High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell

NASA Technical Reports Server (NTRS)

Narayan, Sri; Haines, Brennan; Blosiu, Julian; Marzwell, Neville

2009-01-01

A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an improved configuration using a polymer membrane electrolyte and an alkaline medium. This increases efficiency of the artificial photosynthetic process, achieves high conversion rates, permits the use of inexpensive catalysts, and widens the range of products generated by this type of process. The alkaline membrane electrolyte allows for the continuous generation of sodium formate without the need for any additional separation system. The electrolyte type, pH, electrocatalyst type, and cell voltage were found to have a strong effect on the efficiency of conversion of carbon dioxide to formate. Indium electrodes were found to have higher conversion efficiency compared to lead. Bicarbonate electrolyte offers higher conversion efficiency and higher rates than water solutions saturated with carbon dioxide. pH values between 8 and 9 lead to the maximum values of efficiency. The operating cell voltage of 2.5 V, or higher, ensures conversion of the carbon dioxide to formate, although the hydrogen evolution reaction begins to compete strongly with the formate production reaction at higher cell voltages. Formate is produced at indium and lead electrodes at a conversion efficiency of 48 mg of CO2/kilojoule of energy input. This efficiency is about eight times that of natural photosynthesis in green plants. The electrochemical method of artificial photosynthesis is a promising approach for the conversion, separation and sequestration of carbon dioxide for confined environments as in space habitats, and also for carbon dioxide management in the terrestrial context. The heart of the reactor is a membrane cell fabricated from an alkaline polymer electrolyte membrane and catalyst- coated electrodes. This cell is assembled and held in compression in gold-plated hardware. The cathode side of the cell is supplied with carbon dioxide-saturated water or bicarbonate solution. The anode side of the cell is supplied with sodium hydroxide solution. The solutions are circulated past the electrodes in the electrochemical cell using pumps. A regulated power supply provides the electrical energy required for the reactions. Photovoltaic cells can be used to better mimic the photosynthetic reaction. The current flowing through the electrochemical cell, and the cell voltage, are monitored during experimentation. The products of the electrochemical reduction of carbon dioxide are allowed to accumulate in the cathode reservoir. Samples of the cathode solution are withdrawn for product analysis. Oxygen is generated on the anode side and is allowed to vent out of the reservoir.

Kinetics of the Reduction of Cadmium Sulfate by Thiourea Dioxide in an Aqueous Ammonia Solution upon the Metallization of Carbon Fiber

NASA Astrophysics Data System (ADS)

Polenov, Yu. V.; Egorova, E. V.; Shestakov, G. A.

2018-01-01

The kinetics of the decomposition of thiourea dioxide and the reduction of cadmium cations by thiourea dioxide in an aqueous ammonia solution are studied. The kinetic parameters of these reactions are calculated using experimental data, allowing us to adjust conditions for the synthesis of cadmium coatings on carbon fiber of grade UKN-M-12K. The presence of the metal crystalline phase on the fiber is confirmed by means of X-ray diffraction, and its amount is measured via atomic absorption spectroscopy.

Effect of Greenhouse Gases Dissolved in Seawater

PubMed Central

Matsunaga, Shigeki

2015-01-01

A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region. PMID:26729101

Effect of Greenhouse Gases Dissolved in Seawater.

PubMed

Matsunaga, Shigeki

2015-12-30

A molecular dynamics simulation has been performed on the greenhouse gases carbon dioxide and methane dissolved in a sodium chloride aqueous solution, as a simple model of seawater. A carbon dioxide molecule is also treated as a hydrogen carbonate ion. The structure, coordination number, diffusion coefficient, shear viscosity, specific heat, and thermal conductivity of the solutions have been discussed. The anomalous behaviors of these properties, especially the negative pressure dependence of thermal conductivity, have been observed in the higher-pressure region.

Encapsulated liquid sorbents for carbon dioxide capture

NASA Astrophysics Data System (ADS)

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

2015-02-01

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

International Space Station Carbon Dioxide Removal Assembly (ISS CDRA) Concepts and Advancements

NASA Technical Reports Server (NTRS)

ElSherif, Dina; Knox, James C.

2005-01-01

An important aspect of air revitalization for life support in spacecraft is the removal of carbon dioxide from cabin air. Several types of carbon dioxide removal systems are in use in spacecraft life support. These systems rely on various removal techniques that employ different architectures and media for scrubbing CO2, such as permeable membranes, liquid amine, adsorbents, and absorbents. Sorbent systems have been used since the first manned missions. The current state of key technology is the existing International Space Station (ISS) Carbon Dioxide Removal Assembly (CDRA), a system that selectively removes carbon dioxide from the cabin atmosphere. The CDRA system was launched aboard UF-2 in February 2001 and resides in the U.S. Destiny Laboratory module. During the past four years, the CDRA system has operated with varying degrees of success. There have been several approaches to troubleshooting the CDRA system aimed at developing work-around solutions that would minimize the impact on astronaut time required to implement interim solutions. The paper discusses some of the short-term fixes applied to promote hardware life and restore functionality, as well as long-term plans and solutions for improving operability and reliability. The CDRA is a critical piece of life support equipment in the air revitalization system of the ISS, and is demonstrated technology that may ultimately prove well-suited for use in lunar or Mars base, and Mars transit life support applications.

A hybrid absorption–adsorption method to efficiently capture carbon

PubMed Central

Liu, Huang; Liu, Bei; Lin, Li-Chiang; Chen, Guangjin; Wu, Yuqing; Wang, Jin; Gao, Xueteng; Lv, Yining; Pan, Yong; Zhang, Xiaoxin; Zhang, Xianren; Yang, Lanying; Sun, Changyu; Smit, Berend; Wang, Wenchuan

2014-01-01

Removal of carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture carbon dioxide compared to conventional technologies. The carbon dioxide sorption capacity of our slurry reaches 1.25 mol l−1 at 1 bar and the selectivity of carbon dioxide/hydrogen, carbon dioxide/nitrogen and carbon dioxide/methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only −29 kJ mol−1, indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration. PMID:25296559

Origin of gasoline-range hydrocarbons and their migration by solution in carbon dioxide in Norton basin, Alaska.

USGS Publications Warehouse

Kvenvolden, K.A.; Claypool, G.E.

1980-01-01

Carbon dioxide from a submarine seep in Norton Sound carries a minor component of gas- and gasoline-range hydrocarbons. The molecular and isotopic compositions of the hydrocarbon gases and the presence of gasoline-range hydrocarbons indicate that these molecules are derived from thermal alteration of marine and/or nonmarine organic matter buried within Norton basin. The gasoline-range hydrocarbon distribution suggests that the hydrocarbon mixture is an immature petroleum-like condensate of lower temperature origin than normal crude oil. The submarine seep provides a natural example in support of a carbon dioxide solution transport mechanism thought to be operative in the migration of hydrocarbons in certain reservoirs.-Authors

Bench Remarks: Carbon Dioxide.

ERIC Educational Resources Information Center

Bent, Henry A.

1987-01-01

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

Density and viscosity of some partially carbonated aqueous alkanolamine solutions and their blends

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

Weiland, R.H.; Dingman, J.C.; Cronin, D.B.

1998-05-01

Very little information is available concerning the effect of acid gas loading on the physical properties of amine-treating solutions flowing through the absorption and regeneration columns used in gas processing. The densities and viscosities of partially carbonated monoethanolamine (MEA), diethanolamine (DEA), and N-methyldiethanolamine (MDEA) solutions were measured at 298 K. With increasing carbon dioxide loadings, significant increases in both density and viscosity were observed. These results were combined with literature data to produce correlations for alkanolamine solution density and viscosity as a function of amine concentration, carbon dioxide loading, and temperature. The resulting single-amine correlations were used to predict themore » densities and viscosities of DEA + MDEA and MEA + MDEA blends. Predictions are compared with data measured for these blends.« less

The separation of lanthanides and actinides in supercritical fluid carbon dioxide

DOE PAGES

Mincher, Bruce J.; Wai, Chien M.; Fox, Robert V.; ...

2015-10-28

Supercritical fluid carbon dioxide presents an attractive alternative to conventional solvents for recovery of the actinides and lanthanides. Carbon dioxide is a good solvent for fluorine and phosphate-containing ligands, including the traditional tributylphosphate ligand used in process-scale uranium separations. Actinide and lanthanide oxides may even be directly dissolved in carbon dioxide containing the complexes formed between these ligands and mineral acids, obviating the need for large volumes of acids for leaching and dissolution, and the corresponding organic liquid–liquid solvent extraction solutions. As a result, examples of the application of this novel technology for actinide and lanthanide separations are presented.

Removing oxygen from a solvent extractant in an uranium recovery process

DOEpatents

Hurst, Fred J.; Brown, Gilbert M.; Posey, Franz A.

1984-01-01

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous and accumulation of complex iron phosphates or cruds.

SN1 reactions in supercritical carbon dioxide in the presence of alcohols: the role of preferential solvation.

PubMed

Delgado-Abad, Thais; Martínez-Ferrer, Jaime; Acerete, Rafael; Asensio, Gregorio; Mello, Rossella; González-Núñez, María Elena

2016-07-06

Ethanol () inhibits SN1 reactions of alkyl halides in supercritical carbon dioxide (scCO2) and gives no ethers as products. The unexpected behaviour of alcohols in the reaction of alkyl halides with 1,3-dimethoxybenzene () in scCO2 under different conditions is rationalised in terms of Brønsted and Lewis acid-base equilibria of reagents, intermediates, additives and products in a singular solvent characterised by: (i) the strong quadrupole and Lewis acid character of carbon dioxide, which hinders SN2 paths by strongly solvating basic solutes; (ii) the weak Lewis base character of carbon dioxide, which prevents it from behaving as a proton sink; (iii) the compressible nature of scCO2, which enhances the impact of preferential solvation on carbon dioxide availability for the solvent-demanding rate determining step.

Utilizing Diffusion Theory to predict carbon dioxide concentration in an indoor environment

NASA Astrophysics Data System (ADS)

Kramer, Andrew R.

This research details a new method of relating sources of carbon dioxide to carbon dioxide concentration in a room operating in a reduced ventilation mode by utilizing Diffusion Theory. The theoretical basis of this research involved solving Fick's Second Law of Diffusion in spherical coordinates for a source of carbon dioxide flowing at a constant rate and located in the center of an impermeable spherical boundary. The solution was developed using a Laplace Transformation. A spherical diffusion test chamber was constructed and used to validate and benchmark the developed theory. The method was benchmarked by using Dispersion Coefficients for large carbon dioxide flow rates due to diffusion induced convection. The theoretical model was adapted to model a room operating with restricted ventilation in the presence of a known, constant source of carbon dioxide. The room was modeled as a sphere of volume equal to the room and utilized a Dispersion Coefficient that is consistent with published values. The developed Diffusion Model successfully predicted the spatial concentration of carbon dioxide in a room operating in a reduced ventilation mode in the presence of a source of carbon dioxide. The flow rates of carbon dioxide that were used in the room are comparable to the average flow rate of carbon dioxide from a person during quiet breathing, also known as the Tidal Breathing. This indicates the Diffusion Model developed from this research has the potential to correlate carbon dioxide concentration with static occupancy levels which can lead to energy savings through a reduction in air exchange rates when low occupancy is detected.

Towards Providing Solutions to the Air Quality Crisis in the Mexico City Metropolitan Area: Carbon Sequestration by Succulent Species in Green Roofs

PubMed Central

Collazo-Ortega, Margarita; Rosas, Ulises; Reyes-Santiago, Jerónimo

2017-01-01

INTRODUCTION: In the first months of 2016, the Mexico City Metropolitan Area experienced the worst air pollution crisis in the last decade, prompting drastic short-term solutions by the Mexico City Government and neighboring States. In order to help further the search for long-term sustainable solutions, we felt obliged to immediately release the results of our research regarding the monitoring of carbon sequestration by green roofs. Large-scale naturation, such as the implementation of green roofs, provides a way to partially mitigate the increased carbon dioxide output in urban areas. METHODS: Here, we quantified the carbon sequestration capabilities of two ornamental succulent plant species, Sedum dendroideum and Sedum rubrotinctum, which require low maintenance, and little or no irrigation. To obtain a detailed picture of these plants’ carbon sequestration capabilities, we measured carbon uptake on the Sedum plants by quantifying carbon dioxide exchange and fixation as organic acids, during the day and across the year, on a green roof located in Southern Mexico City. RESULTS: The species displayed their typical CAM photosynthetic metabolism. Moreover, our quantification allowed us to conservatively estimate that a newly planted green roof of Sedum sequesters approximately 180,000,000 ppm of carbon dioxide per year in a green roof of 100 square meters in the short term. DISCUSSION: The patterns of CAM and carbon dioxide sequestration were highly robust to the fluctuations of temperature and precipitation between seasons, and therefore we speculate that carbon sequestration would be comparable in any given year of a newly planted green roof. Older green roof would require regular trimming to mantain their carbon sink properties, but their carbon sequestration capabilities remain to be quantified. Nevertheless, we propose that Sedum green roofs can be part of the long-term solutions to mitigate the air pollution crisis in the Mexico City Metropolitan area, and other “megacities” with marked seasonal drought. PMID:28480127

Towards Providing Solutions to the Air Quality Crisis in the Mexico City Metropolitan Area: Carbon Sequestration by Succulent Species in Green Roofs.

PubMed

Collazo-Ortega, Margarita; Rosas, Ulises; Reyes-Santiago, Jerónimo

2017-03-31

In the first months of 2016, the Mexico City Metropolitan Area experienced the worst air pollution crisis in the last decade, prompting drastic short-term solutions by the Mexico City Government and neighboring States. In order to help further the search for long-term sustainable solutions, we felt obliged to immediately release the results of our research regarding the monitoring of carbon sequestration by green roofs. Large-scale naturation, such as the implementation of green roofs, provides a way to partially mitigate the increased carbon dioxide output in urban areas. Here, we quantified the carbon sequestration capabilities of two ornamental succulent plant species, Sedum dendroideum and Sedum rubrotinctum, which require low maintenance, and little or no irrigation. To obtain a detailed picture of these plants' carbon sequestration capabilities, we measured carbon uptake on the Sedum plants by quantifying carbon dioxide exchange and fixation as organic acids, during the day and across the year, on a green roof located in Southern Mexico City. The species displayed their typical CAM photosynthetic metabolism. Moreover, our quantification allowed us to conservatively estimate that a newly planted green roof of Sedum sequesters approximately 180,000,000 ppm of carbon dioxide per year in a green roof of 100 square meters in the short term. The patterns of CAM and carbon dioxide sequestration were highly robust to the fluctuations of temperature and precipitation between seasons, and therefore we speculate that carbon sequestration would be comparable in any given year of a newly planted green roof. Older green roof would require regular trimming to mantain their carbon sink properties, but their carbon sequestration capabilities remain to be quantified. Nevertheless, we propose that Sedum green roofs can be part of the long-term solutions to mitigate the air pollution crisis in the Mexico City Metropolitan area, and other "megacities" with marked seasonal drought.

Electrochemical behavior of lead dioxide deposited on reticulated vitreous carbon (RVC)

NASA Astrophysics Data System (ADS)

Czerwiński, Andrzej; Żelazowska, Malgorzata

The electrochemical performance of lead dioxide deposited on reticulated vitreous carbon (RVC) has been investigated in basic and acidic solutions (0.1 M NaOH, 0.1 M Na 2BB 4OO 7 and 0.5 M H 2SSO 4)). For comparison, pure lead and lead dioxide deposited on platinized RVC (Pt/ RVC) were also included in the study. Our results indicate that the behavior of RVC covered with lead dioxide (without platinum) resembles that of lead dioxide generated electrochemically on metallic lead.

Acid pre-treatment method for in situ ore leaching

DOEpatents

Mallon, R.G.; Braun, R.L.

1975-10-28

An acid leaching method is described for the recovery of a desired element from a subterranean rubblized body of primary ore containing the element and also having associated therewith a carbonate mineral wherein the rubblized ore body is flooded with an aqueous acidic solution in order to release carbon dioxide from the associated carbonate mineral. After a substantial portion of the available carbon dioxide is released and removed from the ore body, as by venting to the atmosphere, an oxidizing gas is introduced into the flooded, rubblized ore to oxidize the ore and form an acid leach solution effective in the presence of the dissolved oxidizing gas to dissolve the ore and cause the desired element to go into solution. The leach solution is then circulated to the surface where the metal values are recovered therefrom.

Atmospheric CO2 sequestration in iron and steel slag: Consett, Co. Durham, UK.

PubMed

Mayes, William Matthew; Riley, Alex L; Gomes, Helena I; Brabham, Peter; Hamlyn, Joanna; Pullin, Huw; Renforth, Phil

2018-06-12

Carbonate formation in waste from the steel industry could constitute a non-trivial proportion of global requirements to remove carbon dioxide from the atmosphere at potentially low cost. To constrain this potential, we examined atmospheric carbon dioxide sequestration in a >20 million tonne legacy slag deposit in northern England, UK. Carbonates formed from the drainage water of the heap had stable carbon and oxygen isotopes between -12 and -25 ‰ and -5 and -18 ‰ for δ13C and δ18O respectively, suggesting atmospheric carbon dioxide sequestration in high pH solutions. From analysis of solution saturation state, we estimate that between 280 and 2,900 tCO2 have precipitated from the drainage waters. However, by combining a thirty-seven-year dataset of the drainage water chemistry with geospatial analysis, we estimate that <1 % of the maximum carbon capture potential of the deposit may have been realised. This implies that uncontrolled deposition of slag is insufficient to maximise carbon sequestration, and there may be considerable quantities of unreacted legacy deposits available for atmospheric carbon sequestration.

Removing Biostatic Agents From Fermentation Solutions

NASA Technical Reports Server (NTRS)

Du Fresne, E. R.

1984-01-01

Liquid carbon dioxide inexpensive solvent. Inexpensive process proposed for removing such poisons as furfural and related compounds from fermentation baths of biomass hydrolysates. New process based on use of liquid carbon dioxide as extraction solvent. Liquid CO2 preferable to such other liquid solvents as ether or methylene chloride.

Photoproduction of halogens using platinized TiO2

NASA Technical Reports Server (NTRS)

Reichman, B.; Byvik, C. E.

1981-01-01

Unlike electrolysis of halide salt solutions, technique using powdered titanium dioxide catalyst requires no external power other than ultraviolet radiation source. Semiconductor powders photocatalyze and photosynthesize many useful reactions; applications are production of halogen molecules, oxidation of hazardous materials in wastewater, and conversion of carbon monoxide to carbon dioxide.

The origin of high sodium bicarbonate waters in the Atlantic and Gulf Coastal Plains

USGS Publications Warehouse

Foster, M.D.

1950-01-01

Some sodium bicarbonate waters at depth in the Atlantic and Gulf Coastal Plains have the same bicarbonate content as the shallower calcium bicarbonate waters in the same formation and appear to be the result of replacement of calcium by sodium through the action of base-exchange minerals. Others, however, contain several hundred parts per million more of bicarbonate than any of the calcium bicarbonate waters and much more bicarbonate than can be attributed to solution of calcium carbonate through the action of carbon dioxide derived from the air and soil. As the waters in the Potomac group (Cretaceous) are all low in sulphate and as the environmental conditions under which the sediments of the Potomac group were deposited do not indicate that large amounts of sulphate are available for solution, it does not seem probable that carbon dioxide generated by chemical or biochemical breakdown of sulphate is responsible for the high sodium bicarbonate waters in this area. Sulphate as a source of oxygen is not necessary for the generation of carbon dioxide by carbonaceous material. Oxygen is an important constituent of carbonaceous material and carbon dioxide is a characteristic decomposition product of such material-as, for example, peat and lignite. Experimental work showed that distilled water, calcium bicarbonate water, and sodium bicarbonate water, after contact with lignite, calcium carbonate, and permutite (a base-exchange material), had all increased greatly in sodium bicarbonate content and had become similar in chemical character and in mineral content to high sodium bicarbonate waters found in the Coastal Plain. The tests indicated that carbonaceous material can act as a source of carbon dioxide, which, when dissolved in water, enables it to take into solution more calcium carbonate. If base-exchange materials are also present to replace calcium with sodium, a still greater amount of bicarbonate can be held in solution. The presence of carbonaceous material, together with calcium carbonate and base-exchange minerals in a formation is, therefore, sufficient to account for the occurrence in it of high sodium bicarbonate waters. ?? 1950.

Method for oxygen reduction in a uranium-recovery process. [US DOE patent application

DOEpatents

Hurst, F.J.; Brown, G.M.; Posey, F.A.

1981-11-04

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous iron and accumulation of complex iron phosphates or cruds.

Comparing (semi-) analytic solutions used to model the impact of deep carbon injection on the displacement and pressurization of the resident brine

NASA Astrophysics Data System (ADS)

Bandilla, K.; Kraemer, S. R.

2009-12-01

Injection of carbon dioxide into deep saline formations is seen as one possible technology for mitigating carbon emissions from utilities. The safety of the sequestered carbon dioxide is the focus of many studies with leakage through faults or abandoned wells as some of the main failure mechanisms. The focus of this study is on the displacement of resident brine and the resulting changes in pressure due to the injection of large volumes of super-critical phase carbon dioxide into the subsurface. The movement of brine becomes important if it travels vertically and reaches an existing or potential underground source of drinking water where an increase in salt content may threaten the viability of the drinking water source. Vertical displacement of brine may occur slowly through confining layers, or more rapidly through faults and abandoned wells. This presentation compares several (semi-) analytic solutions to determine their applicability to the problem of brine pressurization and displacement. The goal is to find ranges of formation parameters (e.g., formation seal conductivity, distance to lateral boundary, … ) for which simplifying assumption are justifiable Each simplification in the conceptual model (e.g., neglecting the lateral boundary turns a bounded domain into an infinite one) leads to a simpler (semi-) analytic solution. The process involves a solution hierarchy from the most complex solution down to the basic Theis solution. A software tool-kit implementing several (semi-) analytic solutions was developed for this study to facilitate the comparison of the solutions.

Synthetic carbonaceous fuels and feedstocks

DOEpatents

Steinberg, Meyer

1980-01-01

This invention relates to the use of a three compartment electrolytic cell in the production of synthetic carbonaceous fuels and chemical feedstocks such as gasoline, methane and methanol by electrolyzing an aqueous sodium carbonate/bicarbonate solution, obtained from scrubbing atmospheric carbon dioxide with an aqueous sodium hydroxide solution, whereby the hydrogen generated at the cathode and the carbon dioxide liberated in the center compartment are combined thermocatalytically into methanol and gasoline blends. The oxygen generated at the anode is preferably vented into the atmosphere, and the regenerated sodium hydroxide produced at the cathode is reused for scrubbing the CO.sub.2 from the atmosphere.

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

PubMed

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.

Apparatus for extracting and sequestering carbon dioxide

DOEpatents

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.

Method for extracting and sequestering carbon dioxide

DOEpatents

Rau, Gregory H.; Caldeira, Kenneth G.

2005-05-10

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

Highly stable beta-class carbonic anhydrases useful in carbon capture systems

DOEpatents

Alvizo, Oscar; Benoit, Mike; Novick, Scott

2013-04-16

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Highly stable beta-class carbonic anhydrases useful in carbon capture systems

DOEpatents

Alvizo, Oscar; Benoit, Michael R; Novick, Scott J

2013-08-20

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Solubility of mixtures of hydrogen sulfide and carbon dioxide in aqueous N-methyldiethanolamine solutions

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

Jou, Fang Yuan; Carroll, J.J.; Mather, A.E.

1993-01-01

Aqueous solutions of alkanolamines are commonly used to strip acid gases (H[sub 2]S and CO[sub 2]) from streams contaminated with these components. The two most widely used amines are monoethanolamine (MEA) and diethanolamine (DEA). The solubilities of mixtures of hydrogen sulfide and carbon dioxide in a 35 wt% (3.04 kmol/m[sup 3]) aqueous solution of N-methyldiethanolamine at 40 and 100C have been measured. Partial pressures of the acid gases ranged from 0.006 to 101 kPa at 40C and from 4 to 530 kPa at 100C.

Microscopic Structure and Solubility Predictions of Multifunctional Solids in Supercritical Carbon Dioxide: A Molecular Simulation Study.

PubMed

Noroozi, Javad; Paluch, Andrew S

2017-02-23

Molecular dynamics simulations were employed to both estimate the solubility of nonelectrolyte solids, such as acetanilide, acetaminophen, phenacetin, methylparaben, and lidocaine, in supercritical carbon dioxide and understand the underlying molecular-level driving forces. The solubility calculations involve the estimation of the solute's limiting activity coefficient, which may be computed using conventional staged free-energy calculations. For the case of lidocaine, wherein the infinite dilution approximation is not appropriate, we demonstrate how the activity coefficient at finite concentrations may be estimated without additional effort using the dilute solution approximation and how this may be used to further understand the solvation process. Combining with experimental pure-solid properties, namely, the normal melting point and enthalpy of fusion, solubilities were estimated. The results are in good quantitative agreement with available experimental data, suggesting that molecular simulations may be a powerful tool for understanding supercritical processes and the design of carbon dioxide-philic molecular systems. Structural analyses were performed to shed light on the microscopic details of the solvation of different functional groups by carbon dioxide and the observed solubility trends.

Supercritical separation process for complex organic mixtures

DOEpatents

Chum, Helena L.; Filardo, Giuseppe

1990-01-01

A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.

A new method of auxiliary purification for motor vehicle exhaust.

PubMed

Li, Dingqi

2018-07-01

As a result of the limitations of current purification technologies, purification efficiency is relatively low, particularly during startup or in the case of other abnormal automobile exhaust. Therefore, a new method of auxiliary purification is proposed in this paper. The acidic solution of potassium permanganate can oxidize carbon monoxide, nitrogen oxides and sulfur dioxide at relatively high temperatures and the alkaline solution of potassium permanganate can selectively absorb nitrogen oxide and sulfur dioxide. Therefore, we carried out the experiment using a solution of potassium permanganate and sulfuric acid as well as a solution of sodium carbonate and potassium permanganate, which served as the reagents for the auxiliary purification. The results of the test showed that after auxiliary purification by the acidic solution of potassium permanganate and the alkaline solution of potassium permanganate, the concentrations of carbon monoxide, hydrocarbons, nitrogen oxides and solid particles in the emissions were considerably lower than the concentrations prior to purification. It is possible to reduce the motor vehicle exhaust by the auxiliary purification of the solutions.

Using semi-analytic solutions to approximate the area of potential impact for carbon dioxide injection

EPA Science Inventory

This study examines using the threshold critical pressure increase and the extent of the carbon dioxide (CO2) plume to delineate the area of potential impact (AoPI) for geologic CO2 storage projects. The combined area covering both the CO2 plume and the region where the pressure ...

How Can We Use Carbon Dioxide as a Solvent?

ERIC Educational Resources Information Center

Mohamed, Azmi; Eastoe, Julian

2011-01-01

This article describes the work being undertaken to make more use of supercritical carbon dioxide as a green solvent. It discusses how the use of surfactants can address the limitations of supercritical CO[subscript 2] in dissolving solutes that are polar and of higher molecular weight. The design of appropriate hydrocarbon CO[subscript 2]-philic…

Modification of pure oxygen absorption equipment for concurrent stripping of carbon dioxide

USGS Publications Warehouse

Watten, B.J.; Sibrell, P.L.; Montgomery, G.A.; Tsukuda, S.M.

2004-01-01

The high solubility of carbon dioxide precludes significant desorption within commercial oxygen absorption equipment. This operating characteristic of the equipment limits its application in recirculating water culture systems despite its ability to significantly increase allowable fish loading rates (kg/(L min)). Carbon dioxide (DC) is typically removed by air stripping. This process requires a significant energy input for forced air movement, air heating in cold climates and water pumping. We developed a modification for a spray tower that provides for carbon dioxide desorption as well as oxygen absorption. Elimination of the air-stripping step reduces pumping costs while allowing dissolved nitrogen to drop below saturation concentrations. This latter response provides for an improvement in oxygen absorption efficiency within the spray tower. DC desorption is achieved by directing head-space gases from the spray tower (O2, N2, CO2) through a sealed packed tower scrubber receiving a 2 N NaOH solution. Carbon dioxide is selectively removed from the gas stream, by chemical reaction, forming the product Na 2CO3. Scrubber off-gas, lean with regard to carbon dioxide but still rich with oxygen, is redirected through the spray tower for further stripping of DC and absorption of oxygen. Make-up NaOH is metered into the scrubbing solution sump on an as needed basis as directed by a feedback control loop programmed to maintain a scrubbing solution pH of 11.4-11.8. The spent NaOH solution is collected, then regenerated for reuse, in a batch process that requires relatively inexpensive hydrated lime (Ca(OH)2). A by-product of the regeneration step is an alkaline filter cake, which may have use in bio-solids stabilization. Given the enhanced gas transfer rates possible with chemical reaction, the required NaOH solution flow rate through the scrubber represents a fraction of the spray tower water flow rate. Further, isolation of the water being treated from the atmosphere (1), allows for an improvement in oxygen absorption efficiency by maintaining DN well below local saturation concentrations (2), minimizes building energy requirements related to heating and ventilation and (3), reduces the potential for pathogen transmittance. We report on the performance of a test scrubber evaluated over a range of NaOH solution temperatures, pH, packing irrigation rates, and gas stream compositions. We also describe our experience with the process in a pilot scale recirculating water (trout) production system.

FISSION PRODUCT REMOVAL FROM ORGANIC SOLUTIONS

DOEpatents

Moore, R.H.

1960-05-10

The decontamination of organic solvents from fission products and in particular the treatment of solvents that were used for the extraction of uranium and/or plutonium from aqueous acid solutions of neutron-irradiated uranium are treated. The process broadly comprises heating manganese carbonate in air to a temperature of between 300 and 500 deg C whereby manganese dioxide is formed; mixing the manganese dioxide with the fission product-containing organic solvent to be treated whereby the fission products are precipitated on the manganese dioxide; and separating the fission product-containing manganese dioxide from the solvent.

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

DOEpatents

Rau, Gregory Hudson [Castro Valley, CA

2012-05-15

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

Experimental investigation of the phase equilibria in the carbon dioxide-propane-3 M MDEA system

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

Jou, F.Y.; Mather, A.E.; Otto, F.D.

1995-07-01

The treating of liquefied petroleum gas (LPG) to remove carbon dioxide and hydrogen sulfide using aqueous alkanolamine solutions is an important aspect of gas processing. One of the amines used in the natural gas industry is methyldiethanolamine (MDEA). Measurements of the phase equilibria in the carbon dioxide-propane-3 M MDEA system have been made at 25 and 40 C at pressures up to 15.5 MPa. Vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria were determined. The vapor-liquid equilibrium data were compared with the model of Deshmukh and Mather.

Climate-driven changes to the atmospheric CO2 sink in the subtropical North Pacific Ocean.

PubMed

Dore, John E; Lukas, Roger; Sadler, Daniel W; Karl, David M

2003-08-14

The oceans represent a significant sink for atmospheric carbon dioxide. Variability in the strength of this sink occurs on interannual timescales, as a result of regional and basin-scale changes in the physical and biological parameters that control the flux of this greenhouse gas into and out of the surface mixed layer. Here we analyse a 13-year time series of oceanic carbon dioxide measurements from station ALOHA in the subtropical North Pacific Ocean near Hawaii, and find a significant decrease in the strength of the carbon dioxide sink over the period 1989-2001. We show that much of this reduction in sink strength can be attributed to an increase in the partial pressure of surface ocean carbon dioxide caused by excess evaporation and the accompanying concentration of solutes in the water mass. Our results suggest that carbon dioxide uptake by ocean waters can be strongly influenced by changes in regional precipitation and evaporation patterns brought on by climate variability.

A wet chemical method for the estimation of carbon in uranium carbides.

PubMed

Chandramouli, V; Yadav, R B; Rao, P R

1987-09-01

A wet chemical method for the estimation of carbon in uranium carbides has been developed, based on oxidation with a saturated solution of sodium dichromate in 9M sulphuric acid, absorption of the evolved carbon dioxide in a known excess of barium hydroxide solution, and titration of the excess of barium hydroxide with standard potassium hydrogen phthalate solution. The carbon content obtained is in good agreement with that obtained by combustion and titration.

Modeling carbon dioxide, pH, and un-ionized ammonia relationships in serial reuse systems

USGS Publications Warehouse

Colt, J.; Watten, B.; Rust, M.

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity-pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air-water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air-water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems

USGS Publications Warehouse

Watten, Barnaby J.; Rust, Michael; Colt, John

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Solubility of single gases carbon dioxide and hydrogen sulfide in aqueous solutions of N-methyldiethanolamine in the temperature range 313--413 K at pressures up to 5 MPa

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

Kuranov, G.; Smirnova, N.A.; Rumpf, B.

