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Sample records for volume end-tidal co2

  1. End-Tidal CO2-Guided Chest Compression Delivery Improves Survival in a Neonatal Asphyxial Cardiac Arrest Model.

    Science.gov (United States)

    Hamrick, Justin T; Hamrick, Jennifer L; Bhalala, Utpal; Armstrong, Jillian S; Lee, Jeong-Hoo; Kulikowicz, Ewa; Lee, Jennifer K; Kudchadkar, Sapna R; Koehler, Raymond C; Hunt, Elizabeth A; Shaffner, Donald H

    2017-11-01

    To determine whether end-tidal CO2-guided chest compression delivery improves survival over standard cardiopulmonary resuscitation after prolonged asphyxial arrest. Preclinical randomized controlled study. University animal research laboratory. 1-2-week-old swine. After undergoing a 20-minute asphyxial arrest, animals received either standard or end-tidal CO2-guided cardiopulmonary resuscitation. In the standard group, chest compression delivery was optimized by video and verbal feedback to maintain the rate, depth, and release within published guidelines. In the end-tidal CO2-guided group, chest compression rate and depth were adjusted to obtain a maximal end-tidal CO2 level without other feedback. Cardiopulmonary resuscitation included 10 minutes of basic life support followed by advanced life support for 10 minutes or until return of spontaneous circulation. Mean end-tidal CO2 at 10 minutes of cardiopulmonary resuscitation was 34 ± 8 torr in the end-tidal CO2 group (n = 14) and 19 ± 9 torr in the standard group (n = 14; p = 0.0001). The return of spontaneous circulation rate was 7 of 14 (50%) in the end-tidal CO2 group and 2 of 14 (14%) in the standard group (p = 0.04). The chest compression rate averaged 143 ± 10/min in the end-tidal CO2 group and 102 ± 2/min in the standard group (p tidal CO2-guided chest compression delivery. The response of the relaxation arterial pressure and cerebral perfusion pressure to the initial epinephrine administration was greater in the end-tidal CO2 group than in the standard group (p = 0.01 and p = 0.03, respectively). The prevalence of resuscitation-related injuries was similar between groups. End-tidal CO2-guided chest compression delivery is an effective resuscitation method that improves early survival after prolonged asphyxial arrest in this neonatal piglet model. Optimizing end-tidal CO2 levels during cardiopulmonary resuscitation required that chest compression delivery rate exceed current guidelines

  2. ROBUST CONTROL OF END-TIDAL CO2 USING THE H∞ LOOP-SHAPING APPROACH

    Directory of Open Access Journals (Sweden)

    Anake Pomprapa

    2013-12-01

    Full Text Available Mechanically ventilated patients require appropriate settings of respiratory control variables to maintain acceptable gas exchange. To control the carbon dioxide (CO2 level effectively and automatically, system identification based on a human subject was performed using a linear affine model and a nonlinear Hammerstein structure. Subsequently, a robust controller was designed using the H∞ loop-shaping approach, which synthesizes the optimal controller based on a specific objective by achieving stability with guaranteed performance. For demonstration purposes, the closed-loop control ventilation system was successfully tested in a human volunteer. The experimental results indicate that the blood CO2 level may indeed be controlled noninvasively by measuring end-tidal CO2 from expired air. Keeping the limited amount of experimental data in mind, we conclude that H∞ loop-shaping may be a promising technique for control of mechanical ventilation in patients with respiratory insufficiency.

  3. End tidal-to-arterial CO2 and O2 gas gradients at low- and high-altitude during dynamic end-tidal forcing.

    Science.gov (United States)

    Tymko, Michael M; Ainslie, Philip N; MacLeod, David B; Willie, Chris K; Foster, Glen E

    2015-06-01

    We sought to characterize and quantify the performance of a portable dynamic end-tidal forcing (DEF) system in controlling the partial pressure of arterial CO2 (Pa(CO2)) and O2 (Pa(O2)) at low (LA; 344 m) and high altitude (HA; 5,050 m) during an isooxic CO2 test and an isocapnic O2 test, which is commonly used to measure ventilatory and vascular reactivity in humans (n = 9). The isooxic CO2 tests involved step changes in the partial pressure of end-tidal CO2 (PET(CO2)) of -10, -5, 0, +5, and +10 mmHg from baseline. The isocapnic O2 test consisted of a 10-min hypoxic step (PET(O2) = 47 mmHg) from baseline at LA and a 5-min euoxic step (PET(O2) = 100 mmHg) from baseline at HA. At both altitudes, PET(O2) and PET(CO2) were controlled within narrow limits (<1 mmHg from target) during each protocol. During the isooxic CO2 test at LA, PET(CO2) consistently overestimated Pa(CO2) (P < 0.01) at both baseline (2.1 ± 0.5 mmHg) and hypercapnia (+5 mmHg: 2.1 ± 0.7 mmHg; +10 mmHg: 1.9 ± 0.5 mmHg). This P(a)-PET(CO2) gradient was approximately twofold greater at HA (P < 0.05). At baseline at both altitudes, PET(O2) overestimated Pa(O2) by a similar extent (LA: 6.9 ± 2.1 mmHg; HA: 4.5 ± 0.9 mmHg; both P < 0.001). This overestimation persisted during isocapnic hypoxia at LA (6.9 ± 0.6 mmHg) and during isocapnic euoxia at HA (3.8 ± 1.2 mmHg). Step-wise multiple regression analysis, on the basis of the collected data, revealed that it may be possible to predict an individual's arterial blood gases during DEF. Future research is needed to validate these prediction algorithms and determine the implications of end-tidal-to-arterial gradients in the assessment of ventilatory and/or vascular reactivity. Copyright © 2015 the American Physiological Society.

  4. Effects of sodium bicarbonate on the end-tidal CO2, PaCO2, HCO3-, PH and cerebral blood flow

    International Nuclear Information System (INIS)

    Komatani, Akio; Akutsu, Tooru; Yoshida, Michihiko; Yamaguchi, Koichi; Seo, Hiroshi

    1992-01-01

    To estimate the quantitative reactivity of cerebral blood flow (CBF), the effects of sodium bicarbonate on the end-tidal CO 2 , arterial partial pressure of CO 2 (PaCO 2 ), HCO 3 - , pH and CBF were examined. The CBF was measured by 133 Xe inhalation method with ring type SPECT (HEADTOME). Activation study with sodium bicarbonate administration was performed after 30 minutes of resting study, and the reactivity of each parameters was investigated. The arterial HCO 3 - and pH increased with similar reactivity, but PaCO 2 , end-tidal CO 2 and CBF in the non-injured hemisphere changed with irregular reactivity. The excellent correlation between PaCO 2 and end-tidal CO 2 was vanished by the administration of sodium bicarbonate. The reactivity of CBF did not correlate with reactivity of PaCO 2 and end-tidal CO 2 , but correlated with arterial HCO 3 - and pH. Thus the measurement of arterial HCO 3 - and pH may be indispensable to estimate the CBF reactivity with the administration of sodium bicarbonate. (author)

  5. End-tidal CO2 Detection of an Audible Heart Rate During Neonatal Cardiopulmonary Resuscitation Following Asystole in Asphyxiated Piglets

    OpenAIRE

    Chalak, Lina F.; Barber, Chad A.; Hynan, Linda; Garcia, Damian; Christie, Lucy; Wyckoff, Myra H.

    2011-01-01

    Even brief interruption of cardiac compressions significantly reduces critical coronary perfusion pressure during cardiopulmonary resuscitation (CPR). End-tidal CO2 (ETCO2) monitoring may provide a continuous non-invasive method of assessing return of spontaneous circulation (ROSC) without stopping to auscultate for heart rate (HR). However, the ETCO2 value that correlates with an audible HR is unknown. Our objective was to determine the threshold ETCO2 that is associated with ROSC following ...

  6. Haemodynamic and end tidal CO2 changes state after inflation and deflation of pneumatic tourniquet on extremities.

    Science.gov (United States)

    Zaman, S M; Islam, M M; Chowdhury, K K; Rickta, D; Ireen, S T; Choudhury, M R; Alam, M

    2010-10-01

    The use of a tourniquet for obtaining a bloodless field is an essential and accepted tool for extremity surgery. A prospective study was done on 30 adult patients undergoing elective limb surgery requiring tourniquet application for haemodynamic and End tidal CO2 (EtCO2) changes. After the induction of general anaesthesia a tourniquet was applied on the limb. There was gradual increase in heart rate & EtCO2 through out the whole period of tourniquet inflation. There was also significant increase of mean arterial pressure during the inflation period. At the end of surgery tourniquet was deflated. Tourniquet time was 76.83+/-16.94 minutes. After deflation of the tourniquet, heart rate & EtCO2 value increased & the values were maximum at 5 minutes. These values came down to the base line at 15 minutes. There was significant decrease of mean arterial pressure (MAP) at 5 minute; it also came to the base at 15 minute. These changes are usually benign but can be significant in patients with co-existing cardiovascular & intracranial diseases. In conclusion, we recommend the haemodynamic and End tidal CO2 monitoring as well as rapid fluid infusion along with hyperventilation for 15-30 minutes after deflation of tourniquet.

  7. Colorimetric end-tidal CO2 detector for verification of endotracheal tube placement in out-of-hospital cardiac arrest.

    Science.gov (United States)

    Hayden, S R; Sciammarella, J; Viccellio, P; Thode, H; Delagi, R

    1995-06-01

    To evaluate the ability of a disposable, colorimetric end-tidal CO2 detector to verify proper endotracheal (ET) tube placement in out-of-hospital cardiac arrest, and to correlate semiquantitative CO2 measurements with the rate of return of spontaneous circulation (ROSC). Prospective, observational study using a convenience sample of intubated out-of-hospital cardiac arrest patients. A disposable, colorimetric end-tidal CO2 detector was attached to the ET tube after intubation. In the absence of a colorimetric change, the paramedics reassessed the tube placement and could reintubate the patient. Tube placement was verified at the hospital. Paramedics were instructed to contact the base station and report the colorimetric change upon hospital arrival. ROSC was defined as restoration of a self-sustaining pulse until hospital arrival. Between December 1990 and May 1993, ET tubes were placed in 566 victims of out-of-hospital cardiac arrest. 541 of the 566 intubations (95.6%) were associated with a color change. In one case with a color change and out-of-hospital clinical evidence of proper tube placement, the tube was determined to be in the esophagus at the hospital. Correct placement of the remaining 565 of 566 (99.8%) tubes was verified. Of the 566 patients who had a colorimetric change, 91 (16%) had ROSC vs one of 25 (4%) patients who did not have a color change. In one subgroup (n = 179), the degree of color change was highly associated with ROSC (p = 0.004). A disposable, colorimetric end-tidal CO2 detector appears reliable in verifying proper ET tube placement in victims of out-of-hospital cardiac arrest. The degree of color change correlates with the probability of ROSC.

  8. Predictive value of EndTidalCO2, lung mechanics and other standard parameters for weaning neurological patients from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Hala A. Mohammad

    2016-01-01

    Conclusion: We concluded that measurements of RSBI, MIP (maximum inspiratory pressure, EndTidalCO2 and dynamic compliance were more accurate predictors of extubation failure in patients with neurological insults than other standard weaning parameters.

  9. End-tidal CO2 Detection of an Audible Heart Rate During Neonatal Cardiopulmonary Resuscitation Following Asystole in Asphyxiated Piglets

    Science.gov (United States)

    Chalak, Lina F.; Barber, Chad A.; Hynan, Linda; Garcia, Damian; Christie, Lucy; Wyckoff, Myra H.

    2011-01-01

    Even brief interruption of cardiac compressions significantly reduces critical coronary perfusion pressure during cardiopulmonary resuscitation (CPR). End-tidal CO2 (ETCO2) monitoring may provide a continuous non-invasive method of assessing return of spontaneous circulation (ROSC) without stopping to auscultate for heart rate (HR). However, the ETCO2 value that correlates with an audible HR is unknown. Our objective was to determine the threshold ETCO2 that is associated with ROSC following asphyxia-induced asystole. Neonatal swine (n=46) were progressively asphyxiated until asystole occurred. Resuscitation followed current neonatal guidelines with initial ventilation with 100% O2 followed by cardiac compressions followed by epinephrine for continued asystole. HR was auscultated every 30 sec and ETCO2 was continuously recorded. A receiver operator curve was generated using the calculated sensitivity and specificity for various ETCO2 values where a positive test was defined as the presence of HR >60 bpm by auscultation. An ETCO2 cut off value of 14 mmHg is the most sensitive ETCO2 value with the least false positives. When using ETCO2 to guide uninterrupted CPR in this model of asphyxia-induced asystole, auscultative confirmation of return of an adequate HR should be performed when ETCO2 ≥14 mmHg is achieved. Correlation during human neonatal CPR needs further investigation. PMID:21283051

  10. Arterial to end-tidal carbon dioxide tension difference (CO2 gap) as a prognostic marker for adverse outcomes in emergency department patients presenting with suspected sepsis.

    Science.gov (United States)

    Shetty, Amith; Sparenberg, Sebastian; Adams, Kristian; Selvedran, Selwyn; Tang, Benjamin; Hanna, Kim; Iredell, Jonathan

    2018-05-13

    The arterial to end-tidal carbon dioxide tension difference (CO 2 gap) correlates with physiologic dead space. The prognostic value of increased CO 2 gap in trauma and respiratory distress patients is documented. Transpulmonary arteriovenous shunting is identified as a predictor of mortality in non-pulmonary sepsis. We set out to investigate the prognostic value of the CO 2 gap in a pilot study of patients with suspected sepsis from non-respiratory causes. Patients presenting to tertiary Australian ED with suspected sepsis (n = 215) underwent near-simultaneous end-tidal carbon dioxide and partial pressure of carbon dioxide measurements. We investigated the correlation of CO 2 gap levels with the primary outcome of in-hospital mortality (IHM) and secondary outcomes of sepsis (ΔSOFA ≥2) and IHM and/or intensive care unit stay ≥72 h (IHM/ICU72h) in patients with sepsis because of non-respiratory causes. Among patients included in the analysis (n = 165), the CO 2 gap showed modest positive correlation with qSOFA (ρ = 0.39) and weak positive correlation with SOFA scores (ρ = 0.29) (both P < 0.01). The CO 2 gap had modest predictive value for primary outcome (IHM), area under receiver operating curve (AUROC 0.85, 95% confidence interval [CI] 0.78-0.90) and IHM/ICU72h outcome (AUROC 0.80, 95% CI 0.73-0.86), but lower predictive value for sepsis outcome (AUROC 0.64, 95% CI 0.55-0.71) (all P < 0.001). We report modest test performance for primary outcome at CO 2 gap ≥5 and ≥10 mmHg cut-offs. In this pilot study of patients with suspected sepsis from non-respiratory causes, an increased CO 2 gap demonstrates value in risk stratification and needs to be further evaluated and compared to other existent biomarkers. © 2018 Australasian College for Emergency Medicine & Australasian Society for Emergency Medicine.

  11. Evaluation the effect of breathing filters on end-tidal carbon dioxide during inferior abdominal surgery in infants and changes of tidal volume and respiratory rate needs for preventing of increasing end-tidal carbon dioxide.

    Science.gov (United States)

    Sajedi, Parvin; Abooei, Mohsen; Shafa, Amir; Karbalaei, Mahboobeh; Babaei, Atefeh

    2016-01-01

    The aim of this study was to prevent of increasing end-tidal carbon dioxide (ETCO 2) with changing of vital capacity and respiratory rate when using of birthing filter in infants. In a randomized clinical trial study, ninety-four infant' patients were studied in three groups. Basic values, such as peak inspiratory pressure, tidal volume, minute ventilation, respiratory rate, and partial pressure of ET CO 2 (PETCO 2 ) level had been evaluated after intubation, 10 min after intubation and 10 min after filter insertion. In the first group, patients only observed for changing in ETCO 2 level. In the second and the third groups, respiratory rates and tidal volume had been increased retrospectively, until that ETCO 2 ≤35 mmHg was received. We used ANOVA, Chi-square, and descriptive tests for data analysis. P Tidal volume 10 min after filter insertion was statistically higher in Group 3 (145.0 ± 26.3 ml) versus 129.3 ± 38.9 ml in Group 1 and 118.7 ± 20.8 ml in Group 2 ( P = 0.02). Furthermore, respiratory rate at this time was statistically higher in Group 2 (25.82 ± 0.43) versus Groups 1 and 3 (21.05 ± 0.20 ml and 21.02 ± 0.60 ml, respectively) ( P = 0.001). Minute volume and PETCO 2 level were statistically significant between Group 1 and the other two groups after filter insertion ( P = 0.01 and P = 0.00,1 respectively). With changing the vital capacity and respiratory rate we can control PETCO 2 level ≤35 mmHg during using of birthing filters in infants. We recommend this instrument during anesthesia of infants.

  12. Low pre-treatment end-tidal CO2 predicts dropout from cognitive-behavioral therapy for anxiety and related disorders.

    Science.gov (United States)

    Tolin, David F; Billingsley, Amber L; Hallion, Lauren S; Diefenbach, Gretchen J

    2017-03-01

    Recent clinical trial research suggests that baseline low end-tidal CO 2 (ETCO 2 , the biological marker of hyperventilation) may predict poorer response to cognitive-behavioral therapy (CBT) for anxiety-related disorders. The present study examined the predictive value of baseline ETCO 2 among patients treated for such disorders in a naturalistic clinical setting. Sixty-nine adults with a primary diagnosis of a DSM-5 anxiety disorder, obsessive-compulsive disorder, or posttraumatic stress disorder completed a 4-min assessment of resting ETCO 2 , and respiration rate (the first minute was analyzed). Lower ETCO 2 was not associated with a diagnosis of panic disorder, and was associated with lower subjective distress ratings on certain measures. Baseline ETCO 2 significantly predicted treatment dropout: those meeting cutoff criteria for hypocapnia were more than twice as likely to drop out of treatment, and ETCO 2 significantly predicted dropout beyond other pre-treatment variables. Weekly measurement suggested that the lower-ETCO 2 patients who dropped out were not responding well to treatment prior to dropout. The present results, along with previous clinical trial data, suggest that lower pre-treatment ETCO 2 is a negative prognostic indicator for CBT for anxiety-related disorders. It is suggested that patients with lower ETCO 2 might benefit from additional intervention that targets respiratory abnormality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. End-Tidal CO2 Tension Is Predictive of Effective Nocturnal Oxygen Therapy in Patients with Chronic Heart Failure and Central Sleep Apnea.

    Science.gov (United States)

    Sugimura, Koichiro; Shinozaki, Tsuyoshi; Fukui, Shigefumi; Ogawa, Hiromasa; Shimokawa, Hiroaki

    2016-05-01

    Central sleep apnea (CSA) is characterized by recurring cycles of crescendo-decrescendo ventilation during sleep, and enhances sympathetic nerve activity. Thus CSA has a prognostic impact in patients with chronic heart failure (CHF). Although nocturnal oxygen (O2) therapy decreases frequency of CSA and improves functional exercise capacity, it is also known that some non-responders to the therapy exist. We thus aimed to identify predictors of responders to nocturnal O2 therapy in CHF patients with CSA. In 12 CHF patients with CSA hospitalized at our department, sleep study was performed at 2 consecutive nights. Patients nasally inhaled O2 at either the first or second night in a randomized manner. To predict the percentage reduction in apnea-hypopnea index (%ΔAHI) in response to the nocturnal O2 therapy, we performed multiple regression analysis with a stepwise method with variables including age, brain-natriuretic peptide, circulation time, baseline AHI, hypercapnic ventilatory response and end-tidal carbon dioxide tension (PETCO2). Nocturnal O2 therapy significantly decreased AHI (from 32 ± 13 /h to 12 ± 10 /h, P 50% reduction of AHI), with 88.9% of sensitivity and 66.7% of specificity. In conclusion, PETCO2 is useful to predict the efficacy of O2 therapy in CHF patients with CSA, providing important information to the current nocturnal O2 therapy.

  14. Efficacy of chest compressions directed by end-tidal CO2 feedback in a pediatric resuscitation model of basic life support.

    Science.gov (United States)

    Hamrick, Jennifer L; Hamrick, Justin T; Lee, Jennifer K; Lee, Benjamin H; Koehler, Raymond C; Shaffner, Donald H

    2014-04-14

    End-tidal carbon dioxide (ETCO2) correlates with systemic blood flow and resuscitation rate during cardiopulmonary resuscitation (CPR) and may potentially direct chest compression performance. We compared ETCO2-directed chest compressions with chest compressions optimized to pediatric basic life support guidelines in an infant swine model to determine the effect on rate of return of spontaneous circulation (ROSC). Forty 2-kg piglets underwent general anesthesia, tracheostomy, placement of vascular catheters, ventricular fibrillation, and 90 seconds of no-flow before receiving 10 or 12 minutes of pediatric basic life support. In the optimized group, chest compressions were optimized by marker, video, and verbal feedback to obtain American Heart Association-recommended depth and rate. In the ETCO2-directed group, compression depth, rate, and hand position were modified to obtain a maximal ETCO2 without video or verbal feedback. After the interval of pediatric basic life support, external defibrillation and intravenous epinephrine were administered for another 10 minutes of CPR or until ROSC. Mean ETCO2 at 10 minutes of CPR was 22.7±7.8 mm Hg in the optimized group (n=20) and 28.5±7.0 mm Hg in the ETCO2-directed group (n=20; P=0.02). Despite higher ETCO2 and mean arterial pressure in the latter group, ROSC rates were similar: 13 of 20 (65%; optimized) and 14 of 20 (70%; ETCO2 directed). The best predictor of ROSC was systemic perfusion pressure. Defibrillation attempts, epinephrine doses required, and CPR-related injuries were similar between groups. The use of ETCO2-directed chest compressions is a novel guided approach to resuscitation that can be as effective as standard CPR optimized with marker, video, and verbal feedback.

  15. Effects of inhalational anaesthesia with low tidal volume ventilation on end-tidal sevoflurane and carbon dioxide concentrations: prospective randomized study.

    Science.gov (United States)

    de la Matta-Martín, M; López-Herrera, D; Luis-Navarro, J C; López-Romero, J L

    2014-02-01

    We investigated how ventilation with low tidal volumes affects the pharmacokinetics of sevoflurane uptake during the first minutes of inhaled anaesthesia. Forty-eight patients scheduled for lung resection were randomly assigned to three groups. Patients in group 1, 2 and 3 received 3% sevoflurane for 3 min via face mask and controlled ventilation with a tidal volume of 2.2, 8 and 12 ml kg(-1), respectively (Phase 1). After tracheal intubation (Phase 2), 3% sevoflurane was supplied for 2 min using a tidal volume of 8 ml kg(-1) (Phase 3). End-tidal sevoflurane concentrations were significantly higher in group 1 at the end of phase 1 and lower at the end of phase 2 than in the other groups as follows: median of 2.5%, 2.2% and 2.3% in phase 1 for groups 1, 2 and 3, respectively (Ptidal carbon dioxide values in group 1 were significantly lower at the end of phase 1 and higher at the end of phase 2 than in the other groups as follows: median of 16.5, 31 and 29.5 mm Hg in phase 1 for groups 1, 2 and 3, respectively (Ptidal volume approximating the airway dead space volume, end-tidal sevoflurane and end-tidal carbon dioxide may not correctly reflect the concentration of these gases in the alveoli, leading to misinterpretation of expired gas data. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  16. Mainstream end-tidal carbon dioxide monitoring in the neonatal intensive care unit.

    Science.gov (United States)

    Rozycki, H J; Sysyn, G D; Marshall, M K; Malloy, R; Wiswell, T E

    1998-04-01

    Continuous noninvasive monitoring of arterial carbon dioxide (CO2) in neonatal intensive care unit (NICU) patients would help clinicians avoid complications of hypocarbia and hypercarbia. End-tidal CO2 monitoring has not been used in this population to date, but recent technical advances and the introduction of surfactant therapy, which improves ventilation-perfusion matching, might improve the clinical utility of end-tidal monitoring. To determine the accuracy and precision of end-tidal CO2 monitoring in NICU patients. Nonrandomized recording of simultaneous end-tidal and arterial CO2 pairs. Two university NICUs. Forty-five newborn infants receiving mechanical ventilation who had indwelling arterial access, and a predefined subsample of infants who were NICU patients is as accurate as capillary or transcutaneous monitoring but less precise than the latter. It may be useful for trending or for screening patients for abnormal arterial CO2 values.

  17. End-inspiratory rebreathing reduces the end-tidal to arterial PCO2 gradient in mechanically ventilated pigs

    NARCIS (Netherlands)

    Fierstra, Jorn; Machina, Matthew; Battisti-Charbonney, Anne; Duffin, James; Fisher, Joseph Arnold; Minkovich, Leonid

    Noninvasive monitoring of the arterial partial pressures of CO2 (PaCO2) of critically ill patients by measuring their end-tidal partial pressures of CO2 (PetCO(2)) would be of great clinical value. However, the gradient between PetCO(2) and PaCO2 (Pet-aCO(2)) in such patients typically varies over a

  18. Ventilatory effects of hypercapnic end-tidal PCO2 clamps during aerobic exercise of varying intensity.

    Science.gov (United States)

    Essfeld, D; Hoffmann, U; Stegemann, J

    1990-01-01

    Nine subjects performed a sequence of sustained and randomised changes between 40 W and 100 W on a cycle ergometer while the end-tidal PO2 was kept close to 17.3 kPa (130 mm Hg) by means of a dynamic forcing technique (reference experiment). In a second series inspiratory CO2 was additionally manipulated so as to hold end-tidal PCO2 (PETCO2) near 6.5 kPa (49 mm Hg; 'CO2-clamp' experiment). By this forcing PETCO2 oscillations were attenuated and more evenly distributed over the frequency range. Ventilation (VT) responded to this manoeuvre with an upward trend that could not be ascribed to a slow CO2-response component, changes in metabolic rate or a dissociation of end-tidal and arterial PCO2. VT differences between reference and CO2-clamp experiments were abolished within a 3-min period following the termination of the external CO2 control. The present results suggest that the CO2-H+ stimulus plays a major role in adjusting ventilation when exercise intensity is decreased. The underlying CO2 effect appears to be neither additive nor bi-directionally symmetrical.

  19. Assessing Dehydration Employing End-Tidal Carbon Dioxide in Children With Vomiting and Diarrhea.

    Science.gov (United States)

    Freedman, Stephen B; Johnson, David W; Nettel-Aguirre, Alberto; Mikrogianakis, Angelo; Williamson-Urquhart, Sarah; Monfries, Nicholas; Cheng, Adam

    2017-05-23

    Serum bicarbonate reflects dehydration severity in children with gastroenteritis. Previous work in children receiving intravenous rehydration has correlated end-tidal carbon dioxide (EtCO2) with serum bicarbonate. We evaluated whether EtCO2 predicts weight change in children with vomiting and/or diarrhea. A prospective cohort study was conducted. Eligible children were 3 months to 10 years old and presented for emergency department (ED) care because of vomiting and/or diarrhea. End-tidal carbon dioxide measurements were performed after triage. The diagnostic standard was weight change determined from serial measurements after symptom resolution. A receiver operating characteristic curve was constructed to identify a cut-point to predict 5% or more dehydration. In total, 195 children were enrolled. Among the 169 (87%) with EtCO2 measurements, the median (interquartile range [IQR]) was 30.4 (27.8 to 33.1). One hundred fifty-eight had repeat weights performed at home; the median (IQR) weight change from ED presentation to well weight was +0.06 (-0.14 to +0.30) or +0.72% (-1.2% to +2.1%). Sixteen percent (25/158) had 3% or more and 4% (6/158) had 5% or more weight gain (ie, percent dehydration). One hundred sixteen (60%) completed home follow-up and had acceptable EtCO2 recordings. Receiver operating curve analysis revealed an area under the curve of 0.34 (95% confidence interval, 0.06 to 0.62) for EtCO2 as a predictor of 5% or more dehydration. The limited accuracy of EtCO2 measurement to predict 5% or more dehydration precludes its use as a tool to assess dehydration severity in children. End-tidal carbon dioxide monitoring does not have the ability to identify those children with 5% or more dehydration in a cohort of children with vomiting and/or diarrhea presenting for ED care.

  20. Transient influence of end-tidal carbon dioxide tension on the postural restraint in cerebral perfusion

    DEFF Research Database (Denmark)

    Immink, R.V.; Truijen, J.; Secher, Niels H.

    2009-01-01

    In the upright position, cerebral blood flow is reduced, maybe because arterial carbon dioxide partial pressure (Pa(CO(2))) decreases. We evaluated the time-dependent influence of a reduction in Pa(CO(2)), as indicated by the end-tidal Pco(2) tension (Pet(CO(2))), on cerebral perfusion during head......-up tilt. Mean arterial pressure, cardiac output, middle cerebral artery mean flow velocity (MCA V(mean)), and dynamic cerebral autoregulation at supine rest and 70 degrees head-up tilt were determined during free breathing and with Pet(CO(2)) clamped to the supine level. The postural changes in central...... hemodynamic variables were equivalent, and the cerebrovascular autoregulatory capacity was not significantly affected by tilt or by clamping Pet(CO(2)). In the first minute of tilt, the decline in MCA V(mean) (10 +/- 4 vs. 3 +/- 4 cm/s; mean +/- SE; P

  1. Application of end-tidal carbon dioxide monitoring via distal gas samples in ventilated neonates.

    Science.gov (United States)

    Jin, Ziying; Yang, Maoying; Lin, Ru; Huang, Wenfang; Wang, Jiangmei; Hu, Zhiyong; Shu, Qiang

    2017-08-01

    Previous research has suggested correlations between the end-tidal partial pressure of carbon dioxide (P ET CO 2 ) and the partial pressure of arterial carbon dioxide (PaCO 2 ) in mechanically ventilated patients, but both the relationship between P ET CO 2 and PaCO 2 and whether P ET CO 2 accurately reflects PaCO 2 in neonates and infants are still controversial. This study evaluated remote sampling of P ET CO 2 via an epidural catheter within an endotracheal tube to determine the procedure's clinical safety and efficacy in the perioperative management of neonates. Abdominal surgery was performed under general anesthesia in 86 full-term newborns (age 1-30 days, weight 2.55-4.0 kg, American Society of Anesthesiologists class I or II). The infants were divided into 2 groups (n = 43 each), and carbon dioxide (CO 2 ) gas samples were collected either from the conventional position (the proximal end) or a modified position (the distal end) of the epidural catheter. The P ET CO 2 measured with the new method was significantly higher than that measured with the traditional method, and the difference between P ET CO 2 and PaCO 2 was also reduced. The accuracy of P ET CO 2 measured increased from 78.7% to 91.5% when the modified sampling method was used. The moderate correlation between P ET CO 2 and PaCO 2 by traditional measurement was 0.596, which significantly increased to 0.960 in the modified sampling group. Thus, the P ET CO 2 value was closer to that of PaCO 2 . P ET CO 2 detected via modified carbon dioxide monitoring had a better accuracy and correlation with PaCO 2 in neonates. Copyright © 2017. Published by Elsevier B.V.

  2. End-tidal carbon dioxide monitoring during flexible fiberoptic ...

    African Journals Online (AJOL)

    Arterial oxygen saturation is usually monitored with pulse oximetry Spo2) during FFB; END-TIDAL Pco2) (ET-Pco2) monitoring is not routinely used. Two-hundred patients were studied between May 1998 till April 2003, at the divisions of chest surgery and pulmonolgy at King Hussein Medical Center, (khmc). Their ages ...

  3. [Correlation between end-tidal carbon dioxide and partial pressure of arterial carbon dioxide in ventilated newborns].

    Science.gov (United States)

    Feng, Jin-Xing; Liu, Xiao-Hong; Huang, Hui-Jun; Yu, Zhen-Zhu; Yang, Hui; He, Liu-Fang

    2014-05-01

    To study the correlation between end-tidal carbon dioxide (PetCO2) and partial pressure of arterial carbon dioxide (PaCO2) in ventilated newborns. Thirty-one ventilated newborn underwent mainstream PetCO2 monitoring; meanwhile, arterial blood gas analysis was performed. The correlation and consistency between PetCO2 and PaCO2 were assessed. A total of 85 end-tidal and arterial CO2 pairs were obtained from 31 ventilated newborns. The mean PetCO2 (41±10 mm Hg) was significantly lower than the corresponding mean PaCO2 (46±11 mm Hg) (Plimits of consistency, -3.3 to 13.6 mmHg), and 5% (4/85) of the points were beyond the 95%CI. When the oxygenation index (OI) was less than 300 mm Hg (n=48), there was a significant positive correlation between PetCO2 and PaCO2 (r=0.85, Plimits of consistency, -2.6 to 14.5 mm Hg), and 4.2% (2/48) of the points were beyond the 95%CI. When the OI was more than 300 mm Hg (n=37), there was also a significant positive correlation between PetCO2 and PaCO2 (r=0.91, Plimits of consistency, -3.9 to 12.1 mm Hg), and 5% (2/37) of the points were beyond the 95%CI. There is a good correlation and consistency between PetCO2 and PaCO2 in ventilated newborns.

  4. [Transbronchoscopic end-tidal carbon dioxide detection for location of the leading bronchus in patients with pneumothorax].

    Science.gov (United States)

    Zeng, Yiming; Lin, Huihuang

    2015-04-01

    To evaluate the effect of end-tidal carbon dioxide (EtCO2) detection for location of the leading bronchus in patients with pneumothorax. Transbronchoscopic EtCO2 detection was performed in 4 patients with intractable pneumothorax in whom transbronchoscopic balloon detection failed to localize the leading bronchus. A specific bronchus was suspected to be the leading bronchus when its EtCO2 value was significantly lower than that of the main bronchus of the affected lung. After the pleural air leakage was successfully sealed by bronchial occlusion of the suspected bronchus, the EtCO2 was confirmed to indicate the leading bronchus. Transbronchoscopic EtCO2 detection successfully located the leading bronchus in all 4 patients. Transbronchoscopic EtCO2 detection is a new method of locating the leading bronchus in patients with intractable pneumothorax.

  5. Change in end-tidal carbon dioxide outperforms other surrogates for change in cardiac output during fluid challenge.

    Science.gov (United States)

    Lakhal, K; Nay, M A; Kamel, T; Lortat-Jacob, B; Ehrmann, S; Rozec, B; Boulain, T

    2017-03-01

    During fluid challenge, volume expansion (VE)-induced increase in cardiac output (Δ VE CO) is seldom measured. In patients with shock undergoing strictly controlled mechanical ventilation and receiving VE, we assessed minimally invasive surrogates for Δ VE CO (by transthoracic echocardiography): fluid-induced increases in end-tidal carbon dioxide (Δ VE E'CO2 ); pulse (Δ VE PP), systolic (Δ VE SBP), and mean systemic blood pressure (Δ VE MBP); and femoral artery Doppler flow (Δ VE FemFlow). In the absence of arrhythmia, fluid-induced decrease in heart rate (Δ VE HR) and in pulse pressure respiratory variation (Δ VE PPV) were also evaluated. Areas under the receiver operating characteristic curves (AUC ROC s) reflect the ability to identify a response to VE (Δ VE CO ≥15%). In 86 patients, Δ VE E'CO2 had an AUC ROC =0.82 [interquartile range 0.73-0.90], significantly higher than the AUC ROC for Δ VE PP, Δ VE SBP, Δ VE MBP, and Δ VE FemFlow (AUC ROC =0.61-0.65, all P  1 mm Hg (>0.13 kPa) had good positive (5.0 [2.6-9.8]) and fair negative (0.29 [0.2-0.5]) likelihood ratios. The 16 patients with arrhythmia had similar relationships between Δ VE E'CO2 and Δ VE CO to patients with regular rhythm ( r 2 =0.23 in both subgroups). In 60 patients with no arrhythmia, Δ VE E'CO2 (AUC ROC =0.84 [0.72-0.92]) outperformed Δ VE HR (AUC ROC =0.52 [0.39-0.66], P AUC ROC =0.73 [0.60-0.84], P =0.21). In the 45 patients with no arrhythmia and receiving ventilation with tidal volume AUC ROC =0.86 [0.72-0.95] vs 0.66 [0.49-0.80], P =0.02. Δ VE E'CO2 outperformed Δ VE PP, Δ VE SBP, Δ VE MBP, Δ VE FemFlow, and Δ VE HR and, during protective ventilation, arrhythmia, or both, it also outperformed Δ VE PPV. A value of Δ VE E'CO2 >1 mm Hg (>0.13 kPa) indicated a likely response to VE. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  6. CO2 volume fluxes outgassing from champagne glasses: the impact of champagne ageing.

    Science.gov (United States)

    Liger-Belair, Gérard; Villaume, Sandra; Cilindre, Clara; Jeandet, Philippe

    2010-02-15

    It was demonstrated that CO(2) volume fluxes outgassing from a flute poured with a young champagne (elaborated in 2007) are much higher than those outgassing from the same flute poured with an older champagne (elaborated in the early 1990s). The difference in dissolved-CO(2) concentrations between the two types of champagne samples was found to be a crucial parameter responsible for differences in CO(2) volume fluxes outgassing from one champagne to another. Nevertheless, it was shown that, for a given identical dissolved-CO(2) concentration in both champagne types, the CO(2) volume flux outgassing from the flute poured with the old champagne is, in average, significantly lower than that outgassing from the flute poured with the young one. Therefore, CO(2) seems to "escape" more easily from the young champagne than from the older one. The diffusion coefficient of CO(2) in both champagne types was pointed as a key parameter to thoroughly determine in the future, in order to unravel our experimental observation. Copyright 2009 Elsevier B.V. All rights reserved.

  7. Implementation of a novel postoperative monitoring system using automated Modified Early Warning Scores (MEWS) incorporating end-tidal capnography.

    Science.gov (United States)

    Blankush, Joseph M; Freeman, Robbie; McIlvaine, Joy; Tran, Trung; Nassani, Stephen; Leitman, I Michael

    2017-10-01

    Modified Early Warning Scores (MEWS) provide real-time vital sign (VS) trending and reduce ICU admissions in post-operative patients. These early warning calculations classically incorporate oxygen saturation, heart rate, respiratory rate, systolic blood pressure, and temperature but have not previously included end-tidal CO2 (EtCO 2 ), more recently identified as an independent predictor of critical illness. These systems may be subject to failure when physiologic data is incorrectly measured, leading to false alarms and increased workload. This study investigates whether the implementation of automated devices that utilize ongoing vital signs monitoring and MEWS calculations, inclusive of a score for end-tidal CO 2 (EtCO 2 ), can be feasibly implemented on the general care hospital floor and effectively identify derangements in a post-operative patient's condition while limiting the amount of false alarms that would serve to increase provider workload. From July to November 2014, post-operative patients meeting the inclusion criteria (BMI > 30 kg/m 2 , history of obstructive sleep apnea, or the use of patient-controlled analgesia (PCA) or epidural narcotics) were monitored using automated devices that record minute-by-minute VS included in classic MEWS calculations as well as EtCO 2 . Automated messages via pagers were sent to providers for instances when the device measured elevated MEWS, abnormal EtCO 2 , and oxygen desaturations below 85 %. Data, including alarm and message details from the first 133 patients, were recorded and analyzed. Overall, 3.3 alarms and pages sounded per hour of monitoring. Device-only alarms sounded 2.7 times per hour-21 % were technical alarms. The remaining device-only alarms for concerning VS sounded 2.0/h, 70 % for falsely recorded VS. Pages for abnormal EtCO 2 sounded 0.4/h (82 % false recordings) while pages for low blood oxygen saturation sounded 0.1/h (55 % false alarms). 143 times (0.1 pages/h) the devices calculated

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

    African Journals Online (AJOL)

    Metabolic effects of Carbon Dioxide (CO 2 ) insufflation during laparoscopic surgery: changes in pH, arterial partial Pressure of Carbon Dioxide (PaCo 2 ) and End Tidal Carbon Dioxide (EtCO 2 ) ... Respiratory adjustments were done for EtCO2 levels above 60mmHg or SPO2 below 92% or adverse haemodynamic changes.

  9. Use of 'ideal' alveolar air equations and corrected end-tidal PCO2 to estimate arterial PCO2 and physiological dead space during exercise in patients with heart failure.

    Science.gov (United States)

    Van Iterson, Erik H; Olson, Thomas P

    2018-01-01

    Arterial CO 2 tension (PaCO 2 ) and physiological dead space (V D ) are not routinely measured during clinical cardiopulmonary exercise testing (CPET). Abnormal changes in PaCO 2 accompanied by increased V D directly contribute to impaired exercise ventilatory function in heart failure (HF). Because arterial catheterization is not standard practice during CPET, this study tested the construct validity of PaCO 2 and V D prediction models using 'ideal' alveolar air equations and basic ventilation and gas-exchangegas exchange measurements during CPET in HF. Forty-seven NYHA class II/III HF (LVEF=21±7%; age=55±9years; male=89%; BMI=28±5kg/m 2 ) performed step-wise cycle ergometry CPET to volitional fatigue. Breath-by-breath ventilation and gas exchange were measured continuously. Steady-state PaCO 2 was measured at rest and peak exercise via radial arterial catheterization. Criterion V D was calculated via 'ideal' alveolar equations, whereas PaCO 2 or V D models were based on end-tidal CO 2 tension (P ET CO 2 ), tidal volume (V T ), and/or weight. Criterion measurements of PaCO 2 (38±5 vs. 33±5mmHg, Pgas exchange and ventilatory responses demonstrate acceptable agreement with criterion measurements at peak exercise in HF patients. Routine assessment of PaCO 2 and V D can be used to improve interpretability of exercise ventilatory responses in HF. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  10. Influence of CO2 and nitrogen limitation on the coccolith volume of Emiliania huxleyi (Haptophyta

    Directory of Open Access Journals (Sweden)

    A. Talec

    2012-10-01

    Full Text Available Coccolithophores, a key phytoplankton group, are one of the most studied organisms regarding their physiological response to ocean acidification/carbonation. The biogenic production of calcareous coccoliths has made coccolithophores a promising group for paleoceanographic research aiming to reconstruct past environmental conditions. Recently, geochemical and morphological analyses of fossil coccoliths have gained increased interest in regard to changes in seawater carbonate chemistry. The cosmopolitan coccolithophore Emiliania huxleyi (Lohm. Hay and Mohler was cultured over a range of pCO2 levels in controlled laboratory experiments under nutrient replete and nitrogen limited conditions. Measurements of photosynthesis and calcification revealed, as previously published, an increase in particulate organic carbon production and a moderate decrease in calcification from ambient to elevated pCO2. The enhancement in particulate organic carbon production was accompanied by an increase in cell diameter. Changes in coccolith volume were best correlated with the coccosphere/cell diameter and no significant correlation was found between the coccolith volume and the particulate inorganic carbon production. The conducted experiments revealed that the coccolith volume of E. huxleyi is variable with aquatic CO2 concentration but its sensitivity is rather small in comparison with its sensitivity to nitrogen limitation. Comparing coccolith morphological and geometrical parameters like volume, mass and size to physiological parameters under controlled laboratory conditions is an important step to understand variations in fossil coccolith geometry.

  11. Upper airway CO2 receptors in tegu lizards: localization and ventilatory sensitivity.

    Science.gov (United States)

    Coates, E L; Ballam, G O

    1987-01-01

    1. Tidal volume, end-tidal CO2, and ventilatory frequency in Tupinambis nigropunctatus were measured in response to CO2 (1-4%) delivered to either the mouth or nares. Additionally, the sensitivity of the ventilatory response to nasal CO2 was evaluated at CO2 concentrations less than 1%. The ventilatory parameters were also measured in response to CO2 (1-4%) delivered to the nares after the olfactory peduncle was transected. 2. It was found that (0.4-4%) nasal CO2 depressed ventilatory frequency by 9% to 83% respectively, while tidal volume was not significantly altered. CO2 (1-4%) delivered to the mouth produced no apparent changes in any of the ventilatory parameters. Following transection of the olfactory peduncle, nasal CO2 was ineffective in producing any change in ventilatory frequency or depth. 3. These findings indicate that CO2-sensitive receptors are located in either the nasal or vomeronasal membranes of tegu lizards and that the olfactory peduncle must be intact for these receptors to affect ventilatory changes in response to elevated CO2 concentrations. The receptors are capable of mediating a ventilatory response to CO2 concentrations lower than those found in either expired air or in confined spaces such as occupied burrows. 4. The discrepancies in the ventilatory responses of lizards and snakes to inspired CO2 reported in past experiments may be partially explained by the presence of nasal or vomeronasal CO2-sensitive receptors.

  12. CO2 measurements during transcranial Doppler examinations in headache patients

    DEFF Research Database (Denmark)

    Thomsen, L L; Iversen, Helle Klingenberg

    1994-01-01

    Transcranial Doppler (TCD) examinations are increasingly being used in studies of headache pathophysiology. Because blood velocity is highly dependent on PCO2, these parameters should be measured simultaneously. The most common way of performing measurements during TCD examinations is as end......-tidal pCO2 with a capnograph. When patients are nauseated and vomit, as in migraine, the mask or mouthpiece connected to the capnograph represents a problem. We therefore evaluated whether a transcutaneous pCO2 electrode was as useful as the capnograph for pCO2 measurements in TCD examinations. We...... conclude that this is not the case, and recommend capnographic end-tidal pCO2 measurements during TCD examinations. However, transcutaneous pCO2 measurements may represent a supplement to spot measurements of end-tidal pCO2 in stable conditions when long-term monitoring is needed, and the mask...

  13. Increased requirement for minute ventilation and negative arterial to end-tidal carbon dioxide gradient may indicate malignant hyperthermia

    Directory of Open Access Journals (Sweden)

    Ho-Tien Lin

    2014-04-01

    Full Text Available Characteristic signs of malignant hyperthermia (MH include unexplained tachycardia, increased end-tidal carbon dioxide (Etco2 concentration, metabolic and respiratory acidosis, and an increase in body temperature above 38.8°C. We present the case of a patient with highly probable MH. In addition to sinus tachycardia and metabolic and respiratory acidosis, this patient also had a negative arterial to Etco2 gradient and an increased requirement for minute ventilation to maintain a normal Etco2 concentration, with signs of increased CO2 production. Despite these signs of MH, the patient's rectal temperature monitoring equipment did not show an increase in temperature, although the temperature measured in the mouth was increased. This case illustrates the unreliability of measuring rectal temperature as a means of reflecting body temperature during MH and the usefulness of increased CO2 production signs in helping to diagnose MH.

  14. Exhaled CO2 Parameters as a Tool to Assess Ventilation-Perfusion Mismatching during Neonatal Resuscitation in a Swine Model of Neonatal Asphyxia

    OpenAIRE

    Li, Elliott Shang-shun; Cheung, Po-Yin; O'Reilly, Megan; LaBossiere, Joseph; Lee, Tze-Fun; Cowan, Shaun; Bigam, David L.; Schm?lzer, Georg Marcus

    2016-01-01

    Background End-tidal CO2 (ETCO2), partial pressure of exhaled CO2 (PECO2), and volume of expired CO2 (VCO2) can be continuously monitored non-invasively to reflect pulmonary ventilation and perfusion status. Although ETCO2 ?14mmHg has been shown to be associated with return of an adequate heart rate in neonatal resuscitation and quantifying the PECO2 has the potential to serve as an indicator of resuscitation quality, there is little information regarding capnometric measurement of PECO2 and ...

  15. End-tidal control vs. manually controlled minimal-flow anesthesia: a prospective comparative trial.

    Science.gov (United States)

    Wetz, A J; Mueller, M M; Walliser, K; Foest, C; Wand, S; Brandes, I F; Waeschle, R M; Bauer, M

    2017-11-01

    To ensure safe general anesthesia, manually controlled anesthesia requires constant monitoring and numerous manual adjustments of the gas dosage, especially for low- and minimal-flow anesthesia. Oxygen flow-rate and administration of volatile anesthetics can also be controlled automatically by anesthesia machines using the end-tidal control technique, which ensures constant end-tidal concentrations of oxygen and anesthetic gas via feedback and continuous adjustment mechanisms. We investigated the hypothesis that end-tidal control is superior to manually controlled minimal-flow anesthesia (0.5 l/min). In this prospective trial, we included 64 patients undergoing elective surgery under general anesthesia. We analyzed the precision of maintenance of the sevoflurane concentration (1.2-1.4%) and expiratory oxygen (35-40%) and the number of necessary adjustments. Target-concentrations of sevoflurane and oxygen were maintained at more stable levels with the use of end-tidal control (during the first 15 min 28% vs. 51% and from 15 to 60 min 1% vs. 19% deviation from sevoflurane target, P tidal oxygen (5, IQR 3-6). The target-concentrations were reached earlier with the use of end-tidal compared with manual controlled minimal-flow anesthesia but required slightly greater use of anesthetic agents (6.9 vs. 6.0 ml/h). End-tidal control is a superior technique for setting and maintaining oxygen and anesthetic gas concentrations in a stable and rapid manner compared with manual control. Consequently, end-tidal control can effectively support the anesthetist. © 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. Anaesthesia for laparoscopic nephrectomy: Does end-tidal carbon dioxide measurement correlate with arterial carbon dioxide measurement?

    Science.gov (United States)

    Jayan, Nithin; Jacob, Jaya Susan; Mathew, Mohan

    2018-04-01

    Not many studies have explored the correlation between arterial carbon dioxide tension (PaCO 2 ) and end-tidal carbon dioxide tension (ETCO 2 ) in surgeries requiring pneumoperitoneum of more than 1 hour duration with the patient in non-supine position. The aim of our study was to evaluate the correlation of ETCO 2 with PaCO 2 in patients undergoing laparoscopic nephrectomy under general anaesthesia. A descriptive study was performed in thirty patients undergoing laparoscopic nephrectomy from September 2014 to August 2015. The haemodynamic parameters, minute ventilation, PaCO 2 and ETCO 2 measured at three predetermined points during the procedure were analysed. Correlation was checked using Pearson's Correlation Coefficient Test. P <0.05 was considered statistically significant. Statistical analysis of the values showed a positive correlation between ETCO 2 and PaCO 2 ( P < 0.05). Following carbon dioxide insufflation, both ETCO 2 and PaCO 2 increased by 5.4 and 6.63 mmHg, respectively, at the end of the 1 st hour. The PaCO 2 -ETCO 2 gradient was found to increase during the 1 st hour following insufflation (4.07 ± 2.05 mmHg); it returned to the pre-insufflation values in another hour (2.93 ± 1.43 mmHg). Continuous ETCO 2 monitoring is a reliable indicator of the trend in arterial CO 2 fluctuations in the American Society of Anesthesiologists Grades 1 and 2 patients undergoing laparoscopic nephrectomy under general anaesthesia.

  17. Anesthetic Overdose Leading to Cardiac Arrest Diagnosed by End-Tidal Inhalant Concentration Analysis in a Dog

    Directory of Open Access Journals (Sweden)

    Erik Hofmeister

    2013-01-01

    Full Text Available A 5-year-old male-castrated Cocker Spaniel presented to the Veterinary Teaching Hospital of the University of Georgia for a total ear canal ablation. Premedication was with carprofen 2.2 mg/kg SQ, hydromorphone 0.1 mg/kg IM, diazepam 0.2 mg/kg IM, and glycopyrrolate 0.01 mg/kg IM. The patient was induced with lidocaine 2 mg/kg IV and etomidate 1 mg/kg IV and maintained with sevoflurane and a constant rate infusion consisting of lidocaine 0.05 mg/kg/min. Before surgery start, the patient’s systolic arterial blood pressure was 110 mmHg, heart rate (HR was 85 beats/min, respiratory rate was 8 breaths/min, end-tidal sevoflurane concentration was 3.2%, and end-tidal CO2 (ETCO2 was 23 mmHg. As a scrub was being performed, the patient’s HR abruptly dropped to 20 beats/min over the course of 2 minutes. His ETCO2 simultaneously decreased to 16 mmHg. At this time, cardiopulmonary arrest was diagnosed. After two minutes of resuscitation, a spontaneous heart beat was obtained and the patient was successfully recovered and discharged without further incident. The cardiac arrest in this case is most likely attributable to an overdose of inhalant anesthesia, which was diagnosed by an anesthetic inhalant concentration monitor. A gas analyzer may be a helpful contribution to the small animal practitioner, particularly those performing more lengthy or complex procedures.

  18. Quantification of a maximum injection volume of CO2 to avert geomechanical perturbations using a compositional fluid flow reservoir simulator

    Science.gov (United States)

    Jung, Hojung; Singh, Gurpreet; Espinoza, D. Nicolas; Wheeler, Mary F.

    2018-02-01

    Subsurface CO2 injection and storage alters formation pressure. Changes of pore pressure may result in fault reactivation and hydraulic fracturing if the pressure exceeds the corresponding thresholds. Most simulation models predict such thresholds utilizing relatively homogeneous reservoir rock models and do not account for CO2 dissolution in the brine phase to calculate pore pressure evolution. This study presents an estimation of reservoir capacity in terms of allowable injection volume and rate utilizing the Frio CO2 injection site in the coast of the Gulf of Mexico as a case study. The work includes laboratory core testing, well-logging data analyses, and reservoir numerical simulation. We built a fine-scale reservoir model of the Frio pilot test in our in-house reservoir simulator IPARS (Integrated Parallel Accurate Reservoir Simulator). We first performed history matching of the pressure transient data of the Frio pilot test, and then used this history-matched reservoir model to investigate the effect of the CO2 dissolution into brine and predict the implications of larger CO2 injection volumes. Our simulation results -including CO2 dissolution- exhibited 33% lower pressure build-up relative to the simulation excluding dissolution. Capillary heterogeneity helps spread the CO2 plume and facilitate early breakthrough. Formation expansivity helps alleviate pore pressure build-up. Simulation results suggest that the injection schedule adopted during the actual pilot test very likely did not affect the mechanical integrity of the storage complex. Fault reactivation requires injection volumes of at least about sixty times larger than the actual injected volume at the same injection rate. Hydraulic fracturing necessitates much larger injection rates than the ones used in the Frio pilot test. Tested rock samples exhibit ductile deformation at in-situ effective stresses. Hence, we do not expect an increase of fault permeability in the Frio sand even in the presence of

  19. Functional Response of Tumor Vasculature to PaCO2: Determination of Total and Microvascular Blood Volume by MRI

    Directory of Open Access Journals (Sweden)

    Scott D. Packard

    2003-07-01

    Full Text Available In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered PaCO2. Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total CBV increased by 0.6±0.1%/mm Hg CO2 whereas normal striatum increased by 1.5±0.2%/mm Hg CO2, (P < .0001, group t-test. Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO2. Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.

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

    Directory of Open Access Journals (Sweden)

    A. Yaghoobi Notash

    2004-06-01

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

  1. Effect of one-lung ventilation on end-tidal carbon dioxide during cardiopulmonary resuscitation in a pig model of cardiac arrest.

