WorldWideScience

Sample records for hydrogen carbon dioxide

  1. Methanation of hydrogen and carbon dioxide

    International Nuclear Information System (INIS)

    Burkhardt, Marko; Busch, Günter

    2013-01-01

    Highlights: • The biologic methanation of exclusively gases like hydrogen and carbon dioxide is feasible. • Electrical energy can be stored in the established gas grid by conversion to methane. • The quality of produced biogas is very high (c CH4 = 98 vol%). • The conversion rate is depending on H 2 -flow rate. - Abstract: A new method for the methanation of hydrogen and carbon dioxide is presented. In a novel anaerobic trickle-bed reactor, biochemical catalyzed methanation at mesophilic temperatures and ambient pressure can be realized. The conversion of gaseous substrates by immobilized hydrogenotrophic methanogens is a unique feature of this reactor type. The already patented reactor produces biogas which has a very high quality (c CH4 = 97.9 vol%). Therefore, the storage of biogas in the existing natural gas grid is possible without extensive purification. The specific methane production was measured with P = 1.17 Nm CH4 3 /(m R 3 d). It is conceivable to realize the process at sites that generate solar or wind energy and sites subject to the conditions for hydrogen electrolysis (or other methods of hydrogen production). The combination with conventional biogas plants under hydrogen addition to methane enrichment is possible as well. The process enables the coupling of various renewable energy sources

  2. Photobiological hydrogen production and carbon dioxide sequestration

    Science.gov (United States)

    Berberoglu, Halil

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

  3. Sequestration of carbon dioxide with hydrogen to useful products

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

    2017-03-07

    Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

  4. Extraction of Carbon Dioxide and Hydrogen from Seawater and Hydrocarbon Production Therefrom

    Science.gov (United States)

    2016-04-05

    acidification of seawater by subjecting the seawater to an ion exchange reaction to exchange H.sup. ions for Na.sup. ions. Carbon dioxide may be...extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide . The carbon dioxide and hydrogen may be used to produce hydrocarbons.

  5. Method of carbon dioxide-free hydrogen production from hydrocarbon decomposition over metal salts

    Science.gov (United States)

    Erlebacher, Jonah; Gaskey, Bernard

    2017-10-03

    A process to decompose methane into carbon (graphitic powder) and hydrogen (H.sub.2 gas) without secondary production of carbon dioxide, employing a cycle in which a secondary chemical is recycled and reused, is disclosed.

  6. Dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate-hydrogen peroxide

    International Nuclear Information System (INIS)

    Kanekar, A.S.; Pathak, P.N.; Mohapatra, P.K.; Manchanda, V.K.

    2009-01-01

    Direct dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate (TBP) has been attempted. The effects of TBP concentration and pressure on the extraction of uranium have been studied. Addition of hydrogen peroxide in the modifier enhances the dissolution/extraction of uranium. (author)

  7. Sintering uranium oxide in the reaction product of hydrogen-carbon dioxide mixtures

    International Nuclear Information System (INIS)

    De Hollander, W.R.; Nivas, Y.

    1975-01-01

    Compacted pellets of uranium oxide alone or containing one or more additives such as plutonium dioxide, gadolinium oxide, titanium dioxide, silica, and alumina are heated to 900 to 1599 0 C in the presence of a mixture of hydrogen and carbon dioxide, either alone or with an inert carrier gas and held at the desired temperature in this atmosphere to sinter the pellets. The sintered pellets are then cooled in an atmosphere having an oxygen partial pressure of 10 -4 to 10 -18 atm of oxygen such as dry hydrogen, wet hydrogen, dry carbon monoxide, wet carbon monoxide, inert gases such as nitrogen, argon, helium, and neon and mixtures of ayny of the foregoing including a mixture of hydrogen and carbon dioxide. The ratio of hydrogen to carbon dioxide in the gas mixture fed to the furnace is controlled to give a ratio of oxygen to uranium atoms in the sintered particles within the range of 1.98:1 to about 2.10:1. The water vapor present in the reaction products in the furnace atmosphere acts as a hydrolysis agent to aid removal of fluoride should such impurity be present in the uranium oxide. (U.S.)

  8. Iodide-photocatalyzed reduction of carbon dioxide to formic acid with thiols and hydrogen sulfide

    OpenAIRE

    Berton, Mateo Otao; Mello, Rossella C. C.; González Núñez, María Elena

    2016-01-01

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO2 capture coupled with H2S removal may have been relevant as a prebiotic carbon dioxide fixation.

  9. Carbon dioxide management by chemical conversion to methanol: HYDROGENATION and BI-REFORMING

    International Nuclear Information System (INIS)

    Wiesberg, Igor L.; Medeiros, José Luiz de; Alves, Rita M.B.; Coutinho, Paulo L.A.; Araújo, Ofélia Q.F.

    2016-01-01

    Highlights: • Evaluation of carbon dioxide conversion to methanol by two chemical routes. • HYDROGENATION: conversion via catalytic hydrogenation at high pressure. • BI-REFORMING: conversion via syngas from bi-reforming of natural gas. • HYDROGENATION is viable for hydrogen price inferior to 1000 US$/t. • BI-REFORMING is unable to avoid emissions; viable only if gas price is very low. - Abstract: Chemical conversion of carbon dioxide to methanol has the potential to address two relevant sustainability issues: economically feasible replacement of fossil raw materials and avoidance of greenhouse gas emissions. However, chemical stability of carbon dioxide is a challenging impediment to conversion requiring severe reaction conditions at the expense of increased energy input, therefore adding capital, operation and environmental costs, which could result in partial or total override of its potential sustainability as feedstock to the chemical and energy industries. This work investigates two innovative chemical destinations of carbon dioxide to methanol, namely a direct conversion through carbon dioxide hydrogenation (HYDROGENATION), and an indirect via carbon dioxide conversion to syngas through bi-reforming (BI-REFORMING). Process simulation is used to obtain mass and energy balances needed to support assessment of economic and environmental performance. A business scenario is considered where an industrial source of nearly pure carbon dioxide exists and an investment decision for utilization of carbon dioxide is faced. Due to uncertainties in prices of the raw materials, hydrogen (HYDROGENATION) and natural gas (BI-REFORMING), the decision procedure includes the definition of price thresholds to reach profitability. Sensitivity analyses are performed varying costs with greater uncertainty, i.e., carbon dioxide and methanol, and recalculating maximum allowable prices of raw materials. The analyses show that in a Brazilian scenario, BI-REFORMING is unlikely

  10. Study on the production of alternative fuels by carbon dioxide hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Kyu Sung; Han, Sang Do; Kim, Jong Won; Kim, Youn Soon; Seo, Ji Mi [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

    1995-12-01

    The technologies of the fuel production from carbon dioxide by catalytic hydrogenation were surveyed. For the catalytic hydrogenation we made the lab-scale reaction apparatus and carried out some experiments with various catalysts like CuO/ZnO/Al{sub 2}O{sub 3}, Raney nickel and other commercial catalysts. In this year, the third year of the project, the experiments to find optimum catalysts and obtain the good conditions of carbon dioxide were performed followed by second year. And also the processes of the methanol synthesis was investigated simultaneously. (author). 58 refs., 58 figs., 28 tabs.

  11. Influence of adsorbed carbon dioxide on hydrogen electrosorption in palladium-platinum-rhodium alloys

    International Nuclear Information System (INIS)

    Lukaszewski, M.; Grden, M.; Czerwinski, A.

    2004-01-01

    Carbon dioxide electroreduction was applied to examine the processes of hydrogen electrosorption (adsorption, absorption and desorption) by thin electrodeposits of Pd-Pt-Rh alloys under conditions of cyclic voltammetric (CV) experiments. Due to different adsorption characteristics towards the adsorption product of the electroreduction of CO 2 (reduced CO 2 ) exhibited by the alloy components hydrogen adsorption and hydrogen absorption signals can be distinguished on CV curves. Reduced CO 2 causes partial blocking of hydrogen adsorbed on surface Pt and Rh atoms, without any significant effect on hydrogen absorption into alloy. It reflects the fact that adsorbed hydrogen bonded to Pd atoms does not participate in CO 2 reduction, while hydrogen adsorbed on Pt and Rh surface sites is inactive in the absorption reaction. In contrast, CO is adsorbed on all alloy components and causes a marked inhibition of hydrogen sorption (both adsorption and absorption)/desorption reactions

  12. Process and reactor for the production of hydrogen and carbon dioxide and a fuel cell system

    NARCIS (Netherlands)

    2006-01-01

    The invention relates to a process for the production of hydrogen and carbon dioxide from a hydrocarbonaceous feedstock, comprising: a) supplying a gaseous hydrocarbonaceous feedstock and steam to a reaction zone comprising a steam reforming catalyst and catalytically reforming the hydrocarbonaceous

  13. Iodide-Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide.

    Science.gov (United States)

    Berton, Mateo; Mello, Rossella; González-Núñez, María Elena

    2016-12-20

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO 2 capture coupled with H 2 S removal may have been relevant as a prebiotic carbon dioxide fixation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Does Aerobic Respiration Produce Carbon Dioxide or Hydrogen Ion and Bicarbonate?

    Science.gov (United States)

    Swenson, Erik R

    2018-05-01

    Maintenance of intracellular pH is critical for clinical homeostasis. The metabolism of glucose, fatty acids, and amino acids yielding the generation of adenosine triphosphate in the mitochondria is accompanied by the production of acid in the Krebs cycle. Both the nature of this acidosis and the mechanism of its disposal have been argued by two investigators with a long-abiding interest in acid-base physiology. They offer different interpretations and views of the molecular mechanism of this intracellular pH regulation during normal metabolism. Dr. John Severinghaus has posited that hydrogen ion and bicarbonate are the direct end products in the Krebs cycle. In the late 1960s, he showed in brain and brain homogenate experiments that acetazolamide, a carbonic anhydrase inhibitor, reduces intracellular pH. This led him to conclude that hydrogen ion and bicarbonate are the end products, and the role of intracellular carbonic anhydrase is to rapidly generate diffusible carbon dioxide to minimize acidosis. Dr. Erik Swenson posits that carbon dioxide is a direct end product in the Krebs cycle, a more widely accepted view, and that acetazolamide prevents rapid intracellular bicarbonate formation, which can then codiffuse with carbon dioxide to the cell surface and there be reconverted for exit from the cell. Loss of this "facilitated diffusion of carbon dioxide" leads to intracellular acidosis as the still appreciable uncatalyzed rate of carbon dioxide hydration generates more protons. This review summarizes the available evidence and determines that resolution of this question will require more sophisticated measurements of intracellular pH with faster temporal resolution.

  15. Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

    Directory of Open Access Journals (Sweden)

    Burmistrz Piotr

    2016-01-01

    Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

  16. Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage.

    Science.gov (United States)

    Dürr, Stefan; Müller, Michael; Jorschick, Holger; Helmin, Marta; Bösmann, Andreas; Palkovits, Regina; Wasserscheid, Peter

    2017-01-10

    An integration of CO 2 -free hydrogen generation through methane decomposition coupled with hydrogen/methane separation and chemical hydrogen storage through liquid organic hydrogen carrier (LOHC) systems is demonstrated. A potential, very interesting application is the upgrading of stranded gas, for example, gas from a remote gas field or associated gas from off-shore oil drilling. Stranded gas can be effectively converted in a catalytic process by methane decomposition into solid carbon and a hydrogen/methane mixture that can be directly fed to a hydrogenation unit to load a LOHC with hydrogen. This allows for a straight-forward separation of hydrogen from CH 4 and conversion of hydrogen to a hydrogen-rich LOHC material. Both, the hydrogen-rich LOHC material and the generated carbon on metal can easily be transported to destinations of further industrial use by established transport systems, like ships or trucks. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Hydrate dissociation conditions for gas mixtures containing carbon dioxide, hydrogen, hydrogen sulfide, nitrogen, and hydrocarbons using SAFT

    International Nuclear Information System (INIS)

    Li Xiaosen; Wu Huijie; Li Yigui; Feng Ziping; Tang Liangguang; Fan Shuanshi

    2007-01-01

    A new method, a molecular thermodynamic model based on statistical mechanics, is employed to predict the hydrate dissociation conditions for binary gas mixtures with carbon dioxide, hydrogen, hydrogen sulfide, nitrogen, and hydrocarbons in the presence of aqueous solutions. The statistical associating fluid theory (SAFT) equation of state is employed to characterize the vapor and liquid phases and the statistical model of van der Waals and Platteeuw for the hydrate phase. The predictions of the proposed model were found to be in satisfactory to excellent agreement with the experimental data

  18. Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

    Science.gov (United States)

    Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

    2013-06-01

    Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Ammonia, hydrogen sulfide, carbon dioxide and particulate matter emissions from California high-rise layer houses

    Science.gov (United States)

    Lin, X.-J.; Cortus, E. L.; Zhang, R.; Jiang, S.; Heber, A. J.

    2012-01-01

    Ammonia and hydrogen sulfide are hazardous substances that are regulated by the U.S. Environmental Protection Agency through community right-to-know legislation (EPCRA, EPA, 2011). The emissions of ammonia and hydrogen sulfide from large commercial layer facilities are of concern to legislators and nearby neighbors. Particulate matter (PM 10 and PM 2.5) released from layer houses are two of seven criteria pollutants for which EPA has set National Ambient Air Quality Standards as required by the Clean Air Act. Therefore, it is important to quantify the baseline emissions of these pollutants. The emissions of ammonia, hydrogen sulfide, carbon dioxide and PM from two California high-rise layer houses were monitored for two years from October 2007 to October 2009. Each house had 32,500 caged laying hens. The monitoring site was setup in compliance with a U.S. EPA-approved quality assurance project plan. The results showed the average daily mean emission rates of ammonia, hydrogen sulfide and carbon dioxide were 0.95 ± 0.67 (standard deviation) g d -1 bird -1, 1.27 ± 0.78 mg d -1 bird -1 and 91.4 ± 16.5 g d -1 bird -1, respectively. The average daily mean emission rates of PM 2.5, PM 10 and total suspended particulate (TSP) were 5.9 ± 12.6, 33.4 ± 27.4, and 78.0 ± 42.7 mg d -1 bird -1, respectively. It was observed that ammonia emission rates in summer were lower than in winter because the high airflow stabilized the manure by drying it. The reductions due to lower moisture content were greater than the increases due to higher temperature. However, PM 10 emission rates in summer were higher than in winter because the drier conditions coupled with higher internal air velocities increased PM 10 release from feathers, feed and manure.

  20. Hydrogenation of Anthracene in Supercritical Carbon Dioxide Solvent Using Ni Supported on Hβ-Zeolite Catalyst

    Directory of Open Access Journals (Sweden)

    Ashraf Aly Hassan

    2012-01-01

    Full Text Available Catalytic hydrogenation of anthracene was studied over Ni supported on Hβ-zeolite catalyst under supercritical carbon dioxide (sc-CO2 solvent. Hydrogenation of anthracene in sc-CO2 yielded 100% conversion at 100 °C, which is attributed to the reduced mass transfer limitations, and increased solubility of H2 and substrate in the reaction medium. The total pressure of 7 MPa was found to be optimum for high selectivity of octahydroanthracene (OHA. The conversion and selectivity for OHA increased with an increase in H2 partial pressure, which is attributed to higher concentration of hydrogen atoms at higher H2 pressures. The selectivity reduced the pressure below 7 MPa because of enhanced desorption of the tetrahydro-molecules and intermediates from Ni active sites, due to higher solubility of the surface species in sc-CO2. The selectivity of OHA increased with the increase in catalyst weight and reaction time. The rate of hydrogenation of anthracene was compared with that found for napthalene and phenanthrene. The use of acetonitrile as co-solvent or expanded liquid with CO2 decreased the catalytic activity.

  1. Biocatalytic methanation of hydrogen and carbon dioxide in an anaerobic three-phase system.

    Science.gov (United States)

    Burkhardt, M; Koschack, T; Busch, G

    2015-02-01

    A new type of anaerobic trickle-bed reactor was used for biocatalytic methanation of hydrogen and carbon dioxide under mesophilic temperatures and ambient pressure in a continuous process. The conversion of gaseous substrates through immobilized hydrogenotrophic methanogenic archaea in a biofilm is a unique feature of this type of reactor. Due to the formation of a three-phase system on the carrier surface and operation as a plug flow reactor without gas recirculation, a complete reaction could be observed. With a methane concentration higher than c(CH4) = 98%, the product gas exhibits a very high quality. A specific methane production of P(CH4) = 1.49 Nm(3)/(m(3)(SV) d) was achieved at a hydraulic loading rate of LR(H2) = 6.0 Nm(3)/(m(3)(SV) d). The relation between trickle flow through the reactor and productivity could be shown. An application for methane enrichment in combination with biogas facilities as a source of carbon dioxide has also been positively proven. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Removal of hydrogen sulfide and sulfur dioxide by carbons impregnated with triethylenediamine.

    Science.gov (United States)

    Wu, Li-Chun; Chang, Tsu-Hua; Chung, Ying-Chien

    2007-12-01

    Activated carbon (AC) adsorption has long been considered to be a readily available technology for providing protection against exposure to acutely toxic gases. However, ACs without chemical impregnation have proven to be much less efficient than impregnated ACs in terms of gas removal. The impregnated ACs in current use are usually modified with metalloid impregnation agents (ASC-carbons; copper, chromium, or silver) to simultaneously enhance the chemical and physical properties of the ACs in removing specific poisonous gases. These metalloid agents, however, can cause acute poisoning to both humans and the environment, thereby necessitating the search for organic impregnation agents that present a much lower risk. The aim of the study reported here was to assess AC or ASC-carbon impregnated with triethylenediamine (TEDA) in terms of its adsorption capability for simulated hydrogen sulfide (H2S) and sulfur dioxide (SO2) gases. The investigation was undergone in a properly designed laboratory-scale and industrial fume hood evaluation. Using the system reported here, we obtained a significant adsorption: the removal capability for H2S and SO2 was 375 and 229 mg/g-C, respectively. BET measurements, element analysis, scanning electron microscopy, and energy dispersive spectrometry identified the removal mechanism for TEDA-impregnated AC to be both chemical and physical adsorption. Chemical adsorption and oxidation were the primary means by which TEDA-impregnated ASC-carbons removed the simulated gases.

  3. Detection of carbon dioxide in the gases evolved during the hot extraction determination of hydrogen in uranium ingots

    International Nuclear Information System (INIS)

    Jursik, M.L.; Pope, J.D.

    1977-08-01

    The hot extraction method was used at the National Lead Company of Ohio to determine hydrogen in uranium metal at the 2 ppM level. The volume of gas evolved from the heated sample was assumed to be hydrogen. When a liquid nitrogen trap was placed into the system the hydrogen values were reduced 5 to 10%. The gas retained by the nitrogen trap was identified by mass spectrometry as predominantly carbon dioxide. Low hydrogen values were observed only when the nitrogen trap was used in the analysis of high-carbon (300 to 600 ppM) uranium from NLO production ingots. However, hydrogen values for low-carbon (30 to 50 ppM) uranium were unaffected by the nitrogen trap. The formation of carbon dioxide appears to be associated with the carbon content of the uranium metal. Comparisons of hydrogen values obtained with the hot extraction method and with an inert fusion--thermal conductivity method are also presented. 3 tables, 4 figures

  4. Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing.

    Science.gov (United States)

    Godwin, Scott; Kang, Alicia; Gulino, Lisa-Maree; Manefield, Mike; Gutierrez-Zamora, Maria-Luisa; Kienzle, Marco; Ouwerkerk, Diane; Dawson, Kerri; Klieve, Athol V

    2014-09-01

    Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach.

  5. Reactive extraction of carboxylic acids from apolar hydrocarbons using aqueous solutions of sodium hydrogen carbonate with back-recovery using carbon dioxide under pressure

    NARCIS (Netherlands)

    Kuzmanovic, B.; Kuipers, N.J.M.; de Haan, A.B.; Kwant, Gerard

    2005-01-01

    A combination of using an aqueous solution of sodium hydrogen carbonate for forward-extraction of carboxylic acids from a dilute apolar organic solvent, and carbon dioxide under pressure for its back-recovery, is studied. Used in combination, these two steps might provide a technique for the

  6. Conversion from carbon dioxide to organic materials by RF impulse discharges with hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, G.; Kano, M.; Iizuka, S. [Tohoku Univ., Sendai (Japan). Dept. of Electrical Engineering

    2010-07-01

    Carbon dioxide (CO{sub 2}) is among the most serious greenhouse gases emitted from the burning of fossil fuels. The objective of this study was to investigate the fundamental process of reducing CO{sub 2} to generate beneficial and reusable organic materials like methane (CH{sub 4}) and alcohol (CH{sub 3}OH) by using RF impulse discharges in a low gas pressure regime. A low-pressure glow discharge was used to investigate the fundamental processes without catalysts. The discharge took place inside a glass tube by changing the discharge parameters such as voltage, gas flow rate and gas residence time, where the CO{sub 2} was reduced by hydrogen (H{sub 2}). Fourier transform infrared spectroscopy (FTIR) was used to analyze the gas species. Several organic materials were observed, including methane and methanol. The study focused primarily on the reduction of CO{sub 2} by using only H{sub 2}. Carbon monoxide (CO) was clearly a major product from CO{sub 2}, but CH{sub 4} was the most dominant organic species in this experiment. The density of CH{sub 4} increased with the discharge power, and eventually its volume ratio was about 20 percent among the gas species containing carbon via decomposition of CO{sub 2}. This ratio was dependent on the mixing ratio of CO{sub 2} and H{sub 2}. It was concluded that the total pressure is an important factor for efficient production. CH{sub 3}OH formation was observed, but its concentration was low in comparison to CH{sub 4}. 5 refs., 6 figs.

  7. Well materials durability in case of carbon dioxide and hydrogen sulphide geological sequestration

    International Nuclear Information System (INIS)

    Jacquemet, N.

    2006-01-01

    The geological sequestration of carbon dioxide (CO 2 ) and hydrogen sulphide (H 2 S) is a promising solution for the long-term storage of these undesirable gases. It consists in injecting them via wells into deep geological reservoirs. The steel and cement employed in the well casing can be altered and provide pathways for leakage with subsequent human and environmental consequences. The materials ageing was investigated by laboratory experiments in geologically relevant P-T conditions. A new experimental and analysis procedure was designed for this purpose. A numerical approach was also done. The cement and steel were altered in various fluid phases at 500 bar-120 C and 500 bar-200 C: a brine, a brine saturated with H 2 S-CO 2 , a mixture of brine saturated with H 2 S-CO 2 and of supercritical H 2 S-CO 2 phase, a dry supercritical H 2 S-CO 2 phase without liquid water. In all cases, two distinct reactions are observed: the cement carbonation by the CO 2 and the steel sulfidation by the H 2 S. The carbonation and sulfidation are respectively maximal and minimal when they occur within the dry supercritical phase without liquid water. The textural and porosity properties of the cement are weakly affected by all the treatments at 120 C. The porosity even decreases in presence of H 2 S-CO 2 . But these properties are affected at 200 C when liquid water is present in the system. At this temperature, the initial properties are only preserved or improved by the treatments within the dry supercritical phase. The steel is corroded in all cases and thus is the vulnerable material of the wells. (author)

  8. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing; Chen, Fangping; Jin, Guanping; Feng, Xiaoshuang; Li, Xiaoxuan

    2015-01-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  9. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing

    2015-07-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  10. Fluid phase equilibria of the reaction mixture during the selective hydrogenation of 2-butenal in dense carbon dioxide

    DEFF Research Database (Denmark)

    Musko, Nikolai; Jensen, Anker Degn; Baiker, Alfons

    2012-01-01

    Knowledge of the phase behaviour and composition is of paramount importance for understanding multiphase reactions. We have investigated the effect of the phase behaviour in the palladium-catalysed selective hydrogenation of 2-butenal to saturated butanal in dense carbon dioxide. The reactions were...... cell. The results of the catalytic experiments showed that small amounts of carbon dioxide added to the system significantly decrease the conversion, whereas at higher loadings of CO2 the reaction rate gradually increases reaching a maximum. The CPA calculations revealed that this maximum is achieved...... performed using a 5wt% Pd on activated carbon in custom-designed high pressure autoclaves at 323K. The Cubic-Plus-Association (CPA) equation of state was employed to model the phase behaviour of the experimentally studied systems. CPA binary interaction parameters were estimated based on the experimental...

  11. Hydrogenation of silyl formates: sustainable production of silanol and methanol from hydrosilane and carbon dioxide.

    Science.gov (United States)

    Koo, Jangwoo; Kim, Seung Hyo; Hong, Soon Hyeok

    2018-05-10

    A new process for simultaneously obtaining two chemical building blocks, methanol and silanol, was realized starting from silyl formates which can be derived from silane and carbon dioxide. Understanding the reaction mechanism enabled us to improve the reaction efficiency by the addition of a small amount of methanol.

  12. Research Progress on the Indirect Hydrogenation of Carbon Dioxide to Methanol.

    Science.gov (United States)

    Du, Xian-Long; Jiang, Zheng; Su, Dang Sheng; Wang, Jian-Qiang

    2016-02-19

    Methanol is a sustainable source of liquid fuels and one of the most useful organic chemicals. To date, most of the work in this area has focused on the direct hydrogenation of CO2 to methanol. However, this process requires high operating temperatures (200-250 °C), which limits the theoretical yield of methanol. Thus, it is desirable to find a new strategy for the efficient conversion of CO2 to methanol at relatively low reaction temperatures. This Minireview seeks to outline the recent advances on the indirect hydrogenation of CO2 to methanol. Much emphasis is placed on discussing specific systems, including hydrogenation of CO2 derivatives (organic carbonates, carbamates, formates, cyclic carbonates, etc.) and cascade reactions, with the aim of critically highlighting both the achievements and remaining challenges associated with this field. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Storage of hydrogen, methane, and carbon dioxide in highly porous covalent organic frameworks for clean energy applications.

    Science.gov (United States)

    Furukawa, Hiroyasu; Yaghi, Omar M

    2009-07-01

    Dihydrogen, methane, and carbon dioxide isotherm measurements were performed at 1-85 bar and 77-298 K on the evacuated forms of seven porous covalent organic frameworks (COFs). The uptake behavior and capacity of the COFs is best described by classifying them into three groups based on their structural dimensions and corresponding pore sizes. Group 1 consists of 2D structures with 1D small pores (9 A for each of COF-1 and COF-6), group 2 includes 2D structures with large 1D pores (27, 16, and 32 A for COF-5, COF-8, and COF-10, respectively), and group 3 is comprised of 3D structures with 3D medium-sized pores (12 A for each of COF-102 and COF-103). Group 3 COFs outperform group 1 and 2 COFs, and rival the best metal-organic frameworks and other porous materials in their uptake capacities. This is exemplified by the excess gas uptake of COF-102 at 35 bar (72 mg g(-1) at 77 K for hydrogen, 187 mg g(-1) at 298 K for methane, and 1180 mg g(-1) at 298 K for carbon dioxide), which is similar to the performance of COF-103 but higher than those observed for COF-1, COF-5, COF-6, COF-8, and COF-10 (hydrogen at 77 K, 15 mg g(-1) for COF-1, 36 mg g(-1) for COF-5, 23 mg g(-1) for COF-6, 35 mg g(-1) for COF-8, and 39 mg g(-1) for COF-10; methane at 298 K, 40 mg g(-1) for COF-1, 89 mg g(-1) for COF-5, 65 mg g(-1) for COF-6, 87 mg g(-1) for COF-8, and 80 mg g(-1) for COF-10; carbon dioxide at 298 K, 210 mg g(-1) for COF-1, 779 mg g(-1) for COF-5, 298 mg g(-1) for COF-6, 598 mg g(-1) for COF-8, and 759 mg g(-1) for COF-10). These findings place COFs among the most porous and the best adsorbents for hydrogen, methane, and carbon dioxide.

  14. Non-catalytic plasma-arc reforming of natural gas with carbon dioxide as the oxidizing agent for the production of synthesis gas or hydrogen

    OpenAIRE

    Blom, P.W.E.; Basson, G.W.

    2013-01-01

    The world’s energy consumption is increasing constantly due to the growing population of the world. The increasing energy consumption has a negative effect on the fossil fuel reserves of the world. Hydrogen has the potential to provide energy for all our needs by making use of fossil fuel such as natural gas and nuclear-based electricity. Hydrogen can be produced by reforming methane with carbon dioxide as the oxidizing agent. Hydrogen can be produced in a Plasma-arc reforming ...

  15. Hydrogen production by dry reforming of methane with carbon dioxide in one-dimensional nickel-based catalysts

    International Nuclear Information System (INIS)

    Lopez U, A. C.

    2016-01-01

    The main objective of this thesis is development of nickel catalysts supported over 1D matrix of cerium oxide, to be used in dry reforming methane reaction with carbon dioxide for hydrogen production. The catalysts were characterized by: Temperature Programmed Reduction (TPR), Scanning Electronic Microscopy (Sem), Surface Area (Bet method) an X Ray Diffraction (XRD). The TPR technique allowed to define reduction temperature of the active phase in the catalyst, Sem technique showed that the CeO_2 matrix had a nano rod morphology. XRD allowed to identify the crystalline phases of the catalysts. Finally, the catalysts were tested in the dry reforming methane reaction, high catalytic activity and hydrogen production were performed at 700 degrees Celsius and the catalyst with 30 wt.% of nickel. (Author)

  16. Dependence of freshwater plants on quantity of carbon dioxide and hydrogen ion concentration illustrated through experimental investigations

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, E S

    1944-01-01

    By culture experiments with the freshwater plants Helodea canadensis and Ceratophyllum demersum, in which both the contents of carbon dioxide and pH of the water were varied, it was shown that ph within the area 4.5 to 8.2 has no appreciable influence on the growth. The supply of carbon dioxide, on the other hand, has very great influence. The fact that the two freshwater plants mentioned in Denmark are found in alkaline water only, is due to the contents of assimilable carbon dioxide decreasing with decrease of pH. While thus in alkaline water there are generally large quantities of bicarbonate, from which half of the carbon dioxide may be utilized in the assimilation, there is in acid water (pH below 4.5) no bicarbonate. Carbon dioxide in true solution and bicarbonate carbon dioxide behave differently as sources of carbon dioxide for the assimilation; this is amongst other things due to the fact that the absorption of the carbon dioxide through the bicarbonate is made actively on the part of the plant. The investigations which illustrate the influence of the quantity of carbon dioxide on the intensity of assimilation were made on submersed plants in water containing bicarbonate, and therefore give quite different results in relation to terraneous plants, where the carbon dioxide is exclusively assimilated.

  17. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

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

    2013-07-01

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

  18. Carbon dioxide as chemical feedstock

    National Research Council Canada - National Science Library

    Aresta, M

    2010-01-01

    ... Dioxide as an Inert Solvent for Chemical Syntheses 15 Alessandro Galia and Giuseppe Filardo Introduction 15 Dense Carbon Dioxide as Solvent Medium for Chemical Processes 15 Enzymatic Catalysis in Dense Carbon Dioxide 18 Other Reactions in Dense Carbon Dioxide 19 Polymer Synthesis in Supercritical Carbon Dioxide 20 Chain Polymerizations: Synt...

  19. Hydrogen storage and carbon dioxide sequestration in TBAF semi-clathrate hydrates: Kinetics and evolution of hydrate-phase composition by in situ raman spectroscopy - Abstract -

    NARCIS (Netherlands)

    Torres Trueba, A.; Radoviæ, I.R.; Zevenbergen, J.F.; Kroon, M.C.; Peters, C.J.

    2012-01-01

    Carbon dioxide (CO2) represents almost one third of the emissions from the combustion of fossil fuels additionally, CO2 has been identified as the mayor contributor of global warming. Hydrogen (H2), on the other hand, due to its properties is considered a promising energy carrier. Clathrate hydrates

  20. Green methanol from hydrogen and carbon dioxide using geothermal energy and/or hydro power in Iceland or excess renewable electricity in Germany

    NARCIS (Netherlands)

    Kauw, Marco; Benders, Reinerus; Visser, Cindy

    2015-01-01

    The synthesis of green methanol from hydrogen and carbon dioxide can contribute to mitigation of greenhouse gasses. This methanol can be utilized as either a transport fuel or as an energy carrier for electricity storage. It is preferable to use inexpensive, reliable and renewable energy sources to

  1. Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

    Directory of Open Access Journals (Sweden)

    Hongwang Wang

    2014-06-01

    Full Text Available The quest for renewable and cleaner energy sources to meet the rapid population and economic growth is more urgent than ever before. Being the most abundant carbon source in the atmosphere of Earth, CO2 can be used as an inexpensive C1 building block in the synthesis of aromatic fuels for internal combustion engines. We designed a process capable of synthesizing benzene, toluene, xylenes and mesitylene from CO2 and H2 at modest temperatures (T = 380 to 540 °C employing Fe/Fe3O4 nanoparticles as catalyst. The synthesis of the catalyst and the mechanism of CO2-hydrogenation will be discussed, as well as further applications of Fe/Fe3O4 nanoparticles in catalysis.

  2. Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

    Science.gov (United States)

    Dash, Ranjan K.; Bassingthwaighte, James B.

    2014-01-01

    A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O2) and carbon dioxide (CO2) in the blood–tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O2 and CO2 (Bohr and Haldane effects), and since most CO2 is transported as HCO3- (bicarbonate) via the CO2 hydration (buffering) reaction, the transport and exchange of HCO3- and H+ are also simulated along with that of O2 and CO2. Furthermore, the model accounts for the competitive nonlinear binding of O2 and CO2 with the hemoglobin inside the red blood cells (nonlinear O2–CO2 interactions, Bohr and Haldane effects), and myoglobin-facilitated transport of O2 inside the parenchymal cells. The consumption of O2 through cytochrome-c oxidase reaction inside the parenchymal cells is based on Michaelis–Menten kinetics. The corresponding production of CO2 is determined by respiratory quotient (RQ), depending on the relative consumption of carbohydrate, protein, and fat. The model gives a physiologically realistic description of O2 transport and metabolism in the microcirculation of the heart. Furthermore, because model solutions for tracer transients and steady states can be computed highly efficiently, this model may be the preferred vehicle for routine data analysis where repetitive solutions and parameter optimization are required, as is the case in PET imaging for estimating myocardial O2 consumption. PMID:16775761

  3. Co-axial heterostructures integrating palladium/titanium dioxide with carbon nanotubes for efficient electrocatalytic hydrogen evolution

    Science.gov (United States)

    Valenti, Giovanni; Boni, Alessandro; Melchionna, Michele; Cargnello, Matteo; Nasi, Lucia; Bertoni, Giovanni; Gorte, Raymond J.; Marcaccio, Massimo; Rapino, Stefania; Bonchio, Marcella; Fornasiero, Paolo; Prato, Maurizio; Paolucci, Francesco

    2016-12-01

    Considering the depletion of fossil-fuel reserves and their negative environmental impact, new energy schemes must point towards alternative ecological processes. Efficient hydrogen evolution from water is one promising route towards a renewable energy economy and sustainable development. Here we show a tridimensional electrocatalytic interface, featuring a hierarchical, co-axial arrangement of a palladium/titanium dioxide layer on functionalized multi-walled carbon nanotubes. The resulting morphology leads to a merging of the conductive nanocarbon core with the active inorganic phase. A mechanistic synergy is envisioned by a cascade of catalytic events promoting water dissociation, hydride formation and hydrogen evolution. The nanohybrid exhibits a performance exceeding that of state-of-the-art electrocatalysts (turnover frequency of 15000 H2 per hour at 50 mV overpotential). The Tafel slope of ~130 mV per decade points to a rate-determining step comprised of water dissociation and formation of hydride. Comparative activities of the isolated components or their physical mixtures demonstrate that the good performance evolves from the synergistic hierarchical structure.

  4. Carbon dioxide sensor

    Science.gov (United States)

    Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

    2011-11-15

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

  5. Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

    Science.gov (United States)

    Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

    2018-01-10

    An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. Carbon dioxide and climate

    International Nuclear Information System (INIS)

    1991-10-01

    Global climate change is a serious environmental concern, and the US has developed ''An Action Agenda'' to deal with it. At the heart of the US effort is the US Global Change Research Program (USGCRP), which has been developed by the Committee on Earth and Environmental Sciences (CEES) of the Federal Coordinating Council for Sciences, Engineering, and Technology (FCCSET). The USGCRP will provide the scientific basis for sound policy making on the climate-change issue. The DOE contribution to the USGCRP is the Carbon Dioxide Research Program, which now places particular emphasis on the rapid improvement of the capability to predict global and regional climate change. DOE's Carbon Dioxide Research Program has been addressing the carbon dioxide-climate change connection for more than twelve years and has provided a solid scientific foundation for the USGCRP. The expansion of the DOE effort reflects the increased attention that the Department has placed on the issue and is reflected in the National Energy Strategy (NES) that was released in 1991. This Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1991 and gives a brief overview of objectives, organization, and accomplishments. The Environmental Sciences Division of the Office of Health and Environmental Research, Office of Energy Research supports a Carbon Dioxide Research Program to determine the scientific linkage between the rise of greenhouse gases in the atmosphere, especially carbon dioxide, and climate and vegetation change. One facet is the Core CO 2 Program, a pioneering program that DOE established more than 10 years ago to understand and predict the ways that fossil-fuel burning could affect atmospheric CO 2 concentration, global climate, and the Earth's biosphere. Major research areas are: global carbon cycle; climate detection and models of climate change; vegetation research; resource analysis; and, information and integration

  7. Deposition of carbon dioxide

    International Nuclear Information System (INIS)

    2001-01-01

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  8. Experimental study on stress corrosion crack propagation rate of FV520B in carbon dioxide and hydrogen sulfide solution

    Science.gov (United States)

    Qin, Ming; Li, Jianfeng; Chen, Songying; Qu, Yanpeng

    FV520B steel is a kind of precipitation hardening Martensitic stainless steel, it has high-strength, good plasticity and good corrosion resistance. Stress corrosion cracking (SCC) is one of the main corrosion failure mode for FV520B in industrial transportation of natural gas operation. For a better understanding the effect on SCC of FV520B, the improved wedge opening loading (WOL) specimens and constant displacement loading methods were employed in experimental research in carbon dioxide and hydrogen sulfide solution. The test results showed that the crack propagation rate is 1.941 × 10-7-5.748 × 10-7 mm/s, the stress intensity factor KISCC is not more than 36.83 MPa √{ m } . The rate increases with the increasing of the crack opening displacement. Under the condition of different initial loading, KISCC generally shows a decreasing tendency with the increase in H2S concentration, and the crack propagation rate showed an increasing trend substantially. For the enrichment of sulfur ion in the crack tip induced the generation of pitting corrosion, promoting the surrounding metal formed the corrosion micro batteries, the pit defects gradually extended and connected with the adjacent pit to form a small crack, leading to further propagation till cracking happened. Fracture microscopic morphology displayed typical brittle fracture phenomena, accompanying with trans-granular cracking, river shape and sector, many second cracks on the fracture surface.

  9. Experimental study on stress corrosion crack propagation rate of FV520B in carbon dioxide and hydrogen sulfide solution

    Directory of Open Access Journals (Sweden)

    Ming Qin

    Full Text Available FV520B steel is a kind of precipitation hardening Martensitic stainless steel, it has high-strength, good plasticity and good corrosion resistance. Stress corrosion cracking (SCC is one of the main corrosion failure mode for FV520B in industrial transportation of natural gas operation. For a better understanding the effect on SCC of FV520B, the improved wedge opening loading (WOL specimens and constant displacement loading methods were employed in experimental research in carbon dioxide and hydrogen sulfide solution. The test results showed that the crack propagation rate is 1.941 × 10−7–5.748 × 10−7 mm/s, the stress intensity factor KISCC is not more than 36.83 MPa m. The rate increases with the increasing of the crack opening displacement. Under the condition of different initial loading, KISCC generally shows a decreasing tendency with the increase in H2S concentration, and the crack propagation rate showed an increasing trend substantially. For the enrichment of sulfur ion in the crack tip induced the generation of pitting corrosion, promoting the surrounding metal formed the corrosion micro batteries, the pit defects gradually extended and connected with the adjacent pit to form a small crack, leading to further propagation till cracking happened. Fracture microscopic morphology displayed typical brittle fracture phenomena, accompanying with trans-granular cracking, river shape and sector, many second cracks on the fracture surface. Keywords: FV520B, Wedge opening loading specimen, Stress corrosion cracking, Hydrogen sulfide

  10. SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2005-02-03

    Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application of this new development. A two-dimensional, pseudo-homogeneous membrane-reactor model was developed to investigate the steam-methane reforming (SMR) reactions in a Pd-based membrane reactor. Radial diffusion was taken into consideration to account for the concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential equations was derived using the continuity equation for the reaction system. The equations were

  11. Does Carbon Dioxide Predict Temperature?

    OpenAIRE

    Mytty, Tuukka

    2013-01-01

    Does carbon dioxide predict temperature? No it does not, in the time period of 1880-2004 with the carbon dioxide and temperature data used in this thesis. According to the Inter Governmental Panel on Climate Change(IPCC) carbon dioxide is the most important factor in raising the global temperature. Therefore, it is reasonable to assume that carbon dioxide truly predicts temperature. Because this paper uses observational data it has to be kept in mind that no causality interpretation can be ma...