1996-06-01

Experimental results for the solubility of the single gases carbon dioxide and hydrogen sulfide in aqueous solutions of 2,2{prime}-methyliminodiethanol (N-methyldiethanolamine (MDEA)) at temperatures between 313 and 413 K and total pressures up to 5 MPa are reported. A model taking into account chemical reactions as well as physical interactions is used to correlate the new data. The correlation is also used to compare the new experimental data with literature data.

Crystallization of pure anhydrous polymorphs of carbamazepine by solution enhanced dispersion with supercritical fluids (SEDS).

PubMed

Edwards, A D; Shekunov, B Y; Kordikowski, A; Forbes, R T; York, P

2001-08-01

Pure anhydrous polymorphs of carbamazepine were prepared by solution-enhanced dispersion with supercritical fluids (SEDS). Crystallization of the polymorphs was studied. Mechanisms are proposed that consider the thermodynamics of carbamazepine, supersaturation in the SEDS process, and the binary phase equilibria of organic solvents and the carbon dioxide antisolvent. alpha-Carbamazepine was crystallized at high supersaturations and low temperatures, beta-carbamazepine crystallized from a methanol-carbon dioxide phase split, and gamma-carbamazepine crystallized via nucleation at high temperatures and low supersaturation. Copyright 2001 Wiley-Liss, Inc.

Titration of Monoprotic Acids with Sodium Hydroxide Contaminated by Sodium Carbonate.

ERIC Educational Resources Information Center

Michalowski, Tadeusz

1988-01-01

Discusses the effects of using carbon dioxide contaminated sodium hydroxide solution as a titrant for a solution of a weak monoprotic acid and the resulting distortion of the titration curve in comparison to one obtained when an uncontaminated titrant is used. (CW)

Absorption properties of carbon dioxide enhanced-oil-recovery additives. Final Technical report, 12 May 1987-31 August 1989

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

Patton, J.T.; Holbrook, S.T.

1990-01-01

The selection of the optimum foaming agent (surfactant) for enhancing oil production by carbon dioxide flooding is based on foamability and adsorption. Measurement of adsorption on carbonate cores from New Mexico reservoirs showed large adsorption differences between three commercial, high-foaming surfactants. An ethoxylated alcohol structure was least adsorbed, 0.64 mg/cc pore volume; an ethoxylated alcohol sulfate was next, 0.74 mg/cc pore volume; the highest adsorbed was a glyceryl sulfonate, 2.30 mg/cc pore volume. Commercial application of the foaming additive involves injecting alternate slugs of surfactant solution and carbon dioxide. Surfactant concentration should be determined to allow for the adsorption above.

COHO - Utilizing Waste Heat and Carbon Dioxide at Power Plants for Water Treatment

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

Kaur, Sumanjeet; Wilson, Aaron; Wendt, Daniel

The COHO is a breakthrough water purification system that can concentrate challenging feed waters using carbon dioxide and low-grade heat. For this project, we studied feeds in a lab-scale system to simulate COHO’s potential to operate at coal- powered power plants. COHO proved successful at concentrating the highly scaling and challenging wastewaters derived from a power plant’s cooling towers and flue gas desulfurization units. We also found that COHO was successful at scrubbing carbon dioxide from flue gas mixtures. Thermal regeneration of the switchable polarity solvent forward osmosis draw solution ended up requiring higher temperatures than initially anticipated, but wemore » also found that the draw solution could be polished via reverse osmosis. A techno-economic analysis indicates that installation of a COHO at a power plant for wastewater treatment would result in significant savings.« less

Acid sorption regeneration process using carbon dioxide

DOEpatents

King, C. Judson; Husson, Scott M.

2001-01-01

Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.

Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level

NASA Astrophysics Data System (ADS)

Włodarczyk, Barbara; Włodarczyk, Paweł P.

2016-12-01

Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort) from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements). Replacement of the earth gas with a biomass being supplied to the evaporator station from the agricultural fields will both allow to maintain the carbon dioxide emission level and enable the production growth. Moreover, the biomass growing on the agricultural fields being fertilized with the wastewater coming from the yeast production allows consequently to utilize the greater volume of wastewater. Theoretically, the possible increase in the yeasts production, with maintaining the carbon dioxide emission level, can reach even 70%. Therefore, the solution presented in this paper combines both intensification of the yeasts production and maintaining the carbon dioxide emission level.

Chemically modified carbonic anhydrases useful in carbon capture systems

DOEpatents

Novick, Scott; Alvizo, Oscar

2013-01-15

The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

Chemically modified carbonic anhydrases useful in carbon capture systems

DOEpatents

Novick, Scott J; Alvizo, Oscar

2013-10-29

The present disclosure relates to chemically modified carbonic anhydrase polypeptides and soluble compositions, homogenous liquid formulations comprising them. The chemically modified carbonic anhydrase polypeptides have improved properties relative to the same carbonic anhydrase polypeptide that is not chemically modified including the improved properties of increased activity and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides methods of preparing the chemically modified polypeptides and methods of using the chemically modified polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering.

Supercritical separation process for complex organic mixtures

DOEpatents

Chum, H.L.; Filardo, G.

1990-10-23

A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70 C and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution. 1 fig.

Molecular Simulations of Carbon Dioxide and Water: Cation Solvation and Wettability

NASA Astrophysics Data System (ADS)

Criscenti, L. J.; Bracco, J.; Cygan, R. T.

2010-12-01

Proposed carbon dioxide sequestration scenarios in sedimentary basins require investigation into the interaction between supercritical carbon dioxide, brines, and the mineral phases found in the basin and overlying caprock. Classical molecular dynamics (MD) simulations can be used to investigate some of these interactions such as the partitioning of metal cations between aqueous solutions and supercritical carbon dioxide, and the relative wettability of basin and caprock minerals with different fluid phases including water, carbon dioxide, and oil. Initial research has lead to the development of a new flexible carbon dioxide force field that successfully reproduces the vibrational properties of carbon dioxide, and a methodology for extracting contact angle information from large-scale MD simulations. Molecular simulations were performed to compare the solvation of alkali and alkaline metal cations in water and liquid carbon dioxide at 300K, using a flexible simple point charge (SPC) model for water and the new carbon dioxide force field. Solvation energies for Na+, Cs+, Mg2+, and Ba2+ are larger in water than in carbon dioxide, suggesting that these cations will partition preferentially into water. In both solutions, the solvation energy for the cations decreases with ion size and increases with ion charge. However, changes in solvation energy with increasing ionic radii are smaller in carbon dioxide than in water. Therefore, the overall partitioning of cations into carbon dioxide is predicted to increase with ion size. Molecular dynamics simulations are also useful to examine the relative wettability of minerals with different fluid phases. Large-scale MD simulations involving between 100,000 and 200,000 atoms have been conducted to establish a dynamic equilibrium between a drop of liquid water, water vapor, and kaolinite surfaces. The water drops consisted of at least 1700 molecules. Simulations were performed for five nanoseconds. The contact angle calculated for the siloxane surface of kaolinite is approximately 110°, and compares well with calculated contact angles for silica reported in the literature. The contact angle determined for the gibbsite surface of kaolinite is approximately 13° and compares favorably to reported experimental results. As expected, the siloxane surface is calculated to be hydrophobic and the gibbsite surface hydrophilic. This technique should prove useful to investigate the relative wettability of different minerals with subsurface fluids including supercritical CO2. This material is based upon work partially supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Numerically Simulating Carbonate Mineralization of Basalt with Injection of Carbon Dioxide into Deep Saline Formations

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

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.

2006-07-08

The principal mechanisms for the geologic sequestration of carbon dioxide in deep saline formations include geological structural trapping, hydrological entrapment of nonwetting fluids, aqueous phase dissolution and ionization, and geochemical sorption and mineralization. In sedimentary saline formations the dominant mechanisms are structural and dissolution trapping, with moderate to weak contributions from hydrological and geochemical trapping; where, hydrological trapping occurs during the imbibition of aqueous solution into pore spaces occupied by gaseous carbon dioxide, and geochemical trapping is controlled by generally slow reaction kinetics. In addition to being globally abundant and vast, deep basaltic lava formations offer mineralization kinetics that makemore » geochemical trapping a dominate mechanism for trapping carbon dioxide in these formations. For several decades the United States Department of Energy has been investigating Columbia River basalt in the Pacific Northwest as part of its environmental programs and options for natural gas storage. Recently this nonpotable and extensively characterized basalt formation is being reconsidered as a potential reservoir for geologic sequestration of carbon dioxide. The reservoir has an estimated storage capacity of 100 giga tonnes of carbon dioxide and comprises layered basalt flows with sublayering that generally alternates between low permeability massive and high permeability breccia. Chemical analysis of the formation shows 10 wt% Fe, primarily in the +2 valence. The mineralization reaction that makes basalt formations attractive for carbon dioxide sequestration is that of calcium, magnesium, and iron silicates reacting with dissolved carbon dioxide, producing carbonate minerals and amorphous quartz. Preliminary estimates of the kinetics of the silicate-to-carbonate reactions have been determined experimentally and this research is continuing to determine effects of temperature, pressure, rock composition and mineral assemblages on the reaction rates. This study numerically investigates the injection, migration and sequestration of supercritical carbon dioxide in deep Columbia River basalt formations using the multifluid subsurface flow and reactive transport simulator STOMP-CO2 with its ECKEChem module. Simulations are executed on high resolution multiple stochastic realizations of the layered basalt systems and demonstrate the migration behavior through layered basalt formations and the mineralization of dissolved carbon dioxide. Reported results include images of the migration behavior, distribution of carbonate formation, quantities of injected and sequestered carbon dioxide, and percentages of the carbon dioxide sequestered by different mechanisms over time.« less

SWITCHABLE POLARITY SOLVENTS AS DRAW SOLUTES FOR FORWARD OSMOSIS

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

Frederick F. Stewart; Mark L. Stone; Aaron D. Wilson

2013-03-01

Switchable polarity solvents (SPS), mixtures of carbon dioxide, water, and tertiary amines, are presented as viable forward osmosis (FO) draw solutes allowing a novel SPS FO process. In this study substantial osmotic strengths of SPS are measured with freezing point osmometry and were demonstrated to induce competitive ?uxes at high salt concentrations on a laboratory-scale FO unit utilizing a ?at sheet cellulose triacetate (CTA) membrane. Under the experimental conditions the SPS degrades the CTA membrane; however experiments with polyamide reverse osmosis (RO) membranes display stability towards SPS. Once the draw is diluted the major fraction of the switchable polarity solventmore » can be mechanically separated from the puri?ed water after polar to nonpolar phase shift induced by introduction of 1 atm carbon dioxide to 1 atm of air or nitrogen with mild heating. Trace amounts of SPS can be removed from the separated water with RO in a process that avoids solution concentration polarization. The separated nonpolar phase can be regenerated to a full strength draw and recycled with the re-addition of 1 atm of carbon dioxide.« less

The Effects of Voltage and Concentration of Sodium Bicarbonate on Electrochemical Synthesis of Ethanol from Carbon Dioxide Using Brass as Cathode

NASA Astrophysics Data System (ADS)

Ramadan, Septian; Fariduddin, Sholah; Rizki Aminudin, Afianti; Kurnia Hayatri, Antisa; Riyanto

2017-11-01

The effects of voltage and concentration of sodium bicarbonate were investigated to determine the optimum conditions of the electrochemical synthesis process to convert carbon dioxide into ethanol. The conversion process is carried out using a sodium bicarbonate electrolyte solution in an electrochemical synthesis reactor equipped with a cathode and anode. As the cathode was used brass, while as the anode carbon was utilized. Sample of the electrochemical synthesis process was analyzed by gas chromatography to determine the content of the compounds produced. The optimum electrochemical synthesis conditions to convert carbon dioxide into ethanol are voltage and concentration of sodium bicarbonate are 3 volts and 0.4 M with ethanol concentration of 1.33%.

Adsorption properties of carbon dioxide enchanced oil recovery additives

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

Patton, J.T.; Holbrook, S.T.

1990-01-01

The selection of the optimum foaming agent (surfactant) for enhancing oil production by carbon dioxide flooding is based on foamability and adsorption. Measurements of adsorption on carbonate cores from New Mexico reservoirs showed large adsorption differences between three commercial, high-foaming surfactants. An ethoxylated alcohol structure was at least adsorbed, 0.64 mg/cc pore volume; an ethoxylated alcohol sulfate was next, 0.74 mg/cc pore volume; the highest adsorbed was a glyceryl sulfonate, 2.30 mg/cc pore volume. Commercial application of the foaming additive involves injecting alternate slugs of surfactant solution and carbon dioxide. Surfactant concentration should be determined to allow for the adsorptionmore » above. 9 refs., 27 figs., 6 tabs.« less

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

DOEpatents

Rau, Gregory Hudson

2014-07-01

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

CARBON DIOXIDE SEPARATION BY PHASE ENHANCED GAS-LIQUID ABSORPTION

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

Liang Hu

A new process called phase enhanced gas-liquid absorption has been developed in its early stage. It was found that adding another phase into the absorption system of gas/aqueous phase could enhance the absorption rate. A system with three phases was studied. In the system, gas phase was carbon dioxide. Two liquid phases were used. One was organic phase. Another was aqueous phase. By addition of organic phase into the absorption system of CO{sub 2}-aqueous phase, the absorption rate of CO{sub 2} was increased significantly. CO{sub 2} finally accumulated into aqueous phase. The experimental results proved that (1) Absorption rate ofmore » carbon dioxide was enhanced by adding organic phase into gas aqueous phase system; (2) Organic phase played the role of transportation of gas solute (CO{sub 2}). Carbon dioxide finally accumulated into aqueous phase.« less

Temperature effect on pyrene as a polarity probe for supercritical fluid and liquid solutions

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

Chen, H.H.; McGuffin, V.L.

1994-05-01

The effect of temperature on the fluorescence spectrum of pyrene in supercritical and liquid carbon dioxide and liquid organic solvents is systematically studied. The Py parameter (intensity ratio of vibronic bands 1 and 3) is found to increase with the density of supercritical carbon dioxide in the range from 0.54 to 0.75 g/cm{sup 3}. This observation is consistent with the fact that dispersion forces which represent the major interaction between pyrene and carbon dioxide, depend inversely on the sixth power of distance. However, the Py parameter of both supercritical and liquid carbon dioxide is also found to decrease with temperaturemore » at constant density, which is not consistent with expectations for dispersion forces. Carbon dioxide, which is generally regarded as a nonpopular solvent, shows a temperature effect comparable to that for polar liquid solvents. The origin of this temperature effect is examined in this study by computer simulation using both semispherical molecular orbital and molecular mechanic methods. On the basis of these simulations, a strong electrostatic attraction arises between pyrene and carbon dioxide which is similiar in magnitude to that with polar solvents. The temperature dependence of the Py parameter can be qualitatively explained by these simulation results. 45 refs., 15 fig., 5 tab.« less

Performance evaluation of trimethylamine-carbon dioxide thermolytic draw solution for engineered osmosis

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

Boo, C; Khalil, YF; Elimelech, M

We evaluated the performance of trimethylamine-carbon dioxide (TMA-CO2) as a potential thermolytic draw solution for engineered osmosis. Water flux and reverse solute flux with TMA-CO2 draw solution were measured in forward osmosis (FO) and pressure retarded osmosis (PRO) modes using thin-film composite (TFC) and cellulose triacetate (CTA) FO membranes. Water flux with the TMA-CO2 draw solution was comparable to that obtained with the more common ammonia-carbon dioxide (NH3-CO2) thermolytic draw solution at similar (1 M) concentration. Using a TFC-FO membrane, the water fluxes produced by 1 M TMA-CO2 and NH3-CO2 draw solutions with a DI water feed were, respectively, 33.4more » and 35.6 L m(-2) h(-1) in PRO mode and 14.5 and 152 L m(-2) h(-1) in FO mode. Reverse draw permeation of TMA-CO2 was relatively low compared to NH3-CO2, ranging from 0.1 to 0.2 mol m(-2) h(-1) in all experiments, due to the larger molecular size of TMA. Thermal separation and recovery efficiency for TMA-CO2 was compared to NH3-CO2 by modeling low-temperature vacuum distillation utilizing low-grade heat sources. We also discuss possible challenges in the use TMA-CO2, including potential adverse impact on human health and environments. (C) 2014 Elsevier B.V. All rights reserved.« less

Molecular simulation investigation into the performance of Cu-BTC metal-organic frameworks for carbon dioxide-methane separations.

PubMed

Gutiérrez-Sevillano, Juan José; Caro-Pérez, Alejandro; Dubbeldam, David; Calero, Sofía

2011-12-07

We report a molecular simulation study for Cu-BTC metal-organic frameworks as carbon dioxide-methane separation devices. For this study we have computed adsorption and diffusion of methane and carbon dioxide in the structure, both as pure components and mixtures over the full range of bulk gas compositions. From the single component isotherms, mixture adsorption is predicted using the ideal adsorbed solution theory. These predictions are in very good agreement with our computed mixture isotherms and with previously reported data. Adsorption and diffusion selectivities and preferential sitings are also discussed with the aim to provide new molecular level information for all studied systems.

Solubility of small-chain carboxylic acids in supercritical carbon dioxide

DOE PAGES

Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; ...

2010-07-08

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

Experimental evidence for chemo-mechanical coupling during carbon mineralization in ultramafic rocks

NASA Astrophysics Data System (ADS)

Lisabeth, H. P.; Zhu, W.; Kelemen, P. B.; Ilgen, A.

2017-09-01

Storing carbon dioxide in the subsurface as carbonate minerals has the benefit of long-term stability and immobility. Ultramafic rock formations have been suggested as a potential reservoir for this type of storage due to the availability of cations to react with dissolved carbon dioxide and the fast reaction rates associated with minerals common in ultramafic formations; however, the rapid reactions have the potential to couple with the mechanical and hydraulic behavior of the rocks and little is known about the extent and mechanisms of this coupling. In this study, we argue that the dissolution of primary minerals and the precipitation of secondary minerals along pre-existing fractures in samples lead to reductions in both the apparent Young's modulus and shear strength of aggregates, accompanied by reduction in permeability. Hydrostatic and triaxial deformation experiments were run on dunite samples saturated with de-ionized water and carbon dioxide-rich solutions while stress, strain, permeability and pore fluid chemistry were monitored. Sample microstructures were examined after reaction and deformation using scanning electron microscopy (SEM). The results show that channelized dissolution and carbonate mineral precipitation in the samples saturated with carbon dioxide-rich solutions modify the structure of grain boundaries, leading to the observed reductions in stiffness, strength and permeability. A geochemical model was run to help interpret fluid chemical data, and we find that the apparent reaction rates in our experiments are faster than rates calculated from powder reactors, suggesting mechanically enhanced reaction rates. In conclusion, we find that chemo-mechanical coupling during carbon mineralization in dunites leads to substantial modification of mechanical and hydraulic behavior that needs to be accounted for in future modeling efforts of in situ carbon mineralization projects.

Significant solubility of carbon dioxide in Soluplus® facilitates impregnation of ibuprofen using supercritical fluid technology.

PubMed

Obaidat, Rana; Alnaief, Mohammed; Jaeger, Philip

2017-04-13

Treatment of Soluplus ® with supercritical carbon dioxide allows promising applications in preparing dispersions of amorphous solids. Several characterization techniques were employed to reveal this effect, including CO 2 gas sorption under high pressure and physicochemical characterizations techniques. A gravimetric method was used to determine the solubility of carbon dioxide in the polymer at elevated pressure. The following physicochemical characterizations were used: thermal analysis, X-ray diffraction, Fourier transform, infrared spectroscopy and scanning electron microscopy. Drug loading of the polymer with ibuprofen as a model drug was also investigated. The proposed treatment with supercritical carbon dioxide allows to prepare solid solutions of Soluplus ® in less than two hours at temperatures that do not exceed 45 °C, which is a great advantage to be used for thermolabile drugs. The advantages of using this technology for Soluplus ® formulations lies behind the high sorption capability of carbon dioxide inside the polymer. This will ensure rapid diffusion of the dissolved/dispersed drug inside the polymer under process conditions and rapid precipitation of the drug in the amorphous form during depressurization accompanied by foaming of the polymer.

Development of single shot 1D-Raman scattering measurements for flames

NASA Astrophysics Data System (ADS)

Biase, Amelia; Uddi, Mruthunjaya

2017-11-01

The majority of energy consumption in the US comes from burning fossil fuels which increases the concentration of carbon dioxide in the atmosphere. The increasing concentration of carbon dioxide in the atmosphere has negative impacts on the environment. One solution to this problem is to study the oxy-combustion process. A pure oxygen stream is used instead of air for combustion. Products contain only carbon dioxide and water. It is easy to separate water from carbon dioxide by condensation and the carbon dioxide can be captured easily. Lower gas volume allows for easier removal of pollutants from the flue gas. The design of a system that studies the oxy-combustion process using advanced laser diagnostic techniques and Raman scattering measurements is presented. The experiments focus on spontaneous Raman scattering. This is one of the few techniques that can provide quantitative measurements of the concentration and temperature of different chemical species in a turbulent flow. The experimental design and process of validating the design to ensure the data is accurate is described. The Raman data collected form an experimental data base that is used for the validation of spontaneous Raman scattering in high pressure environments for the oxy-combustion process. NSF EEC 1659710.

METHOD OF RECOVERING URANIUM COMPOUNDS

DOEpatents

Poirier, R.H.

1957-10-29

S>The recovery of uranium compounds which have been adsorbed on anion exchange resins is discussed. The uranium and thorium-containing residues from monazite processed by alkali hydroxide are separated from solution, and leached with an alkali metal carbonate solution, whereby the uranium and thorium hydrorides are dissolved. The carbonate solution is then passed over an anion exchange resin causing the uranium to be adsorbed while the thorium remains in solution. The uranium may be recovered by contacting the uranium-holding resin with an aqueous ammonium carbonate solution whereby the uranium values are eluted from the resin and then heating the eluate whereby carbon dioxide and ammonia are given off, the pH value of the solution is lowered, and the uranium is precipitated.

Development of Flexi-Burn™ CFB Power Plant to Meet the Challenge of Climate Change

NASA Astrophysics Data System (ADS)

Hackt, Horst; Fant, Zhen; Seltzert, Andrew; Hotta, Arto; Erikssoni, Timo; Sippu, Ossi

Carbon-dioxide capture and storage (CCS) offers the potential for major reductions in carbon- dioxide emissions of fossil fuel-based power generation in the fairly short term, and oxyfuel combustion is one of the identified CCS technology options. Foster Wheeler (FW) is working on reduction of carbon-dioxide with its integrated Flexi-Burn™ CFB technology. The proven high efficiency circulating fluidized-bed (CFB) technology, when coupled with air separation units and carbon purification units, offers a solution for carbon dioxide reduction both in re-powering and in greenfield power plants. CFB technology has the advantages over pulverized coal technology of a more uniform furnace heat flux, increased fuel flexibility and offers the opportunity to further reduce carbon dioxide emissions by co-firing coal with bio-fuels. Development and design of an integrated Flexi-Bum™ CFB steam generator and balance of plant system was conducted for both air mode and oxyfuel mode. Through proper configuration and design, the same steam generator can be switched from air mode to oxyfuel mode without the need for unit shutdown for modifications. The Flexi-Burn™ CFB system incorporates features to maximize plant efficiency and power output when operating in the oxy-firing mode through firing more fuel in the same boiler.

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

Electrochemical Cell for Obtaining Oxygen from Carbon Dioxide Atmospheres

NASA Technical Reports Server (NTRS)

Hooker, Matthew; Rast, H. Edward; Rogers, Darren K.; Borja, Luis; Clark, Kevin; Fleming, Kimberly; Mcgurren, Michael; Oldaker, Tom; Sweet, Nanette

1989-01-01

To support human life on the Martian surface, an electrochemical device will be required to obtain oxygen from the carbon dioxide rich atmosphere. The electrolyte employed in such a device must be constructed from extremely thin, dense membranes to efficiently acquire the oxygen necessary to support life. A forming process used industrially in the production of multilayer capacitors and electronic substrates was adapted to form the thin membranes required. The process, known as the tape casting, involves the suspension consisting of solvents and binders. The suspension is passed under a blade, resulting in the production of ceramic membranes between 0.1 and 0.5 mm thick. Once fired, the stabilized zirconia membranes were assembled into the cell design by employing a zirconium phosphate solution as the sealing agent. The resulting ceramic-to-ceramic seals were found to be structurally sound and gas-tight. Furthermore, by using a zirconia-based solution to assemble the cell, the problem of a thermal expansion mismatch was alleviated. By adopting an industrial forming process to produce thin membranes, an electrochemical cell for obtaining oxygen from carbon dioxide was produced. The proposed cell design is unique in that it does not require a complicated manifold system for separating the various gases present in this process, nor does it require a series of complex electrical connections. Thus, the device can reliably obtain the vital oxygen supply from the toxic carbon dioxide atmosphere.

New Demonstrations and New Insights on the Mechanism of the Candy-Cola Soda Geyser

ERIC Educational Resources Information Center

Kuntzleman, Thomas S.; Davenport, Laura S.; Cothran, Victoria I.; Kuntzleman, Jacob T.; Campbell, Dean J.

2017-01-01

When carbonated beverages (which are supersaturated solutions of aqueous carbon dioxide) are confined within a narrow-necked container, events which rapidly release the gas from solution produce a fountain out of the beverage. One well-known variant of this experiment is the addition of Mentos candies to a bottle of Diet Coke. Previous reports…

High pressure solubility of carbon dioxide (CO2) in aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) solvent for CO2 capture

NASA Astrophysics Data System (ADS)

Khan, Saleem Nawaz; Hailegiorgis, Sintayehu Mekuria; Man, Zakaria; Shariff, Azmi Mohd

2017-10-01

In this study, the solubility of carbon dioxide (CO2) in the aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) was investigated. In the aqueous solution the concentrations of the N-methyldiethanolamine (MDEA) and piperazine (PZ) were kept constant at 30 wt. % and 3 wt. %, respectively. The solubility experiments were carried out between the temperatures ranges of 303.15 to 333.15 K. The pressure range was selected as 2-50 bar for solubility of carbon dioxide in the aqueous solution. The solubility of the CO2 is reported in terms of CO2 loading capacity of the solvent. The loading capacity of the solvent is the ratio between the numbers of moles of CO2 absorbed to the numbers of moles of solvent used. The experimental data showed that the CO2 loading increased with increase in CO2 partial pressure, while it decreased with increase in system's temperature. It was also observed from the experimental data that the higher pressure favors the absorption process while the increased temperature hinders the absorption process of CO2 capture. The loading capacity of the investigated solvent was compared with the loading capacity of the solvents reported in the literature. The investigated solvent showed better solubility in terms of loading capacity.

Empirical Modeling of Nanoscale Dynamics using Solution Mapping

DTIC Science & Technology

2010-02-27

high performance liquid chromatography (HPLC). Journal of Supercritical Fluids , 44(2):139–147, 2008. 14 30 40 50 60 70 80 90 100 110 120 0 0.5 1 1.5...dioxide. Journal of Supercritical Fluids , 41(2):179–186, 2007. [3] O. Aschenbrenner, N. Dahmen, K. Schaber, and E. Dinjus. Adsorption of dimethyl(1,5...carbon nanotubes in a supercritical carbon dioxide process. The goal is to predict the time-evolution of the nanoparticle size distribution, as well

Solubilities of carbon dioxide in aqueous potassium carbonate solutions mixed with physical solvents

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

Park, S.B.; Lee, H.; Lee, K.H.

1998-09-01

The removal of acidic gases such as CO{sub 2}, H{sub 2}S, and COS from gas streams is a very important operation for petrochemical, oil refineries, ammonia manufacture, coal gasification, and natural gas purification plants. Here, the solubilities of carbon dioxide in aqueous potassium carbonate (K{sub 2}CO{sub 3}) solutions mixed with physical solvents were measured at 298.2 and 323.2 K with a CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. 1,2-propanediol and propylene carbonate were selected as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% 1,2-propanediol and propylene carbonate were selectedmore » as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% propylene carbonate. The experimental solubility results were presented by the mole ratio of CO{sub 2} and K{sub 2}CO{sub 3} contained in the liquid mixture. The addition of 1,2-propanediol to 5 mass% K{sub 2}CO{sub 3} solution lowered the solubility of CO{sub 2} at constant temperature and pressure conditions when CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. In the case of propylene carbonate the addition of propylene carbonate increased the experimental solubilities in the region of low CO{sub 2} partial pressures and decreased as the CO{sub 2} partial pressure was increased above atmospheric. The solubilities of CO{sub 2} decreased with increasing temperature in the range of 298.2 to 323.2 K.« less

Absorption of Carbon Dioxide in Aqueous Solutions of N-methyldiethanolamine Mixtures

NASA Astrophysics Data System (ADS)

Ma’mun, S.; Svendsen, H. F.

2018-05-01

Carbon dioxide (CO2) is one of the greenhouse gases (GHG) that has contributed to the global warming problem. Carbon dioxide is produced in large quantity from coal-fired power plants, iron and steel production, cement production, chemical and petrochemical industries, natural gas purification, and transportation. Some efforts to reduce the CO2 emissions to the atmosphere are then required. Amine-based absorption may be an option for post-combustion capture. The objective of this study is to measure the effect of promoter addition as well as MDEA concentration for the CO2 absorption into the aqueous solutions of MDEA to improve its performances, i.e. increasing the absorption rate and the absorption capacity. Absorption of CO2 in aqueous solutions of MDEA mixtures were measured at 40 °C in a bubble tank reactor. The systems tested were the mixtures of 30 wt% MDEA with 5 and 10 wt% BEA and the mixtures of 40 and 50 wt% MDEA with 6 wt% AEEA. It was found that for MDEA-BEA-H2O mixtures, the higher the promoter concentraation the higher the CO2 absorption rate, while for the MDEA-AEEA-H2O mixtures, the higher the MDEA concentration the lower the CO2 absorption rate.

Lignin-based microporous materials as selective adsorbents for carbon dioxide separation.

PubMed

Meng, Qing Bo; Weber, Jens

2014-12-01

Suitable solid adsorbents are demanded for carbon capture and storage (CCS) processes. In this work, a novel microporous polymer is developed by hypercrosslinking of organosolv lignin, which is a renewable resource. Reaction with formaldehyde dimethyl acetal (FDA) via Friedel-Crafts reaction gives microporous networks, with moderate capacity of carbon dioxide but excellent selectivity towards CO2 /N2 mixture as predicted on the basis of ideal adsorption-solution theory (IAST). Pyrolysis of pure organosolv lignin results in microporous carbon powders, while pyrolysis of hypercrosslinked organosolv lignin yields shape-persistent materials with increased CO2 capacity while maintaining very good selectivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flotation/ultrasound-assisted microextraction followed by HPLC for determination of fat-soluble vitamins in multivitamin pharmaceutical preparations.

PubMed

Shahdousti, Parvin; Aghamohammadi, Mohammad

2018-04-01

Dissolved carbon dioxide flotation-emulsification microextraction technique coupled with high-performance liquid chromatography was developed for separation and determination of fat-soluble vitamins (A, D 3 , E, and K 3 ) in multivitamin pharmaceutical preparations. Dissolved carbon dioxide flotation was used to break up the emulsion of extraction solvent in water and to collect the extraction solvent on the surface of aqueous sample in narrowed capillary part of extraction cell. Carbon dioxide bubbles were generated in situ through the addition of 300 μL of concentrated hydrochloric acid into the alkaline sample solution at pH = 11.5 (1% w/v sodium carbonate), which was sonicated to intensify the carbon dioxide bubble generation. Several factors affecting the extraction process were optimized. Under the optimal conditions, the limits of detection were 0.11, 0.47, 0.20 and 0.35 μg/L for A, E, D 3 , and K 3 vitamins in water samples, respectively. The inter-day and intra-day precision of the proposed method were evaluated in terms of the relative standard deviation and were <10.5%. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct methanol fuel cell and system

DOEpatents

Wilson, Mahlon S.

2004-10-26

A fuel cell having an anode and a cathode and a polymer electrolyte membrane located between anode and cathode gas diffusion backings uses a methanol vapor fuel supply. A permeable polymer electrolyte membrane having a permeability effective to sustain a carbon dioxide flux equivalent to at least 10 mA/cm.sup.2 provides for removal of carbon dioxide produced at the anode by reaction of methanol with water. Another aspect of the present invention includes a superabsorpent polymer material placed in proximity to the anode gas diffusion backing to hold liquid methanol or liquid methanol solution without wetting the anode gas diffusion backing so that methanol vapor from the liquid methanol or liquid methanol-water solution is supplied to the membrane.

