Emitted radiation characteristics of plutonium dioxide radioisotope thermoelectric generators

NASA Technical Reports Server (NTRS)

Gingo, P. J.; Steyn, J. J.

1971-01-01

The nuclear and emitted radiation characteristics of the radioisotope elements and impurities in commercial grade plutonium dioxide are presented in detail. The development of the methods of analysis are presented. Radioisotope thermoelectric generators (RTG) of 1575, 3468 and 5679 thermal watts are characterized with respect to neutron and gamma photon source strength as well as spatial and number flux distribution. The results are presented as a function of detector position and light element contamination concentration for fuel age ranging from 'fresh' to 18 years. The data may be used to obtain results for given O-18 and Pu-236 concentrations. The neutron and gamma photon flux and dose calculations compare favorably with reported experimental values for SNAP-27.

Fire and Pesticides: A Review of Air Quality Considerations

Treesearch

Parshall B. Bush; Daniel G. Neary; Charles K. McMahon

2000-01-01

The classes of primary chemical products naturally produced by the combustion of forest fuels are: carbon dioxide, water, carbon monoxide, particulate matter, methane and non-methane hydrocarbons, polynuclear aromatic hydrocarbons, nitrogen and sulfur oxides, aldehydes, free radicals, and inorganic elements. Secondary chemical products produced by reactions in smoke...

Titanium dioxide in fuel cell technology: An overview

NASA Astrophysics Data System (ADS)

Abdullah, N.; Kamarudin, S. K.

2015-03-01

Fuel cell technology is one of the alternative energy sources for the next generation. Although this technology has proven to be one of the main methods for producing new energy sources, fuel cell technology still has some problems that hinder fuel cell commercialization. Recently, new ideas on titanium dioxide are introduced as potential solution in several applications in fuel cell technology. Thus, this article presents an overview on the applications of titanium dioxide and highlights the unique properties and benefits of titanium dioxide in fuel cell technology.

PREPARATION OF SPHERICAL URANIUM DIOXIDE PARTICLES

DOEpatents

Levey, R.P. Jr.; Smith, A.E.

1963-04-30

This patent relates to the preparation of high-density, spherical UO/sub 2/ particles 80 to 150 microns in diameter. Sinterable UO/sub 2/ powder is wetted with 3 to 5 weight per cent water and tumbled for at least 48 hours. The resulting spherical particles are then sintered. The sintered particles are useful in dispersion-type fuel elements for nuclear reactors. (AEC)

Combined goal gasifier and fuel cell system and method

DOEpatents

Gmeindl, Frank D.; Geisbrecht, Rodney A.

1990-01-01

A molten carbonate fuel cell is combined with a catalytic coal or coal char gasifier for providing the reactant gases comprising hydrogen, carbon monoxide and carbon dioxide used in the operation of the fuel cell. These reactant gases are stripped of sulfur compounds and particulate material and are then separated in discrete gas streams for conveyance to appropriate electrodes in the fuel cell. The gasifier is arranged to receive the reaction products generated at the anode of the fuel cell by the electricity-producing electrochemical reaction therein. These reaction products from the anode are formed primarily of high temperature steam and carbon dioxide to provide the steam, the atmosphere and the heat necessary to endothermically pyrolyze the coal or char in the presence of a catalyst. The reaction products generated at the cathode are substantially formed of carbon dioxide which is used to heat air being admixed with the carbon dioxide stream from the gasifier for providing the oxygen required for the reaction in the fuel cell and for driving an expansion device for energy recovery. A portion of this carbon dioxide from the cathode may be recycled into the fuel cell with the air-carbon dioxide mixture.

Estimating diesel fuel consumption and carbon dioxide emissions from forest road construction

Treesearch

Dan Loeffler; Greg Jones; Nikolaus Vonessen; Sean Healey; Woodam Chung

2009-01-01

Forest access road construction is a necessary component of many on-the-ground forest vegetation treatment projects. However, the fuel energy requirements and associated carbon dioxide emissions from forest road construction are unknown. We present a method for estimating diesel fuel consumed and related carbon dioxide emissions from constructing forest roads using...

Emissions factors for gaseous and particulate pollutants from offshore diesel engine vessels in China

NASA Astrophysics Data System (ADS)

Zhang, F.; Chen, Y.; Tian, C.; Li, J.; Zhang, G.; Matthias, V.

2015-09-01

Shipping emissions have significant influence on atmospheric environment as well as human health, especially in coastal areas and the harbor districts. However, the contribution of shipping emissions on the environment in China still need to be clarified especially based on measurement data, with the large number ownership of vessels and the rapid developments of ports, international trade and shipbuilding industry. Pollutants in the gaseous phase (carbon monoxide, sulfur dioxide, nitrogen oxides, total volatile organic compounds) and particle phase (particulate matter, organic carbon, elemental carbon, sulfates, nitrate, ammonia, metals) in the exhaust from three different diesel engine power offshore vessels in China were measured in this study. Concentrations, fuel-based and power-based emissions factors for various operating modes as well as the impact of engine speed on emissions were determined. Observed concentrations and emissions factors for carbon monoxide, nitrogen oxides, total volatile organic compounds, and particulate matter were higher for the low engine power vessel than for the two higher engine power vessels. Fuel-based average emissions factors for all pollutants except sulfur dioxide in the low engine power engineering vessel were significantly higher than that of the previous studies, while for the two higher engine power vessels, the fuel-based average emissions factors for all pollutants were comparable to the results of the previous studies. The fuel-based average emissions factor for nitrogen oxides for the small engine power vessel was more than twice the International Maritime Organization standard, while those for the other two vessels were below the standard. Emissions factors for all three vessels were significantly different during different operating modes. Organic carbon and elemental carbon were the main components of particulate matter, while water-soluble ions and elements were present in trace amounts. Best-fit engine speeds during actual operation should be based on both emissions factors and economic costs.

Raman spectroscopic investigation of thorium dioxide-uranium dioxide (ThO₂-UO₂) fuel materials.

PubMed

Rao, Rekha; Bhagat, R K; Salke, Nilesh P; Kumar, Arun

2014-01-01

Raman spectroscopic investigations were carried out on proposed nuclear fuel thorium dioxide-uranium dioxide (ThO2-UO2) solid solutions and simulated fuels based on ThO2-UO2. Raman spectra of ThO2-UO2 solid solutions exhibited two-mode behavior in the entire composition range. Variations in mode frequencies and relative intensities of Raman modes enabled estimation of composition, defects, and oxygen stoichiometry in these compounds that are essential for their application. The present study shows that Raman spectroscopy is a simple, promising analytical tool for nondestructive characterization of this important class of nuclear fuel materials.

