Evidence for CO2-rich fluids in rocks from the type charnockite area near Pallavaram, Tamil Nadu

NASA Technical Reports Server (NTRS)

Hansen, E.; Hunt, W.; Jacob, S. C.; Morden, K.; Reddi, R.; Tacy, P.

1988-01-01

Fluid inclusion and mineral chemistry data was presented for samples from the type charnockite area near Pallavaram (Tamil Nadu, India). The results indicate the presence of a dense CO2 fluid phase, but the data cannot distinguish between influx of this fluid from elsewhere or localized migration of CO2-rich fluids associated with dehydration melting.

Spatial and Temporal Variability of Carbon Dioxide Using Structure Functions in Urban Areas: Insights for Future Active Remote CO2 Sensors

NASA Technical Reports Server (NTRS)

Choi, Yonghoon; Yang, Melissa; Kooi, Susan A.; Browell, Edward V.; DiGangi, Joshua P.

2015-01-01

High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaigns during July 2011 over Washington DC/Baltimore, MD; January-February 2013 over the San Joaquin Valley, CA; September 2013 over Houston, TX; and July-August 2014 over Denver, CO. Each of these campaigns have approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 kilometers) at 6-8 different sites in each of the urban areas. In this study, we used structure function analysis, which is a useful way to quantify spatial and temporal variability, by displaying differences with average observations, to evaluate the variability of CO2 in the 0-2 kilometers range (representative of the planetary boundary layer). These results can then be used to provide guidance in the development of science requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission to measure near-surface CO2 variability in different urban areas. We also compare the observed in-situ CO2 variability with the variability of the CO2 column-averaged optical depths in the 0-1 kilometer and 0-3.5 kilometers altitude ranges in the four geographically different urban areas, using vertical weighting functions for potential future ASCENDS lidar CO2 sensors operating in the 1.57 and 2.05 millimeter measurement regions. In addition to determining the natural variability of CO2 near the surface and in the column, radiocarbon method using continuous CO2 and CO measurements are used to examine the variation of emission quantification between anthropogenic and biogenic sources in the DC/Maryland urban site.

CO2 sequestration in two mediterranean dune areas subjected to a different level of anthropogenic disturbance

NASA Astrophysics Data System (ADS)

Bonito, Andrea; Ricotta, Carlo; Iberite, Mauro; Gratani, Loretta; Varone, Laura

2017-09-01

Coastal sand dunes are among the most threatened habitats, especially in the Mediterranean Basin, where the high levels of human pressure impair the presence of plant species, putting at risk the maintenance of the ecosystem services, such as CO2 sequestration provided by these habitats. The aim of this study was to analyze how disturbance-induced changes in plant species abundance patterns account for variations in annual CO2 sequestration flow (CS) of Mediterranean sand dune areas. Two sites characterized by a high (site HAD) and a lower (site LAD) anthropogenic disturbance level were selected. At both sites, plant species number, cover, height and CS based on net photosynthesis measurements were sampled. At the plant species level, our results highlighted that Ammophila arenaria and Pancratium maritimum, had a key role in CS. Moreover, the results revealed a patchy species assemblage in both sites. In particular, HAD was characterized by a higher extension of the anthropogenic aphytoic zone (64% of the total transect length) than LAD. In spite of the observed differences in plant species composition, there were not significant differences between HAD and LAD in structural and functional traits, such as plant height and net photosynthesis. As a consequence, HAD and LAD had a similar CS (443 and 421 Mg CO2 ha-1 y-1, respectively). From a monetary point of view, our estimates based on the social costs of carbon revealed that the flow of sequestered CO2 valued on an average 3181 ± 114 ha-1 year-1 (mean value for the two sites). However, considering also the value of the CO2 negative flow related to loss of vegetated area, the annual net benefit arising from CO2 sequestration amounted to 1641 and 1772 for HAD and LAD, respectively. Overall, the results highlighted the importance to maximize the efforts to preserve dune habitats by applying an effective management policy, which could allow maintaining also a regulatory ecosystem service such as CO2 sequestration.

Elevated CO2 alters distribution of nodal leaf area and enhances nitrogen uptake contributing to yield increase of soybean cultivars grown in Mollisols.

PubMed

Jin, Jian; Li, Yansheng; Liu, Xiaobing; Wang, Guanghua; Tang, Caixian; Yu, Zhenhua; Wang, Xiaojuan; Herbert, Stephen J

2017-01-01

Understanding how elevated CO2 affects dynamics of nodal leaf growth and N assimilation is crucial for the construction of high-yielding canopy via breeding and N management to cope with the future climate change. Two soybean cultivars were grown in two Mollisols differing in soil organic carbon (SOC), and exposed to ambient CO2 (380 ppm) or elevated CO2 (580 ppm) throughout the growth stages. Elevated CO2 induced 4-5 more nodes, and nearly doubled the number of branches. Leaf area duration at the upper nodes from R5 to R6 was 4.3-fold greater and that on branches 2.4-fold higher under elevated CO2 than ambient CO2, irrespective of cultivar and soil type. As a result, elevated CO2 markedly increased the number of pods and seeds at these corresponding positions. The yield response to elevated CO2 varied between the cultivars but not soils. The cultivar-specific response was likely attributed to N content per unit leaf area, the capacity of C sink in seeds and N assimilation. Elevated CO2 did not change protein concentration in seeds of either cultivar. These results indicate that elevated CO2 increases leaf area towards the upper nodes and branches which in turn contributes yield increase.

How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

NASA Astrophysics Data System (ADS)

Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

2017-04-01

Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

Studying emissions of CO2 in the Baltimore/Washington area using airborne measurements: source attribution, flux quantification, and model comparison

NASA Astrophysics Data System (ADS)

Ahn, D.; Hansford, J. R.; Salawitch, R. J.; Ren, X.; Cohen, M.; Karion, A.; Whetstone, J. R.; Salmon, O. E.; Shepson, P. B.; Gurney, K. R.; Osterman, G. B.; Dickerson, R. R.

2017-12-01

We study emissions of CO2 in the Baltimore-Washington area using airborne in-situ measurements, obtained during the February 2015 Fluxes of Greenhouse Gases in Maryland (FLAGG-MD) campaign. In this study, we attributed enhanced signals of CO2 to several power plants and two urban areas (Baltimore City and Washington, DC), using the NOAA HYSPLIT air parcel trajectory model as well as the analysis of chemical ratios to quantify the source/receptor relationship. Then, the fluxes of attributed CO2 are estimated using a mass balance approach. The uncertainty in the aircraft-based mass balance approach is estimated by conducting a detailed sensitivity analysis of CO2 fluxes, considering factors such as the background mixing ratio of CO2, wind direction and speed, PBL heights, the horizontal boundary, and vertical interpolation methods. Estimated fluxes of CO2 with estimated uncertainty ranges are then compared to output from various emissions data and models, such as CEMS, CarbonTracker, FFDAS, and ODIAC. Finally, column CO2 data over the Baltimore-Washington region observed by the OCO-2 satellite instrument are statistically compared to aircraft in-situ observations, to assess how well OCO-2 is able to quantify geographic and synoptic-scale variability.

Strategies for satellite-based monitoring of CO2 from distributed area and point sources

NASA Astrophysics Data System (ADS)

Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

2014-05-01

Atmospheric CO2 budgets are controlled by the strengths, as well as the spatial and temporal variabilities of CO2 sources and sinks. Natural CO2 sources and sinks are dominated by the vast areas of the oceans and the terrestrial biosphere. In contrast, anthropogenic and geogenic CO2 sources are dominated by distributed area and point sources, which may constitute as much as 70% of anthropogenic (e.g., Duren & Miller, 2012), and over 80% of geogenic emissions (Burton et al., 2013). Comprehensive assessments of CO2 budgets necessitate robust and highly accurate satellite remote sensing strategies that address the competing and often conflicting requirements for sampling over disparate space and time scales. Spatial variability: The spatial distribution of anthropogenic sources is dominated by patterns of production, storage, transport and use. In contrast, geogenic variability is almost entirely controlled by endogenic geological processes, except where surface gas permeability is modulated by soil moisture. Satellite remote sensing solutions will thus have to vary greatly in spatial coverage and resolution to address distributed area sources and point sources alike. Temporal variability: While biogenic sources are dominated by diurnal and seasonal patterns, anthropogenic sources fluctuate over a greater variety of time scales from diurnal, weekly and seasonal cycles, driven by both economic and climatic factors. Geogenic sources typically vary in time scales of days to months (geogenic sources sensu stricto are not fossil fuels but volcanoes, hydrothermal and metamorphic sources). Current ground-based monitoring networks for anthropogenic and geogenic sources record data on minute- to weekly temporal scales. Satellite remote sensing solutions would have to capture temporal variability through revisit frequency or point-and-stare strategies. Space-based remote sensing offers the potential of global coverage by a single sensor. However, no single combination of orbit

Physical Activation of Oil Palm Empty Fruit Bunch via CO2 Activation Gas for CO2 Adsorption

NASA Astrophysics Data System (ADS)

Joseph, C. G.; Quek, K. S.; Daud, W. M. A. W.; Moh, P. Y.

2017-06-01

In this study, different parameters for the preparation of activated carbon were investigated for their yield and CO2 capture capabilities. The activated carbon was prepared from Oil Palm Empty Fruit Bunch (OPEFB) via a 2-step physical activation process. The OPEFB was pyrolyzed under inert conditions at 500 °C and activated via CO2. A 2-factorial design was employed and the effects of activation temperature, activation dwell time and gas flow rate on yield and CO2 capture capabilities were compared and studied. The yield obtained ranged from between 20 - 26, whereby the temperature was determined to be the most significant factor in influencing CO2 uptake. The CO2 capture capacity was determined using Temperature Programmed Desorption (TPD) technique. The CO2 uptake of EFB activated carbon achieved was between 1.85 - 2.09 mmol/g. TPD analysis has shown that the surface of AC were of basic nature. AC was found to be able to withhold the CO2 up to 663°C before maximum desorption occurs. The surface area and pore size of OPEFB obtained from BET analysis is 2.17 m2 g-1 and 0.01 cm3 g-1. After activation, both surface area and pore size increased with a maximum observed surface area and pore size of 548.07 m2 g-1 and 0.26 cm3 g-1. Surface morphology, functional groups, pore size and surface area were analyzed using SEM, FT-IR, TPD and BET.

Correlation between CO2 storage at the last minute of gas insufflation and area of retroperitoneal lacuna during retroperitoneal laparoscopic radical nephrectomy.

PubMed

Hu, Jian-Jun; Liu, Ya-Hua; Yu, Chan-Juan; Jialielihan, Nuerbolati

2016-07-22

Adequate operation interspace is the premise of laparoscopy, and carbon dioxide (CO2) was an ideal gas for forming lacuna. A retroperitoneal space is used to form operation interspace in retroperitoneal laparoscopic radical nephrectomy by making ballooning, and the retroperitoneal space has no relative complete and airtight serous membrane, therefore CO2 absorption may be greater in retroperitoneal than transperitoneal laparoscopic radical nephrectomy. Excess CO2 absorption may induce hypercapnemia and further cause physiopathological change of respiratory and circulatory system. Therefore, exact evaluation of amount of CO2 which is eliminated from body via minute ventilation is important during retroperitoneal laparoscopic radical nephrectomy. The aim of the paper is to study the correlation between CO2 storage at the last minute of gas insufflation and area of retroperitoneal lacuna during retroperitoneal laparoscopic radical nephrectomy. Forty ASA I/II patients undergoing retroperitoneal laparoscopic radical nephrectomy were enrolled. CO2 storage at the last minute of gas insufflation and area of a retroperitoneal lacuna were observed. Linear correlation and regression were performed to determine the correlation between them. There was positive correlation between CO2 storage at the last minute of gas insufflation and area of retroperitoneal lacuna (r = 0.880, P = 0.000), and the equation of linear regression was y = -83.097 + 0.925x (R(2) = 0.780, t = 11.610, P = 0.000). Amount of CO2 which is eliminated from body via mechanical ventilation could be calculated by measuring the area of retroperitoneal lacuna during retroperitoneal laparoscopic radical nephrectomy, and an anesthetist should be aware of the size of lacuna to predict high CO2 storage at the last minute of gas insufflation.

Eddy covariance measurement of CO2 flux to the atmosphere from a area of high volcanogenic emissions, Mammoth Mountain, California

USGS Publications Warehouse

Anderson, D.E.; Farrar, C.D.

2001-01-01

Three pilot studies were performed to assess application of the eddy covariance micrometeorological method in the measurement of carbon dioxide (CO2) flux of volcanic origin. The selected study area is one of high diffuse CO2 emission on Mammoth Mountain, CA. Because terrain and source characteristics make this a complex setting for this type of measurement, added consideration was given to source area and upwind fetch. Footprint analysis suggests that the eddy covariance measurements were representative of an upwind elliptical source area (3.8 ?? 103 m2) which can vary with mean wind direction, surface roughness, and atmospheric stability. CO2 flux averaged 8-16 mg m-2 s-1 (0.7-1.4 kg m-2 day-1). Eddy covariance measurements of flux were compared with surface chamber measurements made in separate studies [Geophys. Res. Lett. 25 (1998a) 1947; EOS Trans. 79 (1998) F941.] and were found to be similar. ?? 2001 Elsevier Science B.V. All rights reserved.

High CO2/H+ dialysis in the caudal ventrolateral medulla (Loeschcke's area) increases ventilation in wakefulness.

PubMed

da Silva, Glauber S F; Li, Aihua; Nattie, Eugene

2010-04-15

Central chemoreception, the detection of CO(2)/H(+) within the brain and the resultant effect on ventilation, was initially localized at two areas on the ventrolateral medulla, one rostral (rVLM-Mitchell's) the other caudal (cVLM-Loeschcke's), by surface application of acidic solutions in anesthetized animals. Focal dialysis of a high CO(2)/H(+) artificial cerebrospinal fluid (aCSF) that produced a milder local pH change in unanesthetized rats (like that with a approximately 6.6mm Hg increase in arterial P(CO2)) delineated putative chemoreceptor regions for the rVLM at the retrotrapezoid nucleus and the rostral medullary raphe that function predominantly in wakefulness and sleep, respectively. Here we ask if chemoreception in the cVLM can be detected by mild focal stimulation and if it functions in a state dependent manner. At responsive sites just beneath Loeschcke's area, ventilation was increased by, on average, 17% (P<0.01) only in wakefulness. These data support our hypothesis that central chemoreception is a distributed property with some sites functioning in a state dependent manner. Copyright 2010 Elsevier B.V. All rights reserved.

'Design of CO-O2 recombination catalysts for closed-cycle CO2 lasers'

NASA Technical Reports Server (NTRS)

Guinn, K.; Goldblum, S.; Noskowski, E.; Herz, R.

1989-01-01

Pulsed CO2 lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers is hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalysts and design methods for implementation of catalysts inside lasers. This paper will discuss the performance criteria and constraints involved in the design of monolith catalyst configurations for use in a closed-cycle laser and will present a design study performed with a computerized design program that had been written. Trade-offs between catalyst activity and dimensions, flow channel dimensions, pressure drop, O2 conversion and other variables will be discussed.

Impact of membrane lung surface area and blood flow on extracorporeal CO2 removal during severe respiratory acidosis.

PubMed

Karagiannidis, Christian; Strassmann, Stephan; Brodie, Daniel; Ritter, Philine; Larsson, Anders; Borchardt, Ralf; Windisch, Wolfram

2017-12-01

Veno-venous extracorporeal CO 2 removal (vv-ECCO 2 R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates through the device range from 200 ml/min to more than 1500 ml/min, and the membrane surface areas range from 0.35 to 1.3 m 2 . The present study in an animal model with similar CO 2 production as an adult patient was aimed at determining the optimal membrane lung surface area and technical requirements for successful vv-ECCO 2 R. Four different membrane lungs, with varying lung surface areas of 0.4, 0.8, 1.0, and 1.3m 2 were used to perform vv-ECCO 2 R in seven anesthetized, mechanically ventilated, pigs with experimentally induced severe respiratory acidosis (pH 7.0-7.1) using a 20Fr double-lumen catheter with a sweep gas flow rate of 8 L/min. During each experiment, the blood flow was increased stepwise from 250 to 1000 ml/min. Amelioration of severe respiratory acidosis was only feasible when blood flow rates from 750 to 1000 ml/min were used with a membrane lung surface area of at least 0.8 m 2 . Maximal CO 2 elimination was 150.8 ml/min, with pH increasing from 7.01 to 7.30 (blood flow 1000 ml/min; membrane lung 1.3 m 2 ). The membrane lung with a surface of 0.4 m 2 allowed a maximum CO 2 elimination rate of 71.7 mL/min, which did not result in the normalization of pH, even with a blood flow rate of 1000 ml/min. Also of note, an increase of the surface area above 1.0 m 2 did not result in substantially higher CO 2 elimination rates. The pressure drop across the oxygenator was considerably lower (<10 mmHg) in the largest membrane lung, whereas the smallest revealed a pressure drop of more than 50 mmHg with 1000 ml blood flow/min. In this porcine model, vv-ECCO 2 R was most effective when using blood flow rates ranging between 750 and 1000 ml/min, with a membrane lung surface of at least 0.8 m 2 . In contrast, low blood flow rates (250-500 ml/min) were not sufficient to completely correct severe

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

PubMed

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

2014-10-07

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.

Synthesis of hollow NiCo2O4 nanospheres with large specific surface area for asymmetric supercapacitors.

PubMed

Xu, Kaibing; Yang, Jianmao; Hu, Junqing

2018-02-01

Hollow micro-/nanostructured electrode materials with high active surface area are highly desirable for achieving outstanding electrochemical properties. Herein, we report the successful synthesis of hierarchical hollow NiCo 2 O 4 nanospheres with high surface area as electrode materials for supercapacitors. Electrochemical measurements prove that such electrode materials exhibit excellent electrochemical behavior with a specific capacitance reaching 1229 F/g at 1 A/g, remarkable rate performance (∼83.6% retention from 1 to 25 A/g) and good cycling performance (86.3% after 3000 cycles). Furthermore, the asymmetric supercapacitor is fabricated with hollow NiCo 2 O 4 nanospheres electrode and activated carbon (AC) electrode as the positive and negative, respectively. This device exhibits a maximum energy density of 21.5 W h/kg, excellent cycling performance and coulombic efficiency. The results show that hollow NiCo 2 O 4 nanosphere electrode is a promising electrode material for the future application in high performance supercapacitors. Copyright © 2017 Elsevier Inc. All rights reserved.

Exceptionally High Efficient Co-Co2P@N, P-Codoped Carbon Hybrid Catalyst for Visible Light-Driven CO2-to-CO Conversion.

PubMed

Fu, Wen Gan

2018-05-02

Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light-driven methods to reduce CO2 to form energy-rich carbon-based products. Because CO2 reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO2 adsorption on a catalyst and proton transfer to CO2 are two important factors for the conversion reaction，and catalysts with high surface area and more active sites are required to improve the efficiency of CO2 reduction. Here, we report a visible light-driven system for CO2-to-CO conversion that consists of a heterogeneous hybrid catalyst of Co and Co2P nanoparticles embedded in carbon nanolayers codoped with N and P (Co-Co2P@NPC) and a homogeneous Ru(II)-based complex photosensitizer. The average generation rate of CO of the system was up to 35,000 μmol h-1 g-1 with selectivity of 79.1% in 3 h. Linear CO production at an exceptionally high rate of 63,000 μmol h-1 g-1 was observed in the first hour of reaction. Inspired by this highly active catalyst, we also synthesized Co@NC and Co2P@NPC materials and explored their structure, morphology, and catalytic properties for CO2 photoreduction. The results showed that the nanoparticle size, partially adsorbed H2O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO2 reduction performance. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

PubMed Central

Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian

2015-01-01

Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

High-Surface-Area CO2 Sponge: High Performance CO2 Scrubbing Based on Hollow Fiber-Supported Designer Ionic Liquid Sponges

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

IMPACCT Project: The team from ORNL and Georgia Tech is developing a new technology that will act like a sponge, integrating a new, alcohol-based ionic liquid into hollow fibers (magnified image, right) to capture CO2 from the exhaust produced by coal-fired power plants. Ionic liquids, or salts that exist in liquid form, are promising materials for carbon capture and storage, but their tendency to thicken when combined with CO2 limits their efficiency and poses a challenge for their development as a cost-effective alternative to current-generation solutions. Adding alcohol to the mix limits this tendency to thicken in the presence ofmore » CO2 but can also make the liquid more likely to evaporate, which would add significantly to the cost of CO2 capture. To solve this problem, ORNL is developing new classes of ionic liquids with high capacity for absorbing CO2. ORNL’s sponge would reduce the cost associated with the energy that would need to be diverted from power plants to capture CO2 and release it for storage.« less

Anthropogenic CO2 in a dense water formation area of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Ingrosso, Gianmarco; Bensi, Manuel; Cardin, Vanessa; Giani, Michele

2017-05-01

There is growing evidence that the on-going ocean acidification of the Mediterranean Sea could be favoured by its active overturning circulation. The areas of dense water formation are, indeed, preferential sites for atmospheric carbon dioxide absorption and through them the ocean acidification process can quickly propagate into the deep layers. In this study we estimated the concentration of anthropogenic CO2 (Cant) in the dense water formation areas of the middle and southern Adriatic Sea. Using the composite tracer TrOCA (Tracer combining Oxygen, inorganic Carbon, and total Alkalinity) and carbonate chemistry data collected throughout March 2013, our results revealed that a massive amount of Cant has invaded all the identified water masses. High Cant concentration was detected at the bottom layer of the Pomo Pit (middle Adriatic, 96.8±9.7 μmol kg-1) and Southern Adriatic Pit (SAP, 85.2±9.4 μmol kg-1), associated respectively with the presence of North Adriatic Dense Water (NAdDW) and Adriatic Dense Water (AdDW). This anthropogenic contamination was clearly linked to the dense water formation events, which govern strong CO2 flux from the atmosphere to the sea and the sinking of dense, CO2-rich surface waters to the deep sea. However, a very high Cant level (94.5±12.5 μmol kg-1) was also estimated at the intermediate layer, as a consequence of a recent vertical mixing that determined the physical and biogeochemical modification of the water of Levantine origin (i.e. Modified Levantine Intermediate Water, MLIW) and favoured the atmospheric CO2 intrusion. The penetration of Cant in the Adriatic Sea determined a significant pH reduction since the pre-industrial era (- 0.139±0.019 pH units on average). This estimation was very similar to the global Mediterranean Sea acidification, but it was again more pronounced at the bottom of the Pomo Pit, within the layer occupied by NAdDW (- 0.157±0.018 pH units), and at the intermediate layer of the recently formed MLIW

Temporal dynamics and spatial variability in the enhancement of canopy leaf area under elevated atmospheric CO2

Treesearch

Heather R. McCarthy; Ram Oren; Adrien C. Finzi; David S. Ellsworth; Hyun-Seok Kim; Kurt H. Johnsen; Bonnie Millar

2007-01-01

Increased canopy leaf area (L) may lead to higher forest productivity and alter processes such as species dynamics and ecosystem mass and energy fluxes. Few CO2enrichment studies have been conducted in closed canopy forests and none have shown a sustained enhancement of L. We reconstructed 8 years (1996–2003) of L at Duke’s Free Air CO...

The role of CO 2 as a soft oxidant for dehydrogenation of ethylbenzene to styrene over a high-surface-area ceria catalyst

DOE PAGES

Zhang, Li; Wu, Zili; Nelson, Nicholas; ...

2015-09-22

Catalytic performance and the nature of surface adsorbates were investigated for high-surface-area ceria during ethylbenzene oxidative dehydrogenation (ODH) reaction using CO2 as a soft oxidant. A template assisted method was used to synthesize the high-surface-area ceria. The interactions between ethylbenzene, styrene and CO2 on the surface of ceria and the role of CO2 for the ethylbenzene ODH reaction have been investigated in detail by using activity test, in situ Diffuse Reflectance Infrared and Raman spectroscopy. Not only did CO2 as an oxidant favor the higher yield of styrene, but it also inhibited the deposition of coke during the ethylbenzene ODHmore » reaction. Ethylbenzene ODH reaction over ceria followed a two-step pathway: Ethylbenzene is first dehydrogenated to styrene with H2 formed simultaneously, and then CO2 reacts with H2 via the reverse water gas shift. The styrene produced can easily polymerize to form polystyrene, a key intermediate for coke formation. In the absence of CO2, the polystyrene transforms into graphite-like coke at temperatures above 500 °C, which leads to catalyst deactivation. While in the presence of CO2, the coke deposition can be effectively removed via oxidation with CO2.« less

CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

NASA Astrophysics Data System (ADS)

Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

2012-10-01

Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is challenging, but essential in order to utilize CO2 measurements in an atmospheric inverse framework to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration, during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town-Energy Balance (TEB) urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs) surface scheme, allowing a full interaction of CO2 between the surface and the atmosphere. Statistical scores show a good representation of the Urban Heat Island (UHI) and urban-rural contrasts. Boundary layer heights (BLH) at urban, sub-urban and rural sites are well captured, especially the onset time of the BLH increase and its growth rate in the morning, that are essential for tall tower CO2 observatories. Only nocturnal BLH at sub-urban sites are slightly underestimated a few nights, with a bias less than 50 m. At Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the Atmospheric Boundary Layer (ABL) growth reaches the measurement height. The timing of the CO2 cycle is well captured by the model, with only small biases on CO2 concentrations, mainly linked to the misrepresentation of anthropogenic emissions, as the Eiffel site is at the heart of trafic emission sources. At sub-urban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a very strong spatio-temporal variability. The CO2 cycle at these sites is generally well reproduced by the model, even if some biases on the nocturnal maxima appear in the Paris plume parly due to small errors on the vertical transport, or in

Preliminary study of a potential CO2 reservoir area in Hungary

NASA Astrophysics Data System (ADS)

Sendula, Eszter; Király, Csilla; Szabó, Zsuzsanna; Falus, György; Szabó, Csaba; Kovács, István; Füri, Judit; Kónya, Péter; Páles, Mariann; Forray, Viktória

2014-05-01

CO2 storage environment. From the potential reservoir rock samples (sandstone) thin sections were prepared to determine the mineral composition, pore distribution, pore geometry and grain size. The volume ratio of the minerals was calculated using pixel counter. To have more accurate mineral composition, petrographic observation and SEM analyzes have been carried out. The caprock samples involved in the study can be divided into mudstone and aleurolite samples. To determine the mineral composition of these samples, XRD, DTA, FTIR, SEM analysis has been carried out. To obtain a picture about the geochemical behavior of the potential CO2 storage system, geochemical models were made for the reservoir rocks. For the equilibrium geochemical model, PHREEQC 3.0 was used applying LLNL database. The data used in the model are real pore water compositions from the studied area and an average mineral composition based on petrographic microscope and SEM images. In the model we considered the cation-anion ratio (<10%) and the partial pressure of CO2. First of all, we were interested in the direction of the geochemical reactions during an injection process. Present work is focused on the mineralogy of the most potential storage rock and its caprock, and their expectable geochemical reactions for the effect of scCO2.

Atmospheric inversion of the surface CO2 flux with 13CO2 constraint

NASA Astrophysics Data System (ADS)

Chen, J. M.; Mo, G.; Deng, F.

2013-10-01

Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using the 13CO2/CO2 flux ratio modeled with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and respiration and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. For the 2002-2004 period, the 13CO2 constraint on the inversion increases the total land carbon sink from 3.40 to 3.70 Pg C yr-1 and decreases the total oceanic carbon sink from 1.48 to 1.12 Pg C yr-1. The largest changes occur in tropical areas: a considerable decrease in the carbon source in the Amazon forest, and this decrease is mostly compensated by increases in the ocean region immediately west of the Amazon and the southeast Asian land region. Our further investigation through different treatments of the 13CO2/CO2 flux ratio used in the inversion suggests that variable spatial distributions of the 13CO2 isotopic discrimination rate simulated by the models over land and ocean have considerable impacts on the spatial distribution of the inverted CO2 flux over land and the inversion results are not sensitive to errors in the estimated disequilibria over land and ocean.

Diurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity area

NASA Astrophysics Data System (ADS)

Xueref-Remy, Irène; Dieudonné, Elsa; Vuillemin, Cyrille; Lopez, Morgan; Lac, Christine; Schmidt, Martina; Delmotte, Marc; Chevallier, Frédéric; Ravetta, François; Perrussel, Olivier; Ciais, Philippe; Bréon, François-Marie; Broquet, Grégoire; Ramonet, Michel; Spain, T. Gerard; Ampe, Christophe

2018-03-01

Most of the global fossil fuel CO2 emissions arise from urbanized and industrialized areas. Bottom-up inventories quantify them but with large uncertainties. In 2010-2011, the first atmospheric in situ CO2 measurement network for Paris, the capital of France, began operating with the aim of monitoring the regional atmospheric impact of the emissions coming from this megacity. Five stations sampled air along a northeast-southwest axis that corresponds to the direction of the dominant winds. Two stations are classified as rural (Traînou - TRN; Montgé-en-Goële - MON), two are peri-urban (Gonesse - GON; Gif-sur-Yvette - GIF) and one is urban (EIF, located on top of the Eiffel Tower). In this study, we analyze the diurnal, synoptic and seasonal variability of the in situ CO2 measurements over nearly 1 year (8 August 2010-13 July 2011). We compare these datasets with remote CO2 measurements made at Mace Head (MHD) on the Atlantic coast of Ireland and support our analysis with atmospheric boundary layer height (ABLH) observations made in the center of Paris and with both modeled and observed meteorological fields. The average hourly CO2 diurnal cycles observed at the regional stations are mostly driven by the CO2 biospheric cycle, the ABLH cycle and the proximity to urban CO2 emissions. Differences of several µmol mol-1 (ppm) can be observed from one regional site to the other. The more the site is surrounded by urban sources (mostly residential and commercial heating, and traffic), the more the CO2 concentration is elevated, as is the associated variability which reflects the variability of the urban sources. Furthermore, two sites with inlets high above ground level (EIF and TRN) show a phase shift of the CO2 diurnal cycle of a few hours compared to lower sites due to a strong coupling with the boundary layer diurnal cycle. As a consequence, the existence of a CO2 vertical gradient above Paris can be inferred, whose amplitude depends on the time of the day and on

CO2 clearance by membrane lungs.

PubMed

Sun, Liqun; Kaesler, Andreas; Fernando, Piyumindri; Thompson, Alex J; Toomasian, John M; Bartlett, Robert H

2018-05-01

Commercial membrane lungs are designed to transfer a specific amount of oxygen per unit of venous blood flow. Membrane lungs are much more efficient at removing CO 2 than adding oxygen, but the range of CO 2 transfer is rarely reported. Commercial membrane lungs were studied with the goal of evaluating CO 2 removal capacity. CO 2 removal was measured in 4 commercial membrane lungs under standardized conditions. CO 2 clearance can be greater than 4 times that of oxygen at a given blood flow when the gas to blood flow ratio is elevated to 4:1 or 8:1. The CO 2 clearance was less dependent on surface area and configuration than oxygen transfer. Any ECMO system can be used for selective CO 2 removal.

Estimation of the reactive mineral surface area during CO2-rich fluid-rock interaction: the influence of neogenic phases

NASA Astrophysics Data System (ADS)

Scislewski, A.; Zuddas, P.

2010-12-01

Mineral dissolution and precipitation reactions actively participate to control fluid chemistry during water-rock interaction. It is however, difficult to estimate and well normalize bulk reaction rates if the mineral surface area exposed to the aqueous solution and effectively participating on the reactions is unknown. We evaluated the changing of the reactive mineral surface area during the interaction between CO2-rich fluids and Albitite/Granitoid rocks (similar mineralogy but different abundances), reacting under flow-through conditions. Our methodology, adopting an inverse modeling approach, is based on the estimation of dissolution rate and reactive surface area of the different minerals participating in the reactions by the reconstruction the chemical evolution of the interacting fluids. The irreversible mass-transfer processes is defined by a fractional degree of advancement, while calculations were carried out for Albite, Microcline, Biotite and Calcite assuming that the ion activity of dissolved silica and aluminium ions was limited by the equilibrium with quartz and kaolinite. Irrespective of the mineral abundance in granite and albitite, we found that mineral dissolution rates did not change significantly in the investigated range of time where output solution’s pH remained in the range between 6 and 8, indicating that the observed variation in fluid composition depends not on pH but rather on the variation of the parent mineral’s reactive surface area. We found that the reactive surface area of Albite varied by more than 2 orders of magnitude, while Microcline, Calcite and Biotite surface areas changed by 1-2 orders of magnitude. We propose that parent mineral chemical heterogeneity and, particularly, the stability of secondary mineral phases may explain the observed variation of the reactive surface area of the minerals. Formation of coatings at the dissolving parent mineral surfaces significantly reduced the amount of surface available to react

CO2 fluxes from diffuse degassing in Italy

NASA Astrophysics Data System (ADS)

Cardellini, C.; Chiodini, G.; Frondini, F.; Caliro, S.

2016-12-01

Central and southern Italy are affected by an intense process of CO2 Earth degassing from both active volcanoes, and tectonically active areas. Regional scale studies, based on C mass balance of groundwater of regional aquifers in not volcanically active areas, highlighted the presence of two large CO2 degassing structures that, for magnitude and the geochemical-isotopic features, were related to a regional process of mantle degassing. Quantitative estimates provided a CO2 flux of 9 Mt/y for the region (62000 km2). Besides the magnitude of the process, a strong link between the deep CO2 degassing and the seismicity of the region and a strict correlation between migration of deep CO2-rich fluids and the heat flux have been highlighted. In addition, the region is also characterised by the presence of many cold gas emissions where deeply derived CO2 is released by vents and soil diffuse degassing areas. Both direct CO2 expulsion at the surface and C-rich groundwater are different manifestations of the same process, in fact, the deeply produced gas can be dissolved by groundwater or emitted directly to the atmosphere depending on the gas flux rate, and the geological-structural and hydrogeological settings. Quantitative estimations of the CO2 fluxes are available only for a limited number ( 30) of the about 270 catalogued gas manifestations allowing an estimations of a CO2 flux of 1.4 Mt/y. Summing the two estimates the non-volcanic CO2 flux from the region results globally relevant, being from 2 to 10% of the estimated present-day global CO2 discharge from subaerial volcanoes. Large amounts of CO2 is also discharged by soil diffuse degassing in volcanic-hydrothermal systems. Specific surveys at Solfatara of Pozzuoli (Campi Flegrei Caldera) pointed out the relevance of this process. CO2 diffuse degassing at Solfatara, measured since 1998 shows a persistent CO2 flux of 1300 t/d (± 390 t/d), a flux comparable to an erupting volcano. The quantification of diffuse CO2

Correlation between plant physiology and CO2 removable

NASA Astrophysics Data System (ADS)

Leman, A. M.; Shamsuri, Mohd Mahathir Suhaimi; Hariri, Azian; Kadir, Aeslina Abdul; Idris, Ahmad Fu'ad; Afandi, Azizi

2017-09-01

Certain plants that are able to live in the building are known as indoor plants. Plants have tolerance with indoor environment in order to survive. Usually these plants are able to improve indoor air quality (IAQ). Absorption of carbon dioxide (CO2) by plants is one of the indicators that plants are still alive during photosynthesis process. The possibility of plants structure (plant physiology) to affect CO2 absorption had been the concerns of former researchers. This research intends to study the significant of plant structure (leaf area, fresh weight, and dry weight) that leads to reducing the concentration of CO2 by seven plant species (Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plants, Spider Plants, and Syngonium). The data of CO2 reduction by plants has been obtained from previous studies. Based on results show that, the leaf area is the most contributing the significant effect to the plant absorb CO2 compare to fresh weight and dry weight. It can be prove by Pearson Correlation, where only the value of leaf area is more than 0.5 for every four conditions. This study can be conclude that the leaf area is quite plays an important role to the plant treat air from CO2, while concentration of light and CO2 will become catalytic factor for the plants improve their photosynthesis process.

Shock-induced CO2 loss from CaCO3: Implications for early planetary atmospheres

NASA Technical Reports Server (NTRS)

Lange, M. A.; Ahrens, T. J.

