of this approach, such as CO2-enhanced oil recovery, are already being practiced on a scale >0.05 Gt/year, little attention has been focused on the supply of CO2 for these projects. Here, facility-scale data newly collected by the U.S. Environmental Protection Agency was processed to produce the first comprehensive map of CO2 sources from industrial sectors currently supplying CO2 in the United States. Collectively these sources produce 0.16 Gt/year, but the data reveal the presence of large areas without access to CO2 at an industrially relevant scale (>25 kt/year). Even though some facilities with the capability to capture CO2 are not doing so and in some regions pipeline networks are being built to link CO2 sources and sinks, much of the country exists in "CO2 deserts". A life cycle analysis of the sources reveals that the predominant source of CO2, dedicated wells, has the largest carbon footprint further confounding prospects for rational carbon management strategies.

  17. Effects of CO2 leakage on soil bacterial communities from simulated CO2-EOR areas.

    Science.gov (United States)

    Chen, Fu; Yang, Yongjun; Ma, Yanjun; Hou, Huping; Zhang, Shaoliang; Ma, Jing

    2016-05-18

    CO2-EOR (enhanced oil recovery) has been proposed as a viable option for flooding oil and reducing anthropogenic CO2 contribution to the atmospheric pool. However, the potential risk of CO2 leakage from the process poses a threat to the ecological system. High-throughput sequencing was used to investigate the effects of CO2 emission on the composition and structure of soil bacterial communities. The diversity of bacterial communities notably decreased with increasing CO2 flux. The composition of bacterial communities varied along the CO2 flux, with increasing CO2 flux accompanied by increases in the relative abundance of Bacteroidetes and Firmicutes phyla, but decreases in the relative abundance of Acidobacteria and Chloroflexi phyla. Within the Firmicutes phylum, the genus Lactobacillus increased sharply when the CO2 flux was at its highest point. Alpha and beta diversity analysis revealed that differences in bacterial communities were best explained by CO2 flux. The redundancy analysis (RDA) revealed that differences in bacterial communities were best explained by soil pH values which related to CO2 flux. These results could be useful for evaluating the risk of potential CO2 leakages on the ecosystems associated with CO2-EOR processes.

  18. India Co2 Emissions

    Science.gov (United States)

    Sharan, S.; Diffenbaugh, N. S.

    2010-12-01

    created a balance in between the “developed” and developing countries. If India was producing the same amounts of emissions per capita as the it would have a total of 20 billion metric tons of CO2 emissions annually.

  19. Synthetic biology for CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO2) into fuels and chemicals is a potential approach to reduce CO2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO2-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO2-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO2-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO2-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO2.

  20. Compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2 as substitutes for SF6 to reduce global warming potential

    Science.gov (United States)

    Zhong, Linlin; Rong, Mingzhe; Wang, Xiaohua; Wu, Junhui; Han, Guiquan; Han, Guohui; Lu, Yanhui; Yang, Aijun; Wu, Yi

    2017-07-01

    C5F10O has recently been found to be a very promising alternative to SF6. This paper is devoted to the investigation of compositions, thermodynamic properties, and transport coefficients of high-temperature C5F10O mixed with CO2 and O2. Firstly, the partition functions and enthalpies of formation for a few molecules (CxFy and CxFyO) which are likely to exist in the mixtures, are calculated based on the G4(MP2) theory. The isomers of the above molecules are selected according to their Gibbs energy. The compositions of C5F10O-CO2-O2 mixtures are then determined using the minimization of the Gibbs free energy. Next, the thermodynamic properties (mass density, specific enthalpy, and specific heat) are derived from the previously calculated compositions. Lastly, the transport coefficients (electrical conductivity, viscosity, and thermal conductivity) are calculated based on Chapman-Enskog method. It is found that, as an arc quenching gas, C5F10O could not recombine into itself with the temperature decreasing down to room temperature after the arc extinction. Besides, the key species at room temperature are always CF4, CO2, and C4F6 if graphite is not considered. When taken into account, graphite will replace C4F6 as one of the dominate particles. The mixing of CO2 with C5F10O plasma significantly affects the thermodynamic properties (e.g. vanishing and/or shifting of the peaks in specific heat) and transport coefficients (e.g. reducing viscosity and changing the number of peaks in thermal conductivity), while the addition of O2 with C5F10O-CO2 mixtures has no remarkable influence on both thermodynamic and transport properties.

  1. Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

    Science.gov (United States)

    Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

    2016-04-01

    Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C

  2. Process-dependent residual trapping of CO2 in sandstone

    Science.gov (United States)

    Zuo, Lin; Benson, Sally M.

    2014-04-01

    This paper demonstrates that the nature and extent of residual CO2 trapping depend on the process by which the CO2 phase is introduced into the rock. We compare residual trapping of CO2 in Berea Sandstone by imbibing water into a core containing either exsolved CO2 or CO2 introduced by drainage. X-ray computed tomography measurements are used to map the spatial distribution of CO2 preimbibition and postimbibition. Unlike during drainage where the CO2 distribution is strongly influenced by the heterogeneity of the rock, the distribution of exsolved CO2 is comparatively uniform. Postimbibition, the CO2 distribution retained the essential features for both the exsolved and drainage cases, but twice as much residual trapping is observed for exsolved CO2 even with similar preimbibition gas saturations. Residually trapped exsolved gas also disproportionately reduced water relative permeability. Development of process-dependent parameterization will help better manage subsurface flow processes and unlock benefits from gas exsolution.

  3. Capturing CO2 via reactions in nanopores.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.

    2008-10-01

    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team members expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  4. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    Science.gov (United States)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  5. CO2 laser preionisation

    Science.gov (United States)

    Spiers, Gary D.

    1991-01-01

    The final report for work done during the reporting period of January 25, 1990 to January 24, 1991 is presented. A literature survey was conducted to identify the required parameters for effective preionization in TEA CO2 lasers and the methods and techniques for characterizing preionizers are reviewed. A numerical model of the LP-140 cavity was used to determine the cause of the transverse mode stability improvement obtained when the cavity was lengthened. The measurement of the voltage and current discharge pulses on the LP-140 were obtained and their subsequent analysis resulted in an explanation for the low efficiency of the laser. An assortment of items relating to the development of high-voltage power supplies is also provided. A program for analyzing the frequency chirp data files obtained with the HP time and frequency analyzer is included. A program to calculate the theoretical LIMP chirp is also included and a comparison between experiment and theory is made. A program for calculating the CO2 linewidth and its dependence on gas composition and pressure is presented. The program also calculates the number of axial modes under the FWHM of the line for a given resonator length. A graphical plot of the results is plotted.

  6. Silvering substrates after CO2 snow cleaning

    Science.gov (United States)

    Zito, Richard R.

    2005-09-01

    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  7. CO2 emissions from Super-light Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Bagger, Anne

    2011-01-01

    rise to a substantial reduction of the CO2 emission in the construction phase. The present paper describes how the CO2 emission is reduced when using Super-light technology instead of traditional structural components. Estimations of the CO2 emissions from a number of projects using various...... construction methods suggest that building with Super-light structures may cut the CO2 emission in half, compared to traditional concrete structures, and reduce it to 25% compared to traditional steel structures....

  8. Application of CO2 in BOF%转炉应用CO2技术

    Institute of Scientific and Technical Information of China (English)

    万雪峰; 曹东; 刘祥; 朱晓雷; 廖相巍

    2015-01-01

    By the thermodynamic analysis of top blowing CO2 in the converter,combined with laboratory simulation re-sult of top blowing O2+CO2 mixture gas in converter,some key parameters of CO2 used in converter were established. It is concluded that although pure CO2 injected in the converter could achieve decarburize,the drop of temperature was rath-er large. When the CO2 supplying intensity was 3.0 m3/(t·min),the reduction of temperature was 15.1℃/min;By blow-ing O2+CO2 mixture gas,temperature balance could be realized,but the largest theoretical proportion of CO2 in mixture gas was 79.1%;with the increase of CO2 proportion,the carbon and oxygen product of molten steel at the blowing end was reduced,under the condition of φ(CO2)∶φ(O2)=1∶1,the carbon and oxygen product could be controlled in the range of (25~32)×10-8.%通过对转炉顶吹CO2的热力学分析,结合实验室模拟转炉顶吹O2+CO2混合气体试验结果,确立了CO2在转炉中应用的关键参数。得出在转炉中顶吹纯CO2虽可脱碳,但温降较大,顶吹CO2供气强度为3.0 m3/(t·min)时,钢液温降速率为15.1℃/min;通过喷吹O2+CO2混合气体可实现温度平衡,但CO2配比的最大理论比例为79.1%;随着混合气体中CO2比例增大,吹炼终点钢液碳氧积降低,当φ(CO2)∶φ(O2)=1∶1时可控碳氧积为(25~32)×10-8。

  9. CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

    Science.gov (United States)

    Iglauer, Stefan

    2017-05-16

    Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO2 cannot percolate), (2) residual trapping (where the CO2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO2 through the rock are strongly influenced by the CO2-brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO2-wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO2-wet. Note that CO2-wet surfaces dramatically reduce CO2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO2-wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO2-wettability and the ability to

  10. Investigation of the Prebiotic Synthesis of Amino Acids and RNA Bases from CO2 using FeS/H2S as a Reducing Agent

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.; McDonald, Gene; Bada, Jeffrey

    1995-01-01

    An autotrophic theory of the origin of metabolism and life has been proposed in which carbon dioxide is reduced by ferrous sulfide and hydrogen sulfide by means of a reversed citric acid cycle, leading to the production of amino acids. Similar processes have been proposed for purine synthesis. Ferrous sulfide is a strong reducing agent in the presence of hydrogen sulfide and can produce hydrogen as well as reduce alkenes, alkynes, and thiols to saturated hydrocarbons and reduce ketones to thiols. However, the reduction of carbon dioxide has not been demonstrated. We show here that no amino acids, purines, or pyrimidines are produced from carbon dioxide with the ferrous sulfide and hydrogen sulfide system. Furthermore, this system does not produce amino acids from carboxylic acids by reductive amination and carboxylation. Thus, the proposed autotrophic theory, using carbon dioxide, ferrous sulfide, and hydrogen sulfide, lacks the robustness needed to be a geological process and is, therefore, unlikely to have played a role in the origin of metabolism or the origin of life.

  11. On Leakage from Geologic Storage Reservoirs of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten

    2006-02-14

    Large amounts of CO2 would need to be injected underground to achieve a significant reduction of atmospheric emissions. The large areal extent expected for CO2 plumes makes it likely that caprock imperfections will be encountered, such as fault zones or fractures, which may allow some CO2 to escape from the primary storage reservoir. Leakage of CO2 could also occur along wellbores. Concerns with escape of CO2 from a primary geologic storage reservoir include (1) acidification of groundwater resources, (2) asphyxiation hazard when leaking CO2 is discharged at the land surface, (3) increase in atmospheric concentrations of CO2, and (4) damage from a high-energy, eruptive discharge (if such discharge is physically possible). In order to gain public acceptance for geologic storage as a viable technology for reducing atmospheric emissions of CO2, it is necessary to address these issues and demonstrate that CO2 can be injected and stored safely in geologic formations.

  12. Sugar utilization in the hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324: starch degradation to acetate and CO2 via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming).

    Science.gov (United States)

    Labes, A; Schönheit, P

    2001-11-01

    The hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324, rather than the type strain VC16, was found to grow on starch and sulfate as energy and carbon source. Fermentation products and enzyme activities were determined in starch-grown cells and compared to those of cells grown on lactate and sulfate. During exponential growth on starch, 1 mol of glucose-equivalent was incompletely oxidized with sulfate to approximately 2 mol acetate, 2 mol CO2 and 1 mol H2S. Starch-grown cells did not contain measurable amounts of the deazaflavin factor F420 (reducer A. fulgidus strain 7324 converts starch to acetate via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming). This is the first report of growth of a sulfate reducer on starch, i.e. on a polymeric sugar.

  13. Voluntary agreements as instrument for reducing CO{sub 2} emission from the transportation; Frivillige aftaler som vaerktoej til at reducere CO2-udslippet fra trafikken

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This report presents an analysis of the potential for making voluntary agreements between the Danish state, the counties and the municipalities with the purpose of reducing CO{sub 2} emissions from the transport sector. Voluntary agreements focusing on the use of local means could lead to an estimated reduction of almost 5000,000 tonnes CO{sub 2}, if Danish municipalities make a one-time investment of 600 million DKK. Compared to Denmark's CO{sub 2} commitments following the ratification of the Kyoto Protocol, 500,000 tonnes constitute a rather small but still appreciable amount of CO{sub 2}. It is argued that, presently, Danish municipalities cannot identify appropriate political and economical incentives to launch a specific CO{sub 2} initiative and, finally, it is concluded that the cost-effectiveness of using local means specifically targeted at CO{sub 2} is far too low compared to other means such as using the flexible mechanisms outlined in the Kyoto Protocol. It is problematic to politically legitimate measures that focus specifically on the use of local means to reduce CO{sub 2} emissions from the transport sector. If a wider focus is accepted, including focus on additional effects such as reduced air pollution, reduced number of traffic accidents and improved health, the cost-effectiveness assessment would look rather different and offer more legitimacy to the use of local means in Danish municipalities. A hitch-hiking strategy should be introduced in both existing and coming local spatial planning activities. One example could be the mandatory local Agenda 21 strategies that Danish municipalities must prepare according to the Danish Planning Act. Another example could be strategic environmental assessments of programmes and plans that are introduced in the European Union SEA Directive. In the report it is argued that if a voluntary agreement initiative, with the purpose of introducing CO{sub 2} hitch-hiking strategies in local spatial planning, is

  14. CO2 emissions in the steel industry

    Directory of Open Access Journals (Sweden)

    M. Kundak

    2009-07-01

    Full Text Available Global CO2 emissions caused by the burning of fossil fuels over the past century are presented. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. Reductions in CO2 emissions as a result of technological improvements and structural changes in steel production in industrialized countries during the past 40 years are described. Substantial further reductions in those emissions will not be possible using conventional technologies. Instead, a radical cutback may be achieved if, instead of carbon, hydrogen is used for direct iron ore reduction. The cost and the ensuing CO2 generation in the production of hydrogen as a reducing agent from various sources are analysed.

  15. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration

    2016-01-01

    The Atlas Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  16. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  17. Simulation of CO2-Distribution in Fractured Oil Reservoir

    OpenAIRE

    Furuvik, Nora; Halvorsen, Britt

    2015-01-01

    Deep geologic injections and storage of Carbon dioxide (CO2) for enhanced oil recovery (EOR) are an upcoming combination due to the potential for increased oil production from depleted oilfields at the same time reducing the carbon footprint from industrial sources. CO2-EOR refers to a technique for injection of supercritical-dense CO2 into an oil reservoir. Remaining oil, not producible by primary and secondary techniques, has been successfully produced using EOR with CO2 since early 1970??....

  18. CO 2 Capture Rate Sensitivity Versus Purchase of CO 2 Quotas. Optimizing Investment Choice for Electricity Sector

    OpenAIRE

    Coussy Paula; Raynal Ludovic

    2014-01-01

    International audience; Carbon capture technology (and associated storage), applied to power plants, reduces atmospheric CO2 emissions. This article demonstrates that, in the particular case of the deployment phase of CO2 capture technology during which CO2 quota price may be low, capturing less than 90% of total CO2 emissions from power plants can be economically attractive. Indeed, for an electric power company capture technology is interesting, only if the discounted marginal cost of captu...

  19. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem

    2015-01-01

    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  20. CO2 as a refrigerant

    CERN Document Server

    2014-01-01

    A first edition, the IIR guide “CO2 as a Refrigerant” highlights the application of carbon dioxide in supermarkets, industrial freezers, refrigerated transport, and cold stores as well as ice rinks, chillers, air conditioning systems, data centers and heat pumps. This guide is for design and development engineers needing instruction and inspiration as well as non-technical experts seeking background information on a specific topic. Written by Dr A.B. Pearson, a well-known expert in the field who has considerable experience in the use of CO2 as a refrigerant. Main topics: Thermophysical properties of CO2 – Exposure to CO2, safety precautions – CO2 Plant Design – CO2 applications – Future prospects – Standards and regulations – Bibliography.

  1. Effects of Reducing Nitrogen and Biochar Application on CO2 and N2O Emissions from Summer Maize-Winter Wheat Field in North China%减氮和施生物炭对华北夏玉米-冬小麦田土壤CO2和N2O排放的影响

    Institute of Scientific and Technical Information of China (English)

    范靖尉; 白晋华; 任寰宇; 韩雪; 刁田田; 郭李萍

    2016-01-01

    from a summer maize-winter wheat field using static chamber and gas chromatography method. The results indicated that, (1)soil CO2 emission was 21.8-1022.7mg·m-2·h-1for this agriculture system and was significantly influenced by soil temperature and moisture. Soil moisture was more important for the N2O emissions during the summer maize growth period while N2O emissions during winter wheat growth period was more significantly influenced by the soil temperature. The cumulative CO2 emissions under LF and LFC treatments were significantly lower than F treatment especially during the winter wheat growing season. (2)Soil N2O emission was significantly influenced by fertilizer application and irrigation. N2O emissions during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of cumulative N2O emissions in summer maize and winter maize growing season, respectively. The peak of emission fluxes was primarily affected by fertilizer rate while irrigation determined the occurrence time when emissions would peak and could affect the mitigation effect of practices. Reduce the nitrogen application rate to 200kg·ha-1from 250kg·ha-1 could decrease cumulative N2O emissions by 15.7%-16.8% and 18.1%-18.5% during summer maize and winter wheat growing seasons, respectively, therefore decreasing nitrogen application is an effective N2O mitigation practice for high-yielding and intensive farmland. Biochar application did not show no significant influence on soil N2O mitigation of biochar application at suitable nitrogen level(200kg·ha-1) in the short term. (3)N2O emission factors of applied nitrogen were 0.60% and 0.56% for F and LF treatment, respectively, indicating that reducing the nitrogen application rate is an appropriate measure to mitigate greenhouse gas emissions without impact on crop yields in intensive farmlands in North China.

  2. Policy Options for Reducing CO2 Emissions

    Science.gov (United States)

    2008-02-01

    countries, such as financing a low-emission power plant in China. 7. See Joseph E. Aldy, Peter R. Orszag, and Joseph E. Stiglitz , “Cli- mate Change: An...tives—see Joseph E. Aldy, Peter R. Orszag, and Joseph E. Stiglitz , “Climate Change: An Agenda for Global Collective Action” (paper prepared for the...written by Terry Dinan of CBO’s Microeconomic Studies Division under the guidance of Joseph Kile and David Moore. Robert Dennis, Douglas Hamilton

  3. CO2-adapted legumes ameliorate but do not prevent the negative effect of elevated CO2 on nitrogen fixation

    Science.gov (United States)

    Newton, P.; Bowatte, S.; Lieffering, M.; Li, F.

    2015-12-01

    The response of biological nitrogen fixation (BNF) to climate and elevated CO2 (eCO2) is a key uncertainty in modelling C cycle projections. In addition, as BNF provides 50% of the nitrogen (N) input to agricultural production and as ecosystem responses to eCO2 are strongly influenced by N availability then the eCO2 impact on BNF is central to modelling legume-based system responses to climate change. Greater photoassimilate production under eCO2 should lead to enhanced BNF and this response is a feature of ecosystem models thus providing the N inputs necessary to provide continuing stimulation of NPP. FACE experiments provide a 'realistic' environment for eCO2 studies; however, even if run for multiple years, they still may not capture adaptation to eCO2 particularly in ecosystems dominated by perennial species. We tested the effect of eCO2 on BNF and the potential importance of adaption by growing legumes that had been exposed to high or ambient CO2 concentrations at a natural CO2 spring in a long-running (16 year) FACE experiment on grassland. BNF was significantly lower under eCO2 but the reduction was less marked where plants had originated in a high CO2 environment. An ecosystem model run with reduced BNF proved a better fit to the experimental data for the FACE experiment than where BNF was enhanced or unchanged under eCO2.

  4. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux.

    Science.gov (United States)

    Oishi, A Christopher; Palmroth, Sari; Johnsen, Kurt H; McCarthy, Heather R; Oren, Ram

    2014-04-01

    Soil CO2 efflux (Fsoil ) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity, but the long-term effects of these factors on Fsoil are less clear. Expanding on previous studies at the Duke Free-Air CO2 Enrichment (FACE) site, we quantified the effects of elevated [CO2] and N fertilization on Fsoil using daily measurements from automated chambers over 10 years. Consistent with previous results, compared to ambient unfertilized plots, annual Fsoil increased under elevated [CO2] (ca. 17%) and decreased with N (ca. 21%). N fertilization under elevated [CO2] reduced Fsoil to values similar to untreated plots. Over the study period, base respiration rates increased with leaf productivity, but declined after productivity saturated. Despite treatment-induced differences in aboveground biomass, soil temperature and water content were similar among treatments. Interannually, low soil water content decreased annual Fsoil from potential values - estimated based on temperature alone assuming nonlimiting soil water content - by ca. 0.7% per 1.0% reduction in relative extractable water. This effect was only slightly ameliorated by elevated [CO2]. Variability in soil N availability among plots accounted for the spatial variability in Fsoil , showing a decrease of ca. 114 g C m(-2) yr(-1) per 1 g m(-2) increase in soil N availability, with consistently higher Fsoil in elevated [CO2] plots ca. 127 g C per 100 ppm [CO2] over the +200 ppm enrichment. Altogether, reflecting increased belowground carbon partitioning in response to greater plant nutritional needs, the effects of elevated [CO2] and N fertilization on Fsoil in this stand are sustained beyond the early stages of stand development and

  5. CO2 Emission Factors for Coals

    Directory of Open Access Journals (Sweden)

    P. Orlović-Leko

    2015-03-01

    (calcite and siderite directly contribute CO2 when they decompose during coal combustion. Variations in the maceral content can also influence CO2 emissions; high inertinite contents increase CO2 emissions. Sulphur in coal reduces EF(CO2. Fuel analysis is very important when estimating greenhouse gas emissions and emission factors. In this preliminary study, based on the results of the fuel analysis, CO2 emission factors for coals and peat from Livno, B&H have been calculated. EF(CO2 is defined as the amount of carbon dioxide emission per unit net calorific values of the fuel. Net calorific value (the lower heating value corresponds to the heat produced by combustion where total water in the combustion products exists as water vapour. The EF(CO2 obtained for sub-bituminous coal, lignite and peat were: 98.7, 109.5, and 147.9 t TJ−1, respectively, which correspond to the following net calorific values: 20.6, 11.5 and 3.6 MJ kg−1. The heating value is generally known to increase with the increase in carbon content (this parameter is connected with the degree of coalification, coal age. The other indispensable parameters are hydrogen, which has a positive effect on the net calorific value, and oxygen and water which impact the net calorific value negatively. The differences in net calorific values can be explained in part by the difference of total moisture content among the different fuel types. The CO2 emission factors calculated in this study were compared with those of IPCC. A significant difference was observed for peat (39.5 %, followed by lignite (8.2 % and sub-bituminous coal (4.3 %.

  6. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim......The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  7. CO2 Sequestration short course

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald J. [Lawrence Berkeley National Laboratory; Cole, David R [The Ohio State University; Navrotsky, Alexandra [University of California-Davis; Bourg, Ian C [Lawrence Berkeley National Laboratory

    2014-12-08

    Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

  8. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    , a scenario-part and a cost-benefit part. Air and sea modes are not analyzed. The model adopts a bottom-up approach to allow a detailed assessment of transport policy measures. Four generic areas of intervention were identified and the likely effect on CO2 emissions, socioeconomic efficiency and other...... concerns of the potential measures within those intervention areas: • Reductions in the need to travel • Improved efficiency of the transport system • Improved fuel efficiency of transport activities • Reduced CO2 intensity of the fuels Within each area a number of measures were analysed. The measures...

  9. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration

    2016-01-01

    The ATLAS Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity.

  10. Membraneless water filtration using CO2

    Science.gov (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  11. Determining CO2 storage potential during miscible CO2 enhanced oil recovery: Noble gas and stable isotope tracers

    Science.gov (United States)

    Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter; Drake, Ronald; McCray, John E.

    2016-01-01

    Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination

  12. Non-CO2 greenhouse gases and climate change.

    Science.gov (United States)

    Montzka, S A; Dlugokencky, E J; Butler, J H

    2011-08-03

    Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO(2)) from fossil fuel combustion. Anthropogenic emissions of non-CO(2) greenhouse gases, such as methane, nitrous oxide and ozone-depleting substances (largely from sources other than fossil fuels), also contribute significantly to warming. Some non-CO(2) greenhouse gases have much shorter lifetimes than CO(2), so reducing their emissions offers an additional opportunity to lessen future climate change. Although it is clear that sustainably reducing the warming influence of greenhouse gases will be possible only with substantial cuts in emissions of CO(2), reducing non-CO(2) greenhouse gas emissions would be a relatively quick way of contributing to this goal.

  13. Economics show CO2 EOR potential in central Kansas

    Science.gov (United States)

    Dubois, M.K.; Byrnes, A.P.; Pancake, R.E.; Willhite, G.P.; Schoeling, L.G.

    2000-01-01

    Carbon dioxide (CO2) enhanced oil recovery (EOR) may be the key to recovering hundreds of millions of bbl of trapped oil from the mature fields in central Kansas. Preliminary economic analysis indicates that CO2 EOR should provide an internal rate of return (IRR) greater than 20%, before income tax, assuming oil sells for $20/bbl, CO2 costs $1/Mcf, and gross utilization is 10 Mcf of CO2/bbl of oil recovered. If the CO2 cost is reduced to $0.75/Mcf, an oil price of $17/bbl yields an IRR of 20%. Reservoir and economic modeling indicates that IRR is most sensitive to oil price and CO2 cost. A project requires a minimum recovery of 1,500 net bbl/acre (about 1 million net bbl/1-mile section) under a best-case scenario. Less important variables to the economics are capital costs and non-CO2 related lease operating expenses.

  14. Sensory Transduction of the CO2 Response of Guard Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Eduardo Zeiger

    2003-06-30

    Stomata have a key role in the regulation of gas exchange and intercellular CO2 concentrations of leaves. Guard cells sense internal and external signals in the leaf environment and transduce these signals into osmoregulatory processes that control stomatal apertures. This research proposal addresses the characterization of the sensory transduction of the CO2 signal in guard cells. Recent studies have shown that in Vicia leaves kept at constant light and temperature in a growth chamber, changes in ambient CO2 concentrations cause large changes in guard cell zeaxanthin that are linear with CO2-dependent changes in stomatal apertures. Research proposed here will test the hypothesis that zeaxanthin function as a transducer of CO2 signals in guard cells. Three central aspects of this hypothesis will be investigated: CO2 sensing by the carboxylation reaction of Rubisco in the guard cell chloroplast, which would modulate zeaxanthin concentrations via changes in lumen pH; transduction of the CO2 signal by zeaxanthin via a transducing cascade that controls guard cell osmoregulation; and blue light dependence of the CO2 signal transduction by zeaxanthin, required for the formation of an isomeric form of zeaxanthin that is physiologically active as a transducer. The role of Rubisco in CO2 sensing will be investigated in experiments characterizing the stomatal response to CO2 in the Arabidopsis mutants R100 and rca-, which have reduced rates of Rubisco-dependent carboxylation. The role of zeaxanthin as a CO2 transducer will be studied in npq1, a zeaxanthin-less mutant. The blue light-dependence of CO2 sensing will be studied in experiments characterizing the stomatal response to CO2 under red light. Arabidopsis mutants will also be used in further studies of an acclimation of the stomatal response to CO2, and a possible role of the xanthophyll cycle of the guard cell chloroplast in acclimations of the stomatal response to CO2. Studies on the osmoregulatory role of sucrose in

  15. Global CO2 fluxes estimated from GOSAT retrievals of total column CO2

    Directory of Open Access Journals (Sweden)

    S. Basu

    2013-09-01

    Full Text Available We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SATellite (GOSAT. We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT XCO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land–sea bias in our GOSAT XCO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO2 data (a reduces the estimated global land sink of CO2, and (b shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source–sink inversions, small spatiotemporal biases – beyond what can be detected using current validation techniques – have serious consequences for optimized fluxes, even aggregated over continental scales.

  16. Global CO2 fluxes estimated from GOSAT retrievals of total column CO2

    Directory of Open Access Journals (Sweden)

    M. Torn

    2013-02-01

    Full Text Available We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved from the Greenhouse gases Observing SATellite (GOSAT. We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT XCO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land-sea bias in our GOSAT XCO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO2 data (a reduces the estimated global land sink of CO2, and (b shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source-sink inversions, small spatiotemporal biases – beyond what can be detected using current validation techniques – have serious consequences for optimized fluxes, even aggregated over continental scales.

  17. CO2 storage capacity estimation: Methodology and gaps

    Science.gov (United States)

    Bachu, S.; Bonijoly, D.; Bradshaw, J.; Burruss, R.; Holloway, S.; Christensen, N.P.; Mathiassen, O.M.

    2007-01-01

    Implementation of CO2 capture and geological storage (CCGS) technology at the scale needed to achieve a significant and meaningful reduction in CO2 emissions requires knowledge of the available CO2 storage capacity. CO2 storage capacity assessments may be conducted at various scales-in decreasing order of size and increasing order of resolution: country, basin, regional, local and site-specific. Estimation of the CO2 storage capacity in depleted oil and gas reservoirs is straightforward and is based on recoverable reserves, reservoir properties and in situ CO2 characteristics. In the case of CO2-EOR, the CO2 storage capacity can be roughly evaluated on the basis of worldwide field experience or more accurately through numerical simulations. Determination of the theoretical CO2 storage capacity in coal beds is based on coal thickness and CO2 adsorption isotherms, and recovery and completion factors. Evaluation of the CO2 storage capacity in deep saline aquifers is very complex because four trapping mechanisms that act at different rates are involved and, at times, all mechanisms may be operating simultaneously. The level of detail and resolution required in the data make reliable and accurate estimation of CO2 storage capacity in deep saline aquifers practical only at the local and site-specific scales. This paper follows a previous one on issues and development of standards for CO2 storage capacity estimation, and provides a clear set of definitions and methodologies for the assessment of CO2 storage capacity in geological media. Notwithstanding the defined methodologies suggested for estimating CO2 storage capacity, major challenges lie ahead because of lack of data, particularly for coal beds and deep saline aquifers, lack of knowledge about the coefficients that reduce storage capacity from theoretical to effective and to practical, and lack of knowledge about the interplay between various trapping mechanisms at work in deep saline aquifers. ?? 2007 Elsevier Ltd

  18. Biosequestration of atmospheric CO2 and flue gas-containing CO2 by microalgae.

    Science.gov (United States)

    Cheah, Wai Yan; Show, Pau Loke; Chang, Jo-Shu; Ling, Tau Chuan; Juan, Joon Ching

    2015-05-01

    The unceasing rise of greenhouse gas emission has led to global warming and climate change. Global concern on this phenomenon has put forward the microalgal-based CO2 sequestration aiming to sequester carbon back to the biosphere, ultimately reducing greenhouse effects. Microalgae have recently gained enormous attention worldwide, to be the valuable feedstock for renewable energy production, due to their high growth rates, high lipid productivities and the ability to sequester carbon. The photosynthetic process of microalgae uses atmospheric CO2 and CO2 from flue gases, to synthesize nutrients for their growth. In this review article, we will primarily discuss the efficiency of CO2 biosequestration by microalgae species, factors influencing microalgal biomass productions, microalgal cultivation systems, the potential and limitations of using flue gas for microalgal cultivation as well as the bio-refinery approach of microalgal biomass.

  19. Connecting CO2. Feasibility study CO2 network Southwest Netherlands; Connecting CO2. Haalbaarheidsstudie CO2-netwerk Zuidwest-Nederland

    Energy Technology Data Exchange (ETDEWEB)

    Rutten, M.

    2009-06-10

    An overview is given of supply and demand of CO2 in the region Southwest Netherlands and the regions Antwerp and Gent in Belgium. Also attention is paid to possible connections between these regions [Dutch] Een inventarisatie wordt gegeven van vraag en aanbod van CO2 in de regio Zuidwest- Nederland en de regios Antwerpen en Gent in Belgie. Ook worden mogelijke koppelingen tussen de regios besproken.

  20. A Multi-scale Approach for CO2 Accounting and Risk Analysis in CO2 Enhanced Oil Recovery Sites

    Science.gov (United States)

    Dai, Z.; Viswanathan, H. S.; Middleton, R. S.; Pan, F.; Ampomah, W.; Yang, C.; Jia, W.; Lee, S. Y.; McPherson, B. J. O. L.; Grigg, R.; White, M. D.

    2015-12-01

    Using carbon dioxide in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce carbon sequestration costs in the absence of greenhouse gas emissions policies that include incentives for carbon capture and storage. This study develops a multi-scale approach to perform CO2 accounting and risk analysis for understanding CO2 storage potential within an EOR environment at the Farnsworth Unit of the Anadarko Basin in northern Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil-water flow and transport in the Marrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2 injection rate, CO2 first breakthrough time, CO2 production rate, cumulative net CO2 storage, cumulative oil and CH4 production, and water injection and production rates. A global sensitivity analysis indicates that reservoir permeability, porosity, and thickness are the major intrinsic reservoir parameters that control net CO2 injection/storage and oil/CH4 recovery rates. The well spacing (the distance between the injection and production wells) and the sequence of alternating CO2 and water injection are the major operational parameters for designing an effective five-spot CO2-EOR pattern. The response surface analysis shows that net CO2 injection rate increases with the increasing reservoir thickness, permeability, and porosity. The oil/CH4 production rates are positively correlated to reservoir permeability, porosity and thickness, but negatively correlated to the initial water saturation. The mean and confidence intervals are estimated for quantifying the uncertainty ranges of the risk metrics. The results from this study provide useful insights for understanding the CO2 storage potential and the corresponding risks of commercial-scale CO2-EOR fields.