    Science.gov (United States)

    Ryu, Dong Hyun; Jung, Yong Hun; Jeung, Kyung Woon; Lee, Byung Kook; Jeong, Young Won; Yun, Jong Geun; Lee, Dong Hun; Lee, Sung Min; Heo, Tag; Min, Yong Il

    2018-01-01

    Unrecognized endobronchial intubation frequently occurs after emergency intubation. However, no study has evaluated the effect of one-lung ventilation on end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR). We compared the hemodynamic parameters, blood gases, and ETCO2 during one-lung ventilation with those during conventional two-lung ventilation in a pig model of CPR, to determine the effect of the former on ETCO2. A randomized crossover study was conducted in 12 pigs intubated with double-lumen endobronchial tube to achieve lung separation. During CPR, the animals underwent three 5-min ventilation trials based on a randomized crossover design: left-lung, right-lung, or two-lung ventilation. Arterial blood gases were measured at the end of each ventilation trial. Ventilation was provided using the same tidal volume throughout the ventilation trials. Comparison using generalized linear mixed model revealed no significant group effects with respect to aortic pressure, coronary perfusion pressure, and carotid blood flow; however, significant group effect in terms of ETCO2 was found (P < 0.001). In the post hoc analyses, ETCO2 was lower during the right-lung ventilation than during the two-lung (P = 0.006) or left-lung ventilation (P < 0.001). However, no difference in ETCO2 was detected between the left-lung and two-lung ventilations. The partial pressure of arterial carbon dioxide (PaCO2), partial pressure of arterial oxygen (PaO2), and oxygen saturation (SaO2) differed among the three types of ventilation (P = 0.003, P = 0.001, and P = 0.001, respectively). The post hoc analyses revealed a higher PaCO2, lower PaO2, and lower SaO2 during right-lung ventilation than during two-lung or left-lung ventilation. However, the levels of these blood gases did not differ between the left-lung and two-lung ventilations. In a pig model of CPR, ETCO2 was significantly lower during right-lung ventilation than during two-lung ventilation. However

  2. Financial and environmental costs of manual versus automated control of end-tidal gas concentrations.

    Science.gov (United States)

    Tay, S; Weinberg, L; Peyton, P; Story, D; Briedis, J

    2013-01-01

    Emerging technologies that reduce the economic and environmental costs of anaesthesia have had limited assessment. We hypothesised that automated control of end-tidal gases, a new feature in anaesthesia machines, will consistently reduce volatile agent consumption cost and greenhouse gas emissions. As part of the planned replacement of anaesthesia machines in a tertiary hospital, we performed a prospective before and after study comparing the cost and greenhouse gas emissions of isoflurane, sevoflurane and desflurane when using manual versus automated control of end-tidal gases. We analysed 3675 general anaesthesia cases with inhalational agents: 1865 using manual control and 1810 using automated control. Volatile agent cost was $18.87/hour using manual control and $13.82/hour using automated control: mean decrease $5.05/hour (95% confidence interval: $0.88-9.22/hour, P=0.0243). The 100-year global warming potential decreased from 23.2 kg/hour of carbon dioxide equivalents to 13.0 kg/hour: mean decrease 10.2 kg/hour (95% confidence interval: 2.7-17.7 kg/hour, P=0.0179). Automated control reduced costs by 27%. Greenhouse gas emissions decreased by 44%, a greater than expected decrease facilitated by a proportional reduction in desflurane use. Automated control of end-tidal gases increases participation in low flow anaesthesia with economic and environmental benefits.

  3. The design, development, and test of balloonborne and groundbased lidar systems. Volume 1: Balloonborne coherent CO2 lidar system

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Rappaport, S. A.

    1991-06-01

    This is Volume 1 of a three volume final report on the design, development, and test of balloonborne and groundbased lidar systems. Volume 2 describes the flight test of Atmospheric Balloonborne Lidar Experiment, ABLE 2, which successfully made atmospheric density backscatter measurements during a flight over White Sands Missile Range. Volume 3 describes groundbased lidar development and measurements, including the design of a telescope dome lidar installation, the design of a transportable lidar shed for remote field sites, and field measurements of atmospheric and cloud backscatter from Ascension Island during SABLE 89 and Terciera, Azores during GABLE 90. In this volume, Volume 1, the design and fabrication of a balloonborne CO2 coherent lidar payload are described. The purpose of this payload is to measure, from altitudes greater than 20 km, the 10.6 micrometers backscatter from atmospheric aerosols as a function of altitude. Minor modifications to the lidar would provide for aerosol velocity measurements to be made. The lidar and payload system design was completed, and major components were fabricated and assembled. These tasks have been successfully completed, and recommendations for further lidar measurements and data analysis have been made.

  4. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...

  5. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... in cerebral hemodynamics than noncontrast-enhanced imaging. The results of the deconvolution analysis suggested that perfusion calculation by conventional tracer kinetic methods may be impracticable because of nonlinear effects in contrast-enhanced MR imaging....

  6. Evaluation of a transportable capnometer for monitoring end-tidal carbon dioxide

    DEFF Research Database (Denmark)

    Hildebrandt, T; Tobiasen, Malene Espelund; Olsen, K S

    2010-01-01

    We compared a small and transportable Capnometer (EMMA™) with a reference capnometer, the Siesta i TS Anaesthesia. During air-breathing through a facemask, both the EMMA (nine modules) and reference capnometer sampled expired gas simultaneously. A wide range of end-tidal carbon dioxide values were...... obtained during inhalation of carbon dioxide and voluntary hyperventilation. The median IQR [range] difference between all sets of carbon dioxide values (EMMA - reference) was -0.3 (-0.6 to 0.0 [-1.7 to 1.6] kPa; n = 297) using new batteries, which was statistically significant (p = 0.04) and located...... to two of the nine EMMAs tested. Using batteries with reduced voltage did not influence the measurements. The 95% CI of the medians of the differences were -0.4 to -0.2. We conclude that the EMMA can slightly under-read the end-tidal carbon dioxide but is generally comparable with a free-standing monitor...

  7. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... to be in accordance with results obtained by other methods. Noncontrast functional MR (fMR) imaging showed signal increases in gray matter, but also inconsistent changes in some white matter regions. CONCLUSION: In this experiment, contrast-enhanced imaging seemed to show a somewhat higher sensitivity towards changes...

  8. Evaluation of Low versus High Volume per Minute Displacement CO2 Methods of Euthanasia in the Induction and Duration of Panic-Associated Behavior and Physiology

    Directory of Open Access Journals (Sweden)

    Debra L. Hickman

    2016-08-01

    Full Text Available Current recommendations for the use of CO 2 as a euthanasia agent for rats require the use of gradual fill protocols (such as 10% to 30% volume displacement per minute in order to render the animal insensible prior to exposure to levels of CO 2 that are associated with pain. However, exposing rats to CO 2 , concentrations as low as 7% CO 2 are reported to cause distress and 10%–20% CO 2 induces panic-associated behavior and physiology, but loss of consciousness does not occur until CO 2 concentrations are at least 40%. This suggests that the use of the currently recommended low flow volume per minute displacement rates create a situation where rats are exposed to concentrations of CO 2 that induce anxiety, panic, and distress for prolonged periods of time. This study first characterized the response of male rats exposed to normoxic 20% CO 2 for a prolonged period of time as compared to room air controls. It demonstrated that rats exposed to this experimental condition displayed clinical signs consistent with significantly increased panic-associated behavior and physiology during CO 2 exposure. When atmospheric air was then again delivered, there was a robust increase in respiration rate that coincided with rats moving to the air intake. The rats exposed to CO 2 also displayed behaviors consistent with increased anxiety in the behavioral testing that followed the exposure. Next, this study assessed the behavioral and physiologic responses of rats that were euthanized with 100% CO 2 infused at 10%, 30%, or 100% volume per minute displacement rates. Analysis of the concentrations of CO 2 and oxygen in the euthanasia chamber and the behavioral responses of the rats suggest that the use of the very low flow volume per minute displacement rate (10% may prolong the duration of panicogenic ranges of ambient CO 2 , while the use of the higher flow volume per minute displacement rate (100% increases agitation. Therefore, of the volume displacement per

  9. Appropriate xenon-inhalation speed in xenon-enhanced CT using the end-tidal gas-sampling method

    International Nuclear Information System (INIS)

    Suga, Sadao; Toya, Shigeo; Kawase, Takeshi; Koyama, Hideki; Shiga, Hayao

    1986-01-01

    This report describes some problems when end-tidal xenon gas is substituted for the arterial xenon concentration in xenon-enhanced CT. The authors used a newly developed xenon inhalator with a xenon-gas-concentration analyzer and performed xenon-enhanced CT by means of the ''arterio-venous shunt'' method and the ''end-tidal gas-sampling'' method simultaneously. By the former method, the arterial build-up rate (K) was obtained directly from the CT slices of a blood circuit passing through the phantom. By the latter method, it was calculated from the xenon concentration of end-tidal gas sampled from the mask. The speed of xenon supply was varied between 0.6 - 1.2 L/min. in 11 patients with or without a cerebral lesion. The results revealed that rapid xenon inhalation caused a discrepancy in the arterial K between the ''shunt'' method and the ''end-tidal'' method. This discrepancy may be responsible for the mixing of inhalated gas and expired gas in respiratory dead space, such as the nasal cavity or the mask. The cerebral blood flow was underestimated because of the higher arterial K in the latter method. Too much slow inhalation, however, was timewasting, and it increased the body motion in the subanesthetic state. Therefore, an inhalation speed of the arterial K of as much as 0.2 was ideal to represent the end-tidal xenon concentration for the arterial K in the ''end-tidal gas-sampling'' method. When attention is given to this point, this method may offer a reliable absolute value in xenon-enhanced CT. (author)

  10. Improved method to determine the molar volume and compositions of the NaCl-H2O-CO2 system inclusion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of Parry’s method (1986), an improved method was established to determine the molar volume (Vm) and compositions (X) of the NaCl-H2O-CO2 (NHC) system inclusion. To use this method, the determination of Vm-X only requires three microthermometric data of a NHC inclusion: partial homog-enization temperature (Th ,CO2), salinity (S) and total homogenization temperature (Th). Theoretically, four associated equations are needed containing four unknown parameters: X CO2, XNaCl, Vm and F (volume fraction of CO2 phase in total inclusion when occurring partial homogenization). When they are released, the Vm-X are determined. The former three equations, only correlated with Th ,CO2, S and F, have simplified expressions:XCO2=f1(Th,CO2,S,F),XNaCl=f2(Th,CO2,S,F),Vm=f3(Th,CO2,S,F). The last one is the thermodynamic relationship of X CO2, XNaCl, Vm and Th:f4(XCO2,XNaCl,Vm,Th)=0.Since the above four associated equations are complicated, it is necessary to adopt iterative technique to release them. The technique can be described by:(i) Freely input a F value (0≤F≤1),with Th ,CO2 and S, into the former three equations. As a result,X CO 2,XNaCl and the molar volume value recorded as Vm1 are derived. (ii) Input the X CO2 and XNaCl gotten in the step above into the last equation, and another molar volume value recorded as Vm2 is determined. (iii) If Vm1 is unequal to Vm2, the calculation will be restarted from “(i)”. The iteration is completed until Vm1 is equal to Vm2, which means that the four associated equations are released. Compared to Parry’s (1986) solution method, the improved method is more convenient to use, as well as more accurate to determine X CO 2. It is available for a NHC inlusion whose partial homogenization temperature is higher than clatherate melting temperature and there are no solid salt crystals in the inclusion at parital homogenization.

  11. [Likeness between respiratory responses on CO2 in conditions of natural breathing and voluntary-controlled mechanical ventilation].

    Science.gov (United States)

    Pogodin, M A; Granstrem, M P; Dimitrienko, A I

    2007-04-01

    We did Read CO2 rebreathing tests in 8 adult males. Both at natural breathing, and at self-controlled mechanical ventilation, volunteers increased ventilation proportionally to growth end-tidal PCO2. Inside individual distinctions of responses to CO2 during controlled mechanical ventilation are result of the voluntary motor control.

  12. The effect of two different intra-operative end-tidal carbon dioxide tensions on apnoeic duration in the recovery period in horses.

    Science.gov (United States)

    Thompson, Kate R; Bardell, David

    2016-03-01

    To compare the effect of two different intraoperative end-tidal carbon dioxide tensions on apnoeic duration in the recovery period in horses. Prospective randomized clinical study. Eighteen healthy client-owned adult horses (ASA I-II) admitted for elective surgery. Horses were of a median body mass of 595 (238-706) kg and a mean age of 9 ± 5 years. A standardized anaesthetic protocol was used. Horses were positioned in dorsal recumbency and randomly allocated to one of two groups. Controlled mechanical ventilation (CMV) was adjusted to maintain the end-tidal carbon dioxide tension (Pe'CO2 ) at 40 ± 5 mmHg (5.3 ± 0.7 kPa) (group 40) or 60 ± 5 mmHg (8.0 ± 0.7 kPa) (group 60). Arterial blood gas analysis was performed at the start of the anaesthetic period (T0), at one point during the anaesthetic (T1), immediately prior to disconnection from the breathing system (T2) and at the first spontaneous breath in the recovery box (T3). The time from disconnection from the breathing system to return to spontaneous ventilation (RSV) was recorded. Data were analysed using a two sample t-test or the Mann-Whitney U-test and significance assigned when p breathing significantly earlier than those in group 40, [52 (14-151) and 210 (103-542) seconds, respectively] (p tension (PaO2 ), pH, base excess (BE) and plasma bicarbonate (HCO3-) were not different between the groups at RSV, however, PaO2 was significantly lower in group 60 during (T1) and at the end of anaesthesia (T2). Aiming to maintain intra-operative Pe'CO2 at 60 ± 5 mmHg (8.0 ± 0.7 kPa) in mechanically ventilated horses resulted in more rapid RSV compared with when Pe'CO2 was maintained at 40 ± 5 mmHg (5.3 ± 0.7 kPa). © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  13. Validation of the MIPAS CO2 volume mixing ratio in the mesosphere and lower thermosphere and comparison with WACCM simulations

    Science.gov (United States)

    López-Puertas, Manuel; Funke, B.; Jurado-Navarro, Á. A.; García-Comas, M.; Gardini, A.; Boone, C. D.; Rezac, L.; Garcia, R. R.

    2017-08-01

    We present the validation of Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) CO2 daytime concentration in the mesosphere and lower thermosphere by comparing with Atmospheric Chemistry Experiment (ACE) Fourier transform spectrometer and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) data. MIPAS shows a very good agreement with ACE below 100 km with differences of ˜5%. Above 100 km, MIPAS CO2 is generally lower than ACE with differences growing from ˜5% at 100 km to 20-40% near 110-120 km. Part of this disagreement can be explained by the lack of a nonlocal thermodynamic equilibrium correction in ACE. MIPAS also agrees very well (˜5%) with SABER below 100 km. At 90-105 km, MIPAS is generally smaller than SABER by 10-30% in the polar summers. At 100-120 km, MIPAS and SABER CO2 agree within ˜10% during equinox but, for solstice, MIPAS is larger by 10-25%, except near the polar summer. Whole Atmosphere Community Climate Model (WACCM) CO2 shows the major MIPAS features. At 75-100 km, the agreement is very good (˜5%), with maximum differences of ˜10%. At 95-115 km MIPAS CO2 is larger than WACCM by 20-30% in the winter hemisphere but smaller (20-40%) in the summer. Above 95-100 km WACCM generally overestimates MIPAS CO2 by about 20-80% except in the polar summer where underestimates it by 20-40%. MIPAS CO2 favors a large eddy diffusion below 100 km and suggests that the meridional circulation of the lower thermosphere is stronger than in WACCM. The three instruments and WACCM show a clear increase of CO2 with time, more markedly at 90-100 km.

  14. Improved method to determine the molar volume and compositions of the NaCl-H2O-CO2 system inclusion

    Institute of Scientific and Technical Information of China (English)

    SONG YuCai; HU WenXuan; NI Pei; DUAN ZhenHao; ZHANG XueFeng

    2007-01-01

    On the basis of Parry's method (1986),an improved method was established to determine the molar volume(Vm)and compositions(X)of the NaCl-H2O-CO2(NHC)system inclusion.To use this method,the determination of Vm-X only requires three microthermometric data of a NHC inclusion:partial homogenization temperature(Th,CO2),salinity(s)and total homogenization temperature(Th).Theoretically,four associated equations are needed containing four unknown parameters:Xco2,XNcl,Vm and F (volume fraction of CO2 phase in total inclusion when occurring partial homogenization).When they are released,the Vm-X are determined.The former three equations,only correlated with Th,co2,S and F,have simplified expressions:XCO2=f1(Th,CO2,S,F),XNaCl=f2(Th,CO2,S,F),Vm=f3(Th,CO2,S,F).The last one is the thermodynamic relationship of Xco2,Xnacl,vm and Th:f4(XCO2,XNacl,Vm,Th)=0. Since the above four associated equations are complicated,it is necessary to adopt iterative technique to release them.The technique can be described by:(i)Freely input a F value(0≤F≤1),with Th,co2 and S,into the former three equations.As a result,Xco2,XNacl and the molar volume value recorded as Vm1 are derived.(ii)Input the Xco2 and XNacl gotten in the step above into the last equation,and another molar volume value recorded as Vm2 is determined.(iii) If Vm1 is unequal to Vm2,the calculation will be restarted from"(i)".The iteration is completed until Vm1 is equal to Vm2,which means that the four associated equations are released.Compared to Parry's (1986) solution method,the improved method is more convenient to use,as well as more accurate to determine Xco2.It is available for a NHC inlusion whose partial homogenization temperature is higher than clatherate melting temperature and there are no solid salt crystals in the inclusion at parital homogenization.

  15. Monitoring a large volume CO2 injection: Year two results from SECARB project at Denbury’s Cranfield, Mississippi, USA

    Science.gov (United States)

    Hovorka, Susan D.; Meckel, Timothy A.; Trevino, Ramon H.; Lu, Jiemin; Nicot, Jean-Philippe; Choi, Jong-Won; Freeman, David; Cook, Paul; Daley, Thomas M.; Ajo-Franklin, Jonathan B.; Freifeild, Barry M.; Doughty, Christine; Carrigan, Charles R.; La Brecque, Doug; Kharaka, Yousif K.; Thordsen, James J.; Phelps, Tommy J.; Yang, Changbing; Romanak, Katherine D.; Zhang, Tongwei; Holt, Robert M.; Lindler, Jeffery S.; Butsch, Robert J.

    2011-01-01

    The Southeast Regional Carbon Sequestration Partnership (SECARB) early project in western Mississippi has been testing monitoring tools and approaches to document storage efficiency and storage permanence under conditions of CO2 EOR as well as downdip injection into brine. Denbury Onshore LLC is host for the study and has brought a depleted oil and gas reservoir, Cranfield Field, under CO2 flood. Injection was started in July 2008 and has now achieved injection rates greater than 1.2 million tons/year though 23 wells, with cumulative mass injected as of August, 2010 of 2.2 million metric tons. Injection is into coarse grained fluvial deposits of the Cretaceous lower Tuscaloosa Formation in a gentle anticline at depths of 3300 m. A team of researchers from 10 institutions has collected data from five study areas, each with a different goal and different spatial and temporal scale.

  16. Appropriate xenon-inhalation time in xenon-enhanced CT using the end-tidal gas-sampling method

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Hideo; Furuhata, Shigeru; Onozuka, Satoshi; Uchida, Koichi; Fujii, Koji; Suga, Sadao; Kawase, Takeshi; Toya, Shigeo; Shiga, Hayao

    1988-12-01

    For the end-tidal gas-sampling method of xenon-enhanced CT (Xe-CT), the respective functional images of K, lambda, and the regional cerebral blood flow (rCBF) were studied and compared using the data at 7-, 10-, 15- and 25-minute inhalations. The most appropriate inhalation time of xenon gas was evaluated in 14 clinical cases. An end-tidal xenon curve which represents the arterial xenon concentration was monitored with a xenon analyzer; the xenon concentration was gradually increased to a level of 50% by using a xenon inhalator with a closed circuit to prevent the overestimation of the xenon concentration sampled from the mask. Serial CT scans were taken over a period of 25 minutes of inhalation. The functional images of K, lambda, and rCBF were calculated for serial CT scans for 7, 10, 15 and 25 minutes using Fick's equation. Those various images and absolute values were then compared. The rCBF value of a 15-minute inhalation was approximately 15% greater than that of 25 minutes, while the values of K, lambda, rCBF from a 15-minute inhalation were significantly correlated to those from 25 minutes. The regression line made it possible to estimate 25-minute inhalation values from those of 15 minutes. In imaging, the rCBF mapping of the 15-minute inhalation was found to be more reliable than that of 25 minutes. This study suggests that the minimal time of xenon inhalation is 15 minutes for the end-tidal gas-sampling method. A longer inhalation may be necessary for the estimation of rCBF in the low-flow area, such as the white matter or the pathological region.

  17. CO2 chemical valorization

    International Nuclear Information System (INIS)

    Kerlero De Rosbo, Guillaume; Rakotojaona, Loic; Bucy, Jacques de; Clodic, Denis; Roger, Anne-Cecile; El Khamlichi, Aicha; Thybaud, Nathalie; Oeser, Christian; Forti, Laurent; Gimenez, Michel; Savary, David; Amouroux, Jacques

    2014-07-01

    Facing global warming, different technological solutions exist to tackle carbon dioxide (CO 2 ) emissions. Some inevitable short term emissions can be captured so as to avoid direct emissions into the atmosphere. This CO 2 must then be managed and geological storage seems to currently be the only way of dealing with the large volumes involved. However, this solution faces major economic profitability and societal acceptance challenges. In this context, alternative pathways consisting in using CO 2 instead of storing it do exist and are generating growing interest. This study ordered by the French Environment and Energy Management Agency (ADEME), aims at taking stock of the different technologies used for the chemical conversion of CO 2 in order to have a better understanding of their development potential by 2030, of the conditions in which they could be competitive and of the main actions to be implemented in France to foster their emergence. To do this, the study was broken down into two main areas of focus: The review and characterization of the main CO 2 chemical conversion routes for the synthesis of basic chemical products, energy products and inert materials. This review includes a presentation of the main principles underpinning the studied routes, a preliminary assessment of their performances, advantages and drawbacks, a list of the main R and D projects underway, a focus on emblematic projects as well as a brief analysis of the markets for the main products produced. Based on these elements, 3 routes were selected from among the most promising by 2030 for an in-depth modelling and assessment of their energy, environmental and economic performances. The study shows that the processes modelled do have favorable CO 2 balances (from 1 to 4 t-CO 2 /t-product) and effectively constitute solutions to reduce CO 2 emissions, despite limited volumes of CO 2 in question. Moreover, the profitability of certain solutions will remain difficult to reach, even with an

  18. Compressed liquid densities and excess molar volumes for (CO2 + 1-pentanol) binary system at temperatures from 313 to 363 K and pressures up to 25 MPa

    International Nuclear Information System (INIS)

    Zuniga-Moreno, Abel; Galicia-Luna, Luis A.; Sandler, Stanley I.

    2008-01-01

    Measurements of compressed liquid densities for 1-pentanol and for {CO 2 (1) + 1-pentanol (2)} system were carried out at temperatures from 313 K to 363 K and pressures up to 25 MPa. Densities were measured for binary mixtures at 10 different compositions, x 1 = 0.0816, 0.1347, 0.3624, 0.4651, 0.6054, 0.7274, 0.8067, 0.8573, 0.9216, and 0.9757. A vibrating tube densimeter was used to perform density measurements using two reference calibration fluids. The uncertainty is estimated to be better than ±0.2 kg . m -3 for the experimental density measurements. For each mixture and for 1-pentanol, the experimental densities were correlated using an explicit volume equation of six parameters and an 11-parameter equation of state (EoS). Excess molar volumes were determined for the (CO 2 + 1-pentanol) system using 1-pentanol densities calculated from the 11-parameter EoS and CO 2 densities calculated from a multiparameter reference EoS

  19. Remote operated vehicle with CO2 blasting (ROVCO2): Volume 1. Final report, September 1993--July 1996

    International Nuclear Information System (INIS)

    1996-06-01

    This report documents the second phase of the Remote Operated Vehicle with CO 2 Blasting (ROVCO 2 ) Program. The ROVCO 2 Program's goal is to develop and demonstrate a tool to improve the productivity of concrete floor decontamination. The second phase integrated non-developmental subsystems on to the ROVCO 2 system and performed quantitative decontamination effectiveness, productivity, and reliability testings. The report documents these development activities and the analysis of cost and performance. The results show that the ROVCO 2 system is an efficient decontamination tool

  20. Effect of breathing fluctuations on cerebral blood flow in demented patients and its correction method using end-tidal CO/sub 2/ concentration

    Energy Technology Data Exchange (ETDEWEB)

    Komatani, Akio; Yamaguchi, Koichi; Kera, Masahiro; Takanashi, Toshiyasu; Shinohara, Masao; Kawakatsu, Shinobu; Yazaki, Mitsuyasu

    1989-02-01

    During mouthpiece respiration of Xe-133 for a measurement of regional cerebral blood flow (rCBF), the breathing pattern of patients fluctuated and it caused a change of end-tidal CO/sub 2/ concentration that had an excellent correlation with PaCO/sub 2/ in patients without respiratory disease. The end-tidal CO/sub 2/ concentration of demented patients varied within lower ranges than senile control group. The range of fluctuation on the end-tidal CO/sub 2/ concentration was dependent on the type and the degree of dementia, and it fluctuated most widely at the middle stage of Alzheimer disease. Mean cerebral blood flow increased by 13.9% for each l% increase in end-tidal CO/sub 2/ concentration (3.6%/mmHg PaCO/sub 2/) in the case of demented patients without cerebrovascular disease. To improve the reliability of rCBF in demented patients, especially in Alzheimer disease, the correction of rCBF data for end-tidal CO/sub 2/ concentration should be performed.

  1. Data supporting the use of end-tidal carbon dioxide (ETCO2 measurement to guide management of cardiac arrest: A systematic review

    Directory of Open Access Journals (Sweden)

    Edison F. Paiva

    2018-06-01

    Full Text Available The data presented in this article are related to the research article, “The Use of End-Tidal Carbon Dioxide (ETCO2 Measurement to Guide Management of Cardiac Arrest: A Systematic Review” [1]. This article is a systematic review and meta-analysis of existing data on the subject of whether any level of end-tidal carbon dioxide (ETCO2 measured during cardiopulmonary resuscitation (CPR correlates with return of spontaneous circulation (ROSC or survival in adult patients experiencing cardiac arrest in any setting. These data are made publicly available to enable critical or extended analyses. Keywords: Cardiac arrest, End tidal carbon dioxide, Prognostication, Advanced cardiac life support, Capnography, Systematic review, Meta-analysis

  2. SPATIOTEMPORAL VISUALIZATION OF TIME-SERIES SATELLITE-DERIVED CO2 FLUX DATA USING VOLUME RENDERING AND GPU-BASED INTERPOLATION ON A CLOUD-DRIVEN DIGITAL EARTH

    Directory of Open Access Journals (Sweden)

    S. Wu

    2017-10-01

    Full Text Available The ocean carbon cycle has a significant influence on global climate, and is commonly evaluated using time-series satellite-derived CO2 flux data. Location-aware and globe-based visualization is an important technique for analyzing and presenting the evolution of climate change. To achieve realistic simulation of the spatiotemporal dynamics of ocean carbon, a cloud-driven digital earth platform is developed to support the interactive analysis and display of multi-geospatial data, and an original visualization method based on our digital earth is proposed to demonstrate the spatiotemporal variations of carbon sinks and sources using time-series satellite data. Specifically, a volume rendering technique using half-angle slicing and particle system is implemented to dynamically display the released or absorbed CO2 gas. To enable location-aware visualization within the virtual globe, we present a 3D particlemapping algorithm to render particle-slicing textures onto geospace. In addition, a GPU-based interpolation framework using CUDA during real-time rendering is designed to obtain smooth effects in both spatial and temporal dimensions. To demonstrate the capabilities of the proposed method, a series of satellite data is applied to simulate the air-sea carbon cycle in the China Sea. The results show that the suggested strategies provide realistic simulation effects and acceptable interactive performance on the digital earth.

  3. Thermal decomposition pathway of undoped and doped zinc layered gallate nanohybrid with Fe 3+, Co 2+ and Ni 2+ to produce mesoporous and high pore volume carbon material

    Science.gov (United States)

    Ghotbi, Mohammad Yeganeh; bin Hussein, Mohd Zobir; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

    2009-12-01

    A series of brucite-like materials, undoped and doped zinc layered hydroxide nitrate with 2% (molar) Fe 3+, Co 2+ and Ni 2+ were synthesized. Organic-inorganic nanohybrid material with gallate anion as a guest, and zinc hydroxide nitrate, as an inorganic layered host was prepared by the ion-exchange method. The nanohybrid materials were heat-treated at various temperatures, 400-700 °C. X-ray diffraction, thermal analysis and also Fourier transform infrared results showed that incorporation of the doping agents within the zinc layered hydroxide salt layers has enhanced the heat-resistivity of the nanohybrid materials in the thermal decomposition pathway. Porous carbon materials can be obtained from the heat-treating the nanohybrids at 600 and 700 °C. Calcination of the nanohybrids at 700 °C under nitrogen atmosphere produces mesoporous and high pore volume carbon materials.

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

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2017-01-01

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

  5. Effects of sodium bicarbonate on the end-tidal CO[sub 2], PaCO[sub 2], HCO[sub 3][sup -], PH and cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Komatani, Akio; Akutsu, Tooru; Yoshida, Michihiko; Yamaguchi, Koichi; Seo, Hiroshi (Yamagata Univ. (Japan). School of Medicine)

    1992-09-01

    To estimate the quantitative reactivity of cerebral blood flow (CBF), the effects of sodium bicarbonate on the end-tidal CO[sub 2], arterial partial pressure of CO[sub 2] (PaCO[sub 2]), HCO[sub 3][sup -], pH and CBF were examined. The CBF was measured by [sup 133]Xe inhalation method with ring type SPECT (HEADTOME). Activation study with sodium bicarbonate administration was performed after 30 minutes of resting study, and the reactivity of each parameters was investigated. The arterial HCO[sub 3][sup -] and pH increased with similar reactivity, but PaCO[sub 2], end-tidal CO[sub 2] and CBF in the non-injured hemisphere changed with irregular reactivity. The excellent correlation between PaCO[sub 2] and end-tidal CO[sub 2] was vanished by the administration of sodium bicarbonate. The reactivity of CBF did not correlate with reactivity of PaCO[sub 2] and end-tidal CO[sub 2], but correlated with arterial HCO[sub 3][sup -] and pH. Thus the measurement of arterial HCO[sub 3][sup -] and pH may be indispensable to estimate the CBF reactivity with the administration of sodium bicarbonate. (author).

  6. CO2 blood test

    Science.gov (United States)

    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 ...

  7. Measuring End-Tidal Carbon Monoxide of Jaundiced Neonates in the Birth Hospital to Identify Those with Hemolysis.

    Science.gov (United States)

    Christensen, Robert D; Malleske, Daniel T; Lambert, Diane K; Baer, Vickie L; Prchal, Josef T; Denson, Leslie E; Gerday, Erick; Weaver Lewis, Kimberlee A; Shepherd, JuLyn G

    2016-01-01

    End-tidal breath carbon monoxide (ETCOc) levels correlate with catabolism of heme, but until recently, this measurement was not readily available for application to neonatology practice. We performed a prospective, multihospital, test-of-concept study where ETCOc was measured during the birth hospitalization of neonates with a total bilirubin (TB) value >75th percentile on the Bhutani bilirubin nomogram. This was done to test the feasibility and ease of use of this new device. Neonates with an elevated ETCOc (with a >95th percentile reference interval previously established) were labeled as having 'hemolytic jaundice'. We recommended a follow-up TB check jaundice treatment compared with a rate of 2.99 rehospitalizations per 100 control neonates who had a TB value >75th percentile (p = 0.079). ETCOc measurement is a feasible means of assessing hemolysis in jaundiced neonates during the birth hospitalization. When hemolysis is identified, parents are likely to comply with instructions to bring the infant for a TB checkup <24 h after discharge home. © 2015 S. Karger AG, Basel.

  8. End-tidal CO₂ detection of an audible heart rate during neonatal cardiopulmonary resuscitation after asystole in asphyxiated piglets.

    Science.gov (United States)

    Chalak, Lina F; Barber, Chad A; Hynan, Linda; Garcia, Damian; Christie, Lucy; Wyckoff, Myra H

    2011-05-01

    Even brief interruption of cardiac compressions significantly reduces critical coronary perfusion pressure during cardiopulmonary resuscitation (CPR). End-tidal CO₂ (ETCO₂) monitoring may provide a continuous noninvasive method of assessing return of spontaneous circulation (ROSC) without stopping to auscultate for heart rate (HR). However, the ETCO₂ value that correlates with an audible HR is unknown. Our objective was to determine the threshold ETCO₂ that is associated with ROSC after asphyxia-induced asystole. Neonatal swine (n = 46) were progressively asphyxiated until asystole occurred. Resuscitation followed current neonatal guidelines with initial ventilation with 100% O₂ followed by cardiac compressions followed by epinephrine for continued asystole. HR was auscultated every 30 s, and ETCO₂ was continuously recorded. A receiver operator curve was generated using the calculated sensitivity and specificity for various ETCO₂ values, where a positive test was defined as the presence of HR >60 bpm by auscultation. An ETCO₂ cut-off value of 14 mm Hg is the most sensitive ETCO₂ value with the least false positives. When using ETCO₂ to guide uninterrupted CPR in this model of asphyxia-induced asystole, auscultative confirmation of return of an adequate HR should be performed when ETCO₂ ≥ 14 mm Hg is achieved. Correlation during human neonatal CPR needs further investigation.

  9. Exhaled CO2 Parameters as a Tool to Assess Ventilation-Perfusion Mismatching during Neonatal Resuscitation in a Swine Model of Neonatal Asphyxia

    Science.gov (United States)

    Li, Elliott Shang-shun; Cheung, Po-Yin; O'Reilly, Megan; LaBossiere, Joseph; Lee, Tze-Fun; Cowan, Shaun; Bigam, David L.; Schmölzer, Georg Marcus

    2016-01-01

    Background End-tidal CO2 (ETCO2), partial pressure of exhaled CO2 (PECO2), and volume of expired CO2 (VCO2) can be continuously monitored non-invasively to reflect pulmonary ventilation and perfusion status. Although ETCO2 ≥14mmHg has been shown to be associated with return of an adequate heart rate in neonatal resuscitation and quantifying the PECO2 has the potential to serve as an indicator of resuscitation quality, there is little information regarding capnometric measurement of PECO2 and ETCO2 in detecting return of spontaneous circulation (ROSC) and survivability in asphyxiated neonates receiving cardiopulmonary resuscitation (CPR). Methods Seventeen newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia followed by apnea to induce asphyxia. Protocolized resuscitation was initiated when heart rate decreased to 25% of baseline. Respiratory and hemodynamic parameters including ETCO2, PECO2, VCO2, heart rate, cardiac output, and carotid artery flow were continuously measured and analyzed. Results There were no differences in respiratory and hemodynamic parameters between surviving and non-surviving piglets prior to CPR. Surviving piglets had significantly higher ETCO2, PECO2, VCO2, cardiac index, and carotid artery flow values during CPR compared to non-surviving piglets. Conclusion Surviving piglets had significantly better respiratory and hemodynamic parameters during resuscitation compared to non-surviving piglets. In addition to optimizing resuscitation efforts, capnometry can assist by predicting outcomes of newborns requiring chest compressions. PMID:26766424

  10. Exhaled CO2 Parameters as a Tool to Assess Ventilation-Perfusion Mismatching during Neonatal Resuscitation in a Swine Model of Neonatal Asphyxia.

    Directory of Open Access Journals (Sweden)

    Elliott Shang-shun Li

    Full Text Available End-tidal CO2 (ETCO2, partial pressure of exhaled CO2 (PECO2, and volume of expired CO2 (VCO2 can be continuously monitored non-invasively to reflect pulmonary ventilation and perfusion status. Although ETCO2 ≥14 mmHg has been shown to be associated with return of an adequate heart rate in neonatal resuscitation and quantifying the PECO2 has the potential to serve as an indicator of resuscitation quality, there is little information regarding capnometric measurement of PECO2 and ETCO2 in detecting return of spontaneous circulation (ROSC and survivability in asphyxiated neonates receiving cardiopulmonary resuscitation (CPR.Seventeen newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia followed by apnea to induce asphyxia. Protocolized resuscitation was initiated when heart rate decreased to 25% of baseline. Respiratory and hemodynamic parameters including ETCO2, PECO2, VCO2, heart rate, cardiac output, and carotid artery flow were continuously measured and analyzed.There were no differences in respiratory and hemodynamic parameters between surviving and non-surviving piglets prior to CPR. Surviving piglets had significantly higher ETCO2, PECO2, VCO2, cardiac index, and carotid artery flow values during CPR compared to non-surviving piglets.Surviving piglets had significantly better respiratory and hemodynamic parameters during resuscitation compared to non-surviving piglets. In addition to optimizing resuscitation efforts, capnometry can assist by predicting outcomes of newborns requiring chest compressions.

  11. Gas dispersal potential of infant bedding of sudden death cases. (I): CO2 accumulation around the face of infant mannequin model.

    Science.gov (United States)

    Sakai, Jun; Takahashi, Shirushi; Funayama, Masato

    2009-04-01

    We assessed CO(2) gas dispersal potential of bedding that had actually been used by 26 infants diagnosed with sudden unexpected infant death using a baby mannequin model. The age of victims ranged from 1 to 12 months. In some cases, the parents alleged that the infant faces were not covered with bedding when they were found. The parent's memories, however, may not have been accurate; therefore, we examined the potential for gas dispersal based on the supposition that the bedding had covered their faces. The mannequin was connected with a respirator set on the tidal volume and respiratory rates matched with the baby's age. Before measuring, CO(2) flow was regulated in 5%+/-0.1% of end-tidal PCO(2). After the model was placed on each bedding condition, measurements were performed at least five times under each respiratory condition. Four cases showed a plateau of FiCO(2) bedding. Especially, the latter seven bedding could have high rebreathing potential if they covered the infant's faces and the probability of environmental asphyxia should be considered.

  12. CO2 sequestration

    International Nuclear Information System (INIS)

    Favre, E.; Jammes, L.; Guyot, F.; Prinzhofer, A.; Le Thiez, P.

    2009-01-01

    This document presents the summary of a conference-debate held at the Academie des Sciences (Paris, France) on the topic of CO 2 sequestration. Five papers are reviewed: problems and solutions for the CO 2 sequestration; observation and surveillance of reservoirs; genesis of carbonates and geological storage of CO 2 ; CO 2 sequestration in volcanic and ultra-basic rocks; CO 2 sequestration, transport and geological storage: scientific and economical perspectives

  13. Alberta industrial synergy CO2 programs initiative

    International Nuclear Information System (INIS)

    Yildirim, E.

    1998-01-01

    The various industrial sectors within Alberta produce about 350,000 tonnes of CO 2 per day. This presentation was concerned with how this large volume and high concentration of CO 2 can be used in industrial and agricultural applications, because every tonne of CO 2 used for such purposes is a tonne that does not end up in the atmosphere. There is a good potential for an industrial synergy between the producers and users of CO 2 . The Alberta Industrial Synergy CO 2 Programs Initiative was established to ultimately achieve a balance between the producers of CO 2 and the users of CO 2 by creating ways to use the massive quantities of CO 2 produced by Alberta's hydrocarbon-based economy. The Alberta CO 2 Research Steering Committee was created to initiate and support CO 2 programs such as: (1) CO 2 use in enhanced oil recovery, (2) creation of a CO 2 production inventory, (3) survey of CO 2 users and potential users, (4) investigation of process issues such as power generation, oil sands and cement manufacturing, and (5) biofixation by plants, (6) other disposal options (e.g. in depleted oil and gas reservoirs, in aquifers, in tailings ponds, in coal beds). The single most important challenge was identified as 'rationalizing the formation of the necessary infrastructure'. Failing to do that will greatly impede efforts directed towards CO 2 utilization

  14. End-tidal concentration of sevoflurane for preventing rocuronium-induced withdrawal of the arm in pediatric patients.

    Science.gov (United States)

    Yeom, Jong Hoon; Kim, Yong Oh; Lee, Jae Min; Jeon, Woo Jae

    2014-04-01

    During induction of general anesthesia, the intravenous injection of rocuronium is often associated with withdrawal movement of the arm due to pain, and this abrupt withdrawal may result in dislodgement of the venous catheter, injury, or inadequate injection of rocuronium. We performed this study to evaluate the 50 and 95% effective end-tidal concentrations of sevoflurane (ETsev) for preventing rocuronium-induced withdrawal of the arm. We conducted a prospective double-blind study in 31 pediatric patients. After free flow of lactated Ringer's IV fluid was confirmed, anesthesia was induced in the patients by using 2.5% thiopental sodium (4 mg/kg) and sevoflurane (4 vol%) with 6 L/min of oxygen. When the target ETsev was reached, preservative-free 1% lidocaine (1.5 mg/kg) was intravenously injected during manual venous occlusion and rocuronium (0.6 mg/kg) was injected after lidocaine injection under free-flow intravenous fluid. A nurse who was an investigator and was blinded to the ETsev injected the rocuronium. The nurse evaluated the response. Non-withdrawal movement was observed in 5 out of 11 patients with ETsev 3.0 vol% and in 5 out of 6 patients with ETsev 3.5 vol%. By Dixon's up-and-down method, the 50% effective concentration (EC50) of sevoflurane for non-withdrawal movement at rocuronium injection was 3.1 ± 0.4 vol%. A logistic regression curve of the probability of non-withdrawal movements showed that the 50% effective ETsev for abolishing withdrawal movement at rocuronium injection was 2.9 vol% (95% confidence interval [CI] 2.4-3.8 vol%) and the 95% effective ETsev was 4.3 vol% (95% CI 3.6-9.8 vol%). This study showed that the 50 and 95% effective ETsev that prevent withdrawal movement at rocuronium injection are 2.9 and 4.3 vol%, respectively.

  15. A quantitative comparison of physiologic indicators of cardiopulmonary resuscitation quality: Diastolic blood pressure versus end-tidal carbon dioxide.

    Science.gov (United States)

    Morgan, Ryan W; French, Benjamin; Kilbaugh, Todd J; Naim, Maryam Y; Wolfe, Heather; Bratinov, George; Shoap, Wesley; Hsieh, Ting-Chang; Nadkarni, Vinay M; Berg, Robert A; Sutton, Robert M

    2016-07-01

    The American Heart Association (AHA) recommends monitoring invasive arterial diastolic blood pressure (DBP) and end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR) when available. In intensive care unit patients, both may be available to the rescuer. The objective of this study was to compare DBP vs. ETCO2 during CPR as predictors of cardiac arrest survival. In two models of cardiac arrest (primary ventricular fibrillation [VF] and asphyxia-associated VF), 3-month old swine received either standard AHA guideline-based CPR or patient-centric, BP-guided CPR. Mean values of DBP and ETCO2 in the final 2min before the first defibrillation attempt were compared using receiver operating characteristic curves (area under curve [AUC] analysis). The optimal DBP cut point to predict survival was derived and subsequently validated in two independent, randomly generated cohorts. Of 60 animals, 37 (61.7%) survived to 45min. DBP was higher in survivors than in non-survivors (40.6±1.8mmHg vs. 25.9±2.4mmHg; pAUC analysis, DBP was superior to ETCO2 (0.82 vs. 0.60; p=0.025) in discriminating survivors from non-survivors. The optimal DBP cut point in the derivation cohort was 34.1mmHg. In the validation cohort, this cut point demonstrated a sensitivity of 0.78, specificity of 0.81, positive predictive value of 0.64, and negative predictive value of 0.89 for survival. In both primary and asphyxia-associated VF porcine models of cardiac arrest, DBP discriminates survivors from non-survivors better than ETCO2. Failure to attain a DBP >34mmHg during CPR is highly predictive of non-survival. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Usefulness of end-tidal carbon dioxide as an indicator of dehydration in pediatric emergency departments: A retrospective observational study.

    Science.gov (United States)

    Yang, Hee Won; Jeon, Woochan; Min, Young Gi; Lee, Ji Sook

    2017-09-01

    Physician assessment of hydration status is one of the most important factors in the management of dehydration in the pediatric emergency department (ED). Overestimating dehydration may lead to overtreatment with intravenous fluids or unnecessary hospitalization, whereas underestimation may lead to delayed therapy and aggravation of symptoms. Various methods to estimate hydration status have been proposed, including use of physical findings, body weight, and laboratory results. These methods are subjective, invasive, or inappropriate for application in the ED. A few studies have investigated the use of end-tidal carbon dioxide (ETCO2) as an acidosis parameter in cases of gastroenteritis and diabetic ketoacidosis. We aimed to evaluate the usefulness of ETCO2 as an objective and noninvasive dehydration parameter for children.A retrospective observational study was conducted in the regional emergency center of a tertiary university hospital for a period of 1 year. We included patients from the ED whose primary diagnosis was acute gastroenteritis. Among these, we enrolled patients with recorded ETCO2 and bicarbonate concentration (HCO3) levels. We collected information of clinical characteristics, vital signs, clinical dehydration scale (CDS) scores, laboratory test results, and final disposition. Correlations between ETCO2 and HCO3 as well as CDS scores were analyzed.A total of 105 children were finally enrolled in the study. All participants underwent laboratory testing and were mildly to severely dehydrated, with mean serum HCO3 20.7 ± 3.5 mmol/L. A total 95 (90.5%) patients had a CDS score dehydration, and 10 (9.5%) patients had CDS ≥5, considered moderate-to-severe dehydration. The mean ETCO2 level was 32.1 ± 6.1 mmHg. Pearson correlation indicated a weak link between ETCO2 and HCO3 (correlation coefficient = 0.32), despite being statistically significant (P = .001). In addition, ETCO2 and CDS score showed a weak negative correlation (r

  17. CO2NNIE

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  18. CO2 Capture and Reuse

    International Nuclear Information System (INIS)

    Thambimuthu, K.; Gupta, M.; Davison, J.

    2003-01-01

    CO2 capture and storage including its utilization or reuse presents an opportunity to achieve deep reductions in greenhouse gas emissions from fossil energy use. The development and deployment of this option could significantly assist in meeting a future goal of achieving stabilization of the presently rising atmospheric concentration of greenhouse gases. CO2 capture from process streams is an established concept that has achieved industrial practice. Examples of current applications include the use of primarily, solvent based capture technologies for the recovery of pure CO2 streams for chemical synthesis, for utilization as a food additive, for use as a miscible agent in enhanced oil recovery operations and removal of CO2 as an undesired contaminant from gaseous process streams for the production of fuel gases such as hydrogen and methane. In these applications, the technologies deployed for CO2 capture have focused on gas separation from high purity, high pressure streams and in reducing (or oxygen deficient) environments, where the energy penalties and cost for capture are moderately low. However, application of the same capture technologies for large scale abatement of greenhouse gas emissions from fossil fuel use poses significant challenges in achieving (at comparably low energy penalty and cost) gas separation in large volume, dilute concentration and/or low pressure flue gas streams. This paper will focus on a review of existing commercial methods of CO2 capture and the technology stretch, process integration and energy system pathways needed for their large scale deployment in fossil fueled processes. The assessment of potential capture technologies for the latter purpose will also be based on published literature data that are both 'transparent' and 'systematic' in their evaluation of the overall cost and energy penalties of CO2 capture. In view of the of the fact that many of the existing commercial processes for CO2 capture have seen applications in

  19. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  20. Outsourcing CO2 Emissions

    Science.gov (United States)

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

    2009-12-01

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

  1. CO2 flux from Javanese mud volcanism.

    Science.gov (United States)

    Queißer, M; Burton, M R; Arzilli, F; Chiarugi, A; Marliyani, G I; Anggara, F; Harijoko, A

    2017-06-01

    Studying the quantity and origin of CO 2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO 2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO 2 with a volume fraction of at least 16 vol %. A lower limit CO 2 flux of 1.4 kg s -1 (117 t d -1 ) was determined, in line with the CO 2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO 2 flux of 3 kt d -1 , comparable with the expected back-arc efflux of magmatic CO 2 . After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO 2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO 2 , with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO 2 fluxes.

  2. Modeling of CO2 storage in aquifers

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Santos, Juan E

    2011-01-01

    Storage of CO 2 in geological formations is a means of mitigating the greenhouse effect. Saline aquifers are a good alternative as storage sites due to their large volume and their common occurrence in nature. The first commercial CO 2 injection project is that of the Sleipner field in the Utsira Sand aquifer (North Sea). Nevertheless, very little was known about the effectiveness of CO 2 sequestration over very long periods of time. In this way, numerical modeling of CO 2 injection and seismic monitoring is an important tool to understand the behavior of CO 2 after injection and to make long term predictions in order to prevent CO 2 leaks from the storage into the atmosphere. The description of CO 2 injection into subsurface formations requires an accurate fluid-flow model. To simulate the simultaneous flow of brine and CO 2 we apply the Black-Oil formulation for two phase flow in porous media, which uses the PVT data as a simplified thermodynamic model. Seismic monitoring is modeled using Biot's equations of motion describing wave propagation in fluid-saturated poroviscoelastic solids. Numerical examples of CO 2 injection and time-lapse seismics using data of the Utsira formation show the capability of this methodology to monitor the migration and dispersal of CO 2 after injection.

  3. CO2 cycle

    Science.gov (United States)

    Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.

    2017-01-01

    This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

  4. CO2-strategier

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2008-01-01

    I 2007 henvendte Lyngby-Taarbæk kommunens Agenda 21 koordinator sig til Videnskabsbutikken og spurgte om der var interesse for at samarbejde om CO2-strategier. Da Videnskabsbutikken DTU er en åben dør til DTU for borgerne og deres organisationer, foreslog Videnskabsbutikken DTU at Danmarks...

  5. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

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

  6. CO2 flowrate calculator

    International Nuclear Information System (INIS)

    Carossi, Jean-Claude

    1969-02-01

    A CO 2 flowrate calculator has been designed for measuring and recording the gas flow in the loops of Pegase reactor. The analog calculator applies, at every moment, Bernoulli's formula to the values that characterize the carbon dioxide flow through a nozzle. The calculator electronics is described (it includes a sampling calculator and a two-variable function generator), with its amplifiers, triggers, interpolator, multiplier, etc. Calculator operation and setting are presented

  7. CO2 Acquisition Membrane (CAM)

    Science.gov (United States)

    Mason, Larry W.; Way, J. Douglas; Vlasse, Marcus

    2003-01-01

    The objective of CAM is to develop, test, and analyze thin film membrane materials for separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The membranes are targeted toward In Situ Resource Utilization (ISRU) applications that will operate in extraterrestrial environments and support future unmanned and human space missions. A primary application is the Sabatier Electrolysis process that uses Mars atmosphere CO2 as raw material for producing water, oxygen, and methane for rocket fuel and habitat support. Other applications include use as an inlet filter to collect and concentrate Mars atmospheric argon and nitrogen gases for habitat pressurization, and to remove CO2 from breathing gases in Closed Environment Life Support Systems (CELSS). CAM membrane materials include crystalline faujasite (FAU) zeolite and rubbery polymers such as silicone rubber (PDMS) that have been shown in the literature and via molecular simulation to favor adsorption and permeation of CO2 over nitrogen and argon. Pure gas permeation tests using commercial PDMS membranes have shown that both CO2 permeance and the separation factor relative to other gases increase as the temperature decreases, and low (Delta)P(Sub CO2) favors higher separation factors. The ideal CO2/N2 separation factor increases from 7.5 to 17.5 as temperature decreases from 22 C to -30 C. For gas mixtures containing CO2, N2, and Ar, plasticization decreased the separation factors from 4.5 to 6 over the same temperature range. We currently synthesize and test our own Na(+) FAU zeolite membranes using standard formulations and secondary growth methods on porous alumina. Preliminary tests with a Na(+) FAU membrane at 22 C show a He/SF6 ideal separation factor of 62, exceeding the Knudsen diffusion selectivity by an order of magnitude. This shows that the membrane is relatively free from large defects and associated non-selective (viscous flow) transport

  8. Lower tidal volume strategy (?3?ml/kg) combined with extracorporeal CO2 removal versus ?conventional? protective ventilation (6?ml/kg) in severe ARDS

    OpenAIRE

    Bein, Thomas; Weber-Carstens, Steffen; Goldmann, Anton; M?ller, Thomas; Staudinger, Thomas; Brederlau, J?rg; Muellenbach, Ralf; Dembinski, Rolf; Graf, Bernhard M.; Wewalka, Marlene; Philipp, Alois; Wernecke, Klaus-Dieter; Lubnow, Matthias; Slutsky, Arthur S.

    2013-01-01

    Background Acute respiratory distress syndrome is characterized by damage to the lung caused by various insults, including ventilation itself, and tidal hyperinflation can lead to ventilator induced lung injury (VILI). We investigated the effects of a low tidal volume (V T) strategy (V T???3?ml/kg/predicted body weight [PBW]) using pumpless extracorporeal lung assist in established ARDS. Methods Seventy-nine patients were enrolled after a ?stabilization period? (24?h with optimized therapy an...

  9. CO2 laser development

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The research and development programs on high-energy, short-pulse CO 2 lasers were begun at LASL in 1969. Three large systems are now either operating or are being installed. The Single-Beam System (SBS), a four-stage prototype, was designed in 1971 and has been in operation since 1973 with an output energy of 250 J in a 1-ns pulse with an on-target intensity of 3.5 x 10 14 W/cm 2 . The Dual-Beam System (DBS), now in the final stages of electrical and optical checkout, will provide about ten times more power for two-beam target irradiation experiments. Four such dual-beam modules are being installed in the Laser-Fusion Laboratory to provide an Eight-Beam System (EBS) scheduled for operation at the 5- to 10-TW level in 1977. A fourth system, a 100- to 200-TW CO 2 laser, is being designed for the High-Energy Gas Laser Facility (HEGLF) program

  10. Carbonation and CO2 uptake of concrete

    International Nuclear Information System (INIS)

    Yang, Keun-Hyeok; Seo, Eun-A; Tae, Sung-Ho

    2014-01-01

    This study developed a reliable procedure to assess the carbon dioxide (CO 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 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, and the substitution level of supplementary cementitious materials to the CO 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 2 diffusion coefficient and increased CO 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 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 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 2 emissions from concrete production, which roughly corresponds to 18%–21% of the CO 2 emissions from the production of ordinary Portland cement. - Highlights: • CO 2 uptake assessment approach owing to the

  11. CO2 Laser Market

    Science.gov (United States)

    Simonsson, Samuel

    1989-03-01

    It gives me a great deal of pleasure to introduce our final speaker of this morning's session for two reasons: First of all, his company has been very much in the news not only in our own community but in the pages of Wall Street Journal and in the world economic press. And, secondly, we would like to welcome him to our shores. He is a temporary resident of the United States, for a few months, forsaking his home in Germany to come here and help with the start up of a new company which we believe, probably, ranks #1 as the world supplier of CO2 lasers now, through the combination of former Spectra Physics Industrial Laser Division and Rofin-Sinar GMBH. Samuel Simonsson is the Chairman of the Board of Rofin-Sinar, Inc., here in the U.S. and managing director of Rofin-Sinar GMBH. It is a pleasure to welcome him.

  12. Lower tidal volume strategy (≈3 ml/kg) combined with extracorporeal CO2 removal versus 'conventional' protective ventilation (6 ml/kg) in severe ARDS: the prospective randomized Xtravent-study.

    Science.gov (United States)

    Bein, Thomas; Weber-Carstens, Steffen; Goldmann, Anton; Müller, Thomas; Staudinger, Thomas; Brederlau, Jörg; Muellenbach, Ralf; Dembinski, Rolf; Graf, Bernhard M; Wewalka, Marlene; Philipp, Alois; Wernecke, Klaus-Dieter; Lubnow, Matthias; Slutsky, Arthur S

    2013-05-01

    Acute respiratory distress syndrome is characterized by damage to the lung caused by various insults, including ventilation itself, and tidal hyperinflation can lead to ventilator induced lung injury (VILI). We investigated the effects of a low tidal volume (V(T)) strategy (V(T) ≈ 3 ml/kg/predicted body weight [PBW]) using pumpless extracorporeal lung assist in established ARDS. Seventy-nine patients were enrolled after a 'stabilization period' (24 h with optimized therapy and high PEEP). They were randomly assigned to receive a low V(T) ventilation (≈3 ml/kg) combined with extracorporeal CO2 elimination, or to a ARDSNet strategy (≈6 ml/kg) without the extracorporeal device. The primary outcome was the 28-days and 60-days ventilator-free days (VFD). Secondary outcome parameters were respiratory mechanics, gas exchange, analgesic/sedation use, complications and hospital mortality. Ventilation with very low V(T)'s was easy to implement with extracorporeal CO2-removal. VFD's within 60 days were not different between the study group (33.2 ± 20) and the control group (29.2 ± 21, p = 0.469), but in more hypoxemic patients (PaO2/FIO2 ≤150) a post hoc analysis demonstrated significant improved VFD-60 in study patients (40.9 ± 12.8) compared to control (28.2 ± 16.4, p = 0.033). The mortality rate was low (16.5%) and did not differ between groups. The use of very low V(T) combined with extracorporeal CO2 removal has the potential to further reduce VILI compared with a 'normal' lung protective management. Whether this strategy will improve survival in ARDS patients remains to be determined (Clinical trials NCT 00538928).