TiO2 and its composites as effective photocatalyst for glucose degradation processes

NASA Astrophysics Data System (ADS)

Kukh, A. A.; Ivanenko, I. M.; Astrelin, I. M.

2018-03-01

Titanium-dioxide photocatalyst was impregnated onto the activated carbon using originally developed low-temperature sol-gel method to form a TiO2:AC composite material. 15% (mass.) solution Ti2(SO4)3 in sulphuric acid was used as a precursor for photocatalyst synthesis. The highly effective composite material was obtained through a combination of properties of titanium dioxide and activated carbon. Synthesized composites TiO2 with activated carbon demonstrate highly developed surface characteristics and exhibit significantly higher activity in comparison with samples of pure TiO2 synthesized the same way, existing analogues of pure TiO2 synthesized from TiCl3 and even industrial photocatalyst. This was testified by the degradation of 1% aqueous glucose solution using TiO2:AC, samples of pure TiO2 and commercial TiO2 AEROXIDE® TiO2 P25 produced by EVONIK Industries.

Active Control of pH in the Bioculture System Through Carbon Dioxide Control

NASA Technical Reports Server (NTRS)

Monhollon, Luke; Pletcher, David; Hauss, Jessica

2016-01-01

For successful cell research, the growth culture environment must be tightly controlled. Deviance from the optimal conditions will mask the desired variable being analyzed or lead to inconstancies in the results. In standard laboratories, technology and procedures are readily available for the reliable control of variables such as temperature, pH, nutrient loading, and dissolved gases. Due to the nature of spaceflight, and the inherent constraints to engineering designs, these same elements become a challenge to maintain at stable values by both automated and manual approaches. Launch mass, volume, and power usage create significant constraints to cell culture systems; nonetheless, innovative solutions for active environmental controls are available. The acidity of the growth media cannot be measured through standard probes due to the degradation of electrodes and reliance on indicators for chromatography. Alternatively, carbon dioxide sensors are capable of monitoring the pH by leveraging the relationship between the partial pressure of carbon dioxide and carbonic acid in solution across a membrane. In microgravity cell growth systems, the gas delivery system can be used to actively maintain the media at the proper acidity by maintaining a suitable gas mixture around permeable tubing. Through this method, launch mass and volume are significantly reduced through the efficient use of the limited gas supply in orbit.

Heterogeneous catalytic reactions of carbon dioxide

NASA Astrophysics Data System (ADS)

Krylov, Oleg V.; Mamedov, A. Kh

1995-09-01

The most important classes of heterogeneous catalytic reactions involving CO2 are examined: the incorporation of CO2 in the C-C, C-H, and C-N bonds with formation of carbonyl- and carboxyl-containing compounds and oxidation of other compounds by CO2. Reactions of the second class are more promising from the standpoint of the utilisation of carbon dioxide as a chemical raw material and from the standpoint of the solution of the ecological problems involving its utilisation from the gaseous waste discharged into the atmosphere. The reactions involving the oxidation of C1-C7 hydrocarbons and C1-C2 alcohols by carbon dioxide, which have been investigated by the authors of this review, are examined in detail. Catalysts based on manganese oxides are most effective in these reactions. The bibliography includes 231 references.

DETERMINATION OF SULFUR DIOXIDE, NITROGEN OXIDES, AND CARBON DIOXIDE IN EMISSIONS FROM ELECTRIC UTILITY PLANTS BY ALKALINE PERMANGANATE SAMPLING AND ION CHROMATOGRAPHY

EPA Science Inventory

A manual 24-h integrated method for determining SO2, NOx, and CO2 in emissions from electric utility plants was developed and field tested downstream from an SO2 control system. Samples were collected in alkaline potassium permanganate solution contained in restricted-orifice imp...

Mineral carbonation of gaseous carbon dioxide using a clay-hosted cation exchange reaction.

PubMed

Kang, Il-Mo; Roh, Ki-Min

2013-01-01

The mineral carbonation method is still a challenge in practical application owing to: (1) slow reaction kinetics, (2) high reaction temperature, and (3) continuous mineral consumption. These constraints stem from the mode of supplying alkaline earth metals through mineral acidification and dissolution. Here, we attempt to mineralize gaseous carbon dioxide into calcium carbonate, using a cation exchange reaction of vermiculite (a species of expandable clay minerals). The mineralization is operated by draining NaCI solution through vermiculite powders and continuously dropping into the pool of NaOH solution with CO2 gas injected. The mineralization temperature is regulated here at 293 and 333 K for 15 min. As a result of characterization, using an X-ray powder diffractometer and a scanning electron microscopy, two types of pure CaCO3 polymorphs (vaterite and calcite) are identified as main reaction products. Their abundance and morphology are heavily dependent on the mineralization temperature. Noticeably, spindle-shaped vaterite, which is quite different from a typical vaterite morphology (polycrystalline spherulite), forms predominantly at 333 K (approximately 98 wt%).

Carbon Dioxide Collection and Purification System for Mars

NASA Technical Reports Server (NTRS)

Clark, D. Larry; Trevathan, Joseph R.

2001-01-01

One of the most abundant resources available on Mars is the atmosphere. The primary constituent, carbon dioxide, can be used to produce a wide variety of consumables including propellants and breathing air. The residual gases can be used for additional pressurization tasks including supplementing the oxygen partial pressure in human habitats. A system is presented that supplies pure, high-pressure carbon dioxide and a separate stream of residual gases ready for further processing. This power-efficient method freezes the carbon dioxide directly from the atmosphere using a pulse-tube cryocooler. The resulting CO2 mass is later thawed in a closed pressure vessel, resulting in a compact source of liquefied gas at the vapor pressure of the bulk fluid. Results from a demonstration system are presented along with analysis and system scaling factors for implementation at larger scales. Trace gases in the Martian atmosphere challenge the system designer for all carbon dioxide acquisitions concepts. The approximately five percent of other gases build up as local concentrations of CO2 are removed, resulting in diminished performance of the collection process. The presented system takes advantage of this fact and draws the concentrated residual gases away as a useful byproduct. The presented system represents an excelient volume and mass solution for collecting and compressing this valuable Martian resource. Recent advances in pulse-tube cryocooler technology have enabled this concept to be realized in a reliable, low power implementation.

Formation of inhalable rifampicin-poly(L-lactide) microparticles by supercritical anti-solvent process.

PubMed

Patomchaiviwat, Vipaluk; Paeratakul, Ornlaksana; Kulvanich, Poj

2008-01-01

Formation of inhalable microparticles containing rifampicin and poly(L-lactide) (L-PLA) by using supercritical anti-solvent process (SAS) was investigated. The solutions of drug and polymer in methylene chloride were sprayed into supercritical carbon dioxide. The effect of polymer content and operating conditions, temperature, pressure, carbon dioxide molar fraction, and concentration of solution, on product characteristics were studied. The prepared microparticles were characterized with respect to their morphology, particle size and size distribution, drug content, drug loading efficiency, and drug release characteristic. Discrete, spherical microparticles were obtained at high polymer:drug ratios of 7:3, 8:2, and 9:1. The shape of L-PLA microparticles became more irregular and agglomerated with decreasing polymer content. Microparticles with polymer content higher than 60% exhibited volumetric mean diameter less than 5 microm, but percent drug loading efficiency was relatively low. Drug-loaded microparticles containing 70% and 80% L-PLA showed a sustainable drug release property without initial burst release. Operating temperature level influenced on mean size and size distribution of microparticles. The operating pressure and carbon dioxide molar fraction in the range investigated were unlikely to have an effect on microparticle formation. An increasing concentration of feed solution provided larger size microparticles. Rifampicin-loaded L-PLA microparticles could be produced by SAS in a size range suitable for dry powder inhaler formulation.

LEACHING OF URANIUM ORES USING ALKALINE CARBONATES AND BICARBONATES AT ATMOSPHERIC PRESSURE

DOEpatents

Thunaes, A.; Brown, E.A.; Rabbits, A.T.; Simard, R.; Herbst, H.J.

1961-07-18

A method of leaching uranium ores containing sulfides is described. The method consists of adding a leach solution containing alkaline carbonate and alkaline bicarbonate to the ore to form a slurry, passing the slurry through a series of agitators, passing an oxygen containing gas through the slurry in the last agitator in the series, passing the same gas enriched with carbon dioxide formed by the decomposition of bicarbonates in the slurry through the penultimate agitator and in the same manner passing the same gas increasingly enriched with carbon dioxide through the other agitators in the series. The conditions of agitation is such that the extraction of the uranium content will be substantially complete before the slurry reaches the last agitator.

The Degradation of 14C-Glutamic Acid by L-Glutamic Acid Decarboxylase.

ERIC Educational Resources Information Center

Dougherty, Charles M; Dayan, Jean

1982-01-01

Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)

Enzymatic Conversion of CO2 to Bicarbonate in Functionalized Mesoporous Silica

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

Yu, Yuehua; Chen, Baowei; Qi, Wen N.

2012-05-01

We report here that carbonic anhydrase (CA), the fastest enzyme that can covert carbon dioxide to bicarbonate, can be spontaneously entrapped in functionalized mesoporous silica (FMS) with super-high loading density (up to 0.5 mg of protein/mg of FMS) due to the dominant electrostatic interaction. The binding of CA to HOOC-FMS can result in the protein’s conformational change comparing to the enzyme free in solution, but can be overcome with increased protein loading density. The higher the protein loading density, the less conformational change, hence the higher enzymatic activity and the higher enzyme immobilization efficiency. The electrostatically bound CA can bemore » released by changing pH. The released enzyme still displayed the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. This work opens up a new approach converting carbon dioxide to biocarbonate in a biomimetic nanoconfiguration that can be integrated with the other part of biosynthesis process for the assimilation of carbon dioxide.« less

Characterization of amine-functionalized electrode for aqueous carbon dioxide (CO2) direct detection

NASA Astrophysics Data System (ADS)

Sato, Hiroshi

2017-03-01

In this study, fabrication of amino groups and ferrocenes co-modified sensor electrode and electrochemical detection of carbon dioxide (CO2) in the saline solution is reported. Electrochemical detection of CO2 was carried out using cyclic voltammetry in saline solution containing sodium bicarbonate as CO2 source. Oxidation and reduction peak current intensities computed from cyclic voltammograms varied as a function of concentration of CO2 molecules. The calibration curve was obtained by plotting oxidation peak current intensities as a function of CO2 concentration. The sensor electrode prepared in this study can estimate the differences between concentrations of CO2 in normal seawater up to 10 times higher. Furthermore, the surface analysis was performed to clarify the CO2 detection mechanism.

Visualization of Solution Gas Drive in Viscous Oil, SUPRI TR-126

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

George, D.S.; Kovscek, A.R.

Several experimental studies of solution gas drive are available in this report. Almost all of the studies have used light oil. Solution gas drive behavior, especially in heavy oil reservoirs, is poorly understood. Experiments were performed in which pore-scale solution gas drive phenomena were viewed in water/carbon dioxide and viscous oil/carbon dioxide systems. A new pressure vessel was designed and constructed to house silicon-wafer micromodels that previously operated at low (<3 atm) pressure. The new apparatus is used for the visual studies. Several interesting phenomena were viewed. The repeated nucleation of gas bubbles was observed at a gas-wet site occupiedmore » by dirt. Interestingly, the dissolution of a gas bubble into the liquid phase was previously recorded at the same nucleation site. Gas bubbles in both systems grew to span one ore more pore bodies before mobilization. Liquid viscosity affected the ease with which gas bubbles coalesced. More viscous solutions result in slower rates of coalescence. The transport of solid particles on gas-liquid interfaces was also observed.« less

Carbon Dioxide to Methanol: The Aqueous Catalytic Way at Room Temperature.

PubMed

Sordakis, Katerina; Tsurusaki, Akihiro; Iguchi, Masayuki; Kawanami, Hajime; Himeda, Yuichiro; Laurenczy, Gábor

2016-10-24

Carbon dioxide may constitute a source of chemicals and fuels if efficient and renewable processes are developed that directly utilize it as feedstock. Two of its reduction products are formic acid and methanol, which have also been proposed as liquid organic chemical carriers in sustainable hydrogen storage. Here we report that both the hydrogenation of carbon dioxide to formic acid and the disproportionation of formic acid into methanol can be realized at ambient temperature and in aqueous, acidic solution, with an iridium catalyst. The formic acid yield is maximized in water without additives, while acidification results in complete (98 %) and selective (96 %) formic acid disproportionation into methanol. These promising features in combination with the low reaction temperatures and the absence of organic solvents and additives are relevant for a sustainable hydrogen/methanol economy. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed Central

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

2014-01-01

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

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

PubMed

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

2014-06-02

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

Application of aluminum-supported Pd, Rh, and Rh-Pd nanoparticles in supercritical carbon dioxide system for hydrodebromination of polybrominated diphenyl ethers.

PubMed

Wu, Ben-Zen; Sun, Yu-Jie; Chen, Yan-Hua; Yak, Hwa Kwang; Yu, Jya-Jyun; Liao, Weisheng; Chiu, KongHwa; Peng, Shie-Ming

2016-08-01

Al-powder-supported Pd, Rh, and Rh-Pd catalysts were synthesized through a spontaneous redox reaction in aqueous solutions. These catalysts hydrodebrominated 4- and 4,4'-bromodiphenyl ethers in supercritical carbon dioxide at 200 atm CO2 containing 10 atm H2 and 80 °C in 1 h. Diphenyl ether was the major product of Pd/Al. Rh/Al and Rh-Pd/Al further hydrogenated two benzene rings of diphenyl ether to form dicyclohexyl ether. The hydrogenolysis of CO bonds on diphenyl ether over Rh/Al and Rh-Pd/Al was observed to generate cyclohexanol and cyclohexane (<1%). With respect to hydrodebromination efficiency and catalyst stability, Rh-Pd/Al among three catalysts is suggested to be used for ex situ degradation of polybrominated diphenyl ethers in supercritical carbon dioxide. Copyright © 2016 Elsevier Ltd. All rights reserved.

The preparation of liposomes using compressed carbon dioxide: strategies, important considerations and comparison with conventional techniques.

PubMed

Bridson, R H; Santos, R C D; Al-Duri, B; McAllister, S M; Robertson, J; Alpar, H O

2006-06-01

Numerous strategies are currently available for preparing liposomes, although no single method is ideal in every respect. Two methods for producing liposomes using compressed carbon dioxide in either its liquid or supercritical state were therefore investigated as possible alternatives to the conventional techniques currently used. The first technique used modified compressed carbon dioxide as a solvent system. The way in which changes in pressure, temperature, apparatus geometry and solvent flow rate affected the size distributions of the formulations was examined. In general, liposomes in the nano-size range with an average diameter of 200 nm could be produced, although some micron-sized vesicles were also present. Liposomes were characterized according to their hydrophobic drug-loading capacity and encapsulated aqueous volumes. The latter were found to be higher than in conventional techniques such as high-pressure homogenization. The second method used compressed carbon dioxide as an anti-solvent to promote uniform precipitation of phospholipids from concentrated ethanolic solutions. Finely divided solvent-free phospholipid powders of saturated lipids could be prepared that were subsequently hydrated to produce liposomes with mean volume diameters of around 5 microm.

Activated carbon/manganese dioxide hybrid electrodes for high performance thin film supercapacitors

NASA Astrophysics Data System (ADS)

Jang, Yunseok; Jo, Jeongdai; Jang, Hyunjung; Kim, Inyoung; Kang, Dongwoo; Kim, Kwang-Young

2014-06-01

We combine the activated carbon (AC) and the manganese dioxide (MnO2) in a AC/MnO2 hybrid electrode to overcome the low capacitance of activated carbon and MnO2 by exploiting the large surface area of AC and the fast reversible redox reaction of MnO2. An aqueous permanganate (MnO4 -) is converted to MnO2 on the surface of the AC electrode by dipping the AC electrode into an aqueous permanganate solution. The AC/MnO2 hybrid electrode is found to display superior specific capacitance of 290 F/g. This shows that supercapacitors classified as electric double layer capacitors and pseudocapacitors can be combined together.

Purification of caprolactam from recycled nylon

DOEpatents

Moens, Luc

1999-01-01

A method of removing 1,11-diamino-6-undecanone from the pyrolysis product of nylon comprising: a) pyrolyzing nylon-6 to form a pyrolyzate containing a caprolactam mixture; b) dissolving the caprolactam mixture in a solvent to form a solution; c) passing carbon dioxide gas through the solution to form a precipitate; d) removing the precipitate from the solution; and e) recovering the purified caprolactam from the solution.

Use of carbonates for biological and chemical synthesis

DOEpatents

Rau, Gregory Hudson

2014-09-09

A system of using carbonates, especially water-insoluble or sparing soluble mineral carbonates, for maintaining or increasing dissolved inorganic carbon concentrations in aqueous media. In particular, the system generates concentrated dissolve inorganic carbon substrates for photosynthetic, chemosynthetic, or abiotic chemical production of carbonaceous or other compounds in solution. In some embodiments, the invention can also enhance the dissolution and retention of carbon dioxide in aqueous media, and can produce pH buffering capacity, metal ions, and heat, which can be beneficial to the preceding syntheses.

Carbon dioxide adsorbents containing magnesium oxide suitable for use at high temperatures

DOEpatents

Mayorga, Steven Gerard; Weigel, Scott Jeffrey; Gaffney, Thomas Richard; Brzozowski, Jeffrey Richard

2001-01-01

Adsorption of carbon dioxide from gas streams at temperatures in the range of 300 to 500.degree. C. is carried out with a solid adsorbent containing magnesium oxide, preferably promoted with an alkali metal carbonate or bicarbonate so that the atomic ratio of alkali metal to magnesium is in the range of 0.006 to 2.60. Preferred adsorbents are made from the precipitate formed on addition of alkali metal and carbonate ions to an aqueous solution of a magnesium salt. Atomic ratios of alkali metal to magnesium can be adjusted by washing the precipitate with water. Low surface area adsorbents can be made by dehydration and CO.sub.2 removal of magnesium hydroxycarbonate, with or without alkali metal promotion. The process is especially valuable in pressure swing adsorption operations.

Two-Electron Carbon Dioxide Reduction Catalyzed by Rhenium(I) Bis(imino)acenaphthene Carbonyl Complexes

PubMed Central

Portenkirchner, Engelbert; Kianfar, Elham; Sariciftci, Niyazi Serdar; Knör, Günther

2014-01-01

Rhenium(I) carbonyl complexes carrying substituted bis(arylimino)acenaphthene ligands (BIAN-R) have been tested as potential catalysts for the two-electron reduction of carbon dioxide. Cyclic voltammetric studies as well as controlled potential electrolysis experiments were performed using CO2-saturated solutions of the complexes in acetonitrile and acetonitrile–water mixtures. Faradaic efficiencies of more than 30 % have been determined for the electrocatalytic production of CO. The effects of ligand substitution patterns and water content of the reaction medium on the catalytic performance of the new catalysts are discussed. PMID:24737649

Designing management strategies for carbon dioxide storage and utilization under uncertainty using inexact modelling

NASA Astrophysics Data System (ADS)

Wang, Yu; Fan, Jie; Xu, Ye; Sun, Wei; Chen, Dong

2017-06-01

Effective application of carbon capture, utilization and storage (CCUS) systems could help to alleviate the influence of climate change by reducing carbon dioxide (CO2) emissions. The research objective of this study is to develop an equilibrium chance-constrained programming model with bi-random variables (ECCP model) for supporting the CCUS management system under random circumstances. The major advantage of the ECCP model is that it tackles random variables as bi-random variables with a normal distribution, where the mean values follow a normal distribution. This could avoid irrational assumptions and oversimplifications in the process of parameter design and enrich the theory of stochastic optimization. The ECCP model is solved by an equilibrium change-constrained programming algorithm, which provides convenience for decision makers to rank the solution set using the natural order of real numbers. The ECCP model is applied to a CCUS management problem, and the solutions could be useful in helping managers to design and generate rational CO2-allocation patterns under complexities and uncertainties.

Practical modeling approaches for geological storage of carbon dioxide.

PubMed

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.

Long-Term Evolution of the Sun and our Biosphere: Causes and Effects?

NASA Astrophysics Data System (ADS)

Des Marais, D. J.

2000-05-01

The course of early biological evolution felt the environmental consequences of changes in the solar output (discussed here), as well as long-term decreases in planetary heat flow and the flux of extraterrestrial impactors. A large, early UV flux fueled the photodissociation of atmospheric water vapor, sustaining a significant hydrogen flux to space. This flux caused Earth's crust to become oxidized, relative to its mantle. Accordingly, reduced gases and aqueous solutes that were erupted volcanically into the relatively more oxidized surface environment created sources of chemical redox energy for the origin and early evolution of life. Although the solar constant has increased some 30 percent over Earth's lifetime, oceans remained remarkably stable for more than 3.8 billion years. Thus a very effective climate regulation was probably achieved by decreasing over time the atmospheric inventories of greenhouse gases such as carbon dioxide and methane. Such decreases probably had major consequences for the biosphere. Substantial early marine bicarbonate and carbon dioxide inventories sustained abundant abiotic precipitation of carbonates, with consequences for the stability and habitability of key aqueous environments. A long-term decline in carbon dioxide levels increased the bioenergetic requirements for carbon dioxide as well as other aspects of the physiology of photosynthetic microorganisms. The long-term trend of global mean surface temperature is still debated, as is the role of the sun's evolution in that trend. Future increases in the solar constant will drive atmospheric carbon dioxide levels down further, challenging plants to cope with ever-dwindling concentrations of carbon substrates. Climate regulation will be achieved by modulating an increasing abundance of high-albedo water vapor clouds. Future biological evolution defies precise predictions, however it is certain that the sun's continuing evolution will play a key role.

Purification of caprolactam from recycled nylon

DOEpatents

Moens, L.

1999-07-06

A method is disclosed of removing 1,11-diamino-6-undecanone from the pyrolysis product of nylon comprising: (a) pyrolyzing nylon-6 to form a pyrolyzate containing a caprolactam mixture; (b) dissolving the caprolactam mixture in a solvent to form a solution; (c) passing carbon dioxide gas through the solution to form a precipitate; (d) removing the precipitate from the solution; and (e) recovering the purified caprolactam from the solution. 3 figs.

Optimized heat exchange in a CO2 de-sublimation process

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

Baxter, Larry; Terrien, Paul; Tessier, Pascal

The present invention is a process for removing carbon dioxide from a compressed gas stream including cooling the compressed gas in a first heat exchanger, introducing the cooled gas into a de-sublimating heat exchanger, thereby producing a first solid carbon dioxide stream and a first carbon dioxide poor gas stream, expanding the carbon dioxide poor gas stream, thereby producing a second solid carbon dioxide stream and a second carbon dioxide poor gas stream, combining the first solid carbon dioxide stream and the second solid carbon dioxide stream, thereby producing a combined solid carbon dioxide stream, and indirectly exchanging heat betweenmore » the combined solid carbon dioxide stream and the compressed gas in the first heat exchanger.« less

Acoustic and Hydrodynamic Cavitations for Nano CaCO3 Synthesis

NASA Astrophysics Data System (ADS)

Sonawane, Shirish H.; Kulkarni, Ravindra D.

Calcium carbonate is a common inorganic compound known as limestone. Calcium carbonate has many applications in industries such as medicine, agriculture, paint plastic and surface coatings etc. The vast majority of calcium carbonate used in industry is extracted by mining process. Pure calcium carbonate (e.g. for food or pharmaceutical use), is synthesized by passing carbon dioxide into a solution of calcium hydroxide slurry. In this process calcium carbonate precipitates out, and this grade of product is referred to as precipitate calcium carbonate (abbreviated as PCC).

Conversion coatings prepared or treated with calcium hydroxide solutions

NASA Technical Reports Server (NTRS)

Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor); Minevski, Zoran (Inventor); Clarke, Eric (Inventor)

2002-01-01

A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%.

Uranium dioxide electrolysis

DOEpatents

Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL

2009-12-29

This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

Carbon cycle instability as a cause of the late Pleistocene ice age oscillations - Modeling the asymmetric response

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

Saltzman, B.; Maasch, K.A.

1988-06-01

A dynamical model of the Pleistocene ice ages is presented, which incorporates many of the qualitative ideas advanced recently regarding the possible role of ocean circulation, chemistry, temperature, and productivity in regulating long-term atmospheric carbon dioxide variations. This model involves one additional term (and free parameter) beyond that included in a previous model (Saltzman and Sutera, 1987), providing the capacity for an asymmetric response. It is shown that many of the main features exhibited by the delta(O-18)-derived ice record and the Vostok core/delta(C-13)-derived carbon dioxide record in the late Pleistocene can be deduced as a free oscillatory solution of themore » model. 35 refs.« less

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

DOEpatents

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

2013-01-29

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

Highly selective and active CO2 reduction electrocatalysts based on cobalt phthalocyanine/carbon nanotube hybrid structures

PubMed Central

Zhang, Xing; Wu, Zishan; Zhang, Xiao; Li, Liewu; Li, Yanyan; Xu, Haomin; Li, Xiaoxiao; Yu, Xiaolu; Zhang, Zisheng; Liang, Yongye; Wang, Hailiang

2017-01-01

Electrochemical reduction of carbon dioxide with renewable energy is a sustainable way of producing carbon-neutral fuels. However, developing active, selective and stable electrocatalysts is challenging and entails material structure design and tailoring across a range of length scales. Here we report a cobalt-phthalocyanine-based high-performance carbon dioxide reduction electrocatalyst material developed with a combined nanoscale and molecular approach. On the nanoscale, cobalt phthalocyanine (CoPc) molecules are uniformly anchored on carbon nanotubes to afford substantially increased current density, improved selectivity for carbon monoxide, and enhanced durability. On the molecular level, the catalytic performance is further enhanced by introducing cyano groups to the CoPc molecule. The resulting hybrid catalyst exhibits >95% Faradaic efficiency for carbon monoxide production in a wide potential range and extraordinary catalytic activity with a current density of 15.0 mA cm−2 and a turnover frequency of 4.1 s−1 at the overpotential of 0.52 V in a near-neutral aqueous solution. PMID:28272403

Mathematical modeling and experimental breakthrough curves of carbon dioxide adsorption on metal organic framework CPM-5.

PubMed

Sabouni, Rana; Kazemian, Hossein; Rohani, Sohrab

2013-08-20

It is essential to capture carbon dioxide from flue gas because it is considered one of the main causes of global warming. Several materials and different methods have been reported for CO2 capturing including adsorption onto zeolites and porous membranes, as well as absorption in amine solutions. All such methods require high energy input and high cost. A new class of porous materials called Metal Organic Frameworks (MOFs) exhibited excellent performance in extracting carbon dioxide from a gas mixture. In this study, the breakthrough curves for the adsorption of carbon dioxide on CPM-5 (crystalline porous materials) were obtained experimentally and theoretically using a laboratory-scale fixed-bed column at different experimental conditions such as feed flow rate, adsorption temperature, and feed concentration. It was found that the CPM-5 has a dynamic CO2 adsorption capacity of 11.9 wt % (2.7 mmol/g) (corresponding to 8 mL/min, 298 K, and 25% v/v CO2). The tested CPM-5 showed an outstanding adsorption equilibrium capacity (e.g., 2.3 mmol/g (10.2 wt %) at 298 K) compared to other adsorbents, which can be considered as an attractive adsorbent for separation of CO2 from flue gas.

Gas Exchange of Algae

PubMed Central

Ammann, Elizabeth C. B.; Lynch, Victoria H.

1967-01-01

The oxygen production of a photosynthetic gas exchanger containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present within the culture unit. The internal carbon dioxide concentrations were obtained by manipulating the entrance gas concentration and the flow rate. Carbon dioxide percentages were monitored by means of electrodes placed directly in the nutrient medium. The concentration of carbon dioxide in the nutrient medium which produced maximal photosynthesis was in the range of 1.5 to 2.5% by volume. Results were unaffected by either the level of carbon dioxide in the entrance gas or the rate of gas flow. Entrance gases containing 2% carbon dioxide flowing at 320 ml/min, 3% carbon dioxide at 135 ml/min, and 4% carbon dioxide at 55 ml/min yielded optimal carbon dioxide concentrations in the particular unit studied. By using carbon dioxide electrodes implanted directly in the gas exchanger to optimize the carbon dioxide concentration throughout the culture medium, it should be possible to design more efficient large-scale units. PMID:4382391

Performance characteristics and modeling of carbon dioxide absorption by amines in a packed column

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

Lin, S.H.; Shyu, C.T.

1999-01-01

Carbon dioxide (CO[sub 2]) is widely recognized as a major greenhouse gas contributing to global warming. To mitigate the global warming problem, removal of CO[sub 2] from the industrial flue gases is necessary. Absorption of carbon dioxide by amines in a packed column was experimentally investigated. The amines employed in the present study were the primary mono-ethanolamine (MEA) and tertiary N-methyldiethanolamine (MDEA), two very popular amines widely used in the industries for gas purification. The CO[sub 2] absorption characteristics by these two amines were experimentally examined under various operating conditions. A theoretical model was developed for describing the CO[sub 2]more » absorption behavior. Test data have revealed that the model predictions and the observed CO[sub 2] absorption breakthrough curves agree very well, validating the proposed model. Preliminary regeneration tests of exhausted amine solution were also conducted. The results indicated that the tertiary amine is easier to regenerate with less loss of absorption capacity than the primary one.« less

Consequences of CO2 solubility for hydrate formation from carbon dioxide containing water and other impurities.

PubMed

Kvamme, Bjørn; Kuznetsova, Tatiana; Jensen, Bjørnar; Stensholt, Sigvat; Bauman, Jordan; Sjøblom, Sara; Nes Lervik, Kim

2014-05-14

Deciding on the upper bound of water content permissible in a stream of dense carbon dioxide under pipeline transport conditions without facing the risks of hydrate formation is a complex issue. In this work, we outline and analyze ten primary routes of hydrate formation inside a rusty pipeline, with hydrogen sulfide, methane, argon, and nitrogen as additional impurities. A comprehensive treatment of equilibrium absolute thermodynamics as applied to multiple hydrate phase transitions is provided. We also discuss in detail the implications of the Gibbs phase rule that make it necessary to consider non-equilibrium thermodynamics. The analysis of hydrate formation risk has been revised for the dominant routes, including the one traditionally considered in industrial practice and hydrate calculators. The application of absolute thermodynamics with parameters derived from atomistic simulations leads to several important conclusions regarding the impact of hydrogen sulfide. When present at studied concentrations below 5 mol%, the presence of hydrogen sulfide will only support the carbon-dioxide-dominated hydrate formation on the phase interface between liquid water and hydrate formers entering from the carbon dioxide phase. This is in contrast to a homogeneous hydrate nucleation and growth inside the aqueous solution bulk. Our case studies indicate that hydrogen sulfide at higher than 0.1 mol% concentration in carbon dioxide can lead to growth of multiple hydrate phases immediately adjacent to the adsorbed water layers. We conclude that hydrate formation via water adsorption on rusty pipeline walls will be the dominant contributor to the hydrate formation risk, with initial concentration of hydrogen sulfide being the critical factor.

Quantitative evaluation of the safety of mucosal incision and submucosal dissection for colon during endoscopic submucosal dissection using carbon dioxide laser

NASA Astrophysics Data System (ADS)

Noguchi, Takuma; Honda, Norihiro; Hazama, Hisanao; Morita, Yoshinori; Awazu, Kunio

2018-02-01

Since the increase in the overall mortality rate in patients with colon cancer is remarkably high in recent years, early treatment is required. For this reason, endoscopic submucosal dissection (ESD) has been at the forefront of international attention as a low invasive treatment for early digestive cancer. In current ESD procedure, an electrosurgical knife is used for mucosal incision and subsequent submucosal dissection. However, the perforation has been reported to occur by approximately 5%. Thus, to enhance the tissue selectivity of this modality, we focused on the application of laser for ESD. A carbon dioxide laser was chosen as a surgical knife because the saline or a sodium hyaluronate solution injected into the submucosal layer in current ESD procedure has a high absorption coefficient at the wavelength of the carbon dioxide laser. In this research, ex vivo experiment was performed at the output power of 3-7 W and discuss the optimum irradiation power of laser. As a result of ex vivo experiment using extracted porcine colon tissues, mucosal incision and submucosal dissection were safely and less invasively performed in every output power, without reaching the thermal damage to a muscular layer. This is because a carbon dioxide laser is strongly absorbed by saline injected into submucosa. ESD using a carbon dioxide laser is a safer method for the treatment of early colon cancer. We are planning to measure and compare the optical and thermal properties of porcine colon with those of human colon.