  1. CO2 content of andesitic melts at graphite-saturated upper mantle conditions with implications for redox state of oceanic basalt source regions and remobilization of reduced carbon from subducted eclogite

    Science.gov (United States)

    Eguchi, James; Dasgupta, Rajdeep

    2017-03-01

    We have performed experiments to determine the effects of pressure, temperature and oxygen fugacity on the CO2 contents in nominally anhydrous andesitic melts at graphite saturation. The andesite composition was specifically chosen to match a low-degree partial melt composition that is generated from MORB-like eclogite in the convective, oceanic upper mantle. Experiments were performed at 1-3 GPa, 1375-1550 °C, and fO2 of FMQ -3.2 to FMQ -2.3 and the resulting experimental glasses were analyzed for CO2 and H2O contents using FTIR and SIMS. Experimental results were used to develop a thermodynamic model to predict CO2 content of nominally anhydrous andesitic melts at graphite saturation. Fitting of experimental data returned thermodynamic parameters for dissolution of CO2 as molecular CO2: ln( K 0) = -21.79 ± 0.04, Δ V 0 = 32.91 ± 0.65 cm3mol-1, Δ H 0 = 107 ± 21 kJ mol-1, and dissolution of CO2 as CO3 2-: ln (K 0 ) = -21.38 ± 0.08, Δ V 0 = 30.66 ± 1.33 cm3 mol-1, Δ H 0 = 42 ± 37 kJ mol-1, where K 0 is the equilibrium constant at some reference pressure and temperature, Δ V 0 is the volume change of reaction, and Δ H 0 is the enthalpy change of reaction. The thermodynamic model was used along with trace element partition coefficients to calculate the CO2 contents and CO2/Nb ratios resulting from the mixing of a depleted MORB and the partial melt of a graphite-saturated eclogite. Comparison with natural MORB and OIB data suggests that the CO2 contents and CO2/Nb ratios of CO2-enriched oceanic basalts cannot be produced by mixing with partial melts of graphite-saturated eclogite. Instead, they must be produced by melting of a source containing carbonate. This result places a lower bound on the oxygen fugacity for the source region of these CO2-enriched basalts, and suggests that fO2 measurements made on cratonic xenoliths may not be applicable to the convecting upper mantle. CO2-depleted basalts, on the other hand, are consistent with mixing between

  2. CO2 sequestration in basalts: laboratory measurements

    Science.gov (United States)

    Otheim, L. T.; Adam, L.; van Wijk, K.; McLing, T. L.; Podgorney, R. K.

    2010-12-01

    Geologic sequestration of CO2 is proposed as the only promising large-scale method to help reduce CO2 gas emission by its capture at large point sources and subsequent long-term storage in deep geologic formations. Reliable and cost-effective monitoring will be important aspect of ensuring geological sequestration is a safe, effective, and acceptable method for CO2 emissions mitigation. Once CO2 injection starts, seismic methods can be used to monitor the migration of the carbon dioxide plume. To calibrate changes in rock properties from field observations, we propose to first analyze changes in elastic properties on basalt cores. Carbon dioxide sequestration in basalt rocks results in fluid substitution and mixing of CO2 with water and rock mineralizations. Carbon dioxide sequestration in mafic rocks creates reactions such as Mg2SiO 4 + CaMgSi2O 6 + 4CO2 = Mg 3Ca(CO 3) 4 + 3SiO2 whereby primary silicate minerals within the basalt react with carbonic acid laden water to creating secondary carbonate minerals and silicates. Using time-lapse laboratory scale experiments, such as laser generated ultrasonic wave propagation; it is possible to observe small changes in the physical properties of a rock. We will show velocity and modulus measurements on three basalt core samples for different saturation. The ultimate goal of the project is to track seismic changes due to fluid substitution and mineralization. The porosity of our basalts ranges from 8% to 12%, and the P-wave velocity increases by 20% to 40% from dry to water saturated conditions. Petrographic analysis (CT-scans, thin sections, XRF, XRf) will aid in the characterization of the mineral structure in these basalts and its correlation to seismic properties changes resulting from fluid substitution and mineralization.

  3. Enhanced CO2 Dissolution in Heterogeneous Porous Media

    Science.gov (United States)

    Daniels, K.; Neufeld, J. A.; Bickle, M. J.; Hallworth, M. A.

    2014-12-01

    Long-term and secure geological storage of CO2 through technologies such as Carbon Capture and Storage (CCS) within reservoirs is seen as a technological means to reduce anthropogenic CO2 emissions. The long-term viability of this technology is reliant on the structural and secondary trapping of supercritical CO2 within heterogeneous reservoirs. Secondary trapping, primarily through the dissolution of CO2 into ambient reservoir brine to produce a denser fluid, is capable of retaining CO2 in the subsurface and thus reducing the risks of storage. To model secondary trapping we need to understand how the flow of CO2 through heterogeneous reservoir rocks enhances dissolution of supercritical CO2 in reservoir brines. Here we experimentally investigate the dissolution of CO2 in reservoir brines in layered, heterogeneous geological formations. Using analogue experiments, designed to approximate an enhanced oil recovery (EOR) setting, the processes of mixing, dispersion and dissolution are examined. These are compared against test results from non-layered, homogeneous porous media experiments. We find that heterogeneities significantly enhance mixing, particularly between adjacent porous layers. During fluid propagation, pore-scale viscous fingers grow and retreat, thereby providing an increased surface area between the flow and the ambient reservoir fluid. This enhanced mixing is predicted to substantially increase the dissolution of CO2 in reservoir brines. Both permeability and viscosity differences are found to have a significant effect on the interface between the two fluids, and therefore the likely amount of dissolution of CO2.

  4. Financial development and sectoral CO2 emissions in Malaysia.

    Science.gov (United States)

    Maji, Ibrahim Kabiru; Habibullah, Muzafar Shah; Saari, Mohd Yusof

    2017-03-01

    The paper examines the impacts of financial development on sectoral carbon emissions (CO2) for environmental quality in Malaysia. Since the financial sector is considered as one of the sectors that will contribute to Malaysian economy to become a developed country by 2020, we utilize a cointegration method to investigate how financial development affects sectoral CO2 emissions. The long-run results reveal that financial development increases CO2 emissions from the transportation and oil and gas sector and reduces CO2 emissions from manufacturing and construction sectors. However, the elasticity of financial development is not significant in explaining CO2 emissions from the agricultural sector. The results for short-run elasticities were also consistent with the long-run results. We conclude that generally, financial development increases CO2 emissions and reduces environmental quality in Malaysia.

  5. Electric field controlled CO2 capture and CO2/N2 separation on MoS2 monolayers.

    Science.gov (United States)

    Sun, Qiao; Qin, Gangqiang; Ma, Yingying; Wang, Weihua; Li, Ping; Du, Aijun; Li, Zhen

    2017-01-07

    Developing new materials and technologies for efficient CO2 capture, particularly for separation of CO2 post-combustion, will significantly reduce the CO2 concentration and its impacts on the environment. A challenge for CO2 capture is to obtain high performance adsorbents with both high selectivity and easy regeneration. Here, CO2 capture/regeneration on MoS2 monolayers controlled by turning on/off external electric fields is comprehensively investigated through a density functional theory calculation. The calculated results indicate that CO2 forms a weak interaction with MoS2 monolayers in the absence of an electric field, but strongly interacts with MoS2 monolayers when an electric field of 0.004 a.u. is applied. Moreover, the adsorbed CO2 can be released from the surface of MoS2 without any energy barrier once the electric field is turned off. Compared with the adsorption of CO2, the interactions between N2 and MoS2 are not affected significantly by the external electric fields, which indicates that MoS2 monolayers can be used as a robust absorbent for controllable capture of CO2 by applying an electric field, especially to separate CO2 from the post-combustion gas mixture where CO2 and N2 are the main components.

  6. Enhancing CO2 Capture using Robust Superomniphobic Membranes.

    Science.gov (United States)

    Geyer, Florian; Schönecker, Clarissa; Butt, Hans-Jürgen; Vollmer, Doris

    2017-02-01

    Superomniphobic membranes for post-combustion CO2 capture are introduced. Concentrated aqueous amine solutions stay on the topmost part of the membranes, providing a large liquid/CO2 interface. Wetting of the membrane, which reduces the capture efficiency, is prevented. The CO2 capture rates using the chemically, mechanically, and thermally stable superomniphobic membranes are enhanced by up to 40% relative to commercial membranes.

  7. Potential Improvements of Supercritical CO2 Brayton Cycle by Modifying Critical Point of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Seok; Lee, Jeong Ik; Jeong, Yong Hoon; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-10-15

    A Sodium-cooled Fast Reactor (SFR) is one of strong candidates for a next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is subjected to a sodium water reaction, which can deteriorate the safety of a SFR. To prevent any hazards from sodium-water reaction, a SFR with the Brayton cycle using Helium or Supercritical Carbon dioxide (S-CO2) as working fluids can be an alternative approach to improve the current SFR design. As in a helium cycle, there has been an investigation to modify thermo-physical properties to increase the efficiency of the cycle and reduce the size of turbomachineries. Particularly, He-Xe or He-N2 binary mixture were successful to decrease the stages of turbomachines due to the increment of molecular weight of gas mixture than that of pure helium. Similar to the case of helium, CO2 has a potential to modify its thermo-physical properties by mixing with other gases. For instance, it was reported that critical point of CO2 can be shifted by mixing with different gases. Since, the efficiency of a S-CO2 cycle is limited to the critical point of CO2, the shift in critical point implies that there is a possibility of improving the cycle efficiency than the current design. This paper presents the results of a preliminary analysis to identify the effects of CO2 critical point modification on the Brayton cycle performance.

  8. CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor.

    Science.gov (United States)

    Ma, Ying; Promthaveepong, Kittithat; Li, Nan

    2016-08-16

    Metallic nanoparticles (NPs) coated with stimuli-responsive polymers (SRPs) exhibit tunable optical properties responding to external stimuli and show promising sensing applications. We present a new CO2-responsive polymer, poly(N-(3-amidino)-aniline) (PNAAN), coated gold NPs (AuNPs) synthesized by directly reducing HAuCl4 with a CO2-responsive monomer N-(3-amidino)-aniline (NAAN). The amidine group of PNAAN can be protonated into a hydrophilic amidinium group by dissolved CO2 (dCO2). This induces the PNAAN to swell and detach from the AuNP surface, resulting in AuNP aggregation and color change. By monitoring the UV absorbance change of AuNPs, a sensitive dCO2 sensor with a linear range of 0.0132 to 0.1584 hPa and a limit of detection (LOD) of 0.0024 hPa is developed. This method shows dramatic improvement in sensitivity and convenience of sample preparation compared with the previously reported dCO2 sensor.

  9. CO2 Capture Rate Sensitivity Versus Purchase of CO2 Quotas. Optimizing Investment Choice for Electricity Sector

    Directory of Open Access Journals (Sweden)

    Coussy Paula

    2014-09-01

    Full Text Available Carbon capture technology (and associated storage, applied to power plants, reduces atmospheric CO2 emissions. This article demonstrates that, in the particular case of the deployment phase of CO2 capture technology during which CO2 quota price may be low, capturing less than 90% of total CO2 emissions from power plants can be economically attractive. Indeed, for an electric power company capture technology is interesting, only if the discounted marginal cost of capture is lower than the discounted marginal cost of purchased quotas. When CO2 price is low, it is interesting to have flexibility and reduce the overall capture rate of the site, by stopping the capture system of one of the combustion trains if the site has multiple ones, or by adopting less than 90% CO2 capture rate.

  10. THE DETERMINATION THE POLLUTION EMISSIONS OF SO2, NOX, CO, CO2 AND O2 FROM THE CHANNELS OF BURNT GAS ON BOILER OF 420 T/H - STEAM, IN THE SIGHT APPLICATION PROCEEDING TO REDUCE OF THESE

    Directory of Open Access Journals (Sweden)

    Valentin Nedeff

    2007-03-01

    Full Text Available The work present the results obtained after dynamic analyze the pollution emissions of SO2, NOx, CO, CO2 and O2 on evacuation channels of burnt gas on boiler of 420 t/h steam, having right the basic combustible the lignite, and auxiliary combustible the fuel oil and the natural gas. The values of pollution emission was analyze beside the admissible maxims values required by European legislation for Romania in the year 2005. The conclusion elaborated it adverted to: the values of oxides azoth, carry they frame in the limits provide in Environmental Authorization, under 60 mg/Nmc on 6% oxygen, the concentration values of SO2 which was bigger in report with one authorized comprised between 3500-3900 mg/Nmc confronted by 3400 mg/Nm. For integration in the foresee Government Decision 541/2003 aren't sufficient just proceeding of below reduce SO2, must take and another measures such as: get the fuel with quantity of sulphur 0.5% and with a content of ash below 35%.

  11. ACCURACY OF CO2 SENSORS

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.

    2008-10-01

    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  12. Warming the early Earth - CO2 reconsidered

    CERN Document Server

    Von Paris, P; Grenfell, L; Patzer, B; Hedelt, P; Stracke, B; Trautmann, T; Schreier, F

    2008-01-01

    Despite a fainter Sun, the surface of the early Earth was mostly ice-free. Proposed solutions to this so-called "faint young Sun problem" have usually involved higher amounts of greenhouse gases than present in the modern-day atmosphere. However, geological evidence seemed to indicate that the atmospheric CO2 concentrations during the Archaean and Proterozoic were far too low to keep the surface from freezing. With a radiative-convective model including new, updated thermal absorption coefficients, we found that the amount of CO2 necessary to obtain 273 K at the surface is reduced up to an order of magnitude compared to previous studies. For the late Archaean and early Proterozoic period of the Earth, we calculate that CO2 partial pressures of only about 2.9 mb are required to keep its surface from freezing which is compatible with the amount inferred from sediment studies. This conclusion was not significantly changed when we varied model parameters such as relative humidity or surface albedo, obtaining CO2 ...

  13. Bubble nucleation in polymer–CO2 mixtures.

    Science.gov (United States)

    Xu, Xiaofei; Cristancho, Diego E; Costeux, Stéphane; Wang, Zhen-Gang

    2013-10-28

    We combine density-functional theory with the string method to calculate the minimum free energy path of bubble nucleation in two polymer–CO2 mixture systems, poly(methyl methacrylate) (PMMA)–CO2 and polystyrene (PS)–CO2. Nucleation is initiated by saturating the polymer liquid with high pressure CO2 and subsequently reducing the pressure to ambient condition. Below a critical temperature (Tc), we find that there is a discontinuous drop in the nucleation barrier as a function of increased initial CO2 pressure (P0), as a result of an underlying metastable transition from a CO2-rich-vapor phase to a CO2-rich-liquid phase. The nucleation barrier is generally higher for PS–CO2 than for PMMA–CO2 under the same temperature and pressure conditions, and both higher temperature and higher initial pressure are required to lower the nucleation barrier for PS–CO2 to experimentally relevant ranges. Classical nucleation theory completely fails to capture the structural features of the bubble nucleus and severely underestimates the nucleation barrier.

  14. System-level modeling for geological storage of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    2006-04-24

    One way to reduce the effects of anthropogenic greenhousegases on climate is to inject carbon dioxide (CO2) from industrialsources into deep geological formations such as brine formations ordepleted oil or gas reservoirs. Research has and is being conducted toimprove understanding of factors affecting particular aspects ofgeological CO2 storage, such as performance, capacity, and health, safetyand environmental (HSE) issues, as well as to lower the cost of CO2capture and related processes. However, there has been less emphasis todate on system-level analyses of geological CO2 storage that considergeological, economic, and environmental issues by linking detailedrepresentations of engineering components and associated economic models.The objective of this study is to develop a system-level model forgeological CO2 storage, including CO2 capture and separation,compression, pipeline transportation to the storage site, and CO2injection. Within our system model we are incorporating detailedreservoir simulations of CO2 injection and potential leakage withassociated HSE effects. The platform of the system-level modelingisGoldSim [GoldSim, 2006]. The application of the system model is focusedon evaluating the feasibility of carbon sequestration with enhanced gasrecovery (CSEGR) in the Rio Vista region of California. The reservoirsimulations are performed using a special module of the TOUGH2 simulator,EOS7C, for multicomponent gas mixtures of methane and CO2 or methane andnitrogen. Using this approach, the economic benefits of enhanced gasrecovery can be directly weighed against the costs, risks, and benefitsof CO2 injection.

  15. Drilling and production - Economics show CO2 EOR potential

    Science.gov (United States)

    Dubois, M.K.; Byrnes, A.P.

    2000-01-01

    CO2 EOR may be the key to recovering hundreds of millions of bbl of trapped oil from the mature fields in central Kansas. A simple model aided in assessing the economics of CO2 EOR for central Kansas and the Midcontinent. The model used CO2 Prophet, a DOE freeware reservoir numerical simulation program, to determine reservoir performance, including injected and produced fluid rates, and CO2 utilization. Economic parameters, e.g., oil price, CO2 costs, capital costs, net revenue interest, production taxes, and lease operating expenses, are typical for anticipated conditions in the region and present price climate. Preliminary economic analysis shows that CO2 EOR should give an internal rate of return (IRR) > 20%, before income tax, assuming oil sells for $20/bbl, CO2 costs $1/million cu ft, and gross utilization is 10 million cu ft of CO2/bbl of oil recovered. If the CO2 is reduced to $0.75/million cu ft, an oil price of $17/bbl yields an IRR of 20%. Reservoir and economic modeling shows that IRR is most sensitive to oil price and CO2 cost.

  16. Aridity induces super-optimal investment in leaf venation by Eucalyptus and Corymbia

    Science.gov (United States)

    Drake, Paul L.; de Boer, Hugo J.; Price, Charles A.; Veneklaas, Erik J.

    2016-04-01

    The close relationship between leaf water status and stomatal conductance implies that the hydraulic architecture of leaves poses an important constraint on carbon uptake, specifically in arid environments with high evaporative demands. However, it remains uncertain how morphological, hydraulic and photosynthetic traits are coordinated to achieve optimal leaf functioning in arid environments. Zwieniecki and Boyce (2014) proposed a generic framework on the hydraulic architecture of leaves based on the argument that water is optimally distributed when the lateral distance between neighboring water transport veins (dx) is approximately equal to the distance from these veins to the epidermis (dy), expressed as dx:dy ≈1. Many derived angiosperms realize this optimal hydraulic architecture by closely coordinating leaf vein density with leaf thickness and the lateral position of veins inside the leaf. Zwieniecki and Boyce (2014) further suggested that over-investment in veins (dx:dy photosynthetic traits of 65 species (401 individuals) within the widely distributed and closely related genera Eucalyptus and Corymbia along a 2000-km-long aridity gradient in Western Australia (see Schulze et al., 2006). We inferred the potential functional benefit of reducing dx beyond dy using a semi-empirical model that links leaf morphology and hydraulics to photosynthesis. Our results reveal that Eucalyptus and Corymbia evolved extremely high vein densities in addition to thick amphistomatous leaf morphologies along the natural aridity gradient resulting in dx:dy ratios ranging between 0.8 and 0.08. We propose that as the thickness of amphistomatous leaves increases, the effect of reducing dx beyond dy is to offset the reduction in photosynthesis that would result from the theoretical optimal architecture of dx:dy ≈1. Our model quantified the resulting relative gain in photosynthesis at 10% to 15%, which could provide a crucial gas exchange advantage. We conclude that aridity

  17. Geothermal energy combined with CO2 sequestration: An additional benefit

    NARCIS (Netherlands)

    Salimi, H.; Wolf, K.H.A.A.; Bruining, J.

    2012-01-01

    In this transition period from a fossil-fuel based society to a sustainable-energy society, it is expected that CO2 capture and subsequent sequestration in geological formations plays a major role in reducing greenhouse gas emissions. An alternative for CO2 emission reduction is to partially replace

  18. New methodologies for integrating algae with CO2 capture

    NARCIS (Netherlands)

    Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

    2014-01-01

    It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient fe

  19. CO2 Fixation by Membrane Separated NaCl Electrolysis

    DEFF Research Database (Denmark)

    Park, Hyun Sic; Lee, Ju Sung; Han, Junyoung;

    2015-01-01

    Atmospheric concentrations of carbon dioxide (CO2), a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS), which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical...

  20. New methodologies for integrating algae with CO2 capture

    NARCIS (Netherlands)

    Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

    2014-01-01

    It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient

  1. New methodologies for integrating algae with CO2 capture

    NARCIS (Netherlands)

    Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

    2014-01-01

    It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient fe

  2. Geothermal energy combined with CO2 sequestration: An additional benefit

    NARCIS (Netherlands)

    Salimi, H.; Wolf, K.H.A.A.; Bruining, J.

    2012-01-01

    In this transition period from a fossil-fuel based society to a sustainable-energy society, it is expected that CO2 capture and subsequent sequestration in geological formations plays a major role in reducing greenhouse gas emissions. An alternative for CO2 emission reduction is to partially replace

  3. Electrocatalytic CO2 conversion to oxalate by a copper complex

    NARCIS (Netherlands)

    Angamuthu, R.; Byers, P.; Lutz, M.; Spek, A.L.; Bouwman, E.

    2010-01-01

    Global warming concern has dramatically increased interest in using CO2 as a feedstock for preparation of value-added compounds, thereby helping to reduce its atmospheric concentration. Here, we describe a dinuclear copper(I) complex that is oxidized in air by CO2 rather than O2; the product is a te

  4. Transport Mechanisms for CO2-CH4 Exchange and Safe CO2 Storage in Hydrate-Bearing Sandstone

    Directory of Open Access Journals (Sweden)

    Knut Arne Birkedal

    2015-05-01

    Full Text Available CO2 injection in hydrate-bearing sediments induces methane (CH4 production while benefitting from CO2 storage, as demonstrated in both core and field scale studies. CH4 hydrates have been formed repeatedly in partially water saturated Bentheim sandstones. Magnetic Resonance Imaging (MRI and CH4 consumption from pump logs have been used to verify final CH4 hydrate saturation. Gas Chromatography (GC in combination with a Mass Flow Meter was used to quantify CH4 recovery during CO2 injection. The overall aim has been to study the impact of CO2 in fractured and non-fractured samples to determine the performance of CO2-induced CH4 hydrate production. Previous efforts focused on diffusion-driven exchange from a fracture volume. This approach was limited by gas dilution, where free and produced CH4 reduced the CO2 concentration and subsequent driving force for both diffusion and exchange. This limitation was targeted by performing experiments where CO2 was injected continuously into the spacer volume to maintain a high driving force. To evaluate the effect of diffusion length multi-fractured core samples were used, which demonstrated that length was not the dominating effect on core scale. An additional set of experiments is presented on non-fractured samples, where diffusion-limited transportation was assisted by continuous CO2 injection and CH4 displacement. Loss of permeability was addressed through binary gas (N2/CO2 injection, which regained injectivity and sustained CO2-CH4 exchange.

  5. Density-driven enhanced dissolution of injected CO2 during long-term CO2 geological storage

    Indian Academy of Sciences (India)

    Wei Zhang

    2013-10-01

    Geological storage of CO2 in deep saline formations is increasingly seen as a viable strategy to reduce the release of greenhouse gases into the atmosphere. However, possible leakage of injected CO2 from the storage formation through vertical pathways such as fractures, faults and abandoned wells is a huge challenge for CO2 geological storage projects. Thus, the density-driven fluid flow as a process that can accelerate the phase change of injected CO2 from supercritical phase into aqueous phase is receiving more and more attention. In this paper, we performed higher-resolution reactive transport simulations to investigate the possible density-driven fluid flow process under the ‘real’ condition of CO2 injection and storage. Simulation results indicated that during CO2 injection and geological storage in deep saline formations, the higher-density CO2-saturated aqueous phase within the lower CO2 gas plume migrates downward and moves horizontally along the bottom of the formation, and the higher-density fingers within the upper gas plume propagate downward. These density-driven fluid flow processes can significantly enhance the phase transition of injected CO2 from supercritical phase into aqueous phase, consequently enhancing the effective storage capacity and long-term storage security of injected CO2 in saline formations.

  6. Monitoring subsurface CO2 storage

    NARCIS (Netherlands)

    Winthaegen, P.; Arts, R.; Schroot, B.M.

    2005-01-01

    An overview is given of various currently applied monitoring techniques for CO2 storage. Techniques are subdivided in correspondence to their applicability for monitoring three distinct realms. These are: - the atmosphere and the near-surface; - the overburden (including faults and wells); - the

  7. Changes in the deep subsurface microbial biosphere resulting from a field-scale CO2 geosequestration experiment

    OpenAIRE

    Andre eMu; Chris eBoreham; Leong, Henrietta X.; Ralf eHaese; Moreau, John W.

    2014-01-01

    Subsurface microorganisms may respond to increased CO2 levels in ways that significantly affect pore fluid chemistry. Changes in CO2 concentration or speciation may result from the injection of supercritical CO2 (scCO2) into deep aquifers. Therefore, understanding subsurface microbial responses to scCO2, or unnaturally high levels of dissolved CO2, will help to evaluate the use of geosequestration to reduce atmospheric CO2 emissions. This study characterized microbial community changes at the...

  8. IMPACT OF CO2 ENHANCEMENT ON PHOTOSYNTHESIS AND PROTEIN PROFILE -RESPONSE STUDIES WITH A CO2 RESPONSIVE BLACK GRAM GENOTYPE

    Directory of Open Access Journals (Sweden)

    P. Sathish

    2014-09-01

    Full Text Available Black gram (Vigna mungo (L. Hepper var. IC-282009 - a highly CO2 responsive genotype for biomass and seed yield was grown in Open top chambers (OTCs under three levels of CO2 i.e. ambient (390 ppm and two elevated levels 550ppm and 700ppm to assess photosynthetic acclimation to elevated CO2. Net photosynthetic rate (PN, change in leaf soluble protein profile and leaf carbohydrate constituents such as total soluble sugars, reducing sugars and starch content in leaves was quantified at all three CO2 concentrations. Photosynthetic rate was enhanced by 78% and 30% at flowering stage with 550ppm and 700ppm CO2 as compared with ambient control. It was also observed a higher accumulation of starch, total soluble sugars and reducing sugars in leaves at elevated CO2 levels. However, the leaf protein content recorded a decrease and altered the profile of ploy peptides with enhanced CO2 levels. At elevated CO2 concentrations significant differences were observed in ploy peptide profile at vegetative and flowering stages, the intensity of 260 kDa poly peptide increased at vegetative stage, whereas 72 kDa polypeptide increased at flowering stage, while 52 kDa poly peptide decreased at both stages. Enhanced CO2 concentrations improved the PN though certain polypeptides of leaf protein are down regulated and necessitate further experimentation to confirm their involvement in responsiveness of the selected black gram genotype

  9. CO2 acclimation impacts leaf isoprene emissions: evidence from past to future CO2 levels

    Science.gov (United States)

    de Boer, Hugo; van der Laan, Annick; Dekker, Stefan; Holzinger, Rupert

    2017-04-01

    Isoprene is emitted by many plant species as a side-product of photosynthesis. Once in the atmosphere, isoprene exhibits climate forcing through various feedback mechanisms. In order to quantify the climate feedbacks of biogenic isoprene emission it is crucial to establish how isoprene emissions are effected by plant acclimation to rising atmospheric CO2 levels. A promising development for modelling CO2-induced changes in isoprene emissions is the Leaf-Energetic-Status model (referred to as LES-model hereafter, see Harrison et al., 2013 and Morfopoulos et al., 2014). This model simulates isoprene emissions based on the hypothesis that isoprene biosynthesis depends on the imbalance between the photosynthetic electron supply of reducing power and the electron demands of carbon fixation. The energetic imbalance is critically related to the photosynthetic electron transport capacity (Jmax) and the maximum carboxylation capacity of Rubisco (Vcmax). Here we compare predictions of the LES-model with observed isoprene emission responses of Quercus robur (pedunculate oak) specimen that acclimated to CO2 growth conditions representative of the last glacial, the present and the end of this century (200, 400 and 800 ppm, respectively) for two growing seasons. These plants were grown in walk-in growth chambers with tight control of light, temperature, humidity and CO2 concentrations. Photosynthetic biochemical parameters Vcmax and Jmax were determined with a Licor LI-6400XT photosynthesis system. The relationship between photosynthesis and isoprene emissions was measured by coupling the photosynthesis system with a Proton-Transfer Reaction Time-of-Flight Mass Spectrometer. Our empirical results support the LES-model and show that the fractional allocation of carbon to isoprene biosynthesis is reduced in response to both short-term and long-term CO2 increases. In the short term, an increase in CO2 stimulates photosynthesis through an increase in the leaf interior CO2

  10. Directed technical change and the adoption of CO2 abatement technology: The case of CO2 capture and storage

    NARCIS (Netherlands)

    Otto, V.M.; Reilly, J.

    2008-01-01

    This paper studies the cost-effectiveness of combining traditional environmental policy, such as CO2-trading schemes, and technology policy that has aims of reducing the cost and speeding the adoption of CO2 abatement technology. For this purpose, we develop a dynamic general equilibrium model that

  11. Directed technical change and the adoption of CO2 abatement technology: The case of CO2 capture and storage

    NARCIS (Netherlands)

    Otto, V.M.; Reilly, J.

    2008-01-01

    This paper studies the cost-effectiveness of combining traditional environmental policy, such as CO2-trading schemes, and technology policy that has aims of reducing the cost and speeding the adoption of CO2 abatement technology. For this purpose, we develop a dynamic general equilibrium model that

  12. Excitation of CO2/+/ by electron impact on CO2

    Science.gov (United States)

    Mentall, J. E.; Coplan, M. A.; Kushlis, R. J.

    1973-01-01

    Consideration of a discrepancy concerning the correct value of the cross section for excitation of the CO2(+) B state by electron impact on CO2. It is suggested that the reason for the disparate results obtained by various authors for the B state can be traced to a calibration error due to scattered light. In particular, the tungsten filament lamps used in the experiments cited have very low intensity at wavelengths below 3000 A where the B state emissions occur, so that even a small amount of scattered light in the spectrometer will produce a large error in the measured cross section. In a remeasurement of the cross section for excitation of the B state at an energy of 150 eV it was found that at 2900 A the scattered light signal, if uncorrected for, would introduce an error of about 50%.

  13. CO2 cooling for HEP experiments

    CERN Document Server

    Verlaat; Van Lysebetten, A

    2008-01-01

    The new generation silicon detectors require more efficient cooling of the front-end electronics and the silicon sensors themselves. To minimize reverse annealing of the silicon sensors the cooling temperatures need to be reduced. Other important requirements of the new generation cooling systems are a reduced mass and a maintenance free operation of the hardware inside the detector. Evaporative CO2 cooling systems are ideal for this purpose as they need smaller tubes than conventional systems. The heat transfer capability of evaporative CO2 is high. CO2 is used as cooling fluid for the LHCb-VELO and the AMS-Tracker cooling systems. A special method for the fluid circulation is developed at Nikhef to get a very stable temperature of both detectors without any active components like valves or heaters inside. This method is called 2-phase Accumulator Controlled Loop (2PACL) and is a good candidate technology for the design of the future cooling systems for the Atlas and CMS upgrades.

  14. CO2 reduction using adsorption followed by nonthermal plasma treatment

    Science.gov (United States)

    Nakajima, Kenji; Takahashi, Kazuya; Tanaka, Masanari; Kuroki, Tomoyuki; Okubo, Masaaki

    2015-10-01

    Carbon dioxide (CO2) is one of the main substances linked to global warming, and its emission should be reduced. In this study, a CO2 reduction treatment using an adsorbent and a nonthermal plasma flow is investigated. This treatment comprises a physical adsorption process and nitrogen (N2) plasma reduction process. In the physical adsorption process, CO2 is adsorbed by the adsorbent. In the N2 plasma reduction process, the adsorbed CO2 is reduced to CO by a nonthermal plasma flow that is generated by a plasma reactor with a circulating N2 plasma flow. The generated CO can be reused as a fuel. We estimate this experimental results by calculating conversion efficiency of CO2 to CO. In the N2 plasma reduction process, the CO concentration reaches approximately 1%, regardless of the number of experiments, and conversion efficiency reaches at most 5.3%.

  15. CO2 Sink/Source in the Indonesian Seas

    KAUST Repository

    Kartadikaria, Aditya R.

    2015-04-01

    Two distinct CO2 sink/source characteristics appeared from the compiled observed data 1984-2013 in the tropical Indonesian seas. The western part persistently emits CO2 to the atmosphere, while the eastern is rather dynamic which emits and absorbs smaller amount of CO2 to and from atmosphere, respectively. The segregation is proximal to the virtual Wallace line, where in the continental shelf is located. Lower salinity and higher silicate condition in the western part influenced the higher pCO2 condition in Java Sea. Temperature is found to have a limited influence to control different characteristic in the west and east, but SST change of 2.0 0C during La Ninã condition effectively reduced the source amount of CO2 by 50% compared to Normal year condition. Yet, during La Ninã, higher wind speed increases CO2 flux twice compared to Normal year. In the continental shelf area where CO2 sink area is found, 29 years data showed that pCO2 trend is increasing ±0.6-3.8 μatm/year. From this study, the overall areas have a significant source of CO2 of approximately 10 - 24 μatm.

