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Sample records for acid carbon dioxide

  1. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

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

    2000-01-01

    The Albany Research Center (ARC) of the U.S. Dept. of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. Other participants in this Program include the Los Alamos National Laboratory, Arizona State University, Science Applications International Corporation, and the DOE National Energy Technology Laboratory. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. This slurry is reacted with supercritical carbon dioxide (CO2) to produce magnesite (MgCO3). The CO2 is dissolved in water to form carbonic acid (H2CO3), which dissociates to H+ and HCO3 -. The H+ reacts with the mineral, liberating Mg2+ cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO2 pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185?C and a partial pressure of CO2 (PCO2) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction

  2. Carbon dioxide sequestration by direct mineral carbonation with carbonic acid

    SciTech Connect

    O'Connor, W.K.; Dahlin, D.C.; Nilsen, D.N.; Walters, R.P.; Turner, P.C.

    2000-07-01

    The Albany Research Center (ARC) of the US Department of Energy (DOE) has been conducting a series of mineral carbonation tests at its Albany, Oregon, facility over the past 2 years as part of a Mineral Carbonation Study Program within the DOE. The ARC tests have focused on ex-situ mineral carbonation in an aqueous system. The process developed at ARC utilizes a slurry of water mixed with a magnesium silicate mineral, olivine [forsterite and member (mg{sub 2}SiO{sub 4})], or serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}]. This slurry is reacted with supercritical carbon dioxide (CO{sub 2}) to produce magnesite (MgCO{sub 3}). The CO{sub 2} is dissolved in water to form carbonic acid (H{sub 2}CO{sub 3}), which dissociates to H{sup +} and HCO{sub 3}{sup {minus}}. The H{sup +} reacts with the mineral, liberating Mg{sup 2+} cations which react with the bicarbonate to form the solid carbonate. The process is designed to simulate the natural serpentinization reaction of ultramafic minerals, and for this reason, these results may also be applicable to in-situ geological sequestration regimes. Results of the baseline tests, conducted on ground products of the natural minerals, have been encouraging. Tests conducted at ambient temperature (22 C) and subcritical CO{sub 2} pressures (below 73 atm) resulted in very slow conversion to the carbonate. However, when elevated temperatures and pressures are utilized, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant reaction occurs within much shorter reaction times. Extent of reaction, as measured by the stoichiometric conversion of the silicate mineral (olivine) to the carbonate, is roughly 90% within 24 hours, using distilled water, and a reaction temperature of 185 C and a partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 115 atm. Recent tests using a bicarbonate solution, under identical reaction conditions, have achieved roughly 83% conversion of heat treated serpentine

  3. Hydrogen Storage in the Carbon Dioxide - Formic Acid Cycle.

    PubMed

    Fink, Cornel; Montandon-Clerc, Mickael; Laurenczy, Gabor

    2015-01-01

    This year Mankind will release about 39 Gt carbon dioxide into the earth's atmosphere, where it acts as a greenhouse gas. The chemical transformation of carbon dioxide into useful products becomes increasingly important, as the CO(2) concentration in the atmosphere has reached 400 ppm. One approach to contribute to the decrease of this hazardous emission is to recycle CO(2), for example reducing it to formic acid. The hydrogenation of CO(2) can be achieved with a series of catalysts under basic and acidic conditions, in wide variety of solvents. To realize a hydrogen-based charge-discharge device ('hydrogen battery'), one also needs efficient catalysts for the reverse reaction, the dehydrogenation of formic acid. Despite of the fact that the overwhelming majority of these reactions are carried out using precious metals-based catalysts (mainly Ru), we review here developments for catalytic hydrogen evolution from formic acid with iron-based complexes. PMID:26842324

  4. The Strongest Acid: Protonation of Carbon Dioxide.

    PubMed

    Cummings, Steven; Hratchian, Hrant P; Reed, Christopher A

    2016-01-22

    The strongest carborane acid, H(CHB11F11), protonates CO2 while traditional mixed Lewis/Brønsted superacids do not. The product is deduced from IR spectroscopy and calculation to be the proton disolvate, H(CO2)2(+). The carborane acid H(CHB11F11) is therefore the strongest known acid. The failure of traditional mixed superacids to protonate weak bases such as CO2 can be traced to a competition between the proton and the Lewis acid for the added base. The high protic acidity promised by large absolute values of the Hammett acidity function (H0) is not realized in practice because the basicity of an added base is suppressed by Lewis acid/base adduct formation. PMID:26663640

  5. Tuning the Carbon Dioxide Absorption in Amino Acid Ionic Liquids.

    PubMed

    Firaha, Dzmitry S; Kirchner, Barbara

    2016-07-01

    One of the possible solutions to prevent global climate change is the reduction of CO2 emissions, which is highly desired for the sustainable development of our society. In this work, the chemical absorption of carbon dioxide in amino acid ionic liquids was studied through first-principles methods. The use of readily accessible and biodegradable amino acids as building blocks for ionic liquids makes them highly promising replacements for the widely applied hazardous aqueous solutions of amines. A detailed insight into the reaction mechanism of the CO2 absorption was obtained through state-of-the-art theoretical methods. This allowed us to determine the reason for the specific CO2 capacities found experimentally. Moreover, we have also conducted a theoretical design of ionic liquids to provide valuable insights into the precise tuning of the energetic and kinetic parameters of the CO2 absorption. PMID:27214652

  6. A Simple Demonstration of Carbon Dioxide Fixation and Acid Production in CAM Plants

    ERIC Educational Resources Information Center

    Walker, John R. L.; McWha, James A.

    1976-01-01

    Described is an experiment investigating carbon dioxide fixation in the dark and the diurnal rhythm of acid production in plants exhibiting Crassulacean Acid Metabolism. Included are suggestions for four further investigations. (SL)

  7. Carbonic Acid as a Reserve of Carbon Dioxide on Icy Moons: The Formation of Carbon Dioxide (CO2) in a Polar Environment

    NASA Astrophysics Data System (ADS)

    Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni

    2014-06-01

    Carbon dioxide (CO2) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H2O)-carbon dioxide (CO2) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν3 band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

  8. Direct synthesis of formic acid from carbon dioxide by hydrogenation in acidic media

    PubMed Central

    Moret, Séverine; Dyson, Paul J.; Laurenczy, Gábor

    2014-01-01

    The chemical transformation of carbon dioxide into useful products becomes increasingly important as CO2 levels in the atmosphere continue to rise as a consequence of human activities. In this article we describe the direct hydrogenation of CO2 into formic acid using a homogeneous ruthenium catalyst, in aqueous solution and in dimethyl sulphoxide (DMSO), without any additives. In water, at 40 °C, 0.2 M formic acid can be obtained under 200 bar, however, in DMSO the same catalyst affords 1.9 M formic acid. In both solvents the catalysts can be reused multiple times without a decrease in activity. Worldwide demand for formic acid continues to grow, especially in the context of a renewable energy hydrogen carrier, and its production from CO2 without base, via the direct catalytic carbon dioxide hydrogenation, is considerably more sustainable than the existing routes. PMID:24886955

  9. Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO{sub 2}) in a polar environment

    SciTech Connect

    Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni

    2014-06-20

    Carbon dioxide (CO{sub 2}) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν{sub 3} band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO{sub 2} band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H{sub 2}O)-carbon dioxide (CO{sub 2}) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν{sub 3} band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

  10. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson

    2012-05-15

    A system is described for forming metal hydroxide from a metal carbonate utilizing a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate, in particular water-insoluble calcium carbonate or magnesium carbonate, is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide. Among other uses, the metal hydroxide formed can be employed to absorb acid gases such as carbon dioxide from a gas mixture. The invention can also generate hydrogen and oxidative gases such as oxygen or chlorine.

  11. Carbon dioxide generated from carbonates and acids for sampling blood-feeding arthropods.

    PubMed

    Burkett-Cadena, Nathan D; Blosser, Erik M; Young, Ryan M; Toé, Laurent D; Unnasch, Thomas R

    2015-09-01

    Carbon dioxide (CO2) is utilized to attract mosquitoes and other blood-feeding arthropods to traps around the world. Commercial forms of CO2 (e.g., dry ice and compressed gas) are often unavailable or extremely expensive in developing nations, where vector surveillance is essential to make life-saving decisions. We developed and tested inexpensive and reproducible methods of CO2 production from the combination of acids and carbonates, ranging from very basic (crushed seashells and vinegar) to relatively elaborate (a device that controls the timing of the acid-carbonate reaction and extends the reaction over several hours). When utilized with mosquito traps in Florida, USA and black fly traps in Region des Cascades, Burkina Faso, these carbonate-acid CO2 sources attracted significantly greater numbers of both vector groups, than did unbaited traps. CO2 was generated for more than four hours at levels sufficient to attract vectors over the entire period. The utility of this simple methodology in developing nations should be further evaluated. PMID:26103427

  12. Polymerization of euphorbia oil with Lewis acid in carbon dioxide media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boron trifluoride diethyl etherate (BF3-OEt2) Lewis acid catalyzed ring-opening polymerization of euphorbia oil (EO), a natural epoxy oil, in liquid carbon dioxide was conducted in an effort to develop useful vegetable oil based polymers. The resulting polymers (RPEO) were characterized by FTIR, 1H-...

  13. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson

    2014-07-01

    A system for forming metal hydroxide from a metal carbonate utilizes a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide.

  14. Distribution of Hydrogen Peroxide, Carbon Dioxide, and Sulfuric Acid in Europa's Icy Crust

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    2004-01-01

    Galileo's Near Infrared Mapping Spectrometer (NIMS) detected hydrogen peroxide, carbon dioxide and a hydrated material on Europa's surface, the latter interpreted as hydrated sulfuric acid (H2SO4*nH2O) or hydrated salts. Related compounds are molecular oxygen, sulfur dioxide, and two chromophores, one that is dark in the ultraviolet(UV) and concentrated on the trailing side, the other brighter in the UV and preferentially distributed in the leading hemisphere. The UV-dark material has been suggested to be sulfur.

  15. Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System

    PubMed Central

    Fujioka, Kouki; Futamura, Yasuhiro; Shiohara, Tomoo; Hoshino, Akiyoshi; Kanaya, Fumihide; Manome, Yoshinobu; Yamamoto, Kenji

    2009-01-01

    Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research, several amino acids were detected with an amino acid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin. PMID:19582225

  16. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    SciTech Connect

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; McEwen, Jason; French, Todd

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0 MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.

  17. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    DOE PAGESBeta

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; McEwen, Jason; French, Todd

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0more » MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.« less

  18. Pantethine inhibits cholesterol and fatty acid syntheses and stimulates carbon dioxide formation in isolated rat hepatocytes.

    PubMed

    Cighetti, G; Del Puppo, M; Paroni, R; Fiorica, E; Galli Kienle, M

    1987-02-01

    The effects of pantethine on cholesterol and fatty acid metabolism were investigated in isolated rat hepatocytes. Preincubation of the cells with pantethine induced a concentration-dependent decrease of the radioactivity incorporated into carbon dioxide and lipids in incubations with [2-14C]acetate. When pantethine and the labeled substrate were simultaneously added to the cell suspension, there was an enhancement of carbon dioxide radioactivity at short incubation time (5 min) whereas, at longer incubation time, values were comparable to those of controls; lipid radioactivity, instead, was dramatically reduced by pantethine even at short incubation time and decreased further during the incubation, being 23% of that of controls at 60 min. Analysis of the incubation medium showed that pantethine induced a concentration- and time-dependent release of acetate into the medium. Results of the effect of the acetate concentration on the incorporation of [2-14C]acetate radioactivity into CO2 and lipids in control hepatocytes allowed the conclusion that the above-described modifications induced by pantethine are only partially attributable to the dilution of the labeled substrate, and that catabolism of acetate to carbon dioxide is stimulated by the disulphide pantethine, whereas cholesterol and fatty acid syntheses are inhibited. PMID:3106549

  19. Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide

    PubMed Central

    Hinou, Hiroshi; Saito, Naohiro; Ogawa, Masato; Maeda, Takahiko; Nishimura, Shin-Ichiro

    2009-01-01

    The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule. PMID:20054471

  20. Conversion of carbon dioxide to resorcylic acid under ultrasonication by Kolbe-Schmitt reaction.

    PubMed

    Shanthi, B; Palanivelu, K

    2015-11-01

    The present work focuses on a new approach for the synthesis of β-resorcylic acid based on Kolbe-Schmitt reaction using carbon dioxide under ultrasonic and mild condition. The Kolbe-Schmitt reaction is a process for the synthesis of β-resorcylic acid (2,4-dihydroxybenzoic acid) from resorcinol in aqueous potassium hydroxide solution with gaseous CO2. The influences of carbonation time, flow rate of CO2 and the molar ratio of resorcinol/potassium hydroxide on the yield percentage of resorcylic acid were investigated. The study was assessed with the conventional thermal method (non ultrasonic method) for Kolbe-Schmitt reaction and it was observed that applying ultrasound to save more than 95% and 38.6% energy as shown by energy consumption calculations in bath type and horn type sonicator respectively. β-Resorcylic acid formed was characterized by (1)H NMR, (13)C NMR, DEPT NMR and FTIR spectroscopy. The amount of CO2 utilized in the reaction was evaluated from the yield percentage of β-resorcylic acid yield. The maximum yield of resorcylic acid of 30% and 65% was obtained at the resorcinol/potassium hydroxide ratio of 1:3, carbonation time of 150 min and the CO2 flow rate of 2L/min in bath type and horn type ultrasonicator, respectively. The applicability of the research work was examined in two different positional isomers of resorcinol under optimum conditions. PMID:26186845

  1. Process for sequestering carbon dioxide and sulfur dioxide

    DOEpatents

    Maroto-Valer, M. Mercedes; Zhang, Yinzhi; Kuchta, Matthew E.; Andresen, John M.; Fauth, Dan J.

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  2. Chemical and biological consequences of using carbon dioxide versus acid additions in ocean acidification experiments

    USGS Publications Warehouse

    Yates, Kimberly K.; DuFore, Christopher M.; Robbins, Lisa L.

    2013-01-01

    Use of different approaches for manipulating seawater chemistry during ocean acidification experiments has confounded comparison of results from various experimental studies. Some of these discrepancies have been attributed to whether addition of acid (such as hydrochloric acid, HCl) or carbon dioxide (CO2) gas has been used to adjust carbonate system parameters. Experimental simulations of carbonate system parameter scenarios for the years 1766, 2007, and 2100 were performed using the carbonate speciation program CO2SYS to demonstrate the variation in seawater chemistry that can result from use of these approaches. Results showed that carbonate system parameters were 3 percent and 8 percent lower than target values in closed-system acid additions, and 1 percent and 5 percent higher in closed-system CO2 additions for the 2007 and 2100 simulations, respectively. Open-system simulations showed that carbonate system parameters can deviate by up to 52 percent to 70 percent from target values in both acid addition and CO2 addition experiments. Results from simulations for the year 2100 were applied to empirically derived equations that relate biogenic calcification to carbonate system parameters for calcifying marine organisms including coccolithophores, corals, and foraminifera. Calculated calcification rates for coccolithophores, corals, and foraminifera differed from rates at target conditions by 0.5 percent to 2.5 percent in closed-system CO2 gas additions, from 0.8 percent to 15 percent in the closed-system acid additions, from 4.8 percent to 94 percent in open-system acid additions, and from 7 percent to 142 percent in open-system CO2 additions.

  3. Carbon dioxide concentrator

    NASA Technical Reports Server (NTRS)

    Williams, C. F.; Huebscher, R. G.

    1972-01-01

    Passed exhaled air through electrochemical cell containing alkali metal carbonate aqueous solution, and utilizes platinized electrodes causing reaction of oxygen at cathode with water in electrolyte, producing hydroxyl ions which react with carbon dioxide to form carbonate ions.

  4. Carbon dioxide and organic acids: origin and role in burial diagenesis (Texas Gulf Coast Tertiary)

    SciTech Connect

    Lundegard, P.D.

    1985-01-01

    Carbon dioxide produced by decarboxylation of organic matter is not a dominant factor in secondary porosity development. Material balance calculations indicate the amount of feldspar and carbonate dissolution that has taken place in Tertiary sandstones of the Texas Gulf Coast far exceeds that which is explainable by decarboxylation. Other potential sources of acid for dissolution reactions include reverse weathering reactions in shales, an hydrous pyrolysis reactions between organic carbon and oxygen in H/sub 2/O to yield CO/sub 2/ or organic acids. Considerations of CO/sub 2/ solubility and the temperature distribution of organic acids imply that these species must be generated locally to cause significant dissolution. The CO/sub 2/ content of gas from Gulf Coast Tertiary sandstones is proportional to reservoir age, and increases with depth and temperature at a rate that is approximately exponential. In the Wilcox Formation the increase in CO/sub 2/ content continues beyond depths where dissolved organic acids are abundant and where kerogen has lost its oxygen from functional groups that are readily liberated as CO/sub 2/. In this formation the /sup 13/C of CO/sub 2/ and CH/sub 4/ are proportional to temperature and to each other. Either mixing with fluids derived from the Mesozoic carbonate section of deep CO/sub 2/ generation by kinetically controlled organic reactions may explain these data. Organic acid concentration with depth and temperature indicates a non-biological origin by thermal cracking of kerogen during burial. Continued burial leads to their thermal decomposition. Cessation of burial may lead to meteoric water invasion and organic acid destruction by biological processes. The effect of time on organic acid production is minor compared to temperature.

  5. Ancient low–molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw

    PubMed Central

    Drake, Travis W.; Wickland, Kimberly P.; Spencer, Robert G. M.; McKnight, Diane M.; Striegl, Robert G.

    2015-01-01

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high–temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low–molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters. PMID:26504243

  6. Ancient low-molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw.

    PubMed

    Drake, Travis W; Wickland, Kimberly P; Spencer, Robert G M; McKnight, Diane M; Striegl, Robert G

    2015-11-10

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high-temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low-molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters. PMID:26504243

  7. The carbon dioxide cycle

    USGS Publications Warehouse

    James, P.B.; Hansen, G.B.; Titus, T.N.

    2005-01-01

    The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor. ?? 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  8. Artificial photosynthesis of. beta. -ketocarboxylic acids from carbon dioxide and ketones via enolate complexes of aluminum porphyrin

    SciTech Connect

    Hirai, Yasuhiro; Aida, Takuzo; Inoue, Shohei )

    1989-04-12

    Photochemical fixation of carbon dioxide is of much interest in connection with biological photosynthesis by green plants as well as from the viewpoint of carbon resource utilization. One of the important steps in the assimilation of carbon dioxide is the carboxylation of a carbonyl compound into ketocarboxylic acid, where the reaction proceeds via an enolate species as reactive intermediate. For example, in four carbon (C{sub 4}) pathway and Crassulacean acid metabolism (CAM) processes, pyruvate is converted with the aid of ATP into phosphoenolpyruvate, which is subsequently carboxylated to give oxaloacetate by the action of pyruvate carboxylase. In relation to this interesting biological process, some artificial systems have been exploited for the synthesis of {beta}-ketocarboxylic acid derivatives from carbon dioxide and ketones using nucleophiles such as metal carbonates, thiazolates, phenolates, alkoxides, and strong organic as well as inorganic basis, which promote the enolization of ketones in the intermediate step. We wish to report here a novel, visible light-induced fixation of carbon dioxide with the enolate complex of aluminum porphyrin, giving {beta}-ketocarboxylic acid under mild conditions.

  9. Isolation of anacardic acid from natural cashew nut shell liquid (CNSL) using supercritical carbon dioxide.

    PubMed

    Philip, Joseph Y N; Da Cruz Francisco, José; Dey, Estera S; Buchweishaija, Joseph; Mkayula, Lupituko L; Ye, Lei

    2008-10-22

    Solvent extracted cashew nut shell liquid (CNSL), conventionally known as natural CNSL, is a mixture of several alkenyl phenols. One of these alkenyl phenols is anacardic acid, which is present at the highest concentration. In view of anticipated industrial applications of anacardic acid, the objective of this work was to isolate anacardic acid from natural CNSL by supercritical carbon dioxide (scCO 2). In this study, the solubility data for natural CNSL in scCO 2 under a range of operating conditions of pressure (100, 200, and 300 bar), temperature (40 and 50 degrees C), and CO 2 flow rate (5, 10, and 15 g min (-1)) were established. The best scCO 2 working conditions were found to be 50 degrees C and 300 bar at a flow rate of 5 g min (-1) CO 2. Using 3 g of sample (CNSL/solid adsorbent = 1/2) under these scCO 2 conditions, it was possible to quantitatively isolate high purity anacardic acid from crude natural CNSL (82% of total anacardic acid) within 150 min. The anacardic acid isolated by scCO 2 was analyzed by different spectroscopic techniques (UV-vis, FT-IR, and (1)H NMR) and HPLC analysis, indicating that the anacardic acid isolated by scCO 2 has better quality than that obtained through a conventional method involving several chemical conversion steps. PMID:18811166

  10. Extreme carbon dioxide concentrations in acidic pit lakes provoked by water/rock interaction.

    PubMed

    Sánchez-España, Javier; Boehrer, Bertram; Yusta, Iñaki

    2014-04-15

    We quantify the gas pressure and concentration of a gas-charged acidic pit lake in SW Spain. We measured total dissolved gas pressure, carbon dioxide (CO2) concentration, major ion concentration, isotopic composition of dissolved inorganic carbon (δ(13)C(DIC)), and other physicochemical parameters. CO2 is the dominant dissolved gas in this lake and results mainly from carbonate dissolution during the interaction of acidic water with wall rocks, followed by diffusive and advective transport through the water column. The δ(13)C(DIC) values suggest that the biological contribution is comparatively small. Maximum CO2 concentrations higher than 0.1 M (∼5000 mg/L) have been measured, which are only comparable to those found in volcanic crater lakes. The corresponding gas pressures of CO2 alone (pCO2 ∼3.6 bar) imply 60% saturation relative to local pressure at 50 m depth. High CO2 concentrations have been observed in other pit lakes of the region. We recommend gas-specific monitoring in acidic pit lakes and, if necessary, the design of feasible degassing strategies. PMID:24628479

  11. Carbon Dioxide and Climate.

    ERIC Educational Resources Information Center

    Brewer, Peter G.

    1978-01-01

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

  12. Carbon Dioxide Fountain

    ERIC Educational Resources Information Center

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

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

  13. Lewis acid catalyzed ring-opening polymerization of natural epoxy oil (Euphorbia oil) in carbon dioxide media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an attempt to build up useful application of plant oil based polymers, natural epoxy oil (euphorbia oil-EuO) was polymerized in liquid carbon dioxide in the presence of Lewis acid catalyst [Boron trifluoride diethyl etherate (BF3•OEt2)]. The resulting polymers (RPEuO) were characterized by FTIR ...

  14. Field assessment of yeast- and oxalic Acid-generated carbon dioxide for mosquito surveillance.

    PubMed

    Harwood, James F; Richardson, Alec G; Wright, Jennifer A; Obenauer, Peter J

    2014-12-01

    Carbon dioxide (CO2) sources improve the efficacy of mosquito traps. However, traditional CO2 sources (dry ice or compressed gas) may be difficult to acquire for vector surveillance during military contingency operations. For this reason, a new and convenient source of CO2 is required. Two novel CO2 generators were evaluated in order to address this capability gap: 1) an electrolyzer that converts solid oxalic acid into CO2 gas, and 2) CO2 produced by yeast as it metabolizes sugar. The flow rate and CO2 concentration produced by each generator were measured, and each generator's ability to attract mosquitoes to BG-Sentinel™ traps during day surveillance and to Centers for Disease Control and Prevention light traps with incandescent bulbs during night surveillance was compared to dry ice and compressed gas in Jacksonville, FL. The electrolyzed oxalic acid only slightly increased the number of mosquitoes captured compared to unbaited traps. Based on the modest increase in mosquito collection for traps paired with the oxalic acid, it is not a suitable stand-in for either of the 2 traditional CO2 sources. Conversely, the yeast-generated CO2 resulted in collections with mosquito abundance and species richness more closely resembling those of the traditional CO2 sources, despite achieving a lower CO2 flow rate. Therefore, if dry ice or compressed gas cannot be acquired for vector surveillance, yeast-generated CO2 can significantly improve trap capability. PMID:25843133

  15. Visible light caffeic acid degradation by carbon-doped titanium dioxide.

    PubMed

    Venditti, Francesco; Cuomo, Francesca; Ceglie, Andrea; Avino, Pasquale; Russo, Mario Vincenzo; Lopez, Francesco

    2015-03-31

    The removal of the phenolic compound, caffeic acid, by photodegradation has been investigated using carbon-doped titanium dioxide particles as a photocatalyst under visible light. UV-vis absorption spectroscopy and gas chromatography-ion trap mass spectrometry analyses revealed a substrate concentration dependence of the removal of caffeic acid from a water solution. The k2 and t(0.5) parameters of each reaction were calculated by fitting kinetics data to a second-order kinetic adsorption model. To evaluate the photodegradation event, the effect of the adsorption process on the whole degradation was also monitored in the absence of light. Adsorption isotherm studies supported by ζ potential and scanning electron microscopy data demonstrated the pivotal role of the absorption mechanism. It was found that the whole photodegradation process is governed by a synergic mechanism in which adsorption and photodegradation are involved. This study, centered on the removal of caffeic acid from aqueous solutions, highlights the potential application of this technology for the elimination of phenolic compounds from olive mill wastewater, a fundamental goal in both the agronomical and environmental fields. PMID:25763603

  16. Carbon dioxide removal process

    DOEpatents

    Baker, Richard W.; Da Costa, Andre R.; Lokhandwala, Kaaeid A.

    2003-11-18

    A process and apparatus for separating carbon dioxide from gas, especially natural gas, that also contains C.sub.3+ hydrocarbons. The invention uses two or three membrane separation steps, optionally in conjunction with cooling/condensation under pressure, to yield a lighter, sweeter product natural gas stream, and/or a carbon dioxide stream of reinjection quality and/or a natural gas liquids (NGL) stream.

  17. Environmental carbon dioxide control

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B.; Gidaspow, D.

    1974-01-01

    A study of environmental carbon dioxide control for NASA EVA missions found solid potassium carbonate to be an effective regenerable absorbent in maintaining low carbon dioxide levels. The supported sorbent was capable of repeated regeneration below 150 C without appreciable degradation. Optimum structures in the form of thin pliable sheets of carbonate, inert support and binder were developed. Interpretation of a new solid-gas pore closing model helped predict the optimum sorbent and analysis of individual sorbent sheet performance in a thin rectangular channel sorber can predict packed bed performance.

  18. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K.; Lee, Inhee; Akbar, Sheikh A.

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  19. Lewis Acid Catalyzed Ring-opening Polymerization of Epoxidized Soybean Oil in Liquid Carbon Dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ring-opening polymerization of epoxidized soybean oil (ESO) catalyzed by boron trifluoride diethyl etherate (BF3•OEt2), in liquid carbon dioxide, was conducted in an effort to develop useful biobased biodegradable polymers. The resulting polymers (RPESO) were characterized by FTIR spectroscopy, diff...

  20. Carbon dioxide recycling

    EPA Science Inventory

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

  1. Grafting of poly (lactic acid) with maleic anhydride using supercritical carbon dioxide

    NASA Astrophysics Data System (ADS)

    Khankrua, R.; Pivsa-Art, S.; Hiroyuki, H.; Suttiruengwong, S.