Revised Point of Departure Design Options for Nuclear Thermal Propulsion

NASA Technical Reports Server (NTRS)

Fittje, James E.; Borowski, Stanley K.; Schnitzler, Bruce

2015-01-01

In an effort to further refine potential point of departure nuclear thermal rocket engine designs, four proposed engine designs representing two thrust classes and utilizing two different fuel matrix types are designed and analyzed from both a neutronics and thermodynamic cycle perspective. Two of these nuclear rocket engine designs employ a tungsten and uranium dioxide cermet (ceramic-metal) fuel with a prismatic geometry based on the ANL-200 and the GE-710, while the other two designs utilize uranium-zirconium-carbide in a graphite composite fuel and a prismatic fuel element geometry developed during the Rover/NERVA Programs. Two engines are analyzed for each fuel type, a small criticality limited design and a 111 kN (25 klbf) thrust class engine design, which has been the focus of numerous manned mission studies, including NASA's Design Reference Architecture 5.0. slightly higher T/W ratios, but they required substantially more 235U.

Stabilizing stored PuO2 with addition of metal impurities

NASA Astrophysics Data System (ADS)

Moten, Shafaq; Huda, Muhammad

Plutonium oxides is of widespread significance due its application in nuclear fuels, space missions, as well as the long-termed storage of plutonium from spent fuel and nuclear weapons. The processes to refine and store plutonium bring many other elements in contact with the plutonium metal and thereby affect the chemistry of the plutonium. Pure plutonium metal corrodes to an oxide in air with the most stable form of this oxide is stoichiometric plutonium dioxide, PuO2. Defects such as impurities and vacancies can form in the plutonium dioxide before, during and after the refining processes as well as during storage. An impurity defect manifests itself at the bottom of the conduction band and affects the band gap of the unit cell. Studying the interaction between transition metals and plutonium dioxide is critical for better, more efficient storage plans as well as gaining insights to provide a better response to potential threats of exposure to the environment. Our study explores the interaction of a few metals within the plutonium dioxide structure which have a likelihood of being exposed to the plutonium dioxide powder. Using Density Functional Theory, we calculated a substituted metal impurity in PuO2 supercell. We repeated the calculations with an additional oxygen vacancy. Our results reveal interesting volume contraction of PuO2 supercell when one plutonium atom is substituted with a metal atom. The authors acknowledge the Texas Computing Center (TACC) at The University of Texas at Austin and High Performance Computing (HPC) at The University of Texas at Arlington.

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.

Emission factors of fine particulate matter, organic and elemental carbon, carbon monoxide, and carbon dioxide for four solid fuels commonly used in residential heating by the U.S. Navajo Nation.

PubMed

Champion, Wyatt M; Connors, Lea; Montoya, Lupita D

2017-09-01

Most homes in the Navajo Nation use wood as their primary heating fuel, often in combination with locally mined coal. Previous studies observed health effects linked to this solid-fuel use in several Navajo communities. Emission factors (EFs) for common fuels used by the Navajo have not been reported using a relevant stove type. In this study, two softwoods (ponderosa pine and Utah juniper) and two high-volatile bituminous coals (Black Mesa and Fruitland) were tested with an in-use residential conventional wood stove (homestove) using a modified American Society for Testing and Materials/U.S. Environmental Protection Agency (ASTM/EPA) protocol. Filter sampling quantified PM 2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) and organic (OC) and elemental (EC) carbon in the emissions. Real-time monitoring quantified carbon monoxide (CO), carbon dioxide (CO 2 ), and total suspended particles (TSP). EFs for these air pollutants were developed and normalized to both fuel mass and energy consumed. In general, coal had significantly higher mass EFs than wood for all pollutants studied. In particular, coal emitted, on average, 10 times more PM 2.5 than wood on a mass basis, and 2.4 times more on an energy basis. The EFs developed here were based on fuel types, stove design, and operating protocols relevant to the Navajo Nation, but they could be useful to other Native Nations with similar practices, such as the nearby Hopi Nation. Indoor wood and coal combustion is an important contributor to public health burdens in the Navajo Nation. Currently, there exist no emission factors representative of Navajo homestoves, fuels, and practices. This study developed emission factors for PM 2.5 , OC, EC, CO, and CO 2 using a representative Navajo homestove. These emission factors may be utilized in regional-, national-, and global-scale health and environmental models. Additionally, the protocols developed and results presented here may inform on-going stove design of the first EPA-certified wood and coal combination stove.

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)

40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

Code of Federal Regulations, 2010 CFR

2010-07-01

... sources Method 6A—Determination of sulfur dioxide, moisture, and carbon dioxide emissions from fossil fuel... fossil fuel combustion sources Method 6C—Determination of Sulfur Dioxide Emissions From Stationary... with SO2 to form particulate sulfite and by reacting with the indicator. If free ammonia is present...

40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

Code of Federal Regulations, 2011 CFR

2011-07-01

... sources Method 6A—Determination of sulfur dioxide, moisture, and carbon dioxide emissions from fossil fuel... fossil fuel combustion sources Method 6C—Determination of Sulfur Dioxide Emissions From Stationary... with SO2 to form particulate sulfite and by reacting with the indicator. If free ammonia is present...

40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

Code of Federal Regulations, 2013 CFR

2013-07-01

... sources Method 6A—Determination of sulfur dioxide, moisture, and carbon dioxide emissions from fossil fuel... fossil fuel combustion sources Method 6C—Determination of Sulfur Dioxide Emissions From Stationary... with SO2 to form particulate sulfite and by reacting with the indicator. If free ammonia is present...

40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

Code of Federal Regulations, 2014 CFR

2014-07-01

... sources Method 6A—Determination of sulfur dioxide, moisture, and carbon dioxide emissions from fossil fuel... fossil fuel combustion sources Method 6C—Determination of Sulfur Dioxide Emissions From Stationary... reacting with SO2 to form particulate sulfite and by reacting with the indicator. If free ammonia is...