1984-01-01

Recovered samples from shock recovery experiments on single crystal calcite were subjected to thermogravimetric analysis to determine the amount of post-shock CO2, the decarbonization interval and the activation energy, for the removal of remaining CO2 in shock-loaded calcite. Comparison of post-shock CO2 with that initially present determines shock-induced CO2 loss as a function of shock pressure. Incipient to complete CO2 loss occurs over a pressure range of approximately 10 to approximately 70 GPa. Optical and scanning electron microscopy reveal structural changes, which are related to the shock-loading. The occurrence of dark, diffuse areas, which can be resolved as highly vesicular areas as observed with a scanning electron microscope are interpreted as representing quenched partial melts, into which shock-released CO2 was injected. The experimental results are used to constrain models of shock-produced, primary CO2 atmospheres on the accreting terrestrial planets.

Human Effects and Soil Surface CO2 fluxes in Tropical Urban Green Areas, Singapore

NASA Astrophysics Data System (ADS)

Ng, Bernard; Gandois, Laure; Kai, Fuu Ming; Chua, Amy; Cobb, Alex; Harvey, Charles; Hutyra, Lucy

2013-04-01

Urban green spaces are appreciated for their amenity value, with increasing interest in the ecosystem services they could provide (e.g. climate amelioration and increasingly as possible sites for carbon sequestration). In Singapore, turfgrass occupies approximately 20% of the total land area and is readily found on both planned and residual spaces. This project aims at understanding carbon fluxes in tropical urban green areas, including controls of soil environmental factors and the effect of urban management techniques. Given the large pool of potentially labile carbon, management regimes are recognised to have an influence on soil environmental factors (temperature and moisture), this would affect soil respiration and feedbacks to the greenhouse effect. A modified closed dynamic chamber method was employed to measure total soil respiration fluxes. In addition to soil respiration rates, environmental factors such as soil moisture and temperature, and ambient air temperature were monitored for the site in an attempt to evaluate their control on the observed fluxes. Measurements of soil-atmosphere CO2 exchanges are reported for four experimental plots within the Singtel-Kranji Radio Transmission Station (103o43'49E, 1o25'53N), an area dominated by Axonopus compressus. Different treatments such as the removal of turf, and application of clippings were effected as a means to determine the fluxes from the various components (respiration of soil and turf, and decomposition of clippings), and to explore the effects of human intervention on observed effluxes. The soil surface CO2 fluxes observed during the daylight hours ranges from 2.835 + 0.772 umol m-2 s-1 for the bare plot as compared to 6.654 + 1.134 umol m-2 s-1 for the turfed plot; this could be attributed to both autotrophic and heterotrophic respiration. Strong controls of both soil temperature and soil moisture are observed on measured soil fluxes. On the base soils, fluxes were positively correlated to soil

Effects of elevated CO2 concentrations on denitrifying and nitrifying popualtions at terrestrial CO2 leakeage analogous sites

NASA Astrophysics Data System (ADS)

Christine, Dictor Marie; Catherine, Joulian; Valerie, Laperche; Stephanie, Coulon; Dominique, Breeze

2010-05-01

. Statistical analyses were performed to correlate microbiological measures and physico-chemical parameters. For the soil sampled in a zone with background CO2 content, incubation under an atmosphere with 20% of CO2, induce a sharp decrease of denitrifying activity after 6 months of incubation and only after 3 months with an atmosphere of 50% of CO2. On the contrary, concerning the soil sampled in a zone with 25.5% of CO2, incubation with an atmosphere of 50% has no effect on denitrifying activity and moreover this activity was stimulated with an atmosphere of 90% of CO2.Last, with the soil sampled in an area with 65.8% of CO2, denitrifying activity was negatively impacted from the 3th month of incubation with 90% CO2.and the activity was 2 fold lower after 12th of incubation. Concerning the nitrifying activity, soil sampled in an area with background CO2 content, this one remains little affected by increasing CO2 incubation. At initial times, soil sampled in the areas with 25.5 and 65.8 % of CO2 showed low level of nitrifying activities and further CO2 incubations have no effect on these activities. At the end, denitrifying activities seems to be more sensitive to CO2 concentrations evolution in the soil. More studies need to be done as incubation with lower CO2 content (< 10%) in order to determine the threshold of CO2 that can affect the near-surface bacterial activities and identify a possible candidate of CO2 leakage from deep reservoirs.

Research on the physical properties of supercritical CO2 and the log evaluation of CO2-bearing volcanic reservoirs

NASA Astrophysics Data System (ADS)

Pan, Baozhi; Lei, Jian; Zhang, Lihua; Guo, Yuhang

2017-10-01

CO2-bearing reservoirs are difficult to distinguish from other natural gas reservoirs during gas explorations. Due to the lack of physical parameters for supercritical CO2, particularly neutron porosity, at present a hydrocarbon gas log evaluation method is used to evaluate CO2-bearing reservoirs. The differences in the physical properties of hydrocarbon and CO2 gases have led to serious errors. In this study, the deep volcanic rock of the Songliao Basin was the research area. In accordance with the relationship between the density and acoustic velocity of supercritical CO2 and temperature and pressure, the regularity between the CO2 density and acoustic velocity, and the depth of the area was established. A neutron logging simulation was completed based on a Monte Carlo method. Through the simulation of the wet limestone neutron logging, the relationship between the count rate ratio of short and long space detectors and the neutron porosity was acquired. Then, the nature of the supercritical CO2 neutron moderation was obtained. With consideration given to the complexity of the volcanic rock mineral composition, a volcanic rock volume model was established, and the matrix neutron and density parameters were acquired using the ECS log. The properties of CO2 were applied in the log evaluation of the CO2-bearing volcanic reservoirs in the southern Songliao Basin. The porosity and saturation of CO2 were obtained, and a reasonable application was achieved in the CO2-bearing reservoir.

Catalyzed CO.sub.2-transport membrane on high surface area inorganic support

DOEpatents

Liu, Wei

2014-05-06

Disclosed are membranes and methods for making the same, which membranes provide improved permeability, stability, and cost-effective manufacturability, for separating CO.sub.2 from gas streams such as flue gas streams. High CO.sub.2 permeation flux is achieved by immobilizing an ultra-thin, optionally catalyzed fluid layer onto a meso-porous modification layer on a thin, porous inorganic substrate such as a porous metallic substrate. The CO.sub.2-selective liquid fluid blocks non-selective pores, and allows for selective absorption of CO.sub.2 from gas mixtures such as flue gas mixtures and subsequent transport to the permeation side of the membrane. Carbon dioxide permeance levels are in the order of 1.0.times.10.sup.-6 mol/(m.sup.2sPa) or better. Methods for making such membranes allow commercial scale membrane manufacturing at highly cost-effective rates when compared to conventional commercial-scale CO.sub.2 separation processes and equipment for the same and such membranes are operable on an industrial use scale.

Synthetic biology for CO2 fixation.

PubMed

Gong, Fuyu; Cai, Zhen; Li, Yin

2016-11-01

Recycling of carbon dioxide (CO 2 ) into fuels and chemicals is a potential approach to reduce CO 2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO 2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO 2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO 2 -derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO 2 -fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO 2 -fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO 2 -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 CO 2 .

Leaf Photosynthesis and Respiration of High CO2-Grown Tobacco Plants Selected for Survival under CO2 Compensation Point Conditions 1

PubMed Central

Delgado, Esteban; Azcón-Bieto, Joaquim; Aranda, Xavier; Palazón, Javier; Medrano, Hipólito

1992-01-01

Four self-pollinated, doubled-haploid tobacco, (Nicotiana tabacum L.) lines (SP422, SP432, SP435, and SP451), selected as haploids by survival in a low CO2 atmosphere, and the parental cv Wisconsin-38 were grown from seed in a growth room kept at high CO2 levels (600-700 parts per million). The selected plants were much larger (especially SP422, SP432, and SP451) than Wisconsin-38 nine weeks after planting. The specific leaf dry weight and the carbon (but not nitrogen and sulfur) content per unit area were also higher in the selected plants. However, the chlorophyll, carotenoid, and alkaloid contents and the chlorophyll a/b ratio varied little. The net CO2 assimilation rate per unit area measured in the growth room at high CO2 was not higher in the selected plants. The CO2 assimilation rate versus intercellular CO2 curve and the CO2 compensation point showed no substantial differences among the different lines, even though these plants were selected for survival under CO2 compensation point conditions. Adult leaf respiration rates were similar when expressed per unit area but were lower in the selected lines when expressed per unit dry weight. Leaf respiration rates were negatively correlated with specific leaf dry weight and with the carbon content per unit area and were positively correlated with nitrogen and sulfur content of the dry matter. The alternative pathway was not involved in respiration in the dark in these leaves. The better carbon economy of tobacco lines selected for low CO2 survival was not apparently related to an improvement of photosynthesis rate but could be related, at least partially, to a significantly reduced respiration (mainly cytochrome pathway) rate per unit carbon. ImagesFigure 1 PMID:16668769

Leaf Area Index Drives Soil Water Availability and Extreme Drought-Related Mortality under Elevated CO2 in a Temperate Grassland Model System

PubMed Central

Manea, Anthony; Leishman, Michelle R.

2014-01-01

The magnitude and frequency of climatic extremes, such as drought, are predicted to increase under future climate change conditions. However, little is known about how other factors such as CO2 concentration will modify plant community responses to these extreme climatic events, even though such modifications are highly likely. We asked whether the response of grasslands to repeat extreme drought events is modified by elevated CO2, and if so, what are the underlying mechanisms? We grew grassland mesocosms consisting of 10 co-occurring grass species common to the Cumberland Plain Woodland of western Sydney under ambient and elevated CO2 and subjected them to repeated extreme drought treatments. The 10 species included a mix of C3, C4, native and exotic species. We hypothesized that a reduction in the stomatal conductance of the grasses under elevated CO2 would be offset by increases in the leaf area index thus the retention of soil water and the consequent vulnerability of the grasses to extreme drought would not differ between the CO2 treatments. Our results did not support this hypothesis: soil water content was significantly lower in the mesocosms grown under elevated CO2 and extreme drought-related mortality of the grasses was greater. The C4 and native grasses had significantly higher leaf area index under elevated CO2 levels. This offset the reduction in the stomatal conductance of the exotic grasses as well as increased rainfall interception, resulting in reduced soil water content in the elevated CO2 mesocosms. Our results suggest that projected increases in net primary productivity globally of grasslands in a high CO2 world may be limited by reduced soil water availability in the future. PMID:24632832

Leaf area index drives soil water availability and extreme drought-related mortality under elevated CO2 in a temperate grassland model system.

PubMed

Manea, Anthony; Leishman, Michelle R

2014-01-01

The magnitude and frequency of climatic extremes, such as drought, are predicted to increase under future climate change conditions. However, little is known about how other factors such as CO2 concentration will modify plant community responses to these extreme climatic events, even though such modifications are highly likely. We asked whether the response of grasslands to repeat extreme drought events is modified by elevated CO2, and if so, what are the underlying mechanisms? We grew grassland mesocosms consisting of 10 co-occurring grass species common to the Cumberland Plain Woodland of western Sydney under ambient and elevated CO2 and subjected them to repeated extreme drought treatments. The 10 species included a mix of C3, C4, native and exotic species. We hypothesized that a reduction in the stomatal conductance of the grasses under elevated CO2 would be offset by increases in the leaf area index thus the retention of soil water and the consequent vulnerability of the grasses to extreme drought would not differ between the CO2 treatments. Our results did not support this hypothesis: soil water content was significantly lower in the mesocosms grown under elevated CO2 and extreme drought-related mortality of the grasses was greater. The C4 and native grasses had significantly higher leaf area index under elevated CO2 levels. This offset the reduction in the stomatal conductance of the exotic grasses as well as increased rainfall interception, resulting in reduced soil water content in the elevated CO2 mesocosms. Our results suggest that projected increases in net primary productivity globally of grasslands in a high CO2 world may be limited by reduced soil water availability in the future.

A practical CO2 flux remote sensing technique

NASA Astrophysics Data System (ADS)

Queisser, Manuel; Burton, Mike

2017-04-01

An accurate quantification of CO2 flux from both natural and anthropogenic sources is of great interest in various areas of the Earth, environmental and atmospheric sciences. As emitted excess CO2 quickly dilutes into the 400 ppm ambient CO2 concentration and degassing often occurs diffusively, measuring CO2 fluxes is challenging. Therefore, fluxes are usually derived from grids of in-situ measurements, which are labour intensive measurements. Other than a safe measurement distance, remote sensing offers quick, spatially integrated and thus a more thorough measurement of gas fluxes. Active remote sensing combines these merits with operation independent of sunlight or clear sky conditions. Due to their weight and size, active remote sensing platforms for CO2, such as LIDAR, cannot easily be applied in the field or transported overseas. Moreover, their complexity requires a rather lengthy setup procedure to be undertaken by skilled personal. To meet the need for a rugged, practical CO2 remote sensing technique to scan volcanic plumes, we have developed the CO2 LIDAR. It measures 1-D column densities of CO2 with sufficient sensitivity to reveal the contribution of magmatic CO2. The CO2 LIDAR has been mounted inside a small aircraft and used to measure atmospheric column CO2 concentrations between the aircraft and the ground. It was further employed on the ground, measuring CO2 emissions from mud volcanism. During the measurement campaign the CO2 LIDAR demonstrated reliability, portability, quick set-up time (10 to 15 min) and platform independence. This new technique opens the possibility of rapid, comprehensive surveys of point source, open-vent CO2 emissions, as well as emissions from more diffuse sources such as lakes and fumarole fields. Currently, within the proof-of-concept ERC project CarbSens, a further reduction in size, weight and operational complexity is underway with the goal to commercialize the platform. Areas of potential applications include fugitive

Saturated CO2 inhibits microbial processes in CO2-vented deep-sea sediments

NASA Astrophysics Data System (ADS)

de Beer, D.; Haeckel, M.; Neumann, J.; Wegener, G.; Inagaki, F.; Boetius, A.

2013-02-01

This study focused on biogeochemical processes and microbial activity in sediments of a natural deep-sea CO2 seepage area (Yonaguni Knoll IV hydrothermal system, Japan). The aim was to assess the influence of the geochemical conditions occurring in highly acidic and CO2 saturated sediments on sulphate reduction (SR) and anaerobic methane oxidation (AOM). Porewater chemistry was investigated from retrieved sediment cores and in situ by microsensor profiling. The sites sampled around a sediment-hosted hydrothermal CO2 vent were very heterogeneous in porewater chemistry, indicating a complex leakage pattern. Near the vents, droplets of liquid CO2 were observed to emanate from the sediments, and the pH reached approximately 4.5 in a sediment depth >6 cm, as determined in situ by microsensors. Methane and sulphate co-occurred in most sediment samples from the vicinity of the vents down to a depth of at least 3 m. However, SR and AOM were restricted to the upper 7-15 cm below seafloor, although neither temperature, low pH, nor the availability of methane and sulphate could be limiting microbial activity. We argue that the extremely high subsurface concentrations of dissolved CO2 (1000-1700 mM), through the ensuing high H2CO3 levels (approx. 1-2 mM) uncouples the proton-motive-force (PMF) and thus inhibits biological energy conservation by ATPase-driven phosphorylation. This limits life to the surface sediment horizons above the liquid CO2 phase, where less extreme conditions prevail. Our results may have to be taken into consideration in assessing the consequences of deep-sea CO2 sequestration on benthic element cycling and on the local ecosystem state.

Atlantic cod actively avoid CO2 and predator odour, even after long-term CO2 exposure.

PubMed

Jutfelt, Fredrik; Hedgärde, Maria

2013-12-27

The rising atmospheric CO2 level is continuously driving the dissolution of more CO2 into the oceans, and some emission scenarios project that the surface waters may reach 1000 μatm by the end of the century. It is not known if fish can detect moderately elevated CO2 levels, and if they avoid areas with high CO2. If so, avoidance behaviour to water with high CO2 could affect movement patterns and migrations of fish in the future. It is also being increasingly recognized that fish behaviour can be altered by exposure to CO2. Therefore this study investigated how long-term exposure to elevated pCO2 affects predator avoidance and CO2 avoidance in juvenile Atlantic cod (Gadus morhua). The fish were exposed to control water or CO2-enriched water (1000 μatm) for six weeks before being subjected to tests of behaviour. Despite long term exposure to elevated pCO2 the cod still strongly avoided the smell of a predator. These data are surprising because several coral reef fish have demonstrated reversal of olfactory responses after CO2 exposure, turning avoidance of predator cues into preference for predator cues. Fish from both treatment groups also demonstrated strong avoidance of CO2 when presented with the choice of control or CO2-acidified water, indicating that habituation to the CO2 sensory stimuli is negligible. As Atlantic cod maintained normal behavioural responses to olfactory cues, they may be tolerant to CO2-induced behavioural changes. The results also suggest that despite the long-term exposure to CO2-acidified water, the fish still preferred the control water over CO2-acidified water. Therefore, in the future, fish may alter their movements and migrations in search of waters with a lower CO2 content.

Atlantic cod actively avoid CO2 and predator odour, even after long-term CO2 exposure

PubMed Central

2013-01-01

Introduction The rising atmospheric CO2 level is continuously driving the dissolution of more CO2 into the oceans, and some emission scenarios project that the surface waters may reach 1000 μatm by the end of the century. It is not known if fish can detect moderately elevated CO2 levels, and if they avoid areas with high CO2. If so, avoidance behaviour to water with high CO2 could affect movement patterns and migrations of fish in the future. It is also being increasingly recognized that fish behaviour can be altered by exposure to CO2. Therefore this study investigated how long-term exposure to elevated pCO2 affects predator avoidance and CO2 avoidance in juvenile Atlantic cod (Gadus morhua). The fish were exposed to control water or CO2-enriched water (1000 μatm) for six weeks before being subjected to tests of behaviour. Results Despite long term exposure to elevated pCO2 the cod still strongly avoided the smell of a predator. These data are surprising because several coral reef fish have demonstrated reversal of olfactory responses after CO2 exposure, turning avoidance of predator cues into preference for predator cues. Fish from both treatment groups also demonstrated strong avoidance of CO2 when presented with the choice of control or CO2-acidified water, indicating that habituation to the CO2 sensory stimuli is negligible. Conclusions As Atlantic cod maintained normal behavioural responses to olfactory cues, they may be tolerant to CO2-induced behavioural changes. The results also suggest that despite the long-term exposure to CO2-acidified water, the fish still preferred the control water over CO2-acidified water. Therefore, in the future, fish may alter their movements and migrations in search of waters with a lower CO2 content. PMID:24373523

Uncertainty analyses of CO2 plume expansion subsequent to wellbore CO2 leakage into aquifers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Zhangshuan; Bacon, Diana H.; Engel, David W.

2014-08-01

In this study, we apply an uncertainty quantification (UQ) framework to CO2 sequestration problems. In one scenario, we look at the risk of wellbore leakage of CO2 into a shallow unconfined aquifer in an urban area; in another scenario, we study the effects of reservoir heterogeneity on CO2 migration. We combine various sampling approaches (quasi-Monte Carlo, probabilistic collocation, and adaptive sampling) in order to reduce the number of forward calculations while trying to fully explore the input parameter space and quantify the input uncertainty. The CO2 migration is simulated using the PNNL-developed simulator STOMP-CO2e (the water-salt-CO2 module). For computationally demandingmore » simulations with 3D heterogeneity fields, we combined the framework with a scalable version module, eSTOMP, as the forward modeling simulator. We built response curves and response surfaces of model outputs with respect to input parameters, to look at the individual and combined effects, and identify and rank the significance of the input parameters.« less

The Arizona Radio Observatory CO Mapping Survey of Galactic Molecular Clouds. V. The Sh2-235 Cloud in CO J=2-1, 13CO J=2-1, and CO J=3-2

NASA Astrophysics Data System (ADS)

Bieging, John H.; Patel, Saahil; Peters, William L.; Toth, L. Viktor; Marton, Gábor; Zahorecz, Sarolta

2016-09-01

We present the results of a program to map the Sh2-235 molecular cloud complex in the CO and 13CO J = 2 - 1 transitions using the Heinrich Hertz Submillimeter Telescope. The map resolution is 38″ (FWHM), with an rms noise of 0.12 K brightness temperature, for a velocity resolution of 0.34 km s-1. With the same telescope, we also mapped the CO J = 3 - 2 line at a frequency of 345 GHz, using a 64 beam focal plane array of heterodyne mixers, achieving a typical rms noise of 0.5 K brightness temperature with a velocity resolution of 0.23 km s-1. The three spectral line data cubes are available for download. Much of the cloud appears to be slightly sub-thermally excited in the J = 3 level, except for in the vicinity of the warmest and highest column density areas, which are currently forming stars. Using the CO and 13CO J = 2 - 1 lines, we employ an LTE model to derive the gas column density over the entire mapped region. Examining a 125 pc2 region centered on the most active star formation in the vicinity of Sh2-235, we find that the young stellar object surface density scales as approximately the 1.6-power of the gas column density. The area distribution function of the gas is a steeply declining exponential function of gas column density. Comparison of the morphology of ionized and molecular gas suggests that the cloud is being substantially disrupted by expansion of the H II regions, which may be triggering current star formation.

A Synthesized Model-Observation Approach to Constraining Gross Urban CO2 Fluxes Using 14CO2 and carbonyl sulfide

NASA Astrophysics Data System (ADS)

LaFranchi, B. W.; Campbell, J. E.; Cameron-Smith, P. J.; Bambha, R.; Michelsen, H. A.

2013-12-01

Urbanized regions are responsible for a disproportionately large percentage (30-40%) of global anthropogenic greenhouse gas (GHG) emissions, despite covering only 2% of the Earth's surface area [Satterthwaite, 2008]. As a result, policies enacted at the local level in these urban areas can, in aggregate, have a large global impact, both positive and negative. In order to address the scientific questions that are required to drive these policy decisions, methods are needed that resolve gross CO2 flux components from the net flux. Recent work suggests that the critical knowledge gaps in CO2 surface fluxes could be addressed through the combined analysis of atmospheric carbonyl sulfide (COS) and radiocarbon in atmospheric CO2 (14CO2) [e.g. Campbell et al., 2008; Graven et al., 2009]. The 14CO2 approach relies on mass balance assumptions about atmospheric CO2 and the large differences in 14CO2 abundance between fossil and natural sources of CO2 [Levin et al., 2003]. COS, meanwhile, is a potentially transformative tracer of photosynthesis because its variability in the atmosphere has been found to be influenced primarily by vegetative uptake, scaling linearly will gross primary production (GPP) [Kettle et al., 20027]. Taken together, these two observations provide constraints on two of the three main components of the CO2 budget at the urban scale: photosynthesis and fossil fuel emissions. The third component, respiration, can then be determined by difference if the net flux is known. Here we present a general overview of our synthesized model-observation approach for improving surface flux estimates of CO2 for the upwind fetch of a ~30m tower located in Livermore, CA, USA, a suburb (pop. ~80,000) at the eastern edge of the San Francisco Bay Area. Additionally, we will present initial results from a one week observational intensive, which includes continuous CO2, CH4, CO, SO2, NOx, and O3 observations in addition to measurements of 14CO2 and COS from air samples

Promoting Ethylene Selectivity from CO2 Electroreduction on CuO Supported onto CO2 Capture Materials.

PubMed

Yang, Hui-Juan; Yang, Hong; Hong, Yu-Hao; Zhang, Peng-Yang; Wang, Tao; Chen, Li-Na; Zhang, Feng-Yang; Wu, Qi-Hui; Tian, Na; Zhou, Zhi-You; Sun, Shi-Gang

2018-03-09

Cu is a unique catalyst for CO 2 electroreduction, since it can catalyze CO 2 reduction to a series of hydrocarbons, alcohols, and carboxylic acids. Nevertheless, such Cu catalysts suffer from poor selectivity. High pressure of CO 2 is considered to facilitate the activity and selectivity of CO 2 reduction. Herein, a new strategy is presented for CO 2 reduction with improved C 2 H 4 selectivity on a Cu catalyst by using CO 2 capture materials as the support at ambient pressure. N-doped carbon (N x C) was synthesized through high-temperature carbonization of melamine and l-lysine. We observed that the CO 2 uptake capacity of N x C depends on both the microporous area and the content of pyridinic N species, which can be controlled by the carbonization temperature (600-800 °C). The as-prepared CuO/N x C catalysts exhibit a considerably higher C 2 H 4 faradaic efficiency (36 %) than CuO supported on XC-72 carbon black (19 %), or unsupported CuO (20 %). Moreover, there is a good linear relationship between the C 2 H 4 faradaic efficiency and CO 2 uptake capacity of the supports for CuO. The local high CO 2 concentration near Cu catalysts, created by CO 2 capture materials, was proposed to increase the coverage of CO intermediate, which is favorable for the coupling of two CO units in the formation of C 2 H 4 . This study demonstrates that pairing Cu catalysts with CO 2 capture supports is a promising approach for designing highly effective CO 2 reduction electrocatalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inverse modeling of fossil fuel CO2 emissions at urban scale using OCO-2 retrievals of total column CO2

NASA Astrophysics Data System (ADS)

Ye, X.; Lauvaux, T.; Kort, E. A.; Lin, J. C.; Oda, T.; Yang, E.; Wu, D.

2016-12-01

Rapid economic development has given rise to a steady increase of global carbon emissions, which have accumulated in the atmosphere for the past 200 years. Urbanization has concentrated about 70% of the global fossil-fuel CO2 emissions in large metropolitan areas distributed around the world, which represents the most significant anthropogenic contribution to climate change. However, highly uncertain quantifications of urban CO2 emissions are commonplace for numerous cities because of poorly-documented inventories of energy consumption. Therefore, accurate estimates of carbon emissions from global observing systems are a necessity if mitigation strategies are meant to be implemented at global scales. Space-based observations of total column averaged CO2 concentration (XCO2) provide a very promising and powerful tool to quantify urban CO2 fluxes. For the first time, measurements from the Orbiting Carbon Observatory 2 (OCO-2) mission are assimilated in a high resolution inverse modeling system to quantify fossil-fuel CO2 emissions of multiple cities around the globe. The Open-source Data Inventory for Anthropogenic CO2 (ODIAC) emission inventory is employed as a first guess, while the atmospheric transport is simulated using the WRF-Chem model at 1-km resolution. Emission detection and quantification is performed with an Ensemble Kalman Filter method. We demonstrate here the potential of the inverse approach for assimilating thousands of OCO-2 retrievals along tracks near metropolitan areas. We present the detection potential of the system with real-case applications near power plants and present inverse emissions using actual OCO-2 measurements on various urban landscapes. Finally, we will discuss the potential of OCO-2-like satellite instruments for monitoring temporal variations of fossil-fuel CO2 emissions over multiple years, which can provide valuable insights for future satellite observation strategies.

FTIR study of CO2 and H2O/CO2 nanoparticles and their temporal evolution at 80 K.

PubMed

Taraschewski, M; Cammenga, H K; Tuckermann, R; Bauerecker, S

2005-04-21

Fourier transform infrared (FTIR) spectroscopy combined with a long-path collisional cooling cell was used to investigate the temporal evolution of CO2 nanoparticles and binary H2O/CO2 nanocomposites in the aerosol phase at 80 K. The experimental conditions for the formation of different CO2 particle shapes as slab, shell, sphere, cube, and needle have been studied by comparison with calculated data from the literature. The H2O/CO2 nanoparticles were generated with a newly developed multiple-pulse injection technique and with the simpler flow-in technique. The carbon dioxide nu3-vibration band at 2360 cm(-1) and the water ice OH-dangling band at 3700 cm(-1) were used to study the evolution of structure, shape, and contact area of the nanocomposites over 150 s. Different stages of binary nanocomposites with primary water ice cores were identified dependent on the injected CO2 portion: (a) disordered (amorphous) CO2 slabs on water particle surfaces, (b) globular crystalline CO2 humps sticking on the water cores, and (c) water cores being completely enclosed in bigger predominantly crystalline CO2 nanoparticles. However, regular CO2 shell structures on primary water particles showing both longitudinal (LO) and transverse (TO) optical mode features of the nu3-vibration band could not be observed. Experiments with reversed nucleation order indicate that H2O/CO2 composite particles with different initial structures evolve toward similar molecular nanocomposites with separated CO2 and H2O regions.

Influences of the (NH2)2CO concentration on magnetic photocatalytic composites

NASA Astrophysics Data System (ADS)

Liŭ, Dan; Li, Ziheng; Wang, Wenquan; Liú, Dan; Wang, Guoqiang; Lin, Junhong; He, Yingqiao; Li, Xiangru

2016-11-01

Magnetic photocatalytic Fe3O4@TiO2 composites have been fabricated by changing the concentration of (NH2)2CO. Samples were named as low (NH2)2CO concentration group which the (NH2)2CO concentration in the synthesis process was below 2.25 mol/L and high (NH2)2CO concentration group which the (NH2)2CO concentration was above 2.5 mol/L. Photocatalytic degradation experiments of methyl orange showed that the final degradation rates of low (NH2)2CO concentration group samples were higher than that of high (NH2)2CO concentration group, even better than P25 at the same test conditions. And it was interesting that samples of low (NH2)2CO concentration group had smaller values of BET surface areas than that of high (NH2)2CO concentration group. It indicated that the improvement of photocatalytic activity which was effected by BET surface areas was not obvious. There were two main factors enhancing the photocatalytic property of low (NH2)2CO concentration group: First, diffusing reflection spectra showed that the low (NH2)2CO concentration group samples had lower reflectivity, this suggested that the structure improved the efficiency of light absorption; Second, NH4+ would take up the active sites on the surface of the TiO2 particles, the FT-IR test results showed that the samples of the low (NH2)2CO concentration group samples bonded less NH4+, thus leading to the higher photocatalytic activity. It had enlightenment role for optimizing the performance of photocatalytic materials.

Atmospheric and geogenic CO2 within the crown and root of spruce (Picea abies L. Karst.) growing in a mofette area

NASA Astrophysics Data System (ADS)

Vodnik, D.; Thomalla, A.; Ferlan, M.; Levanič, T.; Eler, K.; Ogrinc, N.; Wittmann, C.; Pfanz, H.

2018-06-01

Mofettes are often investigated in ecology, either as extreme sites, natural analogues to future conditions under climate change, or model ecosystems for environmental impact assessments of carbon capture and storage systems. Much of this research, however, inadequately addresses the complexity of the gas environment at these sites, mainly focusing on aboveground CO2-enrichment. In the current research, the gaseous environment of Norway spruce (Picea abies (L) Karst.) trees growing at the Stavešinske slepice mofette (NE Slovenia) were studied by measuring both soil ([CO2]soil) and atmospheric CO2 concentrations ([CO2]air). Within the studied site (800 m2), soil CO2 enrichment was spatially heterogeneous; about 25% of the area was characterized by very high [CO2]soil (>40%) and hypoxic conditions. Aboveground gas measurements along vertical profiles not only revealed substantially elevated [CO2]air close to the ground (height up to 1.5 m), but also in the upper heights (20-25 m; crown layer). On the basis δ13C of CO2, it was shown that elevated CO2 relates to a geogenic source. Trees grown in high [CO2]soil were characterized by decreased radial growth; the δ13C of their wood was less negative than in trees growing in normal soil. Unfavorable gaseous soil conditions should generally be accepted as being by far the most important factor affecting (i.e. disturbing) the growth of mofette trees.

Distributions of fossil fuel originated CO2 in five metropolitan areas of Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju) according to the Δ14C in ginkgo leaves

NASA Astrophysics Data System (ADS)

Park, J. H.; Hong, W.; Park, G.; Sung, K. S.; Lee, K. H.; Kim, Y. E.; Kim, J. K.; Choi, H. W.; Kim, G. D.; Woo, H. J.

2013-01-01

We collected a batch of ginkgo (Ginkgo biloba Linnaeus) leaf samples at five metropolitan areas of Korea (Seoul, Busan, Daegu, Daejeon, and Gwangju) in 2009 to obtain the regional distribution of fossil fuel originated CO2 (fossil fuel CO2) in the atmosphere. Regions assumed to be free of fossil fuel CO2 were also selected, namely Mt. Chiak, Mt. Kyeryong, Mt. Jiri, Anmyeon Island, and Jeju Island and ginkgo leaf samples were collected in those areas during the same period. The Δ14C values of the samples were measured using Accelerator Mass Spectrometry (AMS) and the fossil fuel CO2 ratios in the atmosphere were obtained in the five metropolitan areas. The average ratio of fossil fuel CO2 in Seoul was higher than that in the other four cities. The leaves from the Sajik Tunnel in Seoul recorded the highest FFCTC (fossil fuel CO2 over total CO2 in atmosphere), 13.9 ± 0.5%, as the air flow of the surrounding neighborhood of the Sajik Tunnel was blocked.

Transient changes in transpiration, and stem and soil CO2 efflux in longleaf pine (Pinus palustris Mill.) following fire-induced leaf area reduction

Treesearch

Barton Clinton; Chris Maier; Chelcy Ford; Robert Mitchell

2011-01-01

In 20-year-old longleaf pine, we examined short-term effects of reduced live leaf area (A L) via canopy scorching on sap flow (Q; kg H2O h−1), transpiration per unit leaf area (E L; mm day−1), stem CO2 efflux (R stem; μmol m−2 s−1) and soil CO2 efflux (R soil; μmol m−2 s−1) over a 2-week period during early summer. R stem and Q were measured at two positions (1.3-m or...

CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

NASA Astrophysics Data System (ADS)

Lac, C.; Donnelly, R. P.; Masson, V.; Pal, S.; Riette, S.; Donier, S.; Queguiner, S.; Tanguy, G.; Ammoura, L.; Xueref-Remy, I.

2013-05-01

Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is a challenging and interesting task needed to be performed in order to utilise CO2 measurements in an atmospheric inverse framework and to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town Energy Balance (TEB) urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs) surface scheme, allowing a full interaction of CO2 modelling between the surface and the atmosphere. Statistical scores show a good representation of the urban heat island (UHI) with stronger urban-rural contrasts on temperature at night than during the day by up to 7 °C. Boundary layer heights (BLH) have been evaluated on urban, suburban and rural sites during the campaign, and also on a suburban site over 1 yr. The diurnal cycles of the BLH are well captured, especially the onset time of the BLH increase and its growth rate in the morning, which are essential for tall tower CO2 observatories. The main discrepancy is a small negative bias over urban and suburban sites during nighttime (respectively 45 m and 5 m), leading to a few overestimations of nocturnal CO2 mixing ratios at suburban sites and a bias of +5 ppm. The diurnal CO2 cycle is generally well captured for all the sites. At the Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the atmospheric boundary layer (ABL) growth reaches the measurement height. At suburban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a strong spatio-temporal variability. A sensitivity test without

Retrieval of average CO2 fluxes by combining in situ CO2 measurements and backscatter lidar information

NASA Astrophysics Data System (ADS)

Gibert, Fabien; Schmidt, Martina; Cuesta, Juan; Ciais, Philippe; Ramonet, Michel; Xueref, IrèNe; Larmanou, Eric; Flamant, Pierre Henri

2007-05-01

The present paper deals with a boundary layer budgeting method which makes use of observations from various in situ and remote sensing instruments to infer regional average net ecosystem exchange (NEE) of CO2. Measurements of CO2 within and above the atmospheric boundary layer (ABL) by in situ sensors, in conjunction with a precise knowledge of the change in ABL height by lidar and radiosoundings, enable to infer diurnal and seasonal NEE variations. Near-ground in situ CO measurements are used to discriminate natural and anthropogenic contributions of CO2 diurnal variations in the ABL. The method yields mean NEE that amounts to 5 μmol m-2 s-1 during the night and -20 μmol m-2 s-1 in the middle of the day between May and July. A good agreement is found with the expected NEE accounting for a mixed wheat field and forest area during winter season, representative of the mesoscale ecosystems in the Paris area according to the trajectory of an air column crossing the landscape. Daytime NEE is seen to follow the vegetation growth and the change in the ratio diffuse/direct radiation. The CO2 vertical mixing flux during the rise of the atmospheric boundary layer is also estimated and seems to be the main cause of the large decrease of CO2 mixing ratio in the morning. The outcomes on CO2 flux estimate are compared to eddy-covariance measurements on a barley field. The importance of various sources of error and uncertainty on the retrieval is discussed. These errors are estimated to be less than 15%; the main error resulted from anthropogenic emissions.