  13. CO2 emissions vs. CO2 responsibility: An input-output approach for the Turkish economy

    International Nuclear Information System (INIS)

    Ipek Tunc, G.; Tueruet-Asik, Serap; Akbostanci, Elif

    2007-01-01

    Recently, global warming (greenhouse effect) and its effects have become one of the hottest topics in the world agenda. There have been several international attempts to reduce the negative effects of global warming. The Kyoto Protocol can be cited as the most important agreement which tries to limit the countries' emissions within a time horizon. For this reason, it becomes important to calculate the greenhouse gas emissions of countries. The aim of this study is to estimate the amount of CO 2 -the most important greenhouse gas-emissions, for the Turkish economy. An extended input-output model is estimated by using 1996 data in order to identify the sources of CO 2 emissions and to discuss the share of sectors in total emission. Besides, 'CO 2 responsibility', which takes into account the CO 2 content of imports, is estimated for the Turkish economy. The sectoral CO 2 emissions and CO 2 responsibilities are compared and these two notions are linked to foreign trade volume. One of the main conclusions is that the manufacturing industry has the first place in both of the rankings for CO 2 emissions and CO 2 responsibilities, while agriculture and husbandry has the last place

  14. Forecasting global atmospheric CO2

    International Nuclear Information System (INIS)

    Agusti-Panareda, A.; Massart, S.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Engelen, R.; Jones, L.; Peuch, V.H.; Chevallier, F.; Ciais, P.; Paris, J.D.; Sherlock, V.

    2014-01-01

    A new global atmospheric carbon dioxide (CO 2 ) real-time forecast is now available as part of the preoperational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO 2 forecasting system is that the land surface, including vegetation CO 2 fluxes, is modelled online within the IFS. Other CO 2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO 2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO 2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO 2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO 2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO 2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO 2 fluxes also lead to accumulating errors in the CO 2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO 2 fluxes compared to total optimized fluxes and the atmospheric CO 2 compared to observations. The largest biases in the atmospheric CO 2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO 2 analyses based on the assimilation of CO 2 products retrieved from satellite

  15. Waste cleaning using CO2-acid microemulsion

    International Nuclear Information System (INIS)

    Park, Kwangheon; Sung, Jinhyun; Koh, Moonsung; Ju, Minsu

    2011-01-01

    Frequently we need to decontaminate radioactive wastes for volume reduction purposes. Metallic contaminants in wastes can be removed by dissolution to acid; however, this process produces a large amount of liquid acid waste. To reduce this 2ndary liquid waste, we suggest CO 2 -acid emulsion in removing metallic contaminants. Micro- and macro-emulsion of acid in liquid/supercritical CO 2 were successfully made. The formation region of microemulsion (water or acid in CO 2 ) was measured, and stability of the microemulsion was analyzed with respect to surfactant types. We applied micro- and macro-emulsion containing acid to the decontamination of radioactive metallic parts contaminated on the surface. The cleaning methods of micro- and macro-emulsion seemed better compared to the conventional acid cleaning. Moreover, these methods produce very small amount of secondary wastes. (author)

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Solubility comparison and partial molar volumes of 1,2-hexanediol before and after end-group modification by methyl oxalyl chloride and ethyl oxalyl monochloride in supercritical CO2

    International Nuclear Information System (INIS)

    Zhao, Lu; Yang, Hai-Jian; Cai, Zhuofu

    2013-01-01

    Highlights: ► Two new “CO 2 -philic” compounds were designed and synthesized. ► The tested solubility data were calculated and correlated with two models. ► Satisfactory agreements were obtained between the tested and calculated data. ► The partial molar volumes V ¯ 2 for three compounds were estimated. - Abstract: Bis(methoxy oxalic)-1,2-haxenediester and bis(ethoxy oxalic)-1,2-haxenediester were synthesized by modifying the end groups of 1,2-hexanediol with methyl oxalyl chloride and ethyl oxalyl monochloride. The solubilities of all three compounds in supercritical carbon dioxide were determined at different conditions of pressures (8.8 to 18.8) MPa and temperatures (313, 333, and 353) K. Then, the solubility data were correlated with the Bartle model and the Chrastil model. The average absolute relative deviation (AARD) for the Bartle model was in the range of (3.89 to 25.46)% which is within a good approximation. The Chrastil model also showed satisfactory agreement and the AARD was in the range of (3.70 to 16.92)%. Furthermore, the partial molar volumes of those compounds were estimated following the theory developed by Kumar and Johnston.

  18. Detection Test for Leakage of CO2 into Sodium Loop

    International Nuclear Information System (INIS)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong

    2015-01-01

    This report is about the facility for the detection test for leakage of CO 2 into sodium loop. The facility for the detection test for leakage of CO 2 into sodium loop was introduced. The test will be carried out. Our experimental results are going to be expected to be used for approach methods to detect CO 2 leaking into sodium in heat exchangers. A sodium-and-carbon dioxide (Na-CO 2 ) heat exchanger is one of the key components for the supercritical CO 2 Brayton cycle power conversion system of sodium-cooled fast reactors (SFRs). A printed circuit heat exchanger (PCHE) is considered for the Na-CO 2 heat exchanger, which is known to have potential for reducing the volume occupied by the exchangers compared to traditional shell-and-tube heat exchangers. Among various issues about the Na- CO 2 exchanger, detection of CO 2 leaking into sodium in the heat exchanger is most important thing for its safe operation. It is known that reaction products from sodium and CO 2 such as sodium carbonate (Na 2 CO 3 ) and amorphous carbon are hardly soluble in sodium, which cause plug sodium channels. Detection technique for Na 2 CO 3 in sodium loop has not been developed yet. Therefore, detection of CO 2 and CO from reaction of sodium and CO 2 are proper to detect CO 2 leakage into sodium loop

  19. CO2 as a refrigerant

    CERN Document Server

    2014-01-01

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

  20. The Influence of CO2 on Genioglossus Muscle After-Discharge Following Arousal From Sleep.

    Science.gov (United States)

    Cori, Jennifer M; Rochford, Peter D; O'Donoghue, Fergal J; Trinder, John; Jordan, Amy S

    2017-11-01

    Ventilatory after-discharge (sustained elevation of ventilation following stimulus removal) occurs during sleep but not when hypocapnia is present. Genioglossus after-discharge also occurs during sleep, but CO2 effects have not been assessed. The relevance is that postarousal after-discharge may protect against upper airway collapse. This study aimed to determine whether arousal elicits genioglossus after-discharge that persists into sleep, and whether it is influenced by CO2. Twenty-four healthy individuals (6 female) slept with a nasal mask and ventilator. Sleep (EEG, EOG, EMG), ventilation (pneumotachograph), end-tidal CO2 (PETCO2), and intramuscular genioglossus EMG were monitored. NREM eucapnia was determined during 5 minutes on continuous positive airway pressure (4 cmH2O). Inspiratory pressure support was increased until PETCO2 was ≥2 mm Hg below NREM eucapnia. Supplemental CO2 was added to reproduce normocapnia, without changing ventilator settings. Arousals were induced by auditory tones and genioglossus EMG compared during steady-state hypocapnia and normocapnia. Eleven participants (4 female) provided data. Prearousal PETCO2 was less (p sleep. For tonic activity, after-discharge lasted four breaths irrespective of CO2 condition. For peak activity, after-discharge lasted one breath during hypocapnia and 6 breaths during normocapnia. However, when peak activity following the return to sleep was compared between CO2 conditions no individual breath differences were observed. Postarousal genioglossal after-discharge may protect against upper airway collapse during sleep. Steady-state CO2 levels minimally influence postarousal genioglossus after-discharge. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  1. Tracking time-varying cerebral autoregulation in response to changes in respiratory PaCO2

    International Nuclear Information System (INIS)

    Liu, Jia; Simpson, M David; Allen, Robert; Yan, Jingyu

    2010-01-01

    Cerebral autoregulation has been studied by linear filter systems, with arterial blood pressure (ABP) as the input and cerebral blood flow velocity (CBFV—from transcranial Doppler Ultrasound) as the output. The current work extends this by using adaptive filters to investigate the dynamics of time-varying cerebral autoregulation during step-wise changes in arterial PaCO 2 . Cerebral autoregulation was transiently impaired in 11 normal adult volunteers, by switching inspiratory air to a CO 2 /air mixture (5% CO 2 , 30% O 2 and 65% N 2 ) for approximately 2 min and then back to the ambient air, causing step-wise changes in end-tidal CO 2 (EtCO 2 ). Simultaneously, ABP and CBFV were recorded continuously. Simulated data corresponding to the same protocol were also generated using an established physiological model, in order to refine the signal analysis methods. Autoregulation was quantified by the time-varying phase lead, estimated from the adaptive filter model. The adaptive filter was able to follow rapid changes in autoregulation, as was confirmed in the simulated data. In the recorded signals, there was a slow decrease in autoregulatory function following the step-wise increase in PaCO 2 (but this did not reach a steady state within approximately 2 min of recording), with a more rapid change in autoregulation on return to normocapnia. Adaptive filter modelling was thus able to demonstrate time-varying autoregulation. It was further noted that impairment and recovery of autoregulation during transient increases in EtCO 2 occur in an asymmetric manner, which should be taken into account when designing experimental protocols for the study of autoregulation

  2. The sequestration of CO2

    International Nuclear Information System (INIS)

    Le Thiez, P.

    2004-01-01

    The reduction of greenhouse gas emissions, especially CO 2 , represents a major technological and societal challenge in the fight against climate change. Among the measures likely to reduce anthropic CO 2 emissions, capture and geological storage holds out promise for the future. (author)

  3. CO2 Sequestration short course

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-08

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

  4. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

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

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

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

    Directory of Open Access Journals (Sweden)

    Knut Arne Birkedal

    2015-05-01

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

  6. Simulasi Numeris Karakteristik Pembakaran CH4/CO2/Udara dan CH4/CO2/O2 pada Counterflow Premixed Burner

    Directory of Open Access Journals (Sweden)

    Hangga Wicaksono

    2017-08-01

    Full Text Available The high amount of CO2 produced in a conventional biogas reactor needs to be considered. A further analysis is needed in order to investigate the effect of CO2 addition especially in thermal and chemical kinetics aspect. This numerical study has been held to analyze the effect of CO2 in CH4/CO2/O­2 and CH4/CO2/Air premixed combustion. In this study one dimensional analisys in a counterflow burner has been performed. The volume fraction of CO2 used in this study was 0%-40% from CH4’s volume fraction, according to the amount of CO2 in general phenomenon. Based on the flammability limits data, the volume fraction of CH4 used was 5-61% in O2 environment and 5-15% in air environment. The results showed a decreasing temperature along with the increasing percentage of CO2 in each mixtures, but the effect was quite smaller especially in stoichiometric and lean mixture. CO2 could affects thermally (by absorbing heat due to its high Cp and also made the production of unburnt fuel species such as CO relatively higher.

  7. End-tidal carbon dioxide output in manual cardiopulmonary resuscitation versus active compression-decompression device during prehospital quality controlled resuscitation: a case series study.

    Science.gov (United States)

    Setälä, Piritta Anniina; Virkkunen, Ilkka Tapani; Kämäräinen, Antti Jaakko; Huhtala, Heini Sisko Annamari; Virta, Janne Severi; Yli-Hankala, Arvi Mikael; Hoppu, Sanna Elisa

    2018-05-16

    Active compression-decompression (ACD) devices have enhanced end-tidal carbon dioxide (ETCO 2 ) output in experimental cardiopulmonary resuscitation (CPR) studies. However, the results in out-of-hospital cardiac arrest (OHCA) patients have shown inconsistent outcomes, and earlier studies lacked quality control of CPR attempts. We compared manual CPR with ACD-CPR by measuring ETCO 2 output using an audiovisual feedback defibrillator to ensure continuous high quality resuscitation attempts. 10 witnessed OHCAs were resuscitated, rotating a 2 min cycle with manual CPR and a 2 min cycle of ACD-CPR. Patients were intubated and the ventilation rate was held constant during CPR. CPR quality parameters and ETCO 2 values were collected continuously with the defibrillator. Differences in ETCO 2 output between manual CPR and ACD-CPR were analysed using a linear mixed model where ETCO 2 output produced by a summary of the 2 min cycles was included as the dependent variable, the patient as a random factor and method as a fixed effect. These comparisons were made within each OHCA case to minimise confounding factors between the cases. Mean length of the CPR episodes was 37 (SD 8) min. Mean compression depth was 76 (SD 1.3) mm versus 71 (SD1.0) mm, and mean compression rate was 100 per min (SD 6.7) versus 105 per min (SD 4.9) between ACD-CPR and manual CPR, respectively. For ETCO 2 output, the interaction between the method and the patient was significant (P<0.001). ETCO 2 output was higher with manual CPR in 6 of the 10 cases. This study suggests that quality controlled ACD-CPR is not superior to quality controlled manual CPR when ETCO 2 is used as a quantitative measure of CPR effectiveness. NCT00951704; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. CO2 pellet blasting studies

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1997-01-01

    Initial tests with CO 2 pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO 2 pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO 2 blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report

  9. Numerical optimization of a transcritical CO2/propylene cascaded ...

    Indian Academy of Sciences (India)

    transcritical CO2/propylene cascade system with parallel compression ... specific volumes, low solidification temperature, low operating pressure of the ...... Kim M, Pettersen J and Bullard C W 2004 Fundamental process and system design ...

  10. CO2: a worldwide myth

    International Nuclear Information System (INIS)

    Gerondeau, Ch.

    2009-01-01

    In this book, the author demonstrates the paradox that reducing CO 2 emissions leads to no CO 2 abatement at all. This assertion is based on an obvious statement. Everybody knows that oil resources are going to be exhausted in few decades. The oil that industrialized countries will not use will be consumed by emerging countries and the CO 2 emissions will remain the same. Who would believe that the oil, gas or coal still available will remain unused? The Kyoto protocol, the national policies, the European agreements of emissions abatement, the carbon taxes, the emissions abatement requests sent to the rest of the world, all these actions cost a lot and are useless. CO 2 concentration in the atmosphere will inescapably double during the 21. century but, according to the author, without any catastrophic consequence for the Earth. (J.S.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Rutten, M.

    2009-06-10

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

  12. Foraminiferal calcification and CO2

    Science.gov (United States)

    Nooijer, L. D.; Toyofuku, T.; Reichart, G. J.

    2017-12-01

    Ongoing burning of fossil fuels increases atmospheric CO2, elevates marine dissolved CO2 and decreases pH and the saturation state with respect to calcium carbonate. Intuitively this should decrease the ability of CaCO3-producing organisms to build their skeletons and shells. Whereas on geological time scales weathering and carbonate deposition removes carbon from the geo-biosphere, on time scales up to thousands of years, carbonate precipitation increases pCO2 because of the associated shift in seawater carbon speciation. Hence reduced calcification provides a potentially important negative feedback on increased pCO2 levels. Here we show that foraminifera form their calcium carbonate by active proton pumping. This elevates the internal pH and acidifies the direct foraminiferal surrounding. This also creates a strong pCO2 gradient and facilitates the uptake of DIC in the form of carbon dioxide. This finding uncouples saturation state from calcification and predicts that the added carbon due to ocean acidification will promote calcification by these organisms. This unknown effect could add substantially to atmospheric pCO2 levels, and might need to be accounted for in future mitigation strategies.

  13. CO2 Emissions From Fuel Combustion. Highlights. 2013 Edition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    In the lead-up to the UN climate negotiations in Warsaw, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process, the IEA is making available for free download the ''Highlights'' version of CO2 Emissions from Fuel Combustion now for sale on IEA Bookshop. This annual publication contains, for more than 140 countries and regions: estimates of CO2 emissions from 1971 to 2011; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; a decomposition of CO2 emissions into driving factors; and CO2emissions from international marine and aviation bunkers, key sources, and other relevant information. The nineteenth session of the Conference of the Parties to the Climate Change Convention (COP-19), in conjunction with the ninth meeting of the Parties to the Kyoto Protocol (CMP 9), met in Warsaw, Poland from 11 to 22 November 2013. This volume of ''Highlights'', drawn from the full-scale study, was specially designed for delegations and observers of the meeting in Warsaw.

  14. The CO2nnect activities

    Science.gov (United States)

    Eugenia, Marcu

    2014-05-01

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

  15. CO2 storage in Sweden

    International Nuclear Information System (INIS)

    Ekstroem, Clas; Andersson, Annika; Kling, Aasa; Bernstone, Christian; Carlsson, Anders; Liljemark, Stefan; Wall, Caroline; Erstedt, Thomas; Lindroth, Maria; Tengborg, Per; Edstroem, Mikael

    2004-07-01

    This study considers options, that could be feasible for Sweden, to transport and geologically store CO 2 , providing that technology for electricity production with CO 2 capture will be available in the future and also acceptable from cost- and reliability point of view. As a starting point, it is assumed that a new 600-1000 MW power plant, fired with coal or natural gas, will be constructed with CO 2 capture and localised to the Stockholm, Malmoe or Goeteborg areas. Of vital importance for storage of carbon dioxide in a reservoir is the possibility to monitor its distribution, i.e. its migration within the reservoir. It has been shown in the SACS-project that the distribution of carbon dioxide within the reservoir can be monitored successfully, mainly by seismic methods. Suitable geologic conditions and a large storage potential seems to exist mainly in South West Scania, where additional knowledge on geology/hydrogeology has been obtained since the year 2000 in connection to geothermal energy projects, and in the Eastern part of Denmark, bordering on South West Scania. Storage of carbon dioxide from the Stockholm area should not be excluded, but more studies are needed to clarify the storage options within this area. The possibilities to use CO 2 for enhanced oil recovery, EOR, in i.a. the North Sea should be investigated, in order to receive incomes from the CO 2 and shared costs for infrastructure, and by this also make the CO 2 regarded as a trading commodity, and thereby achieving a more favourable position concerning acceptance, legal issues and regulations. The dimensions of CO 2 -pipelines should be similar to those for natural natural gas, although regarding some aspects they have different design and construction prerequisites. To obtain cost efficiency, the transport distances should be kept short, and possibilities for co-ordinated networks with short distribution pipelines connected to common main pipelines, should be searched for. Also, synergies

  16. Holiday CO2: Inference from the Salt Lake City data

    Science.gov (United States)

    Ryoo, J.; Fung, I. Y.; Ehleringer, J. R.; Stephens, B. B.

    2013-12-01

    A network of high-frequency CO2 sensors has been established in Salt Lake City (SLC), Utah (http://co2.utah.edu/), and the annual/monthly pattern of CO2 variability is consistent with a priori estimates of CO2 fluxes (McKain et al., 2012). Here we ask if short-term changes in anthropogenic sources can be detected, and present a case study of Thanksgiving holiday, when traffic and energy use patterns are expected to be different from that during the rest of the month. CO2 mole fraction is much higher during the Thanksgiving holidays than the other days in November 2008 for all 5 sites in SLC, and a similar pattern is found in other years. Taking into account that the wind speed is relatively low in downtown SLC compared to the other SLC sites, the downtown site is further investigated to minimize the meteorological influence on CO2. In order to understand the relative contributions to the high level of CO2 during the Thanksgiving holidays, we carried out a multiple linear regression (MLR) analysis of the rate of CO2 change against various sources. Mobile CO2 sources are assumed to be proportional to local traffic data and residential CO2 sources are assumed to depend exponentially on temperature. Vulcan data were used to specify the other anthropogenic sources (commercial, industrial, nonroad, electricity, aircraft, and cement). The MLR analysis shows that during the Thanksgiving holidays CO2 contributions from residential and commercial CO2 are larger than that during the rest of November, and mobile sources represent only a relatively small contribution. The study demonstrates the feasibility of detecting changes in urban source contributions using high-frequency measurements in combination with daily PBL height and local traffic volume data.

  17. On a CO2 ration

    International Nuclear Information System (INIS)

    De Wit, P.

    2003-01-01

    In 2 years all the large energy companies in the European Union will have a CO2 ration, including a system to trade a shortage or surplus of emission rights. A cost effective system to reduce emission, provided that the government does not auction the emission rights [nl

  18. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

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

  19. Practical guidebook about the market of CO2 emission quotas

    International Nuclear Information System (INIS)

    2005-01-01

    Since January 1, 2005, the European directive about the trading of CO 2 emission quotas foresees the allocation of CO 2 emission quotas to the industrial sectors that generate huge amounts of greenhouse gases (energy generation, cement, glass, steel-making, mineral and paper industries). A system of trading of CO 2 quotas has been implemented and allows the companies to exchange, sale or purchase quotas in order to be conformable with the volume of CO 2 they have been authorized to release in the atmosphere. This guidebook is a vade mecum of the management of emission quotas. It explains the actions of the international community in favor of the fight against greenhouse emissions, the 3 flexibility mechanisms, the French environmental policy, the European system of fight against climatic change, the CO 2 quotas system and its practical implementation. (J.S.)

  20. PVTxy properties of CO2 mixtures relevant for CO2 capture, transport and storage: Review of available experimental data and theoretical models

    International Nuclear Information System (INIS)

    Li, Hailong; Jakobsen, Jana P.; Wilhelmsen, Oivind; Yan, Jinyue

    2011-01-01

    Highlights: → Accurate knowledge about the thermodynamic properties of CO 2 is essential in the design and operation of CCS systems. → Experimental data about the phase equilibrium and density of CO 2 -mixtures have been reviewed. → Equations of state have been reviewed too regarding CO 2 -mixtures. None has shown any clear advantage in CCS applications. → Identified knowledge gaps suggest to conducting more experiments and developing novel models. -- Abstract: The knowledge about pressure-volume-temperature-composition (PVTxy) properties plays an important role in the design and operation of many processes involved in CO 2 capture and storage (CCS) systems. A literature survey was conducted on both the available experimental data and the theoretical models associated with the thermodynamic properties of CO 2 mixtures within the operation window of CCS. Some gaps were identified between available experimental data and requirements of the system design and operation. The major concerns are: for the vapour-liquid equilibrium, there are no data about CO 2 /COS and few data about the CO 2 /N 2 O 4 mixture. For the volume property, there are no published experimental data for CO 2 /O 2 , CO 2 /CO, CO 2 /N 2 O 4 , CO 2 /COS and CO 2 /NH 3 and the liquid volume of CO 2 /H 2 . The experimental data available for multi-component CO 2 mixtures are also scarce. Many equations of state are available for thermodynamic calculations of CO 2 mixtures. The cubic equations of state have the simplest structure and are capable of giving reasonable results for the PVTxy properties. More complex equations of state such as Lee-Kesler, SAFT and GERG typically give better results for the volume property, but not necessarily for the vapour-liquid equilibrium. None of the equations of state evaluated in the literature show any clear advantage in CCS applications for the calculation of all PVTxy properties. A reference equation of state for CCS should, thus, be a future goal.

  1. Thermochemical performance analysis of solar driven CO_2 methane reforming

    International Nuclear Information System (INIS)

    Fuqiang, Wang; Jianyu, Tan; Huijian, Jin; Yu, Leng

    2015-01-01

    Increasing CO_2 emission problems create urgent challenges for alleviating global warming, and the capture of CO_2 has become an essential field of scientific research. In this study, a finite volume method (FVM) coupled with thermochemical kinetics was developed to analyze the solar driven CO_2 methane reforming process in a metallic foam reactor. The local thermal non-equilibrium (LTNE) model coupled with radiative heat transfer was developed to provide more temperature information. A joint inversion method based on chemical process software and the FVM coupled with thermochemical kinetics was developed to obtain the thermochemical reaction parameters and guarantee the calculation accuracy. The detailed thermal and thermochemical performance in the metal foam reactor was analyzed. In addition, the effects of heat flux distribution and porosity on the solar driven CO_2 methane reforming process were analyzed. The numerical results can serve as theoretical guidance for the solar driven CO_2 methane reforming application. - Highlights: • Solar driven CO_2 methane reforming process in metal foam reactor is analyzed. • FVM with chemical reactions was developed to analyze solar CO_2 methane reforming. • A joint inversion method was developed to obtain thermochemical reaction parameters. • Results can be a guidance for the solar driven CO_2 methane reforming application.

  2. CO2 Abatement In The Iron And Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

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

  3. Global energy / CO2 projections

    International Nuclear Information System (INIS)

    Sinyak, Y.

    1990-09-01

    Section headings are: (1) Social and economic problems of the 21 st century and the role of energy supply systems (2) Energy-environment interactions as a central point of energy research activities (3) New ways of technological progress and its impacts on energy demand and supply (4) Long-term global energy projections (5) Comparative analysis of global long-term energy / CO 2 studies (6) Conclusions. The author shows that, in order to alleviate the negative impacts of energy systems on the climate, it will be necessary to undertake tremendous efforts to improve the energy use efficiency, to drastically change the primary energy mix, and, at the same time, to take action to reduce greenhouse emissions from other sources and increase the CO 2 sink through enhanced reforestation. (Quittner)

  4. Fang CO2 med Aminosyrer

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai

    2010-01-01

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

  5. CO2 reduction by dematerialization

    Energy Technology Data Exchange (ETDEWEB)

    Hekkert, M.P. [Department of Innovation Studies, Copernicus Institute, Utrecht University, Utrecht (Netherlands)

    2002-04-01

    Current policy for the reduction of greenhouse gases is mainly concerned with a number of types of solutions: energy saving, shifting to the use of low-carbon fuels and the implementation of sustainable energy technologies. Recent research has shown that a strategy directed at a more efficient use of materials could make a considerable contribution to reducing CO2 emissions. Moreover, the costs to society as a whole of such a measure appear to be very low.

  6. Assessing intravascular volume by difference in pulse pressure in pigs submitted to graded hemorrhage.

    Science.gov (United States)

    Pestel, Gunther J; Hiltebrand, Luzius B; Fukui, Kimiko; Cohen, Delphine; Hager, Helmut; Kurz, Andrea M

    2006-10-01

    We assessed changes in intravascular volume monitored by difference in pulse pressure (dPP%) after stepwise hemorrhage in an experimental pig model. Six pigs (23-25 kg) were anesthetized (isoflurane 1.5 vol%) and mechanically ventilated to keep end-tidal CO2 (etCO2) at 35 mmHg. A PA-catheter and an arterial catheter were placed via femoral access. During and after surgery, animals received lactated Ringer's solution as long as they were considered volume responders (dPP>13%). Then animals were allowed to stabilize from the induction of anesthesia and insertion of catheters for 30 min. After stabilization, baseline measurements were taken. Five percent of blood volume was withdrawn, followed by another 5%, and then in 10%-increments until death from exsanguination occurred. After withdrawal of 5% of blood volume, all pigs were considered volume responders (dPP>13%); dPP rose significantly from 6.1+/-3.3% to 19.4+/-4.2%. The regression analysis of stepwise hemorrhage revealed a linear relation between blood loss (hemorrhage in %) and dPP (y=0.99*x+14; R2=0.7764; P<.0001). In addition, dPP was the only parameter that changed significantly between baseline and a blood loss of 5% (P<0.01), whereas cardiac output, stroke volume, heart rate, MAP, central venous pressure, pulmonary artery occlusion pressure, and systemic vascular resistance, respectively, remained unchanged. We conclude that in an experimental hypovolemic pig model, dPP correlates well with blood loss.

  7. Outsourcing CO2 within China.

    Science.gov (United States)

    Feng, Kuishuang; Davis, Steven J; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-07-09

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country's borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world's largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China's emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low-value-added but high-carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China.

  8. Capture, transport and storage of CO2

    International Nuclear Information System (INIS)

    De Boer, B.

    2008-01-01

    The emission of greenhouse gas CO2 in industrial processes and electricity production can be reduced on a large scale. Available techniques include post-combustion, pre-combustion, the oxy-fuel process, CO2 fixation in industrial processes and CO2 mineralization. In the Netherlands, plans for CO2 capture are not developing rapidly (CCS - carbon capture and storage). [mk] [nl

  9. Environmental impacts of ocean disposal of CO2

    International Nuclear Information System (INIS)

    Adams, E.; Herzog, H.; Auerbach, D.

    1995-01-01

    One option to reduce atmospheric CO 2 levels is to capture and sequester power plant CO 2 Commercial CO 2 capture technology, though expensive, exists today. However, the ability to dispose of large quantities of CO 2 is highly uncertain. The deep ocean is one of only a few possible CO 2 disposal options (others are depleted oil and gas wells or deep, confined aquifers) and is a prime candidate because the deep ocean is vast and highly unsaturated in CO 2 . The term disposal is really a misnomer because the atmosphere and ocean eventually equilibrate on a timescale of 1000 years regardless of where the CO 2 is originally discharged. However, peak atmospheric CO 2 concentrations expected to occur in the next few centuries could be significantly reduced by ocean disposal. The magnitude of this reduction will depend upon the quantity of CO 2 injected in the ocean, as well as the depth and location of injection. Ocean disposal of CO 2 will only make sense if the environmental impacts to the ocean are significantly less than the avoided impacts of atmospheric release. Our project has been examining these ocean impacts through a multi-disciplinary effort designed to summarize the current state of knowledge. The end-product will be a report issued during the summer of 1996 consisting of two volumes an executive summary (Vol I) and a series of six, individually authored topical reports (Vol II). A workshop with invited participants from the U.S. and abroad will review the draft findings in January, 1996

  10. RODZAJE METOD SEKWESTRACJI CO2

    Directory of Open Access Journals (Sweden)

    Zofia LUBAŃSKA

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

  11. Dolomite decomposition under CO2

    International Nuclear Information System (INIS)

    Guerfa, F.; Bensouici, F.; Barama, S.E.; Harabi, A.; Achour, S.

    2004-01-01

    Full text.Dolomite (MgCa (CO 3 ) 2 is one of the most abundant mineral species on the surface of the planet, it occurs in sedimentary rocks. MgO, CaO and Doloma (Phase mixture of MgO and CaO, obtained from the mineral dolomite) based materials are attractive steel-making refractories because of their potential cost effectiveness and world wide abundance more recently, MgO is also used as protective layers in plasma screen manufacture ceel. The crystal structure of dolomite was determined as rhombohedral carbonates, they are layers of Mg +2 and layers of Ca +2 ions. It dissociates depending on the temperature variations according to the following reactions: MgCa (CO 3 ) 2 → MgO + CaO + 2CO 2 .....MgCa (CO 3 ) 2 → MgO + Ca + CaCO 3 + CO 2 .....This latter reaction may be considered as a first step for MgO production. Differential thermal analysis (DTA) are used to control dolomite decomposition and the X-Ray Diffraction (XRD) was used to elucidate thermal decomposition of dolomite according to the reaction. That required samples were heated to specific temperature and holding times. The average particle size of used dolomite powders is 0.3 mm, as where, the heating temperature was 700 degree celsius, using various holding times (90 and 120 minutes). Under CO 2 dolomite decomposed directly to CaCO 3 accompanied by the formation of MgO, no evidence was offered for the MgO formation of either CaO or MgCO 3 , under air, simultaneous formation of CaCO 3 , CaO and accompanied dolomite decomposition

  12. Outsourcing CO2 within China

    Science.gov (United States)

    Feng, Kuishuang; Davis, Steven J.; Sun, Laixiang; Li, Xin; Guan, Dabo; Liu, Weidong; Liu, Zhu; Hubacek, Klaus

    2013-01-01

    Recent studies have shown that the high standard of living enjoyed by people in the richest countries often comes at the expense of CO2 emissions produced with technologies of low efficiency in less affluent, developing countries. Less apparent is that this relationship between developed and developing can exist within a single country’s borders, with rich regions consuming and exporting high-value goods and services that depend upon production of low-cost and emission-intensive goods and services from poorer regions in the same country. As the world’s largest emitter of CO2, China is a prominent and important example, struggling to balance rapid economic growth and environmental sustainability across provinces that are in very different stages of development. In this study, we track CO2 emissions embodied in products traded among Chinese provinces and internationally. We find that 57% of China’s emissions are related to goods that are consumed outside of the province where they are produced. For instance, up to 80% of the emissions related to goods consumed in the highly developed coastal provinces are imported from less developed provinces in central and western China where many low–value-added but high–carbon-intensive goods are produced. Without policy attention to this sort of interprovincial carbon leakage, the less developed provinces will struggle to meet their emissions intensity targets, whereas the more developed provinces might achieve their own targets by further outsourcing. Consumption-based accounting of emissions can thus inform effective and equitable climate policy within China. PMID:23754377

  13. Carbon dioxide (CO2) capture and storage : Canadian market development

    International Nuclear Information System (INIS)

    Hendriks, A.

    2006-01-01

    Carbon dioxide (CO 2 ) enhanced oil recovery (EOR) is used to extend the life of light oil reservoirs in Canada. An additional 13 per cent of original oil in place is typically recovered using CO 2 flooding processes. However, a carbon capture and storage (CCS) market is needed in order to commercialize CO 2 flooding technologies. CO 2 can be obtained from naturally-occurring accumulations in underground reservoirs, electrical and coal-fired generation plants, petrochemical facilities, and upstream oil and gas processing facilities. CO 2 is sequestered in EOR processes, in sour gas disposal processes, solvent recovery processes, and in coalbed methane (CBM) extraction. It is also disposed in depleted fields and aquifers. While CCS technologies are mature, project economics remain marginal. However, CCS in EOR is commercially feasible at current high oil prices. No transportation infrastructure is in place to transport sources of CO 2 in the high volumes needed to establish a market. While governments have created a favourable public policy environment for CCS, governments will need to address issues related to infrastructure, public perception of CCS, and stakeholder engagement with CCS projects. It was concluded that CCS and CO 2 flooding techniques have the capacity to reduce greenhouse gas (GHG) emissions while helping to sustain light oil production. tabs., figs

  14. Performance of CO2 enrich CNG in direct injection engine

    Science.gov (United States)

    Firmansyah, W. B.; Ayandotun, E. Z.; Zainal, A.; Aziz, A. R. A.; Heika, M. R.

    2015-12-01

    This paper investigates the potential of utilizing the undeveloped natural gas fields in Malaysia with high carbon dioxide (CO2) content ranging from 28% to 87%. For this experiment, various CO2 proportions by volume were added to pure natural gas as a way of simulating raw natural gas compositions in these fields. The experimental tests were carried out using a 4-stroke single cylinder spark ignition (SI) direct injection (DI) compressed natural gas (CNG) engine. The tests were carried out at 180° and 300° before top dead centre (BTDC) injection timing at 3000 rpm, to establish the effects on the engine performance. The results show that CO2 is suppressing the combustion of CNG while on the other hand CNG combustion is causing CO2 dissociation shown by decreasing CO2 emission with the increase in CO2 content. Results for 180° BTDC injection timing shows higher performance compared to 300° BTDC because of two possible reasons, higher volumetric efficiency and higher stratification level. The results also showed the possibility of increasing the CO2 content by injection strategy.

  15. Trading CO2 emission; Verhandelbaarheid van CO2-emissies

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, J.F.; Looijenga, A.; Moor, R.; Wissema, E.W.J. [Afdeling Energie, Ministerie van VROM, The Hague (Netherlands)

    2000-06-01

    Systems for CO2-emission trading can take many shapes as developments in Europe show. European developments for emission trading tend to comprehend cap and-trade systems for large emission sources. In the Netherlands a different policy is in preparation. A trading system for sheltered sectors with an option to buy reductions from exposed sectors will be further developed by a Commission, appointed by the minister of environment. Exposed sectors are committed to belong to the top of the world on the area of energy-efficiency. The authors point out that a cap on the distribution of energy carriers natural gas, electricity and fuel seems to be an interesting option to shape the trade scheme. A cap on the distribution of electricity is desirable, but not easy to implement. The possible success of the system depends partly on an experiment with emission reductions. 10 refs.

  16. Geological storage of CO2

    International Nuclear Information System (INIS)

    Czernichowski-Lauriol, I.

    2005-01-01

    The industrial storage of CO 2 is comprised of three steps: - capture of CO 2 where it is produced (power plants, cement plants, etc.); - transport (pipe lines or boats); - storage, mainly underground, called geological sequestration... Three types of reservoirs are considered: - salted deep aquifers - they offer the biggest storage capacity; - exhausted oil and gas fields; - non-exploited deep coal mine streams. The two latter storage types may allow the recovery of sellable products, which partially or totally offsets the storage costs. This process is largely used in the petroleum industry to improve the productivity of an oil field, and is called FOR (Enhanced Oil Recovery). A similar process is applied in the coal mining industry to recover the imprisoned gas, and is called ECBM (Enhanced Coal Bed methane). Two storage operations have been initiated in Norway and in Canada, as well as research programmes in Europe, North America, Australia and Japan. International organisations to stimulate this technology have been created such as the 'Carbon Sequestration Leadership Forum' and 'the Intergovernmental Group for Climate Change'. This technology will be taken into account in the instruments provided by the Tokyo Protocol. (author)

  17. ISLSCP II Globalview: Atmospheric CO2 Concentrations

    Data.gov (United States)

    National Aeronautics and Space Administration — The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that were created...

  18. Carbon balance of CO2-EOR for NCNO classification

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Lopez, Vanessa [The University of Texas at Austin; Gil-Egui, Ramon; Gonzalez-Nicolas, Ana; Hovorka, Susan D

    2017-03-18

    The question of whether carbon dioxide enhanced oil recovery (CO2-EOR) constitutes a valid alternative for greenhouse gas emission reduction has been frequently asked by the general public and environmental sectors. Through this technology, operational since 1972, oil production is enhanced by injecting CO2 into depleted oil reservoirs in order displace the residual oil toward production wells in a solvent/miscible process. For decades, the CO2 utilized for EOR has been most commonly sourced from natural CO2 accumulations. More recently, a few projects have emerged where anthropogenic CO2 (A-CO2) is captured at an industrial facility, transported to a depleted oil field, and utilized for EOR. If carbon geologic storage is one of the project objectives, all the CO2 injected into the oil field for EOR could technically be stored in the formation. Even though the CO2 is being prevented from entering the atmosphere, and permanently stored away in a secured geologic formation, a question arises as to whether the total CO2 volumes stored in order to produce the incremental oil through EOR are larger than the CO2 emitted throughout the entire CO2-EOR process, including the capture facility, the EOR site, and the refining and burning of the end product. We intend to answer some of these questions through a DOE-NETL funded study titled “Carbon Life Cycle Analysis of CO2-EOR for Net Carbon Negative Oil (NCNO) Classification”. NCNO is defined as oil whose carbon emissions to the atmosphere, when burned or otherwise used, are less than the amount of carbon permanently stored in the reservoir in order to produce the oil. In this paper, we focus on the EOR site in what is referred to as a gate-to-gate system, but are inclusive of the burning of the refined product, as this end member is explicitly stated in the definition of NCNO. Finally, we use Cranfield, Mississippi, as a case study and come to the conclusion that the incremental oil produced is net carbon negative.

  19. Bioelectrochemical conversion of CO2 to chemicals

    NARCIS (Netherlands)

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

    2017-01-01

    The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology for chemicals from low-value carbon dioxide (CO2) using micro-organisms as biocatalysts. MES from CO2 comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds

  20. Phase behavior of (CO2 + methanol + lauric acid) system

    International Nuclear Information System (INIS)

    Ferreira, Franciele M.; Ramos, Luiz P.; Ndiaye, Papa M.; Corazza, Marcos L.

    2011-01-01

    Highlights: → We measured SVL, LLE and VLE for the binary system {lauric acid + methanol + CO 2 }. → Bubble point and dew point were measured at high pressures. → The experimental data were modeled using the Peng-Robinson equation of state with the classical van der Waals mixing rule. - Abstract: In this study the phase equilibrium behaviors of the binary system (CO 2 + lauric acid) and the ternary system (CO 2 + methanol + lauric acid) were determined. The static synthetic method, using a variable-volume view cell, was employed to obtain the experimental data in the temperature range of (293 to 343) K and pressures up to 24 MPa. The mole fractions of carbon dioxide were varied according to the systems as follows: (0.7524 to 0.9955) for the binary system (CO 2 + lauric acid); (0.4616 to 0.9895) for the ternary system (CO 2 + methanol + lauric acid) with a methanol to lauric acid molar ratio of (2:1); and (0.3414 to 0.9182) for the system (CO 2 + methanol + lauric acid) with a methanol to lauric acid molar ratio of (6:1). For these systems (vapor + liquid), (liquid + liquid), (vapor + liquid + liquid), and (solid + fluid) transitions were observed. The phase equilibrium data obtained for the systems were modeled using the Peng-Robinson equation of state with the classical van der Waals mixing rule with a satisfactory correlation between experimental and calculated values.

  1. Weeks Island gravity stable CO2 pilot: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, J.R.; Perry, G.E.

    1989-01-01

    The Weeks Island ''S'' sand Reservoir B (''S'' RB) gravity-stable CO2 field test was completed during February 1988. Injection started in October 1978 and production began in January 1981 in this high-permeability, steeply-dipping sandstone reservoir. About 264,000 barrels of oil or 65 percent of the starting volume has been recovered. A 24-percent pore-volume slug of CO2 mixed with about six mole percent of natural gas (mostly methane) was injected at the start of the pilot. Since 1983, produced CO2 plus hydrocarbon gases have been recycled. CO2 usage statistics are 9.34 MCF/BO with recycle and 3.24 MCF/BO based on purchased CO2. Previous annual reports document the pilot design, implementation, and early results for the 1977 to June 1981 time period. This report is a review of early pilot history and a more detailed account of the post June 1981 results and overall interpretation. A reservoir-simulation history match of pilot performance plus core and log data from a 1983 swept-zone evaluation well are described in this report. A brief description of the production facility and an account of the corrosion control program are also included. 11 refs., 34 figs.

  2. Limitations to CO2-induced growth enhancement in pot studies.

    Science.gov (United States)

    McConnaughay, K D M; Berntson, G M; Bazzaz, F A

    1993-07-01

    Recently, it has been suggested that small pots may reduce or eliminate plant responses to enriched CO 2 atmospheres due to root restriction. While smaller pot volumes provide less physical space available for root growth, they also provide less nutrients. Reduced nutrient availability alone may reduce growth enhancement under elevated CO 2 . To investigate the relative importance of limited physical rooting space separate from and in conjunction with soil nutrients, we grew plants at ambient and double-ambient CO 2 levels in growth containers of varied volume, shape, nutrient concentration, and total nutrient content. Two species (Abutilon theophrasti, a C 3 dicot with a deep tap root andSetaria faberii, a C 4 monocot with a shallow diffuse root system) were selected for their contrasting physiology and root architecture. Shoot demography was determined weekly and biomass was determined after eight and ten weeks of growth. Increasing total nutrients, either by increasing nutrient concentration or by increasing pot size, increased plant growth. Further, increasing pot size while maintaining equal total nutrients per pot resulted in increased total biomass for both species. CO 2 -induced growth and reproductive yield enhancements were greatest in pots with high nutrient concentrations, regardless of total nutrient content or pot size, and were also mediated by the shape of the pot. CO 2 -induced growth and reproductive yield enhancements were unaffected by pot size (growth) or were greater in small pots (reproductive yield), regardless of total nutrient content, contrary to predictions based on earlier studies. These results suggest that several aspects of growth conditions within pots may influence the CO 2 responses of plants; pot size, pot shape, the concentration and total amount of nutrient additions to pots may lead to over-or underestimates of the CO 2 responses of real-world plants.

  3. Forest succession at elevated CO2; TOPICAL

    International Nuclear Information System (INIS)

    Clark, James S.; Schlesinger, William H.

    2002-01-01

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

  4. CO2 supply from an integrated network : the opportunities and challenges

    International Nuclear Information System (INIS)

    Heath, M.

    2006-01-01

    Strategies for using carbon dioxide (CO 2 ) from an integrated network were discussed. The oil and gas industry is currently considering carbon capture and storage (CCS) scenarios for Alberta. Integrated scenarios are aimed at providing business solution for CO 2 currently being produced in the province as well as optimizing the amounts of CO 2 that can be stored in geologic sinks. The scenarios hope to transform CCS into a value-added market capable of providing optimal returns to stakeholders along the CO 2 supply chain through the creation of an infrastructure designed to transport CO 2 in sufficient volumes. The storage of CO 2 in geologic sinks is expected to remove optimal amounts of anthropogenic CO 2 from larger stationary point sources. Interest in an integrated CO 2 market in Alberta has arisen from both economic and environmental concerns. The most effective CO 2 sources are fertilizer, gas processing, and hydrogen plants. Petrochemical facilities also produce high purity CO 2 . CO 2 capture approaches include post- and pre-combustion capture technologies as well as oxyfuel conversion. It was concluded that the cost of capturing CO 2 depends on concentration and purity levels obtained at the point of capture. Major CO 2 sources in the Western Canadian Sedimentary Basin (WCSB) were provided. tabs., figs

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  6. Residual CO2 trapping in Indiana limestone.

    Science.gov (United States)

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-02

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

  7. CO2 clearance by membrane lungs.

    Science.gov (United States)

    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.

  8. On the limits of CO2 capture capacity of carbons

    OpenAIRE

    Fernández Martín, Claudia; González Plaza, Marta; Pis Martínez, José Juan; Rubiera González, Fernando; Pevida García, Covadonga; Álvarez Centeno, Teresa

    2010-01-01

    This study shows that standard techniques used for carbons characterization, such as physical adsorption of CO2 at 273 K and N2 at 77 K, can be used to assess, with a good accuracy, the maximum capacity of carbons to capture CO2 under post- and pre-combustion conditions. The analysis of the corresponding adsorption isotherms, within the general theoretical framework of Dubinin's theory, leads to the values of the micropore volume, Wo, and the characteristic energy, Eo, of the carbons, which p...

  9. Mesoporous amine-bridged polysilsesquioxane for CO2 capture

    KAUST Repository

    Qi, Genggeng

    2011-01-01

    A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing surface area or pore volume available for CO2 capture, leading to a CO2 capture capacity of 3.2 mmol g−1 under simulated flue gas conditions. The sorbent is readily regenerated at 100°C and exhibits good stability over repetitive adsorption-desorption cycling.

  10. Experimental ion mobility measurements in Xe-CO2

    Science.gov (United States)

    Cortez, A. F. V.; Santos, M. A. G.; Veenhof, R.; Patra, R. N.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

    2017-06-01

    Data on ion mobility is important to improve the performance of large volume gaseous detectors. In the present work the method, experimental setup and results for the ion mobility measurements in Xe-CO2 mixtures are presented. The results for this mixture show the presence of only one peak for all gas ratios of Xe-CO2, low reduced electric fields, E/N, 10-25 Td (2.4-6.1 kV·cm-1·bar-1), low pressures 6-8 Torr (8-10.6 mbar), at room temperature.

  11. Thermal pressure and isochoric thermal conductivity of solid CO2

    International Nuclear Information System (INIS)

    Purs'kij, O.Yi.

    2005-01-01

    The analysis of the correlation between the thermal pressure and the isochoric thermal conductivity of solid CO 2 has been carried out. The temperature dependences of the thermal pressure and isochoric thermal conductivity for samples with various molar volumes have been obtained. The isothermal pressure dependences of the thermal conductivity of solid CO 2 have been calculated. The form of the temperature dependence of the isochoric thermal conductivity taking the thermal pressure into account has been revealed. Behaviour of the isochoric thermal conductivity is explained by phonon-phonon interaction and additional influence of the thermal pressure

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

    Directory of Open Access Journals (Sweden)

    A. Pasquel

    2000-09-01

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

  13. Influence of posture and positive end-tidal expiratory pressure (PEEP) on clearance of Tc99m-DTPA from the lungs

    International Nuclear Information System (INIS)

    Mason, G.R.; Maublant, J.; Sietsema, K.; Effros, R.M.; Mena, I.

    1984-01-01

    The clearance of Tc99m-DTPA aerosols from the lung has been used to detect and quantitate alterations in the permeability of the pulmonary epithelium. Clearance of the radionuclide is accelerated by both chronic and acute injuries to the lung and by smoking. Several laboratories have reported that Tc99m-DTPA clearance from upper lobes exceeded that from lower lobes in upright subjects. To investigate this phenomenon further the authors studied subjects with simultaneous anterior and posterior cameras in upright and supine positions. In the upright position, clearance from both the anterior and posterior upper regions of interest (ROI's) exceeded the lower regions (-1.64 +- .42 S.D. vs. -0.75 +- .41, anterior, p < .05, n=6), -1.04 +- .23 vs. -0.50 +- .36, posterior. All units = %/min. This difference was not observed in the supine subjects. Clearance from the anterior chest exceeded that from the posterior chest in the supine subjects (-1.28 +- .45 vs. -0.05 +- 1.08) and a small increase in radio-activity was observed in at least one ROI of 5 of 6 subjects from the posterior camera. An increase in activity is likely to be secondary to labeling of blood pool, which would have greatest affect where pulmonary blood volume is largest. Computer processing of the entire lung without observer bias in ROI placement showed similar effects of posture over non-peripheral ROI's. Five subjects breathed on PEEP to cause airspace distention, causing clearance to double. Both dependency and airspace distention appear to influence clearance of aerosolized DTPA, the latter may occur by stretching of epithelial pores

  14. A Review of CO2-Enhanced Oil Recovery with a Simulated Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Mandadige Samintha Anne Perera

    2016-06-01

    Full Text Available This paper reports on a comprehensive study of the CO2-EOR (Enhanced oil recovery process, a detailed literature review and a numerical modelling study. According to past studies, CO2 injection can recover additional oil from reservoirs by reservoir pressure increment, oil swelling, the reduction of oil viscosity and density and the vaporization of oil hydrocarbons. Therefore, CO2-EOR can be used to enhance the two major oil recovery mechanisms in the field: miscible and immiscible oil recovery, which can be further increased by increasing the amount of CO2 injected, applying innovative flood design and well placement, improving the mobility ratio, extending miscibility, and controlling reservoir depth and temperature. A 3-D numerical model was developed using the CO2-Prophet simulator to examine the effective factors in the CO2-EOR process. According to that, in pure CO2 injection, oil production generally exhibits increasing trends with increasing CO2 injection rate and volume (in HCPV (Hydrocarbon pore volume and reservoir temperature. In the WAG (Water alternating gas process, oil production generally increases with increasing CO2 and water injection rates, the total amount of flood injected in HCPV and the distance between the injection wells, and reduces with WAG flood ratio and initial reservoir pressure. Compared to other factors, the water injection rate creates the minimum influence on oil production, and the CO2 injection rate, flood volume and distance between the flood wells have almost equally important influence on oil production.

  15. Variability in soil CO2 production and surface CO2 efflux across riparian-hillslope transitions

    Science.gov (United States)

    Vincent Jerald. Pacific

    2007-01-01

    The spatial and temporal controls on soil CO2 production and surface CO2 efflux have been identified as an outstanding gap in our understanding of carbon cycling. I investigated both the spatial and temporal variability of soil CO2 concentrations and surface CO2 efflux across eight topographically distinct riparian-hillslope transitions in the ~300 ha subalpine upper-...

  16. Explaining CO2 fluctuations observed in snowpacks

    Science.gov (United States)

    Graham, Laura; Risk, David

    2018-02-01

    Winter soil carbon dioxide (CO2) respiration is a significant and understudied component of the global carbon (C) cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil-snow systems on the subdiurnal to diurnal (hours to days) timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model-measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil-snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection) responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack) reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux measurement systems.

  17. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-05-01

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

  18. Metal-Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2 Conversion.

    Science.gov (United States)

    Luo, Tian; Zhang, Jianling; Li, Wei; He, Zhenhong; Sun, Xiaofu; Shi, Jinbiao; Shao, Dan; Zhang, Bingxing; Tan, Xiuniang; Han, Buxing

    2017-11-29

    Here, we propose a CO 2 /water interfacial route for photocatalytic CO 2 conversion by utilizing a metal-organic framework (MOF) as both an emulsifier and a catalyst. The CO 2 reduction occurring at the CO 2 /water interface produces formate with remarkably enhanced efficiency as compared with that in conventional solvent. The route is efficient, facile, adjustable, and environmentally benign, which is applicable for the CO 2 transformation photocatalyzed by different kinds of MOFs.

  19. Continuous CO2 gas monitoring to clarify natural pattern and artificial leakage signals

    Science.gov (United States)

    Joun, W.; Ha, S. W.; Joo, Y. J.; Lee, S. S.; Lee, K. K.

    2017-12-01

    Continuous CO2 gas monitoring at shallow aquifer is significant for early detection and immediate handling of an aquifer impacted by leaking CO2 gas from the sequestration reservoir. However, it is difficult to decide the origin of CO2 gas because detected CO2 includes not only leaked CO2 but also naturally emitted CO2. We performed CO2 injection and monitoring tests in a shallow aquifer. Before the injection of CO2 infused water, we have conducted continuous monitoring of multi-level soil CO2 gas concentration and physical parameters such as temperature, humidity, pressure, wind speed and direction, and precipitation. The monitoring data represented that CO2 gas concentrations in unsaturated soil zone borehole showed differences at depths and daily variation (360 to 6980 ppm volume). Based on the observed data at 5 m and 8 m depths, vertical flux of gas was calculated as 0.471 L/min (LPM) for inflow from 5 m to 8 m and 9.42E-2 LPM for outflow from 8 m to 5 m. The numerical and analytical models were used to calculate the vertical flux of gas and to compare with observations. The results showed that pressure-based modeling could not explain the rapid change of CO2 gas concentration in borehole. Acknowledgement Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003)

  20. Modulation of magmatic processes by CO2 flushing

    Science.gov (United States)

    Caricchi, Luca; Sheldrake, Tom E.; Blundy, Jon

    2018-06-01

    Magmatic systems are the engines driving volcanic eruptions and the source of fluids responsible for the formation of porphyry-type ore deposits. Sudden variations of pressure, temperature and volume in magmatic systems can produce unrest, which may culminate in a volcanic eruption and/or the abrupt release of ore-forming fluids. Such variations of the conditions within magmatic systems are commonly ascribed to the injection of new magma from depth. However, as magmas fractionating at depth or rising to the upper crust release CO2-rich fluids, the interaction between carbonic fluids and H2O-rich magmas stored in the upper crust (CO2 flushing), must also be a common process affecting the evolution of subvolcanic magma reservoirs. Here, we investigate the effect of gas injection on the stability and chemical evolution of magmatic systems. We calculate the chemical and physical evolution of magmas subjected to CO2-flushing using rhyolite-MELTS. We compare the calculations with a set of melt inclusion data for Mt. St. Helens, Merapi, Etna, and Stromboli volcanoes. We provide an approach that can be used to distinguish between melt inclusions trapped during CO2 flushing, magma ascent and decompression, or those affected by post-entrapment H2O-loss. Our results show that CO2 flushing is a widespread process in both felsic and mafic magmatic systems. Depending upon initial magma crystallinity and duration of CO2 input, flushing can either lead to volcanic eruption or fluid release. We suggest that CO2 flushing is a fundamental process modulating the behaviour and chemical evolution of crustal magmatic systems.

  1. Advanced technology development reducing CO2 emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sup

    2010-09-15

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

  2. Study of the synthesis and self-assembly of CO2-philic copolymers with complexing groups: application to decontamination in supercritical CO2 medium

    International Nuclear Information System (INIS)

    Ribaut, T.