40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

Code of Federal Regulations, 2012 CFR

2012-07-01

... sources Method 6A—Determination of sulfur dioxide, moisture, and carbon dioxide emissions from fossil fuel... fossil fuel combustion sources Method 6C—Determination of Sulfur Dioxide Emissions From Stationary... with SO2 to form particulate sulfite and by reacting with the indicator. If free ammonia is present...

Seasonal variations in elemental carbon aerosol, carbon monoxide and sulfur dioxide: Implications for sources

NASA Astrophysics Data System (ADS)

Antony Chen, L.-W.; Doddridge, Bruce G.; Dickerson, Russell R.; Chow, Judith C.; Mueller, Peter K.; Quinn, John; Butler, William A.

As part of Maryland Aerosol Research and CHaracterization (MARCH-Atlantic) study, measurements of 24-hr average elemental carbon (EC) aerosol concentration were made at Fort Meade, Maryland, USA, a suburban site within the Baltimore-Washington corridor during July 1999, October 1999, January 2000, April 2000 and July 2000. Carbon monoxide (CO) and sulfur dioxide (SO2) were also measured nearly continuously over the period. Tight correlation between EC and CO in every month suggests common or proximate sources, likely traffic emissions. The EC versus CO slope varies in different seasons and generally increases with ambient temperature. The temperature dependence of EC/CO ratios suggests that EC source strength peaks in summer. By using the well established emission inventory for CO, and EC/CO ratio found in this study, EC emission over North America is estimated at 0.31±0.12 Tg yr-1, on the low end but in reasonable agreement with prior inventories based on emission factors and fuel consumption.

Seasonal variations in elemental carbon aerosol, carbon monoxide and sulfur dioxide: Implications for sources

NASA Astrophysics Data System (ADS)

Chen, L.-W. Antony; Doddridge, Bruce G.; Dickerson, Russell R.; Chow, Judith C.; Mueller, Peter K.; Quinn, John; Butler, William A.

2001-05-01

As part of Maryland Aerosol Research and CHaracterization (MARCH-Atlantic) study, measurements of 24-hr average elemental carbon (EC) aerosol concentration were made at Fort Meade, Maryland, USA, a suburban site within the Baltimore-Washington corridor during July 1999, October 1999, January 2000, April 2000 and July 2000. Carbon monoxide (CO) and sulfur dioxide (SO2) were also measured nearly continuously over the period. Tight correlation between EC and CO in every month suggests common or proximate sources, likely traffic emissions. The EC versus CO slope varies in different seasons and generally increases with ambient temperature. The temperature dependence of EC/CO ratios suggests that EC source strength peaks in summer. By using the well established emission inventory for CO, and EC/CO ratio found in this study, EC emission over North America is estimated at 0.31+/-0.12Tgyr-1, on the low end but in reasonable agreement with prior inventories based on emission factors and fuel consumption.

Estimates of Fossil Fuel Carbon Dioxide Emissions From Mexico at Monthly Time Intervals

NASA Astrophysics Data System (ADS)

Losey, L. M.; Andres, R. J.

2003-12-01

Human consumption of fossil fuels has greatly contributed to the rise of carbon dioxide in the Earth's atmosphere. To better understand the global carbon cycle, it is important to identify the major sources of these fossil fuels. Mexico is among the top fifteen nations in the world for producing fossil fuel carbon dioxide emissions. Based on this information and that emissions from Mexico are a focus of the North American Carbon Program, Mexico was selected for this study. Mexican monthly inland sales volumes for January 1988-May 2003 were collected on natural gas and liquid fuels from the Energy Information Agency in the United States Department of Energy. These sales figures represent a major portion of the total fossil fuel consumption in Mexico. The fraction of a particular fossil fuel consumed in a given month was determined by dividing the monthly sales volumes by the annual sum of monthly sales volumes for a given year. This fraction was then multiplied by the annual carbon dioxide values reported by the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) to estimate the monthly carbon dioxide emissions from the respective fuels. The advantages of this methodology are: 1) monthly fluxes are consistent with the annual flux as determined by the widely-accepted CDIAC values, and 2) its general application can be easily adapted to other nations for determining their sub-annual time scale emissions. The major disadvantage of this methodology is the proxy nature inherent to it. Only a fraction of the total emissions are used as an estimate in determining the seasonal cycle. The error inherent in this approach increases as the fraction of total emissions represented by the proxy decreases. These data are part of a long-term project between researchers at the University of North Dakota and ORNL which attempts to identify and understand the source(s) of seasonal variations of global, fossil-fuel derived, carbon dioxide emissions. Better knowledge of the temporal variation of the annual fossil fuel flux will lead to a better understanding of the global carbon cycle. This research will be archived at CDIAC for public access.

Carbon fuel cells with carbon corrosion suppression

DOEpatents

Cooper, John F [Oakland, CA

2012-04-10

An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

Implementation of a Thermodynamic Solver within a Computer Program for Calculating Fission-Product Release Fractions

NASA Astrophysics Data System (ADS)