    2015-07-01

    The aim of this work was to modify poly lactic acid (PLA) via free radical grafting with maleic anhydride (MA) by using supercritical carbon dioxide (SCCO2). Benzoyl peroxide (BPO) was used as an initiator. The solubility of MA in SCCO2 was first determined to estimate the suitable grafting conditions and equilibrium. From the solubility study of MA in SCCO2, it was found that the solubility of MA in SCCO2 increased with the increasing pressure and dissolution time. PLA films were first prepared by compression molding. The ratio of MA to BPO was 2:1. The reaction temperature and pressure were 70°C and 100 bar respectively. The grafting reaction and the degree of grafting were characterized by nuclear magnetic resonance (NMR) spectroscopy and titration, respectively. Scanning electron microscope (SEM) technique and contact angle were used to confirm the changes in physical properties of PLA film grafted MA. NMR spectrum indicated that the grafting of MA onto PLA was successively achieved. Degree of grafting by using SCCO2 was as high as 0.98%. This provided rather high grafting degree compared with other processes. SEM pictures showed the rough surface structure on modified PLA film. In addition, contact angle results showed an improvement of the hydrophilicity by maleic anhydride grafting onto polymers.

  2. Polymeric Carbon Dioxide

    SciTech Connect

    Yoo, C-S.

    1999-11-02

    Synthesis of polymeric carbon dioxide has long been of interest to many chemists and materials scientists. Very recently we discovered the polymeric phase of carbon dioxide (called CO{sub 2}-V) at high pressures and temperatures. Our optical and x-ray results indicate that CO{sub 2}-V is optically non-linear, generating the second harmonic of Nd: YLF laser at 527 nm and is also likely superhard similar to cubic-boron nitride or diamond. CO{sub 2}-V is made of CO{sub 4} tetrahedra, analogous to SiO{sub 2} polymorphs, and is quenchable at ambient temperature at pressures above 1 GPa. In this paper, we describe the pressure-induced polymerization of carbon dioxide together with the stability, structure, and mechanical and optical properties of polymeric CO{sub 2}-V. We also present some implications of polymeric CO{sub 2} for high-pressure chemistry and new materials synthesis.

  3. An experimental investigation of Lewis acid-base interactions of liquid carbon dioxide using Fourier Transform Infrared (FT-IR) spectroscopy

    NASA Astrophysics Data System (ADS)

    Reilly, J. T.; Bokis, C. P.; Donohue, M. D.

    1995-05-01

    Presented here is an investigation into the solvent properties of liquid carbon dioxide by means of FT-IR spectroscopy. A high-pressure, circulation-type apparatus was designed and built specifically for this study. The spectra for the combination bands for carbon dioxide show that there are interactions between methanol and carbon dioxide. However, the spectra of the fundamental O-D vibration of deuterated methanol in liquid carbon dioxide indicate that there is no hydrogen bonding. Therefore. we conclude that the interactions between carbon dioxide and methanol are Lewis acid-base interactions rather than hydrogen bonding. This conclusion is supported by experiments where acetone is introduced into the CO2/methanol- d binary system. FT-IR measurements show that acetone hydrogen bonds with deuterated methanol.

  4. Carbon Dioxide Laser Guidelines

    PubMed Central

    Krupa Shankar, DS; Chakravarthi, M; Shilpakar, Rachana

    2009-01-01

    The carbon dioxide (CO2) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO2 laser and offers guidelines for use in many of the above indications. PMID:20808594

  5. Carbon dioxide laser guidelines.

    PubMed

    Krupa Shankar, Ds; Chakravarthi, M; Shilpakar, Rachana

    2009-07-01

    The carbon dioxide (CO(2)) laser is a versatile tool that has applications in ablative lasing and caters to the needs of routine dermatological practice as well as the aesthetic, cosmetic and rejuvenation segments. This article details the basics of the laser physics as applicable to the CO(2) laser and offers guidelines for use in many of the above indications. PMID:20808594

  6. Bench Remarks: Carbon Dioxide.

    ERIC Educational Resources Information Center

    Bent, Henry A.

    1987-01-01

    Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

  7. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1993-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  8. Organic syntheses employing supercritical carbon dioxide as a reaction solvent

    NASA Technical Reports Server (NTRS)

    Barstow, Leon E. (Inventor); Ward, Glen D. (Inventor); Bier, Milan (Inventor)

    1991-01-01

    Chemical reactions are readily carried out using supercritical carbon dioxide as the reaction medium. Supercritical carbon dioxide is of special value as a reaction medium in reactions for synthesizing polypeptides, for sequencing polypeptides, or for amino acid analysis.

  9. Carbon dioxide dangers demonstration model

    USGS Publications Warehouse

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  10. Carbon dioxide adsorbent study

    NASA Technical Reports Server (NTRS)

    Onischak, M.; Baker, B. S.

    1973-01-01

    A study was initiated on the feasibility of using the alkali metal carbonate - bi-carbonate solid-gas reaction to remove carbon dioxide from the atmosphere of an EVA life support system. The program successfully demonstrates that carbon dioxide concentrations could be maintained below 0.1 mole per cent using this chemistry. Further a practical method for distributing the carbonates in a coherent sheet form capable of repeated regeneration (50 cycles) at modest temperatures (423 K), without loss in activity was also demonstrated. Sufficiently high reaction rates were shown to be possible with the carbonate - bi-carbonate system such that EVA hardware could be readily designed. Experimental and design data were presented on the basis of which two practical units were designed. In addition to conventional thermally regenerative systems very compact units using ambient temperature cyclic vacuum regeneration may also be feasible. For a one man - 8 hour EVA unit regenerated thermally at the base ship a system volume of 14 liters is estimated.

  11. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2005-01-01

    23 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of some of the widely-varied terrain of the martian south polar residual cap. The landforms here are composed mainly of frozen carbon dioxide. Each year since MGS arrived in 1997, the scarps that bound each butte and mesa, or line the edges of each pit, in the south polar region, have changed a little bit as carbon dioxide is sublimed away. The scarps retreat at a rate of about 3 meters (3 yards) per martian year. Most of the change occurs during each southern summer.

    Location near: 86.7oS, 9.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  12. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

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

  13. CARBON DIOXIDE AS A FEEDSTOCK.

    SciTech Connect

    CREUTZ,C.; FUJITA,E.

    2000-12-09

    This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO{sub 2} levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.

  14. Frozen Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    2005-01-01

    1 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a south polar residual cap landscape, formed in frozen carbon dioxide. There is no place on Earth that one can go to visit a landscape covering thousands of square kilometers with frozen carbon dioxide, so mesas, pits, and other landforms of the martian south polar region are as alien as they are beautiful. The scarps of the south polar region are known from thousands of other MGS MOC images to retreat at a rate of about 3 meters (3 yards) per martian year, indiating that slowly, over the course of the MGS mission, the amount of carbon dioxide in the martian atmosphere has probably been increasing.

    Location near: 86.9oS, 25.5oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  15. Carbon Dioxide Landforms

    NASA Technical Reports Server (NTRS)

    2004-01-01

    19 March 2004 The martian south polar residual ice cap is mostly made of frozen carbon dioxide. There is no place on Earth that a person can go to see the landforms that would be produced by erosion and sublimation of hundreds or thousands of cubic kilometers of carbon dioxide. Thus, the south polar cap of Mars is as alien as alien can get. This image, acquired in February 2004 by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC), shows how the cap appears in summer as carbon dioxide is subliming away, creating a wild pattern of pits, mesas, and buttes. Darker surfaces may be areas where the ice contains impurities, such as dust, or where the surface has been roughened by the removal of ice. This image is located near 86.3oS, 0.8oW. This picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the top/upper left.

  16. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  17. Extraction of rare earth oxides using supercritical carbon dioxide modified with Tri-n-butyl phosphate–nitric acid adducts

    DOE PAGESBeta

    Baek, Donna L.; Fox, Robert V.; Case, Mary E.; Sinclair, Laura K.; Schmidt, Alex B.; McIlwain, Patrick R.; Mincher, Bruce J.; Wai, Chien M.

    2016-06-14

    A new tri-n-butylphosphate–nitric acid (TBP–HNO3) adduct was prepared by combining TBP and fuming (90%) HNO3. The adduct was characterized, and its phase-equilibrium behavior in supercritical carbon dioxide is reported. Supercritical carbon dioxide (sc-CO2) was modified with this new adduct [TBP(HNO3)5.2(H2O)1.7], and the extraction efficacies of selected rare earth oxides (Y, Ce, Eu, Tb, and Dy) at 338 K and 34.5 MPa were compared with those obtained using an adduct formed from concentrated (70%) HNO3 and TBP [TBP(HNO3)1.7(H2O)0.6]. All rare earth oxides tested with both adduct species could be extracted with the exception of cerium oxide. Furthermore, the water and acidmore » concentrations in the different adducts were found to play a significant role in rare earth oxide extraction efficiency.« less

  18. Response of marine and freshwater algae to nitric acid and elevated carbon dioxide levels simulating environmental effects of bolide impact

    NASA Technical Reports Server (NTRS)

    Boston, P. J.

    1988-01-01

    One of the intriguing facets of the Cretaceous-Tertiary extinction is the apparently selective pattern of mortality amongst taxa. Some groups of organisms were severely affected and some remained relatively unscathed as they went through the K/T boundary. While there is argument concerning the exact interpretation of the fossil record, one of the best documented extinctions at the Cretaceous-Tertiary boundary is that of the calcareous nannoplankton. These organisms include coccolithic algae and foraminiferans. Attempts to explain their decline at the K/T boundary center around chemistry which could affect their calcium carbonate shells while leaving their silica-shelled cousins less affected or unaffected. Two environmental consequences of an extraterrestrial body impact which were suggested are the production of large quantities of nitrogen oxides generated by the shock heating of the atmosphere and the possible rise in CO2 from the dissolution of CaCO3 shells. Both of these phenomena would acidify the upper layers of the oceans and bodies of freshwater not otherwise buffered. The effects of nitric acid, carbon dioxide, or both factors on the growth and reproduction of calcareous marine coccoliths and non-calcareous marine and freshwater species of algae were considered. These experiments demonstrate that nitric acid and carbon dioxide have significant effects on important aspects of the physiology and reproduction of modern algae representative of extinct taxa thought to have suffered significant declines at the Cretaceous-Tertiary boundary. Furthermore, calcareous species showed more marked effects than siliceous species and marine species tested were more sensitive than freshwater species.

  19. High Acetic Acid Production Rate Obtained by Microbial Electrosynthesis from Carbon Dioxide.

    PubMed

    Jourdin, Ludovic; Grieger, Timothy; Monetti, Juliette; Flexer, Victoria; Freguia, Stefano; Lu, Yang; Chen, Jun; Romano, Mark; Wallace, Gordon G; Keller, Jurg

    2015-11-17

    High product specificity and production rate are regarded as key success parameters for large-scale applicability of a (bio)chemical reaction technology. Here, we report a significant performance enhancement in acetate formation from CO2, reaching comparable productivity levels as in industrial fermentation processes (volumetric production rate and product yield). A biocathode current density of -102 ± 1 A m(-2) and an acetic acid production rate of 685 ± 30 (g m(-2) day(-1)) have been achieved in this study. High recoveries of 94 ± 2% of the CO2 supplied as the sole carbon source and 100 ± 4% of electrons into the final product (acetic acid) were achieved after development of a mature biofilm, reaching an elevated product titer of up to 11 g L(-1). This high product specificity is remarkable for mixed microbial cultures, which would make the product downstream processing easier and the technology more attractive. This performance enhancement was enabled through the combination of a well-acclimatized and enriched microbial culture (very fast start-up after culture transfer), coupled with the use of a newly synthesized electrode material, EPD-3D. The throwing power of the electrophoretic deposition technique, a method suitable for large-scale production, was harnessed to form multiwalled carbon nanotube coatings onto reticulated vitreous carbon to generate a hierarchical porous structure. PMID:26484732

  20. Carbon dioxide/dewpoint monitor

    NASA Technical Reports Server (NTRS)

    Luczkowski, S.

    1977-01-01

    The portable Carbon Dioxide/Dewpoint Monitor was designed to permit measurements of carbon dioxide partial pressure and dewpoint and ambient gas temperature at any place within the Saturn Workshop. It required no vehicle interface other than storage. All components necessary for operation, including battery power source, were incorporated in the instrument.

  1. Coral reefs and carbon dioxide

    SciTech Connect

    Buddemeier, R.W.

    1996-03-01

    This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

  2. Carbon Dioxide Landscape

    NASA Technical Reports Server (NTRS)

    2004-01-01

    7 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of the south polar residual cap at full MOC resolution, 1.5 m (5 ft) per pixel. During each of the three summers since the start of the MGS mapping mission in March 1999, the scarps that form mesas and pits in the 'Swiss cheese'-like south polar terrain have retreated an average of about 3 meters (1 yard). The material is frozen carbon dioxide; another 3 meters or so of each scarp is expected to be removed during the next summer, in late 2005. This image is located near 86.0oS, 350.8oW, and covers an area about 1.5 km (0.9 mi) wide. Sunlight illuminates the scene from the top/upper left.

  3. Forecasting carbon dioxide emissions.

    PubMed

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. PMID:26081307

  4. Carbon dioxide: atmospheric overload

    SciTech Connect

    Not Available

    1980-04-01

    The level of carbon dioxide in the atmosphere is increasing and may double within the next century. The result of this phenomenon, climatic alterations, will adversely affect crop production, water supplies, and global temperatures. Sources of CO2 include the combustion of fossil fuels, photosynthesis, and the decay of organic matter in soils. The most serious effect of possible climatic changes could occur along the boundaries of arid and semiarid regions. Shifts is precipitation patterns could accelerate the processes of desertification. An increase of 5..cap alpha..C in the average temperature of the top 1000 m of ocean water would raise sea level by 2 m. CO2 releases to the atmosphere can be reduced by controlling emissions from fossil fuel-fired facilities and by careful harvesting of forest regions. (3 photos, 5 references)

  5. FORMATION OF CARBON DIOXIDE, METHANOL, ETHANOL, AND FORMIC ACID ON AN ICY GRAIN ANALOG USING FAST OXYGEN ATOMS

    SciTech Connect

    Madzunkov, S. M.; MacAskill, J. A.; Chutjian, A.

    2010-03-20

    Carbon dioxide (CO{sub 2}), methanol (CH{sub 3}OH), ethanol (CH{sub 3}CH{sub 2}OH), and formic acid (HCOOH) have been formed in collisions of a superthermal, 9 eV beam of O({sup 3} P) atoms with CH{sub 4} molecules, with an over coat of CO molecules, adsorbed on a gold surface at 4.8 K. The products are detected using temperature programmed-desorption and quadrupole mass spectrometry. Identification of the species is carried out through use of the Metropolis random walk algorithm as constrained by the fractionation patterns of the detected species. Relative formation yields are reported and reaction sequences are given to account for possible formation routes.

  6. Numerical simulation of the solvate structures of acetylsalicylic acid in supercritical carbon dioxide containing polar co-solvents

    NASA Astrophysics Data System (ADS)

    Petrenko, V. E.; Antipova, M. L.; Gurina, D. L.; Odintsova, E. G.; Kumeev, R. S.; Golubev, V. A.

    2016-07-01

    Hydrogen-bonded complexes of acetylsalicylic acid with polar co-solvents in supercritical carbon dioxide, modified by methanol, ethanol, and acetone of 0.03 mole fraction concentration, are studied by numerical methods of classical molecular dynamics simulation and quantum chemical calculations. The structure, energy of formation, and lifetime of hydrogen-bonded complexes are determined, along with their temperature dependences (from 318 to 388 K at constant density of 0.7 g cm-3). It is shown that the hydrogen bonds between acetylsalicylic acid and methanol are most stable at 318 K and are characterized by the highest value of absolute energy. At higher supercritical temperatures, however, the longest lifetime is observed for acetylsalicylic acid-ethanol complexes. These results correlate with the known literature experimental data showing that the maximum solubility of acetylsalicylic acid at density values close to those considered in this work and at temperatures of 318 and 328 K is achieved when using methanol and ethanol as co-solvents, respectively.

  7. Dissociation and hydrolysis of ammonia-borane with solid acids and carbon dioxide: An efficient hydrogen generation system

    NASA Astrophysics Data System (ADS)

    Chandra, Manish; Xu, Qiang

    Pure hydrogen generation under mild conditions in a controllable way is important for portable devices. Recently, we have found that an aq. ammonia-borane (NH 3BH 3) solution is a potential hydrogen source with noble metal catalysts. For practical use, the development of a low-cost, efficient and safe system is desired. In this study, we found that solid acids such as cation exchange resins and zeolites, which are low-cost and safe, also exhibit high activities for the dissociation and hydrolysis of NH 3BH 3 to generate hydrogen with an H 2 to NH 3BH 3 ratio up to 3.0 at room temperature. The reaction rate depends on the type of solid acid. Especially, Dowex and Amberlyst, the two low-cost solid acids often used as catalysts in a variety of reactions, exhibit reaction kinetics higher than the noble metal catalysts. Carbon dioxide is also active as an acid for this reaction. The reaction products in solution have been identified by 11B NMR, and the evolved gases have been analyzed by mass spectrometry which indicates high purity hydrogen. This new system may have a high potential for application in fuel cells.

  8. Method for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said method and apparatus hydrates CO.sub.2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  9. Apparatus for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H.; Caldeira, Kenneth G.

    2010-02-02

    An apparatus and method associated therewith to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said apparatus hydrates CO.sub.2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  10. Method for Extracting and Sequestering Carbon Dioxide

    SciTech Connect

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

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

  11. Experimental studies of selective acid gas removal: Absorption of hydrogen sulfide and carbon dioxide into aqueous methyldiethanolamine using packed columns

    SciTech Connect

    Schubert, C.N.

    1988-01-01

    The use of aqueous methyldiethanolamine (MDEA) for selective removal of hydrogen sulfide from acid gas streams has been studied in a 2 inch column packed with 1/4 inch ceramic Intalox saddles. The column was operated in a counter-current, steady state fashion. The feed gas composition varied between 1 and 5 mole % hydrogen sulfide and between 0 and 50 mole % carbon dioxide. In order to assist the development of packed column absorption models, the rate at which pure carbon dioxide absorbs into 2 M MDEA was measured as a function of pressure, liquid flow rate and packed bed length. The importance of end effects was carefully evaluated. In addition, draining and tracer methods were used to estimate the amount of static holdup present in the column. Using classical draining methods, as much as 50 % of the total holdup was found to be static. However, according to the step decrease in tracer method, less than 5 % of the total holdup was static. Since the step decrease in tracer method measures the amount of static holdup present in the bed under irrigated conditions, it seems likely that the draining method provides an unrealistic estimate of static holdup. Thus, although the notion of static holdup may be useful as a means of correlating mass transfer coefficients, the data indicate that very little static holdup exists in the column under irrigated conditions. Hence, in the absence of a mechanistically sound model, the choice of whether to use static holdup or dispersion as a means of accounting for deviations from plug flow in the liquid phase should be made on the basis of computational convenience.

  12. Reducing carbon dioxide to products

    SciTech Connect

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  13. Recuperative supercritical carbon dioxide cycle

    SciTech Connect

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  14. Supercritical carbon dioxide extraction of seed oil from winter melon (Benincasa hispida) and its antioxidant activity and fatty acid composition.

    PubMed

    Bimakr, Mandana; Rahman, Russly Abdul; Taip, Farah Saleena; Adzahan, Noranizan Mohd; Sarker, Md Zaidul Islam; Ganjloo, Ali

    2013-01-01

    In the present study, supercritical carbon dioxide (SC-CO(2)) extraction of seed oil from winter melon (Benincasa hispida) was investigated. The effects of process variables namely pressure (150-300 bar), temperature (40-50 °C) and dynamic extraction time (60-120 min) on crude extraction yield (CEY) were studied through response surface methodology (RSM). The SC-CO(2) extraction process was modified using ethanol (99.9%) as co-solvent. Perturbation plot revealed the significant effect of all process variables on the CEY. A central composite design (CCD) was used to optimize the process conditions to achieve maximum CEY. The optimum conditions were 244 bar pressure, 46 °C temperature and 97 min dynamic extraction time. Under these optimal conditions, the CEY was predicted to be 176.30 mg-extract/g-dried sample. The validation experiment results agreed with the predicted value. The antioxidant activity and fatty acid composition of crude oil obtained under optimized conditions were determined and compared with published results using Soxhlet extraction (SE) and ultrasound assisted extraction (UAE). It was found that the antioxidant activity of the extract obtained by SC-CO(2) extraction was strongly higher than those obtained by SE and UAE. Identification of fatty acid composition using gas chromatography (GC) showed that all the extracts were rich in unsaturated fatty acids with the most being linoleic acid. In contrast, the amount of saturated fatty acids extracted by SE was higher than that extracted under optimized SC-CO(2) extraction conditions. PMID:23322066

  15. Determination of Oleanolic and Ursolic Acids in Hedyotis diffusa Using Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography.

    PubMed

    Wei, Ming-Chi; Yang, Yu-Chiao; Hong, Show-Jen

    2015-01-01

    Oleanolic acid (OA) and ursolic acid (UA) were extracted from Hedyotis diffusa using a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC-CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC-CO2 flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant) and UA (3.540 mg/g of dry plant) were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v) cosolvent (ethanol/water = 82/18, v/v) and SC-CO2 flowing at 2.3 mL/min (STP). The extracted yields were then analyzed by high performance liquid chromatography (HPLC) to quantify the OA and UA. The present findings revealed that H. diffusa is a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA from H. diffusa at high concentrations. PMID:26089939

  16. Determination of Oleanolic and Ursolic Acids in Hedyotis diffusa Using Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography

    PubMed Central

    Hong, Show-Jen

    2015-01-01

    Oleanolic acid (OA) and ursolic acid (UA) were extracted from Hedyotis diffusa using a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC–CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC–CO2 flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant) and UA (3.540 mg/g of dry plant) were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v) cosolvent (ethanol/water = 82/18, v/v) and SC–CO2 flowing at 2.3 mL/min (STP). The extracted yields were then analyzed by high performance liquid chromatography (HPLC) to quantify the OA and UA. The present findings revealed that H. diffusa is a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA from H. diffusa at high concentrations. PMID:26089939

  17. Colloidal methods for the fabrication of carbon nanotube-manganese dioxide and carbon nanotube-polypyrrole composites using bile acids.

    PubMed

    Ata, M S; Zhitomirsky, I

    2015-09-15

    Nature inspired strategies have been developed for the colloidal processing of advanced composites for supercapacitor applications. New approach was based on the use of commercially available bile acid salts, such as sodium cholate (ChNa) and taurocholic acid sodium salt (TChNa). It was demonstrated that cholic acid (ChH) films can be obtained by electrophoretic deposition (EPD) from ChNa solutions. The analysis of deposition yield, quartz crystal microbalance and cyclic voltammetry data provided an insight into the anodic deposition mechanism. The outstanding suspension stability of multiwalled carbon nanotubes (MWCNT), achieved using bile acids as anionic dispersants, allowed the fabrication of MWCNT films by EPD. The use of ChNa for EPD offered advantages of binding and film forming properties of this material. Composite MnO2-MWCNT films, prepared using ChNa as a dispersant and film forming agent for EPD, showed promising capacitive behavior. In another colloidal strategy, TChNa was used as a dispersant for MWCNT for the fabrication of polypyrrole (PPy) coated MWCNT. The use of PPy coated MWCNT allowed the fabrication of electrodes with high active mass loading, high capacitance and excellent capacitance retention at high charge-discharge rates. PMID:26001135

  18. Magnesite disposal of carbon dioxide

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Wendt, C.H.

    1997-08-01

    In this paper we report our progress on developing a method for carbon dioxide disposal whose purpose it is to maintain coal energy competitive even is environmental and political pressures will require a drastic reduction in carbon dioxide emissions. In contrast to most other methods, our approach is not aiming at a partial solution of the problem, or at buying time for phasing out fossil energy. Instead, its purpose is to obtain a complete and economic solution of the problem, and thus maintain access to the vast fossil energy reservoir. A successful development of this technology would guarantee energy availability for many centuries even if world economic growth the most optimistic estimates that have been put forward. Our approach differs from all others in that we are developing an industrial process which chemically binds the carbon dioxide in an exothermic reaction into a mineral carbonate that is thermodynamically stable and environmentally benign.

  19. Engineering Bacteria for Efficient Fuel Production: Novel Biological Conversion of Hydrogen and Carbon Dioxide Directly into Free Fatty Acids

    SciTech Connect

    2010-07-12

    Electrofuels Project: OPX Biotechnologies is engineering a microorganism currently used in industrial biotechnology to directly produce a liquid fuel from hydrogen and carbon dioxide (CO2). The microorganism has the natural ability to use hydrogen and CO2 for growth. OPX Biotechnologies is modifying the microorganism to divert energy and carbon away from growth and towards the production of liquid fuels in larger, commercially viable quantities. The microbial system will produce a fuel precursor that can be chemically upgraded to various hydrocarbon fuels.

  20. Thermochemical generation of hydrogen and carbon dioxide

    NASA Technical Reports Server (NTRS)

    Lawson, Daniel D. (Inventor); England, Christopher (Inventor)

    1984-01-01

    Mixing of carbon in the form of high sulfur coal with sulfuric acid reduces the temperature of sulfuric acid decomposition from 830.degree. C. to between 300.degree. C. and 400.degree. C. The low temperature sulfuric acid decomposition is particularly useful in thermal chemical cycles for splitting water to produce hydrogen. Carbon dioxide is produced as a commercially desirable byproduct. Lowering of the temperature for the sulfuric acid decomposition or oxygen release step simplifies equipment requirements, lowers thermal energy input and reduces corrosion problems presented by sulfuric acid at conventional cracking temperatures. Use of high sulfur coal as the source of carbon for the sulfuric acid decomposition provides an environmentally safe and energy efficient utilization of this normally polluting fuel.

  1. Adsorption of Surface-Modified Silica Nanoparticles to the Interface of Melt Poly(lactic acid) and Supercritical Carbon Dioxide.

    PubMed

    Sarikhani, K; Jeddi, K; Thompson, R B; Park, C B; Chen, P

    2015-05-26

    With the purpose of fabricating polymer nanocomposite foams and preventing coalescence in foaming processes, the interfacial tension of poly(lactic acid) (PLA)-silica composites is investigated in this work. Synthesized silica nanoparticles (SNs) with a CO2-philic surface modification are used as the dispersed nanoparticles. Interfacial tension is a key parameter in processing of polymer foams since it directly affects the final foam properties, such as cell size and cell density. Interfacial tension of silica-containing PLA and supercritical carbon dioxide (CO2) is measured using axisymmetric drop shape analysis profile (ADSA-P) pendant drop method at high pressures and high temperatures. The interfacial tension between PLA and supercritical CO2 is observed to decrease as a result of the nanoparticles' adsorption to the interface. These results indicate that the reduction in interfacial tension with increasing silica content significantly deviates from a linear trend; there is a minimum at 2 wt % loading of the SNs and then the interfacial tension curve reaches a plateau. Contact angle measurements show an affinity of the SNs for the polymer-supercritical CO2 interface, and these obtained results are used to calculate the binding energy of the nanoparticles to the PLA/CO2 interface. In addition to interfacial properties, the adsorption of silica nanoparticles at the interface is also studied in detail with scanning electron microscopy. PMID:25919815

  2. Preparation of poly(L-lactic acid) nanofiber scaffolds with a rough surface by phase inversion using supercritical carbon dioxide.