  16. THE INFLUENCE OF CO2 ON WELL CEMENT

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    2010-12-01

    Full Text Available Carbon capture and storage is one way to reduce emissions of greenhouse gases in the atmosphere. Underground gas storage operations and CO2 sequestration in aquifers relay on both the proper wellbore construction and sealing properties of the cap rock. CO2 injection candidates may be new wells or old wells. In both cases, the long-term wellbore integrity (up to 1 000 years is one of the key performance criteria in the geological storage of CO2. The potential leakage paths are the migration CO2 along the wellbore due to poor cementation and flow through the cap rock. The permeability and integrity of the set cement will determine how effective it is in preventing the leakage. The integrity of the cap rock is assured by an adequate fracture gradient and by sufficient set cement around the casing across the cap rock and without a micro-annulus. CO2 storage in underground formations has revived the researc of long term influence of the injected CO2 on Portland cements and methods for improving the long term efficiency of the wellbore sealant. Some researchers predicted that set cement will fail when exposed to CO2 leading to potential leakage to the atmosphere or into underground formations that may contain potable water. Other researchers show set cement samples from 30 to 50 year-old wells (CO2 EOR projects that have maintained sealing integrity and prevented CO2 leakage, in spite of some degree of carbonation. One of reasons for the discrepancy between certain research lab tests and actual field performance measurements is the absence of standard protocol for CO2 resistance-testing devices, conditions, or procedures. This paper presents potential flow paths along the wellbore, CO2 behaviour under reservoir conditions, and geochemical alteration of hydrated Portland cement due to supercritical CO2 injection.

  17. CO2 injection along a pipeline with transient approach

    Science.gov (United States)

    Bezos, Víctor; Carrera, Jesús; Slooten, Luit Jan; Silva, Orlando; Bear, Jacob; Kitro-Belinkov, Myra

    2013-04-01

    CO2 geological sequestration involves several processes. One of the more relevant of these processes is the CO2 injection along a pipeline, because it links the capture and transport of CO2 with its deep geological storage. The knowledge of the CO2 behavior within injection and monitoring wells is essential for designing efficient CO2 storage strategies. In particular, a thorough modeling and simulation of CO2 flow through the injection pipe is required to define operational protocols and to design the surface CO2 conditioning facilities. Much work has been performed on modeling the steady state multiphase flow in wellbores during CO2 injection. However, relevant problems, including the displacement of the initial brine in the injection well, or the upwards flow of CO2 during a push-pull test, require the modeling of transient conditions, which is the goal of the present work. Here, we present the governing equations and preliminary results for the modeling of dynamic non isothermal CO2 flow through an injection well, including displacement of the initial brine. The model considers continuity, momentum and energy equations, together with equations of state and some thermodynamic relations. These equations are solved using the simulation framework "Proost", which implements the finite element method. The code is verified by comparison with a steady-state solver for a range of surface injection conditions. The results obtained show pressure, velocity and temperature evolution, which allows quantifying the phase changes that gradually experiment the CO2 through the injection pipe. We find the surface pressure required initially is much higher than steady-state because heat exchange with the formation reduces significantly the density of CO2 at the borehole.

  18. Ambient CO2, fish behaviour and altered GABAergic neurotransmission: exploring the mechanism of CO2-altered behaviour by taking a hypercapnia dweller down to low CO2 levels.

    Science.gov (United States)

    Regan, Matthew D; Turko, Andy J; Heras, Joseph; Andersen, Mads Kuhlmann; Lefevre, Sjannie; Wang, Tobias; Bayley, Mark; Brauner, Colin J; Huong, Do Thi Thanh; Phuong, Nguyen Thanh; Nilsson, Göran E

    2016-01-01

    Recent studies suggest that projected rises of aquatic CO2 levels cause acid-base regulatory responses in fishes that lead to altered GABAergic neurotransmission and disrupted behaviour, threatening fitness and population survival. It is thought that changes in Cl(-) and HCO3 (-) gradients across neural membranes interfere with the function of GABA-gated anion channels (GABAA receptors). So far, such alterations have been revealed experimentally by exposing species living in low-CO2 environments, like many oceanic habitats, to high levels of CO2 (hypercapnia). To examine the generality of this phenomenon, we set out to study the opposite situation, hypothesizing that fishes living in typically hypercapnic environments also display behavioural alterations if exposed to low CO2 levels. This would indicate that ion regulation in the fish brain is fine-tuned to the prevailing CO2 conditions. We quantified pH regulatory variables and behavioural responses of Pangasianodon hypophthalmus, a fish native to the hypercapnic Mekong River, acclimated to high-CO2 (3.1 kPa) or low-CO2 (0.04 kPa) water. We found that brain and blood pH was actively regulated and that the low-CO2 fish displayed significantly higher activity levels, which were reduced after treatment with gabazine, a GABAA receptor blocker. This indicates an involvement of the GABAA receptor and altered Cl(-) and HCO3 (-) ion gradients. Indeed, Goldman calculations suggest that low levels of environmental CO2 may cause significant changes in neural ion gradients in P. hypophthalmus. Taken together, the results suggest that brain ion regulation in fishes is fine-tuned to the prevailing ambient CO2 conditions and is prone to disruption if these conditions change.

  19. Fang CO2 med Aminosyrer

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai

    2010-01-01

    Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer.......Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer....

  20. Enhancement of local air pollution by urban CO(2) domes.

    Science.gov (United States)

    Jacobson, Mark Z

    2010-04-01

    Data suggest that domes of high CO(2) levels form over cities. Despite our knowledge of these domes for over a decade, no study has contemplated their effects on air pollution or health. In fact, all air pollution regulations worldwide assume arbitrarily that such domes have no local health impact, and carbon policy proposals, such as "cap and trade", implicitly assume that CO(2) impacts are the same regardless of where emissions occur. Here, it is found through data-evaluated numerical modeling with telescoping domains from the globe to the U.S., California, and Los Angeles, that local CO(2) emissions in isolation may increase local ozone and particulate matter. Although health impacts of such changes are uncertain, they are of concern, and it is estimated that that local CO(2) emissions may increase premature mortality by 50-100 and 300-1000/yr in California and the U.S., respectively. As such, reducing locally emitted CO(2) may reduce local air pollution mortality even if CO(2) in adjacent regions is not controlled. If correct, this result contradicts the basis for air pollution regulations worldwide, none of which considers controlling local CO(2) based on its local health impacts. It also suggests that a "cap and trade" policy should consider the location of CO(2) emissions, as the underlying assumption of the policy is incorrect.

  1. Influence of Sulfate-reducing Bacteria on the Carbon Dioxide Corrosion Behavior of X60 Steel%硫酸盐还原菌对X60钢CO2腐蚀行为的影响

    Institute of Scientific and Technical Information of China (English)

    范梅梅; 赵勇; 闫化云; 刘宏芳

    2010-01-01

    采用API-RP38培养基,从油田含油污水中分离出硫酸盐还原茵(SRB),研究了该菌种的生长特性.用腐蚀失重实验和电化学手段系统地研究了CO2饱和的油田污水中SRB对X60钢CO:腐蚀行为的影响.结果表明,SRB最佳生长温度为30℃,最佳生长pH值为7.5;30℃时SRB的存在减缓了CO2腐蚀,此温度下SRB细胞、胞外聚合物和腐蚀产物能够形成致密膜层,腐蚀产物主要是FeS和FeCO3;随温度升高,SRB的存在会加速CO2腐蚀,且SRB与CO2之间产生协同作用,促进基体材料的腐蚀破坏.

  2. Diamino protic ionic liquids for CO2 capture.

    Science.gov (United States)

    Vijayraghavan, R; Pas, Steven J; Izgorodina, Ekaterina I; MacFarlane, Douglas R

    2013-12-14

    A series of multifunctional protic ionic liquids (PILs), some of which are based on a combination of primary and tertiary amines in the same moiety coupled with a carboxylic acid, have been synthesised and employed for CO2 capture, yielding absorption capacities comparable to standard absorbents. In contrast to traditional amine absorbers, CO2 was found to desorb at lower temperatures and hence could result in a significant reduction in both the energy required to strip the absorber of CO2 and the thermally activated degradation mechanisms, which in traditional absorbers result in the loss of absorber and the production of toxic compounds. The lower basicity of the amine sites resultant from PIL formation decreases the binding energy of the CO2 to the absorber. The weaker basicity is also evidenced by lower pH of the PIL CO2 absorbers, which reduces common corrosion problems associated with traditional amine absorbers.

  3. Subsurface impact of CO2: Response of carbonate rocks and wellbore cement to supercritical CO2 injection and long-term storage. Geologica Ultraiectina (310)

    NARCIS (Netherlands)

    Liteanu, E.

    2009-01-01

    Capture of CO2 at fossil fuel power station coupled with geological storage in empty oil and gas reservoirs is widely viewed as the most promising option for reducing CO2 emissions to the atmosphere, i.e. for climate change mitigation. Injection of CO2 into such reservoirs will change their chemical

  4. RODZAJE METOD SEKWESTRACJI CO2

    Directory of Open Access Journals (Sweden)

    Zofia LUBAŃSKA

    Full Text Available Z pojęciem ochrony środowiska wiąże się bardzo szeroko w ostatnim czasie omawiane zagadnienie dotyczące ograniczenia emisji CO2. Konsekwencją globalnych zmian klimatu wywołanego przez ludzi jest wzrost stężenia atmosferycznego gazów cieplarnianych, które powodują nasilający się efekt cieplarniany. Wzrasta na świecie liczba ludności, a co za tym idzie wzrasta konsumpcja na jednego mieszkańca, szczególnie w krajach szeroko rozwiniętych gospodarczo. Protokół z Kioto ściśle określa działania jakie należy podjąć w celu zmniejszenia stężenia dwutlenku węgla w atmosferze. Pomimo maksymalnej optymalizacji procesu spalania paliw kopalnianych wykorzystywanych do produkcji energii, zastosowania odnawialnych źródeł energii zmiana klimatu jest nieunikniona i konsekwentnie będzie postępować przez kolejne dekady. Prognozuje się, że duże znaczenie odegra nowoczesna technologia, która ma za zadanie wychwycenie CO2 a następnie składowanie go w odpowiednio wybranych formacjach geologicznych (CCS- Carbon Capture and Storage. Eksperci są zgodni, że ta technologia w niedalekiej przyszłości stanie się rozwiązaniem pozwalającym ograniczyć ogromną ilość emisji CO2 pochodzącą z procesów wytwarzania energii z paliw kopalnych. Z analiz Raportu IPCC wynika, iż technologia CSS może się przyczynić do ok. 20% redukcji emisji dwutlenku węgla przewidzianej do 2050 roku [3]. Zastosowanie jej napotyka na wiele barier, nie tylko technologicznych i ekonomicznych, ale także społecznych. Inną metodą dającą ujemne źródło emisji CO2 jest możliwość wykorzystania obszarów leśnych o odpowiedniej strukturze drzewostanu. Środkiem do tego celu, oprócz ograniczenia zużycia emisjogennych paliw kopalnych (przy zachowaniu zasad zrównoważonego rozwoju może być intensyfikacja zalesień. Zwiększanie lesistości i prawidłowa gospodarka leśna należy do najbardziej efektywnych sposobów kompensowania

  5. Surface Condensation of CO2 onto Kaolinite

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; Glezakou, Vassiliki Alexandra; Owen, Antionette T.; Ramprasad, Sudhir; Martin, Paul F.; McGrail, B. Peter

    2014-02-11

    The fundamental adsorption behavior of gaseous and supercritical carbon dioxide (CO2) onto poorly crystalline kaolinite (KGa-2) at conditions relevant to geologic sequestration has been investigated using a quartz crystal microbalance (QCM) and density functional theory (DFT) methods. The QCM data indicated linear adsorption of CO2 (0-0.3 mmol CO2/g KGa-2) onto the kaolinite surface up through the gaseous state (0.186 g/cm3). However in the supercritical region, CO2 adsorption increases dramatically, reaching a peak (0.9-1.0 mmol CO2/g KGa-2) near 0.43 g/cm3, before declining rapidly to surface adsorption values equivalent or below gaseous CO2. This adsorption profile was not observed with He or N2. Comparative density functional studies of CO2 interactions with kaolinite surface models rule out CO2 intercalation and confirm that surface adsorption is favored up to approximately 0.35 g/cm3 of CO2, showing distorted T-shaped CO2-CO2 clustering, typical of supercritical CO2 aggregation over the surface as the density increases. Beyond this point, the adsorption energy gain for any additional CO2 becomes less than the CO2 interaction energy (~0.2 eV) in the supercritical medium resulting in overall desorption of CO2 from the kaolinite surface.

  6. CO2 Removal from Biogas by Water Washing System

    Institute of Scientific and Technical Information of China (English)

    Yong Xiao; Hairong Yuan; Yunzhi Pang; Shulin Chen; Baoning Zhu; Dexun Zou; Jingwei Ma; Liang Yu; Xiujin Li

    2014-01-01

    CO2 removal from biogas by water washing system was investigated with various parameters, including liquid/gas ratio, pressure, temperature, and CO2 content. The results indicate that CO2 removal ratio could reach 34.6%-94.2%as liquid/gas ratio increased from 0.14 to 0.50. Increasing pressure (from 0.8 to 1.2 MPa) could improve gas purification with a constant inflow rate of gas. Temperature played a key role in the process and lower temper-ature in absorption tower was beneficial for reducing CO2 content. CO2 removal ratio could reach 24.4%-83.2%when CO2 content in the simulated gas was 25%-45%. The lowest CO2 content after absorption was 2.6%at 1.2 MPa with 400 L·h-1 gas flow and 200 L·h-1 water flow, which meets the requirement of CO2 content in natural gas for vehicle fuel.

  7. MODEL SIMULASI EMISI DAN PENYERAPAN CO2 DI KOTA BOGOR

    Directory of Open Access Journals (Sweden)

    Rizka Permatayakti Rasyidta Nur

    2015-04-01

    Full Text Available Most of the urban pollution is the result of carbon dioxide (CO2 emission from human activities. This research identified CO2 emission and absorption in Bogor, and also the alternatives to solve the emission problem by system model and simulation. CO2 emission and absorption system model was created using software Stella 9.0.2 based on loss-gain emission concept for 30 years prediction. Human activities that contribute to CO2 emission are transportation, industries, energy consumption such as fuel or electricity, house hold waste, and farms, while the decrease factor is green open spaces as CO2 sequester. The alternatives to solve emission problem in Bogor is created based on green city concept by including the environmental aspects in every urban activity. The result of this research, the CO2 emission of Bogor reached 20.027.878 tons and the absorption reached 93.843 tons in 2042. Combined mitigation alternatives in several sectors could reduce CO2 emission by 2.797.667 tons in 2042 and CO2 emission could be neutralized by reforestation in 2036.

  8. CO2 Abatement In The Iron And Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

    The iron and steel industry is the largest industrial source of CO2 emissions due to the energy intensity of steel production, its reliance on carbon-based fuels and reductants, and the large volume of steel produced -- over 1414 Mt in 2010. With the growing concern over climate change, steel makers are faced with the challenge of finding ways of lowering CO2 emissions without seriously undermining process efficiency or considerably adding to costs. This report examines ways of abating CO2 emissions from raw materials preparation (coking, sintering and pelletising plants) through to the production of liquid steel in basic oxygen furnaces and electric arc furnaces. Direct reduction and smelting reduction processes are covered, as well as iron making in a blast furnace. A range of technologies and measures exist for lowering CO2 emissions including minimising energy consumption and improving energy efficiency, changing to a fuel and/or reducing agent with a lower CO2 emission factor (such as wood charcoal), and capturing the CO2 and storing it underground. Significant CO2 reductions can be achieved by combining a number of the available technologies. If carbon capture and storage is fitted than steel plants could become near zero emitters of CO2.

  9. Target atmospheric CO2: Where should humanity aim?

    CERN Document Server

    Hansen, J; Kharecha, P; Beerling, D; Masson-Delmotte, V; Pagani, M; Raymo, M; Royer, D L; Zachos, J C

    2008-01-01

    Paleoclimate data show that climate sensitivity is ~3 deg-C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6 deg-C for doubled CO2 for the range of climate states between glacial conditions and ice-free Antarctica. Decreasing CO2 was the main cause of a cooling trend that began 50 million years ago, large scale glaciation occurring when CO2 fell to 425 +/- 75 ppm, a level that will be exceeded within decades, barring prompt policy changes. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm. The largest uncertainty in the target arises from possible changes of non-CO2 forcings. An initial 350 ppm CO2 target may be achievable by phasing out coal use except where CO2 is captured and adopting agricultural and forestry practice...

  10. Responses of soil CO2 efflux to changes in plant CO2 uptake and transpiration

    Science.gov (United States)

    Balogh, János; de Luca, Giulia; Mészáros, Ádám; Trieber, Júlia; Gecse, Bernadett; Fóti, Szilvia; Pintér, Krisztina; Nagy, Zoltán

    2017-04-01

    Biotic drivers of soil respiration represent a significant supply-side (plant) control of the process. Those biotic drivers that integrate over longer time periods are useful in describing the phenological changes and physiological state of the vegetation, but they are not suitable to explain the diel variability of soil respiration. Two plant physiological processes, acting in opposite directions, could be relevant at diel timescale: (1) photosynthesis, and (2) transpiration. Firstly, it was recently found that photosynthesis has a time-lagged (a few hours) positive effect on the respiration of roots and root-associated microbes. This can be explainedby an increase in easily accessible non-structural hydrocarbon sources for the roots and root-associated organisms within this period. Secondly, it was found that the effect of transpiration could reduce root respiration due to CO2 transport through the transpiration stream, and this effect is expected to be immediate. Removing the effect of the abiotic drivers from the soil efflux signal could help to clarify the role of other driving variables. In the present study, we conducted manipulation measurements in lab environment to be able to detect the effects of the plant physiological variables (CO2 uptake, transpiration) on soil CO2 efflux. Plant individuals were planted into field soil samples in small pots. Transpiration manipulation was done by regulating vapour pressure of the air around the plant canopy and by inhibitors. Photosynthesis manipulation consisted of programmed absence of light. Isotopic signatures of soil respiration were used for estimating the contribution of the autotrophic and heterotrophic soil respiration components. 13CO2 concentration of the CO2 efflux of the different soil components was measured continuously in open system by cavity ring-down spectroscopy (Picarro G1101-i gas analyser). Keeling-plot approach was also used to calculate the isotopic signals of the sources. According to the

  11. Improving the CO2 performance of cement, part II : Framework for assessing CO2 improvement measures in cement industry

    OpenAIRE

    2015-01-01

    Cement production is among the largest anthropogenic sources of carbon dioxide (CO2) and there is considerable pressure on the cement industry to reduce these emissions. In the effort to reduce CO2 emissions, there is a need for methods to systematically identify, classify and assess different improvement measures, to increase the knowledge about different options and prioritize between them. For this purpose a framework for assessment has been developed, inspired by common approaches within ...

  12. Energy Consumption and Net CO2 Sequestration of Aqueous Mineral Carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.; Comans, R.N.J.; Witkamp, G.J.; Ruijg, G.J.

    2006-01-01

    Aqueous mineral carbonation is a potentially attractive sequestration technology to reduce CO2 emissions. The energy consumption of this technology, however, reduces the net amount of CO2 sequestered. Therefore, the energetic CO2 sequestration efficiency of aqueous mineral carbonation was studied in

  13. Reduction of CO2-TO-graphite conversion time of organic materials for 14C AMS

    DEFF Research Database (Denmark)

    Thomsen, M.S.; Gulliksen, S.

    1992-01-01

    that reduces the impurity content of CO2 produced by combustion of organic material. We found that using water during combustion reduces the average time for graphite conversion of CO2 from organic matter from >3 h to ca. 2 h. This is the time for graphite production from CO2 obtained by acid hydrolysis...

  14. Energy Consumption and Net CO2 Sequestration of Aqueous Mineral Carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.; Comans, R.N.J.; Witkamp, G.J.; Ruijg, G.J.

    2006-01-01

    Aqueous mineral carbonation is a potentially attractive sequestration technology to reduce CO2 emissions. The energy consumption of this technology, however, reduces the net amount of CO2 sequestered. Therefore, the energetic CO2 sequestration efficiency of aqueous mineral carbonation was studied in

  15. Simulated effect of calcification feedback on atmospheric CO2 and ocean acidification

    Science.gov (United States)

    Zhang, Han; Cao, Long

    2016-01-01

    Ocean uptake of anthropogenic CO2 reduces pH and saturation state of calcium carbonate materials of seawater, which could reduce the calcification rate of some marine organisms, triggering a negative feedback on the growth of atmospheric CO2. We quantify the effect of this CO2-calcification feedback by conducting a series of Earth system model simulations that incorporate different parameterization schemes describing the dependence of calcification rate on saturation state of CaCO3. In a scenario with SRES A2 CO2 emission until 2100 and zero emission afterwards, by year 3500, in the simulation without CO2-calcification feedback, model projects an accumulated ocean CO2 uptake of 1462 PgC, atmospheric CO2 of 612 ppm, and surface pH of 7.9. Inclusion of CO2-calcification feedback increases ocean CO2 uptake by 9 to 285 PgC, reduces atmospheric CO2 by 4 to 70 ppm, and mitigates the reduction in surface pH by 0.003 to 0.06, depending on the form of parameterization scheme used. It is also found that the effect of CO2-calcification feedback on ocean carbon uptake is comparable and could be much larger than the effect from CO2-induced warming. Our results highlight the potentially important role CO2-calcification feedback plays in ocean carbon cycle and projections of future atmospheric CO2 concentrations. PMID:26838480

  16. Simulated effect of calcification feedback on atmospheric CO2 and ocean acidification

    Science.gov (United States)

    Zhang, Han; Cao, Long

    2016-02-01

    Ocean uptake of anthropogenic CO2 reduces pH and saturation state of calcium carbonate materials of seawater, which could reduce the calcification rate of some marine organisms, triggering a negative feedback on the growth of atmospheric CO2. We quantify the effect of this CO2-calcification feedback by conducting a series of Earth system model simulations that incorporate different parameterization schemes describing the dependence of calcification rate on saturation state of CaCO3. In a scenario with SRES A2 CO2 emission until 2100 and zero emission afterwards, by year 3500, in the simulation without CO2-calcification feedback, model projects an accumulated ocean CO2 uptake of 1462 PgC, atmospheric CO2 of 612 ppm, and surface pH of 7.9. Inclusion of CO2-calcification feedback increases ocean CO2 uptake by 9 to 285 PgC, reduces atmospheric CO2 by 4 to 70 ppm, and mitigates the reduction in surface pH by 0.003 to 0.06, depending on the form of parameterization scheme used. It is also found that the effect of CO2-calcification feedback on ocean carbon uptake is comparable and could be much larger than the effect from CO2-induced warming. Our results highlight the potentially important role CO2-calcification feedback plays in ocean carbon cycle and projections of future atmospheric CO2 concentrations.

  17. CyclicCO2R: production of cyclic carbonates from CO2 using renewable feedstocks

    NARCIS (Netherlands)

    Kimball, E.; Schuurbiers, C.A.H.; Zevenbergen, J.F.; Håkonsen, S.F.; Heyn, R.; Offermans, W.; Leitner, W.; Ostapowicz, T.; Müller, T. E.; Mul, G.; North, M.; Ngomsik-Fanselow, A.F.; Sarron, E.; Sigurbjörnsson, O.; Schäffner, B.

    2013-01-01

    The consortium behind CyclicCO2R wants to kick-start the implementation of CO2 utilization technologies by converting CO2 into a high value-added product, thus providing a showcase that inspires industry to further develop technologies utilizing CO2 as a sustainable raw material and valorizing CO2

  18. CyclicCO2R: production of cyclic carbonates from CO2 using renewable feedstocks

    NARCIS (Netherlands)

    Kimball, E.; Schuurbiers, C.A.H.; Zevenbergen, J.F.; Håkonsen, S.F.; Heyn, R.; Offermans, W.; Leitner, W.; Ostapowicz, T.; Müller, T. E.; Mul, G.; North, M.; Ngomsik-Fanselow, A.F.; Sarron, E.; Sigurbjörnsson, O.; Schäffner, B.

    2013-01-01

    The consortium behind CyclicCO2R wants to kick-start the implementation of CO2 utilization technologies by converting CO2 into a high value-added product, thus providing a showcase that inspires industry to further develop technologies utilizing CO2 as a sustainable raw material and valorizing CO2 i

  19. CO2-induced changes in mineral stoichiometry of wheat grains

    Science.gov (United States)

    Broberg, Malin; Pleijel, Håkan; Högy, Petra

    2016-04-01

    A comprehensive review of experiments with elevated CO2 (eCO2) presenting data on grain mineral concentration in wheat grain was made. Data were collected both from FACE (Free-Air CO2 Enrichment) and OTC (Open-Top Chamber) experiments. Analysis was made i) by deriving response functions for the relative effect on yield and mineral concentration in relation to CO2 concentration, ii) meta-analysis to test the magnitude and significance of observed effects and iii) comparison of the CO2 effect on the accumulation of different minerals in relation to accumulation of biomass and accumulation of N. Data were obtained for the following minerals: N, Zn, Mn, K, Ca, Mg, P, Fe, S, Cr, Cu, Cd and Na. In addition, data for starch, the dominating carbohydrate of wheat grain, were extracted. The responses ranged from near zero effects to strong negative effects of eCO2 on mineral concentration. The order of effect size was the following (from largest to smallest effect) for the different elements: Fe, Ca, S, Zn, Cd, N, Mg, Mn, P, Cu, Cr, K and Na. Particularly strong negative impacts of eCO2 were found in the essential mineral elements Fe, S, Ca, Zn and Mg. Especially Fe, Zn and Mg are nutrients for which deficiency in humans is a problem in todaýs world. The rather large differences in response of different elements indicated that the CO2-induced responses cannot be explained by a simple growth dilution model. Rather, uptake and transport mechanisms may have to be considered in greater detail, as well as the link of different elements with the uptake of nitrogen, the quantitatively dominating mineral nutrient, to explain the observed pattern. No effect of eCO2 on starch concentration could be demonstrated. This substantiates the rejection of a simple dilution model, since one would expect starch concentrations to be elevated in order to explain reduced mineral concentrations by carbohydrate dilution. The concentrations of toxic Cd was negatively affected, in principle a

  20. Does leaf photosynthesis adapt to CO2-enriched environments? An experiment on plants originating from three natural CO2 springs.

    Science.gov (United States)

    Onoda, Yusuke; Hirose, Tadaki; Hikosaka, Kouki

    2009-01-01

    Atmospheric CO2 elevation may act as a selective agent, which consequently may alter plant traits in the future. We investigated the adaptation to high CO2 using transplant experiments with plants originating from natural CO2 springs and from respective control sites. We tested three hypotheses for adaptation to high-CO2 conditions: a higher photosynthetic nitrogen use efficiency (PNUE); a higher photosynthetic water use efficiency (WUE); and a higher capacity for carbohydrate transport from leaves. Although elevated growth CO2 enhanced both PNUE and WUE, there was no genotypic improvement in PNUE. However, some spring plants had a higher WUE, as a result of a significant reduction in stomatal conductance, and also a lower starch concentration. Higher natural variation (assessed by the coefficient of variation) within populations in WUE and starch concentration, compared with PNUE, might be responsible for the observed population differentiation. These results support the concept that atmospheric CO2 elevation can act as a selective agent on some plant traits in natural plant communities. Reduced stomatal conductance and reduced starch accumulation are highlighted for possible adaptation to high CO2.

  1. Isolation of Organochlorine Pesticide from Ginseng with Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    李淑芬; 王幼君; 全灿; 田松江

    2005-01-01

    The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1 × 10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.

  2. Life cycle inventory of CO2 in an enhanced oil recovery system.

    Science.gov (United States)

    Jaramillo, Paulina; Griffin, W Michael; McCoy, Sean T

    2009-11-01

    Enhanced oil recovery (EOR) has been identified as a method of sequestering CO(2) recovered from power plants. In CO(2)-flood EOR, CO(2) is injected into an oil reservoir to reduce oil viscosity, reduce interfacial tension, and cause oil swelling which improves oil recovery. Previous studies suggest that substantial amounts of CO(2) from power plants could be sequestered in EOR projects, thus reducing the amount of CO(2) emitted into the atmosphere. This claim, however, ignores the fact that oil, a carbon rich fuel, is produced and 93% of the carbon in petroleum is refined into combustible products ultimately emitted into the atmosphere. In this study we analyze the net life cycle CO(2)emissions in an EOR system. This study assesses the overall life cycle emissions associated with sequestration via CO(2)-flood EOR under a number of different scenarios and explores the impact of various methods for allocating CO(2) system emissions and the benefits of sequestration.

  3. CO2 Virtual Science Data Environment API

    Data.gov (United States)

    National Aeronautics and Space Administration — The CO2 Virtual Data Environment is a comprehensive effort at bringing together the models, data, and tools necessary to perform research on atmospheric CO2.This...

  4. Why capture CO2 from the atmosphere?

    National Research Council Canada - National Science Library

    Keith, David W

    2009-01-01

    Air capture is an industrial process for capturing CO2 from ambient air; it is one of an emerging set of technologies for CO2 removal that includes geological storage of biotic carbon and the acceleration of geochemical weathering...

  5. Technological advances in CO2 conversion electro-biorefinery: A step toward commercialization.

    Science.gov (United States)

    ElMekawy, Ahmed; Hegab, Hanaa M; Mohanakrishna, Gunda; Elbaz, Ashraf F; Bulut, Metin; Pant, Deepak

    2016-09-01

    The global atmospheric warming due to increased emissions of carbon dioxide (CO2) has attracted great attention in the last two decades. Although different CO2 capture and storage platforms have been proposed, the utilization of captured CO2 from industrial plants is progressively prevalent strategy due to concerns about the safety of terrestrial and aquatic CO2 storage. Two utilization forms were proposed, direct utilization of CO2 and conversion of CO2 to chemicals and energy products. The latter strategy includes the bioelectrochemical techniques in which electricity can be used as an energy source for the microbial catalytic production of fuels and other organic products from CO2. This approach is a potential technique in which CO2 emissions are not only reduced, but it also produce more value-added products. This review article highlights the different methodologies for the bioelectrochemical utilization of CO2, with distinctive focus on the potential opportunities for the commercialization of these techniques.

  6. Calculating subsurface CO2 storage capacities

    NARCIS (Netherlands)

    Meer, B. van der; Egberts, P.

    2008-01-01

    Often we need to know how much CO2 we can store in a certain underground space, or how much such space we need to store a given amount of CO2. In a recent attempt (Bradshaw et al., 2006) to list various regional and global estimates of CO2 storage capacity (Figure 1), the estimates reported are ofte

  7. Calculating subsurface CO2 storage capacities

    NARCIS (Netherlands)

    Meer, B. van der; Egberts, P.

    2008-01-01

    Often we need to know how much CO2 we can store in a certain underground space, or how much such space we need to store a given amount of CO2. In a recent attempt (Bradshaw et al., 2006) to list various regional and global estimates of CO2 storage capacity (Figure 1), the estimates reported are

  8. Shifting terrestrial feedbacks from CO2 fertilization to global warming

    Science.gov (United States)

    Peñuelas, Josep; Ciais, Philippe; Janssens, Ivan; Canadell, Josep; Obersteiner, Michael; Piao, Shilong; Vautard, Robert; Sardans Jordi Sardans, Jordi

    2016-04-01

    Humans are increasingly fertilizing the planet. Our activities are increasing atmospheric concentrations of carbon dioxide, nitrogen inputs to ecosystems and global temperatures. Individually and combined, they lead to biospheric availability of carbon and nitrogen, enhanced metabolic activity, and longer growing seasons. Plants can consequently grow more and take up more carbon that can be stored in ecosystem carbon pools, thus enhancing carbon sinks for atmospheric CO2. Data on the increased strength of carbon sinks are, however, inconclusive: Some data (eddy covariance, short-term experiments on elevated CO2 and nutrient fertilization) suggest that biospheric carbon uptake is already effectively increasing but some other data suggest it is not, or are not general and conclusive (tree-ring, forest inventory). The combined land-ocean CO2 sink flux per unit of excess atmospheric CO2 above preindustrial levels declined over 1959-2012 by a factor of about 1/3, implying that CO2 sinks increased more slowly than excess CO2. We will discuss the available data, and the discussion will drive us to revisit our projections for enhanced carbon sinks. We will reconsider the performance of the modulators of increased carbon uptake in a CO2 fertilized and warmed world: nutrients, climate, land use and pollution. Nutrient availability in particular plays a crucial role. A simple mass-balance approach indicates that limited phosphorus availability and the corresponding N:P imbalances can jointly reduce the projected future carbon storage by natural ecosystems during this century. We then present a new paradigm: we are shifting from a fertilization to a warming era. Compared to the historical period, future impacts of warming will be larger than the benefits of CO2 fertilization given nutrient limitations, management and disturbance (which reduces C stocks and thus sequestration potential) and because CO2 will decrease by 2050 in RCP2.6, meaning loss of CO2 fertilization, and CO2

  9. CO2 exsolution - challenges and opportunities in subsurface flow management

    Science.gov (United States)

    Zuo, Lin; Benson, Sally

    2014-05-01

    In geological carbon sequestration, a large amount of injected CO2 will dissolve in brine over time. Exsolution occurs when pore pressures decline and CO2 solubility in brine decreases, resulting in the formation of a separate CO2 phase. This scenario occurs in storage reservoirs by upward migration of carbonated brine, through faults, leaking boreholes or even seals, driven by a reverse pressure gradient from CO2 injection or ground water extraction. In this way, dissolved CO2 could migrate out of storage reservoirs and form a gas phase at shallower depths. This paper summarizes the results of a 4-year study regarding the implications of exsolution on storage security, including core-flood experiments, micromodel studies, and numerical simulation. Micromodel studies have shown that, different from an injected CO2 phase, where the gas remains interconnected, exsolved CO2 nucleates in various locations of a porous medium, forms disconnected bubbles and propagates by a repeated process of bubble expansion and snap-off [Zuo et al., 2013]. A good correlation between bubble size distribution and pore size distribution is observed, indicating that geometry of the pore space plays an important role in controlling the mobility of brine and exsolved CO2. Core-scale experiments demonstrate that as the exsolved gas saturation increases, the water relative permeability drops significantly and is disproportionately reduced compared to drainage relative permeability [Zuo et al., 2012]. The CO2 relative permeability remains very low, 10-5~10-3, even when the exsolved CO2 saturation increases to over 40%. Furthermore, during imbibition with CO2 saturated brines, CO2 remains trapped even under relatively high capillary numbers (uv/σ~10-6) [Zuo et al., submitted]. The water relative permeability at the imbibition endpoint is 1/3~1/2 of that with carbonated water displacing injected CO2. Based on the experimental evidence, CO2 exsolution does not appear to create significant risks

  10. Translating crustacean biological responses from CO2 ...

    Science.gov (United States)

    Many studies of animal responses to ocean acidification focus on uniformly conditioned age cohorts that lack complexities typically found in wild populations. These studies have become the primary data source for predicting higher level ecological effects, but the roles of intraspecific interactions in re-shaping biological, demographic and evolutionary responses are not commonly considered. To explore this problem, I assessed responses in the mysid Americamysis bahia to bubbling of CO2-enriched and un-enriched air into the seawater supply in flow-through aquariums. I conducted one experiment using isolated age cohorts and a separate experiment using intact populations. The seawater supply was continuously input from Narragansett Bay (Rhode Island, USA). The 28-day cohort study was maintained without resource or spatial limitations, whereas the 5-month population study consisted of stage-structured populations that were allowed to self-regulate. These differences are common features of experiments and were intentionally retained to demonstrate the effect of methodological approaches on perceptions of effect mechanisms. The CO2 treatment reduced neonate abundance in the cohort experiment (24% reduction due to a mean pH difference of −0.27) but not in the population experiment, where effects were small and were strongest for adult and stage 1 survival (3% change due to a mean pH difference of −0.25). I also found evidence of competition in the population exper

  11. Shocking Results on the Adverse Effects of CO2 Exposures

    Science.gov (United States)

    James, John T.