Barber, Duncan Henry

During some postulated accidents at nuclear power stations, fuel cooling may be impaired. In such cases, the fuel heats up and the subsequent increased fission-gas release from the fuel to the gap may result in fuel sheath failure. After fuel sheath failure, the barrier between the coolant and the fuel pellets is lost or impaired, gases and vapours from the fuel-to-sheath gap and other open voids in the fuel pellets can be vented. Gases and steam from the coolant can enter the broken fuel sheath and interact with the fuel pellet surfaces and the fission-product inclusion on the fuel surface (including material at the surface of the fuel matrix). The chemistry of this interaction is an important mechanism to model in order to assess fission-product releases from fuel. Starting in 1995, the computer program SOURCE 2.0 was developed by the Canadian nuclear industry to model fission-product release from fuel during such accidents. SOURCE 2.0 has employed an early thermochemical model of irradiated uranium dioxide fuel developed at the Royal Military College of Canada. To overcome the limitations of computers of that time, the implementation of the RMC model employed lookup tables to pre-calculated equilibrium conditions. In the intervening years, the RMC model has been improved, the power of computers has increased significantly, and thermodynamic subroutine libraries have become available. This thesis is the result of extensive work based on these three factors. A prototype computer program (referred to as SC11) has been developed that uses a thermodynamic subroutine library to calculate thermodynamic equilibria using Gibbs energy minimization. The Gibbs energy minimization requires the system temperature (T) and pressure (P), and the inventory of chemical elements (n) in the system. In order to calculate the inventory of chemical elements in the fuel, the list of nuclides and nuclear isomers modelled in SC11 had to be expanded from the list used by SOURCE 2.0. A benchmark calculation demonstrates the improvement in agreement of the total inventory of those chemical elements included in the RMC fuel model to an ORIGEN-S calculation. ORIGEN-S is the Oak Ridge isotope generation and depletion computer program. The Gibbs energy minimizer requires a chemical database containing coefficients from which the Gibbs energy of pure compounds, gas and liquid mixtures, and solid solutions can be calculated. The RMC model of irradiated uranium dioxide fuel has been converted into the required format. The Gibbs energy minimizer has been incorporated into a new model of fission-product vaporization from the fuel surface. Calculated release fractions using the new code have been compared to results calculated with SOURCE IST 2.0P11 and to results of tests used in the validation of SOURCE 2.0. The new code shows improvements in agreement with experimental releases for a number of nuclides. Of particular significance is the better agreement between experimental and calculated release fractions for 140La. The improved agreement reflects the inclusion in the RMC model of the solubility of lanthanum (III) oxide (La2O3) in the fuel matrix. Calculated lanthanide release fractions from earlier computer programs were a challenge to environmental qualification analysis of equipment for some accident scenarios. The new prototype computer program would alleviate this concern. Keywords: Nuclear Engineering; Material Science; Thermodynamics; Radioactive Material, Gibbs Energy Minimization, Actinide Generation and Depletion, FissionProduct Generation and Depletion.

A synthesis of carbon dioxide emissions from fossil-fuel combustion

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

Andres, Robert Joseph; Boden, Thomas A; Breon, F.-M.

2012-01-01

This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores 5 our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e. maps); how they are transported in models; and the uncertainties associated with these different aspects of themore » emissions. The magnitude of emissions 10 from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10% uncertainty (95% 15 confidence interval). Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. The information discussed in this manuscript synthesizes global, regional and national fossil-fuel carbon dioxide emissions, their distributions, their transport, and the associated uncertainties.« less

Indoor Spatial Monitoring of Combustion Generated Pollutants (TSP, CO, and BaP) by Indian Cookstoves

DTIC Science & Technology

1988-07-01

various building materials and consumer products, and combustion appliances. People and pets normally emit C02 , moisture, odors, and microbes. Tobacco ...fuels Group II. Sources both indoor and outdoor: Nitric oxide, nitrogen dioxide Fuel-burning, tobacco smoke Polycyclic hydrocarbons Fuel-burning, tobacco ...smoke Carbon monoxide Fuel-burning, tobacco smoke Carbon dioxide Metabolic activity, combustion Suspended particulate matter Resuspension

[FTIR detection of unregulated emissions from a diesel engine with biodiesel fuel].

PubMed

Tan, Pi-qiang; Hu, Zhi-yuan; Lou, Di-ming

2012-02-01

Biodiesel, as one of the most promising alternative fuels, has received more attention because of limited fossil fuels. A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions. A diesel fuel, a pure biodiesel fuel, and fuel with 20% V/V biodiesel blend ratio were tested without engine modification The present study examines six typical unregulated emissions by Fourier transform infrared spectroscopy (FTIR) method: formaldehyde (HCHO), acetaldehyde (C2 H4 O), acetone (C3 H6 O), toluene (C7 H8), sulfur dioxide (SO2), and carbon dioxide (CO2). The results show addition of biodiesel fuel increases the formaldehyde emission, and B20 fuel has little change, but the formaldehyde emission of pure biodiesel shows a clear trend of addition. Compared with the pure diesel fuel, the acetaldehyde of B20 fuel has a distinct decrease, and the acetaldehyde emission of pure biodiesel is lower than that of the pure diesel fuel at low and middle engine loads, but higher at high engine load. The acetone emission is very low, and increases for B20 and pure biodiesel fuels as compared to diesel fuel. Compared with the diesel fuel, the toluene and sulfur dioxide values of the engine show a distinct decrease with biodiesel blend ratio increasing. It is clear that the biodiesel could reduce aromatic compounds and emissions of diesel engines. The carbon dioxide emission of pure biodiesel has a little lower value than diesel, showing that the biodiesel benefits control of greenhouse gas.

Comprehensive laboratory measurements of biomass-burning emissions: 1. Emissions from Indonesian, African, and other fuels

NASA Astrophysics Data System (ADS)

Christian, T. J.; Kleiss, B.; Yokelson, R. J.; Holzinger, R.; Crutzen, P. J.; Hao, W. M.; Saharjo, B. H.; Ward, D. E.

2003-12-01

Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH4, NH3, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21-34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both the laboratory and the field. However, the higher concentrations and more extensive instrumentation in this work allowed quantification of at least 10 species not previously quantified for African field fires (in order of abundance): acetaldehyde, phenol, acetol, glycolaldehyde, methylvinylether, furan, acetone, acetonitrile, propenenitrile, and propanenitrile. Most of these new compounds are oxygenated organic compounds, which further reinforces the importance of these reactive compounds as initial emissions from global biomass burning. A few high-combustion-efficiency fires emitted very high levels of elemental (black) carbon, suggesting that biomass burning may produce more elemental carbon than previously estimated.

TRACKING THE EMISSION OF CARBON DIOXIDE BY NATION, SECTOR, AND FUEL TYPE: A TRACE GAS ACCOUNTING SYSTEM (TGAS)

EPA Science Inventory

The paper describes a new way to estimate an efficient econometric model of global emissions of carbon dioxide (CO2) by nation, sector, and fuel type. Equations for fuel intensity are estimated for coal, oil, natural gas, electricity, and heat for six sectors: agricultural, indus...

Nuclear Energy and Synthetic Liquid Transportation Fuels

NASA Astrophysics Data System (ADS)

McDonald, Richard

2012-10-01

This talk will propose a plan to combine nuclear reactors with the Fischer-Tropsch (F-T) process to produce synthetic carbon-neutral liquid transportation fuels from sea water. These fuels can be formed from the hydrogen and carbon dioxide in sea water and will burn to water and carbon dioxide in a cycle powered by nuclear reactors. The F-T process was developed nearly 100 years ago as a method of synthesizing liquid fuels from coal. This process presently provides commercial liquid fuels in South Africa, Malaysia, and Qatar, mainly using natural gas as a feedstock. Nuclear energy can be used to separate water into hydrogen and oxygen as well as to extract carbon dioxide from sea water using ion exchange technology. The carbon dioxide and hydrogen react to form synthesis gas, the mixture needed at the beginning of the F-T process. Following further refining, the products, typically diesel and Jet-A, can use existing infrastructure and can power conventional engines with little or no modification. We can then use these carbon-neutral liquid fuels conveniently long into the future with few adverse environmental impacts.