    2009-10-01

    In the frame of sustainable development, a priority is to decrease the volume of nuclear wastes. The use of supercritical carbon dioxide (scCO 2 ) could allow to solve this problem. The aim of this study is to extract an ionic or particle cobalt contamination deposited on textile lab coats. The strategy uses CO 2 -philic/CO 2 -phobic copolymers soluble in scCO 2 and containing complexing groups. This approach combines the use of amphiphilic copolymers for steric stabilization of particles, of surfactants able to self-assemble to promote extraction and of ligands. Controlled radical polymerization is used to synthesize fluorinated gradient or block copolymers. Cloud point curves of the copolymers are determined experimentally in scCO 2 . Prediction of polymer/scCO 2 phase diagrams was assessed by Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) modeling. Gradient copolymers appear more advantageous than block copolymers due to their solubility in much milder conditions of pressure and temperature. Small-angle neutron scattering (SANS) allowed us to evidence the pressure-induced aggregation of the gradient copolymers in scCO 2 . Their interface properties were demonstrated: they allow to form water-in-CO 2 microemulsions and to stabilize cobalt hydroxide dispersions in scCO 2 . Lastly, in presence of a very low quantity of water, Co 2+ ions were removed with a rate of 37 % from a cotton/polyester matrix by a gradient copolymer. (author)

  3. CO2 Allowance and Electricity Price Interaction

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

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

  4. CO2 sequestration: Storage capacity guideline needed

    Science.gov (United States)

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

    2006-01-01

    Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

  5. Economic effects on taxing CO2 emissions

    International Nuclear Information System (INIS)

    Haaparanta, P.; Jerkkola, J.; Pohjola, J.

    1996-01-01

    The CO 2 emissions can be reduced by using economic instruments, like carbon tax. This project included two specific questions related to CO 2 taxation. First one was the economic effects of increasing CO 2 tax and decreasing other taxes. Second was the economic adjustment costs of reducing net emissions instead of gross emissions. A computable general equilibrium (CGE) model was used in this analysis. The study was taken place in Helsinki School of Economics

  6. Pilot study assessment of dynamic vascular changes in breast cancer with near-infrared tomography from prospectively targeted manipulations of inspired end-tidal partial pressure of oxygen and carbon dioxide.

    Science.gov (United States)

    Jiang, Shudong; Pogue, Brian W; Michaelsen, Kelly E; Jermyn, Michael; Mastanduno, Michael A; Frazee, Tracy E; Kaufman, Peter A; Paulsen, Keith D

    2013-07-01

    The dynamic vascular changes in the breast resulting from manipulation of both inspired end-tidal partial pressure of oxygen and carbon dioxide were imaged using a 30 s per frame frequency-domain near-infrared spectral (NIRS) tomography system. By analyzing the images from five subjects with asymptomatic mammography under different inspired gas stimulation sequences, the mixture that maximized tissue vascular and oxygenation changes was established. These results indicate maximum changes in deoxy-hemoglobin, oxygen saturation, and total hemoglobin of 21, 9, and 3%, respectively. Using this inspired gas manipulation sequence, an individual case study of a subject with locally advanced breast cancer undergoing neoadjuvant chemotherapy (NAC) was analyzed. Dynamic NIRS imaging was performed at different time points during treatment. The maximum tumor dynamic changes in deoxy-hemoglobin increased from less than 7% at cycle 1, day 5 (C1, D5) to 17% at (C1, D28), which indicated a complete response to NAC early during treatment and was subsequently confirmed pathologically at the time of surgery.

  7. Effect of heat treatment on CO2 adsorption of KOH-activated graphite nanofibers.

    Science.gov (United States)

    Meng, Long-Yue; Park, Soo-Jin

    2010-12-15

    In this work, graphite nanofibers (GNFs) were successfully expanded intercalating KOH followed by heat treatment in the temperature range of 700-1000 °C. The aim was to improve the CO(2) adsorption capacity of the GNFs by increasing the porosity of GNFs. The effects of heat treatment on the pore structures of GNFs were investigated by N(2) full isotherms, XRD, SEM, and TEM. The CO(2) adsorption capacity was measured by CO(2) isothermal adsorption at 25 °C and 1 atm. From the results, it was found that the activation temperature had a major influence on CO(2) adsorption capacity and textural properties of GNFs. The specific surface area, total pore volume, and mesopore volume of the GNFs increased after heat treatment. The CO(2) adsorption isotherms showed that G-900 exhibited the best CO(2) adsorption capacity with 59.2 mg/g. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Production of Microalgal Lipids as Biodiesel Feedstock with Fixation of CO2 by Chlorella vulgaris

    OpenAIRE

    Qiao Hu; Sen-Xiang Zhang; Zhong-Hua Yang; Hao Huang; Rong Zeng

    2014-01-01

    The global warming and shortage of energy are two critical problems for human social development. CO2 mitigation and replacing conventional diesel with biodiesel are effective routes to reduce these problems. Production of microalgal lipids as biodiesel feedstock by a freshwater microalga, Chlorella vulgaris, with the ability to fixate CO2 is studied in this work. The results show that nitrogen deficiency, CO2 volume fraction and photoperiod are the key factors responsible for the lipid accum...

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

    CERN Document Server

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

    2016-01-01

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

  10. Supercritical CO2 uptake by nonswelling phyllosilicates.

    Science.gov (United States)

    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.

  11. Kinetics of CO(2) fluxes outgassing from champagne glasses in tasting conditions: the role of temperature.

    Science.gov (United States)

    Liger-Belair, Gérard; Villaume, Sandra; Cilindre, Clara; Jeandet, Philippe

    2009-03-11

    Measurements of CO(2) fluxes outgassing from a flute poured with a standard Champagne wine initially holding about 11 g L(-1) of dissolved CO(2) were presented, in tasting conditions, all along the first 10 min following the pouring process. Experiments were performed at three sets of temperature, namely, 4 degrees C, 12 degrees C, and 20 degrees C, respectively. It was demonstrated that the lower the champagne temperature, the lower CO(2) volume fluxes outgassing from the flute. Therefore, the lower the champagne temperature, the lower its progressive loss of dissolved CO(2) concentration with time, which constitutes the first analytical proof that low champagne temperatures prolong the drink's chill and helps retains its effervescence. A correlation was also proposed between CO(2) volume fluxes outgassing from the flute poured with champagne and its continuously decreasing dissolved CO(2) concentration. Finally, the contribution of effervescence to the global kinetics of CO(2) release was discussed and modeled by the use of results developed over recent years. The temperature dependence of the champagne viscosity was found to play a major role in the kinetics of CO(2) outgassing from a flute. On the basis of this bubbling model, the theoretical influence of champagne temperature on CO(2) volume fluxes outgassing from a flute was discussed and found to be in quite good accordance with our experimental results.

  12. CO2 sensitivity of the complexity of phrenic neurograms in the piglet during early maturation

    Science.gov (United States)

    Akay, Metin

    2005-06-01

    In this paper, we investigate the influence of hypercapnia on the dynamics of the phrenic neurogram in the piglet in two different age groups: 3-7 days (n = 11) and 10-16 days (n = 9). The phrenic neurogram was recorded from 17 piglets (3-16 days old) during control (40% O2 with 3-5% end-tidal CO2), mild hypercapnia (40% O2 with 7% CO2) and severe hypercapnia (40% O2 with 15% CO2) and analyzed using the approximate entropy (ApEn) method. The mean values of the approximate entropy (complexity) of phrenic neurograms during the first 7 days of the postnatal age were 1.56 ± 0.1 (standard deviation) during normal breathing, 1.51 ± 0.1 during mild hypercapnia and 1.37 ± 0.08 during severe hypercapnia. These values for the 10-16 days age group were 1.51 ± 0.1 during control, 1.49 ± 0.11 during mild hypercapnia and 1.38 ± 0.05 during severe hypercapnia. The mean values of phrenic neurogram durations during the first 7 days of the postnatal age were 0.82 ± 0.03 (standard deviation) s during normal breathing, 0.85 ± 0.007 s during mild hypercapnia and 0.65 ± 0.05 s during severe hypercapnia. These values for the 10-16 days age group were 0.97 ± 0.09 s during control, 1.10 ± 0.05 during mild hypercapnia and 0.78 ± 0.05 s during severe hypercapnia. Our results show that the complexity values of the phrenic neurogram were significantly decreased when the CO2 concentration was shifted from control or mild to severe hypercapnia (p phrenic neurogram decreased when the concentration was shifted from control or mild to severe hypercapnia (p phrenic neurogram were observed between control and mild hypercapnia concentration. These results suggest that severe hypercapnia can be characterized with a significant decrease of the complexity values and durations of the phrenic neurogram during inspiration during early maturation.

  13. Mass transfer of ammonia escape and CO2 absorption in CO2 capture using ammonia solution in bubbling reactor

    International Nuclear Information System (INIS)

    Ma, Shuangchen; Chen, Gongda; Zhu, Sijie; Han, Tingting; Yu, Weijing

    2016-01-01

    Highlights: • Mass transfer coefficient models of ammonia escape were built. • Influences of temperature, inlet CO 2 and ammonia concentration were studied. • Mass transfer coefficients of ammonia escape and CO 2 absorption were obtained. • Studies can provide the basic data as a reference guideline for process application. - Abstract: The mass transfer of CO 2 capture using ammonia solution in the bubbling reactor was studied; according to double film theory, the mass transfer coefficient models and interface area model were built. Through our experiments, the overall volumetric mass transfer coefficients were obtained, while the interface areas in unit volume were estimated. The volumetric mass transfer coefficients of ammonia escaping during the experiment were 1.39 × 10 −5 –4.34 × 10 −5 mol/(m 3 s Pa), and the volumetric mass transfer coefficients of CO 2 absorption were 2.86 × 10 −5 –17.9 × 10 −5 mol/(m 3 s Pa). The estimated interface area of unit volume in the bubbling reactor ranged from 75.19 to 256.41 m 2 /m 3 , making the bubbling reactor a viable choice to obtain higher mass transfer performance than the packed tower or spraying tower.

  14. Corn residue removal and CO2 emissions

    Science.gov (United States)

    Carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) are the primary greenhouse gases (GHG) emitted from the soil due to agricultural activities. In the short-term, increases in CO2 emissions indicate increased soil microbial activity. Soil micro-organisms decompose crop residues and release...

  15. Increasing CO2 storage in oil recovery

    International Nuclear Information System (INIS)

    Jessen, K.; Kovscek, A.R.; Orr, F.M. Jr.

    2005-01-01

    Oil fields offer a significant potential for storing CO 2 and will most likely be the first large scale geological targets for sequestration as the infrastructure, experience and permitting procedures already exist. The problem of co-optimizing oil production and CO 2 storage differs significantly from current gas injection practice due to the cost-benefit imbalance resulting from buying CO 2 for enhanced oil recovery projects. Consequently, operators aim to minimize the amount of CO 2 required to sweep an oil reservoir. For sequestration purposes, where high availability of low cost CO 2 is assumed, the design parameters of enhanced oil recovery processes must be re-defined to optimize the amount of CO 2 left in the reservoir at the time of abandonment. To redefine properly the design parameters, thorough insight into the mechanisms controlling the pore scale displacement efficiency and the overall sweep efficiency is essential. We demonstrate by calculation examples the different mechanisms controlling the displacement behavior of CO 2 sequestration schemes, the interaction between flow and phase equilibrium and how proper design of the injection gas composition and well completion are required to co-optimize oil production and CO 2 storage. [Author

  16. NIST Photoionization of CO2 (ARPES) Database

    Science.gov (United States)

    SRD 119 NIST Photoionization of CO2 (ARPES) Database (Web, free access)   CO2 is studied using dispersed synchrotron radiation in the 650 Å to 850 Å spectral region. The vibrationally resolved photoelectron spectra are analyzed to generate relative vibrational transition amplitudes and the angular asymmetry parameters describing the various transitions observed.

  17. CO2 Capture with Enzyme Synthetic Analogue

    Energy Technology Data Exchange (ETDEWEB)

    Cordatos, Harry

    2010-11-08

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

  18. Eindhoven Airport : towards zero CO2 emissions

    NARCIS (Netherlands)

    Jorge Simoes Pedro, Joana

    2015-01-01

    Eindhoven airport is growing and it is strongly committed to take this opportunity to invest in innovative solutions for a sustainable development. Therefore, this document proposes a strategic plan for reaching Zero CO2 emissions at Eindhoven airport. This document proposes to reduce the CO2

  19. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    Knowledge of the thermodynamic properties and phase equilibria of mixtures containing carbon dioxide (CO2) is important in several industrial processes such as enhanced oil recovery, carbon capture and storage, and supercritical extractions, where CO2 is used as a solvent. Despite this importance...

  20. Increasing CO2 storage in oil recovery

    International Nuclear Information System (INIS)

    Jessen, Kristian; Kovscek, Anthony R.; Orr, Franklin M.

    2005-01-01

    Oil fields offer a significant potential for storing CO 2 and will most likely be the first large scale geological targets for sequestration as the infrastructure, experience and permitting procedures already exist. The problem of co-optimizing oil production and CO 2 storage differs significantly from current gas injection practice due to the cost-benefit imbalance resulting from buying CO 2 for enhanced oil recovery projects. Consequently, operators aim to minimize the amount of CO 2 required to sweep an oil reservoir. For sequestration purposes, where high availability of low cost CO 2 is assumed, the design parameters of enhanced oil recovery processes must be re-defined to optimize the amount of CO 2 left in the reservoir at the time of abandonment. To redefine properly the design parameters, thorough insight into the mechanisms controlling the pore scale displacement efficiency and the overall sweep efficiency is essential. We demonstrate by calculation examples the different mechanisms controlling the displacement behavior of CO 2 sequestration schemes, the interaction between flow and phase equilibrium and how proper design of the injection gas composition and well completion are required to co-optimize oil production and CO 2 storage

  1. CO2 emission calculations and trends

    International Nuclear Information System (INIS)

    Boden, T.A.; Marland, G.; Andres, R.J.

    1995-01-01

    Evidence that the atmospheric CO 2 concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO 2 is believed to result from CO 2 releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO 2 concentration and its potential impact on climate. One of the convention's stated objectives was the ''stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. '' Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO 2 as a greenhouse gas, the relationship between CO 2 emissions and increases in atmospheric CO 2 levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO 2 emissions records be compiled, maintained, updated, and documented

  2. Recent development of capture of CO2

    CERN Document Server

    Chavez, Rosa Hilda

    2014-01-01

    "Recent Technologies in the capture of CO2" provides a comprehensive summary on the latest technologies available to minimize the emission of CO2 from large point sources like fossil-fuel power plants or industrial facilities. This ebook also covers various techniques that could be developed to reduce the amount of CO2 released into the atmosphere. The contents of this book include chapters on oxy-fuel combustion in fluidized beds, gas separation membrane used in post-combustion capture, minimizing energy consumption in CO2 capture processes through process integration, characterization and application of structured packing for CO2 capture, calcium looping technology for CO2 capture and many more. Recent Technologies in capture of CO2 is a valuable resource for graduate students, process engineers and administrative staff looking for real-case analysis of pilot plants. This eBook brings together the research results and professional experiences of the most renowned work groups in the CO2 capture field...

  3. Flow assurance studies for CO2 transport

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.

    2013-01-01

    In order to compensate for the relative lack of experience of the CCTS community, Flow Assurance studies of new CO2 pipelines and networks are a very important step toward reliable operation. This report details a typical approach for Flow Assurance study of CO2 transport pipeline. Considerations to

  4. Silvering substrates after CO2 snow cleaning

    Science.gov (United States)

    Zito, Richard R.

    2005-09-01

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

  5. The ins and outs of CO2

    Science.gov (United States)

    Raven, John A.; Beardall, John

    2016-01-01

    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3 –. The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3 – use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3 – active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3 – can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3 – pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3 –. Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. PMID:26466660

  6. Use of the sitting position for pineal tumour surgery in a five-year-old ...

    African Journals Online (AJOL)

    2011-02-10

    Feb 10, 2011 ... whereby the position's surgical access advantages were considered to ..... heart failure and immediate cardiovascular collapse. Modest volumes of ... Cardiovascular instability, in addition to a fall in end-tidal. CO2, implies a ...

  7. Recycling CO 2 ? Computational Considerations of the Activation of CO 2 with Homogeneous Transition Metal Catalysts

    KAUST Repository

    Drees, Markus; Cokoja, Mirza; Kü hn, Fritz E.

    2012-01-01

    . A similar approach, storing energy from renewable sources in chemical bonds with CO 2 as starting material, may lead to partial recycling of CO 2 created by human industrial activities. Unfortunately, currently available routes for the transformation

  8. Potential and economics of CO2 sequestration

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.; Ciais, Ph.; Orr, J.

    2001-01-01

    Increasing atmospheric level of greenhouse gases are causing global warming and putting at risk the global climate system. The main anthropogenic greenhouse gas is CO 2 . Some techniques could be used to reduced CO 2 emission and stabilize atmospheric CO 2 concentration, including i) energy savings and energy efficiency, ii) switch to lower carbon content fuels (natural gas) and use energy sources with zero CO 2 emissions such as renewable or nuclear energy, iii) capture and store CO 2 from fossil fuels combustion, and enhance the natural sinks for CO 2 (forests, soils, ocean...). The purpose of this report is to provide an overview of the technology and cost for capture and storage of CO 2 and to review the various options for CO 2 sequestration by enhancing natural carbon sinks. Some of the factors which will influence application, including environmental impact, cost and efficiency, are discussed. Capturing CO 2 and storing it in underground geological reservoirs appears as the best environmentally acceptable option. It can be done with existing technology, however, substantial R and D is needed to improve available technology and to lower the cost. Applicable to large CO 2 emitting industrial facilities such as power plants, cement factories, steel industry, etc., which amount to about 30% of the global anthropic CO 2 emission, it represents a valuable tool in the baffle against global warming. About 50% of the anthropic CO 2 is being naturally absorbed by the biosphere and the ocean. The 'natural assistance' provided by these two large carbon reservoirs to the mitigation of climate change is substantial. The existing natural sinks could be enhanced by deliberate action. Given the known and likely environmental consequences, which could be very damaging indeed, enhancing ocean sinks does not appears as a satisfactory option. In contrast, the promotion of land sinks through demonstrated carbon-storing approach to agriculture, forests and land management could

  9. Ordered nanoporous carbon for increasing CO2 capture

    International Nuclear Information System (INIS)

    Yoo, Hye-Min; Lee, Seul-Yi; Park, Soo-Jin

    2013-01-01

    Ordered nanoporous carbons (ONCs) were prepared using a soft-templating method. The prepared ONCs materials were subjected to a controlled carbonization temperature over the temperature range, 700–1000 °C, to increase the specific surface area and total pore volume of ordered nanoporous carbon followed by carbonization of the phenolic resin. ONCs materials synthesized at various carbonization temperatures were used as adsorbents to improve the CO 2 adsorption efficiency. The surface properties of the ONCs materials were examined by X-ray photoelectron spectroscopy. The structural properties of the ONCs materials were analyzed by X-ray diffraction. The textural properties of the ONCs materials were examined using the N 2 /77 K adsorption isotherms according to the Brunauer–Emmett–Teller equation. The CO 2 adsorption capacity was measured by CO 2 isothermal adsorption at 298 K/30 bar and 298 K/1 bar. The carbonization temperature was found to have a major effect on the CO 2 adsorption capacity, resulting from the specific surface area and total pore volumes of the ONCs materials. - Graphical abstract: This schematic diagram described synthesis of ONCs. Highlights: ► ONCs materials can be prepared readily using the direct-triblock-copolymer-templating method. ► The distributions show that prominent development can be observed around the micro-pore region. ► The soft-templating method provides opportunities for controlling the pore structure of ONCs. ► From thermal power plants for CO2 capture by adsorption technology, is a new direction.

  10. Electrocatalytic Alloys for CO2 Reduction.

    Science.gov (United States)

    He, Jingfu; Johnson, Noah J J; Huang, Aoxue; Berlinguette, Curtis P

    2018-01-10

    Electrochemically reducing CO 2 using renewable energy is a contemporary global challenge that will only be met with electrocatalysts capable of efficiently converting CO 2 into fuels and chemicals with high selectivity. Although many different metals and morphologies have been tested for CO 2 electrocatalysis over the last several decades, relatively limited attention has been committed to the study of alloys for this application. Alloying is a promising method to tailor the geometric and electric environments of active sites. The parameter space for discovering new alloys for CO 2 electrocatalysis is particularly large because of the myriad products that can be formed during CO 2 reduction. In this Minireview, mixed-metal electrocatalyst compositions that have been evaluated for CO 2 reduction are summarized. A distillation of the structure-property relationships gleaned from this survey are intended to help in the construction of guidelines for discovering new classes of alloys for the CO 2 reduction reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

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

    2016-07-19

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

  12. Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

  13. Estimating CO2 Emission Reduction of Non-capture CO2 Utilization (NCCU) Technology

    International Nuclear Information System (INIS)

    Lee, Ji Hyun; Lee, Dong Woog; Gyu, Jang Se; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo; Choi, Jong Shin

    2015-01-01

    Estimating potential of CO 2 emission reduction of non-capture CO 2 utilization (NCCU) technology was evaluated. NCCU is sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue gas. For the estimating the CO 2 emission reduction, process simulation using process simulator (PRO/II) based on a chemical plant which could handle CO 2 of 100 tons per day was performed, Also for the estimation of the indirect CO 2 reduction, the solvay process which is a conventional technology for the production of sodium carbonate/sodium bicarbonate, was studied. The results of the analysis showed that in case of the solvay process, overall CO 2 emission was estimated as 48,862 ton per year based on the energy consumption for the production of NaHCO 3 (7.4 GJ/tNaHCO 3 ). While for the NCCU technology, the direct CO 2 reduction through the CO 2 carbonation was estimated as 36,500 ton per year and the indirect CO 2 reduction through the lower energy consumption was 46,885 ton per year which lead to 83,385 ton per year in total. From these results, it could be concluded that sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue was energy efficient and could be one of the promising technology for the low CO 2 emission technology.

  14. CO2 content of electricity losses

    International Nuclear Information System (INIS)

    Daví-Arderius, Daniel; Sanin, María-Eugenia; Trujillo-Baute, Elisa

    2017-01-01

    Countries are implementing policies to develop greener energy markets worldwide. In Europe, the ¨2030 Energy and Climate Package¨ asks for further reductions of green house gases, renewable sources integration, and energy efficiency targets. But the polluting intensity of electricity may be different in average than when considering market inefficiencies, in particular losses, and therefore the implemented policy must take those differences into account. Precisely, herein we study the importance in terms of CO2 emissions the extra amount of energy necessary to cover losses. With this purpose we use Spanish market and system data with hourly frequency from 2011 to 2013. Our results show that indeed electricity losses significantly explain CO2 emissions, with a higher CO2 emissions rate when covering losses than the average rate of the system. Additionally, we find that the market closing technologies used to cover losses have a positive and significant impact on CO2 emissions: when polluting technologies (coal or combined cycle) close the market, the impact of losses on CO2 emissions is high compared to the rest of technologies (combined heat and power, renewables or hydropower). To the light of these results we make some policy recommendations to reduce the impact of losses on CO2 emissions. - Highlights: • Electricity losses significantly explain CO2 emissions. • Policies aimed to reducing losses have a positive impact on CO2 emissions. • The market closing technology used to cover losses have impacts on CO2 emissions. • Pollutant technologies that close the market should be replaced by renewables.

  15. The operation of wholesale electricity, CO2 and natural gas markets in 2010-2011

    International Nuclear Information System (INIS)

    2011-01-01

    The first part analyses the electricity wholesale markets: development of the main wholesale market segments, electricity price, electricity production analysis and transparency of production data, transaction analysis. The second part analyses CO 2 markets: evolution of the institutional framework and perspectives, exchanges volumes on the CO 2 market, the CO 2 price in Europe, fundamentals of the European CO 2 market. The third part addresses the gas market: development of gas trade, gas price, gas infrastructures, supply and outlets for stake holders and new comers

  16. CO2 fluxes near a forest edge

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Leclerc, Monique Y.; Zhang, Gensheng

    2008-01-01

    In contrast with recent advances on the dynamics of the flow at a forest edge, few studies have considered its role on scalar transport and, in particular, on CO2 transfer. The present study addresses the influence of the abrupt roughness change on forest atmosphere CO2 exchange and contrasts...... as a function of both sources/sinks distribution and the vertical structure of the canopy. Results suggest that the ground source plays a major role in the formation of wave-like vertical CO2 flux behavior downwind of a forest edge, despite the fact that the contribution of foliage sources/sinks changes...

  17. CO2, the promises of geological sequestration

    International Nuclear Information System (INIS)

    Rouat, S.

    2006-01-01

    Trapping part of the world CO 2 effluents in the deep underground is a profitable and ecological way to limit the global warming. This digest paper presents the different ways of CO 2 sequestration (depleted oil and gas fields, unexploited coal seams, saline aquifers), the other possible solutions for CO 2 abatement (injection in the bottom of the ocean, conversion into carbonates by injection into basic rocks, fixation by photosynthesis thanks to micro-algae cultivation), and takes stock of the experiments in progress (Snoehvit field in Norway, European project Castor). (J.S.)

  18. Climate change and the CO2 myth

    International Nuclear Information System (INIS)

    Boettcher, C.J.F.

    1994-01-01

    Further increase of the CO 2 concentration in the atmosphere has little effect on the greenhouse effect contrary to the effect of the increase of other greenhouse gases. However, politicians are using targets for the reduction of CO 2 emissions that are unrealistic, taking into account the scientific uncertainties of the applied models, the doubts about the feasibility of quantitative targets and the economic consequences of such drastic measures. Some recommendations are given for a more realistic CO 2 policy. Also attention is paid to the important role that coal will play in the future of the energy supply. 5 figs., 3 ills

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

    Science.gov (United States)

    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.

  20. Some safety aspects of CO2 vapour compression systems

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, J. [Department of Refrigeration and Air Conditioning, Norwegian University of Science and Technology NTNU, Trondheim (Norway); Hafner, A.; Braanaas, M. [SINTEF Energy Research, Refrigeration and Air Conditioning, Trondheim (Norway)

    2000-11-01

    Since CO2 is a non-toxic and non-flammable refrigerant, the major safety issues for CO2 systems are related to the high operating pressure. In case of a component rupture, the explosion energy (stored energy) may characterise the extent of potential damage.The explosion energy can be estimated based on component (refrigerant-side) volumes, pressures and refrigerant property data. The explosion (stored) energies of baseline systems and CO2 systems are calculated and compared. Results show that the explosion energies are not as different as the large difference in pressure would indicate. It has been suggested that a Boiling Liquid Expanding Vapour Explosion (BLEVE) may occur when a vessel containing pressurised liquid or supercritical fluid is rapidly depressurised, e.g. due to a crack or a rupture. The overpressure from a BLEVE may be high enough to rupture the whole vessel, with a resulting blast wave and risk of flying fragments. Some tests on CO2 have been conducted at varying initial conditions and liquid fill levels, and with varying vent areas. No significant overpressure peaks above the initial pressure has been observed in the current test programme. 19 refs.

  1. Unveiling CO2 heterogeneous freezing plumes during champagne cork popping.

    Science.gov (United States)

    Liger-Belair, Gérard; Cordier, Daniel; Honvault, Jacques; Cilindre, Clara

    2017-09-14

    Cork popping from clear transparent bottles of champagne stored at different temperatures (namely, 6, 12, and 20 °C) was filmed through high-speed video imaging in the visible light spectrum. During the cork popping process, a plume mainly composed of gaseous CO 2 with traces of water vapour freely expands out of the bottleneck through ambient air. Most interestingly, for the bottles stored at 20 °C, the characteristic grey-white cloud of fog classically observed above the bottlenecks of champagne stored at lower temperatures simply disappeared. It is replaced by a more evanescent plume, surprisingly blue, starting from the bottleneck. We suggest that heterogeneous freezing of CO 2 occurs on ice water clusters homogeneously nucleated in the bottlenecks, depending on the saturation ratio experienced by gas-phase CO 2 after adiabatic expansion (indeed highly bottle temperature dependent). Moreover, and as observed for the bottles stored at 20 °C, we show that the freezing of only a small portion of all the available CO 2 is able to pump the energy released through adiabatic expansion, thus completely inhibiting the condensation of water vapour found in air packages adjacent to the gas volume gushing out of the bottleneck.

  2. The study of CO2 absorption intensification using porous media material in aqueous AMP solution

    Directory of Open Access Journals (Sweden)

    Min Xiao

    2018-03-01

    Full Text Available In this work, the performance of CO2 absorption into aqueous 2-amino-2-methyl-propanol (AMP solution was investigated by measuring the amount of CO2 in the liquid phase during CO2 absorption process to identify initial CO2 absorption rate. Then, the porous media material named as MCM41 was introduced into the amine solution to test its influence on CO2 absorption. It was found that MCM41 increased initial CO2 absorption rate and enhanced CO2 absorption process. The physico-chemical properties of MCM41 were characterized in terms of specific surface area, average pore diameter, total pore volume and chemical properties, the amount of acidic sites and the Brϕnsted/Lewis (B/L acid sites ratio. Results showed that MCM41 was a type of Lewis acid catalyst with large specific surface area and pore volume. In addition, the pKa of AMP solution with and without MCM41 was obtained using acid titration technology to help understand the effect brought by MCM41. A mechanism illustrating how MCM41 increases the CO2 absorption rate of the AMP solution was proposed and demonstrated that MCM41 is a potential material for enhancing CO2 absorption.

  3. Equilibration of metabolic CO2 with preformed CO2 and bicarbonate

    International Nuclear Information System (INIS)

    Hems, R.; Saez, G.T.

    1983-01-01

    Entry of metabolic 14 CO 2 into urea is shown to occur more readily than it equilibrates with the general pool of cellular plus extracellular bicarbonate plus CO 2 . Since the sites of CO 2 production (pyruvate dehydrogenase and oxoglutarate dehydrogenase) and of fixation (carbamoylphosphate synthetase) are intramitochondrial, it is likely that the fixation of CO 2 is also more rapid than its equilibration with the cytoplasmic pool of bicarbonate plus CO 2 . This observation may point to a more general problem concerning the interpretation of isotope data, with compartmentation or proximity of sites of production and utilisation of metabolites may result in the isotope following a preferred pathway. (Auth.)

  4. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  5. Energy Efficiency instead of CO2 levy

    International Nuclear Information System (INIS)

    Uetz, R.

    2005-01-01

    This article takes a look at ways of avoiding a future, planned Swiss CO 2 levy by improving the efficiency of energy use. The political situation concerning the reduction of CO 2 emissions in Switzerland is reviewed and the likeliness of the introduction of a CO 2 levy is discussed. Strategies for the reduction of fossil fuel consumption and therefore of CO 2 emissions are looked at, including process optimisation. Recommendations are made on how to approach this work systematically - data collection, assessment of the potential for reduction and the planning of measures to be taken are looked at. The high economic efficiency of immediate action is stressed and typical middle and long-term measures are listed

  6. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration

    2016-01-01

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

  7. Capture and geological storage of CO2

    International Nuclear Information System (INIS)

    2013-03-01

    Capture and geological storage of CO 2 could be a contribution to reduce CO 2 emissions, and also a way to meet the factor 4 objective of reduction of greenhouse gas emissions. This publication briefly presents the capture and storage definitions and principles, and comments some key data related to CO 2 emissions, and their natural trapping by oceans, soils and forests. It discusses strengths (a massive and perennial reduction of CO 2 emissions, a well defined regulatory framework) and weaknesses (high costs and uncertain cost reduction perspectives, a technology which still consumes a lot of energy, geological storage capacities still to be determined, health environmental impacts and risks to be controlled, a necessary consultation of population for planned projects) of this option. Actions undertaken by the ADEME are briefly reviewed

  8. CO2 Washout Capability with Breathing Manikin

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon Dioxide (CO2) Washout performance is a critical parameter needed to ensure proper and sufficient designs in a spacesuit and in vehicle applications such as...

  9. Emerging terawatt picosecond CO2 laser technology

    International Nuclear Information System (INIS)

    Pogorelsky, I.V.

    1997-09-01

    The first terawatt picosecond (TWps) CO 2 laser is under construction at the BNL Accelerator Test Facility (ATF). TWps-CO 2 lasers, having an order of magnitude longer wavelength than the well-known table-top terawatt solid state lasers, offer new opportunities for strong-field physics research. For laser wakefield accelerators (LWFA) the advantage of the new class of lasers is due to a gain of two orders of magnitude in the ponderomotive potential. The large average power of CO 2 lasers is important for the generation of hard radiation through Compton back-scattering of the laser off energetic electron beams. The authors discuss applications of TWps-CO 2 lasers for LWFA modules of a tentative electron-positron collider, for γ-γ (or γ-lepton) colliders, for a possible table-top source of high-intensity x-rays and gamma rays, and the generation of polarized positron beams

  10. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang

    2013-01-01

    to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs

  11. Upscaling of enzyme enhanced CO2 capture

    DEFF Research Database (Denmark)

    Gladis, Arne Berthold

    Fossil fuels are the backbone of the energy generation in the coming decades for USA, China, India and Europe, hence high greenhouse gas emissions are expected in future. Carbon capture and storage technology (CCS) is the only technology that can mitigate greenhouse gas emissions from fossil fuel...... the mass transfer of CO2 with slow-capturing but energetically favorable solvents can open up a variety of new process options for this technology. The ubiquitous enzyme carbonic anhydrase (CA), which enhances the mass transfer of CO2 in the lungs by catalyzing the reversible hydration of CO2, is one very...... enhanced CO2 capture technology by identifying the potentials and limitations in lab and in pilot scale and benchmarking the process against proven technologies. The main goal was to derive a realistic process model for technical size absorbers with a wide range of validity incorporating a mechanistic...

  12. Natural Analogues of CO2 Geological Storage

    International Nuclear Information System (INIS)

    Perez del Villar, L.; Pelayo, M.; Recreo, F.

    2007-01-01

    Geological storage of carbon dioxide is nowadays, internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize the global climate change universally accepted. Nevertheless, the possible risks derived of this long-term storage have a direct influence on its public acceptance. Among the favourable geological formations to store CO2, depleted oil and gas fields, deep saline reservoirs, and unamiable coal seams are highlighted. One of the most important objectives of the R and D projects related to the CO2 geological storage is the evaluation of the CO2 leakage rate through the above mentioned geological formations. Therefore, it is absolutely necessary to increase our knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths and the physical resistance of the sealing formation. The quantification of the CO2 leakage rate is essential to evaluate the effects on the human and animal health, as well as for the ecosystem and water quality. To achieve these objectives, the study of the natural analogues is very useful in order to know the natural leakage rate to the atmosphere, its flow paths, the physical, chemical and mineralogical modifications due to the long term interaction processes among the CO2 and the storage and sealing formations, as well as the effects on the groundwaters and ecosystems. In this report, we have tried to summarise the main characteristics of the natural reservoirs and surficial sources of CO2, which are both natural analogues of the geological storage and CO2 leakage, studied in EEUU, Europe and Australia. The main objective of this summary is to find the possible applications for long-term risk prediction and for the performance assessment by means of conceptual and numerical modelling, which will allow to validate the predictive models of the CO2 storage behaviour, to design and develop suitable monitoring techniques to control the CO2 behaviour

  13. CO2 emissions of nuclear power supply

    International Nuclear Information System (INIS)

    Wissel, S.; Mayer-Spohn, O.; Fahl, U.; Voss, A.

    2007-01-01

    Increasingly, supported by the recent reports of the IPCC (International Panel on Climate Change), political, social and scientific institutions call for the use of atomic energy for reducing CO2 emissions. In Germany, the discussion is highly controversial. A life-cycle balance of nuclear power shows that its CO2 emissions are much lower than those of other technologies, even if changes in the nuclear fuel cycle are taken into account. (orig.)

  14. Photoacoustic CO2-Sensor for Automotive Applications

    OpenAIRE

    Huber, J.; Weber, C.; Eberhardt, A.; Wöllenstein, J.

    2016-01-01

    We present a field-tested miniaturized spectroscopic CO2 sensor which is based on the photoacoustic effect. The sensor is developed for automotive applications and considers the requirements for the usage in vehicles. The sensor measures two measurement ranges simultaneously: The monitoring of the indoor air quality and the detection of possible leakages of the coolant in CO2 air-conditioning systems. The sensor consists of a miniaturized innovative photoacoustic sensor unit with integrated e...

  15. Study on CO2 global recycling system

    International Nuclear Information System (INIS)

    Takeuchi, M.; Sakamoto, Y.; Niwa, S.

    2001-01-01

    In order to assist in finding ways to mitigate CO 2 emission and to slow the depletion of fossil fuels we have established and evaluated a representative system, which consists of three technologies developed in our laboratory. These technologies were in CO 2 recovery, hydrogen production and methanol synthesis and in addition we established the necessary supporting systems. Analysis of outline designs of the large scale renewable energy power generation system and this system and energy input for building plant, energy input for running plant has been conducted based on a case using this system for a 1000-MW coal fired power plant, followed by an evaluation of the material balance and energy balance. The results are as follows. Energy efficiency is 34%, the CO 2 reduction rate is 41%, the balance ratio of the energy and CO 2 of the system is 2.2 and 1.8, respectively, on the assumption that the primary renewable energy is solar thermal power generation, the stationary CO 2 emission source is a coal-fired power plant and the generation efficiency of the methanol power plant is 60%. By adopting the system, 3.7 million tons of CO 2 can be recovered, approximately 2.7 million tons of methanol can be produced, and 15.4 billion kWh of electricity can be generated per year. Compared to generating all electrical power using only coal, approximately 2.6 million tons of coal per year can be saved and approximately 2.15 million tons of CO 2 emission can be reduced. Therefore, it is clearly revealed that this system would be effective to reduce CO 2 emissions and to utilize renewable energy

  16. Avaliação da correlação entre o dióxido de carbono expirado e o débito cardíaco em pacientes submetidos à cirurgia cardíaca com circulação extracorpórea Evaluación de la correlación entre el dióxido de carbono expirado y el débito cardíaco en pacientes sometidos a la cirugía cardíaca con circulación extracorpórea Correlation between end-tidal carbon dioxide levels and cardiac output during cardiac surgery with cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Karina Takesaki Miyaji

    2004-10-01

    flujo sanguíneo pulmonar (circulación. Cuando el metabolismo y la ventilación son constantes, el CO2 expirado refleja el flujo sanguíneo pulmonar y, de esta forma, el débito cardíaco (DC. Este estudio tiene como objetivo la evaluación de la correlación entre el dióxido de carbono expirado (P ET CO2 y el débito cardíaco en pacientes sometidos a la cirugía cardíaca con circulación extracorpórea (CEC. MÉTODO: Fueron estudiados 25 pacientes sometidos a la cirugía de revascularización miocárdica con CEC. Después de la intubación traqueal tuvo inicio la monitorización de la P ET CO2. La determinación del débito cardíaco (DC fue hecha por método de termodiluición con el uso de catéter de Swan-Ganz y la PaCO2 fue evaluada a través de gasometría arterial. Los parámetros del estudio fueron evaluados en cuatro momentos: luego después de la inducción de la anestesia general; antes de la circulación extracorpórea, al término de la circulación extracorpórea y al final de la cirugía. RESULTADOS: El teste estadístico no demostró una correlación entre el CO2 expirado y el DC, así como el gradiente de dióxido de carbono arterial y expirado (Ga-eCO2 y el DC. Fue encontrada correlación entre la variación de los valores de la P ET CO2, Ga-eCO2 y DC en relación al basal antes de la CEC con pérdida de la correlación después de la CEC hasta el final de la cirugía. CONCLUSIONES: En este estudio, donde se evalúan pacientes sometidos a cirugía cardíaca con CEC, las alteraciones de relación ventilación/perfusión ocurridas a lo largo del procedimiento son, probablemente, los factores determinantes de la diminución de la correlación entre el débito cardíaco y el valor de dióxido de carbono expirado.BACKGROUND AND OBJECTIVES: End-tidal carbon dioxide (P ET CO2 not only reflects pulmonary ventilation but also carbon dioxide production (metabolism and pulmonary blood supply (circulation. During constant metabolism and ventilation, P ET CO2

  17. Anthropogenic CO2 in the ocean

    Directory of Open Access Journals (Sweden)

    Tsung-Hung Peng

    2005-06-01

    Full Text Available The focus of this review article is on the anthropogenic CO2 taken up by the ocean. There are several methods of identifying the anthropogenic CO2 signal and quantifying its inventory in the ocean. The ?C* method is most frequently used to estimate the global distribution of anthropogenic CO2 in the ocean. Results based on analysis of the dataset obtained from the comprehensive surveys of inorganic carbon distribution in the world oceans in the 1990s are given. These surveys were jointly conducted during the World Ocean Circulation Experiment (WOCE and the Joint Global Ocean Flux Study (JGOFS. This data set consists of 9618 hydrographic stations from a total of 95 cruises, which represents the most accurate and comprehensive view of the distribution of inorganic carbon in the global ocean available today. The increase of anthropogenic CO2 in the ocean during the past few decades is also evaluated using direct comparison of results from repeat surveys and using statistical method of Multi-parameter Linear Regression (MLR. The impact of increasing oceanic anthropogenic CO2 on the calcium carbonate system in the ocean is reviewed briefly as well. Extensive studies of CaCO3 dissolution as a result of increasing anthropogenic CO2 in the ocean have revealed several distinct oceanic regions where the CaCO3 undersaturation zone has expanded.

  18. Recent developments in CO2 lasers

    Science.gov (United States)

    Du, Keming

    1993-05-01

    CO2 lasers have been used in industry mainly for such things as cutting, welding, and surface processing. To conduct a broad spectrum of high-speed and high-quality applications, most of the developments in industrial CO2 lasers at the ILT are aimed at increasing the output power, optimizing the beam quality, and reducing the production costs. Most of the commercial CO2 lasers above 5 kW are transverse-flow systems using dc excitation. The applications of these lasers are limited due to the lower beam quality, the poor point stability, and the lower modulation frequency. To overcome the problems we developed a fast axial- flow CO2 laser using rf excitation with an output of 13 kW. In section 2 some of the results are discussed concerning the gas flow, the discharge, the resonator design, optical effects of active medium, the aerodynamic window, and the modulation of the output power. The first CO2 lasers ever built are diffusion-cooled systems with conventional dc excited cylindrical discharge tubes surrounded by cooling jackets. The output power per unit length is limited to 50 W/m by those lasers with cylindrical tubes. In the past few years considerable increases in the output power were achieved, using new mechanical geometries, excitation- techniques, and resonator designs. This progress in diffusion-cooled CO2 lasers is presented in section 3.

  19. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available 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.

  20. The U.S. Gas Flooding Experience: CO2 Injection Strategies and Impact on Ultimate Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Lopez, Vanessa [The University of Texas at Austin; Hosseini, Seyyed; Gil-Egui, Ramon

    2017-09-29

    The Permian Basin in West Texas and southwestern New Mexico has seen 45 years of oil reserve growth through CO2 enhanced oil recovery (CO2 EOR). More than 60 CO2 EOR projects are currently active in the region’s limestone, sandstone and dolomite reservoirs. Water alternating gas (WAG) has been the development strategy of choice in the Permian for several technical and economic reasons. More recently, the technology started to get implemented in the much more porous and permeable clastic depositional systems of the onshore U.S. Gulf Coast. Continued CO2 injection (CGI), as opposed to WAG, was selected as the injection strategy to develop Gulf Coast oil fields, where CO2 injection volumes are significantly larger (up to 6 times larger) than those of the Permian. We conducted a compositional simulation based study with the objective of comparing the CO2 utilization ratios (volume of CO2 injected to produce a barrel of oil) of 4 conventional and novel CO2 injection strategies: (1) continuous gas injection (CGI), (2) water alternating gas (WAG), (3) water curtain injection (WCI), and (4) WAG and WCI combination. These injection scenarios were simulated using the GEM module from the Computer Modeling Group (CMG). GEM is an advanced general equation-of-state compositional simulator, which includes equation of state, CO2 miscible flood, CO2/brine interactions, and complex phase behavior. The simulator is set up to model three fluid phases including water, oil, and gas. Our study demonstrates how the selected field development strategy has a significant impact on the ultimate recovery of CO2-EOR projects, with GCI injection providing maximum oil recovery in absolute volume terms, but with WAG offering a more balanced technical-economical approach.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2014-05-01

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

  3. Study and characterization of the hexa ferrite Ba2Co2Fe12O22 (Co2-Y)

    International Nuclear Information System (INIS)

    Pires Junior, G.F.M.; Rodrigues, H.O.; Sales, J.C; Sancho, E.O.; Sombra, A.S.B.

    2009-01-01

    The objective of this work is to synthesize and to characterize the Hexaferrita Ba2Co 2 Fe 12 O 22 (Co 2 Y). The Y-type Hexaferrita (Co 2 Y) was prepared by the ceramic conventional method. The mixed powder by 1 h was calcined at 1050 deg C for 3 h. After of the calcination the powders were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) using a diffractometer DMAXB of the Rigaku (Japan), CuK α radiation (λ=1.5405 angstrom) in a tax of 0.5 deg /min and linear band (20 deg at 80 deg) in 2θ. The characterization more detailed by XRD was made using the DBWS9807a program that uses the method of Rietveld for refinement of crystalline structures and confirmed the isolated attainment of the phase (Co 2 Y) with hexagonal crystalline structure (a = b = 5,8560 angstrom and c = 43,4977 angstrom; α = β = 90 deg and γ = 120 deg) with density and volume of the unit cell calculated of 5.45 g/cm 3 and 1292,3 angstrom respectively. (author)

  4. CO2 Emission Factors for Coals

    Directory of Open Access Journals (Sweden)

    P. Orlović-Leko

    2015-03-01

    Full Text Available Emission factors are used in greenhouse gas inventories to estimate emissions from coal combustion. In the absence of direct measures, emissions factors are frequently used as a quick, low cost way to estimate emissions values. Coal combustion has been a major contributor to the CO2 flux into the atmosphere. Nearly all of the fuel carbon (99 % in coal is converted to CO2 during the combustion process. The carbon content is the most important coal parameter which is the measure of the degree of coalification (coal rank. Coalification is the alteration of vegetation to form peat, succeeded by the transformation of peat through lignite, sub-bituminous, bituminous to anthracite coal. During the geochemical or metamorphic stage, the progressive changes that occur within the coal are an increase in the carbon content and a decrease in the hydrogen and oxygen content resulting in a loss of volatiles. Heterogeneous composition of coal causes variation in CO2 emission from different coals. The IPCC (Intergovernmental Panel on Climate Change has produced guidelines on how to produce emission inventories which includes emission factors. Although 2006 IPCC Guidelines provided the default values specified according to the rank of the coal, the application of country-specific emission factors was recommended when estimating the national greenhouse gas emissions. This paper discusses the differences between country-specific emission factors and default IPCC CO2 emission factors, EF(CO2, for coals. Also, this study estimated EF(CO2 for two different types of coals and peat from B&H, on the basis fuel analyses. Carbon emission factors for coal mainly depend on the carbon content of the fuel and vary with both rank and geographic origin, which supports the idea of provincial variation of carbon emission factors. Also, various other factors, such as content of sulphur, minerals and macerals play an important role and influence EF(CO2 from coal. Carbonate minerals

  5. Co2+-doped diopside: crystal structure and optical properties

    Science.gov (United States)

    Gori, C.; Tribaudino, M.; Mezzadri, F.; Skogby, H.; Hålenius, U.

    2018-05-01

    Synthetic clinopyroxenes along the CaMgSi2O6-CaCoSi2O6 join were investigated by a combined chemical-structural-spectroscopic approach. Single crystals were synthesized by flux growth methods, both from Ca-saturated and Ca-deficient starting compositions. Single crystal structure refinements show that the incorporation of Co2+ at the octahedrally coordinated cation sites of diopside, increases the unit-cell as well as the M1 and the M2 polyhedral volumes. Spectroscopic investigations (UV-VIS-NIR) of the Ca-rich samples reveal three main optical absorption bands, i.e. 4 T 1g → 4 T 2g( F), 4 T 1g → 4 A 2g( F) and 4 T 1g → 4 T 1g( P) as expected for Co2+ at a six-coordinated site. The bands arising from the 4 T 1g → 4 T 2g( F) and the 4 T 1g → 4 T 1g( P) electronic transitions, are each split into two components, due to the distortions of the M1 polyhedron from ideal Oh-symmetry. In spectra of both types, a band in the NIR range at ca 5000 cm-1 is caused by the 4 A 2g → 4 T 1g( F) electronic transition in Co2+ in a cubic field in the M2 site. Furthermore, an additional component to a band system at 14,000 cm-1, due to electronic transitions in Co2+ at the M2 site, is recorded in absorption spectra of Ca-deficient samples. No variations in Dq and Racah B parameters for Co2+ at the M1 site in response to compositional changes, were demonstrated, suggesting complete relaxation of the M1 polyhedron within the CaMgSi2O6-CaCoSi2O6 solid solution.

  6. 2-Micron Laser Transmitter for Coherent CO2 DIAL Measurement

    Science.gov (United States)

    Singh, Upendra N.; Bai, Yingxin; Yu, Jirong

    2009-01-01

    size is suitable for high efficiency. For Q-switched operation, the optimal energy extraction relies on the pump intensity, pump volume, and pump duration which is inversely proportion to the repetition rate. CW and Q-switched Ho:YLF lasers with different linear cavity configurations have been designed and demonstrated for a 30 W Tm:fiber pump laser. The CW Ho laser slope efficiency and optical-to-optical efficiencies reach 65% and 55%, respectively. The pulsed laser efficiency depends on the repetition rate. For 1 kHz operation, the optical-to-optical efficiency is 39% when the pump power is 14.5W. Currently, the injection seeding success rate is between 99.4% and 99.95%. After a ten thousand pulses, the standard deviation of the laser frequency jitter is about 3 MHz. It meets the requirements of highly precise CO2 concentration measurement. In conclusion, an injection seeded, high repetition rate, Q-switched Ho:YLF laser has been developed for a coherent CO2 differential absorption lidar. This master-slave laser system has high optical-to-optical efficiency and seeding success rate. It can potentially meet the requirements of the coherent detection of CO2 concentration by a differential absorption lidar technique.

  7. Studies on CO2 removal and reduction. CO2 taisaku kenkyu no genjo

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y [National Institute of Materials and Chemical Research, Tsukuba (Japan)

    1993-02-01

    This paper summarizes study trends mainly in CO2 fixing processes. Underground CO2 storage is a most promising method because it can fix a huge amount of CO2 and has low effects on ecological systems. Storing CO2 in ocean includes such methods as storing it in deep oceans; storing it in deep ocean beds; dissolving it into sea water; neutralizing it with calcium carbonates; and precipitating it as dry ice. Japan, disposing CO2 in these ways, may create international problems. Separation of CO2 may use a chemical absorption process as a superior method. Other processes discussed include a physical adsorption method and a membrane separation method. A useful method for CO2 fixation using marine organisms is fixation using coral reefs. This process will require an overall study including circulation of phosphorus and nitrogen. Marine organisms may include planktons and algae. CO2 fixation using land plants may be able to fix one trillion and 8 hundred billion tons of CO2 as converted to carbon. This process would require forest protection, prevention of desertification, and tree planting. Discussions are being given also on improving power generation cycles, recovering CO2 from automotive exhausts, and backfilling carbons into ground by means of photosynthesis. 23 refs., 7 figs., 1 tab.

  8. Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

    Science.gov (United States)

    Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

    2016-04-01

    In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

  9. Atmospheric inversion of the surface CO2 flux with 13CO2 constraint

    Science.gov (United States)

    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.

  10. Diffuse CO2 degassing at Vesuvio, Italy

    Science.gov (United States)

    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.

  11. Glacial-interglacial atmospheric CO2 change: a possible

    Directory of Open Access Journals (Sweden)

    L. C. Skinner

    2009-09-01

    Full Text Available So far, the exploration of possible mechanisms for glacial atmospheric CO2 drawdown and marine carbon sequestration has tended to focus on dynamic or kinetic processes (i.e. variable mixing-, equilibration- or export rates. Here an attempt is made to underline instead the possible importance of changes in the standing volumes of intra-oceanic carbon reservoirs (i.e. different water-masses in influencing the total marine carbon inventory. By way of illustration, a simple mechanism is proposed for enhancing the marine carbon inventory via an increase in the volume of relatively cold and carbon-enriched deep water, analogous to modern Lower Circumpolar Deep Water (LCDW, filling the ocean basins. A set of simple box-model experiments confirm the expectation that a deep sea dominated by an expanded LCDW-like watermass holds more CO2, without any pre-imposed changes in ocean overturning rate, biological export or ocean-atmosphere exchange. The magnitude of this "standing volume effect" (which operates by boosting the solubility- and biological pumps might be as large as the contributions that have previously been attributed to carbonate compensation, terrestrial biosphere reduction or ocean fertilisation for example. By providing a means of not only enhancing but also driving changes in the efficiency of the biological- and solubility pumps, this standing volume mechanism may help to reduce the amount of glacial-interglacial CO2 change that remains to be explained by other mechanisms that are difficult to assess in the geological archive, such as reduced mass transport or mixing rates in particular. This in turn could help narrow the search for forcing conditions capable of pushing the global carbon cycle between glacial and interglacial modes.

  12. Rates of CO2 Mineralization in Geological Carbon Storage.

    Science.gov (United States)

    Zhang, Shuo; DePaolo, Donald J

    2017-09-19

    200 to 2000 years for conversion of 60-90% of injected CO 2 when the reservoir rock has a sufficient volume fraction of divalent cation-bearing silicate minerals and confirms that when reservoir rock mineralogy is not favorable the fraction of CO 2 converted to carbonate minerals is minimal over 10 4 years. A sufficient amount of reactive minerals is typically about 20% by volume. Our approach may allow for rapid evaluation of mineralization potential of subsurface storage reservoirs and illustrates how reservoir scale modeling can be integrated with other observations to address key issues relating to engineering of geologic systems.

  13. Classification of CO2 Geologic Storage: Resource and Capacity

    Science.gov (United States)

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

    2009-01-01

    The use of the term capacity to describe possible geologic storage implies a realistic or likely volume of CO2 to be sequestered. Poor data quantity and quality may lead to very high uncertainty in the storage estimate. Use of the term "storage resource" alleviates the implied certainty of the term "storage capacity". This is especially important to non- scientists (e.g. policy makers) because "capacity" is commonly used to describe the very specific and more certain quantities such as volume of a gas tank or a hotel's overnight guest limit. Resource is a term used in the classification of oil and gas accumulations to infer lesser certainty in the commercial production of oil and gas. Likewise for CO2 sequestration, a suspected porous and permeable zone can be classified as a resource, but capacity can only be estimated after a well is drilled into the formation and a relatively higher degree of economic and regulatory certainty is established. Storage capacity estimates are lower risk or higher certainty compared to storage resource estimates. In the oil and gas industry, prospective resource and contingent resource are used for estimates with less data and certainty. Oil and gas reserves are classified as Proved and Unproved, and by analogy, capacity can be classified similarly. The highest degree of certainty for an oil or gas accumulation is Proved, Developed Producing (PDP) Reserves. For CO2 sequestration this could be Proved Developed Injecting (PDI) Capacity. A geologic sequestration storage classification system is developed by analogy to that used by the oil and gas industry. When a CO2 sequestration industry emerges, storage resource and capacity estimates will be considered a company asset and consequently regulated by the Securities and Exchange Commission. Additionally, storage accounting and auditing protocols will be required to confirm projected storage estimates and assignment of credits from actual injection. An example illustrates the use of

  14. A microporous MOF with a polar pore surface exhibiting excellent selective adsorption of CO2 from CO2-N2 and CO2-CH4 gas mixtures with high CO2 loading.