SOIL FLUXES OF CO2, CO, NO AND N2O FROM AN OLD-PASTURE AND FROM NATIVE SAVANNA IN BRAZIL

EPA Science Inventory

We compared fluxes of CO2, CO, NO and N2O, soil microbial biomass, and N-mineralization rates in a 20-year old Brachiaria pasture and a native cerrado area (savanna in Central Brazil). In order to assess the spatial variability of CO2 fluxes, we tested the relation between elect...

Can increasing CO2 cool Antarctica?

NASA Astrophysics Data System (ADS)

Schmithuesen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter

2014-05-01

CO2 is the strongest anthropogenic forcing agent for climate change since pre-industrial times. Like other greenhouse gases, CO2 absorbs terrestrial surface radiation and causes emission from the atmosphere to space. As the surface is generally warmer than the atmosphere, the total long-wave emission to space is commonly less than the surface emission. However, this does not hold true for the high elevated areas of central Antarctica. Our investigations show, that for the high elevated areas of Antarctica the greenhouse effect (GHE) of CO2 is commonly around zero or even negative. This is based on the quantification of GHE as the difference between long-wave surface emission and top of atmosphere emission. We demonstrate this behaviour with the help of three models: a simple two-layer model, line-by-line calculations, and an ECMWF experiment. Additionally, in this region an increase in CO2 concentration leads to an instantaneous increased long-wave energy loss to space, which is a cooling effect on the earth-atmosphere system. However, short-wave warming by the weak absorption of solar radiation by CO2 are not taken into account here. The reason for this counter-intuitive behaviour is the fact that in the interior of Antarctica the surface is often colder than the stratosphere above. Radiation from the surface in the atmospheric window emitted to space is then relatively lower compared to radiation in the main CO2 band around 15 microns, which originates mostly from the stratosphere. Increasing CO2 concentration leads to increasing emission from the atmosphere to space, while blocking additional portions of surface emission. If the surface is colder than the stratosphere, this leads to additional long-wave energy loss to space for increasing CO2. Our findings for central Antarctica are in strong contrast to the generally known effect that increasing CO2 has on the long-wave emission to space, and hence on the Antarctic climate.

BioCO2 - a multidisciplinary, biological approach using solar energy to capture CO2 while producing H2 and high value products.

PubMed

Skjånes, Kari; Lindblad, Peter; Muller, Jiri

2007-10-01

Many areas of algae technology have developed over the last decades, and there is an established market for products derived from algae, dominated by health food and aquaculture. In addition, the interest for active biomolecules from algae is increasing rapidly. The need for CO(2) management, in particular capture and storage is currently an important technological, economical and global political issue and will continue to be so until alternative energy sources and energy carriers diminish the need for fossil fuels. This review summarizes in an integrated manner different technologies for use of algae, demonstrating the possibility of combining different areas of algae technology to capture CO(2) and using the obtained algal biomass for various industrial applications thus bringing added value to the capturing and storage processes. Furthermore, we emphasize the use of algae in a novel biological process which produces H(2) directly from solar energy in contrast to the conventional CO(2) neutral biological methods. This biological process is a part of the proposed integrated CO(2) management scheme.

Synthesis of mesoporous cerium compound for CO2 capture

NASA Astrophysics Data System (ADS)

Liu, Guiqing; Tatsuda, Kou; Yoneyama, Yoshiharu; Tsubaki, Noritatsu

2017-11-01

A mesoporous adsorbent was simply synthesized by adding alkaline substances to cerium(III) nitric hydrate. The surface characteristics of the synthesized cerium compound were determined with BET, XRD and TEM analysis. It was found that although the specific surface areas of the synthesized cerium compounds were among about 120-200m2 per gram (BET area) which were smaller than the common used zeolite 13X (BET area 743 m2/g) and activated carbon (BET area 1079 m2/g), but the cerium compounds had excellent performances for CO2 adsorption as well as the CO2 desorption.

Aircraft observations of the urban CO2 dome in London and calculated daytime CO2 fluxes at the urban-regional scale

NASA Astrophysics Data System (ADS)

Font, Anna; Morgui, Josep Anton; Grimmond, Sue; Barratt, Benjamin

2013-04-01

Traffic, industry and energy production and consumption within urban boundaries emit great amounts of CO2 into the atmosphere, creating an urban increment of CO2 mixing ratios compared to the surrounding rural atmosphere. Monitoring CO2 within these 'urban domes' has been proposed as a means to evaluate the effectiveness of policies aiming to mitigate and reduce CO2 urban emissions (CMEGGE, 2010). London is the biggest urban conurbation in Western Europe with more than 8 million inhabitants, and it emitted roughly 45000 ktn CO2 in 2010 (DECC, 2012). In order to develop and implement observational strategies to measure the contribution of urban areas into the global carbon cycle, two airborne surveys were deployed using the Natural and Environment Research Council - Airborne Research and Survey Facility (NERC-ARSF). High frequency measurements of atmospheric CO2, O3, particles and meteorological variables were taken over London in October 2011 and July 2012. CO2 mixing ratios were measured by a Non-Dispersive IR instrument developed by AOS. In July 2012, a Cavity Ring-Down Spectroscopy (CDRS) instrument developed by PICARRO was deployed measuring CO2, CH4 and water vapour at 1Hz resolution. The objectives of the campaigns were to measure the CO2 dome over London and to calculate CO2 emissions at the urban-regional-scale. London was crossed by two transects (SW-NE and SSE-NNW) at an altitude of 360 m and vertical profiles up to 2000 m were carried out to characterize the structure of the atmosphere. Aircraft measurements allowed observation on how CO2 domes were shaped by meteorological conditions. In October 2011, the mean CO2 mixing ratio measured in London was on average 2 ppmv higher than the suburban measurements within the boundary layer. However, under low wind speeds, the CO2 mixing ratio in the urban mixing ratio peaked in central London (>10 ppmv) and decreased towards the city boundaries. Under windy conditions, the structure of the urban dome was

Assessing Methods for Mapping 2D Field Concentrations of CO2 Over Large Spatial Areas for Monitoring Time Varying Fluctuations

NASA Astrophysics Data System (ADS)

Zaccheo, T. S.; Pernini, T.; Botos, C.; Dobler, J. T.; Blume, N.; Braun, M.; Levine, Z. H.; Pintar, A. L.

2014-12-01

This work presents a methodology for constructing 2D estimates of CO2 field concentrations from integrated open path measurements of CO2 concentrations. It provides a description of the methodology, an assessment based on simulated data and results from preliminary field trials. The Greenhouse gas Laser Imaging Tomography Experiment (GreenLITE) system, currently under development by Exelis and AER, consists of a set of laser-based transceivers and a number of retro-reflectors coupled with a cloud-based compute environment to enable real-time monitoring of integrated CO2 path concentrations, and provides 2D maps of estimated concentrations over an extended area of interest. The GreenLITE transceiver-reflector pairs provide laser absorption spectroscopy (LAS) measurements of differential absorption due to CO2 along intersecting chords within the field of interest. These differential absorption values for the intersecting chords of horizontal path are not only used to construct estimated values of integrated concentration, but also employed in an optimal estimation technique to derive 2D maps of underlying concentration fields. This optimal estimation technique combines these sparse data with in situ measurements of wind speed/direction and an analytic plume model to provide tomographic-like reconstruction of the field of interest. This work provides an assessment of this reconstruction method and preliminary results from the Fall 2014 testing at the Zero Emissions Research and Technology (ZERT) site in Bozeman, Montana. This work is funded in part under the GreenLITE program developed under a cooperative agreement between Exelis and the National Energy and Technology Laboratory (NETL) under the Department of Energy (DOE), contract # DE-FE0012574. Atmospheric and Environmental Research, Inc. is a major partner in this development.

Interaction Between CO2-Rich Sulfate Solutions and Carbonate Reservoir Rocks from Atmospheric to Supercritical CO2 Conditions: Experiments and Modeling

NASA Astrophysics Data System (ADS)

Cama, J.; Garcia-Rios, M.; Luquot, L.; Soler Matamala, J. M.

2014-12-01

A test site for CO2 geological storage is situated in Hontomín (Spain) with a reservoir rock that is mainly composed of limestone. During and after CO2 injection, the resulting CO2-rich acid brine gives rise to the dissolution of carbonate minerals (calcite and dolomite) and gypsum (or anhydrite at depth) may precipitate since the reservoir brine contains sulfate. Experiments using columns filled with crushed limestone or dolostone were conducted under different P-pCO2 conditions (atmospheric: 1-10-3.5 bar; subcritical: 10-10 bar; and supercritical: 150-34 bar), T (25, 40 and 60 ºC) and input solution compositions (gypsum-undersaturated and gypsum-equilibrated solutions). We evaluated the effect of these parameters on the coupled reactions of calcite/dolomite dissolution and gypsum/anhydrite precipitation. The CrunchFlow and PhreeqC (v.3) numerical codes were used to perform reactive transport simulations of the experiments. Under the P-pCO2-T conditions, the volume of precipitated gypsum was smaller than the volume of dissolved carbonate minerals, yielding an increase in porosity (Δporosity up to ≈ 4%). A decrease in T favored limestone dissolution regardless of pCO2 owing to increasing undersaturation with decreasing temperature. However, gypsum precipitation was favored at high T and under atmospheric pCO2 conditions but not at high T and under 10 bar of pCO2 conditions. The increase in limestone dissolution with pCO2 was directly attributed to pH, which was more acidic at higher pCO2. Increasing pCO2, carbonate dissolution occurred along the column whereas it was localized in the very inlet under atmospheric conditions. This was due to the buffer capacity of the carbonic acid, which maintains pH at around 5 and keeps the solution undersaturated with respect to calcite and dolomite along the column. 1D reactive transport simulations reproduced the experimental data (carbonate dissolution and gypsum precipitation for different P-pCO2-T conditions). Drawing

Hazardous indoor CO2 concentrations in volcanic environments.

PubMed

Viveiros, Fátima; Gaspar, João L; Ferreira, Teresa; Silva, Catarina

2016-07-01

Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Porosity and thermal collapse measurements of H2O, CH3OH, CO2, and H2O:CO2 ices.

PubMed

Isokoski, K; Bossa, J-B; Triemstra, T; Linnartz, H

2014-02-28

The majority of astronomical and laboratory based studies of interstellar ices have been focusing on ice constituents. Ice structure is a much less studied topic. Particularly the amount of porosity is an ongoing point of discussion. A porous ice offers more surface area than a compact ice, for reactions that are fully surface driven. In this paper we discuss the amount of compaction for four different ices--H2O, CH3OH, CO2 and mixed H2O : CO2 = 2 : 1--upon heating over an astronomically relevant temperature regime. Laser interference and Fourier transform infrared spectroscopy are used to confirm that for amorphous solid water the full signal loss of dangling OH bonds is not a proof for full compaction. These data are compared with the first compaction results for pure CH3OH, pure CO2 and mixed H2O : CO2 = 2 : 1 ice. Here we find that thermal segregation benefits from a higher degree of porosity.

Reduction of CO2 emission from transportation activities in the area of Pasar Besar in Malang City

NASA Astrophysics Data System (ADS)

Sari, K. E.; Sulistyo, D. E.; Utomo, D. M.

2017-06-01

The number of vehicles increases every year. Where vehicles are the largest contributor to air pollution up to 70%-80%, while 20%-30% caused by industrial activities. The increasing number of vehicles which perform movements will result in more emissions of vehicles in the free air of the city. Traffic is also influenced by the presence of land use. One of the types of land use that have considerable influence against the movement of traffic is trade. Along with the development of transport activities in the area of Pasar Besar Malang city (the Biggest Traditional Market in Malang), it will cause problems such as traffic jam and air pollution. Therefore, the need for proper handling of the problem of traffic jam and air pollution in the area of Pasar Besar that is to identify the performance of road traffic around area of Pasar Besar and calculate the quantity of CO2 emissions based on the footprint of transport on the area of Pasar Besar. Where is produced that level of service roads on its way around area of Pasar Besar have an average value between LOS A and B, while the quantity of CO2 emissions is based on the footprint of transport on area of Pasar Besar that is amounting to 4,551.42 tons/year. The magnitude of the emissions have exceeded the standard of composition in the air so that the need for recommendations. Recommendations in this research is in the form of simulated users of private vehicle redirects to public transportation based on the level of willingness to switch by the users of private vehicles. The selected simulation that is the second of four simulations with the output of emissions amounting to 3,952.91 tons/year in which can reduce emissions amounting to 598.51 tons/year or approximately 13.15%.

COCA: deriving urban emissions and the carbon exchange of a forested region using airborne CO2 and CO observations

NASA Astrophysics Data System (ADS)

Geiss, H.; Schmitgen, S.; Ciais, P.; Neininger, B.; Baeumle, M.; Brunet, Y.; Kley, D.

2002-05-01

A crucial challenge in measuring the partitioning of sources and sinks of atmospheric CO2 is the separation of regional anthropogenic CO2 sources from biogenic activity. The aim of the COCA project is to quantify the fossil fuel and biogenic CO2 fractions using continuous airborne CO2 and CO measurements, where CO acts as a tracer for anthropogenic CO2. At first part of the project COCA an attempt was made to measure daytime biogenic CO2 fluxes over a forest area (about 15 by 30 km size). The campaign took place around the CARBOEUROFLUX site ``Le Bray'' (Pinus pinaster) close to Bordeaux in France end of June 2001 Based on continuous airborne CO2, H2O and CO flux and concentration measurements a Lagrangian budgeting approach was chosen to measure regional CO2 deposition fluxes. The objective is to determine the CO2 uptake of the extended forest area from the CO2/CO gradients up- and downwind of the ecosystem, using CO as air mass tracer and such estimating the influence of anthropogenic CO2 advected into the area First results of the summer flight on June 23rd will be shown, where fair wind speeds (~5 m/s) and a low CBL height led to the observation of a clear decrease in CO2 at the downwind flight stacks with basically constant CO concentrations. For other summer flights with very low wind speeds, local effects dominate the observations leading to a larger variability in the observations. Both, correlations and anti-correlations of CO2 with the anthropogenic tracer CO have been observed. Positive correlations indicate fresh plumes of anthropogenic CO2. Negative correlations are indicative of entrainment of free tropospheric air, that was marked by relatively higher CO2 and lower CO concentrations than the average CBL concentrations. During a second campaign the variance of anthropogenic CO and CO2 emissions of a large city unaffected by biogenic processes has been studied. This campaign was carried out on February 16 and 17, 2002 over the Paris metropolitan area

Improved solar-driven photocatalytic performance of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} prepared in-situ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Junbo, E-mail: junbozhong@163.com; Li, Jianzhang, E-mail: lschmanuscript@163.com; Huang, Shengtian

Highlights: • Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} photocatalysts were prepared in-situ. • The photo-induced charge separation rate has been greatly increased. • The photocatalytic activity has been greatly promoted. - Abstract: Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} composites have been fabricated in-situ via a facile parallel flaw co-precipitation method. The specific surface area, structure, morphology, and the separation rate of photo-induced charge pairs of the photocatalysts were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy(DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and surface photovoltage (SPV) spectroscopy, respectively. XRD patterns and DRS demonstrated that Ag{submore » 2}CO{sub 3} has no effect on the crystal phase and bandgap of (BiO){sub 2}CO{sub 3}. The existence of Ag{sub 2}CO{sub 3} in the composites enhances the separation rate of photo-induced charge pairs of the photocatalysts. The photocatalytic performance of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} was evaluated by the decolorization of methyl orange (MO) aqueous solution under simulated solar irradiation. It was found that the simulated solar-induced photocatalytic activity of Ag{sub 2}CO{sub 3}/(BiO){sub 2}CO{sub 3} copmposites was significantly improved, which was mainly attributed to the enhanced surface area and the separation rate of photo-induced charge pairs.« less

Natural analogue study of CO2 storage monitoring using probability statistics of CO2-rich groundwater chemistry

NASA Astrophysics Data System (ADS)

Kim, K. K.; Hamm, S. Y.; Kim, S. O.; Yun, S. T.

2016-12-01

For confronting global climate change, carbon capture and storage (CCS) is one of several very useful strategies as using capture of greenhouse gases like CO2 spewed from stacks and then isolation of the gases in underground geologic storage. CO2-rich groundwater could be produced by CO2 dissolution into fresh groundwater around a CO2 storage site. As consequence, natural analogue studies related to geologic storage provide insights into future geologic CO2 storage sites as well as can provide crucial information on the safety and security of geologic sequestration, the long-term impact of CO2 storage on the environment, and field operation and monitoring that could be implemented for geologic sequestration. In this study, we developed CO2 leakage monitoring method using probability density function (PDF) by characterizing naturally occurring CO2-rich groundwater. For the study, we used existing data of CO2-rich groundwaters in different geological regions (Gangwondo, Gyeongsangdo, and Choongchungdo provinces) in South Korea. Using PDF method and QI (quantitative index), we executed qualitative and quantitative comparisons among local areas and chemical constituents. Geochemical properties of groundwater with/without CO2 as the PDF forms proved that pH, EC, TDS, HCO3-, Ca2+, Mg2+, and SiO2 were effective monitoring parameters for carbonated groundwater in the case of CO2leakage from an underground storage site. KEY WORDS: CO2-rich groundwater, CO2 storage site, monitoring parameter, natural analogue, probability density function (PDF), QI_quantitative index Acknowledgement This study was supported by the "Basic Science Research Program through the National Research Foundation of Korea (NRF), which is funded by the Ministry of Education (NRF-2013R1A1A2058186)" and the "R&D Project on Environmental Management of Geologic CO2 Storage" from KEITI (Project number: 2014001810003).

Field Tests of Real-time In-situ Dissolved CO2 Monitoring for CO2 Leakage Detection in Groundwater

NASA Astrophysics Data System (ADS)

Yang, C.; Zou, Y.; Delgado, J.; Guzman, N.; Pinedo, J.

2016-12-01

Groundwater monitoring for detecting CO2 leakage relies on groundwater sampling from water wells drilled into aquifers. Usually groundwater samples are required be collected periodically in field and analyzed in the laboratory. Obviously groundwater sampling is labor and cost-intensive for long-term monitoring of large areas. Potential damage and contamination of water samples during the sampling process can degrade accuracy, and intermittent monitoring may miss changes in the geochemical parameters of groundwater, and therefore signs of CO2 leakage. Real-time in-situ monitoring of geochemical parameters with chemical sensors may play an important role for CO2 leakage detection in groundwater at a geological carbon sequestration site. This study presents field demonstration of a real-time in situ monitoring system capable of covering large areas for detection of low levels of dissolved CO2 in groundwater and reliably differentiating natural variations of dissolved CO2 concentration from small changes resulting from leakage. The sand-alone system includes fully distributed fiber optic sensors for carbon dioxide detection with a unique sensor technology developed by Intelligent Optical Systems. The systems were deployed to the two research sites: the Brackenridge Field Laboratory where the aquifer is shallow at depths of 10-20 ft below surface and the Devine site where the aquifer is much deeper at depths of 140 to 150 ft. Groundwater samples were periodically collected from the water wells which were installed with the chemical sensors and further compared to the measurements of the chemical sensors. Our study shows that geochemical monitoring of dissolved CO2 with fiber optic sensors could provide reliable CO2 leakage signal detection in groundwater as long as CO2 leakage signals are stronger than background noises at the monitoring locations.

Surface Water pCO2 Variations and Sea-Air CO2 Fluxes During Summer in the Eastern Canadian Arctic

NASA Astrophysics Data System (ADS)

Burgers, T. M.; Miller, L. A.; Thomas, H.; Else, B. G. T.; Gosselin, M.; Papakyriakou, T.

2017-12-01

Based on a 2 year data set, the eastern Canadian Arctic Archipelago and Baffin Bay appear to be a modest summertime sink of atmospheric CO2. We measured surface water CO2 partial pressure (pCO2), salinity, and temperature throughout northern Baffin Bay, Nares Strait, and Lancaster Sound from the CCGS Amundsen during its 2013 and 2014 summer cruises. Surface water pCO2 displayed considerable variability (144-364 μatm) but never exceeded atmospheric concentrations, and average calculated CO2 fluxes in 2013 and 2014 were -12 and -3 mmol C m-2 d-1 (into the ocean), respectively. Ancillary measurements of chlorophyll a reveal low summertime productivity in surface waters. Based on total alkalinity and stable oxygen isotopes (δ18O) data, a strong riverine signal in northern Nares Strait coincided with relatively high surface pCO2, whereas areas of sea-ice melt occur with low surface pCO2. Further assessments, extending the seasonal observation period, are needed to properly constrain both seasonal and annual CO2 fluxes in this region.

Diffuse CO2 degassing at Vesuvio, Italy

NASA Astrophysics Data System (ADS)

Frondini, Francesco; Chiodini, Giovanni; Caliro, Stefano; Cardellini, Carlo; Granieri, Domenico; Ventura, Guido

2004-10-01

At Vesuvio, a significant fraction of the rising hydrothermal-volcanic fluids is subjected to a condensation and separation process producing a CO2-rich gas phase, mainly expulsed through soil diffuse degassing from well defined areas called diffuse degassing structures (DDS), and a liquid phase that flows towards the outer part of the volcanic cone. A large amount of thermal energy is associated with the steam condensation process and subsequent cooling of the liquid phase. The total amount of volcanic-hydrothermal CO2 discharged through diffuse degassing has been computed through a sequential Gaussian simulation (sGs) approach based on several hundred accumulation chamber measurements and, at the time of the survey, amounted to 151 t d-1. The steam associated with the CO2 output, computed assuming that the original H2O/CO2 ratio of hydrothermal fluids is preserved in fumarolic effluents, is 553 t d-1, and the energy produced by the steam condensation and cooling of the liquid phase is 1.47×1012 J d-1 (17 MW). The location of the CO2 and temperature anomalies show that most of the gas is discharged from the inner part of the crater and suggests that crater morphology and local stratigraphy exert strong control on CO2 degassing and subsurface steam condensation. The amounts of gas and energy released by Vesuvio are comparable to those released by other volcanic degassing areas of the world and their estimates, through periodic surveys of soil CO2 flux, can constitute a useful tool to monitor volcanic activity.

Porous carbon from local coconut shell char by CO2 and H2O activation in the presence of K2CO3

NASA Astrophysics Data System (ADS)

Vi, Nguyen Ngoc Thuy; Truyen, Dang Hai; Trung, Bien Cong; An, Ngo Thanh; Van Dung, Nguyen; Long, Nguyen Quang

2017-09-01

Vietnamese coconut shell char was activated by steam and carbon dioxide at low temperatures with the presence of K2CO3 as a catalyst. The effects of process parameters on adsorption capability of the product including different ratio of impregnation of activation agents, activation temperature, activation time were investigated in this study. Iodine number, methylene blue adsorption capacity, specific surface area and pore size distribution were measured to assess the properties of the activated carbon. Accordingly, the porous carbon was applied for toluene removal by adsorption technology. Significant increases in specific surface area and the toluene adsorption capacity were observed when the coconut shell char was activated in CO2 flow at 720 °C for 150 minutes and the K2CO3/char weight ratio of 0.5.

Studies of CW lasing action in CO2-CO, N2O-CO, CO2-H2O, and N2O-H2O mixtures pumped by blackbody radiation

NASA Technical Reports Server (NTRS)

Abel, Robert W.; Christiansen, Walter H.; Li, Jian-Guo

1988-01-01

A proof of principle experiment to evaluate the efficacy of CO and H2O in increasing the power output for N2O and CO2 lasing mixtures has been conducted and theoretically analyzed for a blackbody radiation-pumped laser. The results for N2O-CO, CO2-CO, N2O-H2O and CO2-H2O mixtures are presented. Additions of CO to the N2O lasant increased power up to 28 percent for N2O laser mixtures, whereas additions of CO to the CO2 lasant, and the addition of H2O to both the CO2 and N2O lasants, resulted in decreased output power.

A sensitivity analysis on seismic tomography data with respect to CO2 saturation of a CO2 geological sequestration field

NASA Astrophysics Data System (ADS)

Park, Chanho; Nguyen, Phung K. T.; Nam, Myung Jin; Kim, Jongwook

2013-04-01

Monitoring CO2 migration and storage in geological formations is important not only for the stability of geological sequestration of CO2 but also for efficient management of CO2 injection. Especially, geophysical methods can make in situ observation of CO2 to assess the potential leakage of CO2 and to improve reservoir description as well to monitor development of geologic discontinuity (i.e., fault, crack, joint, etc.). Geophysical monitoring can be based on wireline logging or surface surveys for well-scale monitoring (high resolution and nallow area of investigation) or basin-scale monitoring (low resolution and wide area of investigation). In the meantime, crosswell tomography can make reservoir-scale monitoring to bridge the resolution gap between well logs and surface measurements. This study focuses on reservoir-scale monitoring based on crosswell seismic tomography aiming describe details of reservoir structure and monitoring migration of reservoir fluid (water and CO2). For the monitoring, we first make a sensitivity analysis on crosswell seismic tomography data with respect to CO2 saturation. For the sensitivity analysis, Rock Physics Models (RPMs) are constructed by calculating the values of density and P and S-wave velocities of a virtual CO2 injection reservoir. Since the seismic velocity of the reservoir accordingly changes as CO2 saturation changes when the CO2 saturation is less than about 20%, while when the CO2 saturation is larger than 20%, the seismic velocity is insensitive to the change, sensitivity analysis is mainly made when CO2 saturation is less than 20%. For precise simulation of seismic tomography responses for constructed RPMs, we developed a time-domain 2D elastic modeling based on finite difference method with a staggered grid employing a boundary condition of a convolutional perfectly matched layer. We further make comparison between sensitivities of seismic tomography and surface measurements for RPMs to analysis resolution

Variations of anthropogenic CO2 in urban area deduced by radiocarbon concentration in modern tree rings.

PubMed

Rakowski, Andrzej Z; Nakamura, Toshio; Pazdur, Anna

2008-10-01

Radiocarbon concentration in the atmosphere is significantly lower in areas where man-made emissions of carbon dioxide occur. This phenomenon is known as Suess effect, and is caused by the contamination of clean air with non-radioactive carbon from fossil fuel combustion. The effect is more strongly observed in industrial and densely populated urban areas. Measurements of carbon isotope concentrations in a study area can be compared to those from areas of clear air in order to estimate the amount of carbon dioxide emission from fossil fuel combustion by using a simple mathematical model. This can be calculated using the simple mathematical model. The result of the mathematical model followed in this study suggests that the use of annual rings of trees to obtain the secular variations of 14C concentration of atmospheric CO2 can be useful and efficient for environmental monitoring and modeling of the carbon distribution in local scale.

Temporal variations of atmospheric CO2 and CO at Ahmedabad in western India

NASA Astrophysics Data System (ADS)

Chandra, Naveen; Lal, Shyam; Venkataramani, S.; Patra, Prabir K.; Sheel, Varun

2016-05-01

About 70 % of the anthropogenic carbon dioxide (CO2) is emitted from the megacities and urban areas of the world. In order to draw effective emission mitigation policies for combating future climate change as well as independently validating the emission inventories for constraining their large range of uncertainties, especially over major metropolitan areas of developing countries, there is an urgent need for greenhouse gas measurements over representative urban regions. India is a fast developing country, where fossil fuel emissions have increased dramatically in the last three decades and are predicted to continue to grow further by at least 6 % per year through to 2025. The CO2 measurements over urban regions in India are lacking. To overcome this limitation, simultaneous measurements of CO2 and carbon monoxide (CO) have been made at Ahmedabad, a major urban site in western India, using a state-of-the-art laser-based cavity ring down spectroscopy technique from November 2013 to May 2015. These measurements enable us to understand the diurnal and seasonal variations in atmospheric CO2 with respect to its sources (both anthropogenic and biospheric) and biospheric sinks. The observed annual average concentrations of CO2 and CO are 413.0 ± 13.7 and 0.50 ± 0.37 ppm respectively. Both CO2 and CO show strong seasonality with lower concentrations (400.3 ± 6.8 and 0.19 ± 0.13 ppm) during the south-west monsoon and higher concentrations (419.6 ± 22.8 and 0.72 ± 0.68 ppm) during the autumn (SON) season. Strong diurnal variations are also observed for both the species. The common factors for the diurnal cycles of CO2 and CO are vertical mixing and rush hour traffic, while the influence of biospheric fluxes is also seen in the CO2 diurnal cycle. Using CO and CO2 covariation, we differentiate the anthropogenic and biospheric components of CO2 and found significant contributions of biospheric respiration and anthropogenic emissions in the late night (00:00-05:00 h, IST

Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration

PubMed Central

Liu, Jin-Feng; Sun, Xiao-Bo; Yang, Guang-Chao; Mbadinga, Serge M.; Gu, Ji-Dong; Mu, Bo-Zhong

2015-01-01

Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs. PMID:25873911

Improving CO2 permeation and separation performance of CO2-philic polymer membrane by blending CO2 absorbents

NASA Astrophysics Data System (ADS)

Cheng, Jun; Hu, Leiqing; Li, Yannan; Liu, Jianzhong; Zhou, Junhu; Cen, Kefa

2017-07-01

To research effects of CO2 absorption capacity and type of CO2 absorbent on the CO2 separation and free-volume properties of facilitated transport membranes, two types of CO2 absorbents, namely monoethanolamine (MEA) and ionic liquids (ILs:[P66614][Triz] and [P66614][2-Op]), were adopted. The CO2 absorption capacities of MEA, [P66614][Triz] and [P66614][2-Op] were about 0.561 mol CO2 per mol, 0.95 mol CO2 per mol and 1.60 mol CO2 per mol, respectively. All mean free-volume hole radiuses of membranes decreased after blending CO2 absorbents. After polymer membrane blended with two ILs, number of free-volume hole increased, resulting in modest increase of the fractional free volume. Both CO2 permeability and selectivity increased after blending MEA and ILs. The increasing range of CO2 permeability corresponded with CO2 absorption capacity of CO2 absorbents, and membrane blending with [P66614][2-Op] showed the highest CO2 permeability of 672.1 Barrers at 25 °C. Pebax/PEGDME membrane blending with MEA obtained the highest CO2/H2 and CO2/CH4 selectivity at 17.8 and 20.5, respectively.

Atmospheric measurement of point source fossil CO2 emissions

NASA Astrophysics Data System (ADS)

Turnbull, J. C.; Keller, E. D.; Baisden, T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2014-05-01

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m above ground level. We also determined the surface CO2ff content averaged over several weeks from the 14C content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~ one week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14C sampling strategies.

Constraining CO2 tower measurements in an inhomogeneous area with anthropogenic emissions using a combination of car-mounted instrument campaigns, aircraft profiles, transport modeling and neural networks

NASA Astrophysics Data System (ADS)

Schmidt, A.; Rella, C.; Conley, S. A.; Goeckede, M.; Law, B. E.

2013-12-01

The NOAA CO2 observation network in Oregon has been enhanced by 3 new towers in 2012. The tallest tower in the network (270 m), located in Silverton in the Willamette Valley is affected by anthropogenic emissions from Oregon's busiest traffic routes and urban centers. In summer 2012, we conducted a measurement campaign using a car-mounted PICARRO CRDS CO2/CO analyzer. Over 3 days, the instrument was driven over 1000 miles throughout the northwestern portion of Oregon measuring the CO/ CO2 ratios on main highways, back roads in forests, agricultural sites, and Oregon's biggest urban centers. By geospatial analyses we obtained ratios of CO/ CO2 over distinct land cover types divided into 10 classes represented in the study area. Using the coupled WRF-STILT transport model we calculated the footprints of nearby CO/ CO2 observation towers for the corresponding days of mobile road measurements. Spatiotemporally assigned source areas in combination with the land use classification were then used to calculate specific ratios of CO (anthropogenic origins) and CO2 to separate the anthropogenic portion of CO2 from the mixing ratio time series measured at the tower in Silverton. The WRF modeled boundary layer heights used in out study showed some differences compared to the boundary layer heights derived from profile data of wind, temperature, and humidity measured with an airplane in August, September, and November 2012, repeatedly over 5 tower locations. A Bayesian Regularized Artificial Neural Network (BRANN) was used to correct the boundary layer height calculated with WRF with a temporal resolution of 20 minutes and a horizontal resolution of 4 km. For that purpose the BRANN was trained using height profile data from the flight campaigns and spatiotemporally corresponding meteorological data from WRF. Our analyses provide information needed to run inverse modeling of CO2 exchange in an area that is affected by sources that cannot easily be considered by biospheric models

Temporal characteristics of atmospheric CO2 in urban Nanjing, China

NASA Astrophysics Data System (ADS)

Huang, Xiaoxian; Wang, Tijian; Talbot, Robert; Xie, Min; Mao, Huiting; Li, Shu; Zhuang, Bingliang; Yang, Xiuqun; Fu, Congbin; Zhu, Jialei; Huang, Xing; Xu, Runying

2015-02-01

Although China is a big carbon dioxide (CO2) emitter, in situ measurements of atmospheric CO2 are sparse in urban China. The mixing ratio of carbon dioxide (CO2) and its influencing factors in urban Nanjing were investigated in this study, from the 18th of January to the 31st of December 2011. The annual average mixing ratio of CO2 was 406.5 ± 20.0 ppmv over the study period. The signal analysis using the fast Fourier transform (FFT) algorithm showed that CO2 had different cycles as a result of multiple controlling factors. The seasonal and intra-seasonal fluctuations of CO2 were mainly caused by the terrestrial biospheric uptake and emission and atmospheric oscillation. The weekly variation of CO2 was largely influenced by traffic volume. The diurnal cycle of CO2 presented a bimodal pattern in winter (DJF) probably due to the rush hour emissions. The seasonal mean CO2/CO correlation slope varied from 0.024 ppmv/ppbv to 0.029 ppmv/ppbv, comparable to the fossil fuel combustion emission ratio. The diurnal pattern of CO2/CO was irregular, indicating random anthropogenic emissions in an urban area. Firework setting was a large source of CO2 during the Spring Festival holiday. The backward trajectories by the HYSPLIT model showed that the local anthropogenic emissions contributed the most to the high CO2 mixing ratio in the urban area.

Seasonal dynamics of soil CO2 efflux and soil profile CO2 concentrations in arboretum of Moscow botanical garden

NASA Astrophysics Data System (ADS)

Goncharova, Olga; Udovenko, Maria; Matyshak, Georgy

2016-04-01

To analyse and predict recent and future climate change on a global scale exchange processes of greenhouse gases - primarily carbon dioxide - over various ecosystems are of rising interest. In order to upscale land-use dependent sources and sinks of CO2, knowledge of the local variability of carbon fluxes is needed. Among terrestrial ecosystems, urban areas play an important role because most of anthropogenic emissions of carbon dioxide originate from these areas. On the other hand, urban soils have the potential to store large amounts of soil organic carbon and, thus, contribute to mitigating increases in atmospheric CO2 concentrations. Research objectives: 1) estimate the seasonal dynamics of carbon dioxide production (emission - closed chamber technique and profile concentration - soil air sampling tubes method) by soils of Moscow State University Botanical Garden Arboretum planted with Picea obovata and Pinus sylvestris, 1) identification the factors that control CO2 production. The study was conducted with 1-2 weeks intervals between October 2013 and November 2015 at two sites. Carbon dioxide soil surface efflux during the year ranged from 0 to 800 mgCO2/(m2hr). Efflux values above 0 mgCO2/(m2hr) was observed during the all cold period except for only 3 weeks. Soil CO2 concentration ranged from 1600-3000 ppm in upper 10-cm layer to 10000-40000 ppm at a depth of 60 cm. The maximum concentrations of CO2 were recorded in late winter and late summer. We associate it with high biological activity (both heterotrophic and autotrophic) during the summer, and with physical gas jamming in the winter. The high value of annual CO2 production of the studied soils is caused by high organic matter content, slightly alkaline reaction, good structure and texture of urban soils. Differences in soil CO2 production by spruce and pine urban forest soils (in the pine forest 1.5-2.0 times higher) are caused by urban soil profiles construction, but not temperature regimes. Seasonal

Causes of variation among rice models in yield response to CO2 examined with Free-Air CO2 Enrichment and growth chamber experiments.