Thermodynamic Simulation of Equilibrium Composition of Reaction Products at Dehydration of a Technological Channel in a Uranium-Graphite Reactor

NASA Astrophysics Data System (ADS)

Pavliuk, A. O.; Zagumennov, V. S.; Kotlyarevskiy, S. G.; Bespala, E. V.

2018-01-01

The problems of accumulation of nuclear fuel spills in the graphite stack in the course of operation of uranium-graphite nuclear reactors are considered. The results of thermodynamic analysis of the processes in the graphite stack at dehydration of a technological channel, fuel element shell unsealing and migration of fission products, and activation of stable nuclides in structural elements of the reactor and actinides inside the graphite moderator are given. The main chemical reactions and compounds that are produced in these modes in the reactor channel during its operation and that may be hazardous after its shutdown and decommissioning are presented. Thermodynamic simulation of the equilibrium composition is performed using the specialized code TERRA. The results of thermodynamic simulation of the equilibrium composition in different cases of technological channel dehydration in the course of the reactor operation show that, if the temperature inside the active core of the nuclear reactor increases to the melting temperature of the fuel element, oxides and carbides of nuclear fuel are produced. The mathematical model of the nonstationary heat transfer in a graphite stack of a uranium-graphite reactor in the case of the technological channel dehydration is presented. The results of calculated temperature evolution at the center of the fuel element, the replaceable graphite element, the air gap, and in the surface layer of the block graphite are given. The numerical results show that, in the case of dehydration of the technological channel in the uranium-graphite reactor with metallic uranium, the main reaction product is uranium dioxide UO2 in the condensed phase. Low probability of production of pyrophoric uranium compounds (UH3) in the graphite stack is proven, which allows one to disassemble the graphite stack without the risk of spontaneous graphite ignition in the course of decommissioning of the uranium-graphite nuclear reactor.

Ceria-thoria pellet manufacturing in preparation for plutonia-thoria LWR fuel production

NASA Astrophysics Data System (ADS)

Drera, Saleem S.; Björk, Klara Insulander; Sobieska, Matylda

2016-10-01

Thorium dioxide (thoria) has potential to assist in niche roles as fuel for light water reactors (LWRs). One such application for thoria is its use as the fertile component to burn plutonium in a mixed oxide fuel (MOX). Thor Energy and an international consortium are currently irradiating plutonia-thoria (Th-MOX) fuel in an effort to produce data for its licensing basis. During fuel-manufacturing research and development (R&D), surrogate materials were utilized to highlight procedures and build experience. Cerium dioxide (ceria) provides a good surrogate platform to replicate the chemical nature of plutonium dioxide. The project's fuel manufacturing R&D focused on powder metallurgical techniques to ensure manufacturability with the current commercial MOX fuel production infrastructure. The following paper highlights basics of the ceria-thoria fuel production including powder milling, pellet pressing and pellet sintering. Green pellets and sintered pellets were manufactured with average densities of 67.0% and 95.5% that of theoretical density respectively.

Fuel electrode containing pre-sintered nickel/zirconia for a solid oxide fuel cell

DOEpatents

Ruka, Roswell J.; Vora, Shailesh D.

2001-01-01

A fuel cell structure (2) is provided, having a pre-sintered nickel-zirconia fuel electrode (6) and an air electrode (4), with a ceramic electrolyte (5) disposed between the electrodes, where the pre-sintered fuel electrode (6) contains particles selected from the group consisting of nickel oxide, cobalt and cerium dioxide particles and mixtures thereof, and titanium dioxide particles, within a matrix of yttria-stabilized zirconia and spaced-apart filamentary nickel strings having a chain structure, and where the fuel electrode can be sintered to provide an active solid oxide fuel cell.

Standalone anion- and co-doped titanium dioxide nanotubes for photocatalytic and photoelectrochemical solar-to-fuel conversion.

PubMed

Ding, Yuchen; Nagpal, Prashant

2016-10-14

Several strategies are currently being investigated for conversion of incident sunlight into renewable sources of energy, and photocatalytic or photoelectrochemical production of solar fuels can provide an important alternative. Titanium dioxide (TiO 2 ) has been heavily investigated as a material of choice due to its excellent optoelectronic properties and stability, and anion-doping proposed as a pathway to improve light absorption as well as improving the efficiency of oxygen production. While several studies have used morphological tuning, elemental doping, and surface engineering in TiO 2 to extend its absorption, there is a need to optimize simultaneously charge transport and improve interfacial chemical reaction kinetics. Here we show anion-doped (nitrogen, carbon) standalone TiO 2 nanotube membranes that absorb visible light for the water-splitting reaction, using both wireless (photocatalysis) and wired (photoelectrochemical) solar-to-fuel conversion (STFC) cells. Using simulated solar radiation, we show generation of hydrogen as a solar fuel using visible light photocatalysis. Furthermore, using a model we elucidate detailed photophysics and photoelectrochemical properties of these nanotubes, and explain the kinetics of photogenerated charge carriers following light absorption. We show that while visible light induces a superlinear photoresponse for catalytic reduction and may benefit from higher incident light intensity, ultraviolet light shows a linear photoresponse and saturation with higher light flux due to trapping of photogenerated charges (mainly electrons). These results can have important implications for design of other metal-oxide membranes for solar fuel generation, and appropriate design of dopants and induced energy levels in these photocatalysts.

Inerting Aircraft Fuel Systems Using Exhaust Gases

NASA Technical Reports Server (NTRS)

Hehemann, David G.