    Science.gov (United States)

    Pal, Arun; Chand, Santanu; Elahi, Syed Meheboob; Das, Madhab C

    2017-11-14

    A microporous MOF {[Zn(SDB)(L) 0.5 ]·S} n (IITKGP-5) with a polar pore surface has been constructed by the combination of a V-shaped -SO 2 functionalized organic linker (H 2 SDB = 4,4'-sulfonyldibenzoic acid) with an N-rich spacer (L = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene), forming a network with sql(2,6L1) topology. IITKGP-5 is characterized by TGA, PXRD and single crystal X-ray diffraction. The framework exhibits lozenge-shaped channels of an approximate size of 4.2 × 5.6 Å 2 along the crystallographic b axis with a potential solvent accessible volume of 26%. The activated IITKGP-5a revealed a CO 2 uptake capacity of 56.4 and 49 cm 3 g -1 at 273 K/1 atm and 295 K/1 atm, respectively. On the contrary, it takes up a much smaller amount of CH 4 (17 cm 3 g -1 at 273 K and 13.6 cm 3 g -1 at 295 K) and N 2 (5.5 cm 3 g -1 at 273 K; 4 cm 3 g -1 at 295 K) under 1 atm pressure exhibiting its potential for a highly selective adsorption of CO 2 from flue gas as well as a landfill gas mixture. Based on the ideal adsorbed solution theory (IAST), a CO 2 /N 2 selectivity of 435.5 and a CO 2 /CH 4 selectivity of 151.6 have been realized at 273 K/100 kPa. The values at 295 K are 147.8 for CO 2 /N 2 and 23.8 for CO 2 /CH 4 gas mixtures under 100 kPa. In addition, this MOF nearly approaches the target values proposed for PSA and TSA processes for practical utility exhibiting its prospect for flue gas separation with a CO 2 loading capacity of 2.04 mmol g -1 .

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

    Science.gov (United States)

    Iglauer, Stefan

    2017-05-16

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

  16. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    , a scenario-part and a cost-benefit part. Air and sea modes are not analyzed. The model adopts a bottom-up approach to allow a detailed assessment of transport policy measures. Four generic areas of intervention were identified and the likely effect on CO2 emissions, socioeconomic efficiency and other...... are evaluated according to CO2 reduction potential and according to the ‘shadow price’ on a reduction of one ton CO2. The shadow price reflects the costs (and benefits) of the different measures. Comparing the measures it is possible to identify cost effective measures, but these measures are not necessarily...... by the Ministry of Transport, with the Technical University of Denmark as one of the main contributors. The CO2-strategy was to be based on the principle of cost-effectiveness. A model was set up to assist in the assessment. The model consists of a projection of CO2-emissions from road and rail modes from 2020...

  17. Rangeland -- plant response to elevated CO2

    International Nuclear Information System (INIS)

    Owensby, C.E.; Coyne, P.I.; Ham, J.M.; Parton, W.; Rice, C.; Auen, L.M.; Adam, N.

    1993-01-01

    Plots of a tallgrass prairie ecosystem were exposed to ambient and twice-ambient CO 2 concentrations in open-top chambers and compared to unchambered ambient CO 2 plots during the entire growing season from 1989 through 1992. Relative root production among treatments was estimated using root ingrowth bags which remained in place throughout the growing season. Latent heat flux was simulated with and without water stress. Botanical composition was estimated annuallyin all treatments. Open-top chambers appeared to reduce latent heat flux and increase water use efficiency similar to elevated CO 2 when water stress was not severe, but under severe water stress, chamber effect on water use efficiency was limited. In natural ecosystems with periodic moisture stress, increased water use efficiency under elevated CO 2 apparently would have a greater impact on productivity than photosynthetic pathway. Root ingrowth biomass was greater in 1990 and 1991 on elevated CO 2 plots compared to ambient or chambered-ambient plots. In 1992, there was no difference in root ingrowth biomass among treatments

  18. Economic efficiency of CO2 reduction programs

    International Nuclear Information System (INIS)

    Tahvonen, O.; Storch, H. von; Storch, J. von

    1993-01-01

    A highly simplified time-dependent low-dimensional system has been designed to describe conceptually the interaction of climate and economy. Enhanced emission of carbon dioxide (CO 2 ) is understood as the agent that not only favors instantaneous consumption but also causes unfavorable climate changes at a later time. The problem of balancing these two counterproductive effects of CO 2 emissions on a finite time horizon is considered. The climate system is represented by just two parameters, namely a globally averaged near-surface air-temperature and a globally averaged troposheric CO 2 concentration. The costs of abating CO 2 emissions are monitored by a function which depends quadratically on the percentage reduction of emission compared to an 'uncontrolled emission' scenario. Parameters are fitted to historical climate data and to estimates from studies of CO 2 abatement costs. Two optimization approaches, which differ from earlier attempts to describe the interaction of economy and climate, are discussed. In the 'cost oriented' strategy an optimal emission path is identified which balances the abatement costs and explicitly formulated damage costs. These damage costs, whose estimates are very uncertain, are hypothesized to be a linear function of the time-derivative of temperature. In the 'target oriented' strategy an emission path is chosen so that the abatement costs are minimal while certain restrictions on the terminal temperature and concentration change are met. (orig.)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  1. Evasion of CO2 injected into the ocean in the context of CO2 stabilization

    International Nuclear Information System (INIS)

    Kheshgi, Haroon S.

    2004-01-01

    The eventual evasion of injected CO 2 to the atmosphere is one consideration when assessing deep-sea disposal of CO 2 as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO 2 emissions, including illustrative cases leading to stabilization of CO 2 concentration at various levels. Modeled residence time for CO 2 injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO 2 concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO 2 emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO 2 concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO 2 concentration, with less effect on concentration later on in time

  2. Effect of Uncertainties in CO2 Property Databases on the S-CO2 Compressor Performance

    International Nuclear Information System (INIS)

    Lee, Je Kyoung; Lee, Jeong Ik; Ahn, Yoonhan; Kim, Seong Gu; Cha, Je Eun

    2013-01-01

    Various S-CO 2 Brayton cycle experiment facilities are on the state of construction or operation for demonstration of the technology. However, during the data analysis, S-CO 2 property databases are widely used to predict the performance and characteristics of S-CO 2 Brayton cycle. Thus, a reliable property database is very important before any experiment data analyses or calculation. In this paper, deviation of two different property databases which are widely used for the data analysis will be identified by using three selected properties for comparison, C p , density and enthalpy. Furthermore, effect of above mentioned deviation on the analysis of test data will be briefly discussed. From this deviation, results of the test data analysis can have critical error. As the S-CO 2 Brayton cycle researcher knows, CO 2 near the critical point has dramatic change on thermodynamic properties. Thus, it is true that a potential error source of property prediction exists in CO 2 properties near the critical point. During an experiment data analysis with the S-CO 2 Brayton cycle experiment facility, thermodynamic properties are always involved to predict the component performance and characteristics. Thus, construction or defining of precise CO 2 property database should be carried out to develop Korean S-CO 2 Brayton cycle technology

  3. Surface CO2 leakage during the first shallow subsurface CO2 release experiment

    OpenAIRE

    Lewicki, J.L.; Oldenburg, C.; Dobeck, L.; Spangler, L.

    2008-01-01

    A new field facility was used to study CO2 migration processes and test techniques to detect and quantify potential CO2 leakage from geologic storage sites. For 10 days starting 9 July 2007, and for seven days starting 5 August 2007, 0.1 and 0.3 t CO2 d-1, respectively, were released from a ~;100-m long, sub-water table (~;2.5-m depth) horizontal well. The spatio-temporal evolution of leakage was mapped through repeated grid measurements of soil CO2 flux (FCO2). The surface leakage onset...

  4. The idea of global CO2 trade

    International Nuclear Information System (INIS)

    Svendsen, G.T.

    1999-01-01

    The US has been criticized for wanting to earn a fortune on a global CO 2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO 2 market may provide the world with an epoch-making means of cost-effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO 2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future

  5. Decoupling of CO2 emissions and GDP

    Directory of Open Access Journals (Sweden)

    Yves Rocha de Salles Lima

    2016-12-01

    Full Text Available The objetive of this work is to analyze the variation of CO2 emissions and GDP per capita throughout the years and identify the possible interaction between them. For this purpose, data from the International Energy Agency was collected on two countries, Brazil and the one with the highest GDP worldwide, the United States. Thus, the results showed that CO2 emissions have been following the country’s economic growth for many years. However, these two indicators have started to decouple in the US in 2007 while in Brazil the same happened in 2011. Furthermore, projections for CO2 emissions are made until 2040, considering 6 probable scenarios. These projections showed that even if the oil price decreases, the emissions will not be significantly affected as long as the economic growth does not decelerate.

  6. CO2 utilization: Developments in conversion processes

    Directory of Open Access Journals (Sweden)

    Erdogan Alper

    2017-03-01

    The potential utilization of CO2, captured at power plants, should also been taken into consideration for sustainability. This CO2 source, which is potentially a raw material for the chemical industry, will be available at sufficient quality and at gigantic quantity upon realization of on-going tangible capture projects. Products resulting from carboxylation reactions are obvious conversions. In addition, provided that enough supply of energy from non-fossil resources, such as solar [1], is ensured, CO2 reduction reactions can produce several valuable commodity chemicals including multi-carbon compounds, such as ethylene and acrylic acid, in addition to C1 chemicals and polymers. Presently, there are only few developing technologies which can find industrial applications. Therefore, there is a need for concerted research in order to assess the viability of these promising exploratory technologies rationally.

  7. Crop responses to CO2 enrichment

    International Nuclear Information System (INIS)

    Rogers, H.H.; Dahlman, R.C.

    1993-01-01

    Carbon dioxide is rising in the global atmosphere, and this increase can be expected to continue into the foreseeable future. This compound is an essential input to plant life. Crop function is affected across all scales from biochemical to agroecosystem. An array of methods (leaf cuvettes, field chambers, free-air release systems) are available for experimental studies of CO 2 effects. Carbon dioxide enrichment of the air in which crops grow usually stimulates their growth and yield. Plant structure and physiology are markedly altered. Interactions between CO 2 and environmental factors that influence plants are known to occur. Implications for crop growth and yield are enormous. Strategies designed to assure future global food security must include a consideration of crop responses to elevated atmospheric CO 2 . 137 refs., 4 figs., 4 tabs

  8. Direct electroreduction of CO2 into hydrocarbon

    International Nuclear Information System (INIS)

    Winea, Gauthier; Ledoux, Marc-Jacques; Pham-Huu, Cuong; Gangeri, Miriam; Perathoner, Siglinda; Centi, Gabriele

    2006-01-01

    A lot of methods exist to directly reduce carbon dioxide into hydrocarbons: the photoelectrochemical process is certainly the most interesting, essentially due to the similarities with photosynthesis. As the human activities produce a great quantity of CO 2 , this one can then be considered as an infinite source of carbon. The products of this reaction are identical to those obtained during a Fischer-Tropsch reaction, that is to say hydrocarbons, alcohols and carboxylic acids. These works deal with the electrochemical reduction of CO 2 in standard conditions of temperature and pressure. The photochemical part has been replaced by a current generator as electrons source and a KHCO 3 aqueous solution as protons source. The first catalytic results clearly show that it is possible to reduce CO 2 into light hydrocarbons, typically from C1 to C9. (O.M.)

  9. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Christensen, S.

    2001-01-01

    Stems of Chenopodium album. and Sinapis arvensis. and leaves of Lolium perenne. were cut with a CO2 laser or with a pair of scissors. Treatments were carried out on greenhouse-grown pot plants at three different growth stages and at two heights. Plant dry matter was measured 2 to 5 weeks after...... treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album....... When stems were cut below the meristems, 0.9 and 2.3 J mm(-1) of CO2 laser energy dose was sufficient to reduce by 90% the biomass of C. album and S. arvensis respectively. Regrowth appeared when dicotyledonous plant stems were cut above meristems, indicating that it is important to cut close...

  10. Assessment of CO2 free energy options

    International Nuclear Information System (INIS)

    Cavlina, N.; Raseta, D.; Matutinovic, I.

    2014-01-01

    One of the European Union climate and energy targets is to significantly reduce CO 2 emissions, at least 20% by 2020, compared to 1990. In the power industry, most popular solution is use of solar and wind power. Since their production varies significantly during the day, for the purpose of base-load production they can be paired with gas-fired power plant. Other possible CO 2 -free solution is nuclear power plant. This article compared predicted cost of energy production for newly built nuclear power plant and newly built combination of wind or solar and gas-fired power plant. Comparison was done using Levelized Unit of Energy Cost (LUEC). Calculations were performed using the Monte Carlo method. For input parameters that have biggest uncertainty (gas cost, CO 2 emission fee) those uncertainties were addressed not only through probability distribution around predicted value, but also through different scenarios. Power plants were compared based on their economic lifetime. (authors)

  11. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237783; The ATLAS collaboration; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-01-01

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

  12. Novel concepts for CO2 capture

    International Nuclear Information System (INIS)

    Dijkstra, J.W.; Jansen, D.

    2004-01-01

    This paper describes the possibilities for power generation with CO 2 capture using envisaged key technologies: gas turbines, membranes and solid oxide fuel cells (SOFCs). First, the underlying programs in the Netherlands and at ECN are introduced. Then the key technologies are introduced, and concepts using these technologies are discussed. A literature overview of systems for power generation with fuel cells in combination with CO 2 capture is presented. Then a novel concept is introduced. This concept uses a water gas shift membrane reactor to convert the CO and H 2 in the SOFC anode off-gas to gain a CO 2 rich stream, which can be used for sequestration without elaborate treatment. Several implementation schemes of the technique are discussed such as atmospheric systems and hybrid SOFC-GT systems

  13. Equilibrium Solubility of CO2 in Alkanolamines

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2014-01-01

    Equilibrium solubility of CO2 were measured in aqueous solutions of Monoethanolamine (MEA) and N,N-diethylethanolamine(DEEA). Equilibrium cells are generally used for these measurements. In this study, the equilibrium data were measured from the calorimetry. For this purpose a reaction calorimeter...... (model CPA 122 from ChemiSens AB, Sweden) was used. The advantage of this method is being the measurement of both heats of absorption and equilibrium solubility data of CO2 at the same time. The measurements were performed for 30 mass % MEA and 5M DEEA solutions as a function of CO2 loading at three...... different temperatures 40, 80 and 120 ºC. The measured 30 mass % MEA and 5M DEEA data were compared with the literature data obtained from different equilibrium cells which validated the use of calorimeters for equilibrium solubility measurements....

  14. Growth and Wood/Bark Properties of Abies faxoniana Seedlings as Affected by Elevated CO2

    Institute of Scientific and Technical Information of China (English)

    Yun-Zhou Qiao; Yuan-Bin Zhang; Kai-Yun Wang; Qian Wang; Qi-Zhuo Tian

    2008-01-01

    Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (=1= 25) μmol/mol) under two planting densities (28 or 84 plants/mz) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.

  15. Numerical investigation of CO2 storage in hydrocarbon field using a geomechanical-fluid coupling model

    Directory of Open Access Journals (Sweden)

    Guang Li

    2016-09-01

    Full Text Available Increasing pore pressure due to CO2 injection can lead to stress and strain changes of the reservoir. One of the safely standards for long term CO2 storage is whether stress and strain changes caused by CO2 injection will lead to irreversible mechanical damages of the reservoir and impact the integrity of caprock which could lead to CO2 leakage through previously sealing structures. Leakage from storage will compromise both the storage capacity and the perceived security of the project, therefore, a successful CO2 storage project requires large volumes of CO2 to be injected into storage site in a reliable and secure manner. Yougou hydrocarbon field located in Orods basin was chosen as storage site based on it's stable geological structure and low leakage risks. In this paper, we present a fluid pressure and stress-strain variations analysis for CO2 geological storage based on a geomechanical-fluid coupling model. Using nonlinear elasticity theory to describe the geomechanical part of the model, while using the Darcy's law to describe the fluid flow. Two parts are coupled together using the poroelasticity theory. The objectives of our work were: 1 evaluation of the geomechanical response of the reservoir to different CO2 injection scenarios. 2 assessment of the potential leakage risk of the reservoir caused by CO2 injection.

  16. Spectroscopic technique for measuring atmospheric CO2

    International Nuclear Information System (INIS)

    Stokes, G.M.; Stokes, R.A.

    1979-01-01

    As part of a continuing effort to identify areas in which astronomical techniques and data may be profitably applied to atmospheric problems, both new and archival solar spectra have been collected to prepare for an analysis of their use for studying the changes of the atmospheric CO 2 burden. This analysis has resulted in the initiation of an observing program using the Fourier Transform Spectrometer (FTS) of the McMath Solar Telescope at Kitt Peak National Observatory (KPNO). This program is generating spectra, the quality of which should not only aid the archival CO 2 study but also lead to analyses of other trace gases

  17. 10 MW Supercritical CO2 Turbine Test

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig

    2014-01-29

    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  18. 14CO2 fixation pattern of cyanobacteria

    International Nuclear Information System (INIS)

    Erdmann, N.; Schiewer, U.

    1985-01-01

    The 14 CO 2 fixation pattern of three cyanobacteria in the light and dark were studied. Two different chromatographic methods widely used for separating labelled photosynthetic intermediates were compared. After ethanolic extraction, a rather uniform fixation pattern reflecting mainly the β-carboxylation pathway is obtained for all 3 species. Of the intermediates, glucosylglycerol is specific and high citrulline and low malate contents are fairly specific to cyanobacteria. The composition of the 14 CO 2 fixation pattern is hardly affected by changes in temperature or light intensity, but it is severely affected by changes in the water potential of the medium. (author)

  19. Capture and Geological Storage of CO2

    International Nuclear Information System (INIS)

    Kerr, T.; Brockett, S.; Hegan, L.; Barbucci, P.; Tullius, K.; Scott, J.; Otter, N.; Cook, P.; Hill, G.; Dino, R.; Aimard, N.; Giese, R.; Christensen, N.P.; Munier, G.; Paelinck, Ph.; Rayna, L.; Stromberg, L.; Birat, J.P.; Audigane, P.; Loizzo, M.; Arts, R.; Fabriol, H.; Radgen, P.; Hartwell, J.; Wartmann, S.; Drosin, E.; Willnow, K.; Moisan, F.

    2009-01-01

    To build on the growing success of the first two international symposia on emission reduction and CO 2 capture and geological storage, held in Paris in 2005 and again in 2007, IFP, ADEME and BRGM organised a third event on the same topic the 5-6 November 2009. This time, the focus was on the urgency of industrial deployment. Indeed, the IPCC 4. assessment report indicates that the world must achieve a 50 to 85% reduction in CO 2 emissions by 2050 compared to 2000, in order to limit the global temperature increase to around 2 deg. C. Moreover, IPCC stresses that a 'business as usual' scenario could lead to a temperature increase of between 4 deg. C to 7 deg. C across the planet. The symposium was organized in 4 sessions: Session I - Regulatory framework and strategies for enabling CCS deployment: - CCS: international status of political, regulatory and financing issues (Tom Kerr, IEA); - EC regulatory framework (Scott Brockett, European Commission, DG ENV); - Canada's investments towards implementation of CCS in Canada (Larry Hegan, Office of Energy Research and Development - Government of Canada); - A power company perspective (Pietro Barbucci, ENEL); - EC CCS demonstration network (Kai Tullius, European Commission, DG TREN); - Strategies and policies for accelerating global CCS deployment (Jesse Scott, E3G); - The global CCS Institute, a major initiative to facilitate the rapid deployment of CCS (Nick Otter, GCCSI); Session II - From pilot to demonstration projects: - Otway project, Australia (David Hilditch, CO2 CRC); - US regional partnerships (Gerald Hill, Southeast Regional Carbon Sequestration Partnership - SECARB); - CCS activities in Brazil (Rodolfo Dino, Petrobras); - Lessons learnt from Ketzin CO2Sink project in Germany (Ruediger Giese, GFZ); - CO 2 storage - from laboratory to reality (Niels-Peter Christensen, Vattenfall); - Valuation and storage of CO 2 : A global project for carbon management in South-East France (Gilles Munier, Geogreen); Session III

  20. Design and construction of wave guide CO2 laser

    International Nuclear Information System (INIS)

    Al-Ali, M.S.

    1989-01-01

    This thesis describes the design, construction and operation of a countinous wave (CW) CO2 waveguide laser with axial gas flow in which the multi-electrode technique was used to achieve uniform volume of ionized gas using two and four pairs of electrodes. Resonators of lengths ( 26 - 47.5 ) cm with inside diameter ( 3 - 4 ) mm were used with discharge taking place between four pairs of electordes 8.25 cm long each, in axial direction of the tube. The avearge flow at the tube outlet was ( 5 - 6.5 ) L/min at different gas pressures. ( 4 tabs., 74 figs., 58 refs. )

  1. Reduction of emissions and geological storage of CO2. Innovation an industrial stakes

    International Nuclear Information System (INIS)

    Mandil, C.; Podkanski, J.; Socolow, R.; Dron, D.; Reiner, D.; Horrocks, P.; Fernandez Ruiz, P.; Dechamps, P.; Stromberg, L.; Wright, I.; Gazeau, J.C.; Wiederkehr, P.; Morcheoine, A.; Vesseron, P.; Feron, P.; Feraud, A.; Torp, N.T.; Christensen, N.P.; Le Thiez, P.; Czernichowski, I.; Hartman, J.; Roulet, C.; Roberts, J.; Zakkour, P.; Von Goerne, G.; Armand, R.; Allinson, G.; Segalen, L.; Gires, J.M.; Metz, B.; Brillet, B.

    2005-01-01

    CO 2 emissions in the transport sector (cars and aviation) by A. Morcheoine (ADEME), The contribution of biofuels and alternative fuels to reducing CO 2 emissions in the transport sector by I. Drescher (Volkswagen AG). Session III - Technological progress in the capture and geological storage of CO 2 : European projects on CO 2 capture and storage by P. Dechamps (European Commission, Research Energy Conversion and Transport); Capture of CO 2 : Innovative CO 2 capture concepts by P. Feron (TNO), Capture of CO 2 in pre- and oxy-combustion by A. Feraud, N. Otter (Alstom); Geological storage of CO 2 : Geological storage capacity by N.P. Christensen (GEUS), Feedback from industrial CO 2 storage projects by T. Torp (Statoil), The main avenues of current research by P. Le Thiez (IFP) and I. Czernichowski (BRGM), Long-term industrial experience with underground gas storage by J. Hartman (GDF). Session IV - Regulatory, economic and financial aspects. Legal and regulatory framework for capture and geological storage: UK's perspective on the regulatory framework for CO 2 storage by J. Roberts (DEFRA-UK), Monitoring and reporting of CCS in the European Union Emission Trading Scheme by P. Zakkour (ERM), Social need and public questions and perceptions by G. von Goerne (Greenpeace); Economic and financial impact: The costs of CCS by G. Allinson (CO 2 -CRC), The characteristics of CO 2 markets: players, volumes exchanged, and term and spot transaction prices by L. Segalen (European Carbon Fund), CO 2 management by J.M. Gires (Total), The forthcoming IPCC special report on carbon dioxide capture and storage by B. Metz (IPCC Working Group III). Closing Address by Bernard Brillet, Ministry for Higher Education and Research. (J.S.)

  2. Economics and the refinery's CO2 emissions allocation problem

    International Nuclear Information System (INIS)

    Pierru, A.

    2007-01-01

    The establishment of a market for CO 2 emission rights in Europe leads oil-refining companies to add a cost associated with carbon emissions to the objective function of linear programming models used to manage refineries. These models may be used to compute the marginal contribution of each finished product to the CO 2 emissions of the refinery. Babusiaux (Oil. Gas Sci. Technol., 58, 2003, 685-692) has shown that, under some conditions, this marginal contribution is a relevant means of allocating the carbon emissions of the refinery. Thus, it can be used in a well-to-wheel Life Cycle Assessment. In fact, this result holds if the demand equations are the only binding constraints with a non-zero right-hand side coefficient. This is not the case for short-run models with fixed capacity. Then, allocating CO 2 emissions on a marginal basis tends to over-value (or undervalue) the total volume of emissions. In order to extend the existing methodology, we discuss two distinct solutions to this problem, inspired by economic theory: adapting either the Aumann-Shapley cost sharing method (Values of non-atomic games, 1974, Princeton University Press) or the Ramsey pricing formula (Econ. J., 37, 1927, 47-61; J. Econ. Theory, 3, 1971, 219-240). We compare these two solutions, with a strong argument in favour of Ramsey prices, based on the determination of the optimal environmental tax rate to which imported finished products should be subject. (author)

  3. Mechanism of the CO2-Ca(OH)2 reaction

    International Nuclear Information System (INIS)

    Chew, V.S.; Cheh, C.H.; Glass, R.W.

    1983-01-01

    Recent studies clearly showed the importance of moisture in achieving high Ca(OH) 2 absorbent utilization for removing CO 2 from gas streams at ambient temperatures. However, the role of moisture and the mechanism of the reaction was not well understood. This paper summarizes the results of a study of the mechanism of the CO 2 -Ca(OH) 2 reaction with emphasis on the role of moisture. The reaction between Ca(OH) 2 and CO 2 in moist N 2 was found to be first order with respect to the reactants with a rate constant of about 100 min -1 . At high humidities, the rate of reaction was chemically controlled, but at low humidities, the reaction rate was limited by the diffusion through the carbonate layer formed by the reaction. Calculations showed that capillary condensation could have occurred only in about 2% of the pore volume and was unlikely to have affected the reaction rate significantly by allowing the reaction to occur in the liquid phase. It was, therefore, concluded that the main role of moisture was to improve the Ca(OH) 2 utilization by lowering the resistance to diffusion through the carbonate layer

  4. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard

    2005-01-01

    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  5. Managing CO2 emissions in Nigeria

    International Nuclear Information System (INIS)

    Obioh, I.B.; Oluwole, A.F.; Akeredolu, F.A.

    1994-01-01

    The energy resources in Nigeria are nearly equally divided between fossil fuels and biofuels. The increasing pressure on them, following expected increased population growth, may lead to substantial emissions of carbon into the atmosphere. Additionally agricultural and forestry management practices in vogue are those related to savannah burning and rotational bush fallow systems, which have been clearly implicated as important sources of CO 2 and trace gases. An integrated model for the prediction of future CO 2 emissions based on fossil fuels and biomass fuels requirements, rates of deforestation and other land-use indices is presented. This is further based on trends in population and economic growth up to the year 2025, with a base year in 1988. A coupled carbon cycle-climate model based on the contribution of CO 2 and other trace gases is established from the proportions of integrated global warming effects for a 20-year averaging time using the product of global warming potential (GWP) and total emissions. An energy-technology inventory approach to optimal resources management is used as a tool for establishing the future scope of reducing the CO 2 emissions through improved fossil fuel energy efficiencies. Scenarios for reduction based on gradual to swift shifts from biomass to fossil and renewable fuels are presented together with expected policy options required to effect them

  6. Detection of 14CO2 in radiotoxicology

    International Nuclear Information System (INIS)

    Simonnet, Francoise; Bocquet, Colette.

    1980-12-01

    14 CO 2 is detected in exhaled air by conversion to Ba 14 CO 3 which is then filtered, dried and weighed. The radioactivity is measured by liquid scintillation counting. The radioactivity is expressed in μCi per litre of exhaled air according to the ICRP recommendations. The detection threshold is well below the values indicated by the ICRP [fr

  7. Stereotactic CO2 laser therapy for hydrocephalus

    Science.gov (United States)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

    1994-05-01

    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  8. Chilled ammonia process for CO2 capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; van Well, Willy J. M

    2009-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2-10 degrees C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows...

  9. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van

    2010-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...

  10. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1998-01-01

    -effective control which can solve future global environmental problems. The gains from CO2 trade may give vital financial subsidies from the EU to Eastern Europe, for example, and it will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further...

  11. Climate change and CO2 emission reductions

    International Nuclear Information System (INIS)

    Ha Duong, M.; Campos, A.S.

    2007-04-01

    This paper presents the results of an opinion poll performed on a representative sample of 1000 persons about their sensitivity to climate change and to environment protection, their knowledge about technologies which are useful for environment protection, their opinion about geological CO 2 sequestration, and technologies to be developed to struggle against climate warming

  12. CO2 emissions of nuclear electricity generation

    International Nuclear Information System (INIS)

    Wissel, Steffen; Mayer-Spohn, Oliver; Fahl, Ulrich; Blesl, Markus; Voss, Alfred

    2008-01-01

    A survey of LCA studies on nuclear electricity generation revealed life cycle CO 2 emissions ranging between 3 g/kWhe to 60 g/kWhe and above. Firstly, this paper points out the discrepancies in studies by estimating the CO 2 emissions of nuclear power generation. Secondly, the paper sets out to provide critical review of future developments of the fuel cycle for light water reactors and illustrates the impact of uncertainties on the specific CO 2 emissions of nuclear electricity generation. Each step in the fuel cycle will be considered and with regard to the CO 2 emissions analysed. Thereby different assumptions and uncertainty levels are determined for the nuclear fuel cycle. With the impacts of low uranium ore grades for mining and milling as well as higher burn-up rates future fuel characteristics are considered. Sensitivity analyses are performed for all fuel processing steps, for different technical specifications of light water reactors as well as for further external frame conditions. (authors)

  13. CO2 effect on porous concrete

    Directory of Open Access Journals (Sweden)

    Sauman, Zdenek

    1974-09-01

    Full Text Available Not availableDebido a la acción del CO2 y de la humedad sobre un hormigón poroso, la tobermorita 11 A se descompone en vaterita, calcita y SÍO2 gel. A causa de la pseudomorfosis, la morfología de los cristales de la fase cementante no sufre cambios notables. La menor resistencia a la compresión se obtuvo después de 30 días de conservación en atmósferas de un 10 y un 30% de CO2. Después de un año de conservación, las resistencias no bajaron más de un 10%. En lo que respecta a la retracción de un hormigón poroso, la principal influencia fue la ejercida por la acción del CO2 y solamente en segundo lugar figura la acción ejercida por la humedad ambiente. Los hormigones porosos expuestos al aire (con su 0,03% de CO2 a h. r. de 50, 70 y 100% sufrieron al cabo de un año una expansión muy ligera.

  14. CO2 capture by Condensed Rotational Separation

    NARCIS (Netherlands)

    Benthum, van R.J.; Kemenade, van H.P.; Brouwers, J.J.H.; Golombok, M.

    2010-01-01

    Condensed Rotational Separation (CRS) technology is a patented method to upgrade gas mixtures. A novel application is thecapture of CO2 from coal-combustion fired power stations: Condensed Contaminant Centrifugal Separation in Coal Combustion(C5sep). CRS involves partial condensation of a gas

  15. CO2 contain of the electric heating

    International Nuclear Information System (INIS)

    Bacher, P.

    2008-02-01

    A recent announcement of the RTE and the ADEME on the CO 2 contain of the electric kW, refuting a 2005 study of EDF and ADEME, perturbed the public opinion and was presented as the proof that the nuclear has no part in the fight against the climatic change. The author aims to set things straight. (A.L.B.)

  16. Towards Verifying National CO2 Emissions

    Science.gov (United States)

    Fung, I. Y.; Wuerth, S. M.; Anderson, J. L.

    2017-12-01

    With the Paris Agreement, nations around the world have pledged their voluntary reductions in future CO2 emissions. Satellite observations of atmospheric CO2 have the potential to verify self-reported emission statistics around the globe. We present a carbon-weather data assimilation system, wherein raw weather observations together with satellite observations of the mixing ratio of column CO2 from the Orbiting Carbon Observatory-2 are assimilated every 6 hours into the NCAR carbon-climate model CAM5 coupled to the Ensemble Kalman Filter of DART. In an OSSE, we reduced the fossil fuel emissions from a country, and estimated the emissions innovations demanded by the atmospheric CO2 observations. The uncertainties in the innovation are analyzed with respect to the uncertainties in the meteorology to determine the significance of the result. The work follows from "On the use of incomplete historical data to infer the present state of the atmosphere" (Charney et al. 1969), which maps the path for continuous data assimilation for weather forecasting and the five decades of progress since.

  17. Ocean acidification: the other CO2 problem.

    Science.gov (United States)

    Doney, Scott C; Fabry, Victoria J; Feely, Richard A; Kleypas, Joan A

    2009-01-01

    Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds. One well-known effect is the lowering of calcium carbonate saturation states, which impacts shell-forming marine organisms from plankton to benthic molluscs, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and noncalcifying). The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research. Although ocean pH has varied in the geological past, paleo-events may be only imperfect analogs to current conditions.

  18. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard

    1999-01-01

    -effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably...

  19. Literatuuronderzoek CAM-fotosynthese en CO2-bemesting en CO2-bemesting bij bromelia's

    NARCIS (Netherlands)

    Marissen, A.; Warmenhoven, M.G.

    2004-01-01

    De ‘normale’ wijze van CO2-opname gebeurt bij de meeste planten overdag, wanneer er licht is om de opgenomen CO2 door middel van fotosynthese direct om te zetten in suikers. Hiervoor is het nodig dat de huidmondjes overdag open staan, ‘s nachts zijn huidmondjes meestal dicht. Via de huidmondjes gaat

  20. The Li–CO2 battery: a novel method for CO2 capture and utilization

    KAUST Repository

    Xu, Shaomao; Das, Shyamal K.; Archer, Lynden A.

    2013-01-01

    We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than

  1. Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-01-01

    Soil CO2 efflux (Fsoil) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity,...

  3. Well technologies for CO2 geological storage: CO2-resistant cement

    International Nuclear Information System (INIS)

    Barlet-Gouedard, V.; Rimmele, G.; Porcherie, O.; Goffe, B.

    2007-01-01

    Storing carbon dioxide (CO 2 ) underground is considered the most effective way for long-term safe and low-cost CO 2 sequestration. This recent application requires long-term well-bore integrity. A CO 2 leakage through the annulus may occur much more rapidly than geologic leakage through the formation rock, leading to economic loss, reduction of CO 2 storage efficiency, and potential compromise of the field for storage. The possibility of such leaks raises considerable concern about the long-term well-bore isolation and the durability of hydrated cement that is used to isolate the annulus across the producing/injection intervals in CO 2 -storage wells. We propose a new experimental procedure and methodology to study reactivity of CO 2 -Water-Cement systems in simulating the interaction of the set cement with injected supercritical CO 2 under downhole conditions. The conditions of experiments are 90 deg. C under 280 bars. The evolution of mechanical, physical and chemical properties of Portland cement with time is studied up to 6 months. The results are compared to equivalent studies on a new CO 2 -resistant material; the comparison shows significant promise for this new material. (authors)

  4. Uncertainties in the CO2 buget associated to boundary layer dynamics and CO2-advection

    NARCIS (Netherlands)

    Kaikkonen, J.P.; Pino, D.; Vilà-Guerau de Arellano, J.

    2012-01-01

    The relationship between boundary layer dynamics and carbon dioxide (CO2) budget in the convective boundary layer (CBL) is investigated by using mixed-layer theory. We derive a new set of analytical relations to quantify the uncertainties on the estimation of the bulk CO2 mixing ratio and the

  5. Volcanic CO2 Emissions and Glacial Cycles: Coupled Oscillations

    Science.gov (United States)

    Burley, J. M.; Huybers, P. J.; Katz, R. F.

    2016-12-01

    Following the mid-Pleistocene transition, the dominant period of glacial cycles changed from 40 ka to 100 ka. It is broadly accepted that the 40 ka glacial cycles were driven by cyclical changes in obliquity. However, this forcing does not explain the 100 ka glacial cycles. Mechanisms proposed for 100 ka cycles include isostatic bed depression and proglacial lakes destabilising the Laurentide ice sheet, non-linear responses to orbital eccentricity, and Antarctic ice sheets influencing deep-ocean stratification. None of these are universally accepted. Here we investigate the hypothesis that variations in volcanic CO2 emissions can cause 100 ka glacial cycles. Any proposed mechanism for 100 ka glacial cycles must give the Earth's climate system a memory of 10^4 - 10^5years. This timescale is difficult to achieve for surface processes, however it is possible for the solid Earth. Recent work suggests volcanic CO2 emissions change in response to glacial cycles [1] and that there could be a 50 ka delay in that response [2]. Such a lagged response could drive glacial cycles from 40 ka cycles to an integer multiple of the forcing period. Under what conditions could the climate system admit such a response? To address this, we use a simplified climate model modified from Huybers and Tziperman [3]. Our version comprises three component models for energy balance, ice sheet growth and atmospheric CO2 concentration. The model is driven by insolation alone with other components varying according to a system of coupled, differential equations. The model is run for 500 ka to produce several glacial cycles and the resulting changes in global ice volume and atmospheric CO2 concentration.We obtain a switch from 40 ka to 100 ka cycles as the volcanic CO2 response to glacial cycles is increased. These 100 ka cycles are phase-locked to obliquity, lasting 80 or 120 ka. Whilst the MOR response required (in this model) is larger than plausible estimates based on [2], it illustrates the

  6. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  7. High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules

    KAUST Repository

    Qi, Genggeng; Wang, Yanbing; Estevez, Luis; Duan, Xiaonan; Anako, Nkechi; Park, Ah-Hyung Alissa; Li, Wen; Jones, Christopher W.; Giannelis, Emmanuel P.

    2011-01-01

    A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g-1 under simulated flue gas conditions (pre-humidified 10% CO 2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption-regeneration tests (50 cycles). © 2011 The Royal Society of Chemistry.

  8. Density Fluctuation in Aqueous Solutions and Molecular Origin of Salting-Out Effect for CO2

    International Nuclear Information System (INIS)

    Ho, Tuan Anh; Ilgen, Anastasia

    2017-01-01

    Using molecular dynamics simulation, we studied the density fluctuations and cavity formation probabilities in aqueous solutions and their effect on the hydration of CO 2 . With increasing salt concentration, we report an increased probability of observing a larger than the average number of species in the probe volume. Our energetic analyses indicate that the van der Waals and electrostatic interactions between CO 2 and aqueous solutions become more favorable with increasing salt concentration, favoring the solubility of CO 2 (salting in). However, due to the decreasing number of cavities forming when salt concentration is increased, the solubility of CO 2 decreases. The formation of cavities was found to be the primary control on the dissolution of gas, and is responsible for the observed CO 2 salting-out effect. Finally, our results provide the fundamental understanding of the density fluctuation in aqueous solutions and the molecular origin of the salting-out effect for real gas.

  9. CO2 capture by ionic liquids - an answer to anthropogenic CO2 emissions?

    Science.gov (United States)

    Sanglard, Pauline; Vorlet, Olivier; Marti, Roger; Naef, Olivier; Vanoli, Ennio

    2013-01-01

    Ionic liquids (ILs) are efficient solvents for the selective removal of CO2 from flue gas. Conventional, offthe-shelf ILs are limited in use to physisorption, which restricts their absorption capacity. After adding a chemical functionality like amines or alcohols, absorption of CO2 occurs mainly by chemisorption. This greatly enhances CO2 absorption and makes ILs suitable for potential industrial applications. By carefully choosing the anion and the cation of the IL, equimolar absorption of CO2 is possible. This paper reviews the current state of the art of CO2 capture by ILs and presents the current research in this field performed at the ChemTech Institute of the Ecole d'Ingénieurs et d'Architectes de Fribourg.

  10. The Li–CO2 battery: a novel method for CO2 capture and utilization

    KAUST Repository

    Xu, Shaomao

    2013-01-01

    We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than that at 40 °C, and the temperature dependence is significantly weaker for higher surface area carbon cathodes. Ex-situ FTIR and XRD analyses convincingly show that lithium carbonate (Li2CO3) is the main component of the discharge product. The feasibility of similar primary metal-CO2 batteries based on earth abundant metal anodes, such as Al and Mg, is demonstrated. The metal-CO2 battery platform provides a novel approach for simultaneous capturing of CO2 emissions and producing electrical energy. © 2013 The Royal Society of Chemistry.

  11. CO2 emissions embodied in China-US trade: Input-output analysis based on the emergy/dollar ratio

    International Nuclear Information System (INIS)

    Du Huibin; Guo Jianghong; Mao Guozhu; Smith, Alexander M.; Wang Xuxu; Wang, Yuan

    2011-01-01

    To gain insight into changes in CO 2 emissions embodied in China-US trade, an input-output analysis based on the emergy/dollar ratio (EDR) is used to estimate embodied CO 2 emissions; a structural decomposition analysis (SDA) is employed to analyze the driving factors for changes in CO 2 emissions embodied in China's exports to the US during 2002-2007. The results of the input-output analysis show that net export of CO 2 emissions increased quickly from 2002 to 2005 but decreased from 2005 to 2007. These trends are due to a reduction in total CO 2 emission intensity, a decrease in the exchange rate, and small imports of embodied CO 2 emissions. The results of the SDA demonstrate that total export volume was the largest driving factor for the increase in embodied CO 2 emissions during 2002-2007, followed by intermediate input structure. Direct CO 2 emissions intensity had a negative effect on changes in embodied CO 2 emissions. The results suggest that China should establish a framework for allocating emission responsibilities, enhance energy efficiency, and improve intermediate input structure. - Highlights: → An input-output analysis based on the emergy/dollar ratio estimated embodied CO 2 . → A structural decomposition analysis analyzed the driving factors. → Net export of CO 2 increased from 2002 to 2005 but decreased from 2005 to 2007. → Total export volume was the largest driving factor. → A framework for allocating emission responsibilities.

  12. City density and CO_2 efficiency

    International Nuclear Information System (INIS)

    Gudipudi, Ramana; Fluschnik, Till; Ros, Anselmo García Cantú; Walther, Carsten; Kropp, Jürgen P.

    2016-01-01

    Cities play a vital role in the global climate change mitigation agenda. City population density is one of the key factors that influence urban energy consumption and the subsequent GHG emissions. However, previous research on the relationship between population density and GHG emissions led to contradictory results due to urban/rural definition conundrum and the varying methodologies for estimating GHG emissions. This work addresses these ambiguities by employing the City Clustering Algorithm (CCA) and utilizing the gridded CO_2 emissions data. Our results, derived from the analysis of all inhabited areas in the US, show a sub-linear relationship between population density and the total emissions (i.e. the sum of on-road and building emissions) on a per capita basis. Accordingly, we find that doubling the population density would entail a reduction in the total CO_2 emissions in buildings and on-road sectors typically by at least 42%. Moreover, we find that population density exerts a higher influence on on-road emissions than buildings emissions. From an energy consumption point of view, our results suggest that on-going urban sprawl will lead to an increase in on-road energy consumption in cities and therefore stresses the importance of developing adequate local policy measures to limit urban sprawl. - Highlights: •We use gridded population, land use and CO_2 emissions data. •We attribute building and on-road sectoral emissions to populated settlements. •We apply CCA to identify unique city extents and population densities. •Doubling the population density increases CO_2 efficiency typically by 42%. •Population density has more influence on-road CO_2 efficiency than buildings sector.

  13. Imaging volcanic CO2 and SO2

    Science.gov (United States)

    Gabrieli, A.; Wright, R.; Lucey, P. G.; Porter, J. N.

    2017-12-01

    Detecting and quantifying volcanic carbon dioxide (CO2) and sulfur dioxide (SO2) emissions is of relevance to volcanologists. Changes in the amount and composition of gases that volcanoes emit are related to subsurface magma movements and the probability of eruptions. Volcanic gases and related acidic aerosols are also an important atmospheric pollution source that create environmental health hazards for people, animals, plants, and infrastructures. For these reasons, it is important to measure emissions from volcanic plumes during both day and night. We present image measurements of the volcanic plume at Kīlauea volcano, HI, and flux derivation, using a newly developed 8-14 um hyperspectral imaging spectrometer, the Thermal Hyperspectral Imager (THI). THI is capable of acquiring images of the scene it views from which spectra can be derived from each pixel. Each spectrum contains 50 wavelength samples between 8 and 14 um where CO2 and SO2 volcanic gases have diagnostic absorption/emission features respectively at 8.6 and 14 um. Plume radiance measurements were carried out both during the day and the night by using both the lava lake in the Halema'uma'u crater as a hot source and the sky as a cold background to detect respectively the spectral signatures of volcanic CO2 and SO2 gases. CO2 and SO2 path-concentrations were then obtained from the spectral radiance measurements using a new Partial Least Squares Regression (PLSR)-based inversion algorithm, which was developed as part of this project. Volcanic emission fluxes were determined by combining the path measurements with wind observations, derived directly from the images. Several hours long time-series of volcanic emission fluxes will be presented and the SO2 conversion rates into aerosols will be discussed. The new imaging and inversion technique, discussed here, are novel allowing for continuous CO2 and SO2 plume mapping during both day and night.

  14. CO2 Orbital Trends in Comets

    Science.gov (United States)

    Kelley, Michael; Feaga, Lori; Bodewits, Dennis; McKay, Adam; Snodgrass, Colin; Wooden, Diane

    2014-12-01

    Spacecraft missions to comets return a treasure trove of details of their targets, e.g., the Rosetta mission to comet 67P/Churyumov-Gerasimenko, the Deep Impact experiment at comet 9P/Tempel 1, or even the flyby of C/2013 A1 (Siding Spring) at Mars. Yet, missions are rare, the diversity of comets is large, few comets are easily accessible, and comet flybys essentially return snapshots of their target nuclei. Thus, telescopic observations are necessary to place the mission data within the context of each comet's long-term behavior, and to further connect mission results to the comet population as a whole. We propose a large Cycle 11 project to study the long-term activity of past and potential future mission targets, and select bright Oort cloud comets to infer comet nucleus properties, which would otherwise require flyby missions. In the classical comet model, cometary mass loss is driven by the sublimation of water ice. However, recent discoveries suggest that the more volatile CO and CO2 ices are the likely drivers of some comet active regions. Surprisingly, CO2 drove most of the activity of comet Hartley 2 at only 1 AU from the Sun where vigorous water ice sublimation would be expected to dominate. Currently, little is known about the role of CO2 in comet activity because telluric absorptions prohibit monitoring from the ground. In our Cycle 11 project, we will study the CO2 activity of our targets through IRAC photometry. In conjunction with prior observations of CO2 and CO, as well as future data sets (JWST) and ongoing Earth-based projects led by members of our team, we will investigate both long-term activity trends in our target comets, with a particular goal to ascertain the connections between each comet's coma and nucleus.

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

    Science.gov (United States)

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

    2014-04-01

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

  16. Oxygen isotopic signature of CO2 from combustion processes

    Directory of Open Access Journals (Sweden)

    W. A. Brand

    2011-02-01

    Full Text Available For a comprehensive understanding of the global carbon cycle precise knowledge of all processes is necessary. Stable isotope (13C and 18O abundances provide information for the qualification and the quantification of the diverse source and sink processes. This study focuses on the δ18O signature of CO2 from combustion processes, which are widely present both naturally (wild fires, and human induced (fossil fuel combustion, biomass burning in the carbon cycle. All these combustion processes use atmospheric oxygen, of which the isotopic signature is assumed to be constant with time throughout the whole atmosphere. The combustion is generally presumed to take place at high temperatures, thus minimizing isotopic fractionation. Therefore it is generally supposed that the 18O signature of the produced CO2 is equal to that of the atmospheric oxygen. This study, however, reveals that the situation is much more complicated and that important fractionation effects do occur. From laboratory studies fractionation effects on the order of up to 26%permil; became obvious in the derived CO2 from combustion of different kinds of material, a clear differentiation of about 7‰ was also found in car exhausts which were sampled directly under ambient atmospheric conditions. We investigated a wide range of materials (both different raw materials and similar materials with different inherent 18O signature, sample geometries (e.g. texture and surface-volume ratios and combustion circumstances. We found that the main factor influencing the specific isotopic signatures of the combustion-derived CO2 and of the concomitantly released oxygen-containing side products, is the case-specific rate of combustion. This points firmly into the direction of (diffusive transport of oxygen to the reaction zone as the cause of the isotope fractionation. The original total 18O signature of the material appeared to have little influence, however, a contribution of specific bio

  17. Vapor-liquid Phase Equilibria for CO2+Tertpentanol Binary System at Elevated Pressures

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO Jian-cheng; YANG Hao; CHEN Kai-xun

    2011-01-01

    Vapor-liquid phase equilibrium data of tertpentanol in carbon dioxide were measured at temperatures of 313.4,323.4,333.5 and 343.5 K and in the pressure range of 4.56-11.44 MPa.The phase equilibium apparatus used in the work was a variable-volume high-pressure cell.The experimental data were reasonably correlated with Peng-Robinson equation of state(PR-EOS) together with van der Waals-2 two-parameter mixing rules.Henry's Law constants and partial molar volumes of CO2 at infinite dilution were estimated with Krichevsky-Kasarnovsky equation,and Henry's Law constants increase with increasing temperature,however,partial molar volumes of CO2 at infinite dilution are negative whose magnitudes decrease with temperature.Partial molar volumes of CO2 and tertpentanol in liquid phase at equilibrium were calculated.

  18. Ordered oxygen deficient '112'perovskites, LnBaCo2 O5⋅ 50 ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 32; Issue 3. Ordered oxygen deficient '112' perovskites, LnBaCo2O5.50+: complex magnetism and transport properties. B Raveau Md Motin Seikh V Pralong V Caignaert. Volume 32 Issue 3 June 2009 pp 305-312 ...

  19. Development of a cost-effective CO2 adsorbent from petroleum coke via KOH activation

    Science.gov (United States)

    Jang, Eunji; Choi, Seung Wan; Hong, Seok-Min; Shin, Sangcheol; Lee, Ki Bong

    2018-01-01

    The capture of CO2 via adsorption is considered an effective technology for decreasing global warming issues; hence, adsorbents for CO2 capture have been actively developed. Taking into account cost-effectiveness and environmental concerns, the development of CO2 adsorbents from waste materials is attracting considerable attention. In this study, petroleum coke (PC), which is the carbon residue remaining after heavy oil upgrading, was used to produce high-value-added porous carbon for CO2 capture. Porous carbon materials were prepared by KOH activation using different weight ratios of KOH/PC (1:1, 2:1, 3:1, and 4:1) and activation temperatures (600, 700, and 800 °C). The specific surface area and total pore volume of resulting porous carbon materials increased with KOH amount, reaching up to 2433 m2/g and 1.11 cm3/g, respectively. The sample prepared under moderate conditions with a KOH/PC weight ratio of 2:1 and activation temperature of 700 °C exhibited the highest CO2 adsorption uptake of 3.68 mmol/g at 25 °C and 1 bar. Interestingly, CO2 adsorption uptake was linearly correlated with the volume of micropores less than 0.8 nm, indicating that narrow micropore volume is crucial for CO2 adsorption. The prepared porous carbon materials also exhibited good selectivity for CO2 over N2, rapid adsorption, facile regeneration, and stable adsorption-desorption cyclic performance, demonstrating potential as a candidate for CO2 capture.

  20. Capturing [11C]CO2 for use in aqueous applications

    International Nuclear Information System (INIS)

    Vandehey, Nicholas T.; O’Neil, James P.

    2014-01-01

    We present a simple method for trapping [ 11 C]CO 2 gas and releasing it into a buffered solution using an ion-exchange cartridge. Sodium hydroxide cartridges captured >99% of [ 11 C]CO 2 following NaOH activation. A sodium bicarbonate solution eluted >99% of trapped radioactivity. Trapping [ 11 C]CO 2 directly in small volumes of several solutions was less effective than cartridge methods. The recommended methods allow for fast and simple production of highly concentrated carbon-11 containing aqueous solutions for use in filling phantoms, calibrating detectors, or (bio)geochemical experiments. - Highlights: • An ion exchange resin can trap [ 11 C]CO 2 gas and release it with saturated bicarbonate. • Elution from cartridge requires as little as 300 µL volume, with eluant at pH=10. • SPE trap-and-release provided better results than trapping in solution

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

    Directory of Open Access Journals (Sweden)

    C. Lac

    2013-05-01

    Full Text Available 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

  2. PENGURANGAN KADAR CO2 MENGGUNAKAN SPIRULINA PLATENSIS DALAM TUBULAR BIOREACTOR

    Directory of Open Access Journals (Sweden)

    Zainal Syam Arifin

    2015-06-01

    Full Text Available Increasing the population impact on increasing energy demand. On the other hand, the energy generation industry has been blamed as one of the contributors of carbon dioxide about 25% of total CO2 emissions worldwide. Meanwhile, the production of biogas, which aims to address the increasing need of energy, produces carbon dioxide in the range of 25–50% by volume. To overcome this, a cheap method, optimum and efficient as well as environmentally friendly in reducing CO2 levels by using Spirulina platensis is needed. This research aims to created a mathematical models and found the optimum flow rate to reduced levels of CO2 by using Spirulina platensis. This study used a glass tubular bioreactor (D = 2.6 cm at a temperature of 30°C and irradiated with a fluorescent lamp Philips TL 36 Watt, color temperature: 6,200K cool daylight, light output: 2,600 lm, 72 lm/W. Tubular reactor was placed in a box lined with silver foil walls on three sides. With mathematical models of tubular reactor, the reaction rate constants could be predicted. Based on calculations of data and graphs, optimum volumetric velocity could also be predicted. Variation of flowrate to observed the reduction rate of CO2 was 0.25 mL/sec, 0.35 mL/sec, 0.5 mL/sec, 0.75 mL/sec, 1 mL/sec. Carbon source was 99.99% CO2.Observations of Spirulina growth was made on the flow rate of 0.25 mL/sec at the initial levels of dry weight 2.1208 g/L. The results of this study indicated that the low flowratewas a more effective way to reduced carbon dioxide levels using Spirulina platensis (= 2.82×10-4 sec-1. The highest conversion was obtained at a volumetric flow rate of 0.25 mL/sec and optimum speeds in the range of 0.3 to 0.4 mL/sec. The rate of incoming CO2 flux should be less than 0.047 mL/cm2.detik. Specific Growth Rate (µ of Spirulina platensis in this study was 2.56×10-2 minute-1.   Keywords: Spirulina platensis, a vertical tubular bioreactor, CO2 reduction     ABSTRAK

  3. Study of steam, helium and supercritical CO2 turbine power generations in prototype fusion power reactor

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Muto, Yasushi; Kato, Yasuyoshi; Nishio, Satoshi; Hayashi, Takumi; Nomoto, Yasunobu

    2008-01-01

    Power generation systems such as steam turbine cycle, helium turbine cycle and supercritical CO 2 (S-CO 2 ) turbine cycle are examined for the prototype nuclear fusion reactor. Their achievable cycle thermal efficiencies are revealed to be 40%, 34% and 42% levels for the heat source outlet coolant temperature of 480degC, respectively, if no other restriction is imposed. In the current technology, however, low temperature divertor heat source is included. In this actual case, the steam turbine system and the S-CO 2 turbine system were compared in the light of cycle efficiency and plant cost. The values of cycle efficiency were 37.7% and 36.4% for the steam cycle and S-CO 2 cycle, respectively. The construction cost was estimated by means of component volume. The volume became 16,590 m 3 and 7240 m 3 for the steam turbine system and S-CO 2 turbine system, respectively. In addition, separation of permeated tritium from the coolant is much easier in S-CO 2 than in H 2 O. Therefore, the S-CO 2 turbine system is recommended to the fusion reactor system than the steam turbine system. (author)

  4. Assessment of CO2 Storage Potential in Naturally Fractured Reservoirs With Dual-Porosity Models

    Science.gov (United States)

    March, Rafael; Doster, Florian; Geiger, Sebastian

    2018-03-01

    Naturally Fractured Reservoirs (NFR's) have received little attention as potential CO2 storage sites. Two main facts deter from storage projects in fractured reservoirs: (1) CO2 tends to be nonwetting in target formations and capillary forces will keep CO2 in the fractures, which typically have low pore volume; and (2) the high conductivity of the fractures may lead to increased spatial spreading of the CO2 plume. Numerical simulations are a powerful tool to understand the physics behind brine-CO2 flow in NFR's. Dual-porosity models are typically used to simulate multiphase flow in fractured formations. However, existing dual-porosity models are based on crude approximations of the matrix-fracture fluid transfer processes and often fail to capture the dynamics of fluid exchange accurately. Therefore, more accurate transfer functions are needed in order to evaluate the CO2 transfer to the matrix. This work presents an assessment of CO2 storage potential in NFR's using dual-porosity models. We investigate the impact of a system of fractures on storage in a saline aquifer, by analyzing the time scales of brine drainage by CO2 in the matrix blocks and the maximum CO2 that can be stored in the rock matrix. A new model to estimate drainage time scales is developed and used in a transfer function for dual-porosity simulations. We then analyze how injection rates should be limited in order to avoid early spill of CO2 (lost control of the plume) on a conceptual anticline model. Numerical simulations on the anticline show that naturally fractured reservoirs may be used to store CO2.