    PubMed

    Yang, Ding-Zhu; Chen, Ai-Zheng; Wang, Shi-Bin; Li, Yi; Tang, Xiao-Lin; Wu, Yong-Jing

    2015-06-01

    Phase inversion using supercritical carbon dioxide (SC-CO2) has been widely used in the development of tissue engineering scaffolds, and particular attention has been given to obtaining desired morphology without additional post-treatments. However, the main challenge of this technique is the difficulty in generating a three-dimensional (3D) nanofiber structure with a rough surface in one step. Here, a poly(L-lactic acid) (PLLA) 3D nanofiber scaffold with a rough surface is obtained via phase inversion using SC-CO2 by carefully choosing fabrication conditions and porogens. It is found that this method can effectively modulate the structure morphology, promote the crystallization process of semicrystalline polymer, and induce the formation of rough structures on the surface of nanofibers. Meanwhile, the porogen of ammonium bicarbonate (AB) can produce a 3D structure with large pores, and porogen of menthol can improve the interconnectivity between the micropores of nanofibers. A significant increase in the fiber diameter is observed as the menthol content increases. Furthermore, the menthol may affect the mutual transition between the α' and α crystals of PLLA during the phase separation process. In addition, the results of protein adsorption, cell adhesion, and proliferation assays indicate that cells tend to have higher viability on the nanofiber scaffold. This process combines the characteristic properties of SC-CO2 and the solubility of menthol to tailor the morphology of polymeric scaffolds, which may have potential applications in tissue engineering. PMID:26107415

  3. The Effect of Carbon Dioxide (CO2) Laser on Sandblasting with Large Grit and Acid Etching (SLA) Surface

    PubMed Central

    Foroutan, Tahereh; Ayoubian, Nader

    2013-01-01

    Introduction: The purpose of this study was to investigate the effect of 6W power Carbon Dioxide Laser (CO2) on the biologic compatibility of the Sandblasting with large grit and acid etching (SLA) titanium discs through studying of the Sarcoma Osteogenic (SaOS-2) human osteoblast-like cells viability. Methods: Sterilized titanium discs were used together with SaOS-2 human osteoblast-like cells. 6 sterilized SLA titanium discs of the experimental group were exposed to irradiation by CO2 laser with a power of 6W and 10.600nm wavelength, at fixed frequency of 80Hz during 45 seconds in both pulse and non-contact settings. SaOS-2 human osteoblast-like cells were incubated under 37°C in humid atmosphere (95% weather, 5% CO2) for 72 hours. MTT test was performed to measure the ratio level of cellular proliferation. Results: The results indicated that at 570nm wavelength, the 6W CO2 laser power have not affected the cellular viability. Conclusion: CO2 laser in 6w power has had no effect on the biologic compatibility of the SLA titanium surface PMID:25606313

  4. Manganese Electrocatalysts with Bulky Bipyridine Ligands: Utilizing Lewis Acids To Promote Carbon Dioxide Reduction at Low Overpotentials.

    PubMed

    Sampson, Matthew D; Kubiak, Clifford P

    2016-02-01

    Earth-abundant manganese bipyridine (bpy) complexes are well-established molecular electrocatalysts for proton-coupled carbon dioxide (CO2) reduction to carbon monoxide (CO). Recently, a bulky bipyridine ligand, 6,6'-dimesityl-2,2'-bipyridine (mesbpy), was utilized to significantly lower the potential necessary to access the doubly reduced states of these manganese catalysts by eliminating their ability to dimerize after one-electron reduction. Although this Mn mesbpy catalyst binds CO2 at very low potentials, reduction of a resulting Mn(I)-COOH complex at significantly more negative potentials is required to achieve fast catalytic rates. Without reduction of Mn(I)-COOH, catalysis occurs slowly via a alternate catalytic pathway-protonation of Mn(I)-COOH to form a cationic tetracarbonyl complex. We report the use of Lewis acids, specifically Mg(2+) cations, to significantly increase the rate of catalysis (by over 10-fold) at these low overpotentials (i.e., the same potential as CO2 binding). Reduction of CO2 occurs at one of the lowest overpotentials ever reported for molecular electrocatalysts (η = 0.3-0.45 V). With Mg(2+), catalysis proceeds via a reductive disproportionation reaction of 2CO2 + 2e(-) → CO and CO3(2-). Insights into the catalytic mechanism were gained by using variable concentration cyclic voltammetry, infrared spectroelectrochemistry, and bulk electrolysis studies. The catalytic Tafel behavior (log turnover frequency vs overpotential relationship) of [Mn(mesbpy)(CO)3(MeCN)](OTf) with added Mg(2+) is compared with those of other commonly studied CO2 reduction catalysts. PMID:26745814

  5. Carbon Dioxide - Our Common "Enemy"

    NASA Technical Reports Server (NTRS)

    James, John T.; Macatangay, Ariel

    2009-01-01

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

  6. Generation of aliphatic acid anions and carbon dioxide by hydrous pyrolysis of crude oils

    USGS Publications Warehouse

    Kharaka, Y.K.; Lundegard, P.D.; Ambats, G.; Evans, William C.; Bischoff, J.L.

    1993-01-01

    Two crude oils with relatively high (0.60 wt%) and low (0.18 wt%) oxygen contents were heated in the presence of water in gold-plated reactors at 300??C for 2348 h. The high-oxygen oil was also heated at 200??C for 5711 h. The compositions of aqueous organic acid anions of the oils and of the headspace gases were monitored inn order to investigate the distribution of organic acids that can be generated from liquid petroleum. The oil with higher oxygen content generated about five times as much organic anions as the other oil. The dominant organic anions produced were acetate, propionate and butyrate. Small amounts of formate, succinate, methyl succinate and oxalate were also produced. The dominant oxygen-containing product was CO2, as has been observed in similar studies on the hydrous pyrolysis of kerogen. These results indicate that a significant portion (10-30%) of organic acid anions reported i be generated by thermal alteration of oils in reservoir rocks. The bulk of organic acid anions present in formation waters, however, is most likely generated by thermal alteration of kerogen in source rocks. Kerogen is more abundant than oil in sedimentary basins and the relative yields of organic acid anions reported from the hydrous pyrolysis of kerogen are much higher than the yields obtained for the two oils. ?? 1993.

  7. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  8. Elevated carbon dioxide levels enhance rosmarinic acid production in spearmint plantlets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The C20 diterpene rosmarinic acid (RA) is synthesized in the phenylpropanoid pathway and is constitutively expressed in spearmint (Mentha spicata L.) plantlets grown in vitro. RA levels within plantlet leaves were found to be readily manipulated by the nutritional and physical environments. Higher...

  9. The influence of aliphatic amines, diamines, and amino acids on the polymorph of calcium carbonate precipitated by the introduction of carbon dioxide gas into calcium hydroxide aqueous suspensions

    NASA Astrophysics Data System (ADS)

    Chuajiw, Wittaya; Takatori, Kazumasa; Igarashi, Teruki; Hara, Hiroki; Fukushima, Yoshiaki

    2014-01-01

    The influence of aliphatic organic additives including amines, diamines and amino acids, on the polymorph of calcium carbonate (CaCO3) precipitated from a calcium hydroxide (Ca(OH)2) suspensions and carbon dioxide gas (CO2) was studied by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The amorphous calcium carbonate, vaterite, aragonite and calcite were observed for the precipitated samples with organic additives. While the precipitation without organic additive, only the stable phase; calcite was obtained. The observed crystal phases were related with the alkyl chain length in the aliphatic part of additives. These results suggested that hydrophobic interactions due to the van der Waals force between organic additives and surface of inorganic precipitates could not be ignored. We concluded that covering or adsorbing of these organic additives on the precipitates surfaces retarded the successive dissolution/recrystallisation process in the aqueous systems. The results revealed that not only the polar interaction from the hydrophilic functional groups, as the former reports proposed, but also the van der Waals interactions from the hydrophobic alkyl groups played the important role in the phase transformation of CaCO3.

  10. A miniature chemiresistor sensor for carbon dioxide.

    PubMed

    Srinives, Sira; Sarkar, Tapan; Hernandez, Raul; Mulchandani, Ashok

    2015-05-18

    A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO2 at room temperature. Good sensing performance was observed upon exposing the PEI-PANI device to 50-5000 ppm CO2 in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid-base reaction, CO2 dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO2 in air. PMID:25910446

  11. Formation of molecular complexes of salicylic acid, acetylsalicylic acid, and methyl salicylate in a mixture of supercritical carbon dioxide with a polar cosolvent

    NASA Astrophysics Data System (ADS)

    Petrenko, V. E.; Antipova, M. L.; Gurina, D. L.; Odintsova, E. G.

    2015-08-01

    The solvate structures formed by salicylic acid, acetylsalicylic acid, and methyl salicylate in supercritical (SC) carbon dioxide with a polar cosolvent (methanol, 0.03 mole fractions) at a density of 0.7 g/cm3 and a temperature of 318 K were studied by the molecular dynamics method. Salicylic and acetylsalicylic acids were found to form highly stable hydrogen-bonded complexes with methanol via the hydrogen atom of the carboxyl group. For methyl salicylate in which the carboxyl hydrogen is substituted by a methyl radical, the formation of stable hydrogen bonds with methanol was not revealed. The contribution of other functional groups of the solute to the interactions with the cosolvent was much smaller. An analysis of correlations between the obtained data and the literature data on the cosolvent effect on the solubility of the compounds in SC CO2 showed that the dissolving ability of SC CO2 with respect to a polar organic substance in the presence of a cosolvent increased only when stable hydrogen-bonded complexes are formed between this substance and the cosolvent.

  12. High capacity carbon dioxide sorbent

    SciTech Connect

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

    2015-09-01

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

  13. Extraction of furfural with carbon dioxide

    SciTech Connect

    Gamse, T.; Marr, R.; Froeschl, F.; Siebenhofer, M.

    1997-01-01

    A new approach to separate furfural from aqueous waste has been investigated. Recovery of furfural and acetic acid from aqueous effluents of a paper mill has successfully been applied on an industrial scale since 1981. The process is based on the extraction of furfural and acetic acid by the solvent trooctylphosphineoxide (TOPO). Common extraction of both substances may cause the formation of resin residues. Improvement was expected by selective extraction of furfural with chlorinated hydrocarbons, but ecological reasons stopped further development of this project. The current investigation is centered in the evaluation of extraction of furfural by supercritical carbon dioxide. The influence of temperature and pressure on the extraction properties has been worked out. The investigation has considered the multi-component system furfural-acetic acid-water-carbon dioxide. Solubility of furfural in liquid and supercritical carbon dioxide has been measured, and equilibrium data for the ternary system furfural-water-CO{sub 2} as well as for the quaternary system furfural-acetic acid-water-CO{sub 2} have been determined. A high-pressure extraction column has been used for evaluation of mass transfer rates.

  14. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and....1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No. 124-38-9) occurs as a..., sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon dioxide is prepared as a...

  15. Carbon dioxide transport over complex terrain

    USGS Publications Warehouse

    Sun, Jielun; Burns, Sean P.; Delany, A.C.; Oncley, S.P.; Turnipseed, A.; Stephens, B.; Guenther, A.; Anderson, D.E.; Monson, R.

    2004-01-01

    The nocturnal transport of carbon dioxide over complex terrain was investigated. The high carbon dioxide under very stable conditions flows to local low-ground. The regional drainage flow dominates the carbon dioxide transport at the 6 m above the ground and carbon dioxide was transported to the regional low ground. The results show that the local drainage flow was sensitive to turbulent mixing associated with local wind shear.

  16. Modelling Sublimation of Carbon Dioxide

    ERIC Educational Resources Information Center

    Winkel, Brian

    2012-01-01

    In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

  17. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  18. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  19. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  20. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  1. 21 CFR 582.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is...

  2. Volatile fatty acid impacts on nitrite oxidation and carbon dioxide fixation in activated sludge.

    PubMed

    Oguz, Merve T; Robinson, Kevin G; Layton, Alice C; Sayler, Gary S

    2006-02-01

    Batch test were performed to assess nitrite removal, nitrate formation, CO2 fixation, gaseous nitrogen production and microbial density in activated sludge exposed to volatile fatty acid (VFA) mixtures. Nitrite removal and nitrate formation were both affected by the presence of VFAs, but to different degrees. Nitrate formation rates were reduced to a greater extent (79%) than nitrite removal rates (36%) resulting in an apparent unbalanced nitrite oxidation reaction. Since the total bacterial density and the nitrite oxidizing bacteria (NOB, Nitrospira) concentration remained essentially constant under all test conditions, the reduction in rates was not due to heterotrophic uptake of nitrogen or to a decrease in the NOB population. In contrast to the nitrogen results, VFAs were not found to impact CO2 fixation efficiency. It appeared that nitrite oxidation occurred when VFAs were present since the oxidation of nitrite provides energy for CO2 fixation. However, nitrate produced from the oxidation of nitrite was reduced to gaseous nitrogen products. N2O gas was detected in the presence of VFAs which was a clear indication that VFAs stimulated an alternative pathway, such as aerobic denitrification, during biotransformation of nitrogen in activated sludge. PMID:16436292

  3. Abscisic Acid Induces Rapid Reductions in Mesophyll Conductance to Carbon Dioxide.

    PubMed

    Sorrentino, Giuseppe; Haworth, Matthew; Wahbi, Said; Mahmood, Tariq; Zuomin, Shi; Centritto, Mauro

    2016-01-01

    The rate of photosynthesis (A) of plants exposed to water deficit is a function of stomatal (gs) and mesophyll (gm) conductance determining the availability of CO2 at the site of carboxylation within the chloroplast. Mesophyll conductance often represents the greatest impediment to photosynthetic uptake of CO2, and a crucial determinant of the photosynthetic effects of drought. Abscisic acid (ABA) plays a fundamental role in signalling and co-ordination of plant responses to drought; however, the effect of ABA on gm is not well-defined. Rose, cherry, olive and poplar were exposed to exogenous ABA and their leaf gas exchange parameters recorded over a four hour period. Application with ABA induced reductions in values of A, gs and gm in all four species. Reduced gm occurred within one hour of ABA treatment in three of the four analysed species; indicating that the effect of ABA on gm occurs on a shorter timescale than previously considered. These declines in gm values associated with ABA were not the result of physical changes in leaf properties due to altered turgor affecting movement of CO2, or caused by a reduction in the sub-stomatal concentration of CO2 (Ci). Increased [ABA] likely induces biochemical changes in the properties of the interface between the sub-stomatal air-space and mesophyll layer through the actions of cooporins to regulate the transport of CO2. The results of this study provide further evidence that gm is highly responsive to fluctuations in the external environment, and stress signals such as ABA induce co-ordinated modifications of both gs and gm in the regulation of photosynthesis. PMID:26862904

  4. Abscisic Acid Induces Rapid Reductions in Mesophyll Conductance to Carbon Dioxide

    PubMed Central

    Sorrentino, Giuseppe; Haworth, Matthew; Wahbi, Said; Mahmood, Tariq; Zuomin, Shi; Centritto, Mauro

    2016-01-01

    The rate of photosynthesis (A) of plants exposed to water deficit is a function of stomatal (gs) and mesophyll (gm) conductance determining the availability of CO2 at the site of carboxylation within the chloroplast. Mesophyll conductance often represents the greatest impediment to photosynthetic uptake of CO2, and a crucial determinant of the photosynthetic effects of drought. Abscisic acid (ABA) plays a fundamental role in signalling and co-ordination of plant responses to drought; however, the effect of ABA on gm is not well-defined. Rose, cherry, olive and poplar were exposed to exogenous ABA and their leaf gas exchange parameters recorded over a four hour period. Application with ABA induced reductions in values of A, gs and gm in all four species. Reduced gm occurred within one hour of ABA treatment in three of the four analysed species; indicating that the effect of ABA on gm occurs on a shorter timescale than previously considered. These declines in gm values associated with ABA were not the result of physical changes in leaf properties due to altered turgor affecting movement of CO2, or caused by a reduction in the sub-stomatal concentration of CO2 (Ci). Increased [ABA] likely induces biochemical changes in the properties of the interface between the sub-stomatal air-space and mesophyll layer through the actions of cooporins to regulate the transport of CO2. The results of this study provide further evidence that gm is highly responsive to fluctuations in the external environment, and stress signals such as ABA induce co-ordinated modifications of both gs and gm in the regulation of photosynthesis. PMID:26862904

  5. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  6. Oxygen and carbon dioxide sensing

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  7. Method for carbon dioxide sequestration

    SciTech Connect

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

    2015-09-22

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

  8. Summer Ice and Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Kukla, G.; Gavin, J.

    1981-10-01

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

  9. Summer ice and carbon dioxide

    SciTech Connect

    Kukla, G.; Gavin, J.

    1981-10-30

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

  10. Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.

    PubMed

    Wu, Lipeng; Liu, Qiang; Fleischer, Ivana; Jackstell, Ralf; Beller, Matthias

    2014-01-01

    Alkene carbonylations represent a major technology for the production of value-added bulk and fine chemicals. Nowadays, all industrial carbonylation processes make use of highly toxic and flammable carbon monoxide. Here we show the application of abundantly available carbon dioxide as C1 building block for the alkoxycarbonylations of industrially important olefins in the presence of a convenient and inexpensive ruthenium catalyst system. In our system, carbon dioxide works much better than the traditional combination of carbon monoxide and alcohols. The unprecedented in situ formation of carbon monoxide from carbon dioxide and alcohols permits an efficient synthesis of carboxylic acid esters, which can be used as detergents and polymer-building blocks. Notably, this transformation allows the catalytic formation of C-C bonds with carbon dioxide as C1 source and avoids the use of sensitive and/or expensive reducing agents (for example, Grignard reagents, diethylzinc or triethylaluminum). PMID:24518431

  11. Anti-inflammatory effects of supercritical carbon dioxide extract and its isolated carnosic acid from Rosmarinus officinalis leaves.

    PubMed

    Kuo, Chia-Feng; Su, Jeng-De; Chiu, Chun-Hung; Peng, Chiung-Chi; Chang, Chi-Huang; Sung, Tzu-Ying; Huang, Shiau-Huei; Lee, Wen-Chin; Chyau, Charng-Cherng

    2011-04-27

    Rosemary (Rosmarinus officinalis) leaves possess a variety of bioactivities. Previous studies have shown that the extract of rosemary leaves from supercritical fluid extraction inhibits the expression of inflammatory mediators with apparent dose-dependent responses. In this study, three different extraction conditions (5000 psi at 40, 60, and 80 °C) of supercritical carbon dioxide (SC-CO(2)) toward the extraction of antioxidants from rosemary were investigated. Furthermore, simultaneous comparison of the anti-inflammatory properties between rosemary extract prepared from SC-CO(2) under optimal conditions (5,000 psi and 80 °C) and its purified carnosic acid (CA) using lipopolysaccharide (LPS)-treated murine RAW 264.7 macrophage cells was also presented. Results showed that the yield of 3.92% and total phenolics of 213.5 mg/g extract obtained from the most effective extraction conditions showed a high inhibitory effect on lipid peroxidation (IC(50) 33.4 μg/mL). Both the SC-CO(2) extract and CA markedly suppressed the LPS-induced production of nitric oxide (NO) and tumor necrosis factor-α (TNF-α), as well as the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), phosphorylated inhibitor-kappaB (P-IκB), and nuclear factor-kappaB (NF-κB)/p65 in a dose-dependent manner. The five major compounds of verbenone, cirsimaritin, salvigenin, carnosol, and CA existing in the SC-CO(2) extract were isolated by semipreparative HPLC and identified by HPLC-MS/MS analysis. CA was the most abundant recorded compound and the most important photochemical with an anti-inflammatory effect with an IC(50) of 22.5 μM or 7.47 μg/mL presented to the best inhibitory activity on NO production better than that of the 14.50 μg/mL dosage prepared from the SC-CO(2) extract. Nevertheless, the effective inhibition of LPS-induced NF-κB signaling in RAW 264.7 cells from the SC-CO(2) extract extends the potential application of nutraceutical formulation for the

  12. Asymmetric catalytic transformations in supercritical carbon dioxide

    SciTech Connect

    Feng, Shaoguang; Tumas, W.; Gross, M.F.; Burk, M.J.

    1996-12-31

    Supercritical carbon dioxide can be a useful environmentally benign solvent for a wide range of catalytic reactions. We have been exploring the utility of supercritical carbon dioxide as a reaction medium for catalytic asymmetric transformations. We will present results on the asymmetric hydrogenation of prochiral olefins, ketones, and unsaturated acids by Rh and Ru catalysts containing chiral phosphine ligands using hydrogen or hydrogen transfer agents. We have found that asymmetric catalytic hydrogenation reactions of enamide esters work as well or better in CO{sub 2} than in conventional solvents. We have been able to effect high conversions and ee`s using hydrogen transfer systems such as HCOOH/NEt{sub 3}, We will discuss temperature, pressure and solvent density effects on selectivity and reactivity. Kinetic studies will also be presented in order to understand the enhanced enantioselectivity that we observed in SC CO{sub 2}.

  13. Removing perfluorooctane sulfonate and perfluorooctanoic acid from solid matrices, paper, fabrics, and sand by mineral acid suppression and supercritical carbon dioxide extraction.

    PubMed

    Chen, Hsiang-Yu; Liao, Weisheng; Wu, Ben-Zen; Nian, Hungchi; Chiu, KongHwa; Yak, Hwa-Kwang

    2012-09-01

    The removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from solid matrices has received considerable attention because of the environmental persistence, bioaccumulation, and potential toxicity of these compounds. This study presents a simple method using concentrated HNO(3) as a suppression agent, and methanol-modified supercritical carbon dioxide (Sc-CO(2)) extraction for removing PFOS and PFOA from solid matrices. The optimal conditions were 16 M HNO(3) and 20% (v/v) methanol containing Sc-CO(2), under a pressure of 20.3 MPa and a temperature of 50 °C. Extraction time was set at 70 min (40 min for static and 30 min for dynamic extraction). PFOA and PFOS were identified and quantitated by liquid chromatography/mass spectrometry. The extraction efficiencies (with double extractions) were close to 100% for PFOA and 80% for PFOS for both paper and fabric matrices. The extraction efficiencies for sand were approximately 77% for PFOA and 59% for PFOS. The results show that this method is accurate, and effective, and that it provides a promising and convenient approach to remediate the environment of hazardous PFOA and PFOS contamination. PMID:22748389

  14. Carbon dioxide review 1982

    SciTech Connect

    Clark, W.C.

    1982-01-01

    The buildup of CO/sub 2/ is a reality, monitored with increasing precision since 1957 and inferred for much earlier dates. A statistical section gives the monitored values to 1980, as well as a review of a long series of measurements made at Mauna Loa by the pioneers of such monitoring, Charles D. Keeling, Robert B. Bacastow, and Timothy P. Whorf. The book discusses internal transport processes in the ocean, of ocean-atmosphere interaction, of the magnitude of forest and soil carbon wastage, of the future course of fossil-fuel consumption. Yet something else emerges, too: if the CO/sub 2/ buildup continues; if the big general circulation models are right about its impact on climate, and if we have not miscalculated the potential role of the oceans, then we face a climatic change in the next century and a half like nothing the post-glacial world, and hence civilized humanity, has seen.

  15. Germanium(II) hydride mediated reduction of carbon dioxide to formic acid and methanol with ammonia borane as the hydrogen source.

    PubMed

    Jana, Anukul; Tavčar, Gašper; Roesky, Herbert W; John, Michael

    2010-10-28

    LGeOC(O)H (3) (L = CH{(CMe)(2,6-iPr(2)C(6)H(3)N)}(2)), from the straightforward conversion of LGeH (2) with CO(2), reacts with LiH(2)NBH(3) giving 2 and LiOC(O)H (4), while the corresponding reaction of 3 with H(3)NBH(3) after aqueous workup releases 2 and CH(3)OH (5). This opens the possibility to use hydride 2 as a mediator in the reduction of carbon dioxide to formic acid and methanol. PMID:20830405

  16. Carbon Dioxide Removal via Passive Thermal Approaches

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  17. Synthesis of fluoropolymers in supercritical carbon dioxide

    SciTech Connect

    Guan, Z.; Combes, J.R.; Elsbernd, C.S.; DeSimone, J.M.

    1993-12-31

    The authors` research is focus on the synthesis of fluopolymers is supercritical carbon dioxide. The authors reported earlier the successful homogenous free radical polymerization of a series of highly fluorinated acrylic type monomers in supercritical carbon dioxide. Now it is found that a highly fluorinated styrenic polymer also exhibits very high solubility in carbon dioxide. The fluorinated styrenic polymer was synthesized in supercritical carbon dioxide using homogenous free radical polymerization and was characterized by {sup 1}HNMR, FTIR etc. Some semicrystalline fluoropolymers were also synthesized in supercritical carbon but the polymerization were heterogenous under the condition used. Various conventional nonfluorinated monomers were copolymerized with the fluorinated monomers and the copolymerizations were homogenous at very high nonfluorinated monomer feed ratio. The incorporation of nonfluorinated units onto the fluoropolymer chains increases their solubility greatly in organic solvents. The polymers synthesized in carbon dioxide will be furtherly characterized and the authors will continue the efforts on synthesizing polymers using carbon dioxide as polymerization medium.

  18. Management practices affects soil carbon dioxide emission and carbon storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural practices contribute about 25% of total anthropogenic carbon dioxide emission, a greenhouse gas responsible for global warming. Soil can act both as sink or source of atmospheric carbon dioxide. Carbon dioxide fixed in plant biomass through photosynthesis can be stored in soil as organi...

  19. Capture of carbon dioxide from ethanol fermentation by liquid absorption for use in biological production of succinic acid.

    PubMed

    Nghiem, Nhuan P; Senske, Gerard E

    2015-02-01

    Previously, it was shown that the gas produced in an ethanol fermentor using either corn or barley as feedstock could be sparged directly into an adjacent fermentor as a feedstock for succinic acid fermentation using Escherichia coli AFP184. In the present investigation, it was demonstrated that the CO2 produced in a corn ethanol fermentor could be absorbed in a base solution and the resultant carbonate solution used both for pH control and supply of the CO2 requirement in succinic acid fermentation. Thus, the CO2 produced in a 5-L corn mash containing 30 wt% total solids was absorbed in a packed column containing 2 L of either 5 M NaOH, 5 M KOH, or 15 wt% NH4OH, and the resultant carbonate solutions were used for pH control in a succinic acid fermentor. The results obtained indicated no significant differences between succinic acid production in these experiments and when 2.5 M solutions of Na2CO3, K2CO3, and (NH4)2CO3 from commercial sources were used. In a commercial setting, the demonstrated capture of CO2 in liquid form will allow transportation of the carbonate solutions to locations not in the immediate vicinity of the ethanol plant, and excess carbonate salts can also be recovered as value-added products. PMID:25448631

  20. Solubility of Carbon Dioxide in Water.

    ERIC Educational Resources Information Center

    Bush, Pat; And Others

    1992-01-01

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

  1. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  2. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  3. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  4. 21 CFR 184.1240 - Carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C....

  5. Carbon dioxide detection in adult Odonata.

    PubMed

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

    2016-04-01

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

  6. Carbon dioxide disposal in solid form

    SciTech Connect

    Lackner, K.S.; Butt, D.P.; Sharp, D.H.; Wendt, C.H.

    1995-12-31

    Coal reserves can provide for the world`s energy needs for centuries. However, coal`s long term use may be severely curtailed if the emission of carbon dioxide into the atmosphere is not eliminated. We present a safe and permanent method of carbon dioxide disposal that is based on combining carbon dioxide chemically with abundant raw materials to form stable carbonate minerals. We discuss the availability of raw materials and potential process designs. We consider our initial rough cost estimate of about 3{cents}/kWh encouraging. The availability of a carbon dioxide fixation technology would serve as insurance in case global warming, or the perception of global warming, causes severe restrictions on carbon dioxide emissions. If the increased energy demand of a growing world population is to be satisfied from coal, the implementation of such a technology would quite likely be unavoidable.

  7. Silanediol-catalyzed carbon dioxide fixation.

    PubMed

    Hardman-Baldwin, Andrea M; Mattson, Anita E

    2014-12-01

    Carbon dioxide is an abundant and renewable C1 source. However, mild transformations with carbon dioxide at atmospheric pressure are difficult to accomplish. Silanediols have been discovered to operate as effective hydrogen-bond donor organocatalysts for the atom-efficient conversion of epoxides to cyclic carbonates under environmentally friendly conditions. The reaction system is tolerant of a variety of epoxides and the desired cyclic carbonates are isolated in excellent yields. PMID:25328125

  8. Carbon Dioxide for pH Control

    SciTech Connect

    Wagonner, R.C.

    2001-08-16

    Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

  9. Carbon dioxide sequestration by mineral carbonation

    SciTech Connect

    Gerdemann, Stephen J.; Dahlin David C.; O'Connor William K.; Penner Larry R.