  12. Carbon Dioxide Sensor Technology.

    Science.gov (United States)

    1983-04-01

    second gas permeable membrane separates a compartment containing the non-aqueous " solvent dimethylsulfoxide , ( DMSO ), from the aqueous solution...compartment. In DMSO carbon dioxide can be irreversibly reduced electrochemically to * non-interfering products...current due to its reduction in the DMSO solution is proportional to the partial pressure of CO2 in the gas phase. Overall, the linear response and

  13. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  14. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T J [Discovery Bay Marine Laboratory, Univ. of the West Indies (JM)

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  15. Synthesis and characterization of novel intermetallic catalysts for hydrogenation of carbon dioxide to methanol

    DEFF Research Database (Denmark)

    Fiordaliso, Elisabetta Maria; Sharafutdinov, Irek; Chorkendorff, Ib

    Novel Ni5Ga3 and Pd2Ga catalysts for CO2 hydrogenation to methanol are prepared by impregnation of aqueous Ni-Ga or Pd-Ga solutions of metal nitrates into high surface area SiO2, followed by drying, calcinations and reduction of the precursor in a H2 flow. Steady state experiments are performed...... in a reactor at atmospheric pressure and stoichiometric CO2/H2 mixture, while reaction products are analyzed by gas chromatography. The results are compared to the highly optimized Cu/ZnO/Al2O3. The activity and selectivity of the novel catalysts is close to that of Cu/ZnO/Al2O3 and the equilibrium conversion...... to CH3OH is found to be higher. XRD and XRF are used to investigate the phase and composition of the supported catalysts at the 5 stages of testing, i.e. after drying, calcination, reduction, CO2 hydrogenation, rapid ageing. SEM and TEM images of the exact same locations are acquired after each of the 5...

  16. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

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

  17. Hydrogenation of carbon dioxide towards synthetic natural gas. A route to effective future energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schoder, M. [Hochschule Lausitz, Cottbus (Germany); Armbruster, U.; Martin, A. [Rostock Univ. (Germany). Leibniz Institute for Catalysis

    2012-07-01

    Ni- and Ru-based catalysts are best suited for the so-called Sabatier reaction, i.e., the hydrogenation of CO{sub 2} to synthetic natural gas (SNG). Besides using commercial materials, catalyst syntheses (5 wt% Ru or Ni) were carried out by incipient wetness impregnation of four carriers (TiO{sub 2}, SiO{sub 2}, ZrO{sub 2} and {gamma}-Al{sub 2}O{sub 3}). Some pre-tests revealed that catalysts supported on TiO{sub 2} and SiO{sub 2} mostly produced CO, and therefore, they were not studied in detail. The catalyst tests were carried out in a continuously operated tube reactor at 623-723 K and 1-20 bar. Ru/ZrO{sub 2} and Ni/{gamma}-Al{sub 2}O{sub 3} revealed best catalytic performance at ambient pressure. Methane selectivities of 99.9% at 81.2% CO{sub 2} conversion for Ru/ZrO{sub 2} (623 K) and of 98.9% at 73.8% CO{sub 2} conversion for Ni/{gamma}-Al{sub 2}O{sub 3} (673 K) were obtained. The conversion increased significantly with raising reaction pressure above 10 bar to reach more than 93% for the Ni-containing catalyst and more than 96% for the Zr catalysts. Methane as the target product was formed with a selectivity of 100%. In addition, the catalysts were characterized by various solid-state techniques such as BET, TPR, ICP-OES, XRD, XPS and TEM. (orig.)

  18. Methanation of Carbon Dioxide

    OpenAIRE

    Goodman, Daniel Jacob

    2013-01-01

    The emission of greenhouse gases into the atmosphere has been linked to global warming. Carbon dioxide's (CO2) one of the most abundant greenhouse gases. Natural gas, mainly methane, is the cleanest fossil fuel for electricity production helping meet the United States ever growing energy needs. The methanation of CO2 has the potential to address both of these problems if a catalyst can be developed that meets the activity, economic and environmental requirements to industrialize the process. ...

  19. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

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

  20. Engineering Ralstonia eutropha for Production of Isobutanol (IBT) Motor Fuel from Carbon Dioxide, Hydrogen, and Oxygen Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sinskey, Anthony J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Worden, Robert Mark [Michigan State Univ., East Lansing, MI (United States); Brigham, Christopher [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lu, Jingnan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Quimby, John Westlake [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Gai, Claudia [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Speth, Daan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Elliott, Sean [Boston Univ., MA (United States); Fei, John Qiang [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Bernardi, Amanda [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Li, Sophia [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Grunwald, Stephan [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Grousseau, Estelle [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Maiti, Soumen [Michigan State Univ., East Lansing, MI (United States); Liu, Chole [Michigan State Univ., East Lansing, MI (United States)

    2013-12-16

    This research project is a collaboration between the Sinskey laboratory at MIT and the Worden laboratory at Michigan State University. The goal of the project is to produce Isobutanol (IBT), a branched-chain alcohol that can serve as a drop-in transportation fuel, through the engineered microbial biosynthesis of Carbon Dioxide, Hydrogen, and Oxygen using a novel bioreactor. This final technical report presents the findings of both the biological engineering work at MIT that extended the native branched-chain amino acid pathway of the wild type Ralstonia eutropha H16 to perform this biosynthesis, as well as the unique design, modeling, and construction of a bioreactor for incompatible gasses at Michigan State that enabled the operational testing of the complete system. This 105 page technical report summarizing the three years of research includes 72 figures and 11 tables of findings. Ralstonia eutropha (also known as Cupriavidus necator) is a Gram-negative, facultatively chemolithoautotrophic bacteria. It has been the principle organism used for the study of polyhydroxybutyrate (PHB) polymer biosynthesis. The wild-type Ralstonia eutropha H16 produces PHB as an intracellular carbon storage material while under nutrient stress in the presence of excess carbon. Under this stress, it can accumulate approximately 80 % of its cell dry weight (CDW) as this intracellular polymer. With the restoration of the required nutrients, the cells are then able to catabolize this polymer. If extracted from the cell, this PHB polymer can be processed into biodegradable and biocompatible plastics, however for this research, it is the efficient metabolic pathway channeling the captured carbon that is of interest. R. eutropha is further unique in that it contains two carbon-fixation Calvin–Benson–Bassham cycle operons, two oxygen-tolerant hydrogenases, and several formate dehydrogenases. It has also been much studied for its ability in the presence of oxygen, to fix carbon dioxide

  1. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept

  2. Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

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

  3. Phase equilibria of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions

    International Nuclear Information System (INIS)

    Mohammadi, Amir H.; Richon, Dominique

    2012-01-01

    Highlights: → Dissociation conditions of H 2 S or CO 2 hydrate + inhibitor aqueous solution are reported. → Methanol, methanol + NaCl and EG + NaCl aqueous solutions are considered as inhibitors. → Comparisons are made between our experimental data and the corresponding literature data. - Abstract: This work aims at reporting the dissociation pressures of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions at different temperatures and various concentrations of inhibitor in aqueous solution. The equilibrium results were generated using an isochoric pressure-search method. These values are compared with some selected experimental data from the literature on the dissociation conditions of hydrogen sulfide and carbon dioxide simple hydrates in the presence of pure water to show the inhibition effects of the above mentioned aqueous solutions. Comparisons are finally made between our experimental values and the corresponding literature data. Some disagreements among the literature data and our data are found.

  4. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Selective free radical reactions using supercritical carbon dioxide.

    Science.gov (United States)

    Cormier, Philip J; Clarke, Ryan M; McFadden, Ryan M L; Ghandi, Khashayar

    2014-02-12

    We report herein a means to modify the reactivity of alkenes, and particularly to modify their selectivity toward reactions with nonpolar reactants (e.g., nonpolar free radicals) in supercritical carbon dioxide near the critical point. Rate constants for free radical addition of the light hydrogen isotope muonium to ethylene, vinylidene fluoride, and vinylidene chloride in supercritical carbon dioxide are compared over a range of pressures and temperatures. Near carbon dioxide's critical point, the addition to ethylene exhibits critical speeding up, while the halogenated analogues display critical slowing. This suggests that supercritical carbon dioxide as a solvent may be used to tune alkene chemistry in near-critical conditions.

  6. Carbon dioxide and future climate

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J M

    1977-03-01

    The addition of carbon dioxide to the atmosphere due to burning fossil fuel is discussed. The release rate of carbon dioxide has been growing since at least 1950 at an average rate of 4.3% per year. If all known fossil fuel reserves in the world are consumed, a total of between 5 and 14 times the present amount of carbon dioxide in the atmosphere will be released. The oceans would then be unlikely to withdraw the proportion of perhaps 40% which they are believed to have withdrawn up to the present. The increase in the atmosphere would be in excess of 3 times or conceivably ten times the present amount. If the reserves are used up within a few hundred years, more than half the excess carbon dioxide would remain in the atmosphere after a thousand years. The ''greenhouse'' effect of carbon dioxide is explained. The simulation with numerical models of the effects of carbon dioxide on atmospheric radiation fluxes is discussed. An estimated increase in the average annual temperature of the earth of 2.4 to 2.9C is given for doubling the carbon dioxide content; also a 7% increase in global average precipitation. The effect of increasing carbon dioxide on global mean temperature is viewed in the perspective of the glacial-interglacial cycles. The warming effect of carbon dioxide may induce a ''super-interglacial'' on the present interglacial which is expected to decline toward a new ice age in the next several thousand years. Finally it is proposed that it may be necessary to phase out the use of fossil fuels before all the knowledge is acquired which would necessitate such an action.

  7. Reducing carbon dioxide to products

    Science.gov (United States)

    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.

  8. Method for carbon dioxide sequestration

    Science.gov (United States)

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

    2017-12-05

    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) and water or bine 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.

  9. Recuperative supercritical carbon dioxide cycle

    Science.gov (United States)

    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.

  10. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts

    Directory of Open Access Journals (Sweden)

    Nur Nabillah Mohd Arif

    2016-08-01

    Full Text Available Glycerol, byproduct from the biodiesel production can be effectively utilized as the promising source of synthesis gas (syngas through a dry reforming reaction. Combination of these waste materials with greenhouse gases which is carbon dioxide (CO2 will help to reduce environmental problem such as global warming. This dry reforming reaction has been carried out in a fixed bed batch reactor at 700 °C under the atmospheric pressure for 3 hours. In this experiment, reforming reaction was carried out using Nickel (Ni as based catalyst and supported with zirconium (ZrO2 and calcium (CaO oxides. The catalysts were prepared by wet impregnation method and characterized using Bruanaer-Emmett-Teller (BET surface area, Scanning Electron Microscopy (SEM, X-ray Diffraction (XRD, Thermo Gravimetric (TGA, and Temperature Programmed Reduction (TPR analysis. Reaction studies show that 15% Ni/CaO give the highest hydrogen yield and glycerol conversion that peaked at 24.59% and 30.32%, respectively. This result is verified by XRD analysis where this catalyst shows low crystallinity and fine dispersion of Ni species resulted in high specific surface area which gives 44.93 m2/g that is validated by BET.  Copyright © 2016 BCREC GROUP. All rights reserved Received: 21st January 2016; Revised: 24th February 2016; Accepted: 29th February 2016 How to Cite: Arif, N.M.M., Vo, D.V.N., Azizan,M.T., Abidin S.Z. (2016. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 200-209 (doi:10.9767/bcrec.11.2.551.200-209 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.551.200-209

  11. Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

    Science.gov (United States)

    Wu, Li-Chun; Chung, Ying-Chien

    2009-03-01

    Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream.

  12. Well materials durability in case of carbon dioxide and hydrogen sulphide geological sequestration; Durabilite des materiaux de puits petroliers dans le cadre d'une sequestration geologique de dioxyde de carbone et d'hydrogene sulfure

    Energy Technology Data Exchange (ETDEWEB)

    Jacquemet, N

    2006-01-15

    The geological sequestration of carbon dioxide (CO{sub 2}) and hydrogen sulphide (H{sub 2}S) is a promising solution for the long-term storage of these undesirable gases. It consists in injecting them via wells into deep geological reservoirs. The steel and cement employed in the well casing can be altered and provide pathways for leakage with subsequent human and environmental consequences. The materials ageing was investigated by laboratory experiments in geologically relevant P-T conditions. A new experimental and analysis procedure was designed for this purpose. A numerical approach was also done. The cement and steel were altered in various fluid phases at 500 bar-120 C and 500 bar-200 C: a brine, a brine saturated with H{sub 2}S-CO{sub 2}, a mixture of brine saturated with H{sub 2}S-CO{sub 2} and of supercritical H{sub 2}S-CO{sub 2} phase, a dry supercritical H{sub 2}S-CO{sub 2} phase without liquid water. In all cases, two distinct reactions are observed: the cement carbonation by the CO{sub 2} and the steel sulfidation by the H{sub 2}S. The carbonation and sulfidation are respectively maximal and minimal when they occur within the dry supercritical phase without liquid water. The textural and porosity properties of the cement are weakly affected by all the treatments at 120 C. The porosity even decreases in presence of H{sub 2}S-CO{sub 2}. But these properties are affected at 200 C when liquid water is present in the system. At this temperature, the initial properties are only preserved or improved by the treatments within the dry supercritical phase. The steel is corroded in all cases and thus is the vulnerable material of the wells. (author)

  13. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  14. Carbon dioxide enhances fragility of ice crystals

    International Nuclear Information System (INIS)

    Qin Zhao; Buehler, Markus J

    2012-01-01

    Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.

  15. Carbon dioxide: emissions and effects

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I M

    1982-01-01

    This review provides a comprehensive guide to work carried out since 1978 in the many disciplines involved in this complex issue. Possible scenarios for carbon dioxide emissions, sources and sinks in the carbon cycle and for climatic changes are examined. The current concensus (by no means unanimous) of specialists on this issue appears to be that a continuation of reduced trends in energy consumption since 1973 is likely to double the atmospheric carbon dioxide concentration to 600 ppmv during the latter part of the next century. However, a higher demand scenario, requiring an upper limit of coal production, would bring forward the doubling to about the middle of the next century. Current climatic models predict that such a concentration of carbon dioxide would cause an average global warming of from 1.0 to 4.5/sup 0/C which might be delayed by the thermal inertia of the oceans. A warming due to estimated increases in carbon dioxide should, if the model results are correct, become apparent at the end of this century. Regional climatic changes are likely to vary considerably and prove disadvantageous to some regions and beneficial to others. Different strategies for dealing with the carbon dioxide issue are considered: no response, alleviation, countermeasures and prevention. It is concluded that uncertainties do not justify either the use of carbon dioxide disposal and other technical fixes at present or a policy of no further growth in fossil fuel consumption. On the other hand, major efforts to conserve energy would give more time to adapt to changes. The alleviation of climatic impacts and other desirable dual-benefit measures are advocated in addition to continuing international, interdisciplinary research on all aspects.

  16. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

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

  17. Carbon Dioxide Embolism during Laparoscopic Surgery

    Science.gov (United States)

    Park, Eun Young; Kwon, Ja-Young

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

  18. Hydrogen production by reforming of fossil and biomass fuels accompanied by carbon dioxide capture process is the energy source for the near future

    International Nuclear Information System (INIS)

    Aboudheir, Ahmed; Idem, Raphael; Tontiwachwuthikul, Paitoon; Wilson, Malcolm; Kambietz, Lionel

    2006-01-01

    Hydrogen has a significant future potential as an alternative energy source for the transportation sector as well as in residential homes and offices, H 2 in fuel cell power systems provides an alternative to direct fossil fuel and biomass combustion based technologies and offer the possibility for a significant reduction in greenhouse gas emission based on improved H 2 yield per unit of fossil fuel and biomass, compatibility with renewable energies and motivation to convert to a H 2 -based energy economy. Several practical techniques for H 2 production to service H 2 refuelling stations as well as homes and offices, all of which need to be located at the end of the energy distribution network, include: (1) the carbon dioxide reforming of natural gas; (2) reforming of gasoline; (3) reforming of crude ethanol. Locating the H 2 production at the end of the energy distribution network solves the well-known problems of metal fatigue and high cost of H 2 compression for long distance transportation if H 2 is produced in a large centralized plant. In addition, the ratification of the Kyoto Protocol and the need to reduce emissions of CO 2 to the atmosphere has prompted the capture and utilization of the CO 2 produced from the reforming process. In this research: (1) new efficient catalysts for each reforming process was developed; (2) a new efficient catalyst for our version of the water gas shift reaction to convert carbon monoxide to carbon dioxide was developed; (3) a new membrane separation process for production of high purity, fuel cell-grade H 2 was designed; (4) a numerical model for optimum process design and optimum utilization of resources both at the laboratory and industrial scales was developed; (5) various processes for CO 2 capture were investigated experimentally in order to achieve a net improvement in the absorption process; (6) the utilization of captured CO 2 for enhanced oil recovery and/or storage in an aging oil field were investigated; (7

  19. Process for sequestering carbon dioxide and sulfur dioxide

    Science.gov (United States)

    Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

    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.

  20. High capacity carbon dioxide sorbent

    Science.gov (United States)

    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.

  1. Modelling Sublimation of Carbon Dioxide

    Science.gov (United States)

    Winkel, Brian

    2012-01-01

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

  2. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  3. Oxidation suppressing device for steel materials in carbon dioxide cooled reactors

    International Nuclear Information System (INIS)

    Kawakami, Haruo

    1986-01-01

    Purpose: To effectively reduce impurity hydrogens in carbon dioxide. Constitution: At least three gas chambers are arranged serially each by way of a valve in a gas flow channel branched from a primary carbon dioxide coolant circuits. Then, a polymeric partition membrane having higher permeation rate for hydrogen than for carbon dioxide, e.g., made of polytrifluorochloroethylene is disposed between first and second gas chambers and, further, the first and the third gas chambers are connected each by way of a valve to the primary carbon dioxide coolant circuit to constitute a gas recovery channel. Carbon dioxide is caused to flow through the channel by means of a pump disposed between the second and third gas chambers, hydrogen as impurity passed through the partition walls is concentrated and discharged out of the channel, while the carbon dioxide with reduced hydrogen content is returned from the first and the third gas chambers to the circuit. (Sekiya, K.)

  4. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

    Petersen, Gene; Viviani, Donn; Magrini-Bair, Kim; Kelley, Stephen; Moens, Luc; Shepherd, Phil; DuBois, Dan

    2005-01-01

    Carbon dioxide (CO 2 ) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO 2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO 2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO 2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described

  5. Carbon Dioxide Hydrogenation into Higher Hydrocarbons and Oxygenates: Thermodynamic and Kinetic Bounds and Progress with Heterogeneous and Homogeneous Catalysis.

    Science.gov (United States)

    Prieto, Gonzalo

    2017-03-22

    Under specific scenarios, the catalytic hydrogenation of CO 2 with renewable hydrogen is considered a suitable route for the chemical recycling of this environmentally harmful and chemically refractory molecule into added-value energy carriers and chemicals. The hydrogenation of CO 2 into C 1 products, such as methane and methanol, can be achieved with high selectivities towards the corresponding hydrogenation product. More challenging, however, is the selective production of high (C 2+ ) hydrocarbons and oxygenates. These products are desired as energy vectors, owing to their higher volumetric energy density and compatibility with the current fuel infrastructure than C 1 compounds, and as entry platform chemicals for existing value chains. The major challenge is the optimal integration of catalytic functionalities for both reductive and chain-growth steps. This Minireview summarizes the progress achieved towards the hydrogenation of CO 2 to C 2+ hydrocarbons and oxygenates, covering both solid and molecular catalysts and processes in the gas and liquid phases. Mechanistic aspects are discussed with emphasis on intrinsic kinetic limitations, in some cases inevitably linked to thermodynamic bounds through the concomitant reverse water-gas-shift reaction, which should be considered in the development of advanced catalysts and processes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Carbon dioxide capture and storage

    International Nuclear Information System (INIS)

    Durand, B.

    2011-01-01

    The author first highlights the reasons why storing carbon dioxide in geological formations could be a solution in the struggle against global warming and climate change. Thus, he comments various evolutions and prospective data about carbon emissions or fossil energy consumption as well as various studies performed by international bodies and agencies which show the interest of carbon dioxide storage. He comments the evolution of CO 2 contributions of different industrial sectors and activities, notably in France. He presents the different storage modes and methods which concern different geological formations (saline aquifers, abandoned oil or gas fields, not exploitable coal seams) and different processes (sorption, carbonation). He discusses the risks associated with these storages, the storable quantities, evokes some existing installations in different countries. He comments different ways to capture carbon dioxide (in post-combustion, through oxy-combustion, by pre-combustion) and briefly evokes some existing installations. He evokes the issue of transport, and discusses efficiency and cost aspects, and finally has few words on legal aspects and social acceptability

  7. CARBON DIOXIDE AS A FEEDSTOCK.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,C.; FUJITA,E.

    2000-12-09

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

  8. Perspectives in the use of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Aresta Michele

    1999-01-01

    Full Text Available The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

  9. Carbon dioxide, the feedstock for using renewable energy

    Science.gov (United States)

    Hashimoto, K.; Kumagai, N.; Izumiya, K.; Kato, Z.

    2011-03-01

    Extrapolation of world energy consumption between 1990 and 2007 to the future reveals the complete exhaustion of petroleum, natural gas, uranium and coal reserves on Earth in 2040, 2044, 2049 and 2054, respectively. We are proposing global carbon dioxide recycling to use renewable energy so that all people in the whole world can survive. The electricity will be generated by solar cell in deserts and used to produce hydrogen by seawater electrolysis at t nearby desert coasts. Hydrogen, for which no infrastructures of transportation and combustion exist, will be converted to methane at desert coasts by the reaction with carbon dioxide captured by energy consumers. Among systems in global carbon dioxide recycling, seawater electrolysis and carbon dioxide methanation have not been performed industrially. We created energy-saving cathodes for hydrogen production and anodes for oxygen evolution without chlorine formation in seawater electrolysis, and ideal catalysts for methane formation by the reaction of carbon dioxide with hydrogen. Prototype plant and industrial scale pilot plant have been built.

  10. Manganese oxide as a promoter for C2-C4 olefin production in the hydrogenation of carbon dioxide

    International Nuclear Information System (INIS)

    Kim, C.; Chen, K.; Hanson, F.V.; Oblad, A.G.; Tsai, Y.

    1986-01-01

    A number of active research and development programs have been initiated to explore the potential of CO hydrogenation process as a source of low molecular weight (C 2 -C 4 ) olefins. Metal catalysts such as Co-Mn, Ni-zeolite, Rd and Mo have been evaluated for low molecular weight olefin selectivity. The coprecipitated Fe-Mn system (Mn/Fe=9/1) was reported to be highly olefin selective. Recently, many investigators reported supporting evidence for the promotional effect of Mn for precipitated Fe catalysts. In this study, Raney Fe promoted with Mn has been evaluated for C 2 -C 4 olefin selectivity in the hydrogenation of CO relative to coprecipitated Fe-Mn catalysts. Catalyst characterization, including BET surface area, X-ray diffraction, selective chemisorption and ESCA, has been carried to provide insight into the role of manganese in both the Coprecipitated and Raney catalyst systems

  11. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    Science.gov (United States)

    Ramkumar, Shwetha; Fan, Liang-Shih

    2013-07-30

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  12. Solubility measurements of hydrogen in 1-butyl-3-methylimidazolium tetrafluoroborate and the effect of carbon dioxide and a selected catalyst on the hydrogen solubility in the ionic liquid

    NARCIS (Netherlands)

    Toussaint, V.A.; Kühne, E.; Shariati - Sarabi, A.; Peters, C.J.

    2013-01-01

    The high pressure phase behavior of a binary mixture containing hydrogen (H-2) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) is studied by measuring bubble-point pressures at different temperatures for three compositions with hydrogen mole fractions of 5, 7.5 and 10 mol%. Since

  13. Carbon isotope ratios of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Sakai, Hitoshi; Kishima, Noriaki; Tsutaki, Yasuhiro.

    1982-01-01

    The delta 13 C values relative to PDB were measured for carbon dioxide in air samples collected at various parts of Japan and at Mauna Loa Observatory, Hawaii in the periods of 1977 and 1978. The delta 13 C values of the ''clean air'' are -7.6 % at Hawaii and -8.1 per mille Oki and Hachijo-jima islands. These values are definitely lighter than the carbon isotope ratios (-6.9 per mille) obtained by Keeling for clean airs collected at Southern California in 1955 to 1956. The increase in 12 C in atmospheric carbon dioxide is attributed to the input of the anthropogenic light carbon dioxides (combustion of fossil fuels etc.) Taking -7.6 per mille to be the isotope ratio of CO 2 in the present clean air, a simple three box model predicts that the biosphere has decreased rather than increased since 1955, implying that it is acting as the doner of carbon rather than the sink. (author)

  14. Oxygen and carbon dioxide sensing

    Science.gov (United States)

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

    2012-01-01

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

  15. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

    Florio, J.T.; Mackenzie, D.A.R.; McKenzie, R.S. [ARE Physiological Laboratory, Gosport (United Kingdom)

    1998-04-01

    This report summarises the work carried out at the ARE Physiological Laboratory (ARE(PL)) between July 1978 and December 1983. The work was intended to examine the proposition that some divers have a low ventilatory response to carbon dioxide; that this results in a low ventilatory response to exercise with consequent hypercapnia; and that these characteristics put the diver at a greater-than-normal risk by increasing the individual`s susceptibility to oxygen toxicity and to other hazards associated with diving (e.g. nitrogen narcosis, decompression sickness and hypothermia). The specific aims of the project can be summarised as follows: (a) to demonstrate the existence of divers who exhibit the tendency to `retain carbon dioxide` when working in hyperbaric conditions; (b) to define the circumstances under which such individuals are at risk; (c) to assess the magnitude of the risk; and (d) to recommend ways to eliminate or to reduce the risk. (author)

  16. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    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. Carbon...

  17. Carbon Dioxide Removal via Passive Thermal Approaches

    Science.gov (United States)

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

    2011-01-01

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

  18. Advances in Hydrogen, Carbon Dioxide, and Hydrocarbon Gas Sensor Technology Using GaN and ZnO-Based Devices

    Directory of Open Access Journals (Sweden)

    Jenshan Lin

    2009-06-01

    Full Text Available In this paper, we review our recent results in developing gas sensors for hydrogen using various device structures, including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs. ZnO nanowires are particularly interesting because they have a large surface area to volume ratio, which will improve sensitivity, and because they operate at low current levels, will have low power requirements in a sensor module. GaN-based devices offer the advantage of the HEMT structure, high temperature operation, and simple integration with existing fabrication technology and sensing systems. Improvements in sensitivity, recoverability, and reliability are presented. Also reported are demonstrations of detection of other gases, including CO2 and C2H4 using functionalized GaN HEMTs. This is critical for the development of lab-on-a-chip type systems and can provide a significant advance towards a market-ready sensor application.

  19. Advances in Hydrogen, Carbon Dioxide, and Hydrocarbon Gas Sensor Technology Using GaN and ZnO-Based Devices.

    Science.gov (United States)

    Anderson, Travis; Ren, Fan; Pearton, Stephen; Kang, Byoung Sam; Wang, Hung-Ta; Chang, Chih-Yang; Lin, Jenshan

    2009-01-01

    In this paper, we review our recent results in developing gas sensors for hydrogen using various device structures, including ZnO nanowires and GaN High Electron Mobility Transistors (HEMTs). ZnO nanowires are particularly interesting because they have a large surface area to volume ratio, which will improve sensitivity, and because they operate at low current levels, will have low power requirements in a sensor module. GaN-based devices offer the advantage of the HEMT structure, high temperature operation, and simple integration with existing fabrication technology and sensing systems. Improvements in sensitivity, recoverability, and reliability are presented. Also reported are demonstrations of detection of other gases, including CO(2) and C(2)H(4) using functionalized GaN HEMTs. This is critical for the development of lab-on-a-chip type systems and can provide a significant advance towards a market-ready sensor application.

  20. Nuclear power and carbon dioxide free automobiles

    International Nuclear Information System (INIS)

    Pendergast, D.R.

    1999-01-01

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

  1. Improving crystallization and electron mobility of indium tin oxide by carbon dioxide and hydrogen dual-step plasma treatment

    Science.gov (United States)

    Wang, Fengyou; Du, Rongchi; Ren, Qianshang; Wei, Changchun; Zhao, Ying; Zhang, Xiaodan

    2017-12-01

    Obtaining high conductivity indium tin oxide (ITO) films simultaneously with a "soft-deposited" (low temperature, low ions bombardment) and cost-efficient deposition process are critical aspect for versatile photo-electronic devices application. Usually, the low-cost "soft-deposited" process could be achieved via evaporation technique, but with scarifying the conductivity of the films. Here, we show a CO2 and H2 two-step plasma (TSP) post-treatment applied to ITO films prepared by reactive thermal evaporation (RTE), allows to meet the special trade-off between the deposition techniques and the electrical properties. Upon treatment, an increase in electron concentration and electron mobility is observed, which subsequently resulting a low sheet resistivity. The mobility reaches high values of 80.9 cm2/Vs for the TSP treated ∼100 nm thickness samples. From a combination of X-ray photoelectron spectroscopy and opto-electronic measurements, it demonstrated that: during the TSP process, the first-step CO2 plasma treatment could promote the crystallinity of the RTE ITO films. While the electron traps density at grain boundaries of polycrystalline RTE ITO films could be passivated by hydrogen atom during the second-step H2 plasma treatment. These results inspired that the TSP treatment process has significant application prospects owing to the outstanding electrical properties enhancement for "soft-deposited" RTE ITO films.

  2. Absorption of carbon dioxide in waste tanks

    International Nuclear Information System (INIS)

    Hobbs, D.T.

    1987-01-01

    Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

  3. Carbon Dioxide Separation Using Thermally Optimized Membranes

    Science.gov (United States)

    Young, J. S.; Jorgensen, B. S.; Espinoza, B. F.; Weimer, M. W.; Jarvinen, G. D.; Greenberg, A.; Khare, V.; Orme, C. J.; Wertsching, A. K.; Peterson, E. S.; Hopkins, S. D.; Acquaviva, J.

    2002-05-01

    The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the recovery of hydrogen from nitrogen, carbon monoxide, and methane mixtures, and the removal of carbon dioxide from natural gas. In each of these applications, high fluxes and excellent selectivities have relied on glassy polymer membranes which separate gases based on both size and solubility differences. To date, however, this technology has focused on optimizing materials for near ambient conditions. The development of polymeric materials that achieve the important combination of high selectivity, high permeability, and mechanical stability at temperatures significantly above 25oC and pressures above 10 bar, respectively, has been largely ignored. Consequently, there is a compelling rationale for the exploration of a new realm of polymer membrane separations. Indeed, the development of high temperature polymeric-metallic composite membranes for carbon dioxide separation at temperatures of 100-450 oC and pressures of 10-150 bar would provide a pivotal contribution with both economic and environmental benefits. Progress to date includes the first ever fabrication of a polymeric-metallic membrane that is selective from room temperature to 370oC. This achievement represents the highest demonstrated operating temperature at which a polymeric based membrane has successfully functioned. Additionally, we have generated the first polybenzamidizole silicate molecular composites. Finally, we have developed a technique that has enabled the first-ever simultaneous measurements of gas permeation and membrane compaction at elevated temperatures. This technique provides a unique

  4. Forest response to carbon dioxide

    International Nuclear Information System (INIS)

    Pitelka, L.

    1992-01-01

    It has been suggested that planting trees could help slow the buildup of carbon dioxide in the atmosphere. Since elevated levels of CO 2 are known to enhance photosynthesis and growth in many plants, it is possible that trees could become progressively more effective in storing carbon as atmospheric CO 2 increases. However, early results from experiments with ponderosa and loblolly pines indicate that the relationship between tree growth and rising CO 2 concentrations may be more complex than scientists once thought. In these experiments, the response to elevated CO 2 has been highly dependent both on species and on mineral nutrient levels in the soil. Further work is necessary to clarify the mechanisms involved. This research will ultimately contribute to an integrated model for predicting forest ecosystem response to elevated CO 2

  5. Gettering of carbon dioxide by erbium thin films

    International Nuclear Information System (INIS)

    Mehrhoff, T.K.

    1980-01-01

    The interaction of carbon dioxide and erbium thin films is characterized for temperatures in the region of 300 to 900 0 C and partial pressure of carbon dioxide near 5 x 10 -7 Torr. Dynamic film pumping speeds were measured against a mercury diffusion pump of known pumping speed and conductance. A quadrupole mass spectrometer was used to monitor the carbon dioxide flow which originated from a calibrated leak in the 10 -6 standard cm 3 /s range. Data reduction was via a dedicated minicomputer with associated printer/plotter. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C. The reaction was preceded by the desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface

  6. Mixotrophic growth of two thermophilic Methanosarcina strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, on methanol and hydrogen/carbon dioxide

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Ahring, Birgitte Kiær

    1997-01-01

    Two thermophilic strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, were capable of mixotrophic growth on methanol and H-2/CO2. Activated carbon was, however, found to be necessary to support good growth. Both strains used hydrogen and methanol simultaneously. When methanol...

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

    Science.gov (United States)

    Eid, Mohamed El Gohary

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

  8. Carbon Dioxide for pH Control

    Energy Technology Data Exchange (ETDEWEB)

    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. Trading coalbed methane for carbon dioxide

    International Nuclear Information System (INIS)

    Greenberger, L.S.

    1991-01-01

    This article discusses a proposal for reducing methane emissions in coal mining activities and at the same time reducing the burden on utilities to cut carbon dioxide emissions. Emission credits would be issued to mines that recover the methane for use. These credits could then be bought by utilities and exchanged for the right to emit carbon dioxide

  10. Pressure pumping of carbon dioxide from soil

    Science.gov (United States)

    E. S. Takle; J. R. Brandle; R. A. Schmidt; R. Garcia; I. V. Litvina; G. Doyle; X. Zhou; Q. Hou; C. W. Rice; W. J. Massman

    2000-01-01

    Recent interest in atmospheric increases in carbon dioxide have heightened the need for improved accuracy in measurements of fluxes of carbon dioxide from soils. Diffusional movement has long been considered the dominant process by which trace gases move from the subsurface source to the surface, although there has been some indication that atmospheric pressure...

  11. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

    2008-01-01

    cellars are emptied regularly in a four weeks interval. Due to a high and variable carbon dioxide production in deep straw litter houses and houses with indoor storage of manure longer than four weeks, we do not recommend to calculate the ventilation flow based on the carbon dioxide concentration......This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o...

  12. Electrochemical processing of carbon dioxide.

    Science.gov (United States)

    Oloman, Colin; Li, Hui

    2008-01-01

    With respect to the negative role of carbon dioxide on our climate, it is clear that the time is ripe for the development of processes that convert CO(2) into useful products. The electroreduction of CO(2) is a prime candidate here, as the reaction at near-ambient conditions can yield organics such as formic acid, methanol, and methane. Recent laboratory work on the 100 A scale has shown that reduction of CO(2) to formate (HCO(2)(-)) may be carried out in a trickle-bed continuous electrochemical reactor under industrially viable conditions. Presuming the problems of cathode stability and formate crossover can be overcome, this type of reactor is proposed as the basis for a commercial operation. The viability of corresponding processes for electrosynthesis of formate salts and/or formic acid from CO(2) is examined here through conceptual flowsheets for two process options, each converting CO(2) at the rate of 100 tonnes per day.

  13. Reaction of yttrium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Khokhlov, A.D.; Reznikova, N.F.

    1986-01-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800 0 C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430 0 C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested

  14. Carbon dioxide cleaning pilot project

    International Nuclear Information System (INIS)

    Knight, L.; Blackman, T.E.

    1994-01-01

    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. More bad news about carbon dioxide emissions

    International Nuclear Information System (INIS)

    Stonehouse, D.

    2000-01-01

    The affect that increased carbon dioxide concentrations has on plants and animals was discussed. Most research focuses on the impacts that carbon dioxide concentrations has on climatic change. Recent studies, however, have shown that elevated levels of carbon dioxide in the atmosphere caused by burning fossils fuels changes the chemical structure of plants and could lead to significant disruptions in ecological food chains. High carbon dioxide levels cause plants to speed up photosynthesis, take in the gas, and use the carbon to produce more fibre and starch while giving off oxygen as a byproduct. As plants produce more carbon, their levels of nitrogen diminish making them less nutritious for the insects and animals that feed on them. This has serious implications for farmers, as pests would have to eat more of their crops to survive. In addition, farmers would have to supplement livestock with nutrients

  16. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

  17. Hydrogen production by dry reforming of methane with carbon dioxide in one-dimensional nickel-based catalysts; Produccion de hidrogeno mediante el reformado seco de metano con dioxido de carbono en catalizadores unidimensionales a base de niquel

    Energy Technology Data Exchange (ETDEWEB)

    Lopez U, A. C.

    2016-07-01

    The main objective of this thesis is development of nickel catalysts supported over 1D matrix of cerium oxide, to be used in dry reforming methane reaction with carbon dioxide for hydrogen production. The catalysts were characterized by: Temperature Programmed Reduction (TPR), Scanning Electronic Microscopy (Sem), Surface Area (Bet method) an X Ray Diffraction (XRD). The TPR technique allowed to define reduction temperature of the active phase in the catalyst, Sem technique showed that the CeO{sub 2} matrix had a nano rod morphology. XRD allowed to identify the crystalline phases of the catalysts. Finally, the catalysts were tested in the dry reforming methane reaction, high catalytic activity and hydrogen production were performed at 700 degrees Celsius and the catalyst with 30 wt.% of nickel. (Author)

  18. Hydrogen storage in carbon nanotubes.

    Science.gov (United States)

    Hirscher, M; Becher, M

    2003-01-01

    The article gives a comprehensive overview of hydrogen storage in carbon nanostructures, including experimental results and theoretical calculations. Soon after the discovery of carbon nanotubes in 1991, different research groups succeeded in filling carbon nanotubes with some elements, and, therefore, the question arose of filling carbon nanotubes with hydrogen by possibly using new effects such as nano-capillarity. Subsequently, very promising experiments claiming high hydrogen storage capacities in different carbon nanostructures initiated enormous research activity. Hydrogen storage capacities have been reported that exceed the benchmark for automotive application of 6.5 wt% set by the U.S. Department of Energy. However, the experimental data obtained with different methods for various carbon nanostructures show an extreme scatter. Classical calculations based on physisorption of hydrogen molecules could not explain the high storage capacities measured at ambient temperature, and, assuming chemisorption of hydrogen atoms, hydrogen release requires temperatures too high for technical applications. Up to now, only a few calculations and experiments indicate the possibility of an intermediate binding energy. Recently, serious doubt has arisen in relation to several key experiments, causing considerable controversy. Furthermore, high hydrogen storage capacities measured for carbon nanofibers did not survive cross-checking in different laboratories. Therefore, in light of today's knowledge, it is becoming less likely that at moderate pressures around room temperature carbon nanostructures can store the amount of hydrogen required for automotive applications.

  19. Report of the Carbon Dioxide Committee II

    International Nuclear Information System (INIS)

    1994-01-01

    The Carbon Dioxide Committee was given the task of preparing a suggestion of the acts aimed at reducing the greenhouse gas emissions and increasing the sinks of carbon in Finland. Emissions of all greenhouse gases were in 1990 80 million tons. calculated as carbon dioxide. The carbon dioxide emissions were about 58 million tons of the total. The increase of forest resources binds carbon from the atmosphere and reduces thereby net emissions of Finland at present by nearly 30 million tons of carbon dioxide. Carbon dioxide emissions will grow during the next decades, unless strong measures to control them will not be taken. As a result of the Commissions examination, acts will be needed both in the production of energy and in its consumption. Emissions can be reduced by replacing fossil fuels with nuclear energy, bioenergy and other renewable energy sources. Saving of energy and improvement of energy efficiency will limit carbon dioxide emissions. The Commission has made suggestions both to change the structure of energy production and to control the consumption of energy. (orig.)

  20. Hydrogen storage in carbon nanostruc

    NARCIS (Netherlands)

    Hirscher, M.; Becher, M.; Haluska, M.; Quintel, A.; Skakalova, V.; Choi, M.; Dettlaff-Weglikowska, U.; Roth, S.; Stepanek, I.; Bernier, P.; Leonhardt, A.; Fink, J.

    2002-01-01

    The paper gives a critical review of the literature on hydrogen storage in carbon nanostructures. Furthermore, the hydrogen storage of graphite, graphite nanofibers (GNFs), and single-walled carbon nanotubes (SWNTs) was measured by thermal desorption spectroscopy (TDS). The samples were ball milled

  1. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  2. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  3. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  4. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  5. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

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

  6. Carbon dioxide: making the right connection

    African Journals Online (AJOL)

    This highlights safety issues concerning pipeline provision of carbon dioxide, and that it is of utmost ... capnograph sample line, gas analysis unit, water trap and soda .... The heat generated by the chemical reaction between soda lime.

  7. integrated vertical photobioreactor system for carbon dioxide

    African Journals Online (AJOL)

    Astri Nugroho

    2013-07-02

    Jul 2, 2013 ... efficient system for converting carbon dioxide (CO2) into biomass. The use of ... often been thought to achieve the most efficient mixing and the best ... such process a photobioreactor is designed. Photobioreactor is a device ...

  8. Supercritical carbon dioxide hop extraction

    Directory of Open Access Journals (Sweden)

    Pfaf-Šovljanski Ivana I.

    2005-01-01

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

  9. Method and apparatus for producing food grade carbon dioxide

    International Nuclear Information System (INIS)

    Nobles, J.E.; Swenson, L.K.

    1984-01-01

    A method is disclosed of producing food grade carbon dioxide from an impure carbon dioxide source stream containing contaminants which may include light and heavy hydrocarbons (at least C 1 to C 3 ) and light sulfur compounds such as hydrogen sulfide and carbonyl sulfide as well as heavier sulfur constituents in the nature of mercaptans (RSH) and/or organic mono and disulfides (RSR and RSSR). Nitrogen, water and/or oxygen may also be present in varying amounts in the impure feed stream. The feed gas is first rectified with liquid carbon dioxide condensed from a part of the feed stream to remove heavy hydrocarbons and heavy sulfur compounds, then passed through an absorber to effect removal of the light sulfur compounds, next subjected to an oxidizing atmosphere capable of converting all of the C 2 hydrocarbons and optionally a part of the methane to carbon oxides and water, chilled to condense the water in the remaining gas stream without formation of hydrates, liquefied for ease of handling and storage and finally stripped to remove residual contaminants such as methane, carbon monoxide and nitrogen to produce the final food grade carbon dioxide product

  10. Extraction of Uranium Using Nitrogen Dioxide and Carbon Dioxide for Spent Fuel Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Kayo Sawada; Daisuke Hirabayashi; Youichi Enokida [EcoTopia Science Institute, Nagoya University, Nagoya, 464-8603 (Japan)

    2008-07-01

    For the reprocessing of spent nuclear fuels, a new method to extract actinides from spent fuel using highly compressed gases, nitrogen dioxide and carbon dioxide was proposed. Uranium extraction from broken pieces, whose average grain size was 5 mm, of uranium dioxide pellet with nitrogen dioxide and carbon dioxide was demonstrated in the present study. (authors)

  11. Carbon dioxide warming of the early Earth

    Science.gov (United States)

    Arrhenius, G.