2002-01-01

Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

Thermal Aspects of Using Alternative Nuclear Fuels in Supercritical Water-Cooled Reactors

NASA Astrophysics Data System (ADS)

Grande, Lisa Christine

A SuperCritical Water-cooled Nuclear Reactor (SCWR) is a Generation IV concept currently being developed worldwide. Unique to this reactor type is the use of light-water coolant above its critical point. The current research presents a thermal-hydraulic analysis of a single fuel channel within a Pressure Tube (PT)-type SCWR with a single-reheat cycle. Since this reactor is in its early design phase many fuel-channel components are being investigated in various combinations. Analysis inputs are: steam cycle, Axial Heat Flux Profile (AHFP), fuel-bundle geometry, and thermophysical properties of reactor coolant, fuel sheath and fuel. Uniform and non-uniform AHFPs for average channel power were applied to a variety of alternative fuels (mixed oxide, thorium dioxide, uranium dicarbide, uranium nitride and uranium carbide) enclosed in an Inconel-600 43-element bundle. The results depict bulk-fluid, outer-sheath and fuel-centreline temperature profiles together with the Heat Transfer Coefficient (HTC) profiles along the heated length of fuel channel. The objective is to identify the best options in terms of fuel, sheath material and AHFPS in which the outer-sheath and fuel-centreline temperatures will be below the accepted temperature limits of 850°C and 1850°C respectively. The 43-element Inconel-600 fuel bundle is suitable for SCWR use as the sheath-temperature design limit of 850°C was maintained for all analyzed cases at average channel power. Thoria, UC2, UN and UC fuels for all AHFPs are acceptable since the maximum fuel-centreline temperature does not exceed the industry accepted limit of 1850°C. Conversely, the fuel-centreline temperature limit was exceeded for MOX at all AHFPs, and UO2 for both cosine and downstream-skewed cosine AHFPs. Therefore, fuel-bundle modifications are required for UO2 and MOX to be feasible nuclear fuels for SCWRs.

Extended duration orbiter study: CO2 removal and water recovery

NASA Technical Reports Server (NTRS)

Marshall, R. D.; Ellis, G. S.; Schubert, F. H.; Wynveen, R. A.

1979-01-01

Two electrochemical depolarized carbon dioxide concentrator subsystems were evaluated against baseline lithium hydroxide for (1) the baseline orbiter when expanded to accommodate a crew of seven (mission option one), (2) an extended duration orbiter with a power extension package to reduce fuel cell expendables (mission option two), and (3) an extended duration orbiter with a full capability power module to eliminate fuel cell expendables (mission option three). The electrochemical depolarized carbon dioxide concentrator was also compared to the solid amine regenerable carbon dioxide removal concept. Water recovery is not required for Mission Option One since sufficient water is generated by the fuel cells. The vapor compression distillation subsystem was evaluated for mission option two and three only. Weight savings attainable using the vapor compression distillation subsystem for water recovery versus on-board water storage were determined. Combined carbon dioxide removal and water recovery was evaluated to determine the effect on regenerable carbon dioxide removal subsystem selection.

Segregated exhaust SOFC generator with high fuel utilization capability

DOEpatents

Draper, Robert; Veyo, Stephen E.; Kothmann, Richard E.

2003-08-26

A fuel cell generator contains a plurality of fuel cells (6) in a generator chamber (1) and also contains a depleted fuel reactor or a fuel depletion chamber (2) where oxidant (24,25) and fuel (81) is fed to the generator chamber (1) and the depleted fuel reactor chamber (2), where both fuel and oxidant react, and where all oxidant and fuel passages are separate and do not communicate with each other, so that fuel and oxidant in whatever form do not mix and where a depleted fuel exit (23) is provided for exiting a product gas (19) which consists essentially of carbon dioxide and water for further treatment so that carbon dioxide can be separated and is not vented to the atmosphere.

Calculation of global carbon dioxide emissions: Review of emission factors and a new approach taking fuel quality into consideration

NASA Astrophysics Data System (ADS)

Hiete, Michael; Berner, Ulrich; Richter, Otto

2001-03-01

Anthropogenic carbon dioxide emissions resulting from fossil fuel consumption play a major role in the current debate on climate change. Carbon dioxide emissions are calculated on the basis of a carbon dioxide emission factor (CEF) for each type of fuel. Published CEFs are reviewed in this paper. It was found that for nearly all CEFs, fuel quality is not adequately taken into account. This is especially true in the case of the CEFs for coal. Published CEFs are often based on generalized assumptions and inexact conversions. In particular, conversions from gross calorific value to net calorific value were examined. A new method for determining CEFs as a function of calorific value (for coal, peat, and natural gas) and specific gravity (for crude oil) is presented that permits CEFs to be calculated for specific fuel qualities. A review of proportions of fossil fuels that remain unoxidized owing to incomplete combustion or inclusion in petrochemical products, etc., (stored carbon) shows that these figures need to be updated and checked for their applicability on a global scale, since they are mostly based on U.S. data.

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

EPA Pesticide Factsheets

The Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report is the authoritative reference for carbon dioxide (CO2) emissions, fuel economy, and powertrain technology trends for new personal vehicles in the United States. The ??Trends?? report has been published annually since 1975 and covers all passenger cars, sport utility vehicles, minivans, and all but the largest pickup trucks and vans. This report does not provide formal compliance values for EPA CO2 emissions standards and NHTSA CAFE standards. The downloadable data are available in PDF or spreadsheet (XLS) formats.

Laboratory Studies of Carbon Emission from Biomass Burning for use in Remote Sensing

NASA Technical Reports Server (NTRS)

Wald, Andrew E.; Kaufman, Yoram J.

1998-01-01

Biomass burning is a significant source of many trace gases in the atmosphere. Up to 25% of the total anthropogenic carbon dioxide added to the atmosphere annually is from biomass burning. However, this gaseous emission from fires is not directly detectable from satellite. Infrared radiance from the fires is. In order to see if infrared radiance can be used as a tracer for these emitted gases, we made laboratory measurements to determine the correlation of emitted carbon dioxide, carbon monoxide and total burned biomass with emitted infrared radiance. If the measured correlations among these quantities hold in the field, then satellite-observed infrared radiance can be used to estimate gaseous emission and total burned biomass on a global, daily basis. To this end, several types of biomass fuels were burned under controlled conditions in a large-scale combustion laboratory. Simultaneous measurements of emitted spectral infrared radiance, emitted carbon dioxide, carbon monoxide, and total mass loss were made. In addition measurements of fuel moisture content and fuel elemental abundance were made. We found that for a given fire, the quantity of carbon burned can be estimated from 11 (micro)m radiance measurements only within a factor of five. This variation arises from three sources, 1) errors in our measurements, 2) the subpixel nature of the fires, and 3) inherent differences in combustion of different fuel types. Despite this large range, these measurements can still be used for large-scale satellite estimates of biomass burned. This is because of the very large possible spread of fire sizes that will be subpixel as seen by Moderate Resolution Imaging Spectroradiometer (MODIS). Due to this large spread, even relatively low-precision correlations can still be useful for large-scale estimates of emitted carbon. Furthermore, such estimates using the MODIS 3.9 (micro)m channel should be even more accurate than our estimates based on 11 (micro)m radiance.