    2003-11-01

    Concerns about global warming caused by the increasing concentration of carbon dioxide and other greenhouse gases in the earth’s atmosphere have resulted in the need for research to reduce or eliminate emissions of these gases. Carbonation of magnesium and calcium silicate minerals is one possible method to achieve this reduction. It is possible to carry out these reactions either in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals) or ex situ (above ground in a more traditional chemical processing plant). Research at the Department of Energy’s Albany Research Center has explored both of these routes. This paper will explore parameters that affect the direct carbonation of magnesium silicate minerals serpentine (Mg3Si2O5(OH)4) and olivine (Mg2SiO4) to produce magnesite (MgCO3), as well as the calcium silicate mineral, wollastonite (CaSiO3), to form calcite (CaCO3). The Columbia River Basalt Group is a multi-layered basaltic lava plateau that has favorable mineralogy and structure for storage of CO2. Up to 25% combined concentration of Ca, Fe2+, and Mg cations could react to form carbonates and thus sequester large quantities of CO2. Core samples from the Columbia River Basalt Group were reacted in an autoclave for up to 2000 hours at temperatures and pressures to simulate in situ conditions. Changes in core porosity, secondary minerals, and solution chemistry were measured.

  10. Encapsulated liquid sorbents for carbon dioxide capture.

    PubMed

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-01-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture. PMID:25652243

  11. Encapsulated liquid sorbents for carbon dioxide capture

    NASA Astrophysics Data System (ADS)

    Vericella, John J.; Baker, Sarah E.; Stolaroff, Joshuah K.; Duoss, Eric B.; Hardin, James O.; Lewicki, James; Glogowski, Elizabeth; Floyd, William C.; Valdez, Carlos A.; Smith, William L.; Satcher, Joe H.; Bourcier, William L.; Spadaccini, Christopher M.; Lewis, Jennifer A.; Aines, Roger D.

    2015-02-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  12. Dissolution of Columbia River Basalt Under Mildly Acidic Conditions as a Function of Temperature: Experimental Results Relevant to the Geological Sequestration of Carbon Dioxide

    SciTech Connect

    Schaef, Herbert T.; McGrail, B. Peter

    2009-05-01

    Increasing attention is being focused on the rapid rise of carbon dioxide levels in the atmosphere, which many believe to be the major contributing factor to global climate change. Sequestering CO2 in deep geological formations has been proposed as a long-term solution to help stabilize CO2 levels. However, before such technology can be developed and implemented, a basic understanding of H2O-CO2 systems and the chemical interactions of these fluids with the host formation must be obtained. Important issues concerning mineral stability, reaction rates, and carbonate formation are all controlled or at least significantly impacted by the kinetics of rock-water reactions in mildly acidic, CO2-saturated solutions. Basalt has recently been identified as a potentially important host formation for geological sequestration. Dissolution kinetics of the Columbia River Basalt (CRB) were measured for a range of temperatures (25° to 90°C) under mildly acidic to neutral pH conditions using the single-pass flow-through test method. Under anaerobic conditions, the normalized dissolution rates for CRB decrease with increasing pH (3≤pH≤7) with a slope, η, of -0.12 ± 0.02. An activation energy, Ea, has been estimated at 30.3 ± 2.4 kJ mol-1. Dissolution kinetics measurements like these are essential for modeling the rate at which the CO2 reacts with basalt and ultimately converted to carbonate minerals in situ.

  13. Electrocatalysts for carbon dioxide conversion

    SciTech Connect

    Masel, Richard I; Salehi-Khojin, Amin

    2015-04-21

    Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

  14. Carbon dioxide cleaning pilot project

    SciTech Connect

    Knight, L.; Blackman, T.E.

    1994-01-21

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

  15. Carbon dioxide capture process with regenerable sorbents

    DOEpatents

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

    A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

  16. Carbon dioxide sequestration by ex-situ mineral carbonation

    SciTech Connect

    O'Connor, W.K.; Dahlin, D.C.; Turner, P.C.; and Walters, R.P.

    2000-01-01

    The process developed for carbon dioxide sequestration utilizes a slurry of water mixed with olivine- forsterite end member (Mg{sub 2}SiO{sub 4}), which is reacted with supercritical CO{sub 2} to produce magnesite (MgCO{sub 3}). Carbon dioxide is dissolved in water to form carbonic acid, which likely dissociates to H{sup +} and HCO{sub 3}{sup -}. The H{sup +} hydrolyzes the silicate mineral, freeing the cation (Mg{sup 2+}), which reacts with the HCO{sub 3}{sup -} to form the solid carbonate. Results of the baseline tests, conducted on ground products of the natural mineral, have demonstrated that the kinetics of the reaction are slow at ambient temperature (22 degrees C) and subcritical CO{sub 2} pressures (below 7.4 MPa). However, at elevated temperature and pressure, coupled with continuous stirring of the slurry and gas dispersion within the water column, significant conversion to the carbonate occurs. Extent of reaction is roughly 90% within 24 h, at 185 degrees C and partial pressure of CO{sub 2} (P{sub CO{sub 2}}) of 11.6 MPa. Current studies suggest that reaction kinetics can be improved by pretreatment of the mineral, catalysis of the reaction, and/or solution modification. Subsequent tests are intended to examine these options, as well as other mineral groups.

  17. Electroreduction of carbon dioxide in aqueous solutions at metal electrodes

    SciTech Connect

    Augustynski, J.; Jermann, B.; Kedzierzawski, P.

    1996-12-31

    The quantities of carbon stored in the form of atmospheric carbon dioxide, CO{sub 2} in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates and polycarbonates. However, the situation is expected to change in the future, if effective catalytic systems allowing to activate carbon dioxide will become available. In this connection, the electrochemical reduction of CO{sub 2}, requiring only an additional input of water and electrical energy, appears as an attractive possibility. For more than 100 years formic acid and formates of alkali metals were considered as the only significant products of the electroreduction of carbon dioxide in aqueous solutions. The highest current efficiencies, exceeding 90 %, were obtained either with mercury or with amalgam electrodes. The only comprehensive study regarding kinetics of CO{sub 2} reduction in aqueous solution has been performed by Eyring et al. using a mercury cathode. This paper describes electrolysis studies.

  18. Electrochemical detection of uric acid using ruthenium-dioxide-coated carbon nanotube directly grown onto Si wafer

    NASA Astrophysics Data System (ADS)

    Shih, Yi-Ting; Lee, Kuei-Yi; Lin, Chung-Kuang

    2015-12-01

    Carbon nanotubes (CNTs) directly grown onto a Si substrate by thermal chemical vapor deposition were used in uric acid (UA) detection. The process is simple and formation is easy without the need for additional chemical treatments. However, CNTs lack selectivity and sensitivity to UA. To enhance the electrochemical analysis, ruthenium oxide was used as a catalytic mediator in the modification of electrodes. The electrochemical results show that RuO2 nanostructures coated onto CNTs can strengthen the UA signal. The peak currents of RuO2 nanostructures coated onto CNTs linearly increase with increasing UA concentration, meaning that they can work as electrodes for UA detection. The lowest detection limit and highest sensitivity were 55 nM and 4.36 µA/µM, respectively. Moreover, the characteristics of RuO2 nanostructures coated onto CNTs were examined by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy.

  19. Carbon dioxide conversion over carbon-based nanocatalysts.

    PubMed

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

    2013-07-01

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

  20. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  1. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  2. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  3. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  4. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  5. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  6. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  7. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  8. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  9. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  10. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  11. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  12. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  13. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  14. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  15. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  16. 46 CFR 108.627 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  17. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  18. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  19. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  1. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  2. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  3. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  4. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  5. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  6. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  7. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  8. 46 CFR 78.47-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 78.47-11 Section 78.47-11... Fire and Emergency Equipment, Etc. § 78.47-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into...

  9. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  10. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located within the...

  11. 49 CFR 173.217 - Carbon dioxide, solid (dry ice).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... permit the release of carbon dioxide gas to prevent a buildup of pressure that could rupture...

  12. 46 CFR 97.37-11 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 97.37-11 Section 97.37-11... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-11 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  13. 46 CFR 196.37-8 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8... Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space...

  14. 46 CFR 108.626 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 108.626 Section 108.626... AND EQUIPMENT Equipment Markings and Instructions § 108.626 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  15. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  16. 46 CFR 95.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a... of not more than 300 pounds of carbon dioxide, may have the cylinders located within the...

  17. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  18. 46 CFR 131.817 - Carbon dioxide warning signs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 131.817 Section 131.817... Markings for Fire Equipment and Emergency Equipment § 131.817 Carbon dioxide warning signs. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or...

  19. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  20. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  1. 46 CFR 76.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as... than 300 pounds of carbon dioxide, may have the cylinders located within the space protected. If...

  2. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20... PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide...-5(d), consisting of not more than 300 pounds of carbon dioxide, may have cylinders located...

  3. 46 CFR 169.732 - Carbon dioxide alarm.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  4. 46 CFR 193.15-20 - Carbon dioxide storage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  5. Carbon dioxide-soluble polymers and swellable polymers for carbon dioxide applications

    DOEpatents

    DeSimone, Joseph M.; Birnbaum, Eva; Carbonell, Ruben G.; Crette, Stephanie; McClain, James B.; McCleskey, T. Mark; Powell, Kimberly R.; Romack, Timothy J.; Tumas, William

    2004-06-08

    A method for carrying out a catalysis reaction in carbon dioxide comprising contacting a fluid mixture with a catalyst bound to a polymer, the fluid mixture comprising at least one reactant and carbon dioxide, wherein the reactant interacts with the catalyst to form a reaction product. A composition of matter comprises carbon dioxide and a polymer and a reactant present in the carbon dioxide. The polymer has bound thereto a catalyst at a plurality of chains along the length of the polymer, and wherein the reactant interacts with the catalyst to form a reaction product.

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

    PubMed

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

    2016-09-12

    The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2 ) catalyzed by a zinc β-diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg ) up to 135 °C. These polycarbonates can be efficiently modified by thiols or carboxylic acids in combination with lithium hydroxide or tetrabutylphosphonium bromide as catalysts, respectively, without destruction of the main chain. Moreover, polycarbonates bearing pendent cyclic carbonates can be quantitatively prepared by CO2 insertion catalyzed by lithium bromide. PMID:27529815

  7. Carbon dioxide removal with inorganic membranes

    SciTech Connect

    Judkins, R.R.; Fain, D.E.

    1993-12-31

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

  8. Layered solid sorbents for carbon dioxide capture

    SciTech Connect

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  9. Amino acid-mediated impacts of elevated carbon dioxide and simulated root herbivory on aphids are neutralized by increased air temperatures

    PubMed Central

    Ryalls, James M. W.; Moore, Ben D.; Riegler, Markus; Gherlenda, Andrew N.; Johnson, Scott N.

    2015-01-01

    Changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. This study investigated how mechanically simulated root herbivory of lucerne (Medicago sativa) before and after aphid infestation affected the pea aphid (Acyrthosiphon pisum) under elevated temperature (eT) and carbon dioxide concentrations (eCO2). eT increased plant height and biomass, and eCO2 decreased root C:N. Foliar amino acid concentrations and aphid numbers increased in response to eCO2, but only at ambient temperatures, demonstrating the ability of eT to negate the effects of eCO2. Root damage reduced aboveground biomass, height, and root %N, and increased root %C and C:N, most probably via decreased biological nitrogen fixation. Total foliar amino acid concentrations and aphid colonization success were higher in plants with roots cut early (before aphid arrival) than those with roots cut late (after aphid arrival); however, this effect was counteracted by eT. These results demonstrate the importance of amino acid concentrations for aphids and identify individual amino acids as being potential factors underpinning aphid responses to eT, eCO2, and root damage in lucerne. Incorporating trophic complexity and multiple climatic factors into plant–herbivore studies enables greater insight into how plants and insects will interact in the future, with implications for sustainable pest control and future crop security. PMID:25403916

  10. Polymerization of euphorbia oil in carbon dioxide media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boron trifluoride diethyl etherate (BF3•OEt2), Lewis acid, catalyzed ring-opening polymerization of euphorbia oil (EO), a natural epoxy oil, was conducted in carbon dioxide. The resulting polymers (RPEO) were characterized by FTIR, 1H-NMR, 13C-NMR, solid state 13C-NMR spectroscopies, differential sc...

  11. Polymerization of Plant Oils in Carbon Dioxide Medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lewis acid catalyst, boron trifluoride diethyl etherate (BF3•OEt2), catalyzed polymerization of epoxidized soybean oil (ESO) in liquid carbon dioxide was conducted in an effort to develop useful biodegradable polymers. The ring-opening polymerization was employed at mild conditions, such as at room...

  12. Mineralization strategies for carbon dioxide sequestration

    SciTech Connect

    Penner, Larry R.; O'Connor, William K.; Gerdemann, Stephen J.; Dahlin, David C.

    2003-01-01

    Progress is reported in three primary research areas--each concerned with sequestering carbon dioxide into mineral matrices. Direct mineral carbonation was pioneered at Albany Research Center. The method treats the reactant, olivine or serpentine in aqueous media with carbon dioxide at high temperature and pressure to form stable mineral carbonates. Recent results are introduced for pretreatment by high-intensity grinding to improve carbonation efficiency. To prove feasibility of the carbonation process, a new reactor was designed and operated to progress from batch tests to continuous operation. The new reactor is a prototype high-temperature, high-pressure flow loop reactor that will furnish information on flow, energy consumption, and wear and corrosion resulting from slurry flow and the carbonation reaction. A promising alternative mineralization approach is also described. New data are presented for long-term exposure of carbon dioxide to Colombia River Basalt to determine the extent of conversion of carbon dioxide to permanent mineral carbonates. Batch autoclave tests were conducted using drill-core samples of basalt and reacted under conditions that simulate in situ injection into basalt-containing geological formations.

  13. Removal of organic impurities from liquid carbon dioxide

    NASA Astrophysics Data System (ADS)

    Zito, Richard R.

    2002-09-01

    The use of a high velocity stream of carbon dioxide snowflakes to clean large optics is well known, and has gained widespread acceptance in the astronomical community as a telescope maintenance technique. Ultimately, however, the success of carbon dioxide snow cleaning depends on the availability of high purity carbon dioxide. The higher the purity of the carbon dioxide, the longer will be the time interval between required mirror washings. The highest grades of commercially produced liquid carbon dioxide are often not available in the more remote regions of the world - such as where major astronomical observatories are often located. Furthermore, the purity of even the highest grades of carbon dioxide are only nominal, and wide variations are known to occur from tank to tank. Occasionally, visible deposits of organic impurities are left behind during cleaning with carbon dioxide that is believed to be 99.999% pure. A zeolite molecular sieve based filtration system has proven to be very effective in removing these organic impurities. A zeolite is a complex alumino-silicate. One example has an empirical formula of Na2O(Al2O3)(SiO2)2yH2O, where y=0 to 8. The zeolites have an open crystal structure and are capable of trapping impurities like 8-methylheptadecane (an oil) and 2,6-octadine-1-ol,3,7- dimethyl-,(E)- (a fatty acid). In fact, a zeolite can trap 29.5% of its own weight in SAE 20 lubricant at 25 degree(s)C. After filtration of liquid CO2 through zeolites, the concentration of measured impurities was below the detection limit for state-of-the-art gas chromatography systems.

  14. The anaesthesia of fish by high carbon-dioxide concentrations

    USGS Publications Warehouse

    1942-01-01

    A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

  15. Contribution of C3 carboxylation to the circadian rhythm of carbon dioxide uptake in a Crassulacean acid metabolism plant Kalanchoë daigremontiana.

    PubMed

    Wyka, Tomasz P; Lüttge, Ulrich E

    2003-05-01

    During the endogenous circadian rhythm of carbon dioxide uptake in continuous light by a Crassula cean acid metabolism plant, Kalanchoë daigremontiana, the two carboxylating enzymes, phosphoenolpyruvate carboxylase (PEPC) and ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco), are active simultaneously, although, until now, only the role of PEPC in generating the rhythm has been acknowledged. According to the established model, the rhythm is primarily regulated at the PEPC activity level, modulated by periodic compartmentation of its inhibitor, malate, in the vacuole and controlled by tension/relaxation of the tonoplast. However, the circadian accumulation of malic acid (the main indicator of PEPC activity) dampened significantly within the first few periods without affecting the rhythm's amplitude. Moreover, the amount of malate accumulated during a free-running oscillation was several-fold lower than the amount expected if PEPC were the key carboxylating enzyme, based on a 1:1 stoichiometry of CO(2) and malate. Together with the observation that rates of CO(2) uptake under continuous light were higher than in darkness, the evidence shows that C(3) carboxylation greatly contributes to the generation of rhythmic CO(2) uptake in continuous light in this 'obligate' CAM plant. Because the shift from predominantly CAM to predominantly C(3) carboxylation is smooth and does not distort the trajectory of the rhythm, its control probably arises from a robust network of oscillators, perhaps also involving stomata. PMID:12709493

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

    PubMed

    Khan, Ikhtiar; Azam, Andaleeb; Mahmood, Abid

    2013-01-01

    The global average temperature has witnessed a steady increase during the second half of the twentieth century and the trend is continuing. Carbon dioxide, a major green house gas is piling up in the atmosphere and besides causing global warming, is expected to alter the physico-chemical composition of plants. The objective of this work was to evaluate the hypothesis that increased CO(2) in the air is causing undesirable changes in the nutritional composition of tomato fruits. Two varieties of tomato (Lycopersicon esculentum) were grown in ambient (400 μmol mol(-1)) and elevated (1,000 μmol mol(-1)) concentration of CO(2) under controlled conditions. The fruits were harvested at premature and fully matured stages and analyzed for yield, proximate composition, elemental concentration, fatty acid, and vitamin C contents. The amount of carbohydrates increased significantly under the enhanced CO(2) conditions. The amount of crude protein and vitamin C, two important nutritional parameters, decreased substantially. Fatty acid content showed a mild decrease with a slight increase in crude fiber. Understandably, the effect of enhanced atmospheric CO(2) was more pronounced at the fully matured stage. Mineral contents of the fruit samples changed in an irregular fashion. Tomato fruit has been traditionally a source of vitamin C, under the experimental conditions, a negative impact of enhanced CO(2) on this source of vitamin C was observed. The nutritional quality of both varieties of tomato has altered under the CO(2) enriched atmosphere. PMID:22382378

  17. Formation of Quartz-Carbonate Veins: Evidence From Experimental Supercritical Carbon Dioxide-Brine-Rock System

    NASA Astrophysics Data System (ADS)

    Janecky, D. R.; Kaszuba, J. P.

    2003-12-01

    Quartz-carbonate veins are common in a variety of moderate temperature hydrothermal systems and ore deposits. Associated fluid inclusions have a wide range of compositions, including liquid carbon dioxide fillings. Examination of chemical and physical conditions which result precipitation of quartz and carbonate in veins raises several key questions about multiphase fluid processes and reaction rates. We have been experimentally investigating physical-chemical reaction processes of mixed brine-carbon dioxide fluids for the shallow crust. Synthetic arkose (microcline + oligoclase + quartz + biotite) plus argillaceous shale were reacted with 5.5 molal NaCl brine. The system was held at 200 C and 200 bars for 32 days to approach steady state, then injected with carbon dioxide and allowed to react for an additional 45 days. In a parallel experiment, the system was allowed to react for 77 days without injection of carbon dioxide. Trace ions initially absent from NaCl brine appeared in solution at mM (K, Ca, and silica) to uM (Mg, Al, Fe and Mn) quantities, reflecting reaction of brine with rock. Without carbon dioxide injection, the silica concentration (2.4 mM) was stable below calculated quartz solubility (3.9 mM). Injection of carbon dioxide resulted in decreased pH and increased silica concentration to a level near calculated chalcedony solubility (5.4 mM). Dissolution of silicate minerals is apparently coupled to the acidity, and concomitant inhibition of the precipitation of quartz (and other silicates). A significant increase in concentration of trace metals is consistent with in-situ pH decrease and increased carbon dioxide dissolved in brine. Multi-phase fluid reaction relationships between supercritical carbon dioxide and brine-rock systems allow formation of carbonate vein precipitates in substantial quantities. Brine and continued rock reactions provide a substantial reservoir for Ca, Mg and Fe components. A separate carbon dioxide liquid allows

  18. Turning carbon dioxide into fuel.

    PubMed

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

    2010-07-28

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

  19. Effect of gaseous anaesthesia on blood carbon dioxide measurements

    PubMed Central

    Ogilvie, R. R.; Howie, G. F. A.

    1965-01-01

    The present study of the effect of two common anaesthetic gases on blood acid-base parameters shows that the micro-Astrup measurement of carbon dioxide tension is not invalidated by the presence of nitrous oxide. This result was anticipated from the theoretical aspect of this technique. The mean error involved in estimating plasma carbon dioxide content in the presence of nitrous oxide using the volumetric Van Slyke apparatus without absorption of carbon dioxide by sodium hydroxide can be of the order of 25%. No such effect was measurable in estimating carbon dioxide contents in the presence of halothane. The degree of respiratory alkalosis during anaesthesia reported in earlier papers (Walker, Morgan, Breckenridge, Watt, Ogilvie, and Douglas, 1963; Morgan, Ogilvie, and Walker, 1963) was greater than had been originally appreciated. A `false' increase in carbon dioxide content will also falsely increase buffer base or `base excess' as calculated from standard nomograms (Singer and Hastings, 1948; Davenport, 1958; Siggaard-Andersen, 1963). PMID:14304255

  20. Fourier transform infrared study on hydrogen bonding species of carboxylic acids in supercritical carbon dioxide with ethanol

    SciTech Connect

    Yamamoto, Morio; Iwai, Yoshio; Nakajima, Taro; Arai, Yasuhiko

    1999-05-06

    Supercritical fluid extraction has been given much attention recently as one of the new separation technologies in the chemical industry. Fourier transform infrared (FTIR) spectroscopy has been used to determine the equilibrium constants of the dimerization for carboxylic acid (acetic acid or palmitic acid) and the amount of hydrogen bonding species between carboxylic acid and ethanol in supercritical CO{sub 2}. Experiments were carried out at 308.2--313.2 K and 10.0--20.0 MPa. The noticeable band was the C{double_bond}O stretching band for carboxylic acid. In the binary system (supercritical CO{sub 2} + carboxylic acid), the equilibrium constants of the dimerization between the carboxylic acid monomer and dimer decrease with increasing pressure and temperature. The equilibrium constants of palmitic acid are larger than those of acetic acid. In a ternary system (supercritical CO{sub 2} + carboxylic acid + ethanol), the amount of hydrogen bonding species between carboxylic acid and ethanol in supercritical CO{sub 2} increases with the increasing mole fraction of added ethanol. Furthermore, the authors confirm that the solubility enhancement by ethanol used as an entrainer in supercritical CO{sub 2} related to the amount of hydrogen bonding species between carboxylic acid and ethanol.

  1. Photoassisted carbon dioxide reduction and formation of twoand three-carbon compounds. [prebiological photosynthesis

    NASA Technical Reports Server (NTRS)

    Halmann, M.; Aurian-Blajeni, B.; Bloch, S.

    1981-01-01

    The photoassisted reduction of aqueous carbon dioxide in the presence of naturally occurring minerals is investigated as a possible abiotic precursor of photosynthesis. Aqueous carbon dioxide saturated suspensions or surfaces of the minerals nontronite, bentonite, anatase, wolframite, molybdenite, minium, cinnabar and hematite were irradiated with high-pressure mercury lamps or sunlight. Chemical analyses reveal the production of formic acid, formaldehyde, methanol and methane, and the two and three-carbon compounds glyoxal (CHOCHO) and malonaldehyde (CH2(CHO)2). It is suggested that such photosynthetic reactions with visible light in the presence of semiconducting minerals may provide models for prebiological carbon and nitrogen fixation in both oxidized and reduced atmospheres.

  2. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects listed above, also

  3. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2003-03-10

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The originally-stated, major objectives of the current project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project has developed, an important additional objective has been added to the above original list. Namely, we have been encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we have participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects

  4. Gas-saturated solution process to obtain microcomposite particles of alpha lipoic acid/hydrogenated colza oil in supercritical carbon dioxide.

    PubMed

    Mishima, Kenji; Honjo, Masatoshi; Sharmin, Tanjina; Ito, Shota; Kawakami, Ryo; Kato, Takafumi; Misumi, Makoto; Suetsugu, Tadashi; Orii, Hideaki; Kawano, Hiroyuki; Irie, Keiichi; Sano, Kazunori; Mishima, Kenichi; Harada, Takunori; Ouchi, Mikio

    2016-09-01

    Alpha lipoic acid (ALA), an active substance in anti-aging products and dietary supplements, need to be masked with an edible polymer to obscure its unpleasant taste. However, the high viscosity of the ALA molecules prevents them from forming microcomposites with masking materials even in supercritical carbon dioxide (scCO2). Therefore, the purpose of this study was to investigate and develop a novel production method for microcomposite particles for ALA in hydrogenated colza oil (HCO). Microcomposite particles of ALA/HCO were prepared by using a novel gas-saturated solution (PGSS) process in which the solid-dispersion method is used along with stepwise temperature control (PGSS-STC). Its high viscosity prevents the formation of microcomposites in the conventional PGSS process even under strong agitation. Here, we disperse the solid particles of ALA and HCO in scCO2 at low temperatures and change the temperature stepwise in order to mix the melted ALA and HCO in scCO2. As a result, a homogeneous dispersion of the droplets of ALA in melted HCO saturated with CO2 is obtained at high temperatures. After the rapid expansion of the saturated solution through a nozzle, microcomposite particles of ALA/HCO several micrometers in diameter are obtained. PMID:26024240

  5. Evaluation of the Total Carbon Dioxide Apparatus and pH Meter for the Determination of Acid-Base Status in Diarrheic and Healthy Calves

    PubMed Central

    Naylor, Jonathan M.

    1987-01-01

    Three simple tests of acid-base status were evaluated for field use. Blood samples were collected from 20 diarrheic and 24 healthy calves less than six weeks of age. One sample was collected anaerobically and immediately analyzed on a blood gas analyzer. The other samples were used for measurement of blood and serum pH using a pH meter and pH paper, and for serum total carbon dioxide (TCO2) using a TCO2 apparatus. The TCO2 apparatus gave the best results and would be useful in the field. TCO2 apparatus measurements had a high correlation, r=0.91, with blood gas analyzer blood bicarbonate values. Healthy calves have a serum TCO2 content of 30 mmol/L and bicarbonate requirements for correcting metabolic acidosis in diarrheic calves can be calculated: Bicarbonate required (mmol) = (30-TCO2) × Body Weight × 0.6 This can be converted to grams of sodium bicarbonate by dividing by 12. PMID:17422884

  6. Preparation and Properties of Nonionic Vesicles Prepared with Polyglycerol Fatty Acid Esters Using the Supercritical Carbon Dioxide Reverse Phase Evaporation Method.

    PubMed

    Yamaguchi, Shunsuke; Kimura, Zen; Misono, Takeshi; Tsuchiya, Koji; Sakai, Kenichi; Abe, Masahiko; Sakai, Hideki

    2016-01-01

    Previously, we reported a new preparation method for liposomes and niosomes (nonionic vesicles) using supercritical carbon dioxide (scCO2) as the solvent (scRPE method). In this study, niosomes were prepared from polyglycerol fatty acid ester (PG ester)-type nonionic surfactants. These surfactants are made from naturally derived materials and are neither harmful to the human body nor to the environment. Niosomes were prepared using the scRPE method with ethanol as the co-solvent. Through this method, decaglycerol distearate (DG2S) and decaglycerol diisostearate (DG2IS) formed niosomes. On the other hand, decaglycerol monostearate (DG1S), which has a high hydrophilic-lipophilic balance (HLB) value, yielded a solution of spherical micelles, and decaglycerol tristearate (DG3S), which has a low HLB value, yielded a gel-like solution. Niosomes of DG2IS had higher trapping efficiencies and dispersion stabilities than those of DG2S because the membrane fluidity of the DG2IS niosomes was greater than that of the DG2S niosomes. The niosomes obtained in the present study are candidates for cosmetic and pharmaceutical applications because they are formed from nonionic surfactants derived from natural sources, and prepared using the scRPE method, which avoids the use of harmful organic solvents. PMID:26876680

  7. The brain acid-base homeostasis and serotonin: A perspective on the use of carbon dioxide as human and rodent experimental model of panic.