Analysis of thermo-chemical nonequilibrium models for carbon dioxide flows

NASA Technical Reports Server (NTRS)

Rock, Stacey G.; Candler, Graham V.; Hornung, Hans G.

1992-01-01

The aerothermodynamics of thermochemical nonequilibrium carbon dioxide flows is studied. The chemical kinetics models of McKenzie and Park are implemented in separate three-dimensional computational fluid dynamics codes. The codes incorporate a five-species gas model characterized by a translational-rotational and a vibrational temperature. Solutions are obtained for flow over finite length elliptical and circular cylinders. The computed flowfields are then employed to calculate Mach-Zehnder interferograms for comparison with experimental data. The accuracy of the chemical kinetics models is determined through this comparison. Also, the methodology of the three-dimensional thermochemical nonequilibrium code is verified by the reproduction of the experiments.

Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Matter, Juerg M.; Stute, Martin; Snæbjörnsdottir, Sandra Ó.; Oelkers, Eric H.; Gislason, Sigurdur R.; Aradottir, Edda S.; Sigfusson, Bergur; Gunnarsson, Ingvi; Sigurdardottir, Holmfridur; Gunnlaugsson, Einar; Axelsson, Gudni; Alfredsson, Helgi A.; Wolff-Boenisch, Domenik; Mesfin, Kiflom; Taya, Diana Fernandez de la Reguera; Hall, Jennifer; Dideriksen, Knud; Broecker, Wallace S.

2016-06-01

Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success of this solution depends on the ability to safely and permanently store CO2. This study demonstrates for the first time the permanent disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% of the CO2 injected into the CarbFix site in Iceland was mineralized to carbonate minerals in less than 2 years. This result contrasts with the common view that the immobilization of CO2 as carbonate minerals within geologic reservoirs takes several hundreds to thousands of years. Our results, therefore, demonstrate that the safe long-term storage of anthropogenic CO2 emissions through mineralization can be far faster than previously postulated.

Geoengineering and the blockchain: a near-complete solution to greenhouse emissions?

NASA Astrophysics Data System (ADS)

Lockley, A.; Coffman, D.

2016-12-01

Geoengineering has been proposed to deal partially with the consequences ofanthropogenic global warming. This is composed of two strands - fast acting,incomplete but inexpensive solar radiation management; and carbon dioxide removal,which (if enacted quickly) has the potential to be a complete solution. We propose asystem of smart contracts, executed and made transparent by the blockchain, toprovide an economically and environmentally complete solution to carbon emissions atthe point of combustion. This will integrate CDR futures contracts and SRM carboncredits to ensure that all emissions are fully and transactionally disposed of at themoment of release. Specifically, we suggest use of an SRM 'bridge' contract, tocounter the warming caused between CDR economic activity being undertaken, andthe resultant drawdown of carbon occurring.

Trace Gases, CO2, Climate, and the Greenhouse Effect.

ERIC Educational Resources Information Center

Aubrecht, Gordon J., II

1988-01-01

Reports carbon dioxide and other trace gases can be the cause of the Greenhouse Effect. Discusses some effects of the temperature change and suggests some solutions. Included are several diagrams, graphs, and a table. (YP)

Photosensitized Reduction of Carbon Dioxide in Solution Using Noble-Metal Clusters for Electron Transfer

NASA Astrophysics Data System (ADS)

Toshima, Naoki; Yamaji, Yumi; Teranishi, Toshiharu; Yonezawa, Tetsu

1995-03-01

Carbon dioxide was reduced to methane by visible-light irradiation of a solution composed of tris(bipyridine)ruthenium(III) as photosensitizer, ethylenediaminetetraacetic acid disodium salt as sacrificial reagent, methyl viologen as electron relay, and a colloidal dispersion of polymer-protected noble-metal clusters, prepared by alcohol-reduction, as catalyst. Among the noble-metal clusters examined, Pt clusters showed the highest activity for the formation of methane as well as hydrogen. In order to improve the activity, oxidized clusters and bimetallic clusters were also applied. For example, the CH4 yield in 3-h irradiation increased from 51 x 10-3 μmol with unoxidized Pt clusters to 72 x 10-3 μmol with partially oxidized ones. In the case of Pt/Ru bimetalic systems, the improvement of the catalytic activity by air treatment was much greater than in case of monometallic clusters.

Solvent removal and spore inactivation directly in dispensing vials with supercritical carbon dioxide and sterilant.

PubMed

Howell, Jahna; Niu, Fengui; McCabe, Shannon E; Zhou, Wei; Decedue, Charles J

2012-06-01

A process is described using supercritical carbon dioxide to extract organic solvents from drug solutions contained in 30-mL serum vials. We report drying times of less than 1 h with quantitative recovery of sterile drug. A six-log reduction of three spore types used as biological indicators is achieved with direct addition of peracetic acid to a final concentration of approximately 5 mM (~0.04 %) to the drug solution in the vial. Analysis of two drugs, acetaminophen and paclitaxel, indicated no drug degradation as a result of the treatment. Furthermore, analysis of the processed drug substance showed that no residual peracetic acid could be detected in the final product. We have demonstrated an effective means to simultaneously dry and sterilize active pharmaceutical ingredients from organic solvents directly in a dispensing container.

Methodologies for extraction of dissolved inorganic carbon for stable carbon isotope studies : evaluation and alternatives

USGS Publications Warehouse

Hassan, Afifa Afifi

1982-01-01

The gas evolution and the strontium carbonate precipitation techniques to extract dissolved inorganic carbon (DIC) for stable carbon isotope analysis were investigated. Theoretical considerations, involving thermodynamic calculations and computer simulation pointed out several possible sources of error in delta carbon-13 measurements of the DIC and demonstrated the need for experimental evaluation of the magnitude of the error. An alternative analytical technique, equilibration with out-gassed vapor phase, is proposed. The experimental studies revealed that delta carbon-13 of the DIC extracted from a 0.01 molar NaHC03 solution by both techniques agreed within 0.1 per mil with the delta carbon-13 of the DIC extracted by the precipitation technique, and an increase of only 0.27 per mil in that extracted by the gas evolution technique. The efficiency of extraction of DIC decreased with sulfate concentration in the precipitation technique but was independent of sulfate concentration in the gas evolution technique. Both the precipitation and gas evolution technique were found to be satisfactory for extraction of DIC from different kinds of natural water for stable carbon isotope analysis, provided appropriate precautions are observed in handling the samples. For example, it was found that diffusion of atmospheric carbon dioxide does alter the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the precipitation technique; hot manganese dioxide purification changes the delta carbon-13 of carbon dioxide. (USGS)

Measurement of carbon capture efficiency and stored carbon leakage

DOEpatents

Keeling, Ralph F.; Dubey, Manvendra K.

2013-01-29

Data representative of a measured carbon dioxide (CO.sub.2) concentration and of a measured oxygen (O.sub.2) concentration at a measurement location can be used to determine whether the measured carbon dioxide concentration at the measurement location is elevated relative to a baseline carbon dioxide concentration due to escape of carbon dioxide from a source associated with a carbon capture and storage process. Optionally, the data can be used to quantify a carbon dioxide concentration increase at the first location that is attributable to escape of carbon dioxide from the source and to calculate a rate of escape of carbon dioxide from the source by executing a model of gas-phase transport using at least the first carbon dioxide concentration increase. Related systems, methods, and articles of manufacture are also described.

Hydrogen storage and delivery: the carbon dioxide - formic acid couple.

PubMed

Laurenczy, Gábor

2011-01-01

Carbon dioxide and the carbonates, the available natural C1 sources, can be easily hydrogenated into formic acid and formates in water; the rate of this reduction strongly depends on the pH of the solution. This reaction is catalysed by ruthenium(II) pre-catalyst complexes with a large variety of water-soluble phosphine ligands; high conversions and turnover numbers have been realised. Although ruthenium(II) is predominant in these reactions, the iron(II) - tris[(2-diphenylphosphino)-ethyl]phosphine (PP3) complex is also active, showing a new perspective to use abundant and inexpensive iron-based compounds in the CO2 reduction. In the catalytic hydrogenation cycles the in situ formed metal hydride complexes play a key role, their structures with several other intermediates have been proven by multinuclear NMR spectroscopy. In the other hand safe and convenient hydrogen storage and supply is the fundamental question for the further development of the hydrogen economy; and carbon dioxide has been recognised to be a viable H2 vector. Formic acid--containing 4.4 weight % of H2, that is 53 g hydrogen per litre--is suitable for H2 storage; we have shown that in aqueous solutions it can be selectively decomposed into CO-free (CO < 10 ppm) CO2 and H2. The reaction takes place under mild experimental conditions and it is able to generate high pressure H2 (up to 600 bar). The cleavage of HCOOH is catalysed by several hydrophilic Ru(II) phosphine complexes (meta-trisulfonated triphenylphosphine, mTPPTS, being the most efficient one), either in homogeneous systems or as immobilised catalysts. We have also shown that the iron(II)--hydrido tris[(2-diphenylphosphino)ethyl]phosphine complex catalyses with an exceptionally high rate and efficiency (turnover frequency, TOF = 9425 h(-1)mol(-1); turnover number, TON = 92400) the formic acid cleavage, in environmentally friendly propylene carbonate solution, opening the way to use cheap, non-noble metal based catalysts for this reaction, too.

Carbon Dioxide Embolism during Laparoscopic Surgery

PubMed Central

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

Nonequilibrium gas absorption in rotating permeable media

NASA Astrophysics Data System (ADS)

Baev, V. K.; Bazhaikin, A. N.

2016-08-01

The absorption of ammonia, sulfur dioxide, and carbon dioxide by water and aqueous solutions in rotating permeable media, a cellular porous disk, and a set of spaced-apart thin disks has been considered. The efficiency of cleaning air to remove these impurities is determined, and their anomalously high solubility (higher than equilibrium value) has been discovered. The results demonstrate the feasibility of designing cheap efficient rotor-type absorbers to clean gases of harmful impurities.

Understanding the Phase Behavior of Tetrahydrofuran + Carbon Dioxide, + Methane, and + Water Binary Mixtures from the SAFT-VR Approach.

PubMed

Míguez, J M; Piñeiro, M M; Algaba, J; Mendiboure, B; Torré, J P; Blas, F J

2015-11-05

The high-pressure phase diagrams of the tetrahydrofuran(1) + carbon dioxide(2), + methane(2), and + water(2) mixtures are examined using the SAFT-VR approach. Carbon dioxide molecule is modeled as two spherical segments tangentially bonded, water is modeled as a spherical segment with four associating sites to represent the hydrogen bonding, methane is represented as an isolated sphere, and tetrahydrofuran is represented as a chain of m tangentially bonded spherical segments. Dispersive interactions are modeled using the square-well intermolecular potential. In addition, two different molecular model mixtures are developed to take into account the subtle balance between water-tetrahydrofuran hydrogen-bonding interactions. The polar and quadrupolar interactions present in water, tetrahydrofuran, and carbon dioxide are treated in an effective way via square-well potentials of variable range. The optimized intermolecular parameters are taken from the works of Giner et al. (Fluid Phase Equil. 2007, 255, 200), Galindo and Blas (J. Phys. Chem. B 2002, 106, 4503), Patel et al. (Ind. Eng. Chem. Res. 2003, 42, 3809), and Clark et al. (Mol. Phys. 2006, 104, 3561) for tetrahydrofuran, carbon dioxide, methane, and water, respectively. The phase diagrams of the binary mixtures exhibit different types of phase behavior according to the classification of van Konynenburg and Scott, ranging from types I, III, and VI phase behavior for the tetrahydrofuran(1) + carbon dioxide(2), + methane(2), and + water(2) binary mixtures, respectively. This last type is characterized by the presence of a Bancroft point, positive azeotropy, and the so-called closed-loop curves that represent regions of liquid-liquid immiscibility in the phase diagram. The system exhibits lower critical solution temperatures (LCSTs), which denote the lower limit of immiscibility together with upper critical solution temperatures (UCSTs). This behavior is explained in terms of competition between the incompatibility with the alkyl parts of the tetrahydrofuran ring chain and the hydrogen bonding between water and the ether group. A minimum number of unlike interaction parameters are fitted to give the optimal representation of the most representative features of the binary phase diagrams. In the particular case of tetrahydrofuran(1) + water(2), two sets of intermolecular potential model parameters are proposed to describe accurately either the hypercritical point associated with the closed-loop liquid-liquid immiscibility region or the location of the mixture lower- and upper-critical end-points. The theory is not only able to predict the type of phase behavior of each mixture, but also provides a reasonably good description of the global phase behavior whenever experimental data are available.

Supercritical fluid regeneration of adsorbents

NASA Astrophysics Data System (ADS)

Defilippi, R. P.; Robey, R. J.

1983-05-01

The results of a program to perform studies supercritical (fluid) carbon dioxide (SCF CO2) regeneration of adsorbents, using samples of industrial wastewaters from manufacturing pesticides and synthetic solution, and to estimate the economics of the specific wastewater treatment regenerations, based on test data are given. Processing costs for regenerating granular activated carbon GAC) for treating industrial wastewaters depend on stream properties and regeneration throughput.

Carbon dioxide conversion over carbon-based nanocatalysts.

PubMed

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

2013-07-01

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

Research Progress in Carbon Dioxide Storage and Enhanced Oil Recovery

NASA Astrophysics Data System (ADS)

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.

Adsorption of metal ions by pecan shell-based granular activated carbons.

PubMed

Bansode, R R; Losso, J N; Marshall, W E; Rao, R M; Portier, R J

2003-09-01

The present investigation was undertaken to evaluate the adsorption effectiveness of pecan shell-based granular activated carbons (GACs) in removing metal ions (Cu(2+), Pb(2+), Zn(2+)) commonly found in municipal and industrial wastewater. Pecan shells were activated by phosphoric acid, steam or carbon dioxide activation methods. Metal ion adsorption of shell-based GACs was compared to the metal ion adsorption of a commercial carbon, namely, Calgon's Filtrasorb 200. Adsorption experiments were conducted using solutions containing all three metal ions in order to investigate the competitive effects of the metal ions as would occur in contaminated wastewater. The results obtained from this study showed that acid-activated pecan shell carbon adsorbed more lead ion and zinc ion than any of the other carbons, especially at carbon doses of 0.2-1.0%. However, steam-activated pecan shell carbon adsorbed more copper ion than the other carbons, particularly using carbon doses above 0.2%. In general, Filtrasorb 200 and carbon dioxide-activated pecan shell carbons were poor metal ion adsorbents. The results indicate that acid- and steam-activated pecan shell-based GACs are effective metal ion adsorbents and can potentially replace typical coal-based GACs in treatment of metal contaminated wastewater.

[Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Progress report, May 1991, DOE Grant DE-FG09-84ER60255

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

Lincoln, D.E.

1991-05-01

Experiments were performed to determine the effects of carbon dioxide on plants and on the insects feeding on these plants. Current progress is reported for the following experiments: Response of a Specialist-Feeding Insect Herbivore to Carbon Dioxide Induced Changes in Its Hostplant; Growth and Reproduction of Grasshoppers Feeding on a C{sub 4} Grass Under Elevated Carbon Dioxide; Elevated Carbon Dioxide and Temperature Effects on Growth and Defense of Big Sagebrush; Sagebrush and Grasshopper Responses to Atmospheric Carbon Dioxide Concentration; Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide; and Sagebrush Carbon Allocation Patterns and Grasshopper Nutrition:more » The Influence of Carbon Dioxide Enrichment and Soil Mineral Limitation.« less

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

46 CFR 108.627 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

46 CFR 169.732 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

46 CFR 169.732 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

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

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bicarbonate/carbon dioxide test system. 862.1160... Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a) Identification. A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole...

Carbon dioxide production during cardiopulmonary bypass: pathophysiology, measure and clinical relevance.

PubMed

Ranucci, Marco; Carboni, Giovanni; Cotza, Mauro; de Somer, Filip

2017-01-01

Carbon dioxide production during cardiopulmonary bypass derives from both the aerobic metabolism and the buffering of lactic acid produced by tissues under anaerobic conditions. Therefore, carbon dioxide removal monitoring is an important measure of the adequacy of perfusion and oxygen delivery. However, routine monitoring of carbon dioxide removal is not widely applied. The present article reviews the main physiological and pathophysiological sources of carbon dioxide, the available techniques to assess carbon dioxide production and removal and the clinically relevant applications of carbon dioxide-related variables as markers of the adequacy of perfusion during cardiopulmonary bypass.

Removal of gallium (III) ions from acidic aqueous solution by supercritical carbon dioxide extraction in the green separation process.

PubMed

Chou, Wei-Lung; Wang, Chih-Ta; Yang, Kai-Chiang; Huang, Yen-Hsiang

2008-12-15

Supercritical carbon dioxide extraction, which is a feasible "green" alternative, was applied in this study as a sample pretreatment step for the removal of gallium (III) ions from acidic aqueous solution. The effect of various process parameters, including various chelating agents, extraction pressure and temperature, dimensionless CO(2) volume, the concentration of the chelating agent, and the pH of the solution, governing the efficiency and throughput of the procedure were systematically investigated. The performance of the various chelating agents from different studies indicated that the extraction efficiency of supercritical CO(2) was in the order: thiopyridine (PySH)>thenoyltrifluoroacetone (TTAH)>acetylacetone (AcAcH). The optimal extraction pressure and temperature for the supercritical CO(2) extraction of gallium (III) with chelating agent PySH were found to be 70 degrees C and 3000psi, respectively. The optimum concentration of the chelating agent was found to be 50ppm. A value of 7.5 was selected as the optimum dimensionless CO(2) volume. The optimum pH of the solution for supercritical CO(2) extraction should fall in the range of 2.0-3.0.

Development of a low-cost biogas filtration system to achieve higher-power efficient AC generator

NASA Astrophysics Data System (ADS)

Mojica, Edison E.; Ardaniel, Ar-Ar S.; Leguid, Jeanlou G.; Loyola, Andrea T.

2018-02-01

The paper focuses on the development of a low-cost biogas filtration system for alternating current generator to achieve higher efficiency in terms of power production. A raw biogas energy comprises of 57% combustible element and 43% non-combustible elements containing carbon dioxide (36%), water vapor (5%), hydrogen sulfide (0.5%), nitrogen (1%), oxygen (0 - 2%), and ammonia (0 - 1%). The filtration system composes of six stages: stage 1 is the water scrubber filter intended to remove the carbon dioxide and traces of hydrogen sulfide; stage 2 is the silica gel filter intended to reduce the water vapor; stage 3 is the iron sponge filter intended to remove the remaining hydrogen sulfide; stage 4 is the sodium hydroxide solution filter intended to remove the elemental sulfur formed during the interaction of the hydrogen sulfide and the iron sponge and for further removal of carbon dioxide; stage 5 is the silica gel filter intended to further eliminate the water vapor gained in stage 4; and, stage 6 is the activated carbon filter intended to remove the carbon dioxide. The filtration system was able to lower the non-combustible elements by 72% and thus, increasing the combustible element by 54.38%. The unfiltered biogas is capable of generating 16.3 kW while the filtered biogas is capable of generating 18.6 kW. The increased in methane concentration resulted to 14.11% increase in the power output. The outcome resulted to better engine performance in the generation of electricity.

METHOD 415.3 - MEASUREMENT OF TOTAL ORGANIC ...

EPA Pesticide Factsheets

2.0 SUMMARY OF METHOD2.1 In both TOC and DOC determinations, organic carbon in the water sample is oxidized to form carbon dioxide (CO2), which is then measured by a detection system. There are two different approaches for the oxidation of organic carbon in water samples to carbon dioxide gas: (a) combustion in an oxidizing gas and (b) UV promoted or heat catalized chemical oxidation with a persulfate solution. Carbon dioxide, which is released from the oxidized sample, is detected by a conductivity detector or by a nondispersive infrared (NDIR) detector. Instruments using any combination of the above technologies may be used in this method.2.2. Setteable solids and floating matter may cause plugging of valves, tubing, and the injection needle port. The TOC procedure allows the removal of settleable solids and floating matter. The suspended matter is considered part of the sample. The resulting water sample is then considered a close approximation of the original whole water sample for the purpose of TOC measurement.2.3. The DOC procedure requires that the sample be passed through a 0.45 um filter prior to analysis.2.4. The TOC and DOC procedures require that all inorganic carbon be removed from the sample before the sample is analyzed for organic carbon content. If the inorganic carbon (IC) is not completely removed, significant error will occur. The inorganic carbon interference is removed by converting the mineralized IC to CO2 by acidification and

Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

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

Garcia, Julio Enrique

2003-01-01

Injection of carbon dioxide (CO 2) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO 2 will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO 2 and NaCl has beenmore » conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO 2-H 2O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO2. The basic problem of CO 2 injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO 2 injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO 2 injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO 2. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO 2 into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO 2) the viscosity of carbon dioxide can be less than the viscosity of the aqueous phase by a factor of 15. Because of the lower viscosity, the CO 2 displacement front will have a tendency towards instability. Preliminary simulation results show good agreement between classical instability solutions and numerical predictions of finger growth and spacing obtained using different gas/liquid viscosity ratios, relative permeability and capillary pressure models. Further studies are recommended to validate these results over a broader range of conditions.« less

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

Code of Federal Regulations, 2014 CFR

2014-10-01

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

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

Code of Federal Regulations, 2013 CFR

2013-10-01

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

Solid-state flurbiprofen and methyl-β-cyclodextrin inclusion complexes prepared using a single-step, organic solvent-free supercritical fluid process.

PubMed

Rudrangi, Shashi Ravi Suman; Kaialy, Waseem; Ghori, Muhammad U; Trivedi, Vivek; Snowden, Martin J; Alexander, Bruce David

2016-07-01

The aim of this study was to enhance the apparent solubility and dissolution properties of flurbiprofen through inclusion complexation with cyclodextrins. Especially, the efficacy of supercritical fluid technology as a preparative technique for the preparation of flurbiprofen-methyl-β-cyclodextrin inclusion complexes was evaluated. The complexes were prepared by supercritical carbon dioxide processing and were evaluated by solubility, differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, practical yield, drug content estimation and in vitro dissolution studies. Computational molecular docking studies were conducted to study the possibility of molecular arrangement of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin. The studies support the formation of stable molecular inclusion complexes between the drug and cyclodextrin in a 1:1 stoichiometry. In vitro dissolution studies showed that the dissolution properties of flurbiprofen were significantly enhanced by the binary mixtures prepared by supercritical carbon dioxide processing. The amount of flurbiprofen dissolved into solution alone was very low with 1.11±0.09% dissolving at the end of 60min, while the binary mixtures processed by supercritical carbon dioxide at 45°C and 200bar released 99.39±2.34% of the drug at the end of 30min. All the binary mixtures processed by supercritical carbon dioxide at 45°C exhibited a drug release of more than 80% within the first 10min irrespective of the pressure employed. The study demonstrated the single step, organic solvent-free supercritical carbon dioxide process as a promising approach for the preparation of inclusion complexes between flurbiprofen and methyl-β-cyclodextrin in solid-state. Copyright © 2016 Elsevier B.V. All rights reserved.

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

PubMed

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.

Reducing the chlorine dioxide demand in final disinfection of drinking water treatment plants using activated carbon.

PubMed

Sorlini, Sabrina; Biasibetti, Michela; Collivignarelli, Maria Cristina; Crotti, Barbara Marianna

2015-01-01

Chlorine dioxide is one of the most widely employed chemicals in the disinfection process of a drinking water treatment plant (DWTP). The aim of this work was to evaluate the influence of the adsorption process with granular activated carbon (GAC) on the chlorine dioxide consumption in final oxidation/disinfection. A first series of tests was performed at the laboratory scale employing water samples collected at the outlet of the DWTP sand filter of Cremona (Italy). The adsorption process in batch conditions with seven different types of GAC was studied. A second series of tests was performed on water samples collected at the outlet of four GAC columns installed at the outlet of the DWTP sand filter. The results showed that the best chlorine dioxide demand (ClO2-D) reduction yields are equal to 60-80% and are achieved in the first 30 min after ClO2 addition, during the first 16 days of the column operation using a mineral, coal-based, mesoporous GAC. Therefore, this carbon removes organic compounds that are more rapidly reactive with ClO2. Moreover, a good correlation was found between the ClO2-D and UV absorbance at wavelength 254 nm using mineral carbons; therefore, the use of a mineral mesoporous GAC is an effective solution to control the high ClO2-D in the disinfection stage of a DWTP.

46 CFR 78.47-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

46 CFR 196.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

46 CFR 97.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

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

Code of Federal Regulations, 2010 CFR

2010-10-01

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

46 CFR 196.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

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

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

Code of Federal Regulations, 2014 CFR

2014-10-01

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

A review on the effects of supercritical carbon dioxide on enzyme activity.

PubMed

Wimmer, Zdenek; Zarevúcka, Marie

2010-01-19

Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO(2). The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability.

A Review on the Effects of Supercritical Carbon Dioxide on Enzyme Activity

PubMed Central

Wimmer, Zdeněk; Zarevúcka, Marie

2010-01-01

Different types of enzymes such as lipases, several phosphatases, dehydrogenases, oxidases, amylases and others are well suited for the reactions in SC-CO2. The stability and the activity of enzymes exposed to carbon dioxide under high pressure depend on enzyme species, water content in the solution and on the pressure and temperature of the reaction system. The three-dimensional structure of enzymes may be significantly altered under extreme conditions, causing their denaturation and consequent loss of activity. If the conditions are less adverse, the protein structure may be largely retained. Minor structural changes may induce an alternative active protein state with altered enzyme activity, specificity and stability. PMID:20162013

Compositions for, solutions for, and methods of use of siloxane based aromatic trisureas as viscosifiers

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

Doherty, Mark Daniel; O'Brien, Michael Joseph; Lee, Jason

A compound represented by the following formula is provided: ##STR00001## Also provided is a solution including a compound disclosed herein, a volume of dense carbon dioxide (CO.sub.2), and a co-solvent, where the solution has an increased viscosity greater than the viscosity of dense CO.sub.2. Methods of increasing the viscosity of dense CO.sub.2 and natural gas liquids (NGLs) by, for example, dissolving a compound disclosed herein to form a solution, are also provided.

NASA Carbon Sleuth Begins Year Two

NASA Image and Video Library

2015-10-29

Global average carbon dioxide concentrations as seen by NASA’s Orbiting Carbon Observatory-2 mission, June 1-15, 2015. OCO-2 measures carbon dioxide from the top of Earth's atmosphere to its surface. Higher carbon dioxide concentrations are in red, with lower concentrations in yellows and greens. Scientists poring over data from OCO-2 mission are seeing patterns emerge as they seek answers to questions about atmospheric carbon dioxide. Among the most striking features visible in the first year of OCO-2 data is the increase in carbon dioxide in the northern hemisphere during winter, when trees are not removing carbon dioxide, followed by its decrease in spring, as trees start to grow and remove carbon dioxide from the atmosphere. http://photojournal.jpl.nasa.gov/catalog/PIA20039

Analytical solutions to dissolved contaminant plume evolution with source depletion during carbon dioxide storage.

PubMed

Yang, Yong; Liu, Yongzhong; Yu, Bo; Ding, Tian

2016-06-01

Volatile contaminants may migrate with carbon dioxide (CO2) injection or leakage in subsurface formations, which leads to the risk of the CO2 storage and the ecological environment. This study aims to develop an analytical model that could predict the contaminant migration process induced by CO2 storage. The analytical model with two moving boundaries is obtained through the simplification of the fully coupled model for the CO2-aqueous phase -stagnant phase displacement system. The analytical solutions are confirmed and assessed through the comparison with the numerical simulations of the fully coupled model. Then, some key variables in the analytical solutions, including the critical time, the locations of the dual moving boundaries and the advance velocity, are discussed to present the characteristics of contaminant migration in the multi-phase displacement system. The results show that these key variables are determined by four dimensionless numbers, Pe, RD, Sh and RF, which represent the effects of the convection, the dispersion, the interphase mass transfer and the retention factor of contaminant, respectively. The proposed analytical solutions could be used for tracking the migration of the injected CO2 and the contaminants in subsurface formations, and also provide an analytical tool for other solute transport in multi-phase displacement system. Copyright © 2016 Elsevier B.V. All rights reserved.

Method and system for capturing carbon dioxide and/or sulfur dioxide from gas stream

DOEpatents

Chang, Shih-Ger; Li, Yang; Zhao, Xinglei

2014-07-08

The present invention provides a system for capturing CO.sub.2 and/or SO.sub.2, comprising: (a) a CO.sub.2 and/or SO.sub.2 absorber comprising an amine and/or amino acid salt capable of absorbing the CO.sub.2 and/or SO.sub.2 to produce a CO.sub.2- and/or SO.sub.2-containing solution; (b) an amine regenerator to regenerate the amine and/or amino acid salt; and, when the system captures CO.sub.2, (c) an alkali metal carbonate regenerator comprising an ammonium catalyst capable catalyzing the aqueous alkali metal bicarbonate into the alkali metal carbonate and CO.sub.2 gas. The present invention also provides for a system for capturing SO.sub.2, comprising: (a) a SO.sub.2 absorber comprising aqueous alkali metal carbonate, wherein the alkali metal carbonate is capable of absorbing the SO.sub.2 to produce an alkali metal sulfite/sulfate precipitate and CO.sub.2.

Carbon dioxide separation using adsorption with steam regeneration

DOEpatents

Elliott, Jeannine Elizabeth; Copeland, Robert James; Leta, Daniel P.; McCall, Patrick P.; Bai, Chuansheng; DeRites, Bruce A.

2016-11-29

A process for separating a carbon dioxide from a gas stream is disclosed. The process can include passing the gas stream over a sorbent that adsorbs the carbon dioxide by concentration swing adsorption and adsorptive displacement. The sorbent can be regenerated and the carbon dioxide recaptured by desorbing the carbon dioxide from the sorbent using concentration swing adsorption and desorptive displacement. A carbon dioxide separation system is also disclosed. Neither the system nor the process rely on temperature swing or pressure swing adsorption.

Measuring the Spectral Expression of Carbon Dioxide in the Solar Reflected Spectrum with AVIRIS

NASA Technical Reports Server (NTRS)

Green, Robert O.

2001-01-01

Carbon dioxide is a low-concentration, but important, component of the Earth's atmosphere. This gas absorbs electromagnetic radiation (EMR) in several regions of the spectrum. Absorption of energy by carbon dioxide adds heat to the atmosphere. In the world today, the burning of fossil fuels and other anthropogenic processes adds carbon dioxide to the atmosphere. Other natural processes in the Earth's system both add and remove carbon dioxide. Overall, measurements of atmospheric carbon dioxide at selected sites around the globe show an increased carbon dioxide concentration in the atmosphere. A figure shows the measured carbon dioxide from Mauna Loa, Hawaii, from 1958 to 2000. Overall, the concentration has increased from 315 to 365 ppm at this site over this period. (There is also a yearly cycle to the concentration that is timed with and hypothesized to be related to the vegetation growing season in the Northern Hemisphere.) The overall expected effect of this increase of atmospheric carbon dioxide is trapping of heat in the atmosphere and global warming. While this overall relationship between carbon dioxide and global warming seems straightforward, many of the specific details relating to regional and local sources and sinks and gradients of carbon dioxide are not well understood. A remote sensing capability to measure carbon dioxide could provide important inputs for scientific research to better understand the distribution and change in atmospheric carbon dioxide at detailed spatial and temporal levels. In pursuit of this remote sensing of carbon dioxide objective, this paper analyzes the expression of carbon dioxide in the spectral range measured by the Airborne Visible/Infrared Imagery Spectrometer (AVIRIS). Based on these analyses, a spectral-fitting algorithm that uses AVIRIS measured spectra and MODTRAN radiative-transfer code modeled spectra to derive total column carbon dioxide abundance has been developed. This algorithm has been applied to an AVIRIS data set acquired over Pasadena, California, in 1999 and a data set acquired over the Pacific Ocean near Hawaii in 2000 with promising results. This is ongoing research; the current initial analyses, measurements, and results are reported in this paper.

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 2 2012-10-01 2012-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Carbon dioxide, solid (dry ice). 173.217 Section... Class 7 § 173.217 Carbon dioxide, solid (dry ice). (a) Carbon dioxide, solid (dry ice), when offered for... marked on two sides “WARNING CO2 SOLID (DRY ICE).” (2) Other packagings containing solid carbon dioxide...

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

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... of carbon dioxide per 100 milliliters of wine or where the variation results from the use of methods...

Effects of acidic deposition on the erosion of carbonate stone — experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

NASA Astrophysics Data System (ADS)

Baedecker, Philip A.; Reddy, Michael M.; Reimann, Karl J.; Sciammarella, Cesar A.