  5. Effect of venous (gut) CO2 loading on intrapulmonary gas fractions and ventilation in the tegu lizard.

    Science.gov (United States)

    Ballam, G O; Donaldson, L A

    1988-01-01

    Studies were conducted to determine regional pulmonary gas concentrations in the tegu lizard lung. Additionally, changes in pulmonary gas concentrations and ventilatory patterns caused by elevating venous levels of CO2 by gut infusion were measured. It was found that significant stratification of lung gases was present in the tegu and that dynamic fluctuations of CO2 concentration varied throughout the length of the lung. Mean FCO2 was greater and FO2 less in the posterior regions of the lung. In the posterior regions gas concentrations remained nearly constant, whereas in the anterior regions large swings were observed with each breath. In the most anterior sections of the lung near the bronchi, CO2 and O2 concentrations approached atmospheric levels during inspiration and posterior lung levels during expiration. During gut loading of CO2, the rate of rise of CO2 during the breathing pause increased. The mean level of CO2 also increased. Breathing rate and tidal volume increased to produce a doubling of VE. These results indicate that the method of introduction of CO2 into the tegu respiratory system determines the ventilatory response. If the CO2 is introduced into the venous blood a dramatic increase in ventilation is observed. If the CO2 is introduced into the inspired air a significant decrease in ventilation is produced. The changes in pulmonary CO2 environment caused by inspiratory CO2 loading are different from those caused by venous CO2 loading. We hypothesize that the differences in pulmonary CO2 environment caused by either inspiratory CO2 loading or fluctuations in venous CO2 concentration act differently on the IPC. The differing response of the IPC to the two methods of CO2 loading is the cause of the opposite ventilatory response seen during either venous or inspiratory loading.

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

    Directory of Open Access Journals (Sweden)

    S. Basu

    2013-09-01

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

  7. Geochemical Interaction of Middle Bakken Reservoir Rock and CO2 during CO2-Based Fracturing

    Science.gov (United States)

    Nicot, J. P.; Lu, J.; Mickler, P. J.; Ribeiro, L. H.; Darvari, R.

    2015-12-01

    This study was conducted to investigate the effects of geochemical interactions when CO2 is used to create the fractures necessary to produce hydrocarbons from low-permeability Middle Bakken sandstone. The primary objectives are to: (1) identify and understand the geochemical reactions related to CO2-based fracturing, and (2) assess potential changes of reservoir property. Three autoclave experiments were conducted at reservoir conditions exposing middle Bakken core fragments to supercritical CO2 (sc-CO2) only and to CO2-saturated synthetic brine. Ion-milled core samples were examined before and after the reaction experiments using scanning electron microscope, which enabled us to image the reaction surface in extreme details and unambiguously identify mineral dissolution and precipitation. The most significant changes in the reacted rock samples exposed to the CO2-saturated brine is dissolution of the carbonate minerals, particularly calcite which displays severely corrosion. Dolomite grains were corroded to a lesser degree. Quartz and feldspars remained intact and some pyrite framboids underwent slight dissolution. Additionally, small amount of calcite precipitation took place as indicated by numerous small calcite crystals formed at the reaction surface and in the pores. The aqueous solution composition changes confirm these petrographic observations with increase in Ca and Mg and associated minor elements and very slight increase in Fe and sulfate. When exposed to sc-CO2 only, changes observed include etching of calcite grain surface and precipitation of salt crystals (halite and anhydrite) due to evaporation of residual pore water into the sc-CO2 phase. Dolomite and feldspars remained intact and pyrite grains were slightly altered. Mercury intrusion capillary pressure tests on reacted and unreacted samples shows an increase in porosity when an aqueous phase is present but no overall porosity change caused by sc-CO2. It also suggests an increase in permeability

  8. Determination of free CO2 in emergent groundwaters using a commercial beverage carbonation meter

    Science.gov (United States)

    Vesper, Dorothy J.; Edenborn, Harry M.

    2012-05-01

    SummaryDissolved CO2 in groundwater is frequently supersaturated relative to its equilibrium with atmospheric partial pressure and will degas when it is conveyed to the surface. Estimates of dissolved CO2 concentrations can vary widely between different hydrochemical facies because they have different sources of error (e.g., rapid degassing, low alkalinity, non-carbonate alkalinity). We sampled 60 natural spring and mine waters using a beverage industry carbonation meter, which measures dissolved CO2 based on temperature and pressure changes as the sample volume is expanded. Using a modified field protocol, the meter was found to be highly accurate in the range 0.2-35 mM CO2. The meter provided rapid, accurate and precise measurements of dissolved CO2 in natural waters for a range of hydrochemical facies. Dissolved CO2 concentrations measured in the field with the carbonation meter were similar to CO2 determined using the pH-alkalinity approach, but provided immediate results and avoided errors from alkalinity and pH determination. The portability and ease of use of the carbonation meter in the field made it well-suited to sampling in difficult terrain. The carbonation meter has proven useful in the study of aquatic systems where CO2 degassing drives geochemical changes that result in surficial mineral precipitation and deposition, such as tufa, travertine and mine drainage deposits.

  9. More on the losses of dissolved CO(2) during champagne serving: toward a multiparameter modeling.

    Science.gov (United States)

    Liger-Belair, Gérard; Parmentier, Maryline; Cilindre, Clara

    2012-11-28

    Pouring champagne into a glass is far from being inconsequential with regard to the dissolved CO(2) concentration found in champagne. Three distinct bottle types, namely, a magnum bottle, a standard bottle, and a half bottle, were examined with regard to their loss of dissolved CO(2) during the service of successively poured flutes. Whatever the bottle size, a decreasing trend is clearly observed with regard to the concentration of dissolved CO(2) found within a flute (from the first to the last one of a whole service). Moreover, when it comes to champagne serving, the bottle size definitely does matter. The higher the bottle volume, the better its buffering capacity with regard to dissolved CO(2) found within champagne during the pouring process. Actually, for a given flute number in a pouring data series, the concentration of dissolved CO(2) found within the flute was found to decrease as the bottle size decreases. The impact of champagne temperature (at 4, 12, and 20 °C) on the losses of dissolved CO(2) found in successively poured flutes for a given standard 75 cL bottle was also examined. Cold temperatures were found to limit the decreasing trend of dissolved CO(2) found within the successively poured flutes (from the first to the last one of a whole service). Our experimental results were discussed on the basis of a multiparameter model that accounts for the major physical parameters that influence the loss of dissolved CO(2) during the service of a whole bottle type.

  10. National CO2 emissions trading in European perspective; Nationale CO2-emissiehandel in Europees perspectief

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    This report is the reaction of the Social and economic council (SER) in the Netherlands to the request of the Dutch Ministry of Housing, Spatial Planning en Environment (VROM) to formulate an advice on the final report of the Committee CO2 Trade (a.k.a the Vogtlander Committee). This Committee has drafted a proposal for a CO2 emission trade system in the Netherlands. The SER has also taken into account the proposal of the European Committee on a guideline for CO2 emission trade in the European Union (EU)

  11. Solubility of krypton in liquid CO2

    International Nuclear Information System (INIS)

    Notz, K.J.; Meservey, A.B.

    1976-06-01

    The solubility of krypton in liquid CO 2 was measured experimentally over essentially the entire liquid range of CO 2 , from -53 to 29 0 C. A tracer technique using 85 Kr was employed, and equilibrated gas-liquid samples were analyzed in situ with a collimated counter. Dilute concentrations of krypton were used, and the data are expressed as a distribution ratio, Y/sub Kr//X/sub Kr/, the log of which is nearly linear with respect to temperature from the lowest temperature to about 20 0 C, above which the values fall off rapidly toward a value of unity at the critical temperature. The numerical values obtained for the distribution ratio increase from 1.44 at 29 0 C to 29.4 at -53 0 C

  12. Toxic emissions and devalued CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    With reference to the paradigme shift regarding the formation of dioxins in municiplan solid waste incinerators experimental results are taken into account which lead to the suspicion that the same mechanism of de-novo-synthesis also applies to fireplace chimneys. This can explain the dioxin...... friendly effects of substituting wood burning for fossil fuels. With reference to Bent Sørensen's classical work on 'Renewable Energy' the assumption of CO2-neutrality regarding incineration is problematised when applied to plants with long rotation periods as trees. Registered CO2-emissions from wood...... burning are characterised together with particle and PAH emissions. The positive treatment of wood stove-technology in the Danish strategy for sustainable development (draft 2007) is critically evaluated and approaches to better regulation are identified....

  13. A centrifuge CO2 pellet cleaning system

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.; Nelson, W.D.; Schechter, D.E.

    1993-01-01

    Centrifuge-based cryogenic pellet accelerator technology, originally developed at Oak Ridge National Laboratory (ORNL) for the purpose of refueling fusion reactors with high-speed pellets of frozen deuterium/tritium,is now being developed as a method of cleaning without the use of conventional solvents. In these applications large quantities of pellets made of frozen CO 2 or argon are accelerated in a high-speed rotor. The accelerated pellet stream is used to clean or etch surfaces. The advantage of this system is that the spent pellets and debris resulting from the cleaning process can be filtered leaving only the debris for disposal. This paper discusses the centrifuge CO 2 pellet cleaning system, the physics model of the pellet impacting the surface, the centrifuge apparatus, and some initial cleaning and etching tests

  14. Molecular simulations of CO2 at interfaces

    DEFF Research Database (Denmark)

    Silvestri, Alessandro

    trapping mechanisms that act over dierent time scales, where eectiveness is determined by phenomena that occur at the interfaces between CO2, pore uids and the pore surfaces. Solid theoretical understanding of the nanoscale interactions that result from the interplay of intermolecular and surface forces...... variety of conditions: pressure, temperature, pore solution salinity and various mineral surfaces. However, achieving representative subsurface conditions in experiments is challenging and reported data are aected by experimental uncertainties and sometimes are contradictory. Molecular modelling...... rock record and the formations are generally porous so their probable response to CO2 sequestration needs to be investigated. However, despite the large number of geologic sequestration publications on water{rock interactions over the last decade, studies on carbonate reservoirs remain scarce...

  15. Toxic emissions and devaluated CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    Environmental, energy and climate policies need fresh reflections. In order to evaluate toxics reduction policies the Stockholm Convention on Persistent Organic Pollutants is mandatory. Denmark's function as lead country for dioxin research in the context of the OSPAR Convention is contrasted...... with a climate policy whose goals of CO2-reduction were made operational by green-wash. Arguments are given for the devaluation of CO2- neutrality in case of burning wood. Alternative practices as storing C in high quality wood products and/or leaving wood in the forest are recommended. A counter......-productive effect of dioxin formation in the cooling phase of wood burning appliances has been registered akin to de-novo-synthesis in municipal solid waste incinerators. Researchers, regulators and the public are, however, still preoccupied by notions of oven design and operation parameters, assuming that dioxin...

  16. Sustainable Process Networks for CO2 Conversion

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Kongpanna, P.; Pavarajam, V.

    According to various organizations, especially the Intergovernmental Panel on Climate Change, global warming is an ever-increasing threat to the environment and poses a problem if not addressed. As a result, efforts are being made across academic and industrial fields to find methods of reducing...... drawbacks to this geologic storage system: the CO2 is not eliminated, the implementation is limited due to natural phenomena, and the capturing methods are often expensive. Thus, it is desirable to develop an alternative strategy for reducing the CO2 emissions [2]. An additional process that reduces...... that are thermodynamically feasible, including the co-reactants, catalysts, operating conditions and reactions. Research has revealed that there are a variety of reactions that fulfill the aforementioned criteria. The products that are formed fall into categories: fuels, bulk chemicals and specialty chemicals. While fuels...

  17. Continuous CO2 extractor and methods

    Energy Technology Data Exchange (ETDEWEB)

    None listed

    2010-06-15

    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  18. Continuous CO2 extractor and methods

    International Nuclear Information System (INIS)

    2010-01-01

    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  19. Throat gases against the CO2

    International Nuclear Information System (INIS)

    Michaut, C.

    2006-01-01

    The steel production needs carbon consumption and generates carbon dioxide, the main greenhouse gases. It represents about 6 % of the greenhouse gases emissions in the world. That is why the steel industry began last year a research program, Ideogaz, to reduce its CO 2 releases. The first results on the throat gases recovery seems very promising: it uses 25 % less of carbon. The author presents the program and the main technical aspects of the method. (A.L.B.)

  20. Panorama 2016 - Chemical recycling of CO2

    International Nuclear Information System (INIS)

    Forti, Laurent; Fosse, Florian

    2015-12-01

    The ongoing rise of atmospheric carbon dioxide concentration is a major environmental and societal concern. Among the potential solutions for reducing carbon emissions in the energy sector, the chemical recycling of CO 2 has received considerable attention. Conversion of carbon dioxide into other recoverable substances offers the benefit of reducing the carbon footprint of newly developed products and of shifting away from the use of fossil resources. Various methods to create a wide range of products are currently being studied. (authors)

  1. Influence of CO2 on the climate

    International Nuclear Information System (INIS)

    Junod, A.

    1989-01-01

    The earth's climate is subject to long and short term fluctuations. The recent ones are being caused by mankind. The most important result is the increase in the CO 2 -content of the atmosphere, caused by burning of fossil fuels. This leads to the so-called greenhouse effect. It is judged that the average temperature of the earth's surface will rise by 2 o C between the years 2030 and 2050

  2. CO2 capture takes its industrial turn

    International Nuclear Information System (INIS)

    Remoue, A.; Lutzky, A.

    2009-01-01

    The CO 2 capture and sequestration is entering the industrial era. The technologies are ready, the regulation is progressively put into action, the financing of demonstration facilities is unfreezing and companies are on the starting line from Canada to China, including the USA and Europe. The market takeoff is expected for 2015 but the competition is already hard between equipment manufacturers who wish to develop proprietary technologies. (J.S.)

  3. Aridity under conditions of increased CO2

    Science.gov (United States)

    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

  4. Towards Overhauser DNP in supercritical CO(2).

    Science.gov (United States)

    van Meerten, S G J; Tayler, M C D; Kentgens, A P M; van Bentum, P J M

    2016-06-01

    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Development of longitudinally excited CO2 laser

    Science.gov (United States)

    Masroon, N. S.; Tanaka, M.; Tei, M.; Uno, K.; Tsuyama, M.; Nakano, H.

    2018-05-01

    Simple, compact, and affordable discharged-pumped CO2 laser controlled by a fast high voltage solid state switch has been developed. In this study, longitudinal excitation scheme has been adapted for simple configuration. In the longitudinal excitation scheme, the discharge is produced along the direction of the laser axis, and the electrodes are well separated with a small discharge cross-section. Triggered spark gap switch is usually used to switch out the high voltage because of simple and low cost. However, the triggered spark gap operates in the arc mode and suffer from recovery problem causing a short life time and low efficiency for high repetition rate operation. As a result, there is now considerable interest in replacing triggered spark gap switch with solid state switches. Solid state switches have significant advantages compared to triggered spark gap switch which include longer service lifetime, low cost and stable high trigger pulse. We have developed simple and low cost fast high voltage solid state switch that consists of series connected-MOSFETs. It has been installed to the longitudinally excited CO2 laser to realize the gap switch less operation. Characteristics of laser oscillation by varying the discharge length, charging voltage, capacitance and gas pressure have been evaluated. Longer discharge length produce high power of laser oscillation. Optimum charging voltage and gas pressure were existed for longitudinally excited CO2 laser.

  6. Martian Gullies: Formation by CO2 Fluidification

    Science.gov (United States)

    Cedillo-Flores, Y.; Durand-Manterola, H. J.

    2006-12-01

    Some of the geomorphological features in Mars are the gullies. Some theories developed tried explain its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We propose that the mechanism of formation of the gullies is as follows: In winter CO2 snow mixed with sand falls in the terrain. In spring the CO2 snow sublimate and gaseous CO2 make fluid the sand which flows like liquid eroding the terrain and forming the gullies. By experimental work with dry granular material, we simulated the development of the Martian gullies injecting air in the granular material. We present the characteristics of some terrestrial gullies forms at cold environment, sited at Nevado de Toluca Volcano near Toluca City, México. We compare them with Martian gullies choose from four different areas, to target goal recognize or to distinguish, (to identify) possible processes evolved in its formation. Also, we measured the lengths of those Martian gullies and the range was from 24 m to 1775 meters. Finally, we present results of our experimental work at laboratory with dry granular material.

  7. Effect of CO_2 dilution on combustion and emissions characteristics of the hydrogen-enriched gasoline engine

    International Nuclear Information System (INIS)

    Wang, Shuofeng; Ji, Changwei; Zhang, Bo; Cong, Xiaoyu; Liu, Xiaolong

    2016-01-01

    CO_2 (Carbon dioxide) dilution is a feasible way for controlling NOx (Nitrogen oxides) emissions and loads of the internal combustion engines. This paper investigated the effect of CO_2 dilution on the combustion and emissions characteristics of a hydrogen-enriched gasoline engine. The experiment was conducted on a 1.6 L spark-ignition engine with electronically controlled hydrogen and gasoline injection systems. At two hydrogen volume fractions of 0 and 3%, the CO_2 volume fraction in the intake was gradually increased from 0 to 4%. The fuel-air mixtures were kept at the stoichiometric. The experimental results demonstrated that brake mean effective pressure of the gasoline engine was quickly reduced after adopting CO_2 dilution. Comparatively, Bmep (Brake mean effective pressure) of the 3% hydrogen-enriched engine was gently decreased with the increase of CO_2 dilution level. Thermal efficiency of the 3% hydrogen-enriched gasoline engine was raised under properly increased CO_2 dilution levels. However, thermal efficiency of the pure gasoline engine was generally dropped after the CO_2 dilution. The addition of hydrogen could shorten flame development and propagation durations under CO_2 diluent conditions for the gasoline engine. Increasing CO_2 fraction in the intake caused the dropped NOx and raised HC (Hydrocarbon) emissions. Increasing hydrogen fraction in the intake could effectively reduce HC emissions under CO_2 diluent conditions. - Highlights: • CO_2 dilution reduces cooling loss and NOx of H_2-enriched gasoline engines. • H_2-blended gasoline engine gains better efficiency after CO_2 dilution. • CoVimep of H_2-blended gasoline engine is kept at low level after CO_2 addition. • CO_2 dilution has small effect on reducing Bmep of H_2-blended gasoline engine.

  8. Potential hazards of CO2 leakage in storage systems : learning from natural systems

    International Nuclear Information System (INIS)

    Beaubien, S.E.; Lombardi, S.; Ciotoli, G.; Annunziatellis, A.; Hatziyannis, G.; Metaxas, A.; Pearce, J.M.

    2005-01-01

    The Natural Analogues for the Storage of CO2 in the Geological Environment (NASCENT) Project has examined several naturally occurring carbon dioxide (CO 2 ) deposits throughout Europe to better understand the possible long term geological effects of a man-made CO 2 storage reservoir. Natural geological accumulations of CO 2 also occur widely throughout the world, some of which leak CO 2 to the surface, while others are effectively sealed. It is important to understanding the characteristics of both types of deposits in order to select and design underground storage sites for CO 2 storage. Four naturally occurring CO 2 sites were reviewed in this paper with reference to issues related to risk assessment, such as migration pathways; the speed of migration and mass flux rates; changes in groundwater chemistry; and, the effects these emissions may have on local populations and ecosystems. One site was located in northern Greece, near the Florina CO 2 gas field. The other three sites were in central Italy, including a selected area of the Latera geothermal complex, where natural deep CO 2 migrates upwards along faults and is emitted to the atmosphere; the San Vittorino intermontane basin where CO 2 -charged groundwaters cause the dissolution of limestone to form large sinkholes; and, the Ciampino area southeast of Rome, where CO 2 from deep-seated volcanism migrates along faults in a residential area. Work performed on these sites included soil gas, CO 2 flux and aqueous geochemical surveys. A GIS based model was also developed for the Latera site to assesses the risk of deep gas migration to surface. It was emphasized that these 4 sites are extreme cases compared to a man-made CO 2 geological storage site. For example all sites have an essentially infinite supply of deep CO 2 as the result of the thermo-metamorphic reactions forming this gas, whereas a man-made storage site would have a finite volume of gas which would be limited in its mass transfer out of the

  9. Effects of ERV Filter Degradation on Indoor CO2 Levels of a Classroom

    Directory of Open Access Journals (Sweden)

    Jae-Sol Choi

    2018-04-01

    Full Text Available Energy recovery ventilators (ERVs are widely used to reduce energy losses caused by ventilation and improve indoor air quality for recently-constructed buildings. It is important for spaces with high occupancy density and longer residence times, such as classrooms. In classrooms, the ERV size is typically estimated by the target number of students in the design phase, but the design air volume flow rates (m3/h of the ERV can decrease over time owing to filter degradation such as increased dust loading. In this study, field tests are conducted in a classroom to investigate filter degradation through a visual inspection and by measuring the air volume flow rates at the diffusers connected to the ERV. In addition, variations in carbon dioxide (CO2 concentrations are also measured to verify the effects of filter degradation on the indoor CO2 levels over the entire test period, which includes filter replacement, as well. As the tests are conducted during classes, several adjusting methodologies are proposed to match the different test conditions. The results show that the total air volume flow rate of the ERV increases after the filter replacement (546 to 766 m3/h, but it again decreases as time elapses (659 m3/h. Accordingly, the indoor CO2 concentration decreases after the filter replacement by more than 300 ppm (1404 to 1085 ppm, clearly showing the effect of filter degradation. However, this CO2 concentration remains similar for four months after the replacement, and the total air volume rate decreases again. An interpretation is made using computational fluid dynamics analysis that the measured CO2 concentrations are affected by airflow patterns. The airflow in the cooling system may dilute CO2 concentrations at the measuring location. Thus, periodic filter replacement and management are important to ensure the desired ERV air volume rates and consequently the desired indoor CO2 concentrations.

  10. Modeling experimental stable isotope results from CO2 adsorption and diffusion experiments

    Science.gov (United States)

    Larson, T. E.

    2012-12-01

    Transport of carbon dioxide through porous media can be affected by diffusion, advection and adsorption processes. Developing new tools to understand which of these processes dominates migration of CO2 or other gases in the subsurface is important to a wide range of applications including CO2 storage. Whereas advection rates are not affected by isotope substitution in CO2, adsorption and diffusion constants are. For example, differences in the binary diffusion constant calculated between C12O2-He and C13O2-He results in a carbon isotope fractionation whereby the front of the chromatographic peak is enriched in carbon-12 and the tail of the peak is enriched in carbon-13. Interestingly, adsorption is shown to have an opposite, apparent inverse affect whereby the lighter isotopologues of CO2 are preferentially retained by the chromatographic column and the heavier isotopologues are eluted first. This apparent inverse chromatographic effect has been ascribed to Van der Waals dispersion forces. Smaller molar volumes of the heavier isotopologues resulting from increased bond strength (shorter bond length) effectively decreases Van der Waals forces in heavier isotopologues compared to lighter isotopologues. Here we discuss the possible application of stable isotope values measured across chromatographic peaks to differentiate diffusion-dominated from adsorption-dominated transport processes for CO2. Separate 1-dimensional flow-through columns were packed with quartz and illite, and one remained empty. Dry helium was used as a carrier gas. Constant flow rate, temperature and column pressure were maintained. After background CO2 concentrations were minimized and constant, a sustained pulse of CO2 was injected at the head of the column and the effluent was sampled at 4 minute intervals for CO2 concentration, and carbon and oxygen isotope ratios. The quartz-sand packed and empty columns resulted in similar trends in concentration and isotope ratios whereby CO2 concentrations

  11. Natural Analogues of CO2 Geological Storage; Analogos Naturales del Almacenamiento Geologico de CO2

    Energy Technology Data Exchange (ETDEWEB)

    Perez del Villar, L; Pelayo, M; Recreo, F

    2007-07-20

    Geological storage of carbon dioxide is nowadays, internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize the global climate change universally accepted. Nevertheless, the possible risks derived of this long-term storage have a direct influence on its public acceptance. Among the favourable geological formations to store CO2, depleted oil and gas fields, deep saline reservoirs, and unamiable coal seams are highlighted. One of the most important objectives of the R and D projects related to the CO2 geological storage is the evaluation of the CO2 leakage rate through the above mentioned geological formations. Therefore, it is absolutely necessary to increase our knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths and the physical resistance of the sealing formation. The quantification of the CO2 leakage rate is essential to evaluate the effects on the human and animal health, as well as for the ecosystem and water quality. To achieve these objectives, the study of the natural analogues is very useful in order to know the natural leakage rate to the atmosphere, its flow paths, the physical, chemical and mineralogical modifications due to the long term interaction processes among the CO2 and the storage and sealing formations, as well as the effects on the groundwaters and ecosystems. In this report, we have tried to summarise the main characteristics of the natural reservoirs and surficial sources of CO2, which are both natural analogues of the geological storage and CO2 leakage, studied in EEUU, Europe and Australia. The main objective of this summary is to find the possible applications for long-term risk prediction and for the performance assessment by means of conceptual and numerical modelling, which will allow to validate the predictive models of the CO2 storage behaviour, to design and develop suitable monitoring techniques to control the CO2 behaviour

  12. Optimizing geologic CO2 sequestration by injection in deep saline formations below oil reservoirs

    International Nuclear Information System (INIS)

    Han, Weon Shik; McPherson, Brian J.

    2009-01-01

    The purpose of this research is to present a best-case paradigm for geologic CO 2 storage: CO 2 injection and sequestration in saline formations below oil reservoirs. This includes the saline-only section below the oil-water contact (OWC) in oil reservoirs, a storage target neglected in many current storage capacity assessments. This also includes saline aquifers (high porosity and permeability formations) immediately below oil-bearing formations. While this is a very specific injection target, we contend that most, if not all, oil-bearing basins in the US contain a great volume of such strata, and represent a rather large CO 2 storage capacity option. We hypothesize that these are the best storage targets in those basins. The purpose of this research is to evaluate this hypothesis. We quantitatively compared CO 2 behavior in oil reservoirs and brine formations by examining the thermophysical properties of CO 2 , CO 2 -brine, and CO 2 -oil in various pressure, temperature, and salinity conditions. In addition, we compared the distribution of gravity number (N), which characterizes a tendency towards buoyancy-driven CO 2 migration, and mobility ratio (M), which characterizes the impeded CO 2 migration, in oil reservoirs and brine formations. Our research suggests competing advantages and disadvantages of CO 2 injection in oil reservoirs vs. brine formations: (1) CO 2 solubility in oil is significantly greater than in brine (over 30 times); (2) the tendency of buoyancy-driven CO 2 migration is smaller in oil reservoirs because density contrast between oil and CO 2 is smaller than it between brine and oil (the approximate density contrast between CO 2 and crude oil is ∼100 kg/m 3 and between CO 2 and brine is ∼350 kg/m 3 ); (3) the increased density of oil and brine due to the CO 2 dissolution is not significant (about 7-15 kg/m 3 ); (4) the viscosity reduction of oil due to CO 2 dissolution is significant (from 5790 to 98 mPa s). We compared these competing

  13. Effects of temperature and anion species on CO2 permeability and CO2/N2 separation coefficient through ionic liquid membranes

    International Nuclear Information System (INIS)

    Jindaratsamee, Pinyarat; Shimoyama, Yusuke; Morizaki, Hironobu; Ito, Akira

    2011-01-01

    The permeability of carbon dioxide (CO 2 ) through imidazolium-based ionic liquid membranes was measured by a sweep gas method. Six species of ionic liquids were studied in this work as follows: [emim][BF 4 ], [bmim][BF 4 ], [bmim][PF 6 ], [bmim][Tf 2 N], [bmim][OTf], and [bmim][dca]. The ionic liquids were supported with a polyvinylidene fluoride porous membrane. The measurements were performed at T = (303.15 to 343.15) K. The partial pressure difference between feed and permeate sides was 0.121 MPa. The permeability of the CO 2 increases with temperature for the all ionic liquid species. Base on solution diffusion theory, it can be explained that the diffusion coefficient of CO 2 in an ionic liquid affects the temperature dependence more strongly than the solubility coefficient. The greatest permeability was obtained with the [bmim][Tf 2 N] membrane. The membrane of [bmim][PF 6 ] presents the lowest permeability. The separation coefficient between CO 2 and N 2 through the ionic liquid membranes was also investigated at the volume fraction of CO 2 at feed side 0.10. The separation coefficient decreases with the increase of temperature for the all ionic liquid species. The membrane of [emim][BF 4 ] and [bmim][BF 4 ] gives the highest separation coefficient at constant temperature. The lowest separation coefficient was obtained from [bmim][Tf 2 N] membrane which presents the highest permeability of CO 2 .

  14. Recycling CO 2 ? Computational Considerations of the Activation of CO 2 with Homogeneous Transition Metal Catalysts

    KAUST Repository

    Drees, Markus

    2012-08-10

    Faced with depleting fossil carbon sources, the search for alternative energy carriers and energy storage possibilities has become an important issue. Nature utilizes carbon dioxide as starting material for storing sun energy in plant hydrocarbons. A similar approach, storing energy from renewable sources in chemical bonds with CO 2 as starting material, may lead to partial recycling of CO 2 created by human industrial activities. Unfortunately, currently available routes for the transformation of CO 2 involve high temperatures and are often not selective. With the development of more sophisticated methods and better software, theoretical studies have become both increasingly widespread and useful. This concept article summarizes theoretical investigations of the current state of the feasibility of CO 2 activation with molecular transition metal catalysts, highlighting the most promising reactions of CO 2 with olefins to industrially relevant acrylic acid/acrylates, and the insertion of CO 2 into metal-element bonds, particularly for the synthesis of cyclic carbonates and polymers. Rapidly improving computational power and methods help to increase the importance and accuracy of calculations continuously and make computational chemistry a useful tool helping to solve some of the most important questions for the future. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. CO2 capture by gas hydrate crystallization: Application on the CO2-N2 mixture

    International Nuclear Information System (INIS)

    Bouchemoua, A.

    2012-01-01

    CO 2 capture and sequestration represent a major industrial and scientific challenge of this century. There are different methods of CO 2 separation and capture, such as solid adsorption, amines adsorption and cryogenic fractionation. Although these processes are well developed at industrial level, they are energy intensive. Hydrate formation method is a less energy intensive and has an interesting potential to separate carbon dioxide. Gas hydrates are Document crystalline compounds that consist of hydrogen bonded network of water molecules trapping a gas molecule. Gas hydrate formation is favored by high pressure and low temperature. This study was conducted as a part of the SECOHYA ANR Project. The objective is to study the thermodynamic and kinetic conditions of the process to capture CO 2 by gas hydrate crystallization. Firstly, we developed an experimental apparatus to carry out experiments to determine the thermodynamic and kinetic formation conditions of CO 2 -N 2 gas hydrate mixture in water as liquid phase. We showed that the operative pressure may be very important and the temperature very low. For the feasibility of the project, we used TBAB (Tetrabutylammonium Bromide) as thermodynamic additive in the liquid phase. The use of TBAB may reduce considerably the operative pressure. In the second part of this study, we presented a thermodynamic model, based on the van der Waals and Platteeuw model. This model allows the estimation of thermodynamic equilibrium conditions. Experimental equilibrium data of CO 2 -CH 4 and CO 2 -N 2 mixtures are presented and compared to theoretical results. (author)

  16. CO2/CH4 Separation by a Mixed Matrix Membrane of Polymethylpentyne/MIL-53 Particles

    Directory of Open Access Journals (Sweden)

    Reza Abedini

    2014-10-01

    Full Text Available The effect of Materials Institute Lavoisier-53 (MIL-53 particles on gas transport properties of polymethylpentyne (PMP was investigated. MIL-53 was added to the polymer matrix with different loadings of 10, 20 and 30 wt%. The properties of MIL-53 and prepared membranes were analyzed through FTIR, SEM and TGA methods. The adsorption of CO2 and CH4 was conducted and analyzed accurately through Langmuir equation to investigate the gas transport properties of membranes. The results from TGA showed that degradation temperature (Td increases significantly with increasing MIL-53 loading. SEM images demonstrated that MIL-53 particles dispersed well in polymer matrix with no considerable agglomeration and no non-selective void formation at polymer/filler interface. In addition, CO2 and CH4 permeability measurement along with calculation of CO2/CH4 selectivity were performed. The results showed that the permeability of gases (especially for CO2 increased significantly by increasing the MIL-53 loading. Additionally, CO2/CH4 selectivity showed an increasing trend with increasing the MIL-53 weight percent. Unlike CH4, the CO2 solubility coefficient increased with increasing the MIL-53 loading because of high free volume of membrane and selective adsorption of CO2 with MIL-53. Despite CO2 solubility enhancement its diffusivity coefficient remained more or less unchanged. The enhancement in CH4 permeability has been mainly attributed to its slight incremental diffusivity due to the membrane's increasingly higher free volume. Finally, a comparison between membranes performance and CO2/CH4 Robeson upper bound showed that, the performance of membranes improved due to the presence of MIL-53 which was very close to the Robeson bound.

  17. Wettability impact on supercritical CO2 capillary trapping: Pore-scale visualization and quantification

    Science.gov (United States)

    Hu, Ran; Wan, Jiamin; Kim, Yongman; Tokunaga, Tetsu K.

    2017-08-01

    How the wettability of pore surfaces affects supercritical (sc) CO2 capillary trapping in geologic carbon sequestration (GCS) is not well understood, and available evidence appears inconsistent. Using a high-pressure micromodel-microscopy system with image analysis, we studied the impact of wettability on scCO2 capillary trapping during short-term brine flooding (80 s, 8-667 pore volumes). Experiments on brine displacing scCO2 were conducted at 8.5 MPa and 45°C in water-wet (static contact angle θ = 20° ± 8°) and intermediate-wet (θ = 94° ± 13°) homogeneous micromodels under four different flow rates (capillary number Ca ranging from 9 × 10-6 to 8 × 10-4) with a total of eight conditions (four replicates for each). Brine invasion processes were recorded and statistical analysis was performed for over 2000 images of scCO2 saturations, and scCO2 cluster characteristics. The trapped scCO2 saturation under intermediate-wet conditions is 15% higher than under water-wet conditions under the slowest flow rate (Ca ˜ 9 × 10-6). Based on the visualization and scCO2 cluster analysis, we show that the scCO2 trapping process in our micromodels is governed by bypass trapping that is enhanced by the larger contact angle. Smaller contact angles enhance cooperative pore filling and widen brine fingers (or channels), leading to smaller volumes of scCO2 being bypassed. Increased flow rates suppress this wettability effect.

  18. Breathing response of the tegu lizard to 1-4% CO2 in the mouth and nose or inspired into the lungs.

    Science.gov (United States)

    Ballam, G O

    1985-12-01

    This study investigated the influence on ventilation of elevated CO2 in the nasal and buccal cavities (NaBuCO2) vs the effect of elevated CO2 levels inspired into the lungs (LuCO2). Separate gas sources were used to independently alter NaBuCO2 and LuCO2. As little as 1% NaBuCO2 or LuCO2 significantly increased the pause duration between the active expiratory-inspiratory cycles. Elevated NaBuCO2 caused minor changes in tidal volume, mean inspiratory and expiratory flow, and inspiratory and expiratory durations with a significant reduction in total ventilation. Elevated LuCO2 had little effect on inspiratory or expiratory durations but unlike CO2 in the upper airways, significantly increased tidal volume and mean inspiratory and expiratory flows. This study demonstrates that the increased pause duration seen in the tegu lizard to elevated environmental CO2 is due to a receptor response in the buccal or nasal cavities and also to elevated CO2 concentrations inspired into the lungs. Sensitivity of the ventilatory responses to CO2 in the upper airways is well within a physiologically relevant range.

  19. Characterization of CO2 leakage into the freshwater body

    DEFF Research Database (Denmark)

    Singh, Ashok; Delfs, Jens Olaf; Shao, H.

    2013-01-01

    urrent research into CO2 capture and storage is dominated by improving the CO2 storage capacity. In this context, risk related to CO2 leakage is an important issue which may cause environmental problems, particularly when freshwater resources nearby are intruded by the CO2 plume. In this work...

  20. The effects of CO2 and nutrient fertilisation on the growth and temperature response of the mangrove Avicennia germinans.

    Science.gov (United States)

    Reef, Ruth; Slot, Martijn; Motro, Uzi; Motro, Michal; Motro, Yoav; Adame, Maria F; Garcia, Milton; Aranda, Jorge; Lovelock, Catherine E; Winter, Klaus

    2016-08-01

    In order to understand plant responses to both the widespread phenomenon of increased nutrient inputs to coastal zones and the concurrent rise in atmospheric CO2 concentrations, CO2-nutrient interactions need to be considered. In addition to its potential stimulating effect on photosynthesis and growth, elevated CO2 affects the temperature response of photosynthesis. The scarcity of experiments testing how elevated CO2 affects the temperature response of tropical trees hinders our ability to model future primary productivity. In a glasshouse study, we examined the effects of elevated CO2 (800 ppm) and nutrient availability on seedlings of the widespread mangrove Avicennia germinans. We assessed photosynthetic performance, the temperature response of photosynthesis, seedling growth and biomass allocation. We found large synergistic gains in both growth (42 %) and photosynthesis (115 %) when seedlings grown under elevated CO2 were supplied with elevated nutrient concentrations relative to their ambient growing conditions. Growth was significantly enhanced under elevated CO2 only under high-nutrient conditions, mainly in above-ground tissues. Under low-nutrient conditions and elevated CO2, root volume was more than double that of seedlings grown under ambient CO2 levels. Elevated CO2 significantly increased the temperature optimum for photosynthesis by ca. 4 °C. Rising CO2 concentrations are likely to have a significant positive effect on the growth rate of A. germinans over the next century, especially in areas where nutrient availability is high.

  1. Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen

    Science.gov (United States)

    M. E. Kubiske; V. S. Quinn; P. E. Marquardt; D. F. Karnosky

    2007-01-01

    Three model communities of trembling aspen (monoculture, and mixed with either paper birch or sugar maple) were grown for seven years in elevated atmospheric CO2 and O3 using Free Air CO2 Enrichment (FACE) technology. We utilized trends in species' importance, calculated as an index of volume...

  2. Batch production of micron size particles from poly(ethylene glycol) using supercritical CO2 as a processing solvent

    NARCIS (Netherlands)

    Nalawade, Sameer P.; Picchioni, Francesco; Janssen, L. P. B. M.

    The major advantage of using supercritical carbon dioxide (CO2) as a solvent in polymer processing is an enhancement in the free volume of a polymer due to dissolved CO2, which causes a considerable reduction in the viscosity. This allows spraying the polymer melt at low temperatures to produce

  3. PLAINS CO2 REDUCTION (PCOR) PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; Daniel J. Daly; Lynette L. de Silva; John A. Harju; Melanie D. Jensen; Erin M. O' Leary; Wesley D. Peck; Steven A. Smith; James A. Sorensen

    2006-01-01

    During the period of October 1, 2003, through September 30, 2005, the Plains CO2 Reduction (PCOR) Partnership, identified geologic and terrestrial candidates for near-term practical and environmentally sound carbon dioxide (CO2) sequestration demonstrations in the heartland of North America. The PCOR Partnership region covered nine states and three Canadian provinces. The validation test candidates were further vetted to ensure that they represented projects with (1) commercial potential and (2) a mix that would support future projects both dependent and independent of CO2 monetization. This report uses the findings contained in the PCOR Partnership's two dozen topical reports and half-dozen fact sheets as well as the capabilities of its geographic information system-based Decision Support System to provide a concise picture of the sequestration potential for both terrestrial and geologic sequestration in the PCOR Partnership region based on assessments of sources, sinks, regulations, deployment issues, transportation, and capture and separation. The report also includes concise action plans for deployment and public education and outreach as well as a brief overview of the structure, development, and capabilities of the PCOR Partnership. The PCOR Partnership is one of seven regional partnerships under Phase I of the U.S. Department of Energy National Energy Technology Laboratory's Regional Carbon Sequestration Partnership program. The PCOR Partnership, comprising 49 public and private sector members, is led by the Energy & Environmental Research Center at the University of North Dakota. The international PCOR Partnership region includes the Canadian provinces of Alberta, Saskatchewan, and Manitoba and the states of Montana (part), Wyoming (part), North Dakota, South Dakota, Nebraska, Missouri, Iowa, Minnesota, and Wisconsin.

  4. Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

  5. CO2/ brine substitution experiments at simulated reservoir conditions

    Science.gov (United States)

    Kummerow, Juliane; Spangenberg, Erik

    2015-04-01

    Capillary properties of rocks affect the mobility of fluids in a reservoir. Therefore, the understanding of the capillary pressure behaviour is essential to assess the long-term behaviour of CO2 reservoirs. Beyond this, a calibration of the petrophysical properties on water saturation of reservoir rocks at simulated in situ conditions is crucial for a proper interpretation of field monitoring data. We present a set-up, which allows for the combined measurements of capillary pressure, electric resistivity, and elastic wave velocities under controlled reservoir conditions (pconf = 400 bar, ppore = 180 bar, T = 65 ° C) at different brine-CO2 saturations. The capillary properties of the samples are measured using the micropore membrane technique. The sample is jacketed with a Viton tube (thickness = 4 mm) and placed between two current electrode endcaps, which as well contain pore fluid ports and ultrasonic P and S wave transducers. Between the sample and the lower endcap the hydrophilic semi-permeable micro-pore membrane (pore size = 100 nm) is integrated. It is embedded into filter papers to establish a good capillary contact and to protect the highly sensitive membrane against mechanical damage under load. Two high-precision syringe pumps are used to displace a quantified volume of brine by CO2 and determine the corresponding sample saturation. The fluid displacement induces a pressure gradient along the sample, which corresponds to the capillary pressure at a particular sample saturation. It is measured with a differential pressure sensor in the range between 0 - 0.2 MPa. Drainage and imbibition cycles are performed to provide information on the efficiency of capillary trapping and to get a calibration of the petrophysical parameters of the sample.

  6. Simulated 21st century's increase in oceanic suboxia by CO2-enhanced biotic carbon export

    Science.gov (United States)

    Oschlies, Andreas; Schulz, Kai G.; Riebesell, Ulf; Schmittner, Andreas

    2008-12-01

    The primary impacts of anthropogenic CO2 emissions on marine biogeochemical cycles predicted so far include ocean acidification, global warming induced shifts in biogeographical provinces, and a possible negative feedback on atmospheric CO2 levels by CO2-fertilized biological production. Here we report a new potentially significant impact on the oxygen-minimum zones of the tropical oceans. Using a model of global climate, ocean circulation, and biogeochemical cycling, we extrapolate mesocosm-derived experimental findings of a pCO2-sensitive increase in biotic carbon-to-nitrogen drawdown to the global ocean. For a simulation run from the onset of the industrial revolution until A.D. 2100 under a "business-as-usual" scenario for anthropogenic CO2 emissions, our model predicts a negative feedback on atmospheric CO2 levels, which amounts to 34 Gt C by the end of this century. While this represents a small alteration of the anthropogenic perturbation of the carbon cycle, the model results reveal a dramatic 50% increase in the suboxic water volume by the end of this century in response to the respiration of excess organic carbon formed at higher CO2 levels. This is a significant expansion of the marine "dead zones" with severe implications not only for all higher life forms but also for oxygen-sensitive nutrient recycling and, hence, for oceanic nutrient inventories.

  7. Adsorption of CO2 from flue gas streams by a highly efficient and stable aminosilica adsorbent.

    Science.gov (United States)

    Liu, Shou-Heng; Lin, Yuan-Chung; Chien, Yi-Chi; Hyu, Han-Ren

    2011-02-01

    Three ordered mesoporous silicas (OMSs) with different pore sizes and pore architectures were prepared and modified with amine functional groups by a postgrafting method. The carbon dioxide (CO2) adsorption on these amine-modified OMSs was measured by using microbalances at 348 K, and their adsorption capacities were found to be 0.2-1.4 mmol g(-1) under ambient pressure using dry 15% CO2. It was found experimentally that the CO2 adsorption capacity and adsorption rate were attributed to the density of amine groups and pore volume, respectively. A simple method is described for the production of densely anchored amine groups on a solid adsorbent invoking direct incorporation of tetraethylenepentamine onto the as-synthesized OMSs. Unlike conventional amine-modified OMSs, which typically show CO2 adsorption capacity less than 2 mmol g(-1), such organic template occluded amine-OMS composites possessed remarkably high CO2 uptake of approximately 4.6 mmol g(-1) at 348 K and 1 atm for a dry 15% CO2/nitrogen feed mixture. The enhancement of 8% in CO2 adsorption capacity was also observed in the presence of 10.6% water vapor. Durability tests done by cyclic adsorption-desorption revealed that these adsorbents also possess excellent stability.

  8. Fluoxetine augments ventilatory CO2 sensitivity in Brown Norway but not Sprague Dawley rats.

    Science.gov (United States)

    Hodges, Matthew R; Echert, Ashley E; Puissant, Madeleine M; Mouradian, Gary C

    2013-04-01

    The Brown Norway (BN; BN/NHsdMcwi) rat exhibits a deficit in ventilatory CO2 sensitivity and a modest serotonin (5-HT) deficiency. Here, we tested the hypothesis that the selective serotonin reuptake inhibitor fluoxetine would augment CO2 sensitivity in BN but not Sprague Dawley (SD) rats. Ventilation during room air or 7% CO2 exposure was measured before, during and after 3 weeks of daily injections of saline or fluoxetine (10mg/(kgday)) in adult male BN and SD rats. Fluoxetine had minimal effects on room air breathing in BN and SD rats (p>0.05), although tidal volume (VT) was reduced in BN rats (peffects of fluoxetine on CO2 sensitivity in SD rats, but fluoxetine increased minute ventilation, breathing frequency and VT during hypercapnia in BN rats (pCO2 response was reversible upon withdrawal of fluoxetine. Brain levels of biogenic amines were largely unaffected, but 5-HIAA and the ratio of 5-HIAA/5-HT were reduced (peffective 5-HT reuptake inhibition. Thus, fluoxetine increases ventilatory CO2 sensitivity in BN but not SD rats, further suggesting altered 5-HT system function may contribute to the inherently low CO2 sensitivity in the BN rat. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Modeling and validation of on-road CO2 emissions inventories at the urban regional scale

    International Nuclear Information System (INIS)

    Brondfield, Max N.; Hutyra, Lucy R.; Gately, Conor K.; Raciti, Steve M.; Peterson, Scott A.

    2012-01-01

    On-road emissions are a major contributor to rising concentrations of atmospheric greenhouse gases. In this study, we applied a downscaling methodology based on commonly available spatial parameters to model on-road CO 2 emissions at the 1 × 1 km scale for the Boston, MA region and tested our approach with surface-level CO 2 observations. Using two previously constructed emissions inventories with differing spatial patterns and underlying data sources, we developed regression models based on impervious surface area and volume-weighted road density that could be scaled to any resolution. We found that the models accurately reflected the inventories at their original scales (R 2 = 0.63 for both models) and exhibited a strong relationship with observed CO 2 mixing ratios when downscaled across the region. Moreover, the improved spatial agreement of the models over the original inventories confirmed that either product represents a viable basis for downscaling in other metropolitan regions, even with limited data. - Highlights: ► We model two on-road CO 2 emissions inventories using common spatial parameters. ► Independent CO 2 observations are used to validate the emissions models. ► The downscaled emissions models capture the urban spatial heterogeneity of Boston. ► Emissions estimates show a strong non-linear relationship with observed CO 2 . ► Our study is repeatable, even in areas with limited data. - This work presents a new, reproducible methodology for downscaling and validating on-road CO 2 emissions estimates.

  10. Efficient capture of CO2 over ordered micro-mesoporous hybrid carbon nanosphere

    Science.gov (United States)

    Chen, Changwei; Yu, Yanke; He, Chi; Wang, Li; Huang, Huang; Albilali, Reem; Cheng, Jie; Hao, Zhengping

    2018-05-01

    Four kinds of carbon-based adsorbents (micro-mesoporous hybrid carbon nanosphere and N-doped hollow carbon sphere with single-, double- or ruga-shell morphology) with different structural and textural properties were prepared and systematically studied in CO2 capture. All synthesized samples possess high specific surface area (828-910 m2 g-1), large pore volume (0.71-1.81 cm3 g-1), and different micropore contents varied from 2.1% to 46.4%. Amongst, the ordered micro-mesoporous carbon nanosphere (OM-CNS) exhibits the best adsorption performance with CO2 uptake as high as 3.01 mmol g-1 under conditions of 298 K and 1.0 bar, better than most of the reported CO2 adsorbents. The excellent CO2 adsorption capacity of OM-CNS can be reasonably attributed to the synergistic effect of ordered mesopore channels and abundant structural micropores which are beneficial for the diffusion and trapping of CO2 adsorbate. Moreover, the OM-CNS shows excellent CO2 trapping selectivity and superior stability and recyclability, which endow the OM-CNS as a promising and environmental-friendly adsorbent for CO2 capture and separation under practical conditions.

  11. Reconsideration of atmospheric CO2 lifetime: potential mechanism for explaining CO2 missing sink

    Science.gov (United States)

    Kikuchi, R.; Gorbacheva, T.; Gerardo, R.

    2009-04-01

    Carbon cycle data (Intergovernmental Panel on Climate Change 1996) indicate that fossil fuel use accounts for emissions to the atmosphere of 5.5±0.5 GtC (Gigatons of carbon) annually. Other important processes in the global CO2 budget are tropical deforestation, estimated to generate about 1.6±1.0 GtC/yr; absorption by the oceans, removing about 2.0±0.8 GtC/yr; and regrowth of northern forests, taking up about 0.5±0.5 GtC/yr. However, accurate measurements of CO2 show that the atmosphere is accumulating only about 3.3±0.2 GtC/yr. The imbalance of about 1.3±1.5 GtC/yr, termed the "missing sink", represents the difference between the estimated sources and the estimated sinks of CO2; that is, we do not know where all of the anthropogenic CO2 is going. Several potential mechanisms have been proposed to explain this missing carbon, such as CO2 fertilization, climate change, nitrogen deposition, land use change, forest regrowth et al. Considering the complexity of ecosystem, most of ecosystem model cannot handle all the potential mechanisms to reproduce the real world. It has been believed that the dominant sink mechanism is the fertilizing effects of increased CO2 concentrations in the atmosphere and the addition to soils of fixed nitrogen from fossil-fuel burning and agricultural fertilizers. However, a recent analysis of long-term observations of the change in biomass and growth rates suggests that such fertilization effects are much too small to explain more than a small fraction of the observed sink. In addition, long-term experiments in which small forest patches and other land ecosystems have been exposed to elevated CO2 levels for extended periods show a rapid decrease of the fertilization effect after an initial enhancement. We will explore this question of the missing sink in atmospheric CO2 residence time. Radioactive and stable carbon isotopes (13-C/12-C) show the real CO2 lifetime is about 5 years; i.e. CO2 is quickly taken out of the atmospheric

  12. Interactions between CO2, saline water and minerals during geological storage of CO2

    International Nuclear Information System (INIS)

    Hellevang, Helge

    2006-06-01

    The topic of this thesis is to gain a better understanding of interactions between injected CO 2 , aqueous solutions and formation mineralogies. The main focus is concerned with the potential role mineral reactions play in safe long term storage of CO 2 . The work is divided into an experimental part concentrated on the potential of dawsonite (NaAl(OH) 2 CO 3 ) as a permanent storage host of CO 2 , and the development of a new geochemical code ACCRETE that is coupled with the ATHENA multiphase flow simulator. The thesis is composed of two parts: (I) the first part introducing CO 2 storage, geochemical interactions and related work; and (II) the second part that consists of the papers. Part I is composed as follows: Chapter 2 gives a short introduction to geochemical reactions considered important during CO 2 storage, including a thermodynamic framework. Chapter 3 presents objectives of numerical work related to CO 2 -water-rock interactions including a discussion of factors that influence the outcome of numerical simulations. Chapter 4 presents the main results from paper A to E. Chapter 5 give some details about further research that we propose based on the present work and related work in the project. Several new activities have emerged from research on CO 2 -water-rock interaction during the project. Several of the proposed activities are already initiated. Papers A to F are then listed in Part II of the thesis after the citation list. The thesis presents the first data on the reaction kinetics of dawsonite at different pH (Paper A), and comprehensive numerical simulations, both batch- and large scale 3D reactive transport, that illustrate the role different carbonates have for safe storage of CO 2 in geological formations (Papers C to F). The role of dawsonite in CO 2 storage settings is treated throughout the study (Papers A to E) After the main part of the thesis (Part I and II), two appendices are included: Appendix A lists reactions that are included in the

  13. Stable isotope measurements of atmospheric CO2

    International Nuclear Information System (INIS)

    White, J.W.C.; Ferretti, D.F.; Vaughn, B.H.; Francey, R.J.; Allison, C.E.

    2002-01-01

    The measurement of stable carbon isotope ratios of atmospheric carbon dioxide, δ 13 CO 2 are useful for partitioning surface-atmospheric fluxes into terrestrial and oceanic components. δC 18 OO also has potential for segregating photosynthetic and respiratory fluxes in terrestrial ecosystems. Here we describe in detail the techniques for making these measurements. The primary challenge for all of the techniques used to measure isotopes of atmospheric CO 2 is to achieve acceptable accuracy and precision and to maintain them over the decades needed to observe carbon cycle variability. The keys to success such an approach are diligent intercalibrations of laboratories from around the world, as well as the use of multiple techniques such as dual inlet and GC-IRMS and the intercomparison of such measurements. We focus here on two laboratories, the Stable Isotope Lab at the Institute for Arctic and Alpine Research (INSTAAR) at the University of Colorado is described and the Commonwealth Scientific and Industrial Research Organisation - Atmospheric Research (CSIRO). Different approaches exist at other laboratories (e.g. programs operated by Scripps Institution of Oceanography (SIO) and The Center for Atmospheric and Oceanic Studies, Toboku University (TU)) however these are not discussed here. Finally, we also discuss the recently developed Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) technique which holds significant promise for measuring ultra-small samples of gas with good precision. (author)

  14. CO2 reduction through energy conservation

    International Nuclear Information System (INIS)

    1991-05-01

    A study was carried out of the potential to economically reduce carbon dioxide emissions through energy conservation in the petroleum and natural gas industry. The study examined current and projected emissions levels, cogeneration at gas plants, flaring, economics, regulation, reporting requirements, implementation, and research and development. Economically attractive energy conservation measures can reduce oil and gas industry, exclusive of Athabasca oil sands operations, CO 2 emissions by 6-7%. The energy conservation options identified range from field energy awareness committees through to equipment retrofits and replacement. At ca 3 million tonnes/y, these reductions will not offset the increases in oil and gas related CO 2 emissions anticipated by producers and Alberta government agencies. There will be increasing emphasis on in-situ bitumen production, more energy intensive light crude oil production and increasing natural gas sales, increasing energy inputs in excess of reductions. Cogeneration of electricity for utility company distribution and for internally required steam at gas plants and in-situ production sites is not economic due to low electricity prices. 8 tabs

  15. Global CO2 emissions from cement production

    Science.gov (United States)

    Andrew, Robbie M.