    2012-01-01

    Carbon dioxide (CO2) is released in large quantities from humans while they live and work in spacecraft or work outside the spacecraft during extravehicular activity (EVA). Removal of this anthropogenic pollutant requires major resources, and these resources increase dramatically as the levels of CO2 set to protect human health and performance are reduced. The current Spacecraft Maximum Allowable Concentration of CO2 aboard the ISS is 0.7% or 5.3 mmHg; however, according to Chits (mission action requests), NASA and its international partners have agreed to control CO2 levels to less than 4 mmHg. In the meantime, retrospective investigations attempting to associate crew symptoms with elevated CO2 levels over the life if the International Space Station (ISS) are underway to determine if this level is sufficient to protect against health and performance decrements. Anecdotal reports suggest that crewmembers are not able to perform complex tasks as readily in spaceflight as they were able during ground-based training. While physiological effects of CO2 have been studied for many decades, it is only recently that the effects of CO2 on higher reasoning capabilities have been studied. The initial results are shocking. For example, one study published in the respected journal Environmental Health Perspectives showed obvious adverse effects of CO2 exposures on higher reasoning at 1.9 mmHg. The implications and limitations of this study are paramount in determining future CO2 SMACs for human spaceflight, both aboard the ISS and in exploration-class missions. Key Words: carbon dioxide, spacecraft, air quality, toxic effects

  12. CO2 Capture for Cement Technology

    OpenAIRE

    2013-01-01

    Production of cement is an energy intensive process and is the source of considerable CO2emissions. Itis estimated that the cement industry contributes around 8% of total global CO2emissions. CO2is oneof the major greenhouse gases. In the atmosphere, the CO2concentration has increased from 310 ppmvin 1960 to 390 ppmv in 2012, probably due to human activity. A lot of research is being carried out forreducing CO2emissions from large stationary sources. Ofwhich, the carbonate looping process is ...

  13. Forest succession at elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Clark, James S.; Schlesinger, William H.

    2002-02-01

    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response.

  14. Climate impacts on rising atmospheric CO2 from long-term time-series of CO2 and O2

    Science.gov (United States)

    Keeling, R. F.; Rafelski, L. E.; Piper, S. C.

    2009-04-01

    The long-term time series of atmospheric CO2 and O2 concentrations from the Scripps Institution of oceanography now span 51 and 19 years, respectively. These time series will be presented together with the ice-core CO2 records and discussed in terms of the processes controlling the atmospheric CO2 rise, particularly the sensitivity of the natural sinks for CO2 in the land and ocean to climate changes. The CO2 record provides constraints on the sensitivity of the land sinks to climate. The CO2 rise can be expressed as an anomaly relative to the trend expected from fossil-fuel burning, land use emissions, and uptake by the land biosphere and oceans, with the latter two processes depicted by simple reservoir models (land sink driven by CO2 fertilization). Despite uncertainties, the anomaly computed this way shows an evident link with global land temperature, with both the anomaly and temperature trend showing breaks in slope around 1940 and 1980. Climate effects on the land biosphere may thus explain two otherwise puzzling features in the CO2 record: the plateau in growth in the 1940s and the persistent high growth after 1980. The implied effect of warming on CO2 suggested by this decadal variability is too small to be a significant climate feedback, however. Additional constraints on the climate sensitivity of ocean sinks can be obtained by combining the CO2 and O2 records. The ocean CO2 sink that would have been obtained in the absence of climate change is quite well constrained based on ocean observations of chlorofluorocarbons. This sink can be compared to the sink computed from the global O2 budget, assuming the oceans have not been a long-term source or sink for O2. The comparison reveals a significant discrepancy, which suggests that climate changes are impacting some combination of the long-term O2 and CO2 fluxes. The climate effect is qualitatively consistent with ocean models, which predict that warming will reduce oceanic uptake of CO2 and induce oceanic

  15. CO2capture by Li-functionalized silicene

    KAUST Repository

    Zhu, Jiajie

    2016-05-18

    CO2 capture and storage technology is of key importance to reduce the greenhouse effect. By its large surface area and sp3 hybridization, Li-functionalized silicene is demonstrated to be a promising CO2 absorbent that is stable up to at least 500 K and has a very high storage capacity of 28.6 mol/kg (55.7 wt%). The adsorption energy of CO2 on Li-functionalized silicene is enhanced as compared to pristine silicene, to attain an almost ideal value that still facilitates easy release. In addition, the band gap is found to change sensitively with the CO2 coverage. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  16. 低分压CO2回收新技术捕集水泥窑气中CO2的侧线试验%Bypass experiment for capturing CO2 from cement furnace flue gas by low pressure CO2 recovery technology

    Institute of Scientific and Technical Information of China (English)

    黄汉根

    2011-01-01

    A bypass experiment facility for capturing CO2 from cement furnace flue gas is designed. A self-developed blended amine is used for CO2 capturing. The experimental results show that the CO2 volume content in the purified gas is lower than 1.41%, while the CO2 purity of the product gas is higher than 99 %. Using this technology, CO2 emission reduction can be realized. At the same time, CO2 product with high purity can be produced. This technology can be used as an effective technological support for enterprises to reduce CO2 emission.%设计了一套水泥窑气CO2捕集的侧线试验装置,利用自主研发的复合胺溶剂捕集窑气中的CO2.试验结果表明.新型复合胺溶剂能使净化气中CO2体积分数降至1.41%以下,产品气中CO2体积分数达到99%以上.采用该技术,可实现CO2减排并获得高纯度的CO2产品气,为企业的CO2减排提供技术支持.

  17. Interfacial Interactions and Wettability Evaluation of Rock Surfaces for CO2 Storage

    NARCIS (Netherlands)

    Shojai Kaveh, N.

    2014-01-01

    To reduce CO2 emissions into the atmosphere, different scenarios are proposed to capture and store carbon dioxide (CO2) in geological formations (CCS). Storage strategies include CO2 injection into deep saline aquifers, depleted gas and oil reservoirs, and unmineable coal seams. To identify a secure

  18. Geological Sequestration of CO2 A Brief Overview and Potential for Application for Oklahoma

    Science.gov (United States)

    Geologic sequestration of CO2 is a component of C capture and storage (CCS), an emerging technology for reducing CO2 emissions to the atmosphere, and involves injection of captured CO2 into deep subsurface formations. Similar to the injection of hazardous wastes, before injection...

  19. Model calibration on cement experiments at realistic CO2 storage conditions

    NARCIS (Netherlands)

    Wasch, L.J.; Koenen, M.; Wollenweber, J.; Heege, J.H. ter; Tambach, T.J.

    2013-01-01

    Large scale implementation of CO2 storage can significantly reduce emission of greenhouse gasses into the atmosphere. However, safe and long-term containment of CO2 in storage reservoirs must be ensured. Wellbores in the subsurface present possible leakage pathways for CO2 to the surface and hence w

  20. Residual CO2 trapping in Indiana limestone.

    Science.gov (United States)

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-01

    We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers.

  1. Potential environmental impacts of offshore UK geological CO2 storage

    Science.gov (United States)

    Carruthers, Kit; Wilkinson, Mark; Butler, Ian B.

    2016-04-01

    . The origin of the increased trace element concentrations was investigated using sequential leaching experiments. The analysis of the experimental results showed that prediction of trace element release from sandstones with weak CO2-acid leaching is difficult. However, the experiments did show that carbonate and feldspar mineral dissolution was a primary source of these elements, where mobilised, regardless of their abundance within the sandstone. While the environmental risks associated with future offshore CO2 storage are considered to be comparable with existing oil and gas operations, treatment of produced waters may be required to reduce the trace element load and should be assessed on a field-by-field basis.

  2. Active CO2 Reservoir Management: A Strategy for Controlling Pressure, CO2 and Brine Migration in Saline-Formation CCS

    Science.gov (United States)

    Buscheck, T. A.; Sun, Y.; Hao, Y.; Court, B.; Celia, M. A.; Wolery, T.; Tompson, A. F.; Aines, R. D.; Friedmann, J.

    2010-12-01

    CO2 capture and sequestration (CCS) in deep geological formations is regarded as a promising means of lowering the amount of CO2 emitted to the atmosphere and thereby mitigate global warming. The most promising systems for CCS are depleted oil reservoirs, particularly those suited to CO2-based Enhanced Oil Recovery (CCS-EOR), and deep saline formations, both of which are well separated from the atmosphere. For conventional, industrial-scale, saline-formation CCS, pressure buildup can have a limiting effect on CO2 storage capacity. To address this concern, we analyze Active CO2 Reservoir Management (ACRM), which combines brine extraction and residual-brine reinjection with CO2 injection, comparing it with conventional saline-formation CCS. We investigate the influence of brine extraction on pressure response and CO2 and brine migration using the NUFT code. By extracting brine from the lower portion of the storage formation, from locations progressively further from the center of injection, we can counteract buoyancy that drives CO2 to the top of the formation, which is useful in dipping formations. Using “push-pull” manipulation of the CO2 plume, we expose less of the caprock seal to CO2 and more of the storage formation to CO2, with more of the formation utilized for trapping mechanisms. Plume manipulation can also counteract the influence of heterogeneity. We consider the impact of extraction ratio, defined as net extracted brine volume (extraction minus reinjection) divided by injected CO2 volume. Pressure buildup is reduced with increasing extraction ratio, which reduces CO2 and brine migration, increases CO2 storage capacity, and reduces other risks, such as leakage up abandoned wells, caprock fracturing, fault activation, and induced seismicity. For a 100-yr injection period, a 10-yr delay in brine extraction does not diminish the magnitude of pressure reduction. Moreover, it is possible to achieve pressure management with just a few brine-extraction wells

  3. Stomatal response of Pinus sylvestriformis to elevated CO2 concentrations during the four years of exposure

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-mei; HAN Shi-jie; LIU Ying; JIA Xia

    2005-01-01

    Four-year-old Pinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol-1) and high CO2 concentrations (500 and 700 μmol·mol-1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China (42oN, 128oE). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (gs), ratio of intercellular to ambient CO2 concentration (ci/ca) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol-1 CO2 grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol-1CO2). High-[CO2]-grown plants exhibited lower ci/ca ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However, ci/ca ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation pattern of stomata between upper and lower surface of needle.

  4. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

    2001-01-01

    In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

  5. Extraction of stevia glycosides with CO2 + water, CO2 + ethanol, and CO2 + water + ethanol

    Directory of Open Access Journals (Sweden)

    A. Pasquel

    2000-09-01

    Full Text Available Stevia leaves are an important source of natural sugar substitute. There are some restrictions on the use of stevia extract because of its distinctive aftertaste. Some authors attribute this to soluble material other than the stevia glycosides, even though it is well known that stevia glycosides have to some extent a bitter taste. Therefore, the purpose of this work was to develop a process to obtain stevia extract of a better quality. The proposed process includes two steps: i Pretreatment of the leaves by SCFE; ii Extraction of the stevia glycosides by SCFE using CO2 as solvent and water and/or ethanol as cosolvent. The mean total yield for SCFE pretreatment was 3.0%. The yields for SCFE with cosolvent of stevia glycosides were below 0.50%, except at 120 bar, 16°C, and 9.5% (molar of water. Under this condition, total yield was 3.4%. The quality of the glycosidic fraction with respect to its capacity as sweetener was better for the SCFE extract as compared to extract obtained by the conventional process. The overall extraction curves were well described by the Lack extended model.

  6. Covalent Organic Frameworks for CO2 Capture.

    Science.gov (United States)

    Zeng, Yongfei; Zou, Ruqiang; Zhao, Yanli

    2016-04-20

    As an emerging class of porous crystalline materials, covalent organic frameworks (COFs) are excellent candidates for various applications. In particular, they can serve as ideal platforms for capturing CO2 to mitigate the dilemma caused by the greenhouse effect. Recent research achievements using COFs for CO2 capture are highlighted. A background overview is provided, consisting of a brief statement on the current CO2 issue, a summary of representative materials utilized for CO2 capture, and an introduction to COFs. Research progresses on: i) experimental CO2 capture using different COFs synthesized based on different covalent bond formations, and ii) computational simulation results of such porous materials on CO2 capture are summarized. Based on these experimental and theoretical studies, careful analyses and discussions in terms of the COF stability, low- and high-pressure CO2 uptake, CO2 selectivity, breakthrough performance, and CO2 capture conditions are provided. Finally, a perspective and conclusion section of COFs for CO2 capture is presented. Recent advancements in the field are highlighted and the strategies and principals involved are discussed.

  7. Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture

    Science.gov (United States)

    Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan

    2017-05-01

    Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

  8. A rapid transition from ice covered CO2-rich waters to a biologically mediated CO2 sink in the eastern Weddell Gyre

    Directory of Open Access Journals (Sweden)

    W. Geibert

    2008-03-01

    Full Text Available Circumpolar Deep Water (CDW, locally called Warm Deep Water (WDW, enters the Weddell Gyre in the southeast, roughly at 25° E to 30° E. In December~2002 and January 2003} we studied the effect of entrainment of WDW on the fugacity of carbon dioxide (fCO2 and dissolved inorganic carbon (DIC in Weddell Sea surface waters. Ultimately the fCO2 difference across the sea surface drives CO2 air-sea fluxes. Deep CTD sections and surface transects of fCO2 were made along the Prime Meridian, a northwest-southeast section, and along 17° E to 23° E during cruise ANT XX/2 on FS Polarstern. Upward movement and entrainment of WDW into the winter mixed layer had significantly increased DIC and fCO2 below the sea ice along 0° W and 17° E to 23° E, notably in the southern Weddell Gyre. Nonetheless, the ice cover largely prevented outgassing of CO2 to the atmosphere. During and upon melting of the ice, biological activity rapidly reduced surface water fCO2 by up to 100 μatm, thus creating a sink for atmospheric CO2. Despite the tendency of the surfacing WDW to cause CO2 supersaturation, the Weddell Gyre may well be a CO2 sink on an annual basis due to this effective mechanism involving ice cover and ensuing biological fCO2 reduction. Dissolution of calcium carbonate (CaCO3 in melting sea ice may also play a role in this rapid reduction of surface water fCO2. The CO2 source tendency deriving from the upward movement of "pre-industrial" CDW is declining, as atmospheric CO2 levels continue to increase, and thus the CO2 sink of the Weddell Gyre will continue to increase as well (provided the upward movement of WDW does not change significantly.

  9. Reservoir engineering to accelerate the dissolution of CO2 stored in aquifers.

    Science.gov (United States)

    Leonenko, Yuri; Keith, David W

    2008-04-15

    It is possible to accelerate the dissolution of CO2 injected into deep aquifers by pumping brine from regions where it is undersaturated into regions occupied by CO2. For a horizontally confined reservoir geometry, we find that it is possible to dissolve most of the injected CO2 within a few hundred years at an energy cost that is less than 20% of the cost of compressing the CO2 to reservoir conditions. We anticipate that use of reservoir engineering to accelerate dissolution can reduce the risks of CO2 storage by reducing the duration over which buoyant free-phase CO2 is present underground. Such techniques could simplify risk assessment by reducing uncertainty about the long-term fate of injected CO2, and could expand the range of reservoirs which are acceptable for storage.

  10. Directly converting CO2 into a gasoline fuel

    Science.gov (United States)

    Wei, Jian; Ge, Qingjie; Yao, Ruwei; Wen, Zhiyong; Fang, Chuanyan; Guo, Lisheng; Xu, Hengyong; Sun, Jian

    2017-05-01

    The direct production of liquid fuels from CO2 hydrogenation has attracted enormous interest for its significant roles in mitigating CO2 emissions and reducing dependence on petrochemicals. Here we report a highly efficient, stable and multifunctional Na-Fe3O4/HZSM-5 catalyst, which can directly convert CO2 to gasoline-range (C5-C11) hydrocarbons with selectivity up to 78% of all hydrocarbons while only 4% methane at a CO2 conversion of 22% under industrial relevant conditions. It is achieved by a multifunctional catalyst providing three types of active sites (Fe3O4, Fe5C2 and acid sites), which cooperatively catalyse a tandem reaction. More significantly, the appropriate proximity of three types of active sites plays a crucial role in the successive and synergetic catalytic conversion of CO2 to gasoline. The multifunctional catalyst, exhibiting a remarkable stability for 1,000 h on stream, definitely has the potential to be a promising industrial catalyst for CO2 utilization to liquid fuels.

  11. Energy efficiency and CO2 emissions in Swedish manufacturing industries

    Energy Technology Data Exchange (ETDEWEB)

    Pardo Martinez, C.I. [Faculty of Environmental Engineering, University of La Salle, Bogota (Colombia); Silveira, S [Energy and Climate Studies, Department of Energy Technology, KTH, Stockholm (Sweden)

    2013-02-15

    This paper analyses the trends in energy consumption and CO2 emissions as a result of energy efficiency improvements in Swedish manufacturing industries between 1993 and 2008. Using data at the two-digit level, the performance of this sector is studied in terms of CO2 emissions, energy consumption, energy efficiency measured as energy intensity, value of production, fuel sources, energy prices and energy taxes. It was found that energy consumption, energy intensity and CO2 emission intensity, measured as production values, have decreased significantly in the Swedish manufacturing industries during the period studied. The results of the decomposition analysis show that output growth has not required higher energy consumption, leading to a reduction in both energy and CO2 emission intensities. The role of structural changes has been minor, and the trends of energy efficiency and CO2 emissions have been similar during the sample period. A stochastic frontier model was used to determine possible factors that may have influenced these trends. The results demonstrate that high energy prices, energy taxes, investments and electricity consumption have influenced the reduction of energy and CO2 emission intensities, indicating that Sweden has applied an adequate and effective energy policy. The study confirms that it is possible to achieve economic growth and sustainable development whilst also reducing the pressure on resources and energy consumption and promoting the shift towards a low-carbon economy.

  12. Nucleation Pathways of CO2 Condensation under Mesoporous Templated Glass

    Science.gov (United States)

    Wang, Bo; Byran, Matthew S.; Warren, Garfield T.; Sokol, Paul E.; Indiana University Team; NIST Collaboration

    2015-03-01

    Carbon capture and storage (CCS) are important elements in reducing greenhouse gas emission and combating global warming. The adsorption behavior of CO2 under mesoporous confinement at room temperature is particularly relevant. , Small Angle Scattering of X-ray (SAXS) and Neutron (SANS) were used to probe the adsorption process of CO2 under such mesoporous confinement MCM-41 and details of nucleation pathways were mapped out by fitting the scattering intensities with adsorption models. From both experiments, the nucleation of CO2 on the inner pore surface of MCM-41 is found to be a two-step process; high density liquid phase CO2 first forms uniform layers following the long range translational symmetry of the porous matrix, above one CO2 filling, determined by the pore size and temperature, capillary condensation initiates. The nucleation sites formed during capillary condensation start to separate the long range symmetry from the one at uniform layers. Finally, SAXS and SANS techniques are compared and they both showed their unique properties of probing the filling-dependent structures of adsorbed CO2 under such mesoporous system.

  13. Electrocatalytic recycling of CO2 and small organic molecules.

    Science.gov (United States)

    Lee, Jaeyoung; Kwon, Youngkook; Machunda, Revocatus L; Lee, Hye Jin

    2009-10-05

    As global warming directly affects the ecosystems and humankind in the 21st century, attention and efforts are continuously being made to reduce the emission of greenhouse gases, especially carbon dioxide (CO2). In addition, there have been numerous efforts to electrochemically convert CO2 gas to small organic molecules (SOMs) and vice versa. Herein, we highlight recent advances made in the electrocatalytic recycling of CO2 and SOMs including (i) the overall trend of research activities made in this area, (ii) the relations between reduction conditions and products in the aqueous phase, (iii) the challenges in the use of gas diffusion electrodes for the continuous gas phase CO2 reduction, as well as (iv) the development of state of the art hybrid techniques for industrial applications. Perspectives geared to fully exploit the potential of zero-gap cells for CO2 reduction in the gaseous phase and the high applicability on a large scale are also presented. We envision that the hybrid system for CO2 reduction supported by sustainable solar, wind, and geothermal energies and waste heat will provide a long term reduction of greenhouse gas emissions and will allow for continued use of the abundant fossil fuels by industries and/or power plants but with zero emissions.

  14. Atmospheric CO2 enrichment facilitates cation release from soil.

    Science.gov (United States)

    Cheng, L; Zhu, J; Chen, G; Zheng, X; Oh, N-H; Rufty, T W; Richter, D deB; Hu, S

    2010-03-01

    Atmospheric CO(2) enrichment generally stimulates plant photosynthesis and nutrient uptake, modifying the local and global cycling of bioactive elements. Although nutrient cations affect the long-term productivity and carbon balance of terrestrial ecosystems, little is known about the effect of CO(2) enrichment on cation availability in soil. In this study, we present evidence for a novel mechanism of CO(2)-enhancement of cation release from soil in rice agricultural systems. Elevated CO(2) increased organic C allocation belowground and net H(+) excretion from roots, and stimulated root and microbial respiration, reducing soil redox potential and increasing Fe(2+) and Mn(2+) in soil solutions. Increased H(+), Fe(2+), and Mn(2+) promoted Ca(2+) and Mg(2+) release from soil cation exchange sites. These results indicate that over the short term, elevated CO(2) may stimulate cation release from soil and enhance plant growth. Over the long-term, however, CO(2)-induced cation release may facilitate cation losses and soil acidification, negatively feeding back to the productivity of terrestrial ecosystems.

  15. Deep aquifer prokaryotic community responses to CO2 geosequestration

    Science.gov (United States)

    Mu, A.; Moreau, J. W.

    2015-12-01

    Little is known about potential microbial responses to supercritical CO2 (scCO2) injection into deep subsurface aquifers, a currently experimental means for mitigating atmospheric CO2 pollution being trialed at several locations around the world. One such site is the Paaratte Formation of the Otway Basin (~1400 m below surface; 60°C; 2010 psi), Australia. Microbial responses to scCO2 are important to understand as species selection may result in changes to carbon and electron flow. A key aim is to determine if biofilm may form in aquifer pore spaces and reduce aquifer permeability and storage. This study aimed to determine in situ, using 16S rRNA gene, and functional metagenomic analyses, how the microbial community in the Otway Basin geosequestration site responded to experimental injection of 150 tons of scCO2. We demonstrate an in situ sampling approach for detecting deep subsurface microbial community changes associated with geosequestration. First-order level analyses revealed a distinct shift in microbial community structure following the scCO2 injection event, with proliferation of genera Comamonas and Sphingobium. Similarly, functional profiling of the formation revealed a marked increase in biofilm-associated genes (encoding for poly-β-1,6-N-acetyl-D-glucosamine). Global analysis of the functional gene profile highlights that scCO2 injection potentially degraded the metabolism of CH4 and lipids. A significant decline in carboxydotrophic gene abundance (cooS) and an anaerobic carboxydotroph OTU (Carboxydocella), was observed in post-injection samples. The potential impacts on the flow networks of carbon and electrons to heterotrophs are discussed. Our findings yield insights for other subsurface systems, such as hydrocarbon-rich reservoirs and high-CO2 natural analogue sites.

  16. Modeling Atmospheric CO2 Processes to Constrain the Missing Sink

    Science.gov (United States)

    Kawa, S. R.; Denning, A. S.; Erickson, D. J.; Collatz, J. C.; Pawson, S.

    2005-01-01

    We report on a NASA supported modeling effort to reduce uncertainty in carbon cycle processes that create the so-called missing sink of atmospheric CO2. Our overall objective is to improve characterization of CO2 source/sink processes globally with improved formulations for atmospheric transport, terrestrial uptake and release, biomass and fossil fuel burning, and observational data analysis. The motivation for this study follows from the perspective that progress in determining CO2 sources and sinks beyond the current state of the art will rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. The major components of this effort are: 1) Continued development of the chemistry and transport model using analyzed meteorological fields from the Goddard Global Modeling and Assimilation Office, with comparison to real time data in both forward and inverse modes; 2) An advanced biosphere model, constrained by remote sensing data, coupled to the global transport model to produce distributions of CO2 fluxes and concentrations that are consistent with actual meteorological variability; 3) Improved remote sensing estimates for biomass burning emission fluxes to better characterize interannual variability in the atmospheric CO2 budget and to better constrain the land use change source; 4) Evaluating the impact of temporally resolved fossil fuel emission distributions on atmospheric CO2 gradients and variability. 5) Testing the impact of existing and planned remote sensing data sources (e.g., AIRS, MODIS, OCO) on inference of CO2 sources and sinks, and use the model to help establish measurement requirements for future remote sensing instruments. The results will help to prepare for the use of OCO and other satellite data in a multi-disciplinary carbon data assimilation system for analysis and prediction of carbon cycle changes and carbodclimate interactions.

  17. Increased CO2 stimulates reproduction in a coral reef fish.

    Science.gov (United States)

    Miller, Gabrielle M; Watson, Sue-Ann; McCormick, Mark I; Munday, Philip L

    2013-10-01

    Ocean acidification is predicted to negatively impact the reproduction of many marine species, either by reducing fertilization success or diverting energy from reproductive effort. While recent studies have demonstrated how ocean acidification will affect larval and juvenile fishes, little is known about how increasing partial pressure of carbon dioxide (pCO(2)) and decreasing pH might affect reproduction in adult fishes. We investigated the effects of near-future levels of pCO(2) on the reproductive performance of the cinnamon anemonefish, Amphiprion melanopus, from the Great Barrier Reef, Australia. Breeding pairs were held under three CO(2) treatments [Current-day Control (430 μatm), Moderate (584 μatm) and High (1032 μatm)] for a 9-month period that included the summer breeding season. Unexpectedly, increased CO(2) dramatically stimulated breeding activity in this species of fish. Over twice as many pairs bred in the Moderate (67% of pairs) and High (55%) compared to the Control (27%) CO(2) treatment. Pairs in the High CO(2) group produced double the number of clutches per pair and 67% more eggs per clutch compared to the Moderate and Control groups. As a result, reproductive output in the High group was 82% higher than that in the Control group and 50% higher than that in the Moderate group. Despite the increase in reproductive activity, there was no difference in adult body condition among the three treatment groups. There was no significant difference in hatchling length between the treatment groups, but larvae from the High CO(2) group had smaller yolks than Controls. This study provides the first evidence of the potential effects of ocean acidification on key reproductive attributes of marine fishes and, contrary to expectations, demonstrates an initially stimulatory (hormetic) effect in response to increased pCO(2). However, any long-term consequences of increased reproductive effort on individuals or populations remain to be determined.

  18. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone....... The CO2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO2 capture capacity of limestone. At 850 °C in N2...

  19. Enhancement of CO2 sorption uptake on hydrotalcite by impregnation with K2CO3.

    Science.gov (United States)

    Lee, Jung Moo; Min, Yoon Jae; Lee, Ki Bong; Jeon, Sang Goo; Na, Jeong Geol; Ryu, Ho Jung

    2010-12-21

    The awareness of symptoms of global warming and its seriousness urges the development of technologies to reduce greenhouse gas emissions. Carbon dioxide (CO(2)) is a representative greenhouse gas, and numerous methods to capture and storage CO(2) have been considered. Recently, the technology to remove high-temperature CO(2) by sorption has received lots of attention. In this study, hydrotalcite, which has been known to have CO(2) sorption capability at high temperature, was impregnated with K(2)CO(3) to enhance CO(2) sorption uptake, and the mechanism of CO(2) sorption enhancement on K(2)CO(3)-promoted hydrotalcite was investigated. Thermogravimetric analysis was used to measure equilibrium CO(2) sorption uptake and to estimate CO(2) sorption kinetics. The analyses based on N(2) gas physisorption, X-ray diffractometry, Fourier transform infrared spectrometry, Raman spectrometry, transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were carried out to elucidate the characteristics of sorbents and the mechanism of enhanced CO(2) sorption. The equilibrium CO(2) sorption uptake on hydrotalcite could be increased up to 10 times by impregnation with K(2)CO(3), and there was an optimal amount of K(2)CO(3) for a maximum equilibrium CO(2) sorption uptake. In the K(2)CO(3)-promoted hydrotalcite, K(2)CO(3) was incorporated without changing the structure of hydrotalcite and it was thermally stabilized, resulting in the enhanced equilibrium CO(2) sorption uptake and fast CO(2) sorption kinetics.

  20. CO2 Allowance and Electricity Price Interaction

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    With the introduction of CO2 emission constraints on power generators in the European Union, climate policy is starting to have notable effects on energy markets. This paper sheds light on the links between CO2 prices, electricity prices, and electricity costs to industry. It is based on a series of interviews with industrial and electricity stakeholders, as well as a rich literature seeking to estimate the exact effect of CO2 prices on electricity prices.

  1. [A new colorimetric CO2 indicator Colibri].

    Science.gov (United States)

    Nishiyama, T; Hanaoka, K

    1996-06-01

    A new colorimetric carbon dioxide (CO2) indicator Colibri is a disposable, compact and light weighted device. Colibri does not need to be calibrated and is easily usable in an emergency. It indicates blue with CO2 below 4 mmHg and becomes yellow with CO2 above 40 mmHg. In comparison with EASY CAP, Colibri functions for a longer period and it has a humidifier and a bacterial filter. Colibri is useful for emergency situations and anesthetic care.

  2. Can Producing Oil Store Carbon? Greenhouse Gas Footprint of CO2EOR, Offshore North Sea.

    Science.gov (United States)

    Stewart, R Jamie; Haszeldine, R Stuart

    2015-05-05

    Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields while permanently storing large tonnages of injected CO2. Although this technology has been used successfully onshore in North America and Europe, there are currently no CO2EOR projects in the United Kingdom. Here, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using a high-level Life Cycle system approach, we find that the largest contribution to offshore emissions is from flaring or venting of reproduced CH4 and CO2. These can already be greatly reduced by regulation. If CO2 injection is continued after oil production has been optimized, then offshore CO2EOR has the potential to be carbon negative--even when emissions from refining, transport, and combustion of produced crude oil are included. The carbon intensity of oil produced can be just 0.056-0.062 tCO2e/bbl if flaring/venting is reduced by regulation. This compares against conventional Saudi oil 0.040 tCO2e/bbl or mined shale oil >0.300 tCO2e/bbl.

  3. CO2 capture in different carbon materials.

    Science.gov (United States)

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya

    2012-07-03

    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  4. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    performed recently has focused on CO2capture from fossil fuel-based power plants. Inherently,this process is especially suitablefor cement plants, as CaO used for CO2capture is also a majoringredient for clinker production. Thus, a detailed investigation was carried outto study the applicationof......% of the inlet CO2 was captured by highly deactivated limestone, which had a maximum CO2 capture capacity of 11.5%, with an inlet Ca/C ratio of 13. So, the performance of the carbonator can be defined by the inlet Ca/C ratio, which can be estimated if the maximum capture capacity of limestone is known...

  5. Growth strategy of Norway spruce under air elevated [CO2

    Science.gov (United States)

    Pokorny, R.; Urban, O.; Holisova, P.; Sprtova, M.; Sigut, L.; Slipkova, R.