    1997-01-01

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

  12. Study of volumetric properties (PVT) of mixtures made of light hydrocarbons (C1-C4), carbon dioxide and hydrogen sulfide - Experimental measurements through a vibrating tube densimeter and modelling; Etude des proprietes volumetriques (PVT) d'hydrocarbures legers (C1-C4), du dioxyde de carbone et de l'hydrogene sulfure. Mesures par densimetrie a tube vibrant et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Rivollet, F.

    2005-12-15

    Various pollutant contents (i.e. carbon dioxide, hydrogen sulphide or other sulphur products) are found in produced oils. These latter must undergo a number of transformations and purifications. The design and dimensioning of the corresponding units can well be optimized only if one has reliable and accurate data about phase equilibria and volumetric properties and of course reliable and accurate modeling. This work was devoted partly to measurements of volumetric properties on three binary mixtures (ethane - hydrogen sulphide, ethane - propane and carbon dioxide - hydrogen sulphide). These measurements were carried out using equipment, comprising a vibrating tube densimeter (Paar, model DMA 512 P), which was especially designed and built for this work. The binary mixtures were studied in the 253 to 363 K temperature range from at pressures up to either 20 or 40 MPa. Two calibration methods of the vibrating tube were used: the FPMC method (Forced Path Mechanical Calibration) described in the literature and an original method containing neural network, developed herein. The study undertaken about the modeling of volumetric properties made it possible to highlight the inadequacy of the traditional use of cubic equations of state to represent simultaneously volumetric properties and phase equilibria. Among the equations of state investigated, a close attention however was paid to cubic equations of state because of their very great use in the oil field. A new tool was found to adapt cubic equations of state to the simultaneous and satisfactory representation of volumetric properties and phase equilibria. It concerns the coupling of the cubic Redlich-Kwong-Soave equation of state with volume correction through a neural network. This new model was tested successfully, it makes it possible to benefit from the existing work of representation of phase equilibria (mixing rules and interaction coefficients) while improving calculation of the volumetric data.

  13. Effective utilization technology of carbon dioxide. CO sub 2 no yuko riyo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Ibusuki, T. (National Research Inst. for pollution and Resources, Tsukuba (Japan))

    1991-03-12

    As carbon dioxide-related environmental measures, method was explained to chemically convert and utilize carbon dioxide. Synthesis is possible of methanol, carbon monoxide, different carbohydrates, etc. by catalytic hydrogenation of carbon dioxide, using hydrogen produced by the electrolysis of water. Task consists of heightening in both convertibility and selectivity, and abundant supply of low cost hydrogen. Methane, alcohol, etc. can be synthesized by electrochemical reducion of carbon dioxide. Because of effectively inserting multiple electron, discssion is being made of catalyst, intergrated with electrode, and electron transmitter. The photoelectrochemical reduction of carbon dioxide can be also made by utilizing photoelectric current, generated upon photoradiation on the semiconductive electrode. However, task consists of heightening in both efficiency and selectivity. Photochemical reduction of carbon dioxide, actually made by green plant, consists of oxidationlike decomposition of water and reduction of carbon dioxide. Both those reactions are skillfully separated by intermediation of very quick electron transmission system. Reduction is being studied with semiconductor, metallic colloid, enzyme, metallic complex and other various catalysts. 10 refs., 3 figs., 4 tabs.

  14. Understanding the carbon dioxide gaps.

    Science.gov (United States)

    Scheeren, Thomas W L; Wicke, Jannis N; Teboul, Jean-Louis

    2018-06-01

    The current review attempts to demonstrate the value of several forms of carbon dioxide (CO2) gaps in resuscitation of the critically ill patient as monitor for the adequacy of the circulation, as target for fluid resuscitation and also as predictor for outcome. Fluid resuscitation is one of the key treatments in many intensive care patients. It remains a challenge in daily practice as both a shortage and an overload in intravascular volume are potentially harmful. Many different approaches have been developed for use as target of fluid resuscitation. CO2 gaps can be used as surrogate for the adequacy of cardiac output (CO) and as marker for tissue perfusion and are therefore a potential target for resuscitation. CO2 gaps are easily measured via point-of-care analysers. We shed light on its potential use as nowadays it is not widely used in clinical practice despite its potential. Many studies were conducted on partial CO2 pressure differences or CO2 content (cCO2) differences either alone, or in combination with other markers for outcome or resuscitation adequacy. Furthermore, some studies deal with CO2 gap to O2 gap ratios as target for goal-directed fluid therapy or as marker for outcome. CO2 gap is a sensitive marker of tissue hypoperfusion, with added value over traditional markers of tissue hypoxia in situations in which an oxygen diffusion barrier exists such as in tissue oedema and impaired microcirculation. Venous-to-arterial cCO2 or partial pressure gaps can be used to evaluate whether attempts to increase CO should be made. Considering the potential of the several forms of CO2 measurements and its ease of use via point-of-care analysers, it is recommendable to implement CO2 gaps in standard clinical practice.

  15. Graphite suspension in carbon dioxide

    International Nuclear Information System (INIS)

    Roche, R.

    1965-01-01

    Since 1963 the Atomic Division of SNECMA has been conducting, under a contract with the CEA, an experimental work with a two-component fluid comprised of carbon dioxide and small graphite particles. The primary purpose was the determination of basic engineering information pertaining to the stability and the flowability of the suspension. The final form of the experimental loop consists mainly of the following items: a light-phase compressor, a heavy-phase pump, an electrical-resistance type heater section, a cooling heat exchanger, a hairpin loop, a transparent test section and a separator. During the course of the testing, it was observed that the fluid could be circulated quite easily in a broad range of variation of the suspension density and velocity - density from 30 to 170 kg/m 3 and velocity from 2 to 24 m/s. The system could be restarted and circulation maintained without any difficulty, even with the heavy-phase pump alone. The graphite did not have a tendency to pack or agglomerate during operation. No graphite deposition was observed on the wall of the tubing. A long period run (250 hours) has shown the evolution of the particle dimensions. Starting with graphite of surface area around 20 m 2 /g (graphite particles about 1 μ), the powder surface area reaches an asymptotic value of 300 m 2 /g (all the particles less than 0.3 μ). Moisture effect on flow stability, flow distribution between two parallel channels, pressure drop in straight tubes, recompression ratio in diffusers were also investigated. (author) [fr

  16. Reaction of titanium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

    1987-01-01

    It has been ascertained that heating titanium and tantalum in carbon dioxide to temperatures of 500 or 800 0 C alters the composition of the gas phase, causing the advent of carbon monoxide and lowering the oxygen content. Investigation of the thermal stability of titanium polonides in a carbon dioxide medium has shown that titanium mono- and hemipolonides are decomposed at temperatures below 350 0 C. The temperature dependence of the vapor pressure of polonium produced in the decomposition of these polonides in a carbon dioxide medium have been determined by a radiotensimetric method. The enthalpy of the process, calculated from this relationship, is close to the enthalpy of vaporization of elementary polonium in vacuo

  17. The chemistry of subcritical water reactions of a hardwood derived lignin and lignin model compounds with nitrogen, hydrogen, carbon monoxide and carbon dioxide

    Science.gov (United States)

    Hill Bembenic, Meredith A.

    collected solids from the CO reactions appeared to be the most reacted (i.e., the most changed from the unreacted lignin) according to solid state 13C-NMR analysis, and the widest variety of products (methoxy-substituted phenolic compounds) were obtained when using CO according to GC/MS analysis. Therefore, reactions with CO were completed that varied the initial reaction pressure (300, 500 and 800 psi) in order to elucidate the effects of CO pressure. Similar conversion (≈54--58%) and DCM-soluble liquid product yields (≈53--62%) were obtained for the different pressure reactions, but the reactions with an initial pressure of 500 psi had the greatest change in aromaticity from the unreacted lignin. Additional reactions between Organosolv lignin and H2O with CO (initial pressure of 500 psi) were conducted where the reaction time was varied (15, 30 and 60 min.) to determine the effect of reaction time. Longer reaction time (60 min.) appeared to inhibit conversion to low molecular weight compounds (i.e., conversion and DCM-soluble yields were lower at ≈53% and ≈28%, respectively). Solid state 13C-NMR of collected residues also showed that there are losses in carbons representative of both guaiacyl and syringyl components as reaction time increases, which may indicate that methoxy groups are being cleaved or the products are reacting with each other (i.e., repolymerization) to form high molecular weight compounds as reaction time is increased. The role of H2O and the gases during the baseline reactions and the expanded CO reactions is not intuitive based on the results, so reactions with lignin model compounds (i.e., aromatic aldehydes represented by vanillin and syringaldehyde, aromatic ketones represented by acetovanillone and acetosyringone, and aromatic ethers represented by dibenzyl ether and 2-phenethyl phenyl ether) were completed to study this. From these results, the suggested reaction pathway of Organosolv lignin reactions in subcritical H2O with and without

  18. Method for Extracting and Sequestering Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

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

  19. Apparatus for extracting and sequestering carbon dioxide

    Science.gov (United States)

    Rau, Gregory H [Castro Valley, CA; Caldeira, Kenneth G [Livermore, CA

    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.

  20. Carbon Dioxide Separation with Supported Ionic Liquid Membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-04-01

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

  1. Gettering of carbon dioxide by erbium thin films

    International Nuclear Information System (INIS)

    Mehrhoff, T.K.

    1980-01-01

    The interaction of carbon dioxide and erbium thin films is characterized at 300 to 900 0 C and 5 x 10 -7 torr. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C, preceded by desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface. The sticking coefficients were plotted as a function of Langmuirs of carbon dioxide exposure. Between 400 and 600 0 C, the length of the exposure was found to be more important than the temperature of the exposure in determining the sticking coefficient. Some evolution of carbon monoxide was noted particularly in the 400 to 500 0 C region. An 80% conversion of carbon dioxide to carbon monoxide was measured at 500 0 C. The film pumping speeds were compared with published vapor pressure data for erbium. This comparison indicated that a significant portion of the pumping action observed at temperatures of 800 0 C and above was due to evaporation of erbium metal

  2. Preparation of HZSM-5 membrane packed CuO–ZnO–Al{sub 2}O{sub 3} nanoparticles for catalysing carbon dioxide hydrogenation to dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Rong; Tian, Haifeng; Yang, Aimei; Zha, Fei, E-mail: zhafei@nwnu.edu.cn; Ding, Jian; Chang, Yue

    2015-08-01

    Highlights: • CuO–ZnO–Al{sub 2}O{sub 3} composite nanoparticles were successfully prepared using carbon sphere as template. • HZSM-5@CuO–ZnO–Al{sub 2}O{sub 3} capsule catalyst was prepared hydrothermally. • Zeolite capsule catalysts exhibited an extremely good selectivity for DME compared with the conventional hybrid catalyst. - Abstract: Spherical carbons were prepared successfully from aqueous glucose using hydrothermal method. After covered with aqueous Cu{sup 2+}, Zn{sup 2+} and Al{sup 3+} ions during the co-precipitation treatment, carbons were removed via calcination to yield CuO–ZnO–Al{sub 2}O{sub 3} nanoparticles. HZSM-5 membrane, which was synthesized using tetrapropylammonium hydroxide as templating agent, was packed onto CuO–ZnO–Al{sub 2}O{sub 3} nanoparticles hydrothermally to form HZSM-5 packed CuO–ZnO–Al{sub 2}O{sub 3} nanoparticles. It was characterized by the method of X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and nitrogen sorption measurement. HZSM-5 packed CuO–ZnO–Al{sub 2}O{sub 3} nanoparticles were used as catalysts for the CO{sub 2} hydrogenation to dimethyl ether. The catalyst activity was investigated in a fixed-bed reactor. Under the reaction conditions of pressure at 3.0 MPa, space velocity (SV) of 1800 mL g{sub cat}{sup −1} h{sup −1}, volume ratio of CO{sub 2}/H{sub 2} to 1:3 and temperature at 270 °C, the conversion of CO{sub 2} could reach to 48.3%, with a dimethyl ether yield and selectivity of 23.4% and 48.5%, respectively.

  3. Carbon dioxide problem: solution by technical countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Bach, W

    1978-02-15

    A rough assessment indicates that anthropogenic influences might raise the mean global surface temperature by 0.8 to 1.2 C in 2000 AD and by 2 to 4 C in 2050 AD. The rapidly increasing levels of atmospheric carbon dioxide are largely responsible for this warming trend. A variety of measures for the reduction of carbon dioxide emissions is presented. One promising approach is to work out a world-wide energy mix that can counteract a temperature increase. (In German)

  4. Environmental effects of increased atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Soon, W.; Baliunas, S.L.; Robinson, A.B.; Robinson, Z.W.

    1999-01-01

    A review of the literature concerning the environmental consequences of increased levels of atmospheric carbon dioxide leads to the conclusion that increases during the 20th century have produced no deleterious effects upon global climate or temperature. Increased carbon dioxide has, however, markedly increased plant growth rates as inferred from numerous laboratory and field experiments. There is no clear evidence, nor unique attribution, of the global effects of anthropogenic CO 2 on climate. Meaningful integrated assessments of the environmental impacts of anthropogenic CO 2 are not yet possible because model estimates of global and regional climate changes on interannual, decadal and centennial timescales remain highly uncertain.(author)

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

    Science.gov (United States)

    Meisinger, Philipp; Wittlich, Christian

    2014-05-01

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

  6. Catalyst retention in continuous flow with supercritical carbon dioxide

    NARCIS (Netherlands)

    Stouten, S.C.; Noel, T.; Wang, Q.; Hessel, V.

    2014-01-01

    This review discusses the retention of organometallic catalysts in continuous flow processes utilizing supercritical carbon dioxide. Due to its innovative properties, supercritical carbon dioxide offers interesting possibilities for process intensification. As a result of safety and cost

  7. Human population and carbon dioxide

    International Nuclear Information System (INIS)

    Schaffer, W.M.

    2008-01-01

    A recently proposed model of human population and carbon utilization is reviewed. Depending on parameter values, one of three possible long-term outcomes is obtained. (1) Atmospheric carbon, (CO 2 ) atm , and human populations equilibrate at positive values. (2) The human population stabilizes, while (CO 2 ) atm increases without bound. (3) The human population goes extinct and atmospheric carbon declines to 0. The final possibility is qualitatively compatible with both 'consensus' views of climate change and the opinions of those who are more impressed with the manifestly adverse consequences of carbon-mitigation to human reproduction and survival

  8. Carbon dioxide capture and air quality

    NARCIS (Netherlands)

    Horssen, A. van; Ramirez, C.A.; Harmelen, T. van; Koornneef, J.

    2011-01-01

    Carbon dioxide (CO2) is one of the most important greenhouse gases (GHG). The most dominant source of anthropogenic CO2 contributing to the rise in atmospheric concentration since the industrial revolution is the combustion of fossil fuels. These emissions are expected to result in global climate

  9. Electrocatalytic carbon dioxide reduction - a mechanistic study

    NARCIS (Netherlands)

    Schouten, Klaas Jan Schouten

    2013-01-01

    This thesis presents new insights into the reduction of carbon dioxide to methane and ethylene on copper electrodes. This electrochemical process has great potential for the storage of surplus renewable electrical energy in the form of hydrocarbons. The research described in this thesis focuses on

  10. Diiodination of Alkynes in supercritical Carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    李金恒; 谢叶香; 尹笃林; 江焕峰

    2003-01-01

    A general,green and efficient method for the synthesis of transdiiodoalkenes in CO2(sc) has been developed.Trans-diiodoalkenes were obtained stereospecifically in quantitative yields via diiodination of both electron-rich and electron-deficient alkynes in the presence of KI,Ce(SO4)2 and water in supercritical carbon dioxide [CO2(sc)]at 40℃.

  11. Tourism Transport, Technology, and Carbon Dioxide Emissions

    NARCIS (Netherlands)

    Peeters, P.M.

    2010-01-01

    Technological development from horse-drawn carriages to the new Airbus A380 has led to a remarkable increase in both the capacity and speed of tourist travel. This development has an endogenous systemic cause and will continue to increase carbon dioxide emissions/energy consumption if left

  12. Carbon dioxide sensing with sulfonated polyaniline

    NARCIS (Netherlands)

    Doan, D.C.T.; Ramaneti, R.; Baggerman, J.; Bent, van der J.; Marcelis, A.T.M.; Tong, H.D.; Rijn, van C.J.M.

    2012-01-01

    The use of polyaniline and especially sulfonated polyaniline (SPAN) is explored for sensing carbon dioxide (CO2) at room temperature. Frequency-dependent AC measurements were carried out to detect changes in impedance of the polymer, drop casted on interdigitated electrodes, when exposed to CO2 gas.

  13. Conductive polymers for carbon dioxide sensing

    NARCIS (Netherlands)

    Doan, T.C.D.

    2012-01-01

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

  14. Transport properties of supercritical carbon dioxide

    NARCIS (Netherlands)

    Lavanchy, F.; Fourcade, E.; de Koeijer, E.A.; Wijers, J.G.; Meyer, T.; Keurentjes, J.T.F.; Kemmere, M.F.; Meyer, T.

    2005-01-01

    Recently, supercritical fluids have emerged as more sustainable alternatives for the organic solvents often used in polymer processes. This is the first book emphasizing the potential of supercritical carbon dioxide for polymer processes from an engineering point of view. It develops a

  15. Hydrogen adsorption in carbon nanostructures compared

    NARCIS (Netherlands)

    Schimmel, H.G.; Nijkamp, M.G.; Kearley, G.J.; Rivera, A.; de Jong, K.P.; Mulder, F.M.

    2004-01-01

    Recent reports continue to suggest high hydrogen storage capacities for some carbon nanostructures due to a stronger interaction between hydrogen and carbon. Here the interaction of hydrogen with activated charcoal, carbon nanofibers, single walled carbon nanotubes (SWNT), and electron beam ‘opened’

  16. Carbon material for hydrogen storage

    Science.gov (United States)

    Bourlinos, Athanasios; Steriotis, Theodore; Stubos, Athanasios; Miller, Michael A

    2016-09-13

    The present invention relates to carbon based materials that are employed for hydrogen storage applications. The material may be described as the pyrolysis product of a molecular precursor such as a cyclic quinone compound. The pyrolysis product may then be combined with selected transition metal atoms which may be in nanoparticulate form, where the metals may be dispersed on the material surface. Such product may then provide for the reversible storage of hydrogen. The metallic nanoparticles may also be combined with a second metal as an alloy to further improve hydrogen storage performance.

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

    African Journals Online (AJOL)

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

  18. 27 CFR 24.319 - Carbon dioxide record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., 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 to...

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

    Science.gov (United States)

    2010-04-01

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

  20. 27 CFR 26.52 - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

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

  1. Integrated Assessment of Carbon Dioxide Removal

    Science.gov (United States)

    Rickels, W.; Reith, F.; Keller, D.; Oschlies, A.; Quaas, M. F.

    2018-03-01

    To maintain the chance of keeping the average global temperature increase below 2°C and to limit long-term climate change, removing carbon dioxide from the atmosphere (carbon dioxide removal, CDR) is becoming increasingly necessary. We analyze optimal and cost-effective climate policies in the dynamic integrated assessment model (IAM) of climate and the economy (DICE2016R) and investigate (1) the utilization of (ocean) CDR under different climate objectives, (2) the sensitivity of policies with respect to carbon cycle feedbacks, and (3) how well carbon cycle feedbacks are captured in the carbon cycle models used in state-of-the-art IAMs. Overall, the carbon cycle model in DICE2016R shows clear improvements compared to its predecessor, DICE2013R, capturing much better long-term dynamics and also oceanic carbon outgassing due to excess oceanic storage of carbon from CDR. However, this comes at the cost of a (too) tight short-term remaining emission budget, limiting the model suitability to analyze low-emission scenarios accurately. With DICE2016R, the compliance with the 2°C goal is no longer feasible without negative emissions via CDR. Overall, the optimal amount of CDR has to take into account (1) the emission substitution effect and (2) compensation for carbon cycle feedbacks.

  2. Ocean uptake of carbon dioxide

    International Nuclear Information System (INIS)

    Peng, Tsung-Hung; Takahashi, Taro

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0 2 include carbon chemistry, distribution of alkalinity, pCO 2 and total concentration of dissolved C0 2 , sea-air pCO 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 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 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 2 fertilization is a potential candidate for such missing carbon sinks

  3. High pressure measurement and CPA equation of state for solubility of carbon dioxide and hydrogen sulfide in 1-butyl-3-methylimidazolium acetate

    International Nuclear Information System (INIS)

    Haghtalab, Ali; Kheiri, Alireza

    2015-01-01

    Highlights: • Solubility of carbon dioxide in pure [bmim][acetate] is measured. • Simultaneous solubility of CO 2 + H 2 S in [bmim][acetate] is measured. • Both physical and chemical models are applied to modelling the (acid gas + IL) systems. • The CPA EoS is used for phase equilibrium calculation. • A reaction thermodynamic equilibrium model is used in liquid phase. - Abstract: Removal of acid gases such as CO 2 and H 2 S from natural gas is essential for commercial, safety and environmental protection that demonstrate the importance of gas sweetening process. Ionic liquids (IL) have been highly demanded as a green solvent to remove acid gases from sour natural gas and capturing of CO 2 from flue gases. In this work, the solubility of CO 2 in 1-butyl-3-methylimidazolium acetate ([bmim][Ac]) is measured at temperatures (303.15, 328.15, 343.15) K and pressure range of (0.1 to 3.9) MPa. Moreover, the experiments are carried out for simultaneous measurements of (CO 2 + H 2 S) (70% + 30% on a mole basis) solubility in the same ionic liquid at T = (303.15, 323.15, 343.15) K and a pressure range of (0.1 to 2.2) MPa. To model the solubility of acid gases in IL, both physical and chemical equilibria are applied so that the (vapour + liquid) equilibrium calculation is carried out through Cubic-Plus-Association (CPA) EoS. The reaction equilibrium thermodynamic model is used in liquid phase so that the chemical reaction is taking place between IL and acid gasses. The Henry’s and reaction equilibrium constants are obtained though optimization of the solubility data. Using CPA EOS, the pure parameters of [bmim][acetate] are optimised and consequently using these parameters, gas partial pressure calculation is performed for the (CO 2 + IL) and (CO 2 + H 2 S + IL) systems. For the (CO 2 + IL) system, the percent average absolute deviation (AAD%) of 4.83 is resulted and for the (H 2 S + CO 2 + IL) system the values of 18.8 and 13.7 are obtained for H 2 S and CO 2

  4. Adsorption and methanation of carbon dioxide on a nickel/silica catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Falconer, J.L.; Zagli, A.E.

    1980-04-01

    Temperature-programed desorption and reaction studies showed that increasing amounts of CO/sub 2/ adsorbed on silica-supported 6.9% nickel with increasing temperature to a maximum adsorption at approx. 443/sup 0/K, i.e., that the adsorption was activated; that CO/sub 2/ desorbed partly as CO/sub 2/ with the peak at 543/sup 0/K, and partly as CO with several peaks; that in the presence of hydrogen, nearly all adsorbed CO/sub 2/ desorbed as methane, and a small amount as CO; and that the methane desorption peaks from adsorbed CO and CO/sub 2/ both occurred at 473/sup 0/K. These results suggested that carbon dioxide adsorbed dissociatively as a carbon monoxide and an oxygen species. An observed absence of higher hydrocarbons in the methanation products of carbon dioxide was attributed to a high hydrogen/carbon monoxide surface ratio caused by the activated carbon dioxide adsorption.

  5. Monitoring carbon dioxide in mechanically ventilated patients during hyperbaric treatment

    DEFF Research Database (Denmark)

    Bjerregård, Asger; Jansen, Erik

    2012-01-01

    Measurement of the arterial carbon dioxide (P(a)CO(2)) is an established part of the monitoring of mechanically ventilated patients. Other ways to get information about carbon dioxide in the patient are measurement of end-tidal carbon dioxide (P(ET)CO(2)) and transcutaneous carbon dioxide (PTCCO2......). Carbon dioxide in the blood and cerebral tissue has great influence on vasoactivity and thereby blood volume of the brain. We have found no studies on the correlation between P(ET)CO(2) or P(TC)CO(2), and P(a)CO(2) during hyperbaric oxygen therapy (HBOT)....

  6. Energy efficient solvent regeneration process for carbon dioxide capture

    Science.gov (United States)

    Zhou, Shaojun; Meyer, Howard S.; Li, Shiguang

    2018-02-27

    A process for removing carbon dioxide from a carbon dioxide-loaded solvent uses two stages of flash apparatus. Carbon dioxide is flashed from the solvent at a higher temperature and pressure in the first stage, and a lower temperature and pressure in the second stage, and is fed to a multi-stage compression train for high pressure liquefaction. Because some of the carbon dioxide fed to the compression train is already under pressure, less energy is required to further compress the carbon dioxide to a liquid state, compared to conventional processes.

  7. Materials for carbon dioxide separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingqing

    2014-10-01

    The CO{sub 2} adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO{sub 2} adsorption ability. Another promising class of materials for CO{sub 2} capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO{sub 3} and the relationship between physisorption and chemisorption properties of CaO-based materials.

  8. Materials for carbon dioxide separation

    International Nuclear Information System (INIS)

    Xu, Qingqing

    2014-01-01

    The CO 2 adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO 2 adsorption ability. Another promising class of materials for CO 2 capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO 3 and the relationship between physisorption and chemisorption properties of CaO-based materials.

  9. Hydrogenation of carbon monoxide over supported palladium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K.; Hashimoto, H.; Kunugi, T.

    1978-03-01

    An alumina-supported 2% palladium catalyst had higher activity for carbon monoxide hydrogenation than a silica-supported 2% palladium catalyst, at 250/sup 0/-400/sup 0/C and 1 atm. The addition of lanthanum oxide or thorium oxide, but not of potassium oxide, to the silica-supported catalyst increased the conversion at 350/sup 0/C from 1.1% to 81.0% with a selectivity of 56.1% for methane, 1.4% for C/sub 2/ compounds, 0.1% for C/sub 3/ compounds, and 42.5% for carbon dioxide. Temperature-programed desorption of carbon monoxide in a hydrogen stream showed that of two desorption peaks observed for carbon monoxide, the one at higher temperature corresponded to the carbon monoxide species which hydrogenates to methane and that the area of this peak increased with increasing thorium content of the catalyst. Graphs, tables, and 12 references.

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

    International Nuclear Information System (INIS)

    1983-02-01

    The DOE program focuses on three areas each of which requires more research before the many CO 2 -related questions can be answered. These areas include the global carbon cycle, climate effects, and vegetation effects. Additional information is needed to understand the sources and sinks of CO 2 . Research efforts include an attempt to estimate regional and global changes in temperature and precipitation. Increased atmospheric CO 2 may be a potential benefit to vegetation and crops because it is an essential element required for plant growth. Eight separate papers are included

  11. Research Progress in Carbon Dioxide Storage and Enhanced Oil Recovery

    Science.gov (United States)

    Wang, Keliang; Wang, Gang; Lu, Chunjing

    2018-02-01

    With the rapid development of global economy, human beings have become highly dependent upon fossil fuel such as coal and petroleum. Much fossil fuel is consumed in industrial production and human life. As a result, carbon dioxide emissions have been increasing, and the greenhouse effects thereby generated are posing serious threats to environment of the earth. These years, increasing average global temperature, frequent extreme weather events and climatic changes cause material disasters to the world. After scientists’ long-term research, ample evidences have proven that emissions of greenhouse gas like carbon dioxide have brought about tremendous changes to global climate. To really reduce carbon dioxide emissions, governments of different countries and international organizations have invested much money and human resources in performing research related to carbon dioxide emissions. Manual underground carbon dioxide storage and carbon dioxide-enhanced oil recovery are schemes with great potential and prospect for reducing carbon dioxide emissions. Compared with other schemes for reducing carbon dioxide emissions, aforementioned two schemes exhibit high storage capacity and yield considerable economic benefits, so they have become research focuses for reducing carbon dioxide emissions. This paper introduces the research progress in underground carbon dioxide storage and enhanced oil recovery, pointing out the significance and necessity of carbon dioxide-driven enhanced oil recovery.

  12. Electrocatalytic reduction of carbon dioxide under plasma DBD process

    International Nuclear Information System (INIS)

    Amouroux, Jacques; Cavadias, Simeon

    2017-01-01

    Carbon dioxide can be converted, by reaction with hydrogen, into fine chemicals and liquid fuels such as methanol and DME. Methane production by the Sabatier reaction opens the way of carbon recycling for a circular economy of carbon resources. The catalytic process of methanation of carbon dioxide produces two molecules of water as a by-product. A current limitation in the CO 2 methanation is the ageing of catalysts, mainly due to water adsorption during the process. To avoid this adsorption, the process is operated at high temperature (300 °C–400 °C), leading to carbon deposition on the catalyst and its deactivation. To overcome this problem, a methanation plasma-catalytic process has been developed, which achieves high CO 2 conversion rate (80%), and a selectivity close to 100%, working from room temperature to 150 °C, instead of 300 °C–400 °C for the thermal catalytic process. The main characteristics of this process are high-voltage pulses of few nanoseconds duration, activating the adsorption of CO 2 in bent configuration and the polarization of the catalyst. The key step in this process is the desorption of water from the polarized catalyst. The high CO 2 conversion at low temperature could be explained by the creation of a plasma inside the nanopores of the catalyst. (paper)

  13. Electrocatalytic reduction of carbon dioxide under plasma DBD process

    Science.gov (United States)

    Amouroux, Jacques; Cavadias, Simeon

    2017-11-01

    Carbon dioxide can be converted, by reaction with hydrogen, into fine chemicals and liquid fuels such as methanol and DME. Methane production by the Sabatier reaction opens the way of carbon recycling for a circular economy of carbon resources. The catalytic process of methanation of carbon dioxide produces two molecules of water as a by-product. A current limitation in the CO2 methanation is the ageing of catalysts, mainly due to water adsorption during the process. To avoid this adsorption, the process is operated at high temperature (300 °C-400 °C), leading to carbon deposition on the catalyst and its deactivation. To overcome this problem, a methanation plasma-catalytic process has been developed, which achieves high CO2 conversion rate (80%), and a selectivity close to 100%, working from room temperature to 150 °C, instead of 300 °C-400 °C for the thermal catalytic process. The main characteristics of this process are high-voltage pulses of few nanoseconds duration, activating the adsorption of CO2 in bent configuration and the polarization of the catalyst. The key step in this process is the desorption of water from the polarized catalyst. The high CO2 conversion at low temperature could be explained by the creation of a plasma inside the nanopores of the catalyst.

  14. Carbon dioxide emissions from biochar in soil

    DEFF Research Database (Denmark)

    Bruun, Sander; Clauson-Kaas, Anne Sofie Kjærulff; Bobuľská, L.

    2014-01-01

    The stability of biochar in soil is of importance if it is to be used for carbon sequestration and long-term improvement of soil properties. It is well known that a significant fraction of biochar is highly stable in soil, but carbon dioxide (CO2) is also released immediately after application....... This study investigated the nature of the early release of CO2 and the degree to which stabilizing mechanisms protect biochar from microbial attack. Incubations of 14C-labelled biochar produced at different temperatures were performed in soils with different clay contents and in sterilized and non......-sterilized soils. It emerged that carbonate may be concentrated or form during or after biochar production, resulting in significant carbonate contents. If CO2 released from carbonates in short-term experiments is misinterpreted as mineralization of biochar, the impact of this process may be significantly over...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. Recycling technology of emitted carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hironori [National Inst. of Materials and Chemical Research (NIMC), Ibaraki (Japan)

    1993-12-31

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

  18. Carbon dioxide may become a resource

    International Nuclear Information System (INIS)

    Haugneland, Petter; Areklett, Ivar

    2002-01-01

    The greenhouse gas CO 2 may become a product that the oil companies would pay for. In an extensive international resource project methods for CO 2 capture, transport and storage are being investigated. CO 2 capture means that carbon dioxide that is formed in the combustion of fossil fuels is separated out from the process, either from the fuel (decarbonization), or from the flue gas, and then stored. The article briefly describes the international joint project CO 2 Capture Project (CCP), in which eight oil companies are participating. If one can find a method for injecting CO 2 into oil reservoirs that leads to increased oil production, then part of the extra cost of removing the carbon dioxide from flue gas may be repaid

  19. Hydrogen retention and release from uranium dioxide

    International Nuclear Information System (INIS)

    Sherman, D.F.

    1987-08-01

    The ceramic samples (UO 2 ) are exposed to high pressure hydrogen gas at a fixed temperature for a time sufficient to achieve equilibrium. After rapid quenching, the hydrogen-saturated sample is transferred to a vacuum-outgassing furnace. The sample is outgassed in a linear temperature ramp and the released hydrogen is detected by an in-situ mass spectrometer. This technique measures the rate of release of hydrogen with a sensitivity level of about 2 ng of hydrogen (as D 2 ) per hour. In this study, experiments were conducted on both polycrystalline and single-crystal UO 2 . Experimental variables included temperature (1000 to 1600 0 C) and infusion pressure (5 to 32 atm D 2 ), and for the polycrystalline specimen, stoichiometry. Dissolution of H 2 in both single-crystal and polycrystalline UO 2 was found to obey Seivert's law. The Sievert's law constant of deuterium in single-crystal UO 2 was determined to be: 3.0 x 10 7 exp(-235 kJ/RT) ppM atomic/√atm and for polycrystalline UO 2 : 5.5 x 10 4 exp(-100 kJ/RT) ppM atomic/√atm. The solubility of hydrogen in hypostoichiometric urania was found to be up to three orders of magnitude greater than in stoichiometric UO 2 depending on the O/U ratios, implying the anion vacancy is the primary solution site in the UO 2 lattice. The release-rate curves for the single crystal and polycrystalline UO 2 specimens exhibited multiple peaks, with most of the deuterium released between 600 and 1200 0 C for the polycrystalline samples, and between 700 and 1800 0 C in the single-crystal specimens. This release of hydrogen from UO 2 could not be adequately modeled as diffusion or diffusion with trapping and resolution. It was determined that release was governed by release from traps in both the polycrystalline and single crystal UO 2 specimens. 40 refs., 72 figs., 6 tabs

  20. Direct carbon dioxide emissions from civil aircraft

    OpenAIRE

    Grote, Matt; Williams, Ian; Preston, John

    2014-01-01

    Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories – policy and legal-related measures, and technological and operational measures. Results of the review are used to develop sever...

  1. Dependence of carbon dioxide concentration on microalgal carbon dioxide fixation

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Yeoung Sang; Park, Song Moon [Department of Chemical Engineering, School of Environmental Engineering, Pohang University of Science and Technology, Pohang (Korea); Bolesky, Bohumil [Department of Chemical Engineering, McGill University (Canada)

    1999-10-01

    Batch cultivation of chlorella vulgaris was carried out under various CO{sub 2} concentrations in order to understand and describe mathematically the CO{sub 2} inhibition of microalgal CO{sub 2} fixation. The volumetric CO{sub 2} transfer coefficient from mixture gas to culture medium was estimated from the volumetric O{sub 2} transfer coefficient obtained experimentally. Using this transfer coefficient and aquatic equilibrium relationship between dissolved inorganic carbons, the behavior of dissolved CO{sub 2} was calculated during microalgal culture. When air containing 0.035%(v/v) CO{sub 2} was supplied into microalgal culture, the fixation rate was limited by CO{sub 2} transfer rate. However, the limitation was disappeared by supplying mixture gas containing above 2%(v/v) CO{sub 2} and the dissolved CO{sub 2} concentration was maintained at the saturated value. In the range of CO{sub 2} partial pressure in the flue gases from thermal power sations and steel-making plants, the microalgal CO{sub 2} fixation rate was inhibited. The CO{sub 2} fixation rate was successfully formulated by a new empirical equation as a function of dissolved CO{sub 2} concentration, which could be useful for modeling and simulating the performance of photobioreaction with enriched CO{sub 2}. Also, it was found that the CO{sub 2} inhibition of microalgal CO{sub 2} fixation was reversible and that microalgal CO{sub 2} fixation process could be stable against a shock of unusually high CO{sub 2} concentration. 29 refs., 8 figs.

  2. Electrocatalytic process for carbon dioxide conversion

    Science.gov (United States)

    Masel, Richard I.; Salehi-Khojin, Amin; Kutz, Robert

    2017-11-14

    An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of 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, (COO.sup.-).sub.2, and CF.sub.3COOH.

  3. Carbon dioxide in Arctic and subarctic regions

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-03-01

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

  4. Natural deep eutectic solvents (NADES) as green solvents for carbon dioxide capture

    Science.gov (United States)

    Mulia, Kamarza; Putri, Sylvania; Krisanti, Elsa; Nasruddin

    2017-03-01

    This study was conducted to determine the effectiveness of Natural Deep Eutectic Solvent (NADES), consisting of choline chloride and a hydrogen bonding donor (HBD) compound, in terms of carbon dioxide absorption. Solubility of carbon dioxide in NADES was found to be influenced HBD compound used and choline chloride to HBD ratio, carbon dioxide pressure, and contact time. HBD and choline/HBD ratios used were 1,2-propanediol (1:2), glycerol (1:2), and malic acid (1:1). The carbon dioxide absorption measurement was conducted using an apparatus that utilizes the volumetric method. Absorption curves were obtained up to pressures of 30 bar, showing a linear relationship between the amount absorbed and the final pressure of carbon dioxide. The choline and 1,2-propanediol eutectic mixture absorbs the highest amount of carbon dioxide, approaching 0.1 mole-fraction at 3.0 MPa and 50°C. We found that NADES ability to absorb carbon dioxide correlates with its polarity as tested using Nile Red as a solvatochromic probe.

  5. Supercritical Carbon Dioxide–Based Sterilization of Decellularized Heart Valves

    Directory of Open Access Journals (Sweden)

    Ryan S. Hennessy, MD

    2017-02-01

    Full Text Available Summary: Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid– and supercritical carbon dioxide–treated valves were found to be sterile using histology, microbe culture, and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxide–treated valves were higher compared with valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Key Words: decellularized, decontamination, heart valve, tensile properties, tissue engineering

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  7. Catalytic applications of immobilized ionic liquids for synthesis of cyclic carbonates from carbon dioxide and epoxides

    International Nuclear Information System (INIS)

    Kim, Dong-Woo; Roshan, Roshith; Tharun, Jose; Cherian, Amal; Park, Dae-Won

    2013-01-01

    The catalytic applicability of ionic liquids immobilized on various support materials such as silica, polystyrene and biopolymers in the cycloaddition of carbon dioxide with epoxides is reviewed in this work. Comparisons of the catalytic efficiency of these various catalysts have been done from the aspect of turnover number and reusability. The studies revealed that ionic liquids or support materials possessing hydrogen bonding capable groups exhibited enhanced catalytic activity towards cyclic carbonate synthesis. Moreover, the increased quest towards environmentally benign materials has renewed the search for biocompatible materials as support for ionic liquids

  8. Determination of hydrogen sulphide and sulphur dioxide in a mixture

    International Nuclear Information System (INIS)

    Narayanan, S.S.; Rao, V.R.S.

    1989-01-01

    A method is proposed for the determination of hydrogen sulfide and sulfur dioxide in a mixture. The method is based on the quantitative oxidation of sulfide and sulfite with an excess of radiochloramine-T in alkaline medium (0.1N NaOH). The released chloride activity is proportional to the total amount of sulfide and sulfite present. Addition of 1% CdSO 4 solution to the mixture of sulfide and sulfite precipitates sulfide and sulfite in the filtrate determined by the reagent. From the difference in activities, the amount of sulfide can be calculated. This method can be employed for the determination of hydrogen sulfide and sulfur dioxide in air samples. (author) 11 refs.; 3 tabs

  9. The carbon dioxide thermometer and the cause of global warming

    International Nuclear Information System (INIS)

    Calder, Nigel

    1999-01-01

    Carbon dioxide in the air may be increasing because the world is warming. This possibility, which contradicts the hypothesis of an enhanced greenhouse warming driven by manmade emissions, is here pursued in two ways. First, increments in carbon dioxide are treated as readings of a natural thermometer that tracks global and hemispheric temperature deviations, as gauged by meteorologists' thermometers. Calibration of the carbon dioxide thermometer to conventional temperatures then leads to a history of carbon dioxide since 1856 that diverges from the ice-core record. Secondly, the increments of carbon dioxide can also be accounted for, without reference to temperature, by the combined effects of cosmic rays, El Nino and volcanoes. The most durable effect is due to cosmic rays. A solar wind history, used as a long-term proxy for the cosmic rays, gives a carbon dioxide history similar to that inferred from the global temperature deviations. (author)

  10. Amperometric sensor for carbon dioxide: design, characteristics, and perforance

    International Nuclear Information System (INIS)

    Evans, J.; Pletcher, D.; Warburton, P.R.G.; Gibbs, T.K.