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30° to horizontal at the five NAPAP materials exposure sites range from ˜ 15 to ˜ 30 μm yr -1 for marble, and from ˜ 25 to ˜ 45 μm yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ˜ 30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ˜ 70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ("clean rain"). These results are for marble and limestone slabs exposed at an angle of 30° from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60° or 85°. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC, and Steubenville, OH.

Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

USGS Publications Warehouse

Baedecker, P.A.; Reddy, M.M.; Reimann, K.J.; Sciammarella, C.A.

1992-01-01

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30?? to horizontal at the five NAPAP materials exposure sites range from ~15 to ~30?? ??m yr-1 for marble, and from ~25 to ~45 ??m yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ~30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ~70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ('clean rain'). These results are for marble and limestone slabs exposed at an angle of 30?? from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60?? or 85??. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC, and Steubenville, OH.

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Carbon dioxide systems: General. (a) Sections 108.431 through 108.457 apply to high pressure carbon dioxide fire extinguishing systems. (b) Low pressure systems, that is, those in which the carbon dioxide...

Demonstrating Phase Changes.

ERIC Educational Resources Information Center

Rohr, Walter

1995-01-01

Presents two experiments that demonstrate phase changes. The first experiment explores phase changes of carbon dioxide using powdered dry ice sealed in a piece of clear plastic tubing. The second experiment demonstrates an equilibrium process in which a crystal grows in equilibrium with its saturated solution. (PVD)

Superfund Innovative Technology Evaluation: Demonstration Bulletin: Organic Extraction Utilizing Solvents

EPA Science Inventory

This technology utilizes liquified gases as the extracting solvent to remove organics, such as hydrocarbons, oil and grease, from wastewater or contaminated sludges and soils. Carbon dioxide is generally used for aqueous solutions, and propane is used for sediment, sludges and ...

IMPROVEMENTS IN OR RELATING TO THE PRODUCTION OF SINTERED URANIUM DIOXIDE

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

Russell, L.E.; Harrison, J.D.L.; Brett, N.H.

A method is described for producing a dense sintered body of uranium dioxide or a mixture thereof with plutonium dioxide. Compacted uranium dioxide or a compacted uranium dioxide-plutonium dioxide mixture is heated to at least 1300 deg C in an atmosphere of carbon dioxide or carbon dioxide mixed with carbon monoxide. (R.J.S.)

Designed amyloid fibers as materials for selective carbon dioxide capture

PubMed Central

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

2014-01-01

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

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...

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

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Use of carbon dioxide in... Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still wine... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0...

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...

Crustal solute fluxes and transient carbon dioxide drawdown in the Scottbreen Basin, Svalbard in 2002

NASA Astrophysics Data System (ADS)

Krawczyk, Wiesława Ewa; Bartoszewski, Stefan A.

2008-12-01

SummarySolute fluxes and transient carbon dioxide drawdown in a small glacierized basin investigated on Svalbard in 2002 are presented. It was a sample year within a period of significant climate warming in the Arctic. Discharge was recorded in the Scottbreen Basin (10.1 km 2), Bellsund Fjord, between July 8 and September 10, 2002. Specific runoff for this period was 0.784 m, 22% more than the mean for 1986-2001. The runoff for all of 2002 (i.e. the hydrologic year) was estimated by comparison with Bayelva, the only glacial river with longer records on Svalbard. The specific runoff for 2002 was ˜1.228 m, yielding crustal solute fluxes of 69.4 t km -2 yr -1 (25.8 m 3 km -2 yr -1). This rate is the highest chemical denudation rate reported from glacierized basins on Svalbard, and it may be underestimated because higher solute fluxes at the beginning of the melt season were not taken into account. Crustal fluxes in the fall may also have been higher because it is probable that crustal ion concentrations were increasing after recording stopped in September. The cation denudation rate was 1213 ∑ meq + m -2 yr -1 and the mean annual crustal ion concentration derived from it amounted to 981 μeq L -1. Transient CO 2 drawdown in 2002 was 5242 kg C km -2 yr -1. Most of the carbon dioxide was removed in the summer ablation waters, estimated CO 2 drawdown in the fall being only 13% of the total. Comparison with crustal solute fluxes (CSF) computed from specific conductivity in the 1980s and 1990s suggests that earlier fluxes may have been overestimated by around 19%. Comparing earlier data with the 2002 rates may confirm the influence of climate warming on increasing chemical denudation rates. It was also found that a globally derived equation relating specific conductivity to concentrations of dissolved limestone in water gave estimates of the crustal solute fluxes that were only 1.1% less than those obtained via comprehensive chemical analyses of waters and ion partitioning procedures.

Carbon dioxide dangers demonstration model

USGS Publications Warehouse

Venezky, Dina; Wessells, Stephen

2010-01-01

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

Energy efficient solvent regeneration process for carbon dioxide capture

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

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

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.

Dynamics of the Exchange of Carbon Dioxide in Arctic and Subarctic Regions,

DTIC Science & Technology

1973-01-01

snow, at temperatures too low for significant biological activity. The phenomena of gas evasion under conditions of 3 freezing soil solution , confirmed...1972) have observed a de- pression rather than an acceleration in soil respiration, as the soil solution undergoes a phase change near 0C. On the other...temperatures are too low for significant biological activity. CO2 from biological sources expressed by freezing the soil solution , evidently leaks to the

Controlling the size and morphology of precipitated calcite particles by the selection of solvent composition

NASA Astrophysics Data System (ADS)

Konopacka-Łyskawa, Donata; Kościelska, Barbara; Karczewski, Jakub

2017-11-01

Precipitated calcium carbonate is used as an additive in the manufacture of many products. Particles with specific characteristics can be obtained by the selection of precipitation conditions, including temperature and the composition of solvent. In this work, calcium carbonate particles were obtained in the reaction of calcium hydroxide with carbon dioxide at 65 °C. Initial Ca(OH)2 suspensions were prepared in pure water and aqueous solutions of ethylene glycol or glycerol of the concentration range up to 20% (vol.). The course of reaction was monitored by conductivity measurements. Precipitated solids were analyzed by FTIR, XRD, SEM and the particles size distribution was determined by a laser diffraction method. The adsorption of ethylene glycol or glycerol on the surface of scalenohedral and rhombohedral calcite was testes by a normal-phase high-performance liquid chromatography. The addition of organic solvents changed the viscosity of reaction mixtures, the rate of carbon dioxide absorption and the solubility of inorganic components and therefore influence calcium carbonate precipitation conditions. All synthesized calcium carbonate products were in a calcite form. Scalenohedral calcite crystals were produced when water was a liquid phase, whereas addition of organic solvents resulted in the formation of rhombo-scalenohedral particles. The increase in organic compounds concentration resulted in the decrease of mean particles size from 2.4 μm to 1.7 μm in ethylene glycol solutions and to 1.4 μm in glycerol solutions. On the basis of adsorption tests, it was confirm that calcite surface interact stronger with glycerol than ethylene glycol. The interaction between scalenohedral calcite and used organic additives was higher in comparison to the pure rhombohedral form applied as a stationary phase.

Development of a carbonate absorption-based process for post-combustion CO2 capture: The role of biocatalyst to promote CO2 absorption rate

USGS Publications Warehouse

Lu, Y.; Ye, X.; Zhang, Z.; Khodayari, A.; Djukadi, T.

2011-01-01

An Integrated Vacuum Carbonate Absorption Process (IVCAP) for post-combustion carbon dioxide (CO2) capture is described. IVCAP employs potassium carbonate (PC) as a solvent, uses waste or low quality steam from the power plant for CO2 stripping, and employs a biocatalyst, carbonic anhydrase (CA) enzyme, for promoting the CO2 absorption into PC solution. A series of experiments were performed to evaluate the activity of CA enzyme mixed in PC solutions in a stirred tank reactor system under various temperatures, CA dosages, CO2 loadings, CO2 partial pressures, and the presence of major flue gas contaminants. It was demonstrated that CA enzyme is an effective biocatalyst for CO2 absorption under IVCAP conditions. ?? 2011 Published by Elsevier Ltd.

Polymer formulations for gettering hydrogen

DOEpatents

Shepodd, Timothy J.; Even, Jr., William R.

2000-01-01

A novel method for preparing a hydrogenation composition comprising organic polymer molecules having carbon--carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces and particularly from atmospheres within enclosed spaces that contain air, water vapor, oxygen, carbon dioxide or ammonia. The organic polymers molecules containing carbon--carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble noble metal catalyst composition. High molecular weight polymers may be added to the organic polymer/catalyst mixture in order to improve their high temperature performance. The hydrogenation composition is prepared by dispersing the polymers in a suitable solvent, forming thereby a solution suspension, flash-freezing droplets of the solution in a liquid cryogen, freeze-drying the frozen droplets to remove frozen solvent incorporated in the droplets, and recovering the dried powder thus formed.

Screen for Carbon Dioxide.

ERIC Educational Resources Information Center

Foster, John; And Others

1986-01-01

Presents a set of laboratory experiments that can assist students in the detection of carbon dioxide. Offers a variation of the supported drop method of carbon dioxide detection that provides readily visible positive results. Includes background information on carbon dioxide. (ML)

Method of immobilizing carbon dioxide from gas streams

DOEpatents

Holladay, David W.; Haag, Gary L.

1979-01-01

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

A dynamic system for the simulation of fasting luminal pH-gradients using hydrogen carbonate buffers for dissolution testing of ionisable compounds.

PubMed

Garbacz, Grzegorz; Kołodziej, Bartosz; Koziolek, Mirko; Weitschies, Werner; Klein, Sandra

2014-01-23

The hydrogen carbonate buffer is considered as the most biorelevant buffer system for the simulation of intestinal conditions and covers the physiological pH range of the luminal fluids from pH 5.5 to about pH 8.4. The pH value of a hydrogen carbonate buffer is the result of a complex and dynamic interplay of the concentration of hydrogen carbonate ions, carbonic acid, the concentration of dissolved and solvated carbon dioxide and its partial pressure above the solution. The complex equilibrium between the different ions results in a thermodynamic instability of hydrogen carbonate solutions. In order to use hydrogen carbonate buffers with pH gradients in the physiological range and with the dynamics observed in vivo without changing the ionic strength of the solution, we developed a device (pHysio-grad®) that provides both acidification of the dissolution medium by microcomputer controlled carbon dioxide influx and alkalisation by degassing. This enables a continuous pH control and adjustment during dissolution of ionisable compounds. The results of the pH adjustment indicate that the system can compensate even rapid pH changes after addition of a basic or acidic moiety in amounts corresponding up to 90% of the overall buffer capacity. The results of the dissolution tests performed for a model formulation containing ionizable compounds (Nexium 20mg mups) indicate that both the simulated fasting intraluminal pH-profiles and the buffer species can significantly affect the dissolution process by changing the lag time prior to initial drug release and the release rate of the model compound. A prediction of the in vivo release behaviour of this formulation is thus most likely strongly related to the test conditions such as pH and buffer species. Copyright © 2013 Elsevier B.V. All rights reserved.

Carbon dioxide transport over complex terrain

USGS Publications Warehouse

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

2004-01-01

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

46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2) Are...

46 CFR 147.65 - Carbon dioxide and halon fire extinguishing systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Carbon dioxide and halon fire extinguishing systems. 147... dioxide and halon fire extinguishing systems. (a) Carbon dioxide or halon cylinders forming part of a...) Carbon dioxide or halon cylinders must be rejected for further service when they— (1) Leak; (2) Are...

Diffusivity of Carbon Dioxide in Aqueous Solutions under Geologic Carbon Sequestration Conditions.

PubMed

Perera, Pradeep N; Deng, Hang; Schuck, P James; Gilbert, Benjamin

2018-04-26

Accurate assessment of the long-term security of geologic carbon sequestration requires knowledge of the mobility of carbon dioxide in brines under pressure and temperature conditions that prevail in subsurface aquifers. Here, we report Raman spectroscopic measurements of the rate of CO 2 diffusion in water and brines as a function of pressure, salinity, and concentration of CO 2 . In pure water at 50 ± 2 °C and 90 ± 2 bar, we find the diffusion coefficient, D, to be (3.08 ± 0.03) × 10 -9 m 2 /s, a value that is consistent with a recent microfluidic study but lower than earlier PVT measurements. Under reservoir conditions, salinity affects the mobility of CO 2 significantly and D decreased by 45% for a 4 M solution of NaCl. We find significant differences of diffusivity of CO 2 in brines (0-4 M NaCl), in both the absolute values and the trend compared to the Stokes-Einstein prediction under our experimental conditions. We observe that D decreases significantly at the high CO 2 concentrations expected in subsurface aquifers (∼15% reduction at 0.55 mol/kg of CO 2 ) and provides an empirical correction to the commonly reported D values that assume a tracer concentration dependence on diffusivity.

KINETICS OF THE DISSOLUTION OF URANIUM DIOXIDE IN CARBONATE-BICARBONATE SOLUTIONS

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

Schortmann, W.E.; DeSesa, M.A.

The kinetics of the dissolution of uranium dioxide in sodium carbonate- sodium bicarbonate solutions were determined. The study was undertaken in order to obtain fundamental information about the commercial carbonate process for leaching uranium from its ores. A rate equation incorporating the effects of surface area oxygen partial pressure, temperature, and reagent concentrations was empirically developed. A mechanism consisting essentially of two consecutive reactions at steady state is proposed. These reactions are the oxidation of U/ sup 4+/ to U/sup 6+/ and the subsequent formation of the uranyl dicarbonate complexion. Depending on the conditions, either or both of these reactionsmore » can determine the over-all rate. The conversion of uranyl dicarbonate to the uranyl tricarbonate complexion is postulated to be very rapid. In the suggested mechanism, the rate-determining phase of the oxidation is the dissociation of adsorbed molecular oxygen. and both the carbonate and bicarbonate ions play equivalent roles in the formation of the uranyl dicarbonate. As indicated by their high activation energies of about 13 and 14 kcal per mole uranium, both reactions are chemical rather than diffusional processes. A mathematical examination of the proposed mechanism produced a rate equation consistent with the experimental information. The credibility of the mechanism was thereby strengthened. (auth)« less

Method and solvent composition for regenerating an ion exchange resin

DOEpatents

Even, William R.; Irvin, David J.; Irvin, Jennifer A.; Tarver, Edward E.; Brown, Gilbert M.; Wang, James C. F.

2002-01-01

A method and composition for removing perchlorate from a highly selective ion exchange resin is disclosed. The disclosed approach comprises treating the resin in a solution of super critical or liquid carbon dioxide and one or more quaternary ammonium chloride surfactant compounds.

HYDROSILATION POLYMERIZATIONS WITH DIALLYL MONOMER - BENZENE SOLUTION VERSUS SUPERCRITICAL CARBON DIOXIDE. (R825503)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Solubility prediction of naphthalene in carbon dioxide from crystal microstructure

NASA Astrophysics Data System (ADS)

Sang, Jiarong; Jin, Junsu; Mi, Jianguo

2018-03-01

Crystals dissolved in solvents are ubiquitous in both natural and artificial systems. Due to the complicated structures and asymmetric interactions between the crystal and solvent, it is difficult to interpret the dissolution mechanism and predict solubility using traditional theories and models. Here we use the classical density functional theory (DFT) to describe the crystal dissolution behavior. As an example, naphthalene dissolved in carbon dioxide (CO2) is considered within the DFT framework. The unit cell dimensions and microstructure of crystalline naphthalene are determined by minimizing the free-energy of the crystal. According to the microstructure, the solubilities of naphthalene in CO2 are predicted based on the equality of naphthalene's chemical potential in crystal and solution phases, and the interfacial structures and free-energies between different crystal planes and solution are determined to investigate the dissolution mechanism at the molecular level. The theoretical predictions are in general agreement with the available experimental data, implying that the present model is quantitatively reliable in describing crystal dissolution.

Self-assembly of (perfluoroalkyl)alkanes on a substrate surface from solutions in supercritical carbon dioxide.

PubMed

Gallyamov, Marat O; Mourran, Ahmed; Tartsch, Bernd; Vinokur, Rostislav A; Nikitin, Lev N; Khokhlov, Alexei R; Schaumburg, Kjeld; Möller, Martin

2006-06-14

Toroidal self-assembled structures of perfluorododecylnonadecane and perfluorotetradecyloctadecane have been deposited on mica and highly oriented pyrolytic graphite surfaces by exposure of the substrates to solutions of the (pefluoroalkyl)alkanes in supercritical carbon dioxide. Scanning force microscopy (SFM) images have displayed a high degree of regularity of these self-assembled nanoobjects regarding size, shape, and packing in a monolayer. Analysis of SFM images allowed us to estimate that each toroidal domain has an outer diameter of about 50 nm and consists of several thousands of molecules. We propose a simple model explaining the clustering of the molecules to objects with a finite size. The model based on the close-packing principles predicts formation of toroids, whose size is determined by the molecular geometry. Here, we consider the amphiphilic nature of the (perfluoroalkyl)alkane molecules in combination with incommensurable packing parameters of the alkyl- and the perfluoralkyl-segments to be a key factor for such a self-assembly.

Carbon Dioxide Insufflation Increases Colonoscopic Adenoma Detection Rate Compared With Air Insufflation.

PubMed

Mills, Christopher D; McCamley, Chere; Swan, Michael P

2018-03-07

To determine the effect of carbon dioxide insufflation on the most important outcome measure of colonoscopic quality: adenoma detection rate (ADR). Bowel cancer is the second most common cause of cancer deaths in males and females in Australia. Carbon dioxide has in recent times become the insufflation methodology of choice for screening colonoscopy for bowel cancer, as this has been shown to have significant advantages when compared with traditional air insufflation. Endoscopies performed over a period of 9 months immediately before and after the implementation of carbon dioxide insufflation at endoscopy centers were eligible for inclusion. The difference in ADR between the carbon dioxide and air insufflation methods was statistically significant, with an increased ADR in the carbon dioxide group. The superiority of carbon dioxide insufflation was sustained with a logistic regression model, which showed ADR was significantly impacted by insufflation method. Carbon dioxide insufflation is known to reduce abdominal pain, postprocedural duration of abdominal pain, abdominal distension, and analgesic requirements. This study represents for the first time the beneficial effect of carbon dioxide insufflation upon the key quality colonoscopy indicator of ADR.

Biomineralized diamond-like carbon films with incorporated titanium dioxide nanoparticles improved bioactivity properties and reduced biofilm formation.

PubMed

Lopes, F S; Oliveira, J R; Milani, J; Oliveira, L D; Machado, J P B; Trava-Airoldi, V J; Lobo, A O; Marciano, F R

2017-12-01

Recently, the development of coatings to protect biomedical alloys from oxidation, passivation and to reduce the ability for a bacterial biofilm to form after implantation has emerged. Diamond-like carbon films are commonly used for implanted medical due to their physical and chemical characteristics, showing good interactions with the biological environment. However, these properties can be significantly improved when titanium dioxide nanoparticles are included, especially to enhance the bactericidal properties of the films. So far, the deposition of hydroxyapatite on the film surface has been studied in order to improve biocompatibility and bioactive behavior. Herein, we developed a new route to obtain a homogeneous and crystalline apatite coating on diamond-like carbon films grown on 304 biomedical stainless steel and evaluated its antibacterial effect. For this purpose, films containing two different concentrations of titanium dioxide (0.1 and 0.3g/L) were obtained by chemical vapor deposition. To obtain the apatite layer, the samples were soaked in simulated body fluid solution for up to 21days. The antibacterial activity of the films was evaluated by bacterial eradication tests using Staphylococcus aureus biofilm. Scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy, and goniometry showed that homogeneous, crystalline, and hydrophilic apatite films were formed independently of the titanium dioxide concentration. Interestingly, the diamond-like films containing titanium dioxide and hydroxyapatite reduced the biofilm formation compared to controls. A synergism between hydroxyapatite and titanium dioxide that provided an antimicrobial effect against opportunistic pathogens was clearly observed. Copyright © 2017 Elsevier B.V. All rights reserved.

Kinetic study of carbon dioxide absorption into glycine promoted diethanolamine (DEA)

NASA Astrophysics Data System (ADS)

Pudjiastuti, Lily; Susianto, Altway, Ali; IC, Maria Hestia; Arsi, Kartika

2015-12-01

In industry, especially petrochemical, oil and natural gas industry, required separation process of CO2 gas which is a corrosive gas (acid gas). This characteristic can damage the plant utility and piping systems as well as reducing the caloric value of natural gas. Corrosive characteristic of CO2 will appear in areas where there is a decrease in temperature and pressure, such as at the elbow pipe, tubing, cooler and injector turbine. From disadvantages as described above, then it is important to do separation process in the CO2 gas stream, one of the method for remove CO2 from the gas stream is reactive absorption using alkanolamine based solution with promotor. Therefore, this study is done to determine the kinetics constant of CO2 absorption in diethanolamine (DEA) solution using a glycine promoter. Glycine is chosen as a promoter because glycine is a primary amine compound which is reactive, moreover, glycine has resistance to high temperatures so it will not easy to degradable and suitable for application in industry. The method used in this study is absorption using laboratory scale wetted wall column equipment at atmospheric of pressure. This study will to provide the reaction kinetics data information in order to optimize the separation process of CO2 in the industrialized world. The experimental results show that rising temperatures from 303,15 - 328,15 K and the increase of concentration of glycine from 1% - 3% weight will increase the absorption rate of carbon dioxide in DEA promoted with glycine by 24,2% and 59,764% respectively, also the reaction kinetic constant is 1.419 × 1012 exp (-3634/T) (m3/kmol.s). This result show that the addition of glycine as a promoter can increase absorption rate of carbon dioxide in diethanolamine solution and cover the weaknesses of diethanolamine solution.

Preparation and characterization of Polyacrylonitrile/ Manganese Dioxides- based Carbon Nanofibers via electrospinning process

NASA Astrophysics Data System (ADS)

Che Othman, F. E.; Yusof, N.; Jaafar, J.; Ismail, A. F.; Hasbullah, H.; Abdullah, N.; Ismail, M. S.

2016-06-01

This research reports the production of precursor polyacrylonitrile (PAN)/ manganese dioxide (MnO2) nanofibers (NFs) via electrospinning method followed by stabilization and carbonization processes. Nowadays, electrospinning has become a suitable method in manufacturing continuous NFs, thus it is employed to fabricate NFs in this study. The microstructural properties and adsorption competencies of the produced NFs were also studied. The NFs were prepared by electrospinning the polymer solution of Polyacrylonitrile (PAN) and Manganese Dioxide (MnO2) in, N, N-Dimethylformamide (DMF) solvent. The factors considered in this study were various polymer PAN/MnO2 concentrations which will significantly affect the specific surface area, fiber morphology and the diameter of the NFs prepared. Subsequently, heat treatment is applied by setting up the stabilization temperature at 275 °C and carbonization temperature at 800 °C with constant dwelling time (30 min). Nitrogen gas at constant rate 0.2 L/min was used for stabilization and carbonization with the stabilization rate (2 °C/min) and carbonization rate (5 °C/min). The carbon nanofibers (CNFs) produced were characterized using Scanning Electron Microscopy (SEM), Brunauer Emmett and Teller (BET) surface area and Fourier Transmission Infrared Spectroscopy (FTIR). It was found that the PAN/MnO2 CNFs were successfully produced with the carbonization temperature of 800 °C. The prepared PAN/MnO2 CNFs prepared showed an enhanced in specific surface area about two times compared to it precursor NFs.

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

PubMed

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

2018-06-20

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

Carbon dioxide elimination and regeneration of resources in a microwave plasma torch.

PubMed

Uhm, Han S; Kwak, Hyoung S; Hong, Yong C

2016-04-01

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 CO2 + 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discussion of Refrigeration Cycle Using Carbon Dioxide as Refrigerant

NASA Astrophysics Data System (ADS)

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

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

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

DOEpatents

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

2004-06-08

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

Efficient Hydrogen-Dependent Carbon Dioxide Reduction by Escherichia coli.

PubMed

Roger, Magali; Brown, Fraser; Gabrielli, William; Sargent, Frank

2018-01-08

Hydrogen-dependent reduction of carbon dioxide to formic acid offers a promising route to greenhouse gas sequestration, carbon abatement technologies, hydrogen transport and storage, and the sustainable generation of renewable chemical feedstocks [1]. The most common approach to performing direct hydrogenation of CO 2 to formate is to use chemical catalysts in homogeneous or heterogeneous reactions [2]. An alternative approach is to use the ability of living organisms to perform this reaction biologically. However, although CO 2 fixation pathways are widely distributed in nature, only a few enzymes have been described that have the ability to perform the direct hydrogenation of CO 2 [3-5]. The formate hydrogenlyase (FHL) enzyme from Escherichia coli normally oxidizes formic acid to carbon dioxide and couples that reaction directly to the reduction of protons to molecular hydrogen [6]. In this work, the reverse reaction of FHL is unlocked. It is established that FHL can operate as a highly efficient hydrogen-dependent carbon dioxide reductase when gaseous CO 2 and H 2 are placed under pressure (up to 10 bar). Using intact whole cells, the pressurized system was observed to rapidly convert 100% of gaseous CO 2 to formic acid, and >500 mM formate was observed to accumulate in solution. Harnessing the reverse reaction has the potential to allow the versatile E. coli system to be employed as an exciting new carbon capture technology or as a cell factory dedicated to formic acid production, which is a commodity in itself as well as a feedstock for the synthesis of other valued chemicals. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Do fossil plants signal palaeoatmospheric carbon dioxide concentration in the geological past?

PubMed Central

McElwain, J. C.

1998-01-01

Fossil, subfossil, and herbarium leaves have been shown to provide a morphological signal of the atmospheric carbon dioxide environment in which they developed by means of their stomatal density and index. An inverse relationship between stomatal density/index and atmospheric carbon dioxide concentration has been documented for all the studies to date concerning fossil and subfossil material. Furthermore, this relationship has been demonstrated experimentally by growing plants under elevated and reducedcarbon dioxide concentrations. To date, the mechanism that controls the stomatal density response to atmospheric carbon dioxide concentration remains unknown. However, stomatal parameters of fossil plants have been successfully used as a proxy indicator of palaeo-carbon dioxide levels. This paper presents new estimates of palaeo-atmospheric carbon dioxide concentrations for the Middle Eocene (Lutetian), based on the stomatal ratios of fossil Lauraceae species from Bournemouth in England. Estimates of atmospheric carbon dioxide concentrations derived from stomatal data from plants of the Early Devonian, Late Carboniferous, Early Permian and Middle Jurassic ages are reviewed in the light of new data. Semi-quantitative palaeo-carbon dioxide estimates based on the stomatal ratio (a ratio of the stomatal index of a fossil plant to that of a selected nearest living equivalent) have in the past relied on the use of a Carboniferous standard. The application of a new standard based on the present-day carbon dioxide level is reported here for comparison. The resultant ranges of palaeo-carbon dioxide estimates made from standardized fossil stomatal ratio data are in good agreement with both carbon isotopic data from terrestrial and marine sources and long-term carbon cycle modelling estimates for all the time periods studied. These data indicate elevated atmospheric carbon dioxide concentrations during the Early Devonian, Middle Jurassic and Middle Eocene, and reduced concentrations during the Late Carboniferous and Early Permian. Such data are important in demonstrating the long-term responses of plants to changing carbon dioxide concentrations and in contributing to the database needed for general circulation model climatic analogues.

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive... relative changes in a hemodynamically stable patient's cutaneous carbon dioxide tension as an adjunct to...

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868... dioxide (PcCO 2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive... relative changes in a hemodynamically stable patient's cutaneous carbon dioxide tension as an adjunct to...

40 CFR 60.1230 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

... systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I... sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the outlet of the air pollution... according to the “Monitoring Requirements” in § 60.13. (c) You must monitor the oxygen (or carbon dioxide...

40 CFR 60.1230 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

... systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I... sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the outlet of the air pollution... according to the “Monitoring Requirements” in § 60.13. (c) You must monitor the oxygen (or carbon dioxide...

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

PubMed

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

2015-12-17

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

Carbon Dioxide Removal via Passive Thermal Approaches

NASA Technical Reports Server (NTRS)

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

2011-01-01

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

Triple-Pulse Integrated Path Differential Absorption Lidar for Carbon Dioxide Measurement - Novel Lidar Technologies and Techniques with Path to Space

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Refaat, Tamer F.; Petros, Mulugeta

2017-01-01

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

Methods and systems for utilizing carbide lime or slag

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

Devenney, Martin; Fernandez, Miguel; Chen, Irvin

Provided herein are methods comprising a) treating a slag solid or carbide lime suspension with an ammonium salt in water to produce an aqueous solution comprising calcium salt, ammonium salt, and solids; b) contacting the aqueous solution with carbon dioxide from an industrial process under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the precipitation material and the supernatant aqueous solution comprise residual ammonium salt; and c) removing and optionally recovering ammonia and/or ammonium salt using one or more steps of (i) recovering a gas exhaust stream comprising ammoniamore » during the treating and/or the contacting step; (ii) recovering the residual ammonium salt from the supernatant aqueous solution; and (iii) removing and optionally recovering the residual ammonium salt from the precipitation material.« less

Aqueous photolysis of niclosamide

USGS Publications Warehouse

Graebing, P.W.; Chib, J.S.; Hubert, T.D.; Gingerich, W.H.

2004-01-01

The photodegradation of [14C]niclosamide was studied in sterile, pH 5, 7, and 9 buffered aqueous solutions under artificial sunlight at 25.0 A? 1.0 A?C. Photolysis in pH 5 buffer is 4.3 times faster than in pH 9 buffer and 1.5 times faster than in pH 7 buffer. In the dark controls, niclosamide degraded only in the pH 5 buffer. After 360 h of continuous irradiation in pH 9 buffer, the chromatographic pattern of the degradates was the same regardless of which ring contained the radiolabel. An HPLC method was developed that confirmed these degradates to be carbon dioxide and two- and four-carbon aliphatic acids formed by cleavage of both aromatic rings. Carbon dioxide was the major degradate, comprising 40% of the initial radioactivity in the 360 h samples from both labels. The other degradates formed were oxalic acid, maleic acid, glyoxylic acid, and glyoxal. In addition, in the chloronitroaniline-labeled irradiated test solution, 2-chloro-4-nitroaniline was observed and identified after 48 h of irradiation but was not detected thereafter. No other aromatic compounds were isolated or observed in either labeled test system.

Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone

USGS Publications Warehouse

Lahvis, Matthew A.; Baehr, Arthur L.

1996-01-01

The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 g yr−1 (11.7 gal. yr−1) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 g m−2 yr−1(1.45 × 10−3 and 1.51 × 10−3 gal. ft.−2yr−1) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization.

Membrane Separation Processes at Low Temperatures

NASA Technical Reports Server (NTRS)

Parrish, Clyde

2002-01-01

The primary focus of Kennedy Space Center's gas separation activities has been for carbon dioxide, nitrogen, and argon used in oxygen production technologies for Martian in-situ resource utilization (ISRU) projects. Recently, these studies were expanded to include oxygen for regenerative life support systems. Since commercial membrane systems have been developed for separation of carbon dioxide, nitrogen, and oxygen, initially the studies focused on these membrane systems, but at lower operating temperatures and pressures. Current investigations art examining immobilized liquids and solid sorbents that have the potential for higher selectivity and lower operating temperatures. The gas separation studies reported here use hollow fiber membranes to separate carbon dioxide, nitrogen, and argon in the temperature range from 230 to 300 K. Four commercial membrane materials were used to obtain data at low feed and permeate pressures. These data were used with a commercial solution-diffusion modeling tool to design a system to prepare a buffer gas from the byproduct of a process to capture Martian carbon dioxide. The system was designed to operate, at 230 K with a production rate 0.1 sLpm; Feed composition 30% CO2, 44% N2, and 26% Ar; Feed pressure 104 kPa (780); and Permeate pressure 1 kPa (6 torr); Product concentration 600 ppm CO2. This new system was compared with a similar system designed to operate at ambient temperatures (298 K). The systems described above, along with data, test apparatus, and models are presented.

Rheology and physical-chemical characteristics of the solutions of the medicines

NASA Astrophysics Data System (ADS)

Urakov, A.; Urakova, N.

2015-04-01

In the laboratory studied the dynamics of rheology of water solutions with plasma- inflammatory and antiseptic funds when mixing them with blood, plasma and pus under the influence of the following physical and chemical factors of local interaction: gravity, specific gravity, temperature, relative viscosity, internal pressure, sparkling water, total concentration of the ingredients, surface activity, volume of acid and osmotic activity of medicines. Found that the rheology of biological liquids improve hyperthermic, highly alkaline and highly carbonated solution medicines. For the dilution of pus, dense festering mass of sulfur plugs and tear stones invited to apply heated to +39 - +42°C with aqueous solution of 0.5 - 3% hydrogen peroxide and 0.5 - 10% sodium bicarbonate saturated with carbon dioxide to excess pressure 0.2 ATM.