    PubMed

    Leibold, N K; van den Hove, D L A; Esquivel, G; De Cort, K; Goossens, L; Strackx, E; Buchanan, G F; Steinbusch, H W M; Lesch, K P; Schruers, K R J

    2015-06-01

    Panic attacks (PAs), the core feature of panic disorder, represent a common phenomenon in the general adult population and are associated with a considerable decrease in quality of life and high health care costs. To date, the underlying pathophysiology of PAs is not well understood. A unique feature of PAs is that they represent a rare example of a psychopathological phenomenon that can be reliably modeled in the laboratory in panic disorder patients and healthy volunteers. The most effective techniques to experimentally trigger PAs are those that acutely disturb the acid-base homeostasis in the brain: inhalation of carbon dioxide (CO2), hyperventilation, and lactate infusion. This review particularly focuses on the use of CO2 inhalation in humans and rodents as an experimental model of panic. Besides highlighting the different methodological approaches, the cardio-respiratory and the endocrine responses to CO2 inhalation are summarized. In addition, the relationships between CO2 level, changes in brain pH, the serotonergic system, and adaptive physiological and behavioral responses to CO2 exposure are presented. We aim to present an integrated psychological and neurobiological perspective. Remaining gaps in the literature and future perspectives are discussed. PMID:25930682

  8. A Comparison between the Effects of Glucantime, Topical Trichloroacetic Acid 50% plus Glucantime, and Fractional Carbon Dioxide Laser plus Glucantime on Cutaneous Leishmaniasis Lesions

    PubMed Central

    Jaffary, Fariba; Nilforoushzadeh, Mohammad Ali; Siadat, Amirhossein; Haftbaradaran, Elaheh; Ansari, Nazli; Ahmadi, Elham

    2016-01-01

    Background. Cutaneous leishmaniasis is an endemic disease in Iran. Pentavalent antimonial drugs have been the first line of therapy in cutaneous leishmaniasis for many years. However, the cure rate of these agents is still not favorable. This study was carried out to compare the efficacies of intralesional glucantime with topical trichloroacetic acid 50% (TCA 50%) + glucantime and fractional carbon dioxide laser + glucantime in the treatment of cutaneous leishmaniasis. Methods. A total of 90 patients were randomly divided into three groups of 30 to be treated with intralesional injection of glucantime, a combination of topical TCA 50% and glucantime, or a combination of fractional laser and glucantime. The overall clinical improvement and changes in sizes of lesions and scars were assessed and compared among three groups. Results. The mean duration of treatment was 6.1 ± 2.1 weeks in all patients (range: 2–12 weeks) and 6.8 ± 1.7, 5.2 ± 1.0, and 6.3 ± 3.0 weeks in glucantime, topical TCA plus glucantime, and fractional laser plus glucantime groups, respectively (P = 0.011). Complete improvement was observed in 10 (38.5%), 27 (90%), and 20 (87%) patients of glucantime, glucantime + TCA, and glucantime + laser groups, respectively (P < 0.001). Conclusion. Compared to glucantime alone, the combination of intralesional glucantime and TCA 50% or fractional CO2 laser had significantly higher and faster cure rate in patients with cutaneous leishmaniasis. PMID:27148363

  9. Polymers for metal extractions in carbon dioxide

    DOEpatents

    DeSimone, Joseph M.; Tumas, William; Powell, Kimberly R.; McCleskey, T. Mark; Romack, Timothy J.; McClain, James B.; Birnbaum, Eva R.

    2001-01-01

    A composition useful for the extraction of metals and metalloids comprises (a) carbon dioxide fluid (preferably liquid or supercritical carbon dioxide); and (b) a polymer in the carbon dioxide, the polymer having bound thereto a ligand that binds the metal or metalloid; with the ligand bound to the polymer at a plurality of locations along the chain length thereof (i.e., a plurality of ligands are bound at a plurality of locations along the chain length of the polymer). The polymer is preferably a copolymer, and the polymer is preferably a fluoropolymer such as a fluoroacrylate polymer. The extraction method comprises the steps of contacting a first composition containing a metal or metalloid to be extracted with a second composition, the second composition being as described above; and then extracting the metal or metalloid from the first composition into the second composition.

  10. [Pharmaceutical applications of supercritical carbon dioxide].

    PubMed

    Delattre, L

    2007-01-01

    The supercritical state of a fluid is intermediate between that of gases and liquids. Supercritical fluids exhibit some solvent power which is tunable in function of pressure and temperature. In the pharmaceutical field, supercritical carbon dioxide is by far the most commonly used fluid; of course, the first applications of supercritical fluids were the replacement of organic solvents in extraction processes; other applications appeared during the last twenty years: supercritical fluids are also used as eluents in chromatography, as solvents in organic synthesis or for the processing of solid dosage forms by drug micronization, by the production of nanospheres, of solid dispersions, of porous polymeric matrices containing different active substances. Supercritical carbon dioxide has been proposed for encapsulating both hydrophilic and hydrophobic drug substances into liposomes as well as for including different active substances into cyclodextrins. There are also future prospects for the use of pressurized carbon dioxide as a sterilizing agent. PMID:17299352

  11. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  12. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  13. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  14. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  15. 21 CFR 868.1400 - Carbon dioxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon...

  16. Carbon Dioxide Chemistry on Titan's Surface

    NASA Astrophysics Data System (ADS)

    Hodyss, R. P.; Cable, M. L.; Malaska, M. J.; Vu, T. H.

    2015-12-01

    The surfaces of the moons of the outer Solar System are usually considered too cold (30-100 K) for significant chemistry to occur without the input of energy from exogenic sources (such as charged particles or VUV irradiation). In particular, Titan's thick atmosphere prevents significant amounts of high energy radiation from reaching the surface, limiting opportunities for surface chemical reactivity. Recently, we have identified carbamation, the reaction of carbon dioxide with primary amines to form carbamic acids, as a reaction that could occur thermally on Titan's surface. Amines should be present on Titan's surface, formed by photochemical reactions of N2 and CH4 in the upper atmosphere, and amine-containing molecules have been detected as a component of laboratory tholins made in terrestrial laboratories. There is some spectral evidence that CO2 is present on the surface, and CO2 has been definitively identified in the atmosphere. We use a combination of micro-Raman spectroscopy and UHV FTIR spectroscopy to examine the reaction products and kinetics of the carbamation reaction for a variety of primary amines. The reaction occurs readily at Titan surface temperatures (94 K), and leads to both carbamic acids and ammonium carbamate salts. Our kinetic data can be used to estimate the lifetime of CO2 on Titan's surface, and thus constrain the age of possible CO2-bearing cryovolcanic deposits.

  17. Carbon dioxide hydrate and floods on Mars

    NASA Technical Reports Server (NTRS)

    Milton, D. J.

    1974-01-01

    Ground ice on Mars probably consists largely of carbon dioxide hydrate. This hydrate dissociates upon release of pressure at temperatures between 0 and 10 C. The heat capacity of the ground would be sufficient to produce up to 4% (by volume) of water at a rate equal to that at which it can be drained away. Catastrophic dissociation of carbon dioxide hydrate during some past epoch when the near-surface temperature was in this range would have produced chaotic terrain and flood channels.

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

    SciTech Connect

    Klaus Lackner; Hans-Joachim Ziock; Patrick Grimes

    1999-02-01

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

  19. Controls on the Time Scale of Carbonate Neutralization of Carbon Dioxide Released to the Atmosphere

    NASA Astrophysics Data System (ADS)

    Caldeira, K.; Cao, L.

    2007-12-01

    Once released to the atmosphere, carbon dioxide is removed on a range of time scales. On the time scale of years to centuries, carbon dioxide removal from the atmosphere is dominated by transport processes within the ocean. On the time scale of hundreds of thousands of years, carbon dioxide removal from the atmosphere is dominated by processes related to the weathering of silicate rocks on land. Between these time scales, carbon dioxide removal is dominated by interactions involving carbonate minerals both on land and in the sea. Net dissolution of carbonate minerals (on land or in the sea) increases ocean alkalinity to an extent that exceeds the amount of carbon addition; the result is a transfer of carbon from the atmosphere to the ocean and moderation of the effects of added carbon on ocean chemical parameters such as pH and carbonate mineral saturation. There has been some controversy over how fast equilibration with carbonate minerals can neutralize carbon acidity, with claims ranging from the extreme and untenable claim that this process is essentially instantaneous to more plausible claims that the equilibration time scale may approach 10 kyr. Even within the domain of informed discourse, estimates of the carbonate neutralization timescale can vary by an order-of-magnitude. Here, in an effort to understand the sources of the lack of consensus on this issue, we examine how various processes (e.g., ocean transport, sediment pore water diffusion, carbonate-mineral dissolution, and carbonate weathering on land) influence the time scale for carbonate neutralization of carbon dioxide releases to the atmosphere.

  20. Global deforestation: contribution to atmospheric carbon dioxide.

    PubMed

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

    1983-12-01

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

  1. Global deforestation: contribution to atmospheric carbon dioxide

    SciTech Connect

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

    1983-12-09

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

  2. Effects of acid rain and sulfur dioxide on marble dissolution

    SciTech Connect

    Schuster, P.F.; Reddy, M.M. ); Sherwood, S.I. )

    1994-01-01

    Acid precipitation and the dry deposition of sulfur dioxide (SO[sub 2]) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO[sub 2] gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

  3. Effects of acid rain and sulfur dioxide on marble dissolution

    USGS Publications Warehouse

    Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

    1994-01-01

    Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

  4. Capture of carbon dioxide from ethanol fermentation by liquid absorption for use in biological production of succinic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously it was shown that the gas produced in an ethanol fermentor using either corn or barley as feedstock could be sparged directly into an adjacent fermentor using Escherichia coli AFP184 to provide the CO2 required for succinic acid production. In the present investigation it has been demons...

  5. Copper-Catalyzed Carboxylation of Alkenylzirconocenes with Carbon Dioxide Leading to α,β-Unsaturated Carboxylic Acids.

    PubMed

    Wang, Sheng; Shao, Peng; Chen, Chao; Xi, Chanjuan

    2015-10-16

    A variety of alkenylzirconocenes were efficiently carboxylated by CO2 utilizing the (IMes)CuCl catalyst yielding the corresponding α,β-unsaturated carboxylic acids in good yields. This reaction could be carried out in a one-pot operation via sequential carbozirconation of alkynes and carboxylation using CO2 as starting materials under room temperature. PMID:26406296

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  7. Solubility of Sulfur Dioxide in Sulfuric Acid

    NASA Technical Reports Server (NTRS)

    Chang, K. K.; Compton, L. E.; Lawson, D. D.

    1982-01-01

    The solubility of sulfur dioxide in 50% (wt./wt.) sulfuric acid was evaluated by regular solution theory, and the results verified by experimental measurements in the temperature range of 25 C to 70 C at pressures of 60 to 200 PSIA. The percent (wt./wt.) of sulfur dioxide in 50% (wt./wt.) sulfuric acid is given by the equation %SO2 = 2.2350 + 0.0903P - 0.00026P 10 to the 2nd power with P in PSIA.

  8. International Space Station Carbon Dioxide Removal Assembly Testing

    NASA Technical Reports Server (NTRS)

    Knox, James C.

    2000-01-01

    Performance testing of the International Space Station Carbon Dioxide Removal Assembly flight hardware in the United States Laboratory during 1999 is described. The CDRA exceeded carbon dioxide performance specifications and operated flawlessly. Data from this test is presented.

  9. Gas diffusion cell removes carbon dioxide from occupied airtight enclosures

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Small, lightweight permeable cell package separates and removes carbon dioxide from respiratory gas mixtures. The cell is regenerative while chemically inert in the presence of carbon dioxide so that only adsorption takes place.

  10. Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic

    SciTech Connect

    Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

    2000-02-01

    The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

  11. Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

    NASA Astrophysics Data System (ADS)

    Ji, Amin; Sun, Miming; Li, Jie; Yin, Gang; Cheng, Keyong; Zhen, Bing; Sun, Ying

    Nowadays, the problem of the environment goes worse, it urges people to research and study new energy-saving and environment-friendly refrigerants, such as carbon dioxide, at present, people do research on carbon dioxide at home and abroad. This paper introduces the property of carbon dioxide as a refrigerant, sums up and analyses carbon dioxide refrigeration cycles, and points out the development and research direction in the future.

  12. Rising atmospheric carbon dioxide and crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increase in carbon dioxide concentration in the earth's atmosphere and its potential effect on atmospheric temperature is a major concern. Changes in global environment will have major effects for natural and agricultural ecosystems. Plants have been directly affected by rising atmospheric CO2...

  13. Carboxylation of alkylboranes by N-heterocyclic carbene copper catalysts: synthesis of carboxylic acids from terminal alkenes and carbon dioxide.

    PubMed

    Ohishi, Takeshi; Zhang, Liang; Nishiura, Masayoshi; Hou, Zhaomin

    2011-08-22

    Caught in the act: N-Heterocyclic carbene copper(I) complexes (1; IPr=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) serve as an excellent catalyst for the carboxylation of alkylboranes (2; R=alkyl) with CO(2) to afford a variety of functionalized carboxylic acids (3) in high yields. A novel copper methoxide/alkylborane adduct (A) and its subsequent CO(2) insertion product (B) have been isolated and shown to be true active catalyst species. PMID:21739544

  14. Catalyst cartridge for carbon dioxide reduction unit

    NASA Technical Reports Server (NTRS)

    Holmes, R. F. (Inventor)

    1973-01-01

    A catalyst cartridge, for use in a carbon dioxide reducing apparatus in a life support system for space vehicles, is described. The catalyst cartridge includes an inner perforated metal wall, an outer perforated wall space outwardly from the inner wall, a base plate closing one end of the cartridge, and a cover plate closing the other end of the cartridge. The cover plate has a central aperture through which a supply line with a heater feeds a gaseous reaction mixture comprising hydrogen and carbon dioxide at a temperature from about 1000 to about 1400 F. The outer surfaces of the internal wall and the inner surfaces of the outer wall are lined with a ceramic fiber batting material of sufficient thickness to prevent carbon formed in the reaction from passing through it. The portion of the surfaces of the base and cover plates defined within the inner and outer walls are also lined with ceramic batting. The heated reaction mixture passes outwardly through the inner perforated wall and ceramic batting and over the catalyst. The solid carbon product formes is retained within the enclosure containing the catalyst. The solid carbon product formed is retained within the enclosure containing the catalyst. The water vapor and unreacted carbon dioxide and any intermediate products pass through the perforations of the outer wall.

  15. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  16. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  17. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  18. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  19. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  20. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  1. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  2. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  3. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  4. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  5. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  6. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  7. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  8. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  9. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2013-10-01 2013-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  10. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  11. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  12. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  13. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  14. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  15. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2014-10-01 2014-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  16. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  17. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  18. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  19. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  20. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  1. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  2. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  3. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  4. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  5. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  6. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2011-10-01 2011-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  7. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  8. 21 CFR 868.5300 - Carbon dioxide absorbent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a device intended for medical purposes that consists of...

  9. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  10. 40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.124-78 Carbon dioxide analyzer calibration. Prior to its introduction into service and monthly thereafter the NDIR carbon dioxide analyzer shall be calibrated:...

  11. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  12. 27 CFR 26.222 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... carbon dioxide. 26.222 Section 26.222 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From the Virgin Islands § 26.222 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of...

  13. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www... 49 Transportation 3 2012-10-01 2012-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1... Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated...

  14. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  15. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  16. 21 CFR 868.5310 - Carbon dioxide absorber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a device that is intended for medical purposes and that is used in...

  17. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  18. 9 CFR 313.5 - Chemical; carbon dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Chemical; carbon dioxide. 313.5... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.5 Chemical; carbon dioxide. The slaughtering of sheep, calves and swine with the use of carbon dioxide gas and the handling in...

  19. 27 CFR 24.319 - Carbon dioxide record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted...

  20. 46 CFR 108.431 - Carbon dioxide systems: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure...

  1. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

  2. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... carbon dioxide. 26.52 Section 26.52 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ISLANDS Formulas for Products From Puerto Rico § 26.52 Still wines containing carbon dioxide. (a) General. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine;...

  3. 46 CFR 169.565 - Fixed carbon dioxide system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565... Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide required for each space protected must be equal to the gross volume...

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

    PubMed

    Frick, R; Junker, B

    1999-01-01

    Various factors which influence dissolved carbon dioxide levels were indirectly evaluated in pilot scale and laboratory studies. For pilot scale studies, off-gas carbon dioxide (percentage in exit air) was measured using a mass spectrometer and then its potential impact on dissolved carbon dioxide concentrations qualitatively examined. Greater volumetric air flowrates reduced off-gas carbon dioxide levels more effectively at lower airflow ranges and thus lowered expected dissolved carbon dioxide levels through gas stripping. Lower broth pH values decreased off-gas carbon dioxide levels but increased expected dissolved carbon dioxide levels due to the pH-dependence of the gas/liquid carbon dioxide equilibrium. While back-pressure increases had an insignificant effect on off-gas carbon dioxide levels, they directly affected expected dissolved carbon dioxide levels according to Henry's law. Laboratory studies, conducted using both uninoculated and inoculated fermentation media, quantified the response of the media to pH changes with bicarbonate addition, specifically its buffering capacity. This effect then was related qualitatively to expected dissolved carbon dioxide levels. Higher dissolved carbon dioxide levels, as demonstrated by reduced pH changes with bicarbonate addition, thus would be expected for salt solutions of increased ionic strength and higher protein content media. In addition, pH changes with greater bicarbonate additions declined for fermentation samples taken over the course of a one week cultivation, most likely due to the higher protein content associated with biomass growth. The presence of weak acids/bases initially in the media or formed as metabolic by products, as well as the concentration of buffering ions such as phosphate, also were believed to be important contributing elements to the buffering capacity of the solution. PMID:16232479

  5. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung ); Takahashi, Taro . Lamont-Doherty Earth Observatory)

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0[sup 2] include carbon chemistry, distribution of alkalinity, pCO[sup 2] and total concentration of dissolved C0[sup 2], sea-air pCO[sup 2] difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0[sup 2] uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0[sup 2] from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0[sup 2] fertilization is a potential candidate for such missing carbon sinks.

  6. Ocean uptake of carbon dioxide

    SciTech Connect

    Peng, Tsung-Hung; Takahashi, Taro

    1993-06-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0{sup 2} include carbon chemistry, distribution of alkalinity, pCO{sup 2} and total concentration of dissolved C0{sup 2}, sea-air pCO{sup 2} difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0{sup 2} uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0{sup 2} from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0{sup 2} fertilization is a potential candidate for such missing carbon sinks.

  7. Extraction fatty acid as a source to produce biofuel in microalgae Chlorella sp. and Spirulina sp. using supercritical carbon dioxide

    NASA Astrophysics Data System (ADS)

    Tai, Do Chiem; Hai, Dam Thi Thanh; Vinh, Nguyen Hanh; Phung, Le Thi Kim

    2016-06-01

    In this research, the fatty acids of isolated microalgae were extracted by some technologies such as maceration, Soxhlet, ultrasonic-assisted extraction and supercritical fluid extraction; and analyzed for biodiesel production using GC-MS. This work deals with the extraction of microalgae oil from dry biomass by using supercritical fluid extraction method. A complete study at laboratory of the influence of some parameters on the extraction kinetics and yields and on the composition of the oil in terms of lipid classes and profiles is proposed. Two types of microalgae were studied: Chlorella sp. and Spirulina sp. For the extraction of oil from microalgae, supercritical CO2 (SC-CO2) is regarded with interest, being safer than n-hexane and offering a negligible environmental impact, a short extraction time and a high-quality final product. Whilst some experimental papers are available on the supercritical fluid extraction (SFE) of oil from microalgae, only limited information exists on the kinetics of the process. These results demonstrate that supercritical CO2 extraction is an efficient method for the complete recovery of the neutral lipid phase.

  8. Effects of acid irrigation on carbon dioxide evolution, extractable nitrogen, phosphorus, and aluminum in a deciduous forest soil

    SciTech Connect

    Johnson, D.W.; Todd, D.E.

    1984-01-01

    A study was initiated to determine the effects of sulfuric and nitric acid irrigation on CO/sub 2/ evolution, and N, P, and Al availability in a deciduous forest soil. Irrigation with H/sub 2/O, H/sub 2/SO/sub 4/, or HNO/sub 3/ at 0.05 mol (p/sup +/) m/sup -2/ and 0.5 mol (p/sup +/) m/sup -2/ for 1 yr had no consistent effect on CO/sub 2/ evolution, soil NH/sub 4//sup +/, extractable P, or extractable Al in a deciduous forest soil under field conditions. Irrigation with HNO/sub 3/ caused temporary increases in soil NO/sub 3//sup -/, but irrigation with H/sub 2/SO/sub 4/ had no effect on soil NO/sub 3//sup -/. Nitrogen mineralization and nitrification by aerobic incubation were also unaffected by treatments. Seasonal variations in CO/sub 2/ evolution, NH/sub 4//sup +/, and extractable P were pronounced, with peaks in CO/sub 2/ evolution, NH/sub 4//sup +/, in June and a peak extractable P in August. 19 references, 2 tables.

  9. Somewhere beyond the sea? The oceanic - carbon dioxide - reactions

    NASA Astrophysics Data System (ADS)

    Meisinger, Philipp; Wittlich, Christian

    2014-05-01

    In correlation to climate change and CO2 emission different campaigns highlight the importance of forests and trees to regulate the concentration of carbon dioxide in the earths' atmosphere. Seeing millions of square miles of rainforest cut down every day, this is truly a valid point. Nevertheless, we often tend to forget what scientists like Spokes try to raise awareness for: The oceans - and foremost deep sea sections - resemble the second biggest deposit of carbon dioxide. Here carbon is mainly found in form of carbonate and hydrogen carbonate. The carbonates are needed by corals and other sea organisms to maintain their skeletal structure and thereby to remain vital. To raise awareness for the protection of this fragile ecosystem in schools is part of our approach. Awareness is achieved best through understanding. Therefore, our approach is a hands-on activity that aims at showing students how the carbon dioxide absorption changes in relation to the water temperature - in times of global warming a truly sensitive topic. The students use standard syringes filled with water (25 ml) at different temperatures (i.e. 10°C, 20°C, 40°C). Through a connector students inject carbon dioxide (25ml) into the different samples. After a fixed period of time, students can read of the remaining amount of carbon dioxide in relation to the given water temperature. Just as with every scientific project, students need to closely monitor their experiments and alter their setups (e.g. water temperature or acidity) according to their initial planning. A digital template (Excel-based) supports the analysis of students' experiments. Overview: What: hands-on, minds -on activity using standard syringes to exemplify carbon dioxide absorption in relation to the water temperature (Le Chatelier's principle) For whom: adjustable from German form 11-13 (age: 16-19 years) Time: depending on the prior knowledge 45-60 min. Sources (extract): Spokes, L.: Wie Ozeane CO2 aufnehmen. Environmental

  10. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  11. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  12. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers....

  13. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  14. The Perils of Carbonic Acid and Equilibrium Constants.

    ERIC Educational Resources Information Center

    Jencks, William P.; Altura, Rachel A.

    1988-01-01

    Discusses the effects caused by small amounts of carbon dioxide usually present in water and acid-base equilibria of dilute solutions. Notes that dilute solutions of most weak acids and bases undergo significant dissociation or protonation. (MVL)

  15. Hidden carbon dioxide on Mars

    NASA Astrophysics Data System (ADS)

    Haberle, M. R.

    1985-12-01

    A recent proposal that much of the outgassed CO2 on Mars is tied up in the planet's crust in the form of carbonate mineral is discussed. According to this hypothesis, carbonate formation on Mars continued after open bodies of liquid water became unstable. A consequence of the hypothesis is that, in the absence of a recycling mechanism for CO2, the surface pressure on Mars will monotonically decrease until it reaches the minimum atmospheric overburden pressure required for liquid water to form. The theory explains Mars' low surface pressure, and also implies that the climate of Mars has evolved linearly over geologic time, rather than cyclically.

  16. Hidden carbon dioxide on Mars

    NASA Technical Reports Server (NTRS)

    Haberle, R. M.

    1985-01-01

    A recent proposal that much of the outgassed CO2 on Mars is tied up in the planet's crust in the form of carbonate mineral is discussed. According to this hypothesis, carbonate formation on Mars continued after open bodies of liquid water became unstable. A consequence of the hypothesis is that, in the absence of a recycling mechanism for CO2, the surface pressure on Mars will monotonically decrease until it reaches the minimum atmospheric overburden pressure required for liquid water to form. The theory explains Mars' low surface pressure, and also implies that the climate of Mars has evolved linearly over geologic time, rather than cyclically.

  17. Separation of Carbon Dioxide from Flue Gas Using Ion Pumping

    SciTech Connect

    Aines, R; Bourcier, W L; Johnson, M R

    2006-04-21

    We are developing a new way of separating carbon dioxide from flue gas based on ionic pumping of carbonate ions dissolved in water. Instead of relying on large temperature or pressure changes to remove carbon dioxide from solvent used to absorb it from flue gas, the ion pump increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, which can be removed from the downstream side of the ion pump as a nearly pure gas. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas. The slightly basic water used as the extraction medium is impervious to trace acid gases that destroy existing solvents, and no pre-separation is necessary. The simple, robust nature of the process lends itself to small separation plants. Although the energy cost of the ion pump is significant, we anticipate that it will be compete favorably with the current 35% energy penalty of chemical stripping systems in use at power plants. There is the distinct possibility that this simple method could be significantly more efficient than existing processes.

  18. Climate impact of increasing atmospheric carbon dioxide.

    PubMed

    Hansen, J; Johnson, D; Lacis, A; Lebedeff, S; Lee, P; Rind, D; Russell, G

    1981-08-28

    The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 degrees C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage. PMID:17789014

  19. Recycling technology of emitted carbon dioxide

    SciTech Connect

    Arakawa, Hironori

    1993-12-31

    Ways to halt global warming are being discussed worldwide. Global warming is an energy problem which is mainly attributed to the large volumes of carbon dioxide (CO{sub 2}) released into the atmosphere from the rapid increase in energy consumption since the Industrial Revolution. The basic solution to the problem, therefore, is to cut consumption of fossil fuels. To this end, it is important to promote energy conservation by improving the fuel efficiency of machines, as well as shift to energy sources that do not emit carbon dioxide and develop related technologies. If current trends in economic growth continue in the devloping world as well as the developed countries, there can be no doubt that energy consumption will increase. Therefore, alongside energy conservation and the development of alternative energies, the importance of technologies to recover and fix CO{sub 2} will increase in the fight against global warming.

  20. Carbon dioxide in vascular imaging and intervention.

    PubMed

    Yang, X; Manninen, H; Soimakallio, S

    1995-07-01

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

  1. Sequestering ADM ethanol plant carbon dioxide

    USGS Publications Warehouse

    Finley, R.J.; Riddle, D.

    2008-01-01

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

  2. Carbon Dioxide Laser Fiber Optics In Endoscopy

    NASA Astrophysics Data System (ADS)

    Fuller, Terry A.