PubMed

Hasegawa, Toshihiro; Li, Tao; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Baker, Jeffrey; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fugice, Job; Fumoto, Tamon; Gaydon, Donald; Kumar, Soora Naresh; Lafarge, Tanguy; Marcaida Iii, Manuel; Masutomi, Yuji; Nakagawa, Hiroshi; Oriol, Philippe; Ruget, Françoise; Singh, Upendra; Tang, Liang; Tao, Fulu; Wakatsuki, Hitomi; Wallach, Daniel; Wang, Yulong; Wilson, Lloyd Ted; Yang, Lianxin; Yang, Yubin; Yoshida, Hiroe; Zhang, Zhao; Zhu, Jianguo

2017-11-01

The CO 2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO 2 ] (E-[CO 2 ]) by comparison to free-air CO 2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO 2 ] varied significantly among the rice models. The variation was not random: models that overestimated at one experiment simulated greater yield enhancements at the others. The variation was not associated with model structure or magnitude of photosynthetic response to E-[CO 2 ] but was significantly associated with the predictions of leaf area. This suggests that modelled secondary effects of E-[CO 2 ] on morphological development, primarily leaf area, are the sources of model uncertainty. Rice morphological development is conservative to carbon acquisition. Uncertainty will be reduced by incorporating this conservative nature of the morphological response to E-[CO 2 ] into the models. Nitrogen levels, particularly under limited situations, make the prediction more uncertain. Improving models to account for [CO 2 ] × N interactions is necessary to better evaluate management practices under climate change.

Impacts of upwind wildfire emissions on CO, CO2, and PM2.5 concentrations in Salt Lake City, Utah

Treesearch

D. V. Mallia; J. C. Lin; S. Urbanski; J. Ehleringer; T. Nehrkorn

2015-01-01

Biomass burning is known to contribute large quantities of CO2, CO, and PM2.5 to the atmosphere. Biomass burning not only affects the area in the vicinity of fire but may also impact the air quality far downwind from the fire. The 2007 and 2012 western U.S. wildfire seasons were characterized by significant wildfire...

Separation of biospheric and fossil fuel fluxes of CO2 by atmospheric inversion of CO2 and 14CO2 measurements: Observation System Simulations

NASA Astrophysics Data System (ADS)

Basu, Sourish; Bharat Miller, John; Lehman, Scott

2016-05-01

National annual total CO2 emissions from combustion of fossil fuels are likely known to within 5-10 % for most developed countries. However, uncertainties are inevitably larger (by unknown amounts) for emission estimates at regional and monthly scales, or for developing countries. Given recent international efforts to establish emission reduction targets, independent determination and verification of regional and national scale fossil fuel CO2 emissions are likely to become increasingly important. Here, we take advantage of the fact that precise measurements of 14C in CO2 provide a largely unbiased tracer for recently added fossil-fuel-derived CO2 in the atmosphere and present an atmospheric inversion technique to jointly assimilate observations of CO2 and 14CO2 in order to simultaneously estimate fossil fuel emissions and biospheric exchange fluxes of CO2. Using this method in a set of Observation System Simulation Experiments (OSSEs), we show that given the coverage of 14CO2 measurements available in 2010 (969 over North America, 1063 globally), we can recover the US national total fossil fuel emission to better than 1 % for the year and to within 5 % for most months. Increasing the number of 14CO2 observations to ˜ 5000 per year over North America, as recently recommended by the National Academy of Science (NAS) (Pacala et al., 2010), we recover monthly emissions to within 5 % for all months for the US as a whole and also for smaller, highly emissive regions over which the specified data coverage is relatively dense, such as for the New England states or the NY-NJ-PA tri-state area. This result suggests that, given continued improvement in state-of-the art transport models, a measurement program similar in scale to that recommended by the NAS can provide for independent verification of bottom-up inventories of fossil fuel CO2 at the regional and national scale. In addition, we show that the dual tracer inversion framework can detect and minimize biases in

CO2 efflux from cleared mangrove peat.

PubMed

Lovelock, Catherine E; Ruess, Roger W; Feller, Ilka C

2011-01-01

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. 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. 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.

Assessing the impact of urban land cover composition on CO2 flux

NASA Astrophysics Data System (ADS)

Becker, K.; Hinkle, C.

2013-12-01

Urbanization is an ever increasing trend in global land use change, and has been identified as a key driver of CO2 emissions. Therefore, understanding how urbanization affects CO2 flux across a range of climatic zones and development patterns is critical to projecting the impact of future land use on CO2 flux dynamics. A growing number of studies are applying the eddy covariance method to urban areas to quantify the CO2 flux dynamics of these systems. However, interpretation of eddy covariance data in these urban systems presents a challenge, particularly in areas with high heterogeneity due to a mixing of built and green space. Here we present a study aimed at establishing a relationship between land cover composition and CO2 flux for a heterogeneous urban area of Orlando, FL. CO2 flux has been measured at this site for > 4 years using an open path eddy covariance system. Land cover at this site was classified into built and green space, and relative weight of both land covers were calculated for each 30 min CO2 flux measurement using the Schuepp model and a source area based on +/- one standard deviation of wind direction. The results of this analysis established a relationship between built land cover and CO2 flux within the measured footprint of this urban area. These results, in combination with future projected land use data, will be a valuable resource for providing insight into the impact of future urbanization on CO2 flux dynamics in this region.

The Coca-campaign: An Attempt To Derive The Carbon Exchange of A Forested Region Using Airborne Co2 and Co Observations

NASA Astrophysics Data System (ADS)

Schmitgen, S.; Ciais, P.; Geiß, H.; Kley, D.; Neininger, B.; Baeumle, M.; Fuchs, W.; Brunet, Y.

As part of the project COCA an attempt was made to measure the daytime biogenic CO2 fluxes over a forest area (about 15 by 30 km). This campaign took place around the CARBOEUROFLUX site "Le Bray" (Pinus pinaster) close to Bordeaux in France end of June 2001. Based on continuous airborne CO2, H2O and CO flux and concen- tration measurements a Lagrangian budgeting approach was chosen for the determi- nation of the regional CO2 fluxes. The objective is to determine the CO2 uptake of the extended forest area from the CO2/CO gradients up- and downwind of the ecosystem, using CO as air mass tracer and such eliminating the influence of anthropogenic CO2 advected into the area. First results will be shown of a flight on June 23rd, where fair wind speeds (about 5 m/s) and a low CBL height led to the observation of a clear decrease in CO2 at the downwind flight stacks with basically constant CO concentrations. For other flights with very low wind speeds, local effects dominate the observa- tions leading to a larger variability in the observations. Both, correlations and anti- correlations of CO2 with the anthropogenic tracer CO have been observed. Positive correlations indicate fresh plumes of anthropogenic CO2. Negative correlations are indicative of entrainment of free tropospheric air, that was marked by relatively higher CO2 and lower CO concentrations than the average CBL concentrations.

Supercritical CO2 uptake by nonswelling phyllosilicates

PubMed Central

Tokunaga, Tetsu K.; Ashby, Paul D.; Kim, Yongman; Voltolini, Marco; Gilbert, Benjamin; DePaolo, Donald J.

2018-01-01

Interactions between supercritical (sc) CO2 and minerals are important when CO2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubation with scCO2), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO2, can increase CO2 storage capacity by up to ∼30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO2 uptake constitutes a previously unrecognized potential trapping mechanism. PMID:29339499

Assessing Paris megacity CO2 urban dome: first lessons from the CO2-Megaparis project (2009-2013)

NASA Astrophysics Data System (ADS)

Xueref-Remy, I. C.; Dieudonné, E.; Ammoura, L.; Cellier, P.; Gibert, F.; Lac, C.; Lauvaux, T.; Lopez, M.; Pal, S.; Ampe, C.; Puygrenier, V.; Ramonet, M.; Schmidt, M.; Thiruchittampallam, B.; Vuillemin, C.

2013-05-01

About 80% of global CO2 emissions come from punctual sources such as megacities. Among those, Paris is the third megacity in Europe. However, the estimates of urban CO2 emissions are based on activity proxies and benchmarked emission factors, leading to uncertainties as high as several tenths of percents in some sectors of bottom-up CO2 emissions inventories. Since 2009, the CO2-Megaparis project aims to quantify CO2 emissions from Paris using a top-down approach based on a synergy between atmospheric observations and modeling. A mini-network of 3 stations was developed by LSCE in Paris agglomeration within the infrastructure of the air quality monitoring agency of Paris region, AIRPARIF, completing 2 other stations from the ICOS network leaded at LSCE. The mean CO2 concentration dome over Paris in the mid-afternoon over 1 year of data is about 2.2 ppm, and is strongly wind speed and direction dependent. Analysis of correlations between CO2, CO and 14C02 was carried out and a comparison to available inventories will be presented. Direct modeling of CO2 at a very fine resolution (2x2 km2, 1h) was performed by CNRM and matched well with observations. Results from inverse modeling will be presented. Furthermore, we conducted a campaign using lidar facilities showing that due to the effect of the urban heat island, the boundary layer height (a key parameter in assessing CO2 fluxes from the atmospheric approach) is 10 to 40% time higher in Paris than in surrounding rural areas. Also, a sonic anemometer and a 10 Hz CO2 analyzer were deployed to assess CO2 fluxes from observations, as well as CO2 flux analyzers on crops. Using the data from this instrumentation, a mass balance calculation was carried out and allowed the identification and quantification of Paris CO2 traffic plume to a rural region, about 100 km south of Paris, that matched well with inventories. Finally, an attempt of defining the strengths and weaknesses of the atmospheric approach to quantify urban CO2

Zeolites for CO2-CO-O2 Separation to Obtain CO2-Neutral Fuels.

PubMed

Perez-Carbajo, Julio; Matito-Martos, Ismael; Balestra, Salvador R G; Tsampas, Mihalis N; van de Sanden, Mauritius C M; Delgado, José A; Águeda, V Ismael; Merkling, Patrick J; Calero, Sofia

2018-06-20

Carbon dioxide release has become an important global issue due to the significant and continuous rise in atmospheric CO 2 concentrations and the depletion of carbon-based energy resources. Plasmolysis is a very energy-efficient process for reintroducing CO 2 into energy and chemical cycles by converting CO 2 into CO and O 2 utilizing renewable electricity. The bottleneck of the process is that CO remains mixed with O 2 and residual CO 2 . Therefore, efficient gas separation and recuperation are essential for obtaining pure CO, which, via water gas shift and Fischer-Tropsch reactions, can lead to the production of CO 2 -neutral fuels. The idea behind this work is to provide a separation mechanism based on zeolites to optimize the separation of carbon dioxide, carbon monoxide, and oxygen under mild operational conditions. To achieve this goal, we performed a thorough screening of available zeolites based on topology and adsorptive properties using molecular simulation and ideal adsorption solution theory. FAU, BRE, and MTW are identified as suitable topologies for these separation processes. FAU can be used for the separation of carbon dioxide from carbon monoxide and oxygen and BRE or MTW for the separation of carbon monoxide from oxygen. These results are reinforced by pressure swing adsorption simulations at room temperature combining adsorption columns with pure silica FAU zeolite and zeolite BRE at a Si/Al ratio of 3. These zeolites have the added advantage of being commercially available.

Microwave-assisted nitric acid treatment of sepiolite and functionalization with polyethylenimine applied to CO2 capture and CO2/N2 separation

NASA Astrophysics Data System (ADS)

Vilarrasa-García, E.; Cecilia, J. A.; Bastos-Neto, M.; Cavalcante, C. L.; Azevedo, D. C. S.; Rodríguez-Castellón, E.

2017-07-01

Sepiolite was treated in HNO3 solutions with the assistance of microwave radiation. This treatment caused the progressive depletion of Mg2+, the gradual degradation of the sepiolite structure and the formation of an amorphous silica phase, which contributes to a noticeable increase of the surface area. The use of microwaves during acid treatment, after few minutes, led to materials with similar SBET to those obtained after 48 h with conventional heating methods. The influence of mineralogical impurities, crystallinity and chemical composition in the reactivity of sepiolite to this treatment was also studied. The obtained materials were impregnated with polyethylenimine and assessed for CO2 capture and CO2/N2 selectivity at different temperatures. Experimental equilibrium data were fitted to Langmuir and Sips models. The adsorption data revealed that sepiolite can be an interesting adsorbent for CO2 capture, achieving a capacity of 1.70 mmol g-1 at 338 K and 1 bar, providing a high CO2/N2 selectivity (440 mol CO2/mol N2).

Global sea-air CO 2 flux based on climatological surface ocean pCO 2, and seasonal biological and temperature effects

NASA Astrophysics Data System (ADS)

Takahashi, Taro; Sutherland, Stewart C.; Sweeney, Colm; Poisson, Alain; Metzl, Nicolas; Tilbrook, Bronte; Bates, Nicolas; Wanninkhof, Rik; Feely, Richard A.; Sabine, Christopher; Olafsson, Jon; Nojiri, Yukihiro

Based on about 940,000 measurements of surface-water pCO 2 obtained since the International Geophysical Year of 1956-59, the climatological, monthly distribution of pCO 2 in the global surface waters representing mean non-El Niño conditions has been obtained with a spatial resolution of 4°×5° for a reference year 1995. The monthly and annual net sea-air CO 2 flux has been computed using the NCEP/NCAR 41-year mean monthly wind speeds. An annual net uptake flux of CO 2 by the global oceans has been estimated to be 2.2 (+22% or -19%) Pg C yr -1 using the (wind speed) 2 dependence of the CO 2 gas transfer velocity of Wanninkhof (J. Geophys. Res. 97 (1992) 7373). The errors associated with the wind-speed variation have been estimated using one standard deviation (about±2 m s -1) from the mean monthly wind speed observed over each 4°×5° pixel area of the global oceans. The new global uptake flux obtained with the Wanninkhof (wind speed) 2 dependence is compared with those obtained previously using a smaller number of measurements, about 250,000 and 550,000, respectively, and are found to be consistent within±0.2 Pg C yr -1. This estimate for the global ocean uptake flux is consistent with the values of 2.0±0.6 Pg C yr -1 estimated on the basis of the observed changes in the atmospheric CO 2 and oxygen concentrations during the 1990s (Nature 381 (1996) 218; Science 287 (2000) 2467). However, if the (wind speed) 3 dependence of Wanninkhof and McGillis (Res. Lett. 26 (1999) 1889) is used instead, the annual ocean uptake as well as the sensitivity to wind-speed variability is increased by about 70%. A zone between 40° and 60° latitudes in both the northern and southern hemispheres is found to be a major sink for atmospheric CO 2. In these areas, poleward-flowing warm waters meet and mix with the cold subpolar waters rich in nutrients. The pCO 2 in the surface water is decreased by the cooling effect on warm waters and by the biological drawdown of pCO 2 in

Atmospheric measurement of point source fossil fuel CO2 emissions

NASA Astrophysics Data System (ADS)

Turnbull, J. C.; Keller, E. D.; Baisden, W. T.; Brailsford, G.; Bromley, T.; Norris, M.; Zondervan, A.

2013-11-01

We use the Kapuni Gas Treatment Plant to examine methodologies for atmospheric monitoring of point source fossil fuel CO2 (CO2ff) emissions. The Kapuni plant, located in rural New Zealand, removes CO2 from locally extracted natural gas and vents that CO2 to the atmosphere, at a rate of ~0.1 Tg carbon per year. The plant is located in a rural dairy farming area, with no other significant CO2ff sources nearby, but large, diurnally varying, biospheric CO2 fluxes from the surrounding highly productive agricultural grassland. We made flask measurements of CO2 and 14CO2 (from which we derive the CO2ff component) and in situ measurements of CO2 downwind of the Kapuni plant, using a Helikite to sample transects across the emission plume from the surface up to 100 m a.g.l. We also determined the surface CO2ff content averaged over several weeks from the 14CO2 content of grass samples collected from the surrounding area. We use the WindTrax plume dispersion model to compare the atmospheric observations with the emissions reported by the Kapuni plant, and to determine how well atmospheric measurements can constrain the emissions. The model has difficulty accurately capturing the fluctuations and short-term variability in the Helikite samples, but does quite well in representing the observed CO2ff in 15 min averaged surface flask samples and in ~1 week integrated CO2ff averages from grass samples. In this pilot study, we found that using grass samples, the modeled and observed CO2ff emissions averaged over one week agreed to within 30%. The results imply that greater verification accuracy may be achieved by including more detailed meteorological observations and refining 14CO2 sampling strategies.

Shallow soil CO2 flow along the San Andreas and Calaveras Faults, California

USGS Publications Warehouse

Lewicki, J.L.; Evans, William C.; Hilley, G.E.; Sorey, M.L.; Rogie, J.D.; Brantley, S.L.

2003-01-01

We evaluate a comprehensive soil CO2 survey along the San Andreas fault (SAF) in Parkfield, and the Calaveras fault (CF) in Hollister, California, in the context of spatial and temporal variability, origin, and transport of CO2 in fractured terrain. CO2 efflux was measured within grids with portable instrumentation and continously with meteorological parameters at a fixed station, in both faulted and unfaulted areas. Spatial and temporal variability of surface CO2 effluxes was observed to be higher at faulted SAF and CF sites, relative to comparable background areas. However, ??13C (-23.3 to - 16.4???) and ??14C (75.5 to 94.4???) values of soil CO2 in both faulted and unfaulted areas are indicative of biogenic CO2, even though CO2 effluxes in faulted areas reached values as high as 428 g m-2 d-1. Profiles of soil CO2 concentration as a function of depth were measured at multiple sites within SAF and CF grids and repeatedly at two locations at the SAF grid. Many of these profiles suggest a surprisingly high component of advective CO2 flow. Spectral and correlation analysis of SAF CO2 efflux and meteorological parameter time series indicates that effects of wind speed variations on atmospheric air flow though fractures modulate surface efflux of biogenic CO2. The resulting areal patterns in CO2 effluxes could be erroneously attributed to a deep gas source in the absence of isotopic data, a problem that must be addressed in fault zone soil gas studies.

Supercritical CO2 uptake by nonswelling phyllosilicates.

PubMed

Wan, Jiamin; Tokunaga, Tetsu K; Ashby, Paul D; Kim, Yongman; Voltolini, Marco; Gilbert, Benjamin; DePaolo, Donald J

2018-01-30

Interactions between supercritical (sc) CO 2 and minerals are important when CO 2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO 2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO 2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubation with scCO 2 ), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO 2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO 2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO 2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO 2 , can increase CO 2 storage capacity by up to ∼30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO 2 uptake constitutes a previously unrecognized potential trapping mechanism. Copyright © 2018 the Author(s). Published by PNAS.

Supercritical CO 2 uptake by nonswelling phyllosilicates

DOE PAGES

Wan, Jiamin; Tokunaga, Tetsu K.; Ashby, Paul D.; ...

2018-01-16

Interactions between supercritical (sc) CO 2 and minerals are important when CO 2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO 2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO 2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubationmore » with scCO 2 ), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO 2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO 2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO 2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO 2, can increase CO 2 storage capacity by up to ~30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO 2 uptake constitutes a previously unrecognized potential trapping mechanism.« less

CO2 Washout Testing of NASA Space Suits

NASA Technical Reports Server (NTRS)

Norcross, Jason

2012-01-01

During the presentation "CO2 Washout Testing of NASA Spacesuits," Jason Norcross discussed the results of recent carbon dioxide CO2 washout testing of NASA spacesuits including the Rear Entry I-suit (REI), Enhanced Mobility Advanced Crew Escape Suit (EM-ACES), and possibly the ACES and Z-1 EVA prototype. When a spacesuit is used during ground testing, adequate CO2 washout must be provided for the suited subject. Symptoms of acute CO2 exposure depend on the partial pressure of CO2 (ppCO2) available to enter the lungs during respiration. The primary factors during ground-based testing that influence the ppCO2 level in the oronasal area include the metabolic rate of the subject and air flow through the suit. These tests were done to characterize inspired oronasal ppCO2 for a range of workloads and flow rates for which ground testing is nominally performed. During this presentation, Norcross provided descriptions of the spacesuits, test hardware, methodology, and results, as well as implications for future ground testing and verification of flight requirements.

CO2 Efflux from Cleared Mangrove Peat

PubMed Central

Lovelock, Catherine E.; Ruess, Roger W.; Feller, Ilka C.

2011-01-01

Background CO2 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 CO2 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 CO2 efflux. CO2 efflux from soils declines from time of clearing from ∼10 600 tonnes km−2 year−1 in the first year to 3000 tonnes km2 year−1 after 20 years since clearing. Disturbing peat leads to short term increases in CO2 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 CO2 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. PMID:21738628

In situ quantitative analysis of individual H2O-CO2 fluid inclusions by laser Raman spectroscopy

USGS Publications Warehouse

Azbej, T.; Severs, M.J.; Rusk, B.G.; Bodnar, R.J.

2007-01-01

Raman spectral parameters for the Raman ??1 (1285??cm- 1) and 2??2 (1388??cm- 1) bands for CO2 and for the O-H stretching vibration band of H2O (3600??cm- 1) were determined in H2O-CO2 fluid inclusions. Synthetic fluid inclusions containing 2.5 to 50??mol% CO2 were analyzed at temperatures equal to or greater than the homogenization temperature. The results were used to develop an empirical relationship between composition and Raman spectral parameters. The linear peak intensity ratio (IR = ICO2/(ICO2 + IH2O)) is related to the CO2 concentration in the inclusion according to the relation:Mole % C O2 = e- 3.959 IR2 + 8.0734 IRwhere ICO2 is the intensity of the 1388 cm- 1 peak and IH2O is the intensity of the 3600 cm- 1 peak. The relationship between linear peak intensity and composition was established at 350????C for compositions ranging from 2.5 to 50??mol% CO2. The CO2-H2O linear peak intensity ratio (IR) varies with temperature and the relationship between composition and IR is strictly valid only if the inclusions are analyzed at 350????C. The peak area ratio is defined as AR = ACO2/(ACO2 + AH2O), where ACO2 is the integrated area under the 1388??cm- 1 peak and AH2O is the integrated area under the 3600??cm- 1 peak. The relationship between peak area ratio (AR) and the CO2 concentration in the inclusions is given as:Mole % C O2 = 312.5 AR. The equation relating peak area ratio and composition is valid up to 25??mol% CO2 and from 300 to 450????C. The relationship between linear peak intensity ratio and composition should be used for inclusions containing ??? 50??mol% CO2 and which can be analyzed at 350????C. The relationship between composition and peak area ratios should be used when analyzing inclusions at temperatures less than or greater than 350????C (300-450) but can only be used for compositions ??? 25??mol% CO2. Note that this latter relationship has a somewhat larger standard deviation compared to the intensity ratio relationship. Calibration

Ar + CO2 and He + CO2 Plasmas in ASTRAL

NASA Astrophysics Data System (ADS)

Boivin, R. F.; Gardner, A.; Munoz, J.; Kamar, O.; Loch, S.

2007-11-01

Spectroscopy study of the ASTRAL helicon plasma source running Ar + CO2 and He + CO2 gas mixes is presented. ASTRAL produces plasmas with the following parameters: ne = 10^10 - 10^13 cm-3, Te = 2 - 10 eV and Ti = 0.03 - 0.5 eV, B-field <= 1.3 kGauss, rf power <= 2 kWatt. A 0.33 m scanning monochromator is used for this study. Using Ar + CO2 gas mixes, very different plasmas are observed as the concentration of CO2 is changed. At low CO2 concentration, the bluish plasma is essentially atomic and argon transitions dominate the spectra. Weak C I and O I lines are present in the 750 - 1000 nm range. At higher CO2 concentration, the plasma becomes essentially molecular and is characterized by intense, white plasma columns. Here, spectra are filled with molecular bands (CO2, CO2^+, CO and CO^+). Limited molecular dissociative excitation processes associated with the production of C I and O I emission are also observed. On the other hand, He + CO2 plasmas are different. Here, rf matches are only possible at low CO2 concentration. Under these conditions, the spectra are characterized by strong C I and O I transitions with little or no molecular bands. Strong dissociative processes observed in these plasmas can be link to the high Te associated with He plasmas. An analysis of the spectra with possible scientific and industrial applications will be presented.

Increasing CO2 flux at Pisciarelli, Campi Flegrei, Italy

NASA Astrophysics Data System (ADS)

Queißer, Manuel; Granieri, Domenico; Burton, Mike; Arzilli, Fabio; Avino, Rosario; Carandente, Antonio

2017-09-01

The Campi Flegrei caldera is located in the metropolitan area of Naples (Italy) and has been undergoing different stages of unrest since 1950, evidenced by episodes of significant ground uplift followed by minor subsidence, increasing and fluctuating emission strengths of water vapor and CO2 from fumaroles, and periodic seismic crises. We deployed a scanning laser remote-sensing spectrometer (LARSS) that measured path-integrated CO2 concentrations in the Pisciarelli area in May 2017. The resulting mean CO2 flux is 578 ± 246 t d-1. Our data suggest a significant increase in CO2 flux at this site since 2015. Together with recent geophysical observations, this suggests a greater contribution of the magmatic source to the degassing and/or an increase in permeability at shallow levels. Thanks to the integrated path soundings, LARSS may help to give representative measurements from large regions containing different CO2 sources, including fumaroles, low-temperature vents, and degassing soils, helping to constrain the contribution of deep gases and their migration mechanisms towards the surface.

Application of Space Borne CO2 and Fluorescence Measurements to Detect Urban CO2 Emissions and Anthropogenic Influence on Vegetation

NASA Astrophysics Data System (ADS)

Paetzold, Johannes C.; Chen, Jia; Ruisinger, Veronika

2017-04-01

The Orbiting Carbon Observatory 2 (OCO-2) is a NASA satellite mission dedicated to make global, space-based observations of atmospheric, column-averaged carbon dioxide (XCO2). In addition, the OCO-2 also measures Solar Induced Chlorophyll Fluorescence (SIF). In our research we have studied the combination of OCO-2's XCO2 and SIF measurements for numerous urban areas on the different continents. Applying GIS and KML visualization techniques as well as statistical approaches we are able to reliably detect anthropogenic CO2 emissions in CO2 column concentration enhancements over urban areas. Moreover, we detect SIF decreases over urban areas compared to their rural vicinities. We are able to obtain those findings for urban areas on different continents, of diverse sizes, dissimilar topographies and urban constructions. Our statistical analysis finds robust XCO2 enhancements of up to 3 ppm for urban areas in Europe, Asia and North America. Furthermore, the analysis of SIF indicates that urban construction, population density and seasonality influence urban vegetation, which can be observed from space. Additionally, we find that OCO-2's SIF measurements have the potential to identify and approximate green areas within cities. For Berlin's Grunewald Forest as well as Mumbai's Sanjay Gandhi and Tungareshwar National Parks we observe enhancements in SIF measurements at sub-city scales.

Syngas Production from CO2 Reforming and CO2-steam Reforming of Methane over Ni/Ce-SBA-15 Catalyst

NASA Astrophysics Data System (ADS)

Tan, J. S.; Danh, H. T.; Singh, S.; Truong, Q. D.; Setiabudi, H. D.; Vo, D.-V. N.

2017-06-01

This study compares the catalytic performance of mesoporous 10 Ni/Ce-SBA-15 catalyst for CO2 reforming and CO2-steam reforming of methane reactions in syngas production. The catalytic performance of 10 Ni/Ce-SBA-15 catalyst for CO2 reforming and CO2-steam reforming of methane was evaluated in a temperature-controlled tubular fixed-bed reactor at stoichiometric feed composition, 1023 K and atmospheric pressure for 12 h on-stream with gas hourly space velocity (GHSV) of 36 L gcat -1 h-1. The 10 Ni/Ce-SBA-15 catalyst possessed a high specific BET surface area and average pore volume of 595.04 m2 g-1. The XRD measurement revealed the presence of NiO phase with crystallite dimension of about 13.60 nm whilst H2-TPR result indicates that NiO phase was completely reduced to metallic Ni0 phase at temperature beyond 800 K and the reduction temperature relied on different degrees of metal-support interaction associated with the location and size of NiO particles. The catalytic reactivity was significantly enhanced with increasing H2O/CO2 feed ratio. Interestingly, the H2/CO ratio for CO2-steam reforming of methane varied between 1 and 3 indicated the occurrence of parallel reactions, i.e., CH4 steam reforming giving a H2/CO of 3 whilst reverse water-gas shift (RWGS) reaction consuming H2 to produce CO gaseous product.

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

NASA Astrophysics Data System (ADS)

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

, located far from the injection zone. For an extraction ratio of 1, pressure buildup is minimized, greatly reducing the Area of Review, as well as the area required for securing mineral rights. For an extraction ratio of 1, CO2 and brine migration are unaffected by neighboring CO2 operations, which allows planning, assessing, and conducting of each operation to be carried out independently; thus, permits could be granted on a single-site basis. Brine-extraction wells will be useful during monitoring, providing information for system calibration and history matching. One of several key aspects that ACRM has in common with CCS-EOR is the possibility of generating revenue from the extracted fluids; namely, fresh water produced via brine desalination, using technologies such as Reverse Osmosis. These benefits can offset brine extraction and treatment costs, streamline permitting, and help gain public acceptance. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Electrochemical CO2 Reduction via Gas-Phase Catholyte

NASA Astrophysics Data System (ADS)

Carter, Brittany E.; Nesbitt, Nathan T.; D'Imperio, Luke A.; Naughton, Jeffrey R.; Courtney, Dave T.; Shepard, Steve; Burns, Michael J.; Vermaas, David A.; Smith, Wilson A.; Naughton, Michael J.

Reducing CO2 to CO through electrolysis, for the eventual conversion to hydrocarbons, provides a path towards utility-scale seasonal storage of renewable energy. Electrochemical reduction of CO2 has previously been achieved using a two chamber system. The chambers are typically separated by a semipermeable Nafion membrane, with an oxygen evolution catalyst anode on one side, a gold cathode on the other, and a solution containing CO2 on both sides. If instead, CO2 gas was in the second chamber, the reaction should yield more CO formed from CO2 at a given overpotential; this would result from the increased concentration of CO2 at the cathode surface and more facile mass transport of the CO and CO2. With liquid in one chamber and gas in the other, electrolysis is performed by integrating the cathode onto the semipermeable Nafion membrane. This membrane electrode assembly is fabricated via nanoimprint lithography (NIL), simultaneously achieving high active surface area and permeability. Challenges to the Nafion NIL process, and the performance of the system in CO2 reduction, will be presented. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. (DGE-1258923).

Pore-scale supercritical CO 2 dissolution and mass transfer under drainage conditions

DOE PAGES

Chang, Chun; Zhou, Quanlin; Oostrom, Mart; ...

2016-12-05

Recently, both core- and pore-scale imbibition experiments have shown non-equilibrium dissolution of supercritical CO 2 (scCO 2) and a prolonged depletion of residual scCO 2. In this paper, pore-scale scCO 2 dissolution and mass transfer under drainage conditions were investigated using a two-dimensional heterogeneous micromodel and a novel fluorescent water dye with a sensitive pH range between 3.7 and 6.5. Drainage experiments were conducted at 9 MPa and 40 °C by injecting scCO 2 into the sandstone-analogue pore network initially saturated by water without dissolved CO 2 (dsCO 2). During the experiments, time-lapse images of dye intensity, reflecting water pH,more » were obtained. These images show non-uniform pH in individual pores and pore clusters, with average pH levels gradually decreasing with time. Further analysis on selected pores and pore clusters shows that (1) rate-limited mass transfer prevails with slowly decreasing pH over time when the scCO 2-water interface area is low with respect to the volume of water-filled pores and pore clusters, (2) fast scCO 2 dissolution and phase equilibrium occurs when scCO 2 bubbles invade into water-filled pores, significantly enhancing the area-to-volume ratio, and (3) a transition from rate-limited to diffusion-limited mass transfer occurs in a single pore when a medium area-to-volume ratio is prevalent. The analysis also shows that two fundamental processes – scCO 2 dissolution at phase interfaces and diffusion of dsCO 2 at the pore scale (10–100 µm) observed after scCO 2 bubble invasion into water-filled pores without pore throat constraints – are relatively fast. The overall slow dissolution of scCO 2 in the millimeter-scale micromodel can be attributed to the small area-to-volume ratios that represent pore-throat configurations and characteristics of phase interfaces. Finally, this finding is applicable for the behavior of dissolution at pore, core, and field scales when water-filled pores and pore

Pore-scale supercritical CO 2 dissolution and mass transfer under drainage conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chun; Zhou, Quanlin; Oostrom, Mart

Recently, both core- and pore-scale imbibition experiments have shown non-equilibrium dissolution of supercritical CO 2 (scCO 2) and a prolonged depletion of residual scCO 2. In this paper, pore-scale scCO 2 dissolution and mass transfer under drainage conditions were investigated using a two-dimensional heterogeneous micromodel and a novel fluorescent water dye with a sensitive pH range between 3.7 and 6.5. Drainage experiments were conducted at 9 MPa and 40 °C by injecting scCO 2 into the sandstone-analogue pore network initially saturated by water without dissolved CO 2 (dsCO 2). During the experiments, time-lapse images of dye intensity, reflecting water pH,more » were obtained. These images show non-uniform pH in individual pores and pore clusters, with average pH levels gradually decreasing with time. Further analysis on selected pores and pore clusters shows that (1) rate-limited mass transfer prevails with slowly decreasing pH over time when the scCO 2-water interface area is low with respect to the volume of water-filled pores and pore clusters, (2) fast scCO 2 dissolution and phase equilibrium occurs when scCO 2 bubbles invade into water-filled pores, significantly enhancing the area-to-volume ratio, and (3) a transition from rate-limited to diffusion-limited mass transfer occurs in a single pore when a medium area-to-volume ratio is prevalent. The analysis also shows that two fundamental processes – scCO 2 dissolution at phase interfaces and diffusion of dsCO 2 at the pore scale (10–100 µm) observed after scCO 2 bubble invasion into water-filled pores without pore throat constraints – are relatively fast. The overall slow dissolution of scCO 2 in the millimeter-scale micromodel can be attributed to the small area-to-volume ratios that represent pore-throat configurations and characteristics of phase interfaces. Finally, this finding is applicable for the behavior of dissolution at pore, core, and field scales when water-filled pores and pore

Pore-scale supercritical CO 2 dissolution and mass transfer under drainage conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chun; Zhou, Quanlin; Oostrom, Mart

Abstract: Recently, both core- and pore-scale imbibition experiments have shown non-equilibrium dissolution of supercritical CO 2 (scCO 2) and a prolonged depletion of residual scCO 2. In this study, pore-scale scCO 2 dissolution and mass transfer under drainage conditions were investigated using a two-dimensional heterogeneous micromodel and a novel fluorescent water dye with a sensitive pH range between 3.7 and 6.5. Drainage experiments were conducted at 9 MPa and 40 °C by injecting scCO 2 into the sandstone-analogue pore network initially saturated by water without dissolved CO 2 (dsCO 2). During the experiments, time-lapse images of dye intensity, reflecting watermore » pH, were obtained. These images show non-uniform pH in individual pores and pore clusters, with average pH levels gradually decreasing with time. Further analysis on selected pores and pore clusters shows that (1) rate-limited mass transfer prevails with slowly decreasing pH over time when the scCO 2-water interface area is low with respect to the volume of water-filled pores and pore clusters, (2) fast scCO 2 dissolution and phase equilibrium occurs when scCO 2 bubbles invade into water-filled pores, significantly enhancing the area-to-volume ratio, and (3) a transition from rate-limited to diffusion-limited mass transfer occurs in a single pore when a medium area-to-volume ratio is prevalent. The analysis also shows that two fundamental processes – scCO 2 dissolution at phase interfaces and diffusion of dsCO 2 at the pore scale (10-100 µm) observed after scCO 2 bubble invasion into water-filled pores without pore throat constraints – are relatively fast. The overall slow dissolution of scCO 2 in the millimeter-scale micromodel can be attributed to the small area-to-volume ratios that represent pore-throat configurations and characteristics of phase interfaces. This finding is applicable for the behavior of dissolution at pore, core, and field scales when water-filled pores and pore

Diffuse CO 2 soil degassing and CO 2 and H 2S concentrations in air and related hazards at Vulcano Island (Aeolian arc, Italy)

NASA Astrophysics Data System (ADS)

Carapezza, M. L.; Barberi, F.; Ranaldi, M.; Ricci, T.; Tarchini, L.; Barrancos, J.; Fischer, C.; Perez, N.; Weber, K.; Di Piazza, A.; Gattuso, A.