Influence of drinking water treatments on chlorine dioxide consumption and chlorite/chlorate formation.

PubMed

Sorlini, Sabrina; Gialdini, Francesca; Biasibetti, Michela; Collivignarelli, Carlo

2014-05-01

Disinfection is the last treatment stage of a Drinking Water Treatment Plant (DWTP) and is carried out to maintain a residual concentration of disinfectant in the water distribution system. Chlorine dioxide (ClO2) is a widely used chemical employed for this purpose. The aim of this work was to evaluate the influence of several treatments on chlorine dioxide consumption and on chlorite and chlorate formation in the final oxidation/disinfection stage. A number of tests was performed at laboratory scale employing water samples collected from the DWTP of Cremona (Italy). The following processes were studied: oxidation with potassium permanganate, chlorine dioxide and sodium hypochlorite, coagulation/flocculation with ferric chloride and aluminum sulfate, filtration and adsorption onto activated carbon. The results showed that the chlorine dioxide demand is high if sodium hypochlorite or potassium permanganate are employed in pre-oxidation. On the other hand, chlorine dioxide leads to the highest production of chlorite and chlorate. The coagulation/flocculation process after pre-oxidation shows that chlorine dioxide demand decreases if potassium permanganate is employed as an oxidant, both with ferric chloride and aluminum sulfate. Therefore, the combination of these processes leads to a lower production of chlorite and chlorate. Aluminum sulfate is preferable in terms of the chlorine dioxide demand reduction and minimization of the chlorite and chlorate formation. Activated carbon is the most effective solution as it reduced the chlorine dioxide consumption by about 50% and the DBP formation by about 20-40%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Overhead Projector Demonstrations: Some Ideas from the Past.

ERIC Educational Resources Information Center

Kolb, Doris

1987-01-01

Describes nine chemistry demonstrations that can be done using an overhead projector. Includes demonstrations on common ion effect, crystal formation from supersaturated solutions, making iron positive with nitric acid, optical activity, carbon dioxide in human breath, amphoteric hydroxides, the surface tension of mercury, and natural acid-base…

Technique for Simultaneous Determination of [35S]Sulfide and [14C]Carbon Dioxide in Anaerobic Aqueous Samples †

PubMed Central

Taylor, Craig D.; Ljungdahl, Per O.; Molongoski, John J.

1981-01-01

A technique for the simultaneous determination of [35S]sulfide and [14C]carbon dioxide produced in anaerobic aqueous samples dual-labeled with [35S]sulfate and a 14C-organic substrate is described. The method involves the passive distillation of sulfide and carbon dioxide from an acidified water sample and their subsequent separation by selective chemical absorption. The recovery of sulfide was 93% for amounts ranging from 0.35 to 50 μmol; recovery of carbon dioxide was 99% in amounts up to 20 μmol. Within these delineated ranges of total sulfide and carbon dioxide, 1 nmol of [35S]sulfide and 7.5 nmol of [14C]carbon dioxide were separated and quantified. Correction factors were formulated for low levels of radioisotopic cross-contamination by sulfide, carbon dioxide, and volatile organic acids. The overall standard error of the method was ±4% for sulfide and ±6% for carbon dioxide. PMID:16345742

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

PubMed

Walker, J C; Kasting, J F

1992-01-01

We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the formulation of the rock cycle and to the dissolution of deep sea carbonate sediments. Atmospheric carbon dioxide continues to increase as long fossil fuel is burned at a significant rate, because the rate of fossil fuel production of carbon dioxide far exceeds the rates at which geochemical processes can remove carbon dioxide from the atmosphere. The maximum concentration of carbon dioxide achieved in the atmosphere depends on the total amount of fossil fuel burned, but only weakly on the rate of burning. The future course of atmospheric carbon dioxide is, however, very sensitive to the fate of the forests in this simulation because of the important role assigned to carbon dioxide fertilization of plant growth rate. Forest clearance drives up atmospheric carbon dioxide not only by converting biomass into atmospheric carbon dioxide but more importantly by reducing the capacity of the biota to sequester fossil fuel carbon dioxide. In this simulation, atmospheric carbon dioxide levels could be sustained indefinitely below 500 parts per million (ppm) if fossil fuel combustion rates were immediately cut from their present value of 5 x 10(14) m/y to 0.2 x 10(14) m/y (a factor of 25 reduction) and if further forest clearance were halted. If neither of these conditions is met and if we consume most of the world's fossil fuel reserves, peak carbon dioxide concentrations of 1000-2000 ppm are probable within the next few centuries.

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

21 CFR 184.1240 - Carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

An integrated experimental and first-principles computational study of carbon dioxide mineral carbonation reactions in olivine and serpentine

NASA Astrophysics Data System (ADS)

Gormley, Deirdre Marie

This dissertation is a unique integration of experimental and theoretical methods. The central issue that is being addressed is to find a long term and economically viable solution to the disposal of carbon dioxide gas from coal power plants. Mineral carbonation reactions have emerged as a permanent solution to the well-known "Greenhouse Gas" issue. Our group here at ASU along with groups at Los Alamos National Laboratory (LANL), National Energy Technology Laboratory (NETL), Pennsylvania State in Utah (SAIC), and the Albany Research Center (ARC) comprise the working group managed by the US Department of Energy (DOE). We have been collaborating to develop a fundamental understanding of the carbonation reactions of candidate minerals which will ultimately be used to develop a pilot plant process. Two of the candidate minerals used in mineral sequestration processes are forsterite (olivine) and lizardite (serpentine). Both candidates require pre-treatment prior to reaction with carbon dioxide. Forsterite requires attrition (grinding), while lizardite requires a pre-heat treatment (dehydroxylation) step which removes chemically bound water. In Chapter 3 of this thesis, the thermodynamic properties of seven primary oxides involved in reactions with forsterite and lizardite are compared. A novel method was developed using a theoretical molecular quantum physics approach which reproduced experimental results with great accuracy. This method can now be used for other systems where experimental thermodynamic data is unavailable. In Chapters 4 and 5, the dehydroxylation mechanism for lizardite is studied using theoretical models in conjunction with experimental results. A possible mechanism for the dehydroxylation pathway is suggested. This long-awaited result may provide new insight regarding carbonation reactions in lizardite. Chapters 6 and 7 explore the carbonation reactions in forsterite. With the help of high resolution electron microscopy images and extremely large, 10,000 atom models, we have gained new understanding of the reaction layer on the surface of the forsterite crystal. Several computer codes were tested for calculations of electron energy loss near edge spectra, as comparison with experimental electron energy loss spectra, and a reliable strategy for calculation has been suggested. The electron energy loss results have enhanced our knowledge of the forsterite reaction layer.

U.S. Energy-Related Carbon Dioxide Emissions

EIA Publications

2017-01-01

U.S. Energy Information Administration releases its online analysis of 2016 energy-related carbon dioxide emissions today. It indicates U.S. carbon dioxide emissions from the consumption of fossil fuels were 5,170 million metric tons carbon dioxide in 2016, a decrease of 1.7 percent from the 2015 level. Energy-related carbon dioxide emissions have declined in six of the last ten years. This analysis is based on data contained in the August 2017 Monthly Energy Review.

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

PubMed Central

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

2015-01-01

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

Environmental Assessment for Anti-Terrorism/Force Protection Upgrades at Beale Air Force Base, California

DTIC Science & Technology

2004-04-01

triple-awn grass, annual fescues, and foxtail barley . Intermixed with these dominant grasses are an assemblage of native and non-native forb species...as a wheat- stem rust (fungal disease) biological production test site. Chemicals associated with the wheat- stem rust program included freon, carbon...Carboxide treatment (using a solution of 10 percent ethylene oxide and 90 percent carbon dioxide) was used to destroy the rust fungus stocks. Residual

Diffusive counter dispersion of mass in bubbly media.

PubMed

Goldobin, Denis S; Brilliantov, Nikolai V

2011-11-01

We consider a liquid bearing gas bubbles in a porous medium. When gas bubbles are immovably trapped in a porous matrix by surface-tension forces, the dominant mechanism of transfer of gas mass becomes the diffusion of gas molecules through the liquid. Essentially, the gas solution is in local thermodynamic equilibrium with vapor phase all over the system, i.e., the solute concentration equals the solubility. When temperature and/or pressure gradients are applied, diffusion fluxes appear and these fluxes are faithfully determined by the temperature and pressure fields, not by the local solute concentration, which is enslaved by the former. We derive the equations governing such systems, accounting for thermodiffusion and gravitational segregation effects, which are shown not to be neglected for geological systems-marine sediments, terrestrial aquifers, etc. The results are applied for the treatment of non-high-pressure systems and real geological systems bearing methane or carbon dioxide, where we find a potential possibility of the formation of gaseous horizons deep below a porous medium surface. The reported effects are of particular importance for natural methane hydrate deposits and the problem of burial of industrial production of carbon dioxide in deep aquifers.

Enrichment and Purification of Casein Glycomacropeptide from Whey Protein Isolate Using Supercritical Carbon Dioxide Processing and Membrane Ultrafiltration

PubMed Central

Bonnaillie, Laetitia M.; Qi, Phoebe; Wickham, Edward; Tomasula, Peggy M.

2014-01-01

Whey protein concentrates (WPC) and isolates (WPI), comprised mainly of β-lactoglobulin (β-LG), α-lactalbumin (α-LA) and casein glycomacropeptide (GMP), are added to foods to boost nutritional and functional properties. Supercritical carbon dioxide (SCO2) has been shown to effectively fractionate WPC and WPI to obtain enriched fractions of α-LA and β-LG, thus creating new whey ingredients that exploit the properties of the individual component proteins. In this study, we used SCO2 to further fractionate WPI via acid precipitation of α-LA, β-LG and the minor whey proteins to obtain GMP-enriched solutions. The process was optimized and α-LA precipitation maximized at low pH and a temperature (T) ≥65 °C, where β-LG with 84% purity and GMP with 58% purity were obtained, after ultrafiltration and diafiltration to separate β-LG from the GMP solution. At 70 °C, β-LG also precipitated with α-LA, leaving a GMP-rich solution with up to 94% purity after ultrafiltration. The different protein fractions produced with the SCO2 process will permit the design of new foods and beverages to target specific nutritional needs. PMID:28234306

Electrochemical oxidation of wine polyphenols in the presence of sulfur dioxide.

PubMed

Makhotkina, Olga; Kilmartin, Paul A

2013-06-12

Electrochemical oxidation of three representative wine polyphenols (catechin, caffeic acid, and quercetin) in the presence of sulfur dioxide in a model wine solution (pH = 3.3) was investigated. The oxidation was undertaken using chronoamperometry at a rotating glassy carbon rod electrode, and the reaction products were characterized by HPLC-MS. The mechanism of electrochemical oxidation of polyphenols in the presence of sulfur dioxide was proposed to be an ECEC mechanism. The polyphenols first underwent a one-electron oxidation to a semiquinone radical, which can be reduced back to the original polyphenol by sulfur dioxide, or further oxidized to the quinone form. In the cases of caffeic acid and catechin, the quinone combined with sulfur dioxide and produced new derivatives. The quercetin quinone underwent further chemical transformations, producing several new compounds. The proposed mechanisms were confirmed by digital simulation of cyclic voltammograms.

New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

PubMed

Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

2015-12-01

The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bubble nucleation in stout beers

NASA Astrophysics Data System (ADS)

Lee, W. T.; McKechnie, J. S.; Devereux, M. G.

2011-05-01

Bubble nucleation in weakly supersaturated solutions of carbon dioxide—such as champagne, sparkling wines, and carbonated beers—is well understood. Bubbles grow and detach from nucleation sites: gas pockets trapped within hollow cellulose fibers. This mechanism appears not to be active in stout beers that are supersaturated solutions of nitrogen and carbon dioxide. In their canned forms these beers require additional technology (widgets) to release the bubbles which will form the head of the beer. We extend the mathematical model of bubble nucleation in carbonated liquids to the case of two gases and show that this nucleation mechanism is active in stout beers, though substantially slower than in carbonated beers and confirm this by observation. A rough calculation suggests that despite the slowness of the process, applying a coating of hollow porous fibers to the inside of a can or bottle could be a potential replacement for widgets.

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

NASA Technical Reports Server (NTRS)

Hagedorn, Norman H. (Inventor)

1993-01-01

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

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

40 CFR 86.524-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

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

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

46 CFR 95.15-60 - Odorizing units.

Code of Federal Regulations, 2012 CFR

2012-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

46 CFR 193.15-17 - Odorizing units.

Code of Federal Regulations, 2014 CFR

2014-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-17 Odorizing units. Each carbon dioxide extinguishing system installed or altered after July 9, 2013, must have an approved... carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may...

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

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

46 CFR 193.15-17 - Odorizing units.

Code of Federal Regulations, 2013 CFR

2013-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-17 Odorizing units. Each carbon dioxide extinguishing system installed or altered after July 9, 2013, must have an approved... carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may...

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

46 CFR 76.15-60 - Odorizing units.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-60 Odorizing units. Each carbon dioxide... the scent of wintergreen, the detection of which will serve as an indication that carbon dioxide gas is present in a protected area and any other area into which the carbon dioxide may migrate. “Altered...

40 CFR 86.124-78 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

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

21 CFR 884.1300 - Uterotubal carbon dioxide insufflator and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Uterotubal carbon dioxide insufflator and... Gynecological Diagnostic Devices § 884.1300 Uterotubal carbon dioxide insufflator and accessories. (a) Identification. A uterotubal carbon dioxide insufflator and accessories is a device used to test the patency...

27 CFR 24.319 - Carbon dioxide record.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., 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... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Carbon dioxide record. 24...

21 CFR 582.1240 - Carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a...

46 CFR 76.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide storage. 76.15-20 Section 76.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-20 Carbon dioxide storage. (a) Except as...

Remediation of Contaminated Soils By Supercritical Carbon Dioxide Extraction

NASA Astrophysics Data System (ADS)

Ferri, A.; Zanetti, M. C.; Banchero, M.; Fiore, S.; Manna, L.

The contaminants that can be found in soils are many, inorganic, like heavy metals, as well as organic. Among the organic contaminants, oil and coal refineries are responsi- ble for several cases of soil contamination with PAHs (Polycyclic Aromatic Hydrocar- bons). Polynuclear aromatic hydrocarbons (PAHs) have toxic, carcinogenic and mu- tagenic effects. Limits have been set on the concentration of most contaminants, and growing concern is focusing on soil contamination issues. USA regulations set the maximum acceptable level of contamination by PAHs equal to 40 ppm at residential sites and 270 ppm at industrial sites. Stricter values are usually adopted in European Countries. Supercritical carbon dioxide extraction is a possible alternative technology to remove volatile organic compounds from contaminated soils. Supercritical fluid extraction (SFE) offers many advantages over conventional solvent extraction. Super- critical fluids combine gaseous properties as a high diffusion coefficient, and liquid properties as a high solvent power. The solvent power is strongly pressure-dependent near supercritical conditions: selective extractions are possible without changing the solvent. Solute can be separate from the solvent depressurising the system; therefore, it is possible to recycle the solvent and recover the contaminant. Carbon dioxide is frequently used as supercritical fluid, because it has moderate critical conditions, it is inert and available in pure form. In this work, supercritical fluid extraction technology has been used to remove a polynuclear aromatic hydrocarbon from contaminated soils. The contaminant choice for the experiment has been naphthalene since several data are available in literature. G. A. Montero et al. [1] studied soil remediation with supercrit- ical carbon dioxide extraction technology; these Authors have found that there was a mass-transfer limitation. In the extraction vessel, the mass transfer coefficient in- creases with the superficial velocity of the supercritical carbon dioxide; therefore, the mass transfer resistance can be reduced increasing such velocity. In this work, higher values of superficial velocity were investigated. The experimental apparatus includes a pump, an extraction vessel, an adjustable restrictor and a trap to collect the extracted substance. Liquid carbon dioxide coming from a cylinder with a dip-tube is cooled by a cryostatic bath and then it is compressed by a pneumatic drive pump (the max- imum available pressure is 69 MPa). Subsequently, the pressurised current flows into 1 a heating coil and then into the extraction vessel, which is contained in a stove; the outlet flow is depressurised in an adjustable restrictor and the extracted substance is collected in a trap by dissolution into a solvent. The extracted naphthalene quantity was obtained by weighting the solvent and measuring the naphthalene concentration with a gas chromatograph. The soil sample is a sandy soil geologically representative of the North of Italy that was sampled and physically and chemically characterized: particle-size distribution analysis, diffractometric analysis, Cation Exchange Capac- ity, Total Organic Carbon, iron content and manganese content in order to evaluate the potential sorption degree. The soil was artificially polluted by means of a naphta- lene and methylene chloride solution. The experimental work consists in a number of naphthalene extractions from the spiked soil, that were carried out at different operat- ing conditions, temperature, pressure and flow rate by means of supercritical carbon dioxide evaluating the corresponding recovery efficiencies. The results obtained were analysed and compared in order to determine which parameters influence the system. [1] G. A. Montero, T.D. Giorgio, and K. B. Schnelle, Jr..Removal of Hazardous ,1994, Contaminants form Soils by Supercritical Fluid Extraction. Innovations in Supercriti- cal Fluids. ACS Symposium Series, 608, 280-197. 2

Precipitation characteristics of uranyl ions at different pHs depending on the presence of carbonate ions and hydrogen peroxide.

PubMed

Kim, Kwang-Wook; Kim, Yeon-Hwa; Lee, Se-yoon; Lee, Jae-Won; Joe, Kih-Soo; Lee, Eil-Hee; Kim, Jong-Seung; Song, Kyuseok; Song, Kee-Chan

2009-04-01

This work studied the dissolution of uranium dioxide and precipitation characteristics of uranyl ions in alkaline and acidic solutions depending on the presence of carbonate ions and H2O2 in the solutions at different pHs controlled by adding HNO3 or NaOH in the solution. The chemical structures of the precipitates generated in different conditions were evaluated and compared by using XRD, SEM, TG-DT, and IR analyses together. The sizes and forms of the precipitates in the solutions were evaluated, as well. The uranyl ions were precipitated in the various forms, depending on the solution pH and the presences of hydrogen peroxide and carbonate ions in the solution. In a 0.5 M Na2CO3 solution with H2O2, where the uranyl ions formed mixed uranyl peroxy-carbonato complexes, the uranyl ions were precipitated as a uranium peroxide of UO4(H20)4 at pH 3-4, and precipitated as a clarkeite of Na2U2Ox(OH)y(H2O)z above pH 13. In the same carbonate solution without H2O2, where the uranyl ions formed uranyl tris-carbonato complex, the uranyl ions were observed to be precipitated as a different form of clarkeite above pH 13. The precipitate of uranyl ions in a nitrate solution without carbonate ions and H2O2 at a high pH were studied together to compare the precipitate forms in the carbonate solutions.

Transition Organometallic Heterobimettalic Microns-Carbon Dioxide and Microns-Format Complexes in Homogeneous Carbon Dioxide Fixation

DTIC Science & Technology

1992-08-12

AD-A254 538 OFFICE OF NAVAL RESEARCH FINAL REPORT FCR Contract N00014-87-K-0465 R&T Code 413j006 "Transition Organometallic Heterobimetallic ix...ransition Organometallic Heterobimetallic P-Carbon Dioxide and p-FormateComplexes in Homogeneous Carbon Dioxide Fixation 12. PERSONAL AUTHOR(S) Alan R...J. L. Shibley, and A. R. Cutler, J. Organomet. Chem. 1989,378, 421.* "Characterization of the Heterobimetallic ±(r011-C: T12 -O,O’) Carbon Dioxide

Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

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

Ho, C.S.; Smith, M.D.

The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

Supercritical carbon dioxide fractionation of whey protein isolate for new food-grade ingredients

USDA-ARS?s Scientific Manuscript database

A new, environmentally benign whey protein fractionation process was developed using supercritical CO2 (SCO2) as an acid aggregating agent to separate a-lactalbumin (a-LA) aggregates from soluble beta-lactoglobulin (beta-LG) protein in concentrated whey protein isolate (WPI) solutions. The process e...

ABSORPTION OF CO2 AND SUBSEQUENT VISCOSITY REDUCTION OF AN ACRYLONITRILE COPOLYMER. (R829555)

EPA Science Inventory

Acrylonitrile (AN) copolymers (AN content greater than about 85 mol%) are traditionally solution processed to avoid a cyclization and crosslinking reaction that takes place at temperatures where melt processing would be feasible. It is well known that carbon dioxide (CO

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

USGS Publications Warehouse

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

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

Ion-Selective Deposition of Manganese Sulphate Solution from Trenggalek Manganese Ore by Active Carbon and Sodium Hydroxide

NASA Astrophysics Data System (ADS)

Andriyah, L.; Sulistiyono, E.

2017-02-01

One of the step in manganese dioxide manufacturing process for battery industry is a purification process of lithium manganese sulphate solution. The elimination of impurities such as iron removal is important in hydrometallurgical processes. Therefore, this paper present the purification results of manganese sulphate solution by removing impurities using a selective deposition method, namely activated carbon adsorption and NaOH. The experimental results showed that the optimum condition of adsorption process occurs on the addition of 5 g adsorbent and the addition of 10 ml NaOH 1 N, processing time of 30 minutes and the best is the activated carbon adsorption of Japan. Because the absolute requirement of the cathode material of lithium ion manganese are free of titanium then of local wood charcoal is good enough in terms of eliminating ions Ti is equal to 70.88%.

A strategic decision-making model considering the social costs of carbon dioxide emissions for sustainable supply chain management.

PubMed

Tseng, Shih-Chang; Hung, Shiu-Wan

2014-01-15

Incorporating sustainability into supply chain management has become a critical issue driven by pressures from governments, customers, and various stakeholder groups over the past decade. This study proposes a strategic decision-making model considering both the operational costs and social costs caused by the carbon dioxide emissions from operating such a supply chain network for sustainable supply chain management. This model was used to evaluate carbon dioxide emissions and operational costs under different scenarios in an apparel manufacturing supply chain network. The results showed that the higher the social cost rate of carbon dioxide emissions, the lower the amount of the emission of carbon dioxide. The results also suggested that a legislation that forces the enterprises to bear the social costs of carbon dioxide emissions resulting from their economic activities is an effective approach to reducing carbon dioxide emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Semiconductor-Based Photoelectrochemical Conversion of Carbon Dioxide: Stepping Towards Artificial Photosynthesis.

PubMed

Pang, Hong; Masuda, Takuya; Ye, Jinhua

2018-01-18

The photoelectrochemical (PEC) carbon dioxide reduction process stands out as a promising avenue for the conversion of solar energy into chemical feedstocks, among various methods available for carbon dioxide mitigation. Semiconductors derived from cheap and abundant elements are interesting candidates for catalysis. Whether employed as intrinsic semiconductors or hybridized with metallic cocatalysts, biocatalysts, and metal molecular complexes, semiconductor photocathodes exhibit good performance and low overpotential during carbon dioxide reduction. Apart from focusing on carbon dioxide reduction materials and chemistry, PEC cells towards standalone devices that use photohybrid electrodes or solar cells have also been a hot topic in recent research. An overview of the state-of-the-art progress in PEC carbon dioxide reduction is presented and a deep understanding of the catalysts of carbon dioxide reduction is also given. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of carbon dioxide on Penicillium chrysogenum: an autoradiographic study

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

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

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 ofmore » 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.« less

The Formation of Ethane from Carbon Dioxide under Cold Plasma

NASA Astrophysics Data System (ADS)

Zhang, Xiu-ling; Zhang, Lin; Dai, Bin; Gong, Wei-min; Liu, Chang-hou

2001-04-01

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 in this paper. 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 increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase 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.

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2) monitor is a noninvasive heated...

40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Carbon dioxide; exemption from the... Exemptions From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the requirement of a tolerance when used after harvest in modified...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2010 CFR

2010-04-01

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

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

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

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

40 CFR 180.1049 - Carbon dioxide; exemption from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Carbon dioxide; exemption from the... Exemptions From Tolerances § 180.1049 Carbon dioxide; exemption from the requirement of a tolerance. The insecticide carbon dioxide is exempted from the requirement of a tolerance when used after harvest in modified...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Carbon dioxide and certain other gases. 201.161... (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene, helium, and nitrous oxide gases intended for drug use are...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2014 CFR

2014-04-01

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

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

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

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

21 CFR 868.1150 - Indwelling blood carbon dioxide partial pressure (PCO2) analyzer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Indwelling blood carbon dioxide partial pressure....1150 Indwelling blood carbon dioxide partial pressure (PCO2) analyzer. (a) Identification. An indwelling blood carbon dioxide partial pressure PCO2 analyzer is a device that consists of a catheter-tip...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

21 CFR 868.1400 - Carbon dioxide gas analyzer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide gas analyzer. 868.1400 Section 868.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1400 Carbon dioxide gas analyzer. (a) Identification. A carbon dioxide gas analyzer...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a) Except as provided in...

46 CFR 108.627 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 108.431 - Carbon dioxide systems: General.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide systems: General. 108.431 Section 108.431 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.431 Carbon dioxide systems: General. (a)...

46 CFR 169.565 - Fixed carbon dioxide system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.565 Fixed carbon dioxide system. (a) The number of pounds of carbon dioxide...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

21 CFR 868.5300 - Carbon dioxide absorbent.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon dioxide absorbent. 868.5300 Section 868.5300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5300 Carbon dioxide absorbent. (a) Identification. A carbon dioxide absorbent is a...

21 CFR 868.5310 - Carbon dioxide absorber.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon dioxide absorber. 868.5310 Section 868.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5310 Carbon dioxide absorber. (a) Identification. A carbon dioxide absorber is a devic...

27 CFR 26.222 - Still wines containing carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

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

Process for sequestering carbon dioxide and sulfur dioxide

DOEpatents

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.

Effect of Carbon Dioxide on Testing of Susceptibilities of Respiratory Tract Pathogens to Macrolide and Azalide Antimicrobial Agents

PubMed Central

Johnson, M. M.; Hill, S. L.; Piddock, Laura J. V.

1999-01-01

The in vitro activities of erythromycin, azithromycin, and clarithromycin against 178 clinical isolates from the lower respiratory tract of patients with chronic obstructive pulmonary disease were determined by an agar dilution method. The plates were incubated in air alone or in 5% carbon dioxide. The MICs measured in air alone were lower for most isolates than those measured in 5% carbon dioxide, illustrating the “pH effect” of incubation in carbon dioxide. Testing of isolates in 5% carbon dioxide on pH-adjusted medium (pH 8.4) resulted in MICs of one or two doubling dilutions lower than those obtained on agar with a neutral pH. A bioassay of the three agents incubated in air and in 5% carbon dioxide resulted in a significant loss of activity of all three agents in the carbon dioxide-enriched atmosphere. However, this loss-of-activity effect was significantly reduced when the bioassay medium was adjusted to pH 8.4 prior to incubation in 5% carbon dioxide. PMID:10428903

Elevated atmospheric carbon dioxide concentration affects interactions between Spodoptera exigua (Lepidoptera: Noctuidae) larvae and two host plant species outdoors

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

Caulfield, F.; Bunce, J.A.

1994-08-01

Beet armyworm, Spodoptera exigua (Huebner), larvae were placed on sugarbeet (Beta vulgaris L.) and pigweed (Amaranthus hybridus L.) plants in outdoor chambers in which the plants were growing at either the ambient ([approximately] 350 [mu]l liter[sup [minus]1]) or ambient plus 350 [mu]l liter[sup [minus]1] ([approximately] 700 [mu]l liter[sup [minus]1]) carbon dioxide concentration. A series of experiments was performed to determine if larvae reduced plant growth differently at the two carbon dioxide concentrations in either species and if the insect growth or survival differed with carbon dioxide concentration. Leaf nitrogen, water, starch, and soluble carbohydrate contents were measured to assess carbonmore » dioxide concentration effects on leaf quality. Insect feeding significantly reduced plant growth in sugarbeet plants at 350 [mu]l liter[sup [minus]1] but not at 700 [mu]l liter[sup [minus]1] nor in pigweed at either carbon dioxide concentration. Larval survival was greater on sugarbeet plants at the elevated carbon dioxide concentration. Increased survival occurred only if the insects were at the elevated carbon dioxide concentration and consumed leaf material grown at the elevated concentration. Leaf quality was only marginally affected by growth at elevated carbon dioxide concentration in these experiments. The results indicate that in designing experiments to predict effects of elevated atmospheric carbon dioxide concentrations on plant-insect interactions, both plants and insects should be exposed to the experimental carbon dioxide concentrations, as well as to as realistic environmental conditions as possible.« less

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

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon...

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

PubMed Central

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

Improvement of Carbon Dioxide Sweep Efficiency by Utilization of Microbial Permeability Profile Modification to Reduce the Amount of Oil Bypassed During Carbon Dioxide Flood

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

Schmitz, Darrel; Brown, Lewis; Lynch, F. Leo

2010-12-31

The objective of this project was to couple microbial permeability profile modification (MPPM), with carbon dioxide flooding to improve oil recovery from the Upper Cretaceous Little Creek Oil Field situated in Lincoln and Pike counties, MS. This study determined that MPPM technology, which improves production by utilizing environmentally friendly nutrient solutions to simulate the growth of the indigenous microflora in the most permeable zones of the reservoir thus diverting production to less permeable, previously unswept zones, increased oil production without interfering with the carbon dioxide flooding operation. Laboratory tests determined that no microorganisms were produced in formation waters, but weremore » present in cores. Perhaps the single most significant contribution of this study is the demonstration that microorganisms are active at a formation temperature of 115°C (239°F) by using a specially designed culturing device. Laboratory tests were employed to simulate the MPPM process by demonstrating that microorganisms could be activated with the resulting production of oil in coreflood tests performed in the presence of carbon dioxide at 66°C (the highest temperature that could be employed in the coreflood facility). Geological assessment determined significant heterogeneity in the Eutaw Formation, and documented relatively thin, variably-lithified, well-laminated sandstone interbedded with heavily-bioturbated, clay-rich sandstone and shale. Live core samples of the Upper Cretaceous Eutaw Formation from the Heidelberg Field, MS were quantitatively assessed using SEM, and showed that during MPPM permeability modification occurs ubiquitously within pore and throat spaces of 10-20 μm diameter. Testing of the MPPM procedure in the Little Creek Field showed a significant increase in production occurred in two of the five production test wells; furthermore, the decline curve in each of the production wells became noticeably less steep. This project greatly extends the number of oil fields in which MPPM can be implemented.« less

Influence of the preparation method on the physicochemical properties of indomethacin and methyl-β-cyclodextrin complexes.

PubMed

Rudrangi, Shashi Ravi Suman; Bhomia, Ruchir; Trivedi, Vivek; Vine, George J; Mitchell, John C; Alexander, Bruce David; Wicks, Stephen Richard

2015-02-20

The main objective of this study was to investigate different manufacturing processes claimed to promote inclusion complexation between indomethacin and cyclodextrins in order to enhance the apparent solubility and dissolution properties of indomethacin. Especially, the effectiveness of supercritical carbon dioxide processing for preparing solid drug-cyclodextrin inclusion complexes was investigated and compared to other preparation methods. The complexes were prepared by physical mixing, co-evaporation, freeze drying from aqueous solution, spray drying and supercritical carbon dioxide processing methods. The prepared complexes were then evaluated by scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction, solubility and dissolution studies. The method of preparation of the inclusion complexes was shown to influence the physicochemical properties of the formed complexes. Indomethacin exists in a highly crystalline solid form. Physical mixing of indomethacin and methyl-β-cyclodextrin appeared not to reduce the degree of crystallinity of the drug. The co-evaporated and freeze dried complexes had a lower degree of crystallinity than the physical mix; however the lowest degree of crystallinity was achieved in complexes prepared by spray drying and supercritical carbon dioxide processing methods. All systems based on methyl-β-cyclodextrin exhibited better dissolution properties than the drug alone. The greatest improvement in drug dissolution properties was obtained from complexes prepared using supercritical carbon dioxide processing, thereafter by spray drying, freeze drying, co-evaporation and finally by physical mixing. Supercritical carbon dioxide processing is well known as an energy efficient alternative to other pharmaceutical processes and may have application for the preparation of solid-state drug-cyclodextrin inclusion complexes. It is an effective and economic method that allows the formation of solid complexes with a high yield, without the use of organic solvents and problems associated with their residues. Copyright © 2015 Elsevier B.V. All rights reserved.

A carbon dioxide stripping model for mammalian cell culture in manufacturing scale bioreactors.