    1982-12-01

    Carbon dioxide laser surgery has been limited to a great extent to surgical application on the integument and accessible cavities such as the cervix, vagina, oral cavities, etc. This limitation has been due to the rigid delivery systems available to all carbon dioxide lasers. Articulating arms (series of hollow tubes connected by articulating mirrors) have provided an effective means of delivery of laser energy to the patient as long as the lesion was within the direct line of sight. Even direct line-of-sight applications were restricted to physical dimension of the articulating arm or associated hand probes, manipulators and hollow tubes. The many attempts at providing straight endoscopic systems to the laser only stressed the need for a fiber optic capable of carrying the carbon dioxide laser wavelength. Rectangular and circular hollow metal waveguides, hollow dielectric waveguides have proven ineffective to the stringent requirements of a flexible surgical delivery system. One large diameter (1 cm) fiber optic delivery system, incorporates a toxic thalliumAbased fiber optic material. The device is an effective alternative to an articulating arm for external or conventional laser surgery, but is too large and stiff to use as a flexible endoscopic tool. The author describes the first highly flexible inexpensive series of fiber optic systems suitable for either conventional or endoscopic carbon dioxide laser surgery. One system (IRFLEX 3) has been manufactured by Medlase, Inc. for surgical uses capable of delivering 2000w, 100 mJ pulsed energy and 15w continuous wave. The system diameter is 0.035 inches in diameter. Surgically suitable fibers as small as 120 um have been manufactured. Other fibers (IRFLEX 142,447) have a variety of transmission characteristics, bend radii, etc.

  3. Carbon dioxide laser stomaplasty for tracheostomal stenosis.

    PubMed

    Sani, A

    1998-05-01

    A method of treating tracheostomal stenosis post-laryngectomy is described. The carbon dioxide (CO2) laser is used to fashion and ablate two triangular areas lateral to the stenosed stoma to provide an immediate enlarged stoma for comfortable breathing. This simple procedure is done under local anaesthesia, is almost bloodless, safe and takes just 10 minutes. Over the last five years eight patients underwent this procedure and seven had a satisfactory stoma without the need to use a tracheostomy tube. PMID:9747477

  4. Electrochemical carbon dioxide concentrator: Math model

    NASA Technical Reports Server (NTRS)

    Marshall, R. D.; Schubert, F. H.; Carlson, J. N.

    1973-01-01

    A steady state computer simulation model of an Electrochemical Depolarized Carbon Dioxide Concentrator (EDC) has been developed. The mathematical model combines EDC heat and mass balance equations with empirical correlations derived from experimental data to describe EDC performance as a function of the operating parameters involved. The model is capable of accurately predicting performance over EDC operating ranges. Model simulation results agree with the experimental data obtained over the prediction range.

  5. Carbon dioxide makes heat therapy work

    SciTech Connect

    Sherman, H.

    1987-01-01

    Scientists can now propagate healthy blueberry and raspberry plants from virus-infected stock by treating it with heat and carbon dioxide. Plants are grown at 100/sup 0/F, which makes them develop faster than the virus can spread. Then cuttings are taken of the new growth - less than an inch long - and grown into full-sized, virus-free plants. But in this race to outdistance the virus, some plant species are not able to take the heat. Some even die. Chemical reactions double for every 14/sup 0/F rise in temperature. So, if you try to grow a plant at 100/sup 0/F that was originally growing at 86/sup 0/F, it will double its respiration rate. Adding carbon dioxide increases the rate of photosynthesis in plants, which increases the plant's food reserves. What carbon dioxide does to allow some plants to grow at temperatures at which they would otherwise not survive and it allows other plants to grow for longer periods at 100/sup 0/F. One problem with the process, says Converse, is that the longer plants are exposed to heat the greater the mutation rate. So, resulting clones should be closely examined for trueness to horticultural type.

  6. Carbon dioxide embolism during laparoscopic sleeve gastrectomy

    PubMed Central

    Zikry, Amir Abu; DeSousa, Kalindi; Alanezi, Khaled H

    2011-01-01

    Bariatric restrictive and malabsorptive operations are being carried out in most countries laparoscopically. Carbon dioxide or gas embolism has never been reported in obese patients undergoing bariatric surgery. We report a case of carbon dioxide embolism during laparoscopic sleeve gastrectomy (LSG) in a young super obese female patient. Early diagnosis and successful management of this complication are discussed. An 18-year-old super obese female patient with enlarged fatty liver underwent LSG under general anesthesia. During initial intra-peritoneal insufflation with CO2 at high flows through upper left quadrant of the abdomen, she had precipitous fall of end-tidal CO2 and SaO2 % accompanied with tachycardia. Early suspicion led to stoppage of further insufflation. Clinical parameters were stabilized after almost 30 min, while the blood gas analysis was restored to normal levels after 1 h. The area of gas entrainment on the damaged liver was recognized by the surgeon and sealed and the surgery was successfully carried out uneventfully. Like any other laparoscopic surgery, carbon dioxide embolism can occur during bariatric laparoscopic surgery also. Caution should be exercised when Veress needle is inserted through upper left quadrant of the abdomen in patients with enlarged liver. A high degree of suspicion and prompt collaboration between the surgeon and anesthetist can lead to complete recovery from this potentially fatal complication. PMID:21772696

  7. Carbon dioxide in Arctic and subarctic regions

    SciTech Connect

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

    1981-03-01

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

  8. Elevated atmospheric carbon dioxide increases soil carbon

    SciTech Connect

    Norby, Richard J; Jastrow, Julie D; Miller, Michael R; Matamala, Roser; Boutton, Thomas W; Rice, Charles W; Owensby, Clenton E

    2005-01-01

    In a study funded by the U.S. Department of Energy's Office of Science, researchers from Argonne and Oak Ridge National Laboratories and Kansas State and Texas A&M Universities evaluated the collective results of earlier studies by using a statistical procedure called meta-analysis. They found that on average elevated CO2 increased soil carbon by 5.6 percent over a two to nine year period. They also measured comparable increases in soil carbon for Tennessee deciduous forest and Kansas grassland after five to eight years of experimental exposure to elevated CO2.

  9. Carbon dioxide reduction by the Bosch process

    NASA Technical Reports Server (NTRS)

    Manning, M. P.; Reid, R. C.

    1975-01-01

    Prototype units for carrying out the reduction of carbon dioxide to elementary carbon have been built and operated successfully. In some cases, however, startup difficulties have been reported. Moreover, the recycle reactor product has been reported to contain only small amounts of water and undesirably high yields of methane. This paper presents the results of the first phase of an experimental study that was carried out to define the mechanisms occurring in the reduction process. Conclusions are drawn and possible modifications to the present recycle process are suggested.

  10. Sequestering Naturally Occurring Liquid Carbon Dioxide in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Capron, M. E.

    2008-12-01

    Liquid carbon dioxide has been found as shallow as 1,500 meters in seafloor ooze. Did the liquid carbon dioxide originate from volcanic activity? Or did bacteria convert organic matter, which started as atmospheric carbon dioxide, into methane and liquid carbon dioxide? At typical ocean temperatures carbon dioxide coming out of solution below 600 meters will be liquid. Therefore, one likely mechanism for generating liquid carbon dioxide in seafloor ooze is the bacterial decomposition of organic matter. This paper examines quantitative and qualitative bacterial decomposition of aquatic biomass, with an emphasis on assessing and demonstrating feasibility. Calculations suggest natural processes sequestering liquid carbon dioxide in the seafloor can be sustainably increased to decrease atmospheric carbon dioxide concentrations. First, algae growing on the ocean surface absorb carbon dioxide. The algae are then gathered into a submerged container. Naturally occurring bacteria will digest the algae producing methane, liquid carbon dioxide, and ammonium. The ammonium can be recycled as a nutrient for growing more algae. Bacterial decomposition continues in dilute solutions with any biomass. The process does not require any particular biomass. Also, concentrating the biomass by removing water is not essential. The buoyancy provided by water allows relatively inexpensive tension fabric structures to contain the dilute algae and decomposition products. Calculations based on algae growth in open ponds and experience with bacterial decomposition at 1 to 5 bar pressures suggest the economics of the associated macro-algae growing and harvesting can favor increasing ocean species diversity.

  11. Will peak oil accelerate carbon dioxide emissions?

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  12. Automated carbon dioxide cleaning system

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1991-01-01

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

  13. Method of immobilizing carbon dioxide from gas streams

    DOEpatents

    Holladay, David W.; Haag, Gary L.

    1979-01-01

    This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

  14. Carbon Dioxide Transport through Membranes*

    PubMed Central

    Missner, Andreas; Kügler, Philipp; Saparov, Sapar M.; Sommer, Klaus; Mathai, John C.; Zeidel, Mark L.; Pohl, Peter

    2008-01-01

    Several membrane channels, like aquaporin-1 (AQP1) and the RhAG protein of the rhesus complex, were hypothesized to be of physiological relevance for CO2 transport. However, the underlying assumption that the lipid matrix imposes a significant barrier to CO2 diffusion was never confirmed experimentally. Here we have monitored transmembrane CO2 flux (JCO2) by imposing a CO2 concentration gradient across planar lipid bilayers and detecting the resulting small pH shift in the immediate membrane vicinity. An analytical model, which accounts for the presence of both carbonic anhydrase and buffer molecules, was fitted to the experimental pH profiles using inverse problems techniques. At pH 7.4, the model revealed that JCO2 was entirely rate-limited by near-membrane unstirred layers (USL), which act as diffusional barriers in series with the membrane. Membrane tightening by sphingomyelin and cholesterol did not alter JCO2 confirming that membrane resistance was comparatively small. In contrast, a pH-induced shift of the CO2 hydration-dehydration equilibrium resulted in a relative membrane contribution of about 15% to the total resistance (pH 9.6). Under these conditions, a membrane CO2 permeability (3.2 ± 1.6 cm/s) was estimated. It indicates that cellular CO2 uptake (pH 7.4) is always USL-limited, because the USL size always exceeds 1 μm. Consequently, facilitation of CO2 transport by AQP1, RhAG, or any other protein is highly unlikely. The conclusion was confirmed by the observation that CO2 permeability of epithelial cell monolayers was always the same whether AQP1 was overexpressed in both the apical and basolateral membranes or not. PMID:18617525

  15. Enzymatic conversion of carbon dioxide.

    PubMed

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

    2015-10-01

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

  16. Sulfur dioxide leaching of spent zinc-carbon-battery scrap

    NASA Astrophysics Data System (ADS)

    Avraamides, J.; Senanayake, G.; Clegg, R.

    Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2 M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25 °C. Alkaline leaching with 6 M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30 min at 30 °C using 0.1-1.0 M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1 M to 2 M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide.

  17. Methanofuran (carbon dioxide reduction factor), a formyl carrier in methane production from carbon dioxide in Methanobacterium

    SciTech Connect

    Leigh, J.A.; Rinehart, K.L. Jr.; Wolfe, R.S.

    1985-02-12

    Methanofuran (carbon dioxide reduction factor) became labeled when incubated in cell extracts of Methanobacterium under hydrogen and /sup 14/CO/sub 2/ in the absence of methanopterin. Proton NMR spectroscopy revealed that a formyl group was bound to the primary amine of methanofuran. (/sup 14/C)Formylmethanofuran was enzymically converted to /sup 14/CH/sub 4/ in the presence of CH/sub 3/-S-CoM (2-(methylthio)ethanesulfonic acid), hydrogen, and methanopterin, establishing the formyl moiety as an intermediate in methanogenesis. In the absence of methanopterin, a substantial portion of the formyl label was oxidized to /sup 14/CO/sub 2/ rather than reduced to /sup 14/CH/sub 4/, consistent with a model in which the C1 intermediate is first bound to methanofuran and then to methanopterin, during its reduction. When CH/sub 3/-S-CoM was replaced by HS-CoM (2-mercaptoethanesulfonic acid), most of the formyl label was oxidized to /sup 14/CO/sub 2/, indicating that methyl group reduction by the CH/sub 3/-S-CoM methylreductase is required for the conversion of formylmethanofuran to methane.

  18. Carbon dioxide: A substitute for phosgene

    SciTech Connect

    Aresta, M.; Quaranta, E.

    1997-03-01

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

  19. Electrocatalytic reduction of carbon dioxide to carbon monoxide and methane at an immobilized cobalt protoporphyrin

    PubMed Central

    Shen, Jing; Kortlever, Ruud; Kas, Recep; Birdja, Yuvraj Y.; Diaz-Morales, Oscar; Kwon, Youngkook; Ledezma-Yanez, Isis; Schouten, Klaas Jan P.; Mul, Guido; Koper, Marc T. M.

    2015-01-01

    The electrochemical conversion of carbon dioxide and water into useful products is a major challenge in facilitating a closed carbon cycle. Here we report a cobalt protoporphyrin immobilized on a pyrolytic graphite electrode that reduces carbon dioxide in an aqueous acidic solution at relatively low overpotential (0.5 V), with an efficiency and selectivity comparable to the best porphyrin-based electrocatalyst in the literature. While carbon monoxide is the main reduction product, we also observe methane as by-product. The results of our detailed pH-dependent studies are explained consistently by a mechanism in which carbon dioxide is activated by the cobalt protoporphyrin through the stabilization of a radical intermediate, which acts as Brønsted base. The basic character of this intermediate explains how the carbon dioxide reduction circumvents a concerted proton–electron transfer mechanism, in contrast to hydrogen evolution. Our results and their mechanistic interpretations suggest strategies for designing improved catalysts. PMID:26324108

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

    SciTech Connect

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

    2001-07-01

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

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

    PubMed Central

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

    2014-01-01

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture. PMID:24367077

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

    SciTech Connect

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

    1988-06-20

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

  3. Enriching blast furnace gas by removing carbon dioxide.

    PubMed

    Zhang, Chongmin; Sun, Zhimin; Chen, Shuwen; Wang, Baohai

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent. PMID:25078829

  4. Copolymerization of carbon dioxide and butadiene via a lactone intermediate.

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide. PMID:24651200

  5. Carbon Dioxide and the Greenhouse Effect: A Problem Evaluation Activity.

    ERIC Educational Resources Information Center

    Brewer, Carol A.; Beiswenger, Jane M.

    1993-01-01

    Describes exercises to examine the global carbon cycle. Students are asked to predict consequences of increased carbon dioxide emissions into the atmosphere and to suggest ways to mitigate problems associated with these higher levels of atmospheric carbon dioxide. A comparison modeling exercise examines some of the variables related to the success…

  6. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  7. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  8. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  9. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  10. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  11. 40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.524-78 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service and monthly thereafter the NDIR carbon...

  12. Light-induced degradation of perfluorocarboxylic acids in the presence of titanium dioxide.

    PubMed

    Dillert, Ralf; Bahnemann, Detlef; Hidaka, Hisao

    2007-03-01

    The UV-photon-induced degradation of heptafluorobutanoic acid was investigated in acidic aqueous solutions in the presence of titanium dioxide. Heptafluorobutanoic acid could be degraded with this photocatalyst in a light-induced reaction generating carbon dioxide and fluoride anions. Carbon dioxide evolution in a significant amount occurred only in the presence of molecular oxygen and the photocatalyst. The light-induced degradation of trifluoroacetic acid, pentafluoropropanoic acid, nonafluorobutanoic acid, pentadecafluorooctanoic acid, nonafluorobutanesulfonic acid, and heptadecafluorooctanesulfonic acid in the presence of titanium dioxide was also studied. The perfluorocarboxylic acids under investigation are degraded to generate CO(2) and fluoride anions while both perfluorinated sulfonic acids are persistent under the experimental conditions employed in this study. For all compounds photonic efficiencies of the mineralization reaction were estimated to be smaller than 1x10(-5). To increase the photocatalytic activity mixed systems containing homogeneous phosphotungstic acid and heterogeneous titanium dioxide catalysts were also investigated. In the mixtures of these two photocatalysts, the formation rate of CO(2) increased with illumination time. PMID:17126882

  13. Supercritical carbon dioxide: a solvent like no other

    PubMed Central

    Peach, Jocelyn

    2014-01-01

    Summary Supercritical carbon dioxide (scCO2) could be one aspect of a significant and necessary movement towards green chemistry, being a potential replacement for volatile organic compounds (VOCs). Unfortunately, carbon dioxide has a notoriously poor solubilising power and is famously difficult to handle. This review examines attempts and breakthroughs in enhancing the physicochemical properties of carbon dioxide, focusing primarily on factors that impact solubility of polar and ionic species and attempts to enhance scCO2 viscosity. PMID:25246947

  14. Six-fold Coordinated Carbon Dioxide VI

    SciTech Connect

    Iota, V; Yoo, C; Klepeis, J; Jenei, Z

    2006-03-01

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

  15. Toward Solar Fuels: Photocatalytic Conversion of Carbon Dioxide to Hydrocarbons

    SciTech Connect

    Roy, SC; Varghese, OK; Paulose, M; Grimes, CA

    2010-03-01

    The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle carbon dioxide into readily transportable hydrocarbon fuel (i.e., a solar fuel) would help reduce atmospheric CO2 levels and partly fulfill energy demands within the present hydrocarbon based fuel infrastructure. We review the present status of carbon dioxide conversion techniques, with particular attention to a recently developed photocatalytic process to convert carbon dioxide and water vapor into hydrocarbon fuels using sunlight.

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

    NASA Technical Reports Server (NTRS)

    Carlson, R. W.

    1999-01-01

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

  17. [Determination of carbon dioxide released from soil at different humidities].

    PubMed

    Imshenetskiĭ, A A; Murzakov, B G

    1978-01-01

    The detection of soil microorganisms by their evolution of carbon dioxide does not always correlate with the number of microorganisms and the rate of biochemical processes in soil. New microbial populations appear in the incubation chamber as the concentration of carbon dioxide increases; this results in an increase in the activity of such processes as photosynthesis, chemosynthesis and heterotrophic assimilation of carbon dioxide. Life detection on other planets by determining carbon dioxide evolved from the ground may lead to erroneous conclusions on the presence of microorganism in the ground. PMID:745559

  18. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2015-12-29

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

  19. Carbon dioxide absorbent and method of using the same

    SciTech Connect

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

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

  20. Cost analysis of carbon dioxide concentrators

    NASA Technical Reports Server (NTRS)

    Yakut, M. M.

    1972-01-01

    A methodology is developed to predict the relevant contributions of the more intangible cost elements encountered in the development of flight-qualified hardware and is used to predict the costs of three carbon dioxide concentration systems. The cost and performance data from Gemini, Skylab, and other programs are utilized as a basis for establishing the cost estimating relationships. The concentration systems analyzed are the molecular sieves C02 concentrator, the hydrogen-depolarized concentrator, and the regenerable solid desiccant concentrator. Besides the cost estimates for each system, their comparative criteria including relative characteristics, operational differences, and development status are considered.

  1. Electrochemical carbon dioxide concentrator subsystem development

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Dahlausen, M. J.; Schubert, F. H.

    1983-01-01

    The fabrication of a one-person Electrochemical Depolarized Carbon Dioxide Concentrator subsystem incorporating advanced electrochemical, mechanical, and control and monitor instrumentation concepts is discussed. This subsystem included an advanced liquid cooled unitized core composite cell module and integrated electromechanical components. Over 1800 hours with the subsystem with removal efficiencies between 90%. and 100%; endurance tests with a Fluid Control Assembly which integrates 11 gas handling components of the subsystem; and endurance testing of a coolant control assembly which integrates a coolant pump, diverter valve and a liquid accumulator were completed.

  2. Searching for clues to ancient carbon dioxide

    SciTech Connect

    Appenzeller, T.

    1993-02-12

    Something on Earth just won't stop fiddling with the thermostat. In the past 500 million years, the planet has shivered through ice ages lasting millions of years and sweltered through episodes of global warmth. Climatologists, eager to know what keeps jiggling the planet's temperature setting, have focused their suspicions on carbon dioxide, the same heat-trapping gas expected to drive up temperatures in coming decades. Catching this suspect in the act has been difficult, however; the atmospheres of millions of years ago are gone with the wind.

  3. Capture of carbon dioxide by hybrid sorption

    SciTech Connect

    Srinivasachar, Srivats

    2014-09-23

    A composition, process and system for capturing carbon dioxide from a combustion gas stream. The composition has a particulate porous support medium that has a high volume of pores, an alkaline component distributed within the pores and on the surface of the support medium, and water adsorbed on the alkaline component, wherein the proportion of water in the composition is between about 5% and about 35% by weight of the composition. The process and system contemplates contacting the sorbent and the flowing gas stream together at a temperature and for a time such that some water remains adsorbed in the alkaline component when the contact of the sorbent with the flowing gas ceases.

  4. A Vortex Contactor for Carbon Dioxide Separations

    SciTech Connect

    Raterman, Kevin Thomas; Mc Kellar, Michael George; Turner, Terry Donald; Podgorney, Anna Kristine; Stacey, Douglas Edwin; Stokes, B.; Vranicar, J.

    2001-05-01

    Many analysts identify carbon dioxide (CO2) capture and separation as a major roadblock in efforts to cost effectively mitigate greenhouse gas emissions via sequestration. An assessment 4 conducted by the International Energy Agency (IEA) Greenhouse Gas Research and Development Programme cited separation costs from $35 to $264 per tonne of CO2 avoided for a conventional coal fired power plant utilizing existing capture technologies. Because these costs equate to a greater than 40% increase in current power generation rates, it appears obvious that a significant improvement in CO2 separation technology is required if a negative impact on the world economy is to be avoided.

  5. Adsorption of lanthanides(III), uranium(VI) and thorium(IV) from nitric acid solutions by carbon inverse opals modified with tetraphenylmethylenediphospine dioxide.

    PubMed

    Turanov, A N; Karandashev, V K; Masalov, V M; Zhokhov, A A; Emelchenko, G A

    2013-09-01

    Carbon inverse opals (C-IOP) were noncovalently modified with tetraphenylmethylenediphospine dioxide (TPMDPDO). The distribution of TPMDPDO between C-IOP and aqueous HNO3 solutions has been studied. The effect of HNO3 concentration in the aqueous phase and that of the TPMDPDO concentration in the sorbent phase on the adsorption of microquantities of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, U, and Th nitrates from HNO3 solutions by C-IOP modified with TPMDPDO is considered. The stoichiometry of the sorbed complexes has been determined by the slope analysis method. The efficiency of lanthanide(III) adsorption from moderate-concentration HNO3 solutions decreases with increasing element atomic number. PMID:23786834

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

    USGS Publications Warehouse

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  7. Carbon dioxide research plan. A summary

    SciTech Connect

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

    1983-11-01

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

  8. The kinetics of binding carbon dioxide in magnesium carbonate

    SciTech Connect

    Butt, D.P.; Lackner, K.S.; Wendt, C.H.; Vaidya, R.; Pile, D.L.; Park, Y.; Holesinger, T.; Harradine, D.M.; Nomura, Koji |

    1998-08-01

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

  9. Chemical Reactions in Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Wai, Chien M.; Hunt, Fred; Ji, Min; Chen, Xiaoyuan

    1998-12-01

    Utilizing supercritical fluids as environmentally benign solvents for chemical synthesis is one of the new approaches in the "greening" of chemistry. Carbon dioxide is the most widely used gas for supercritical fluid studies because of its moderate critical constants, nontoxic nature, and availability in pure form. One unique property of supercritical carbon dioxide (sc-CO2) is its high solubility for fluorinated compounds. Thus sc-CO2 can be used to replace Freons that are conventionally used as solvents for synthesis of perfluoro-polymers. Another property of sc-CO2 is its miscibility with gases such as H2. Heterogeneous reactions involving these gases may become homogeneous reactions in sc-CO2. Reactions in sc-CO2 may offer several advantages including controlling phase behavior and products, increasing speed of reactions, and obtaining specific reaction channels. This paper describes the following nine types of chemical reactions reported in the literature utilizing sc-CO2 as a solvent to illustrate the unique properties of the supercritical fluid reaction systems: (i) hydrogenation and hydroformylation, (ii) synthesis of organometallic compounds, (iii) metal chelation and extraction, (iv) preparation of inorganic nanoparticles, (v) stereo-selectivity of lipase-catalyzed reactions, (vi) asymmetric catalytic hydrogenation, (vii) polymerization, (viii) Diels-Alder reaction, and (ix) free radical reactions.

  10. Six-fold coordinated carbon dioxide VI

    SciTech Connect

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

    2008-06-16

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

  11. Pharmaceutical applications of supercritical carbon dioxide.

    PubMed

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

    2001-12-01

    The appearance of a supercritical state was already observed at the beginning of the 19th century. Nevertheless, the industrial extraction of plant and other natural materials started about twenty years ago with the decaffeination of coffee. Today carbon dioxide is the most common gas for supercritical fluid extraction in food and pharmaceutical industry. Since pure supercritical carbon dioxide is a lipophilic solvent, mixtures with organic solvents, especially alcohols, are used to increase the polarity of the extraction fluid; more polar compounds can be extracted in this way. The main fields of interest are the extraction of vegetable oils from plant material in analytical and preparative scale, the preparation of essential oils for food and cosmetic industry and the isolation of substances of pharmaceutical relevance. Progress in research was made by the precise measurement of phase equilibria data by means of different methods. Apart from extraction, supercritical fluid chromatography was introduced in the field of analytics, as well as micro- and nanoparticle formation using supercritical fluids as solvent or antisolvent. This review presents pharmaceutical relevant literature of the last twenty years with special emphasis on extraction of natural materials. PMID:11802652

  12. Carbon dioxide extraction from air: Is it an option?

    SciTech Connect

    Lackner, K.S.; Grimes, P.; Ziock, H.J.

    1999-07-01

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

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

    PubMed Central

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

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10−3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10−7, nO2/nN = 5.39 × 10−5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

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

    PubMed

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

    2015-01-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10-3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10-7, nO2/nN = 5.39 × 10-5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

  16. Electrocatalytic Transformation of Carbon Dioxide into Low Carbon Compounds on Conducting Polymers Derived from Multimetallic Porphyrins.

    PubMed

    Dreyse, Paulina; Honores, Jessica; Quezada, Diego; Isaacs, Mauricio

    2015-11-01

    The electrochemical reduction of carbon dioxide is studied herein by using conducting polymers based on metallotetraruthenated porphyrins (MTRPs). The polymers on glassy carbon electrodes were obtained by electropolymerization processes of the monomeric MTRP. The linear sweep voltammetry technique resulted in polymeric films that showed electrocatalytic activity toward carbon dioxide reduction with an onset potential of -0.70 V. The reduction products obtained were hydrogen, formic acid, formaldehyde, and methanol, with a tendency for a high production of methanol with a maximum value of turnover frequency equal to 15.07 when using a zinc(II) polymeric surface. Studies of the morphology (AFM) and electrochemical impedance spectroscopy results provide an adequate background to explain that the electrochemical reduction is governed by the roughness of the polymer, for which the possible mechanism involves a series of one-electron reduction reactions. PMID:26383015

  17. Cationic Polymerization of Vegetable Oils in Supercritical Carbon Dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polymers derived from vegetable oils have been prepared in supercritical carbon dioxide (scCO2) medium by cationic polymerization. Boron trifluoride diethyl etherate BF3.O(C2H2)2 are used as initiator. Influences of polymerization temperature, initiator amount, and carbon dioxide pressure on the m...

  18. Carbon Dioxide and Global Warming: A Failed Experiment

    ERIC Educational Resources Information Center

    Ribeiro, Carla

    2014-01-01

    Global warming is a current environmental issue that has been linked to an increase in anthropogenic carbon dioxide in the atmosphere. To raise awareness of the problem, various simple experiments have been proposed to demonstrate the effect of carbon dioxide on the planet's temperature. This article describes a similar experiment, which…

  19. Solid amine compounds as sorbents for carbon dioxide: A concept

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Solid amine compounds were examined as possible absorbents for removal of carbon dioxide in life support systems of type which may be employed in high altitude aircraft, spacecraft, or submarines. Many solid amine compounds release absorbed carbon dioxide when heated in vacuum, therefore, when properly packaged spent amine compounds can be readily regenerated and put back into service.

  20. Promising flame retardant textile in supercritical carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since carbon dioxide is non-toxic, non-flammable and cost-effective, supercritical carbon dioxide (scCO2) is widely used in textile dyeing applications. Due to its environmentally benign character, scCO2 is considered in green chemistry as a substitute for organic solvents in chemical reactions. O...

  1. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  2. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  3. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  4. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  5. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., system check, and calibration test procedures specified in 40 CFR part 1065, subparts C and D, may be... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 90... Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its initial use and...

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

    ERIC Educational Resources Information Center

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

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

  7. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  8. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 89... Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its introduction...