    1989-01-01

    A new sensor for atmospheric carbon dioxide is described. It is an amperometric device based on a porous electrode in a three-electrode cell and the electrolyte is a copper diamine complex in aqueous potassium chloride. The platinum cathode, held at constant potential, is used to detect the formation of Cu 2+ following the change in the pH of the solution when the sensor is exposed to an atmosphere containing carbon dioxide. The sensor described is designed to monitor carbon dioxide concentrations in the range 0-5%, although with some modifications, other ranges would be possible. The response to a change in the carbon dioxide content of the atmosphere is rapid (about 10s) while the monitored current is strongly (but nonlinearly) dependent on carbon dioxide concentration. Unlike other amperometric devices for carbon dioxide, there is no interference from oxygen although other acid gases would lead to an interfering response

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

    International Nuclear Information System (INIS)

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

    1988-01-01

    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

  12. Hydrogen adsorption in new carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Zubizarreta, L.; Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2006-07-01

    Hydrogen physi-sorption on porous carbon materials is one among the different technologies which could be used for hydrogen storage. In addition hydrogen spillover on a carbon supports can enhance the hydrogen adsorption capacities obtained by physi-sorption. In this study two different carbon supports were synthesised: carbon gels and carbon microspheres. Carbon microspheres were doped with Ni(NO{sub 3}){sub 2} to study the hydrogen spillover on carbon support. The texture of the materials was characterised by CO{sub 2} adsorption at 0 C and their hydrogen storage capacity was evaluated at -196 and 10 C with a Micromeritics Tristar 3000, and at room temperature with a high pressure gravimetric analyser. (authors)

  13. Hydrogen adsorption in new carbon materials

    International Nuclear Information System (INIS)

    Zubizarreta, L.; Arenillas, A.; Rubiera, F.; Pis, J.J.

    2006-01-01

    Hydrogen physi-sorption on porous carbon materials is one among the different technologies which could be used for hydrogen storage. In addition hydrogen spillover on a carbon supports can enhance the hydrogen adsorption capacities obtained by physi-sorption. In this study two different carbon supports were synthesised: carbon gels and carbon microspheres. Carbon microspheres were doped with Ni(NO 3 ) 2 to study the hydrogen spillover on carbon support. The texture of the materials was characterised by CO 2 adsorption at 0 C and their hydrogen storage capacity was evaluated at -196 and 10 C with a Micromeritics Tristar 3000, and at room temperature with a high pressure gravimetric analyser. (authors)

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

    OpenAIRE

    Mpho Bosupeng

    2016-01-01

    This study aims to determine the effects of the automotive industry on carbon dioxide emissions for the period from 1997 to 2010 for diverse economies, as well as the relationships between carbon dioxide discharges and output. The study applies cointegration and causality tests to validate these associations. The results of the Johansen cointegration test depict long-run associations between the quantity of passenger cars and carbon dioxide emissions in France, Sweden, Spain, Hungary and Japa...

  15. On reaction of titanium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Malyshev, M.L.; Reznikova, N.F.

    1986-01-01

    The reaction between titanium polonides and carbon dioxide has been studied by comparing titanium polonide thermal resistance in vacuum and in carbon dioxide. The investigation has shown that titanium mono- and semipolonides fail at temperatures below 350 deg C. Temperature dependence of polonium vapor pressure prepared at failure of the given polonides is determined by the radiotensiometry in carbon dioxide. Enthalpy calculated for this dependence is close to the enthalpy of elementary polonium evaporation in vacuum

  16. Supercritical carbon dioxide: a solvent like no other

    Directory of Open Access Journals (Sweden)

    Jocelyn Peach

    2014-08-01

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

  17. Changes in plasma potassium concentration during carbon dioxide pneumoperitoneum

    DEFF Research Database (Denmark)

    Perner, A; Bugge, K; Lyng, K M

    1999-01-01

    Hyperkalaemia with ECG changes had been noted during prolonged carbon dioxide pneumoperitoneum in pigs. We have compared plasma potassium concentrations during surgery in 11 patients allocated randomly to undergo either laparoscopic or open appendectomy and in another 17 patients allocated randomly...... to either carbon dioxide pneumoperitoneum or abdominal wall lifting for laparoscopic colectomy. Despite an increasing metabolic acidosis, prolonged carbon dioxide pneumoperitoneum resulted in only a slight increase in plasma potassium concentrations, which was both statistically and clinically insignificant....... Thus hyperkalaemia is unlikely to develop in patients with normal renal function undergoing carbon dioxide pneumoperitoneum for laparoscopic surgery....

  18. Carbon dioxide absorbent and method of using the same

    Science.gov (United States)

    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.

  19. Carbon dioxide absorbent and method of using the same

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. A two-stage biological gas to liquid transfer process to convert carbon dioxide into bioplastic

    KAUST Repository

    Al Rowaihi, Israa; Kick, Benjamin; Grö tzinger, Stefan W.; Burger, Christian; Karan, Ram; Weuster-Botz, Dirk; Eppinger, Jö rg; Arold, Stefan T.

    2018-01-01

    The fermentation of carbon dioxide (CO2) with hydrogen (H2) uses available low-cost gases to synthesis acetic acid. Here, we present a two-stage biological process that allows the gas to liquid transfer (Bio-GTL) of CO2 into the biopolymer

  1. Multiple-diffusion flame synthesis of pure anatase and carbon-coated titanium dioxide nanoparticles

    KAUST Repository

    Memon, Nasir; Anjum, Dalaver H.; Chung, Suk-Ho

    2013-01-01

    A multi-element diffusion flame burner (MEDB) is useful in the study of flame synthesis of nanomaterials. Here, the growth of pure anatase and carbon-coated titanium dioxide (TiO2) using an MEDB is demonstrated. Hydrogen (H2), oxygen (O2), and argon

  2. Heat transfer coefficient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1998-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The calculated heat transfer coeeficient has been compared with the Chart correlation of Shah. The Chart Correlation predits too low heat transfer coefficient but the ratio...... between the measured and the calculated heat transfer coefficient is nearly constant and equal 1.9. With this factor the correlation predicts the measured data within 14% (RMS). The pressure drop is of the same order as the measuring uncertainty and the pressure drop has not been compared with correlation's....

  3. Carbon Dioxide Mitigation by Microalgal Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mijeong Lee; Gillis, James M.; Hwang, Jiann Yang [Michigan Technological University, Houghton (United States)

    2003-12-15

    Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 μg CO{sub 2}/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

  4. Nuclear energy significantly reduces carbon dioxide emissions

    International Nuclear Information System (INIS)

    Koprda, V.

    2006-01-01

    This article is devoted to nuclear energy, to its acceptability, compatibility and sustainability. Nuclear energy is non-dispensable part of energy sources with vast innovation potential. The safety of nuclear energy, radioactive waste deposition, and prevention of risk from misuse of nuclear material have to be very seriously adjudged and solved. Nuclear energy is one of the ways how to decrease the contamination of atmosphere with carbon dioxide and it solves partially also the problem of global increase of temperature and climate changes. Given are the main factors responsible for the renaissance of nuclear energy. (author)

  5. The carbon dioxide capture and geological storage

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the carbon dioxide capture and geological storage. One possible means of climate change mitigation consists of storing the CO 2 generated by the greenhouse gases emission in order to stabilize atmospheric concentrations. This sheet presents the CO 2 capture from lage fossil-fueled combustion installations, the three capture techniques and the CO 2 transport options, the geological storage of the CO 2 and Total commitments in the domain. (A.L.B.)

  6. INTERACTION OF CARBON DIOXIDE WITH CARBON ADSORBENTS BELOW 400 C

    Energy Technology Data Exchange (ETDEWEB)

    Deitz, V R; Carpenter, F G; Arnold, R G

    1963-06-15

    The adsorption of carbon dioxide on carbon adsorbents (FT carbon, coconut charcoal, acid-washed bone char) and adsorbents containing basic calcium phosphate (hydroxylapatite, bone char, ash of bone char) was studied. Special consideration was given to the pretreatment of the materials. The carbons equilibrated as rapidly as the temperature; the basic calcium phosphates showed a rapid initial adsorption followed by a very slow rate which continued for days. Linear adsorption isotherms were found on FT carbon and the isosteric heats varied slightiy with coverage. The isotherms for the remaining materials had varying curvature and were for the most part in the same sequence as the estimated surface areas. The isosteric heats of carbon dioxide correlated very well with the magnitude of surface hydroxyl groups, an estimate of which was made from the chemical composition. There appeared to be three increasing levels of interaction: (1) pure physical adsorption; (2) an adsorption complex having 'bicarbonate structure'; and (3) an adsorption complex having 'carbonate structure'. (auth)

  7. Catalytic hydrogenation of carbon monoxide

    International Nuclear Information System (INIS)

    Wayland, B.B.

    1993-12-01

    Focus of this project is on developing new approaches for hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. The strategies to accomplish CO reduction are based on favorable thermodynamics manifested by rhodium macrocycles for producing a series of intermediates implicated in the catalytic hydrogenation of CO. Metalloformyl complexes from reactions of H 2 and CO, and CO reductive coupling to form metallo α-diketone species provide alternate routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics are promising candidates for future development

  8. Combined effect of sulfur dioxide and carbon dioxide gases on mold fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kochurova, A.I.; Karpova, T.N.

    1974-01-01

    Sulfur dioxide at 0.08% killed Penicillium expansum, Stemphylium macrosporium, and Botrytis cinerea within 24 hours. At 0.2%, it killed P. citrinum, Alternaria tenuis, and Fusarium moniliforme. Sulfur dioxide (at 0.04%) and Sulfur dioxide-carbon dioxide mixtures (at 0.02 and 5% respectively) completely suppressed the growth of P. citrinum, P. expansum, P. rubrum, A. tenuis, S. macrosporium, B. cinerea, and F. moniliforme in laboratory experiments. 1 table.

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

    Energy Technology Data Exchange (ETDEWEB)

    Avraamides, J.; Senanayake, G.; Clegg, R. [A.J. Parker Cooperative Research Centre for Hydrometallurgy, Murdoch University, Perth, WA 6150 (Australia)

    2006-09-22

    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 2M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25{sup o}C. Alkaline leaching with 6M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30min at 30{sup o}C using 0.1-1.0M 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 1M to 2M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide. (author)

  10. Catalytic hydrogenation of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  11. Methanol absorption characteristics for the removal of H2S (hydrogen sulfide), COS (carbonyl sulfide) and CO2 (carbon dioxide) in a pilot-scale biomass-to-liquid process

    International Nuclear Information System (INIS)

    Seo, Myung Won; Yun, Young Min; Cho, Won Chul; Ra, Ho Won; Yoon, Sang Jun; Lee, Jae Goo; Kim, Yong Ku; Kim, Jae Ho; Lee, See Hoon; Eom, Won Hyun; Lee, Uen Do; Lee, Sang Bong

    2014-01-01

    The BTL (biomass-to-liquid) process is an attractive process that produces liquid biofuels from biomass. The FT (Fisher–Tropsch) process is used to produce synfuels such as diesel and gasoline from gasified biomass. However, the H 2 S (hydrogen sulfide), COS (carbonyl sulfide) and CO 2 (carbon dioxide) in the syngas that are produced from the biomass gasifiers cause a decrease of the conversion efficiency and deactivates the catalyst that is used in the FT process. To remove the acid gases, a pilot-scale methanol absorption tower producing diesel at a rate of 1 BPD (barrel per day) was developed, and the removal characteristics of the acid gases were determined. A total operation time of 500 h was achieved after several campaigns. The average syngas flow rate at the inlet of methanol absorption tower ranged from 300 to 800 L/min. The methanol absorption tower efficiently removed H 2 S from 30 ppmV to less than 1 ppmV and COS from 2 ppmV to less than 1 ppmV with a removal of CO 2 from 20% to 5%. The outlet gas composition adhered to the guidelines for FT reactors. No remaining sulfurous components were found, and the tar component was analyzed in the spent methanol after long-term operations. - Highlights: • The gas cleaning system in a pilot-scale BTL (biomass-to-liquid) process is reported. • Although methanol absorption tower is conventional process, its application to BTL process is attempted. • The methanol absorption tower efficiently removed H 2 S, COS and CO 2 in the syngas. • The sulfurous and tar components in the methanol are analyzed

  12. Analytical study on carbon dioxide reforming of natural gas

    International Nuclear Information System (INIS)

    Ohashi, Hirofumi; Sakaki, Akihiro; Inagaki, Yoshiyuki

    2001-01-01

    In recent years, considerable attention has been paid to carbon dioxide reforming of natural gas, namely CO 2 reforming, since it can produce synthesis gas with low hydrogen-to-carbon ratio preferentially used for production of liquid hydrocarbons in the Fischer-Tropsch and methanol syntheses. This reaction has also very important environmental implications because CO 2 , a green house gas, may be converted into valuable feedstock. In JAERI, CO 2 reforming using the out-of-pile test facility, which is a 1/30 scale model of the HTTR hydrogen production system, is also being considered as an application of steam reforming. For the purpose to estimate the reformer performance in the facility, numerical analysis of natural gas reforming processes of CO 2 and combined reactions with steam and CO 2 has been carried out using mathematical model on heat and mass balance accompanied by chemical reactions. The reformer performance was evaluated in the effect of pressure, temperature, process gas composition and reaction rate constants of the catalyst on conversion, product gas composition and heat consumption of He gas. And also, the potential of carbon formation by CH 4 cracking reaction and Boudouard reaction was estimated. (author)

  13. Existence of both blue-shifting hydrogen bond and Lewis acid-base interaction in the complexes of carbonyls and thiocarbonyls with carbon dioxide.

    Science.gov (United States)

    Nguyen, Tien Trung; Nguyen, Phi Hung; Tran, Thanh Hue; Minh, Tho Nguyen

    2011-08-21

    In this study, 16 gas phase complexes of the pairs of XCHZ and CO(2) (X = F, Cl, Br; Z = O, S) have been identified. Interaction energies calculated at the CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ level including both BSSE and ZPE corrections range from -5.6 to -10.5 kJ mol(-1) for XCHOCO(2) and from -5.7 to -9.1 kJ mol(-1) for XCHS···CO(2). Substitution of one H atom by one halogen in formaldehyde and thioformaldehyde reduces the interaction energy of XCHZ···CO(2), while a CH(3) substitution increases the interaction energy of both CH(3)CHO···CO(2) and CH(3)CHS···CO(2). NBO and AIM analyses also point out that the strength of Lewis acid-base interactions decreases going from >C1=S3···C6 to >C1=O3C6 and to >C1-X4···C6. This result suggests the higher capacity of solubility of thiocarbonyl compounds in scCO(2), providing an enormous potential application for designing CO(2)-philic materials based on the >C=S functional group in competition with >C=O. The Lewis acid-base interaction of the types >C=S···C, >C-Cl···C and >C-Br···C is demonstrated for the first time. The contribution of the hydrogen bonding interaction to the total interaction energy is larger for XCHS···CO(2) than for XCHO···CO(2). Upon complexation, a contraction of the C1-H2 bond length and a blue shift of its stretching frequency have been observed, as compared to the isolated monomer, indicating the existence of a blue-shifting hydrogen bond in all complexes examined. Calculated results also lend further support for the viewpoint that when acting as proton donor, a C-H bond having a weaker polarization will induce a stronger distance contraction and frequency blue shift upon complexation, and vice versa.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Use of supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Masayuki (Niigata Univ., Faculty of Engineering, Niigata, (Japan))

    1989-09-25

    Supercritical fluid extraction is a novel diffusion and separation technique which exploits simultaneously the increase of vapor pressure and the difference of chemical affinities of fluids near the critical point. A solvent which is used as the supercritical fluid has the following features: the critical point exists in the position of relatively ease of handling, the solvent is applicable to the extraction of a physiological active substance of thermal instability. Carbon dioxide as the solvent is non-flammable, non-corrosive, non-toxic, cheap, and readily available of high purity. The results of studies on the use of supercritical carbon dioxide (SC-CO{sub 2}) as a solvent for natural products in the fermentation and food industries, were collected. SC-CO{sub 2} extraction are used in many fields, examples for the application are as follows: removal of organic solvents from antibiotics; extraction of vegetable oils contained in wheat germ oil, high quality mustard seeds, rice bran and so on; brewing of sake using rice and rice-koji; use as a non-aqueous medium for the synthesis of precursors of the Aspartame; and use in sterilization. 66 refs., 17 figs., 21 tabs.

  16. Studies on carbon dioxide power plant, (3)

    International Nuclear Information System (INIS)

    Akagawa, Koji; Fujii, Terushige; Sakaguchi, Tadashi; Kawabata, Yasusuke; Kuroda, Toshihiro.

    1980-01-01

    A power generating plant using carbon dioxide instead of water has been studied by the authors, as high efficiency can be obtained in high temperature range (higher than 650 deg C) and turbines become compact as compared with the Rankine steam cycle. In this paper, the theoretical analysis of the dynamic characteristics of this small power generating plant of supercritical pressure and the comparison with the experimental results are reported. In the theoretical analysis, the linear approximation method using small variation method was adopted for solution. Every component was modeled as the concentrated constant system, and the transfer function for each component was determined, then simulation was carried out for the total system synthesizing these components. The approximation of physical values, and the analysis of a plunger pump, a regenerator, a heater, a vapor valve, a turbine and a blower, piping, and pressure drop are described. The response to the stepwise changes of heating, flow rate, opening of a vapor valve and a load control valve for a blower was investigated. The theoretical anaysis and the experimental results were in good agreement, and this analysis is applicable to the carbon dioxide plant of practical scale. (Kako, I.)

  17. Adaptation to carbon dioxide tax in shipping

    International Nuclear Information System (INIS)

    Olsen, Kristian

    2000-01-01

    This note discusses the consequences for the sea transport sector between Norway and continental Europe of levying a carbon dioxide tax on international bunker. The influence of such a tax on the operational costs of various types of ship and various transport routes is calculated. The profit obtainable from the following ways of adapting to an increased tax level is assessed: (1) Reducing the speed, (2) Rebuilding the engine to decrease fuel consumption, (3) Changing the design speed for new ships. It is found that a carbon dioxide tax of NOK 200 per tonne of CO 2 will increase the transport costs by 3 - 15 percent. In the long run much of this may be transferred to the freight rates since so much of the sea transport are in segments in which the demand for the service is not sensitive to the prices. Even if the freight rates are not changed, a tax this size will not make it necessary to reduce the speed of the existing fleet. The income lost by taking fewer trips will exceed the costs saved in reducing the speed. However, the optimum design speed for new ships may be somewhat reduced (0.5 knots). Rebuilding engines to reduce the fuel consumption would pay off were it not for the fact that the remaining life of the present fleet is probably too short for this to be interesting

  18. Hydrogen Storage in Carbon Nano-materials

    International Nuclear Information System (INIS)

    David Eyler; Michel Junker; Emanuelle Breysse Carraboeuf; Laurent Allidieres; David Guichardot; Fabien Roy; Isabelle Verdier; Edward Mc Rae; Moulay Rachid Babaa; Gilles Flamant; David Luxembourg; Daniel Laplaze; Patrick Achard; Sandrine Berthon-Fabry; David Langohr; Laurent Fulcheri

    2006-01-01

    This paper presents the results of a French project related to hydrogen storage in carbon nano-materials. This 3 years project, co-funded by the ADEME (French Agency for the Environment and the Energy Management), aimed to assess the hydrogen storage capacity of carbon nano-materials. Four different carbon materials were synthesized and characterized in the frame of present project: - Carbon Nano-tubes; - Carbon Nano-fibres; - Carbon Aerogel; - Carbon Black. All materials tested in the frame of this project present a hydrogen uptake of less than 1 wt% (-20 C to 20 C). A state of the art of hydrogen storage systems has been done in order to determine the research trends and the maturity of the different technologies. The choice and design of hydrogen storage systems regarding fuel cell specifications has also been studied. (authors)

  19. Carbon dioxide adsorption in graphene sheets

    Directory of Open Access Journals (Sweden)

    Ashish Kumar Mishra

    2011-09-01

    Full Text Available Control over the CO2 emission via automobiles and industrial exhaust in atmosphere, is one of the major concerns to render environmental friendly milieu. Adsorption can be considered to be one of the more promising methods, offering potential energy savings compared to absorbent systems. Different carbon nanostructures (activated carbon and carbon nanotubes have attracted attention as CO2 adsorbents due to their unique surface morphology. In the present work, we have demonstrated the CO2 adsorption capacity of graphene, prepared via hydrogen induced exfoliation of graphitic oxide at moderate temperatures. The CO2 adsorption study was performed using high pressure Sieverts apparatus and capacity was calculated by gas equation using van der Waals corrections. Physical adsorption of CO2 molecules in graphene was confirmed by FTIR study. Synthesis of graphene sheets via hydrogen exfoliation is possible at large scale and lower cost and higher adsorption capacity of as prepared graphene compared to other carbon nanostructures suggests its possible use as CO2 adsorbent for industrial application. Maximum adsorption capacity of 21.6 mmole/g was observed at 11 bar pressure and room temperature (25 ºC.

  20. The effect of cutting on carbon dioxide absorption and carbohydrate ...

    African Journals Online (AJOL)

    grass) and Osteospermun sinuatum (Karoo-bush) plants during the flag leaf and flower bud stages respectively resulted in a sharp decline in net carbon dioxide absorption. As new photosynthetic material was produced the total carbon ...

  1. Robust optical carbon dioxide isotope analyzer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Isotopic analysis of carbon dioxide is an important tool for characterization of the exchange and transformation of carbon between the biosphere and the atmosphere....

  2. Carbon dioxide effects research and assessment program

    International Nuclear Information System (INIS)

    Jacoby, G.

    1980-12-01

    Information about the past and present concentrations of CO 2 in the atmosphere and variations in climate can be obtained from measurements of stable isotopes in tree rings; specifically carbon-13, oxygen-18 and deuterium. The analysis of these stable isotopes in tree rings is a relatively new and rapidly developing field. This proceedings volume contains most of the papers presented at the meeting. The first paper gives an overview of the status of carbon-13 research. Papers relating to carbon-13 are in section I and grouped separately from the contributions on carbon-14. Although the meeting was primarily concerned with stable isotopes, all carbon isotopic analysis may be helpful in understanding the carbon-13 record in tree rings. The papers on hydrogen and oxygen isotope studies are in sections II and III respectively. The remaining sections contain papers that consider more than one isotope at a time, general topics related to isotopes, atmospheric changes and tree growth, and methods of isotopic analysis

  3. Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

    Science.gov (United States)

    Long, H. E.; Waldron, S.; Hoey, T.; Newton, J.; Quemin, S.

    2013-12-01

    Intensive research has been undertaken on carbon dioxide efflux from lakes, estuaries and oceans, but much less attention has been given to rivers and streams, especially lower order streams. River systems are often over-saturated with carbon dioxide and so tend to act as sources of carbon dioxide to the atmosphere. It has been thought that rivers act as pipes carrying this terrestrial carbon to the oceans. However, recent studies have shown that a significant amount of the carbon is reprocessed within the system in a series of transformations and losses. Fluvial evasion of carbon dioxide is now recognised to be a significant component of carbon cycles, however the factors controlling carbon dioxide efflux and its magnitude remain poorly understood and quantified. This research aims to quantify, and better understand the controls on, freshwater carbon dioxide evasion. Data are presented here from field measurements that commenced in Sept 2013 in two contrasting Scottish rivers: the River Kelvin which has a large (335 km.sq) part-urban catchment with predominantly non-peat soils and Drumtee Water, a small (9.6 km.sq) rural catchment of peat soils and agricultural land. Using a floating chamber with the headspace connected to an infrared gas analyser to measure changes in carbon dioxide concentration, efflux rates from 0.22 - 47.4 μmol CO2/m.sq/sec were measured, these close to the middle of the range of previously reported values. At one site on the River Kelvin in May 2013 an influx of -0.61 - -3.53 μmol CO2/m.sq/sec was recorded. Whereas previous research finds carbon dioxide efflux to increase with decreasing river size and a more organic-rich soil catchment, here the controls on carbon dioxide evasion are similar across the contrasting catchments. Carbon dioxide evasion shows seasonality, with maximum fluxes in the summer months being up to twice as high as the winter maxima. Linear regression demonstrates that evasion increases with increased flow velocity

  4. Effect of carbon dioxide on the rate of iodine vapor absorption by aqueous solution of sodium hydroxide

    International Nuclear Information System (INIS)

    Eguchi, Wataru; Adachi, Motonari; Miyake, Yoshikazu

    1978-01-01

    There is always carbon dioxide in the atmosphere as an impurity. Since this is an acid gas similar to iodine, each absorption rate seems to be affected by the other due to the coexistence of these two. Experiments have been conducted to clarify the absorption rate and absorption mechanism of iodine in the simultaneous absorption of iodine and carbon dioxide. Carbon dioxide coexisting with gas phases as an impurity decreases the absorption rate of iodine in the removal by washing with water of iodine mixed in the air. The first cause of this is that the diffusion coefficient of iodine in gas phase decreases with the carbon dioxide content in the gas phase. The second cause is that coexistent carbon dioxide is an acid gas, dissociates by dissolving into the absorbing solution, increases hydrogen ion concentration together with the formation of negative ions of bicarbonate and carbonate, and reduces hydroxyl ion concentration as a result. It is more important that existence of iodine has a catalytic effect to the rate of basic catalytic hydrolysis of carbon dioxide simultaneously dissolved in water phase, and accelerates this reaction rate. The mechanism of catalytic effect of iodine for the hydrolysis of carbon dioxide can not be clarified in detail only by this experiment, but the simultaneous absorption rate of iodine and carbon dioxide can be explained satisfactorily. (Wakatsuki, Y

  5. Carbon monoxide and carbon dioxide interaction with tantalum

    International Nuclear Information System (INIS)

    Belov, V.D.; Ustinov, Yu.K.; Komar, A.P.

    1978-01-01

    The adsorption of carbon monoxide and carbon dioxide on tantalum and the dissolution of these gases in the adsorbent at T >= 300 K have been studied. The flash-filament method (FFM) in a monopole mass-spectrometer and a field emission microscopy was used in the same apparatus. Carbon monoxide and carbon dioxide dissociate on the tantalum surface, carbon monoxide being desorbed in both cases during the flash. The desorption curves of CO reveal three different binding states: two of them (α and β' 1 ) for the adsorbed particles whereas the high temperature desorption state relates to the adsorbate dissolved in the metal. For the β' 1 state of CO the activation energy, the pre-exponential factor and the kinetic order in the kinetic equation of desorption have been estimated. They turned out to be E = 110 kcal/mol, C = 3 X 10 12 sec -1 , and γ = 1. The activation energy of diffusion for CO in tantalum and the energy of outgassing for the metal were found to be 9.4 and 49 kcal/mole, respectively. (Auth.)

  6. Carbon monoxide and carbon dioxide interaction with tantalum

    Energy Technology Data Exchange (ETDEWEB)

    Belov, V D; USTINOV, YU K; KOMAR, A P [AN SSSR, LENINGRAD. FIZIKO-TEKHNICHESKIJ INST.

    1978-03-01

    The adsorption of carbon monoxide and carbon dioxide on tantalum and the dissolution of these gases in the adsorbent at T >= 300 K have been studied. The flash-filament method (FFM) in a monopole mass-spectrometer and a field emission microscopy was used in the same apparatus. Carbon monoxide and carbon dioxide dissociate on the tantalum surface, carbon monoxide being desorbed in both cases during the flash. The desorption curves of CO reveal three different binding states: two of them (..cap alpha.. and ..beta..'/sub 1/) for the adsorbed particles whereas the high temperature desorption state relates to the adsorbate dissolved in the metal. For the ..beta..'/sub 1/ state of CO the activation energy, the pre-exponential factor and the kinetic order in the kinetic equation of desorption have been estimated. They turned out to be E = 110 kcal/mol, C = 3 X 10/sup 12/ sec/sup -1/, and ..gamma.. = 1. The activation energy of diffusion for CO in tantalum and the energy of outgassing for the metal were found to be 9.4 and 49 kcal/mole, respectively.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...

  8. Carbon Dioxide and Global Warming: A Failed Experiment

    Science.gov (United States)

    Ribeiro, Carla

    2014-01-01

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

  9. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  10. Model studies of limitation of carbon dioxide emissions reduction

    International Nuclear Information System (INIS)

    1992-01-01

    The report consists of two papers concerning mitigation of CO 2 emissions in Sweden, ''Limitation of carbon dioxide emissions. Socio-economic effects and the importance of international coordination'', and ''Model calculations for Sweden's energy system with carbon dioxide limitations''. Separate abstracts were prepared for both of the papers

  11. Balance and forecasts of french carbon dioxide emissions

    International Nuclear Information System (INIS)

    1992-11-01

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

  12. Storage of hydrogen in nanostructured carbon materials

    OpenAIRE

    Yürüm, Yuda; Yurum, Yuda; Taralp, Alpay; Veziroğlu, T. Nejat; Veziroglu, T. Nejat

    2009-01-01

    Recent developments focusing on novel hydrogen storage media have helped to benchmark nanostructured carbon materials as one of the ongoing strategic research areas in science and technology. In particular, certain microporous carbon powders, carbon nanomaterials, and specifically carbon nanotubes stand to deliver unparalleled performance as the next generation of base materials for storing hydrogen. Accordingly, the main goal of this report is to overview the challenges, distinguishing trait...

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

    Directory of Open Access Journals (Sweden)

    Mpho Bosupeng

    2016-05-01

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

  14. Carbon dioxide for enhanced oil recovery in Canada

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, S.; Manbybura, F.; Sparks, N.

    1985-01-01

    This paper examines the potential for carbon dioxide as a major miscible solvent in Canada and describes Shell Canada's carbon dioxide exploration efforts over the last few years. Enhanced oil recovery, specifically miscible flooding, has been recognized as a technically and economically feasible method for adding reserves and productive capacity to Canada's light and medium oil. The fiscal regime has been altered by both the federal and provincial governments to encourage miscible flooding development. As a result many projects have been initiated with others being evaluated and designed. This paper analyzes the history and the direction of miscible flooding in the United States, where carbon dioxide is becoming the predominant miscible solvent. The potential for future use of carbon dioxide in Canada is specifically addressed: potential oil recovery solvent supply, and economics. Shell's carbon dioxide exploration play currently underway is also discussed.

  15. Carbon dioxide from fossil fuels: adapting to uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Chen, K; Winter, R C; Bergman, M K

    1980-12-01

    If present scientific information is reasonable, the world is likely to experience noticeable global warming by the beginning of the next century if high annual growth rates of fossil-fuel energy use continue. Only with optimistic assumptions and low growth rates will carbon-dioxide-induced temperature increases be held below 2/sup 0/C or so over the next century. Conservation, flexible energy choices, and control options could lessen the potential effects of carbon dioxide. Though perhaps impractical from the standpoint of costs and efficiency losses, large coastal centralized facilities would be the most amenable to carbon dioxide control and disposal. Yet no country can control carbon dioxide levels unilaterally. The USA, however, which currently contributes over a quarter of all fossil-fuel carbon dioxide emissions and possesses a quarter of the world's coal resources, could provide a much needed role in leadership, research and education. 70 references.

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

    Science.gov (United States)

    Colt, John; Watten, Barnaby; Pfeiffer, Tim

    2012-01-01

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

  17. Carbon dioxide absorbent and method of using the same

    Science.gov (United States)

    Perry, Robert James [Niskayuna, NY; Lewis, Larry Neil [Scotia, NY; O'Brien, Michael Joseph [Clifton Park, NY; Soloveichik, Grigorii Lev [Latham, NY; Kniajanski, Sergei [Clifton Park, NY; Lam, Tunchiao Hubert [Clifton Park, NY; Lee, Julia Lam [Niskayuna, NY; Rubinsztajn, Malgorzata Iwona [Ballston Spa, NY

    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.

  18. Carbon Dioxide Detection and Indoor Air Quality Control.

    Science.gov (United States)

    Bonino, Steve

    2016-04-01

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

  19. Difficult colonoscopy: air, carbon dioxide, or water insufflation?

    Science.gov (United States)

    Chaubal, Alisha; Pandey, Vikas; Patel, Ruchir; Poddar, Prateik; Phadke, Aniruddha; Ingle, Meghraj; Sawant, Prabha

    2018-04-01

    This study aimed to compare tolerance to air, carbon dioxide, or water insufflation in patients with anticipated difficult colonoscopy (young, thin, obese individuals, and patients with prior abdominal surgery or irradiation). Patients with body mass index (BMI) less than 18 kg/m 2 or more than 30 kg/m 2 , or who had undergone previous abdominal or pelvic surgeries were randomized to air, carbon dioxide, or water insufflation during colonoscopy. The primary endpoint was cecal intubation with mild pain (less than 5 on visual analogue scale [VAS]), without use of sedation. The primary end point was achieved in 32.7%, 43.8%, and 84.9% of cases with air, carbon dioxide and water insufflation ( P carbon dioxide, and water insufflation ( P carbon dioxide for pain tolerance. This was seen in the subgroups with BMI 30 kg/m 2 .

  20. New technology for carbon dioxide at high pressure

    International Nuclear Information System (INIS)

    Hassina, Bazaze; Raouf, Zehioua; Menial, A. H.

    2006-01-01

    Carbon dioxide has long been the nemesis of environmentalists because of its role in global warming, but under just the right conditions-namely, high pressure and high temperature its one of nature's best and most environmentally benign solvents. Decaf-coffee lovers, for instance, benefit from its ability to remove caffeine from coffee beans.During the last few years, carbon dioxide has also made inroads in the dry-cleaning industry, providing a safe cleaning alternative to the chemical perchloroethylene. But it's on the high-tech front that carbon dioxide may make its biggest impact. T here are huge opportunities. Scientists have known for more than a century that at 75 times atmospheric pressure and 31 degree centigrade, carbon dioxide goes into and odd state that chemists called s upercritical . What's interesting to industry is that supercritical carbon dioxide may be an enabling technology for going to smaller dimensions.(Author)

  1. Carbon Dioxide Reduction Post-Processing Sub-System Development

    Science.gov (United States)

    Abney, Morgan B.; Miller, Lee A.; Greenwood, Zachary; Barton, Katherine

    2012-01-01

    The state-of-the-art Carbon Dioxide (CO2) Reduction Assembly (CRA) on the International Space Station (ISS) facilitates the recovery of oxygen from metabolic CO2. The CRA utilizes the Sabatier process to produce water with methane as a byproduct. The methane is currently vented overboard as a waste product. Because the CRA relies on hydrogen for oxygen recovery, the loss of methane ultimately results in a loss of oxygen. For missions beyond low earth orbit, it will prove essential to maximize oxygen recovery. For this purpose, NASA is exploring an integrated post-processor system to recover hydrogen from CRA methane. The post-processor, called a Plasma Pyrolysis Assembly (PPA) partially pyrolyzes methane to recover hydrogen with acetylene as a byproduct. In-flight operation of post-processor will require a Methane Purification Assembly (MePA) and an Acetylene Separation Assembly (ASepA). Recent efforts have focused on the design, fabrication, and testing of these components. The results and conclusions of these efforts will be discussed as well as future plans.

  2. Carbon dioxide emission from bamboo culms.

    Science.gov (United States)

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

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  3. Systematic framework for carbon dioxide capture and utilization processes to reduce the global carbon dioxide emissions

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Plaza, Cristina Calvera; Gani, Rafiqul

    information-data on various carbon dioxide emission sources and available capture-utilization technologies; the model and solution libraries [2]; and the generic 3-stage approach for determining more sustainable solutions [3] through superstructure (processing networks) based optimization – adopted for global...... need to provide, amongst other options: useful data from in-house databases on carbon dioxide emission sources; mathematical models from a library of process-property models; numerical solvers from library of implemented solvers; and, work-flows and data-flows for different benefit scenarios...... to be investigated. It is useful to start by developing a prototype framework and then augmenting its application range by increasing the contents of its databases, libraries and work-flows and data-flows. The objective is to present such a prototype framework with its implemented database containing collected...

  4. Miniaturized remission sensor for carbon dioxide detection

    International Nuclear Information System (INIS)

    Martan, T; Will, M

    2010-01-01

    Recently, optical sensors for detection of carbon dioxide (CO 2 ) have been explored for variety of applications in chemistry, industry, and medicine. This paper deals with the development of a planar optical remission sensor employing a dye immobilized in a polymer layer designed for gaseous CO 2 detection. The principle of CO 2 detection was based on colour changes of Tetraethylammonium Cresol red immobilized in a special composed polymer layer that was irradiated by LED diodes. Absorption properties of the dye were changed due to its chemical reaction with CO 2 and corresponding colour changes were detected by PIN diodes. These changes were analyzed by using a PC-controlled board connected by USB. The sensitivity, response time, and the detection limit of the remission sensor were characterized.

  5. Carbon dioxide: Global warning for nephrologists.

    Science.gov (United States)

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

    2016-09-06

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

  6. Carbon dioxide neutral, integrated biofuel facility

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2010-12-15

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO{sub 2} from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce biodiesel, can result in an integrated, economical, large-scale process for biofuel production. Each bioreactor acts as an electrode for a coupled complete microbial fuel cell system; the integrated cultures produce electricity that is consumed as an energy source within the process. Finally, both the produced yeast and spent algae biomass can be used as added value byproducts in the feed or food industries. Using cost and revenue estimations, an IRR of up to 25% is calculated using a 5 year project lifespan. (author)

  7. Carbon dioxide removal with inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  8. Heat transfer coeffcient for boiling carbon dioxide

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik

    1997-01-01

    Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The pipe is heated by condensing R22 outside the pipe. The heat input is supplied by an electrical heater wich evaporates the R22. With the heat flux assumed constant over...... the whole surface and with measured temperature difference between the inner surface and the evaporation temperature a mean heat transfer coefficient is calculated. The calculated heat transfer coefficient has been compared with the Chart Correlation of Shah. The Chart Correlation predicts too low heat...... transfer coefficient but the ratio between the measured and the calculated heat transfer coefficient is nearly constant and equal 1.9. With this factor the correlation predicts the measured data within 14% (RMS). The pressure drop is of the same order as the measuring uncertainty and the pressure drop has...

  9. Carbon Dioxide in Arable Soil Profiles

    DEFF Research Database (Denmark)

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

    2014-01-01

    on the comparability of results obtained using different methods is limited. We therefore aimed to compare the dynamics in soil CO2 concentrations obtained from an automated system (GMP343 sensors) to those from a manually operated measurement system (i.e., soil gas sampled using stainless steel needles and rods......Carbon dioxide (CO2) concentrations in arable soil profiles are influenced by autotrophic and heterotrophic respiration as well as soil physical properties that regulate gas transport. Whereas different methods have been used to assess dynamics of soil CO2 concentrations, our understanding...... systems. Within the measurement range for the GMP343 sensors (0-20,000 ppm), mean results from the two systems were similar within the plough layer at the upslope (P = 0.060) and footslope (P = 0.139) position, and also below the plough layer at the upslope position (P = 0.795). However, results from...

  10. Coiled tubing drilling with supercritical carbon dioxide

    Science.gov (United States)

    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.

  11. The application of the zeolyte powder for the construction of the dense composite membranes for the carbon-dioxide separation

    Directory of Open Access Journals (Sweden)

    Nedeljković Dragutin M.

    2015-01-01

    Full Text Available The main task of the work is to construct the polymeric membrane that could be used for the waste gases treatment. For this purpose, membrane must have high permeability for the carbon dioxide and low permeability of the other gases commonly present in waste gases (hydrogen, oxygen, nitrogen and methane. The constructed membranes were of a dense type, based on a solubility/diffusivity mechanism. In order to enchase the permeability of carbon dioxide, four different zeolytes were added, and in order to improve mechanical stability two different additives were tested. Three zeolytes were with the 3-dimensional pores (ZSM5; Faujasite Linde type A and one was with the 1-dimensional pores (Linde type L. As an additive, n-tetradecyldimethylamonium bromide - n-C14TMABr was tested. The aim of an additive was to provide good wetting of a highly electrically charged zeolyte particle by the hydrophobic polymer chains. The other examined additive was dimethylaminopyridine (DMAP which should improve the solubility of carbon dioxide due to its alkali properties. The best results in carbon dioxide/hydrogen selectivity and permeability were obtained with the membrane constructed with PEBAX 1657 and surface treated zeolyte. The obtained permeability of carbon dioxide was 128 Barrer, and the carbon dioxide/hydrogen selectivity was 9.7.

  12. Carbon Dioxide Mitigation Benefit of High-Speed Railway in Terms of Carbon Tax

    Directory of Open Access Journals (Sweden)

    Fu Yanbing

    2013-01-01

    Full Text Available This paper calculates the carbon dioxide mitigation benefit of high-speed railway based on the carbon dioxide tax policy. We define the carbon dioxide emission system boundary for high-speed railway in its whole life cycle and estimate the life cycle carbon dioxide inventories during its construction, application, and recovery stages. And then we establish a theoretical model to calculate the life cycle carbon dioxide mitigation quantity for high-speed railway when compared with road transport and then calculate its carbon dioxide mitigation benefit. The numerical example shows that the carbon dioxide mitigation benefit of high-speed railway is better than that of road transport from the whole life cycle perspective.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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.