2011-10-01

La Fossa crater on Vulcano Island is quiescent since 1890. Periodically it undergoes "crises" characterized by marked increase of temperature (T), gas output and concentration of magmatic components in the crater fumaroles (T may exceed 600 °C). During these crises, which so far did not lead to any eruptive reactivation, the diffuse CO 2 soil degassing also increases and in December 2005 an anomalous CO 2 flux of 1350 tons/day was estimated by 1588 measurements over a surface of 1.66 km 2 extending from La Fossa crater to the inhabited zone of Vulcano Porto. The crater area and two other anomalously degassing sites (Levante Beach and Palizzi) have been periodically investigated from December 2004 to August 2010 for diffuse CO 2 soil flux. They show a marked variation with time of the degassing rate, with synchronous maxima in December 2005. Carbon dioxide soil flux and environmental parameters have been also continuously monitored for over one year by an automatic station at Vulcano Porto. In order to assess the hazard of the endogenous gas emissions, CO 2 and H 2S air concentrations have been measured by Tunable Diode Laser profiles near the fumaroles of the crater rim and of the Levante Beach area, where also the viscous gas flux has been estimated. In addition, CO 2 air concentration has been measured both indoor and outdoor in an inhabited sector of Vulcano Porto. Results show that in some sites usually frequented by tourists there is a dangerous H 2S air concentration and CO 2 exceeds the hazardous thresholds in some Vulcano houses. These zones should be immediately monitored for gas hazard should a new crisis arise.

Orthorhombic Zr2Co11 phase revisited

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, X. -Z.; Zhang, W. Y.; Sellmyer, D. J.

2014-10-01

The structure of the orthorhombic Zr2Co11 phase was revisited in the present work. Selected-area electron diffraction (SAED) and high-resolution electron microscopy (HREM) techniques were used to investigate the structure. They show the orthorhombic Zr2Co11 phase has a 1-D incommensurate modulated structure. The structure can be approximately described as a B-centered orthorhombic lattice. The lattice parameters of the orthorhombic Zr2Co11 phase have been determined by a tilt series of SAED patterns. A hexagonal network with a modulation wave has been observed in the HREM image and the hexagonal motif is considered as the basic structural unit.

sCO2 Brayton Cycle: Roadmap to sCO2 Power Cycles NE Commercial Applications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendez Cruz, Carmen Margarita; Rochau, Gary E.

The mission of the Energy Conversion (EC) area of the Advanced Reactor Technology (ART) program is to commercialize the sCO2 Brayton cycle for Advance Reactors and for the Supercritical Transformational Electric Production (STEP) program. The near-term objective of the EC team efforts is to support the development of a commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the first STEP demonstration system with the lowest risk possible. This document details the status of technology, policy and market considerations, documentation of gaps and needs, and outlines the steps necessary for the successful development and deployment of commercial sCO2more » Brayton Power Systems along the path to nuclear reactor applications. Document Control Version Creation Date Revisions Created By Release Date 1.0 2/29/2016 Preliminary Draft Mendez, C. 3/2/2016 2.0 7/29/2016 Preliminaty/Partial Report -- updated Focus Area structure, added commercial path forward Mendez, C. 8/10/16 3.0 5/1/2018 Updated Roadmap supports timeline changes and inclusion of grid qualification goals Mendez, C. 6/6/18« less

Advanced CO2 Removal Technology Development

NASA Technical Reports Server (NTRS)

Finn, John E.; Verma, Sunita; Forrest, Kindall; LeVan, M. Douglas

2001-01-01

The Advanced CO2 Removal Technical Task Agreement covers three active areas of research and development. These include a study of the economic viability of a hybrid membrane/adsorption CO2 removal system, sorbent materials development, and construction of a database of adsorption properties of important fixed gases on several adsorbent material that may be used in CO2 removal systems. The membrane/adsorption CO2 removal system was proposed as a possible way to reduce the energy consumption of the four-bed molecular sieve system now in use. Much of the energy used by the 4BMS is used to desorb water removed in the device s desiccant beds. These beds might be replaced by a desiccating membrane that moves the water from [he incoming stream directly into the outlet stream. The approach may allow the CO2 removal beds to operate at a lower temperature. A comparison between models of the 4BMS and hybrid systems is underway at Vanderbilt University. NASA Ames Research Center has been investigating a Ag-exchanged zeolites as a possible improvement over currently used Ca and Na zeolites for CO2 removal. Silver ions will complex with n:-bonds in hydrocarbons such as ethylene, giving remarkably improved selectivity for adsorption of those materials. Bonds with n: character are also present in carbon oxides. NASA Ames is also continuing to build a database for adsorption isotherms of CO2, N2, O2, CH4, and Ar on a variety of sorbents. This information is useful for analysis of existing hardware and design of new processes.

Graphene-based porous materials with tunable surface area and CO2 adsorption properties synthesized by fluorine displacement reaction with various diamines.

PubMed

Li, Baoyin; Fan, Kun; Ma, Xin; Liu, Yang; Chen, Teng; Cheng, Zheng; Wang, Xu; Jiang, Jiaxing; Liu, Xiangyang

2016-09-15

A mild, operationally simple and controllable protocol for preparing graphene-based porous materials is essential to achieve a good pore-design development. In this paper, graphene-based porous materials with tunable surface area were constructed by the intercalation of fluorinated graphene (FG) based on the reaction of reactive CF bonds attached to graphene sheets with various amine-terminated molecules. In the porous materials, graphene sheets are like building blocks, and the diamines covalently grafted onto graphene framework act as pillars. Various diamines are successfully grafted onto graphene sheets, but the grafting ratio of diamines and reduction degree of FG differ greatly and depend on the chemical reactivity of diamines. Pillared diamine molecules chemically anchor at one end and are capable of undergoing a different reaction on the other end, resulting in three different conformations of graphene derivatives. Nitrogen sorption isotherms revealed that the surface area and pore distribution of the obtained porous materials depend heavily on the size and structure of diamine pillars. CO2 uptake capacity characterization showed that ethylenediamine intercalated FG achieved a high CO2 uptake density of 18.0 CO2 molecules per nm(2) at 0°C and 1.1bars, and high adsorption heat, up to 46.1kJmol(-1) at zero coverage. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of urban parks on CO2 concentrations in Toluca, Mexico

NASA Astrophysics Data System (ADS)

Vieyra Gómez, J. A.; González Sosa, E.; Mastachi-Loza, C. A.; Cervantes, M.; Martínez Valdéz, H.

2013-05-01

Despite green areas are used for amusement, they have several benefits such as: microclimate regulation, groundwater recharge, noise abatement, oxygen production and CO2 capture. The last one has a notable importance, as CO2 is considered to be one of the most pollutant gases of the greenhouse effect. The city of Toluca, has a considerable urban growth. However, there are few studies aimed to assess the importance of the green areas in urban locations. About this, it is estimated than only 4m2/hab of vegetal coverage is found in big cities, which means a 50% deficit according to the international standards.The aim of this study was to assess the urban parks impact in Toluca, as regulators of CO2 means through measurements in autumn-winter seasonal period, 2012-2013.It was performed 20 measurements in 4 local parks (Urawa, Alameda, Municipal and Metropolitano), in order to evaluate the possible effect of urban parks on CO2 concentrations. Transects were made inside and outside the parks and the CO2 concentrations were registered by a portable quantifier (GMP343).The data analysis allowed the separation of the parks based on CO2 concentrations; however, it was perceived a decreasing of CO2 inside the parks (370ppm), between 10 and 40 ppm less than those areas with traffic and pedestrians (399 ppm).

Carbonation and CO{sub 2} uptake of concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Keun-Hyeok, E-mail: yangkh@kgu.ac.kr; Seo, Eun-A, E-mail: ssooaa@naver.com; Tae, Sung-Ho, E-mail: jnb55@hanyang.ac.kr

This study developed a reliable procedure to assess the carbon dioxide (CO{sub 2}) uptake of concrete by carbonation during the service life of a structure and by the recycling of concrete after demolition. To generalize the amount of absorbable CO{sub 2} per unit volume of concrete, the molar concentration of carbonatable constituents in hardened cement paste was simplified as a function of the unit content of cement, and the degree of hydration of the cement paste was formulated as a function of the water-to-cement ratio. The contribution of the relative humidity, type of finishing material for the concrete surface, andmore » the substitution level of supplementary cementitious materials to the CO{sub 2} diffusion coefficient in concrete was reflected using various correction factors. The following parameters varying with the recycling scenario were also considered: the carbonatable surface area of concrete crusher-runs and underground phenomena of the decreased CO{sub 2} diffusion coefficient and increased CO{sub 2} concentration. Based on the developed procedure, a case study was conducted for an apartment building with a principal wall system and an office building with a Rahmen system, with the aim of examining the CO{sub 2} uptake of each structural element under different exposure environments during the service life and recycling of the building. As input data necessary for the case study, data collected from actual surveys conducted in 2012 in South Korea were used, which included data on the surrounding environments, lifecycle inventory database, life expectancy of structures, and recycling activity scenario. Ultimately, the CO{sub 2} uptake of concrete during a 100-year lifecycle (life expectancy of 40 years and recycling span of 60 years) was estimated to be 15.5%–17% of the CO{sub 2} emissions from concrete production, which roughly corresponds to 18%–21% of the CO{sub 2} emissions from the production of ordinary Portland cement. - Highlights: �

Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.

PubMed

Ma, Wenqing; Liu, Xizheng; Li, Chao; Yin, Huiming; Xi, Wei; Liu, Ruirui; He, Guang; Zhao, Xian; Luo, Jun; Ding, Yi

2018-05-21

The excessive emission of CO 2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO 2 and its utilization in metal-CO 2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO 2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO 2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO 2 ↔ 2Al 2 (CO 3 ) 3 + 3C, by which CO 2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO 2 fixation/utilization strategy with stable Al. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spatial variability structure of soil CO2 emission and soil physical and chemical properties characterized by fractal dimension in sugarcane areas

NASA Astrophysics Data System (ADS)

Bicalho, E. S.; Teixeira, D. B.; Panosso, A. R.; Perillo, L. I.; Iamaguti, J. L.; Pereira, G. T.; La Scala, N., Jr.

2012-04-01

Soil CO2 emission (FCO2) is influenced by chemical, physical and biological factors that affect the production of CO2 in the soil and its transport to the atmosphere, varying in time and space depending on environmental conditions, including the management of agricultural area. The aim of this study was to investigate the structure of spatial variability of FCO2 and soil properties by using fractal dimension (DF), derived from isotropic variograms at different scales, and construction of fractograms. The experimental area consisted of a regular grid of 60 × 60 m on sugarcane area under green management, containing 141 points spaced at minimum distances ranging from 0.5 to 10 m. Soil CO2 emission, soil temperature and soil moisture were evaluated over a period of 7 days, and soil chemical and physical properties were determined by sampling at a depth of 0.0 to 0.1 m. FCO2 showed an overall average of 1.51 µmol m-2 s-1, correlated significantly (p < 0.05) with soil physical factors such as soil bulk density, air-filled pore space, macroporosity and microporosity. Significant DF values were obtained in the characterization of FCO2 in medium and large scales (from 20 m). Variations in DF with the scale, which is the fractogram, indicate that the structure of FCO2 variability is similar to that observed for the soil temperature and total pore volume, and reverse for the other soil properties, except for macroporosity, sand content, soil organic matter, carbon stock, C/N ratio and CEC, which fractograms were not significantly correlated to the FCO2 fractogram. Thus, the structure of spatial variability for most soil properties, characterized by fractogram, presents a significant relationship with the structure of spatial variability of FCO2, generally with similar or dissimilar behavior, indicating the possibility of using the fractogram as tool to better observe the behavior of the spatial dependence of the variables along the scale.

Porous carbon derived via KOH activation of a hypercrosslinked porous organic polymer for efficient CO{sub 2}, CH{sub 4}, H{sub 2} adsorptions and high CO{sub 2}/N{sub 2} selectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Modak, Arindam; Bhaumik, Asim, E-mail: msab@iacs.res.in

2015-12-15

Microporous carbon having Brunauer-Emmett-Teller (BET) surface area of 2186 m{sup 2} g{sup −1} and micropore volume of 0.85 cm{sup 3} g{sup −1} has been synthesized via KOH induced high temperature carbonization of a non-conjugated hypercrosslinked organic polymer. Owing to the templating and activation by KOH, we have succeeded in making a microporous carbon from this porous polymer and the resultant carbon material showed high uptake for CO{sub 2} (7.6 mmol g{sup −1}) and CH{sub 4} (2.4 mmol g{sup −1}) at 1 atm, 273 K together with very good selectivity for the CO{sub 2}/N{sub 2} (30.2) separation. Furthermore, low pressure (1more » atm) H{sub 2} (2.6 wt%, 77 K) and water uptake (57.4 wt%, 298 K) ability of this polymer derived porous activated carbon is noteworthy. - Graphical abstract: Microporous carbon with BET surface area of 2186 m{sup 2} g{sup −1} has been synthesized via KOH activation of a porous organic polymer and it showed high uptake for CO{sub 2} (7.6 mmol g{sup −1}), CH{sub 4} (2.4 mmol g{sup −1}) and H{sub 2} (2.6 wt%) at 1 atm together with very good selectivity for CO{sub 2}. - Highlights: • Porous carbon from hypercrosslinked organic polymer. • KOH activated carbon with BET surface area 2186 m{sup 2} g{sup −1}. • High CO2 uptake (7.6 mmol g{sup −1}) and CO{sub 2}/N{sub 2} selectivity (30.2). • Porous carbon also showed high H{sub 2} (2.6 wt%) and H{sub 2}O (57.4 wt%) uptakes.« less

Mapping the Spatial Distribution of CO2 release from Kīlauea Volcano, Hawaii, USA

NASA Astrophysics Data System (ADS)

Elias, T.; Werner, C. A.; Kern, C.; Sutton, A. J.; Hauri, E. H.; Kelly, P. J.

2014-12-01

Kīlauea Volcano is a large emitter of volcanic CO2 with emission rates ranging from 7500-30,000 t/d. However, Kīlauea presents a challenging situation for CO2 emission rate measurement in that the main source of SO2 is the active vent in Halema'uma'u Crater, whereas CO2 emits mainly from a large (> 1km2) diffuse region east of the vent. Previous researchers recognized this issue and advocated for the use of a plume-integrated concentration ratio paired with the SO2 emission to determine CO2 emission rates; however, this worked best prior to the opening of the summit vent in 2008, or when SO2emission was still diffuse as opposed to focused degassing from the vent. We used two techniques to study the spatial distribution and temporal variability of CO2 release from the summit caldera in July, 2014. Eddy covariance measurements made at 14 locations in the area of diffuse emission resulted in elevated fluxes that generally ranged from 500 to > 5000 g/m2d, or typical of other volcanic and hydrothermal areas worldwide. MultiGas measurements of the CO2 and SO2 concentration in air at 1-m above the ground identified approximately seven areas of elevated area of CO2 degassing in the caldera. The CO2 concentrations in air were spatially well correlated to approximately 100 m and displayed anisotropy that was consistent with the measured wind direction. Areas of highest CO2 concentration correlated with the areas of highest flux using the eddy covariance method and were found near the middle of the caldera approximately 1 km NE of the active vent. This area overlies the inferred location of the shallow summit reservoir, and is characterized by linear fractures with adhered sublimate deposits at the surface. A few of the fractures are visibly fuming, but much of the degassing in the area is not apparent. Future work includes monitoring the fluxes in this area over time, and attempting to quantify emission rates from the areas of measured flux.

Delta13C values of grasses as a novel indicator of pollution by fossil-fuel-derived greenhouse gas CO2 in urban areas.

PubMed

Lichtfouse, Eric; Lichtfouse, Michel; Jaffrézic, Anne

2003-01-01

A novel fossil fuel pollution indicator based on the 13C/12C isotopic composition of plants has been designed. This bioindicator is a promising tool for future mapping of the sequestration of fossil fuel CO2 into urban vegetation. Theoretically, plants growing in fossil-fuel-CO2-contaminated areas, such as major cities, industrial centers, and highway borders, should assimilate a mixture of global atmospheric CO2 of delta13C value of -8.02 per thousand and of fossil fuel CO2 of average delta13C value of -27.28 per thousand. This isotopic difference should, thus, be recorded in plant carbon. Indeed, this study reveals that grasses growing near a major highway in Paris, France, have strikingly depleted delta13C values, averaging at -35.08 per thousand, versus rural grasses that show an average delta13C value of -30.59 per thousand. A simple mixing model was used to calculate the contributions of fossil-fuel-derived CO2 to the plant tissue. Calculation based on contaminated and noncontaminated isotopic end members shows that urban grasses assimilate up to 29.1% of fossil-fuel-CO2-derived carbon in their tissues. The 13C isotopic composition of grasses thus represents a promising new tool for the study of the impact of fossil fuel CO2 in major cities.

The CO 2 permeability and mixed gas CO 2/H 2 selectivity of membranes composed of CO 2-philic polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barillas, Mary Katharine; Enick, Robert M.; O’Brien, Michael

2011-04-01

The objective of this work was to design polymeric membranes that have very high CO 2 permeability and high mixed gas selectivity toward CO 2 rather than hydrogen. Therefore the membranes were based on "CO 2-philic" polymers that exhibit thermodynamically favorable Lewis acid:Lewis base and hydrogen bonding interactions with CO 2. CO 2-philic polymers that are solid at ambient temperature include polyfluoroacrylate (PFA); polyvinyl acetate (PVAc); and amorphous polylactic acid (PLA). Literature CO 2 permeability values for PVAc and PLA are disappointingly low. The cast PFA membranes from this study had low permeabilities (45 barrers at 25º C) and verymore » low CO 2/H 2 selectivity of 1.4. CO 2-philic polymers that are liquid at ambient conditions include polyethylene glycol (PEG), polypropylene glycol (PPG), polybutylene glycol with a linear -((CH 2) 4O)-repeat unit (i.e., polytetramethylene ether glycol (PTMEG)), polybutylene glycol (PBG) with a branched repeat unit, perfluoropolyether (PFPE), poly(dimethyl siloxane) (PDMS), and polyacetoxy oxetane (PAO). A small compound, glycerol triacetate (GTA) was also considered because it is similar in chemical structure to a trimer of PVAc. These liquids were tested as supported liquid membranes (SLM) and also (with the exception of PAD and GTA) as rubbery, crosslinked materials. Mixed gas permeability was measured using equimolar mixtures of CO 2 and H 2 feed streams at one atmosphere total pressure in steady-state flux experiments over the 298-423 K temperature range. The most promising SLMs were those composed of PEG, PTMEG, GTA, and PDMS. For example, at 37º C the PEG-, PTMEG-, GTA- and PDMS-based SLMs exhibited CO 2/H 2 selectivity values of ~11, 9, 9, and 3.5, respectively, and CO 2 permeability values of ~800, 900, 1900, and 2000 barrers, respectively. Crosslinked versions of the PEG, PTMEG and PDMS membranes at 37º C exhibited selectivity values of ~5, 6, and 3.5, respectively, and CO 2 permeability values of

Climatological mean and decadal change in surface ocean pCO 2, and net sea-air CO 2 flux over the global oceans

NASA Astrophysics Data System (ADS)

Takahashi, Taro; Sutherland, Stewart C.; Wanninkhof, Rik; Sweeney, Colm; Feely, Richard A.; Chipman, David W.; Hales, Burke; Friederich, Gernot; Chavez, Francisco; Sabine, Christopher; Watson, Andrew; Bakker, Dorothee C. E.; Schuster, Ute; Metzl, Nicolas; Yoshikawa-Inoue, Hisayuki; Ishii, Masao; Midorikawa, Takashi; Nojiri, Yukihiro; Körtzinger, Arne; Steinhoff, Tobias; Hoppema, Mario; Olafsson, Jon; Arnarson, Thorarinn S.; Tilbrook, Bronte; Johannessen, Truls; Olsen, Are; Bellerby, Richard; Wong, C. S.; Delille, Bruno; Bates, N. R.; de Baar, Hein J. W.

2009-04-01

A climatological mean distribution for the surface water pCO 2 over the global oceans in non-El Niño conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO 2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea-air CO 2 flux based on climatological surface ocean pCO 2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601-1622]. A time-trend analysis using deseasonalized surface water pCO 2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO 2 over these oceanic areas has increased on average at a mean rate of 1.5 μatm y -1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4 μatm y -1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Niño periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO 2 and the sea-air pCO 2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO 2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net air-sea CO 2 flux is estimated using the sea-air pCO 2 difference and the air-sea gas transfer rate that is parameterized as a function of (wind speed) 2 with a scaling factor of 0.26. This is estimated by inverting

Practical method of CO.sub.2 sequestration

DOEpatents

Goswami, D Yogi [Gainesville, FL; Lee, Man Su [Houston, TX; Kothurkar, Nikhil K [Tampa, FL; Stefanakos, Elias K [Tampa, FL

2011-03-01

A process and device to capture of CO.sub.2 at its originating source, such as a power plant, is disclosed. Absorbent material is recharged by desorbing CO.sub.2, so that it may be sequestered or used in another application. Continual recharging results in loss of absorbent surface area, due to pore plugging and sintering of particles. Calcium oxide or calcium hydroxide was immobilized to a fibrous ceramic-based fabric substrate as a thin film and sintered, creating an absorbent material. The samples were characterized, showing continuous cyclic carbonation conversions between about 62% and 75% under mild calcination conditions at 750.degree. C. and no CO.sub.2 in N.sub.2. Under the more severe calcination condition at 850.degree. C. and 20 wt % CO.sub.2 in N.sub.2, yttria fabric was superior to alumina as a substrate for carbon dioxide capture and the reactivity of the calcium oxide absorbent immobilized to yttria was maintained at the same level in the 12 cycles.

Monitoring Atmospheric CO2 From Space: Challenge & Approach

NASA Technical Reports Server (NTRS)

Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Kooi, Susan; Fan, Tai-Fang;

[Study on the change of dune CO2 concentration in the autumn at Minqin in Tengger desert].

PubMed

Shao, Tian-Jie; Zhao, Jing-Bo; Yu, Ke-Ke; Dong, Zhi-Bao

2010-12-01

In order to find out the CO2 concentration of the desert area, the influence of it on the CO2 in the atmosphere and the role that it played on the global carbon cycle, the research team utilized in September 2009 infrared CO2 monitor to observe the CO2 concentration of the 12 drill holes day and night in Minqin desert area in the Tengger desert. The difference of various observation spots' CO2 concentration of the desert area in the Tengger desert area is relatively big. The CO2 concentration at night is low but high in the daytime and the CO2 concentration at each observation spot changes from 310 x 10(-6) to 2 630 x 10(-6). The CO2 concentration is also obviously different in depth and the CO2 concentration at different depths in order of size is as follows: 4 m(3m) > 2 m > 1m. Compared with Xi' an area where is in the temperate and semi-humid region, the CO2 concentration of the desert area in Tengger desert is very low. The diurnal variation of CO2 concentration of the desert area in Tengger desert is obvious, and from the day 09:00 am to 09:00 am the next day, the CO2 concentrations at different depths which rang from 1 m to 4 m present the regularity that it changes from low to high, and then from high to low. The diurnal variation in temperature is the main reason that causes the change of the CO2 concentration in the sand layer, both of which have the positive correlation. The sand layer's CO2 concentration with higher water content is obviously higher than that with lower water content. The moisture content of sand layer is the main factor of the CO2 concentration. The CO2 concentration above 4m in the desert area is higher than that above the surface, which maybe indicates that the CO2 from the highest desert area is also the resource of CO2 in the atmosphere.

Feasibility of biodiesel production and CO2 emission reduction by Monoraphidium dybowskii LB50 under semi-continuous culture with open raceway ponds in the desert area.

PubMed

Yang, Haijian; He, Qiaoning; Hu, Chunxiang

2018-01-01

Compared with other general energy crops, microalgae are more compatible with desert conditions. In addition, microalgae cultivated in desert regions can be used to develop biodiesel. Therefore, screening oil-rich microalgae, and researching the algae growth, CO 2 fixation and oil yield in desert areas not only effectively utilize the idle desertification lands and other resources, but also reduce CO 2 emission. Monoraphidium dybowskii LB50 can be efficiently cultured in the desert area using light resources, and lipid yield can be effectively improved using two-stage induction and semi-continuous culture modes in open raceway ponds (ORPs). Lipid content (LC) and lipid productivity (LP) were increased by 20% under two-stage industrial salt induction, whereas biomass productivity (BP) increased by 80% to enhance LP under semi-continuous mode in 5 m 2 ORPs. After 3 years of operation, M. dybowskii LB50 was successfully and stably cultivated under semi-continuous mode for a month during five cycles of repeated culture in a 200 m 2 ORP in the desert area. This culture mode reduced the supply of the original species. The BP and CO 2 fixation rate were maintained at 18 and 33 g m -2  day -1 , respectively. Moreover, LC decreased only during the fifth cycle of repeated culture. Evaporation occurred at 0.9-1.8 L m -2  day -1 , which corresponded to 6.5-13% of evaporation loss rate. Semi-continuous and two-stage salt induction culture modes can reduce energy consumption and increase energy balance through the energy consumption analysis of life cycle. This study demonstrates the feasibility of combining biodiesel production and CO 2 fixation using microalgae grown as feedstock under culture modes with ORPs by using the resources in the desert area. The understanding of evaporation loss and the sustainability of semi-continuous culture render this approach practically viable. The novel strategy may be a promising alternative to existing technology for CO 2 emission

Seasonal variation of air-sea CO2 fluxes in the Terra Nova Bay of the Ross Sea, Antarctica, based on year-round pCO2 observations

NASA Astrophysics Data System (ADS)

Zappa, C. J.; Rhee, T. S.; Kwon, Y. S.; Choi, T.; Yang, E. J.; Kim, J.

2017-12-01

The polar oceans are rapidly changing in response to climate variability. In particular, augmented inflow of glacial melt water and shrinking sea-ice extent impacts the polar coastal oceans, which may in turn shift the biogeochemistry into an unprecedented paradigm not experienced previously. Nonetheless, most research in the polar oceans is limited to the summer season. Here, we present the first direct observations of ocean and atmospheric pCO2 measured near the coast of Terra Nova Bay in the Ross Sea, Antarctica, ongoing since February, 2015 at Jang Bogo Station. The coastal area is covered by landfast sea-ice from spring to fall while continually exposed to the atmosphere during summer season only. The pCO2 in seawater swung from 120 matm in February to 425 matm in early October. Although sea-ice still covers the coastal area, pCO2 already started decreasing after reaching the peak in October. In November, the pCO2 suddenly dropped as much as 100 matm in a week. This decrease of pCO2 continued until late February when the sea-ice concentration was minimal. With growing sea ice, the pCO2 increased logarithmically reaching the atmospheric concentration in June/July, depending on the year, and continued to increase until October. Daily mean air-sea CO2 flux in the coastal area widely varied from -70 mmol m-2 d-1 to 20 mmol m-2 d-1. Based on these observations of pCO2 in Terra Nova Bay, the annual uptake of CO2 is 8 g C m-2, estimated using the fraction of sea-ice concentration estimated from AMSR2 microwave emission imagery. Extrapolating to all polynyas surrounding Antarctica, we expect the annual uptake of 8 Tg C in the atmosphere. This is comparable to the amount of CO2 degassed into the atmosphere south of the Antarctic Polar Front (62°S).

Subtask 2.18 - Advancing CO 2 Capture Technology: Partnership for CO 2 Capture (PCO 2C) Phase III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kay, John; Azenkeng, Alexander; Fiala, Nathan

2016-03-31

Industries and utilities continue to investigate ways to decrease their carbon footprint. Carbon capture and storage (CCS) can enable existing power generation facilities to meet the current national CO 2 reduction goals. The Partnership for CO2 Capture Phase III focused on several important research areas in an effort to find ways to decrease the cost of capture across both precombustion and postcombustion platforms. Two flue gas pretreatment technologies for postcombustion capture, an SO 2 reduction scrubbing technology from Cansolv Technologies Inc. and the Tri-Mer filtration technology that combines particulate, NOx, and SO 2 control, were evaluated on the Energy &more » Environmental Research Center’s (EERC’s) pilot-scale test system. Pretreating the flue gas should enable more efficient, and therefore less expensive, CO 2 capture. Both technologies were found to be effective in pretreating flue gas prior to CO 2 capture. Two new postcombustion capture solvents were tested, one from the Korea Carbon Capture and Sequestration R&D Center (KCRC) and one from CO 2 Solutions Incorporated. Both of these solvents showed the ability to capture CO 2 while requiring less regeneration energy, which would reduce the cost of capture. Hydrogen separation membranes from Commonwealth Scientific and Industrial Research Organisation were evaluated through precombustion testing. They are composed of vanadium alloy, which is less expensive than the palladium alloys that are typically used. Their performance was comparable to that of other membranes that have been tested at the EERC. Aspen Plus® software was used to model the KCRC and CO 2 Solutions solvents and found that they would result in significantly improved overall plant performance. The modeling effort also showed that the parasitic steam load at partial capture of 45% is less than half that of 90% overall capture, indicating savings that could be accrued if 90% capture is not required. Modeling of three regional

Retrieval of Paris CO2 and CO emissions using a boundary layer budget method in the framework of the CO2-MEGAPARIS project

NASA Astrophysics Data System (ADS)

Dieudonné, E.; Gibert, F.; Xueref-remy, I. C.; Lopez, M.; Schmidt, M.; Ravetta, F.

2012-12-01

The development of anthropogenic activities since the pre-industrial era has greatly increased CO2 concentrations in the atmosphere, very likely causing the observed rise in global temperature. Therefore, accurate estimations of CO2 emission fluxes are very important for climate predictions. At the continental scale, CO2 fluxes can be estimated rather precisely using inverse modeling while tower turbulent flux measurements (eddy-covariance or EC) can provide an estimation of local-scale fluxes. However, this method cannot be applied to monitor urban CO2 emissions due to their large horizontal variability, so that a regional scale approach seems more suited. Unfortunately, at this scale, anthropogenic and biospheric fluxes are mixed, diluted and advected in the atmospheric boundary-layer (ABL) and the balance between these processes is not well known. Yet, independent estimations of CO2 fluxes would be needed to verify existing high resolution emission inventories and assess the efficiency of future mitigation policies. Several experiments dedicated to quantifying CO2 emissions from megacities are ongoing, like the CO2-MEGAPARIS research project [a,b]. In this framework, a network of lidars and in-situ sensors has been set up in Paris region. An original ABL mass budget method is used to infer the properties of advected anthropogenic CO2 and CO emissions from Paris urban area [c]. The method is applied in the center of Paris, at neighboring suburban sites located 20 km away, and at a rural station (100 km downwind). The budget uses ABL depths from elastic lidars, CO2 and CO concentrations from both the ICOS [d] and CO2-MEGAPARIS networks to quantify vertical advection and storage terms in the ABL mass budget. EC measurements are used to monitor biospheric surface fluxes. The budget in Paris provides a direct estimation of the average CO2 and CO fluxes from the city, while the budget at the suburban and rural stations provides an estimation of the advected fluxes

Quantifying Paris CO2 urban dome: a first synthesis of results from the CO2-Megaparis project (2009-2013)

NASA Astrophysics Data System (ADS)

Xueref-Remy, Irène; Dieudonné, Elsa; Ammoura, Lamia; Cellier, Pierre; Gibert, Fabien; Lac, Christine; Lauvaux, Thomas; Lopez, Morgan; Pal, Sandip; Perrussel, Olivier; Puygrenier, Vincent; Ramonet, Michel; Schmidt, Martina; Thiruchittampalam, Balendra; Vuillemin, Cyrille

2013-04-01

About 80% of global CO2 emissions come from punctual sources such as megacities. Among those, Paris is the third megacity in Europe. However, the estimates of urban CO2 emissions are based on activity proxies and benchmarked emission factors, leading to uncertainties as high as several tenths of percents in some sectors of bottom-up CO2 emissions inventories. Since 2009, the CO2-Megaparis project aims to quantify CO2 emissions from Paris using a top-down approach based on a synergy between atmospheric observations and modeling. A mini-network of 3 stations was developed by LSCE in Paris agglomeration within the infrastructure of the air quality monitoring agency of Paris region, AIRPARIF, completing 2 other stations from the ICOS network leaded at LSCE. The mean CO2 concentration dome over Paris in the mid-afternoon over 1 year of data is about 2.2 ppm, and is strongly wind speed and direction dependent. Analysis of correlations between CO2, CO and 14C02 was carried out and a comparison to available inventories will be presented. Direct modeling of CO2 at a very fine resolution (2x2 km2, 1h) was performed by CNRM and matched well with observations. Results from inverse modeling will be presented. Furthermore, we conducted a campaign using lidar facilities showing that due to the effect of the urban heat island, the boundary layer height (a key parameter in assessing CO2 fluxes from the atmospheric approach) is 10 to 40% time higher in Paris than in surrounding rural areas. Also, a sonic anemometer and a 10 Hz CO2 analyzer were deployed to assess CO2 fluxes from observations, as well as CO2 flux analyzers on crops. Using the data from this instrumentation, a mass balance calculation was carried out and allowed the identification and quantification of Paris CO2 traffic plume to a rural region, about 100 km south of Paris, that matched well with inventories. Finally, an attempt of defining the strengths and weaknesses of the atmospheric approach to quantify urban CO2

An attempt at estimating Paris area CO2 emissions from atmospheric concentration measurements

NASA Astrophysics Data System (ADS)

Bréon, F. M.; Broquet, G.; Puygrenier, V.; Chevallier, F.; Xueref-Rémy, I.; Ramonet, M.; Dieudonné, E.; Lopez, M.; Schmidt, M.; Perrussel, O.; Ciais, P.

2014-04-01

Atmospheric concentration measurements are used to adjust the daily to monthly budget of CO2 emissions from the AirParif inventory of the Paris agglomeration. We use 5 atmospheric monitoring sites including one at the top of the Eiffel tower. The atmospheric inversion is based on a Bayesian approach, and relies on an atmospheric transport model with a spatial resolution of 2 km with boundary conditions from a global coarse grid transport model. The inversion tool adjusts the CO2 fluxes (anthropogenic and biogenic) with a temporal resolution of 6 h, assuming temporal correlation of emissions uncertainties within the daily cycle and from day to day, while keeping the a priori spatial distribution from the emission inventory. The inversion significantly improves the agreement between measured and modelled concentrations. However, the amplitude of the atmospheric transport errors is often large compared to the CO2 gradients between the sites that are used to estimate the fluxes, in particular for the Eiffel tower station. In addition, we sometime observe large model-measurement differences upwind from the Paris agglomeration, which confirms the large and poorly constrained contribution from distant sources and sinks included in the prescribed CO2 boundary conditions These results suggest that (i) the Eiffel measurements at 300 m above ground cannot be used with the current system and (ii) the inversion shall rely on the measured upwind-downwind gradients rather than the raw mole fraction measurements. With such setup, realistic emissions are retrieved for two 30 day periods. Similar inversions over longer periods are necessary for a proper evaluation of the results.

In situ experimental assessment of lake whitefish development following a freshwater oil spill.

PubMed

Debruyn, Adrian M H; Wernick, Barbara G; Stefura, Corey; McDonald, Blair G; Rudolph, Barri-Lynn; Patterson, Luanne; Chapman, Peter M

2007-10-15

Wabamun Lake (Alberta, Canada) has been subject to ongoing contamination with polycyclic aromatic hydrocarbons (PAHs) from multiple sources for decades and in August 2005 was exposed to ca. 149 500 L of bunker C oil following a train derailment. We compared the pattern, frequency, and severity of deformity in larvae of lake whitefish (Coregonus clupeaformis) incubated in situ in areas of Wabamun Lake exposed only to "background" PAH contamination and in areas additionally exposed to PAHs from the oil. All sites in the lake (including reference areas) showed incidences of deformity higher than are typically observed in laboratory studies. A small number of oil-exposed sites showed higher incidences of some teratogenic deformities and a tendency to exhibit deformities of higher severity than sites not exposed to oil. The frequency of moderate to severe deformities in 8 of 16 classes was correlated with PAH exposure. Nonmetric multivariate ordination of deformity data revealed a general pattern of increasing incidence and severity of several skeletal (lordosis, scoliosis) and craniofacial (ocular, jaw) deformities at sites with relatively high exposure to oil-derived PAHs. A simultaneous consideration of incidence, severity, and pattern of deformity enabled us to detect a consistent (overall approximately 5% above background) response to the oil despite high variability and high background deformity rates in this historically contaminated environment.