Fuel and Carbon Dioxide Emissions Savings Calculation Methodology for Combined Heat and Power Systems

EPA Pesticide Factsheets

This paper provides the EPA Combined Heat and Power Partnership's recommended methodology for calculating fuel and carbon dioxide emissions savings from CHP compared to SHP, which serves as the basis for the EPA's CHP emissions calculator.

LIGHT WATER REACTOR ACCIDENT TOLERANT FUELS IRRADIATION TESTING

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

Carmack, William Jonathan; Barrett, Kristine Eloise; Chichester, Heather Jean MacLean

2015-09-01

The purpose of Accident Tolerant Fuels (ATF) experiments is to test novel fuel and cladding concepts designed to replace the current zirconium alloy uranium dioxide (UO2) fuel system. The objective of this Research and Development (R&D) is to develop novel ATF concepts that will be able to withstand loss of active cooling in the reactor core for a considerably longer time period than the current fuel system while maintaining or improving the fuel performance during normal operations, operational transients, design basis, and beyond design basis events. It was necessary to design, analyze, and fabricate drop-in capsules to meet the requirementsmore » for testing under prototypic LWR temperatures in Idaho National Laboratory's Advanced Test Reactor (ATR). Three industry led teams and one DOE team from Oak Ridge National Laboratory provided fuel rodlet samples for their new concepts for ATR insertion in 2015. As-built projected temperature calculations were performed on the ATF capsules using the BISON fuel performance code. BISON is an application of INL’s Multi-physics Object Oriented Simulation Environment (MOOSE), which is a massively parallel finite element based framework used to solve systems of fully coupled nonlinear partial differential equations. Both 2D and 3D models were set up to examine cladding and fuel performance.« less

Evolution of spent nuclear fuel in dry storage conditions for millennia and beyond

NASA Astrophysics Data System (ADS)

Wiss, Thierry; Hiernaut, Jean-Pol; Roudil, Danièle; Colle, Jean-Yves; Maugeri, Emilio; Talip, Zeynep; Janssen, Arne; Rondinella, Vincenzo; Konings, Rudy J. M.; Matzke, Hans-Joachim; Weber, William J.

2014-08-01

Significant amounts of spent uranium dioxide nuclear fuel are accumulating worldwide from decades of commercial nuclear power production. While such spent fuel is intended to be reprocessed or disposed in geologic repositories, out-of-reactor radiation damage from alpha decay can be detrimental to its structural stability. Here we report on an experimental study in which radiation damage in plutonium dioxide, uranium dioxide samples doped with short-lived alpha-emitters and urano-thorianite minerals have been characterized by XRD, transmission electron microscopy, thermal desorption spectrometry and hardness measurements to assess the long-term stability of spent nuclear fuel to substantial alpha-decay doses. Defect accumulation is predicted to result in swelling of the atomic structure and decrease in fracture toughness; whereas, the accumulation of helium will produce bubbles that result in much larger gaseous-induced swelling that substantially increases the stresses in the constrained spent fuel. Based on these results, the radiation-ageing of highly-aged spent nuclear fuel over more than 10,000 years is predicted.

Electrochemical device for syngas and liquid fuels production

DOEpatents

Braun, Robert J.; Becker, William L.; Penev, Michael

2017-04-25

The invention relates to methods for creating high value liquid fuels such as gasoline, diesel, jet and alcohols using carbon dioxide and water as the starting raw materials and a system for using the same. These methods combine a novel solid oxide electrolytic cell (SOEC) for the efficient and clean conversion of carbon dioxide and water to hydrogen and carbon monoxide, uniquely integrated with a gas-to-liquid fuels producing method.

“Artificial Leaf” Turns Carbon Dioxide Into Fuel

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

None

Researchers at Argonne and the University of Illinois at Chicago have found a way to convert carbon dioxide into a usable energy source using sunlight. The process is similar to photosynthesis, the way plants make fuel from light, so the system is called the “artificial leaf.”

Open-cycle magnetohydrodynamic power plant with CO.sub.2 recycling

DOEpatents

Berry, Gregory F.

1991-01-01

A method of converting the chemical energy of fossil fuel to electrical and mechanical energy with a MHD generator. The fossil fuel is mixed with preheated oxygen and carbon dioxide and a conducting seed of potassium carbonate to form a combustive and electrically conductive mixture which is burned in a combustion chamber. The burned combustion mixture is passed through a MHD generator to generate electrical energy. The burned combustion mixture is passed through a diffuser to restore the mixture approximately to atmospheric pressure, leaving a spent combustion mixture which is used to heat oxygen from an air separation plant and recycled carbon dioxide for combustion in a high temperature oxygen preheater and for heating water/steam for producing superheated steam. Relatively pure carbon dioxide is separated from the spent combustion mixture for further purification or for exhaust, while the remainder of the carbon dioxide is recycled from the spent combustion mixture to a carbon dioxide purification plant for removal of water and any nitrous oxides present, leaving a greater than 98% pure carbon dioxide. A portion of the greater then 98% pure carbon dioxide stream is recovered and the remainder is recycled to combine with the oxygen for preheating and combination with the fossil fuel to form a combustion mixture.

The Effect of Fuel Quality on Carbon Dioxide and Nitrogen Oxide Emissions, While Burning Biomass and RDF

NASA Astrophysics Data System (ADS)

Kalnacs, J.; Bendere, R.; Murasovs, A.; Arina, D.; Antipovs, A.; Kalnacs, A.; Sprince, L.