    2018-01-01

    The global production of cement has grown very rapidly in recent years, and after fossil fuels and land-use change, it is the third-largest source of anthropogenic emissions of carbon dioxide. The required data for estimating emissions from global cement production are poor, and it has been recognised that some global estimates are significantly inflated. Here we assemble a large variety of available datasets and prioritise official data and emission factors, including estimates submitted to the UNFCCC plus new estimates for China and India, to present a new analysis of global process emissions from cement production. We show that global process emissions in 2016 were 1.45±0.20 Gt CO2, equivalent to about 4 % of emissions from fossil fuels. Cumulative emissions from 1928 to 2016 were 39.3±2.4 Gt CO2, 66 % of which have occurred since 1990. Emissions in 2015 were 30 % lower than those recently reported by the Global Carbon Project. The data associated with this article can be found at https://doi.org/10.5281/zenodo.831455.

  16. Public Acceptance for Geological CO2-Storage

    Science.gov (United States)

    Schilling, F.; Ossing, F.; Würdemann, H.; Co2SINK Team

    2009-04-01

    Public acceptance is one of the fundamental prerequisites for geological CO2 storage. In highly populated areas like central Europe, especially in the vicinity of metropolitan areas like Berlin, underground operations are in the focus of the people living next to the site, the media, and politics. To gain acceptance, all these groups - the people in the neighbourhood, journalists, and authorities - need to be confident of the security of the planned storage operation as well as the long term security of storage. A very important point is to show that the technical risks of CO2 storage can be managed with the help of a proper short and long term monitoring concept, as well as appropriate mitigation technologies e.g adequate abandonment procedures for leaking wells. To better explain the possible risks examples for leakage scenarios help the public to assess and to accept the technical risks of CO2 storage. At Ketzin we tried the following approach that can be summed up on the basis: Always tell the truth! This might be self-evident but it has to be stressed that credibility is of vital importance. Suspiciousness and distrust are best friends of fear. Undefined fear seems to be the major risk in public acceptance of geological CO2-storage. Misinformation and missing communication further enhance the denial of geological CO2 storage. When we started to plan and establish the Ketzin storage site, we ensured a forward directed communication. Offensive information activities, an information centre on site, active media politics and open information about the activities taking place are basics. Some of the measures were: - information of the competent authorities through meetings (mayor, governmental authorities) - information of the local public, e.g. hearings (while also inviting local, regional and nation wide media) - we always treated the local people and press first! - organizing of bigger events to inform the public on site, e.g. start of drilling activities (open

  17. Material Processing with High Power CO2-Lasers

    Science.gov (United States)

    Bakowsky, Lothar

    1986-10-01

    After a period of research and development lasertechnique now is regarded as an important instrument for flexible, economic and fully automatic manufacturing. Especially cutting of flat metal sheets with high power C02-lasers and CNC controlled two or three axes handling systems is a wide spread. application. Three dimensional laser cutting, laser-welding and -heat treatment are just at the be ginning of industrial use in production lines. The main. advantages of laser technology. are - high. accuracy - high, processing velocity - law thermal distortion. - no tool abrasion. The market for laser material processing systems had 1985 a volume of 300 Mio S with growth rates between, 20 % and 30 %. The topic of this lecture are hiTrh. power CO2-lasers. Besides this systems two others are used as machining tools, Nd-YAG- and Eximer lasers. All applications of high. power CO2-lasers to industrial material processing show that high processing velocity and quality are only guaranteed in case of a stable intensity. profile on the workpiece. This is only achieved by laser systems without any power and mode fluctuations and by handling systems of high accuracy. Two applications in the automotive industry are described, below as examples for laser cutting and laser welding of special cylindrical motor parts.

  18. CO2 laser-driven Stirling engine. [space power applications

    Science.gov (United States)

    Lee, G.; Perry, R. L.; Carney, B.

    1978-01-01

    A 100-W Beale free-piston Stirling engine was powered remotely by a CO2 laser for long periods of time. The engine ran on both continuous-wave and pulse laser input. The working fluid was helium doped with small quantities of sulfur hexafluoride, SF6. The CO2 radiation was absorbed by the vibrational modes of the sulfur hexafluoride, which in turn transferred the energy to the helium to drive the engine. Electrical energy was obtained from a linear alternator attached to the piston of the engine. Engine pressures, volumes, and temperatures were measured to determine engine performance. It was found that the pulse radiation mode was more efficient than the continuous-wave mode. An analysis of the engine heat consumption indicated that heat losses around the cylinder and the window used to transmit the beam into the engine accounted for nearly half the energy input. The overall efficiency, that is, electrical output to laser input, was approximately 0.75%. However, this experiment was not designed for high efficiency but only to demonstrate the concept of a laser-driven engine. Based on this experiment, the engine could be modified to achieve efficiencies of perhaps 25-30%.

  19. Understanding the basic concepts of CO2 angiography

    Science.gov (United States)

    Zannoli, Romano; Bianchini, David; Rossi, Pier Luca; Caridi, James G.; Corazza, Ivan

    2016-11-01

    The diagnostic quality of carbon dioxide angiography depends both on optimal setting of radiological aspects (X-ray emission and image post-processing) and on the mechanical behavior of the injected gas bubbles. The gas behavior differs in large cavities (d > 12 mm), medium sized vessels (d > 6 mm), and small diameter vessels (d rules governing the phenomenon in the particular situation. In most cases, it is impossible to fill a vessel completely with gas, and to obtain an adequate angiogram, the gas volume and injection pressure must be properly selected, patient's position must be adjusted and radiological image optimization algorithms, like Digital Subtraction Angiography (DSA) and stacking, must be applied. In this optimization process, the cultural and practical intervention of a medical physicist is fundamental. Obtaining a good quality CO2 angiogram is not only a matter of medical operator experience or radiological system performance, but involves matching a wide knowledge of medical physics to particular pathophysiological conditions and to unusual measurement tests. Most medical physicists are used to dealing mainly with radiological problems, and other physical aspects are considered beyond their interest. In CO2 angiography, non-radiological aspects strongly interfere with radiological issues and an optimal result can only be obtained by tackling the two simultaneously.

  20. Problems in the Relationship between CO2 Emissions and Global Warming

    Directory of Open Access Journals (Sweden)

    Ferenc Kovács

    2005-03-01

    Full Text Available In the analysis of environmental conditions and impacts, the viewpoint that greenhouse gases, primarily anthropogenic (industrial, human carbon dioxide, play a determining role in the change of global temperatures, ( the increase experienced in the last one and a half decade, has been given widespread publicity recently. Coal-fired power plants are the first to blame for the increase in atmospheric CO2 concentrations in the last two centuries. The study indicates possibilities to increase the efficiency of coal-fired power plants, which would involve a considerable reduction in CO2 emissions with an identical production volume of electrical energy. On the basis of the analysis of the amount of fossil fuels used, the amount of CO2 emissions and changes in the concentrations of atmospheric CO2, it is shown that no correlation can be proved between the factors investigated and changes in global temperatures.

  1. Impact of thermal processes on CO2 injectivity into a coal seam

    International Nuclear Information System (INIS)

    Qu, H Y; Liu, J S; Pan, Z J; Connell, L

    2010-01-01

    The objective of this study is to investigate how thermal gradients, caused by CO2 injection, expansion and adsorption, affect the permeability and adsorption capacity of coal during CO2 sequestration. A new permeability model is developed in which the concept of elastic modulus reduction ratio is introduced to partition the effective strain between coal matrix and fracture. This model is implemented into a fully coupled mechanical deformation, gas flow and heat transport finite element simulator. To predict the amount of CO2 sequested, the extended Langmuir sorption model is used, with parameters values taken from the literature. The coupled heat and gas flow equations, are solved in COMSOL using the finite element method. The simulation results for a constant volume reservoir demostrate that thermal strain acts to significantly reduce both CO2 injectivity and adsorption capacity. These impacts need to be considered in the calculation of the optimum injection rate and the total sequestration capacity.

  2. An analysis of the driving forces of CO2 emissions embodied in Japan-China trade

    International Nuclear Information System (INIS)

    Dong Yanli; Ishikawa, Masanobu; Liu Xianbing; Wang Can

    2010-01-01

    By using the latest China-Japan input-output data sets and the index decomposition analysis (IDA) approach, this article analyzes the driving forces of CO 2 emissions embodied in trade between the two countries during 1990-2000. We found that the growth of trade volume had a large influence on the increase of CO 2 emissions embodiments in bilateral trade. The dramatic decline in carbon intensity of the Chinese economy is a primary cause in offsetting CO 2 emissions exported from China to Japan over 1995-2000. We argue that a better understanding of the factors affecting CO 2 emissions embodied in international trade will assist in seeking more effective climate policies with wider participation in the post-Kyoto regime.

  3. Field demonstration of CO2 leakage detection in potable aquifers with a pulselike CO2-release test.

    Science.gov (United States)

    Yang, Changbing; Hovorka, Susan D; Delgado-Alonso, Jesus; Mickler, Patrick J; Treviño, Ramón H; Phillips, Straun

    2014-12-02

    This study presents two field pulselike CO2-release tests to demonstrate CO2 leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO2 sensor for real-time in situ monitoring of dissolved CO2 in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO2 clearly deviated from their background values, showing responses to CO2 leakage. Dissolved CO2 observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO2-release tests to other field tests suggests that pulselike CO2-release tests can provide reliable assessment of geochemical parameters indicative of CO2 leakage. Measurements by the fiber-optic CO2 sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO2 for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO2 observed in the pulselike CO2-release tests were caused by dissolution of CO2 whereas alkalinity was likely affected by carbonate dissolution.

  4. Response of atmospheric CO2 to changes in land use

    International Nuclear Information System (INIS)

    King, A.W.; Emanuel, W.R.; Post, W.M.

    1991-01-01

    This chapter examines how different histories of CO 2 release from past changes in land use influence the simulation of past and future changes in atmospheric CO 2 . The authors first simulate past change in atmospheric CO 2 using reconstructed histories of land-use CO 2 release from a historical-ecological model of land-use change and CO 2 release. They examine the impact of each history on the coincidence between simulated and observed atmospheric CO 2 . They then compare these CO 2 release histories, and their contribution to coincidence or noncoincidence of simulation and observation, with histories reconstructed by deconvolution of the atmospheric CO 2 record. They conclude by exploring the implications of these deconvolved reconstructions for the simulation of future changes in atmospheric CO 2

  5. CO2 Emissions from Fuel Combustion 2011: Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Durban, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: - estimates of CO2 emissions by country from 1971 to 2009; - selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; - CO2 emissions from international marine and aviation bunkers, and other relevant information. These estimates have been calculated using the IEA energy databases and the default methods and emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories.

  6. CO2 Emissions from Fuel Combustion - 2012 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Doha, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: estimates of CO2 emissions by country from 1971 to 2010; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; and CO2 emissions from international marine and aviation bunkers, and other relevant information.

  7. CO2 Emissions from Fuel Combustion 2011: Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Durban, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: - estimates of CO2 emissions by country from 1971 to 2009; - selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; - CO2 emissions from international marine and aviation bunkers, and other relevant information. These estimates have been calculated using the IEA energy databases and the default methods and emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories.

  8. CO2 Emissions from Fuel Combustion - 2012 Highlights

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Doha, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: estimates of CO2 emissions by country from 1971 to 2010; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; and CO2 emissions from international marine and aviation bunkers, and other relevant information.

  9. Phase equilibrium data and thermodynamic modeling of the system (CO2 + biodiesel + methanol) at high pressures

    International Nuclear Information System (INIS)

    Pinto, Leandro F.; Segalen da Silva, Diogo Italo; Rosa da Silva, Fabiano; Ramos, Luiz P.; Ndiaye, Papa M.; Corazza, Marcos L.

    2012-01-01

    Highlights: → We measured phase behavior for the system involving {CO 2 + biodiesel + methanol}. → The saturation pressures were obtained using a variable-volume view cell. → The experimental data were modeled using PR-vdW2 and PR-WS equations of state. - Abstract: The main objective of this work was to investigate the high pressure phase behavior of the binary systems {CO 2 (1) + methanol(2)} and {CO 2 (1) + soybean methyl esters (biodiesel)(2)} and the ternary system {CO 2 (1) + biodiesel(2) + methanol(3)} were determined. Biodiesel was produced from soybean oil, purified, characterized and used in this work. The static synthetic method, using a variable-volume view cell, was employed to obtain the experimental data in the temperature range of (303.15 to 343.15) K and pressures up to 21 MPa. The mole fractions of carbon dioxide were varied according to the systems as follows: (0.2383 to 0.8666) for the binary system {CO 2 (1) + methanol(2)}; (0.4201 to 0.9931) for the binary system {CO 2 (1) + biodiesel(2)}; (0.4864 to 0.9767) for the ternary system {CO 2 (1) + biodiesel(2) + methanol(3)} with a biodiesel to methanol molar ratio of (1:3); and (0.3732 to 0.9630) for the system {CO 2 + biodiesel + methanol} with a biodiesel to methanol molar ratio of (8:1). For these systems, (vapor + liquid), (liquid + liquid), (vapor + liquid + liquid) transitions were observed. The phase equilibrium data obtained for the systems were modeled using the Peng-Robinson equation of state with the classical van der Waals (PR-vdW2) and Wong-Sandler (PR-WS) mixing rules. Both thermodynamic models were able to satisfactorily correlate the phase behavior of the systems investigated and the PR-WS presented the best performance.

  10. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

    2002-01-01

    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  11. Plasma catalytic process for CO2 methanation

    International Nuclear Information System (INIS)

    Nizio, Magdalena

    2016-01-01

    The limited resources of oil and natural gas, together with an increasing energy demand, forces us to seek more and more efficient and cleaner energy production alternatives. Hydrogen has been recently considered as a promising energy carrier. However, there are several inherent problems to the utilization of H 2 , from its transportation to its distribution. Transformation of the H 2 molecule by fixing into a carbon-containing compound, i.e. CH 4 , will offer the possibility of using the conventional transportation network. Indeed, the Sabatier reaction, which is highly exothermic, involves the reaction of carbon dioxide and hydrogen gas in order to produce methane and water. This process, called methanation, represents a feasible approach contributing to the reduction of the CO 2 emissions in our atmosphere, through a closed carbon cycle involving the valorization of CO 2 , i.e. from capture. However, below a temperature of 250 C, the conversion becomes practically close to 0 %, whereas at higher temperatures, i.e., (≥300 C), the co-existence of secondary reactions favours the formation of CO and H 2 . This is the reason why new catalysts and process conditions are continuously being investigated in order to maximize the methane selectivity at low reaction temperatures at atmospheric pressure. Therefore, by using catalysts combined to Dielectric Barrier Discharge plasmas (DBD), the activation of the methanation reaction can be enhanced and overcome the drawbacks of existing conventional processes. Several Ni-containing catalysts were prepared using various ceria-zirconia oxides as supports, with different Ce/Zr ratios. The results obtained in the adiabatic conditions at low temperatures (ranging between 100-150 C), in the presence of catalysts activated by plasma, are promising. Indeed, the conversion of CO 2 to CH 4 is about 85 % with a selectivity close to 100 %. The same conversion in the absence of the plasma activation of the catalyst is observed at 350 C

  12. Variations in pCO2 during summer in the surface water of an unproductive lake in northern Sweden

    International Nuclear Information System (INIS)

    Jonsson, A.; Aaberg, J.; Jansson, M.

    2007-01-01

    Unproductive lakes are generally supersaturated with carbon dioxide (CO 2 ) and emit CO 2 to the atmosphere continuously during ice-free periods. However, temporal variation of the partial pressure of CO 2 (pCO 2 ) and thus of CO 2 evasion to atmosphere is poorly documented. We therefore carried out temporally high-resolution (every 6 h) measurements of the pCO 2 using an automated logger system in the surface water of a subarctic, unproductive, lake in the birch forest belt. The study period was June-September 2004. We found that the pCO 2 showed large seasonal variation, but low daily variation. The seasonal variation was likely mainly caused by variations in input and mineralization of allochthonous organic matter. Stratification depth probably also influenced pCO 2 of the surface water by controlling the volume in which mineralization of dissolved organic carbon (DOC) occurred. In lakes, with large variations in pCO 2 , as in our study lake a high (weekly) sampling intensity is recommended for obtaining accurate estimates of the evasion of CO 2

  13. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

    2001-01-01

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

  14. Tritium removal by CO2 laser heating

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Mueller, D.

    1997-01-01

    Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

  15. Tritium removal by CO2 laser heating

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Mueller, D.

    1997-10-01

    Efficient techniques for rapid tritium removal will be necessary for ITER (International Thermonuclear Experimental Reactor) to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO 2 or Nd:YAG laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm 2 flux with an exposure time of order 10 msec is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally

  16. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    , whereas in a normal cement plant, it is 0.9 kg/ kg cl. However the thermal energy demand in the integrated plant increases from 3.9 MJ/ kg cl to 5.6 MJ/ kg cl. But on the other side this additional energy spent can be recovered as a high quality heat to generate electricity. The potential to generate...... electricity depends on the scale of the plant, the bigger the production capacity of cement plant the better, with capacity higher than 3400 tons of clinker/day is required to produce captive electricity to meet the demand both from the cement plant operations and from the CO2 capture system operations....

  17. Smart Transportation CO2 Emission Reduction Strategies

    Science.gov (United States)

    Tarulescu, S.; Tarulescu, R.; Soica, A.; Leahu, C. I.

    2017-10-01

    Transport represents the sector with the fastest growing greenhouse gas emissions around the world. The main global objective is to reduce energy usage and associated greenhouse gas emissions from the transportation sector. For this study it was analyzed the road transportation system from Brasov Metropolitan area. The study was made for the transportation route that connects Ghimbav city to the main surrounding objectives. In this study ware considered four optimization measures: vehicle fleet renewal; building the detour belt for the city; road increasing the average travel speed; making bicycle lanes; and implementing an urban public transport system for Ghimbav. For each measure it was used a mathematical model to calculate the energy consumption and carbon emissions from the road transportation sector. After all four measures was analyzed is calculated the general energy consumption and CO2 reduction if this are applied from year 2017 to 2020.

  18. Power stabilized CO2 gas transport laser

    International Nuclear Information System (INIS)

    Foster, J.D.; Kirk, R.F.; Moreno, F.E.; Ahmed, S.A.

    1975-01-01

    The output power of a high power (1 kW or more) CO 2 gas transport laser is stabilized by flowing the gas mixture over copper plated baffles in the gas channel during operation of the laser. Several other metals may be used instead of copper, for example, nickel, manganese, palladium, platinum, silver and gold. The presence of copper in the laser gas circuit stabilizes output power by what is believed to be a compensation of the chemical changes in the gas due to the cracking action of the electrical discharge which has the effect of diminishing the capactiy of the carbon dioxide gas mixture to maintain the rated power output of the laser. (U.S.)

  19. CO2 laser-aided waste incineration

    International Nuclear Information System (INIS)

    Costes, J.R.; Guiberteau, P.; Caminat, P.; Bournot, P.

    1994-01-01

    Lasers are widely employed in laboratories and in certain industrial applications, notably for welding, cutting and surface treatments. This paper describes a new application, incineration, which appears warranted when the following features are required: high-temperature incineration (> 1500 deg C) with close-tolerance temperature control in an oxidizing medium while ensuring containment of toxic waste. These criteria correspond to the application presented here. Following a brief theoretical introduction concerning the laser/surface interaction, the paper describes the incineration of graphite waste contaminated with alpha-emitting radionuclides. Process feasibility has been demonstrated on a nonradioactive prototype capable of incinerating 10 kg -h-1 using a 7 kW CO 2 laser. An industrial facility with the same capacity, designed to operate within the constraints of an alpha-tight glove box environment, is now at the project stage. Other types of applications with similar requirements may be considered. (authors). 3 refs., 7 figs

  20. US calls for CO2 cut

    International Nuclear Information System (INIS)

    Roberts, M.

    1996-01-01

    The US Government has outraged energy-intensive industries by calling for an international agreement to reduce global emissions of carbon dioxide (CO 2 ) and other greenhouse gases. In a clear policy shift, the US--the world's largest emitter of greenhouse gases and not previously an advocate of curbing them--says it now intends to lead moves to prevent global warming. At last week's Second Conference of the Parties (COP-2) to the United Nations Framework Convention on Climate Change (FCCC), US Undersecretary for Global Affairs Timothy Wirth called for open-quotes an agreement that sets a realistic, verifiable, and binding medium-term emissions target.close quotes Individual countries should be free to choose how to meet targets, and the US favors market-based mechanisms, he says. open-quotes Climate change is a serious problem and will require sustained long-term investment to be addressed successfully,close quotes Wirth says

  1. Anterior capsulotomy using the CO2 laser

    Science.gov (United States)

    Barak, Adiel; Ma-Naim, Tova; Rosner, Mordechai; Eyal, Ophir; Belkin, Michael

    1998-06-01

    Continuous circular capsulorhexis (CCC) is the preferred technique for removal of the anterior capsule during cataract surgery due to this technique assuring accurate centration of the intraocular lens. During modern cataract surgery, especially with small or foldable intra ocular lenses, centration of the lens is obligatory. Radial tears at the margin of an anterior capsulotomy may be associated with the exit of at least one loop of an intraocular lens out of the capsular bag ('pea pod' effect) and its subsequent decentration. The anterior capsule is more likely to ream intact if the continuous circular capsulorhexis (CCC) technique is used. Although manual capsulorhexis is an ideal anterior capsulectomy technique for adults, many ophthalmologists are still uncomfortable with it and find it difficult to perform, especially in complicated cases such as these done behind small pupil, cataract extraction in children and pseudoexfoliation syndrome. We have developed a technique using a CO2 laser system for safe anterior capsulotomy and tested it in animal eyes.

  2. Intrinsic positive end-expiratory pressure during one-lung ventilation of patients with pulmonary hyperinflation. Influence of low respiratory rate with unchanged minute volume.

    Science.gov (United States)

    Szegedi, L L; Barvais, L; Sokolow, Y; Yernault, J C; d'Hollander, A A

    2002-01-01

    We measured lung mechanics and gas exchange during one-lung ventilation (OLV) of patients with chronic obstructive pulmonary disease, using three respiratory rates (RR) and unchanged minute volume. We studied 15 patients about to undergo lung surgery, during anaesthesia, and placed in the lateral position. Ventilation was with constant minute volume, inspiratory flow and FIO2. For periods of 15 min, RR of 5, 10, and 15 bpm were applied in a random sequence and recordings were made of lung mechanics and an arterial blood gas sample was taken. Data were analysed with the repeated measures ANOVA and paired t-test with Bonferroni correction. PaO2 changes were not significant. At the lowest RR, PaCO2 decreased (from 42 (SD 4) mm Hg at RR 15-41 (4) mm Hg at RR 10 and 39 (4) mm Hg at RR 5, P<0.01), and end-tidal carbon dioxide increased (from 33 (5) mm Hg at RR 15 to 35 (5) mm Hg at RR 10 and 36 (6) mm Hg at RR 5, P<0.01). Intrinsic positive end-expiratory pressure (PEEPi) was reduced even with larger tidal volumes (from 6 (4) cm H2O at RR 15-5 (4) cm H2O at RR 10, and 3 (3) cm H2O at RR 5, P<0.01), most probably caused by increased expiratory time at the lowest RR. A reduction in RR reduces PEEPi and hypercapnia during OLV in anaesthetized patients with chronic obstructive lung disease.

  3. Experimental Investigations into CO2 Interactions with Injection Well Infrastructure for CO2 Storage

    Science.gov (United States)

    Syed, Amer; Shi, Ji-Quan; Durucan, Sevket; Nash, Graham; Korre, Anna

    2013-04-01

    Wellbore integrity is an essential requirement to ensure the success of a CO2 Storage project as leakage of CO2 from the injection or any other abandoned well in the storage complex, could not only severely impede the efficiency of CO2 injection and storage but also may result in potential adverse impact on the surrounding environment. Early research has revealed that in case of improper well completions and/or significant changes in operating bottomhole pressure and temperature could lead to the creation of microannulus at cement-casing interface which may constitute a preferential pathway for potential CO2 leakage during and post injection period. As a part of a European Commission funded CO2CARE project, the current research investigates the sealing behaviour of such microannulus at the cement-casing interface under simulated subsurface reservoir pressure and temperature conditions and uses the findings to develop a methodology to assess the overall integrity of CO2 storage. A full scale wellbore experimental test set up was constructed for use under elevated pressure and temperature conditions as encountered in typical CO2 storage sites. The wellbore cell consists of an assembly of concentric elements of full scale casing (Diameter= 0.1524m), cement sheath and an outer casing. The stainless steel outer ring is intended to simulate the stiffness offered by the reservoir rock to the displacement applied at the wellbore. The Central Loading Mechanism (CLM) consists of four case hardened shoes that can impart radial load onto the well casing. The radial movement of the shoes is powered through the synchronised movement of four precision jacks controlled hydraulically which could impart radial pressures up to 15 MPa. The cell body is a gas tight enclosure that houses the wellbore and the central loading mechanism. The setup is enclosed in a laboratory oven which acts both as temperature and safety enclosure. Prior to a test, cement mix is set between the casing and

  4. CO2 laser milling of hard tissue

    Science.gov (United States)

    Werner, Martin; Ivanenko, Mikhail; Harbecke, Daniela; Klasing, Manfred; Steigerwald, Hendrik; Hering, Peter

    2007-02-01

    Drilling of bone and tooth tissue belongs to recurrent medical procedures (screw- and pin-bores, bores for implant inserting, trepanation etc.). Small round bores can be in general quickly produced with mechanical drills. Problems arise however by angled drilling, by the necessity to fulfill the drilling without damaging of sensitive soft tissue beneath the bone, or by the attempt to mill precisely noncircular small cavities. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The "milling" is done with a CO2 laser (10.6 μm) with pulse duration of 50 - 100 μs, combined with a PC-controlled galvanic beam scanner and with a fine water-spray, which helps to avoid thermal side-effects. The damaging of underlying soft tissue can be prevented through control of the optical or acoustical ablation signal. The ablation of hard tissue is accompanied with a strong glowing, which is absent during the laser beam action on soft tissue. The acoustic signals from the diverse tissue types exhibit distinct differences in the spectral composition. Also computer image analysis could be a useful tool to control the operation. Laser "milling" of noncircular cavities with 1 - 4 mm width and about 10 mm depth is particularly interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser "milling" of the cavities without thermal damage and with minimal tapering. It included exploration of different filling patterns (concentric rings, crosshatch, parallel lines and their combinations), definition of maximal pulse duration, repetition rate and laser power, optimal position of the spray. The optimized results give evidences for the applicability of the CO2 laser for biologically tolerable "milling" of deep cavities in the hard tissue.

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

    Science.gov (United States)

    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.

  6. Monitoring CO2 penetration and storage in the brine-saturated low permeable sandstone by the geophysical exploration technologies

    Science.gov (United States)

    Honda, H.; Mitani, Y.; Kitamura, K.; Ikemi, H.; Imasato, M.

    2017-12-01

    Carbon dioxide (CO2) capture and storage (CCS) plays a vital role in reducing greenhouse gas emissions. In the northern part of Kyushu region of Japan, complex geological structure (Coalfield) is existed near the CO2 emission source and has 1.06 Gt of CO2 storage capacity. The geological survey shows that these layers are formed by low permeable sandstone. It is necessary to monitor the CO2 behavior and clear the mechanisms of CO2 penetration and storage in the low permeable sandstone. In this study, measurements of complex electrical impedance (Z) and elastic wave velocity (P-wave velocity: Vp) were conducted during the supercritical CO2 injection experiment into the brine-saturated low permeable sandstone. The experiment conditions were as follows; Confining pressure: 20 MPa, Initial pore pressure: 10 MPa, 40 °, CO2 injection rate: 0.01 to 0.5 mL/min. Z was measured in the center of the specimen and Vp were measured at three different heights of the specimen at constant intervals. In addition, we measured the longitudinal and lateral strain at the center of the specimen, the pore pressure and CO2 injection volume (CO2 saturation). During the CO2 injection, the change of Z and Vp were confirmed. In the drainage terms, Vp decreased drastically once CO2 reached the measurement cross section.Vp showed the little change even if the flow rate increased (CO2 saturation increased). On the other hand, before the CO2 front reached, Z decreased with CO2-dissolved brine. After that, Z showed continuously increased as the CO2 saturation increased. From the multi-parameter (Hydraulic and Rock-physics parameters), we revealed the detail CO2 behavior in the specimen. In the brine-saturated low permeable sandstone, the slow penetration of CO2 was observed. However, once CO2 has passed, the penetration of CO2 became easy in even for brine-remainded low permeable sandstone. We conclude low permeable sandstone has not only structural storage capacity but also residual tapping

  7. CO2 Solubilities in Amide-based Brφnsted Acidic Ionic Liquids

    International Nuclear Information System (INIS)

    Palgunadi, Jelliarko; Im, Jin Kyu; Kang, Je Eun; Kim, Hoon Sik; Cheong, Min Serk

    2010-01-01

    A distinguished class of hydrophobic ionic liquids bearing a Brφnsted acidic character derived from amide-like compounds were prepared by a neutralization reaction of N,N-diethylformamide, N,N-dibutylformamide, 1-formylpiperidine, and ε-caprolactam with trifluoroacetic acid and physical absorptions of CO 2 in these ionic liquids were demonstrated and evaluated. CO 2 solubilities in these ionic liquids were influenced by the molecular structure of the cation and were apparently increased with the molar volume. Comparison based on a volume unit reveals that CO 2 solubilities in these liquids are relatively higher than those in imidazolium-based ionic liquids. Henry's coefficients calculated from low-pressure solubility tests at 313 to 333 K were used to derive the thermodynamics quantities. Enthalpy and entropy of solvation may share equal contributions in solubility

  8. Comparative CO2 flux measurements by eddy covariance technique using open- and closed-path gas analysers over the equatorial Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Fumiyoshi Kondo

    2012-04-01

    Full Text Available Direct comparison of air–sea CO2 fluxes by open-path eddy covariance (OPEC and closed-path eddy covariance (CPEC techniques was carried out over the equatorial Pacific Ocean. Previous studies over oceans have shown that the CO2 flux by OPEC was larger than the bulk CO2 flux using the gas transfer velocity estimated by the mass balance technique, while the CO2 flux by CPEC agreed with the bulk CO2 flux. We investigated a traditional conflict between the CO2 flux by the eddy covariance technique and the bulk CO2 flux, and whether the CO2 fluctuation attenuated using the closed-path analyser can be measured with sufficient time responses to resolve small CO2 flux over oceans. Our results showed that the closed-path analyser using a short sampling tube and a high volume air pump can be used to measure the small CO2 fluctuation over the ocean. Further, the underestimated CO2 flux by CPEC due to the attenuated fluctuation can be corrected by the bandpass covariance method; its contribution was almost identical to that of H2O flux. The CO2 flux by CPEC agreed with the total CO2 flux by OPEC with density correction; however, both of them are one order of magnitude larger than the bulk CO2 flux.

  9. Dynamics of soil CO2 efflux under varying atmospheric CO2 concentrations reveal dominance of slow processes.

    Science.gov (United States)

    Kim, Dohyoung; Oren, Ram; Clark, James S; Palmroth, Sari; Oishi, A Christopher; McCarthy, Heather R; Maier, Chris A; Johnsen, Kurt

    2017-09-01

    We evaluated the effect on soil CO 2 efflux (F CO 2 ) of sudden changes in photosynthetic rates by altering CO 2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO 2 (eCO 2 ) ranging 1.0-1.8 times ambient did not affect F CO 2 . F CO 2 did not decrease until 4 months after termination of the long-term eCO 2 treatment, longer than the 10 days observed for decrease of F CO 2 after experimental blocking of C flow to belowground, but shorter than the ~13 months it took for increase of F CO 2 following the initiation of eCO 2 . The reduction of F CO 2 upon termination of enrichment (~35%) cannot be explained by the reduction of leaf area (~15%) and associated carbohydrate production and allocation, suggesting a disproportionate contraction of the belowground ecosystem components; this was consistent with the reductions in base respiration and F CO 2 -temperature sensitivity. These asymmetric responses pose a tractable challenge to process-based models attempting to isolate the effect of individual processes on F CO2 . © 2017 John Wiley & Sons Ltd.

  10. 13CO2/12CO2 isotope ratio analysis in human breath using a 2 μm diode laser

    Science.gov (United States)

    Sun, Mingguo; Cao, Zhensong; Liu, Kun; Wang, Guishi; Tan, Tu; Gao, Xiaoming; Chen, Weidong; Yinbo, Huang; Ruizhong, Rao

    2015-04-01

    The bacterium H. pylori is believed to cause peptic ulcer. H. pylori infection in the human stomach can be diagnosed through a CO2 isotope ratio measure in exhaled breath. A laser spectrometer based on a distributed-feedback semiconductor diode laser at 2 μm is developed to measure the changes of 13CO2/12CO2 isotope ratio in exhaled breath sample with the CO2 concentration of ~4%. It is characterized by a simplified optical layout, in which a single detector and associated electronics are used to probe CO2 spectrum. A new type multi-passes cell with 12 cm long base length , 29 m optical path length in total and 280 cm3 volume is used in this work. The temperature and pressure are well controlled at 301.15 K and 6.66 kPa with fluctuation amplitude of 25 mK and 6.7 Pa, respectively. The best 13δ precision of 0.06o was achieved by using wavelet denoising and Kalman filter. The application of denoising and Kalman filter not only improved the signal to noise ratio, but also shorten the system response time.

  11. Interface characteristics in Co2MnSi/Ag/Co2MnSi trilayer

    International Nuclear Information System (INIS)

    Li, Yang; Chen, Hong; Wang, Guangzhao; Yuan, Hongkuan

    2016-01-01

    Highlights: • Inferface DO 3 disorder is most favorable in Co 2 MnSi/Ag/Co 2 MnSi trilayer. • Interface itself and inferface DO 3 disorder destroy the half-metallicity of interface layers. • Magnetoresistance is reduced by the interface itself and interface disorder. • Magnetotransport coefficient is largely reduced by the interface itself and interface disorder. - Abstract: Interface characteristics of Co 2 MnSi/Ag/Co 2 MnSi trilayer have been investigated by means of first-principles. The most likely interface is formed by connecting MnSi-termination to the bridge site between two Ag atoms. As annealed at high temperature, the formation of interface DO 3 disorder is most energetically favorable. The spin polarization is reduced by both the interface itself and interface disorder due to the interface state occurs in the minority-spin gap. As a result, the magneto-resistance ratio has a sharp drop based on the estimation of a simplified modeling.

  12. CO2-ECBM and CO2 Sequestration in Polish Coal Seam – Experimental Study

    Directory of Open Access Journals (Sweden)

    Paweł Baran

    2014-01-01

    Originality/value: The results indicate successful sorption of carbon dioxide in each experiment. This provides the rationale to study the application of the coal tested to obtain methane genetic origin genetic methane with the use of the CO2 injection.

  13. DEPLETED HYDROCARBON RESERVOIRS AND CO2 INJECTION WELLS –CO2 LEAKAGE ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    2017-03-01

    Full Text Available Migration risk assessment of the injected CO2 is one of the fi rst and indispensable steps in determining locations for the implementation of projects for carbon dioxide permanent disposal in depleted hydrocarbon reservoirs. Within the phase of potential storage characterization and assessment, it is necessary to conduct a quantitative risk assessment, based on dynamic reservoir models that predict the behaviour of the injected CO2, which requires good knowledge of the reservoir conditions. A preliminary risk assessment proposed in this paper can be used to identify risks of CO2 leakage from the injection zone and through wells by quantifying hazard probability (likelihood and severity, in order to establish a risk-mitigation plan and to engage prevention programs. Here, the proposed risk assessment for the injection well is based on a quantitative risk matrix. The proposed assessment for the injection zone is based on methodology used to determine a reservoir probability in exploration and development of oil and gas (Probability of Success, abbr. POS, and modifi ed by taking into account hazards that may lead to CO2 leakage through the cap rock in the atmosphere or groundwater. Such an assessment can eliminate locations that do not meet the basic criteria in regard to short-term and long-term safety and the integrity of the site

  14. Faults as Windows to Monitor Gas Seepage: Application to CO2 Sequestration and CO2-EOR

    Directory of Open Access Journals (Sweden)

    Ronald W. Klusman

    2018-03-01

    Full Text Available Monitoring of potential gas seepage for CO2 sequestration and CO2-EOR (Enhanced Oil Recovery in geologic storage will involve geophysical and geochemical measurements of parameters at depth and at, or near the surface. The appropriate methods for MVA (Monitoring, Verification, Accounting are needed for both cost and technical effectiveness. This work provides an overview of some of the geochemical methods that have been demonstrated to be effective for an existing CO2-EOR (Rangely, CA, USA and a proposed project at Teapot Dome, WY, USA. Carbon dioxide and CH4 fluxes and shallow soil gas concentrations were measured, followed by nested completions of 10-m deep holes to obtain concentration gradients. The focus at Teapot Dome was the evaluation of faults as pathways for gas seepage in an under-pressured reservoir system. The measurements were supplemented by stable carbon and oxygen isotopic measurements, carbon-14, and limited use of inert gases. The work clearly demonstrates the superiority of CH4 over measurements of CO2 in early detection and quantification of gas seepage. Stable carbon isotopes, carbon-14, and inert gas measurements add to the verification of the deep source. A preliminary accounting at Rangely confirms the importance of CH4 measurements in the MVA application.

  15. SOLUBILITY OF ORGANIC BIOCIDES IN SUPERCRITICAL CO2 AND CO2+ COSOLVENT MIXTURES

    Science.gov (United States)

    Solubilities of four organic biocides in supercritical carbon dioxide (Sc-CO2) were measured using a dynamic flowr apparatus over a pressure range of 10 to 30 MPa and temperature of 35-80 degrees C. The biocides studied were: Amical-48 (diiodomethyl p-tolyl sulfone), chlorothalo...

  16. Enhanced transport phenomena in CO2 sequestration and CO2 EOR

    NARCIS (Netherlands)

    Farajzadeh, R.

    2009-01-01

    The results of this thesis give insight into the (mass)-transfer during flow of gases, especially CO2, in various gas-liquid systems. A number of experiments was performed to investigate the transport phenomena through interfaces with and without surfactant monolayers. The observed phenomena have

  17. Decontamination of solid matrices using supercritical CO2: study of contaminant-additives-CO2

    International Nuclear Information System (INIS)

    Galy, J.

    2006-11-01

    This work deals with the decontamination of solid matrices by supercritical CO 2 and more particularly with the study of the interactions between the surfactants and the CO 2 in one part, and with the interactions between the contaminant and the surfactants in another part. The first part of this study has revealed the different interactions between the Pluronics molecules and the supercritical CO 2 . The diagrams graphs have shown that the pluronics (PE 6100, PE 8100 and PE 10100) present a solubility in the supercritical CO 2 low but sufficient (0.1% m/m at 25 MPa and 313 K) for the studied application: the treatment of weak quantities of cerium oxide (or plutonium). An empirical approach based on the evolutions of the slops value and of the origin ordinates of the PT diagrams has been carried out to simulate the phase diagrams PT of the Pluronics. A modeling based on the state equations 'SAFT' (Statistical Associating Fluid Theory) has been studied in order to confirm the experimental results of the disorder points and to understand the role of the different blocks 'PEO' and 'PPO' in the behaviour of Pluronics; this modeling confirms the evolution of the slopes value with the 'CO 2 -phily' of the system. The measure of the surface tension in terms of the Pluronics concentration (PE 6100, 81000 and 10100) has shown different behaviours. For the PE 6100, the surface tension decreases when the surfactant concentration increases (at constant pressure and temperature); on the other hand, for the PE 8100 a slop rupture appears and corresponds to the saturation of the interface water/CO 2 and allows then to determine the Interface Saturation Concentration (ISC). The ISC value (at constant pressure and temperature) increases with an increase of the 'CO 2 -phily'). The model hydrophilous medium being an approximation, it has been replaced by a solid polar phase of CeO 2 . A parallel has been established between the evolution of the surface tension between the water and

  18. Framework for Assessing Biogenic CO2 Emissions from Stationary Sources

    Science.gov (United States)

    This revision of the 2011 report, Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, evaluates biogenic CO2 emissions from stationary sources, including a detailed study of the scientific and technical issues associated with assessing biogenic carbon dioxide...

  19. Vertically averaged approaches for CO 2 migration with solubility trapping

    KAUST Repository

    Gasda, S. E.; Nordbotten, J. M.; Celia, M. A.

    2011-01-01

    The long-term storage security of injected carbon dioxide (CO2) is an essential component of geological carbon sequestration operations. In the postinjection phase, the mobile CO2 plume migrates in large part because of buoyancy forces, following

  20. High-resolution transmission measurements of CO2 at high temperatures for industrial applications

    DEFF Research Database (Denmark)

    Evseev, Vadim; Fateev, Alexander; Clausen, Sønnik

    2012-01-01

    . The spectra have been recorded in a high-temperature flow gas cell and using a Fourier transform infrared (FTIR) spectrometer at a nominal resolution of 0.125 cm-1. The volume fractions of CO2 in the measurements were 1,10 and 100%. The measurements have been validated by comparison with medium...

  1. [Effects of plastic film mulching on soil CO2 efflux and CO2 concentration in an oasis cotton field].

    Science.gov (United States)

    Yu, Yong-xiang; Zhao, Cheng-yi; Jia, Hong-tao; Yu, Bo; Zhou, Tian-he; Yang, Yu-guang; Zhao, Hua

    2015-01-01

    A field study was conducted to compare soil CO2 efflux and CO2 concentration between mulched and non-mulched cotton fields by using closed chamber method and diffusion chamber technique. Soil CO2 efflux and CO2 concentration exhibited a similar seasonal pattern, decreasing from July to October. Mulched field had a lower soil CO2 efflux but a higher CO2 concentration, compared to those of non-mulched fields. Over the measurement period, cumulative CO2 efflux was 1871.95 kg C . hm-2 for mulched field and 2032.81 kg C . hm-2 for non-mulched field. Soil CO2 concentration was higher in mulched field (ranging from 5137 to 25945 µL . L-1) than in non- mulched field (ranging from 2165 to 23986 µL . L-1). The correlation coefficients between soil CO2 concentrations at different depths and soil CO2 effluxes were 0.60 to 0.73 and 0.57 to 0.75 for the mulched and non-mulched fields, indicating that soil CO2 concentration played a crucial role in soil CO2 emission. The Q10 values were 2.77 and 2.48 for the mulched and non-mulched fields, respectively, suggesting that CO2 efflux in mulched field was more sensitive to the temperature.

  2. The Influence of CO2 Solubility in Brine on Simulation of CO2 Injection into Water Flooded Reservoir and CO2 WAG

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2010-01-01

    Injection of CO2 into depleted oil reservoirs is not only a traditional way to enhance oil recovery but also a relatively cheaper way to sequester CO2 underground since the increased oil production can offset some sequestration cost. CO2 injection process is often applied to water flooded...... simulations were made for seven oil samples within a wide range of temperature, pressure and salinity. The results were analyzed in terms of the change in oil recovery due to different phase equilibrium descriptions, the delay in breakthrough and the CO2 lost to the aqueous phase. The influence of different...

  3. CO2 in Alberta - a vision of the future

    International Nuclear Information System (INIS)

    Edwards, K.

    1999-01-01

    The potential to develop a province-wide infrastructure for carbon dioxide (CO 2 ) collection and transmission was discussed. The petroleum industry's original interest in CO 2 was its potential for enhanced oil recovery (EOR) for Alberta's depleted oil fields. However, new interest has stemmed from its perceived role in global climate change and the potentially negative business and economic implications of emitting CO 2 into the atmosphere. It was suggested that the development of a province wide infrastructure to collect CO 2 would address both interests. A simple screening of the reservoirs was carried out to determine if Alberta has the right oil reservoirs and sufficient CO 2 supplies to support a large-scale CO 2 infrastructure. The proposed infrastructure would consist of CO 2 supplies from electrical power generation plants, CO 2 trunklines, feeder pipelines to deliver CO 2 from the trunklines to the field and the oil reservoirs where the CO 2 would be injected. Such infrastructures already exist in Texas and Mexico where more than 1 billion scf per day of CO 2 is used for EOR. This study compared the factors leading to a large-scale CO 2 industry with factors in place during the 1970s and 1980s, when most of the hydrocarbon miscible floods were initiated in Alberta. It was concluded that the preliminary economics suggest that the concept has merit. 12 refs., 3 tabs., 9 figs

  4. CO2 hydrogenation to hydrocarbons over iron nanoparticles ...

    Indian Academy of Sciences (India)

    481–486. c Indian Academy of Sciences. CO2 ... degrees of CO2 conversion shows that reverse water gas shift equilibrium had been ... rise in CO2 emission.1 Additionally, depletion in crude .... detectors (FID) using argon as internal standard.

  5. Polyether based block copolymer membranes for CO2 separation

    NARCIS (Netherlands)

    Reijerkerk, Sander

    2010-01-01

    The work described in this thesis is dedicated to the development of polymeric membrane materials for the separation of CO2 from light gases, and in particular to the separation of CO2 from nitrogen as required in a post-combustion capture conguration for the separation of CO2 from flue gases. An

  6. Effect of CO2 supply strategy on specific energy consumption

    NARCIS (Netherlands)

    Zwart, de H.F.

    1998-01-01

    This paper studies the effect of CO2-dosing with exhaust gases on the efficiency of glasshouse tomato production. The paper shows that it can be recommended to ensure a continuing CO2 supply during the warm period. The discussion focuses on exhaust gases as a CO2 source, but the results also

  7. A model for estimating CO2 solubility in aqueous alkanolamines

    DEFF Research Database (Denmark)

    Gabrielsen, Jostein; Michelsen, Michael Locht; Stenby, Erling Halfdan

    2005-01-01

    of CO2 over an aqueous alkanolamine solution. Accurate values for the partial pressure of CO2 are obtained for a limited loading, temperature, and pressure range that is useful in modeling CO2 capture from coal-fired power plants. Heat of absorption values derived from the model agree with experimental...

  8. CO2 emission trade from a fiscal perspective

    International Nuclear Information System (INIS)

    Klaassen, F.A.H.; Derksen, R.T.; Keijel, J.J.C.

    2004-06-01

    The report gives answers to questions as 'are CO2 emission permits assets or supplies?'; how to deal with forward contracts and options in CO2 emission permits 'fiscal-wise'; and 'which are the consequences of CO2 emissions trade for the rebate of pre-taxes?' Als attention is paid to trading system for NOx emission [nl

  9. Biomass waste carbon materials as adsorbents for CO2 capture under post-combustion conditions

    Directory of Open Access Journals (Sweden)

    Elisa M Calvo-Muñoz

    2016-05-01

    Full Text Available A series of porous carbon materials obtained from biomass waste have been synthesized, with different morphologies and structural properties, and evaluated as potential adsorbents for CO2 capture in post-combustion conditions. These carbon materials present CO2 adsorption capacities, at 25 ºC and 101.3 kPa, comparable to those obtained by other complex carbon or inorganic materials. Furthermore, CO2 uptakes under these conditions can be well correlated to the narrow micropore volume, derived from the CO2 adsorption data at 0 ºC (VDRCO2. In contrast, CO2 adsorption capacities at 25 ºC and 15 kPa are more related to only pores of sizes lower than 0.7 nm. The capacity values obtained in column adsorption experiments were really promising. An activated carbon fiber obtained from Alcell lignin, FCL, presented a capacity value of 1.3 mmol/g (5.7 %wt. Moreover, the adsorption capacity of this carbon fiber was totally recovered in a very fast desorption cycle at the same operation temperature and total pressure and, therefore, without any additional energy requirement. Thus, these results suggest that the biomass waste used in this work could be successfully valorized as efficient CO2 adsorbent, under post-combustion conditions, showing excellent regeneration performance.

  10. Modified ZIF-8 mixed matrix membrane for CO2/CH4 separation

    Science.gov (United States)

    Nordin, Nik Abdul Hadi Md; Ismail, Ahmad Fauzi; Misdan, Nurasyikin; Nazri, Noor Aina Mohd

    2017-10-01

    Tunability of metal-organic frameworks (MOFs) properties enables them to be tailored for specific applications. In this study, zeolitic imidazole framework 8 (ZIF-8), sub-class of MOF, underwent pre-synthesis and post-synthesis modifications. The pre-synthesis modification using GO (ZIF-8/GO) shows slight decrease in textural properties, while the post-synthesis modification using amine solution (ZIF-8/NH2) resulted in superior BET surface area and pore volume. Mixed matrix membranes (MMMs) derived from polysulfone (PSf) and the modified ZIF-8s were then prepared via dry/wet phase inversion. The polymer chain flexibility of the resulted MMMs shows rigidification, where ZIF-8/NH2 as filler resulting higher rigidification compared to ZIF-8/GO. The MMMs were further subjected to pure CO2 and CH4 gas permeation experiments. The PSf/ZIF-8/NH2 shows superior CO2/CH4 selectivity (88% increased) while sacrificing CO2 permeance due to combination of severe polymer chain rigidification and the presence of CO2-philic group, amine. Whereas, the PSf/ZIF-8/GO possess 64% increase in CO2 permeance without notable changes in CO2/CH4 selectivity.

  11. Estimation of mesophyll conductance to CO2 flux by three different methods

    International Nuclear Information System (INIS)

    Loreto, F.; Harley, P.C.; Di Marco, G.; Sharkey, T.D.

    1992-01-01

    The resistance to diffusion of CO2 from the intercellular airspaces within the leaf through the mesophyll to the sites of carboxylation during photosynthesis was measured using three different techniques, The three techniques include a method based on discrimination against the heavy stable isotope of carbon, 13C, and two modeling methods. The methods rely upon different assumptions, but the estimates of mesophyll conductance were similar with all three methods. The mesophyll conductance of leaves from a number of species was about 1.4 times the stomatal conductance for CO2 diffusion determined in unstressed plants at high light. The relatively low CO2 partial pressure inside chloroplasts of plants with a low mesophyll conductance did not lead to enhanced O2 sensitivity of photosynthesis because the low conductance caused a significant drop in the chloroplast CO2 Partial pressure upon switching to low O2. We found no correlation between mesophyll conductance and the ratio of internal leaf area to leaf surface area and only a weak correlation between mesophyll conductance and the proportion of leaf volume occupied by air. Mesophyll conductance was independent of CO2 and O2 partial pressure during the measurement, indicating that a true physical parameter, independent of biochemical effects, was being measured. No evidence for accumulating mechanisms was found. Some plants, notably Citrus aurantium and Simmondsia chinensis, had very low conductances that limit the rate of photosynthesis these plants can attain at atmospheric CO2 level

  12. How far does the CO2 travel beyond a leaky point?

    Science.gov (United States)

    Kong, X.; Delshad, M.; Wheeler, M.

    2012-12-01

    Xianhui Kong, Mojdeh Delshad, Mary F. Wheeler The University of Texas at Austin Numerous research studies have been carried out to investigate the long term feasibility of safe storage of large volumes of CO2 in subsurface saline aquifers. The injected CO2 will undergo complex petrophysical and geochemical processes. During these processes, part of CO2 will be trapped while some will remain as a mobile phase, causing a leakage risk. The comprehensive and accurate characterizations of the trapping and leakage mechanisms are critical for accessing the safety of sequestration, and are challenges in this research area. We have studied different leakage scenarios using realistic aquifer properties including heterogeneity and put forward a comprehensive trapping model for CO2 in deep saline aquifer. The reservoir models include several geological layers and caprocks up to the near surface. Leakage scenarios, such as fracture, high permeability pathways, abandoned wells, are studied. In order to accurately model the fractures, very fine grids are needed near the fracture. Considering that the aquifer usually has a large volume and reservoir model needs large number of grid blocks, simulation would be computational expensive. To deal with this challenge, we carried out the simulations using our in-house parallel reservoir simulator. Our study shows the significance of capillary pressure and permeability-porosity variations on CO2 trapping and leakage. The improved understanding on trapping and leakage will provide confidence in future implementation of sequestration projects.

  13. CO2 bubble generation and migration during magma-carbonate interaction

    Science.gov (United States)

    Blythe, L. S.; Deegan, F. M.; Freda, C.; Jolis, E. M.; Masotta, M.; Misiti, V.; Taddeucci, J.; Troll, V. R.

    2015-04-01

    We conducted quantitative textural analysis of vesicles in high temperature and pressure carbonate assimilation experiments (1200 °C, 0.5 GPa) to investigate CO2 generation and subsequent bubble migration from carbonate into magma. We employed Mt. Merapi (Indonesia) and Mt. Vesuvius (Italy) compositions as magmatic starting materials and present three experimental series using (1) a dry basaltic-andesite, (2) a hydrous basaltic-andesite (2 wt% H2O), and (3) a hydrous shoshonite (2 wt% H2O). The duration of the experiments was varied from 0 to 300 s, and carbonate assimilation produced a CO2-rich fluid and CaO-enriched melts in all cases. The rate of carbonate assimilation, however, changed as a function of melt viscosity, which affected the 2D vesicle number, vesicle volume, and vesicle size distribution within each experiment. Relatively low-viscosity melts (i.e. Vesuvius experiments) facilitated efficient removal of bubbles from the reaction site. This allowed carbonate assimilation to continue unhindered and large volumes of CO2 to be liberated, a scenario thought to fuel sustained CO2-driven eruptions at the surface. Conversely, at higher viscosity (i.e. Merapi experiments), bubble migration became progressively inhibited and bubble concentration at the reaction site caused localised volatile over-pressure that can eventually trigger short-lived explosive outbursts. Melt viscosity therefore exerts a fundamental control on carbonate assimilation rates and, by consequence, the style of CO2-fuelled eruptions.

  14. PEAT-CO2. Assessment of CO2 emissions from drained peatlands in SE Asia

    International Nuclear Information System (INIS)

    Hooijer, A.; Silvius, M.; Woesten, H.; Page, S.

    2006-12-01

    Forested tropical peatlands in SE Asia store at least 42,000 Megatonnes of soil carbon. This carbon is increasingly released to the atmosphere due to drainage and fires associated with plantation development and logging. Peatlands make up 12% of the SE Asian land area but account for 25% of current deforestation. Out of 27 million hectares of peatland, 12 million hectares (45%) are currently deforested and mostly drained. One important crop in drained peatlands is palm oil, which is increasingly used as a biofuel in Europe. In the PEAT-CO2 project, present and future emissions from drained peatlands were quantified using the latest data on peat extent and depth, present and projected land use and water management practice, decomposition rates and fire emissions. It was found that current likely CO2 emissions caused by decomposition of drained peatlands amounts to 632 Mt/y (between 355 and 874 Mt/y). This emission will increase in coming decades unless land management practices and peatland development plans are changed, and will continue well beyond the 21st century. In addition, over 1997-2006 an estimated average of 1400 Mt/y in CO2 emissions was caused by peatland fires that are also associated with drainage and degradation. The current total peatland CO2 emission of 2000 Mt/y equals almost 8% of global emissions from fossil fuel burning. These emissions have been rapidly increasing since 1985 and will further increase unless action is taken. Over 90% of this emission originates from Indonesia, which puts the country in 3rd place (after the USA and China) in the global CO2 emission ranking. It is concluded that deforested and drained peatlands in SE Asia are a globally significant source of CO2 emissions and a major obstacle to meeting the aim of stabilizing greenhouse gas emissions, as expressed by the international community. It is therefore recommended that international action is taken to help SE Asian countries, especially Indonesia, to better conserve

  15. Advanced turbine/CO2 pellet accelerator

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.