Preparation and photocatalytic properties of nanometer-sized magnetic TiO2/SiO2/CoFe2O4 composites.

PubMed

Li, Hansheng; Zhang, Yaping; Wu, Qin; Wang, Xitao; Liu, Changhao

2011-11-01

Magnetic TiO2/SiO2/CoFe2O4 nanoparticles (TiO2/SCFs) were prepared by a sol-gel process in a reverse microemulsion combined with solvent-thermal technique. TiO2/SCFs were characterized by Fourier transform infrared spectrometry, thermogravimetric analysis-differential scanning calorimetry, X-ray diffraction, Raman spectrometry, TEM, BET specific surface area measurement, and magnetic analysis. Structure analyses indicated that TiO2/SCFs presented a core-shell structure with TiO2 uniformly coating on SiO2/CoFe2O4 nanomagnets (SCFs) and typical ferromagnetic hysteresis. TiO2/SCFs showed larger specific surface area and better photocatalytic activities than TiO2 and TiO2/CoFe2O4 photocatalysts prepared by the same method. The doping interaction between TiO2 and CoFe2O4 reduced thanks to the inert SiO2 mesosphere.

CO2 exchange in the Hudson Bay lowlands: Community characteristics and multispectral reflectance properties

NASA Technical Reports Server (NTRS)

Whiting, Gary J.

1994-01-01

Net ecosystem CO2 exchange was measured during the 1990 growing season (June to August) along a transect starting 10 km inland from James Bay and extending 100 km interior to Kinosheo Lake, Ontario. Sites were chosen in three distinct areas: a coastal fen, an interior fen, and a bog. For the most productive sites in the bog, net daily uptake rates reached a maximum of 2.5 g C-CO2 m(exp -2)/d with an area-weighted exchange of 0.3 g C-CO2 m(exp -2)/d near midsummer. This site was estimated to be a net carbon source of 9 g C-CO2 m(exp -2) to the atmosphere over a 153-day growing season. The interior fen was less productive on a daily basis with a net maximum uptake of 0.5 g C-CO2 m(exp -2)/d and with corresponding area-weighted uptake of 0.1 g C-CO2 m(exp -2)/d during midsummer. Early and late season release of carbon to the atmosphere resulted in a net loss of 21 g C-CO2 m(exp -2) over the growing season from this site. The coastal fen was the most productive site with uptake rates peaking near 1.7 g C-CO2 m(exp -2)/d which corresponded to an area-weighted uptake of 0.8 g C-CO2 m(exp -2)/d during midsummer and an estimated net uptake of 6 g C-CO2 m(exp -2) for the growing season. Associated with net CO2 exchange measurements, multispectral reflectance properties of the sites were measured over the growing season using portable radiometers. These properties were related to exchange rates with the goal of examining the potential for satellite remote sensing to monitor biosphere/atmosphere CO2 exchange in this biome. The normalized difference vegetation index (NDVI) computed from surface reflectance was correlated with net CO2 exchange for all sites with the exception of areas with large proportions of Sphagnum moss cover. These mosses have greater near-infrared reflectance than typical surrounding vegetation and may require special adjustment for regional exchange/remote sensing applications.

CO2 Permeability of Biological Membranes and Role of CO2 Channels

PubMed Central

Endeward, Volker; Arias-Hidalgo, Mariela; Al-Samir, Samer; Gros, Gerolf

2017-01-01

We summarize here, mainly for mammalian systems, the present knowledge of (a) the membrane CO2 permeabilities in various tissues; (b) the physiological significance of the value of the CO2 permeability; (c) the mechanisms by which membrane CO2 permeability is modulated; (d) the role of the intracellular diffusivity of CO2 for the quantitative significance of cell membrane CO2 permeability; (e) the available evidence for the existence of CO2 channels in mammalian and artificial systems, with a brief view on CO2 channels in fishes and plants; and, (f) the possible significance of CO2 channels in mammalian systems. PMID:29064458

Adsorptive separation of CO 2 in sulfur-doped nanoporous carbons: Selectivity and breakthrough simulation

DOE PAGES

Saha, Dipendu; Orkoulas, Gerassimos; Chen, Jihua; ...

2017-03-01

In this research, we have synthesized two sulfur functionalized nanoporous carbons by post-synthesis modifications with sulfur bearing activating agents that simultaneously enhanced the surface area and introduced sulfur functionalities on the carbon surface. The Brunauer–Emmett–Teller (BET) surface areas of these materials were 2865 and 837 m 2/g with total sulfur contents of 8.2 and 12.9 %, respectively. The sulfur-functionalized carbons were characterized with pore textural properties, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and electron microscopy (SEM and TEM). In both the carbons, CO 2 adsorption isotherms and kinetics were measured in three different temperatures of 298, 288 and 278more » K and pressures up to 760 torr. The gravimetric CO 2 uptake followed the trend with BET surface area but the surface area-based uptake was reversed and it followed the trend of sulfur content. The heat of adsorption of CO 2 in low uptake was 60-65 kJ/mol, which is the highest for CO 2 adsorption in porous carbons. In order to investigate the adsorptive separation of CO 2, N 2 and CH 4 adsorption isotherms were also measured at 298 K and 760 torr. The selectivity of separation for CO 2/N 2 and CO 2/CH 4 was calculated based on the Ideal Adsorbed Solution Theory (IAST) and all the results demonstrated the high CO 2 selectivity for the carbon with higher sulfur content. The adsorption isotherms were combined with mass balances to calculate the breakthrough behavior of the binary mixtures of CO 2/N 2 and CO 2/CH 4. The simulation results demonstrated that the dimensionless breakthrough time is a decreasing function of the mole fraction of CO 2 in the feed stream. The overall results suggest that the sulfurfunctionalized carbons can be employed as potential adsorbents for CO 2 separation.« less

Comparative study of fractional CO2 laser and fractional CO2 laser-assisted drug delivery of topical steroid and topical vitamin C in macular amyloidosis.

PubMed

Sobhi, Rehab Mohamed; Sharaoui, Iman; El Nabarawy, Eman Ahmad; El Nemr Esmail, Reham Shehab; Hegazy, Rehab Aly; Aref, Dina Hesham Fouad

2018-05-01

Macular amyloidosis (MA) represents a common variant of primary localized cutaneous amyloidosis. It has a characteristic female predominance; none of the treatment modalities described is either curative or uniformly effective in patients with macular amyloidosis. To determine the effect of fractional CO 2 laser in macular amyloidosis in comparison to fractional CO 2 laser-assisted drug delivery of topical steroids and topical vitamin C, the study includes 10 female patients with cutaneous macular amyloidosis aged between 20 and 62 years. Patients were treated with four sessions of fractional CO 2 laser with 4 weeks interval. Laser treatments were performed using fractional CO 2 laser with the following parameters (power 18 W, spacing 800 μm, dwell time 600 μs, stacking 3). The lesion is divided into three areas: area 1, treated by fractional laser only; area 2, treated by fractional laser followed by topical corticosteroid application under occlusion for 24 h; and area 3, treated by fractional laser followed by topical vitamin C serum application under occlusion for 24 h. All lesions were examined clinically and histologically before the therapy and 1 month after the end of the therapy to evaluate the degree of improvement. All treated areas show significant decrease in pigmentation score after treatment, significant drop in rippling (P value < 0.016), and improvement of lichenification; as regards the histological improvement, there was a significant decrease of the amyloid amount after treatment. As regards the amyloid amount, results show significant decrease in the amount of amyloid in all of the three treated areas. Area 2 reported the highest decrease in the amyloid amount followed by areas 1 and 3. One patient (10%) was highly satisfied by the treatment, 6 (60%) reported moderate degree of satisfaction, while only 3 (30%) reported mild satisfaction. Minimal complication occurred in the form of post-inflammatory hyperpigmentation in 1 patient

Large-area Co-silicide nanodot arrays produced by colloidal nanosphere lithography and thermal annealing.

PubMed

Cheng, S L; Wong, S L; Lu, S W; Chen, H

2008-09-01

We report here the successful fabrication of large-area size-tunable periodic arrays of cobalt and Co-silicide nanodots on silicon substrates by employing the colloidal nanosphere lithography (NSL) technique and heat treatments. The growth of low-resistivity epitaxial CoSi(2) was found to be more favorable for the samples with smaller Co nanodot sizes. The sizes of the epitaxial CoSi(2) nanodots can be tuned from 50 to 100 nm by varying the diameter of the colloidal spheres and annealing temperatures. The epitaxial CoSi(2) nanodots were found to grow with an epitaxial orientation with respect to the (001)Si substrates: [001]CoSi(2)//[001]Si and (200)CoSi(2)//(400)Si. From the results of planview HRTEM, XTEM, and SAED analysis, the epitaxial CoSi(2) nanodots were identified to be inverse pyramids in shape, and the average sizes of the faceted silicide nanodots were measured to decrease with annealing temperature. The observed results present the exciting prospect that with appropriate controls, the colloidal NSL technique promises to facilitate the growth of a variety of well-ordered silicide nanodots with selected shape, size, and periodicity.

The effect of CO2 laser treatment on skin tissue.

PubMed

Baleg, Sana Mohammed Anayb; Bidin, Noriah; Suan, Lau Pik; Ahmad, Muhammad Fakarruddin Sidi; Krishnan, Ganesan; Johari, Abd Rahman; Hamid, Asma

2015-09-01

The aim of this study was to evaluate the effects of multiple pulses on the depth of injury caused by CO2 laser in an in vivo rat model. A 10 600-nm CO2 laser was applied to rat skin, with one side of the rat dorsal skin being exposed, leaving the other side as a control. All of the various laser pulses tested led to gradual loss of epidermal thickness as well as a dramatic increase in thermal damage depth. Collagen coagulation was most effective with ten pulses of CO2 laser, while the strength of irradiated skin tissue increased as the influence of the laser increased. Fundamental laser-skin interaction effects were studied using a CO2 laser. The photodamaged areas obtained from laser interaction were recorded via couple charge device video camera and analyzed via ImageJ software. Photodamage induced by CO2 laser is due to photothermal effects, which involve burning and vaporizing mechanisms to ablate the epidermis layer. The burning area literally expands and penetrates deep into the dermis layer, subsequently causing collagen coagulation. This fundamental study shows in detail the effect of CO2 laser interaction with skin. The CO2 attributed severe burning, producing deep coagulation, and induced strength to treated skin. © 2015 Wiley Periodicals, Inc.

CO2 Efflux from Shrimp Ponds in Indonesia

PubMed Central

Sidik, Frida; Lovelock, Catherine E.

2013-01-01

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored ‘blue’ carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO2) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO2 efflux from the floors and walls of shrimp ponds. Rates of CO2 efflux within shrimp ponds were 4.37 kg CO2 m−2 y−1 from the walls and 1.60 kg CO2 m−2 y−1 from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO2 emissions to the atmosphere between 5.76 and 13.95 Tg y−1. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO2 emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO2 released to atmosphere. PMID:23755306

Winter crop CO2 uptake inferred from CONTRAIL measurements over Delhi, India

NASA Astrophysics Data System (ADS)

Umezawa, Taku; Niwa, Yosuke; Sawa, Yousuke; Machida, Toshinobu; Matsueda, Hidekazu

2016-11-01

Recent studies have shown the impact of expanding agricultural activities on atmospheric CO2 variations and the global carbon cycle. In this study, we show clear evidence of the measureable impact of Indian wintertime crops (mainly wheat) on the regional carbon budget using high-frequency atmospheric CO2 measurements by Comprehensive Observation Network for Trace gases by Airliners (CONTRAIL) over Delhi; this phenomenon is not detected by the existing network of surface CO2 sites. While a general increase in the vertical profiles of CO2 toward the ground in the boundary layer was observed throughout December-April, we frequently observed sharp decreases below 2 km during January-March. Seasonal circulations during these 3 months indicated influences from neighboring croplands (with patchy urban areas) located upwind. We conclude that the observed CO2 decrease is attributable to active uptake by the crops grown in winter and that the uptake exceeds in magnitude the urban CO2 emissions from the Delhi metropolitan area.

CO2 reforming of methane: valorizing CO2 by means of Dielectric Barrier Discharge

NASA Astrophysics Data System (ADS)

Machrafi, H.; Cavadias, S.; Amouroux, J.

2011-03-01

The impact of pollution on the environment is causing several problems that are to be reduced as much as possible. One important example is the production of CO2 that is emitted by many transport and industrial applications. An interesting solution is to view CO2 as a source instead of a product that can be stocked. The case considered in this work is the CO2 reformation of methane producing hydrogen and CO. It is an endothermic reaction, for which the activition barrier needs to be overcome. The method of Dielectric Barrier Discharge can do this efficiently. The process relies on the collision of electrons, which are accelerated under an electrical field that is created in the discharge area. This leads to the formation of reactive species, which facilitate the abovementioned reaction. The determination of the electron density is performed by PLASIMO. The study is subsequently continued using the Reaction Engineering module in COMSOL (with an incorporated kinetic mechanism) in order to model the discharge phase. Then COMSOL (continuity and Navier-Stokes equations) is used to model the flow in the post-discharge phase. The results showed that both a 2D and 3D model can be used to model the chemical-plasma process. These methods need strongly reduced kinetic mechanism, which in some cases can cause loss of precision. It is also observed that the present experimental set-up that is modeled needs to be improved. A suggestion is made.

Effect of Mineral Dissolution/Precipitation and CO2 Exsolution on CO2 transport in Geological Carbon Storage.

PubMed

Xu, Ruina; Li, Rong; Ma, Jin; He, Di; Jiang, Peixue

2017-09-19

continuously injected through the core. The MRI results indicate dissolution of the carbonates during the experiments since the porosity has been increased after the core-flooding experiments. The mineral dissolution changes the pore structure by enlarging the throat diameters and decreasing the pore specific surface areas, resulting in lower CO 2 /water capillary pressures and changes in the relative permeability. When the reservoir pressure decreases, the CO 2 exsolution occurs due to the reduction of solubility. The CO 2 bubbles preferentially grow toward the larger pores instead of toward the throats or the finer pores during the depressurization. After exsolution, the exsolved CO 2 phase shows low mobility due to the highly dispersed pore-scale morphology, and the well dispersed small bubbles tend to merge without interface contact driven by the Ostwald ripening mechanism. During depressurization, the dissolved carbonate could also precipitate as a result of increasing pH. There is increasing formation water flow resistance and low mobility of the CO 2 in the presence of CO 2 exsolution and carbonate precipitation. These effects produce a self-sealing mechanism that may reduce unfavorable CO 2 migration even in the presence of sudden reservoir depressurization.

Fluid inclusion from drill hole DW-5, Hohi geothermal area, Japan: Evidence of boiling and procedure for estimating CO2 content

USGS Publications Warehouse

Sasada, M.; Roedder, E.; Belkin, H.E.

1986-01-01

Fluid inclusion studies have been used to derive a model for fluid evolution in the Hohi geothermal area, Japan. Six types of fluid inclusions are found in quartz obtained from the drill core of DW-5 hole. They are: (I) primary liquid-rich with evidence of boiling; (II) primary liquid-rich without evidence of boiling; (III) primary vapor-rich (assumed to have been formed by boiling); (IV) secondary liquid-rich with evidence of boiling; (V) secondary liquid-rich without evidence of boiling; (VI) secondary vapor-rich (assumed to have been formed by boiling). Homogenization temperatures (Th) range between 196 and 347??C and the final melting point of ice (Tm) between -0.2 and -4.3??C. The CO2 content was estimated semiquantitatively to be between 0 and 0.39 wt. % based on the bubble behavior on crushing. NaCl equivalent solid solute salinity of fluid inclusions was determined as being between 0 and 6.8 wt. % after minor correction for CO2 content. Fluid inclusions in quartz provide a record of geothermal activity of early boiling and later cooling. The CO2 contents and homogenization temperatures of fluid inclusions with evidence of boiling generally increase with depth; these changes, and NaCl equivalent solid solute salinity of the fluid can be explained by an adiabatic boiling model for a CO2-bearing low-salinity fluid. Some high-salinity inclusions without CO2 are presumed to have formed by a local boiling process due to a temperature increase or a pressure decrease. The liquid-rich primary and secondary inclusions without evidence of boiling formed during the cooling process. The salinity and CO2 content of these inclusions are lower than those in the boiling fluid at the early stage, probably as a result of admixture with groundwater. ?? 1986.

Subtask – CO 2 storage and enhanced bakken recovery research program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorensen, James; Hawthorne, Steven; Smith, Steven

Small improvements in productivity could increase technically recoverable oil in the Bakken Petroleum System by billions of barrels. The use of CO 2 for enhanced oil recovery (EOR) in tight oil reservoirs is a relatively new concept. The large-scale injection of CO 2 into the Bakken would also result in the geological storage of significant amounts of CO 2. The Energy & Environmental Research Center (EERC) has conducted laboratory and modeling activities to examine the potential for CO 2 storage and EOR in the Bakken. Specific activities included the characterization and subsequent modeling of North Dakota study areas as wellmore » as dynamic predictive simulations of possible CO 2 injection schemes to predict the potential CO 2 storage and EOR in those areas. Laboratory studies to evaluate the ability of CO 2 to remove hydrocarbons from Bakken rocks and determine minimum miscibility pressures for Bakken oil samples were conducted. Data from a CO 2 injection test conducted in the Elm Coulee area of Montana in 2009 were evaluated with an eye toward the possible application of knowledge gained to future injection tests in other areas. A first-order estimation of potential CO 2 storage capacity in the Bakken Formation in North Dakota was also conducted. Key findings of the program are as follows. The results of the research activities suggest that CO 2 may be effective in enhancing the productivity of oil from the Bakken and that the Bakken may hold the ability to geologically store between 120 Mt and 3.2 Gt of CO 2. However, there are no clear-cut answers regarding the most effective approach for using CO 2 to improve oil productivity or the storage capacity of the Bakken. The results underscore the notion that an unconventional resource will likely require unconventional methods of both assessment and implementation when it comes to the injection of CO 2. In particular, a better understanding of the fundamental mechanisms controlling the interactions between CO 2

High-performance cobalt carbonate hydroxide nano-dot/NiCo(CO3)(OH)2 electrode for asymmetric supercapacitors

NASA Astrophysics Data System (ADS)

Lee, Damin; Xia, Qi Xun; Yun, Je Moon; Kim, Kwang Ho

2018-03-01

Binder-free mesoporous NiCo(CO3)(OH)2 nanowire arrays were grown using a facile hydrothermal technique. The Co2(CO3)(OH)2 in NiCo(CO3)(OH)2 nanowire arrays was well-decorated as nano-dot scale (a few nanometer). In addition, increasing cobalt content in nickel compound matrix, NiCo(CO3)(OH)2 nanowire arrays were separately uniformly grown without agglomeration on Ni foam, providing a high specific surface area to help electrolyte access and ion transfer. The enticing composition and morphology of the NiCo(CO3)(OH)2 nanowire exhibit a superior specific capacity of 1288.2 mAh g-1 at a current density of 3 A g-1 and excellent cycling stability with the capacity retention of 80.7% after 10,000 cycles. Furthermore, an asymmetric supercapacitor composed of the NiCo(CO3)(OH)2 composite as a positive electrode and the graphene as a negative electrode presented a high energy density of 35.5 W h kg-1 at a power density of 2555.6 W kg-1 and satisfactory cycling stability with 71.3% capacity retention after 10,000 cycles. The great combination of the active nano-dot Co2(CO3)(OH)2 and the individually grown NiCo(CO3)(OH)2 nanowires made it a promising electrode material for asymmetric supercapacitors. A well-developed nanoarchitecture of the nano-dot Co2(CO3)(OH)2 decorated NiCo(CO3)(OH)2 composite could pave the way for an excellent electrode design for high-performance supercapacitors.

The Field-Laboratory for CO2 Storage 'CO2SINK

NASA Astrophysics Data System (ADS)

Würdemann, Hilke; Möller, Fabian; Kühn, Michael; Borm, Günter; Schilling, Frank R.

2010-05-01

The first European onshore geological CO2 storage project in a saline aquifer CO2SINK is designed as a field size experiment to better understand in situ storage processes and to test various monitoring techniques. This EU project is run by 18 partners from universities, research institutes and industry out of 9 European countries (www.co2sink.org). The CO2 is injected into Upper Triassic sandstones (Stuttgart Formation) of a double-anticline at a depth of 650 m. The Stuttgart Formation represents a flu vial environment comprised of sandstone channels and silty to muddy deposits. The anticline forms a classical multibarrier system: The first caprock is a playa type mudstone of the Weser and Arnstadt formations directly overlying the Stuttgart formation. Laboratory tests revealed permeabilities in a µDarcy-range. The second main caprock is a tertiary clay, the so-called Rupelton. To determine the maximum injection pressure modified leak-off tests (without fracturing the caprock) were performed resulting in values around 120 bar. Due to safety standards the pressure threshold is set to 82 bar until more experience on the reservoir behaviour is available. The sealing property of the secondary cap rock is well known from decades of natural gas storage operations at the testing site and was the basis for the permission to operate the CO2 storage by the mining authority. Undisturbed, initial reservoir conditions are 35 °C and 62 bar. The initial reservoir fluid is highly saline with about 235 g/l total dissolved solids primarily composed of sodium chloride with notable amounts of calcium chloride. The initial pH value is 6.6. Hydraulic tests as well as laboratory tests revealed a permeability between 50 and 100 mDarcy for the sand channels of the storage formation. Within twenty months of storage operation, about 30,000 t of CO2 have been injected. Spreading of the CO2 plume is monitored by a broad range of geophysical techniques. The injection well and the two

Photodissociation of CO2 and quenching of metastables

NASA Technical Reports Server (NTRS)

Slanger, T. G.

1978-01-01

Investigations in four different areas were carried out to further our understanding of the chemistry of the atmospheres of Mars and Venus. CO2 photodissociation quantum yields were determined in the 1300-1500 A spectral region by measuring both CO and oxygen atoms. The O(1S) quantum yield was determined for CO2 photodissociation in the 1060-1175 A spectral region. The measurement resolves the differences between two earlier experiments, and demonstrates that the O(1S) yield is unity throughout most of the measured region. The pathways for the quenching of O(1S) by N2O, CO2, H2O and NO were investigated and the source of the Venus nightglow, detected by Venera 9 and 10, was investigated. What appears to be a new O2 band system, was detected although the identity of the transition is not yet evident.

Measurement of Urban fluxes of CO2 and water

NASA Astrophysics Data System (ADS)

Grimmond, S.; Crawford, B.; Offerle, B.; Hom, J.

2006-05-01

Measurements of surface-atmosphere fluxes of carbon dioxide (FCO2) and latent heat in urban environments are rare even though cities are a major source of atmospheric CO2 and users of water. In this paper, an overview of urban FCO2 measurements will be presented to illustrate how and where such measurements are being conducted and emerging results to date. Most of these studies have been conducted over short periods of time; few studies have considered annual sources/sinks. More investigations have been conducted, and are planned, in European cities than elsewhere, most commonly in areas of medium density urban development. The most dense urban sites are significant net sources of carbon. However, in areas where there is large amounts of vegetation present, there is a net sink of carbon during the summertime. In the second part of the presentation, more detailed attention will be directed to an ongoing measurement program in Baltimore, MD (part of the Baltimore Ecosystem Study). Eddy covariance instrumentation mounted on a tall-tower at 41.2 m has continuously measured local-scale fluxes of carbon dioxide from a suburban environment since 2001. Several features make this particular study unique: 1) for an urban area, the study site is extensively vegetated, 2) the period of record (2001-2005) is among the longest available for urban FCO2 measurements, 3) both closed-path and open-path infrared gas analyzers are used for observations, and 4) several unique data quality control and gap-filling methods have been developed for use in an urban environment. Additionally, detailed surface datasets and GIS software are used to perform flux source area analysis. Results from Baltimore indicate that FCO2 is very dependent on source area land-cover characteristics, particularly the proportion of vegetated and built surfaces. Over the course of a year, the urban surface is a strong net source of CO2, though there is considerable inter-annual variability depending on

Absorption of the Martian regolith: Specific surface area and missing CO(sub 2)

NASA Technical Reports Server (NTRS)

Zent, A. P.; Fanale, F. P.; Postawko, S. E.

1987-01-01

For most estimates of available regolith and initial degassed CO(sub 2) inventories, it appears that any initial inventory must have been lost to space or incorporated into carbonates. Most estimates of the total available degassed CO(sub 2) inventory are only marginally sufficient to allow for a major early greenhouse effect. It is suggested that the requirements for greenhouse warming to produce old dessicated terrain would be greatly lessened if groundwater brines rather than rainfall were involved and if a higher internal gradient were involved to raise the water (brine) table, leading to more frequent sapping.

Low pCO2 Air-Polarized CO2 Concentrator Development

NASA Technical Reports Server (NTRS)

Schubert, Franz H.

1997-01-01

Life Systems completed a Ground-based Space Station Experiment Development Study Program which verifies through testing the performance and applicability of the electrochemical Air-Polarized Carbon Dioxide Concentrator (APC) process technology for space missions requiring low (i.e., less than 3 mm Hg) CO2 partial pressure (pCO2) in the cabin atmosphere. Required test hardware was developed and testing was accomplished at an approximate one-person capacity CO2 removal level. Initially, two five-cell electrochemical modules using flight-like 0.5 sq ft cell hardware were tested individually, following by their testing at the integrated APC system level. Testing verified previously projected performance and established a database for sizing of APC systems. A four person capacity APC system was sized and compared with four candidate CO2 removal systems. At its weight of 252 lb, a volume of 7 cu ft and a power consumption of 566 W while operating at 2.2 mm Hg pCO2, the APC was surpassed only by an Electrochemical Depolarized CO2 Concentrator (EDC) (operating with H2), when compared on a total equivalent basis.

Northern California CO 2 Reduction Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hymes, Edward

2010-06-16

C6 Resources LLC, a wholly owned subsidiary of Shell Oil Company, worked with the US Department of Energy (DOE) under a Cooperative Agreement to develop the Northern California CO 2 Reduction Project. The objective of the Project is to demonstrate the viability of using Carbon Capture and Sequestration (CCS) to reduce existing greenhouse gas emissions from industrial sources on a large-scale. The Project will capture more than 700,000 metric tonnes of CO 2 per year, which is currently being vented to the atmosphere from the Shell Martinez Refinery in Contra Costa County. The CO 2 will be compressed and dehydratedmore » at the refinery and then transported via pipeline to a sequestration site in a rural area in neighboring Solano County. The CO 2 will be sequestered into a deep saline formation (more than two miles underground) and will be monitored to assure secure, long-term containment. The pipeline will be designed to carry as much as 1,400,000 metric tonnes of CO 2 per year, so additional capacity will be available to accommodate CO 2 captured from other industrial sources. The Project is expected to begin operation in 2015. The Project has two distinct phases. The overall objective of Phase 1 was to develop a fully definitive design basis for the Project. The Cooperative Agreement with the DOE provided cost sharing for Phase 1 and the opportunity to apply for additional DOE cost sharing for Phase 2, comprising the design, construction and operation of the Project. Phase 1 has been completed. DOE co-funding is provided by the American Recovery and Reinvestment Act (ARRA) of 2009. As prescribed by ARRA, the Project will stimulate the local economy by creating manufacturing, transportation, construction, operations, and management jobs while addressing the need to reduce greenhouse gas emissions at an accelerated pace. The Project, which will also assist in meeting the CO 2 reduction requirements set forth in California's Climate Change law, presents a major

Flight prototype CO2 and humidity control system

NASA Technical Reports Server (NTRS)

Rudy, K. M.

1977-01-01

A regenerable CO2 and humidity control system is presently being developed for potential use on the space shuttle as an alternative to the baseline lithium hydroxide system. The system utilizes a sorbent material (designated HS-C) to adsorb CO2 and water vapor from the cabin atmosphere and desorb the CO2 and water vapor overboard when exposed to a space vacuum. Continuous operation is achieved by utilizing two beds which are alternately cycled between adsorption and desorption. A shuttle vehicle integration study showed that the HS-C system offers substantial weight advantages compared to the baseline shuttle orbiter expendable lithium hydroxide CO2 removal system for extended missions beyond the nominal design of four men for seven days. This study defined a system packaging envelope in the area presently occupied by the LiOH cartridges.

Local Area Co-Ordination: Strengthening Support for People with Learning Disabilities in Scotland

ERIC Educational Resources Information Center

Stalker, Kirsten Ogilvie; Malloch, Margaret; Barry, Monica Anne; Watson, June Ann

2008-01-01

This paper reports the findings of a study commissioned by the Scottish Executive which examined the introduction and implementation of local area co-ordination (LAC) in Scotland. A questionnaire about their posts was completed by 44 local area co-ordinators, interviews were conducted with 35 local area co-ordinators and 14 managers and case…

Riverine CO2 supersaturation and outgassing in a subtropical monsoonal mountainous area (Three Gorges Reservoir Region) of China

NASA Astrophysics Data System (ADS)

Li, Siyue; Ni, Maofei; Mao, Rong; Bush, Richard T.

2018-03-01

Rivers are an important source of CO2 to the atmosphere, however, mountainous rivers and streams with high emission rates are not well studied particularly in China. We report the first detailed investigation on monsoonal mountainous rivers in the Three Gorges Reservoir (TGR) region, with a focus on the riverine CO2 partial pressure (pCO2), CO2 degassing and their potential controls. The pCO2 levels ranged from 50 to 6019 μatm with averages of 1573 (SD. ±1060) in dry Autumn and 1276 (SD. ±1166) μatm in wet Summer seasons. 94% of samples were supersaturated with CO2 with respect to the atmospheric equilibrium (410 μatm). Monsoonal precipitation controlled pCO2 seasonality, with both the maximal and minimal levels occurring in the wet season, and showing the overall effects of dilution. Riverine pCO2 could be predicted better in the dry season using pH, DO% and DTP, whereas pH and DOC were better predictors in the wet season. We conclude that in-situ respiration of allochthonous organic carbon, rather than photosynthesis, resulted in negative relationships between pCO2 and DO and pH, and thus CO2 supersaturation. Photosynthetic primary production was effectively limited by rapid flow velocity and short residence time. The estimated water-to-air CO2 emission rate in the TGR rivers was 350 ± 319 in the Autumn and lower, yet more variable at 326 ± 439 mmol/m2/d in Summer. Our calculated CO2 areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO2 degassing, to address a global data gap for these environments.

When CO2 kills: effects of magmatic CO2 flux on belowground biota at Mammoth Mountain, CA

NASA Astrophysics Data System (ADS)

McFarland, J.; Waldrop, M. P.; Mangan, M.

2011-12-01

. This observation was concomitant with a relative increase in bacterial and archaeal contributions to microbial community structure. Root tip analyses among lodgepole seedlings recolonizing the kill zone area demonstrated a significant reduction in the overall diversity of fungal symbionts, as well as a distinct shift in fungal assemblages. In particular, within elevated CO2 areas, we observed a high infection level for the ascomycetous fungi, Wilcoxina spp., which appear particularly well-adapted for colonization in disturbed environments. It remains unclear whether dominance by ascomycetes among seedlings in elevated CO2 areas represents a coordinated shift orchestrated by the plant in response to physiological stress, or whether these fungi are simply more opportunistic than their basdiomycetous counterparts. Our results demonstrate the impact of large-scale disturbances on plant-microbial interactions and belowground processes in previously forested ecosystems.

Seasonal soil CO2 flux under big sagebrush (Artemisia tridentata Nutt.)

Treesearch

Michael C. Amacher; Cheryl L. Mackowiak

2011-01-01

Soil respiration is a major contributor to atmospheric CO2, but accurate landscape-scale estimates of soil CO2 flux for many ecosystems including shrublands have yet to be established. We began a project to measure, with high spatial and temporal resolution, soil CO2 flux in a stand (11 x 25 m area) of big sagebrush (Artemisia tridentata Nutt.) at the Logan, Utah,...

CO(2) partial pressure and calcite saturation in springs - useful data for identifying infiltration areas in mountainous environments.

PubMed

Hilberg, Sylke; Brandstätter, Jennifer; Glück, Daniel

2013-04-01

Mountainous regions such as the Central European Alps host considerable karstified or fractured groundwater bodies, which meet many of the demands concerning drinking water supply, hydropower or agriculture. Alpine hydrogeologists are required to describe the dynamics in fractured aquifers in order to assess potential impacts of human activities on water budget and quality. Delineation of catchment areas by means of stable isotopes and hydrochemical data is a well established method in alpine hydrogeology. To achieve reliable results, time series of (at least) one year and spatial and temporal close-meshed data are necessary. In reality, test sites in mountainous regions are often inaccessible due to the danger of avalanches in winter. The aim of our work was to assess a method based on the processes within the carbonic acid system to delineate infiltration areas by means of single datasets consisting of the main hydrochemical parameters of each spring. In three geologically different mountainous environments we managed to classify the investigated springs into four groups. (1) High PCO2 combined with slight super-saturation in calcite, indicating relatively low infiltration areas. (2) Low PCO2 near atmospheric conditions in combination with calcite saturation, which is indicative of relatively high infiltration areas and a fractured aquifer which is not covered by topsoil layers. (3) High PCO2 in combination with sub-saturation in calcite, representing a shallow aquifer with a significant influence of the topsoil layer. (4) The fourth group of waters is characterized by low PCO2 and sub-saturation in calcite, which is interpreted as evidence for a shallow aquifer without significant influence of any hard rock aquifer or topsoil layer. This study shows that CO2-partial pressure can be an ideal natural tracer to estimate the elevation of infiltration areas, especially in non-karstified fractured groundwater bodies.

Variability in soil CO2 efflux across distinct urban land cover types

NASA Astrophysics Data System (ADS)

Weissert, Lena F.; Salmond, Jennifer A.; Schwendenmann, Luitgard

2015-04-01

As a main source of greenhouse gases urban areas play an important role in the global carbon cycle. To assess the potential role of urban vegetation in mitigating carbon emissions we need information on the magnitude of biogenic CO2 emissions and its driving factors. We examined how urban land use types (urban forest, parklands, sportsfields) vary in their soil CO2 efflux. We measured soil CO2 efflux and its isotopic signature, soil temperature and soil moisture over a complete growing season in Auckland, New Zealand. Soil physical and chemical properties and vegetation characteristics were also measured. Mean soil CO2 efflux ranged from 4.15 to 12 μmol m-2 s-1. We did not find significant differences in soil CO2 efflux among land cover types due to high spatial variability in soil CO2 efflux among plots. Soil (soil carbon and nitrogen density, texture, soil carbon:nitrogen ratio) and vegetation characteristics (basal area, litter carbon density, grass biomass) were not significantly correlated with soil CO2 efflux. We found a distinct seasonal pattern with significantly higher soil CO2 efflux in autumn (Apr/May) and spring (Oct). In urban forests and sportsfields over 80% of the temporal variation was explained by soil temperature and soil water content. The δ13C signature of CO2 respired from parklands and sportsfields (-20 permil - -25 permil) were more positive compared to forest plots (-29 permil) indicating that parkland and sportsfields had a considerable proportion of C4 grasses. Despite the large intra-urban variability, our results compare to values reported from other, often climatically different cities, supporting the hypothesis of homogenization across urban areas as a result of human management practices.