    2012-04-01

    quality and above-ground and bellow-ground biomass increment. We found that Norway spruce ecological valence to low-light intensities and reduced soil water availability will increase. We also found that thinning will be the most powerful management tool for stand productivity enhancement as CO2 assimilation is stimulated under high-light intensities and as Norway spruce is able to build secondary branch and root structures to reduce acclimation depression. Therefore, it is highly presumable that Norway spruce will profit from elevated [CO2] under the conditions of sufficient nitrogen supply. Acknowledgement The authors are grateful for the financial support by grant no. GAP501/10/0340 of Grant Agency of the Czech Republic. Glass domes form a part of the National Infrastructure for Carbon Observation - CzeCOS/ICOS supported by Ministry of Education CR (LM2010007) under CzechGlobe (CZ.1.05/1.1.00/02.0073).

  6. CO2 Interaction with Geomaterials (Invited)

    Science.gov (United States)

    Romanov, V.; Howard, B. H.; Lynn, R. J.; Warzinski, R. P.; Hur, T.; Myshakin, E. M.; Lopano, C. L.; Voora, V. K.; Al-Saidi, W. A.; Jordan, K. D.; Cygan, R. T.; Guthrie, G. D.

    2010-12-01

    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas #3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or “geopolymer”) theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO2

  7. CO2 Fixation by Membrane Separated NaCl Electrolysis

    Directory of Open Access Journals (Sweden)

    Hyun Sic Park

    2015-08-01

    Full Text Available Atmospheric concentrations of carbon dioxide (CO2, a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS, which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical disadvantages. Carbon capture and utilization (CCU, which has been introduced to cover such disadvantages, makes it possible to capture CO2, recycling byproducts as resources. However, CCU also requires large amounts of energy in order to induce reactions. Among existing CCU technologies, the process for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated at room temperature and pressure. Following the experiment, the resulting product CaCO3 was analyzed with Fourier transform infrared spectroscopy (FT-IR; field emission scanning electron microscopy (FE-SEM image and X-ray diffraction (XRD patterns were also analyzed. The results showed that the CaCO3 crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.

  8. CO2对脱磷转炉物料和能量的影响%Effect of CO2 on material and energy in dephosphorization converters

    Institute of Scientific and Technical Information of China (English)

    李智峥; 朱荣; 朱益强

    2016-01-01

    Based on the characteristics of CO2 at high temperature, material and energy models for CO2 using in a dephosphoriza-tion converter were established to verify the feasibility of CO2 for oxidation reactions. Based on practical working conditions in a facto-ry, the effects of CO2 on the converter temperature and gas were studied. It is discovered that the CO2 ratio can be controlled within 28%, the oxygen consumption can be reduced by 16%, and the CO ratio in the gas can be increased by about 12% when the scrap ratio is 8% and the utilization ratio of CO2 is 85%. Besides, as the utilization ratio of CO2 increases, the semi-steel temperature of the converter gradually decreases, and the oxygen consumption also lowers.%基于CO2在高温条件下的反应特性,建立了CO2用于脱磷炉冶炼的物料和能量分析模型,验证CO2用于脱磷炉冶炼过程参与氧化反应的可行性。在此基础上,基于某厂脱磷炉的实际冶炼工况,研究喷吹CO2对脱磷转炉温度、煤气等的影响。研究发现:当废钢比为8%和CO2利用率为85%时,CO2的喷吹比例可控制在28%以内,氧耗可降低16%,炉气中CO比例可提高约12%;同时随着CO2利用率的提高,脱磷炉的半钢温度逐渐降低,氧耗逐渐降低。

  9. IGCC系统减排CO2的性能比较和分析%PERFORMANCE COMPARISON AND ANALYSIS OF IGCC WITH CO2 EMISSION REDUCTION

    Institute of Scientific and Technical Information of China (English)

    范江; 刘姝玮; 马素霞

    2012-01-01

    Gas producing ratio and energy consumption rate were computed respectively in the IGCC system, the IGCC system with pre-combustion CO2 capturing and that with oxy-combustion CO2 recycling. It was showed from the computed results that when coal and the gasification were in the same condition, the steam and gas turbine's work declined and the IGCC system thermal efficiency reduced by 5. 851%, which was due to the capturing of CO2 gas. When CO2 reduction rate was 86. 55% , the thermal efficiency was 42% and conducive to the operating of IGCC efficiently and cleanly. If adopting the CO2 recycling combustion technology, the system thermal efficiency was lower than that of the pre-combustion CO2 capturing system, but in which zero CO2 emission could be achieved.%分别对IGCC系统、IGCC燃烧前捕捉CO2系统以及CO2循环利用的纯氧燃烧系统的产气率和能耗进行了计算.结果表明,当煤种和气化条件不变时,燃烧前捕捉CO2会使IGCC系统的燃气轮机和蒸汽轮机做功量减少,热效率降低5.851%.当减排86.55%的CO2时,系统热效率为42%,有利于IGCC清洁高效运行.若采用CO2循环的纯氧燃烧技术,其系统热效率比未循环CO2的燃烧前捕捉系统低,但可以实现CO2的零排放.

  10. Numerical simulation of CO2 dispersion from punctures and ruptures of buried high-pressure dense phase CO2 pipelines with experimental validation

    OpenAIRE

    Wareing, CJ; Fairweather, M.; Woolley, RM; Falle, SAEG

    2014-01-01

    Carbon capture and storage (CCS) presents an option for significantly reducing the amount of carbon dioxide (CO2) released into the atmosphere and mitigating the effects of climate change. Pipelines are considered to be the most likely method for transporting captured CO2 and their safe operation is of paramount importance as their contents are likely to be in the region of several thousand tonnes and CO2 poses a number of concerns upon release due to its unusual physical properties. To this ...

  11. Strain development in smectite clays upon exposure to CO2

    Science.gov (United States)

    de Jong, S. M.; Spiers, C. J.; Busch, A.

    2012-04-01

    swelling (0.55 ± 0.46% at 10MPa CO2 pressure) is found for clay with an initial d001 spacing equivalent to 9.8Å. For an initial spacing of 9.8Å ≤ d001 ≤ 11Å, swelling decreases systematically with decreasing d-spacing at all pressures investigated. The strain effect is already observed at low CO2 pressure (1MPa) and expansion appears to be completed at PCO2 ~ 8MPa. Shale/claystone samples containing 53% smectite displays a volume increase of ~1.0%, at T = 45°C and PCO2 = 10MPa. No swelling effects were observed in identical experiments performed using Argon gas. Our results demonstrate that montmorillonite swells by up to a few percent due to uptake of CO2. Whether the CO2 actually penetrates the interlayer region or is adsorbed at clay crystallite surfaces remains unclear. No evidence is found for CO2 induced dehydration (shrinkage) of the crystal structure. For smectite-bearing caprocks above carbon sequestration reservoirs, our results suggest that a minor swelling can be expected if CO2 migrates into caprocks and faults, probably closing any open fractures or joints and thus reducing bulk permeability. Acknowledgement: this project is funded by Shell Global Solutions International B.V.

  12. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost-effective co...

  13. Monitoring Options for CO2 Storage

    NARCIS (Netherlands)

    Arts, R.; Winthaegen, P.

    2005-01-01

    This chapter provides an overview of various monitoring techniques for CO2 storage that is structured into three categories-instrumentation in a well (monitoring well); instrumentation at the (near) surface (surface geophysical methods); and sampling at the (near) surface measuring CO2 concentration

  14. Photocatalytic CO2 Activation by Water

    NARCIS (Netherlands)

    Yang, Chieh-Chao

    2011-01-01

    Photocatalytic activation of CO2 and water has potential for producing fuels by conversion of photon energy. However, the low productivity still limits practical application. In this study, the goal was to gain more fundamental insight in CO2 activation, and to provide guidelines for rational design

  15. CO2 Capture with Enzyme Synthetic Analogue

    Energy Technology Data Exchange (ETDEWEB)

    Cordatos, Harry

    2010-11-08

    Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.

  16. CO2 Rekentool voor Tuinbouw: Handleiding

    NARCIS (Netherlands)

    Hiller, S.R.C.H.; Danse, M.G.

    2009-01-01

    Dit document is een handleiding bij de online CO2 Rekentool voor Tuinbouw Ketens. De CO2 tool is mogelijk gemaakt door de financiële bijdrage van Productschap Tuinbouw en het Ministerie van Landbouw, Natuur en Voedselkwaliteit (LNV). De tool is ontwikkeld door het onderzoeksconsortium WUR, BMA en AI

  17. Trends in global CO2 emissions. 2013 Report

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, J.G.J.; Peters, J.A.H.W. [PBL Netherlands Environmental Assessment Agency, Den Haag (Netherlands); Janssens-Maenhout, G. [Institute for Environment and Sustainability IES, European Commission' s Joint Research Centre JRC, Ispra (Italy); Muntean, M. [Institute for Environment and Sustainability IES, Joint Research Centre JRC, Ispra (Italy)

    2013-10-15

    greenhouse gas emissions. Chapter 3 focuses on the energy trends and possible fuel shifts, as the special topic for this year's report. Compared to last year's report, global energy trends are described more fully, including an analysis of the main options for reducing emissions, being renewable energy, nuclear power, energy efficiency and carbon capture and storage. In addition, the extent to which structural changes have caused the observed slowdown in the increase in global CO2 emissions is discussed. Finally, Chapter 4 summarises the main conclusions on trends, mitigation achievements and prospects.

  18. Geophysical monitoring technology for CO2 sequestration

    Science.gov (United States)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  19. Microfluidic study for investigating migration and residual phenomena of supercritical CO2 in porous media

    Science.gov (United States)

    Park, Gyuryeong; Wang, Sookyun; Lee, Minhee; Um, Jeong-Gi; Kim, Seon-Ok

    2017-04-01

    The storage of CO2 in underground geological formation such as deep saline aquifers or depleted oil and gas reservoirs is one of the most promising technologies for reducing the atmospheric CO2 release. The processes in geological CO2 storage involves injection of supercritical CO2 (scCO2) into porous formations saturated with brine and initiates CO2 flooding with immiscible displacement. The CO2 migration and porewater displacement within geological formations, and , consequentially, the storage efficiency are governed by the interaction of fluid and rock properties and are affected by the interfacial tension, capillarity, and wettability in supercritical CO2-brine-mineral systems. This study aims to observe the displacement pattern and estimate storage efficiency by using micromodels. This study aims to conduct scCO2 injection experiments for visualization of distribution of injected scCO2 and residual porewater in transparent pore networks on microfluidic chips under high pressure and high temperature conditions. In order to quantitatively analyze the porewater displacement by scCO2 injection under geological CO2 storage conditions, the images of invasion patterns and distribution of CO2 in the pore network are acquired through a imaging system with a microscope. The results from image analysis were applied in quantitatively investigating the effects of major environmental factors and scCO2 injection methods on porewater displacement process by scCO2 and storage efficiency. The experimental observation results could provide important fundamental information on capillary characteristics of reservoirs and improve our understanding of CO2 sequestration progress.

  20. Differential behavioral sensitivity to carbon dioxide (CO2) inhalation in rats.

    Science.gov (United States)

    Winter, Andrew; Ahlbrand, Rebecca; Naik, Devanshi; Sah, Renu

    2017-03-27

    Inhalation of carbon dioxide (CO2) is frequently employed as a biological challenge to evoke intense fear and anxiety. In individuals with panic disorder, CO2 reliably evokes panic attacks. Sensitivity to CO2 is highly heterogeneous among individuals, and although a genetic component is implicated, underlying mechanisms are not clear. Preclinical models that can simulate differential responsivity to CO2 are therefore relevant. In the current study we investigated CO2-evoked behavioral responses in four different rat strains: Sprague-Dawley (SD), Wistar (W), Long Evans (LE) and Wistar-Kyoto, (WK) rats. We also assessed tryptophan hydroxylase 2 (TPH-2)-positive serotonergic neurons in anxiety/panic regulatory subdivisions of the dorsal raphe nucleus (DR), as well as dopamine β hydroxylase (DβH)-positive noradrenergic neurons in the locus coeruleus, implicated in central CO2-chemosensitivity. Behavioral responsivity to CO2 inhalation varied between strains. CO2-evoked immobility was significantly higher in LE and WK rats as compared with W and SD cohorts. Differences were also observed in CO2-evoked rearing and grooming behaviors. Exposure to CO2 did not produce conditioned behavioral responses upon re-exposure to CO2 context in any strain. Reduced TPH-2-positive cell counts were observed specifically in the panic-regulatory dorsal raphe ventrolateral (DRVL)-ventrolateral periaqueductal gray (VLPAG) subdivision in CO2-sensitive strains. Conversely, DβH-positive cell counts within the LC were significantly higher in CO2-sensitive strains. Collectively, our data provide evidence for strain dependent, differential CO2-sensitivity and potential differences in monoaminergic systems regulating panic and anxiety. Comparative studies between CO2-vulnerable and resistant strains may facilitate the mechanistic understanding of differential CO2-sensitivity in the development of panic and anxiety disorders.

  1. Direct Capture of CO2 from Ambient Air.

    Science.gov (United States)

    Sanz-Pérez, Eloy S; Murdock, Christopher R; Didas, Stephanie A; Jones, Christopher W

    2016-10-12

    The increase in the global atmospheric CO2 concentration resulting from over a century of combustion of fossil fuels has been associated with significant global climate change. With the global population increase driving continued increases in fossil fuel use, humanity's primary reliance on fossil energy for the next several decades is assured. Traditional modes of carbon capture such as precombustion and postcombustion CO2 capture from large point sources can help slow the rate of increase of the atmospheric CO2 concentration, but only the direct removal of CO2 from the air, or "direct air capture" (DAC), can actually reduce the global atmospheric CO2 concentration. The past decade has seen a steep rise in the use of chemical sorbents that are cycled through sorption and desorption cycles for CO2 removal from ultradilute gases such as air. This Review provides a historical overview of the field of DAC, along with an exhaustive description of the use of chemical sorbents targeted at this application. Solvents and solid sorbents that interact strongly with CO2 are described, including basic solvents, supported amine and ammonium materials, and metal-organic frameworks (MOFs), as the primary classes of chemical sorbents. Hypothetical processes for the deployment of such sorbents are discussed, as well as the limited array of technoeconomic analyses published on DAC. Overall, it is concluded that there are many new materials that could play a role in emerging DAC technologies. However, these materials need to be further investigated and developed with a practical sorbent-air contacting process in mind if society is to make rapid progress in deploying DAC as a means of mitigating climate change.

  2. A review of mineral carbonation technologies to sequester CO2.

    Science.gov (United States)

    Sanna, A; Uibu, M; Caramanna, G; Kuusik, R; Maroto-Valer, M M

    2014-12-07

    Carbon dioxide (CO2) capture and sequestration includes a portfolio of technologies that can potentially sequester billions of tonnes of CO2 per year. Mineral carbonation (MC) is emerging as a potential CCS technology solution to sequester CO2 from smaller/medium emitters, where geological sequestration is not a viable option. In MC processes, CO2 is chemically reacted with calcium- and/or magnesium-containing materials to form stable carbonates. This work investigates the current advancement in the proposed MC technologies and the role they can play in decreasing the overall cost of this CO2 sequestration route. In situ mineral carbonation is a very promising option in terms of resources available and enhanced security, but the technology is still in its infancy and transport and storage costs are still higher than geological storage in sedimentary basins ($17 instead of $8 per tCO2). Ex situ mineral carbonation has been demonstrated on pilot and demonstration scales. However, its application is currently limited by its high costs, which range from $50 to $300 per tCO2 sequestered. Energy use, the reaction rate and material handling are the key factors hindering the success of this technology. The value of the products seems central to render MC economically viable in the same way as conventional CCS seems profitable only when combined with EOR. Large scale projects such as the Skyonic process can help in reducing the knowledge gaps on MC fundamentals and provide accurate costing and data on processes integration and comparison. The literature to date indicates that in the coming decades MC can play an important role in decarbonising the power and industrial sector.

  3. CO2 plume management in saline reservoir sequestration

    Science.gov (United States)

    Frailey, S.M.; Finley, R.J.

    2011-01-01

    A significant difference between injecting CO2 into saline aquifers for sequestration and injecting fluids into oil reservoirs or natural gas into aquifer storage reservoirs is the availability and use of other production and injection wells surrounding the primary injection well(s). Of major concern for CO2 sequestration using a single well is the distribution of pressure and CO2 saturation within the injection zone. Pressure is of concern with regards to caprock integrity and potential migration of brine or CO2 outside of the injection zone, while CO2 saturation is of interest for storage rights and displacement efficiency. For oil reservoirs, the presence of additional wells is intended to maximize oil recovery by injecting CO2 into the same hydraulic flow units from which the producing wells are withdrawing fluids. Completing injectors and producers in the same flow unit increases CO2 throughput, maximizes oil displacement efficiency, and controls pressure buildup. Additional injectors may surround the CO2 injection well and oil production wells in order to provide external pressure to these wells to prevent the injected CO2 from migrating from the pattern between two of the producing wells. Natural gas storage practices are similar in that to reduce the amount of "cushion" gas and increase the amount of cycled or working gas, edge wells may be used for withdrawal of gas and center wells used for gas injection. This reduces loss of gas to the formation via residual trapping far from the injection well. Moreover, this maximizes the natural gas storage efficiency between the injection and production wells and reduces the areal extent of the natural gas plume. Proposed U.S. EPA regulations include monitoring pressure and suggest the "plume" may be defined by pressure in addition to the CO2 saturated area. For pressure monitoring, it seems that this can only be accomplished by injection zone monitoring wells. For pressure, these wells would not need to be very

  4. Estimation of CO2 Transport Costs in South Korea Using a Techno-Economic Model

    Directory of Open Access Journals (Sweden)

    Kwangu Kang

    2015-03-01

    Full Text Available In this study, a techno–economic model was used to calculate the costs of CO2 transport and specify the major equipment required for transport in order to demonstrate and implement CO2 sequestration in the offshore sediments of South Korea. First, three different carbon capture and storage demonstration scenarios were set up involving the use of three CO2 capture plants and one offshore storage site. Each transport scenario considered both the pipeline transport and ship transport options. The temperature and pressure conditions of CO2 in each transport stage were determined from engineering and economic viewpoints, and the corresponding specifications and equipment costs were calculated. The transport costs for a 1 MtCO2/year transport rate were estimated to be US$33/tCO2 and US$28/tCO2 for a pipeline transport of ~530 km and ship transport of ~724 km, respectively. Through the economies of scale effect, the pipeline and ship transport costs for a transport rate of 3 MtCO2/year were reduced to approximately US$21/tCO2 and US$23/tCO2, respectively. A CO2 hub terminal did not significantly reduce the cost because of the short distance from the hub to the storage site and the small number of captured sources.

  5. Measuring water adsorption on mineral surfaces in air, CO2, and supercritical CO2 with a quartz-crystal microbalance

    Science.gov (United States)

    Bryan, C. R.; Wells, R. K.; Burton, P. D.; Heath, J. E.; Dewers, T. A.; Wang, Y.

    2011-12-01

    Carbon sequestration via underground storage in geologic formations is a proposed approach for reducing industrial CO2 emissions. However, current models for carbon injection and long-term storage of supercritical CO2 (scCO2) do not consider the development and stability of adsorbed water films at the scCO2-hydrophilic mineral interface. The thickness and properties of the water films control the surface tension and wettability of the mineral surface, and on the core scale, affect rock permeability, saturation, and capillary properties. The film thickness is strongly dependent upon the activity of water in the supercritical fluid, which will change as initially anhydrous scCO2 absorbs water from formation brine. As described in a companion paper by the coauthors, the thickness of the adsorbed water layer is controlled by the disjoining pressure; structural and van der Waals components dominate at low water activity, while electrostatic forces become more important with increasing film thickness (higher water activities). As scCO2 water activity and water layer thickness increase, concomitant changes in mineral surface properties and reservoir/caprock hydrologic properties will affect the mobility of the aqueous phase and of scCO2. Moreover, the development of a water layer may be critical to mineral dissolution reactions in scCO2. Here, we describe the use of a quartz-crystal microbalance (QCM) to monitor adsorption of water by mineral surfaces. QCMs utilize a piezoelectrically-stimulated quartz wafer to measure adsorbed or deposited mass via changes in vibrational frequency. When used to measure the mass of adsorbed liquid films, the frequency response of the crystal must be corrected for the viscoelastic, rather than elastic, response of the adsorbed layer. Results are presented for adsorption to silica in N2 and CO2 at one bar, and in scCO2. Additional data are presented for water uptake by clays deposited on a QCM wafer. In this case, water uptake occurs by the

  6. Role of CO2 in the formation of gold deposits.

    Science.gov (United States)

    Phillips, G N; Evans, K A

    2004-06-24

    Much of global gold production has come from deposits with uneconomic concentrations of base metals, such as copper, lead and zinc. These 'gold-only' deposits are thought to have formed from hot, aqueous fluids rich in carbon dioxide, but only minor significance has been attached to the role of the CO2 in the process of gold transport. This is because chemical bonding between gold ions and CO2 species is not strong, and so it is unlikely that CO2 has a direct role in gold transport. An alternative indirect role for CO2 as a weak acid that buffers pH has also appeared unlikely, because previously inferred pH values for such gold-bearing fluids are variable. Here we show that such calculated pH values are unlikely to record conditions of gold transport, and propose that CO2 may play a critical role during gold transport by buffering the fluid in a pH range where elevated gold concentration can be maintained by complexation with reduced sulphur. Our conclusions, which are supported by geochemical modelling, may provide a platform for new gold exploration methods.

  7. Adsorption and desorption on coals for CO2 sequestration

    Institute of Scientific and Technical Information of China (English)

    WANG Zuo-tang; FU Zhen-kun; ZHANG Ban-gan; WANG Guo-xiong; RUDOLPH Victor; HUO Li-wen

    2009-01-01

    Adsorption and desorption of carbon dioxide, methane and other gases on coals has been investigated experimentally using representative Zhongliangshan coals. Gas adsorption is one of the major concerns for both CO2 sequestration and methane recovery processes. The experiments were carried out using both single and multi-component mixtures at 25 ℃ and 30 ℃ with the highest pressure of 12 MPa. The coal was under moisture equilibrated conditions. This provides experimental data from which a predictive assessment of CO2 sequestration and/or methane recovery can be conducted. The results show that for pure gasses the CH4 adsorption capacity is higher than the N2 adsorption capacity but lower than the CO2 adsorption capacity. Injection of CO2 or other gases into the coal significantly affects CH4 desorption. This allows the enhancement of CH4 recovery from the coals, thus supplying more clean energy while sequestering significant amounts of CO2 thereby reducing the greenhouse effect from human beings.

  8. Environmental Kuznets curves for CO2. Heterogeneity versus homogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Vollebergh, Herman R.J.; Dijkgraaf, Elbert [Department of Economics, Erasmus University Rotterdam, Rotterdam (Netherlands); Melenberg, Bertrand [CentER for Economic Research, Tilburg University, Tilburg (Netherlands)

    2005-01-11

    We explore the emissions income relationship for CO2 in OECD countries using various modelling strategies.Even for this relatively homogeneous sample, we find that the inverted-U-shaped curve is quite sensitive to the degree of heterogeneity included in the panel estimations.This finding is robust, not only across different model specifications but also across estimation techniques, including the more flexible non-parametric approach.Differences in restrictions applied in panel estimations are therefore responsible for the widely divergent findings for an inverted-U shape for CO2.Our findings suggest that allowing for enough heterogeneity is essential to prevent spurious correlation from reduced-form panel estimations.Moreover, this inverted U for CO2 is likely to exist for many, but not for all, countries.

  9. Production of solar fuels by CO2 plasmolysis

    Directory of Open Access Journals (Sweden)

    Goede Adelbert P.H.

    2014-01-01

    Full Text Available A storage scheme for Renewable Energy (RE based on the plasmolysis of CO2into CO and O2 has been experimentally investigated, demonstrating high energy efficiency (>50% combined with high energy density, rapid start-stop and no use of scarce materials. The key parameter controlling energy efficiency has been identified as the reduced electric field. Basic plasma parameters including density and temperature are derived from a simple particle and energy balance model, allowing parameter specification of an upscale 100 kW reactor. With RE powered plasmolysis as the critical element, a CO2 neutral energy system becomes feasible when complemented by effective capture of CO2 at the input and separation of CO from the output gas stream followed by downstream chemical processing into hydrocarbon fuels.

  10. Capture CO2 from Ambient Air Using Nanoconfined Ion Hydration.

    Science.gov (United States)

    Shi, Xiaoyang; Xiao, Hang; Lackner, Klaus S; Chen, Xi

    2016-03-14

    Water confined in nanoscopic pores is essential in determining the energetics of many physical and chemical systems. Herein, we report a recently discovered unconventional, reversible chemical reaction driven by water quantities in nanopores. The reduction of the number of water molecules present in the pore space promotes the hydrolysis of CO3(2-) to HCO3(-) and OH(-). This phenomenon led to a nano-structured CO2 sorbent that binds CO2 spontaneously in ambient air when the surrounding is dry, while releasing it when exposed to moisture. The underlying mechanism is elucidated theoretically by computational modeling and verified by experiments. The free energy of CO3 (2-) hydrolysis in nanopores reduces with a decrease of water availability. This promotes the formation of OH(-), which has a high affinity to CO2 . The effect is not limited to carbonate/bicarbonate, but is extendable to a series of ions. Humidity-driven sorption opens a new approach to gas separation technology.

  11. A low energy aqueous ammonia CO2 capture process

    DEFF Research Database (Denmark)

    Gaspar, Jozsef; Waseem Arshad, Muhammad; Blaker, Eirik Ask

    2014-01-01

    The most pressing challenges regarding the use of ammonia for CO2 capture are the precipitation limitation and the energy penalty of solvent regeneration. Precipitation-free operation is a vital task since solids may cause the shutdown of the plant. Precipitation and slurry formation can be avoided...... by increasing temperature and L/G ratio but this leads to higher heat consumption, jeopardizing the economic feasibility. Here we developed, investigated, and optimized a novel CO2 capture process design using aqueous ammonia as solvent. The proposed configuration replaces the traditional stripper for solvent...... based CO2 capture with a thermal decomposition reactor. The overall energy penalty is reduced at the expense of introducing a solid handling section which consists of a saturation reactor, a crystallizer and a belt filter. The feasibility of the present approach is demonstrated by simulation. Flow...

  12. Effects of elevated CO2 and temperature on seed quality

    DEFF Research Database (Denmark)

    Hampton, John G; Boelt, Birte; Rolston, M P

    2013-01-01

    Successful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO2) and temperature during seed...... production on three seed quality components: seed mass, germination and seed vigour. In response to elevated CO2, seed mass has been reported to both increase and decrease in C3 plants, but not change in C4 plants. Increases are greater in legumes than non-legumes, and there is considerable variation among...... seed mass, reported seed germination responses to elevated CO2 have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High...

  13. Glacial CO2 Cycles: A Composite Scenario

    Science.gov (United States)

    Broecker, W. S.

    2015-12-01

    There are three main contributors to the glacial drawdown of atmospheric CO2 content: starvation of the supply of carbon to the ocean-atmosphere reservoir, excess CO2 storage in the deep sea, and surface-ocean cooling. In this talk, I explore a scenario in which all three play significant roles. Key to this scenario is the assumption that deep ocean storage is related to the extent of nutrient stratification of the deep Atlantic. The stronger this stratification, the larger the storage of respiration CO2. Further, it is my contention that the link between Milankovitch insolation cycles and climate is reorganizations of the ocean's thermohaline circulation leading to changes in the deep ocean's CO2 storage. If this is the case, the deep Atlantic d13C record kept in benthic foraminifera shells tells us that deep ocean CO2 storage follows Northern Hemisphere summer insolation cycles and thus lacks the downward ramp so prominent in the records of sea level, benthic 18O and CO2. Rather, the ramp is created by the damping of planetary CO2 emissions during glacial time intervals. As it is premature to present a specific scenario, I provide an example as to how these three contributors might be combined. As their magnitudes and shapes remain largely unconstrained, the intent of this exercise is to provoke creative thinking.

  14. Elevated CO2 and Soil Nitrogen Cycling

    Science.gov (United States)

    Hofmockel, K.; Schlesinger, W.

    2002-12-01

    Although forests can be large terrestrial carbon sinks, soil fertility can limit carbon sequestration in response to increased atmospheric CO2. During five years of CO2 fertilization (ambient + 200ppm) at the Duke Free-Air CO2 Enrichment (FACE) site, net primary production increased significantly by an average of 25% in treatment plots. Total nitrogen in the foliar canopy increased by 16%, requiring an additional 1.3 g N m-2yr-1 to be taken up from soils under elevated CO2. Mechanisms supporting increased nitrogen acquisition have not been identified. Here we report on biological N-fixation rates, using the acetylene reduction assay, in litter and mineral soil during three years of the CO2 enrichment experiment. Lack of a significant CO2 treatment effect on acetylene reduction indicates that carbon is not directly limiting biological N fixation. Nutrient addition experiments using a complete block design with glucose, Fe, Mo and P indicate biological N fixation is co-limited by molybdenum and carbon. These results suggest even if elevated atmospheric CO2 enhances below-ground carbon availability via root exudation, biological nitrogen fixation may not be stimulated due to micronutrient limitations. Assessment of future carbon sequestration by forest stands must consider limitations imposed by site fertility, including micronutrients.

  15. Magnetic properties of PrCo 2 and its ternary hydride PrCo 2H 4

    Science.gov (United States)

    de Jongh, L. J.; Bartolomé, J.; Greidanus, F. J. A. M.; de Groot, H. J. M.; Stipdonk, H. L.; Buschow, K. H. J.

    1981-12-01

    Magnetization and susceptibility data on PrCo 2 and PrCo 2H 4 are presented. The ac susceptibility of PrCo 2 measured in zero dc field displays a sharp and high peak at Tc = (39.9 ± 0.2) K. The magnetization versus temperature curves show ferromagnetic behaviour for B >1 T, but display a maximum at lower values of the applied field. These results, together with the behaviour of the hysteresis loops at different temperatures below Tc, indicate that PrCo 2 orders ferromagnetically, the magnetic hardness increasing strongly for T → 0. The saturation moment at 4.2 K equals 3.9 μ B per formula unit, as found from the magnetization curve measured in a pulsed-field magnet up to B = 30 T. Similar experiments on PrCo 2H 4 provide evidence that the introduction of hydrogen in PrCo 2 not only destroys the long-range atomic order, but also considerably reduces the ferromagnetic interactions. Such an effect of the hydrogen is commonly observed in cobalt intermetallics. Part of the PrCo 2H 4 is found to have decomposed into PrH 2 and free Co. The clusters of free Co atoms give rise to a maximum in the zero-field ac susceptibility versus temperature curves, similar as observed in spin glasses or magnetic glasses. By increasing the ac frequency, the maximum shifts to higher temperatures. The behavior can be explained in terms of the Néel model for superparamagnetic particles with randomly oriented local anisotropy axes.

  16. Adjusting the CO2 cap to subsidised RES generation: Can CO2 prices be decoupled from renewable policy?

    NARCIS (Netherlands)

    Richstein, J.C.; Chappin, E.J.L.; De Vries, L.J.

    2015-01-01

    The low prices in the European Emission Trading System (EU ETS) have triggered discussions of various possible reforms. One option is to decouple the CO 2 prices from renewable energy policy by adjusting the emission cap to renewable energy investment overshoots. We introduce two ways of reducing th

  17. Prediction of the viscosity reduction due to dissolved CO2 of and an elementary approach in the supercritical CO2 assisted continuous particle production of a polyester resin

    NARCIS (Netherlands)

    Nalawade, Sameer P.; Nieborg, Vincent H. J.; Picchioni, Francesco; Janssen, L. P. B. M.

    2006-01-01

    The dissolution of CO2 in a polymer causes plasticization of the polymer and hence, its viscosity is reduced. A model based on the free volume theory has been used for a polyester resin, which shows a considerable reduction in the viscosity due to dissolved M. Therefore, superctitical CO2 has been u

  18. Calcification by juvenile corals under heterotrophy and elevated CO2

    Science.gov (United States)

    Drenkard, E. J.; Cohen, A. L.; McCorkle, D. C.; de Putron, S. J.; Starczak, V. R.; Zicht, A. E.

    2013-09-01

    Ocean acidification (OA) threatens the existence of coral reefs by slowing the rate of calcium carbonate (CaCO3) production of framework-building corals thus reducing the amount of CaCO3 the reef can produce to counteract natural dissolution. Some evidence exists to suggest that elevated levels of dissolved inorganic nutrients can reduce the impact of OA on coral calcification. Here, we investigated the potential for enhanced energetic status of juvenile corals, achieved via heterotrophic feeding, to modulate the negative impact of OA on calcification. Larvae of the common Atlantic golf ball coral, Favia fragum, were collected and reared for 3 weeks under ambient (421 μatm) or significantly elevated (1,311 μatm) CO2 conditions. The metamorphosed, zooxanthellate spat were either fed brine shrimp (i.e., received nutrition from photosynthesis plus heterotrophy) or not fed (i.e., primarily autotrophic). Regardless of CO2 condition, the skeletons of fed corals exhibited accelerated development of septal cycles and were larger than those of unfed corals. At each CO2 level, fed corals accreted more CaCO3 than unfed corals, and fed corals reared under 1,311 μatm CO2 accreted as much CaCO3 as unfed corals reared under ambient CO2. However, feeding did not alter the sensitivity of calcification to increased CO2; ∆ calcification/∆Ω was comparable for fed and unfed corals. Our results suggest that calcification rates of nutritionally replete juvenile corals will decline as OA intensifies over the course of this century. Critically, however, such corals could maintain higher rates of skeletal growth and CaCO3 production under OA than those in nutritionally limited environments.