PubMed

Xing, Zizhuo; Lewis, Amanda M; Borys, Michael C; Li, Zheng Jian

2017-06-01

Control of carbon dioxide within the optimum range is important in mammalian bioprocesses at the manufacturing scale in order to ensure robust cell growth, high protein yields, and consistent quality attributes. The majority of bioprocess development work is done in laboratory bioreactors, in which carbon dioxide levels are more easily controlled. Some challenges in carbon dioxide control can present themselves when cell culture processes are scaled up, because carbon dioxide accumulation is a common feature due to longer gas-residence time of mammalian cell culture in large scale bioreactors. A carbon dioxide stripping model can be used to better understand and optimize parameters that are critical to cell culture processes at the manufacturing scale. The prevailing carbon dioxide stripping models in literature depend on mass transfer coefficients and were applicable to cell culture processes with low cell density or at stationary/cell death phase. However, it was reported that gas bubbles are saturated with carbon dioxide before leaving the culture, which makes carbon dioxide stripping no longer depend on a mass transfer coefficient in the new generation cell culture processes characterized by longer exponential growth phase, higher peak viable cell densities, and higher specific production rate. Here, we present a new carbon dioxide stripping model for manufacturing scale bioreactors, which is independent of carbon dioxide mass transfer coefficient, but takes into account the gas-residence time and gas CO 2 saturation time. The model was verified by CHO cell culture processes with different peak viable cell densities (7 to 12 × 10 6  cells mL -1 ) for two products in 5,000-L and 25,000-L bioreactors. The model was also applied to a next generation cell culture process to optimize cell culture conditions and reduce carbon dioxide levels at manufacturing scale. The model provides a useful tool to understand and better control cell culture carbon dioxide profiles for process development, scale up, and characterization. Biotechnol. Bioeng. 2017;114: 1184-1194. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

High Temperature Raman Spectroscopy Study of the Conversion of Formate into Oxalate: Search for the Elusive CO 2 2 - Intermediate

NASA Astrophysics Data System (ADS)

Ryan, Charles; Mead, Anna; Lakkaraju, Prasad; Kaczur, Jerry; Bennett, Christopher; Dobbins, Tabbetha

Research on conversion of carbon dioxide into chemicals and fuels has the potential to address three problems of global relevance. (a) By removing carbon dioxide from the atmosphere, we are able to reduce the amount of greenhouse gases in the atmosphere, (b) by converting carbon dioxide into fuels, we are providing pathways for renewable energy sources, (c) by converting carbon dioxide into C2 and higher order compounds, and we are able to generate valuable precursors for organic synthesis. Formate salts are formed by the electrochemical reduction of carbon dioxide in aqueous media. However, in order to increase the utilization of carbon dioxide, methods need to be developed for the conversion of formate into compounds containing two carbon atoms such as oxalate or oxalic acid. Recently, we examined the thermal conversion of sodium formate into sodium oxalate utilizing a hydride ion catalyst. The proposed mechanism for this reaction involves the carbon dioxide dianion. Currently at NASA Goddard Space Flight Center.

Oxygen and Carbon Dioxide Fluxes from Barley Shoots Depend on Nitrate Assimilation 1

PubMed Central

Bloom, Arnold J.; Caldwell, Richard M.; Finazzo, John; Warner, Robert L.; Weissbart, Joseph

1989-01-01

A custom oxygen analyzer in conjunction with an infrared carbon dioxide analyzer and humidity sensors permitted simultaneous measurements of oxygen, carbon dioxide, and water vapor fluxes from the shoots of intact barley plants (Hordeum vulgare L. cv Steptoe). The oxygen analyzer is based on a calciazirconium sensor and can resolve concentration differences to within 2 microliters per liter against the normal background of 210,000 microliters per liter. In wild-type plants receiving ammonium as their sole nitrogen source or in nitrate reductase-deficient mutants, photosynthetic and respiratory fluxes of oxygen equaled those of carbon dioxide. By contrast, wild-type plants exposed to nitrate had unequal oxygen and carbon dioxide fluxes: oxygen evolution at high light exceeded carbon dioxide consumption by 26% and carbon dioxide evolution in the dark exceeded oxygen consumption by 25%. These results indicate that a substantial portion of photosynthetic electron transport or respiration generates reductant for nitrate assimilation rather than for carbon fixation or mitochondrial electron transport. PMID:16667024

The influence of deep-seabed CO2 sequestration on small metazoan (meiofaunal) viability and community structure: final technical report

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

Thistle, D

2008-09-30

Since the industrial revolution, the burning of fossil fuel has produced carbon dioxide at an increasing rate. Present atmospheric concentration is about ~1.5 times the preindustrial level and is rising. Because carbon dioxide is a greenhouse gas, its increased concentration in the atmosphere is thought to be a cause of global warming. If so, the rate of global warming could be slowed if industrial carbon dioxide were not released into the atmosphere. One suggestion has been to sequester it in the deep ocean, but theory predicts that deep-sea species will be intolerant of the increased concentrations of carbon dioxide andmore » the increased acidity it would cause. The aim of our research was to test for consequences of carbon dioxide sequestration on deep-sea, sediment-dwelling meiofauna. Recent technical advances allowed us to test for effects in situ at depths proposed for sequestration. The basic experimental unit was an open-topped container into which we pumped ~20 L of liquid carbon dioxide. The liquid carbon dioxide mixed with near-bottom sea water, which produced carbon dioxide-rich sea water that flowed out over the near-by seabed. We did 30-day experiments at several locations and with different numbers of carbon dioxide-filled containers. Harpacticoid copepods (Crustacea) were our test taxon. In an experiment we did during a previous grant period, we found that large numbers of individuals exposed to carbon dioxide-rich sea water had been killed (Thistle et al. 2004). During the present grant period, we analyzed the species-level data in greater detail and discovered that, although individuals of many species had been killed by exposure to carbon dioxide-rich sea water, individuals of some species had not (Thistle et al. 2005). This result suggests that seabed sequestration of carbon dioxide will not just reduce the abundance of the meiofauna but will change the composition of the community. In another experiment, we found that some harpacticoid species swim away from an advancing front of carbon dioxide-rich sea water (Thistle et al. 2007). This result demonstrates a second way that deep-sea meiofauna react negatively to carbon dioxide-rich sea water. In summary, we used in situ experiments to show that carbon dioxide-rich sea water triggers an escape response in some harpacticoid species. It kills most individuals of most harpacticoid species that do not flee, but a few species seem to be unaffected. Proposals to reduce global warming by sequestering industrial carbon dioxide in the deep ocean should take note of these environmental consequences when pros and cons are weighed.« less

Degradation of metaldehyde in water by nanoparticle catalysts and powdered activated carbon.

PubMed

Li, Zhuojun; Kim, Jong Kyu; Chaudhari, Vrushali; Mayadevi, Suseeladevi; Campos, Luiza C

2017-07-01

Metaldehyde, an organic pesticide widely used in the UK, has been detected in drinking water in the UK with a low concentration (<1 μg L -1 ) which is still above the European and UK standard requirements. This paper investigates the efficiency of four materials: powdered activated carbon (PAC) and carbon-doped titanium dioxide nanocatalyst with different concentrations of carbon (C-1.5, C-40, and C-80) for metaldehyde removal from aqueous solutions by adsorption and oxidation via photocatalysis. PAC was found to be the most effective material which showed almost over 90% removal. Adsorption data were well fitted to the Langmuir isotherm model, giving a q m (maximum/saturation adsorption capacity) value of 32.258 mg g -1 and a K L (Langmuir constant) value of 2.013 L mg -1 . In terms of kinetic study, adsorption of metaldehyde by PAC fitted well with a pseudo-second-order equation, giving the adsorption rate constant k 2 value of 0.023 g mg -1  min -1 , implying rapid adsorption. The nanocatalysts were much less effective in oxidising metaldehyde than PAC with the same metaldehyde concentration and 0.2 g L -1 loading concentration of materials under UV light; the maximum removal achieved by carbon-doped titanium dioxide (C-1.5) nanocatalyst was around 15% for a 7.5 ppm metaldehyde solution. Graphical abstract ᅟ.

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

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

Code of Federal Regulations, 2014 CFR

2014-04-01

... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0.009 grams per 100 milliliters to the maximum limitation of carbon dioxide in still wine will be allowed where the amount of carbon dioxide in excess of 0.392 grams per 100 milliliters is due to...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

27 CFR 27.42a - Still wines containing carbon dioxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Still wines may contain not more than 0.392 gram of carbon dioxide per 100 milliliters of wine; except that a tolerance to this maximum limitation, not to exceed 0.009 gram of carbon dioxide per 100 milliliters of wine, will be allowed where the amount of carbon dioxide in excess of 0.392 gram per 100...

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

Code of Federal Regulations, 2012 CFR

2012-04-01

... than 0.392 grams of carbon dioxide per 100 milliliters of wine. However, a tolerance of not more than 0.009 grams per 100 milliliters to the maximum limitation of carbon dioxide in still wine will be allowed where the amount of carbon dioxide in excess of 0.392 grams per 100 milliliters is due to...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Carbon dioxide and certain other gases. 201.161 Section 201.161 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

46 CFR 97.37-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as provided in paragraph (b) of this...

46 CFR 78.47-9 - Carbon dioxide alarm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM...

46 CFR 169.732 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...

46 CFR 95.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide storage. 95.15-20 Section 95.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-20 Carbon dioxide storage. (a) Except as provided in paragraph (b) of this...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Carbon dioxide and certain other gases. 201.161 Section 201.161 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL LABELING Other Exemptions § 201.161 Carbon dioxide and certain other gases. (a) Carbon dioxide, cyclopropane, ethylene,...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 131.815 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 108.627 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...

Carbon dioxide absorbent and method of using the same

DOEpatents

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.

Carbon dioxide absorbent and method of using the same

DOEpatents

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.

Carbon dioxide absorbent and method of using the same

DOEpatents

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.

Novel Technique and Technologies for Active Optical Remote Sensing of Greenhouse Gases

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Refaat, Tamer F.; Petros, Mulugeta

2017-01-01

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

GaN High Power Electronics

DTIC Science & Technology

2011-02-01

ARL) does not yet match the best work being done in Japan, the reasons for this have been identified as the relatively large carbon background...hand, SiC is a compound with a fixed composition. Second phases are formed, as opposed to solid solutions, when the group IV elements, carbon (C...Si, or germanium (Ge), are added to it. In order to form a 2DEG, a dielectric, usually silicon dioxide (SiO2), has to be grown or deposited on the

Carbon sequestration in depleted oil shale deposits

DOEpatents

Burnham, Alan K; Carroll, Susan A

2014-12-02

A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

Forecasting carbon dioxide emissions based on a hybrid of mixed data sampling regression model and back propagation neural network in the USA.

PubMed

Zhao, Xin; Han, Meng; Ding, Lili; Calin, Adrian Cantemir

2018-01-01

The accurate forecast of carbon dioxide emissions is critical for policy makers to take proper measures to establish a low carbon society. This paper discusses a hybrid of the mixed data sampling (MIDAS) regression model and BP (back propagation) neural network (MIDAS-BP model) to forecast carbon dioxide emissions. Such analysis uses mixed frequency data to study the effects of quarterly economic growth on annual carbon dioxide emissions. The forecasting ability of MIDAS-BP is remarkably better than MIDAS, ordinary least square (OLS), polynomial distributed lags (PDL), autoregressive distributed lags (ADL), and auto-regressive moving average (ARMA) models. The MIDAS-BP model is suitable for forecasting carbon dioxide emissions for both the short and longer term. This research is expected to influence the methodology for forecasting carbon dioxide emissions by improving the forecast accuracy. Empirical results show that economic growth has both negative and positive effects on carbon dioxide emissions that last 15 quarters. Carbon dioxide emissions are also affected by their own change within 3 years. Therefore, there is a need for policy makers to explore an alternative way to develop the economy, especially applying new energy policies to establish a low carbon society.

Carbon-14 analyses reveal fine structure of the urban carbon dioxide dome in the Salt Lake Valley, Utah, USA

NASA Astrophysics Data System (ADS)

Ehleringer, J. R.; Hopkins, F. M.; Xu, X.; Barnette, J.; Randerson, J. T.; Bush, S.; Lai, C.

2013-12-01

Carbon-14 analyses of mature deciduous tree leaves (aspen and cottonwood) were used to measure the increases in atmospheric carbon dioxide within the expansive urbanizing Salt Lake Valley, Utah, USA associated with fossil fuel combustion. Our objectives were twofold: to understand the fine scale spatial structure of elevated carbon dioxide levels in this urban environment and to relate these observations to actual carbon dioxide observations collected using both long-term monitoring sites and a mobile measurement vehicle. Paired observations of aspen and cottonwood at sites across the valley showed that there was no significant difference in carbon-14 values, allowing spatial pattern evaluations at sites where one but not the other species was present. Statistically significant patterns were observed over a two-year measurement period, with elevated carbon dioxide levels associated with carbon-14 depleted leaves, particularly in regions with higher vehicle travel. Carbon-14 content of leaves was significantly lower on 4-lane roads than on nearby 2-lane roads in both residential and commercial zones, consistent with atmospheric carbon dioxide observations. The analysis of spatial patterns in the carbon-14 in leaves was then used to evaluate how well these observations compared to instantaneous and long-term observations of carbon dioxide using traditional infrared gas analyzer approaches.

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

NASA Astrophysics Data System (ADS)

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, water surface disturbance indicated by Froude number, and turbulent mixing indicated by Reynolds number. Similar relationships with season, flow velocity and turbulence have been reported previously, but there is little known about the mechanisms involved. When comparing spot carbon dioxide efflux measurements to river stage time series data, carbon dioxide efflux is more sensitive to an increase in stage at more turbulent measurement points. Further investigation of the mechanisms will be obtained by measurement of DIC concentration and isotopic composition to assess the controls of carbon source versus degassing, and the analysis of the interactions between hydraulic and seasonal controls and carbon dioxide fluxes extended.

The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

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

Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana

Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR andmore » {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.« less

Utilization of heat from High Temperature Reactors (HTR) for dry reforming of methane

NASA Astrophysics Data System (ADS)

Jastrząb, Krzysztof

2018-01-01

One of the methods for utilization of waste carbon dioxide consists in reaction of methane with carbon dioxide, referred to as dry reforming of methane. It is an intensely endothermic catalytic process that takes place at the temperature above 700°C. Reaction of methane with carbon dioxide leads to formation of synthesis gas (syngas) that is a valuable chemical raw material. The energy that is necessary for the process to take place can be sourced from High Temperature Nuclear Reactors (HTR). The completed studies comprises a series of thermodynamic calculations and made it possible to establish optimum conditions for the process and demand for energy from HTR units. The dry reforming of methane needs also a catalytic agent with appropriate activity, therefore the hydrotalcite catalyser with admixture of cerium and nickel, developed at AGH University of Technology seems to be a promising solution. Thus, the researchers from the Institute for Chemical Processing of Coal (IChPW) in Zabrze have developed a methodology for production of the powdery hydrotalcite catalyser and investigated catalytic properties of the granulate obtained. The completed experiments confirmed that the new catalyser demonstrated high activity and is suitable for the process of methane dry reforming. In addition, optimum parameters of the were process (800°C, CO2:CH4 = 3:1) were established as well. Implementation of the technology in question into industrial practice, combined with utilization of HTR heat can be a promising method for management of waste carbon dioxide and may eventually lead to mitigation of the greenhouse effect.

Carbon dioxide emissions, GDP, energy use, and population growth: a multivariate and causality analysis for Ghana, 1971-2013.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2016-07-01

In this study, the relationship between carbon dioxide emissions, GDP, energy use, and population growth in Ghana was investigated from 1971 to 2013 by comparing the vector error correction model (VECM) and the autoregressive distributed lag (ARDL). Prior to testing for Granger causality based on VECM, the study tested for unit roots, Johansen's multivariate co-integration and performed a variance decomposition analysis using Cholesky's technique. Evidence from the variance decomposition shows that 21 % of future shocks in carbon dioxide emissions are due to fluctuations in energy use, 8 % of future shocks are due to fluctuations in GDP, and 6 % of future shocks are due to fluctuations in population. There was evidence of bidirectional causality running from energy use to GDP and a unidirectional causality running from carbon dioxide emissions to energy use, carbon dioxide emissions to GDP, carbon dioxide emissions to population, and population to energy use. Evidence from the long-run elasticities shows that a 1 % increase in population in Ghana will increase carbon dioxide emissions by 1.72 %. There was evidence of short-run equilibrium relationship running from energy use to carbon dioxide emissions and GDP to carbon dioxide emissions. As a policy implication, the addition of renewable energy and clean energy technologies into Ghana's energy mix can help mitigate climate change and its impact in the future.

46 CFR 35.40-10 - Steam, foam, carbon dioxide, or clean agent fire smothering apparatus-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Steam, foam, carbon dioxide, or clean agent fire... TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-10 Steam, foam, carbon dioxide, or clean agent fire smothering apparatus—TB/ALL. Each steam, foam, carbon dioxide, or clean agent...

46 CFR 35.40-10 - Steam, foam, carbon dioxide, or clean agent fire smothering apparatus-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Steam, foam, carbon dioxide, or clean agent fire... TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-10 Steam, foam, carbon dioxide, or clean agent fire smothering apparatus—TB/ALL. Each steam, foam, carbon dioxide, or clean agent...

46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2N)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2N) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.2 x 8.5 km nadir ... Contact User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

46 CFR 34.15-20 - Carbon dioxide storage-T/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide storage-T/ALL. 34.15-20 Section 34.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-20 Carbon dioxide storage—T/ALL. (a) Except as provided in paragraph (b) of this section, the cylinders...

46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...

46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...

TES/Aura L2 Carbon Dioxide (CO2) Nadir V6 (TL2CO2NS)

Atmospheric Science Data Center

2018-01-22

TES/Aura L2 Carbon Dioxide (CO2) Nadir (TL2CO2NS) News:  TES News ... Level:  L2 Platform:  TES/Aura L2 Carbon Dioxide Spatial Coverage:  5.3 x 8.5 km nadir ... Contact ASDC User Services Parameters:  Carbon Dioxide Legacy:  Retired data product , click here ...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2012 CFR

2012-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2014 CFR

2014-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2011 CFR

2011-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

40 CFR 60.1745 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2013 CFR

2013-07-01

... carbon dioxide instead of oxygen as a diluent gas? 60.1745 Section 60.1745 Protection of Environment... choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous emission monitoring...

The carbon dioxide cycle

USGS Publications Warehouse

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

2005-01-01

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

The impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution: evidence from Ghana.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2017-03-01

In this study, the impact of energy, agriculture, macroeconomic and human-induced indicators on environmental pollution from 1971 to 2011 is investigated using the statistically inspired modification of partial least squares (SIMPLS) regression model. There was evidence of a linear relationship between energy, agriculture, macroeconomic and human-induced indicators and carbon dioxide emissions. Evidence from the SIMPLS regression shows that a 1% increase in crop production index will reduce carbon dioxide emissions by 0.71%. Economic growth increased by 1% will reduce carbon dioxide emissions by 0.46%, which means that an increase in Ghana's economic growth may lead to a reduction in environmental pollution. The increase in electricity production from hydroelectric sources by 1% will reduce carbon dioxide emissions by 0.30%; thus, increasing renewable energy sources in Ghana's energy portfolio will help mitigate carbon dioxide emissions. Increasing enteric emissions by 1% will increase carbon dioxide emissions by 4.22%, and a 1% increase in the nitrogen content of manure management will increase carbon dioxide emissions by 6.69%. The SIMPLS regression forecasting exhibited a 5% MAPE from the prediction of carbon dioxide emissions.

Carbon dioxide sensor

DOEpatents

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).

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

Waldhoff, Stephanie T.; Anthoff, David; Rose, Steven K.

We use FUND 3.8 to estimate the social cost of four greenhouse gases: carbon dioxide, methane, nitrous oxide, and sulphur hexafluoride emissions. The damage potential for each gas—the ratio of the social cost of the non-carbon dioxide greenhouse gas to the social cost of carbon dioxide—is also estimated. The damage potentials are compared to several metrics, focusing in particular on the global warming potentials, which are frequently used to measure the trade-off between gases in the form of carbon dioxide equivalents. We find that damage potentials could be significantly higher than global warming potentials. This finding implies that previous papersmore » have underestimated the relative importance of reducing non-carbon dioxide greenhouse gas emissions from an economic damage perspective. We show results for a range of sensitivity analyses: carbon dioxide fertilization on agriculture productivity, terrestrial feedbacks, climate sensitivity, discounting, equity weighting, and socioeconomic and emissions scenarios. The sensitivity of the results to carbon dioxide fertilization is a primary focus as it is an important element of climate change that has not been considered in much of the previous literature. We estimate that carbon dioxide fertilization has a large positive impact that reduces the social cost of carbon dioxide with a much smaller effect on the other greenhouse gases. As a result, our estimates of the damage potentials of methane and nitrous oxide are much higher compared to estimates that ignore carbon dioxide fertilization. As a result, our base estimates of the damage potential for methane and nitrous oxide that include carbon dioxide fertilization are twice their respective global warming potentials. Our base estimate of the damage potential of sulphur hexafluoride is similar to the one previous estimate, both almost three times the global warming potential.« less

Experimental measurement and thermodynamic modeling of the solubility of carbon dioxide in aqueous blends of monoethanolamine and diethanolamine

NASA Astrophysics Data System (ADS)

Suleman, Humbul; Maulud, Abdulhalim Shah; Man, Zakaria

2017-12-01

In this study, the solubilities of carbon dioxide in aqueous mixtures of monoethanolamine (MEA) and diethanolamine (DEA) were determined using a high pressure vapor-liquid equilibrium apparatus. The carbon dioxide loadings (mole of CO2/mole of amine mixture) were reported for a wide range of temperature (303.15, 323.15, 343.15 K) and pressure (100 - 4100 kPa). The carbon dioxide solubility shows an increase with increase in pressure and amine concentration and a decrease with increase in temperature in the aqueous blends of MEA and DEA. At carbon dioxide loadings above 1.0, the carbon dioxide solubility becomes a weak function of pressure and follows the general trend of carbon dioxide solubility in aqueous alkanolamines. The new experimental data points determined in this study were correlated by using a recently developed, enhanced Kent-Eisenberg model. An average absolute relative error of 9.4 % was observed between the model results and experimental data, indicating good correlative capability of the thermodynamic model.

Apparatus and method for removing solvent from carbon dioxide in resin recycling system

DOEpatents

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

Epoxide-functionalization of polyethyleneimine for synthesis of stable carbon dioxide adsorbent in temperature swing adsorption

PubMed Central

Choi, Woosung; Min, Kyungmin; Kim, Chaehoon; Ko, Young Soo; Jeon, Jae Wan; Seo, Hwimin; Park, Yong-Ki; Choi, Minkee

2016-01-01

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g−1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation. PMID:27572662

The Impact of Carbon Dioxide on Climate.

ERIC Educational Resources Information Center

MacDonald, Gordon J.

1979-01-01

Examines the relationship between climatic change and carbon dioxide from the historical perspective; details the contributions of carbon-based fuels to increasing carbon dioxide concentrations; and using global circulation models, discusses the future impact of the heavy reliance of our society on carbon-based fuels on climatic change. (BT)

Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

EPA Science Inventory

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 dehydra...

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

NASA Technical Reports Server (NTRS)

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.

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

NASA Technical Reports Server (NTRS)

Hintze, Paul E.; Muscatello, Anthony C.; Meier, Anne J.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.

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.

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

NASA Technical Reports Server (NTRS)

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 it is a promising alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon, and the resulting carbon buildup eventually fouls the 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.

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... GRAS § 184.1613 Potassium bicarbonate. (a) Potassium bicarbonate (KHCO3, CAS Reg. No. 298-14-6) is made by the following processes: (1) By treating a solution of potassium hydroxide with carbon dioxide; (2...

Primary discussion of a carbon sink in the oceans

NASA Astrophysics Data System (ADS)

Ma, Caihua; You, Kui; Ji, Dechun; Ma, Weiwei; Li, Fengqi

2015-04-01

As a consequence of global warming and rising sea levels, the oceans are becoming a matter of concern for more and more people because these changes will impact the growth of living organisms as well as people's living standards. In particular, it is extremely important that the oceans absorb massive amounts of carbon dioxide. This paper takes a pragmatic approach to analyzing the oceans with respect to the causes of discontinuities in oceanic variables of carbon dioxide sinks. We report on an application of chemical, physical and biological methods to analyze the changes of carbon dioxide in oceans. Based on the relationships among the oceans, land, atmosphere and sediment with respect to carbon dioxide, the foundation of carbon dioxide in shell-building and ocean acidification, the changes in carbon dioxide in the oceans and their impact on climate change, and so on, a vital conclusion can be drawn from this study. Specifically, under the condition that the oceans are not disturbed by external forces, the oceans are a large carbon dioxide sink. The result can also be inferred by the formula: C=A-B and G=E+F when the marine ecosystem can keep a natural balance and the amount of carbon dioxide emission is limited within the carrying capacity of the oceans.

Fluid extraction

DOEpatents

Wai, Chien M.; Laintz, Kenneth E.

1999-01-01

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

Solubility and precipitation of nicotinic acid in supercritical carbon dioxide.

PubMed

Rehman, M; Shekunov, B Y; York, P; Colthorpe, P

2001-10-01

Solubilities of a model compound (nicotinic acid) in pure supercritical carbon dioxide (SC-CO(2)) and SC-CO(2) modified with methanol have been measured in the pressure range of 80-200 bar and between temperatures of 35 and 90 degrees C. On-line ultraviolet detection enabled a simple and relatively fast measurement of very low levels of solubility (10(-7) mol fraction) with good accuracy in pure and modified SC-CO(2). The solute solubility in both pure SC-CO(2) and SC-CO(2) modified with methanol increased with pressure at all investigated temperatures. A retrograde solubility behavior was observed in that, at pressures below 120 bar, a solubility decrease on temperature increase occurred. Solubility data were used to calculate supersaturation values and to define optimum operating conditions to obtain crystalline particles 1-5 microm in diameter using the solution-enhanced dispersion by supercritical fluids (SEDS) process, thereby demonstrating the feasibility of a one-step production process for particulate pharmaceuticals suitable for respiratory drug delivery. Copyright 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:1570-1582, 2001

Enhanced open ocean storage of CO2 from shelf sea pumping.

PubMed

Thomas, Helmuth; Bozec, Yann; Elkalay, Khalid; de Baar, Hein J W

2004-05-14

Seasonal field observations show that the North Sea, a Northern European shelf sea, is highly efficient in pumping carbon dioxide from the atmosphere to the North Atlantic Ocean. The bottom topography-controlled stratification separates production and respiration processes in the North Sea, causing a carbon dioxide increase in the subsurface layer that is ultimately exported to the North Atlantic Ocean. Globally extrapolated, the net uptake of carbon dioxide by coastal and marginal seas is about 20% of the world ocean's uptake of anthropogenic carbon dioxide, thus enhancing substantially the open ocean carbon dioxide storage.

Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

DOEpatents

Koc, Rasit; Glatzmaier, Gregory C.

1995-01-01

A process for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

DOEpatents

Koc, R.; Glatzmaier, G.C.

1995-05-23

A process is disclosed for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, C.E.; Robinson, P.R.

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cyclic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, Carlos E.; Robinson, Paul R.

1980-01-01

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cylic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

46 CFR 76.15-1 - Application.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Dioxide Extinguishing Systems, Details § 76.15-1 Application. (a) Where a carbon dioxide extinguishing... “high pressure system”, i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems”, i.e., those in which the carbon dioxide is stored in liquid...

[Simplified identification and filter device of carbon dioxide].

PubMed

Mei, Xue-qin; Zhang, Yi-ping

2009-11-01

This paper presents the design and implementation ways of a simplified device to identify and filter carbon dioxide. The gas went through the test interface which had wet litmus paper before entering the abdominal cavity. Carbon dioxide dissolving in water turned acidic, making litmus paper change color to identify carbon dioxide, in order to avoid malpractice by connecting the wrong gas when making Endoscopic surgery.

46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or clean agent fire extinguishing alarm...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2012 CFR

2012-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2010 CFR

2010-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2011 CFR

2011-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2014 CFR

2014-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

40 CFR 62.15200 - What must I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas?

Code of Federal Regulations, 2013 CFR

2013-07-01

... carbon dioxide instead of oxygen as a diluent gas? 62.15200 Section 62.15200 Protection of Environment... I do if I choose to monitor carbon dioxide instead of oxygen as a diluent gas? You must establish the relationship between oxygen and carbon dioxide during the initial evaluation of your continuous...

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

ERIC Educational Resources Information Center

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…

Feasibility of measuring dissolved carbon dioxide based on head space partial pressures

USGS Publications Warehouse

Watten, B.J.; Boyd, C.E.; Schwartz, M.F.; Summerfelt, S.T.; Brazil, B.L.

2004-01-01

We describe an instrument prototype that measures dissolved carbon dioxide (DC) without need for standard wetted probe membranes or titration. DC is calculated using Henry's Law, water temperature, and the steady-state partial pressure of carbon dioxide that develops within the instrument's vertical gas-liquid contacting chamber. Gas-phase partial pressures were determined with either an infrared detector (ID) or by measuring voltage developed by a pH electrode immersed in an isolated sodium carbonate solution (SC) sparged with recirculated head space gas. Calculated DC concentrations were compared with those obtained by titration over a range of DC (2, 4, 8, 12, 16, 20, 24, and 28mg/l), total alkalinity (35, 120, and 250mg/l as CaCO3), total dissolved gas pressure (-178 to 120 mmHg), and dissolved oxygen concentrations (7, 14, and 18 mg/l). Statistically significant (P < 0.001) correlations were established between head space (ID) and titrimetrically determined DC concentrations (R2 = 0.987-0.999, N = 96). Millivolt and titrimetric values from the SC solution tests were also correlated (P < 0.001, R 2 = 0.997, N = 16). The absolute and relative error associated with the use of the ID and SC solution averaged 0.9mg/l DC and 7.0% and 0.6 mg/l DC and 9.6%, respectively. The precision of DC estimates established in a second test series was good; coefficients of variation (100(SD/mean)) for the head space (ID) and titration analyses were 0.99% and 1.7%. Precision of the SC solution method was 1.3%. In a third test series, a single ID was coupled with four replicate head space units so as to permit sequential monitoring (15 min intervals) of a common water source. Here, appropriate gas samples were secured using a series of solenoid valves (1.6 mm bore) activated by a time-based controller. This system configuration reduced the capital cost per sample site from US$ 2695 to 876. Absolute error averaged 2.9, 3.1, 3.7, and 2.7 mg/ l for replicates 1-4 (N = 36) during a 21-day test period (DC range, 36-40 mg/l). The ID meter was then modified so as to provide for DO as well as DC measurements across components of an intensive fish production system. ?? 2003 Elsevier B.V. All rights reserved.

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

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

Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni, E-mail: brantmj@hawaii.edu

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

Fixation of carbon dioxide into dimethyl carbonate over ...

EPA Pesticide Factsheets

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.

The Path of Carbon in Photosynthesis IX. Photosynthesis, Photoreduction, and the Hydrogen-Oxygen-Carbon Dioxide Dark Reaction

DOE R&D Accomplishments Database

Badin, E. J.; Calvin, M.

1950-02-01

A comparison of the rates of fixation of Carbon 14 dioxide in algae for the processes of photosynthesis, photoreduction and the hydrogen-oxygen-carbon dioxide dark reaction has been made. For the same series of experiments, rates of incorporation of tracer carbon into the separate soluble components using the radiogram method have been determined. The mechanism of carbon dioxide uptake has been shown to occur via two distinct paths. In all cases studied, essentially the same compounds appear radioactive. The distribution with time, however, differs markedly.