  14. Amazon River carbon dioxide outgassing fuelled by wetlands

    NARCIS (Netherlands)

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

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle(1). A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial

  15. Absorption of carbon dioxide and isotope exchange rate of carbon in a reaction system between carbon dioxide and carbamic acid

    International Nuclear Information System (INIS)

    Takeshita, Kenji; Kitamoto, Asashi

    1985-01-01

    The performance of isotope separation of carbon-13 by chemical exchange between carbon dioxide and carbamic acid was studied. The working fluid used in the study was a solution of DNBA, (C 4 H 9 ) 2 NH and n-octane mixture. Factors related to the isotope exchange rate were measured, such as the absorption rate of carbon dioxide into the solution of DNBA and n-octane, the isotope exchange rate and the separation factor in the reaction between CO 2 and carbamic acid. The absorption of CO 2 into the working fluid was the sum of chemical absorption by DNBA and physical absorption by n-octane. The absorption of carbon dioxide into the working fluid was negligible at temperatures over 90 0 C, but increased gradually at lower temperatures. Carbon dioxide was absorbed into DNBA by chemical absorption, and DNBA was converted to carbamic acid by the reaction. The reaction for synthesis and decomposition of carbamic acid was reversible. The separation factor in equilibrium reached a large value at lower temperatures. The isotope exchange rate between gas and liquid was proportional to the product of the concentration of carbamic acid and the concentration of CO 2 by physical absorption. The isotope separation of carbon by chemical exchange reaction is better operated under the conditions of lower temperature and higher pressure. (author)

  16. Air-sea exchange of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, D C.E.; De Baar, H J.W.; De Jong, E; Koning, F A [Netherlands Institute for Sea Research NIOZ, Den Burg Texel (Netherlands)

    1996-12-31

    The greenhouse gas carbon dioxide is emitted by anthropogenic activities. The oceans presumably serve as a net sink for 17 to 39% of these emissions. The objective of this project is to quantify more accurately the locality, seasonality and magnitude of the net air-sea flux of CO2 with emphasis on the South Atlantic Ocean. In situ measurements of the fugacity of CO2 in surface water and marine air, of total dissolved inorganic carbon, alkalinity and of air-sea exchange of CO2 have been made at four Atlantic crossings, in the Southern Ocean, in a Norwegian fjord and in the Dutch coastal zone. Skin temperature was detected during several of the cruises. The data collected in the course of the project support and refine previous findings. Variability of dissolved CO2 in surface water is related in a complex way to biological and physical factors. The carbonate equilibria cause dissolved gaseous CO2 to react in an intricate manner to disturbances. Dissolved gaseous CO2 hardly ever attains equilibrium with the atmospheric CO2 content by means of air-sea exchange, before a new disturbance occurs. Surface water fCO2 changes could be separated in those caused by seasonal warming and those by biological uptake in a Southern Ocean spring. Incorporation of a thermal skin effect and a change of the wind speed interval strongly increased the small net oceanic uptake for the area. The Atlantic crossings point to a relationship between water mass history and surface water CO2 characteristics. In particular, current flow and related heat fluxes leave their imprint on the concentration dissolved gaseous CO2 and on air-sea exchange. In the Dutch coastal zone hydrography and inorganic carbon characteristics of the water were heterogeneous, which yielded variable air-sea exchange of CO2. figs., tabs., refs.

  17. Formic Acid Manufacture: Carbon Dioxide Utilization Alternatives

    Directory of Open Access Journals (Sweden)

    Marta Rumayor

    2018-06-01

    Full Text Available Carbon dioxide (CO2 utilization alternatives for manufacturing formic acid (FA such as electrochemical reduction (ER or homogeneous catalysis of CO2 and H2 could be efficient options for developing more environmentally-friendly production alternatives to FA fossil-dependant production. However, these alternatives are currently found at different technological readiness levels (TRLs, and some remaining technical challenges need to be overcome to achieve at least carbon-even FA compared to the commercial process, especially ER of CO2, which is still farther from its industrial application. The main technical limitations inherited by FA production by ER are the low FA concentration achieved and the high overpotentials required, which involve high consumptions of energy (ER cell and steam (distillation. In this study, a comparison in terms of carbon footprints (CF using the Life Cycle Assessment (LCA tool was done to evaluate the potential technological challenges assuring the environmental competitiveness of the FA production by ER of CO2. The CF of the FA conventional production were used as a benchmark, as well as the CF of a simulated plant based on homogeneous catalysts of CO2 and H2 (found closer to be commercial. Renewable energy utilization as PV solar for the reaction is essential to achieve a carbon-even product; however, the CF benefits are still negligible due to the enormous contribution of the steam produced by natural gas (purification stage. Some ER reactor configurations, plus a recirculation mode, could achieve an even CF versus commercial process. It was demonstrated that the ER alternatives could lead to lower natural resources consumption (mainly, natural gas and heavy fuel oil compared to the commercial process, which is a noticeable advantage in environmental sustainability terms.

  18. Modeling and calculation of open carbon dioxide refrigeration system

    International Nuclear Information System (INIS)

    Cai, Yufei; Zhu, Chunling; Jiang, Yanlong; Shi, Hong

    2015-01-01

    Highlights: • A model of open refrigeration system is developed. • The state of CO 2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO 2 has little relation to the state of CO 2 . • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

  19. The formation of ethane from carbon dioxide under cold plasma

    International Nuclear Information System (INIS)

    Zhang Xiuling; Zhang Lin; Dai Bin; Gong Weimin; Liu Changhou

    2001-01-01

    Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increasing in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increasing in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane, carbon dioxide and the yield of acetylene, and induces carbon deposit as well

  20. Forest management techniques for carbon dioxide storage

    Energy Technology Data Exchange (ETDEWEB)

    Fujimori, Takao [Forestry and Forest Products Research Inst., Tsukuba, Ibaraki (Japan)

    1993-12-31

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

  1. Hydrogen storage property of nanoporous carbon aerogels

    International Nuclear Information System (INIS)

    Shen Jun; Liu Nianping; Ouyang Ling; Zhou Bin; Wu Guangming; Ni Xingyuan; Zhang Zhihua

    2011-01-01

    Carbon aerogels were prepared from resorcinol and formaldehyde via sol-gel process, high temperature carbonization and atmospheric pressure drying technology with solvent replacement. By changing the resorcinol-sodium carbonate molar ratio and the mass fraction of the reactants,resorcinol and formaldehyde, the pore structure of carbon aerogels can be controlled and the palladium-doped carbon aerogels were prepared.By transmission electron microscopy (TEM), X-ray diffraction (XRD) spectra, it is confirmed that the Pd exists in the skeleton structure of carbon aerogels as a form of nano simple substance pellet. The specific surface area is successfully raised by 2 times, and palladium-doped carbon aerogels with a specific surface area of 1 273 m 2 /g have been obtained by carrying out the activation process as the post-processing to the doped carbon aerogels. The hydrogen adsorption results show that the saturated hydrogen storage mass fraction of the carbon aerogels with the specific surface area of 3 212 m 2 /g is 3% in the condition of 92 K, 3.5 MPa, and 0.84% in the condition of 303 K, 3.2 MPa. In addition, the hydrogen adsorption test of palladium-doped carbon aerogels at room temperature (303 K) shows that the total hydrogen storage capacity of doped carbon aerogels is declined due to the relative small specific surface, but the hydrogen storage of unit specific surface area is enhanced. (authors)

  2. Kinetics of absorption of carbon dioxide in aqueous amine and carbonate solutions with carbonic anhydrase

    NARCIS (Netherlands)

    Penders-van Elk, Nathalie J. M. C.; Hamborg, Espen S.; Huttenhuis, Patrick J. G.; Fradette, Sylvie; Carley, Jonathan A.; Versteeg, Geert F.

    In the present work the absorption of carbon dioxide in aqueous N-methyldiethanolamine (MDEA) and aqueous sodium carbonate with and without carbonic anhydrase (CA) was studied in a stirred cell contactor in the temperature range 298-333 K. The CA was present as free enzyme and is compared to the

  3. Chemoselective alternating copolymerization of limonene dioxide and carbon dioxide : a new highly functional aliphatic epoxy polycarbonate

    NARCIS (Netherlands)

    Li, C.; Sablong, R.J.; Koning, C.E.

    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

  4. Investigation of the adsorption of water vapor and carbon dioxide by KA zeolite

    International Nuclear Information System (INIS)

    Khanitonov, V.P.; Shtein, A.S.

    1984-01-01

    According to the present data, KA zeolite, which can adsorb only water vapor, helium, and hydrogen, has the greatest selectivity in drying. The feasibility of using this zeolite in devices for selective drying of gases used in gas-analysis systems was studied. The results of the experiments were approximated by the thermal equation of the theory of bulk filling of micropores. The limiting value of the adsorption depends on the temperature, and it can be calculated according to the density of the adsorbed phase and the adsorption volume. The critical diameters of the water and carbon dioxide molecules are close to the dimensions of the KA-zeolite pores, something that determines the activated nature of the adsorption of these substances. Experiments on coadsorption of water vapor and carbon dioxide by a fixed bed of KA-zeolite under dynamic conditions showed that the adsorption of these substances has a frontal nature. The time of the protective action of the layer of zeolite during adsorption af water vapor exceeded by more than an order the time of the protective action during adsorption of carbon dioxide. The results showed that this adsorbent can be used for selective drying of gas mixtures containing carbon dioxide in batch-operation devices. Beforehand, the adsorbent should be regenerated with respect to moisture, and then it should be saturated with carbon dioxide by blowing the adsorbent with a gas mixture of the working composition until the equilibrium state is reached

  5. Carbon dioxide fluid-flow modeling and injectivity calculations

    Science.gov (United States)

    Burke, Lauri

    2011-01-01

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

  6. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Chen, Y.H.; Chikindas, M.L.

    2000-01-01

    This paper examines the synergistic action of carbon dioxide and nisin on Listeria monocytogenes Scott A wild-type and nisin-resistant (Nis(r)) cells grown in broth at 4 degrees C. Carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree...... for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic membrane...

  7. Production and emission of methane and carbon dioxide by ruminants

    International Nuclear Information System (INIS)

    Chouinard, Y.

    2003-01-01

    Animal digestion is responsible for the production of both carbon dioxide and methane, while breathing produces only carbon dioxide. The author described the digestion mechanism of ruminants, explaining that they produce higher levels of methane and carbon dioxide than other animals. Fermentation stoichiometry of ruminants was also discussed along with the influence that diet has on methane production. It was noted that methane production can be decreased by increasing animal productivity, or by using ionophore antibiotics and long chain fatty acids. Test results from each of these methods have revealed side effects and none appears to be applicable for the time being. 10 refs., 1 tab., 1 fig

  8. Interaction of titanium and vanadium with carbon dioxide under heating

    International Nuclear Information System (INIS)

    Vlasyuk, R.Z.; Kurovskij, V.Ya.; Lyapunov, V.P.; Radomysel'skij, I.D.

    1986-01-01

    The methods of gravitmetric and X-ray phase analysis as well as analysis of composition of gases in the heating chamber have been used to investigate the mechanism of titanium and vanadium interaction with carbon dioxide in the 300-1000 deg C temperature range. The analogy of mechanisms of the interaction of titanium and vanadium with carbon dioxide in oxides production on the metal surface with subsequent carbidizing treatment at temperatures above 800 deg C is shown. Temperature limits of material operation on the base of titanium or vanadium in carbon dioxide must not exceed 400 or 600 deg C, respectively

  9. Understanding how individuals perceive carbon dioxide. Implications for acceptance of carbon dioxide capture and storage

    Energy Technology Data Exchange (ETDEWEB)

    Itaoka, K.; Saito, A. [Mizuho Information and Research Institute, Tokyo (Japan); Paukovic, M.; De Best-Waldhober, M. [ECN Policy Studies, Petten (Netherlands); Dowd, A.M.; Jeanneret, T.; Ashworth, P.; James, M. [The Global CCS Institute, Canberra (Australia)

    2012-06-15

    Carbon dioxide capture and storage (CCS) presents one potential technological solution for mitigating the atmospheric emission of carbon dioxide sources. However, CCS is a relatively new technology with associated uncertainties and perceived risks. For this reason, a growing body of research now focuses on public perceptions and potential for societal acceptance of CCS technology. Almost all explanations of CCS technology make reference to carbon dioxide, with an assumption that the general public understands CO2. It has become apparent that the general public’s knowledge and understanding of CO2’s properties influences how they engage with CO2 emitting industries and CCS technologies. However, surprisingly little research has investigated public perceptions, knowledge, and understanding of CO2. This investigation attempts to fill that gap. This report describes an investigation of how citizens of three countries (Japan, Australia, and the Netherlands) perceive CO2. Furthermore, it attempts to relate individual perceptions of CO2 to perceptions of CCS, and to determine how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards low carbon energy options, particularly CCS. In brief, the research had four ultimate aims. It aimed to: Explore the public’s knowledge and understanding of the properties of CO2; Examine the influence of that knowledge on their perceptions of CO2 and CCS; Investigate how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards CCS; and Identify if any differences between countries exist in relation to values and beliefs, knowledge of CO2’s properties, and CCS perceptions.

  10. Incorporation of catalytic dehydrogenation into Fischer-Tropsch synthesis to lower carbon dioxide emissions

    Science.gov (United States)

    Huffman, Gerald P

    2012-09-18

    A method for producing liquid fuels includes the steps of gasifying a starting material selected from a group consisting of coal, biomass, carbon nanotubes and mixtures thereof to produce a syngas, subjecting that syngas to Fischer-Tropsch synthesis (FTS) to produce a hyrdrocarbon product stream, separating that hydrocarbon product stream into C1-C4 hydrocarbons and C5+ hydrocarbons to be used as liquid fuels and subjecting the C1-C4 hydrocarbons to catalytic dehydrogenation (CDH) to produce hydrogen and carbon nanotubes. The hydrogen produced by CDH is recycled to be mixed with the syngas incident to the FTS reactor in order to raise the hydrogen to carbon monoxide ratio of the syngas to values of 2 or higher, which is required to produce liquid hydrocarbon fuels. This is accomplished with little or no production of carbon dioxide, a greenhouse gas. The carbon is captured in the form of a potentially valuable by-product, multi-walled carbon nanotubes (MWNT), while huge emissions of carbon dioxide are avoided and very large quantities of water employed for the water-gas shift in traditional FTS systems are saved.

  11. Synthesis pf dimethyl carbonate in supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ballivet-Tkatchenko, D.; Plasseraud, L. [Universite de Bourgogne-UFR Sciences et Techniques, Dijon (France). Lab. de Synthese et Electrosynthese Organometalliques]. E-mail: ballivet@u-bourgogne.fr; Ligabue, R.A. [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Dept. de Quimica Pura

    2006-01-15

    The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu{sub 3}SnOCH{sub 3}, n-Bu{sub 2}Sn(OCH{sub 3}){sub 2}, and [n-Bu{sub 2}(CH{sub 3}O)Sn]{sub 2}O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO{sub 2} pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO{sub 2} pressure higher than 16 MPa. Under these conditions, CO{sub 2} acted as a reactant and a solvent. (author)

  12. Membranes for separation of carbon dioxide

    Science.gov (United States)

    Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Ramaswamy, Vidya [Niskayuna, NY; Willson, Patrick Daniel [Latham, NY; Gao, Yan [Niskayuna, NY

    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.

  13. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

    2016-01-01

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts. PMID:27958290

  14. A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

    Science.gov (United States)

    Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

    2016-12-01

    Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

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

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

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

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

  17. 49 CFR 195.4 - Compatibility necessary for transportation of hazardous liquids or carbon dioxide.

    Science.gov (United States)

    2010-10-01

    ... hazardous liquids or carbon dioxide. 195.4 Section 195.4 Transportation Other Regulations Relating to... necessary for transportation of hazardous liquids or carbon dioxide. No person may transport any hazardous liquid or carbon dioxide unless the hazardous liquid or carbon dioxide is chemically compatible with both...

  18. Carbon deposition and hydrogen retention in tokamak

    International Nuclear Information System (INIS)

    Tanabe, Tetsuo

    2006-01-01

    The results of measurements on co-deposition of hydrogen isotopes and wall materials, hydrogen retention, redeposition of carbon and deposition of hydrogen on PMI of JT-60U are described. From above results, selection of plasma facing material and ability of carbon wall is discussed. Selection of plasma facing materials in fusion reactor, characteristics of carbon materials as the plasma facing materials, erosion, transport and deposition of carbon impurity, deposition of tritium in JET, results of PMI in JT-60, application of carbon materials to PFM of ITER, and future problems are stated. Tritium co-deposition in ITER, erosion and transport of carbon in tokamak, distribution of tritium deposition on graphite tile used as bumper limiter of TFTR, and measurement results of deposition of tritium on the Mark-IIA divertor tile and comparison between them are described. (S.Y.)

  19. Carbon compound used in hydrogen storage

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.

    2004-01-01

    In the present work it is studied the activated carbon of mineral origin for the sorption of hydrogen. The carbon decreased of particle size by means of the one alloyed mechanical. The time of mill was of 10 hours. The characterization one carries out by scanning electron microscopy and X-ray diffraction. The hydrogen sipped in the carbon material it was determined using the Thermal gravimetric method (TGA). The conditions of hydrogenation went at 10 atm of pressure and ambient temperature during 18 hours. They were also carried out absorption/desorption cycles of hydrogen in the same one system of thermal gravimetric analysis. The results showed percentages of sorption of 2% approximately in the cycles carried out in the system TGA and of 4.5% in weight of hydrogen at pressure of 10 atmospheres and ambient temperature during 18 hours. (Author)

  20. Electrochemical Reactor for Producing Oxygen From Carbon Dioxide, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — An electrochemical reactor is proposed by MicroCell Technologies, LLC to electrochemically reduce carbon dioxide to oxygen. In support of NASA's advanced life...

  1. Carbon dioxide inhalation treatments of neurotic anxiety. An overview.

    Science.gov (United States)

    Wolpe, J

    1987-03-01

    A lucky chance more than 30 years ago revealed the remarkable efficacy of single inhalations of high concentrations of carbon dioxide in eliminating or markedly reducing free-floating anxiety. The reduction of anxiety lasts for days, weeks, or longer--well beyond the persistence of carbon dioxide in the body. The effects are explicable on the hypothesis that free-floating anxiety is anxiety conditioned to continuously present sources of stimulation, such as background noise or the awareness of space or time, and that the anxiety response habit is weakened when the anxiety is inhibited by the competition of responses that carbon dioxide induces. More recently, it has become apparent that inhalations of carbon dioxide, applied in a different manner, are effective in overcoming maladaptive anxiety responses to specific stimuli, e.g., social stimuli. The substance is also proving to be a valuable resource in the treatment of the common variety of panic attacks.

  2. Monthly Carbon Dioxide in Troposphere (AIRS on AQUA)

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon dioxide (CO2) is an important greenhouse gas released through natural processes such as respiration and volcano eruptions and through huma activities such as...

  3. Studies on carbon dioxide system in central Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    AnilKumar, N.; Singbal, S.Y.S.

    significantly with depth Bicarbonate ion is quantitatively the major component of the carbon dioxide system The observed vertical distributions are discussed in terms of biological and geochemical processes in the sea...

  4. Energy costs of carbon dioxide concentrating mechanisms in aquatic organisms

    Czech Academy of Sciences Publication Activity Database

    Raven, John A.; Beardall, J.; Giordano, Mario

    2014-01-01

    Roč. 121, 2-3 (2014), s. 111-124 ISSN 0166-8595 Institutional support: RVO:61388971 Keywords : carbon dioxide * environmental change * radiation Subject RIV: EE - Microbiology, Virology Impact factor: 3.502, year: 2014

  5. Quantitative aspects of oxygen and carbon dioxide exchange ...

    African Journals Online (AJOL)

    Quantitative aspects of oxygen and carbon dioxide exchange through the ... ceratophthalmus (Crustacea: Decapoda) during rest and exercise in water and ... intersects zero time on the x-axis, indicating rapid gas exchange at the lung surface.

  6. Carbon dioxide and water vapour characteristics on the west coast ...

    Indian Academy of Sciences (India)

    Carbon dioxide, water vapour, air temperature and wind measurements at 10 Hz sampling rate were carried out over the ... seasonal and annual variations in the CO2 bal- ance. Hence, it is .... motion below produced by shear stress near the.

  7. Gas flaring: Carbon dioxide contribution to global warming ...

    African Journals Online (AJOL)

    Journal Home > Vol 20, No 2 (2016) > ... The quantitative method of analysis showed that carbon dioxide from gas ... gas flaring cause environmental degradation, health risks and constitute financial loss to the local oil producing communities.

  8. ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based on...

  9. Carbon dioxide and nitrous oxide in the North Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; Naqvi, S.W.A; Jayakumar, D.A; George, M.D.; Narvekar, P.V.; DeSousa, S

    The understanding of biogeochemical cycling of carbon dioxide and nitrous oxide in the oceans is essential for predicting the fate of anthropogenically emitted components. The North Indian Ocean, with its diverse regimes, provides us with a natural...

  10. Gas Flaring: Carbon dioxide Contribution to Global Warming ...

    African Journals Online (AJOL)

    PROF HORSFALL

    emissions resulting from high consumption of fossil fuels. Flaring been a ... method of analysis showed that carbon dioxide from gas flaring constitute 1% of the total ... Although of these, methane is potentially the most .... in some gas plants.

  11. Drying of supercritical carbon dioxide with membrane processes

    NARCIS (Netherlands)

    Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

    2015-01-01

    In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

  12. A Carbon Dioxide Laser Bibliography, 1964-1969,

    Science.gov (United States)

    A bibliography concerning carbon dioxide lasers has been compiled covering the period 1964 through 1969. The chronologically listed references have also been catalogued into an author index and a subject index. (Author)

  13. Elevated carbon dioxide: impacts on soil and plant water relations

    National Research Council Canada - National Science Library

    Kirkham, M. B

    2011-01-01

    .... Focusing on this critical issue, Elevated Carbon Dioxide: Impacts on Soil and Plant Water Relations presents research conducted on field-grown sorghum, winter wheat, and rangeland plants under elevated CO2...

  14. Precision remote sensor for oxygen and carbon dioxide, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes development of a passive optical sensor for simultaneous high-precision measurement of oxygen and carbon dioxide profiles within the full...

  15. Designing Microporus Carbons for Hydrogen Storage Systems

    Energy Technology Data Exchange (ETDEWEB)

    Alan C. Cooper

    2012-05-02

    An efficient, cost-effective hydrogen storage system is a key enabling technology for the widespread introduction of hydrogen fuel cells to the domestic marketplace. Air Products, an industry leader in hydrogen energy products and systems, recognized this need and responded to the DOE 'Grand Challenge' solicitation (DOE Solicitation DE-PS36-03GO93013) under Category 1 as an industry partner and steering committee member with the National Renewable Energy Laboratory (NREL) in their proposal for a center-of-excellence on Carbon-Based Hydrogen Storage Materials. This center was later renamed the Hydrogen Sorption Center of Excellence (HSCoE). Our proposal, entitled 'Designing Microporous Carbons for Hydrogen Storage Systems,' envisioned a highly synergistic 5-year program with NREL and other national laboratory and university partners.

  16. Carbon dioxide removal in gas treating processes

    International Nuclear Information System (INIS)

    Lidal, H.

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO 2 in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140 o C, for CO 2 loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO 2 into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO 2 in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO 2 /TEG/MEA system for estimation of CO 2 partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs

  17. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  18. Euthanasia of neonatal mice with carbon dioxide

    Science.gov (United States)

    Pritchett, K.; Corrow, D.; Stockwell, J.; Smith, A.

    2005-01-01

    Exposure to carbon dioxide (CO2) is the most prevalent method used to euthanize rodents in biomedical research. The purpose of this study was to determine the time of CO2 exposure required to euthanize neonatal mice (0 to 10 days old). Multiple groups of mice were exposed to 100% CO 2 for time periods between 5 and 60 min. Mice were placed in room air for 10 or 20 min after CO2 exposure, to allow for the chance of recovery. If mice recovered at one time point, a longer exposure was examined. Inbred and outbred mice were compared. Results of the study indicated that time to death varied with the age of the animals and could be as long as 50 min on the day of birth and differed between inbred and outbred mice. Institutions euthanizing neonatal mice with CO2 may wish to adjust their CO 2 exposure time periods according the age of the mice and their genetic background. Copyright 2005 by the American Association for Laboratory Animal Science.

  19. Periorbital area rejuvenation using carbon dioxide therapy.

    Science.gov (United States)

    Paolo, Fioramonti; Nefer, Fallico; Paola, Parisi; Nicolò, Scuderi

    2012-09-01

    Different conservative and surgical approaches are used for periorbital region rejuvenation, but none of them is effective in the treatment of the medial third of the lower eyelid. The present study is designed to assess the effectiveness of carboxytherapy in the treatment of wrinkles on the median and medial region of the lower eyelid and dark circles around the eyes. From January 2008 to December 2010, 90 patients with moderate to severe periorbital wrinkles and/or dark circles underwent subcutaneous injections of CO(2) once a week for 7 weeks. Patients were assessed before and 2 months after the treatment through photographic documentation and the compilation of visual analog scales. At the end of the study period, patients reported a reduction of facial fine lines and wrinkles as well as a decrease in periorbital hyperpigmentation. A few side effects were observed but they were all transient and did not require discontinuation of treatment. Carbon dioxide therapy results as an effective noninvasive modality for the rejuvenation of the periorbital area. © 2012 Wiley Periodicals, Inc.

  20. Carbon dioxide removal in gas treating processes

    Energy Technology Data Exchange (ETDEWEB)

    Lidal, H

    1992-06-01

    The main contribution of this work is the development of a simple and reliable modelling technique on carbon dioxide removal describing the vapor-liquid equilibria of CO{sub 2} in aqueous alkanolamine solutions. By making use of measured pH data, the author has circumvented the problem of estimating interaction parameters, activity coefficients, and equilibrium constants in the prediction of vapor-liquid equilibria. The applicability of the model is best demonstrated on the tertiary amine system using MDEA. For this system, the VLE is accurately represented for temperatures in the range 25 to 140{sup o}C, for CO{sub 2} loadings from 0.001 to 1 mol/mol, and for amine molarities usually encountered in acid gas treating processes. The absorption of CO{sub 2} into solutions containing the sterically hindered amine AMP, is also well described by the model. The equilibrium of CO{sub 2} in mixed solvents containing a glycol (TEG,DEG) and an alkonolamine (MEA,DEA) has been measured at temperatures encountered in the absorption units. An equilibrium model has been developed for the CO{sub 2}/TEG/MEA system for estimation of CO{sub 2} partial pressures, covering loadings and temperatures for both absorption and desorption conditions. An important spin-off of the work described is that two new experimental set-ups have been designed and built. 154 refs., 38 figs., 22 tabs.

  1. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm.

  2. Medium temperature carbon dioxide gas turbine reactor

    International Nuclear Information System (INIS)

    Kato, Yasuyoshi; Nitawaki, Takeshi; Muto, Yasushi

    2004-01-01

    A carbon dioxide (CO 2 ) gas turbine reactor with a partial pre-cooling cycle attains comparable cycle efficiencies of 45.8% at medium temperature of 650 deg. C and pressure of 7 MPa with a typical helium (He) gas turbine reactor of GT-MHR (47.7%) at high temperature of 850 deg. C. This higher efficiency is ascribed to: reduced compression work around the critical point of CO 2 ; and consideration of variation in CO 2 specific heat at constant pressure, C p , with pressure and temperature into cycle configuration. Lowering temperature to 650 deg. C provides flexibility in choosing materials and eases maintenance through the lower diffusion leak rate of fission products from coated particle fuel by about two orders of magnitude. At medium temperature of 650 deg. C, less expensive corrosion resistant materials such as type 316 stainless steel are applicable and their performance in CO 2 have been proven during extensive operation in AGRs. In the previous study, the CO 2 cycle gas turbomachinery weight was estimated to be about one-fifth compared with He cycles. The proposed medium temperature CO 2 gas turbine reactor is expected to be an alternative solution to current high-temperature He gas turbine reactors

  3. Carbon dioxide removal and the futures market

    Science.gov (United States)

    Coffman, D.'Maris; Lockley, Andrew

    2017-01-01

    Futures contracts are exchange-traded financial instruments that enable parties to fix a price in advance, for later performance on a contract. Forward contracts also entail future settlement, but they are traded directly between two parties. Futures and forwards are used in commodities trading, as producers seek financial security when planning production. We discuss the potential use of futures contracts in Carbon Dioxide Removal (CDR) markets; concluding that they have one principal advantage (near-term price security to current polluters), and one principal disadvantage (a combination of high price volatility and high trade volume means contracts issued by the private sector may cause systemic economic risk). Accordingly, we note the potential for the development of futures markets in CDR, but urge caution about the prospects for market failure. In particular, we consider the use of regulated markets: to ensure contracts are more reliable, and that moral hazard is minimised. While regulation offers increased assurances, we identify major insufficiencies with this approach—finding it generally inadequate. In conclusion, we suggest that only governments can realistically support long-term CDR futures markets. We note existing long-term CDR plans by governments, and suggest the use of state-backed futures for supporting these assurances.

  4. Carbon dioxide balneotherapy and cardiovascular disease

    Science.gov (United States)

    Pagourelias, Efstathios D.; Zorou, Paraskevi G.; Tsaligopoulos, Miltiadis; Athyros, Vasilis G.; Karagiannis, Asterios; Efthimiadis, Georgios K.

    2011-09-01

    Carbon dioxide (CO2) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO2 baths in various cardiovascular diseases. The three main effects of CO2 hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO2 baths in other cardiovascular substrates is discussed.

  5. Supercritical fluid carbon dioxide extraction of actinides

    International Nuclear Information System (INIS)

    Rao, Ankita; Tomar, B.S.

    2016-01-01

    Supercritical fluid extraction (SFE) is a process akin to liquid-liquid or solvent extraction where a Supercritical fluid (SCF) is contacted with a solid/ liquid matrix for the purpose of separating the component of interest from the original matrix. Carbon dioxide is a preferred choice as supercritical fluid (SCF) owing to its moderate critical parameter (P c = 7.38 MPa and T c = 304.1K) coupled with radiation and chemical stability, non toxic nature and low cost. Despite widespread applications for extraction of organic compounds and associated advantages especially liquid waste minimization, the SFE of metal ions was left unexplored for quite some time, as direct metal ion extraction is inefficient due charge neutralization requirement and weak solute-solvent interaction. Neutral SCF soluble metal-ligand complexation is imperative and SFE of actinides was reported only in 1994. Several studies have been carried out on SFE of uranium, thorium and plutonium from nitric acid medium employing different sets of ligands (organophosphorus, diketones, amides). Especially attractive is the possibility of direct dissolution and extraction of actinides employing ligand-acid adducts (like TBP.HNO 3 adduct) from solid matrices of different stages of nuclear fuel cycle viz. ores, spent nuclear fuels and radioactive wastes. Also, partitioning of actinides from fission products has been explored in spent nuclear fuel. These studies on supercritical fluid extraction of actinides indicate a more efficient and environmentally sustainable technology. (author)

  6. Purification of hydrogen sulfide

    International Nuclear Information System (INIS)

    Tsao, U.

    1978-01-01

    A process is described for purifying a hydrogen sulfide gas stream containing carbon dioxide, comprising (a) passing the gas stream through a bed of solid hydrated lime to form calcium hydrosulfide and calcium carbonate and (b) regenerating hydrogen sulfide from said calcium hydrosulfide by reacting the calcium hydrosulfide with additional carbon dioxide. The process is especially applicable for use in a heavy water recovery process wherein deuterium is concentrated from a feed water containing carbon dioxide by absorption and stripping using hydrogen sulfide as a circulating medium, and the hydrogen sulfide absorbs a small quantity of carbon dioxide along with deuterium in each circulation

  7. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  8. POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

    OpenAIRE

    Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

    2013-01-01

    Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

  9. Decontamination of radioactive clothing using microemulsion in carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jaeryong; Jang, Jina; Park, Kwangheon; Kim, Hongdoo; Kim, Hakwon [Kyunghee Univ., Seoul (Korea, Republic of); Yim, Sanghak; Yoon, Weonseob [Ulchin Nuclear Power Site, Ulchin (Korea, Republic of)

    2006-07-01

    Nuclear power is intrinsically a clean energy source due to its high energy density and low generation of waste. However, as the nuclear industry grows, a variety of radioactive wastes are increased gradually. Major subjects include contaminated components, tools, equipment, containers and facilities as well as nuclear waste such as uranium scrap and radioactive clothing. The radioactive waste can be classified by its creation. There are Trans-Uranium Nuclides (TRU), Fission Products (FP) and corrosion products. Nuclear decontamination has become an important issue in the nuclear industry. The conventional methods have some problems such as the production of secondary wastes and the use of toxic solvents. We need to develop a new method of decontamination and suggest a use of microemulsion in carbon dioxide to overcome these disadvantages. The microemulsion is the clear solution that contains the water, surfactant and carbon dioxide. The surfactant surrounded the droplet into carbon dioxide and this state is thermodynamically stable. That is, the microemulsion has a structure similar to that of a conventional water-based surfactant system. Generally, the size of droplet is about 5 {approx} 10nm. The microemulsion is able to decontaminate radioactive waste so that the polar substance is removed by water and the non-polar substance is removed by carbon dioxide. After the decontamination process, the microemulsion is separated easily to surfactant and water by decreasing the pressure under the cloud point. This way, only radioactive wastes are left in the system. Cleaned carbon dioxide is then collected and reused. Thus, there are no secondary wastes. Carbon dioxide is considered an alternative process medium. This is because it is non-toxic, non-flammable, inexpensive and easy to handle. Additionally, the tunable properties of carbon dioxide through pressure and temperature control are versatile for use in extracting organic materials. In this paper, we examine the

  10. Carbon dioxide efflux from leaves in light and darkness

    Energy Technology Data Exchange (ETDEWEB)

    Holmgren, P; Jarvis, P G

    1967-01-01

    The efflux of carbon dioxide in light and darkness was measured at low ambient CO/sub 2/ concentrations in leaves of Rumex acetosa. Light carbon dioxide production (photorespiration) was found to depend on irradiance and to differ from dark production as to the response to temperature and ambient concentrations of O/sub 2/ and CO/sub 2/. These observations support previously made suggestions that photorespiration follows a different metabolic pathway to dark respiration.

  11. Tethered catalysts for the hydration of carbon dioxide

    Science.gov (United States)

    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.

  12. Decontamination of radioactive clothing using microemulsion in carbon dioxide

    International Nuclear Information System (INIS)

    Yoo, Jaeryong; Jang, Jina; Park, Kwangheon; Kim, Hongdoo; Kim, Hakwon; Yim, Sanghak; Yoon, Weonseob

    2006-01-01

    Nuclear power is intrinsically a clean energy source due to its high energy density and low generation of waste. However, as the nuclear industry grows, a variety of radioactive wastes are increased gradually. Major subjects include contaminated components, tools, equipment, containers and facilities as well as nuclear waste such as uranium scrap and radioactive clothing. The radioactive waste can be classified by its creation. There are Trans-Uranium Nuclides (TRU), Fission Products (FP) and corrosion products. Nuclear decontamination has become an important issue in the nuclear industry. The conventional methods have some problems such as the production of secondary wastes and the use of toxic solvents. We need to develop a new method of decontamination and suggest a use of microemulsion in carbon dioxide to overcome these disadvantages. The microemulsion is the clear solution that contains the water, surfactant and carbon dioxide. The surfactant surrounded the droplet into carbon dioxide and this state is thermodynamically stable. That is, the microemulsion has a structure similar to that of a conventional water-based surfactant system. Generally, the size of droplet is about 5 ∼ 10nm. The microemulsion is able to decontaminate radioactive waste so that the polar substance is removed by water and the non-polar substance is removed by carbon dioxide. After the decontamination process, the microemulsion is separated easily to surfactant and water by decreasing the pressure under the cloud point. This way, only radioactive wastes are left in the system. Cleaned carbon dioxide is then collected and reused. Thus, there are no secondary wastes. Carbon dioxide is considered an alternative process medium. This is because it is non-toxic, non-flammable, inexpensive and easy to handle. Additionally, the tunable properties of carbon dioxide through pressure and temperature control are versatile for use in extracting organic materials. In this paper, we examine the

  13. The Greenness of Cities: Carbon Dioxide Emissions and Urban Development

    OpenAIRE

    Glaeser, Edward L.; Kahn, Matthew E.

    2008-01-01

    Carbon dioxide emissions may create significant social harm because of global warming, yet American urban development tends to be in low density areas with very hot summers. In this paper, we attempt to quantify the carbon dioxide emissions associated with new construction in different locations across the country. We look at emissions from driving, public transit, home heating, and household electricity usage. We find that the lowest emissions areas are generally in California and that the h...

  14. Nanoengineered Carbon Scaffolds for Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, A. D.; Hudson, J. L.; Fan, H.; Booker, R.; Simpson, L. J.; O' Neill, K. J.; Parilla, P. A.; Heben, M. J.; Pasquali, M.; Kittrell, C.; Tour, J. M.

    2009-01-01

    Single-walled carbon nanotube (SWCNT) fibers were engineered to become a scaffold for the storage of hydrogen. Carbon nanotube fibers were swollen in oleum (fuming sulfuric acid), and organic spacer groups were covalently linked between the nanotubes using diazonium functionalization chemistry to provide 3-dimensional (3-D) frameworks for the adsorption of hydrogen molecules. These 3-D nanoengineered fibers physisorb twice as much hydrogen per unit surface area as do typical macroporous carbon materials. These fiber-based systems can have high density, and combined with the outstanding thermal conductivity of carbon nanotubes, this points a way toward solving the volumetric and heat-transfer constraints that limit some other hydrogen-storage supports.

  15. Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

    International Nuclear Information System (INIS)

    Yoon, Duk-Joo; Ko, Jae-Hwa

    2008-01-01

    Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

  16. Microfluidic platform for studying the electrochemical reduction of carbon dioxide

    Science.gov (United States)

    Whipple, Devin Talmage

    Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world's rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: • Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). • Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). • Study of amine based electrolytes for lowering the overpotentials for CO2

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

    NARCIS (Netherlands)

    Shen, J.; Kortlever, R.; Kas, Recep; Mul, Guido; Koper, M.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

  18. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yixin [McGill Univ., Montreal, QC (Canada)

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  19. Hydrogen adsorption in carbon nanostructures compared

    International Nuclear Information System (INIS)

    Schimmel, H.G.; Nijkamp, G.; Kearley, G.J.; Rivera, A.; Jong, K.P. de; Mulder, F.M.

    2004-01-01

    Recent reports continue to suggest high hydrogen storage capacities for some carbon nanostructures due to a stronger interaction between hydrogen and carbon. Here the interaction of hydrogen with activated charcoal, carbon nanofibers, single walled carbon nanotubes (SWNT), and electron beam 'opened' SWNT are compared and shown to be similar. The storage capacity below 77 K of these materials correlates with the surface area of the material with the activated charcoal having the largest. SWNT and 'opened' SWNT have a relatively low accessible surface area due to bundling of the tubes. Pressure-temperature curves give the interaction potential, which was found to be ∼580 K or 50 meV in all samples, leading to significant adsorption below ∼50 K. Using the inelastic neutron scattering signal associated with rotation of the hydrogen molecule as a sensitive probe for the surroundings of the molecule, no difference was found between the hydrogen molecules adsorbed in the investigated materials. These combined spectroscopic and macroscopic results show that SWNT, nanofibers and activated carbons store molecular hydrogen due to their graphitic nature and not because they possess special morphologies. Results from a density functional theory computer calculation suggest molecular hydrogen bonding to an aromatic C-C bond of graphite, irrespective of the surface morphology farther away

  20. Supercritical carbon dioxide for textile applications and recent developments

    Science.gov (United States)

    Eren, H. A.; Avinc, O.; Eren, S.

    2017-10-01

    In textile industry, supercritical carbon dioxide (scCO2), possessing liquid-like densities, mostly find an application on textile dyeing processes such as providing hydrophobic dyes an advantage on dissolving. Their gas-like low viscosities and diffusion properties can result in shorter dyeing periods in comparison with the conventional water dyeing process. Supercritical carbon dioxide dyeing is an anhydrous dyeing and this process comprises the usage of less energy and chemicals when compared to conventional water dyeing processes leading to a potential of up to 50% lower operation costs. The advantages of supercritical carbon dioxide dyeing method especially on synthetic fiber fabrics hearten leading textile companies to alter their dyeing method to this privileged waterless dyeing technology. Supercritical carbon dioxide (scCO2) waterless dyeing is widely known and applied green method for sustainable and eco-friendly textile industry. However, not only the dyeing but also scouring, desizing and different finishing applications take the advantage of supercritical carbon dioxide (scCO2). In this review, not only the principle, advantages and disadvantages of dyeing in supercritical carbon dioxide but also recent developments of scCO2 usage in different textile processing steps such as scouring, desizing and finishing are explained and commercial developments are stated and summed up.

  1. Phase equilibrium condition of marine carbon dioxide hydrate

    International Nuclear Information System (INIS)

    Sun, Shi-Cai; Liu, Chang-Ling; Ye, Yu-Guang

    2013-01-01

    Highlights: ► CO 2 hydrate phase equilibrium was studied in simulated marine sediments. ► CO 2 hydrate equilibrium temperature in NaCl and submarine pore water was depressed. ► Coarse-grained silica sand does not affect CO 2 hydrate phase equilibrium. ► The relationship between equilibrium temperature and freezing point was discussed. - Abstract: The phase equilibrium of ocean carbon dioxide hydrate should be understood for ocean storage of carbon dioxide. In this paper, the isochoric multi-step heating dissociation method was employed to investigate the phase equilibrium of carbon dioxide hydrate in a variety of systems (NaCl solution, submarine pore water, silica sand + NaCl solution mixture). The experimental results show that the depression in the phase equilibrium temperature of carbon dioxide hydrate in NaCl solution is caused mainly by Cl − ion. The relationship between the equilibrium temperature and freezing point in NaCl solution was discussed. The phase equilibrium temperature of carbon dioxide hydrate in submarine pore water is shifted by −1.1 K to lower temperature region than that in pure water. However, the phase equilibrium temperature of carbon dioxide hydrate in mixture samples of coarsed-grained silica sand and NaCl solution is in agreement with that in NaCl solution with corresponding concentrations. The relationship between the equilibrium temperature and freezing point in mixture samples was also discussed.

  2. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    Science.gov (United States)

    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.

  3. The role of renewable bioenergy in carbon dioxide sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, C.M. [Hawaii Natural Energy Inst., Honolulu, HI (United States)

    1993-12-31

    The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

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

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry Y. S. [Arizona State Univ., Tempe, AZ (United States)

    2015-01-31

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

  5. Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

    Science.gov (United States)

    Boyd, Philip W.

    The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

  6. Studies of the surface of titanium dioxide. IV. The hydrogen-deuterium equilibration reaction

    International Nuclear Information System (INIS)

    Iwaki, T.; Katsuta, K.; Miura, M.