  19. Emission Mitigation of CO2 in Steel Industry:Current Status and Future Scenarios

    Institute of Scientific and Technical Information of China (English)

    HU Chang-qing; CHEN Li-yun; ZHANG Chun-xia; QI Yuan-hong; YIN Rui-yu

    2006-01-01

    The sustainable development against global warming is a challenge faced by societies at global level. For steel industry, the pressure of reducing CO2 emission is likely to last many years. During the past decades, the CO2 emission per ton steel has been reduced mainly due to the improvement of energy efficiency. Entering the 21st century, the steel manufacturing route must have three functions, namely, production of high performance steel products, conversion of energy, and treatment of waste. In the near future, it is expected that existing BF-BOF and EAF routes will be improved, in order to produce high performance steels, increase the use of scrap, and integrate steel industry with other industries for mitigating CO2 emission. In the long term, using carbon-free energy, reducing agents, and storing CO2 securely or converting CO2 into a harmless substance can be presumed for tremendous reduction in CO2 emission.

  20. CO2 laser in vitreoretinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Karlin, D.B.; Patel, C.K.; Wood, O.R.; Llovera, I.

    1980-01-01

    Radiation from a CO2 laser has the dual effect of phototransection and photocoagulation. Incisions have been made in scleral-chorioretinal tissue, lens tissue, and the vitreous body (with and without membrane formation). Results indicate that the CO2 laser may be useful in intravitreal surgery. Its simultaneous cutting and coagulating properties may make the experimental transvitreal chorioretinal biopsy and the full-thickness ocular wall resection for small melanosarcomas of the choroid clinical possibilities in the not too distant future. Finally, the effects of CO2 laser radiation on the normal human lens suggests the possibility of the dissolution of cataracts by laser irradiation.

  1. Spin polarization effect for Co2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Bao Wen-Sheng

    2007-01-01

    The density functional theory (DFT)(b3p86) of Gaussian 03 has been used to optimize the structure of the Co2molecule, a transition metal element molecule. The result shows that the ground state for the Co2 molecule is a 7-multiple state, indicating a spin polarization effect in the Co2 molecule. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state is not mingled with wavefunctions of higher-energy states. So for the ground state of Co2 molecule to be a 7-multiple state is the indicative of spin polarization effect of the Co2molecule, that is, there exist 6 parallel spin electrons in a Co2 molecule. The number of non-conjugated electrons is the greatest. These electrons occupy different spacial orbitals so that the energy of the Co2 molecule is minimized. It can be concluded that the effect of parallel spin in the Co2 molecule is larger than the effect of the conjugated molecule,which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state and the other states of the Co2 molecule are derived. The dissociation energy De for the ground state of Co2 molecule is 4.0489eV, equilibrium bond length Re is 0.2061 nm, and vibration frequency 11.2222 aJ.nm-4respectively(1 a.J=10-18 J). The other spectroscopic data for the ground state of Co2 molecule ωexe,Be, and αe are 0.7202 cm-1, 0.1347 cm-1, and 2.9120× 10-1 cm-1 respectively. And ωexe is the non-syntonic part of frequency, Be is the rotational constant, αe is revised constant of rotational constant for non-rigid part of Co2 molecule.

  2. Structurally simple complexes of CO2

    OpenAIRE

    Murphy, Luke J.; Robertson, Katherine N.; Richard A. Kemp; TUONONEN, Heikki; Clyburne, Jason A. C.

    2015-01-01

    The ability to bind CO2 through the formation of low-energy, easily-broken, bonds could prove invaluable in a variety of chemical contexts. For example, weak bonds to CO2 would greatly decrease the cost of the energy-intensive sorbent-regeneration step common to most carbon capture technologies. Furthermore, exploration of this field could lead to the discovery of novel CO2 chemistry. Reduction of complexed carbon dioxide might generate chemical feedstocks for the preparation of value-added p...

  3. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost-effective...... control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably...

  4. Reactivity of CO2 Activated on Transition Metals and Sulfur Ligands.

    Science.gov (United States)

    Kobayashi, Katsuaki; Tanaka, Koji

    2015-06-01

    Dicationic dicarbonyl [Ru(bpy)2(CO)2](2+) (bpy = 2,2'- bipyridyl) exists as equilibrium mixtures with [Ru(bpy)2(CO)(COOH)](+) and [Ru(bpy)2(CO)(CO2)](0) depending on the pH in H2O. Those three complexes work as the precursors to CO, HCOOH production, and CO2 carrier, respectively, in electro- and photochemical CO2 reduction in aqueous solutions. However, [Ru(bpy)2(CO)2](2+) loses the catalytic activity toward CO2 reduction under aprotic conditions because [Ru(bpy)2(CO)2](2+) is not regenerated from [Ru(bpy)2(CO)(CO2)](0) in the absence of proton sources. Analogous monocarbonylruthenium complexes such as [Ru(tpy)(bpy)(CO)](2+) and [Ru(bpy)2(qu)(CO)](2+) catalyze CO2 reduction in the absence and presence of proton sources. Both complexes are reproduced through oxide transfer from the corresponding Ru-CO2 to CO2 in CO2 reduction and produce the same amount of CO and CO3(2-) in the absence of proton donors. The reduction of CO2 catalyzed by polypyridylrhenium complexes in the presence of proton sources takes place via essentially the similar mechanism as that in the case of ruthenium complexes. On the other hand, CO evolution in CO2 reduction under aprotic conditions is ascribed to the dissociation of CO from a dimeric Re-C(O)OC(O)O-Re scaffold. Visible-light irradiation to a catalytic system composed of [Ru(bpy)2(CO)2](2+)/[Ru(bpy)3](2+)/Me2NH2(+)/Me2NH as the catalyst, photosensitizer, proton donor, and nucleophile in addition to the electron donor, respectively, in CO2-saturated CH3CN selectively produces N,N-dimethylformamide without concomitant CO and HCOOH formation. Structurally robust μ3-S of reduced metal-sulfur clusters provides a suitable site for reductive activation of CO2 with retention of the framework. Indeed, CO2 activated on μ3-S of [Fe6Mo2S8(SEt)3](5-) is fixed at the carbonyl carbon of thioesters trapped on a neighboring iron of the cluster, and α-keto acids are produced catalytically. Furthermore, two-electron reduction of [(CpMen)3M3S3](2+) (n

  5. Characterizing Uncertainties in Atmospheric Inversions of Fossil Fuel CO2 Emissions in California

    Science.gov (United States)

    Brophy, K. J.; Graven, H. D.; Manning, A.; Arnold, T.; Fischer, M. L.; Jeong, S.; Cui, X.; Parazoo, N.

    2016-12-01

    In 2006 California passed a law requiring greenhouse gas emissions be reduced to 1990 levels by 2020, equivalent to a 20% reduction over 2006-2020. Assessing compliance with greenhouse gas mitigation policies requires accurate determination of emissions, particularly for CO2 emitted by fossil fuel combustion (ffCO2). We found differences in inventory-based ffCO2 flux estimates for California total emissions of 11% (standard deviation relative to the mean), and even larger differences on some smaller sub-state levels. Top-down studies may be useful for validating ffCO2 flux estimates, but top-down studies of CO2 typically focus on biospheric CO2 fluxes and they are not yet well-developed for ffCO2. Implementing top-down studies of ffCO2 requires observations of a fossil fuel combustion tracer such as 14C to distinguish ffCO2 from biospheric CO2. However, even if a large number of 14C observations are available, multiple other sources of uncertainty will contribute to the uncertainty in posterior ffCO2 flux estimates. With a Bayesian inverse modelling approach, we use simulated atmospheric observations of ffCO2 at a network of 11 tower sites across California in an observing system simulation experiment to investigate uncertainties. We use four different prior ffCO2 flux estimates, two different atmospheric transport models, different types of spatial aggregation, and different assumptions for observational and model transport uncertainties to investigate contributions to posterior ffCO2 emission uncertainties. We show how various sources of uncertainty compare and which uncertainties are likely to limit top-down estimation of ffCO2 fluxes in California.

  6. Conversion of CO2 into biomass by microalgae: how realistic a contribution may it be to significant CO2 removal?

    Science.gov (United States)

    Acién Fernández, F Gabriel; González-López, C V; Fernández Sevilla, J M; Molina Grima, E

    2012-11-01

    Microalgae have been proposed as a CO(2) removal option to contribute to climate change avoidance and problems coming from the use of fossil fuels. However, even though microalgae can be used to fix CO(2) from air or flue gases, they do not permit long-term CO(2) storage because they are easily decomposed. On the other hand, microalgae can contribute to an enhancement in human sustainability by producing biofuels as an alternative to fossil fuels in addition to the production of other useful chemicals and commodities. Moreover, microalgae can contribute to enhancing the sustainability of waste treatment processes, reducing the energy consumed, and improving the recycling of nutrients contained within them. This paper reviews the potential contribution of these processes and the existing knowledge in these areas.

  7. COUPLING NORSOK CO2 CORROSION PREDICTION MODEL WITH PIPELINES THERMAL/HYDRAULIC MODELS TO SIMULATE CO2 CORROSION ALONG PIPELINES

    Directory of Open Access Journals (Sweden)

    MOKHTAR CHE ISMAIL

    2011-12-01

    Full Text Available Pipelines transporting oil and gas are vulnerable to internal corrosion when water forms a part of the transported fluids. The presence of carbon dioxide (CO2 in the fluid accelerates the corrosion rate due to its reaction with water which results in forming carbonic acid, and hence, water pH is reduced. The corrosion rate prediction is an important task needed to manage and control the corrosion. The prediction can be carried on by selecting one of many empirical and mechanistic models that developed for corrosion rate prediction. One of these models is NORSOK model, an empirical model developed by NORSOK Norwegian standard for CO2 corrosion prediction in straight pipes. In this paper NORSOK model has been coupled to thermal and hydraulic models to predict CO2 corrosion rate along pipelines.

  8. On the statistical optimality of CO2 atmospheric inversions assimilating CO2 column retrievals

    Directory of Open Access Journals (Sweden)

    F. Chevallier

    2015-04-01

    Full Text Available The extending archive of the Greenhouse Gases Observing SATellite (GOSAT measurements (now covering about six years allows increasingly robust statistics to be computed, that document the performance of the corresponding retrievals of the column-average dry air-mole fraction of CO2 (XCO2. Here, we compare a model simulation constrained by surface air-sample measurements with one of the GOSAT retrieval products (NASA's ACOS. The retrieval-minus-model differences result from various error sources, both in the retrievals and in the simulation: we discuss the plausibility of the origin of the major patterns. We find systematic retrieval errors over the dark surfaces of high-latitude lands and over African savannahs. More importantly, we also find a systematic over-fit of the GOSAT radiances by the retrievals over land for the high-gain detector mode, which is the usual observation mode. The over-fit is partially compensated by the retrieval bias-correction. These issues are likely common to other retrieval products and may explain some of the surprising and inconsistent CO2 atmospheric inversion results obtained with the existing GOSAT retrieval products. We suggest that reducing the observation weight in the retrieval schemes (for instance so that retrieval increments to the retrieval prior values are halved for the studied retrieval product would significantly improve the retrieval quality and reduce the need for (or at least reduce the complexity of ad-hoc retrieval bias correction. More generally, we demonstrate that atmospheric inversions cannot be rigorously optimal when assimilating XCO2 retrievals, even with averaging kernels.

  9. Large-scale CO2 storage — Is it feasible?

    Directory of Open Access Journals (Sweden)

    Johansen H.

    2013-06-01

    Full Text Available CCS is generally estimated to have to account for about 20% of the reduction of CO2 emissions to the atmosphere. This paper focuses on the technical aspects of CO2 storage, even if the CCS challenge is equally dependent upon finding viable international solutions to a wide range of economic, political and cultural issues. It has already been demonstrated that it is technically possible to store adequate amounts of CO2 in the subsurface (Sleipner, InSalah, Snøhvit. The large-scale storage challenge (several Gigatons of CO2 per year is more an issue of minimizing cost without compromising safety, and of making international regulations.The storage challenge may be split into 4 main parts: 1 finding reservoirs with adequate storage capacity, 2 make sure that the sealing capacity above the reservoir is sufficient, 3 build the infrastructure for transport, drilling and injection, and 4 set up and perform the necessary monitoring activities. More than 150 years of worldwide experience from the production of oil and gas is an important source of competence for CO2 storage. The storage challenge is however different in three important aspects: 1 the storage activity results in pressure increase in the subsurface, 2 there is no production of fluids that give important feedback on reservoir performance, and 3 the monitoring requirement will have to extend for a much longer time into the future than what is needed during oil and gas production. An important property of CO2 is that its behaviour in the subsurface is significantly different from that of oil and gas. CO2 in contact with water is reactive and corrosive, and may impose great damage on both man-made and natural materials, if proper precautions are not executed. On the other hand, the long-term effect of most of these reactions is that a large amount of CO2 will become immobilized and permanently stored as solid carbonate minerals. The reduced opportunity for direct monitoring of fluid samples

  10. Hoeveel CO2 kostte deze paprika?

    NARCIS (Netherlands)

    Smit, P.X.

    2011-01-01

    Ondernemers in de tuinbouwsector kunnen dankzij een nieuw protocol de CO2-voetafdruk van hun product van zaaigoed tot supermarktschap berekenen. Daarbij zit een tool die de telers, handelaren en transporteurs kan laten zien waar de uitstoot plaatsvindt.

  11. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase II proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  12. Translucent CO2 ice on Mars ?

    Science.gov (United States)

    Schmidt, Frederic; Andrieu, Francois; Douté, Sylvain; Schmitt, Bernard

    2016-10-01

    The Martian climate is driven by the condensation/sublimation of CO2 representing 95% of the atmosphere. Many active surface features (such dark spot, dark flows), have been potentially linked to CO2 exchange. Understanding the surface/atmosphere interactions is a major issue, for both atmospheric but also surface science. This study aims at estimating the physical properties of the seasonal CO2 ice deposits. Are these deposits granular or compact? What is the thickness of the ice? How much impurities are included within the ice? These questions have been highly debated in the literature, in particular the presence of a translucent slab ice, the link with the H2O cycle. In particular the cold jet geyser model requires translucent CO2 ice. We use radiative transfer models to simulate spectroscopic data from the CRISM instrument and perform an inversion to estimate model's parameters though time. We then discuss the consistency of the results with other datasets.

  13. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  14. CO2 Removal from Mars EMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CO2 control for during ExtraVehicular Activity (EVA) on mars is challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable...

  15. CO2 phytotron established in Ailaoshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Understanding the Uinteractions between ecological systems and the environment is a priority for the studies of global change, evolutionary biology, and functional genomics.Controlled environment facilities,like CO2 phytotrons, are necessary for acquiring such an understanding.

  16. CO2 Removal from Mars EMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A practical CO2 control system for ExtraVehicular Activity (EVA) on Mars have not yet been developed. TDA Research, Inc. proposes to develop a durable,...

  17. CO2-induced seawater acidification affects physiological performance of the marine diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    U. Riebesell

    2010-09-01

    Full Text Available CO2/pH perturbation experiments were carried out under two different pCO2 levels (39.3 and 101.3 Pa to evaluate effects of CO2-induced ocean acidification on the marine diatom Phaeodactylum tricornutum. After acclimation (>20 generations to ambient and elevated CO2 conditions (with corresponding pH values of 8.15 and 7.80, respectively, growth and photosynthetic carbon fixation rates of high CO2 grown cells were enhanced by 5% and 12%, respectively, and dark respiration stimulated by 34% compared to cells grown at ambient CO2. The half saturation constant (Km for carbon fixation (dissolved inorganic carbon, DIC increased by 20% under the low pH and high CO2 condition, reflecting a decreased affinity for HCO3– or/and CO2 and down-regulated carbon concentrating mechanism (CCM. In the high CO2 grown cells, the electron transport rate from photosystem II (PSII was photoinhibited to a greater extent at high levels of photosynthetically active radiation, while non-photochemical quenching was reduced compared to low CO2 grown cells. This was probably due to the down-regulation of CCM, which serves as a sink for excessive energy. The balance between these positive and negative effects on diatom productivity will be a key factor in determining the net effect of rising atmospheric CO2 on ocean primary production.

  18. Udvikling af CO2 neutralt byrumsarmatur

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Corell, Dennis Dan

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt.......Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt....

  19. The Twelve Principles of CO2 CHEMISTRY.

    Science.gov (United States)

    Poliakoff, Martyn; Leitner, Walter; Streng, Emilia S

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  20. The twelve principles of CO2 Chemistry

    OpenAIRE

    Poliakoff, Martyn; Leitner, Walter; Streng, Emelia S.

    2015-01-01

    This paper introduces a set of 12 Principles, based on the acronym CO2 CHEMISTRY, which are intended to form a set of criteria for assessing the viability of different processes or reactions for using CO2 as a feedstock for making organic chemicals. The principles aim to highlight the synergy of Carbon Dioxide Utilisation (CDU) with the components of green and sustainable chemistry as well as briefly pointing out the connection to the energy sector.

  1. Trapping atmospheric CO2 with gold.

    Science.gov (United States)

    Collado, Alba; Gómez-Suárez, Adrián; Webb, Paul B; Kruger, Hedi; Bühl, Michael; Cordes, David B; Slawin, Alexandra M Z; Nolan, Steven P

    2014-10-07

    The ability of gold-hydroxides to fix CO2 is reported. [Au(IPr)(OH)] and [{Au(IPr)}2(μ-OH)][BF4] react with atmospheric CO2 to form the trigold carbonate complex [{Au(IPr)}3(μ(3)-CO3)][BF4]. Reactivity studies revealed that this complex behaves as two basic and one cationic Au centres, and that it is catalytically active. DFT calculations and kinetic experiments have been carried out.

  2. Supercritical CO2 Extraction of Ethanol

    OpenAIRE

    GÜVENÇ, A.; MEHMETOĞLU, Ü.; ÇALIMLI, A.

    1999-01-01

    Extraction of ethanol was studied from both synthetic ethanol solution and fermentation broth using supercritical CO2 in an extraction apparatus in ranges of 313 to 333 K and 80 to 160 atmospheres, for varying extraction times. The experimental system consists mainly of four parts: a CO2 storage system, a high-pressure liquid pump, an extractor and a product collection unit. Samples were analyzed by gas chromatography. Effects of temperature, pressure, extraction time, initial ethan...

  3. Effect of elevated ambient CO2 concentration on water use efficiency of Pinus sylvestriformis

    Institute of Scientific and Technical Information of China (English)

    Han Shijie; Zhang Junhui; Wang Chenrui; Zou Chunjing; Zhou Yumei; Wang Xiaochun

    1999-01-01

    Pinus sylvestriformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species ( 11-year old ) was studied on response to elevated CO2 concentration at 500± 100 μL· L-1 by directly injecting CO2 into the canopy under natural condition in 1998-1999. The results showed that the elevated CO2 concentration reduced averagely stomatal opening, stomatal conductance and stomatal density to 78%, 80% and 87% respectively, as compared to normal ambient. The elevated CO2 reduced the transpiration and enhances the water use efficiency (WUE) of plant.

  4. Density of aqueous solutions of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio E.

    2001-10-10

    In this report, we present a numerical representation for the partial molar volume of CO2 in water and the calculation of the corresponding aqueous solution density. The motivation behind this work is related to the importance of having accurate representations for aqueous phase properties in the numerical simulation of carbon dioxide disposal into aquifers as well as in geothermal applications. According to reported experimental data the density of aqueous solutions of CO2 can be as much as 2-3% higher than pure water density. This density variation might produce an influence on the groundwater flow regime. For instance, in geologic sequestration of CO2, convective transport mixing might occur when, several years after injection of carbon dioxide has stopped, the CO2-rich gas phase is concentrated at the top of the formation, just below an overlaying caprock. In this particular case the heavier CO2 saturated water will flow downward and will be replaced by water with a lesser CO2 content.

  5. On the Vertical Gradient in CO2

    Science.gov (United States)

    Stine, A. R.; Fung, I. Y.

    2008-12-01

    Attempts to constrain surface fluxes of carbon from atmospheric measurements of carbon dioxide have primarily focused on surface boundary layer measurements, because information about surface fluxes is least diluted close to the locations where the fluxes occur. However, errors in model ventilation of air in the vertical can be misinterpreted as local surface fluxes. Satellites which measure column integrated CO2 are expected to represent a major advance in part because they observe the entire atmospheric column. Recent work has highlighted the fact that vertical gradients in carbon concentrations can give us information about where vertical mixing errors are likely to be misinterpreted as local surface fluxes, but passive tracer evidence suggests that models that capture vertical profiles on the ocean do poorly on the land (and vice versa), suggesting that the problem of correctly treating vertical mixing in inverse studies is more fundamental than picking the "best" model. We consider observations of the vertical gradient in CO2 from aircrafts and from a comparison of satellites that observe in the near infrared (which observe the column integrated CO2 field) and the thermal infrared (which observe the upper troposphere). We evaluate the feasibility of using these satellites for determining the vertical gradient in CO2. We examine how observations of the vertical gradient of CO2 allow us to differentiate the imprint of vertical mixing and the imprint in surface fluxes on the observed field of atmospheric CO2.

  6. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available BACKGROUND: CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. METHODOLOGY/PRINCIPAL FINDINGS: We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days. CONCLUSIONS/SIGNIFICANCE: Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  7. Interactive Effects of Elevated CO2 and Temperature on Rice Planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    SHI Bao-kun; HUANG Jian-li; HU Chao-xing; HOU Mao-lin

    2014-01-01

    It is predicted that the current atmospheric CO2 concentration will be doubled and global mean temperature will increase by 1.5-6°C by the end of this century. Although a number of studies have addressed the separate effects of CO2 and temperature on plant-insect interactions, few have concerned with their combined impacts. In the current study, a factorial experiment was carried out to examine the effect of a doubling CO2 concentration and a 3°C temperature increase on a complete generation of the brown planthopper (Nilaparvata lugens) on rice (Oryza sativa). Both elevated CO2 and temperature increased rice stem height and biomass of stem parts. Leaf chlorophyll content increased under elevated CO2, but only in ambient temperature treatment. Water content of stem parts was reduced under elevated temperature, but only when coupled with elevated CO2. Elevated CO2 alone increased biomass of root and elevated temperature alone enhanced leaf area and reduced ratio of root to stem parts. Brown planthopper (BPH) nymphal development was accelerated, and weight of and honeydew excretion by the F1 adults was reduced under elevated temperature only. Longevity of brachypterous females was affected by a signiifcant interaction between CO2 and temperature. At elevated temperature, CO2 had no effect on female longevity, but at ambient temperature, the females lived shorter under elevated CO2. Female fecundity was higher at elevated than at ambient temperature and higher at elevated CO2 than at ambient CO2. These results indicate that the combined effects of elevated temperature and CO2 may enhance the brown planthopper population size.

  8. CO2 Capture by Carbon Aerogel–Potassium Carbonate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2016-01-01

    Full Text Available Recently, various composites for reducing CO2 emissions have been extensively studied. Because of their high sorption capacity and low cost, alkali metal carbonates are recognized as a potential candidate to capture CO2 from flue gas under moist conditions. However, undesirable effects and characteristics such as high regeneration temperatures or the formation of byproducts lead to high energy costs associated with the desorption process and impede the application of these materials. In this study, we focused on the regeneration temperature of carbon aerogel–potassium carbonate (CA–KC nanocomposites, where KC nanocrystals were formed in the mesopores of the CAs. We observed that the nanopore size of the original CA plays an important role in decreasing the regeneration temperature and in enhancing the CO2 capture capacity. In particular, 7CA–KC, which was prepared from a CA with 7 nm pores, exhibited excellent performance, reducing the desorption temperature to 380 K and exhibiting a high CO2 capture capacity of 13.0 mmol/g-K2CO3, which is higher than the theoretical value for K2CO3 under moist conditions.

  9. Catalytic gasification of biomass (Miscanthus) enhanced by CO2 sorption.

    Science.gov (United States)

    Zamboni, I; Debal, M; Matt, M; Girods, P; Kiennemann, A; Rogaume, Y; Courson, C

    2016-11-01

    The main objective of this work concerns the coupling of biomass gasification reaction and CO2 sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO2 sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca12Al14O33/olivine bi-functional materials to reduce heavy tar production. Experiments have been carried out in a fluidized bed gasifier using steam as the fluidizing medium to improve hydrogen production. Bed materials consisting of CaO-based oxide for CO2 sorption (CaO-Ca12Al14O33) deposited on olivine for tar reduction were synthesized, their structural and textural properties were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and temperature-programmed reduction (TPR) methods, and the determination of their sorption capacity and stability analyzed by thermogravimetric analysis (TGA). It appears that this CaO-Ca12Al14O33/olivine sorbent/catalyst presents a good CO2 sorption stability (for seven cycles of carbonation/decarbonation). Compared to olivine and Fe/olivine in a fixed bed reactor for steam reforming of toluene chosen as tar model compound, it shows a better hydrogen production rate and a lower CO2 selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca12Al14O33/olivine as bed material at 700 °C leads to a higher H2 production than olivine at 800 °C thanks to CO2 sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 °C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.

  10. A rapid transition from ice covered CO2–rich waters to a biologically mediated CO2 sink in the eastern Weddell Gyre

    Directory of Open Access Journals (Sweden)

    W. Geibert

    2008-09-01

    Full Text Available Circumpolar Deep Water (CDW, locally called Warm Deep Water (WDW, enters the Weddell Gyre in the southeast, roughly at 25° E to 30° E. In December 2002 and January 2003 we studied the effect of entrainment of WDW on the fugacity of carbon dioxide (fCO2 and dissolved inorganic carbon (DIC in Weddell Sea surface waters. Ultimately the fCO2 difference across the sea surface drives air-sea fluxes of CO2. Deep CTD sections and surface transects of fCO2 were made along the Prime Meridian, a northwest-southeast section, and along 17° E to 23° E during cruise ANT XX/2 on FS Polarstern. Upward movement and entrainment of WDW into the winter mixed layer had significantly increased DIC and fCO2 below the sea ice along 0° W and 17° E to 23° E, notably in the southern Weddell Gyre. Nonetheless, the ice cover largely prevented outgassing of CO2 to the atmosphere. During and upon melting of the ice, biological activity rapidly reduced surface water fCO2 by up to 100 μatm, thus creating a sink for atmospheric CO2. Despite the tendency of the surfacing WDW to cause CO2 supersaturation, the Weddell Gyre may well be a CO2 sink on an annual basis due to this effective mechanism involving ice cover and ensuing biological fCO2 reduction. Dissolution of calcium carbonate (CaCO3 in melting sea ice may play a minor role in this rapid reduction of surface water fCO2.

  11. CO2 capture using fly ash from coal fired power plant and applications of CO2-captured fly ash as a mineral admixture for concrete.

    Science.gov (United States)

    Siriruang, Chaichan; Toochinda, Pisanu; Julnipitawong, Parnthep; Tangtermsirikul, Somnuk

    2016-04-01

    The utilization of fly ash as a solid sorbent material for CO2 capture via surface adsorption and carbonation reaction was evaluated as an economically feasible CO2 reduction technique. The results show that fly ash from a coal fired power plant can capture CO2 up to 304.7 μmol/g fly ash, consisting of 2.9 and 301.8 μmol/g fly ash via adsorption and carbonation, respectively. The CO2 adsorption conditions (temperature, pressure, and moisture) can affect CO2 capture performance of fly ash. The carbonation of CO2 with free CaO in fly ashes was evaluated and the results indicated that the reaction consumed most of free CaO in fly ash. The fly ashes after CO2 capture were further used for application as a mineral admixture for concrete. Properties such as water requirement, compressive strength, autoclave expansion, and carbonation depth of mortar and paste specimens using fly ash before and after CO2 capture were tested and compared with material standards. The results show that the expansion of mortar specimens using fly ash after CO2 capture was greatly reduced due to the reduction of free CaO content in the fly ash compared to the expansion of specimens using fresh fly ash. There were no significant differences in the water requirement and compressive strength of specimens using fly ash, before and after CO2 capture process. The results from this study can lead to an alternative CO2 capture technique with doubtless utilization of fly ash after CO2 capture as a mineral admixture for concrete.

  12. CO2地质封存和提高天然气采收率%Geological Storage of CO2 and Enhanced Gas Recovery

    Institute of Scientific and Technical Information of China (English)

    孙晓岭; 曾凡桂; 刘贺娟

    2012-01-01

    The CCS technology (CO2 capture and storage)that was addressed by developed countries , such as USA, Canada, Germany, Holland and so on demonstrating that the C02 can be injected underground or deep sea to reduce the emission of CO2 into atmosphere. These sites include saline aquifer, unmineral coal seam (CO2—ECBM), depleted oil or gas field (CO2-EOR/EGR). The CCS technology seems like become the most important way to solve the CO2 emission problem and at the same time, which can also produce some commercial belief. In this paper, as one kind of the CCS technology, CO2-EGR technology has been summarized, including the projects in the world, the critical issues, challenges and the prospect.%目前发达国家,如美国、加拿大、德国、荷兰等兴起的CCS(CO2 capture and storage)技术,即将CO2储存到地下或深海中,包括盐水层、不可开采煤层(CO2-ECBM)、废弃油田(CO2-EOR)、废弃气田(CO2-EGR),已成为解决CO2排放和保护环境的重要举措,而且也可能产生相应的商业利益.本文从CO2提高天然气的采收率角度就这一技术进行概括,研究世界上该类工程的开展情况、技术的关键问题、面临的挑战以及发展前景.

  13. Integrated Solvent Design for CO2 Capture and Viscosity Tuning

    Energy Technology Data Exchange (ETDEWEB)

    Cantu Cantu, David; Malhotra, Deepika; Koech, Phillip K.; Heldebrant, David J.; Zheng, Feng; Freeman, Charles J.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra

    2017-07-03

    We present novel design strategies for reduced viscosity single-component, water-lean CO2 capture organic solvent systems. Through molecular simulation, we identify the main molecular-level descriptor that influences bulk solvent viscosity. Upon loading, a zwitterionic structure forms with a small activation energy of ca 16 kJ/mol and a small stabilization of ca 6 kJ/mol. Viscosity increases exponentially with CO2 loading due to hydrogen-bonding between neighboring Zwitterions. We find that molecular structures that promote internal hydrogen bonding (within the same molecule) and suppress interactions with neighboring molecules have low viscosities. In addition, tuning the acid/base properties leads to a shift of the equilibrium toward a non-charged (acid) form that further reduces the viscosity. Based on the above structural criteria, a reduced order model is also presented that allows for the quick screening of large compound libraries and down selection of promising candidates for synthesis and testing.

  14. Precursory volcanic CO2 signals from space

    Science.gov (United States)

    Schwandner, Florian M.; Carn, Simon A.; Kataoka, Fumie; Kuze, Akihiko; Shiomi, Kei; Goto, Naoki

    2016-04-01

    Identification of earliest signals heralding volcanic unrest benefits from the unambiguous detection of precursors that reflect deviation of magmatic systems from metastable background activity. Ascent and emplacement of new basaltic magma at depth may precede eruptions by weeks to months. Transient localized carbon dioxide (CO2) emissions stemming from exsolution from depressurized magma are expected, and have been observed weeks to months ahead of magmatic surface activity. Detecting such CO2 precursors by continuous ground-based monitoring operations is unfortunately not a widely implemented method yet, save a handful of volcanoes. Detecting CO2 emissions from space offers obvious advantages - however it is technologically challenging, not the least due to the increasing atmospheric burden of CO2, against which a surface emission signal is hard to discern. In a multi-year project, we have investigated the feasibility of space-borne detection of pre-eruptive volcanic CO2 passive degassing signals using observations from the Greenhouse Gas Observing SATellite (GOSAT). Since 2010, we have observed over 40 active volcanoes from space using GOSAT's special target mode. Over 72% of targets experienced at least one eruption over that time period, demonstrating the potential utility of space-borne CO2 observations in non-imaging target-mode (point source monitoring mode). While many eruption precursors don't produce large enough CO2 signals to exceed space-borne detection thresholds of current satellite sensors, some of our observations have nevertheless already shown significant positive anomalies preceding eruptions at basaltic volcanoes. In 2014, NASA launched its first satellite dedicated to atmospheric CO2 observation, the Orbiting Carbon Observatory (OCO-2). Its observation strategy differs from the single-shot GOSAT instrument. At the expense of GOSAT's fast time series capability (3-day repeat cycle, vs. 16 for OCO-2), its 8-footprint continuous swath can slice

  15. Primary, secondary, and tertiary amines for CO2 capture: designing for mesoporous CO2 adsorbents.

    Science.gov (United States)

    Ko, Young Gun; Shin, Seung Su; Choi, Ung Su

    2011-09-15

    CO(2) emissions, from fossil-fuel-burning power plants, the breathing, etc., influence the global worming on large scale and the man's work efficiency on small scale. The reversible capture of CO(2) is a prominent feature of CO(2) organic-inorganic hybrid adsorbent to sequester CO(2). Herein, (3-aminopropyl) trimethoxysilane (APTMS), [3-(methylamino)propyl] trimethoxysilane (MAPTMS), and [3-(diethylamino) propyl] trimethoxysilane (DEAPTMS) are immobilized on highly ordered mesoporous silicas (SBA-15) to catch CO(2) as primary, secondary, and tertiary aminosilica adsorbents. X-ray photoelectron spectroscopy was used to analyze the immobilized APTMS, MAPTMS, and DEAPTMS on the SBA-15. We report an interesting discovery that the CO(2) adsorption and desorption on the adsorbent depend on the amine type of the aminosilica adsorbent. The adsorbed CO(2) was easily desorbed from the adsorbent with the low energy consumption in the order of tertiary, secondary, and primary amino-adsorbents while the adsorption amount and the bonding-affinity increased in the reverse order. The effectiveness of amino-functionalized (1(o), 2(o), and 3(o) amines) SBA-15s as a CO(2) capturing agent was investigated in terms of adsorption capacity, adsorption-desorption kinetics, and thermodynamics. This work demonstrates apt amine types to catch CO(2) and regenerate the adsorbent, which may open new avenues to designing "CO(2) basket".