    1994-01-01

    An advanced turbine/CO 2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory. The program, sponsored by Warner Robins Air Logistics Center, Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air sandblast pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies. Applications include removal of epoxy-based points from aircraft and the cleaning of surfaces contaminated with toxic, hazardous, or radioactive substances. The lack of a secondary contaminated waste stream is of great benefit

  16. Charcoal cuts the CO2-emissions

    International Nuclear Information System (INIS)

    Aakervik, Anne Lise.

    1999-01-01

    According to this article, bio carbon, or charcoal, may be the way out for the Norwegian processing industry in attempting to reduce the emission of carbon dioxide. Norwegian ferro-alloy plants emit 3 million ton carbon dioxide per year, which comes from the use of coal and coke as reducing agents in the smelting process. If the fraction of bio carbon is increased by 15%, the emission of CO 2 may be reduced by about 1/2 million tonne per year. But the price of charcoal is much greater than that of fix C from coal and coke. Research is in progress on trying to produce bio carbon cheaper. Charcoal can be produced from all types of forest by pyrolysis. Waste heat from the pyrolysis can be sold and used for district heating. The most expensive part in the use of bio carbon will be timber felling and transport to the log pile. Small-scale and large-scale tests will be made to see if it is possible to make adequate charcoal from subarctic timber

  17. A centrifuge CO2 pellet cleaning system

    Science.gov (United States)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-01-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  18. CO2 Emission Reduction in Energy Sector

    International Nuclear Information System (INIS)

    Bole, A.; Sustersic, A.; Voncina, R.

    2013-01-01

    Due to human activities, concentrations of the greenhouse gases increase in the atmosphere much quicker than they naturally would. Today it is clear that climate change is the result of human activities. With the purpose of preventing, reducing and mitigating of climate change, the EU, whose member is also Slovenia, set ambitious goals. In order to keep rise of the global atmosphere temperature below 2 degrees of C, the European Council set an objective of reducing greenhouse gas emissions by 80 - 95 % by 2050 compared to 1990. It is important that every single individual is included in achieving of these goals. Certainly, the most important role is assumed by individual sectors especially Public Electricity and Heat Production sector as one of the greatest emitters of the greenhouse gases. As a possible solution of radical reduction of the greenhouse gases emission from mentioned sector Carbon Capture and Storage (CCS) technology is implemented. In the article the range of CO 2 reduction possibilities, technology demands and environmental side effects of CCS technology are described. Evaluation of CCS implementation possibilities in Slovenia is also included.(author)

  19. DF--CO2 transfer laser development

    International Nuclear Information System (INIS)

    Tregay, G.W.; Drexhage, M.G.; Wood, L.M.; Andrysiak, S.J.

    1975-01-01

    Power extraction and chemiluminescence experiments have been conducted in the large-scale DF-CO 2 transfer chemical laser (TCL) (IRIS-I and IRIS-II) facility at Bell Aerospace Company (BAC). The modular design of the device allowed testing to be conducted with both a supersonic nozzle bank and also in subsonic flow with sonic injection for the deuterium. Power levels of 15 kW at 10.6 μ were obtained in IRIS-I (subsonic) employing an unstable resonator with a 50 percent output coupling ratio and cavity pressure of 35 torr. For IRIS-II (supersonic) somewhat lower power was obtained. In both systems the fluorine dissociation (α = F/F + 2F 2 ) was less than 0.01. Chemiluminescent emission from HF and DF was monitored under zero-power conditions along an axis parallel to the laser-mirror axis. From the measured DF-concentration profiles it can be inferred that vibrationally excited DF is being produced throughout the cavity and, accordingly, the production of DF must be attributed largely to the chain reaction

  20. Effects of inspired CO2, hyperventilation, and time on VA/Q inequality in the dog

    Science.gov (United States)

    Tsukimoto, K.; Arcos, J. P.; Schaffartzik, W.; Wagner, P. D.; West, J. B.

    1992-01-01

    In a recent study by Tsukimoto et al. (J. Appl. Physiol. 68: 2488-2493, 1990), CO2 inhalation appeared to reduce the size of the high ventilation-perfusion ratio (VA/Q) mode commonly observed in anesthetized mechanically air-ventilated dogs. In that study, large tidal volumes (VT) were used during CO2 inhalation to preserve normocapnia. To separate the influences of CO2 and high VT on the VA/Q distribution in the present study, we examined the effect of inspired CO2 on the high VA/Q mode using eight mechanically ventilated dogs (4 given CO2, 4 controls). The VA/Q distribution was measured first with normal VT and then with increased VT. In the CO2 group at high VT, data were collected before, during, and after CO2 inhalation. With normal VT, there was no difference in the size of the high VA/Q mode between groups [10.5 +/- 3.5% (SE) of ventilation in the CO2 group, 11.8 +/- 5.2% in the control group]. Unexpectedly, the size of the high VA/Q mode decreased similarly in both groups over time, independently of the inspired PCO2, at a rate similar to the fall in cardiac output over time. The reduction in the high VA/Q mode together with a simultaneous increase in alveolar dead space (estimated by the difference between inert gas dead space and Fowler dead space) suggests that poorly perfused high VA/Q areas became unperfused over time. A possible mechanism is that elevated alveolar pressure and decreased cardiac output eliminate blood flow from corner vessels in nondependent high VA/Q regions.

  1. CO2 production in animals: analysis of potential errors in the doubly labeled water method

    International Nuclear Information System (INIS)

    Nagy, K.A.

    1979-03-01

    Laboratory validation studies indicate that doubly labeled water ( 3 HH 18 O and 2 HH 18 O) measurements of CO 2 production are accurate to within +-9% in nine species of mammals and reptiles, a bird, and an insect. However, in field studies, errors can be much larger under certain circumstances. Isotopic fraction of labeled water can cause large errors in animals whose evaporative water loss comprises a major proportion of total water efflux. Input of CO 2 across lungs and skin caused errors exceeding +80% in kangaroo rats exposed to air containing 3.4% unlabeled CO 2 . Analytical errors of +-1% in isotope concentrations can cause calculated rates of CO 2 production to contain errors exceeding +-70% in some circumstances. These occur: 1) when little decline in isotope concentractions has occured during the measurement period; 2) when final isotope concentrations closely approach background levels; and 3) when the rate of water flux in an animal is high relative to its rate of CO 2 production. The following sources of error are probably negligible in most situations: 1) use of an inappropriate equation for calculating CO 2 production, 2) variations in rates of water or CO 2 flux through time, 3) use of H 2 O-18 dilution space as a measure of body water volume, 4) exchange of 0-18 between water and nonaqueous compounds in animals (including excrement), 5) incomplete mixing of isotopes in the animal, and 6) input of unlabeled water via lungs and skin. Errors in field measurements of CO 2 production can be reduced to acceptable levels (< 10%) by appropriate selection of study subjects and recapture intervals

  2. Sectoral analysis of energy consumption and energy related CO2 emissions in Finland 1990-1999

    International Nuclear Information System (INIS)

    Kirjavainen, M.; Tamminen, E.

    2002-03-01

    This study describes the development of energy consumption and energy related CO 2 emissions in Finland between 1990-1999. For better understanding of the factors behind the development in main sectors, special indicators are calculated to evaluate how the overall development of the sector is affected by the general activity of the sector, changes in sectoral structure and changes in end-use intensities within the sector. The specific energy consumption of space heating reduced especially during the first half of the decade. Also the total CO 2 emissions caused by space heating reduced, in spite of the increase in the building stock. The main reason for this has been the reduction in specific CO 2 emissions in production of district heat. Regardless of the increased traffic and slightly increased use of passenger cars over public transport, the total energy consumption as well as total CO 2 emissions in passenger transport reduced during the decade. The main reason for this is that the specific fuel consumption of passenger cars has reduced significantly. Volumes in freight traffic increased rapidly after the recession, and as no significant changes have occurred in either specific consumptions or in shares of different transport modes, the total energy use as well as total CO 2 emissions of freight transport have increased. The major factors affecting the energy use and CO 2 emissions of the manufacturing sector have been changes in production volumes. After the recession, growth has been rapid and that has resulted in increased total energy use and CO 2 emissions. Anyway, the especially rapid growth of the less energy intensive electronics industry has resulted in downward overall energy intensity within manufacturing sector. Major factors affecting the specific CO 2 emissions in energy production have been changes in the primary energy supply mix. In electricity production, the major factors have been the increase in nuclear capacity and the variation in net

  3. El CO2 como disolvente y como reactivo

    OpenAIRE

    La Franca Pitarresi, Vincenzo Rosario

    2016-01-01

    Existen numerosas ventajas asociada con el uso de CO2 , tanto como disolvente que como reactivo, y todas se pueden resumir en cuatro categorías generales: beneficios ambiental, beneficios de salud y seguridad, beneficios en el procedimiento y beneficios químicos. Los procesos que implican el CO2 como disolvente no aumentaría las emisiones de CO2, más bien proporcionaría una oportunidad para el reciclaje de CO2 residual. Además, los esfuerzos para secuestrar el CO2 producido de los gases de co...

  4. Least cost planning for CO2-reduction strategies

    International Nuclear Information System (INIS)

    Seifritz, W.

    1990-01-01

    A first recommendation for the determination of the minimum costs for a carbon-dioxide reduction strategy is presented. For this, the tabulation of so-called, 'CO 2 -ranking-lists', containing the relationship between the costs of a distinct measure to avoid the emission of certain amount of CO 2 (in dollar/t CO 2 ) versus its potential (in t CO 2 /yr), is indispensable. Some basic aspects of this approach are discussed and a first guess of the costs of some measures to avoid CO 2 -emissions into the atmosphere is presented. (orig.) [de

  5. Granular bamboo-derived activated carbon for high CO(2) adsorption: the dominant role of narrow micropores.

    Science.gov (United States)

    Wei, Haoran; Deng, Shubo; Hu, Bingyin; Chen, Zhenhe; Wang, Bin; Huang, Jun; Yu, Gang

    2012-12-01

    Cost-effective biomass-derived activated carbons with a high CO(2) adsorption capacity are attractive for carbon capture. Bamboo was found to be a suitable precursor for activated carbon preparation through KOH activation. The bamboo size in the range of 10-200 mesh had little effect on CO(2) adsorption, whereas the KOH/C mass ratio and activation temperature had a significant impact on CO(2) adsorption. The bamboo-derived activated carbon had a high adsorption capacity and excellent selectivity for CO(2) , and also the adsorption process was highly reversible. The adsorbed amount of CO(2) on the granular activated carbon was up to 7.0 mmol g(-1) at 273 K and 1 bar, which was higher than almost all carbon materials. The pore characteristics of activated carbons responsible for high CO(2) adsorption were fully investigated. Based on the analysis of narrow micropore size distribution of several activated carbons prepared under different conditions, a more accurate micropore range contributing to CO(2) adsorption was proposed. The volume of micropores in the range of 0.33-0.82 nm had a good linear relationship with CO(2) adsorption at 273 K and 1 bar, and the narrow micropores of about 0.55 nm produced the major contribution, which could be used to evaluate CO(2) adsorption on activated carbons. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Sensitivity of Terrestrial Water and Energy Budgets to CO2-Physiological Forcing: An Investigation Using an Offline Land Model

    Science.gov (United States)

    Gopalakrishnan, Ranjith; Bala, Govindsamy; Jayaraman, Mathangi; Cao, Long; Nemani, Ramakrishna; Ravindranath, N. H.

    2011-01-01

    Increasing concentrations of atmospheric carbon dioxide (CO2) influence climate by suppressing canopy transpiration in addition to its well-known greenhouse gas effect. The decrease in plant transpiration is due to changes in plant physiology (reduced opening of plant stomata). Here, we quantify such changes in water flux for various levels of CO2 concentrations using the National Center for Atmospheric Research s (NCAR) Community Land Model. We find that photosynthesis saturates after 800 ppmv (parts per million, by volume) in this model. However, unlike photosynthesis, canopy transpiration continues to decline at about 5.1% per 100 ppmv increase in CO2 levels. We also find that the associated reduction in latent heat flux is primarily compensated by increased sensible heat flux. The continued decline in canopy transpiration and subsequent increase in sensible heat flux at elevated CO2 levels implies that incremental warming associated with the physiological effect of CO2 will not abate at higher CO2 concentrations, indicating important consequences for the global water and carbon cycles from anthropogenic CO2 emissions. Keywords: CO2-physiological effect, CO2-fertilization, canopy transpiration, water cycle, runoff, climate change 1.

  7. Modelling the effects of ice-sheet activity on CO2 outgassing by Icelandic volcanoes

    Science.gov (United States)

    Armitage, J. J.; Ferguson, D.; Petersen, K. D.; Creyts, T. T.

    2017-12-01

    Glacial cycles may play a significant role in mediating the flux of magmatic CO2 between the Earth's mantle and atmosphere. In Iceland, it is thought that late-Pleistocene deglaciation led to a significant volcanic pulse, evidenced by increased post-glacial lava volumes and changes in melt chemistry consistent with depressurization. Investigating the extent to which glacial activity may have affected volcanic CO2 emissions from Iceland, and crucially over what timescale, requires detailed knowledge of how the magma system responded to the growth and collapse of the ice-sheet before and after the LGM. To investigate this, we coupled a model of magma generation and transport with a history of ice-sheet activity. Our results show that the emplacement and removal of the LGM ice-sheet likely led to two significant pulses of magmatic CO2. The first, and most significant of these, is associated with ice-sheet growth and occurs as the magma system recovers from glacial loading. This recovery happens from the base of the melting region upwards, producing a pulse of CO2 rich magma that is predicted to reach the surface around 20 ka after the loading event, close in time to the LGM. The second peak in CO2 output occurs abruptly following deglaciation as a consequence of increased rates of melt generation and transport in the shallow mantle. Although these post-glacial melts are relatively depleted in CO2, the increase in magma flux leads to a short-lived period of elevated CO2 emissions. Our results therefore suggest a negative feedback, whereby ice-sheet growth produces a delayed pulse of magmatic CO2, which, in addition to increased geothermal heat flux, may contribute towards driving deglaciation, which itself then causes further magmatism and CO2 outgassing. This model is consistent with the seismic structure of the asthenosphere below Iceland, and the established compositional and volumetric trends for sub- and post-glacial volcanism in Iceland. These trends show that

  8. Hydro-geophysical responses to the injection of CO2 in core plugs of Berea sandstone

    Science.gov (United States)

    Song, I.; Park, K. G.

    2017-12-01

    We have built a laboratory-scale core flooding system to measure the relative permeability of a core sample and the acoustic response to the CO2 saturation degree at in situ condition of pressure and temperature down to a few kilometer depths. The system consisted of an acoustic velocity core holder (AVC model from the Core Laboratories) between upstream where CO2 and H2O were injected separately and downstream where the mixed fluids came out of a core sample. Core samples with 4 cm in diameter and 5 cm in length of Berea sandstone were in turn placed in the core holder for confining and axial pressures. The flooding operations of the multiphase fluids were conducted through the sample at 40ºC in temperature and 8 MPa in backpressure. CO2 and H2O in the physical condition were injected separately into a sample at constant rate with various ratios. The two phases were mixed during flowing through the sample. The mixed fluids out of the sample were separated again by their different densities in a chamber equipped with a level gauge of the interface. From the level change of the water in the separator, we measured the volume of water coming out of the sample for each test with a constant ratio of the injection rates. Then it was possible to calculate the saturation degree of CO2 from the difference between input volume and output volume of water. The differential pressure between upstream and downstream was directly measured to calculate the relative permeability as a function of the CO2 saturation degree. We also conducted ultrasonic measurements using piezoelectric sensors on the end plugs. An electric pulse was given to a sensor on one end of sample, and then ultrasonic waves were recorded from the other end. The various ratios of injection rate of CO2 and H2O into Berea sandstone yielded a range of 0.1-0.7 in CO2 saturation degree. The relative permeability was obtained at the condition of steady-state flow for given stages from the velocity of each phase and

  9. The effects of CO2-differentiated vehicle tax systems on car choice, CO2 emissions and tax revenues

    NARCIS (Netherlands)

    Kok, R.

    2011-01-01

    This paper assesses the impacts of a CO2-differentiated tax policy designed to influence car purchasing trends towards lower CO2 emitting vehicles in the Netherlands. Since 2009, gasoline and diesel cars up to 110 and 95 gram CO2 per km are exempted from the vehicle registration tax (VRT). In

  10. Modeling CO2 Storage in Fractured Reservoirs: Fracture-Matrix Interactions of Free-Phase and Dissolved CO2

    Science.gov (United States)

    Oldenburg, C. M.; Zhou, Q.; Birkholzer, J. T.

    2017-12-01

    The injection of supercritical CO2 (scCO2) in fractured reservoirs has been conducted at several storage sites. However, no site-specific dual-continuum modeling for fractured reservoirs has been reported and modeling studies have generally underestimated the fracture-matrix interactions. We developed a conceptual model for enhanced CO2 storage to take into account global scCO2 migration in the fracture continuum, local storage of scCO2 and dissolved CO2 (dsCO2) in the matrix continuum, and driving forces for scCO2 invasion and dsCO2 diffusion from fractures. High-resolution discrete fracture-matrix models were developed for a column of idealized matrix blocks bounded by vertical and horizontal fractures and for a km-scale fractured reservoir. The column-scale simulation results show that equilibrium storage efficiency strongly depends on matrix entry capillary pressure and matrix-matrix connectivity while the time scale to reach equilibrium is sensitive to fracture spacing and matrix flow properties. The reservoir-scale modeling results shows that the preferential migration of scCO2 through fractures is coupled with bulk storage in the rock matrix that in turn retards the fracture scCO2 plume. We also developed unified-form diffusive flux equations to account for dsCO2 storage in brine-filled matrix blocks and found solubility trapping is significant in fractured reservoirs with low-permeability matrix.

  11. CO2 niet meer dan genoeg: Teelt van Tomaat in 2012 bij Improvement Centre met lichtafhankelijk doseren van CO2

    NARCIS (Netherlands)

    Gelder, de A.; Warmenhoven, M.G.; Dieleman, J.A.; Klapwijk, P.; Baar, van P.H.

    2014-01-01

    Wageningen UR Glastuinbouw heeft met financiering van Kas als Energiebron en Samenwerken aan Vaardigheden onderzoek gedaan naar efficienter gebruik van CO2. In een kasproef bij GreenQ/Improvement Centre is een CO2 doseerstrategie getest, waarbij iets meer CO2 wordt gegeven dan er op basis van de

  12. Detection of CO2 leaks from carbon capture and storage sites with combined atmospheric CO2 and O-2 measurements

    NARCIS (Netherlands)

    van Leeuwen, Charlotte; Meijer, Harro A. J.

    2015-01-01

    This paper presents a transportable instrument that simultaneously measures the CO2 and (relative) O-2 concentration of the atmosphere with the purpose to aid in the detection of CO2 leaks from CCS sites. CO2 and O-2 are coupled in most processes on earth (e.g., photosynthesis, respiration and

  13. Recent global CO2 flux inferred from atmospheric CO2 observations and its regional analyses

    Directory of Open Access Journals (Sweden)

    J. M. Chen

    2011-11-01

    Full Text Available The net surface exchange of CO2 for the years 2002–2007 is inferred from 12 181 atmospheric CO2 concentration data with a time-dependent Bayesian synthesis inversion scheme. Monthly CO2 fluxes are optimized for 30 regions of the North America and 20 regions for the rest of the globe. Although there have been many previous multiyear inversion studies, the reliability of atmospheric inversion techniques has not yet been systematically evaluated for quantifying regional interannual variability in the carbon cycle. In this study, the global interannual variability of the CO2 flux is found to be dominated by terrestrial ecosystems, particularly by tropical land, and the variations of regional terrestrial carbon fluxes are closely related to climate variations. These interannual variations are mostly caused by abnormal meteorological conditions in a few months in the year or part of a growing season and cannot be well represented using annual means, suggesting that we should pay attention to finer temporal climate variations in ecosystem modeling. We find that, excluding fossil fuel and biomass burning emissions, terrestrial ecosystems and oceans absorb an average of 3.63 ± 0.49 and 1.94 ± 0.41 Pg C yr−1, respectively. The terrestrial uptake is mainly in northern land while the tropical and southern lands contribute 0.62 ± 0.47, and 0.67 ± 0.34 Pg C yr−1 to the sink, respectively. In North America, terrestrial ecosystems absorb 0.89 ± 0.18 Pg C yr−1 on average with a strong flux density found in the south-east of the continent.

  14. Improved Efficiency of Miscible CO2 Floods and Enhanced Prospects for CO2 Flooding Heterogeneous Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, Reid B.; Schechter, David S.

    1999-10-15

    The goal of this project is to improve the efficiency of miscible CO2 floods and enhance the prospects for flooding heterogeneous reservoirs. This report provides results of the second year of the three-year project that will be exploring three principles: (1) Fluid and matrix interactions (understanding the problems). (2) Conformance control/sweep efficiency (solving the problems. 3) Reservoir simulation for improved oil recovery (predicting results).

  15. Approach to novel design of CO2 based centrifugal compressor

    Directory of Open Access Journals (Sweden)

    Kura Tomasz

    2016-01-01

    Full Text Available Even though turbomachinery design issues have been investigated almost since the beginning of engineering, its optimization process is still important. With the development of refrigeration devices and ORC based distributed generation facilities, a need for efficient and low-energy compressors and turbines became even more demanding. Such machines working with typical fluid, like air, are well described, but there is a room regarding the fluids like CO2, vapour of organic fluids, etc. The main objective of present studies is to propose a numerical model of the centrifugal compressor, with CO2 as the working fluid. Such unit may be a part of refrigeration cycle. Commonly, the scroll or piston compressors are used in such cases, however some discussed disadvantages show that the novel designs should be looked for. Properly designed centrifugal compressors can have higher efficiency than the presently used. Three dimensional analyses of proposed geometries were conducted – using a model including heat, mass and momentum conservation laws as well as ideal gas law. Verification of the proposed mesh and results was performed in the basis of values obtained using theoretical and empirical equations. With about 700 000 control volumes in the validated model, error of the results was no higher than 5%, with only about 1% in regards to the thermal parameters. Two design proposals were analysed, with performance maps as the main comparison factor. Apart from performance characteristics, the pressure and velocity fields were presented, showing the process of flow structure optimization. The main goal was to reduce negative effects of pressure and velocity gradients on the performance. Proposed precursory design might be a good starting point for further development of compressors. The results of numerical analysis were promising and shows the possibility of proposed design usage in practical applications, however to obtain deep understanding of the

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

    Science.gov (United States)

    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.

  17. CO2 recovery system using solar energy; Taiyo energy wo riyoshita CO2 bunri kaishu system

    Energy Technology Data Exchange (ETDEWEB)

    Hosho, F; Naito, H; Yugami, H; Arashi, H [Tohoku University, Sendai (Japan)

    1997-11-25

    As a part of studies on chemical absorption process with MEA (monoethanolamine) for CO2 recovery from boiler waste gas in thermal power plants, use of solar heat as MEA regenerating energy was studied. An integrated stationary evacuated concentrator (ISEC) effective as collector in a medium temperature range was used to realize a regenerating temperature range of 100-120degC. ISEC is featured by vacuum insulation, use of selective absorbing membranes for an absorber, a CPC (compound parabolic concentrator)-shaped reflection mirror, and high-efficiency. An MEA regenerator is composed of an ISEC and PG(propylene glycol)-MEA heat exchanger, and circulates PG as heat medium. Heat collection experiment was also made using water instead of MEA. Both batch and continuous systems could supply a heat quantity necessary for MEA regeneration. CO2 concentration in the top of the regenerator rapidly decreased with PG circulation regenerating MEA. As mol ratios of CO2/MEA were compared between before and after regeneration, a recovery rate was estimated to be 59.4% for the batch system. 8 figs., 4 tabs.

  18. Pressure, O2, and CO2, in aquatic Closed Ecological Systems

    Science.gov (United States)

    Taub, Frieda B.; McLaskey, Anna K.

    2013-03-01

    Pressure increased during net photosynthetic O2 production in the light and decreased during respiratory O2 uptake during the dark in aquatic Closed Ecological Systems (CESs) with small head gas volumes. Because most CO2 will be in the liquid phase as bicarbonate and carbonate anions, and CO2 is more soluble than O2, volumes of gaseous CO2 and gaseous O2 will not change in a compensatory manner, leading to the development of pressure. Pressure increases were greatest with nutrient rich medium with NaHCO3 as the carbon source. With more dilute media, pressure was greatest with NaHCO3, and less with cellulose or no-added carbon. Without adequate turbulence, pressure measurements lagged dissolved O2 concentrations by several hours and dark respiration would have been especially underestimated in our systems (250-1000 ml). With adequate turbulence (rotary shaker), pressure measurements and dissolved O2 concentrations generally agreed during lights on/off cycles, but O2 measurements provided more detail. At 20 °C, 29.9 times as much O2 will distribute into the gas phase as in the liquid, per unit volume, as a result of the limited solubility of O2 in water and according to Henry's Law. Thus even a small head gas volume can contain more O2 than a larger volume of water. When both dissolved and gaseous O2 and CO2 are summed, the changes in Total O2 and CO2 are in relatively close agreement when NaHCO3 is the carbon source. These findings disprove an assumption made in some of Taub's earlier research that aquatic CESs would remain at approximately atmospheric pressure because approximately equal molar quantities of O2 and CO2 would exchange during photosynthesis and respiration; this assumption neglected the distribution of O2 between water and gas phases. High pressures can occur when NaHCO3 is the carbon source in nutrient rich media and if head-gas volumes are small relative to the liquid volume; e.g., one "worse case" condition developed 800 mm Hg above atmospheric

  19. Feasibility of CO2 Sequestration as a Closure Option for Underground Coal Mine

    Science.gov (United States)

    Ray, Sutapa; Dey, Kaushik

    2018-01-01

    The Kyoto Protocol, 1998, was signed by member countries to reduce greenhouse gas (GHG) emissions to a minimum acceptable level. India agreed to Kyoto Protocol since 2002 and started its research on GHG mitigation. Few researchers have carried out research work on CO2 sequestration in different rock formations. However, CO2 sequestration in abandoned mines has yet not drawn its attention largely. In the past few years or decades, a significant amount of research and development has been done on Carbon Capture and Storage (CCS) technologies, since it is a possible solution for assuring less emission of CO2 to the atmosphere from power plants and some other major industrial plants. CCS mainly involves three steps: (a) capture and compression of CO2 from source (power plants and industrial areas), (b) transportation of captured CO2 to the storage mine and (c) injecting CO2 into underground mine. CO2 is stored at an underground mine mainly in three forms: (1) adsorbed in the coals left as pillars of the mine, (2) absorbed in water through a chemical process and (3) filled in void with compressed CO2. Adsorption isotherm is a graph developed between the amounts of adsorbate adsorbed on the surface of adsorbent and the pressure at constant temperature. Various types of adsorption isotherms are available, namely, Freundlich, Langmuir and BET theory. Indian coal is different in origin from most of the international coal deposits and thus demands isotherm experiments of the same to arrive at the right adsorption isotherm. To carry out these experiments, adsorption isotherm set up is fabricated in the laboratory with a capacity to measure the adsorbed volume up to a pressure level of 100 bar. The coal samples are collected from the pillars and walls of the underground coal seam using a portable drill machine. The adsorption isotherm experiments have been carried out for the samples taken from a mine. From the adsorption isotherm experiments, Langmuir Equation is found to be

  20. Feasibility of CO2 Sequestration as a Closure Option for Underground Coal Mine

    Science.gov (United States)

    Ray, Sutapa; Dey, Kaushik

    2018-04-01

    The Kyoto Protocol, 1998, was signed by member countries to reduce greenhouse gas (GHG) emissions to a minimum acceptable level. India agreed to Kyoto Protocol since 2002 and started its research on GHG mitigation. Few researchers have carried out research work on CO2 sequestration in different rock formations. However, CO2 sequestration in abandoned mines has yet not drawn its attention largely. In the past few years or decades, a significant amount of research and development has been done on Carbon Capture and Storage (CCS) technologies, since it is a possible solution for assuring less emission of CO2 to the atmosphere from power plants and some other major industrial plants. CCS mainly involves three steps: (a) capture and compression of CO2 from source (power plants and industrial areas), (b) transportation of captured CO2 to the storage mine and (c) injecting CO2 into underground mine. CO2 is stored at an underground mine mainly in three forms: (1) adsorbed in the coals left as pillars of the mine, (2) absorbed in water through a chemical process and (3) filled in void with compressed CO2. Adsorption isotherm is a graph developed between the amounts of adsorbate adsorbed on the surface of adsorbent and the pressure at constant temperature. Various types of adsorption isotherms are available, namely, Freundlich, Langmuir and BET theory. Indian coal is different in origin from most of the international coal deposits and thus demands isotherm experiments of the same to arrive at the right adsorption isotherm. To carry out these experiments, adsorption isotherm set up is fabricated in the laboratory with a capacity to measure the adsorbed volume up to a pressure level of 100 bar. The coal samples are collected from the pillars and walls of the underground coal seam using a portable drill machine. The adsorption isotherm experiments have been carried out for the samples taken from a mine. From the adsorption isotherm experiments, Langmuir Equation is found to be

  1. Economics show CO2 EOR potential in central Kansas

    Science.gov (United States)

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

    2000-01-01

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

  2. Supercritical CO2 Compressor with Active Magnetic Bearing

    International Nuclear Information System (INIS)

    Cha, Jae Eun; Cho, Seong Kuk; Lee, JeKyoung; Lee, Jeong Ik

    2016-01-01

    For the stable operation of the sCO 2 integral test facility SCIEL, KAERI prepared Active Magnetic Bearing sCO 2 compressor for the 70,000RPM operation. Power generation test with AMB compressor will be finished within first half year of 2016 under supercritical state. The principal advantages of the sCO 2 Cycle are high efficiency at moderate temperature range, compact components size, simple cycle configuration, and compatibility with various heat sources. The Supercritical CO 2 Brayton Cycle Integral Experiment Loop (SCIEL) has been installed in Korea Atomic Energy Research Institute (KAERI) to develop the base technologies for the sCO 2 cycle power generation system. The operation of the SCIEL has mainly focused on sCO 2 compressor development and establishing sCO 2 system control logic

  3. Modeling CO2-facilitated transport across a diethanolamine liquid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Lihong Bao; Michael C. Trachtenberg [Carbozyme Inc., Monmouth Junction, NJ (United States)

    2005-12-15

    We compared experimental and model data for the facilitated transport of CO2 from a CO2-air mixture across an aqueous solution of diethanolamine (DEA) via a hollow fiber, contained liquid membrane (HFCLM) permeator. A two-step carbamate formation model was devised to analyze the data instead of the one-step mechanism used by previous investigators. The effects of DEA concentration, liquid membrane thickness and feed CO2 concentration were also studied. With a 20% (wt) DEA liquid membrane and feed of 15% CO2 in CO2-air mixture at atmosphere pressure, the permeance reached 1.51E-8 mol/m{sup 2} s Pa with a CO2/N2 selectivity of 115. Model predictions compared well with the experimental results at CO2 concentrations of industrial importance. Short-term stability of the HFCLM permeator performance was examined. The system was stable during 5-days of testing.

  4. What does CO2 geological storage really mean?

    International Nuclear Information System (INIS)

    2008-01-01

    It is now accepted that human activities are disturbing the carbon cycle of the planet. CO 2 , a greenhouse gas, has accumulated in the atmosphere where it contributes to climate change. Amongst the spectrum of short term measures that need to be urgently implemented to mitigate climate change, CO 2 capture and storage can play a decisive role as it could contribute 33% of the CO 2 reduction needed by 2050. This document aims to explain this solution by answering the following questions: where and how much CO 2 can we store underground, How can we transport and inject large quantities of CO 2 , What happens to the CO 2 once in the storage reservoir? Could CO 2 leak from the reservoir and if so, what might be the consequences? How can we monitor the storage site at depth and at the surface? What safety criteria need to be imposed and respected? (A.L.B.)

  5. Porous carbon derived via KOH activation of a hypercrosslinked porous organic polymer for efficient CO_2, CH_4, H_2 adsorptions and high CO_2/N_2 selectivity

    International Nuclear Information System (INIS)

    Modak, Arindam; Bhaumik, Asim

    2015-01-01

    Microporous carbon having Brunauer-Emmett-Teller (BET) surface area of 2186 m"2 g"−"1 and micropore volume of 0.85 cm"3 g"−"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_2 (7.6 mmol g"−"1) and CH_4 (2.4 mmol g"−"1) at 1 atm, 273 K together with very good selectivity for the CO_2/N_2 (30.2) separation. Furthermore, low pressure (1 atm) H_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"2 g"−"1 has been synthesized via KOH activation of a porous organic polymer and it showed high uptake for CO_2 (7.6 mmol g"−"1), CH_4 (2.4 mmol g"−"1) and H_2 (2.6 wt%) at 1 atm together with very good selectivity for CO_2. - Highlights: • Porous carbon from hypercrosslinked organic polymer. • KOH activated carbon with BET surface area 2186 m"2 g"−"1. • High CO2 uptake (7.6 mmol g"−"1) and CO_2/N_2 selectivity (30.2). • Porous carbon also showed high H_2 (2.6 wt%) and H_2O (57.4 wt%) uptakes.

  6. Study of the hyperfine magnetic field at Ta181 site in the Heusler Co2 Sc Sn, Co2 Sc Ga and Co2 Hf Sn alloys

    International Nuclear Information System (INIS)

    Attili, R.N.

    1992-01-01

    The hyperfine magnetic fields acting on 181 Ta nuclei at the Sc and Hf sites have been measured in Heusler alloys Co 2 Sc Sn and Co 2 Sc Ga and Co 2 Hf Sn using the Time Differential Perturbed γ-γ Angular Correlation (TDPAC) technique. The measurements were carried out using an automatic spectrometer consisting of two Ba F 2 detectors and the conventional electronics. The magnitude of hyperfine magnetic field at 181 Ta was measured for all the alloys. The signs of the were determined in the cases of Co 2 Sc Sn and Co 2 Hf Sn alloys by performing the Perturbed Angular Correlation measurements with an external polarizing magnetic field of ≅ 5 k Gauss. The hyperfine magnetic fields obtained are -187,6± 3,3 and 90,0 ± 2,1 kOe measured at 77 K for Co 2 Sc Sn and Co 2 Sc Ga alloys respectively, and -342,4 ± 10,1 kOe measured at the room temperature for Co 2 Hf Sn alloy. These results are discussed and compared with the hyperfine magnetic field systematics in Co-based Heusler alloy. (author)

  7. Sequestering CO2 in the Built Environment

    Science.gov (United States)

    Constantz, B. R.

    2009-12-01

    Calera’s Carbonate Mineralization by Aqueous Precipitation (CMAP) technology with beneficial reuse has been called, “game-changing” by Carl Pope, Director of the Sierra Club. Calera offers a solution to the scale of the carbon problem. By capturing carbon into the built environment through carbonate mineralization, Calera provides a sound and cost-effective alternative to Geologic Sequestration and Terrestrial Sequestration. The CMAP technology permanently converts carbon dioxide into a mineral form that can be stored above ground, or used as a building material. The process produces a suite of carbonate-containing minerals of various polymorphic forms. Calera product can be substituted into blends with ordinary Portland cements and used as aggregate to produce concrete with reduced carbon, carbon neutral, or carbon negative footprints. For each ton of product produced, approximately half a ton of carbon dioxide can be sequestered using the Calera process. Coal and natural gas are composed of predominately istopically light carbon, as the carbon in the fuel is plant-derived. Thus, power plant CO2 emissions have relatively low δ13C values.The carbon species throughout the CMAP process are identified through measuring the inorganic carbon content, δ13C values of the dissolved carbonate species, and the product carbonate minerals. Measuring δ13C allows for tracking the flue gas CO2 throughout the capture process. Initial analysis of the capture of propane flue gas (δ13C ˜ -25 ‰) with seawater (δ13C ˜ -10 ‰) and industrial brucite tailings from a retired magnesium oxide plant in Moss Landing, CA (δ13C ˜ -7 ‰ from residual calcite) produced carbonate mineral products with a δ13C value of ˜ -20 ‰. This isotopically light carbon, transformed from flue gas to stable carbonate minerals, can be transferred and tracked through the capture process, and finally to the built environment. CMAP provides an economical solution to global warming by producing

  8. Experimental investigation of CO_2 separation by adsorption methods in natural gas purification

    International Nuclear Information System (INIS)

    Chen, S.J.; Fu, Y.; Huang, Y.X.; Tao, Z.C.; Zhu, M.

    2016-01-01

    Highlights: • The ideal swing adsorption tank can improve the adsorption performance. • Pure CO_2 adsorption experimental data agrees well with extended Langmuir model. • Langmuir-Freundlich model correlates CO_2/CH_4 mixture adsorption data fairly well. • The temperature increases in the order swing 2 > swing1 > static for pure CO_2 adsorption. • Swinging the adsorption tank can improve the separation efficiency. - Abstract: CO_2 separation for natural gas purification by the adsorption method was studied in detail using volumetric adsorption apparatus. The crystalline phase and microstructure of the experimental sample were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Micromeritics ASAP 2020 instrument. The XRD pattern proves that the experimental sample consists of 13X zeolites. The SEM images show that the 13X zeolites expose a large number of micro-channels on the surface of the particles. The microporous volume is 0.22 cm"3 (STP)/g. The ideal swing frequency for the adsorption tank can improve the adsorption performance of an adsorbent compared with a static adsorption tank. The pure CO_2 adsorption experimental data agrees well with the extended Langmuir model. The Langmuir-Freundlich model correlates the CO_2/CH_4 mixture adsorption experimental data fairly well. The relative errors between the simulated results and the experimental data are very little, which indicates that these fitted models are correct. The average selectivity of CO_2/CH_4 in a static and swing adsorption tank are, respectively, 3.57 and 3.93, considerably higher than 1, indicating preferential CO_2 adsorption over CH_4 in CO_2/CH_4 mixtures. This also shows that the swing can improve CO_2 separation for natural gas purification. For the three types of motion status, the temperature of the adsorption tank increased in the order swing 2 > swing1 > static state for pure CO_2 adsorption in 13X zeolites. The temperature variation decreased as the

  9. Comparative Study of Textural Characteristics on Methane Adsorption for Carbon Spheres Produced by CO2 Activation

    OpenAIRE

    Yang, Wen; Feng, Yanyan; Chu, Wei

    2014-01-01

    Resorcinol-formaldehyde resin polymer was used as raw material for preparation of carbon spheres. Samples were treated with CO2 flow at 850°C by varying activation times. The CO2 activation granted better pore development of pore structure. The experimental data of CH4 adsorption as a function of equilibrium pressure was fitted by Langmuir and Dubinin-Astakhov (D-A) models. It was concluded that the high surface area and micropore volume of carbon spheres did unequivocally determine methane c...

  10. State of Energy Consumption and CO2 Emission in Bangladesh

    International Nuclear Information System (INIS)

    Azad, Abul K.; Nashreen, S.W.; Sultana, J.

    2006-01-01

    Carbon dioxide (CO 2 ) is one of the most important gases in the atmosphere, and is necessary for sustaining life on Earth. It is also considered to be a major greenhouse gas contributing to global warming and climate change. In this article, energy consumption in Bangladesh is analyzed and estimates are made of CO 2 emission from combustion of fossil fuel (coal, gas, petroleum products) for the period 1977 to 1995. International Panel for Climate Change guidelines for national greenhouse gas inventories were used in estimating CO 2 emission. An analysis of energy data shows that the consumption of fossil fuels in Bangladesh is growing by more than 5% per year. The proportion of natural gas in total energy consumption is increasing, while that of petroleum products and coal is decreasing. The estimated total CO 2 release from all primary fossil fuels used in Bangladesh amounted to 5,072 Gg in 1977, and 14,423 Gg in 1995. The total amounts of CO 2 released from petroleum products, natural gas, and coal in the period 1977-1995 were 83,026 Gg (50% of CO 2 emission), 72,541 Gg (44% of CO 2 emission), and 9,545 Gg (6% CO 2 emission), respectively. A trend in CO 2 emission with projections to 2070 is generated. In 2070, total estimated CO 2 emission will be 293,260 Gg with a current growth rate of 6.34%/y. CO 2 emission from fossil fuels is increasing. Petroleum products contribute the majority of CO 2 emission load, and although the use of natural gas is increasing rapidly, its contribution to CO 2 emission is less than that of petroleum products. The use of coal as well as CO 2 emission from coal is expected to gradually decrease

  11. Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2.

    Science.gov (United States)

    Favaro, Marco; Xiao, Hai; Cheng, Tao; Goddard, William A; Yano, Junko; Crumlin, Ethan J

    2017-06-27

    A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.

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

    Science.gov (United States)

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

    2015-12-01

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

  13. Interpreting plant-sampled ¿14CO2 to study regional anthropogenic CO2 signals in Europe

    OpenAIRE

    Bozhinova, D.N.

    2015-01-01

    "Interpreting plant-sampled Δ14CO2 to study regional anthropogenic CO2 signals in Europe" Author: Denica Bozhinova This thesis investigates the quantitative interpretation of plant-sampled ∆14CO2 as an indicator of fossil fuel CO2 recently added to the atmosphere. We present a methodology to calculate the ∆14CO2 that has accumulated in a plant over its growing period, based on a modeling framework consisting of a plant growth model (SUCROS) and an atmospheric transport model (WRF-Chem). We ve...

  14. Quantitative analysis of an engineered CO2-fixing Escherichia coli reveals great potential of heterotrophic CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Liu, Guoxia; Zhai, Xiaoyun; Zhou, Jie; Cai, Zhen; Li, Yin

    2015-01-01

    Production of fuels from the abundant and wasteful CO2 is a promising approach to reduce carbon emission and consumption of fossil fuels. Autotrophic microbes naturally assimilate CO2 using energy from light, hydrogen, and/or sulfur. However, their slow growth rates call for investigation of the possibility of heterotrophic CO2 fixation. Although preliminary research has suggested that CO2 fixation in heterotrophic microbes is feasible after incorporation of a CO2-fixing bypass into the central carbon metabolic pathway, it remains unclear how much and how efficient that CO2 can be fixed by a heterotrophic microbe. A simple metabolic flux index was developed to indicate the relative strength of the CO2-fixation flux. When two sequential enzymes of the cyanobacterial Calvin cycle were incorporated into an E. coli strain, the flux of the CO2-fixing bypass pathway accounts for 13 % of that of the central carbon metabolic pathway. The value was increased to 17 % when the carbonic anhydrase involved in the cyanobacterial carbon concentrating mechanism was introduced, indicating that low intracellular CO2 concentration is one limiting factor for CO2 fixation in E. coli. The engineered CO2-fixing E. coli with carbonic anhydrase was able to fix CO2 at a rate of 19.6 mg CO2 L(-1) h(-1) or the specific rate of 22.5 mg CO2 g DCW(-1) h(-1). This CO2-fixation rate is comparable with the reported rates of 14 autotrophic cyanobacteria and algae (10.5-147.0 mg CO2 L(-1) h(-1) or the specific rates of 3.5-23.7 mg CO2 g DCW(-1) h(-1)). The ability of CO2 fixation was created and improved in E. coli by incorporating partial cyanobacterial Calvin cycle and carbon concentrating mechanism, respectively. Quantitative analysis revealed that the CO2-fixation rate of this strain is comparable with that of the autotrophic cyanobacteria and algae, demonstrating great potential of heterotrophic CO2 fixation.

  15. Dynamics of soil CO 2 efflux under varying atmospheric CO 2 concentrations reveal dominance of slow processes

    Science.gov (United States)

    Dohyoung Kim; Ram Oren; James S. Clark; Sari Palmroth; A. Christopher Oishi; Heather R. McCarthy; Chris A. Maier; Kurt Johnsen

    2017-01-01

    We evaluated the effect on soil CO2 efflux (FCO2) of sudden changes in photosynthetic rates by altering CO2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO2 (eCO2) ranging 1.0–1.8 times ambient did not affect FCO2. FCO2 did not decrease until 4 months after termination of the long-term eCO2 treatment, longer...

  16. Stem girdling affects the quantity of CO2 transported in xylem as well as CO2 efflux from soil.

    Science.gov (United States)

    Bloemen, Jasper; Agneessens, Laura; Van Meulebroek, Lieven; Aubrey, Doug P; McGuire, Mary Anne; Teskey, Robert O; Steppe, Kathy

    2014-02-01

    There is recent clear evidence that an important fraction of root-respired CO2 is transported upward in the transpiration stream in tree stems rather than fluxing to the soil. In this study, we aimed to quantify the contribution of root-respired CO2 to both soil CO2 efflux and xylem CO2 transport by manipulating the autotrophic component of belowground respiration. We compared soil CO2 efflux and the flux of root-respired CO2 transported in the transpiration stream in girdled and nongirdled 9-yr-old oak trees (Quercus robur) to assess the impact of a change in the autotrophic component of belowground respiration on both CO2 fluxes. Stem girdling decreased xylem CO2 concentration, indicating that belowground respiration contributes to the aboveground transport of internal CO2 . Girdling also decreased soil CO2 efflux. These results confirmed that root respiration contributes to xylem CO2 transport and that failure to account for this flux results in inaccurate estimates of belowground respiration when efflux-based methods are used. This research adds to the growing body of evidence that efflux-based measurements of belowground respiration underestimate autotrophic contributions. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  17. Spatial and temporal distribution of onroad CO2 emissions at the Urban spatial scale

    Science.gov (United States)

    Song, Y.; Gurney, K. R.; Zhou, Y.; Mendoza, D. L.

    2011-12-01

    The Hestia Project is a multi-disciplinary effort to help better understand the spatial and temporal distribution of fossil fuel carbon dioxide (CO2) emission at urban scale. Onroad transportation is an essential source of CO2 emissions. This study examines two urban domains: Marion County (Indianapolis) and Los Angeles County and explores the methods and results associated with the spatial and temporal distribution of local urban onroad CO2 emissions. We utilize a bottom-up approach and spatially distribute county emissions based on the Annual Average Daily Traffic (AADT) counts provided by local Department of Transportation. The total amount of CO2 emissions is calculated by the National Mobile Inventory Model (NMIM) for Marion County and the EMission FACtors (EMFAC) model for Los Angeles County. The NMIM model provides CO2 emissions based on vehicle miles traveled (VMT) data at the county-level from the national county database (NCD). The EMFAC model provides CO2 emissions for California State based on vehicle activities, including VMT, vehicle population and fuel types. A GIS road atlas is retrieved from the US Census Bureau. Further spatial analysis and integration are performed by GIS software to distribute onroad CO2 emission according to the traffic volume. The temporal allocation of onroad CO2 emission is based on the hourly traffic data obtained from the Metropolitan Planning Orgnizations (MPO) for Marion County and Department of Transportation for Los Angeles County. The annual CO2 emissions are distributed according to each hourly fraction of traffic counts. Due to the fact that ATR stations are unevenly distributed in space, we create Thiessen polygons such that each road segment is linked to the nearest neighboring ATR station. The hourly profile for each individual station is then combined to create a "climatology" of CO2 emissions in time on each road segment. We find that for Marion County in the year 2002, urban interstate and arterial roads have

  18. Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO2 During Part of the Tertiary

    Science.gov (United States)

    Royer, Dana L.; Wing, Scott L.; Beerling, David J.; Jolley, David W.; Koch, Paul L.; Hickey, Leo J.; Berner, Robert A.

    2001-06-01

    Understanding the link between the greenhouse gas carbon dioxide (CO2) and Earth's temperature underpins much of paleoclimatology and our predictions of future global warming. Here, we use the inverse relationship between leaf stomatal indices and the partial pressure of CO2 in modern Ginkgo biloba and Metasequoia glyptostroboides to develop a CO2 reconstruction based on fossil Ginkgo and Metasequoia cuticles for the middle Paleocene to early Eocene and middle Miocene. Our reconstruction indicates that CO2 remained between 300 and 450 parts per million by volume for these intervals with the exception of a single high estimate near the Paleocene/Eocene boundary. These results suggest that factors in addition to CO2 are required to explain these past intervals of global warmth.

  19. Enhancing CO2 Electroreduction with the Metal-Oxide Interface.

    Science.gov (United States)

    Gao, Dunfeng; Zhang, Yi; Zhou, Zhiwen; Cai, Fan; Zhao, Xinfei; Huang, Wugen; Li, Yangsheng; Zhu, Junfa; Liu, Ping; Yang, Fan; Wang, Guoxiong; Bao, Xinhe

    2017-04-26

    The electrochemical CO 2 reduction reaction (CO 2 RR) typically uses transition metals as the catalysts. To improve the efficiency, tremendous efforts have been dedicated to tuning the morphology, size, and structure of metal catalysts and employing electrolytes that enhance the adsorption of CO 2 . We report here a strategy to enhance CO 2 RR by constructing the metal-oxide interface. We demonstrate that Au-CeO x shows much higher activity and Faradaic efficiency than Au or CeO x alone for CO 2 RR. In situ scanning tunneling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au-CeO x interface is dominant in enhancing CO 2 adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au-CeO x interface is the active site for CO 2 activation and the reduction to CO, where the synergy between Au and CeO x promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO 2 RR. Similar interface-enhanced CO 2 RR is further observed on Ag-CeO x , demonstrating the generality of the strategy for enhancing CO 2 RR.

  20. CO2 impulse response curves for GWP calculations

    International Nuclear Information System (INIS)

    Jain, A.K.; Wuebbles, D.J.

    1993-01-01

    The primary purpose of Global Warming Potential (GWP) is to compare the effectiveness of emission strategies for various greenhouse gases to those for CO 2 , GWPs are quite sensitive to the amount of CO 2 . Unlike all other gases emitted in the atmosphere, CO 2 does not have a chemical or photochemical sink within the atmosphere. Removal of CO 2 is therefore dependent on exchanges with other carbon reservoirs, namely, ocean and terrestrial biosphere. The climatic-induced changes in ocean circulation or marine biological productivity could significantly alter the atmospheric CO 2 lifetime. Moreover, continuing forest destruction, nutrient limitations or temperature induced increases of respiration could also dramatically change the lifetime of CO 2 in the atmosphere. Determination of the current CO 2 sinks, and how these sinks are likely to change with increasing CO 2 emissions, is crucial to the calculations of GWPs. It is interesting to note that the impulse response function is sensitive to the initial state of the ocean-atmosphere system into which CO 2 is emitted. This is due to the fact that in our model the CO 2 flux from the atmosphere to the mixed layer is a nonlinear function of ocean surface total carbon

  1. Economic evaluation of CO2 pipeline transport in China

    International Nuclear Information System (INIS)

    Zhang Dongjie; Wang Zhe; Sun Jining; Zhang Lili; Li Zheng

    2012-01-01

    Highlights: ► We build a static hydrodynamic model of CO 2 pipeline for CCS application. ► We study the impact on pressure drop of pipeline by viscosity, density and elevation. ► We point out that density has a bigger impact on pressure drop than viscosity. ► We suggest dense phase transport is preferred than supercritical state. ► We present cost-optimal pipeline diameters for different flowrates and distances. - Abstract: Carbon capture and sequestration (CCS) is an important option for CO 2 mitigation and an optimized CO 2 pipeline transport system is necessary for large scale CCS implementation. In the present work, a hydrodynamic model for CO 2 pipeline transport was built up and the hydrodynamic performances of CO 2 pipeline as well as the impacts of multiple factors on pressure drop behavior along the pipeline were studied. Based on the model, an economic model was established to optimize the CO 2 pipeline transport system economically and to evaluate the unit transport cost of CO 2 pipeline in China. The hydrodynamic model results show that pipe diameter, soil temperature, and pipeline elevation change have significant influence on the pressure drop behavior of CO 2 in the pipeline. The design of pipeline system, including pipeline diameter and number of boosters etc., was optimized to achieve a lowest unit CO 2 transport cost. In regarding to the unit cost, when the transport flow rate and distance are between 1–5 MtCO 2 /year and 100–500 km, respectively, the unit CO 2 transport cost mainly lies between 0.1–0.6 RMB/(tCO 2 km) and electricity consumption cost of the pipeline inlet compressor was found to take more than 60% of the total cost. The present work provides reference for CO 2 transport pipeline design and for feasibility evaluation of potential CCS projects in China.

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

    Science.gov (United States)

    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).

  3. A high-flow nasal cannula system with relatively low flow effectively washes out CO2 from the anatomical dead space in a sophisticated respiratory model made by a 3D printer.

    Science.gov (United States)

    Onodera, Yu; Akimoto, Ryo; Suzuki, Hiroto; Okada, Masayuki; Nakane, Masaki; Kawamae, Kaneyuki

    2018-03-15

    Although clinical studies of the high-flow nasal cannula (HFNC) and its effect on positive end-expiratory pressure (PEEP) have been done, the washout effect has not been well evaluated. Therefore, we made an experimental respiratory model to evaluate the respiratory physiological effect of HFNC. An airway model was made by a 3D printer using the craniocervical 3D-CT data of a healthy 32-year-old male. CO 2 was infused into four respiratory lung models (normal-lung, open- and closed-mouth models; restrictive- and obstructive-lung, open-mouth models) to maintain the partial pressure of end-tidal CO 2 (P ET CO 2 ) at 40 mmHg. HFNC flow was changed from 10 to 60 L/min. Capnograms were recorded at the upper pharynx, oral cavity, subglottic, and inlet sites of each lung model. With the normal-lung, open-mouth model, 10 L/min of HFNC flow decreased the subglottic P ET CO 2 to 30 mmHg. Increasing the HFNC flow did not further decrease the subglottic P ET CO 2 . With the normal-lung, closed-mouth model, HFNC flow of 40 L/min was required to decrease the P ET CO 2 at all sites. Subglottic P ET CO 2 reached 30 mmHg with an HFNC flow of 60 L/min. In the obstructive-lung, open-mouth model, P ET CO 2 at all sites had the same trend as in the normal-lung, open-mouth model. In the restrictive-lung, open-mouth model, 20 L/min of HFNC flow decreased the subglottic P ET CO 2 to 25 mmHg, and it did not decrease further. As HFNC flow was increased, PEEP up to 7 cmH 2 O was gradually generated in the open-mouth models and up to 17 cmH 2 O in the normal-lung, closed-mouth model. The washout effect of the HFNC was effective with relatively low flow in the open-mouth models. The closed-mouth model needed more flow to generate a washout effect. Therefore, HFNC flow should be considered based on the need for the washout effect or PEEP.

  4. 3rd Sino-German Conference “Underground Storage of CO2 and Energy”

    CERN Document Server

    Xie, Heping; Were, Patrick

    2013-01-01

    Anthropogenic greenhouse gas emissions, energy security and sustainability are three of the greatest contemporary global challenges today. This year the Sino-German Cooperation Group “Underground Storage of CO2 and Energy”, is meeting on the 21-23 May 2013 for the second time in Goslar, Germany, to convene its 3rd Sino-German conference on the theme “Clean Energy Systems in the Subsurface: Production, Storage and Conversion”.   This volume is a collection of diverse quality scientific works from different perspectives elucidating on the current developments in CO2 geologic sequestration research to reduce greenhouse emissions including measures to monitor surface leakage, groundwater quality and the integrity of caprock, while ensuring a sufficient supply of clean energy. The contributions herein have been structured into 6 major thematic research themes: Integrated Energy and Environmental Utilization of Geo-reservoirs: Law, Risk Management & Monitoring CO2 for Enhanced Gas and Oil Recovery, Coa...

  5. Endogenous CO2 may inhibit bacterial growth and induce virulence gene expression in enteropathogenic Escherichia coli.

    Science.gov (United States)

    Martínez, Haydee; Buhse, Thomas; Rivera, Marco; Parmananda, P; Ayala, Guadalupe; Sánchez, Joaquín

    2012-07-01

    Analysis of the growth kinetics of enteropathogenic Escherichia coli (EPEC) revealed that growth was directly proportional to the ratio between the exposed surface a