    1981-01-01

    The interaction of hydrogen with the surface of titanium dioxide has been studied in connection with the hydrogen-reduction mechanism of titanium dioxide, by means of such measurements as weight decrease, magnetic susceptibility, hydrogen uptake, and electrical conductance. It was postulated in the previous study that the rate-determining step of the hydrogen-reduction reaction may be the formation of surface hydroxyl groups, followed by the rapid removal of water molecules from the surface. In this study, the interactions between hydrogen and the surface of titanium dioxide were investigated by measuring the hydrogen-deuterium equilibration reaction, H 2 + D 2 = 2HD, at temperatures above 200 0 C on both surfaces before and after hydrogen reduction to compare the differences in the reactivities

  7. Stabilization of carbon dioxide and chromium slag via carbonation.

    Science.gov (United States)

    Wu, Xingxing; Yu, Binbin; Xu, Wei; Fan, Zheng; Wu, Zucheng; Zhang, Huimin

    2017-08-01

    As the main greenhouse gas, CO 2 is considered as a threat in the context of global warming. Many available technologies to reduce CO 2 emission was about CO 2 separation from coal combustion and geological sequestration. However, how to deal with the cost-effective storage of CO 2 has become a new challenge. Moreover, chromium pollution, the treatment of which requires huge energy consumption, has attracted people's widespread attention. This study is aimed to develop the sequestration of CO 2 via chromium slag. A dynamic leaching experiment of chromium slag was designed to testify the ability of CO 2 adsorption onto chromium slag and to release Cr(VI) for stabilization. The results showed that the accumulative amounts of Cr(VI) were ca. 2.6 mg/g released from the chromium slag after 24 h of leaching. In addition, ca. 89 mg/g CO 2 was adsorbed by using pure CO 2 in the experiment at 12 h. Calcite is the only carbonate species in the post-carbonated slag analyzed by powder X-ray diffraction and thermal analysis. The approach provides the feasibility of the utilization of chromium slag and sequestration of the carbon dioxide at the same time at ordinary temperatures and pressures.

  8. It is time to put carbon dioxide to work

    Energy Technology Data Exchange (ETDEWEB)

    Lipinsky, E.S. [Battelle, Columbus, OH (United States)

    1993-12-31

    The need to control emissions of carbon dioxide into the atmosphere is the subject of vigorous debate at this time. There is growing evidence that rising levels of carbon dioxide increase global warming, with perhaps highly adverse impacts for the human economy. There are calls for carbon taxes and other harsh measures. Japan has established a national goal of holding carbon dioxide emissions in the year 2000 to 1990 levels. I hope that this conference will be a turning point in the United States position on this issue. The current major end uses for CO{sub 2} include refrigeration, beverage carbonation, soda ash production, fire fighting, and urea fertilizer production. They are all based on chemistry that would not surprise a good chemist of the 19th century. Consumption of carbon dioxide in synthesis of industrial chemicals is limited. Usually one explains low production of chemicals from a candidate feedstock in terms of poor availability, price, purity, or reactivity. We can eliminate the first three as the causes of the underutilization of carbon dioxide.

  9. Hydrogen adsorption on partially oxidised microporous carbons

    International Nuclear Information System (INIS)

    J B Parra; C O Ania; C J Duran Valle; M L Sanchez; C Otero Arean

    2005-01-01

    The search for cost effective adsorbents for large scale gas separation, storage and transport constitutes a present day strategic issue in the energy sector, propelled mainly by the potential use of hydrogen as an energy vector in a sustainable (and cleaner) energy scenario. Both, activated carbons and carbon based nano-structured materials have been proposed as potential candidates for reversible hydrogen storage in cryogenically cooled vessels. For that purpose, surface modification so as to enhance the gas solid interaction energy is desirable. We report on hydrogen adsorption on microporous (active) carbons which have been partially oxidised with nitric acid and ammonium persulfate. From the corresponding hydrogen adsorption isotherms (Fig. 1) an isosteric heat of about 3 kJ mol -1 was derived. This value is in agreement with that of about 3 to 4 kJ mol -1 obtained by quantum chemical calculations on the interaction between the hydrogen molecule and simple model systems (Fig. 2) of both, hydroxyl and carboxyl groups. Further research is in progress with a view to further increases the gas solid interaction energy. However, the values so far obtained are significantly larger than the liquefaction enthalpy of hydrogen: 0.90 kJ mol -1 ; and this is relevant to both, hydrogen separation from gas mixtures and cryogenic hydrogen storage. (authors)

  10. Kinetics of hydrogen reduction of titanium-doped molybdenum dioxide

    International Nuclear Information System (INIS)

    He, Qian; Marin-Flores, Oscar; Hu, Shuozhen; Scudiero, Louis; Ha, Su; Norton, M. Grant

    2015-01-01

    Ti-doped MoO 2 was synthesized to broaden the oxygen-to-carbon ratio operating range of MoO 2 for partial oxidation of long-chain hydrocarbons by increasing the redox stability. The structure modification causes the hydrogen reduction mechanism to change from three-dimensional nuclei growth with an activation energy of 61.3 kJ mol −1 to a three-dimensional hydrogen diffusion limited model with an activation energy of 317.9 kJ mol −1 . Because of the enhanced redox stability, Ti-doped MoO 2 has potential as an alternative anode in direct liquid-fed solid oxide fuel cells

  11. Nuclear power and the carbon dioxide problem

    International Nuclear Information System (INIS)

    Bijlsma, J.J.; Blok, K.; Turkenburg, W.C.

    1989-05-01

    This study deals with the question, which contribution can be delivered by nuclear power to the redution of the emission of carbon dioxide (CO 2 ) from the power supply. The emphasis lays upon the following aspects: the emissions of CO 2 which occur in the nuclear-power cycle (the so-called indirect emission of CO 2 power plants); the amount of uranium stocks; the change of CO 2 emission caused by replacement of fossil fuels, in particular coal, by nuclear power. First an energy-analysis of the nuclear power cycle is presented. On the base of this analysis the CO 2 uranium can be calculated. The role of nuclear power in the reduction of CO 2 emission depends on the development of the final power demand. Therefore in this study two scenarios derived from the 'IIASA-low' scenario; 'low-energy'-scenario in which the world-energy consumption remains at about the same level. In the calculations the indirect emissions of CO 2 , also dependent on the ore richness and the technology used, have always been taken into account. In the calculations two uranium-reserve variants of resp. 5.7 and 30 mln. tons have been assumed. From the results of the calculations it can be concluded that whether or not taking account of the indirect emissions of CO 2 in the nuclear power cycle, has only limited effect on the calculated contribution of nuclear power to the solution of the greenhouse effect. The uranium reserves turn out to be determining for the potential contribution of nuclear power. By putting on the surely available reserve of 5.7 mln. tons, or the speculative reserve of 30 mln. tons, with the actual technology, an emission of resp. 130-140 billion and 880 billion tons CO 2 can be avoided in replacing coal. With maximal employment of improved conversion techniques these contributions may be doubled. (H.W.). 40 refs.; 13 figs.; 10 tabs

  12. Carbon Dioxide Physiological Training at NASA.

    Science.gov (United States)

    Law, Jennifer; Young, Millennia; Alexander, David; Mason, Sara S; Wear, Mary L; Méndez, Claudia M; Stanley, David; Ryder, Valerie Meyers; Van Baalen, Mary

    2017-10-01

    Astronauts undergo CO2 exposure training to recognize their symptoms that can arise acutely both on the ground and in spaceflight. This article describes acute CO2 exposure training at NASA and examines the symptoms reported by astronauts during training. In a controlled training environment, astronauts are exposed to up to 8% CO2 (60 mmHg) by a rebreathing apparatus. Symptoms are reported using a standard form. Symptom documentation forms between April 1994 and February 2012 were obtained for 130 astronauts. The number of symptoms reported per session out of the possible 24 was related to age and sex, with those older slightly more likely to report symptoms. Women reported more symptoms on average than men (men: 3.7, women: 4.7). Respiratory symptoms (90%), flushing sensation/sweating (56%), and dizziness/feeling faint/lightheadedness (43%) were the top symptoms. Only headache reached statistical significance in differences between men (13%) and women (37%) after adjustment for multiple testing. Among those with multiple training sessions, respiratory symptoms were the most consistently reported. CO2 exposure training is an important tool to educate astronauts about their potential acute CO2 symptoms. Wide interindividual and temporal variations were observed in symptoms reported during astronaut CO2 exposure training. Headache could not be relied on as a marker of acute exposure during testing since fewer than half the subjects reported it. Our results support periodic refresher training since symptoms may change over time. Further study is needed to determine the optimal interval of training to maximize symptom recognition and inform operational decisions.Law J, Young M, Alexander D, Mason SS, Wear ML, Méndez CM, Stanley D, Meyers Ryder V, Van Baalen M. Carbon dioxide physiological training at NASA. Aerosp Med Hum Perform. 2017; 88(10):897-902.

  13. Carbon dioxide and climate: an astrophysical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, R S

    1979-01-01

    In this survey the earth is viewed from the astrophysical perspective, i.e. using global mean values of environmental parameters. The role of carbon dioxide is described in the processes of energy transfer from the earth's surface to space, which determine global climate as measured by the mean surface temperature. Analogies and differences between the problems of the terrestrial atmosphere and those of the solar and stellar atmospheres are examined, both in the computation of model atmospheres and in remote sensing of atmospheric temperature and composition. Subsequently, the temporal astrophysical perspective, with a review of the evolution of CO/sub 2/ abundance and climate on astrophysical or geological time scales, on earth as an Venus (the runaway greenhouse) and on Mars is introduced. Variation of CO/sub 2/ may have been critical to the maintenance of an environment in which life could originate and evolve, and may itself have been affected by life. On human time scales, the recent and continuing increase in atmospheric CO/sub 2/ raises new problems, which are briefly surveyed. It is argued, that the differential greenhouse effect of increased CO/sub 2/ in the earth's atmosphere is essentially identifical to the blanketing effect of spectral lines on the temperature structure of stellar atmospheres. The methods used by astrophysicists in such studies are reviewed and compared with those used to evaluate the differential greenhouse effect of CO/sub 2/ in radiative-convective models of the earth's atmosphere. The latter methods remain relatively crude, but recent results by different authors are in reasonably good agreement; however, the astrophysical perspective, i.e. the use of one-dimensional global mean models, remains a gross simplification of the real complexity of the earth's climate system, which is also true in stellar atmospheres.

  14. Deep Conversion of Carbon Monoxide to Hydrogen and Formation of Acetate by the Anaerobic Thermophile Carboxydothermus hydrogenoformans

    OpenAIRE

    Henstra, Anne M.; Stams, Alfons J. M.

    2011-01-01

    Carboxydothermus hydrogenoformans is a thermophilic strictly anaerobic bacterium that catalyses the water gas shift reaction, the conversion of carbon monoxide with water to molecular hydrogen and carbon dioxide. The thermodynamically favorable growth temperature, compared to existing industrial catalytic processes, makes this organism an interesting alternative for production of cheap hydrogen gas suitable to fuel CO-sensitive fuel cells in a future hydrogen economy, provided sufficiently lo...

  15. Reactor design considerations in mineral sequestration of carbon dioxide

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

  17. Dissolved Carbon Dioxide in Tropical East Atlantic Surface Waters

    NARCIS (Netherlands)

    Bakker, D.C.E.; Baar, H.J.W. de; Jong, E. de

    1999-01-01

    Variability of dissolved inorganic carbon (DIC) and the fugacity of carbon dioxide (fCO2) is discussed for tropical East Atlantic surface waters in October–November 1993 and May–June 1994. High precipitation associated with the Intertropical Convergence Zone, river input and equatorial upwelling

  18. Regional carbon dioxide implications of forest bioenergy production

    NARCIS (Netherlands)

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

    2011-01-01

    Strategies for reducing carbon dioxide emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be recaptured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here, we use forest

  19. Assessing Carbon Dioxide Emissions from Energy Use at a University

    Science.gov (United States)

    Riddell, William; Bhatia, Krishan Kumar; Parisi, Matthew; Foote, Jessica; Imperatore, John, III

    2009-01-01

    Purpose: The purpose of this paper is to assess the carbon dioxide emissions associated with electric, HVAC, and hot water use from a US university. Design/methodology/approach: First, the total on-campus electrical, natural gas and oil consumption for an entire year was assessed. For each category of energy use, the carbon associated with…

  20. Ions in carbon dioxide at an atmospheric pressure

    International Nuclear Information System (INIS)

    Ikezoe, Yasumasa; Onuki, Kaoru; Shimizu, Saburo; Nakajima, Hayato; Sato, Shoichi; Matsuoka, Shingo; Nakamura, Hirone; Tamura, Takaaki

    1985-01-01

    The formation and the subsequent reactions of positive and negative ions were observed by a time resolved atmospheric pressure ionization mass spectrometer (TRAPI) in an atmospheric pressure carbon dioxide added with small amounts of carbon monoxide and oxygen. A relatively stable ion of (44 x n) + (n >= 2) having a different reactivity from that of (CO 2 ) + sub(n) was found to be one of major ionic species in this gas system. This species was tentatively assigned as [O 2 (CO) 2 ] + (CO 2 )sub(n-2). A new reaction sequence of positive ions is proposed which can be operative in the radiolysis of carbon dioxide at 1 atm. (author)

  1. 27.12 MHz plasma generation in supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Kawashima, Ayato; Toyota, Hiromichi; Nomura, Shinfuku; Takemori, Toshihiko; Mukasa, Shinobu; Maehara, Tsunehiro; Yamashita, Hiroshi

    2007-01-01

    An experiment was conducted for generating high-frequency plasma in supercritical carbon dioxide; it is expected to have the potential for applications in various types of practical processes. It was successfully generated at 6-20 MPa using electrodes mounted in a supercritical cell with a gap of 1 mm. Emission spectra were then measured to investigate the physical properties of supercritical carbon dioxide plasma. The results indicated that while the emission spectra for carbon dioxide and carbon monoxide could be mainly obtained at a low pressure, the emission spectra for atomic oxygen could be obtained in the supercritical state, which increased with the pressure. The temperature of the plasma in supercritical state was estimated to be approximately 6000-7000 K on the assumption of local thermodynamic equilibrium and the calculation results of thermal equilibrium composition in this state showed the increase of atomic oxygen by the decomposition of CO 2

  2. Carbon: Hydrogen carrier or disappearing skeleton?

    International Nuclear Information System (INIS)

    De Jong, K.P.; Van Wechem, H.M.H.

    1994-01-01

    The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently developed Shell Middle Distillate Hydrogenation process for the manufacture of high quality diesel from aromatic refinery streams fits this picture. In the future, the hydrogen required to raise the product H/C ratio will be increasingly produced via gasification of large amounts of heavy residues. In the light of the strong preference towards using liquid fuels in the transport sector, the Shell Middle Distillate Synthesis process to convert natural gas into diesel of very high quality is discussed. Finally, a few comments on the use of hydrogen without a carbon carrier are made. Long lead times and the likelihood of producing the 'first' hydrogen from fossil fuel are highlighted. 13 figs., 6 tabs., 5 refs

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

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Nelson; David Green; Paul Box; Raghubir Gupta; Gennar Henningsen

    2007-06-30

    Regenerable sorbents based on sodium carbonate (Na{sub 2}CO{sub 3}) can be used to separate carbon dioxide (CO{sub 2}) from coal-fired power plant flue gas. Upon thermal regeneration and condensation of water vapor, CO{sub 2} is released in a concentrated form that is suitable for reuse or sequestration. During the research project described in this report, the technical feasibility and economic viability of a thermal-swing CO{sub 2} separation process based on dry, regenerable, carbonate sorbents was confirmed. This process was designated as RTI's Dry Carbonate Process. RTI tested the Dry Carbonate Process through various research phases including thermogravimetric analysis (TGA); bench-scale fixed-bed, bench-scale fluidized-bed, bench-scale co-current downflow reactor testing; pilot-scale entrained-bed testing; and bench-scale demonstration testing with actual coal-fired flue gas. All phases of testing showed the feasibility of the process to capture greater than 90% of the CO{sub 2} present in coal-fired flue gas. Attrition-resistant sorbents were developed, and these sorbents were found to retain their CO{sub 2} removal activity through multiple cycles of adsorption and regeneration. The sodium carbonate-based sorbents developed by RTI react with CO{sub 2} and water vapor at temperatures below 80 C to form sodium bicarbonate (NaHCO3) and/or Wegscheider's salt. This reaction is reversed at temperatures greater than 120 C to release an equimolar mixture of CO{sub 2} and water vapor. After condensation of the water, a pure CO{sub 2} stream can be obtained. TGA testing showed that the Na{sub 2}CO3 sorbents react irreversibly with sulfur dioxide (SO{sub 2}) and hydrogen chloride (HCl) (at the operating conditions for this process). Trace levels of these contaminants are expected to be present in desulfurized flue gas. The sorbents did not collect detectable quantities of mercury (Hg). A process was designed for the Na{sub 2}CO{sub 3}-based sorbent that

  4. Biomass combustion for greenhouse carbon dioxide enrichment

    International Nuclear Information System (INIS)

    Roy, Yves; Lefsrud, Mark; Orsat, Valerie; Filion, Francis; Bouchard, Julien; Nguyen, Quoc; Dion, Louis-Martin; Glover, Antony; Madadian, Edris; Lee, Camilo Perez

    2014-01-01

    Greenhouses in northern climates have a significant heat requirement that is mainly supplied by non-renewable fuels such as heating oil and natural gas. This project's goal was the development of an improved biomass furnace able to recover the heat and the CO 2 available in the flue gas and use them in the greenhouse. A flue gas purification system was designed, constructed and installed on the chimney of a wood pellet furnace (SBI Caddy Alterna). The purification system consists of a rigid box air filter (MERV rating 14, 0.3 μm pores) followed by two sets of heating elements and a catalytic converter. The air filter removes the particulates present in the flue gas while the heating elements and catalysers transform the noxious gases into less harmful gases. Gas analysis was sampled at different locations in the system using a TESTO 335 flue gas analyzer. The purification system reduces CO concentrations from 1100 cm 3  m −3 to less than 1 cm 3  m −3 NO x from 70 to 5.5 cm 3  m −3 SO 2 from 19 cm 3  m −3 to less than 1 cm 3  m −3 and trapped particulates down to 0.3 μm with an efficiency greater than 95%. These results are satisfactory since they ensure human and plant safety after dilution into the ambient air of the greenhouse. The recuperation of the flue gas has several obvious benefits since it increases the heat usability per unit biomass and it greatly improves the CO 2 recovery of biomass heating systems for the benefit of greenhouse grown plants. - Highlights: • Biomass furnace shows high potential for greenhouse carbon dioxide enrichment. • Flue gas recuperation significantly increases the thermal efficiency of a furnace. • Catalytic converter can reduce CO and NOx below humans and plants exposure limit. • Particulates control is essential to maintain the efficiency of the catalytic conversion. • CO 2 recovery from biomass heating systems reduces farmer's reliance on fossil fuel

  5. Direct carbon dioxide emissions from civil aircraft

    Science.gov (United States)

    Grote, Matt; Williams, Ian; Preston, John

    2014-10-01

    Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories - policy and legal-related measures, and technological and operational measures. Results of the review are used to develop several insights into the challenges faced. The analysis shows that forecasts for strong growth in air-traffic will result in civil aviation becoming an increasingly significant contributor to anthropogenic CO2 emissions. Some mitigation-measures can be left to market-forces as the key-driver for implementation because they directly reduce airlines' fuel consumption, and their impact on reducing fuel-costs will be welcomed by the industry. Other mitigation-measures cannot be left to market-forces. Speed of implementation and stringency of these measures will not be satisfactorily resolved unattended, and the current global regulatory-framework does not provide the necessary strength of stewardship. A global regulator with ‘teeth' needs to be established, but investing such a body with the appropriate level of authority requires securing an international agreement which history would suggest is going to be very difficult. If all mitigation-measures are successfully implemented, it is still likely that traffic growth-rates will continue to out-pace emissions reduction-rates. Therefore, to achieve an overall reduction in CO2 emissions, behaviour change will be necessary to reduce demand for air-travel. However, reducing demand will be strongly resisted by all stakeholders in the industry; and the ticket price-increases necessary to induce the required reduction in traffic growth-rates place a monetary-value on CO2 emissions of approximately 7-100 times greater than other common

  6. Predator-induced reduction of freshwater carbon dioxide emissions

    Science.gov (United States)

    Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

    2013-03-01

    Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

  7. Carbon dioxide and the greenhouse effect: an unresolved problem

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I M

    1978-01-01

    This paper evaluates current scientific literature concerned with the accumulation of carbon dioxide in the atmosphere. The extent and possible causes of natural variations in global climate are outlined as a background to potential variations due to human activity. Estimates are given on relative contributions of carbon dioxide to the atmosphere due to fossil fuel combustion, deforestation and other land modifications. The possibility of a rise in global temperature as a result of increasing the amount of carbon dioxide in the atmosphere is discussed including model predictions, natural factors which could compensate for or emphasize a warming effect, and the implications if extensive warming actually occurred. Carbon dioxide disposal is discussed but there appears to be no practicable long-term means of accomplishing this. It is concluded that there is no evidence of a rise in global temperature due to carbon dioxide at present. Predictions, which involve a high degree of uncertainty, indicate that the global temperature could rise appreciably in the next century. An increase in precipitation rate is also expected.

  8. Carbon dioxide and the 'greenhouse effect': an unresolved problem

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I

    1978-01-01

    This executive review evaluates current scientific literature concerned with the accumulation of carbon dioxide in the atmosphere. The extent and possible causes of natural variations in global climate are outlined as a background to potential variations due to human activity. Estimates are given on relative contributions of carbon dioxide to the atmosphere due to fossil fuel combustion, deforestation and other land modifications. The possibility of a rise in global temperature as a result of increasing the amount of carbon dioxide in the atmosphere is dicusssed including model predictions, natural factors which could compensate for or emphasize a warming effect, and the implications if extensive warming actually occurred. Carbon dioxide disposal is discussed, but there appears to be no practicable long-term means of accomplishing this. It is concluded that there is no evidence of a rise in global temperature due to carbon dioxide at present. Predictions, which involve a high degree of uncertainty, indicate that the global temperature could rise appreciably in the next century. An increase in precipitation rate is also expected. If these changes result in a redistribution of climatic zones, there may be problems in adapting agricultural belts in some regions. Complete melting of all the ice sheets would take several millenia. A partial melting of continental ice sheets would not necessarily occur in view of the increase in precipitation rates, but if it did, there would be a rise in sea level of a few metres. Melting of the Arctic sea ice would affect climate, but not sea level.

  9. Measures for carbon dioxide problem and utilization of energy

    International Nuclear Information System (INIS)

    Kojima, Toshinori

    1992-01-01

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

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

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; Ambus, Per; Michelsen, Anders

    2011-01-01

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

  11. Method and aparatus for flue gas cleaning by separation and liquefaction of sulfur dioxide and carbon dioxide

    International Nuclear Information System (INIS)

    Abdelmalek, F.T.

    1992-01-01

    This patent describes a method for recovering sulfur dioxide, carbon dioxide, and cleaning flue gases emitted from power plants. It comprises: electronically treating the flue gases to neutralize its electrostatic charges and to enhance the coagulation of its molecules and particles; exchanging sensible and latent heat of the neutralized flue gases to lower its temperature down to a temperature approaching the ambient temperature while recovering its separating the flue gas in a first stage; cooling the separated enriched carbon dioxide gas fraction, after each separation stage, while removing its vapor condensate, then compressing the enriched carbon dioxide gas fraction and simultaneously cooling the compressed gas to liquefy the sulfur dioxide gas then; allowing the sulfur dioxide gas to condense, and continuously removing the liquefied sulfur dioxide; compressing he desulfurized enriched carbon dioxide fraction to further increase its pressure, and simultaneously cooling he compressed gas to liquefy the carbon dioxide gas, then; allowing the carbon dioxide gas to condense and continuously removing the liquefied carbon dioxide; allowing the light components of the flue gas to be released in a cooling tower discharge plume

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

    Hlubek, W.; Spalthoff, F.J.

    1989-01-01

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

  14. Interaction of titanium and vanadium with carbon dioxide in heating

    International Nuclear Information System (INIS)

    Vlasyuk, R.Z.; Kurovskii, V.Y.; Lyapunov, A.P.; Radomysel'skii, I.D.

    1986-01-01

    To obtain prediction data on the change in properties of titaniumand vanadium-base powder metallurgy materials operating in a carbon dioxide atmosphere, and also to clarify the mechanism of their interaction with the gas in this work, gravimetric investigations of specimens heated at temperatures of 300-1000 C and an x-ray diffraction analysis of their surface were made and the composition of the gas in the heating chamber was studied. The results of the investigations indicate a similarity between the mechanisms of interaction of titanium and vanadium with carbon dioxide including the formation of oxides on the surface of the metal with subsequent carbidization at temperatures above 800 C. On the basis of the data obtained, it may be concluded that the operating temperature limits of titanium- or vanadium-base materials in carbon dioxide must not exceed 400 and 600 C, respectively

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Carbon dioxide (CO 2 ) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν 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 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 2 O)-carbon dioxide (CO 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 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.

  16. Paramagnetic defects in hydrogenated amorphous carbon powders

    International Nuclear Information System (INIS)

    Keeble, D J; Robb, K M; Smith, G M; Mkami, H El; Rodil, S E; Robertson, J

    2003-01-01

    Hydrogenated amorphous carbon materials typically contain high concentrations of paramagnetic defects, the density of which can be quantified by electron paramagnetic resonance (EPR). In this work EPR measurements near 9.5, 94, and 189 GHz have been performed on polymeric and diamond-like hydrogenated amorphous carbon (a-C:H) powder samples. A similar single resonance line was observed at all frequencies for the two forms of a-C:H studied. No contributions to the spectrum from centres with resolved anisotropic g-values as reported earlier were detected. An increase in linewidth with microwave frequency was observed. Possible contributions to this frequency dependence are discussed

  17. Effect of Elevated Carbon Dioxide Concentration on Carbon Assimilation under Fluctuating Light

    Czech Academy of Sciences Publication Activity Database

    Holišová, Petra; Zitová, Martina; Klem, Karel; Urban, Otmar

    2012-01-01

    Roč. 41, č. 6 (2012), s. 1931-1938 ISSN 0047-2425 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA ČR(CZ) GAP501/10/0340; GA MŠk(CZ) LM2010007; GA AV ČR IAA600870701 Institutional support: RVO:67179843 Keywords : carbon * light * beech * spruce * carbon assimilation * elevat e carbon * dioxide concentration * mol * photosynthetic * assimilation * carbon dioxide * dioxide * concentracion * leave * photosynthetic efficiency Subject RIV: EH - Ecology, Behaviour Impact factor: 2.353, year: 2012

  18. BOREAS TGB-12 Isotropic Carbon Dioxide Data over the NSA

    Science.gov (United States)

    Trumbore, Susan; Hall, Forrest G. (Editor); Sundquist, Eric; Winston, Greg; Conrad, Sara K. (Editor)

    2000-01-01

    The BOREAS TGB-12 team made measurements of soil carbon inventories, carbon concentration in soil gases, and rates of soil respiration at several sites to estimate the rates of carbon accumulation and turnover in each of the major vegetation types. This data set contains information on the carbon isotopic content of carbon dioxide sampled from soils in the NSA-OBS, NSA-YJP, and NSA-OJP sites. Data were collected from 14-Nov-1993 to 10-Oct-1996. The data are stored in tabular ASCII files.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  20. Kinetic study of coals gasification into carbon dioxide atmosphere

    Directory of Open Access Journals (Sweden)

    Korotkikh A.G.

    2015-01-01

    Full Text Available The solid fuel gasification process was investigated to define chemical reactions rate and activation energy for a gas-generator designing and regime optimizing. An experimental procedure includes coal char samples of Kuznetskiy and Kansko-Achinskiy deposits consequent argon pyrolysis into argon and oxidating into carbon dioxide with different temperatures. The thermogravimetric analysis data of coal char gasification into carbon dioxide was obtained in the temperature range 900–1200 ºC. The mass loss and gasification time dependencies from temperature were defined to calculate chemical reaction frequency factor and activation energy. Two coal char gasification physico-mathematical models were proposed and recommendations for them were formed.

  1. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION; SEMIANNUAL

    International Nuclear Information System (INIS)

    Jerry Y.S. Lin; Jun-ichi Ida

    2001-01-01

    This project is aimed at demonstrating technical feasibility for a lithium zirconate based dense ceramic membrane for separation of carbon dioxide from flue gas at high temperature. The research work conducted in this reporting period was focused on several fundamental issues of lithium zirconate important to the development of the dense inorganic membrane. These fundamental issues include material synthesis of lithium zirconate, phases and microstructure of lithium zirconate and structure change of lithium zirconate during sorption/desorption process. The results show difficulty to prepare the dense ceramic membrane from pure lithium zirconate, but indicate a possibility to prepare the dense inorganic membrane for carbon dioxide separation from a composite lithium zirconate

  2. Historic and projected vehicle use and carbon dioxide emissions

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Data are presented in this chapter that show a decline in total carbon dioxide emissions per vehicle of about 20 between 1970 and 1987. However, it is also shown that the fuel economy gains of the 1970s and early 1980s in many countries have begun to erode. In the US, low fuel prices combined with a failure to strengthen fuel efficiency standards have led to recent declines in new-car fuel efficiency. Even if these trends are reversed carbon dioxide in the transport sector will not be reduced if over all motor vehicle use continues along present lines

  3. Visual and reversible carbon dioxide sensing enabled by doctor blade coated macroporous photonic crystals.

    Science.gov (United States)

    Lin, Yi-Han; Suen, Shing-Yi; Yang, Hongta

    2017-11-15

    With significant impacts of carbon dioxide on global climate change, carbon dioxide sensing is of great importance. However, most of the existing sensing technologies are prone to interferences from carbon monoxide, or suffer from the use of sophisticated instruments. This research reports the development of reproducible carbon dioxide sensor using roll-to-roll compatible doctor blade coated three-dimensional macroporous photonic crystals. The pores are functionalized with amine groups to allow the reaction with carbon dioxide in the presence of humidity. The adsorption of carbon dioxide leads to red-shift and amplitude reduction of the optical stop bands, resulting in carbon dioxide detection with visible readout. The dependences of the diffraction wavelength on carbon dioxide partial pressure for various amine-functionalized photonic crystals and different humidities in the environment are systematically investigated. In addition, the reproducibility of carbon dioxide sensing has also been demonstrated in this research. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Plant growth and physiology of vegetable plants as influenced by carbon dioxide environment

    International Nuclear Information System (INIS)

    Ito, Tadashi

    1973-01-01

    In order to obtain basic knowledge on the increased giving of carbon dioxide to vegetables, the carbon dioxide environment in growing houses was analyzed, and the physiological and ecological properties of vegetables cultivated in carbon dioxide environment were elucidated. To improve the carbon dioxide environment, giving increased quantity of carbon dioxide, air flow, ventilation, and others were examined. The concentration of carbon dioxide began to decrease when the illumination intensity on growing layer reached 1 -- 1.5 lux, owing to the photo-synthetic activity of vegetables, and decreased rapidly at 3 -- 5 lux. The lowering of carbon dioxide concentration lowered the photo-synthesis of vegetables extremely, and the transfer of synthesized carbohydrate to roots was obstructed. The effect suffered in low carbon dioxide concentration left some aftereffect even after ventilation and the recovery of carbon dioxide concentration. But this aftereffect was not observed in case of cucumber. To improve carbon dioxide environment, the air flow or ventilation required for minimizing the concentration lowering was determined, but giving increased quantity of carbon dioxide was most effective. The interaction of carbon dioxide concentration and light was examined regarding the effect on photo-synthesis, and some knowledge of practical application was obtained. The effect of giving more carbon dioxide was more remarkable as the treatment was given to younger seedlings and in the period when the capacity of absorbing assimilation products was higher. (Kako, I.)

  5. Industrial structural transformation and carbon dioxide emissions in China

    International Nuclear Information System (INIS)

    Zhou, Xiaoyan; Zhang, Jie; Li, Junpeng

    2013-01-01

    Using provincial panel data from the period 1995–2009 to analyze the relationship between the industrial structural transformation and carbon dioxide emissions in China, we find that the first-order lag of industrial structural adjustment effectively reduced the emissions; technical progress itself did not reduce the emissions, but indirectly led to decreasing emissions through the upgrading and optimization of industrial structure. Foreign direct investment and intervention by local governments reduced carbon dioxide emissions, but urbanization significantly increased the emissions. Thus, industrial structural adjustment is an important component of the development of a low-carbon economy. In the context of industrial structural transformation, an effective way to reduce a region’s carbon dioxide emissions is to promote the upgrading and optimization of industrial structure through technical progress. Tighter environmental access policies, selective utilization of foreign direct investment, and improvements in energy efficiency can help to reduce carbon dioxide emissions. - Highlights: ► Relationship between the transformation of industrial structure and CO 2 emissions in China. ► Dynamic panel data model. ► Industrial structural adjustments can effectively reduce current CO 2 emissions. ► Technical progress leads to decreasing CO 2 emissions through upgrading of industrial structure

  6. Carbon Dioxide Effects Research and Assessment Program: Proceedings of the carbon dioxide and climate research program conference

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, L E [ed.

    1980-12-01

    Papers presented at the Carbon Dioxide and Climate Research Program Conference are included in this volume. Topics discussed are: the carbon cycle; modeling the carbon system; climatic response due to increased CO2; climate modeling; the use of paleoclimatic data in understanding climate change; attitudes and implications of CO2; social responses to the CO2 problem; a scenario for atmospheric CO2 to 2025; marine photosynthesis and the global carbon cycle; and the role of tropical forests in the carbon balance of the world. Separate abstracts of nine papers have been prepared for inclusion in the Energy Data Base. (RJC)

  7. Classroom Demonstration: Combustion of Diamond to Carbon Dioxide Followed by Reduction to Graphite

    Science.gov (United States)

    Miyauchi, Takuya; Kamata, Masahiro

    2012-01-01

    An educational demonstration shows the combustion of carbon to carbon dioxide and then the reduction of carbon dioxide to carbon. A melee diamond is the source of the carbon and the reaction is carried out in a closed flask. The demonstration helps students to realize that diamonds are made of carbon and that atoms do not change or vanish in…

  8. Reaction mechanisms for enhancing carbon dioxide mineral sequestration

    Science.gov (United States)

    Jarvis, Karalee Ann

    Increasing global temperature resulting from the increased release of carbon dioxide into the atmosphere is one of the greatest problems facing society. Nevertheless, coal plants remain the largest source of electrical energy and carbon dioxide gas. For this reason, researchers are searching for methods to reduce carbon dioxide emissions into the atmosphere from the combustion of coal. Mineral sequestration of carbon dioxide reacted in electrolyte solutions at 185°C and 2200 psi with olivine (magnesium silicate) has been shown to produce environmentally benign carbonates. However, to make this method feasible for industrial applications, the reaction rate needs to be increased. Two methods were employed to increase the rate of mineral sequestration: reactant composition and concentration were altered independently in various runs. The products were analyzed with complete combustion for total carbon content. Crystalline phases in the product were analyzed with Debye-Scherrer X-ray powder diffraction. To understand the reaction mechanism, single crystals of San Carlos Olivine were reacted in two solutions: (0.64 M NaHCO3/1 M NaCl) and (5.5 M KHCO3) and analyzed with scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and fluctuation electron microscopy (FEM) to study the surface morphology, atomic crystalline structure, composition and amorphous structure. From solution chemistry studies, it was found that increasing the activity of the bicarbonate ion increased the conversion rate of carbon dioxide to magnesite. The fastest conversion, 60% conversion in one hour, occurred in a solution of 5.5 M KHCO3. The reaction product particles, magnesium carbonate, significantly increased in both number density and size on the coupon when the bicarbonate ion activity was increased. During some experiments reaction vessel corrosion also altered the mineral sequestration mechanism. Nickel ions from vessel

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

    Science.gov (United States)

    Graves, Christopher Ronald

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

  10. Hydrogen storage in sonicated carbon materials

    NARCIS (Netherlands)

    Hirscher, M.; Becher, M.; Haluska, M.; Dettlaff-Weglikowska, U.; Quintel, A.; Duesberg, G.S.; Choi, Y.J.; Downes, P.; Hulman, M.; Roth, S.; Stepanek, I.; Bernier, P.

    2001-01-01

    The hydrogen storage in purified single-wall carbon nanotubes (SWNTs), graphite and diamond powder was investigated at room temperature and ambient pressure. The samples were sonicated in 5 M HNO3 for various periods of time using an ultrasonic probe of the alloy Ti-6Al-4V. The goal of this

  11. Hydrogen storage using microporous carbon materials

    International Nuclear Information System (INIS)

    Buczek, B.; Wolak, E.

    2005-01-01

    higher temperatures than liquefaction [3]. Last years have brought the interest in hydrogen storage in porous carbon materials, caused by the design and accessibility of new materials, such as fullerenes, carbon nano-tubes and nano-fibers. In particular the tubular carbon structures are perspective highly adsorbing materials, for their surface adsorption (on the internal and external surface of the nano-tubes), and for the effect of capillary condensation [4]. Data presented in Table 1 show that the amount of hydrogen adsorbed on these new materials depends of their modification and on the type of carbon precursor [5]. In this work the concept of hydrogen storage by adsorption was analyzed. The discussion is based on measurements of hydrogen adsorption on commercial active carbon in the temperature range 77 - 298 K at pressures up to 4 MPa. The amount of gas that can be stored in an adsorption system depends on the adsorbent characteristics and the operating conditions. Adsorption method was compared with another one taking into account both technical and economical aspects. The results show that the adsorption technique could provide a viable method for hydrogen storage. [1]G. D. Berry, A. D. Pastemak, G. D. Rambach, J. R. Smith, N. Schock, Energy. 21, 289, 1996; [2]L. Czepirski, Przem. Chem. 70, 129, 1991 (in Polish); [3]B. Buczek, L. Czepirski, Inz. Chem. Proc., 24, 545, 2003; [4]U. Huczko, Przem. Chem. 81, 19, 2002 (in Polish); [5]U. Buenger, W. Zittel, Appl. Phys. A 72, 147, 2001. (authors)

  12. Hydrogen storage using microporous carbon materials

    International Nuclear Information System (INIS)

    B Buczek; E Wolak

    2005-01-01

    temperatures than liquefaction. Last years have brought the interest in hydrogen storage in porous carbon materials, caused by the design and accessibility of new materials, such as fullerenes, carbon nano-tubes and nano-fibers. In particular the tubular carbon structures are perspective highly adsorbing materials, for their surface adsorption (on the internal and external surface of the nano-tubes), and for the effect of capillary condensation. Data presented in Table 1 show that the amount of hydrogen adsorbed on these new materials depends of their modification and on the type of carbon precursor. In this work the concept of hydrogen storage by adsorption was analyzed. The discussion is based on measurements of hydrogen adsorption on commercial active carbon in the temperature range 77 - 298 K at pressures up to 4 MPa. The amount of gas that can be stored in an adsorption system depends on the adsorbent characteristics and the operating conditions. Adsorption method was compared with another one taking into account both technical and economical aspects. The results show that the adsorption technique could provide a viable method for hydrogen storage

  13. Energy Saving High-Capacity Moderate Pressure Carbon Dioxide Storage System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our approach to high-pressure carbon dioxide storage will directly address the challenges associated with storage of compressed carbon dioxide - the need to reduce...

  14. Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report is the authoritative reference for carbon dioxide (CO2) emissions,...

  15. Preparation and elementary research on electrocatalytic hydrogen evolution of highly ordered titanium dioxide nanotube arrays

    International Nuclear Information System (INIS)

    Wu Qinglong; Liao Junsheng; Bai Yun

    2010-01-01

    Well ordered and uniform titanium dioxide nanotube arrays were fabricated by anodiaing process from a bath containing 1% NaF, 1mol/L Na 2 SO 4 , 0.5 mol/L H 2 SO 4 at room temperature. Surface morphology of titanium dioxide nanotube arrays were observed with SEM. The formation process of titanium dioxide nanotube arrays was suggested by current-time transient. Its catalytic hydrogen evolution behavior was studied by electrochemical measurements in a 5%(mass fraction) H 2 SO 4 solution. The results showed that the titanium dioxide nanotube arrays on titanium had better hydrogen evolution activity and trace palladium lead to the maximum electrocatalytic activity of hydrogen production. (authors)

  16. Carbon dioxide sequestration by aqueous mineral carbonation of magnesium silicate minerals

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-01

    The dramatic increase in atmospheric carbon dioxide since the Industrial Revolution has caused concerns about global warming. Fossil-fuel-fired power plants contribute approximately one third of the total human-caused emissions of carbon dioxide. Increased efficiency of these power plants will have a large impact on carbon dioxide emissions, but additional measures will be needed to slow or stop the projected increase in the concentration of atmospheric carbon dioxide. By accelerating the naturally occurring carbonation of magnesium silicate minerals it is possible to sequester carbon dioxide in the geologically stable mineral magnesite (MgCO3). The carbonation of two classes of magnesium silicate minerals, olivine (Mg2SiO4) and serpentine (Mg3Si2O5(OH)4), was investigated in an aqueous process. The slow natural geologic process that converts both of these minerals to magnesite can be accelerated by increasing the surface area, increasing the activity of carbon dioxide in the solution, introducing imperfections into the crystal lattice by high-energy attrition grinding, and in the case of serpentine, by thermally activating the mineral by removing the chemically bound water. The effect of temperature is complex because it affects both the solubility of carbon dioxide and the rate of mineral dissolution in opposing fashions. Thus an optimum temperature for carbonation of olivine is approximately 185 degrees C and 155 degrees C for serpentine. This paper will elucidate the interaction of these variables and use kinetic studies to propose a process for the sequestration of the carbon dioxide.

  17. Solar hydrogen hybrid system with carbon storage

    International Nuclear Information System (INIS)

    Zini, G.; Marazzi, R.; Pedrazzi, S.; Tartarini, P.