  16. Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

    Science.gov (United States)

    Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

    2016-04-01

    In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

  17. Accelerated carbonation of steel slags using CO2 diluted sources: CO2 uptakes and energy requirements

    Directory of Open Access Journals (Sweden)

    Renato eBaciocchi

    2016-01-01

    Full Text Available This work presents the results of carbonation experiments performed on Basic Oxygen Furnace (BOF steel slag samples employing gas mixtures containing 40 and 10% CO2 vol. simulating the gaseous effluents of gasification and combustion processes respectively, as well as 100% CO2 for comparison purposes. Two routes were tested, the slurry phase (L/S=5 l/kg, T=100 °C and Ptot=10 bar and the thin film (L/S =0.3-0.4 l/kg, T=50 °C and Ptot=7-10 bar routes. For each one, the CO2 uptake achieved as a function of the reaction time was analyzed and on this basis the energy requirements associated to each carbonation route and gas mixture composition were estimated considering to store the CO2 emissions of a medium size natural gas fired power plant (20 MW. For the slurry phase route, maximum CO2 uptakes ranged from around 8% at 10% CO2, to 21.1% (BOF-a and 29.2% (BOF-b at 40% CO2 and 32.5% (BOF-a and 40.3% (BOF-b at 100% CO2. For the thin film route, maximum uptakes of 13% (BOF-c and 19.5% (BOF-d at 40% CO2, and 17.8% (BOF-c and 20.2% (BOF-d at 100% were attained. The energy requirements of the two analyzed process routes appeared to depend chiefly on the CO2 uptake of the slag. For both process route, the minimum overall energy requirements were found for the tests with 40% CO2 flows (i.e. 1400-1600 MJ/t CO2 for the slurry phase and 2220-2550 MJ/t CO2 for the thin film route.

  18. Energy analysis of the cryogenic CO2 capture process based on Stirling coolers

    OpenAIRE

    Song, Chunfeng; Kitamura, Yutaka; Li, Shuhong

    2014-01-01

    In the existing coal-fired power plants, the energy penalty associated with CO2 capture process is an important challenge. For this reason, energy analysis has been widely used as a powerful tool to optimize the capture efficiency and reduce energy consumption. In our previous work, a Stirling cooler based cryogenic CO2 capture system was outlined. Process simulation and energy analysis of the system were undertaken in this research. The whole CO2 capture process is composed of three sections...

  19. Regional CO2 flux estimates for 2009–2010 based on GOSAT and ground-based CO2 observations

    Directory of Open Access Journals (Sweden)

    S. Maksyutov

    2013-09-01

    Full Text Available We present the application of a global carbon cycle modeling system to the estimation of monthly regional CO2 fluxes from the column-averaged mole fractions of CO2 (XCO2 retrieved from spectral observations made by the Greenhouse gases Observing SATellite (GOSAT. The regional flux estimates are to be publicly disseminated as the GOSAT Level 4 data product. The forward modeling components of the system include an atmospheric tracer transport model, an anthropogenic emissions inventory, a terrestrial biosphere exchange model, and an oceanic flux model. The atmospheric tracer transport was simulated using isentropic coordinates in the stratosphere and was tuned to reproduce the age of air. We used a fossil fuel emission inventory based on large point source data and observations of nighttime lights. The terrestrial biospheric model was optimized by fitting model parameters to observed atmospheric CO2 seasonal cycle, net primary production data, and a biomass distribution map. The oceanic surface pCO2 distribution was estimated with a 4-D variational data assimilation system based on reanalyzed ocean currents. Monthly CO2 fluxes of 64 sub-continental regions, between June 2009 and May 2010, were estimated from GOSAT FTS SWIR Level 2 XCO2 retrievals (ver. 02.00 gridded to 5° × 5° cells and averaged on a monthly basis and monthly-mean GLOBALVIEW-CO2 data. Our result indicated that adding the GOSAT XCO2 retrievals to the GLOBALVIEW data in the flux estimation brings changes to fluxes of tropics and other remote regions where the surface-based data are sparse. The uncertainties of these remote fluxes were reduced by as much as 60% through such addition. Optimized fluxes estimated for many of these regions, were brought closer to the prior fluxes by the addition of the GOSAT retrievals. In most of the regions and seasons considered here, the estimated fluxes fell within the range of natural flux variabilities estimated with the component models.

  20. Effect of coadsorbed CO 2 on the magnetic properties of O 2 confined in graphitic slit-shaped micropores

    Science.gov (United States)

    Tohdoh, A.; Kaneko, K.

    2001-05-01

    The magnetic susceptibility of coadsorbed O 2 and CO 2 confined in a slit-shaped graphitic micropore was measured over the temperature range 2-300 K. Coadsorbed CO 2 markedly repressed the susceptibility of confined O 2 because CO 2 restricts the O 2 molecular arrangement to form spin clusters. Curie-Weiss plots show that the coadsorbed CO 2 reduced the effective spin concentration while the negative Weiss constant with CO 2 was larger than that of pure O 2. These results also indicate that the coadsorbed CO 2 promotes the formation of smaller clusters of O 2 molecules than for pure O 2.

  1. Carbon Dioxide Clusters: (CO_2)_6 to (CO_2)13

    Science.gov (United States)

    McKellar, A. R. W.; Oliaee, J. Norooz; Dehghany, M.; Moazzen-Ahmadi, N.

    2011-06-01

    We recenty reported assignments of specific infrared bands in the CO_2 νb{3} region (˜2350 wn) to (CO_2)_6, (CO_2)_7, (CO_2)_9, (CO_2)10, (CO_2)11, (CO_2)12, and (CO_2)13. Spectra are obtained by direct absorption using a rapid-scan tuneable diode laser spectrometer to probe a pulsed supersonic slit-jet expansion and assignments are facilitated by recent calculations of Takeuchi based on the Murthy potential. (CO_2)_6 is a symmetric top with S_6 point group symmetry which can be thought of as a stack of two planar cyclic trimers. (CO_2)13 is also an S_6 symmetric top, and consists of a single CO_2 monomer surrounded by an slightly distorted icosahedral cage. The remaining clusters are asymmetric tops without symmetry. Here we report additional CO_2 cluster results. Calculations based on the SAPT-s potential indicate that the structure of (CO_2)10 may be slightly different from that given by Takeuchi/Murthy. An additional band is observed for each of (CO_2)13 and (CO_2)10. A feature observed at 2378.2 wn is assigned as a (CO_2)_6 parallel combination band involving the sum of a fundamental and a low-lying intermolecular vibration. Most significantly, two bands are assigned to a second isomer of (CO_2)_6. This is also a symmetric top, but now with S_4 symmetry. The two symmetric hexamer isomers observed spectroscopically correspond well with the lowest energy structures given by both the SAPT-s and Murthy intermolecular potentials. [1] J. Norooz Oliaee, M. Dehgany, N. Moazzen-Ahmadi, and A.R.W. McKellar, Phys. Chem. Chem. Phys. 13, 1297 (2011). [2] H. Takeuchi, J. Phys. Chem. A 107, 5703 (2008); C.S. Murthy, S.F. O'Shea, and I.R. McDonald, Mol. Phys. 50, 531 (1983). [3] R. Bukowski, J. Sadlej, B. Jeziorski, P. Jankowski, K. Szalewicz, S.A. Kucharski, H.L. Williams, and B.M. Rice, J. Chem. Phys. 110, 3785 (1999)

  2. Effect of dolomite decomposition under CO2 on its multicycle CO2 capture behaviour under calcium looping conditions.

    Science.gov (United States)

    de la Calle Martos, Antonio; Valverde, Jose Manuel; Sanchez-Jimenez, Pedro E; Perejón, Antonio; García-Garrido, Cristina; Perez-Maqueda, Luis A

    2016-06-28

    One of the major drawbacks that hinder the industrial competitiveness of the calcium looping (CaL) process for CO2 capture is the high temperature (∼930-950 °C) needed in practice to attain full calcination of limestone in a high CO2 partial pressure environment for short residence times as required. In this work, the multicycle CO2 capture performance of dolomite and limestone is analysed under realistic CaL conditions and using a reduced calcination temperature of 900 °C, which would serve to mitigate the energy penalty caused by integration of the CaL process into fossil fuel fired power plants. The results show that the fundamental mechanism of dolomite decomposition under CO2 has a major influence on its superior performance compared to limestone. The inert MgO grains resulting from dolomite decomposition help preserve a nanocrystalline CaO structure wherein carbonation in the solid-state diffusion controlled phase is promoted. The major role played by the dolomite decomposition mechanism under CO2 is clearly demonstrated by the multicycle CaO conversion behaviour observed for samples decomposed at different preheating rates. Limestone decomposition at slow heating rates yields a highly crystalline and poorly reactive CaCO3 structure that requires long periods to fully decarbonate and shows a severely reduced capture capacity in subsequent cycles. On the other hand, the nascent CaCO3 produced after dolomite half-decomposition consists of nanosized crystals with a fast decarbonation kinetics regardless of the preheating rate, thus fully decomposing from the very first cycle at a reduced calcination temperature into a CaO skeleton with enhanced reactivity as compared to limestone derived CaO.

  3. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2

    Science.gov (United States)

    Kawa, Randy; Huisheng, Bian

    2004-01-01

    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  4. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost-effective co...... profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future.......The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost......-effective control which can solve future global environmental problems. The gains from CO2 trade may give vital financial subsidies from the EU to Eastern Europe, for example, and it will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further...

  5. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost-effective co...... not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future.......The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost......-effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably...

  6. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    by the Ministry of Transport, with the Technical University of Denmark as one of the main contributors. The CO2-strategy was to be based on the principle of cost-effectiveness. A model was set up to assist in the assessment. The model consists of a projection of CO2-emissions from road and rail modes from 2020...... are evaluated according to CO2 reduction potential and according to the ‘shadow price’ on a reduction of one ton CO2. The shadow price reflects the costs (and benefits) of the different measures. Comparing the measures it is possible to identify cost effective measures, but these measures are not necessarily......, a scenario-part and a cost-benefit part. Air and sea modes are not analyzed. The model adopts a bottom-up approach to allow a detailed assessment of transport policy measures. Four generic areas of intervention were identified and the likely effect on CO2 emissions, socioeconomic efficiency and other...

  7. Infrared absorption spectroscopy of CO2-HX complexes using the CO2 asymmetric stretch chromophore: CO2HF(DF) and CO2HCl(DCl) linear and CO2HBr bent equilibrium geometries

    Science.gov (United States)

    Sharpe, S. W.; Zeng, Y. P.; Wittig, C.; Beaudet, R. A.

    1990-01-01

    Infrared absorption spectra associated with the CO2 asymmetric stretch vibration have been recorded for weakly bonded gas-phase complexes of CO2 with HF, DF, HCl, DCl, and HBr, using tunable diode laser spectroscopy and a pulsed slit expansion (0.15×38 mm2) that provides >20 MHz overall resolution. Results obtained with CO2-HF are in agreement with earlier studies, in which the HF-stretch region near 3900 cm-1 was examined. In both cases, broad linewidths suggest subnanosecond predissociation. With CO2-DF, the natural linewidths are markedly narrower than with CO2-HF (e.g., 28 vs 182 MHz), and this difference is attributed to slower predissociation, possibly implicating resonances in the case of CO2-HF. Both CO2-HF and CO2-DF exhibited overlapping features: simple P and R branches associated with a linear rotor, and P and R branches containing doublets. As in earlier studies, the second feature can be assigned to either a slightly asymmetric rotor with Ka=1, or a hot band involving a low-frequency intermolecular bend mode. Results obtained with CO2-HCl are in excellent agreement with earlier microwave measurements on the ground vibrational state, and the vibrationally excited state is almost identical to the lower state. Like CO2-DF, linewidths of CO2-HCl and CO2-DCl are much sharper than those of CO2-HF, and in addition, CO2-HCl and CO2-DCl exhibited weak hot bands, as were also evident with CO2-HF and CO2-DF. Upon forming complexes with either HF or HCl, the asymmetric stretch mode of CO2 underwent a blue shift relative to uncomplexed CO2. This can be understood in terms of the nature of the hydrogen bonds, and ab initio calculations are surprisingly good at predicting these shifts. Deuteration of both HF and HCl resulted in further blue shifts of the band origins. These additional shifts are attributed to stronger intermolecular interactions, i.e., deuteration lowers the zero-point energy, and in a highly anharmonic field this results in a more compact average

  8. Subsurface Barrier Formation as a CO2 Leakage Mitigation Technology

    Science.gov (United States)

    Castaneda Herrera, C. A.; Stevens, G.; Haese, R. R.

    2015-12-01

    Long-term CO2 containment in a geological storage reservoir is a key criterion for successfully implementing carbon capture and storage (CCS), however, CO2 leakage through different pathways cannot be completely ruled out in some instances. In this study we investigate the conditions for reactive barrier formation as a technology to mitigate and remediate CO2 leakage. We propose to inject a liquid reagent consistent of an alkaline sodium-silicate solution on top of the storage caprock, which will lead to silica mineral precipitation when in contact with an acidic, CO2-enriched fluid. This reaction will create a barrier that seals the leakage by reducing the permeability. Preliminary modelling has shown that the density, viscosity and alkalinity of the reagent fluid are critical for a successful seal formation, whereas differences in formation water composition and in the rock mineral composition are less important. In order to study the reaction through experiments, different reagent solutions were prepared and characterised in terms of silica concentration, density, viscosity and buffer capacity. In a static, diffusion-controlled batch experiment we observed silica mineral precipitation in the outer layer of the piece of rock inhibiting further mixing of the two fluids and slowing down the initial reaction rate. Core-flood experiments will be carried out to simulate barrier formation under fluid flow conditions. Here, the sealing efficiency of the reaction will be continuously measured in terms of a change in permeability.

  9. Overview on CO2 valorisation: challenge of molten carbonates

    Directory of Open Access Journals (Sweden)

    Déborah eChery

    2015-10-01

    Full Text Available The capture and utilisation of CO2 is becoming progressively one of the significant challenges in the field of energetic resources. Whatever the energetic device, it is impossible to avoid completely the production of greenhouse gas, even parting from renewable energies. Transforming CO2 in a valuable fuel, such as alcohols, CO or even C, could constitute a conceptual revolution in the energetic bouquet offering a huge application domain. Although several routes have been tested for this purpose, on which a general panorama will be given here, molten carbonates are attracting a renewed interest aiming at dissolving and reducing carbon dioxide in such melts. Because of their unique properties, molten carbonates are already used as electrolytes in molten carbonate fuel cells; they can also provoke a breakthrough in a new economy considering CO2 as an energetic source rather than a waste. Molten carbonates science and technology is becoming a strategic field of research for energy and environmental issues. Our aim in this review is to put in evidence the benefits of molten carbonates to valorise CO2 and to show that it is one of the most interesting routes for such application.

  10. Costs of mitigating CO2 emissions from passenger aircraft

    Science.gov (United States)

    Schäfer, Andreas W.; Evans, Antony D.; Reynolds, Tom G.; Dray, Lynnette

    2016-04-01

    In response to strong growth in air transportation CO2 emissions, governments and industry began to explore and implement mitigation measures and targets in the early 2000s. However, in the absence of rigorous analyses assessing the costs for mitigating CO2 emissions, these policies could be economically wasteful. Here we identify the cost-effectiveness of CO2 emission reductions from narrow-body aircraft, the workhorse of passenger air transportation. We find that in the US, a combination of fuel burn reduction strategies could reduce the 2012 level of life cycle CO2 emissions per passenger kilometre by around 2% per year to mid-century. These intensity reductions would occur at zero marginal costs for oil prices between US$50-100 per barrel. Even larger reductions are possible, but could impose extra costs and require the adoption of biomass-based synthetic fuels. The extent to which these intensity reductions will translate into absolute emissions reductions will depend on fleet growth.

  11. Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

    Science.gov (United States)

    Adler, Stuart B.

    2009-01-01

    Gadolinia-doped ceria, or GDC, (Gd(0.4)Ce(0.6)O(2-delta), where the value of delta in this material varies, depending on the temperature and oxygen concentration in the atmosphere in which it is being used) has shown promise as a cathode material for high-temperature electrolysis of carbon dioxide in solid oxide electrolysis cells. The polarization resistance of a GDC electrode is significantly less than that of an otherwise equivalent electrode made of any of several other materials that are now in use or under consideration for use as cathodes for reduction of carbon dioxide. In addition, GDC shows no sign of deterioration under typical temperature and gas-mixture operating conditions of a high-temperature electrolyzer. Electrolysis of CO2 is of interest to NASA as a way of generating O2 from the CO2 in the Martian atmosphere. On Earth, a combination of electrolysis of CO2 and electrolysis of H2O might prove useful as a means of generating synthesis gas (syngas) from the exhaust gas of a coal- or natural-gas-fired power plant, thereby reducing the emission of CO2 into the atmosphere. The syngas a mixture of CO and H2 could be used as a raw material in the manufacture, via the Fisher-Tropsch process, of synthetic fuels, lubrication oils, and other hydrocarbon prod

  12. Effects of high CO2 levels on dynamic photosynthesis: carbon gain, mechanisms, and environmental interactions.

    Science.gov (United States)

    Tomimatsu, Hajime; Tang, Yanhong

    2016-05-01

    Understanding the photosynthetic responses of terrestrial plants to environments with high levels of CO2 is essential to address the ecological effects of elevated atmospheric CO2. Most photosynthetic models used for global carbon issues are based on steady-state photosynthesis, whereby photosynthesis is measured under constant environmental conditions; however, terrestrial plant photosynthesis under natural conditions is highly dynamic, and photosynthetic rates change in response to rapid changes in environmental factors. To predict future contributions of photosynthesis to the global carbon cycle, it is necessary to understand the dynamic nature of photosynthesis in relation to high CO2 levels. In this review, we summarize the current body of knowledge on the photosynthetic response to changes in light intensity under experimentally elevated CO2 conditions. We found that short-term exposure to high CO2 enhances photosynthetic rate, reduces photosynthetic induction time, and reduces post-illumination CO2 burst, resulting in increased leaf carbon gain during dynamic photosynthesis. However, long-term exposure to high CO2 during plant growth has varying effects on dynamic photosynthesis. High levels of CO2 increase the carbon gain in photosynthetic induction in some species, but have no significant effects in other species. Some studies have shown that high CO2 levels reduce the biochemical limitation on RuBP regeneration and Rubisco activation during photosynthetic induction, whereas the effects of high levels of CO2 on stomatal conductance differ among species. Few studies have examined the influence of environmental factors on effects of high levels of CO2 on dynamic photosynthesis. We identified several knowledge gaps that should be addressed to aid future predictions of photosynthesis in high-CO2 environments.

  13. The effects of CO2 on growth and transpiration of radish (Raphanus sativus) in hypobaria

    Science.gov (United States)

    Gohil, H. L.; Bucklin, R. A.; Correll, M. J.

    2010-04-01

    Plants grown on long-term space missions will likely be grown in low pressure environments (i.e., hypobaria). However, in hypobaria the transpiration rates of plants can increase and may result in wilting if the water is not readily replaced. It is possible to reduce transpiration by increasing the partial pressure of CO2 (pCO2), but the effects of pCO2 at high levels (>120 Pa) on the growth and transpiration of plants in hypobaria are not known. Therefore, the effects of pCO2 on the growth and transpiration of radish (Raphanus sativus var. Cherry Bomb II) in hypobaria were studied. The fresh weight (FW), leaf area, dry weight (DW), CO2 assimilation rates (CA), dark respiration rates (DR), and transpiration rates from 26 day-old radish plants that were grown for an additional seven days at different total pressures (33, 66 or 101 kPa) and pCO2 (40 Pa, 100 Pa and 180 Pa) were measured. In general, the dry weight of plants increased with CO2 enrichment and with lower total pressure. In limiting pCO2 (40 Pa) conditions, the transpiration for plants grown at 33 kPa was approximately twice that of controls (101 kPa total pressure with 40 Pa pCO2). Increasing the pCO2 from 40 Pa to 180 Pa reduced the transpiration rates for plants grown in hypobaria and in standard atmospheric pressures. However, for plants grown in hypobaria and high pCO2 (180 Pa) leaf damage was evident. Radish growth can be enhanced and transpiration reduced in hypobaria by enriching the gas phase with CO2 although at high levels leaf damage may occur.

  14. Investigation into optimal CO2 concentration for CO2 capture from aluminium production

    OpenAIRE

    Mathisen, Anette; Sørensen, Henriette; Melaaen, Morten Christian; Müller, Gunn-Iren

    2013-01-01

    Capture of CO2 from aluminum production has been simulated using Aspen Plus and Aspen Hysys. The technology used for aluminum production is the Hall-Héroult and the current cell design necessitates that large amounts of false air is supplied to the cells. This results in a CO2 concentration in the process gas at around 1 vol%, which is considered uneconomical for CO2 capture. Therefore, the aim of this investigation is to evaluate the CO2 capture from aluminum production when the process g...

  15. Measuring Nitrous Oxide Mass Transfer into Non-Aqueous CO2BOL CO2 Capture Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Whyatt, Greg A.; Freeman, Charles J.; Zwoster, Andy; Heldebrant, David J.

    2016-03-28

    This paper investigates CO2 absorption behavior in CO2BOL solvents by decoupling the physical and chemical effects using N2O as a non-reactive mimic. Absorption measurements were performed using a wetted-wall contactor. Testing was performed using a “first generation” CO2 binding organic liquid (CO2BOL), comprised of an independent base and alcohol. Measurements were made with N2O at a lean (0.06 mol CO2/mol BOL) and rich (0.26 mol CO2/mol BOL) loading, each at three temperatures (35, 45 and 55 °C). Liquid-film mass transfer coefficients (kg') were calculated by subtracting the gas film resistance – determined from a correlation from literature – from the overall mass transfer measurement. The resulting kg' values for N2O in CO2BOLs were found to be higher than that of 5 M aqueous MEA under comparable conditions, which is supported by published measurements of Henry’s coefficients for N2O in various solvents. These results suggest that the physical solubility contribution for CO2 absorption in CO2BOLs is greater than that of aqueous amines, an effect that may pertain to other non-aqueous solvents.

  16. Behavior of CO2/water flow in porous media for CO2 geological storage.

    Science.gov (United States)

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen

    2017-04-01

    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin(-1). For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO2 and water became miscible in the beginning of CO2 injection. CO2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO2 and water to invade into small pore spaces more easily. The study also showed CO2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO2 slightly decreases with the increase of capillary number.

  17. The Abundance of Atmospheric CO2 in Ocean Exoplanets: a Novel CO2 Deposition Mechanism

    Science.gov (United States)

    Levi, A.; Sasselov, D.; Podolak, M.

    2017-03-01

    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO2, the amount of CO2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO2. We find that, in a steady state, the abundance of CO2 in the atmosphere has two possible states. When wind-driven circulation is the dominant CO2 exchange mechanism, an atmosphere of tens of bars of CO2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO2 is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO2 into the atmosphere to increase the greenhouse effect.

  18. Metal-CO2 Batteries on the Road: CO2 from Contamination Gas to Energy Source.

    Science.gov (United States)

    Xie, Zhaojun; Zhang, Xin; Zhang, Zhang; Zhou, Zhen

    2017-01-20

    Rechargeable nonaqueous metal-air batteries attract much attention for their high theoretical energy density, especially in the last decade. However, most reported metal-air batteries are actually operated in a pure O2 atmosphere, while CO2 and moisture in ambient air can significantly impact the electrochemical performance of metal-O2 batteries. In the study of CO2 contamination on metal-O2 batteries, it has been gradually found that CO2 can be utilized as the reactant gas alone; namely, metal-CO2 batteries can work. On the other hand, investigations on CO2 fixation are in focus due to the potential threat of CO2 on global climate change, especially for its steadily increasing concentration in the atmosphere. The exploitation of CO2 in energy storage systems represents an alternative approach towards clean recycling and utilization of CO2 . Here, the aim is to provide a timely summary of recent achievements in metal-CO2 batteries, and inspire new ideas for new energy storage systems. Moreover, critical issues associated with reaction mechanisms and potential directions for future studies are discussed.

  19. Tuning the Surface Polarity of Microporous Organic Polymers for CO2 Capture.

    Science.gov (United States)

    Chen, Jian; Li, He; Zhong, Mingmei; Yang, Qihua

    2017-09-05

    CO2 capture is very important to reduce the CO2 concentration in atmosphere. Herein, we report the preparation of microporous polymers with tunable surface polarity for CO2 capture. Porous polymers functionalized with -NH2 , -SO3 H, and -SO3 Li have been successfully prepared by using a post-synthesis modification of microporous polymers (P-PhPh3 prepared with 1,3,5-triphenylbenzene as the monomer and AlCl3 as the catalyst) by chemical transformations, such as nitration-reduction, sulfonation, and cationic exchange. The CO2 adsorption selectivity (CO2 /N2 and CO2 /H2 ) and isosteric heats of the microporous polymers increase markedly after modification, P-PhPh3 -NH2 and P-PhPh3 -SO3 Li afford higher CO2 uptake capacity than P-PhPh3 at pressures of less than 0.15 bar due to the enhanced interaction between CO2 and the -NH2 and -SO3 Li functional groups. Moreover, functionalized porous polymers could be stably used for CO2 capture. Surface modification is an efficient approach to tune the CO2 capture properties of porous polymers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Stem CO2 release under illumination: corticular photosynthesis, photorespiration or inhibition of mitochondrial respiration?

    Science.gov (United States)

    Wittmann, Christiane; Pfanz, Hardy; Loreto, Francesco; Centritto, Mauro; Pietrini, Fabrizio; Alessio, Giorgio

    2006-06-01

    In illuminated stems and branches, CO2 release is often reduced. Many light-triggered processes are thought to contribute to this reduction, namely photorespiration, corticular photosynthesis or even an inhibition of mitochondrial respiration. In this study, we investigated these processes with the objective to discriminate their influence to the overall reduction of branch CO2 release in the light. CO2 gas-exchange measurements of young birch (Betula pendula Roth.) branches (photorespiration does not play a pre-dominant role in carbon exchange. This suppression of photorespiration was attributed to the high CO2 concentrations (C(i)) within the bark tissues (1544 +/- 227 and 618 +/- 43 micromol CO2 mol(-1) in the dark and in the light, respectively). Changes in xylem CO2 were not likely to explain the observed decrease in stem CO2 release as gas-exchange measurements before and after cutting of the branches did not effect CO2 efflux to the atmosphere. Combined fluorescence and gas-exchange measurements provided evidence that the light-dependent reduction in CO2 release can pre-dominantly be attributed to corticular refixation, whereas an inhibition of mitochondrial respiration in the light is unlikely to occur. Corticular photosynthesis was able to refix up to 97% of the CO2 produced by branch respiration, although it rarely led to a positive net photosynthetic rate.

  1. A Review of CO2-Enhanced Oil Recovery with a Simulated Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Mandadige Samintha Anne Perera

    2016-06-01

    Full Text Available This paper reports on a comprehensive study of the CO2-EOR (Enhanced oil recovery process, a detailed literature review and a numerical modelling study. According to past studies, CO2 injection can recover additional oil from reservoirs by reservoir pressure increment, oil swelling, the reduction of oil viscosity and density and the vaporization of oil hydrocarbons. Therefore, CO2-EOR can be used to enhance the two major oil recovery mechanisms in the field: miscible and immiscible oil recovery, which can be further increased by increasing the amount of CO2 injected, applying innovative flood design and well placement, improving the mobility ratio, extending miscibility, and controlling reservoir depth and temperature. A 3-D numerical model was developed using the CO2-Prophet simulator to examine the effective factors in the CO2-EOR process. According to that, in pure CO2 injection, oil production generally exhibits increasing trends with increasing CO2 injection rate and volume (in HCPV (Hydrocarbon pore volume and reservoir temperature. In the WAG (Water alternating gas process, oil production generally increases with increasing CO2 and water injection rates, the total amount of flood injected in HCPV and the distance between the injection wells, and reduces with WAG flood ratio and initial reservoir pressure. Compared to other factors, the water injection rate creates the minimum influence on oil production, and the CO2 injection rate, flood volume and distance between the flood wells have almost equally important influence on oil production.

  2. CO2 utilization: Developments in conversion processes

    Directory of Open Access Journals (Sweden)

    Erdogan Alper

    2017-03-01

    The potential utilization of CO2, captured at power plants, should also been taken into consideration for sustainability. This CO2 source, which is potentially a raw material for the chemical industry, will be available at sufficient quality and at gigantic quantity upon realization of on-going tangible capture projects. Products resulting from carboxylation reactions are obvious conversions. In addition, provided that enough supply of energy from non-fossil resources, such as solar [1], is ensured, CO2 reduction reactions can produce several valuable commodity chemicals including multi-carbon compounds, such as ethylene and acrylic acid, in addition to C1 chemicals and polymers. Presently, there are only few developing technologies which can find industrial applications. Therefore, there is a need for concerted research in order to assess the viability of these promising exploratory technologies rationally.

  3. The ATLAS IBL CO2 cooling system

    Science.gov (United States)

    Verlaat, B.; Ostrega, M.; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-02-01

    The ATLAS Pixel detector has been equipped with an extra pixel layer in the space obtained by a smaller radius beam pipe. This new pixel layer called the Insertable B-Layer (IBL) was installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the expected high radiation dose received at an integrated luminosity of 550 fb1. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  4. Upscaling of enzyme enhanced CO2 capture

    DEFF Research Database (Denmark)

    Gladis, Arne Berthold

    the mass transfer of CO2 with slow-capturing but energetically favorable solvents can open up a variety of new process options for this technology. The ubiquitous enzyme carbonic anhydrase (CA), which enhances the mass transfer of CO2 in the lungs by catalyzing the reversible hydration of CO2, is one very...... promising mass transfer rate promoter for CCS. This process has been previously been tested successfully in lab scale and in some rare cases in pilot scale, but no validated process model for this technology has been published yet. This PhD thesis presents an investigation of the feasibility of enzyme...... enzyme kinetic model and validating it against in-house pilot plant experiments. The work consisted of identifying a suitable enzyme-solvent system and the ideal process conditions by comparing mass transfer rates of different solvents and enzyme enhanced solvents in a lab scale wetted wall column...

  5. CO2 fluxes near a forest edge

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Leclerc, Monique Y.; Zhang, Gensheng

    2008-01-01

    In contrast with recent advances on the dynamics of the flow at a forest edge, few studies have considered its role on scalar transport and, in particular, on CO2 transfer. The present study addresses the influence of the abrupt roughness change on forest atmosphere CO2 exchange and contrasts...... as a function of both sources/sinks distribution and the vertical structure of the canopy. Results suggest that the ground source plays a major role in the formation of wave-like vertical CO2 flux behavior downwind of a forest edge, despite the fact that the contribution of foliage sources/sinks changes...... monotonously. Such a variation is caused by scalar advection in the trunk space and reveals itself as a decrease or increase in vertical fluxes over the forest relative to carbon dioxide exchange of the underlying forest. The effect was more pronounced in model forests where the leaf area is concentrated...

  6. Equilibrium Solubility of CO2 in Alkanolamines

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2014-01-01

    Equilibrium solubility of CO2 were measured in aqueous solutions of Monoethanolamine (MEA) and N,N-diethylethanolamine(DEEA). Equilibrium cells are generally used for these measurements. In this study, the equilibrium data were measured from the calorimetry. For this purpose a reaction calorimeter...... (model CPA 122 from ChemiSens AB, Sweden) was used. The advantage of this method is being the measurement of both heats of absorption and equilibrium solubility data of CO2 at the same time. The measurements were performed for 30 mass % MEA and 5M DEEA solutions as a function of CO2 loading at three...... different temperatures 40, 80 and 120 ºC. The measured 30 mass % MEA and 5M DEEA data were compared with the literature data obtained from different equilibrium cells which validated the use of calorimeters for equilibrium solubility measurements....