Spectral nature of CO2 adsorption onto meteorites

USGS Publications Warehouse

Berlanga, Genesis; Hibbitts, Charles A; Takir, Driss; Dyar, Draby M; Elizabeth Sklute,

2016-01-01

Previous studies have identified carbon dioxide (CO2) on the surfaces of Jovian and Galilean satellites in regions of non-ice material that are too warm for CO2 ice to exist. CO2 ice would quickly sublimate if not retained by a less-volatile material. To ascertain what non-ice species may be responsible for stabilizing this CO2, we performed CO2 gas adsorption experiments on thirteen powdered CM, CI, and CV carbonaceous chondrite meteorites. Reflectance spectra of the ν3 feature associated with adsorbed CO2 near 4.27 μm were recorded. Results show that many meteorites adsorbed some amount of CO2, as evidenced by an absorption feature that was stable over several hours at ultra-high vacuum (UHV) and high vacuum, (1.0×10−8 and 1.0×10−7 Torr, respectively). Ivuna, the only CI chondrite studied, adsorbed significantly more CO2 than the others. We found that CO2 abundance did not vary with ‘water’ abundance, organics, or carbonates as inferred from the area of the 3-μm band, the 3.2-3.4 μm C-H feature, and the ∼3.8-μm band respectively, but did correlate with hydrous/anhydrous phyllosilicate ratios. Furthermore, we did not observe CO2 ice because the position of the CO2 feature was generally shifted 3-10 nm from that of the 4.27 μm absorption characteristic of ice. The strongest compositional relationship observed was a possible affinity of CO2 for total FeO abundance and complex clay minerals, which make up the bulk of the CI chondrite matrix. This finding implies that the most primitive refractory materials in the Solar System may also act as reservoirs of CO2, and possibly other volatiles, delivering them to parts of the Solar System where their ices would not be stable.

CO2CARE - Site Closure Assessment Research - Recent Results

NASA Astrophysics Data System (ADS)

Wipki, Mario; Liebscher, Axel; Kühn, Michael; Lüth, Stefan; Durucan, Sevket; Deflandre, Jean-Pierre; Wollenweber, Jens; Chadwick, Andy; Böhm, Gualtiero

2013-04-01

The EU project CO2CARE, which started in January 2011, supports the large scale demonstration of CCS technology by addressing requirements of operators and regulators face in terms of CO2 storage site abandonment. The CO2CARE consortium, consisting of 24 project partners from universities, research institutes, and the industry, investigate technologies and procedures for abandonment and post-closure safety, satisfying the regulatory requirements for the transfer of responsibility. Nine key injections sites in Europe, USA, Japan, and Australia, each with a specific (hydro) geological and environmental character, were selected for investigations. These sites can be divided into the CO2 storage types on-shore, off-shore, natural CO2 reservoir, depleted gas reservoirs, and saline aquifers. The project mainly focuses on three key areas: - well abandonment and long-term integrity; - reservoir management and prediction from closure to the long-term; - risk management methodologies for long-term safety. These key areas are in turn closely linked to the three high-level requirements of the EU Directive 2009/31/EC, Article 18 for CO2 storage which are: (i) absence of any detectable leakage, (ii) conformity of actual behaviour of the injected CO2 with the modeled behaviour, and (iii) the storage site is evolving towards a situation of long-term stability. The identification of criteria and the development of site abandonment procedures and technologies, which guarantee the fulfillment of the high-level requirements, are the major objectives in CO2CARE. These criteria have to be fulfilled prior to subsequent transfer of responsibility to the competent authorities, typically 20 or 30 years after site closure. Finally, the essential results of the different working groups in CO2CARE will feed into overall guidelines for regulatory compliance and "Best Practice" for site abandonment. Dissemination of the results will show policy makers and the general public how site abandonment

Laboratory Investigations of Physical State of CO2 Ice on Mars

NASA Astrophysics Data System (ADS)

Portyankina, G.; Merrison, J.; Iversen, J. J.; Yoldi, Z.; Hansen, C. J.; Aye, K.-M.; Pommeroll, A.

2016-09-01

We used Environmental Wind Tunnel to simulate CO2 ice condensation under the conditions of the martian polar areas. We find that under conditions usual for martian fall and winter, CO2 ice always deposits from atmosphere as a translucent slab.

Overlap corrections for emissivity calculations of H2O-CO2-CO-N2 mixtures

NASA Astrophysics Data System (ADS)

Alberti, Michael; Weber, Roman; Mancini, Marco

2018-01-01

Calculations of total gas emissivities of gas mixtures containing several radiatively active species require corrections for band overlapping. In this paper, we generate such overlap correction charts for H2O-CO2-N2, H2O-CO-N2, and CO2-CO-N2 mixtures. These charts are applicable in the 0.1-40 bar total pressure range and in the 500 K-2500 K temperature range. For H2O-CO2-N2 mixtures, differences between our charts and Hottel's graphs as well as models of Leckner and Modak are highlighted and analyzed.

Multi-scale observations of the variability of magmatic CO2 emissions, Mammoth Mountain, CA, USA

NASA Astrophysics Data System (ADS)

Lewicki, J. L.; Hilley, G. E.

2014-09-01

One of the primary indicators of volcanic unrest at Mammoth Mountain is diffuse emission of magmatic CO2, which can effectively track this unrest if its variability in space and time and relationship to near-surface meteorological and hydrologic phenomena versus those occurring at depth beneath the mountain are understood. In June-October 2013, we conducted accumulation chamber soil CO2 flux surveys and made half-hourly CO2 flux measurements with automated eddy covariance and accumulation chamber (auto-chamber) instrumentation at the largest area of diffuse CO2 degassing on Mammoth Mountain (Horseshoe Lake tree kill; HLTK). Estimated CO2 emission rates for HLTK based on 20 June, 30 July, and 24-25 October soil CO2 flux surveys were 165, 172, and 231 t d- 1, respectively. The average (June-October) CO2 emission rate estimated for this area was 123 t d- 1 based on an inversion of 4527 eddy covariance CO2 flux measurements and corresponding modeled source weight functions. Average daily eddy covariance and auto-chamber CO2 fluxes consistently declined over the four-month observation time. Wavelet analysis of auto-chamber CO2 flux and environmental parameter time series was used to evaluate the periodicity of, and local correlation between these variables in time-frequency space. Overall, CO2 emissions at HLTK were highly dynamic, displaying short-term (hourly to weekly) temporal variability related to meteorological and hydrologic changes, as well as long-term (monthly to multi-year) variations related to migration of CO2-rich magmatic fluids beneath the volcano. Accumulation chamber soil CO2 flux surveys were also conducted in the four additional areas of diffuse CO2 degassing on Mammoth Mountain in July-August 2013. Summing CO2 emission rates for all five areas yielded a total for the mountain of 311 t d- 1, which may suggest that emissions returned to 1998-2009 levels, following an increase from 2009 to 2011.

Multi-scale observations of the variability of magmatic CO2 emissions, Mammoth Mountain, CA, USA

USGS Publications Warehouse

Lewicki, Jennifer L.; Hilley, George E.

2014-01-01

One of the primary indicators of volcanic unrest at Mammoth Mountain is diffuse emission of magmatic CO2, which can effectively track this unrest if its variability in space and time and relationship to near-surface meteorological and hydrologic phenomena versus those occurring at depth beneath the mountain are understood. In June–October 2013, we conducted accumulation chamber soil CO2 flux surveys and made half-hourly CO2 flux measurements with automated eddy covariance and accumulation chamber (auto-chamber) instrumentation at the largest area of diffuse CO2 degassing on Mammoth Mountain (Horseshoe Lake tree kill; HLTK). Estimated CO2 emission rates for HLTK based on 20 June, 30 July, and 24–25 October soil CO2 flux surveys were 165, 172, and 231 t d− 1, respectively. The average (June–October) CO2 emission rate estimated for this area was 123 t d− 1 based on an inversion of 4527 eddy covariance CO2 flux measurements and corresponding modeled source weight functions. Average daily eddy covariance and auto-chamber CO2 fluxes consistently declined over the four-month observation time. Wavelet analysis of auto-chamber CO2 flux and environmental parameter time series was used to evaluate the periodicity of, and local correlation between these variables in time–frequency space. Overall, CO2 emissions at HLTK were highly dynamic, displaying short-term (hourly to weekly) temporal variability related to meteorological and hydrologic changes, as well as long-term (monthly to multi-year) variations related to migration of CO2-rich magmatic fluids beneath the volcano. Accumulation chamber soil CO2 flux surveys were also conducted in the four additional areas of diffuse CO2 degassing on Mammoth Mountain in July–August 2013. Summing CO2 emission rates for all five areas yielded a total for the mountain of 311 t d− 1, which may suggest that emissions returned to 1998–2009 levels, following an increase from 2009 to 2011.

Variation in Maternal Co-morbidities and Obstetric Interventions across Area-Level Socio-economic Status: A Cross-Sectional Study.

PubMed

Adhikari Dahal, Kamala; Premji, Shahirose; Patel, Alka B; Williamson, Tyler; Peng, Mingkai; Metcalfe, Amy

2017-07-01

Multiple studies indicate a significant association between area-level socio-economic status (SES) and adverse maternal health outcomes; however, the impact of area-level SES on maternal co-morbidities and obstetric interventions has not been examined. To examine the variation in maternal co-morbidities and obstetric interventions across area-level SES. This study used data from the Discharge Abstract Database that comprised birth data in Alberta between 2005-2007 (n = 120 285). Co-morbidities and obstetric interventions were identified using validated case-definitions. Material deprivation index was obtained for each dissemination area through linkage of hospitalisation and census data. Multilevel logistic regression was used to analyse the data adjusting for potential confounding variables. The prevalence of any co-morbidity varied across area-level SES. Drug abuse odds ratio (OR) 2.5 (95% confidence interval (CI) 1.8, 3.5), pre-existing diabetes OR 1.7 (95% CI 1.1, 2.6), and prolonged hospital stay OR 1.5 (95% CI 1.4, 1.6) were significantly more likely to occur in the most deprived areas compared to the least deprived areas. In contrast, caesarean delivery OR 0.9 (95% CI 0.8, 0.9) was less likely to occur in the most deprived areas compared to the least deprived areas. Area-level deprivation explained area-level variance of drug abuse, HIV, and other mental diseases only. Many co-morbidities and obstetric interventions vary at the area-level, but only some are associated with area-level SES, and few of them vary due to the area-level SES. This indicates that other area-level factors, in addition to area-level SES, need to be considered when investigating maternal health and use of health interventions. © 2017 John Wiley & Sons Ltd.

Charged Covalent Triazine Frameworks for CO2 Capture and Conversion.

PubMed

Buyukcakir, Onur; Je, Sang Hyun; Talapaneni, Siddulu Naidu; Kim, Daeok; Coskun, Ali

2017-03-01

The quest for the development of new porous materials addressing both CO 2 capture from various sources and its conversion into useful products is a very active research area and also critical in order to develop a more sustainable and environmentally-friendly society. Here, we present the first charged covalent triazine framework (cCTF) prepared by simply heating nitrile functionalized dicationic viologen derivatives under ionothermal reaction conditions using ZnCl 2 as both solvent and trimerization catalyst. It has been demonstrated that the surface area, pore volume/size of cCTFs can be simply controlled by varying the synthesis temperature and the ZnCl 2 content. Specifically, increasing the reaction temperature led to controlled increase in the mesopore content and facilitated the formation of hierarchical porosity, which is critical to ensure efficient mass transport within porous materials. The resulting cCTFs showed high specific surface areas up to 1247 m 2 g -1 , and high physicochemical stability. The incorporation of ionic functional moieties to porous organic polymers improved substantially their CO 2 affinity (up to 133 mg g -1 , at 1 bar and 273 K) and transformed them into hierarchically porous organocatalysts for CO 2 conversion. More importantly, the ionic nature of cCTFs, homogeneous charge distribution together with hierarchical porosity offered a perfect platform for the catalytic conversion of CO 2 into cyclic carbonates in the presence of epoxides through an atom economy reaction in high yields and exclusive product selectivity. These results clearly demonstrate the promising aspect of incorporation of charged units into the porous organic polymers for the development of highly efficient porous organocatalysts for CO 2 capture and fixation.

Detection of CO2 leakage by the surface-soil CO2-concentration monitoring (SCM) system in a small scale CO2 release test

NASA Astrophysics Data System (ADS)

Chae, Gitak; Yu, Soonyoung; Sung, Ki-Sung; Choi, Byoung-Young; Park, Jinyoung; Han, Raehee; Kim, Jeong-Chan; Park, Kwon Gyu

2015-04-01

Monitoring of CO2 release through the ground surface is essential to testify the safety of CO2 storage projects. We conducted a feasibility study of the multi-channel surface-soil CO2-concentration monitoring (SCM) system as a soil CO2 monitoring tool with a small scale injection. In the system, chambers are attached onto the ground surface, and NDIR sensors installed in each chamber detect CO2 in soil gas released through the soil surface. Before injection, the background CO2 concentrations were measured. They showed the distinct diurnal variation, and were positively related with relative humidity, but negatively with temperature. The negative relation of CO2 measurements with temperature and the low CO2 concentrations during the day imply that CO2 depends on respiration. The daily variation of CO2 concentrations was damped with precipitation, which can be explained by dissolution of CO2 and gas release out of pores through the ground surface with recharge. For the injection test, 4.2 kg of CO2 was injected 1 m below the ground for about 30 minutes. In result, CO2 concentrations increased in all five chambers, which were located less than 2.5 m of distance from an injection point. The Chamber 1, which is closest to the injection point, showed the largest increase of CO2 concentrations; while Chamber 2, 3, and 4 showed the peak which is 2 times higher than the average of background CO2. The CO2 concentrations increased back after decreasing from the peak around 4 hours after the injection ended in Chamber 2, 4, and 5, which indicated that CO2 concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data in Chamber 2 and 5, which had low increase rates in the CO2 injection test, were used for statistical analysis. The result shows that the coefficient of variation (CV) of CO2 measurements for 30 minutes is efficient to determine a leakage signal, with reflecting the abnormal change in CO2

Devices and methods to measure H2 and CO2 concentrations in gases released from soils and low temperature fumaroles in volcanic areas

NASA Astrophysics Data System (ADS)

di Martino, R. M. R.; Camarda, M.; Gurrieri, S.; Valenza, M.

2009-04-01

Hydrogen solubility and diffusion have a great relevance to change the redox state of magmas, usually expressed by oxygen fugacity. This influences many chemical and physical properties, such as oxidation state of multivalent elements, kind and abundance of minerals and gas species. These processes change the phase ratios into the volcanic system and so the magma movement capability toward the earth surface and the eruptive dynamics. In past studies several authors (Carapezza et al., 1980; Sato et al., 1982; Sato and McGee, 1985; Wakita et al., 1980) proposed the application of the fuel cells in order to measure reducing capacity of volcanic gases. Their found some clear correlations between variation peaks and volcanic activity but a few reducing capacity changes showed no correlation with it. In this study we characterize a fuel cell device designed to measure hydrogen concentration in a gas mixture. We present test results obtained in laboratory and in field trip, carried out to verify the major interferences of others reducing gas species, commonly present in volcanic emissions, in the measurement carried out with a hydrogen fuel cell sensor. Tests were performed at controlled temperature ad pressure conditions and at air saturated pressure vapour in the cell cathode. A new device to measure simultaneously hydrogen (H2) and carbon dioxide (CO2) concentrations in soil and in low temperature fumaroles in volcanic areas was proposed. The H2-detector is a hydrogen fuel cell, whereas CO2 is measured using an I.R. spectrometer. To build a continuous monitoring station of volcanic activity both sensors were put in a case together with a data logger. Our device has 0.2 mV ppm-1 sensitivity, accuracy of ± 5 ppm and about 10 ppm resolution whit respect to the hydrogen concentration. These instrumental characteristics were obtained applying a 500 ohm resistor to the external circuit that represents the best compromise between sensitivity, resolution, instrumental

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

NASA Astrophysics Data System (ADS)

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.

Occurrence of Volcanic CO2 by Groundwater Flow Systems in the Eifel Mountains, Germany

NASA Astrophysics Data System (ADS)

Weyer, K.; May, F.; Ellis, J. C.

2011-12-01

Weyer (2010) showed why and how discharge areas of regional groundwater flow systems are also discharge points of natural and stored CO2. As groundwater flow systems reach to great depth by penetrating aquitards and caprocks any successful design of on-shore geological carbon storage must regard the migration effects groundwater flow systems exert on stored CO2. Eventually all of the CO2 will be dissolved by groundwater and migrate to the discharge areas of these flow systems. By implication there will rarely be the anticipated permanent storage of CO2 in the subsurface. Instead the deep ground water flow will transport the dissolved CO2 into surface waters. A telling example of such a system is the Green River in Utah with its natural discharge points of volcanic CO2 and the artificial discharge point Crystal Geyser, a flowing abandoned well located at the bank of the Green River. The advantage of this situation is that there have been hydrogeological tools developed which allow the determination of the flow path of the groundwater flow systems and their approximate time scale to reach their groundwater discharge areas. These time spans may be as large as 50,000 to 100,000 years. In any case residence times of a thousand years and more would suffice in mitigating the atmospheric effect of CO2 discharge. The above concepts have so far not created much resonance in the scientific and practical world of geologic CO2 storage. Therefore the investigation of groundwater dynamics at areas with natural discharge of volcanic CO2 provides a test for the effect groundwater flow systems will exert on the geologic storage of CO2. The Eifel Mountains in Germany present such a natural laboratory as it contains over a hundred known Tertiary and Quaternary volcanoes. Its discharge points of water carrying CO2 are well-known as they have been used for generations for the production of carbonated mineral waters. For the western part of the Eifel-Mountains, May (2002) listed all

CO2 blood test

MedlinePlus

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

Evaluation of bias in lower and middle tropospheric GOSAT/TANSO-FTS TIR V1.0 CO2 data through comparisons with aircraft and NICAM-TM CO2 data

NASA Astrophysics Data System (ADS)

Saitoh, N.; Hatta, H.; Imasu, R.; Shiomi, K.; Kuze, A.; Niwa, Y.; Machida, T.; Sawa, Y.; Matsueda, H.

2016-12-01

Thermal and Near Infrared Sensor for Carbon Observation (TANSO)-Fourier Transform Spectrometer (FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) has been observing carbon dioxide (CO2) concentrations in several atmospheric layers in the thermal infrared (TIR) band since its launch on 23 January 2009. We have compared TANSO-FTS TIR Version 1 (V1) CO2 data from 2010 to 2012 and CO2 data obtained by the Continuous CO2 Measuring Equipment (CME) installed on several JAL aircraft in the framework of the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project to evaluate bias in the TIR CO2 data in the lower and middle troposphere. Here, we have regarded the CME data obtained during the ascent and descent flights over several airports as part of CO2 vertical profiles there. The comparisons showed that the TIR V1 CO2 data had a negative bias against the CME CO2 data; the magnitude of the bias varied depending on season and latitude. We have estimated bias correction values for the TIR V1 lower and middle tropospheric CO2 data in each latitude band from 40°S to 60°N in each season on the basis of the comparisons with the CME CO2 profiles in limited areas over airports, applied the bias correction values to the TIR V1 CO2 data, and evaluated the quality of the bias-corrected TIR CO2 data globally through comparisons with CO2 data taken from the Nonhydrostatic Icosahedral Atmospheric Model (NICAM)-based Transport Model (TM). The bias-corrected TIR CO2 data showed a better agreement with the NICAM-TM CO2 than the original TIR data, which suggests that the bias correction values estimated in the limited areas are basically applicable to global TIR CO2 data. We have compared XCO2 data calculated from both the original and bias-corrected TIR CO2 data with TANSO-FTS SWIR and NICAM-TM XCO2 data; both the TIR XCO2 data agreed with SWIR and NICAM-TM XCO2 data within 1% except over the Sahara desert and strong source and sink regions.

Heteroatom-doped nanoporous carbon derived from MOF-5 for CO2 capture

NASA Astrophysics Data System (ADS)

Ma, Xiancheng; Li, Liqing; Chen, Ruofei; Wang, Chunhao; Li, Hailong; Wang, Shaobin

2018-03-01

Four nanoporous carbons (MUCT) were prepared from metal-organic framework (MOF-5) template and additional carbon source (i.e. urea) by carbonization at different temperatures (600-900 °C). The results showed that specific surface area of four samples was obtained in the range from 1030 to 2307 m2 g-1. By changing the carbonization temperature it can finely tune the pore volume of the MUCT, which having a uniform pore size of around 4.0 nm. With an increasing carbonization temperature, the micropore surface area of MUCT samples varied slightly, but mesopore surface area increased obviously, which had little influence on carbon dioxide (CO2) adsorption capacity. The as-obtained sample MUC900 exhibited the superior CO2 capture capacity of 3.7 mmol g-1 at 0 °C (1 atm). First principle calculations were conducted on carbon models with various functional groups to distinguish heterogeneity and understand carbon surface chemistry for CO2 adsorption. The interaction between CO2 and N-containing functional groups is mainly weak Lewis acid-base interaction. On the other hand, the pyrrole and amine groups show exceptional hydrogen-bonding interaction. The hydroxyls promote the interaction between carbon dioxide and functional groups through hydrogen-bonding interactions and electrostatic potentials, thereby increasing CO2 capture of MUCT.

An ensemble approach to simulate CO2 emissions from natural fires

NASA Astrophysics Data System (ADS)

Eliseev, A. V.; Mokhov, I. I.; Chernokulsky, A. V.

2014-06-01

This paper presents ensemble simulations with the global climate model developed at the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM). These simulations are forced by historical reconstructions of concentrations of well-mixed greenhouse gases (CO2, CH4, and N2O), sulfate aerosols (both in the troposphere and stratosphere), extent of crops and pastures, and total solar irradiance for AD 850-2005 (hereafter all years are taken as being AD) and by the Representative Concentration Pathway (RCP) scenarios for the same forcing agents until the year 2300. Our model implements GlobFIRM (Global FIRe Model) as a scheme for calculating characteristics of natural fires. Comparing to the original GlobFIRM model, in our implementation, the scheme is extended by a module accounting for CO2 release from soil during fires. The novel approach of our paper is to simulate natural fires in an ensemble fashion. Different ensemble members in the present paper are constructed by varying the values of parameters of the natural fires module. These members are constrained by the GFED-3.1 data set for the burnt area and CO2 release from fires and further subjected to Bayesian averaging. Our simulations are the first coupled model assessment of future changes in gross characteristics of natural fires. In our model, the present-day (1998-2011) global area burnt due to natural fires is (2.1 ± 0.4) × 106 km2 yr-1 (ensemble mean and intra-ensemble standard deviation are presented), and the respective CO2 emissions to the atmosphere are (1.4 ± 0.2) Pg C yr-1. The latter value is in agreement with the corresponding GFED estimates. The area burnt by natural fires is generally larger than the GFED estimates except in boreal Eurasia, where it is realistic, and in Australia, where it is smaller than these estimates. Regionally, the modelled CO2 emissions are larger (smaller) than the GFED estimates in Europe (in the tropics and north-eastern Eurasia). From

New Directions for the Photocatalytic Reduction of CO2: Supramolecular, scCO2 or Biphasic Ionic Liquid-scCO2 Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grills, D.C.; Fujita, E.

2010-09-02

There is an urgent need for the discovery of carbon-neutral sources of energy to avoid the consequences of global warming caused by ever-increasing atmospheric CO{sub 2} levels. An attractive possibility is to use CO{sub 2} captured from industrial emissions as a feedstock for the production of useful fuels and precursors such as carbon monoxide and methanol. An active field of research to achieve this goal is the development of catalysts capable of harnessing solar energy for use in artificial photosynthetic processes for CO{sub 2} reduction. Transition-metal complexes are excellent candidates, and it has already been shown that they can bemore » used to reduce CO{sub 2} with high quantum efficiency. However, they generally suffer from poor visible light absorption, short catalyst lifetimes, and poor reaction rates. In this Perspective, the field of photocatalytic CO{sub 2} reduction is introduced, and recent developments that seek to improve the efficiency of such catalytic processes are highlighted, especially CO{sub 2} reduction with supramolecules and molecular systems in supercritical CO{sub 2} (scCO{sub 2}) or biphasic ionic liquid-scCO{sub 2} mixtures.« less

Geological factors affecting CO2 plume distribution

USGS Publications Warehouse

Frailey, S.M.; Leetaru, H.

2009-01-01

Understanding the lateral extent of a CO2 plume has important implications with regards to buying/leasing pore volume rights, defining the area of review for an injection permit, determining the extent of an MMV plan, and managing basin-scale sequestration from multiple injection sites. The vertical and lateral distribution of CO2 has implications with regards to estimating CO2 storage volume at a specific site and the pore pressure below the caprock. Geologic and flow characteristics such as effective permeability and porosity, capillary pressure, lateral and vertical permeability anisotropy, geologic structure, and thickness all influence and affect the plume distribution to varying degrees. Depending on the variations in these parameters one may dominate the shape and size of the plume. Additionally, these parameters do not necessarily act independently. A comparison of viscous and gravity forces will determine the degree of vertical and lateral flow. However, this is dependent on formation thickness. For example in a thick zone with injection near the base, the CO2 moves radially from the well but will slow at greater radii and vertical movement will dominate. Generally the CO2 plume will not appreciably move laterally until the caprock or a relatively low permeability interval is contacted by the CO2. Conversely, in a relatively thin zone with the injection interval over nearly the entire zone, near the wellbore the CO2 will be distributed over the entire vertical component and will move laterally much further with minimal vertical movement. Assuming no geologic structure, injecting into a thin zone or into a thick zone immediately under a caprock will result in a larger plume size. With a geologic structure such as an anticline, CO2 plume size may be restricted and injection immediately below the caprock may have less lateral plume growth because the structure will induce downward vertical movement of the CO2 until the outer edge of the plume reaches a spill

MgO-based adsorbents for CO2 adsorption: Influence of structural and textural properties on the CO2 adsorption performance.

PubMed

Elvira, Gutiérrez-Bonilla; Francisco, Granados-Correa; Víctor, Sánchez-Mendieta; Alberto, Morales-Luckie Raúl

2017-07-01

A series of MgO-based adsorbents were prepared through solution-combustion synthesis and ball-milling process. The prepared MgO-based powders were characterized using X-ray diffraction, scanning electron microscopy, N 2 physisorption measurements, and employed as potential adsorbents for CO 2 adsorption. The influence of structural and textural properties of these adsorbents over the CO 2 adsorption behaviour was also investigated. The results showed that MgO-based products prepared by solution-combustion and ball-milling processes, were highly porous, fluffy, nanocrystalline structures in nature, which are unique physico-chemical properties that significantly contribute to enhance their CO 2 adsorption. It was found that the MgO synthesized by solution combustion process, using a molar ratio of urea to magnesium nitrate (2:1), and treated by ball-milling during 2.5hr (MgO-BM2.5h), exhibited the maximum CO 2 adsorption capacity of 1.611mmol/g at 25°C and 1atm, mainly via chemisorption. The CO 2 adsorption behaviour on the MgO-based adsorbents was correlated to their improved specific surface area, total pore volume, pore size distribution and crystallinity. The reusability of synthesized MgO-BM2.5h was confirmed by five consecutive CO 2 adsorption-desorption times, without any significant loss of performance, that supports the potential of MgO-based adsorbent. The results confirmed that the special features of MgO prepared by solution-combustion and treated by ball-milling during 2.5hr are favorable to be used as effective MgO-based adsorbent in post-combustion CO 2 capture technologies. Copyright © 2016. Published by Elsevier B.V.

CO2-Switchable Membranes Prepared by Immobilization of CO2-Breathing Microgels.

PubMed

Zhang, Qi; Wang, Zhenwu; Lei, Lei; Tang, Jun; Wang, Jianli; Zhu, Shiping

2017-12-20

Herein, we report the development of a novel CO 2 -responsive membrane system through immobilization of CO 2 -responsive microgels into commercially available microfiltration membranes using a method of dynamic adsorption. The microgels, prepared from soap-free emulsion polymerization of CO 2 -responsive monomer 2-(diethylamino)ethyl methacrylate (DEA), can be reversibly expanded and shrunken upon CO 2 /N 2 alternation. When incorporated into the membranes, this switching behavior was preserved and further led to transformation between microfiltration and ultrafiltration membranes, as indicated from the dramatic changes on water flux and BSA rejection results. This CO 2 -regulated performance switching of membranes was caused by the changes of water transportation channel, as revealed from the dynamic water contact angle tests and SEM observation. This work represents a simple yet versatile strategy for making CO 2 -responsive membranes.

High-Density Nanosharp Microstructures Enable Efficient CO2 Electroreduction.

PubMed

Saberi Safaei, Tina; Mepham, Adam; Zheng, Xueli; Pang, Yuanjie; Dinh, Cao-Thang; Liu, Min; Sinton, David; Kelley, Shana O; Sargent, Edward H

2016-11-09

Conversion of CO 2 to CO powered by renewable electricity not only reduces CO 2 pollution but also is a means to store renewable energy via chemical production of fuels from CO. However, the kinetics of this reaction are slow due its large energetic barrier. We have recently reported CO 2 reduction that is considerably enhanced via local electric field concentration at the tips of sharp gold nanostructures. The high local electric field enhances CO 2 concentration at the catalytic active sites, lowering the activation barrier. Here we engineer the nucleation and growth of next-generation Au nanostructures. The electroplating overpotential was manipulated to generate an appreciably increased density of honed nanoneedles. Using this approach, we report the first application of sequential electrodeposition to increase the density of sharp tips in CO 2 electroreduction. Selective regions of the primary nanoneedles are passivated using a thiol SAM (self-assembled monolayer), and then growth is concentrated atop the uncovered high-energy planes, providing new nucleation sites that ultimately lead to an increase in the density of the nanosharp structures. The two-step process leads to a new record in CO 2 to CO reduction, with a geometric current density of 38 mA/cm 2 at -0.4 V (vs reversible hydrogen electrode), and a 15-fold improvement over the best prior reports of electrochemical surface area (ECSA) normalized current density.

Synthetic CO2-fixation enzyme cascades immobilized on self-assembled nanostructures that enhance CO2/O2 selectivity of RubisCO.

PubMed

Satagopan, Sriram; Sun, Yuan; Parquette, Jon R; Tabita, F Robert

2017-01-01

With increasing concerns over global warming and depletion of fossil-fuel reserves, it is attractive to develop innovative strategies to assimilate CO 2 , a greenhouse gas, into usable organic carbon. Cell-free systems can be designed to operate as catalytic platforms with enzymes that offer exceptional selectivity and efficiency, without the need to support ancillary reactions of metabolic pathways operating in intact cells. Such systems are yet to be exploited for applications involving CO 2 utilization and subsequent conversion to valuable products, including biofuels. The Calvin-Benson-Bassham (CBB) cycle and the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) play a pivotal role in global CO 2 fixation. We hereby demonstrate the co-assembly of two RubisCO-associated multienzyme cascades with self-assembled synthetic amphiphilic peptide nanostructures. The immobilized enzyme cascades sequentially convert either ribose-5-phosphate (R-5-P) or glucose, a simpler substrate, to ribulose 1,5-bisphosphate (RuBP), the acceptor for incoming CO 2 in the carboxylation reaction catalyzed by RubisCO. Protection from proteolytic degradation was observed in nanostructures associated with the small dimeric form of RubisCO and ancillary enzymes. Furthermore, nanostructures associated with a larger variant of RubisCO resulted in a significant enhancement of the enzyme's selectivity towards CO 2 , without adversely affecting the catalytic activity. The ability to assemble a cascade of enzymes for CO 2 capture using self-assembling nanostructure scaffolds with functional enhancements show promise for potentially engineering entire pathways (with RubisCO or other CO 2 -fixing enzymes) to redirect carbon from industrial effluents into useful bioproducts.

Biocatalytic CO2 sequestration based on shell regeneration

NASA Astrophysics Data System (ADS)

Lee, S.

2012-04-01

Carbon dioxide, CO2, is one of the green gases, being uniformly distributed over the earth's surface. Recently, a variety of methods exists or has been proposed for pre- or post-emission capture and sequestration of CO2. However, CCS (carbon capture & storage) do not quarntee permanent treatment of CO2 and could ingenerate environment risks. Some organisms convert CO2 into exoskeleton (e.g., mollusks) or energy sources (e.g., plants) during metabolism under atmospheric conditions. One of representative biomaterials in ocean is bivalve shell to be composed of CaCO3. Calcium carbonate is not only abundant material in the world but also thermodynamically stable mineral in the capture of CO2. Bivalve has produced CaCO3 under seawater condition, in other word, near atmospheric conditions (1 atm. and around 20-25 oC). At the inorganic point, the synthesis of CaCO3 is as followed. Ca2+ + CO32- -> CaCO3 The bivalve shell plays an important role to protect bivalve's internal organs from prodetor. What will be happened if the shell is damaged and a hole is made? Bivalve must cover the hole to prevent the oxidation of internal organs as fast as possible. From in vitro crystallization test of a notched shell, rapid CaCO3 production was identified at the damaged area. The biocatalyst related to shell regeneration was purified and named as SPSR (Soluble Protein related to Shell Regeneration) that is obtained from the oyster, Crassostrea gigas. And in vitro CaCO3 crystallization test was used to calculate the crystal growth rate of SPSR on CaCO3 crystallization. The characteristics of SPRR are discussed at the point of CO2 hydration and rapid CaCO3 synthesis. To develop the bioinspired process based on shell regeneration concept, the analysis of protein structure has been studied and the immobilization has been carried out for easy recovery of SPSR.

Wollastonite Carbonation in Water-Bearing Supercritical CO2: Effects of Particle Size.

PubMed

Min, Yujia; Li, Qingyun; Voltolini, Marco; Kneafsey, Timothy; Jun, Young-Shin

2017-11-07

The performance of geologic CO 2 sequestration (GCS) can be affected by CO 2 mineralization and changes in the permeability of geologic formations resulting from interactions between water-bearing supercritical CO 2 (scCO 2 ) and silicates in reservoir rocks. However, without an understanding of the size effects, the findings in previous studies using nanometer- or micrometer-size particles cannot be applied to the bulk rock in field sites. In this study, we report the effects of particle sizes on the carbonation of wollastonite (CaSiO 3 ) at 60 °C and 100 bar in water-bearing scCO 2 . After normalization by the surface area, the thickness of the reacted wollastonite layer on the surfaces was independent of particle sizes. After 20 h, the reaction was not controlled by the kinetics of surface reactions but by the diffusion of water-bearing scCO 2 across the product layer on wollastonite surfaces. Among the products of reaction, amorphous silica, rather than calcite, covered the wollastonite surface and acted as a diffusion barrier to water-bearing scCO 2 . The product layer was not highly porous, with a specific surface area 10 times smaller than that of the altered amorphous silica formed at the wollastonite surface in aqueous solution. These findings can help us evaluate the impacts of mineral carbonation in water-bearing scCO 2 .

Studies on redox H 2-CO 2 cycle on CoCr xFe 2- xO 4

NASA Astrophysics Data System (ADS)

Ma, Ling Juan; Chen, Lin Shen; Chen, Song Ying

2009-01-01

Completely reduced CoCr xFe 2-xO 4 can be used to decompose CO 2. It was found that for pure CoFe 2O 4 there is no FeO formation in the first step while there is formation in the second step. For CoCr 0.08Fe 2-0.08O 4, there is no FeO formed in all the oxidation process, because of effect of Cr 3+. Pure CoFe 2O 4 was destroyed at the first reaction cycle of H 2 reduction and CO 2 oxidation, while doped Cr 3+ spinel CoCr 0.08Fe 1.92O 4 showed good stability. The results from H 2-TG, CO 2-TG and XRD show that the addition of Cr 3+ to CoFe 2O 4 can inhibit the increasing of crystallite size and the sintering of alloy. Most importantly, the CoCr 0.08Fe 1.92O 4 can be used to decompose CO 2 repeatedly, implying that it is a potential catalyst for dealing with the CO 2 as a 'green house effect' gas.

Does Silicate Weathering of Loess Affect Atmospheric CO2?

NASA Astrophysics Data System (ADS)

Anderson, S. P.