  9. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  10. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  11. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  12. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  13. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  14. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon dioxide analyzer calibration. 91....320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service, and...

  15. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  16. 40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and calibration test procedures specified in 40 CFR part 86, subpart D, may be used in lieu of the... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Exhaust Test Procedures § 86.1324-84 Carbon dioxide analyzer calibration. Prior to its introduction...

  17. 40 CFR 91.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 1065, subparts C and D, may be used in lieu of the procedures in this section. ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Provisions § 91.320 Carbon dioxide analyzer calibration. (a) Prior to its introduction into service,...

  18. 40 CFR 89.322 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration... Test Equipment Provisions § 89.322 Carbon dioxide analyzer calibration. (a) Prior to its...

  19. 40 CFR 90.320 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon dioxide analyzer calibration... Emission Test Equipment Provisions § 90.320 Carbon dioxide analyzer calibration. (a) Prior to its...

  20. Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms

    ERIC Educational Resources Information Center

    Buth, Jeffrey M.

    2016-01-01

    Ocean acidification refers to the process by which seawater absorbs carbon dioxide from the atmosphere, producing aqueous carbonic acid. Acidic conditions increase the solubility of calcium carbonate, threatening corals and other calcareous organisms that depend on it for protective structures. The global nature of ocean acidification and the…

  1. Highly Chemoselective Catalytic Coupling of Substituted Oxetanes and Carbon Dioxide.

    PubMed

    Rintjema, Jeroen; Guo, Wusheng; Martin, Eddy; Escudero-Adán, Eduardo C; Kleij, Arjan W

    2015-07-20

    The chemoselective coupling of oxetanes and carbon dioxide to afford functional, heterocyclic organic compounds known as six-membered cyclic carbonates remains a challenging topic. Here, an effective method for their synthesis relying on the use of Al catalysis is described. The catalytic reactions can be carried out with excellent selectivity for the cyclic carbonate product tolerating various (functional) groups present in the 2- and 3-position(s) of the oxetane ring. The presented methodology is the first general approach towards the formation of six-membered cyclic carbonates (6MCCs) through oxetane/CO2 coupling chemistry. Apart from a series of substituted six-membered cyclic carbonates, also the unprecedented room-temperature coupling of oxetanes and CO2 is disclosed giving, depending on the structural features of the substrate, a variety of five- and six-membered heterocyclic products. A mechanistic rationale is presented for their formation and support for the intermediary presence of a carbonic acid derivative is given. The presented functional carbonates may hold great promise as building blocks in organic synthesis and the development of new, biodegradable polymers. PMID:26095260

  2. Carbon Dioxide Detection and Indoor Air Quality Control.

    PubMed

    Bonino, Steve

    2016-04-01

    When building ventilation is reduced, energy is saved because it is not necessary to heat or cool as much outside air. Reduced ventilation can result in higher levels of carbon dioxide, which may cause building occupants to experience symptoms. Heating or cooling for ventilation air can be enhanced by a DCV system, which can save energy while providing a comfortable environment. Carbon dioxide concentrations within a building are often used to indicate whether adequate fresh air is being supplied to the building. These DCV systems use carbon dioxide sensors in each space or in the return air and adjust the ventilation based on carbon dioxide concentration; the higher the concentration, the more people occupy the space relative to the ventilation rate. With a carbon dioxide sensor DCV system, the fresh air ventilation rate varies based on the number ofpeople in the space, saving energy while maintaining a safe and comfortable environment. PMID:27183813

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

    USGS Publications Warehouse

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  4. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; Lewis, Larry Neil; O'Brien, Michael Joseph; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lam, Tunchiao Hubert; Lee, Julia Lam; Rubinsztajn, Malgorzata Iwona

    2011-10-04

    In accordance with one aspect, the present invention provides an amino-siloxane composition comprising at least one of structures I, II, III, IV or V said compositions being useful for the capture of carbon dioxide from gas streams such as power plant flue gases. In addition, the present invention provides methods of preparing the amino-siloxane compositions are provided. Also provided are methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention as species which react with carbon dioxide to form an adduct with carbon dioxide. The reaction of the amino-siloxane compositions provided by the present invention with carbon dioxide is reversible and thus, the method provides for multicycle use of said compositions.

  5. Photobiological hydrogen production and carbon dioxide sequestration

    NASA Astrophysics Data System (ADS)

    Berberoglu, Halil

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

  6. Carbon dioxide emission from bamboo culms.

    PubMed

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

    2016-05-01

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

  7. Global carbon dioxide emissions from inland waters

    USGS Publications Warehouse

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

    2013-01-01

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

  8. The Fluid Mechanics of Carbon Dioxide Sequestration

    NASA Astrophysics Data System (ADS)

    Huppert, Herbert E.; Neufeld, Jerome A.

    2014-01-01

    Humans are faced with a potentially disastrous global problem owing to the current emission of 32 gigatonnes of carbon dioxide (CO2) annually into the atmosphere. A possible way to mitigate the effects is to store CO2 in large porous reservoirs within the Earth. Fluid mechanics plays a key role in determining both the feasibility and risks involved in this geological sequestration. We review current research efforts looking at the propagation of CO2 within the subsurface, the possible rates of leakage, the mechanisms that act to stably trap CO2, and the geomechanical response of the crust to large-scale CO2 injection. We conclude with an outline for future research.

  9. Thermodynamical effects during carbon dioxide release

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  10. Pulsed-discharge carbon dioxide lasers

    NASA Technical Reports Server (NTRS)

    Willetts, David V.

    1990-01-01

    The purpose is to attempt a general introduction to pulsed carbon dioxide lasers of the kind used or proposed for laser radar applications. Laser physics is an excellent example of a cross-disciplinary topic, and the molecular spectroscopy, energy transfer, and plasma kinetics of the devices are explored. The concept of stimulated emission and population inversions is introduced, leading on to the molecular spectroscopy of the CO2 molecule. This is followed by a consideration of electron-impact pumping, and the pertinent energy transfer and relaxation processes which go on. Since the devices are plasma pumped, it is necessary to introduce a complex subject, but this is restricted to appropriate physics of glow discharges. Examples of representative devices are shown. The implications of the foregoing to plasma chemistry and gas life are discussed.

  11. Biochemical Capture and Removal of Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Trachtenberg, Michael C.

    1998-01-01

    We devised an enzyme-based facilitated transport membrane bioreactor system to selectively remove carbon dioxide (CO2) from the space station environment. We developed and expressed site-directed enzyme mutants for CO2 capture. Enzyme kinetics showed the mutants to be almost identical to the wild type save at higher pH. Both native enzyme and mutant enzymes were immobilized to different supports including nylons, glasses, sepharose, methacrylate, titanium and nickel. Mutant enzyme could be attached and removed from metal ligand supports and the supports reused at least five times. Membrane systems were constructed to test CO2 selectivity. These included proteic membranes, thin liquid films and enzyme-immobilized teflon membranes. Selectivity ratios of more than 200:1 were obtained for CO2 versus oxygen with CO2 at 0.1%. The data indicate that a membrane based bioreactor can be constructed which could bring CO2 levels close to Earth.

  12. Dissociation-excitation reactions of argon metastables with carbon dioxide.

    NASA Technical Reports Server (NTRS)

    Starr, W. L.

    1971-01-01

    Results of a study showing that a metastable argon-carbon dioxide reaction results in dissociation of carbon dioxide and electronic excitation of one of the products, carbon monoxide or oxygen. A flow system using a 2450-MHz discharge was used to produce metastable argon atoms. Metastable argon in the afterglow was confirmed by adding nitrogen to the afterglow. Without addition of carbon dioxide no argon line emission, or any other emission, is observed from the reaction zone. Absence of argon line emission produced by recombination indicates the absence of charged species.

  13. Six-fold coordinated carbon dioxide VI.

    PubMed

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

    2007-01-01

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

  14. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J.

    2002-01-01

    A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  16. Intraosseous Venography with Carbon Dioxide in Percutaneous Vertebroplasty: Carbon Dioxide Retention in Renal Veins

    SciTech Connect

    Komemushi, Atsushi Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Tokuda, Takanori; Nomura, Motoo; Terada, Jiro; Kamata, Minoru; Sawada, Satoshi

    2008-11-15

    The objective of the present study was to determine the frequency of gas retention in the renal vein following carbon dioxide intraosseous venography in the prone position and, while citing references, to examine its onset mechanisms. All percutaneous vertebroplasties performed at our hospital from January to December 2005 were registered and retrospectively analyzed. Of 43 registered procedures treating 79 vertebrae, 28 procedures treating 54 vertebrae were analyzed. Vertebral intraosseous venography was performed using carbon dioxide as a contrast agent in all percutaneous vertebroplasty procedures. In preoperative and postoperative vertebral CT, gas retention in the renal vein and other areas was assessed. Preoperative CT did not show gas retention (0/28 procedures; 0%). Postoperative CT confirmed gas retention in the renal vein in 10 of the 28 procedures (35.7%). Gas retention was seen in the right renal vein in 8 procedures (28.6%), in the left renal vein in 5 procedures (17.9%), in the left and right renal veins in 3 procedures (10.7%), in vertebrae in 22 procedures (78.6%), in the soft tissue around vertebrae in 14 procedures (50.0%), in the spinal canal in 12 procedures (42.9%), and in the subcutaneous tissue in 5 procedures (17.9%). In conclusion, in our study, carbon dioxide gas injected into the vertebra frequently reached and remained in the renal vein.

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

    SciTech Connect

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

    2005-01-01

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

  18. Carbon dioxide exchange and growth of a pine plantation

    SciTech Connect

    Murphy, Jr, C E

    1981-01-01

    The exchange of materials between the atmosphere and terrestrial ecosystem is important to an understanding of the cycling of essential elements, the deposition of mateials from the atmosphere and the entrance of pollutants into the forest ecosystems. This paper reports the results of measurements of carbon dioxide exchange in a vigorously growing pine plantation. Measurement data were incorporated into a model used to estimate annual carbon dioxide exchange and measured annual biomass accumulation in the same plantation were used to determine a carbon dioxide to biomass conversion efficiency. Carbon dioxide exchange was 10.5 metric tons per hectare and biomass accumulation was 4.5 metric tons per hectare. The conversion efficiency of cabon dioxide to biomass is about 25% less than the theoretical chemical conversion efficiency. 27 refs., 8 figs.

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

    PubMed Central

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

    1999-01-01

    The three most common methods of sterilization in use today are ethylene oxide exposure, γ-irradiation, and steam sterilization. Each of these methods has serious limitations for the sterilization of some materials used in medicine, especially thermally and hydrolytically sensitive polymers by themselves and in combination with proteins. In this work, we demonstrate a potential new method of sterilization by using supercritical fluid carbon dioxide. Using this method we achieve complete inactivation of a wide variety of bacterial organisms at moderate temperatures and in the absence of organic solvents or irradiation. Sterilization is a function of both the proximity to the fluid’s critical point and the chemical nature of the fluid itself. When biodegradable polymers poly(lactic-co-glycolic) acid and polylactic acid were included in the sterilization process, there was no effect on the inactivation efficiency, yet no physical or chemical damage to these thermally and hydrolytically labile materials was observed. PMID:10468610

  20. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

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

    2011-04-01

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

  1. 75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... AGENCY Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft... draft ecological risk assessment for the registration review of inorganic nitrates - nitrites, carbon and carbon dioxide, and gas cartridge uses of sulfur, and opens a public comment period on...

  2. Herbivore responses to plants grown in enriched carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.

    1990-05-01

    Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient and carbon dioxide regimes and grasshopper feeding responses. The study of a specialist feeding caterpillar, the cabbage butterfly, and a mustard hostplant has recently been completed. We were able to identify the principal allelochemicals of the mustard plants, butenyl and pentenyl isothiocyanates, by combined gas chromatography and mass spectrometry. Measurement of these chemicals has been a critical component of this study since these compounds contain nitrogen and sulphur and act as a feeding stimulant to the caterpillar. This insect responds to elevated carbon dioxide by consuming more leaves and we can now say that this is not due to a change in the feeding stimulants. Reduced leaf protein content is a critical factor for even specialist feeding insect herbivores under elevated carbon dioxide conditions. The study on Grasshopper Population Responses to Enriched Carbon Dioxide Concentration is currently in progress at the Duke University Phytotron. We have changed hostplant species in order to complement the investigations of carbon dioxide effects on tallgrass prairie. Specifically, we are using big bluestem, Andropogon geradii, as the host plant to feed to the grasshoppers. This experiment will be completed in July 1990.

  3. Forest management techniques for carbon dioxide storage

    SciTech Connect

    Fujimori, Takao

    1993-12-31

    In the global ecosystem concerning carbon dioxide content in the atmosphere, the forest ecosystem plays an important role. In effect, the ratio of forest biomass to total terrestrial biomass is about 90%, and the ratio of carbon stored in the forest biomass to that in the atmosphere is two thirds. When soils and detritus of forests are added, there is more C stored in forests than in the atmosphere, about 1.3 times or more. Thus, forests can be regarded as the great holder of C on earth. If the area of forest land on the earth is constantly maintained and forests are in the climax stage, the uptake of C and the release of C by and from the forests will balance. In this case, forests are neither sinks nor sources of CO{sub 2} although they store a large amount of C. However, when forests are deforested, they become a source of C; through human activities, forests have become a source of C. According to a report by the IPCC, 1.6{+-}1.2 PgC is annually added to the atmosphere by deforestation. According to the FAO (1992), the area of land deforested annually in the tropics from 1981 to 1990 was 16.9 x 10{sup 6} ha. This value is nearly half the area of Japanese land. The most important thing for the CO{sub 2} environment concerning forests is therefore how to reduce deforestation and to successfully implement a forestation or reforestation.

  4. Carbon dioxide warming of the early Earth.

    PubMed

    Arrhenius, G

    1997-02-01

    Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure. PMID:11541253

  5. Carbon dioxide warming of the early Earth

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1997-01-01

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

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

    SciTech Connect

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

    2005-07-01

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

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

    NASA Technical Reports Server (NTRS)

    Hagedorn, Norman H. (Inventor)

    1993-01-01

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

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

    ERIC Educational Resources Information Center

    Alcamo, Joseph; De Vries, Bert

    1992-01-01

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

  9. Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU

    NASA Technical Reports Server (NTRS)

    Walton, Krista S.; LeVan, M. Douglas

    2004-01-01

    The atmosphere of Mars has many resources that can be processed to produce things such as oxygen, fuel, buffer gas, and water for support of human exploration missions. Successful manipulation of these resources is crucial for safe, cost-effective, and self-sufficient long-term human exploration of Mars. In our research, we are developing enabling technologies that require fundamental knowledge of adsorptive gas storage and separation processes. In particular, we are designing and constructing an innovative, low mass, low power separation device to recover carbon dioxide and carbon monoxide for Mars ISRU (in-situ resource utilization). The technology has broad implications for gas storage and separations for gas-solid systems that are ideally suited for reduced gravitational environments. This paper describes our separation process design and experimental procedures and reports results for the separation of CO2 and CO by a four-step adsorption cycle.

  10. Membranes for separation of carbon dioxide

    DOEpatents

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

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

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

    PubMed

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

    1972-09-29

    The rate of invasion of carbon dioxide into an artificially eutrophic Canadian Shield lake with insufficient internal sources of carbon was determined by two methods: measuring the carbon : nitrogen : phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the epilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophication of any body of water receiving an adequate supply of phosphorus and nitrogen. PMID:5057624

  12. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  13. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  14. Carbon dioxide utilization via carbonate-promoted C-H carboxylation

    NASA Astrophysics Data System (ADS)

    Banerjee, Aanindeeta; Dick, Graham R.; Yoshino, Tatsuhiko; Kanan, Matthew W.

    2016-03-01

    Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO32-) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)—a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO32--promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds.

  15. Carbon dioxide utilization via carbonate-promoted C-H carboxylation.

    PubMed

    Banerjee, Aanindeeta; Dick, Graham R; Yoshino, Tatsuhiko; Kanan, Matthew W

    2016-03-10

    Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO3(2-)) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)--a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO3(2-)-promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds. PMID:26961655

  16. Pretreatment for cellulose hydrolysis by carbon dioxide explosion

    SciTech Connect

    Zheng, Y.; Lin, H.M.; Tsao, G.T.

    1998-11-01

    Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis. In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 C for a controlled time period. Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis. Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose. An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment. This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50%. Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol. As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

  17. REACTION OF ACTIVATED CARBON WITH AQUEOUS CHLORINE AND CHLORINE DIOXIDE

    EPA Science Inventory

    The objective of this research was to determine whether aqueous chlorine and chlorine dioxide react with activated carbon, or with compounds adsorbed on activated carbon, to produce compounds that would not form in the absence of activated carbon. The experimental conditions were...

  18. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  19. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  20. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  1. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  2. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  3. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  4. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  5. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  6. 46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  7. 46 CFR 167.45-45 - Carbon dioxide fire-extinguishing system requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide fire-extinguishing system requirements... Carbon dioxide fire-extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  8. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  9. 46 CFR 35.40-8 - Carbon dioxide warning signs-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide warning signs-T/ALL. 35.40-8 Section 35... Marking Requirements-TB/ALL § 35.40-8 Carbon dioxide warning signs—T/ALL. Each entrance to a space storing carbon dioxide cylinders, a space protected by carbon dioxide systems, or any space into which...

  10. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  11. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than...

  12. 46 CFR 167.45-45 - Carbon dioxide fire extinguishing system requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide fire extinguishing system requirements... Carbon dioxide fire extinguishing system requirements. (a) When a carbon dioxide (CO2) smothering system is fitted in the boiler room, the quantity of carbon dioxide carried shall be sufficient to give...

  13. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  14. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  15. 21 CFR 179.43 - Carbon dioxide laser for etching food.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Carbon dioxide laser for etching food. 179.43... § 179.43 Carbon dioxide laser for etching food. Carbon dioxide laser light may be safely used for... consists of a carbon dioxide laser designed to emit pulsed infrared radiation with a wavelength of...

  16. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  17. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with...

  18. Partitioning Carbon Dioxide and Water Vapor Fluxes Using Correlation Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Partitioning of eddy covariance flux measurements is routinely done to quantify the contributions of separate processes to the overall fluxes. Measurements of carbon dioxide fluxes represent the difference between gross ecosystem photosynthesis and total respiration, while measurements of water vapo...

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

    NASA Technical Reports Server (NTRS)

    Johnson, F. S.

    1975-01-01

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

  20. Plants Can't Do without Carbon Dioxide.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1992-01-01

    Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

  1. INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED SALT BRINE TO MAKE BICARBONATE OF SODA. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

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

    PubMed

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

    2016-01-01

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

  3. Laser surgery: using the carbon dioxide laser.

    PubMed Central

    Wright, V. C.

    1982-01-01

    In 1917 Einstein theorized tha through an atomic process a unique kind of electromagnetic radiation could be produced by stimulated emission. When such radiation is in the optical or infrared spectrum it is termed laser (light amplification by stimulated emission of radiation) light. A laser, a high-intensity light source, emits a nearly parallel electromagnetic beam of energy at a given wavelength that can be captured by a lens and concentrated in the focal spot. The wavelength determines how the laser will be used. The carbon dioxide laser is now successfully employed for some surgical procedures in gynecology, otorhinolaryngology, neurosurgery, and plastic and general surgery. The CO2 laser beam is directed through the viewing system of an operating microscope or through a hand-held laser component. Its basic action in tissue is thermal vaporization; it causes minimal damage to adjacent tissues. Surgeons require special training in the basic methods and techniques of laser surgery, as well as in the safety standards that must be observed. Images FIG. 5 PMID:7074503

  4. Synthetic fuels, carbon dioxide and climate

    NASA Astrophysics Data System (ADS)

    Sapre, Alex R.; Hummel, John R.; Reck, Ruth A.

    1982-05-01

    The observed increase in atmospheric carbon dioxide (CO2) has been attributed to the use of fossil fuels. There is concern that the generation and use of synthetic fuels derived from oil shale and coal will accelerate the increase of CO2. Depending on the source, 39 or 72 percent more CO2 would be produced per unit of energy if synthetic fuels were used instead of petroleum. The use of synthetic fuels derivved from biomass would make no net addition to atmospheric CO2 provided no fossil fuels are used in biomass production and/or conversion. Assuming that synthetic liquid fuels would gradually replace petroleum and that they would supply all of the worldwide liquid fuel demand by the year 2060, we calculated that the atmospheric CO2 concentration would increase from the current 335 parts per million on a volume basis (ppmv) to 778 ppmv in 2060. However, even if the liquid fuel demand were met by petroleum alone, the CO2 level would be 715 ppmv in that year. Furthermore, we estimated that as a result of these increases in the CO2 level, the globally averaged earth's surface temperature in the year 2060 will have risen by 2.6 K with the use of synthetic liquids and 2.2 K without their use.

  5. Effects of carbon dioxide on laryngeal receptors

    SciTech Connect

    Anderson, J.W.; Sant'Ambrogio, F.B.; Orani, G.P.; Sant'Ambrogio, G.; Mathew, O.P. )

    1990-02-26

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

  6. Carbon Dioxide Angiography: Scientific Principles and Practice

    PubMed Central

    Cho, Kyung Jae

    2015-01-01

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

  7. Carbon dioxide balneotherapy and cardiovascular disease

    NASA Astrophysics Data System (ADS)

    Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  8. Electrocatalytic Reduction of Carbon Dioxide to Methane

    NASA Technical Reports Server (NTRS)

    Sammells, Anthony F.; Spiegel, Ella F.

    2008-01-01

    A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O yields CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for use in a spacecraft life-support system, in which the methane would be vented to outer space. The process may also have potential utility in terrestrial applications in which either or both of the methane and oxygen produced might be utilized or vented to the atmosphere. A typical cell used to implement the process includes a polymer solid-electrolyte membrane, onto which are deposited cathode and anode films. The cathode film is catalytic for electrolytic reduction of CO2 at low overpotential. The anode film is typically made of platinum. When CO2 is circulated past the cathode, water is circulated past the anode, and a suitable potential is applied, the anode half-cell reaction is 4H2O yields 2O2 + 8H(+) + 8e(-). The H(+) ions travel through the membrane to the cathode, where they participate in the half-cell reaction CO2 + 8H(+) + 8e(-) yields CH4 + 2H2O.

  9. Carbon Dioxide Angiography: Scientific Principles and Practice.

    PubMed

    Cho, Kyung Jae

    2015-09-01

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

  10. Euthanasia of neonatal mice with carbon dioxide

    USGS Publications Warehouse

    Pritchett, K.; Corrow, D.; Stockwell, J.; Smith, A.

    2005-01-01

    Exposure to carbon dioxide (CO2) is the most prevalent method used to euthanize rodents in biomedical research. The purpose of this study was to determine the time of CO2 exposure required to euthanize neonatal mice (0 to 10 days old). Multiple groups of mice were exposed to 100% CO 2 for time periods between 5 and 60 min. Mice were placed in room air for 10 or 20 min after CO2 exposure, to allow for the chance of recovery. If mice recovered at one time point, a longer exposure was examined. Inbred and outbred mice were compared. Results of the study indicated that time to death varied with the age of the animals and could be as long as 50 min on the day of birth and differed between inbred and outbred mice. Institutions euthanizing neonatal mice with CO2 may wish to adjust their CO 2 exposure time periods according the age of the mice and their genetic background. Copyright 2005 by the American Association for Laboratory Animal Science.

  11. Miniaturized Amperometric Solid Electrolyte Carbon Dioxide Sensors

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Xu, J. C.; Liu, C. C.; Hammond, J. W.; Ward, B.; Lukco, D.; Lampard, P.; Artale, M.; Androjna, D.

    2006-01-01

    A miniaturized electrochemical carbon dioxide (CO2) sensor using Na3Z r2Si2PO12 (NASICON) as a solid electrolyte has been fabricated and de monstrated. Microfabrication techniques were used for sensor fabricat ion to yield a sensing area around 1.0 mm x 1.1 mm. The NASICON solid electrolyte and the Na2CO3/BaCO3 (1:1.7 molar ratio) auxiliary elect rolyte were deposited by sputtering in between and on top of the inte rdigitated finger-shaped platinum electrodes. This structure maximize s the length of the three-phase boundary (electrode, solid electrolyt e, and auxiliary electrolyte), which is critical for gas sensing. The robust CO2 sensor operated up to 600 C in an amperometric mode and a ttempts were made to optimize sensor operating parameters. Concentrat ions of CO2 between 0.02% and 4% were detected and the overall sensor performance was evaluated. Linear response of sensor current output to ln[CO2 concentration] ranging from 0.02% to 1% was achieved.

  12. Carbon dioxide dynamics in an artificial ecosystem

    NASA Astrophysics Data System (ADS)

    Hu, Enzhu; Hu, Dawei; Tong, Ling; Li, Ming; Fu, Yuming; He, Wenting; Liu, Hong

    An experimental artificial ecosystem was established as a tool to understand the behavior of closed ecosystem and to develop the technology for a future bioregenerative life support system for lunar or planetary exploration. Total effective volume of the system is 0.7 m3 . It consists of a higher plant chamber, an animal chamber and a photo-bioreactor which cultivated lettuce (Lactuca sativa L.), silkworm (Bombyx Mori L.) and microalgae (Chlorella), respectively. For uniform and sustained observations, lettuce and silkworms was cultivated using sequential cultivation method, and microalgae using continuous culture. Four researchers took turns breathing the system air through a tube for brief periods every few hours. A mathematic model, simulating the carbon dioxide dynamics was developed. The main biological parameters concerning photosynthesis of lettuce and microalgae, respiration of silkworms and human were validated by the experimental data. The model described the respiratory relationship between autotrophic and heterotrophic compartments. A control strategy was proposed as a tool for the atmosphere management of the artificial ecosystem.

  13. System-Level Analysis Modeling of Impacts of Operation Schemes of Geologic Carbon Dioxide Storage on Deep Groundwater and Carbon Dioxide Leakage Risk

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The objectives of this study are to predict quantitatively groundwater and carbon dioxide flow in deep saline sandstone aquifers under various carbon dioxide injection schemes (injection rate, injection period) and to analyze integratively impacts of such carbon dioxide injection schemes on deep groundwater (brine) and carbon dioxide leakage risk through abandoned wells or faults. In order to achieve the first objective, a series of process-level prediction modeling of groundwater and carbon dioxide flow in a deep saline sandstone aquifer under several carbon dioxide injection schemes was performed using a multiphase thermo-hydrological numerical model TOUGH2 (Pruess et al., 1999). The prediction modeling results show that the extent of carbon dioxide plume is significantly affected by such carbon dioxide injection schemes. In order to achieve the second objective, a series of system-level analysis modeling of deep groundwater and carbon dioxide leakage risk through an abandoned well or a fault under several carbon dioxide injection schemes was then performed using a brine and carbon dioxide leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault increase as the carbon dioxide injection rate increases. However, the rates and amounts of deep groundwater and carbon dioxide leakage through an abandoned well or a fault decrease as the carbon dioxide injection period increases. These system-level analysis modeling results for deep groundwater and carbon dioxide leakage risk can be utilized as baseline data for establishing guidelines to mitigate anticipated environmental adverse effects on shallower groundwater systems (aquifers) when deep groundwater and carbon dioxide leakage occur. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute

  14. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  15. Tethered catalysts for the hydration of carbon dioxide

    SciTech Connect

    Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

    2014-11-04

    A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

  16. Carbon dioxide in the ocean surface: The homogeneous buffer factor

    USGS Publications Warehouse

    Sundquist, E.T.; Plummer, L.N.; Wigley, T.M.L.

    1979-01-01

    The amount of carbon dioxide that can be dissolved in surface seawater depends at least partially on the homogeneous buffer factor, which is a mathematical function of the chemical equilibrium conditions among the various dissolved inorganic species. Because these equilibria are well known, the homogeneous buffer factor is well known. Natural spatial variations depend very systematically on sea surface temperatures, and do not contribute significantly to uncertainties in the present or future carbon dioxide budget. Copyright ?? 1979 AAAS.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  19. Simulations of Carbon Dioxide Cloud Formation at the Martian Poles

    NASA Astrophysics Data System (ADS)

    Colaprete, A.; Toon, O. B.