Development of an On-Demand, Generic, Drug-Delivery System

DTIC Science & Technology

1985-08-06

systems Two systems were evaluated for CO2 evolution. The first of these was an enzymatic system based on urea and urease . The second system was based...PHM 84 Research pH Meter was used te monitor pH. Solutions of various buffer concen- trations and pHs were prepared for each buffer system. One urease ...Measurement of carbon dio~ide production was accomplished using the apparatus shown in Figure 2. Carbon dioxide was generated by putting a urease tablet in the

Biotransformation of carbon dioxide in bioelectrochemical systems: State of the art and future prospects

NASA Astrophysics Data System (ADS)

Bajracharya, Suman; Srikanth, Sandipam; Mohanakrishna, Gunda; Zacharia, Renju; Strik, David PBTB; Pant, Deepak

2017-07-01

Carbon dioxide (CO2) utilization/recycling for the production of chemicals and gaseous/liquid energy-carriers is a way to moderate the rising CO2 in the atmosphere. One of the possible solutions for the CO2 sequestration is the electrochemical reduction of this stable molecule to useful fuel/products. Nevertheless, the surface chemistry of CO2 reduction is a challenge due to the presence of large energy barriers, requiring noticeable catalysis. The recent approach of microbial electrocatalysis of CO2 reduction has promising prospects to reduce the carbon level sustainably, taking full advantage of CO2-derived chemical commodities. We review the currently investigated bioelectrochemical approaches that could possibly be implemented to enable the handling of CO2 emissions. This review covers the most recent advances in the bioelectrochemical approaches of CO2 transformations in terms of biocatalysts development and process design. Furthermore, the extensive research on carbon fixation and conversion to different value added chemicals is reviewed. The review concludes by detailing the key challenges and future prospects that could enable economically feasible microbial electrosynthesis technology.

Seasonal analyses of carbon dioxide and energy fluxes above an oil palm plantation using the eddy covariance method

NASA Astrophysics Data System (ADS)

Ibrahim, Anis; Haniff Harun, Mohd; Yusup, Yusri

2017-04-01

A study presents the measurements of carbon dioxide and latent and sensible heat fluxes above a mature oil palm plantation on mineral soil in Keratong, Pahang, Peninsular Malaysia. The sampling campaign was conducted over an 25-month period, from September 2013 to February 2015 and May 2016 to November 2016, using the eddy covariance method. The main aim of this work is to assess carbon dioxide and energy fluxes over this plantation at different time scales, seasonal and diurnal, and determine the effects of season and relevant meteorological parameters on the latter fluxes. Energy balance closure analyses gave a slope between latent and sensible heat fluxes and total incoming energy to be 0.69 with an R2 value of 0.86 and energy balance ratio of 0.80. The averaged net radiation was 108 W m-2. The results show that at the diurnal scale, carbon dioxide, latent and sensible heat fluxes exhibited a clear diurnal trend where carbon dioxide flux was at its minimum - 3.59 μmol m-2 s-1 in the mid-afternoon and maximum in the morning while latent and sensible behaved conversely to the carbon dioxide flux. The average carbon dioxide flux was - 0.37 μmol m-2 s-1. At the seasonal timescale, carbon dioxide fluxes did not show any apparent trend except during the Northeast Monsoon where the highest variability of the monthly means of carbon dioxide occurred.

Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

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

Kern, F.H.; Ungerleider, R.M.; Quill, T.J.

1991-04-01

We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbonmore » dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow.« less

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

PubMed

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

2016-09-01

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

Production of magnesium metal

DOEpatents

Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

2010-02-23

A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

Revisiting the emissions-energy-trade nexus: evidence from the newly industrializing countries.

PubMed

Ahmed, Khalid; Shahbaz, Muhammad; Kyophilavong, Phouphet

2016-04-01

This paper applies Pedroni's panel cointegration approach to explore the causal relationship between trade openness, carbon dioxide emissions, energy consumption, and economic growth for the panel of newly industrialized economies (i.e., Brazil, India, China, and South Africa) over the period of 1970-2013. Our panel cointegration estimation results found majority of the variables cointegrated and confirm the long-run association among the variables. The Granger causality test indicates bidirectional causality between carbon dioxide emissions and energy consumption. A unidirectional causality is found running from trade openness to carbon dioxide emission and energy consumption and economic growth to carbon dioxide emissions. The results of causality analysis suggest that the trade liberalization in newly industrialized economies induces higher energy consumption and carbon dioxide emissions. Furthermore, the causality results are checked using an innovative accounting approach which includes forecast-error variance decomposition test and impulse response function. The long-run coefficients are estimated using fully modified ordinary least square (FMOLS) method, and results conclude that the trade openness and economic growth reduce carbon dioxide emissions in the long run. The results of FMOLS test sound the existence of environmental Kuznets curve hypothesis. It means that trade liberalization induces carbon dioxide emission with increased national output, but it offsets that impact in the long run with reduced level of carbon dioxide emissions.

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

USGS Publications Warehouse

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

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

Does shaking increase the pressure inside a bottle of champagne?

PubMed

Vreme, A; Pouligny, B; Nadal, F; Liger-Belair, G

2015-02-01

Colas, beers and sparkling wines are all concentrated solutions of carbon dioxide in aqueous solvents. Any such carbonated liquid is ordinarily conditioned inside a closed bottle or a metal can as a liquid-gas 2-phase system. At thermodynamic equilibrium, the partial pressure of carbon-dioxide in the gas phase and its concentration in the liquid are proportional (Henry's law). In practical conditions and use (transport, opening of the container, exterior temperature change, etc.), Henry's equilibrium can be perturbed. The goal of this paper is to describe and understand how the system responds to such perturbations and evolves towards a new equilibrium state. Formally, we investigate the dynamics around Henry's equilibrium of a closed system, through dedicated experiments and modeling. We focus on the response to a sudden pressure change and to mechanical shaking (the latter point inspired the article's title). Observations are rationalized through basic considerations including molecular diffusion, bubble dynamics (based on Epstein-Plesset theory) and chemi-convective hydrodynamic instabilities. Copyright © 2014 Elsevier Inc. All rights reserved.

Environment and Materials Stewardship | NREL

Science.gov Websites

dioxide equivalent of natural gas in heating facilities and experiments; 105metric tons of carbon dioxide equivalent in fleet and equipment; 15 metric tons of carbon dioxide equivalent in fluorinated gases and refrigerants; and 10 metric tons of carbon dioxide equivalent in dry ice use in laboratories. Scope 2 accounts

40 CFR 62.15175 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring system for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 60.1720 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring systems for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 60.1720 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring systems for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

40 CFR 62.15175 - What continuous emission monitoring systems must I install for gaseous pollutants?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., maintain, and operate continuous emission monitoring systems for oxygen (or carbon dioxide), sulfur dioxide, and carbon monoxide. If you operate a Class I municipal waste combustion unit, also install, calibrate... emission monitoring system for sulfur dioxide, nitrogen oxides, and oxygen (or carbon dioxide) at the...

Selective free radical reactions using supercritical carbon dioxide.

PubMed

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.

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... monthly thereafter, or within one month prior to the certification test, calibrate the NDIR carbon dioxide... the analyzer to optimize performance. (2) Zero the carbon dioxide analyzer with either purified synthetic air or zero-grade nitrogen. (3) Calibrate on each normally used operating range with carbon...

Three-Phase Melting Curves in the Binary System of Carbon Dioxide and Water

NASA Astrophysics Data System (ADS)

Abramson, E. H.

2017-10-01

Invariant, three-phase melting curves, of ice VI in equilibrium with solid CO2, of ice VII in equilibrium with solid CO2, and of solid CO2 in simultaneous equilibrium with a majority aqueous and a majority CO2 fluid, were explored in the binary system of carbon dioxide and water. Diamond-anvil cells were used to develop pressures of 5 GPa. Water exhibits a large melting temperature depression (73°C less than its pure melting temperature of 253°C at 5 GPa) indicative of large concentrations of CO2 in the aqueous solution. The melting point of water-saturated CO2 does not show a measureable departure from that of the pure system at temperatures lower than ∼200°C and only 10°C at 5 GPa (from 327°C).

Extraction of metals and/or metalloids from acidic media using supercritical fluids and salts

DOEpatents

Wai, Chien M.; Smart, Neil G.; Lin, Yuehe

1998-01-01

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent is described. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

A Carbon Dioxide Bubble-Induced Vortex Triggers Co-Assembly of Nanotubes with Controlled Chirality.

PubMed

Zhang, Ling; Zhou, Laicheng; Xu, Na; Ouyang, Zhenjie

2017-07-03

It is challenging to prepare co-organized nanotube systems with controlled nanoscale chirality in an aqueous liquid flow field. Such systems are responsive to a bubbled external gas. A liquid vortex induced by bubbling carbon dioxide (CO 2 ) gas was used to stimulate the formation of nanotubes with controlled chirality; two kinds of achiral cationic building blocks were co-assembled in aqueous solution. CO 2 -triggered nanotube formation occurs by formation of metastable intermediate structures (short helical ribbons and short tubules) and by transition from short tubules to long tubules in response to chirality matching self-assembly. Interestingly, the chirality sign of these assemblies can be selected for by the circulation direction of the CO 2 bubble-induced vortex during the co-assembly process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two-electron carbon dioxide reduction catalyzed by rhenium(I) bis(imino)acenaphthene carbonyl complexes.

PubMed

Portenkirchner, Engelbert; Kianfar, Elham; Sariciftci, Niyazi Serdar; Knör, Günther

2014-05-01

Rhenium(I) carbonyl complexes carrying substituted bis(arylimino)acenaphthene ligands (BIAN-R) have been tested as potential catalysts for the two-electron reduction of carbon dioxide. Cyclic voltammetric studies as well as controlled potential electrolysis experiments were performed using CO2-saturated solutions of the complexes in acetonitrile and acetonitrile-water mixtures. Faradaic efficiencies of more than 30 % have been determined for the electrocatalytic production of CO. The effects of ligand substitution patterns and water content of the reaction medium on the catalytic performance of the new catalysts are discussed. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Analytical methods for toxic gases from thermal degradation of polymers

NASA Technical Reports Server (NTRS)

Hsu, M.-T. S.

1977-01-01

Toxic gases evolved from the thermal oxidative degradation of synthetic or natural polymers in small laboratory chambers or in large scale fire tests are measured by several different analytical methods. Gas detector tubes are used for fast on-site detection of suspect toxic gases. The infrared spectroscopic method is an excellent qualitative and quantitative analysis for some toxic gases. Permanent gases such as carbon monoxide, carbon dioxide, methane and ethylene, can be quantitatively determined by gas chromatography. Highly toxic and corrosive gases such as nitrogen oxides, hydrogen cyanide, hydrogen fluoride, hydrogen chloride and sulfur dioxide should be passed into a scrubbing solution for subsequent analysis by either specific ion electrodes or spectrophotometric methods. Low-concentration toxic organic vapors can be concentrated in a cold trap and then analyzed by gas chromatography and mass spectrometry. The limitations of different methods are discussed.

Selectivity of adsorption of gases on doped graphene

NASA Astrophysics Data System (ADS)

Nnabugwu, Jordan; Maiga, Sidi; Gatica, Silvina

We report our results on the selectivity of carbon dioxide being adsorbed onto doped graphene. Using the Ideal Adsorption Solution theory (IAST) we calculate the selectivity using the uptake pressures of pure gases. We focus on the adsorption of atmospheric gases such as carbon dioxide (CO2) , Nitrogen (N2) , and Methane (CH4) on a pure and doped monolayer graphene slab placed at the bottom of a simulation cell. Grand Canonical Monte Carlo (GCMC) simulations allow us to calculate the amount of gases adsorbed at a given temperature and pressure of the system. We found that including impurities of varying strength and concentration can increase significantly the selectivity at room temperature. Financial support from the National Science Foundation Research Experiences for Undergraduates Program for the REU Site in Physics at Howard University (NSF Award No. PHY-1358727) is gratefully acknowledged.

Contribution to Conversion of CO2 to fuel by electro-photo-catalytic reduction in hydro-genocarbonated aqueous solution tion

NASA Astrophysics Data System (ADS)

Nezzal, Ghania; Benammar, Souad; Hamouni, Samia; Meziane, Dalila; Naama, Sabrina; Abdessemed, Djamel

2015-04-01

Referring to the last World Conference COPENHAGEN (2010), endorsed by the United Nations,to '' RISKS OF CLIMATE CHANGES ', states had not reached an agreement to work fairly, in an international program, to limit Carbon dioxide emissions into the atmosphere, to put off it, to the next (in 2015), the right decisions, despite the recommendations of the 'IPCC'. Based on the natural reaction of photosynthesis, which converts carbon dioxide in the presence of water and sun, to '' OSA'' ', it is natural that scientists believe to implement an artificial conversion of CO2 in a renewable energy faster. Our contribution focuses on the same goals, by a different line. In this perspective, nano-materials, catalysts, pervaporation membranes, pervaporation unit, and a photo-reactor prototype, have been made. A summary of the preliminary results presented: For example, are given the concentrations of the various species present in a aqueous solution of sodium hydrogen carbonate, 0.5M, saturated with CO2, at standard temperature and pressure: (CO2) = 1M; (H2CO3) = 0,038M; (HCO3-) = 0,336M; (CO3 --) = 0,34M; pH = 7.33, an overall concentration = 1,714M, more than three times that of the initial solution. It is in such conditions that the conversion of carbon dioxide by the hydrogen produced in situ by electrolysis, in fuel, must be done in the presence of catalyst, under UV radiation. For electrodes, a nano-porous layer was formed on their surface to receive the suitable catalyst. These lats prepared, are made of porous supports (montmorillonite, aluminum and silicon oxides) into which are inserted the metal precursor, by impregnation interactive, in Iron, cobalt, nickel salt solutions, cobalt, nickel. Their performance has been identified by the reduction of para- nitrophenol, to para-aminophenol in aqueous medium in the presence of sodium borohydride. This is the catalyst 'Cobalt supported by SiO2'' that gave the best conversion, 99.5% instead of 99.7%, for a platinum catalyst. The separation of hydrocarbon products, in the considered aqueous medium, continuously, has been studied to determine optimum conditions by pervaporation. For this purpose, membranes of poly-sulfone and poly-dimethylsiloxane, were prepared and characterized in terms of flow pervaporat (J), and solute / solvent separation factor (α). Thus, the developed membranes have equivalent performance to commercial membranes. More accurate results will be the subject of this communication.

Tehran Air Pollutants Prediction Based on Random Forest Feature Selection Method

NASA Astrophysics Data System (ADS)

Shamsoddini, A.; Aboodi, M. R.; Karami, J.

2017-09-01

Air pollution as one of the most serious forms of environmental pollutions poses huge threat to human life. Air pollution leads to environmental instability, and has harmful and undesirable effects on the environment. Modern prediction methods of the pollutant concentration are able to improve decision making and provide appropriate solutions. This study examines the performance of the Random Forest feature selection in combination with multiple-linear regression and Multilayer Perceptron Artificial Neural Networks methods, in order to achieve an efficient model to estimate carbon monoxide and nitrogen dioxide, sulfur dioxide and PM2.5 contents in the air. The results indicated that Artificial Neural Networks fed by the attributes selected by Random Forest feature selection method performed more accurate than other models for the modeling of all pollutants. The estimation accuracy of sulfur dioxide emissions was lower than the other air contaminants whereas the nitrogen dioxide was predicted more accurate than the other pollutants.

Carbon dioxide capture process with regenerable sorbents

DOEpatents

Pennline, Henry W.; Hoffman, James S.

2002-05-14

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

Mechanisms of scale formation and carbon dioxide partial pressure influence. Part I. Elaboration of an experimental method and a scaling model.

PubMed

Gal, Jean-Yves; Fovet, Yannick; Gache, Nathalie

2002-02-01

Scale formation in industrial or domestic installations is still an important economic problem. The existence of a metastable domain for calcium carbonate supersaturated solutions and its breakdown are observed under conditions rarely well defined. In most cases it is the pH rise caused by the carbon dioxide loss that involves calcium carbonate precipitation. Before studying this problem, we suggest in this first part, a new model for the evolution of the calcocarbonic system that takes into account the hydrated forms of CaCO3: CaCO3 amorphous, CaCO3 x 6H2O (ikaite) and CaCO3 x H2O (monohydrate). According to this model, the precipitation of any one of these hydrated forms could be responsible for the breakdown of the metastable state. After this first step, the solids evolve into dehydrated forms. At first, the metastable domain spread of the calcium carbonate supersaturated solutions was studied by the elaboration of computer programs in which the formation of CaCO3(0)(aq) ion pairs was taken into account. These ion pairs are supposed to evolve through dehydration to form the various calcium carbonate solid form precursors. This thermodynamic study was then compared to the experimental methods of the critical pH. Here the pH rise was caused by adding sodium hydroxide under different conditions for sodium hydroxide addition speed, agitation mode and ageing of solutions. For the highest speed of sodium hydroxide addition, the CaCO3 ionic product reached the value of the amorphous calcium carbonate solubility product, and the reaction of the amorphous calcium carbonate precipitation was of the homogenous type. Decreasing the reagent's addition speed caused an extension of the titration time. Then, the breakdown of the metastable state was obtained with the CaCO3 x H2O heterogeneous precipitation. This clearly illustrates the probable ageing of the precursors of the solid states that are considered in this model.

Development of a prototype regenerable carbon dioxide absorber

NASA Technical Reports Server (NTRS)

Onischak, M.

1976-01-01

Design information was obtained for a new, regenerable carbon dioxide control system for extravehicular activity life support systems. Solid potassium carbonate was supported in a thin porous sheet form and fabricated into carbon dioxide absorber units. Carbon dioxide and water in the life support system atmosphere react with the potassium carbonate and form potassium bicarbonate. The bicarbonate easily reverts to the carbonate by heating to 150 deg C. The methods of effectively packing the sorbent material into EVA-sized units and the effects of inlet concentrations, flowrate, and temperature upon performance were investigated. The cycle life of the sorbent upon the repeated thermal regenerations was demonstrated through 90 cycles.

Relative Permeabilities of Plastic Films to Water and Carbon Dioxide

PubMed Central

Woolley, Joseph T.

1967-01-01

The permeabilities of several types of plastic films to water and to carbon dioxide were measured. No material was found to have a carbon dioxide permeability as great as its water permeability. PMID:16656548

Investigations about the quantitative changes of carbon dioxide production in humans. Report 2: Carbon dioxide production during fever and its relationship with heat production

NASA Technical Reports Server (NTRS)

Liebermeister, C.

1978-01-01

Investigations are cited and explained for carbon dioxide production during fever and its relationship with heat production. The general topics of discussion are: (1) carbon dioxide production for alternating fever attacks; (2) heat balance during the perspiration phase; (3) heat balance during the chill phase; (4) the theory of fever; and (5) chill phase for other fever attacks.

Hydraulic studies of drilling microbores with supercritical steam, nitrogen and carbon dioxide

DOE Data Explorer

Ken Oglesby

2010-01-01

Hydraulic studies of drilling microbores at various depths and with various hole sizes, tubing, fluids and rates showed theoretical feasibility. WELLFLO SIMULATIONS REPORT STEP 4: DRILLING 10,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE STEP 5: DRILLING 20,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE STEP 6: DRILLING 30,000 FT WELLS WITH SUPERCRITICAL STEAM, NITROGEN AND CARBON DIOXIDE Mehmet Karaaslan, MSI

Carbon Dioxide Detection and Indoor Air Quality Control.

PubMed

Bonino, Steve

2016-04-01

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

Advanced air revitalization system modeling and testing

NASA Technical Reports Server (NTRS)

Dall-Baumann, Liese; Jeng, Frank; Christian, Steve; Edeer, Marybeth; Lin, Chin

1990-01-01

To support manned lunar and Martian exploration, an extensive evaluation of air revitalization subsystems (ARS) is being conducted. The major operations under study include carbon dioxide removal and reduction; oxygen and nitrogen production, storage, and distribution; humidity and temperature control; and trace contaminant control. A comprehensive analysis program based on a generalized block flow model was developed to facilitate the evaluation of various processes and their interaction. ASPEN PLUS was used in modelling carbon dioxide removal and reduction. Several life support test stands were developed to test new and existing technologies for their potential applicability in space. The goal was to identify processes which use compact, lightweight equipment and maximize the recovery of oxygen and water. The carbon dioxide removal test stands include solid amine/vacuum desorption (SAVD), regenerative silver oxide chemisorption, and electrochemical carbon dioxide concentration (EDC). Membrane-based carbon dioxide removal and humidity control, catalytic reduction of carbon dioxide, and catalytic oxidation of trace contaminants were also investigated.

Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

DOEpatents

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2011-10-11

Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

Geologic map showing springs rich in carbon dioxide or or chloride in California

USGS Publications Warehouse

Barnes, Ivan; Irwin, William P.; Gibson, H.A.

1975-01-01

Carbon dioxide- and chloride-rich springs occur in all geologic provinces in California, but are most abundant in the Coast Ranges and the Great Valley. The carbon-dioxide-rich springs issue mainly from Franciscan terrane; they also are rich in boron and are of the metamorphic type (White, 1957). Based on isotopic data, either the carbon dioxide or the water, or both, may be of metamorphic origin. Because of high magnesium values, the water of many of the carbon-dioxide-rich springs is thought to have passed through serpentinite. The chloride-rich waters are most common in rocks of the Great Valley sequence. Nearly all are more dilute than present-day sea water. The similarity in isotopic compositions of the metamorphic carbon-dioxide-rich water and the chloride-rich water may indicate a similar extent of water-rock interaction.

Effect of Novel Quercetin Titanium Dioxide-Decorated Multi-Walled Carbon Nanotubes Nanocomposite on Bacillus subtilis Biofilm Development

PubMed Central

Raie, Diana S.; Mhatre, Eisha; El-Desouki, Doaa S.; Labena, Ahmed; El-Ghannam, Gamal; Farahat, Laila A.; Youssef, Tareq; Fritzsche, Wolfgang; Kovács, Ákos T.

2018-01-01

The present work was targeted to design a surface against cell seeding and adhering of bacteria, Bacillus subtilis. A multi-walled carbon nanotube/titanium dioxide nano-power was produced via simple mixing of carbon nanotube and titanium dioxide nanoparticles during the sol-gel process followed by heat treatment. Successfully, quercetin was immobilized on the nanocomposite via physical adsorption to form a quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite. The adhesion of bacteria on the coated-slides was verified after 24 h using confocal laser-scanning microscopy. Results indicated that the quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite had more negativity and higher recovery by glass surfaces than its counterpart. Moreover, coating surfaces with the quercetin-modified nanocomposite lowered both hydrophilicity and surface-attached bacteria compared to surfaces coated with the multi-walled carbon nanotubes/titanium dioxide nanocomposite. PMID:29346268

Production of magnesium metal

DOEpatents

Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

2012-04-10

A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention also relates to the magnesium metal produced by the processes described herein.

Control of Large Actuator Arrays Using Pattern-Forming Systems

DTIC Science & Technology

1998-01-01

carbon dioxide in motor vehicles [1, 3, 4, 5]. Physics examples include patterns observed in shaken collections of small spherical particles, gas...181 6.5 Narrow spike equilibrium shape as a function of β . . . . . . . . . . . . . . . . .182 7.1 One cycle of the...value after a cycle of the pattern solution has been excited as in figure 7.1

Recovery of butanol by counter-current carbon dioxide fractionation with its potential application to butanol fermentation

USDA-ARS?s Scientific Manuscript database

A counter-current CO2 fractionation method was studied as a means to recover butanol (also known as 1-butanol or n-butanol) and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating parameters, such as solvent-to-feed ratio,...

Environmental issues and process risks for operation of carbon capture plant

NASA Astrophysics Data System (ADS)

Lajnert, Radosław; Nowak, Martyna; Telenga-Kopyczyńska, Jolanta

2018-01-01

The scope of this publication is a presentation of environmental issues and process risks connected with operation an installation for carbon capture from waste gas. General technological assumptions, typical for demonstration plant for carbon capture from waste gas (DCCP) with application of two different solutions - 30% water solution of monoethanoloamine (MEA) and water solution with 30% AMP (2-amino-2-methyl-1-propanol) and 10% piperazine have been described. The concept of DCCP installation was made for Łaziska Power Plant in Łaziska Górne owned by TAURON Wytwarzanie S.A. Main hazardous substances, typical for such installation, which can be dangerous for human life and health or for the environment have been presented. Pollution emission to the air, noise emission, waste water and solid waste management have been described. The environmental impact of the released substances has been stated. Reference to emission standards specified in regulations for considered substances has been done. Principles of risk analysis have been presented and main hazards in carbon dioxide absorption node and regeneration node have been evaluated.

Method of preparing electrolyte for use in fuel cells

DOEpatents

Kinoshita, Kimio; Ackerman, John P.

1978-01-01

An electrolyte compact for fuel cells includes a particulate support material of lithium aluminate that contains a mixture of alkali metal compounds, such as carbonates or hydroxides, as the active electrolyte material. The porous lithium aluminate support structure is formed by mixing alumina particles with a solution of lithium hydroxide and another alkali metal hydroxide, evaporating the solvent from the solution and heating to a temperature sufficient to react the lithium hydroxide with alumina to form lithium aluminate. Carbonates are formed by reacting the alkali metal hydroxides with carbon dioxide gas in an exothermic reaction which may proceed simultaneously with the formation with the lithium aluminate. The mixture of lithium aluminate and alkali metal in an electrolyte active material is pressed or otherwise processed to form the electrolyte structure for assembly into a fuel cell.

Ruthenium-catalysed alkoxycarbonylation of alkenes with carbon dioxide.

PubMed

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

2014-01-01

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

W.A. Parish Post Combustion CO 2 Capture and Sequestration Project Final Public Design Report

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

Armpriester, Anthony

The Petra Nova Project is a commercial scale post-combustion carbon dioxide capture project that is being developed by a joint venture between NRG Energy (NRG) and JX Nippon Oil and Gas Exploration (JX). The project is designed to separate and capture carbon dioxide from an existing coal-fired unit's flue gas slipstream at NRG's W.A. Parish Generation Station located southwest of Houston, Texas. The captured carbon dioxide will be transported by pipeline and injected into the West Ranch oil field to boost oil production. The project, which is partially funded by financial assistance from the U.S. Department of Energy will usemore » Mitsubishi Heavy Industries of America, Inc.'s Kansai Mitsubishi Carbon Dioxide Recovery (KM-CDR(R)) advanced amine-based carbon dioxide absorption technology to treat and capture at least 90% of the carbon dioxide from a 240 megawatt equivalent flue gas slipstream off of Unit 8 at W.A. Parish. The project will capture approximately 5,000 tons of carbon dioxide per day or 1.5 million tons per year that Unit 8 would otherwise emit, representing the largest commercial scale deployment of post-combustion carbon dioxide capture at a coal power plant to date. The joint venture issued full notice to proceed in July 2014 and when complete, the project is expected to be the world's largest post-combustion carbon dioxide capture facility on an existing coal plant. The detailed engineering is sufficiently complete to prepare and issue the Final Public Design Report.« less

Selection of inactivation medium for fungal spores in clinical wastes by supercritical carbon dioxide.

PubMed

Noman, Efaq; Norulaini Nik Ab Rahman, Nik; Al-Gheethi, Adel; Nagao, Hideyuki; Talip, Balkis A; Ab Kadir, Omar

2018-05-21

The present study aimed to select the best medium for inactivation of Aspergillus fumigatus, Aspergillus spp. in section Nigri, A. niger, A. terreus var. terreus, A. tubingensis, Penicillium waksmanii, P. simplicissimum, and Aspergillus sp. strain no. 145 spores in clinical wastes by using supercritical carbon dioxide (SC-CO 2 ). There were three types of solutions used including normal saline, seawater, distilled water, and physiological saline with 1% of methanol; each solution was tested at 5, 10, and 20 mL of the water contents. The experiments were conducted at the optimum operating parameters of supercritical carbon dioxide (30 MPa, 75 °C, 90 min). The results showed that the inactivation rate was more effective in distilled water with the presence of 1% methanol (6 log reductions). Meanwhile, the seawater decreases inactivation rate more than normal saline (4.5 vs. 5.1 log reduction). On the other hand, the experiments performed with different volumes of distilled water (5, 10, and 20 mL) indicated that A. niger spores were completely inactivated with 10 mL of distilled water. The inactivation rate of fungal spores decreased from 6 to 4.5 log as the amount of distilled water increased from 10 to 20 mL. The analysis for the spore morphology of A. fumigatus and Aspergillus spp. in section Nigri using scanning electron microscopy (SEM) has revealed the role of temperature and pressure in the SC-CO 2 in the destruction of the cell walls of the spores. It can be concluded that the distilled water represent the best medium for inactivation of fungal spores in the clinical solid wastes by SC-CO 2 .

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

DTIC Science & Technology

2016-04-05

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.

International Space Station Carbon Dioxide Removal Assembly Testing

NASA Technical Reports Server (NTRS)

Knox, James C.

2000-01-01

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

Clonidine versus nitroglycerin infusion in laparoscopic cholecystectomy.

PubMed

Mishra, Manjaree; Mishra, Shashi Prakash; Mathur, Sharad Kumar

2014-01-01

Laparoscopic surgery offers the advantages of minimally invasive surgery; however, pneumoperitoneum and the patient's position induce pathophysiological changes that may complicate anesthetic management. We studied the effect of clonidine and nitroglycerin on heart rate and blood pressure, if any, in association with these drugs or the procedure, as well as the effect of these drugs, if any, on end-tidal carbon dioxide pressure and intraocular pressure. Sixty patients (minimum age of 20 years and maximum age of 65 years, American Society of Anesthesiologists class I or II) undergoing laparoscopic cholecystectomy were randomized into 3 groups and given an infusion of clonidine (group I), nitroglycerin (group II), or normal saline solution (group III) after induction and before creation of pneumoperitoneum. We observed and recorded the following parameters: heart rate, mean arterial blood pressure, end-tidal carbon dioxide pressure, and intraocular pressure. The mean and standard deviation of the parameters studied during the observation period were calculated for the 3 treatment groups and compared by use of analysis of variance tests. Intragroup comparison was performed with the paired t test. The critical value of P, indicating the probability of a significant difference, was taken as < .05 for comparisons. Statistically significant differences in heart rate were observed among the various groups, whereas comparisons of mean arterial pressure, intraocular pressure, and end-tidal carbon dioxide pressure showed statistically significant differences only between groups I and III and between groups II and III. We found clonidine to be more effective than nitroglycerin at preventing changes in hemodynamic parameters and intraocular pressure induced by carbon dioxide insufflation during laparoscopic cholecystectomy. It was also found not to cause hypotension severe enough to stop the infusion and warrant treatment.

Clonidine Versus Nitroglycerin Infusion in Laparoscopic Cholecystectomy

PubMed Central

Mishra, Manjaree; Mishra, Shashi Prakash

2014-01-01

Background and Objectives: Laparoscopic surgery offers the advantages of minimally invasive surgery; however, pneumoperitoneum and the patient's position induce pathophysiological changes that may complicate anesthetic management. We studied the effect of clonidine and nitroglycerin on heart rate and blood pressure, if any, in association with these drugs or the procedure, as well as the effect of these drugs, if any, on end-tidal carbon dioxide pressure and intraocular pressure. Methods: Sixty patients (minimum age of 20 years and maximum age of 65 years, American Society of Anesthesiologists class I or II) undergoing laparoscopic cholecystectomy were randomized into 3 groups and given an infusion of clonidine (group I), nitroglycerin (group II), or normal saline solution (group III) after induction and before creation of pneumoperitoneum. We observed and recorded the following parameters: heart rate, mean arterial blood pressure, end-tidal carbon dioxide pressure, and intraocular pressure. The mean and standard deviation of the parameters studied during the observation period were calculated for the 3 treatment groups and compared by use of analysis of variance tests. Intragroup comparison was performed with the paired t test. The critical value of P, indicating the probability of a significant difference, was taken as < .05 for comparisons. Results: Statistically significant differences in heart rate were observed among the various groups, whereas comparisons of mean arterial pressure, intraocular pressure, and end-tidal carbon dioxide pressure showed statistically significant differences only between groups I and III and between groups II and III. Conclusion: We found clonidine to be more effective than nitroglycerin at preventing changes in hemodynamic parameters and intraocular pressure induced by carbon dioxide insufflation during laparoscopic cholecystectomy. It was also found not to cause hypotension severe enough to stop the infusion and warrant treatment. PMID:25392635

Method for enhanced oil recovery

DOEpatents

Comberiati, Joseph R.; Locke, Charles D.; Kamath, Krishna I.

1980-01-01

The present invention is directed to an improved method for enhanced recovery of oil from relatively "cold" reservoirs by carbon dioxide flooding. In oil reservoirs at a temperature less than the critical temperature of 87.7.degree. F. and at a pore pressure greater than the saturation pressure of carbon dioxide at the temperature of the reservoir, the carbon dioxide remains in the liquid state which does not satisfactorily mix with the oil. However, applicants have found that carbon dioxide can be vaporized in situ in the reservoir by selectively reducing the pore pressure in the reservoir to a value less than the particular saturated vapor pressure so as to greatly enhance the mixing of the carbon dioxide with the oil.

Decreased abundance of crustose coralline algae due to ocean acidification

USGS Publications Warehouse

Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

2008-01-01

Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

46 CFR 95.15-1 - Application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-1 Application. (a) Where a carbon dioxide... are based on a “high pressure system,” i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for “low pressure systems,” i. e., those in which the carbon...