    2009-01-01

    A complete solar hydrogen hybrid system has been developed to convert, store and use energy from renewable energy sources. The theoretical model has been implemented in a dynamic model-based software environment and applied to real data to simulate its functioning over a one-year period. Results are used to study system design and performance. A photovoltaic sub-system directly drives a residential load and, if a surplus of energy is available, an electrolyzer to produce hydrogen which is stored in a cluster of nitrogen-cooled tanks filled with AX-21 activated carbons. When the power converted from the sun is not sufficient to cover load needs, hydrogen is desorbed from activated carbon tanks and sent to the fuel-cell sub-system so to obtain electrical energy. A set of sub-systems (bus-bar, buck- and boost-converters, inverter, control circuits), handle the electrical power according to a Programmable Logic Control unit so that the load can be driven with adequate Quality of Service. Hydrogen storage is achieved through physisorption (weak van der Waals interactions) between carbon atoms and hydrogen molecules occurring at low temperature (77 K) in carbon porous solids at relatively low pressures. Storage modeling has been developed using a Langmuir-Freundlich 1st type isotherm and experimental data available in literature. Physisorption storage provides safer operations along with good gravimetric (10.8% at 6 MPa) and volumetric (32.5 g/l at 6 MPa) storage capacities at costs that can be comparable to, or smaller than, ordinary storage techniques (compression or liquefaction). Several test runs have been performed on residential user data-sets: the system is capable of providing grid independence and can be designed to yield a surplus production of hydrogen which can be used to recharge electric car batteries or fill tanks for non-stationary uses. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-05-01

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  20. Synthesis of hydrogen-carbon clathrate material and hydrogen evolution therefrom at moderate temperatures and pressures

    Science.gov (United States)

    Lueking, Angela [State College, PA; Narayanan, Deepa [Redmond, WA

    2011-03-08

    A process for making a hydrogenated carbon material is provided which includes forming a mixture of a carbon source, particularly a carbonaceous material, and a hydrogen source. The mixture is reacted under reaction conditions such that hydrogen is generated and/or released from the hydrogen source, an amorphous diamond-like carbon is formed, and at least a portion of the generated and/or released hydrogen associates with the amorphous diamond-like carbon, thereby forming a hydrogenated carbon material. A hydrogenated carbon material including a hydrogen carbon clathrate is characterized by evolution of molecular hydrogen at room temperature at atmospheric pressure in particular embodiments of methods and compositions according to the present invention.

  1. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    An increase in carbon dioxide (CO2) concentrations in the atmosphere due to ... The changes in land ... the air quality and climate models. 2. ... soon period of 2011 as a part Cloud Aerosol .... density effects due to heat and water vapour trans-.

  2. TWO-PHASE EJECTOR of CARBON DIOXIDE HEAT PUMP CALCULUS

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2010-12-01

    Full Text Available It is presented the calculus of the two-phase ejector for carbon dioxide heat pump. The method of calculus is based on the method elaborated by S.M. Kandil, W.E. Lear, S.A. Sherif, and is modified taking into account entrainment ratio as the input for the calculus.

  3. Convergence of carbon dioxide emissions in different sectors in China

    International Nuclear Information System (INIS)

    Wang, Juan; Zhang, Kezhong

    2014-01-01

    In this paper, we analyze differences in per capita carbon dioxide emissions from 1996 to 2010 in six sectors across 28 provinces in China and examine the σ-convergence, stochastic convergence and β-convergence of these emissions. We also investigate the factors that impact the convergence of per capita carbon dioxide emissions in each sector. The results show that per capita carbon dioxide emissions in all sectors converged across provinces from 1996 to 2010. Factors that impact the convergence of per capita carbon dioxide emissions in each sector vary: GDP (gross domestic product) per capita, industrialization process and population density impact convergence in the Industry sector, while GDP per capita and population density impact convergence in the Transportation, Storage, Postal, and Telecommunications Services sector. Aside from GDP per capita and population density, trade openness also impacts convergence in the Wholesale, Retail, Trade, and Catering Service sector. Population density is the only factor that impacts convergence in the Residential Consumption sector. - Highlights: • Analyze differences in CO 2 emissions in six sectors among 28 provinces in China. • Examine the convergence of CO 2 emissions in six sectors. • Investigate factors impact on convergence of CO 2 emissions in each sector. • Factors impact on convergence of per capita CO 2 emissions in each sector vary

  4. Carbon dioxide (CO 2 ) utilizing strain database | Saini | African ...

    African Journals Online (AJOL)

    Culling of excess carbon dioxide from our environment is one of the major challenges to scientific communities. Many physical, chemical and biological methods have been practiced to overcome this problem. The biological means of CO2 fixation using various microorganisms is gaining importance because database of ...

  5. Intravenous carbon dioxide as an echocardiographic contrast agent

    NARCIS (Netherlands)

    R.S. Meltzer (Richard); P.W.J.C. Serruys (Patrick); P.G. Hugenholtz (Paul); J.R.T.C. Roelandt (Jos)

    1981-01-01

    textabstractIntravenous carbon dioxide (CO2) was employed to cause echocardiographic contrast in 40 patients. One to 3 cc of medically pure CO2 were agitated with 5 to 8 cc of 5% dextrose in water and rapidly injected into an upper extremity vein. Contrast was obtained in all patients. In 33

  6. 2001-2002 carbon dioxide emissions in OECD

    International Nuclear Information System (INIS)

    2004-11-01

    This document provides carbon dioxide emissions data, from energy uses and production, from 2001 to 2002 in the OECD. It concerns the climate corrected CO 2 emissions in France, the non corrected CO 2 emissions (M tons), the emissions intensity / the Gross Domestic Product and the emissions intensity / the population (tons per inhabitant). (A.L.B.)

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

    NARCIS (Netherlands)

    Beurskens, Charlotte J.; Brevoord, Daniel; Lagrand, Wim K.; van den Bergh, Walter M.; Vroom, Margreeth B.; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P.

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical

  8. Cavitation-induced reactions in high-pressure carbon dioxide

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; van Eck, D.; Kemmere, M.F.; Keurentjes, J.T.F.

    2002-01-01

    The feasibility of ultrasound-induced in situ radical formation in liquid carbon dioxide was demonstrated. The required threshold pressure for cavitation could be exceeded at a relatively low acoustic intensity, as the high vapor pressure of CO2 counteracts the hydrostatic pressure. With the use of

  9. Removing carbon dioxide from a stationary source through co ...

    African Journals Online (AJOL)

    Except temperature of solvent, all study variables showed strong relation with the amount of carbon dioxide absorbed (with a P-value < 0.05). Uniquely, this study has evaluated the potential for sodium bicarbonate production from the CO2 absorbed using gravimetric analysis. It is also possible to recover over 28% crystal ...

  10. Carbon dioxide angiography: a simple and safe system of delivery

    International Nuclear Information System (INIS)

    Cronin, P.; Patel, J.V.; Kessel, D.O.; Robertson, I.; McPherson, S.J.

    2005-01-01

    Carbon dioxide (CO 2 ) is an established alternate angiographic contrast agent, which can be delivered by pump or hand injection. We describe a simple, safe and inexpensive hand injection system that delivers a known volume of CO 2 at atmospheric pressure and prevents contamination with room air

  11. Intertidal zones as carbon dioxide sources to coastal oceans

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  12. Extended-length fiber optic carbon dioxide monitoring

    Science.gov (United States)

    Delgado-Alonso, Jesus; Lieberman, Robert A.

    2013-05-01

    This paper discusses the design and performance of fiber optic distributed intrinsic sensors for dissolved carbon dioxide, based on the use optical fibers fabricated so that their entire lengths are chemically sensitive. These fibers use a polymer-clad, silica-core structure where the cladding undergoes a large, reversible, change in optical absorbance in the presence of CO2. The local "cladding loss" induced by this change is thus a direct indication of the carbon dioxide concentration in any section of the fiber. To create these fibers, have developed a carbon dioxide-permeable polymer material that adheres well to glass, is physically robust, has a refractive index lower than fused silica, and acts as excellent hosts for a unique colorimetric indicator system that respond to CO2. We have used this proprietary material to produce carbon-dioxide sensitive fibers up to 50 meters long, using commercial optical fiber fabrication techniques. The sensors have shown a measurement range of dissolved CO2 of 0 to 1,450 mg/l (0 to 100% CO2 saturation), limit of detection of 0.3 mg/l and precision of 1.0 mg/l in the 0 to 50 mg/l dissolved CO2 range, when a 5 meter-long sensor fiber segment is used. Maximum fiber length, minimum detectable concentration, and spatial resolution can be adjusted by adjusting indicator concentration and fiber design.

  13. Electrochemical carbon dioxide reduction on rough copper surfaces

    NARCIS (Netherlands)

    Kas, Recep

    2016-01-01

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

  14. Distribution of Carbon Dioxide Produced by People in a Room:

    DEFF Research Database (Denmark)

    Naydenov, Kiril Georgiev; Baránková, Petra; Sundell, Jan

    2004-01-01

    Carbon dioxide exhaled by people can be used as a tracer gas for air change measurements in homes. Good mixing of tracer gas with room air is a necessary condition to obtain accurate results. However, the use of fans to ensure mixing is inconvenient. The natural room distribution of metabolic CO2...

  15. The effect of carbon dioxide at high pressure under different ...

    African Journals Online (AJOL)

    user

    2011-03-14

    Mar 14, 2011 ... the pulse beetle, Callosobruchus maculates. J. Insect Sci. 9: 58-61. George NM, Sonny BR (1998). Comparative effect of short term exposures of Callosobruchus subinnotatus to carbon dioxide, nitrogen, or low temperature on behaviour and fecundity. Entomologia Experimentalis et Applicata Vol. 89, No.

  16. Integrated biofuel facility, with carbon dioxide consumption and power generation

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering

    2009-07-01

    This presentation provided details of an economical design for a large-scale integrated biofuel facility for coupled production of bioethanol and biodiesel, with carbon dioxide capture and power generation. Several designs were suggested for both batch and continuous culture operations, taking into account all costs and revenues associated with the complete plant integration. The microalgae species Chlorella vulgaris was cultivated in a novel photobioreactor (PBR) in order to consume industrial carbon dioxide (CO{sub 2}). This photosynthetic culture can also act as a biocathode in a microbial fuel cell (MFC), which when coupled to a typical yeast anodic half cell, results in a complete biological MFC. The photosynthetic MFC produces electricity as well as valuable biomass and by-products. The use of this novel photosynthetic microalgae cathodic half cell in an integrated biofuel facility was discussed. A series of novel PBRs for continuous operation can be integrated into a large-scale bioethanol facility, where the PBRs serve as cathodic half cells and are coupled to the existing yeast fermentation tanks which act as anodic half cells. These coupled MFCs generate electricity for use within the biofuel facility. The microalgae growth provides oil for biodiesel production, in addition to the bioethanol from the yeast fermentation. The photosynthetic cultivation in the cathodic PBR also requires carbon dioxide, resulting in consumption of carbon dioxide from bioethanol production. The paper also discussed the effect of plant design on net present worth and internal rate of return. tabs., figs.

  17. Dry-cleaning with high-pressure carbon dioxide

    NARCIS (Netherlands)

    Van Roosmalen, M.J.E.

    2003-01-01

    Dry-cleaning is a process for removing soils and stains from fabrics and garments which uses a non-aqueous solvent with detergent added. The currently most used dry-cleaning solvent is perchloroethylene (PER), which is toxic, environmentally harmful and suspected to be carcinogenic. Carbon dioxide

  18. Carbon dioxide hydrate formation in a fixed-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Fan, S.; Lang, X. [South China Univ. of Technology, Guangzhou (China). Key Laboratory of Enhanced Heat Transfer and Energy Conservation; Wang, Y.; Liang, D. [Chinese Academy of Sciences, Guangzhou (China). Guangzhou Inst. of Energy Conversion and Guangzhou Center of Natural Gas Hydrate; Sun, X.; Jurcik, B. [Air Liquide Laboratories, Tsukuba (Japan)

    2008-07-01

    Gas hydrates are thermodynamically stable at high pressures and near the freezing temperature of pure water. Methane hydrates occur naturally in sediments in the deep oceans and permafrost regions and constitute an extensive hydrocarbon reservoir. Carbon dioxide (CO{sub 2}) hydrates are of interest as a medium for marine sequestration of anthropogenic carbon dioxide. Sequestering CO{sub 2} as hydrate has potential advantages over most methods proposed for marine CO{sub 2} sequestration. Because this technique requires a shallower depth of injection when compared with other ocean sequestration methods, the costs of CO{sub 2} hydrate sequestration may be lower. Many studies have successfully used different continuous reactor designs to produce CO{sub 2} hydrates in both laboratory and field settings. This paper discussed a study that involved the design and construction of a fixed-bed reactor for simulation of hydrate formation system. Water, river sands and carbon dioxide were used to simulate the seep kind of hydrate formation. Carbon dioxide gas was distributed as small bubbles to enter from the bottom of the fixed-bed reactor. The paper discussed the experimental data and presented a diagram of the gas hydrate reactor system. The morphology as well as the reaction characters of CO{sub 2} hydrate was presented in detail. The results were discussed in terms of experimental phenomena and hydrate formation rate. A mathematical model was proposed for describing the process. 17 refs., 7 figs.

  19. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... cylinder storage area must be properly ventilated and the temperature inside must not exceed 130 °F. (g...

  20. Permeation of supercritical carbon dioxide through polymeric hollow fiber membranes

    NARCIS (Netherlands)

    Patil, V.E.; Broeke, van den L.J.P.; Vercauteren, F.F.; Keurentjes, J.T.F.

    2006-01-01

    Permeation of carbon dioxide was measured for two types of composite polymeric hollow fiber membranes for feed pressures up to 18 MPa at a temp. of 313 K. support membrane. The membranes consist of a polyamide copolymer (IPC) layer or a poly(vinyl alc.) (PVA) layer on top of a polyethersulfone

  1. Kinetics of absorption of carbon dioxide in aqueous ammonia solutions

    NARCIS (Netherlands)

    Derks, P. W. J.; Versteeg, G. F.

    2009-01-01

    In the present work the absorption of carbon dioxide into aqueous ammonia solutions has been studied in a stirred cell reactor, at low temperatures and ammonia concentrations ranging from 0.1 to about 7 kmol m-3. The absorption experiments were carried out at conditions where the so-called pseudo

  2. Classroom Carbon Dioxide Concentration, School Attendance, and Educational Attainment

    Science.gov (United States)

    Gaihre, Santosh; Semple, Sean; Miller, Janice; Fielding, Shona; Turner, Steve

    2014-01-01

    Background: We tested the hypothesis that classroom carbon dioxide (CO[subscript 2]) concentration is inversely related to child school attendance and educational attainment. Methods: Concentrations of CO[subscript 2] were measured over a 3-5?day period in 60 naturally ventilated classrooms of primary school children in Scotland. Concentrations of…

  3. Carbon Dioxide Absorption in a Membrane Contactor with Color Change

    Science.gov (United States)

    Pantaleao, Ines; Portugal, Ana F.; Mendes, Adelio; Gabriel, Joaquim

    2010-01-01

    A pedagogical experiment is described to examine the physical absorption of gases, in this case carbon dioxide, in a hollow fiber membrane contactor (HFMC) where the absorption concentration profile can be followed by a color change. The HFMC is used to teach important concepts and can be used in interesting applications for students, such as…

  4. Carbon dioxide laser resurfacing of rhytides and photodamaged skin

    OpenAIRE

    Kelly, KM; Nelson, JS

    1998-01-01

    Carbon dioxide (CO 2 ) laser resurfacing has been used as a method to treat rhytides and photodamaged skin. This laser offers several advantages over previously utilised modalities but its use has several inherent risks. This article will review important aspects of CO 2 laser resurfacing including laser-skin interactions, patient selection, effective pre- and post-operative regimens and potential complications.

  5. Water vapour and carbon dioxide decrease nitric oxide readings

    NARCIS (Netherlands)

    vanderMark, TW; Kort, E; Meijer, RJ; Postma, DS; Koeter, GH

    Measurement of nitric oxide levels in exhaled ah-is commonly performed using a chemiluminescence detector. However, water vapour and carbon dioxide affect the chemiluminescence process, The influence of these gases at the concentrations present in exhaled air has not vet been studied. For this in

  6. Catalytic polymerization of olefins in supercritical carbon dioxide

    NARCIS (Netherlands)

    Kemmere, M.F.; Vries, de T.J.; Keurentjes, J.T.F.

    2004-01-01

    A novel process is being developed for the catalytic polymerization of olefins in supercritical carbon dioxide (sc CO2), for which potential applications will mainly be in the production of EPDM and other elastomers. For this purpose, the Brookhart catalyst has been tested for the homopolymerization

  7. Thermal Properties of Supercritical Carbon Dioxide by Monte Carlo Simulations

    Czech Academy of Sciences Publication Activity Database

    Colina, C. M.; Olivera-Fuentes, C. G.; Siperstein, F. R.; Lísal, Martin; Gubbins, K. E.

    2003-01-01

    Roč. 29, 6-7 (2003), s. 405-412 ISSN 0892-7022 R&D Projects: GA ČR GA203/02/0805 Grant - others:NSF(US) CHE-9876674291 Institutional research plan: CEZ:AV0Z4072921 Keywords : fluctuations * carbon dioxide * 2CLJQ Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.721, year: 2003

  8. SELECTIVE OXIDATION IN SUPERCRITICAL CARBON DIOXIDE USING CLEAN OXIDANTS

    Science.gov (United States)

    We have systematically investigated heterogeneous catalytic oxidation of different substrates in supercritical carbon dioxide (SC-CO2). Three types of catagysts: a metal complex, 0.5% platinum g-alumina and 0.5% palladium g-alumina were used at a pressure of 200 bar, temperatures...

  9. Solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide

    DEFF Research Database (Denmark)

    Kazemi, Somayeh; Belandria, Veronica; Janssen, Nico

    2012-01-01

    In this work, the solubilities of ferrocene and acetylferrocene in supercritical carbon dioxide (scCO2) were measured using an analytical method in a quasi-flow apparatus. High-performance liquid chromatography was applied through an online sampling procedure to determine the concentration...

  10. Carbon Dioxide Utilization by the Five-Membered Ring Products of Cyclometalation Reactions

    Science.gov (United States)

    Omae, Iwao

    2016-01-01

    In carbon dioxide utilization by cyclometalated five-membered ring products, the following compounds are used in four types of applications: 1. 2-Phenylpyrazole iridium compounds, pincer phosphine iridium compounds and 2-phenylimidazoline iridium compounds are used as catalysts for both formic acid production from CO2 and H2, and hydrogen production from the formic acid. This formic acid can be a useful agent for H2 production and storage for fuel cell electric vehicles. 2. Other chemicals, e.g., dimethyl carbonate, methane, methanol and CO, are produced with dimethylaminomethylphenyltin compounds, pincer phosphine iridium compounds, pincer phosphine nickel compound and ruthenium carbene compound or 2-phenylpyridine iridium compounds, and phenylbenzothiazole iridium compounds as the catalysts for the reactions with CO2. 3. The five-membered ring intermediates of cyclometalation reactions with the conventional substrates react with carbon dioxide to afford their many types of carboxylic acid derivatives. 4. Carbon dioxide is easily immobilized at room temperature with immobilizing agents such as pincer phosphine nickel compounds, pincer phosphine palladium compounds, pincer N,N-dimethylaminomethyltin compounds and tris(2-pyridylthio)methane zinc compounds. PMID:28503084

  11. The thermodynamics of direct air capture of carbon dioxide

    International Nuclear Information System (INIS)

    Lackner, Klaus S.

    2013-01-01

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

  12. Practical modeling approaches for geological storage of carbon dioxide.

    Science.gov (United States)

    Celia, Michael A; Nordbotten, Jan M

    2009-01-01

    The relentless increase of anthropogenic carbon dioxide emissions and the associated concerns about climate change have motivated new ideas about carbon-constrained energy production. One technological approach to control carbon dioxide emissions is carbon capture and storage, or CCS. The underlying idea of CCS is to capture the carbon before it emitted to the atmosphere and store it somewhere other than the atmosphere. Currently, the most attractive option for large-scale storage is in deep geological formations, including deep saline aquifers. Many physical and chemical processes can affect the fate of the injected CO2, with the overall mathematical description of the complete system becoming very complex. Our approach to the problem has been to reduce complexity as much as possible, so that we can focus on the few truly important questions about the injected CO2, most of which involve leakage out of the injection formation. Toward this end, we have established a set of simplifying assumptions that allow us to derive simplified models, which can be solved numerically or, for the most simplified cases, analytically. These simplified models allow calculation of solutions to large-scale injection and leakage problems in ways that traditional multicomponent multiphase simulators cannot. Such simplified models provide important tools for system analysis, screening calculations, and overall risk-assessment calculations. We believe this is a practical and important approach to model geological storage of carbon dioxide. It also serves as an example of how complex systems can be simplified while retaining the essential physics of the problem.

  13. Application of a systematic methodology for sustainable carbon dioxide utilization process design

    DEFF Research Database (Denmark)

    Plaza, Cristina Calvera; Frauzem, Rebecca; Gani, Rafiqul

    than carbon capture and storage. To achieve this a methodology is developed to design sustainable carbon dioxide utilization processes. First, the information on the possible utilization alternatives is collected, including the economic potential of the process and the carbon dioxide emissions...... emission are desired in order to reduce the carbon dioxide emissions. Using this estimated preliminary evaluation, the top processes, with the most negative carbon dioxide emission are investigated by rigorous detailed simulation to evaluate the net carbon dioxide emissions. Once the base case design...

  14. Carbon Dioxide (CO2) in Blood: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/carbondioxideco2inblood.html Carbon Dioxide (CO2) in Blood To use the sharing features ... this page, please enable JavaScript. What is a Carbon Dioxide (CO2) Blood Test? Carbon dioxide (CO2) is an ...

  15. 75 FR 75059 - Mandatory Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide

    Science.gov (United States)

    2010-12-01

    ... Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide; Final Rule #0;#0;Federal Register... Mandatory Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide AGENCY... greenhouse gas monitoring and reporting from facilities that conduct geologic sequestration of carbon dioxide...

  16. 27 CFR 27.42a - Still wines containing carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... carbon dioxide. 27.42a Section 27.42a Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... On Imported Distilled Spirits, Wines, and Beer Wines § 27.42a Still wines containing carbon dioxide. Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except...

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

    NARCIS (Netherlands)

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

    2012-01-01

    Carbon dioxide capture and separation are important industrial processes that allow the use of carbon dioxide for the production of a range of chemical products and materials, and to minimize the effects of carbon dioxide emission. Porous metal-organic frameworks are promising materials to achieve

  18. Carbon dioxide euthanasia in rats: Oxygen supplementation minimizes signs of agitation and asphyxia

    NARCIS (Netherlands)

    Coenen, A.M.L.; Drinkenburg, W.H.I.M.; Hoenderken, R.; Luijtelaar, E.L.J.M. van

    1995-01-01

    This paper records the effects of carbon dioxide when used for euthanasia, on behaviour, electrical brain activity and heart rate in rats. Four different methods were used. Animals were placed in a box (a) that was completely filled with carbon dioxide; (b) into which carbon dioxide was streamed at

  19. Syngas and hydrogen production from the natural gas reforming with carbon dioxide; Producao de gas de sintese e hidrogenio a partir da reforma do gas natural com dioxido de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Pacifico, Jose Adair; Silva, Hollyson William da; Moura, Diego de Lima; Soares, Cicero Henrique Macedo; Abreu, Cesar Augusto Moraes de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)]. E-mail: adairpacifico@hotmail.com

    2008-07-01

    In order to establish operational previews for the catalytic reforming of methane with carbon dioxide process a unidimensional Kunii-Levenspiel heterogeneous model was elaborated for the fluidized bed reaction system. Simulations showing the reactants (CH{sub 4} + CO{sub 2}) and products (CO + H{sub 2}) concentration outlines are accomplished, showing the effect of temperature. The operational system composed by the fluidized bed reactor has the following dimensions: (Ht 1,180 mm, Dint = 56 mm) and a 4.98 wt.% Ni/{gamma}-Al{sub 2}O{sub 3} catalysts (mcat 224.74g), operating at 1,023.15K, 1,073.15K, and 1,123.15K and atmospheric pressure. Under the conditions above and adopting a Langmuir-Hinshelwood kinetic law for catalysts decomposition of methane and not catalytic heterogeneous kinetic law for gas shift and Boudouard reverse reaction. The adopted mathematic model it allowed the establishing of profile concentration for the reactants and products showing. Conversion at 97.89% and 85.45% for the CH{sub 4} and CO{sub 2}, at 1,123.15K. (author)

  20. Measurement and correlation of solubility of carbon dioxide in triglycerides

    International Nuclear Information System (INIS)

    Howlader, Md Shamim; French, William Todd; Toghiani, Hossein; Hartenbower, Ben; Pearson, Larry; DuBien, Janice; Rai, Neeraj

    2017-01-01

    Graphical abstract: Comparison of experimental results with correlation for solubility of CO 2 in triglycerides as a function pressure at two different temperatures of 289.15 and 303.15 K, respectively. - Highlights: • New pressure drop gas apparatus was developed to determine the solubility of gases in liquids. • Solubility of CO 2 in triglycerides was measured at different temperatures and pressures. • Experimental solubility data were correlated using three thermodynamic models. • Enthalpy, entropy and Gibbs energy of dissolution for CO 2 -triglyceride were determined. - Abstract: A new pressure drop solubility gas apparatus was developed to determine the solubility of carbon dioxide in canola oil, a triglyceride consisting primarily of oleic, linoleic, and alpha linoleic acid radicals. Solubility of CO 2 in triglycerides was determined at different temperatures (283.2–303.2 K) and pressures (600–2450 kPa). It was found that the solubility of CO 2 in triglycerides is higher than that of pure water because triglycerides lack strong hydrogen bond networks that exist in liquid water at the ambient conditions. The experimental solubility was correlated using Krichevsky–Kasarnovsky (KK), Mather-Jou (MJ), and Carvalho-Coutinho (CC) correlations. We find that KK and MJ equations can predict the solubility with higher accuracy. The enthalpy and entropy of absorption of CO 2 were calculated using the van’t Hoff plot and were found to be −7.165 kJ.mol −1 , and −28.791 J.mol −1 .K −1 , respectively.

  1. Methane and Carbon Dioxide Emissions from Different Composting Periods

    Directory of Open Access Journals (Sweden)

    Cheng-Hsiung Chang

    2009-01-01

    Full Text Available To investigate green house gas emissions from compost preparations, methane and carbon dioxide concentrations and emission rates at different accumulative times and composting periods were determined. While the accumulative time was less than 10 min with a closed acrylic chamber, meth ane and carbon dioxide emissions in creased slightly but with high fluntuation in the sampling e ror, and these values decreased significantly when the accumulative time was more than 20 min. During the 8 weeks of composting, the methane emission rate reaches its peak near the end of the second week and the carbon dioxide emission rate does the same near the end of third week. Meth ane and carbon dioxide emissions had high val ues at the first stage of com post ing and then de creased grad u ally for the ma tu rity of com post. Carbon dioxide emission (y was significantly related to temperature (x1, moisture content (x2, and total or ganiccarbon (x3; and there gression equation is: y = 3.11907x1 + 6.19236x2 - 6.63081x3 - 50.62498. The re gres sion equa tion be tween meth ane emis sion (y? and mois ture con tent (x2, pH (x4, C/N ra tio (x5, and ash con tent (x6 is: y?= 0.13225x2 - 0.97046x4 - 1.10599x5 - 0.55220x6 + 50.77057 in the ini tial com post ing stage (weeks 1 to 3; while, the equa tion is: y?= 0.02824x2 - 0.0037x4 - 0.1499x5 - 0.07013x6 + 4.13589 in the later compost ing stage (weeks 4 to 8. Dif ferent stage composts have significant variation of properties and greenhouse gas emissions. Moreover, the emissions may be reduced by manipulating the proper factors.

  2. urbanization and climate chang carbon dioxide emission

    African Journals Online (AJOL)

    userpc

    t efficient public urban mass transit that involves low carbon emissi individual car usage should be discouraged. ent, automobile density, climate change, global warming, greenhou e change .... Lagos, Port Harcourt, Abuja and Kano (Federal.

  3. Mineralization of Carbon Dioxide: Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, V; Soong, Y; Carney, C; Rush, G; Nielsen, B; O' Connor, W

    2015-01-01

    CCS research has been focused on CO2 storage in geologic formations, with many potential risks. An alternative to conventional geologic storage is carbon mineralization, where CO2 is reacted with metal cations to form carbonate minerals. Mineralization methods can be broadly divided into two categories: in situ and ex situ. In situ mineralization, or mineral trapping, is a component of underground geologic sequestration, in which a portion of the injected CO2 reacts with alkaline rock present in the target formation to form solid carbonate species. In ex situ mineralization, the carbonation reaction occurs above ground, within a separate reactor or industrial process. This literature review is meant to provide an update on the current status of research on CO2 mineralization. 2

  4. Synthesis of Chiral Cyclic Carbonates via Kinetic Resolution of Racemic Epoxides and Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Xiao Wu

    2016-01-01

    Full Text Available The catalytic synthesis of cyclic carbonates using carbon dioxide as a C1-building block is a highly active area of research. Here, we review the catalytic production of enantiomerically enriched cyclic carbonates via kinetic resolution of racemic epoxides catalysed by metal-containing catalyst systems.

  5. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    L Balan; L Duclaux; S Los

    2005-01-01

    Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H 2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7-8]. Presently, the best performance of hydrogen adsorption was found in super-activated microporous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physi-sorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field at the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

  6. Hydrogen adsorption in doped porous carbons

    International Nuclear Information System (INIS)

    Balan, L.; Duchaux, L.; Los, S.

    2005-01-01

    Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H 2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7- 8]. Presently, the best performance of hydrogen adsorption was found in super-activated micro-porous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physisorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field al the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

  7. Past explosive outbursts of entrapped carbon dioxide in salt mines provide a new perspective on the hazards of carbon dioxide

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2013-01-01

    This paper reports on a source of past carbon dioxide accidents which so far has only been sporadically mentioned in the literature. Violent and highly destructive outbursts of hundreds of tons of CO2 occurred regularly, if not routinely, in the now closed salt mines of the former DDR. The Menzen...

  8. The carbon dioxide content in ice cores - climatic curves of carbon dioxide. Zu den CO sub 2 -Klimakurven aus Eisbohrkernen

    Energy Technology Data Exchange (ETDEWEB)

    Heyke, H.E.

    1992-05-01

    The 'greenhouse effect', which implies a temperature of 15 deg C as against -18 deg C, owes its effect to 80% from water (clouds and gaseous phase) and to 10% from carbon dioxide, besides other components. Whereas water is largely unaccounted for, carbon dioxide has been postulated as the main cause of anticipated climatic catastrophe. The carbon dioxide concentration in the atmosphere has risen presently to such levels that all previous figures seem to have been left far behind. The reference point is the concentration of carbon dioxide in the air bubbles trapped in ice cores of Antartic and Greenland ice dated 160 000 years ago, which show much lower values than at present. A review of the most relevant publications indicates that many basic laws of chemistry seem to have been left largely unconsidered and experimental errors have made the results rather doubtful. Appropriate arguments have been presented. The investigations considered should be repeated under improved and more careful conditions. (orig.).

  9. Do we need to sequester carbon dioxide?

    International Nuclear Information System (INIS)

    Delbecq, D.

    2011-01-01

    Carbon sequestration may be the solution to face our difficulty to cut down the use of fossil energies. CO 2 has to be separated from other gases released by thermal power plants before being stored in deep geological layers, there it can stay as a gas, or it can be dissolved in a fluid phase, or it can react with minerals and be integrated to a solid phase. Oil fields and deep saline water reservoirs are natural candidates for carbon sequestration. Carbon sequestration implies the installation of a network of pipelines to transport CO 2 from the place of production to the place of sequestration. The high cost of carbon sequestration implies the implementation of financial incentives from governments. Some economists foresee a raise of the electricity cost up to 50% if carbon sequestration is used. Other economists see a contradiction: sequestration techniques will not be available in a short term range while numerous thermal power plants are planned to be built in the decade. So carbon sequestration may arrive too late and at a cost that may be not competitive with some renewable energies like off-shore wind energy or thermal solar energy which will be full-grown at that time. (A.C.)

  10. Fugitive carbon dioxide: It's not hiding in the ocean

    International Nuclear Information System (INIS)

    Kerr, R.A.

    1992-01-01

    The fugitive carbon is the difference between the 7 billion or so tons that spew as carbon dioxide from smokestacks and burning tropical forests and the 3.4 billion tons known to stay in the atmosphere. Finding the other 3 billion or 4 billion tons has frustrated researchers for the past 15 years. The oceans certainly take up some of it. Any forecast of global warming has to be based on how much of the carbon dioxide released by human activity will remain in the atmosphere, and predictions vary by 30% depending on the mix of oceanic and terrestrial processes assumed to be removing the gas. What's more, those predictions assume that the processes at work today will go on operating. But not knowing where all the carbon is going raises the unnerving possibility that whatever processes are removing it may soon fall down on the job without warning, accelerating any warming. Such concerns add urgency to the question of whether the ocean harbors the missing carbon. But there's no simple way to find out. The obvious strategy might seem to be to measure the carbon content of the ocean repeatedly to see how much it increases year by year. The trouble is that several billion tons of added carbon, though impressive on a human scale, are undetectable against the huge swings in ocean carbon that occur from season to season, year to year, and place to place

  11. Carbon dioxide elimination and regeneration of resources in a microwave plasma torch

    International Nuclear Information System (INIS)

    Uhm, Han S.; Kwak, Hyoung S.; Hong, Yong C.

    2016-01-01

    Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO_2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials. - Highlights: • Carbon dioxide gas produces a plasma-torch by making use of 2.45 GHz microwaves. • The temperature measurement of torch flame by optical spectroscopy. • Disintegration of carbon dioxide into carbon monoxide and oxygen atom. • Emission profiles of carbon monoxide confirm disintegration theory. • Conversion of carbon dioxide into carbon monoxide in the plasma torch. - This article presents carbon-dioxide plasma torch operated by microwaves and its applications to regeneration of new resources, eliminating carbon dioxide molecules.

  12. Titanium dioxide modified with various amines used as sorbents of carbon dioxide

    International Nuclear Information System (INIS)

    Kapica-Kozar, Joanna; Pirog, Ewa; Kusiak-Nejman, Ewelina; Wrobel, Rafal J.; Gesikiewicz-Puchalska, Andzelika; Morawski, Antoni W.; Narkiewicz, Urszula; Michalkiewicz, Beata

    2017-01-01

    In this study, titanium dioxide was modified with various amines through hydrothermal treatment for adsorption of CO_2. The carbon dioxide adsorption performance of the prepared samples was measured using an STA 449 C thermo-balance (Netzsch Company, Germany). The morphological structures, functional groups and elemental compositions of the unmodified and amine-modified titanium dioxide sorbents were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR/DR) and scanning electron microscopy (SEM), respectively. The results showed that modification of TiO_2 with amines through hydrothermal treatment is a simple method to prepare CO_2 sorbents with high adsorption capacities. Moreover, the results revealed that TEPA-modified titanium dioxide shoved the highest adsorption capacity, enabling an increase in CO_2 uptake from 0.45 mmol CO_2 g"-"1 in the case of raw TiO_2 to 1.63 mmol CO_2 g"-"1. This result could be indirectly related to the fact that TEPA has the highest amino group content among the three amines used in our research. Additionally, durability tests performed by cyclic adsorption-desorption revealed that TEPA modified titanium dioxide also possesses excellent stability, despite a slight decrease in adsorption capacity over time. (authors)

  13. Production of precipitated calcium carbonate from calcium silicates and carbon dioxide

    International Nuclear Information System (INIS)

    Teir, Sebastian; Eloneva, Sanni; Zevenhoven, Ron

    2005-01-01

    The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating 200 kt of carbon dioxide emissions per year, considering only the PCC used in the pulp and paper industry. A preliminary investigation of the feasibility to produce PCC from calcium silicates and the potential to replace calcium carbonate as the raw material was made. Calcium carbonate can be manufactured from calcium silicates by various methods, but only a few have been experimentally verified. The possibility and feasibility of these methods as a replacement for the current PCC production process was studied by thermodynamic equilibrium calculations using HSC software and process modelling using Aspen Plus[reg]. The results from the process modelling showed that a process that uses acetic acid for extraction of the calcium ions is a high potential option for sequestering carbon dioxide by mineral carbonation. The main obstacle seems to be the limited availability and relatively high price of wollastonite, which is a mineral with high calcium silicate content. An alternative is to use the more common, but also more complex, basalt rock instead

  14. Development of a reduction process of ammonium uranyl carbonate to uranium dioxide in a fluidized bed

    International Nuclear Information System (INIS)

    Gomes, R.P.; Riella, H.G.

    1990-07-01

    Laboratory development of ammonium uranyl carbonate (AUC) reduction to uranium dioxide (UO 2 ) using fluidized bed furnace technique is described. The reaction is carried out at 500-550 0 C using hydrogen, liberated from cracking of ammonia, as a reducing agent. As the AUC used is obtained from uranium hexafluoride (UF 6 ) it contains considerable amount of fluoride (approx. 500μg/g) as contaminant. The presence of fluoride leads to high corrosion rates and hence the fluoride concentration is reduced by pyrohydrolisis of UO 2 . Physical and Chemical properties of the final product (UO 2 ) obtained were characterized. (author) [pt

  15. Development of ammonium uranyl carbonate reduction to uranium dioxide using fluidized bed

    International Nuclear Information System (INIS)

    Gomes, R.P.; Riella, H.G.

    1988-01-01

    Laboratory development of Ammonium Uranyl Carbonate (AUC) reduction to uranium dioxide (UO 2 ) using fluidized bed furnace technique is described. The reaction is carried out at 500-550 0 C using hydrogen, liberated from cracking of ammonia, as a reducing agent. As the AUC used is obtained from uranium hexafluoride (UF 6 ) it contains considerable amounts of fluoride ( - 500μgF - /gTCAU) as contaminant. The presence of fluoride leads to high corrosion rates and hence the fluoride concentrations is reduced by pyrohydrolisis of UO 2 . Physical and Chemical proterties of the final product (UO 2 ) obtained were characterized. (author) [pt

  16. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

    International Nuclear Information System (INIS)

    Ghafari, Shahin; Hasan, Masitah; Aroua, Mohamed Kheireddine

    2009-01-01

    Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO 2 and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO 2 , (II) bicarbonate plus continuous sparging of CO 2 , and (III) only bicarbonate. The pH-reducing nature of CO 2 showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO 3 - -N/g MLVSS/h for degrading 20 and 30 mg NO 3 - -N/L and 9.09 mg NO 3 - -N/g MLVSS/h for degrading 50 mg NO 3 - -N/L

  17. Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growth and adaptation of autohydrogenotrophic denitrifying bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Ghafari, Shahin; Hasan, Masitah [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Aroua, Mohamed Kheireddine [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)], E-mail: mk_aroua@um.edu.my

    2009-03-15

    Acclimation of autohydrogenotrophic denitrifying bacteria using inorganic carbon source (CO{sub 2} and bicarbonate) and hydrogen gas as electron donor was performed in this study. In this regard, activated sludge was used as the seed source and sequencing batch reactor (SBR) technique was applied for accomplishing the acclimatization. Three distinct strategies in feeding of carbon sources were applied: (I) continuous sparging of CO{sub 2}, (II) bicarbonate plus continuous sparging of CO{sub 2}, and (III) only bicarbonate. The pH-reducing nature of CO{sub 2} showed an unfavorable impact on denitrification rate; however bicarbonate resulted in a buffered environment in the mixed liquor and provided a suitable mean to maintain the pH in the desirable range of 7-8.2. As a result, bicarbonate as the only carbon source showed a faster adaptation, while carbon dioxide as the only carbon source as well as a complementary carbon source added to bicarbonate resulted in longer acclimation period. Adapted hydrogenotrophic denitrifying bacteria, using bicarbonate and hydrogen gas in the aforementioned pH range, caused denitrification at a rate of 13.33 mg NO{sub 3}{sup -}-N/g MLVSS/h for degrading 20 and 30 mg NO{sub 3}{sup -}-N/L and 9.09 mg NO{sub 3}{sup -}-N/g MLVSS/h for degrading 50 mg NO{sub 3}{sup -}-N/L.

  18. Incentives of carbon dioxide regulation for investment in low-carbon electricity technologies in Texas

    International Nuclear Information System (INIS)

    Castillo, Anya; Linn, Joshua

    2011-01-01

    This paper compares the incentives a carbon dioxide emissions price creates for investment in low carbon dioxide-emitting technologies in the electricity sector. We consider the extent to which operational differences across generation technologies - particularly, nuclear, wind and solar photovoltaic - create differences in the incentives for new investment, which is measured by the operating profits of a potential entrant. First, astylized model of an electricity system demonstrates that the composition of the existing generation system may cause electricity prices to increase by different amounts over time when a carbon dioxide price is imposed. Differences in operation across technologies therefore translate to differences in the operating profits of a potential entrant. Then, a detailed simulation model is used to consider a hypothetical carbon dioxide price of $10-$50 per metric ton for the Electric Reliability Council of Texas (ERCOT) market. The simulations show that, for the range of prices considered, the increase in electricity prices is positively correlated with output from a typical wind unit, but the correlation is much weaker for nuclear and photovoltaic. Consequently, a carbon dioxide price creates much stronger investment incentives for wind than for nuclear or photovoltaic technologies in the Texas market. - Highlights: → Compare incentives for new investment in low-emission electricity technologies created by carbon dioxide price. → Focus on ERCOT power system using stochastic unit commitment model. →Find a greater incentive for wind than solar or nuclear because of correlation between wind generation and increase in electricity prices.