  7. Absence of OsβCA1 causes CO2 deficit and affects leaf photosynthesis and stomatal response to CO2 in rice.

    Science.gov (United States)

    Chen, Taiyu; Wu, Huan; Wu, Jiemin; Fan, Xiaolei; Li, Xianghua; Lin, Yongjun

    2017-01-31

    Plants always adjust the opening of stomatal pores to adapt to the environments, such as [CO2 ], humidity and temperature. Low [CO2 ] will trigger the opening of stomatal pores to absorb extra CO2 . However, little is known about how CO2 supply affects the carbon fixation and opening of stomatal pores in rice. Here, a chloroplast-located β-carbonic anhydrase (β-CA) coding gene was found to be involved in carbon assimilation and CO2 -mediated stomatal pore response in rice. OsβCA1 was constitutively expressed in all tissues and its transcripts were induced by high [CO2 ] in leaves. Both T-DNA mutant and RNAi lines showed phenotypes of lower biomass and CA activities. The knock-out of OsβCA1 obviously decreased the photosynthesis capacity, as demonstrated by the increased CO2 compensation point and decreased light saturation point in the mutant; while the knock-out increased the opening ratio of stomatal pores and water loss rate. Moreover, the mutant showed a delayed response to low [CO2 ], and they could not be closed to the degree of wild plants even though the stomatal pores could rapidly respond to high [CO2 ]. Genome-wide gene expression analysis via RNA-seq demonstrated that the transcript abundance of the genes related to RuBisCO, photosystem compounds and opening of stomatal pores were globally up-regulated in the mutant. Taken together, the inadequate CO2 supply caused by the absence of OsβCA1 reduces photosynthesis efficiency, triggers the opening of stomatal pores and finally decreases their sensitivity to CO2 fluctuation. This article is protected by copyright. All rights reserved.

  8. Concurrent elevation of CO2, O3 and temperature severely affects oil quality and quantity in rapeseed

    DEFF Research Database (Denmark)

    Namazkar, Shahla; Stockmarr, Anders; Frenck, Georg;

    2016-01-01

    FAs remained unchanged or even increased. Most reduced was the FA essential for human nutrition, C18:3-ω3, which decreased by 39% and 45% in the combined scenarios with elevated [CO2]+T+[O3] and [CO2]+T, respectively. Average oil content decreased 3–17%. When [CO2] and T were elevated concurrently...

  9. Local CO2-induced swelling of shales

    Science.gov (United States)

    Pluymakers, Anne; Dysthe, Dag Kristian

    2017-04-01

    In heterogeneous shale rocks, CO2 adsorbs more strongly to organic matter than to the other components. CO2-induced swelling of organic matter has been shown in coal, which is pure carbon. The heterogeneity of the shale matrix makes an interesting case study. Can local swelling through adsorption of CO2 to organic matter induce strain in the surrounding shale matrix? Can fractures close due to CO2-induced swelling of clays and organic matter? We have developed a new generation of microfluidic high pressure cells (up to 100 bar), which can be used to study flow and adsorption phenomena at the microscale in natural geo-materials. The devices contain one transparent side and a shale sample on the other side. The shale used is the Pomeranian shale, extracted from 4 km depth in Poland. This formation is a potential target of a combined CO2-storage and gas extraction project. To answer the first question, we place the pressure cell under a Veeco NT1100 Interferometer, operated in Vertical Scanning Interferometry mode and equipped with a Through Transmissive Media objective. This allows for observation of local swelling or organic matter with nanometer vertical resolution and micrometer lateral resolution. We expose the sample to CO2 atmospheres at different pressures. Comparison of the interferometry data and using SEM-EDS maps plus optical microscopy delivers local swelling maps where we can distinguish swelling of different mineralogies. Preliminary results indicate minor local swelling of organic matter, where the total amount is both time- and pressure-dependent.

  10. Re-evaluating the 1940s CO2 plateau

    Science.gov (United States)

    Bastos, Ana; Ciais, Philippe; Barichivich, Jonathan; Bopp, Laurent; Brovkin, Victor; Gasser, Thomas; Peng, Shushi; Pongratz, Julia; Viovy, Nicolas; Trudinger, Cathy M.

    2016-09-01

    observed stabilization of atmospheric CO2 cannot be confirmed nor discarded, as TRENDY models do not reproduce the expected concurrent strong decrease in terrestrial uptake. Nevertheless, this would further increase the mismatch between observed and modelled CO2 growth rate during the CO2 plateau epoch. Tests performed using the OSCAR (v2.2) model indicate that changes in land use not correctly accounted for during the period (coinciding with drastic socioeconomic changes during the Second World War) could contribute to the additional sink required. Thus, the previously proposed ocean hypothesis for the 1940s plateau cannot be confirmed by independent data. Further efforts are required to reduce uncertainty in the different terms of the carbon budget during the first half of the 20th century and to better understand the long-term variability of the ocean and terrestrial CO2 sinks.

  11. Effect of elevated atmospheric CO2 and vegetation type on microbiota associated with decomposing straw

    DEFF Research Database (Denmark)

    Frederiksen, Helle B.; Ronn, R.; Christensen, S.

    2001-01-01

    concentration in the recovered straw samples. After five months of decomposition, hyphal biomass was significantly lower in straw from plants grown at elevated CO2 (-30% and -13% in the fallow and wheat field, respectively). Bacterial biomass was not significantly affected by the CO2 induced changes...... in the litter quality, but the lower decomposition rate and fewer bacterial grazers in the straw from plants grown at elevated CO2 together indicate reduced microbial activity and turnover. Notwithstanding this, these data show that growth at elevated atmospheric CO2 concentration results in slower...

  12. Amine-Functionalized ZnO Nanosheets for Efficient CO2 Capture and Photoreduction

    Directory of Open Access Journals (Sweden)

    Yusen Liao

    2015-10-01

    Full Text Available Amine-functionalized ZnO nanosheets were prepared through a one-step hydrothermal method by using monoethanolamine, which has a hydroxyl group, for covalent attachment on ZnO and a primary amine group to supply the amine-functionalization. We demonstrate that the terminal amine groups on ZnO surfaces substantially increase the capability of CO2 capture via chemisorption, resulting in effective CO2 activation. As a result, the photogenerated electrons from excited ZnO can more readily reduce the surface-activated CO2, which thereby enhances the activity for photocatalytic CO2 reduction.

  13. Do Tree Stems Recapture Respired CO2?

    Science.gov (United States)

    Hilman, B.; Angert, A.

    2016-12-01

    Tree stem respiration is an important, yet not well understood, component of the terrestrial carbon cycle. Predicting how trees as whole organisms respond to changes in climate and atmospheric CO2 requires understanding of the variability in the fraction of assimilated carbon allocated to respiration, versus the allocation to growth, damage repair, and to rhizosphere symbionts. Here we used the ratio of CO2 efflux/O2 influx (Apparent Respiratory Quotient, ARQ) to study stem respiration. The ARQ in trees stems is predicted to be 1.0, as a result of carbohydrates metabolism. Lower than 1.0 ARQ values may indicate a local assimilation of respired CO2, or dissolution and transport of CO2 in the xylem stream. We measured stems ARQ in 16 tree species at tropical, Mediterranean and temperate ecosystems using stem chambers and in-vitro incubations. The CO2 and O2 were measured by a system we developed, which is based on an IRGA and a Fuel-cell O2 analyzer (Hilman and Angert 2016). We found typical values of ARQ in the range of 0.4-0.8. Since incubations of detach stem tissues yielded similar ARQ values, and since the influence of natural variations in the transpiration stream on ARQ was found to be small, we conclude that the removal of the respired CO2 is not via dissolution in the xylem stream. Using 13C labeling, dark fixation of stem tissues was detected, which is most probably phosphoenolpyruvate carboxylase (PEPC) mediated. Hence, we suggest that in-stem dark fixation of respired CO2 to organic acids (e.g. malate) affects the outgoing efflux. Further research should determine if these organic acids are transported to the canopy, stored in the stem, or transported to the roots to serve as exudates. Hilman B, Angert A (2016) Measuring the ratio of CO2 efflux to O2 influx in tree stem respiration. Tree Physiol 2016, doi: 10.1093/treephys/tpw057

  14. 10 MW Supercritical CO2 Turbine Test

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  15. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van

    2010-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...... perspectives for decreasing the heat requirement. However, a scientific understanding of the processes is required. The thermodynamic properties of the NH3–CO2–H2O system were described using the extended UNIQUAC electrolyte model developed by Thomsen and Rasmussen in a temperature range from 0 to 110°C...

  16. Leak Path Development in CO2 Wells

    Science.gov (United States)

    Torsater, M.; Todorovic, J.; Opedal, N.; Lavrov, A.

    2014-12-01

    Wells have in numerous scientific works been denoted the "weak link" of safe and cost-efficient CO2 Capture and Storage (CCS). Whether they are active or abandoned, all wells are man-made intrusions into the storage reservoir with sealing abilities depending on degradable materials like steel and cement. If dense CO2 is allowed to expand (e.g. due to leakage) it will cool down its surroundings and cause strong thermal and mechanical loading on the wellbore. In addition, CO2 reacts chemically with rock, cement and steel. To ensure long-term underground containment, it is therefore necessary to study how, why, where and when leakage occurs along CO2wells. If cement bonding to rock or casing is poor, leak paths can form already during drilling and completion of the well. In the present work, we have mapped the bonding quality of cement-rock and cement-steel interfaces - and measured their resistance towards CO2 flow. This involved a large experimental matrix including different rocks, steels, cement types and well fluids. The bonding qualities were measured on composite cores using micro computed tomography (µ-CT), and CO2 was flooded through the samples to determine leakage rates. These were further compared to numerical simulations of leakage through the digitalized µ-CT core data, and CO2chemical interactions with the materials were mapped using electron microscopy. We also present a new laboratory set-up for measuring how well integrity is affected by downhole temperature variations - and we showcase some initial results. Our work concludes that leak path development in CO2 wells depends critically on the drilling fluids and presflushes/spacers chosen already during drilling and completion of a well. Fluid films residing on rock and casing surfaces strongly degrade the quality of cement bonding. The operation of the well is also important, as even slight thermal cycling (between 10°C and 95°C on casing) leads to significant de-bonding of the annular cement.

  17. Toxic emissions and devaluated CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    with a climate policy whose goals of CO2-reduction were made operational by green-wash. Arguments are given for the devaluation of CO2- neutrality in case of burning wood. Alternative practices as storing C in high quality wood products and/or leaving wood in the forest are recommended. A counter......-productive effect of dioxin formation in the cooling phase of wood burning appliances has been registered akin to de-novo-synthesis in municipal solid waste incinerators. Researchers, regulators and the public are, however, still preoccupied by notions of oven design and operation parameters, assuming that dioxin...

  18. Carbon monoxide : A quantitative tracer for fossil fuel CO2?

    NARCIS (Netherlands)

    Gamnitzer, Ulrike; Karstens, Ute; Kromer, Bernd; Neubert, Rolf E. M.; Meijer, Harro A. J.; Schroeder, Hartwig; Levin, Ingeborg

    2006-01-01

    Carbon monoxide (CO), carbon dioxide (CO2), and radiocarbon ((CO2)-C-14) measurements have been made in Heidelberg from 2001 to 2004 in order to determine the regional fossil fuel CO2 component and to investigate the application of CO as a quantitative tracer for fossil fuel CO2 (CO2(foss)). The obs

  19. Sequestering CO2 in the Built Environment

    Science.gov (United States)

    Constantz, B. R.

    2009-12-01

    Calera’s Carbonate Mineralization by Aqueous Precipitation (CMAP) technology with beneficial reuse has been called, “game-changing” by Carl Pope, Director of the Sierra Club. Calera offers a solution to the scale of the carbon problem. By capturing carbon into the built environment through carbonate mineralization, Calera provides a sound and cost-effective alternative to Geologic Sequestration and Terrestrial Sequestration. The CMAP technology permanently converts carbon dioxide into a mineral form that can be stored above ground, or used as a building material. The process produces a suite of carbonate-containing minerals of various polymorphic forms. Calera product can be substituted into blends with ordinary Portland cements and used as aggregate to produce concrete with reduced carbon, carbon neutral, or carbon negative footprints. For each ton of product produced, approximately half a ton of carbon dioxide can be sequestered using the Calera process. Coal and natural gas are composed of predominately istopically light carbon, as the carbon in the fuel is plant-derived. Thus, power plant CO2 emissions have relatively low δ13C values.The carbon species throughout the CMAP process are identified through measuring the inorganic carbon content, δ13C values of the dissolved carbonate species, and the product carbonate minerals. Measuring δ13C allows for tracking the flue gas CO2 throughout the capture process. Initial analysis of the capture of propane flue gas (δ13C ˜ -25 ‰) with seawater (δ13C ˜ -10 ‰) and industrial brucite tailings from a retired magnesium oxide plant in Moss Landing, CA (δ13C ˜ -7 ‰ from residual calcite) produced carbonate mineral products with a δ13C value of ˜ -20 ‰. This isotopically light carbon, transformed from flue gas to stable carbonate minerals, can be transferred and tracked through the capture process, and finally to the built environment. CMAP provides an economical solution to global warming by producing

  20. Effects of diffusion impairment on O2 and CO2 time courses in pulmonary capillaries.

    Science.gov (United States)

    Wagner, P. D.; West, J. B.

    1972-01-01

    Simultaneous time courses for O2 and CO2 exchange along the capillary have been calculated for homogeneous lungs, allowing for O2-CO2 interactions, dissolved O2, and chemical reaction rates. As diffusing capacity (Dl) was reduced, the transfer of CO2 and O2 was impaired by similar amounts, in spite of the 20-fold greater diffusing capacity for CO2. The reason why CO2 is affected so much is that the slope of the content against partial pressure is so much greater in blood than tissue for this gas. Because of the shapes of their respective dissociation curves, O2 transfer was most affected at normal ventilation-perfusion ratios, whereas CO2 was most affected at high ratios. Exercise exaggerated the impairment of transfer of both gases.

  1. Design and package of a 14CO2 field analyzer: the Global Monitor Platform (GMP)

    Science.gov (United States)

    Marino, Bruno D. V.; Bright, Michelle; Gronniger, Glen

    2011-09-01

    Carbon Capture and Sequestration (CCS) is widely accepted as a means to reduce and eliminate the fossil fuel CO2 (ff- CO2) emissions from coal fired power plants. Success of CCS depends on near zero leakage rates over decadal time scales. Currently no commercial methods to determine leakage of ff-CO2 are available. The Global Monitor Platform (GMP) field analyzer provides high precision analysis of CO2 isotopes [12C (99%), 13C (GMP for field deployment. The system will conduct atmosphere monitoring then adapt to water and soil evaluations. Measuring 14CO2 in real time will provide quantitative concentration data for ff-CO2 in the atmosphere and CCS leakage detection. Initial results will be discussed along with design changes for improved detection sensitivity and manufacturability.

  2. Enhancement of CO2 Affinity in a Polymer of Intrinsic Microporosity by Amine Modification.

    Science.gov (United States)

    Mason, Christopher R; Maynard-Atem, Louise; Heard, Kane W J; Satilmis, Bekir; Budd, Peter M; Friess, Karel; Lanc̆, Marek; Bernardo, Paola; Clarizia, Gabriele; Jansen, Johannes C

    2014-02-11

    Nitrile groups in the polymer of intrinsic microporosity PIM-1 were reduced to primary amines using borane complexes. In adsorption experiments, the novel amine-PIM-1 showed higher CO2 uptake and higher CO2/N2 sorption selectivity than the parent polymer, with very evident dual-mode sorption behavior. In gas permeation with six light gases, the individual contributions of solubility and diffusion to the overall permeability was determined via time-lag analysis. The high CO2 affinity drastically restricts diffusion at low pressures and lowers CO2 permeability compared to the parent PIM-1. Furthermore, the size-sieving properties of the polymer are increased, which can be attributed to a higher stiffness of the system arising from hydrogen bonding of the amine groups. Thus, for the H2/CO2 gas pair, whereas PIM-1 favors CO2, amine-PIM-1 shows permselectivity toward H2, breaking the Robeson 2008 upper bound.

  3. Comparative Study on Different IGCC Systems with Quasi-Zero CO2 Emission

    Directory of Open Access Journals (Sweden)

    Yongping Yang

    2007-06-01

    Full Text Available This paper studies different IGCC systems with CO2 recovery. In order to effectively reduce CO2 emissions from the IGCC system, several kinds of IGCC systems with quasizero CO2 emissions have been studied in this paper. The key parameters affecting the IGCC systems’ performance have been analyzed and compared. The systems’ performances have been investigated based on comparison of different IGCC systems. The obtained results show that integrating the IGCC system with an advanced thermal cycle is an effective and feasible way. The performances of the IGCC systems with O2/CO2 cycle and syngas separation are better than that with a simple semi-closed O2/CO2 cycle. The research achievements will provide valuable information for further study on IGCC systems with low CO2 emissions.

  4. Reversible CO2 Capture by Conjugated Ionic Liquids through Dynamic Covalent Carbon-Oxygen Bonds.

    Science.gov (United States)

    Pan, Mingguang; Cao, Ningning; Lin, Wenjun; Luo, Xiaoyan; Chen, Kaihong; Che, Siying; Li, Haoran; Wang, Congmin

    2016-09-08

    The strong chemisorption of CO2 is always accompanied by a high absorption enthalpy, and traditional methods to reduce the absorption enthalpy lead to decreased CO2 capacities. Through the introduction of a large π-conjugated structure into the anion, a dual-tuning approach for the improvement of CO2 capture by anion-functionalized ionic liquids (ILs) resulted in a high capacity of up to 0.96 molCO2  mol-1IL and excellent reversibility. The increased capacity and improved desorption were supported by quantum chemical calculations, spectroscopic investigations, and thermogravimetric analysis. The increased capacity may be a result of the strengthened dynamic covalent bonds in these π-electron-conjugated structures through anion aggregation upon the uptake of CO2 , and the improved desorption originates from the charge dispersion of interaction sites through the large π-electron delocalization. These results provide important insights into effective strategies for CO2 capture.

  5. Multi-technique monitoring of CO2 leakage from an engineered CO2 leakage experiment

    Science.gov (United States)

    Zhou, X.; Apple, M. E.; Dobeck, L.; Cunningham, A. B.; Spangler, L.

    2012-12-01

    Monitoring of canopy and soil geophysical and geochemical properties in vadose zone by multiple techniques were carried out from 1999 to 2012 using an engineered CO2 release to simulate the CO2 leakage from CO2 storage at an agricultural plot at Bozeman, MT. The CO2 release was based on a horizontally-drilled well of 100 m at a depth of about 2.0-2.3m (Fig.1). Techniques utilized include hyperspectral and infrared radiation of various vegetations, electric conductivity in soil, magnetic field at the ground surface, and soil gas composition and dynamics using various gas sensors and soil moisture sensors. Measurements were made at several sites along a transect perpendicular to the releasing well, along which the soil CO2 concentration attenuated from high to normal condition at control site. The response of the canopy hyperspectral reflectance, infrared radiation, soil geophysical properties such as soil electric conductivity, top soil magnetic susceptibility and magnetic field, soil gas composition such as CO2 and O2 concentration to CO2 release at different rates were quantified and will be shown at this presentation. Fig.2 shows some examples of the results. The different responses at the impact and control sites are used to assess the effectiveness for CO2 surface and near-surface detection when a possible CO2 leakage occurs.ig.1. A schematic showing the injection and release of CO2 at an agricultral plot in Bozeman, MT. ig.2. Some examples of results showing the response of vegetation, hyperspectral reflectance, soil electric conductivity, soil O2 concentration to the release of CO2.

  6. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Directory of Open Access Journals (Sweden)

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  7. CO2-induced seawater acidification affects physiological performance of the marine diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    U. Riebesell

    2010-05-01

    Full Text Available CO2/pH perturbation experiments were carried out under two different pCO2 levels (39.3 and 101.3 Pa to evaluate effects of CO2-induced ocean acidification on the marine diatom Phaeodactylum tricornutum. After acclimation (>20 generations to ambient and elevated CO2 conditions (with corresponding pH values of 8.15 and 7.80, respectively, growth and photosynthetic carbon fixation rates of high CO2 grown cells were enhanced by 5% and 12%, respectively, and dark respiration stimulated by 34% compared to cells grown at ambient CO2. The K1/2 (dissolved inorganic carbon, DIC for carbon fixation increased by 20% under the low pH and high CO2 condition, reflecting a decreased photosynthetic affinity for HCO3− or/and CO2 and down-regulated carbon concentrating mechanism (CCM. In the high CO2 grown cells, the electron transport rate from photosystem II (PSII was photoinhibited to a greater extent at high levels of photosynthetically active radiation, while non-photochemical quenching was reduced compared to low CO2 grown cells. This was probably due to the down-regulation of CCM, which serves as a sink for excessive energy. Increasing seawater pCO2 and decreasing pH associated with atmospheric CO2 rise may enhance diatom growth, down-regulate their CCM, and enhanced their photo-inhibition and dark respiration. The balance between these positive and negative effects on diatom productivity will be a key factor in determining the net effect of rising atmospheric CO2 on ocean primary production.

  8. Modelling ruptures of buried high pressure dense phase CO2 pipelines in carbon capture and storage applications - Part I. Validation

    OpenAIRE

    Wareing, CJ; Fairweather, M.; Falle, SAEG; Woolley, RM

    2015-01-01

    Carbon dioxide (CO2) capture and storage presents a short-term option for significantly reducing the amount of CO2 released into the atmosphere and mitigating the effects of climate change. To this end, National Grid initiated the COOLTRANS research programme to consider the pipeline transportation of high pressure dense phase CO2, including the development and application of a mathematical model for predicting the sonic near-field dispersion of pure CO2 following the venting or failure of su...

  9. Influencing Factors of Energy-Related CO2 Emissions in China: A Decomposition Analysis

    Directory of Open Access Journals (Sweden)

    Guokui Wang

    2015-10-01

    Full Text Available China is the largest CO2 emitter in the world and is still reliant on energy consumption for economic growth. Research has focused on effective approaches of reducing and mitigating CO2 emissions. This paper undertakes a decomposition study of energy-related CO2 emissions from the industrial and household sectors during the period 1996–2012, with the objectives of investigating trends of the changes in energy-related CO2 emissions, the driving forces of these changes, and approaches of mitigating CO2 emission. Results show the following: (1 the expansion of economic activity is the dominant stimulatory factor of the increase of CO2 emissions in China and that a sustained increase in CO2 emissions can be expected; (2 the decline in energy intensity and the adjustment of energy mix and industrial structure effectively mitigate CO2 emissions; and (3 the government should give more attention to enhancing the energy utility efficiency and reducing CO2 emissions in rural households.

  10. The Perfomativity of Economics in Trading CO2-Reducation Certificates

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    Since 2013, Interpol publicly points to illegal practices in carbon trading and markets. To open up the governability of carbon through markets, this paper employs the Science and Technology Studies perspectives of performativity of economics and the performativity of data practices. Using...... ethnographic insight into voluntary corporate carbon accounting and into the agency of emission reduction certificates, the governability of emissions through markets is questioned. The paper provides evidence for dubious practices in accounting and, thus, the voluntary carbon market and therewith qualifies...

  11. A leak monitoring method for CO2 storage sites using ratio of ∆CO2:∆O2 at the soil surface

    Science.gov (United States)

    Alam, M. M.; Norman, A. L.; Layzell, D. B.; Amiri, N.

    2016-12-01

    Carbon Capture and Storage (CCS) technology has a high potential for reducing carbon emission at large scales. However, the success of CCS projects vastly depends on the continuous monitoring of injected CO2 and ensuring it remains below ground. The technology currently available for monitoring sites are mainly adopted from disciplines which are effective at detecting high volume leaks but may not be reliable in distinguishing seepage of CO2 from underground and fossil fuel combustion at the surface. We have constructed a numerical model that includes soil characteristics and the bio-geo-chemical dynamics of near surface soils and soil gases. The simulation of our model can predict O2 and CO2 profiles in soil and differential ratios with respect to atmospheric concentrations (∆CO2 and ∆O2), and distinguish CO2 leaks. Experiments on a 1-m soil column have been conducted using dual channel IR and fuel cell analyzers to verify our model predictions. The preliminary results show that measured O2 and CO2 concentrations in near-surface soil layers and the ratio of ∆CO2:∆O2 at the soil surface are in agreement with our model. Based on initial results it is expected that this method of monitoring will able to detect fluxes as small as 2-6µmole/m2/s of CO 2 leakage.

  12. The Realization of a CO2 Heat Pump Defrosting Method%一种CO2热泵除霜方法的实现

    Institute of Scientific and Technical Information of China (English)

    杨军红

    2016-01-01

    空气源CO2热泵在冬季运行时,由于外部环境温度低、空气湿度大等原因,往往会在蒸发器表面形成霜层,从而降低热泵运行效率,甚至影响热泵机组的正常运行,根据CO2热泵的实际应用,设计一种CO2热泵智能除霜方法,用于解决空气源CO2热泵低温、高湿环境下的除霜问题。%Air source CO2 heat pump running in winter, due to the external environment of low temperature, high air humidity and so on, often formation frost layer in the evaporator surface, thereby reducing the efficiency of the heat pump, and even affect the normal operation of the heat pump units, this paper will according to the practical application of the CO2 heat pump, design a CO2 heat pump intelligent defrosting method, is used to solve the CO2 air source heat pump defrost problem under the low temperature, high humidity environment.

  13. Carbon sequestration and atmospheric CO2 removal: climate consequence and long-term commitment

    Science.gov (United States)

    Cao, L.; Caldeira, K.

    2010-12-01

    A variety of methods have been proposed to remove anthropogenic CO2 from the atmosphere and thus mitigate climate change, such as biospheric carbon sequestration, carbon sequestration through enhanced ocean and land weathering, and direct carbon capture from ambient air. Although these proposed methods differ substantially in their physical, chemical, and biological implementations, the ultimate outcome of all schemes is to remove anthropogenic CO2 from the atmosphere. However, the climate effect of atmospheric CO2 removal has not been studied. Here we use an Earth system model to investigate the response of the coupled climate-carbon system to an idealized removal of anthropogenic CO2 from the atmosphere. We use idealized scenarios in our analysis to facilitate exploration of the basic response of the coupled climate-carbon cycle system to proposed methods of removing anthropogenic CO2. In our extreme and idealized simulations, anthropogenic CO2 emissions are halted and all anthropogenic CO2 is removed from the atmosphere at year 2050 under the IPCC A2 CO2 emission scenario. In our simulations a one-time removal of all anthropogenic CO2 in the atmosphere reduces surface air temperature by 0.8°C within a few years, but 1°C surface warming above pre-industrial levels lasts for several centuries. In other words, a one-time removal of 100% excess CO2 from the atmosphere offsets less than 50% of the warming experienced at the time of removal. To maintain atmospheric CO2 and temperature at low levels, not only does anthropogenic CO2 in the atmosphere need to be removed, but anthropogenic CO2 stored in the ocean and land needs to be removed as well when it outgasses to the atmosphere. Our study indicts that the amount of CO2 that would need to be removed from the atmosphere, either by biological means or other means, could be much greater than the desired reduction in atmospheric CO2 concentrations, and may exceed the total burden of excess atmospheric CO2 at the time

  14. Sampling Soil CO2 for Isotopic Flux Partitioning: Non Steady State Effects and Methodological Biases

    Science.gov (United States)

    Snell, H. S. K.; Robinson, D.; Midwood, A. J.

    2014-12-01

    Measurements of δ13C of soil CO2 are used to partition the surface flux into autotrophic and heterotrophic components. Models predict that the δ13CO2 of the soil efflux is perturbed by non-steady state (NSS) diffusive conditions. These could be large enough to render δ13CO2 unsuitable for accurate flux partitioning. Field studies sometimes find correlations between efflux δ13CO2 and flux or temperature, or that efflux δ13CO2 is not correlated as expected with biological drivers. We tested whether NSS effects in semi-natural soil were comparable with those predicted. We compared chamber designs and their sensitivity to changes in efflux δ13CO2. In a natural soil mesocosm, we controlled temperature to generate NSS conditions of CO2 production. We measured the δ13C of soil CO2 using in situ probes to sample the subsurface, and dynamic and forced-diffusion chambers to sample the surface efflux. Over eight hours we raised soil temperature by 4.5 OC to increase microbial respiration. Subsurface CO2 concentration doubled, surface efflux became 13C-depleted by 1 ‰ and subsurface CO2 became 13C-enriched by around 2 ‰. Opposite changes occurred when temperature was lowered and CO2 production was decreasing. Different chamber designs had inherent biases but all detected similar changes in efflux δ13CO2, which were comparable to those predicted. Measurements using dynamic chambers were more 13C-enriched than expected, probably due to advection of CO2 into the chamber. In the mesocosm soil, δ13CO2 of both efflux and subsurface was determined by physical processes of CO2 production and diffusion. Steady state conditions are unlikely to prevail in the field, so spot measurements of δ13CO2 and assumptions based on the theoretical 4.4 ‰ diffusive fractionation will not be accurate for estimating source δ13CO2. Continuous measurements could be integrated over a period suitable to reduce the influence of transient NSS conditions. It will be difficult to disentangle

  15. Root damage by insects reverses the effects of elevated atmospheric CO2 on Eucalypt seedlings.

    Directory of Open Access Journals (Sweden)

    Scott N Johnson

    Full Text Available Predicted increases in atmospheric carbon dioxide (CO2 are widely anticipated to increase biomass accumulation by accelerating rates of photosynthesis in many plant taxa. Little, however, is known about how soil-borne plant antagonists might modify the effects of elevated CO2 (eCO2, with root-feeding insects being particularly understudied. Root damage by insects often reduces rates of photosynthesis by disrupting root function and imposing water deficits. These insects therefore have considerable potential for modifying plant responses to eCO2. We investigated how root damage by a soil-dwelling insect (Xylotrupes gideon australicus modified the responses of Eucalyptus globulus to eCO2. eCO2 increased plant height when E. globulus were 14 weeks old and continued to do so at an accelerated rate compared to those grown at ambient CO2 (aCO2. Plants exposed to root-damaging insects showed a rapid decline in growth rates thereafter. In eCO2, shoot and root biomass increased by 46 and 35%, respectively, in insect-free plants but these effects were arrested when soil-dwelling insects were present so that plants were the same size as those grown at aCO2. Specific leaf mass increased by 29% under eCO2, but at eCO2 root damage caused it to decline by 16%, similar to values seen in plants at aCO2 without root damage. Leaf C:N ratio increased by >30% at eCO2 as a consequence of declining leaf N concentrations, but this change was also moderated by soil insects. Soil insects also reduced leaf water content by 9% at eCO2, which potentially arose through impaired water uptake by the roots. We hypothesise that this may have impaired photosynthetic activity to the extent that observed plant responses to eCO2 no longer occurred. In conclusion, soil-dwelling insects could modify plant responses to eCO2 predicted by climate change plant growth models.

  16. Second Generation CO2 FEP Analysis: CASSIF - Carbon Storage Scenario Identification Framework

    NARCIS (Netherlands)

    Yavuz, F.; Tilburg, T. van; David, P.; Spruijt, M.; Wildenborg, T.

    2009-01-01

    Carbon dioxide Capture and Storage (CCS) is a promising contribution to reduce further increase of atmospheric CO2 emissions from fossil fuels. The CCS concept anticipates that large amounts of CO2 are going to be stored in the subsurface for the long term. Since CCS is a rather new technology, unce

  17. Reduction of CO2 Emissions in Houses of Historic and Visual Importance

    NARCIS (Netherlands)

    Van Hal, A.; Dulski, B.; Postel, A.M.

    2010-01-01

    According to the ‘Climate Programme’ the municipality of Amsterdam has the ambition to reduce the CO2 emissions within the city limits by 40% in the year 2025 compared to the year 1990. To realize this ambition substantial CO2 savings have to be realized at the 375,000 current houses in the city. A

  18. Soil [N] modulates soil C cycling in CO2-fumigated tree stands

    DEFF Research Database (Denmark)

    Dieleman, W. I. J.; Luyssaert, S.; Rey, A.

    2010-01-01

    Under elevated atmospheric CO2 concentrations, soil carbon (C) inputs are typically enhanced, suggesting larger soil C sequestration potential. However, soil C losses also increase and progressive nitrogen (N) limitation to plant growth may reduce the CO2 effect on soil C inputs with time. We com...

  19. Impact of chemical and mechanical processes on wellbore integrity in CO2 storage systems

    NARCIS (Netherlands)

    Wolterbeek, T.K.T.

    2016-01-01

    Carbon Capture and Storage (CCS), involving the capture of CO2 at large point sources, such as power plants, followed by long-term storage in depleted hydrocarbon reservoirs or saline aquifers remains a key option for reducing CO2 emissions while fossil fuel use continues. For CCS to be effective, t

  20. Incentives for subcontractors to adopt CO2 emission reporting and reduction techniques

    NARCIS (Netherlands)

    Scholtens, Bert; Kleinsmann, Renske

    2011-01-01

    We investigate the incentives for subcontractors (couriers) of a transport and logistics company to report about their CO2 emissions and to implement CO2 reducing technologies. Furthermore, we try to find out whether these incentives differ between British and Dutch couriers. We find that several in

  1. Methodology and framework architecture for the evaluation of effects of ICT measures on CO2 emissions

    NARCIS (Netherlands)

    Jonkers, E.; Klunder, G.; Mahmod, M.; Benz, T.

    2013-01-01

    Applications of Information and Communication Technologies (ICT) have been identified to have a significant contribution to reduce energy consumption and CO2 emissions in the field of transport. The mechanisms by which ICT have an impact on CO2 emissions can be very complex, and calculating this imp

  2. Lidar Measurements of Atmospheric CO2 From Regional to Global Scales

    Science.gov (United States)

    Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Ismail, Syed; Kooi, Susan; Fan, Tai-Fang

    2015-01-01

    Atmospheric CO2 is a critical forcing for the Earth's climate and the knowledge on its distributions and variations influences predictions of the Earth's future climate. Large uncertainties in the predictions persist due to limited observations. This study uses the airborne Intensity-Modulated Continuous-Wave (IMCW) lidar developed at NASA Langley Research Center to measure regional atmospheric CO2 spatio-temporal variations. Further lidar development and demonstration will provide the capability of global atmospheric CO2 estimations from space, which will significantly advances our knowledge on atmospheric CO