2002-12-01

Weathering of glacial loess may be a significant, yet unrecognized, component of the carbon cycle. Glaciers produce fine-grained sediment, exposing vast amounts of mineral surface area to weathering processes, yet silicate mineral weathering rates at glacier beds and of glacial till are not high. Thus, despite the tremendous potential for glaciers to influence global weathering rates and atmospheric CO2 levels, this effect has not been demonstrated. Loess, comprised of silt-clay sizes, may be the key glacial deposit in which silicate weathering rates are high. Loess is transported by wind off braid plains of rivers, and deposited broadly (order 100 km from the source) in vegetated areas. Both the fine grain size, and hence large mineral surface area, and presence of vegetation should render loess deposits highly susceptible to silicate weathering. These deposits effectively extend the geochemical impact of glaciation in time and space, and bring rock flour into conditions conducive to chemical weathering. A simple 1-d model of silicate weathering fluxes from a soil profile demonstrates the potential of loess deposition to enhance CO2 consumption. At each time step, computed mineral dissolution (using anorthite and field-based rate constants) modifies the size of mineral grains within the soil. In the case of a stable soil surface, this results in a gradual decline in weathering fluxes and CO2 consumption through time, as finer grain sizes dissolve away. Computed weathering fluxes for a typical loess, with an initial mean grain size of 25 μm, are an order of magnitude greater than fluxes from a non-loess soil that differs only in having a mean grain size of 320 μm. High weathering fluxes are maintained through time if loess is continually deposited. Deposition rates as low as 0.01 mm/yr (one loess grain thickness per year) can lead to a doubling of CO2 consumption rates within 5 ka. These results suggest that even modest loess deposition rates can significantly

Hybrid Membrane/Absorption Process for Post-combustion CO2 Capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Shiguang; Shou, S.; Pyrzynski, Travis

2013-12-31

This report summarizes scientific/technical progress made for bench-scale membrane contactor technology for post-combustion CO2 capture from DOE Contract No. DE-FE-0004787. Budget Period 1 (BP1) membrane absorber, Budget Period 2 (BP2) membrane desorber and Budget Period 3 (BP3) integrated system and field testing studies have been completed successfully and met or exceeded the technical targets (≥ 90% CO2 removal and CO2 purity of 97% in one membrane stage). Significant breakthroughs are summarized below: BP1 research: The feasibility of utilizing the poly (ether ether ketone), PEEK, based hollow fiber contractor (HFC) in combination with chemical solvents to separate and capture at leastmore » 90% of the CO2 from simulated flue gases has been successfully established. Excellent progress has been made as we have achieved the BP1 goal: ≥ 1,000 membrane intrinsic CO2 permeance, ≥ 90% CO2 removal in one stage, ≤ 2 psi gas side pressure drop, and ≥ 1 (sec)-1 mass transfer coefficient. Initial test results also show that the CO2 capture performance, using activated Methyl Diethanol Amine (aMDEA) solvent, was not affected by flue gas contaminants O2 (~3%), NO2 (66 ppmv), and SO2 (145 ppmv). BP2 research: The feasibility of utilizing the PEEK HFC for CO2-loaded solvent regeneration has been successfully established High CO2 stripping flux, one order of magnitude higher than CO2 absorption flux, have been achieved. Refined economic evaluation based on BP1 membrane absorber and BP2 membrane desorber laboratory test data indicate that the CO2 capture costs are 36% lower than DOE’s benchmark amine absorption technology. BP3 research: A bench-scale system utilizing a membrane absorber and desorber was integrated into a continuous CO2 capture process using contactors containing 10 to 20 ft2 of membrane area. The integrated process operation was stable through a 100-hour laboratory test, utilizing a simulated flue gas stream. Greater than 90% CO2 capture combined

Microwave spectroscopy of the seeded binary and ternary clusters CO-(pH{sub 2}){sub 2}, CO-pH{sub 2}-He, CO-HD, and CO-(oD{sub 2}){sub N=1,2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raston, Paul L., E-mail: paul.raston@adelaide.edu.au; Jäger, Wolfgang

We report the Fourier transform microwave spectra of the a-type J = 1-0 transitions of the binary and ternary CO-(pH{sub 2}){sub 2}, CO-pH{sub 2}-He, CO-HD, and CO-(oD{sub 2}){sub N=1,2} clusters. In addition to the normal isotopologue of CO for all clusters, we observed the transitions of the minor isotopologues, {sup 13}C{sup 16}O, {sup 12}C{sup 18}O, and {sup 13}C{sup 18}O, for CO-(pH{sub 2}){sub 2} and CO-pH{sub 2}-He. All transitions lie within 335 MHz of the experimentally or theoretically predicted values. In comparison to previously reported infrared spectra [Moroni et al., J. Chem. Phys. 122, 094314 (2005)], we are able to tentativelymore » determine the vibrational shift for CO-pH{sub 2}-He, in addition to its b-type J = 1-0 transition frequency. The a-type frequency of CO-pH{sub 2}-He is similar to that of CO-He{sub 2} [Surin et al., Phys. Rev. Lett. 101, 233401 (2008)], suggesting that the pH{sub 2} molecule has a strong localizing effect on the He density. Perturbation theory analysis of CO-oD{sub 2} reveals that it is approximately T-shaped, with an anisotropy of the intermolecular potential amounting to ∼9 cm{sup −1}.« less

Hierarchical Co(OH)2 nanostructures/glassy carbon electrode derived from Co(BTC) metal-organic frameworks for glucose sensing

NASA Astrophysics Data System (ADS)

He, Juan; Lu, Xingping; Yu, Jie; Wang, Li; Song, Yonghai

2016-07-01

A novel Co(OH)2/glassy carbon electrode (GCE) has been fabricated via metal-organic framework (MOF)-directed method. In the strategy, the Co(BTC, 1,3,5-benzentricarboxylic acid) MOFs/GCE was firstly prepared by alternately immersing GCE in Co2+ and BTC solution based on a layer-by-layer method. And then, the Co(OH)2 with hierarchical flake nanostructure/GCE was constructed by immersing Co(BTC) MOFs/GCE into 0.1 M NaOH solution at room temperature. Such strategy improves the distribution of hierarchical Co(OH)2 nanostructures on electrode surface greatly, enhances the stability of nanomaterials on the electrode surface, and increases the use efficiency of the Co(OH)2 nanostructures. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and Raman spectra were used to characterize the Co(BTC) MOFs/GCE and Co(OH)2/GCE. Based on the hierarchical Co(OH)2 nanostructures/GCE, a novel and sensitive nonenzymatic glucose sensor was developed. The good performance of the resulted sensor toward the detection of glucose was ascribed to hierarchical flake nanostructures, good mechanical stability, excellent distribution, and large specific surface area of Co(OH)2 nanostructures. The proposed preparation method is simple, efficient, and cheap .

Fate of terrestrial organic carbon and associated CO2 and CO emissions from two Southeast Asian estuaries

NASA Astrophysics Data System (ADS)

Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Mujahid, A.; Bange, H. W.; Notholt, J.

2016-02-01

Southeast Asian rivers convey large amounts of organic carbon, but little is known about the fate of this terrestrial material in estuaries. Although Southeast Asia is, by area, considered a hotspot of estuarine carbon dioxide (CO2) emissions, studies in this region are very scarce. We measured dissolved and particulate organic carbon, as well as CO2 partial pressures and carbon monoxide (CO) concentrations in two tropical estuaries in Sarawak, Malaysia, whose coastal area is covered by carbon-rich peatlands. We surveyed the estuaries of the rivers Lupar and Saribas during the wet and dry season, respectively. Carbon-to-nitrogen ratios suggest that dissolved organic matter (DOM) is largely of terrestrial origin. We found evidence that a large fraction of this carbon is respired. The median pCO2 in the estuaries ranged between 640 and 5065 µatm with little seasonal variation. CO2 fluxes were determined with a floating chamber and estimated to amount to 14-268 mol m-2 yr-1, which is high compared to other studies from tropical and subtropical sites. Estimates derived from a merely wind-driven turbulent diffusivity model were considerably lower, indicating that these models might be inappropriate in estuaries, where tidal currents and river discharge make an important contribution to the turbulence driving water-air gas exchange. Although an observed diurnal variability of CO concentrations suggested that CO was photochemically produced, the overall concentrations and fluxes were relatively moderate (0.4-1.3 nmol L-1 and 0.7-1.8 mmol m-2 yr-1) if compared to published data for oceanic or upwelling systems. We attributed this to the large amounts of suspended matter (4-5004 mg L-1), limiting the light penetration depth and thereby inhibiting CO photoproduction. We concluded that estuaries in this region function as an efficient filter for terrestrial organic carbon and release large amounts of CO2 to the atmosphere. The Lupar and Saribas rivers deliver 0.3 ± 0.2 Tg C

Effect of heterogeneousatmospheric CO2 on simulated global carbon budget

USGS Publications Warehouse

Zhang, Zhen; Jiang, Hong; Liu, Jinxun; Ju, Weimin; Zhang, Xiuying

2013-01-01

The effects of rising atmospheric carbon dioxide (CO2) on terrestrial carbon (C) sequestration have been a key focus in global change studies. As anthropological CO2 emissions substantially increase, the spatial variability of atmospheric CO2 should be considered to reduce the potential bias on C source and sink estimations. In this study, the global spatial–temporal patterns of near surface CO2 concentrations for the period 2003-2009 were established using the SCIAMACHY satellite observations and the GLOBALVIEW-CO2 field observations. With this CO2 data and the Integrated Biosphere Simulator (IBIS), our estimation of the global mean annual NPP and NEP was 0.5% and 7% respectively which differs from the traditional C sequestration assessments. The Amazon, Southeast Asia, and Tropical Africa showed higher C sequestration than the traditional assessment, and the rest of the areas around the world showed slightly lower C sequestration than the traditional assessment. We find that the variability of NEP is less intense under heterogeneous CO2 pattern on a global scale. Further studies of the cause of CO2 variation and the interactions between natural and anthropogenic processes of C sequestration are needed.

One-dimensional CuIn alloy nanowires as a robust and efficient electrocatalyst for selective CO2-to-CO conversion

NASA Astrophysics Data System (ADS)

Jang, Youn Jeong; Lee, Jaehyuk; Kim, Ju Hun; Lee, Byeong Jun; Lee, Jae Sung

2018-02-01

Electrical anodization of Cu foil produces one-dimensional Cu nanowires of high surface areas, which turns to CuIn alloy nanowires by indium electrodeposition replacing edge site Cu atoms. An electrochemical pre-activation forms a highly conformal amorphous In(OH)3 overlayer with oxygen vacancy on the CuIn alloy that facilitates CO2 adsorption to promote selective CO formation suppressing competing H2 adsorption. Thus the activated CuIn alloy nanowires catalyse electrochemical CO2 conversion to CO with high CO selectivity (>68.2%) and high current density (ca. -3.9 mAcm-2) at -0.6 VRHE, which represents the higher partial CO current density (ca. -2.66 mAcm-2) than that of previously reported CuIn alloy powders without nanostructuring. The performance remains stable for more than 15 h without significant degradation.

Comparison of carbohydrate sources in yeast-fermentation CO2 generators for mosquito surveillance

USDA-ARS?s Scientific Manuscript database

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source, such as the natural production of CO2 from yeast fermentation of several carbohydrate sources. In this study, we document the differences in mosquito and n...

Aridity under conditions of increased CO2

NASA Astrophysics Data System (ADS)

Greve, Peter; Roderick, Micheal L.; Seneviratne, Sonia I.

2016-04-01

A string of recent of studies led to the wide-held assumption that aridity will increase under conditions of increasing atmospheric CO2 concentrations and associated global warming. Such results generally build upon analyses of changes in the 'aridity index' (the ratio of potential evaporation to precipitation) and can be described as a direct thermodynamic effect on atmospheric water demand due to increasing temperatures. However, there is widespread evidence that contradicts the 'warmer is more arid' interpretation, leading to the 'global aridity paradox' (Roderick et al. 2015, WRR). Here we provide a comprehensive assessment of modeled changes in a broad set of dryness metrics (primarily based on a range of measures of water availability) over a large range of realistic atmospheric CO2 concentrations. We use an ensemble of simulations from of state-of-the-art climate models to analyse both equilibrium climate experiments and transient historical simulations and future projections. Our results show that dryness is, under conditions of increasing atmospheric CO2 concentrations and related global warming, generally decreasing at global scales. At regional scales we do, however, identify areas that undergo changes towards drier conditions, located primarily in subtropical climate regions and the Amazon Basin. Nonetheless, the majority of regions, especially in tropical and mid- to northern high latitudes areas, display wetting conditions in a warming world. Our results contradict previous findings and highlight the need to comprehensively assess all aspects of changes in hydroclimatological conditions at the land surface. Roderick, M. L., P. Greve, and G. D. Farquhar (2015), On the assessment of aridity with changes in atmospheric CO2, Water Resour. Res., 51, 5450-5463

Amine–mixed oxide hybrid materials for carbon dioxide adsorption from CO2/H2 mixture

NASA Astrophysics Data System (ADS)

Ravi, Navin; Aishah Anuar, Siti; Yusuf, Nur Yusra Mt; Isahak, Wan Nor Roslam Wan; Shahbudin Masdar, Mohd

2018-05-01

Bio-hydrogen mainly contains hydrogen and high level of carbon dioxide (CO2). High concentration of CO2 lead to a limitation especially in fuel cell application. In this study, the amine-mixed oxide hybrid materials for CO2 separation from bio-hydrogen model (50% CO2:50% H2) have been studied. Fourier-transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) characterizations showed that the amine–mixed oxide hybrid materials successfully adsorbed CO2 physically with no chemical adsorption evidence. The dry gas of CO2/H2 mixture adsorbed physically on amine–CuO–MgO hybrid material. No carbonates were detected after several times of adsorption, which indicated the good recyclability of adsorbents. The adsorbent system of diethanolamine (DEA)/15% CuO–75% MgO showed the highest CO2 adsorption capacity of 21.2 wt% due to the presence of polar substance on MgO surface, which can adsorb CO2 at ambient condition. The alcohol group of DEA can enhance the CO2 solubility on the adsorbent surface. In the 20% CuO–50% MgO adsorbent system, DEA as amine type showed a high CO2 adsorption of 19.4 wt%. The 10% amine loading system showed that the DEA adsorption system provided high CO2 adsorption. The BET analysis confirmed that a high amine loading contributed to the decrease in CO2 adsorption due to the low surface area of the adsorbent system.

Cellular Immune Responses to Live Attenuated Japanese Encephalitis (JE) Vaccine SA14-14-2 in Adults in a JE/Dengue Co-Endemic Area.

PubMed

Turtle, Lance; Tatullo, Filippo; Bali, Tanushka; Ravi, Vasanthapuram; Soni, Mohammed; Chan, Sajesh; Chib, Savita; Venkataswamy, Manjunatha M; Fadnis, Prachi; Yaïch, Mansour; Fernandez, Stefan; Klenerman, Paul; Satchidanandam, Vijaya; Solomon, Tom

2017-01-01

Japanese encephalitis (JE) virus (JEV) causes severe epidemic encephalitis across Asia, for which the live attenuated vaccine SA14-14-2 is being used increasingly. JEV is a flavivirus, and is closely related to dengue virus (DENV), which is co-endemic in many parts of Asia, with clinically relevant interactions. There is no information on the human T cell response to SA14-14-2, or whether responses to SA14-14-2 cross-react with DENV. We used live attenuated JE vaccine SA14-14-2 as a model for studying T cell responses to JEV infection in adults, and to determine whether these T cell responses are cross-reactive with DENV, and other flaviviruses. We conducted a single arm, open label clinical trial (registration: clinicaltrials.gov NCT01656200) to study T cell responses to SA14-14-2 in adults in South India, an area endemic for JE and dengue. Ten out of 16 (62.5%) participants seroconverted to JEV SA14-14-2, and geometric mean neutralising antibody (NAb) titre was 18.5. Proliferation responses were commonly present before vaccination in the absence of NAb, indicating a likely high degree of previous flavivirus exposure. Thirteen of 15 (87%) participants made T cell interferon-gamma (IFNγ) responses against JEV proteins. In four subjects tested, at least some T cell epitopes mapped cross-reacted with DENV and other flaviviruses. JEV SA14-14-2 was more immunogenic for T cell IFNγ than for NAb in adults in this JE/DENV co-endemic area. The proliferation positive, NAb negative combination may represent a new marker of long term immunity/exposure to JE. T cell responses can cross-react between JE vaccine and DENV in a co-endemic area, illustrating a need for greater knowledge on such responses to inform the development of next-generation vaccines effective against both diseases. clinicaltrials.gov (NCT01656200).

A Southern Ocean driver of atmospheric CO2

NASA Astrophysics Data System (ADS)

Ronge, T.; Geibert, W.; Lippold, J.; Lamy, F.; Schnetger, B.; Tiedemann, R.

2017-12-01

A prominent two-step rise in atmospheric CO2 marked the end of the last glacial. The steps coincided with climatic intervals Heinrich Stadial 1 (HS1) and the Younger Dryas (YD). Records of 231Pa/230Th on sediment cores bathed by NADW, revealed a rapid reduction of the Atlantic Meridional Overturning Circulation (AMOC), during these intervals. It was argued that a weakened AMOC would have significantly reduced the efficiency of the biological pump and thus might have contributed to the rise in atmospheric CO2. Despite playing an important role, this process fails to account for the enigmatic drop in atmospheric Δ14C and δ13C during HS1 that marks the first step of the CO2-rise. Increasing CO2-concentrations with a simultaneous drop in their Δ14C, call for the ventilation of an old and 14C-depleted carbon reservoir. In this respect, several studies point to the presence of very old, 14C-depleted deep-waters in the glacial Southern Ocean, which rejuvenated during the last deglaciation. However, the accumulation of 14C-depleted, carbon-rich waters in the deep Southern Ocean requires circulation patterns that significantly differ from todays. Here we present a combined set of 231Pa/230Th-, Rare Earth Element- and XRF-proxy records to understand the evolution of the South Pacific Overturning Circulation (SPOC) over the last 35,000 years. Our reconstructions are based on a transect of five sediment cores from the Southwest Pacific, covering the AAIW as well as the UCDW and LCDW. Our data show that throughout the last glacial the SPOC was significantly weakened. This reduction favored the observed accumulation of 14C-depleted CO2 in Circumpolar Deep Waters (CDW). Parallel to the HS1 increase of atmospheric CO2, the deep circulation picked up its pace and recovered toward the Holocene. This trend is in remarkable agreement with water mass radiocarbon reconstructions from the very same area, as well as with atmospherical changes in CO2, Δ14C and δ13C. Hence, we are

Light-duty vehicle CO2 targets consistent with 450 ppm CO2 stabilization.

PubMed

Winkler, Sandra L; Wallington, Timothy J; Maas, Heiko; Hass, Heinz

2014-06-03

We present a global analysis of CO2 emission reductions from the light-duty vehicle (LDV) fleet consistent with stabilization of atmospheric CO2 concentration at 450 ppm. The CO2 emission reductions are described by g CO2/km emission targets for average new light-duty vehicles on a tank-to-wheel basis between 2010 and 2050 that we call CO2 glide paths. The analysis accounts for growth of the vehicle fleet, changing patterns in driving distance, regional availability of biofuels, and the changing composition of fossil fuels. New light-duty vehicle fuel economy and CO2 regulations in the U.S. through 2025 and in the EU through 2020 are broadly consistent with the CO2 glide paths. The glide path is at the upper end of the discussed 2025 EU range of 68-78 g CO2/km. The proposed China regulation for 2020 is more stringent than the glide path, while the 2017 Brazil regulation is less stringent. Existing regulations through 2025 are broadly consistent with the light-duty vehicle sector contributing to stabilizing CO2 at approximately 450 ppm. The glide paths provide long-term guidance for LDV powertrain/fuel development.

Low-temperature CO oxidation over Cu/Pt co-doped ZrO2 nanoparticles synthesized by solution combustion.

PubMed

Singhania, Amit; Gupta, Shipra Mital

2017-01-01

Zirconia (ZrO 2 ) nanoparticles co-doped with Cu and Pt were applied as catalysts for carbon monoxide (CO) oxidation. These materials were prepared through solution combustion in order to obtain highly active and stable catalytic nanomaterials. This method allows Pt 2+ and Cu 2+ ions to dissolve into the ZrO 2 lattice and thus creates oxygen vacancies due to lattice distortion and charge imbalance. High-resolution transmission electron microscopy (HRTEM) results showed Cu/Pt co-doped ZrO 2 nanoparticles with a size of ca. 10 nm. X-ray diffraction (XRD) and Raman spectra confirmed cubic structure and larger oxygen vacancies. The nanoparticles showed excellent activity for CO oxidation. The temperature T 50 (the temperature at which 50% of CO are converted) was lowered by 175 °C in comparison to bare ZrO 2 . Further, they exhibited very high stability for CO reaction (time-on-stream ≈ 70 h). This is due to combined effect of smaller particle size, large oxygen vacancies, high specific surface area and better thermal stability of the Cu/Pt co-doped ZrO 2 nanoparticles. The apparent activation energy for CO oxidation is found to be 45.6 kJ·mol -1 . The CO conversion decreases with increase in gas hourly space velocity (GHSV) and initial CO concentration.

Global estimation of CO emissions using three sets of satellite data for burned area

NASA Astrophysics Data System (ADS)

Jain, Atul K.

Using three sets of satellite data for burned areas together with the tree cover imagery and a biogeochemical component of the Integrated Science Assessment Model (ISAM) the global emissions of CO and associated uncertainties are estimated for the year 2000. The available fuel load (AFL) is calculated using the ISAM biogeochemical model, which accounts for the aboveground and surface fuel removed by land clearing for croplands and pasturelands, as well as the influence on fuel load of various ecosystem processes (such as stomatal conductance, evapotranspiration, plant photosynthesis and respiration, litter production, and soil organic carbon decomposition) and important feedback mechanisms (such as climate and fertilization feedback mechanism). The ISAM estimated global total AFL in the year 2000 was about 687 Pg AFL. All forest ecosystems account for about 90% of the global total AFL. The estimated global CO emissions based on three global burned area satellite data sets (GLOBSCAR, GBA, and Global Fire Emissions Database version 2 (GFEDv2)) for the year 2000 ranges between 320 and 390 Tg CO. Emissions from open fires are highest in tropical Africa, primarily due to forest cutting and burning. The estimated overall uncertainty in global CO emission is about ±65%, with the highest uncertainty occurring in North Africa and Middle East region (±99%). The results of this study suggest that the uncertainties in the calculated emissions stem primarily from the area burned data.

Reactivity of NO2 and CO2 with hardened cement paste containing activated carbon

NASA Astrophysics Data System (ADS)

Horgnies, M.; Dubois-Brugger, I.; Krou, N. J.; Batonneau-Gener, I.; Belin, T.; Mignard, S.

2015-07-01

The development of building materials to reduce the concentration of NO2 is growing interest in a world where the air quality in urban areas is affected by the car traffic. The main binder in concrete is the cement paste that is partly composed of calcium hydroxide. This alkaline hydrate composing the hardened cement paste shows a high BET surface area (close to 100 m2.g-1) and can absorb low-concentrations of NO2. However, the presence of CO2 in the atmosphere limits the de-polluting effect of reference cement paste, mainly due to carbonation of the alkaline hydrates (reaction leading to the formation of calcium carbonate). The results established in this paper demonstrate that the addition of activated carbon in the cement paste, because of its very high BET surface area (close to 800 m2.g-1) and its specific reactivity with NO2, can significantly improve and prolong the de-polluting effect in presence of CO2 and even after complete carbonation of the surface of the cement paste.

Sites of action of elevated CO2 on leaf development in rice: discrimination between the effects of elevated CO2 and nitrogen deficiency.

PubMed

Tsutsumi, Koichi; Konno, Masae; Miyazawa, Shin-Ichi; Miyao, Mitsue

2014-02-01

Elevated CO2 concentrations (eCO2) trigger various plant responses. Despite intensive studies of these responses, the underlying mechanisms remain obscure. In this work, we investigated when and how leaf physiology and anatomy are affected by eCO2 in rice plants. We analyzed the most recently fully expanded leaves that developed successively after transfer of the plant to eCO2. To discriminate between the effects of eCO2 and those of nitrogen deficiency, we used three different levels of N application. We found that a decline in the leaf soluble protein content (on a leaf area basis) at eCO2 was only observed under N deficiency. The length and width of the leaf blade were reduced by both eCO2 and N deficiency, whereas the blade thickness was increased by eCO2 but was not affected by N deficiency. The change in length by eCO2 became detectable in the secondly fully expanded leaf, and those in width and thickness in the thirdly fully expanded leaf, which were at the leaf developmental stages P4 and P3, respectively, at the onset of the eCO2 treatment. The decreased blade length at eCO2 was associated with a decrease in the epidermal cell number on the adaxial side and a reduction in cell length on the abaxial side. The decreased width resulted from decreased numbers of small vascular bundles and epidermal cell files. The increased thickness was ascribed mainly to enhanced development of bundle sheath extensions at the ridges of vascular bundles. These observations enable us to identify the sites of action of eCO2 on rice leaf development.

CO2 Capture by Injection of Flue Gas or CO2-N2 Mixtures into Hydrate Reservoirs: Dependence of CO2 Capture Efficiency on Gas Hydrate Reservoir Conditions.

PubMed

Hassanpouryouzband, Aliakbar; Yang, Jinhai; Tohidi, Bahman; Chuvilin, Evgeny; Istomin, Vladimir; Bukhanov, Boris; Cheremisin, Alexey

2018-04-03

Injection of flue gas or CO 2 -N 2 mixtures into gas hydrate reservoirs has been considered as a promising option for geological storage of CO 2 . However, the thermodynamic process in which the CO 2 present in flue gas or a CO 2 -N 2 mixture is captured as hydrate has not been well understood. In this work, a series of experiments were conducted to investigate the dependence of CO 2 capture efficiency on reservoir conditions. The CO 2 capture efficiency was investigated at different injection pressures from 2.6 to 23.8 MPa and hydrate reservoir temperatures from 273.2 to 283.2 K in the presence of two different saturations of methane hydrate. The results showed that more than 60% of the CO 2 in the flue gas was captured and stored as CO 2 hydrate or CO 2 -mixed hydrates, while methane-rich gas was produced. The efficiency of CO 2 capture depends on the reservoir conditions including temperature, pressure, and hydrate saturation. For a certain reservoir temperature, there is an optimum reservoir pressure at which the maximum amount of CO 2 can be captured from the injected flue gas or CO 2 -N 2 mixtures. This finding suggests that it is essential to control the injection pressure to enhance CO 2 capture efficiency by flue gas or CO 2 -N 2 mixtures injection.

Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2

NASA Astrophysics Data System (ADS)

Landschützer, Peter; Gruber, Nicolas; Bakker, Dorothee C. E.; Stemmler, Irene; Six, Katharina D.

2018-01-01

The increase of atmospheric CO2 (ref. 1) has been predicted to impact the seasonal cycle of inorganic carbon in the global ocean2,3, yet the observational evidence to verify this prediction has been missing. Here, using an observation-based product of the oceanic partial pressure of CO2 (pCO2) covering the past 34 years, we find that the winter-to-summer difference of the pCO2 has increased on average by 2.2 ± 0.4 μatm per decade from 1982 to 2015 poleward of 10° latitude. This is largely in agreement with the trend expected from thermodynamic considerations. Most of the increase stems from the seasonality of the drivers acting on an increasing oceanic pCO2 caused by the uptake of anthropogenic CO2 from the atmosphere. In the high latitudes, the concurrent ocean-acidification-induced changes in the buffer capacity of the ocean enhance this effect. This strengthening of the seasonal winter-to-summer difference pushes the global ocean towards critical thresholds earlier, inducing stress to ocean ecosystems and fisheries4. Our study provides observational evidence for this strengthening seasonal difference in the oceanic carbon cycle on a global scale, illustrating the inevitable consequences of anthropogenic CO2 emissions.

Canopy leaf area constrains [CO2]-induced enhancement of productivity and partitioning among aboveground carbon pools.

Treesearch

Heather R. McCarthy; Ram Oren; Adrien C. Finzi; Kurt H. Johnsen

2006-01-01

Net primary productivity (NPP) is enhanced under future atmospheric [CO2] in temperate forests representing a broad range of productivity. Yet questions remain in regard to how elevated [CO2]-induced NPP enhancement may be affected by climatic variations and limiting nutrient resources, as well as how this additional...

The Density and Compressibility of BaCO3-SrCO3-CaCO3-K2CO3-Na2CO3-Li2CO3 Liquids: New Measurements and a Systematic Trend with Cation Field Strength

NASA Astrophysics Data System (ADS)

Hurt, S. M.; Lange, R. A.; Ai, Y.

2015-12-01

The volumetric properties of multi-component carbonate liquids are required to extend thermodynamic models that describe partial melting of the deep mantle (e.g. pMELTS; Ghiorso et al., 2003) to carbonate-bearing lithologies. Carbonate in the mantle is an important reservoir of carbon, which is released to the atmosphere as CO2 through volcanism, and thus contributes to the carbon cycle. Although MgCO3 is the most important carbonate component in the mantle, it is not possible to directly measure the 1-bar density and compressibility of MgCO3 liquid because, like other alkaline-earth carbonates, it decomposes at a temperature lower than its melting temperature. Despite this challenge, Liu and Lange (2003) and O'Leary et al. (2015) showed that the one bar molar volume, thermal expansion and compressibility of the CaCO3 liquid component could be obtained by measuring the density and sound speeds of stable liquids in the CaCO3-Li2CO3-Na2CO3-K2CO3 quaternary system at one bar. In this study, this same strategy is employed on SrCO3- and BaCO3-bearing alkali carbonate liquids. The density and sound speed of seven liquids in the SrCO3-Li2CO3-Na2CO3-K2CO3 quaternary and three liquids in the BaCO3-Li2CO3-Na2CO3-K2CO3 quaternary were measured from 739-1367K, with SrCO3 and BaCO3 concentrations ranging from 10-50 mol%. The density measurements were made using the double-bob Archimedean method and sound speeds were obtained with a frequency-sweep acoustic interferometer. The molar volume and sound speed measurements were used to calculate the isothermal compressibility of each liquid, and the results show the volumetric properties mix ideally with composition. The partial molar volume and compressibility of the SrCO3 and BaCO3 components are compared to those obtained for the CaCO3 component as a function of cation field strength. The results reveal a systematic trend that allows the partial molar volume and compressibility of the MgCO3 liquid component to be estimated.

STM/STS Study of LixCoO2 Single Crystals

NASA Astrophysics Data System (ADS)

Iwaya, Katsuya; Minato, Taketoshi; Miyoshi, Kiyotaka; Takeuchi, Jun; Kim, Yousoo; Hitosugi, Taro

2012-02-01

We have performed low temperature scanning tunneling microscopy/spectroscopy (STM/STS) measurements on LixCoO2 (x=0.66) single crystal surfaces. A (1x1) hexagonal lattice was clearly observed and found to be moved by changing bias-voltage polarity, indicating that this could be associated with Li ions on the surface. Under the (1x1) hexagonal lattice, we imaged almost randomly distributed bright dots that were strongly dependent on bias-voltage, with insulating spectroscopic features. Different area on the surface showed a (2x2) hexagonal lattice that could be related to an ordering of Co^3+ and Co^4+ ions. These results suggest the electronic structure of LixCoO2 surface is inhomogeneous possibly due to segregation of Li ions.

CO2 laser induced refractive index changes in optical polymers.

PubMed

Liu, Qing; Chiang, Kin Seng; Reekie, Laurence; Chow, Yuk Tak

2012-01-02

We study the infrared photosensitivity properties of two optical polymer materials, benzocyclobutene (BCB) and epoxy OPTOCAST 3505, with a 10.6 μm CO2 laser. We discover that the CO2 laser radiation can lower the refractive index of BCB by as much as 5.5 × 10(-3), while inducing no measurable index change in the epoxy. As confirmed by Fourier transform infrared spectroscopy, the observed index change in BCB can be attributed to photothermal modification of chemical bonds in the material by the CO2 laser radiation. Our findings open up a new possibility of processing polymer materials with a CO2 laser, which could be further developed for application in the areas of post-processing and direct-writing of polymer waveguide devices.

CO2 laser modeling

NASA Technical Reports Server (NTRS)

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.

Imidazolium salt-modified porous hypercrosslinked polymers for synergistic CO2 capture and conversion.

PubMed

Wang, Jinquan; Sng, Waihong; Yi, Guangshun; Zhang, Yugen

2015-08-04

A new type of imidazolium salt-modified porous hypercrosslinked polymer (BET surface area up to 926 m(2) g(-1)) was reported. These porous materials exhibited good CO2 capture capacities (14.5 wt%) and catalytic activities for the conversion of CO2 into various cyclic carbonates under metal-free conditions. The synergistic effect of CO2 capture and conversion was observed.

Formation and decomposition of siderite for CO2 treatment

NASA Astrophysics Data System (ADS)

Y Mora, E.; Sarmiento, A.; Vera, E.; Drozd, V.; Durigyn, A.; Saxena, S.

2017-12-01

In this research work, we studied the conditions for formation and decomposition of siderite FeCO3 from hematite Fe2O3 along with carbon dioxide CO2 at suitable thermodynamic conditions. As reductant agents were used mixtures of two elements, metallic iron and graphite. Best levels of carbonation were found in mixtures with bigger amounts of metallic iron. It was demonstrated that CO2 capture capacity by hematite depends of temperature, CO2 pressure, and reaction time. Temperatures between 100 and 150°C, pressures between 10 and 30bar and reaction times between 1 and 4h were adjusted for analyse the carbonation behaviour; siderite formation was improved by increases of these three variables. There was no carbonation without water in the mixtures, due to kinetic limitations. CO2 capture capacity was calculated from Rietveld refinement results. Using vacuum system and Dielectric Barrier Discharge, DBD plasma, the siderite was decomposed at 300°C, and 320°C respectively. Techniques as X-ray diffraction, and surface area analysis were employed to study the material.

Graphene-Based Photocatalysts for CO2 Reduction to Solar Fuel.

PubMed

Low, Jingxiang; Yu, Jiaguo; Ho, Wingkei

2015-11-05

Recently, photocatalytic CO2 reduction for solar fuel production has attracted much attention because of its potential for simultaneously solving energy and global warming problems. Many studies have been conducted to prepare novel and efficient photocatalysts for CO2 reduction. Graphene, a two-dimensional material, has been increasingly used in photocatalytic CO2 reduction. In theory, graphene shows several remarkable properties, including excellent electronic conductivity, good optical transmittance, large specific surface area, and superior chemical stability. Attributing to these advantages, fabrication of graphene-based materials has been known as one of the most feasible strategies to improve the CO2 reduction performance of photocatalysts. This Perspective mainly focuses on the recent important advances in the fabrication and application of graphene-based photocatalysts for CO2 reduction to solar fuels. The existing challenges and difficulties of graphene-based photocatalysts are also discussed for future application.

TES/Aura L2 Carbon Dioxide (CO2) Nadir V7 (TL2CO2N)

Atmospheric Science Data Center

2018-01-18

... TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News:  TES News Join TES News List Project ... TES Order Tool Parameters:  Earth Science Atmosphere Atmospheric Chemistry/Carbon and Hydrocarbon Compounds ...

Nonlinear CO 2 flux response to 7 years of experimentally induced permafrost thaw

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauritz, Marguerite; Bracho, Rosvel; Celis, Gerardo

Rapid Arctic warming is expected to increase global greenhouse gas concentrations as permafrost thaw exposes immense stores of frozen carbon (C) to microbial decomposition. Permafrost thaw also stimulates plant growth, which could offset C loss. Using data from 7 years of experimental Air and Soil warming in moist acidic tundra, we show that Soil warming had a much stronger effect on CO 2 flux than Air warming. Soil warming caused rapid permafrost thaw and increased ecosystem respiration (R eco), gross primary productivity (GPP), and net summer CO 2 storage (NEE). Over 7 years R eco, GPP, and NEE also increasedmore » in Control (i.e., ambient plots), but this change could be explained by slow thaw in Control areas. In the initial stages of thaw, R eco, GPP, and NEE increased linearly with thaw across all treatments, despite different rates of thaw. As thaw in Soil warming continued to increase linearly, ground surface subsidence created saturated microsites and suppressed R eco, GPP, and NEE. However R eco and GPP remained high in areas with large Eriophorum vaginatum biomass. In general NEE increased with thaw, but was more strongly correlated with plant biomass than thaw, indicating that higher R eco in deeply thawed areas during summer months was balanced by GPP. Summer CO 2 flux across treatments fit a single quadratic relationship that captured the functional response of CO 2 flux to thaw, water table depth, and plant biomass. These results demonstrate the importance of indirect thaw effects on CO 2 flux: plant growth and water table dynamics. Nonsummer R eco models estimated that the area was an annual CO 2 source during all years of observation. As a result, nonsummer CO 2 loss in warmer, more deeply thawed soils exceeded the increases in summer GPP, and thawed tundra was a net annual CO 2 source.« less

Nonlinear CO 2 flux response to 7 years of experimentally induced permafrost thaw

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