  19. SISGR - Hydrogen Caged in Carbon-Exploration of Novel Carbon-Hydrogen Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lueking, Angela [Pennsylvania State Univ., State College, PA (United States); Badding, John [Pennsylvania State Univ., State College, PA (United States); Crespi, Vinent [Pennsylvania State Univ., State College, PA (United States)

    2015-12-01

    Hydrogen trapped in a carbon cage, captured through repulsive interactions, is a novel concept in hydrogen storage. Trapping hydrogen via repulsive interactions borrows an idea from macroscale hydrogen storage (i.e. compressed gas storage tanks) and reapplies these concepts on the nanoscale in specially designed molecular containers. Under extreme conditions of pressure, hydrogen solubility in carbon materials is expected to increase and carbon is expected to restructure to minimize volume via a mixed sp2/sp3 hydrogenated state. Thermodynamics dictate that pre-formed C-H structures will rearrange with increased pressure, yet the final carbon-hydrogen interactions may be dependent upon the mechanism by which hydrogen is introduced. Gas “trapping” is meant to denote gas present in a solid in a high density, adsorbed-like state, when the external pressure is much less than that necessary to provide a comparable fluid density. Trapping thus denotes a kinetically metastable state rather than thermodynamic equilibrium. This project probed mechanochemical means to polymerize select hydrocarbons in the presence of gases, in an attempt to form localized carbon cages that trap gases via repulsive interactions. Aromatic, polyaromatic, and hydroaromatic molecules expected to undergo cyclo-addition reactions were polymerized at high (~GPa) pressures to form extended hydrogenated amorphous carbon networks. Notably, aromatics with a pre-existing internal free volume (such as Triptycene) appeared to retain an internal porosity upon application of pressure. However, a high photoluminescence background after polymerization precluded in situ identification of trapped gases. No spectroscopic evidence was found after depressurization that would be indicative of pockets of trapped gases in a localized high-pressure environment. Control studies suggested this measurement may be insensitive to gases at low pressure. Similarly, no spectral fingerprint was found for gas-imbued spherical

  20. Comparison between two methods of methanol production from carbon dioxide

    International Nuclear Information System (INIS)

    Anicic, B.; Trop, P.; Goricanec, D.

    2014-01-01

    Over recent years there has been a significant increase in the amount of technology contributing to lower emissions of carbon dioxide. The aim of this paper is to provide a comparison between two technologies for methanol production, both of which use carbon dioxide and hydrogen as initial raw materials. The first methanol production technology includes direct synthesis of methanol from CO 2 , and the second has two steps. During the first step CO 2 is converted into CO via RWGS (reverse water gas shift) reaction, and methanol is produced during the second step. A comparison between these two methods was achieved in terms of economical and energy-efficiency bases. The price of electricity had the greatest impact from the economical point of view as hydrogen is produced via the electrolysis of water. Furthermore, both the cost of CO 2 capture and the amounts of carbon taxes were taken into consideration. Energy-efficiency comparison is based on cold gas efficiency, while economic feasibility is compared using net present value. Even though the mentioned processes are similar, it was shown that direct methanol synthesis has higher energy and economic efficiency. - Highlights: • We compared two methods for methanol production. • Process schemes for both, direct synthesis and two-step synthesis, are described. • Direct synthesis has higher economical and energy efficiency

  1. Carbon dioxide emissions from Indian monsoonal estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Viswanadham, R.; Rao, G.D.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Kumar, N.A.; Rao, D.B.; Sridevi, T.; Krishna, M.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.

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

  2. Hydrogen storage in engineered carbon nanospaces.

    Science.gov (United States)

    Burress, Jacob; Kraus, Michael; Beckner, Matt; Cepel, Raina; Suppes, Galen; Wexler, Carlos; Pfeifer, Peter

    2009-05-20

    It is shown how appropriately engineered nanoporous carbons provide materials for reversible hydrogen storage, based on physisorption, with exceptional storage capacities (approximately 80 g H2/kg carbon, approximately 50 g H2/liter carbon, at 50 bar and 77 K). Nanopores generate high storage capacities (a) by having high surface area to volume ratios, and (b) by hosting deep potential wells through overlapping substrate potentials from opposite pore walls, giving rise to a binding energy nearly twice the binding energy in wide pores. Experimental case studies are presented with surface areas as high as 3100 m(2) g(-1), in which 40% of all surface sites reside in pores of width approximately 0.7 nm and binding energy approximately 9 kJ mol(-1), and 60% of sites in pores of width>1.0 nm and binding energy approximately 5 kJ mol(-1). The findings, including the prevalence of just two distinct binding energies, are in excellent agreement with results from molecular dynamics simulations. It is also shown, from statistical mechanical models, that one can experimentally distinguish between the situation in which molecules do (mobile adsorption) and do not (localized adsorption) move parallel to the surface, how such lateral dynamics affects the hydrogen storage capacity, and how the two situations are controlled by the vibrational frequencies of adsorbed hydrogen molecules parallel and perpendicular to the surface: in the samples presented, adsorption is mobile at 293 K, and localized at 77 K. These findings make a strong case for it being possible to significantly increase hydrogen storage capacities in nanoporous carbons by suitable engineering of the nanopore space.

  3. COCAP: a carbon dioxide analyser for small unmanned aircraft systems

    Science.gov (United States)

    Kunz, Martin; Lavric, Jost V.; Gerbig, Christoph; Tans, Pieter; Neff, Don; Hummelgård, Christine; Martin, Hans; Rödjegård, Henrik; Wrenger, Burkhard; Heimann, Martin

    2018-03-01

    Unmanned aircraft systems (UASs) could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). The accuracy of COCAP's carbon dioxide (CO2) measurements is ensured by calibration in an environmental chamber, regular calibration in the field and by chemical drying of sampled air. In addition, the package contains a lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by 2 orders of magnitude. During validation of COCAP's CO2 measurements in simulated and real flights we found a measurement error of 1.2 µmol mol-1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for the operation on board small UASs. Besides carbon dioxide dry air mole fraction it also measures air temperature, humidity and pressure. We describe the measurement system and our calibration strategy in detail to support others in tapping the potential of UASs for atmospheric trace gas measurements.

  4. Adsorption of Carbon Dioxide, Ammonia, Formaldehyde, and Water Vapor on Regenerable Carbon Sorbents

    Science.gov (United States)

    Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is nonregenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for simultaneous carbon dioxide, ammonia, formaldehyde, and water sorption. Multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also the enhancement of formaldehyde sorption by the presence of ammonia in the gas mixture.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  7. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    Science.gov (United States)

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  8. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Y. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)]. E-mail: inui@eee.tut.ac.jp; Urata, A. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Ito, N. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Nakajima, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Tanaka, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

    2006-08-15

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide.

  9. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    International Nuclear Information System (INIS)

    Inui, Y.; Urata, A.; Ito, N.; Nakajima, T.; Tanaka, T.

    2006-01-01

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide

  10. An Optimal Centralized Carbon Dioxide Repository for Florida, USA

    Directory of Open Access Journals (Sweden)

    Brandon Poiencot

    2011-03-01

    Full Text Available For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida’s electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels, from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s is also presented.

  11. Uranium tetracyclopentadienyl interaction with carbon oxide and dioxide

    International Nuclear Information System (INIS)

    Leonov, M.R.; Solov'eva, G.V.; Kozina, I.Z.; Bolotova, G.T.

    1983-01-01

    Using the methods of gas-liquid chromatography, IR and UV spectroscopy and element analysis, the reactions of tetracyclogentadienyluranium with carbon oxide and dioxide have been studied. It is shown that complete uranium cyclopentadienyl π-complex-tetracyclopentadienyluranium - in pentane under normal conditions for 100 hr reacts with carbon oxide and dioxide with the formation of polymeric complex ([(etasup(5)-Csub(5)Hsub(5))x(-CO-)U(etasup(5)-Csub(5)Hsub(4))(-CO-)]sub(2)]sub(n), in which two uranium atoms are bonded with two bridge fragments (eta 5 -C 5 H 4 -CO-), and dimeric complex [(eta 5 -C 5 H 5 ) 2 UH 2 xCO 2 ] 2 respectively

  12. Heterogeneously Catalysed Chemical Reactions in Carbon Dioxide Medium

    DEFF Research Database (Denmark)

    Musko, Nikolai E.

    In this PhD-study the different areas of chemical engineering, heterogeneous catalysis, supercritical fluids, and phase equilibrium thermodynamics have been brought together for selected reactions. To exploit the beneficial properties of supercritical fluids in heterogeneous catalysis, experimental...... studies of catalytic chemical reactions in dense and supercritical carbon dioxide have been complemented by the theoretical calculations of phase equilibria using advanced thermodynamic models. In the recent years, the use of compressed carbon dioxide as innovative, non-toxic and non-flammable, cheap......, and widely available reaction medium for many practical and industrial applications has drastically increased. Particularly attractive are heterogeneously catalysed chemical reactions. The beneficial use of CO2 is attributed to its unique properties at dense and supercritical states (at temperatures...

  13. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    Science.gov (United States)

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

    2014-09-16

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

  14. Climatic response to a gradual increase of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Stouffer, R.J.; Manabe, S.; Bryan, K.

    1990-01-01

    The transient response of a coupled ocean-atmosphere model to an increase of carbon dioxide has been the subject of several studies. The models used in these studies explicitly incorporate the effect of heat transport by ocean currents and are different from the model used by Hansen et al. Here the authors evaluate the climatic influence of increasing atmospheric carbon dioxide using a coupled model recently developed at the NOAA Geophysical Fluid Dynamics Laboratory. The model response exhibits a marked and unexpected interhemispheric asymmetry. In the circumpolar ocean of the southern hemisphere, a region of deep vertical mixing, the increase of surface air temperature is very slow. In the Northern hemisphere of the model, the rise of surface air temperature is faster and increases with latitude, with the exception of the northern North Atlantic, where it is relatively slow because of the weakening of the thermohaline circulation

  15. The underground storages of carbon dioxide. Juridical aspects

    International Nuclear Information System (INIS)

    Bersani, F.

    2006-04-01

    In the framework of the reduction of the carbon dioxide emissions in the air, the underground storage of the CO 2 is studied. Some experimentation are already realized in the world and envisaged in France. This document aims to study the juridical aspects of these first works in France. After a presentation of the realization conditions and some recalls on the carbon dioxide its capture and storage, the natural CO 2 underground storages and the first artificial storages are discussed. The CO 2 waste qualification, in the framework of the environmental legislation is then detailed with a special task on the Lacq region. The problem of the sea underground storages is also presented. (A.L.B.)

  16. Carbon dioxide capture processes: Simulation, design and sensitivity analysis

    DEFF Research Database (Denmark)

    Zaman, Muhammad; Lee, Jay Hyung; Gani, Rafiqul

    2012-01-01

    equilibrium and associated property models are used. Simulations are performed to investigate the sensitivity of the process variables to change in the design variables including process inputs and disturbances in the property model parameters. Results of the sensitivity analysis on the steady state...... performance of the process to the L/G ratio to the absorber, CO2 lean solvent loadings, and striper pressure are presented in this paper. Based on the sensitivity analysis process optimization problems have been defined and solved and, a preliminary control structure selection has been made.......Carbon dioxide is the main greenhouse gas and its major source is combustion of fossil fuels for power generation. The objective of this study is to carry out the steady-state sensitivity analysis for chemical absorption of carbon dioxide capture from flue gas using monoethanolamine solvent. First...

  17. Carbon strategy and management in the hydrogen economy

    International Nuclear Information System (INIS)

    Snyder, C.

    2006-01-01

    Greenhouse gas (carbon) emission reduction related to the beneficial use of hydrogen is an important aspect in the development and public acceptance of a greater role for hydrogen in the economy. This presentation is an overview of potential effects of the evolving regulatory framework for carbon emissions management in Canada on hydrogen infrastructure development and compare it with activities in other jurisdictions

  18. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Parilla, P.A.; Jones, K.M.; Riker, G.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    Carbon single-wall nanotubes (SWNTs) are essentially elongated pores of molecular dimensions and are capable of adsorbing hydrogen at relatively high temperatures and low pressures. This behavior is unique to these materials and indicates that SWNTs are the ideal building block for constructing safe, efficient, and high energy density adsorbents for hydrogen storage applications. In past work the authors developed methods for preparing and opening SWNTs, discovered the unique adsorption properties of these new materials, confirmed that hydrogen is stabilized by physical rather than chemical interactions, measured the strength of interaction to be {approximately} 5 times higher than for adsorption on planar graphite, and performed infrared absorption spectroscopy to determine the chemical nature of the surface terminations before, during, and after oxidation. This year the authors have made significant advances in synthesis and characterization of SWNT materials so that they can now prepare gram quantities of high-purity SWNT samples and measure and control the diameter distribution of the tubes by varying key parameters during synthesis. They have also developed methods which purify nanotubes and cut nanotubes into shorter segments. These capabilities provide a means for opening the tubes which were unreactive to the oxidation methods that successfully opened tubes, and offer a path towards organizing nanotube segments to enable high volumetric hydrogen storage densities. They also performed temperature programmed desorption spectroscopy on high purity carbon nanotube material obtained from collaborator Prof. Patrick Bernier and finished construction of a high precision Seivert`s apparatus which will allow the hydrogen pressure-temperature-composition phase diagrams to be evaluated for SWNT materials.

  19. Carbon dioxide fixation in isolated Kalanchoe chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    Levi, C.; Gibbs, M.

    1975-07-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 ..mu..moles of CO/sub 2/ per milligram of chlorophyll per hour. The dark rate of fixation was about 1 percent of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1, 6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO/sub 2/ fixation were primarily those of the photosynthetic carbon reduction cycle. (auth)

  20. Current views on the regulation of autotrophic carbon dioxide fixation via the Calvin cycle in bacteria

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for the synthesis of all components of cell

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

    OpenAIRE

    Alawadhi, Khaled

    2009-01-01

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

  2. Remote operated vehicle with carbon dioxide blasting (ROVCO2)

    International Nuclear Information System (INIS)

    Resnick, A.M.

    1995-01-01

    The Remote Operated Vehicle with Carbon Dioxide Blasting (ROVCO 2 ), as shown in a front view, is a six-wheeled remote land vehicle used to decontaminate concrete floors. The remote vehicle has a high pressure Cryogenesis blasting subsystem, Oceaneering Technologies (OTECH) developed a CO 2 xY Orthogonal Translational End Effector (COYOTEE) subsystem, and a vacuum/filtration and containment subsystem. Figure 2 shows a block diagram with the various subsystems labeled

  3. Production of Solar Fuels by Photoelectrochemical Conversion of Carbon Dioxide

    OpenAIRE

    Irtem, Ibrahim Erdem

    2017-01-01

    Growing global emission of carbon dioxide gas (CO2) reflects the world’s energy dependence on fossil fuels. The conversion of CO2 emission into value-added products, like fuels completes a circular CO2 economy which requires a renewable energy conversion and storage system. Amongst a few, photo/electrochemistry has been particularly appealing thanks to its energy efficiency and enormous potential for industrial applications. Formic acid (HCOOH) production from CO2 reduction appears as an al...

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

    International Nuclear Information System (INIS)

    Fenstermacher, C.A.

    1979-01-01

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

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

    OpenAIRE

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arr...

  6. Effect Of Geothermal Heat Pump On Carbon Dioxide Emissions

    Directory of Open Access Journals (Sweden)

    Ahmed F. Atwan

    2015-08-01

    Full Text Available In this research the calculations of carbon dioxide emissions CO2 in summer May to September 150 day and winter seasons December to February 90 day were performed by using the coefficient of performance for each air and ground source heat pump. The place of study case take relative to solar path in to account and the study case was three halls men women and surgery halls in Al-Musayyib hospital in Babylon.

  7. Titanium dioxide, single-walled carbon nanotube composites

    Science.gov (United States)

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

    2015-07-14

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

  8. The effect of carbon dioxide therapy on composite graft survival

    OpenAIRE

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino Júnior, Ruy de Souza; Sousa, João Batista de

    2013-01-01

    PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, h...

  9. Carbon dioxide laser for de-epithelialization of periodontal flaps.

    Science.gov (United States)

    Centty, I G; Blank, L W; Levy, B A; Romberg, E; Barnes, D M

    1997-08-01

    Regeneration of mineralized and soft connective tissue components of the attachment apparatus is the main goal in the treatment of periodontal diseases. Often, apical migration of epithelium (long junctional epithelium) effectively prevents the formation of bone and connective tissue attachment after periodontal surgery. The purpose of the present study was to compare conventional periodontal surgery combined with carbon dioxide laser and conventional periodontal surgery alone with respect to epithelial elimination and degree of necrosis of mucoperiosteal flaps. After signing a consent form, five patients with at least two comparable bilateral periodontal defects needing pocket elimination surgery participated in this study. The investigators randomly divided each side into test and control sites. Each patient received oral hygiene instruction and initial therapy prior to surgery. At surgery, the test site received a sulcular incision and carbon dioxide laser de-epithelialization of the outer and inner aspects of the flap. The control group received reverse bevel incision only. The surgeon performed open flap debridement on all teeth. At the time of surgery, the surgeon did a biopsy of each site and submitted specimens for histologic evaluation. A matched pairs t-test was used to analyze the data. The results show significant differences between the carbon dioxide laser and reverse bevel incision with respect to sulcular (P test sites, with a predominance of plasma cells. Lining the sulcular and gingival (external) lased areas, investigators found coagulation necrosis covered by fibrin and coagulated blood. The laser appears to effectively remove epithelium at the time of surgery; however, future long-term, well-controlled quantitative histologic studies are needed to evaluate the effect of repeated carbon dioxide laser de-epithelialization of the gingival (external) surface of mucoperiosteal flaps at intervals during the healing period.

  10. Collision and radiative processes in emission of atmospheric carbon dioxide

    Science.gov (United States)

    Smirnov, B. M.

    2018-05-01

    The peculiarities of the spectroscopic properties of CO2 molecules in air due to vibration-rotation radiative transitions are analyzed. The absorption coefficient due to atmospheric carbon dioxide and other atmospheric components is constructed within the framework of the standard atmosphere model, on the basis of classical molecular spectroscopy and the regular model for the spectroscopy absorption band. The radiative flux from the atmosphere toward the Earth is represented as that of a blackbody, and the radiative temperature for emission at a given frequency is determined with accounting for the local thermodynamic equilibrium, a small gradient of the tropospheric temperature and a high optical thickness of the troposphere for infrared radiation. The absorption band model with an absorption coefficient averaged over the frequency and line-by-line model are used for evaluating the radiative flux from the atmosphere to the Earth which values are nearby for these models and are equal W m‑2 for the contemporary concentration of atmospheric CO2 molecules and W m‑2 at its doubled value. The absorption band model is not suitable to calculate the radiative flux change at doubling of carbon dioxide concentration because averaging over oscillations decreases the range where the atmospheric optical thickness is of the order of one, and just this range determines this change. The line-by-line method gives the change of the global temperature K as a result of doubling the carbon dioxide concentration. The contribution to the global temperature change due to anthropogenic injection of carbon dioxide in the atmosphere, i.e. resulted from combustion of fossil fuels, is approximately 0.02 K now.

  11. Efficiency of Carbon Dioxide Fractional Laser in Skin Resurfacing

    Directory of Open Access Journals (Sweden)

    Andrej Petrov

    2016-05-01

    CONCLUSION: Multifunctional fractional carbon dioxide laser used in treatment of patients with acne and pigmentation from acne, as well as in the treatment of scars from different backgrounds, is an effective and safe method that causes statistically significant better effect of the treatment, greater patients’ satisfaction, minimal side effects and statistically better response to the therapy, according to assessments by the patient and the therapist.

  12. Renewable Methane Generation from Carbon Dioxide and Sunlight.

    Science.gov (United States)

    Steinlechner, Christoph; Junge, Henrik

    2018-01-02

    The direct approach: Methane is a potential key player in the world's transition to a more sustainable energy future. The direct conversion of carbon dioxide into methane is highly desirable to lower the concentration of CO 2 in the atmosphere and also to store renewable energy. This Highlight describes the first homogeneous system for the light-driven conversion of CO 2 into CH 4 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Spontaneous oxygen isotope exchange between carbon dioxide and\

    Czech Academy of Sciences Publication Activity Database

    Knížek, Antonín; Zukalová, Markéta; Kavan, Ladislav; Zukal, Arnošt; Kubelík, Petr; Rojík, P.; Skřehot, P.; Ferus, Martin; Civiš, Svatopluk

    2017-01-01

    Roč. 137, MAR 2017 (2017), s. 6-10 ISSN 0169-1317 R&D Projects: GA MŠk LD14115; GA ČR(CZ) GA14-12010S; GA ČR GA13-07724S; GA MŠk(CZ) LM2015073 Institutional support: RVO:61388955 Keywords : clay * carbon dioxide * FTIR spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.101, year: 2016

  14. Determination of carbon chlorine and fluorine in uranium dioxide

    International Nuclear Information System (INIS)

    Kijko, N.I.; Timofeev, G.A.

    1983-01-01

    Techniques of chlorine and fluorine determination and simultaneous determination of carbon and chlorine in electrolytic uranium dioxide are described. The method of chlorine and fluorine determination is based on their separation during oxide pyrohydrolysis with subsequent spectrophotometric analysis of condensate. Lower determination limits constitute 1 μg for chlorine, 0.5 μg for fluorine. Relative standard deviation when the content of impurities analyzed is 10 -3 % constitutes 0.05-0.07

  15. Study on carbon dioxide conversion by radiation

    International Nuclear Information System (INIS)

    Cho, Young Hyun; Park, Geun Il; Cho, Il Hoon; Choi, Sang Do; Hong, Kwang Hee; Lee, Chang Woo

    1999-09-01

    This study was carried out to investigate the synergistic effects on the CO 2 conversion by the application of semiconductor in the field of gamma-ray. Gamma-ray irradiation was performed to examine the effects of semiconductor application on CO 2 conversion in water and the formation of organic material from carbonate solution. From experimental results it is clear that the supplication of semiconductor in the field of gamma-ray increases the efficiency for CO 2 conversion to organic matter. Based on the obtained experimental results it is obvious that the synergistic effects of semiconductor materials in the gamma-ray field leads to increase of the CO 2 conversion yield to organic matter up to 50 percent compared to the gamma-ray irradiation. The way of achieving higher activity is due to the catalytic action of semiconductor by gamma-ray irradiation. Zr-doped TiO 2 catalyst prepared by sol-gel method exhibits the higher efficiency for CO 2 conversion in aqueous solution and carbonate containing solution. This effect of Zr-doping can be explained by the formation of additional defects in surface of TiO 2 film. (author)

  16. Exponential growth and atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    Laurmann, J.A.; Rotty, R.M.

    1983-01-01

    The adequacy of assumptions required to project atmospheric CO 2 concentrations in time frames of practical importance is reviewed. Relevant issues concern the form assumed for future fossil fuel release, carbon cycle approximations, and the implications of revisions in fossil fuel patterns required to maintain atmospheric CO 2 levels below a chosen threshold. In general, we find that with a judiciously selected exponential fossil fuel release rate, and with a constant airborn fraction, we can estimate atmospheric CO 2 growth over the next 50 years based on essentially surprise free scenarios. Resource depletion effects must be included for projections beyond about 50 years, and on this time frame the constant airborne fraction approximation has to be questioned as well (especially in later years when the fossil fuel use begins to taper off). For projections for over 100 years, both energy demand scenarios and currently available carbon cycle models have sufficient uncertainties that atmospheric CO 2 levels derived from them are not much better than guesses

  17. Minimizing emission of carbon dioxide in the coconut processing

    International Nuclear Information System (INIS)

    Lozada, Ernesto P.

    1998-01-01

    About 90% of the world's coconut production is made into copra. There are 2-3 million smoke kilns which are used by the coconut farmers for making copra. It is estimated that these kilns emit carbon dioxide from 247 to 366 gram of carbon per kg of copra produced. From the world copra production of 10 M tons, the total carbon released in copra making range is 2-3 Tg(telegram=10 12 grams) or 2-3M tons of carbon per year. To minimize carbon dioxide emission in copra making, kilns with better combustion characteristics and heat utilization efficiencies must be used. One of the most promising alternative dryers is a direct-fired, natural draft dryer known as the Los Banos (Lozada) Dryer. Developed at the University of the Philippines Los Banos, the dryer consist of a simple burner, a heat distributor and a drying bin. The burner combust coconut shell, corn cob, and wood pieces with extremely high efficiency thus minimizing fuel consumption and dramatically reducing the release of airborne pollutants. The resulting copra is practically smoke free. Tests have shown that carbon dioxide emissions from the Los Banos (Lozada) Dryer are about half of that released by the traditional smoke kilns. Furthermore, the dryer emits lower concentrations of CO (50 ppm vs 2000-3000 ppm), of NO x (5 ppm vs 400 ppm), and SO x (5 ppm vs 400 ppm). When used widely, significant reductions in the emissions of greenhouse and acid rain gases from biomass combustion will be attained. (About 500 units of the Los Banos (Lozada) Dryer are now in use in the Philippines and Papua New Guinea). (Author)

  18. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo; Car, Anja; Peinemann, Klaus-Viktor

    2010-01-01

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  19. Irreversible climate change due to carbon dioxide emissions

    Science.gov (United States)

    Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre

    2009-01-01

    The severity of damaging human-induced climate change depends not only on the magnitude of the change but also on the potential for irreversibility. This paper shows that the climate change that takes place due to increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop. Following cessation of emissions, removal of atmospheric carbon dioxide decreases radiative forcing, but is largely compensated by slower loss of heat to the ocean, so that atmospheric temperatures do not drop significantly for at least 1,000 years. Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450–600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the “dust bowl” era and inexorable sea level rise. Thermal expansion of the warming ocean provides a conservative lower limit to irreversible global average sea level rise of at least 0.4–1.0 m if 21st century CO2 concentrations exceed 600 ppmv and 0.6–1.9 m for peak CO2 concentrations exceeding ≈1,000 ppmv. Additional contributions from glaciers and ice sheet contributions to future sea level rise are uncertain but may equal or exceed several meters over the next millennium or longer. PMID:19179281

  20. The effect of carbon dioxide therapy on composite graft survival.

    Science.gov (United States)

    Durães, Eliana Ferreira Ribeiro; Durães, Leonardo de Castro; Carneiro, Fabiana Pirani; Lino, Ruy de Souza; Sousa, João Batista de

    2013-08-01

    To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, histopathology features and histomorphometry of collagen. The treated group had a significantly lower weight gain (p=0.038). Histopathology was not significantly different between groups. There was an increase in amount of collagen in 2 cm grafts submitted to carbon dioxide therapy (p=0.003). Carboxytherapy didn't influence graft survival rate for 1.5 cm grafts or 2 cm grafts (p=0.567 and p=0.777, respectively). Carbon dioxide therapy increased the amount of collagen in 2 cm grafts. CO2 was not significantly different from saline infusion on composite grafts survival, but this study suggests that there is a mechanical effect caused by distension which favored graft survival.

  1. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo

    2010-03-15

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  2. Balance of emissions and consumptions of carbon dioxide in Spain

    International Nuclear Information System (INIS)

    Valero, A.; Subiela, V.; Cortes, C.

    1994-01-01

    The amount of carbon dioxide in atmosphere increase due to deforestation and anthropogenic emissions. The consumption of this gas in vegetal ecosystems must also be considered to know the net mass of CO 2 that gets into the atmosphere. This article summarizes the methodology, results and conclusions of the carbon dioxide balance in Spain by autonomous communities. The different fossil fuel consumer sectors (Thermal power plants, industry, transport, domestic and agricultural), forest biomass reduction due to fires and wood extractions for firewood are considered as sources. As sinks, natural and reforested forests, and the equivalent sea are noticed. Basically, the article presents a new methodology to estimate carbon dioxide consumption in forest biomass. The average emissions for 1981 to 1990 are presented. A per capita value of 5 t(CO 2 /year is obtained in contrast to the EC average of 8,6 t(CO 2 ) year. The resulting net balance shows that it is only consumed between 20 and 50% of the emitted CO 2 . (Author) 47 refs

  3. Modeling the dynamics of carbon dioxide removal in the atmosphere

    Directory of Open Access Journals (Sweden)

    Shyam Sundar

    2014-12-01

    Full Text Available The temperature of Earth's surface is increasing over the past few years due to emission of global warming gases such as CO2, CH4 and NOx from industries, power plants, etc., leading to several adverse effects on human and his environment. Therefore, the question of their removal/reduction from the atmosphere is very important. In this paper, a nonlinear mathematical model to study the removal/reduction of carbon dioxide by using suitable absorbent (such as aqueous ammonia solution, amines, sodium hydroxide, etc. near the source of emission and externally introducing liquid species in the atmosphere is presented. Dynamical properties of the model which include local and global stabilities for the equilibrium are analyzed carefully. Model analysis is performed by considering three physical situations i.e. when both absorbent and the liquid species are used, only absorbent is used and only liquid species is used. It is shown that the concentration of carbon dioxide decreases as the rate of introduction of absorbent in the absorber increases. It decreases further as the rate of introduction of liquid species. Thus, the concentration of carbon dioxide would be reduced by a large amount if adequate amount of absorbent is used near the source of emission. The remaining amount can be reduced further by infusing liquid drops in the atmosphere. Numerical simulations are also carried out to support the analytical results.

  4. Diffuse volcanic emissions of carbon dioxide from Vulcano Island, Italy.

    Science.gov (United States)

    Baubron, J C; Allard, P; Toutain, J P

    1990-03-01

    RECENT investigations on Mount Etna (Sicily)(1-3) have revealed that volcanoes may release abundant carbon dioxide not only from their active craters, but also from their flanks, as diffuse soil emanations. Here we present analyses of soil gases and air in water wells on Vulcano Island which provide further evidence of such lateral degassing. Nearly pure carbon dioxide, enriched in helium and radon, escapes from the slopes of the Fossa active cone, adding a total output of 30 tonnes per day to the fumarolic crater discharge ( 180 tonnes CO(2) per day). This emanation has similar He/CO(2) and (13)C/(12)C ratios to those of the crater fumaroles (300%ndash;500 degrees C) and therefore a similar volcanic origin. Gases rich in carbon dioxide also escape at sea level along the isthmus between the Fossa and Vulcanello volcanic cones, but their depletion in both He and (13)C suggests a distinct source. Diffuse volcanic gas emanations, once their genetic link with central fumarole degassing has been demonstrated, can be used for continuous volcano monitoring, at safe distances from active craters. Such monitoring has been initiated at Vulcano, where soil and well emanations of nearly pure CO(2) themselves represent a threat to the local population.

  5. [Thoracoscopic thymectomy with carbon dioxide insufflation in the mediastinum].

    Science.gov (United States)

    Ferrero-Coloma, C; Navarro-Martinez, J; Bolufer, S; Rivera-Cogollos, M J; Alonso-García, F J; Tarí-Bas, M I

    2015-02-01

    The case is presented of a 71 year-old male, diagnosed with a thymoma. A thoracoscopic thymectomy was performed using the carbon dioxide insufflation technique in the mediastinum. During the procedure, while performing one-lung ventilation, the patient's respiration worsened. The contralateral lung had collapsed, as carbon dioxide was travelling from the mediastinum to the thorax through the opened pleura. Two-lung ventilation was decided upon, which clearly improved oxygenation in the arterial gases and airway pressures. Both pH and pCO2 stabilized. The surgical approach and the carbon dioxide technique were continued because 2-lung ventilation did not affect the surgical procedure. This technique has many serious complications and it should always be performed using 2-lung ventilation. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Effects of elevated carbon dioxide concentration on growth and N2 fixation of young Robinia pseudoacacia

    International Nuclear Information System (INIS)

    Feng, Z; Flessa, H.; Dyckmans, J.

    2004-01-01

    The effects of elevated carbon dioxide concentration on carbon and nitrogen uptake and nitrogen source partitioning were determined in one year-old locust trees using a dual 13 C and 15 N continuous labelling experiment. Elevated carbon dioxide increased the fraction of new carbon in total carbon, but it did not alter carbon partitioning among plant compartments. Elevated carbon dioxide also increased the fraction of new nitrogen in total nitrogen. This was coupled with a shift in nitrogen source partitioning toward nitrogen fixation. Soil nitrogen uptake was not affected, but nitrogen fixation was markedly increased by elevated carbon dioxide treatment. The increased nitrogen fixation tended to decrease the C/N ratio in the presence of elevated carbon dioxide. Total dry mass of root nodules doubled in response to elevated carbon dioxide, however, this effect was not considered significant because of the great variability in root nodule formation. Overall, it was concluded that the growth of locust trees in an elevated carbon dioxide environment will not primarily be limited by nitrogen availability, giving the R. pseudoacacia species a competitive advantage over non-nitrogen-fixing tree species. It was also suggested that the increase in nitrogen fixation observed in response to elevated carbon dioxide treatment may play a key role in the growth response of forest ecosystems to elevated carbon dioxide by improving nitrogen availability for non-nitrogen-fixing trees. 51 refs., 1 tab., 4 figs

  7. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  8. Biotransformations of carbon dioxide in photobioreactors

    International Nuclear Information System (INIS)

    Jacob-Lopes, Eduardo; Gimenes Scoparo, Carlos Henrique; Queiroz, Maria Isabel; Franco, Telma Teixeira

    2010-01-01

    Laboratory experiments were performed to study the capacity of CO 2 sequestration and carbon fixation into biomass during the cultivation of the cyanobacteria Aphanothece microscopica Naegeli in refinery wastewater. The influence of the photoperiod (day/night) on the rates of CO 2 sequestration and O 2 release was also determined. Rates of CO 2 sequestration were measured both in the liquid and gaseous phases. The results showed that the capacity of CO 2 sequestration and O 2 release during the day/night experiment was about one-fourth less than that achieved in the continuously illuminated experiment. Equivalence was found between rates of CO 2 sequestration measured in the two phases. Despite large amounts of CO 2 that were sequestered during the cultivation, it is demonstrated that only a small fraction (about 3%) was effectively fixed as microalgae biomass, indicating the existence of other routes of CO 2 conversion in the photobioreactor.

  9. An in situ infrared study of dimethyl carbonate synthesis from carbon dioxide and methanol over zirconia

    International Nuclear Information System (INIS)

    Jung, Kyeong Taek; Bell, Alexis T.

    2001-01-01

    The mechanism of dimethyl carbonate (DMC) synthesis from methanol and carbon dioxide over monoclinic zirconia has been investigated using in situ infrared spectroscopy. The dissociative adsorption of methanol occurs more slowly than the adsorption of carbon dioxide, but the species formed from methanol are bound more strongly. Upon adsorption, the oxygen atom of methanol binds to coordinately unsaturated Zr4+ cations present at the catalyst surface. Rapid dissociation of the adsorbed methanol leads to the formation of a methoxide group (Zr-OCH3) and the release of a proton, which reacts with a surface hydroxyl group to produce water. Carbon dioxide inserts in the Zr-O bond of the methoxide to form a mondentate methyl carbonate group (Zr-OC(O)OCH3). This process is facilitated by the interactions of C and O atoms in CO2 with Lewis acid-base pairs of sites (Zr4+O2-) on the surface of the catalyst. Methyl carbonate species can also be produced via the reaction of methanol with carbon dioxide adsorbed in the form of bicarbonate species with methanol, a process that results in the transfer of a methyl group to the carbonate and restores a hydroxyl group to the zirconia surface. The decomposition of DMC on monoclinic zirconia has also been investigated and has been observed to occur via the reverse of the processes described for the synthesis of DMC

  10. Arbuscular mycorrhizal fungi increase organic carbon decomposition under elevated carbon dioxide

    Science.gov (United States)

    A major goal of climate change research is to understand whether and how terrestrial ecosystems can sequester more carbon to mitigate rising atmospheric carbon dioxide (CO2) levels. The stimulation of arbuscular mycorrhizal fungi (AMF) by elevated atmospheric CO2 has been assumed to be a major mecha...

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

    International Nuclear Information System (INIS)

    Luxmoore, R.J.; Baldocchi, D.D.

    1994-01-01

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

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

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    2017-01-01

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

  13. Kinetic of formation for single carbon dioxide and mixed carbon dioxide and tetrahydrofuran hydrates in water and sodium chloride aqueous solution

    NARCIS (Netherlands)

    Sabil, K.M.; Duarte, A.R.C.; Zevenbergen, J.F.; Ahmad, M.M.; Yusup, S.; Omar, A.A.; Peters, C.J.

    2010-01-01

    A laboratory-scale reactor system is built and operated to measure the kinetic of formation for single and mixed carbon dioxide-tetrahydrofuran hydrates. The T-cycle method, which is used to collect the kinetic data, is briefly discussed. For single carbon dioxide hydrate, the induction time

  14. Review on Carbon Dioxide Absorption by Choline Chloride/Urea Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Rima J. Isaifan

    2018-01-01

    Full Text Available In the recent past few years, deep eutectic solvents (DESs were developed sharing similar characteristics to ionic liquids but with more advantageous features related to preparation cost, environmental impact, and efficiency for gas separation processes. Amongst many combinations of DES solvents that have been prepared, reline (choline chloride as the hydrogen bond acceptor mixed with urea as the hydrogen bond donor was the first DES synthesized and is still the one with the lowest melting point. Choline chloride/urea DES has proven to be a promising solvent as an efficient medium for carbon dioxide capture when compared with amine alone or ionic liquids under the same conditions. This review sheds light on the preparation method, physical and chemical characteristics, and the CO2 absorption capacity of choline chloride/urea DES under different temperatures and pressures reported up to date.

  15. Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Mogensen, Mogens Bjerg

    2009-01-01

    of the current density and irreversible when operated at conditions that would oxidise carbon. This clearly shows that the passivation was not caused by coke formation. On the other hand, the passivation was partly reversible when introducing hydrogen. The passivation may be a consequence of impurities...

  16. Fluxes of Methane and Carbon Dioxide from a Subarctic Lake

    DEFF Research Database (Denmark)

    Jammet, Mathilde Manon

    ) and carbon dioxide (CO2) with the atmosphere. Yet uncertainties in the magnitude and drivers of these fluxes remain, partly due to a lack of direct observations covering all seasons of the year, but also because of the diversity in measurement methods that often miss components of the transport processes......Ongoing climate warming is expected to affect the carbon functioning of subarctic ecosystems. Lakes and wetlands, which are common ecosystems of the high northern latitudes, are of utmost interest in this context because they exchange large amounts of the climate-forcing gases methane (CH4......-out and the release of CH4 and CO2 was established. These results underline the crucial importance of shoulder seasons in the annual carbon emissions from seasonally frozen lakes. Overall, the lake was an important annual source of carbon to the atmosphere, partially compensating the higher, annual sink function...

  17. Carbon dioxide concentrations are very high in developing oilseeds.

    Science.gov (United States)

    Goffman, Fernando D; Ruckle, Mike; Ohlrogge, John; Shachar-Hill, Yair

    2004-09-01

    A new method has been developed to rapidly determine the total inorganic carbon concentration (gaseous [CO2] + aqueous [CO(2)] + [HCO3-] + [CO3(2)-]) in developing seeds. Seeds are rapidly dissected and homogenized in 1 N HCl in gas-tight vials. The headspace gas is then analyzed by infrared gas analysis. Developing rapeseed (Brassica napus L.) and soybean [Glycine max (L.) Merr.] seeds were analyzed and found to have up to 40 and 12 mM total inorganic carbon, respectively. These concentrations are ca. 600-2000-fold higher than in ambient air or values reported for leaves. Carbon dioxide concentrations in rapeseed peaked during the stage of maximum oil synthesis and declined as seeds matured. The consequences for seed metabolism, physiology and carbon economy are discussed.

  18. Reduced graphene oxide supported gold nanoparticles for electrocatalytic reduction of carbon dioxide

    Science.gov (United States)

    Saquib, Mohammad; Halder, Aditi

    2018-02-01

    Electrochemical reduction of carbon dioxide is one of the methods which have the capability to recycle CO2 into valuable products for energy and industrial applications. This research article describes about a new electrocatalyst "reduced graphene oxide supported gold nanoparticles" for selective electrochemical conversion of carbon dioxide to carbon monoxide. The main aim for conversion of CO2 to CO lies in the fact that the latter is an important component of syn gas (a mixture of hydrogen and carbon monoxide), which is then converted into liquid fuel via well-known industrial process called Fischer-Tropsch process. In this work, we have synthesized different composites of the gold nanoparticles supported on defective reduced graphene oxide to evaluate the catalytic activity of reduced graphene oxide (RGO)-supported gold nanoparticles and the role of defective RGO support towards the electrochemical reduction of CO2. Electrochemical and impedance measurements demonstrate that higher concentration of gold nanoparticles on the graphene support led to remarkable decrease in the onset potential of 240 mV and increase in the current density for CO2 reduction. Lower impedance and Tafel slope values also clearly support our findings for the better performance of RGOAu than bare Au for CO2 reduction.

  19. Amazon River carbon dioxide outgassing fuelled by wetlands.

    Science.gov (United States)

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

    2014-01-16

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

  20. Biomass fuels - effects on the carbon dioxide budget

    International Nuclear Information System (INIS)

    Eriksson, H.; Hallsby, G.

    1992-02-01

    It is highly desirable that the effects on the carbon dioxide balance of alternative energy sources are evaluated. Two important alternatives studied in Sweden are the extraction of logging residues left in the forest and willow production on farmland. Considered in isolation, a conversion from stem-wood harvest to whole-tree harvest has a negative effect on the carbon dioxide balance, because the amount of soil organic matter decreases. With the assumption that it takes 20 years for the logging residues to decompose, the net decrease in emissions that would result from the replacement of fossil fuels by logging residues appear moderate after 20 years. However, it will grow significantly as time passes. After 100 years with an annual combustion of logging residues the emissions are 12% of those associated with the production of an equivalent amount of energy through oil combustion. Corresponding values for 300 and 500 years are 4% and 2.5% respectively. In less than 100 years there should be a considerable reduction in the Swedish CO 2 -C emissions even if only every second new logging residue-produced TWH replaces a fossil-fuel-produced TWh. From a long-term perspective, effects on carbon reservoirs in Sweden, caused by conversions to whole-tree harvesting in forestry and to willow production on redundant farmland, can be considered negligible in terms of their influence on the carbon dioxide budget of Sweden. The orders of magnitude of influencing fluxes is exemplified in the following: The annual production of 50 TWh, whereof 40 TWh from logging residues, 8 TWh from willow and 2 TWh from annual crops is estimated to cause a total net decrease of the carbon reservoirs within Sweden corresponding to 32 Tg CO 2 -C, whereas the annual production of 50 TWh from oil combustion should emit 1200 Tg CO 2 -C in 300 years, 2000 Tg CO 2 -C in 500 years and so on. (au). 17 refs., 4 tabs