    1999-09-01

    The Mars Orbiter Laser Altimeter (MOLA) experiment flying onboard the Mars Global Surveyor has observed echoes from cloud tops above the north polar cap. Due to the location and time of year that these clouds are forming, it has been assumed that these clouds consist primarily of carbon dioxide ice particles. The structure of these echoes suggests that a number of these clouds may be the product of buoyancy or gravity waves (Zuber et al., 1998). While the presence of carbon dioxide clouds in the Martian atmosphere is generally accepted, how and where they form is still not understood and little is known about the physics of carbon dioxide particle formation. Recently, Glandorf et al. (personal communication) measured the critical saturation ratio required for carbon dioxide to nucleate onto ice. From this measurement, using nucleation theory, the contact parameter between ice and carbon dioxide under Martian conditions was determined. Using the nucleation rates measured by Glandorf et al. we have developed a 2D time dependent microphyical simulation of carbon dioxide clouds forming in the Mars polar regions. In this simulation we explore the mechanism of cloud initiation by orographic waves and compare our results to MOLA observations.

  20. Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

    PubMed Central

    Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

    2015-01-01

    Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO2) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO2 sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review. PMID:26690155

  1. Carbon dioxide sequestration by direct aqueous mineral carbonation

    SciTech Connect

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

    2000-01-01

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

  2. Carbon Dioxide Reduction Technology Trade Study

    NASA Technical Reports Server (NTRS)

    Jeng, Frank F.; Anderson, Molly S.; Abney, Morgan B.

    2011-01-01

    For long-term human missions, a closed-loop atmosphere revitalization system (ARS) is essential to minimize consumables. A carbon dioxide (CO2) reduction technology is used to reclaim oxygen (O2) from metabolic CO2 and is vital to reduce the delivery mass of metabolic O2. A key step in closing the loop for ARS will include a proper CO2 reduction subsystem that is reliable and with low equivalent system mass (ESM). Sabatier and Bosch CO2 reduction are two traditional CO2 reduction subsystems (CRS). Although a Sabatier CRS has been delivered to International Space Station (ISS) and is an important step toward closing the ISS ARS loop, it recovers only 50% of the available O2 in CO2. A Bosch CRS is able to reclaim all O2 in CO2. However, due to continuous carbon deposition on the catalyst surface, the penalties of replacing spent catalysts and reactors and crew time in a Bosch CRS are significant. Recently, technologies have been developed for recovering hydrogen (H2) from Sabatier-product methane (CH4). These include methane pyrolysis using a microwave plasma, catalytic thermal pyrolysis of CH4 and thermal pyrolysis of CH4. Further, development in Sabatier reactor designs based on microchannel and microlith technology could open up opportunities in reducing system mass and enhancing system control. Improvements in Bosch CRS conversion have also been reported. In addition, co-electrolysis of steam and CO2 is a new technology that integrates oxygen generation and CO2 reduction functions in a single system. A co-electrolysis unit followed by either a Sabatier or a carbon formation reactor based on Bosch chemistry could improve the overall competitiveness of an integrated O2 generation and CO2 reduction subsystem. This study evaluates all these CO2 reduction technologies, conducts water mass balances for required external supply of water for 1-, 5- and 10-yr missions, evaluates mass, volume, power, cooling and resupply requirements of various technologies. A system

  3. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, Richard; Steinberg, Meyer

    1981-01-01

    This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  4. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  5. Capture of green-house carbon dioxide in Portland cement

    SciTech Connect

    Wagh, A.S.; Singh, D.; Pullockaran, J.; Knox, L.

    1993-12-31

    A novel process has been developed to sequester green-house carbon dioxide produced by the cement industry in precast cement products. Typically, 10--24 wt % of CO{sub 2} produced by calcination of calcium carbonate during clinkering of the cement may be captured. The carbonation process also cures the cement paste within minutes into hard bodies. The process maintains high pH conditions during curing, to allow conventional steel reinforcement of concrete. The process will save time and money to the cement industry, and at the same time, help them to comply with the Clean Air Act by sequestering the green-house carbon dioxide.

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

    SciTech Connect

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

    2011-09-30

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

  7. The role of renewable bioenergy in carbon dioxide sequestration

    SciTech Connect

    Kinoshita, C.M.

    1993-12-31

    The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

  8. Purification of SoyScreen using critical carbon dioxide in a counter-current fractionation column

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research evaluated the use of critical carbon dioxide (CO2) in a counter-current fractionation column for purifying SoyScreen, a mixture of feruloylated glycerides. The process concept was tested using a mixture consisting of triacylglycerides (TAGs), ethyl ferulate and fatty acid ethyl esters...

  9. Carbon Dioxide Flooding: A Classroom Case Study Derived from Surgical Practice

    NASA Astrophysics Data System (ADS)

    Kerber, Robert C.

    2003-12-01

    The surgical opening in open-heart surgery is often flooded with carbon dioxide gas to avoid air embolisms when the heart is closed and restarted. This practice can be used in chemistry courses to illustrate concepts of gas density, solubility, and acid base equilibria, including buffering.

  10. SUPERCRITICAL CARBON DIOXIDE-SOLUBLE LIGANDS FOR EXTRACTING ACTINIDE METAL IONS FROM POROUS SOLIDS

    EPA Science Inventory

    The objective of this project is to develop novel, substituted diphosphonic acid ligands that can be used for supercritical carbon dioxide extraction (SCDE) of actinide ions from solid wastes. These ligands will be used to investigate fundamental aspects of metal extraction into...

  11. Fractionation of whey protein isolate with supercritical carbon dioxide – process modeling and cost estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An economical and environmentally friendly whey protein fractionation process was developed using supercritical carbon dioxide (sCO2) as an acid to produce enriched fractions of alpha-lactalbumin (alpha-La) and beta-lactoglobulin (beta-Lg) from a commercial whey protein isolate (WPI) containing 55% ...

  12. Tunnelling in carbonic acid.

    PubMed

    Wagner, J Philipp; Reisenauer, Hans Peter; Hirvonen, Viivi; Wu, Chia-Hua; Tyberg, Joseph L; Allen, Wesley D; Schreiner, Peter R

    2016-06-14

    The cis,trans-conformer of carbonic acid (H2CO3), generated by near-infrared radiation, undergoes an unreported quantum mechanical tunnelling rotamerization with half-lives in cryogenic matrices of 4-20 h, depending on temperature and host material. First-principles quantum chemistry at high levels of theory gives a tunnelling half-life of about 1 h, quite near those measured for the fastest rotamerizations. PMID:27248671

  13. Renewable and metal-free carbon nanofibre catalysts for carbon dioxide reduction

    NASA Astrophysics Data System (ADS)

    Kumar, Bijandra; Asadi, Mohammad; Pisasale, Davide; Sinha-Ray, Suman; Rosen, Brian A.; Haasch, Richard; Abiade, Jeremiah; Yarin, Alexander L.; Salehi-Khojin, Amin

    2013-12-01

    The development of an efficient catalyst system for the electrochemical reduction of carbon dioxide into energy-rich products is a major research topic. Here we report the catalytic ability of polyacrylonitrile-based heteroatomic carbon nanofibres for carbon dioxide reduction into carbon monoxide, via a metal-free, renewable and cost-effective route. The carbon nanofibre catalyst exhibits negligible overpotential (0.17 V) for carbon dioxide reduction and more than an order of magnitude higher current density compared with the silver catalyst under similar experimental conditions. The carbon dioxide reduction ability of carbon nanofibres is attributed to the reduced carbons rather than to electronegative nitrogen atoms. The superior performance is credited to the nanofibrillar structure and high binding energy of key intermediates to the carbon nanofibre surfaces. The finding may lead to a new generation of metal-free and non-precious catalysts with much greater efficiency than the existing noble metal catalysts.

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

    SciTech Connect

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

    2004-07-01

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

  15. Interaction of Surface Modified Carbon Nanotubes with Supercritical Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Baysal, Nihat; Unsal, Banu; Ozisik, Rahmi

    2006-03-01

    The properties of carbon nanotube (CNT)-polymer nanocomposites are far below than those calculated, mainly due to poor dispersion or interface quality. This is particularly difficult for single walled carbon nanotubes (SWNTs) as they tend to form bundles or ropes that are difficult to exfoliate. Supercritical fluid (SCF) assisted processing is one of the methods that can be used to exfoliate/disperse CNTs along with modifiying the interface of the CNTs. Molecular dynamics simulations were performed to understand how the surface modifiers behave near SWNT surface with and without the presence of SCF molecules. It is also important to understand the diffusivity of SCF molecules between SWNT bundles and the effect of surface modifiers on diffusion. Octane and n-perflourooctane molecules were used as surface modifiers with varying tethering density and carbon dioxide (CO2) was chosen as the SCF. Results showed that the system with highest number of n-perfluorooctanes presented the highest degree of success in separating the SWNTs in the presence of CO2.

  16. It is time to put carbon dioxide to work

    SciTech Connect

    Lipinsky, E.S.

    1993-12-31

    The need to control emissions of carbon dioxide into the atmosphere is the subject of vigorous debate at this time. There is growing evidence that rising levels of carbon dioxide increase global warming, with perhaps highly adverse impacts for the human economy. There are calls for carbon taxes and other harsh measures. Japan has established a national goal of holding carbon dioxide emissions in the year 2000 to 1990 levels. I hope that this conference will be a turning point in the United States position on this issue. The current major end uses for CO{sub 2} include refrigeration, beverage carbonation, soda ash production, fire fighting, and urea fertilizer production. They are all based on chemistry that would not surprise a good chemist of the 19th century. Consumption of carbon dioxide in synthesis of industrial chemicals is limited. Usually one explains low production of chemicals from a candidate feedstock in terms of poor availability, price, purity, or reactivity. We can eliminate the first three as the causes of the underutilization of carbon dioxide.

  17. Ionic Liquid Membranes for Carbon Dioxide Separation

    SciTech Connect

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

    2008-07-12

    Recent scientific studies are rapidly advancing novel technological improvements and engineering developments that demonstrate the ability to minimize, eliminate, or facilitate the removal of various contaminants and green house gas emissions in power generation. The Integrated Gasification Combined Cycle (IGCC) shows promise for carbon dioxide mitigation not only because of its higher efficiency as compared to conventional coal firing plants, but also due to a higher driving force in the form of high partial pressure. One of the novel technological concepts currently being developed and investigated is membranes for carbon dioxide (CO2) separation, due to simplicity and ease of scaling. A challenge in using membranes for CO2 capture in IGCC is the possibility of failure at elevated temperatures or pressures. Our earlier research studies examined the use of ionic liquids on various supports for CO2 separation over the temperature range, 37°C-300°C. The ionic liquid, 1-hexyl-3methylimidazolium Bis(trifluoromethylsulfonyl)imide, ([hmim][Tf2N]), was chosen for our initial studies with the following supports: polysulfone (PSF), poly(ether sulfone) (PES), and cross-linked nylon. The PSF and PES supports had similar performance at room temperature, but increasing temperature caused the supported membranes to fail. The ionic liquid with the PES support greatly affected the glass transition temperature, while with the PSF, the glass transition temperature was only slightly depressed. The cross-linked nylon support maintained performance without degradation over the temperature range 37-300°C with respect to its permeability and selectivity. However, while the cross-linked nylon support was able to withstand temperatures, the permeability continued to increase and the selectivity decreased with increasing temperature. Our studies indicated that further testing should examine the use of other ionic liquids, including those that form chemical complexes with CO2 based on

  18. The carbon dioxide challenge facing aviation

    NASA Astrophysics Data System (ADS)

    Hileman, James I.; De la Rosa Blanco, Elena; Bonnefoy, Philippe A.; Carter, Nicholas A.

    2013-11-01

    This paper investigates the challenge that U.S. aviation would face in meeting future Greenhouse Gas (GHG) reduction goals to mitigate global climate change via technological options. This investigation is done within a framework that considers aviation GHG emissions as a function of aviation growth, aircraft efficiency, operational efficiency, and life cycle GHG emissions of aviation fuels. The concept of life cycle GHG intensity (LGI) with units of grams carbon dioxide equivalent per payload distance traveled is used for this purpose as it can be decomposed into components that quantify improvements in aircraft design, operations, and alternative fuels. For example, the life cycle GHG intensity of U.S. aviation in 2005 was 1.37 g CO2e/kg km. If U.S. aviation is to meet the IATA 2050 goal of a 50% reduction in CO2 relative to a 2005 baseline while allowing for a 3.2% annual growth rate in payload-distance traveled, it will need to decrease to 0.22 g CO2e/kg km in 2050, an 84% reduction. The analysis framework that is developed in this manuscript was used to compare the improvements in life cycle GHG intensity that could accompany the use of advanced aircraft designs, operational improvements, and alternative fuels to those required on a fleet-wide basis to meet the future GHG reduction goals under varied aviation growth scenarios. The results indicate that the narrow body segment of the fleet could indeed meet ambitious goals of reducing GHG emissions by 50%, relative to 2005 levels, with a 3.2% annual growth rate; however, it would require relatively rapid adoption of innovative aircraft designs and the widespread use of alternative fuels with relatively low life cycle GHG emissions.

  19. Urban carbon dioxide in Portland, Oregon

    NASA Astrophysics Data System (ADS)

    Bostrom, G. A.; Brooks, M.; Rice, A. L.

    2010-12-01

    Ambient concentrations of atmospheric carbon dioxide (CO2) are reported for the Portland, Oregon (USA) metropolitan region since late July, 2009. Three stationary locations were established: a downtown location on the campus of Portland State University; a residential site in southeast Portland; and a rural station on Sauvie Island, located ~30km northwest of Portland in the Columbia River Gorge. Continuous measurements of CO2 at the sites average 400-410ppm and show considerable variability due to CO2 sources, sinks and meteorological drivers of ventilation. Within this variability, a marked 20-30ppm diurnal cycle is observed due to photosynthetic activity and variations in the planetary boundary layer. In-city CO2 concentrations are on average enhanced by 5-6ppm over the Sauvie Island site during upgorge wind conditions, a difference which is greatest in the afternoon. Measurements of the 13C/12C ratio of CO2 in downtown Portland are significantly depleted in 13C relative to 12C compared with background air and suggest that regional CO2 is dominated by petroleum sources (70-80%). High degrees of relationship between CO2 variability and primary air pollutants CO and NO (r2=0.70 to 0.80), measured by the Oregon Department of Environmental Quality at the Southeast Portland location, corroborate this finding and illustrate the importance of traffic emissions on elevated ambient CO2 concentrations. In addition to CO2 at the fixed sites, measurements of street-level CO2 concentrations were obtained using a mobile instrument mounted in a bike trailer. Results from these field data show relatively homogenous CO2 concentrations throughout residential Portland neighborhoods with significant enhancements in CO2 on busy roadways or near areas of traffic congestion.

  20. The Headache of Carbon Dioxide Exposures

    NASA Technical Reports Server (NTRS)

    James, John T.

    2007-01-01

    Carbon dioxide (CO2), a natural product of human metabolism, accumulates quickly in sealed environments when humans are present, and can induce headaches, among other symptoms. Major resources are expended to control CO2 levels to concentrations that are tolerable to the crews of spacecraft and submersible craft. It is not practical to control CO2 levels to those found in the ambient environment on earth. As NASA looks ahead to long-duration missions conducted far from earth, difficult issues arise related to the management and effects of human exposure to CO2. One is the problem of pockets of CO2 in the habitat caused by excess generation of the gas in one location without a mechanism to purge the area with fresh air. This results in the crew rebreathing CO2 from their exhaled breath, exposing them to a much higher concentration of CO2 than whole-module measurements would suggest. Another issue is the potential increased sensitivity to CO2 in microgravity. For example, based on anecdotal information, it appears that space crews may be more susceptible than submarine crews to some of the subtle, yet adverse effects of CO2 exposure. Another issue, not unique to spaceflight, is the possibility of inter-individual differences in the susceptibility of crewmembers to CO2 exposure. Again, anecdotal reports from the International Space Station (ISS) crews suggest that certain individuals may experience a greater susceptibility. The implications associated with these issues are extremely important as NASA sets CO2 exposure limits that protect the crew from this compound s subtle adverse effects, without causing an unwarranted expenditure of resources to scrub CO2 from the habitat atmosphere.

  1. Carbon dioxide catastrophes: Past and future menace

    NASA Technical Reports Server (NTRS)

    Baur, Mario E.

    1988-01-01

    Carbon dioxide is important in its role as coupler of the terrestrial biosphere to inorganic chemical processes and as the principal greenhouse gas controlling Earth's surface temperature. The hypothesis that atmospheric CO2 levels have diminished with time, with the resulting cooling effect offsetting an increase in the solar constant, seems firmly established, and it is shown that feedback mechanisms exist which can maintain the terrestrial surface in a relatively narrow temperature range over geological time. Of the factors involved in such CO2 variation, the oceanic reservoir appears the most important. Surface waters are probably in approximate equilibrium with regard to CO2 exchange with the ambient atmosphere in most regions, but data from deep-ocean water sampling indicates that such waters are somewhat undersaturated in the sense that they would tend to absorb CO2 from the atmosphere if brought to the surface without change in composition or temperature. If major impacts into the ocean can result in loss of a substantial portion of the atmospheric CO2 reservoir, then any such future event could imperil the continuation of most higher forms of life on Earth. The most likely candidate for an inverse Nyos global event in previous Earth history is the Cretaceous-Tertiary terminal extinction event. The Cretaceous was characterized by warm, equable temperatures presumably indicative of relatively high CO2 levels and an intense greenhouse heating. Cooling of the oceans in absence of massive transfer of CO2 to the oceanic reservoir in itself would promote a condition of CO2 undersaturation in abyssal waters, and this is made even more extreme by the pattern of ocean water circulation. It is possible to envision a situation in which deep ocean waters were at least occasionally profoundly undersaturated with regard to CO2. Turnover of a major fraction of such an ocean would then remove, on a very short time scale, as much as 90 percent of the atmospheric CO2

  2. 46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2)...

  3. SN1 reactions in supercritical carbon dioxide in the presence of alcohols: the role of preferential solvation.

    PubMed

    Delgado-Abad, Thais; Martínez-Ferrer, Jaime; Acerete, Rafael; Asensio, Gregorio; Mello, Rossella; González-Núñez, María Elena

    2016-07-01

    Ethanol () inhibits SN1 reactions of alkyl halides in supercritical carbon dioxide (scCO2) and gives no ethers as products. The unexpected behaviour of alcohols in the reaction of alkyl halides with 1,3-dimethoxybenzene () in scCO2 under different conditions is rationalised in terms of Brønsted and Lewis acid-base equilibria of reagents, intermediates, additives and products in a singular solvent characterised by: (i) the strong quadrupole and Lewis acid character of carbon dioxide, which hinders SN2 paths by strongly solvating basic solutes; (ii) the weak Lewis base character of carbon dioxide, which prevents it from behaving as a proton sink; (iii) the compressible nature of scCO2, which enhances the impact of preferential solvation on carbon dioxide availability for the solvent-demanding rate determining step. PMID:27303826

  4. Vegetation Response to Carbon Dioxide and Climate: Data from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, and models and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to vegetation response to carbon dioxide and climate includes: • Area and Carbon Content of Sphagnum Since Last Glacial Maximum (2002) (Trends Online) • TDE Model Intercomparison Project Data Archive • Presentations and abstracts from the recent DOE Terrestrial Science Team Meeting (Argonne National Laboratory, October 29-31, 2001) • FACE (Free-Air CO2 Enrichment) • Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth (2001) • Bibliography on CO2 Effects on Vegetation and Ecosystems: 1990-1999 Literature (2000) • Direct effects of atmospheric CO2 enrichment on plants and ecosystems: An updated bibliographic data base (1994) • A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO2 (1999) • A Database of Woody Vegetation Responses to Elevated Atmospheric CO2 (1999) • Forest Responses to Anthropogenic Stress (FORAST) Database (1995) • Effects of CO2 and Nitrogen Fertilization on Growth and Nutrient Content of Juvenile Ponderosa Pine (1998) • Carbon Dioxide Enrichment: Data on the Response of Cotton to Varying CO2Irrigation, and Nitrogen (1992) • Growth and Chemical Responses to CO2 Enrichment Virginia Pine Pinus Virginiana Mill.(1985)

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

    SciTech Connect

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

    1980-04-01

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

  6. Photoelectrochemical reduction of carbon dioxide using Ge doped GaN nanowire photoanodes

    NASA Astrophysics Data System (ADS)

    Wang, Yichen; AlOtaibi, Bandar; Chowdhury, Faqrul A.; Fan, Shizhao; Kibria, Md G.; Li, Lu; Li, Chao-Jun; Mi, Zetian

    2015-11-01

    We report on the direct conversion of carbon dioxide (CO2) in a photoelectrochemical cell consisting of germanium doped gallium nitride nanowire anode and copper (Cu) cathode. Various products including methane (CH4), carbon monoxide (CO), and formic acid (HCOOH) were observed under light illumination. A Faradaic efficiency of ˜10% was measured for HCOOH. Furthermore, this photoelectrochemical system showed enhanced stability for 6 h CO2 reduction reaction on low cost, large area Si substrates.

  7. Reactor design considerations in mineral sequestration of carbon dioxide

    SciTech Connect

    Ityokumbul, M.T.; Chander, S.; O'Connor, William K.; Dahlin, David C.; Gerdemann, Stephen J.

    2001-01-01

    One of the promising approaches to lowering the anthropogenic carbon dioxide levels in the atmosphere is mineral sequestration. In this approach, the carbon dioxide reacts with alkaline earth containing silicate minerals forming magnesium and/or calcium carbonates. Mineral carbonation is a multiphase reaction process involving gas, liquid and solid phases. The effective design and scale-up of the slurry reactor for mineral carbonation will require careful delineation of the rate determining step and how it changes with the scale of the reactor. The shrinking core model was used to describe the mineral carbonation reaction. Analysis of laboratory data indicates that the transformations of olivine and serpentine are controlled by chemical reaction and diffusion through an ash layer respectively. Rate parameters for olivine and serpentine carbonation are estimated from the laboratory data.

  8. Carbon Dioxide Carbonates in the Earth;s Mantle: Implications to the Deep Carbon Cycle

    SciTech Connect

    Yoo, Choong-Shik; Sengupta, Amartya; Kim, Minseob

    2012-05-22

    An increase in the ionic character in C-O bonds at high pressures and temperatures is shown by the chemical/phase transformation diagram of CO{sub 2}. The presence of carbonate carbon dioxide (i-CO{sub 2}) near the Earth's core-mantle boundary condition provides insights into both the deep carbon cycle and the transport of atmospheric CO{sub 2} to anhydrous silicates in the mantle and iron core.

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

    PubMed

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

    2016-06-01

    Ripening of climacteric fruits is associated with pronounced changes in fruit gas composition caused by a concomitant rise in respiration and ethylene production. There is a discrepancy in the literature since some authors reported that changes in fruit gas compositions differ in attached and detached fruits. This study presents for the first time an overview of pre- and post-harvest factors that lead to variations in the climacteric respiration and ethylene production, and attempts to determine their impacts on fruit composition, i.e., dry matter, total soluble solids content and acidity. The impact of growing conditions such as the fruit position in the canopy and the fruit carbon supply; fruit detachment from the tree, including the maturity stage at harvest; and storage conditions after harvest, i.e., relative humidity and temperature were considered as well as changes in fruit skin resistance to gas diffusion during fruit growth and storage. Results showed that fruit gas composition vary with all pre and post-harvest factors studied. Although all mangoes underwent a respiratory climacteric and an autocatalytic ethylene production, whatever pre and post-harvest factors studied, large differences in ethylene production, climacteric respiration and fruit quality were measured. Results suggested that the ripening capacity is not related to the fruit ability to produce great amount of ethylene. In agreement with precedent studies, this work provided several lines of evidence that gas composition of fruit is related to its water balance. Our measurements indicated that skin resistance to gas diffusion increased after the harvest and during storage. It was so suggested that the faster ripening of detached fruit may be explained in part by changes in fruit water balance and skin resistance to gas diffusion caused by fruit detachment. PMID:27085177

  10. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, Jerome W.; Klingler, Robert J.

    1993-01-01

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

  11. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, J.W.; Klingler, R.J.

    1993-03-30

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

  12. CARBON DIOXIDE FLUX DURING THE FIRST YEAR FOLLOWING SWITCHGRASS ESTABLISHMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial grasslands managed for biofuel production could provide additional environmental benefits by sequestering carbon in the soil. An eddy covariance flux tower was used to quantify the net carbon dioxide flux during 2005 for a switchgrass (Panicum virgatum L) field that had been planted in 200...

  13. Capturing carbon dioxide as a polymer from natural gas

    NASA Astrophysics Data System (ADS)

    Hwang, Chih-Chau; Tour, Josiah J.; Kittrell, Carter; Espinal, Laura; Alemany, Lawrence B.; Tour, James M.

    2014-06-01

    Natural gas is considered the cleanest and recently the most abundant fossil fuel source, yet when it is extracted from wells, it often contains 10-20 mol% carbon dioxide (20-40 wt%), which is generally vented to the atmosphere. Efforts are underway to contain this carbon dioxide at the well-head using inexpensive and non-corrosive methods. Here we report nucleophilic porous carbons are synthesized from simple and inexpensive carbon-sulphur and carbon-nitrogen precursors. Infrared, Raman and 13C nuclear magnetic resonance signatures substantiate carbon dioxide fixation by polymerization in the carbon channels to form poly(CO2) under much lower pressures than previously required. This growing chemisorbed sulphur- or nitrogen-atom-initiated poly(CO2) chain further displaces physisorbed hydrocarbon, providing a continuous carbon dioxide selectivity. Once returned to ambient conditions, the poly(CO2) spontaneously depolymerizes, leading to a sorbent that can be easily regenerated without the thermal energy input that is required for traditional sorbents.

  14. Assessing Carbon Dioxide Emissions from Energy Use at a University

    ERIC Educational Resources Information Center

    Riddell, William; Bhatia, Krishan Kumar; Parisi, Matthew; Foote, Jessica; Imperatore, John, III

    2009-01-01

    Purpose: The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design/methodology/approach: First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated with…

  15. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  16. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  17. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon dioxide analyzer calibration. 86.224-94 Section 86.224-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon...

  18. 40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  19. Carbon dioxide fluid-flow modeling and injectivity calculations

    USGS Publications Warehouse

    Burke, Lauri

    2011-01-01

    These results were used to classify subsurface formations into three permeability classifications for the probabilistic calculations of storage efficiency and containment risk of the U.S. Geological Survey geologic carbon sequestration assessment methodology. This methodology is currently in use to determine the total carbon dioxide containment capacity of the onshore and State waters areas of the United States.

  20. Response of the oceans to increasing atmospheric carbon dioxide

    SciTech Connect

    Baes, C.F. Jr.

    1981-08-01

    The rate at which the oceans take up excess atmospheric carbon dioxide from the burning of fossil fuels is an important factor in determining the rate of increase in the atmospheric concentration of carbon dioxide and the maximum value it will reach. In this review are considered the relevant physical and chemical features of the ocean, the observational evidence of its response to increasing atmospheric carbon dioxide, and the uncertainties involved in modeling this response. The deep oceans are near saturation with calcite (the least soluble form of calcium carbonate). While the pressure dependence of this solubility and ocean circulation tend to produce calcite supersaturation of the upper ocean, these effects cannot account for the far greater supersaturation of the surface waters. This condition is probably maintained by the effects of photosynthesis and the biogenically controlled precipitation of calcium carbonate. After correcting for the expected effects of biological processes on the composition of seawater, several investigators have found evidence that the increasing carbon dioxide content of the atmosphere has already detectably affected the distribution of carbon in the upper ocean. While there are some complications and uncertainties from mixing effects, there seems reason to hope that this signature of excess carbon may soon become a valuable tracer for monitoring ocean response.