2018-02-01

The article analyses the variations in carbon dioxide emission factor depending on parameters characterising biomass and RDF (refuse-derived fuel). The influence of moisture, ash content, heat of combustion, carbon and nitrogen content on the amount of emission factors has been reviewed, by determining their average values. The options for the improvement of the fuel to result in reduced emissions of carbon dioxide and nitrogen oxide have been analysed. Systematic measurements of biomass parameters have been performed, by determining their average values, seasonal limits of variations in these parameters and their mutual relations. Typical average values of RDF parameters and limits of variations have been determined.

Final Report - "CO2 Sequestration in Cell Biomass of Chlorobium Thiosulfatophilum"

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

James L. Gaddy, PhD; Ching-Whan Ko, PhD

2009-05-04

World carbon dioxide emissions from the combustion of fossil fuels have increased at a rate of about 3 percent per year during the last 40 years to over 24 billion tons today. While a number of methods have been proposed and are under study for dealing with the carbon dioxide problem, all have advantages as well as disadvantages which limit their application. The anaerobic bacterium Chlorobium thiosulfatophilum uses hydrogen sulfide and carbon dioxide to produce elemental sulfur and cell biomass. The overall objective of this project is to develop a commercial process for the biological sequestration of carbon dioxide andmore » simultaneous conversion of hydrogen sulfide to elemental sulfur. The Phase I study successfully demonstrated the technical feasibility of utilizing this bacterium for carbon dioxide sequestration and hydrogen sulfide conversion to elemental sulfur by utilizing the bacterium in continuous reactor studies. Phase II studies involved an advanced research and development to develop the engineering and scale-up parameters for commercialization of the technology. Tasks include culture isolation and optimization studies, further continuous reactor studies, light delivery systems, high pressure studies, process scale-up, a market analysis and economic projections. A number of anaerobic and aerobic microorgansims, both non-photosynthetic and photosynthetic, were examined to find those with the fastest rates for detailed study to continuous culture experiments. C. thiosulfatophilum was selected for study to anaerobically produce sulfur and Thiomicrospira crunogena waws selected for study to produce sulfate non-photosynthetically. Optimal conditions for growth, H2S and CO2 comparison, supplying light and separating sulfur were defined. The design and economic projections show that light supply for photosynthetic reactions is far too expensive, even when solar systems are considered. However, the aerobic non-photosynthetic reaction to produce sulfate with T. crunogena produces a reasonable return when treating a sour gas stream of 120 million SCFD containing 2.5 percent H2S. In this case, the primary source of revenue is from desulfurization of the gas stream. While the technology has significant application in sequestering carbon dioxide in cell biomass or single cell proten (SCP), perhaps the most immediate application is in desulfurizing LGNG or other gas streams. This biological approach is a viable economical alternative to existing hydrogen sulfide removal technology, and is not sensitive to the presence of hydrocarbons which act as catalyst poisons.« less

Methods and systems for producing syngas

DOEpatents

Hawkes, Grant L; O& #x27; Brien, James E; Stoots, Carl M; Herring, J. Stephen; McKellar, Michael G; Wood, Richard A; Carrington, Robert A; Boardman, Richard D

2013-02-05

Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced.

Molybdenum-UO2 cermet irradiation at 1145 K.

NASA Technical Reports Server (NTRS)

Mcdonald, G.

1971-01-01

Two molybdenum-uranium dioxide cermet fuel pins with molybdenum clad were fission-heated in a forced-convection helium coolant for sufficient time to achieve 5.3% burnup. The cermet core contained 20 wt % of 93.2% enriched uranium dioxide. The results were as follows: there was no visible change in the appearance of the molybdenum clad during irradiation; the maximum increase in diameter of the fuel pins was 0.8%; there was no migration of uranium dioxide along grain boundaries and no evident interaction between molybdenum and uranium dioxide; and, finally, approximately 12% of the fission gas formed was released from the cermet core into the gas plenum.

Nitrogen dioxide detection

DOEpatents

Sinha, Dipen N.; Agnew, Stephen F.; Christensen, William H.

1993-01-01

Method and apparatus for detecting the presence of gaseous nitrogen dioxide and determining the amount of gas which is present. Though polystyrene is normally an insulator, it becomes electrically conductive in the presence of nitrogen dioxide. Conductance or resistance of a polystyrene sensing element is related to the concentration of nitrogen dioxide at the sensing element.

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.

Carbon deposition during oxygen production using high temperature electrolysis and mitigation methods

NASA Astrophysics Data System (ADS)

Bernadowski, Timothy Adam, Jr.

Carbon dioxide in the Martian atmosphere can be converted to oxygen during high temperature electrolysis for use in life-support and fuel systems on manned missions to the red planet. During electrolysis of carbon dioxide to produce oxygen, carbon can deposit on the electrolysis cell resulting in lower efficiency and possibly cell damage. This would be detrimental, especially when the oxygen product is used as the key element of a space life support system. In this thesis, a theoretical model was developed to predict hazardous carbon deposition conditions under various operating conditions within the Martian atmosphere. The model can be used as a guide to determine the ideal operating conditions of the high-temperature oxygen production system. A parallel experimental investigation is underway to evaluate the accuracy of the theoretical model. The experimental design, cell fabrication, and some preliminary results as well as future work recommendations are also presented in this thesis.

Emission factors for gaseous and particulate pollutants from offshore diesel engine vessels in China

NASA Astrophysics Data System (ADS)

Zhang, Fan; Chen, Yingjun; Tian, Chongguo; Lou, Diming; Li, Jun; Zhang, Gan; Matthias, Volker

2016-05-01

Shipping emissions have significant influence on atmospheric environment as well as human health, especially in coastal areas and the harbour districts. However, the contribution of shipping emissions on the environment in China still need to be clarified especially based on measurement data, with the large number ownership of vessels and the rapid developments of ports, international trade and shipbuilding industry. Pollutants in the gaseous phase (carbon monoxide, sulfur dioxide, nitrogen oxides, total volatile organic compounds) and particle phase (particulate matter, organic carbon, elemental carbon, sulfates, nitrate, ammonia, metals) in the exhaust from three different diesel-engine-powered offshore vessels in China (350, 600 and 1600 kW) were measured in this study. Concentrations, fuel-based and power-based emission factors for various operating modes as well as the impact of engine speed on emissions were determined. Observed concentrations and emission factors for carbon monoxide, nitrogen oxides, total volatile organic compounds, and particulate matter were higher for the low-engine-power vessel (HH) than for the two higher-engine-power vessels (XYH and DFH); for instance, HH had NOx EF (emission factor) of 25.8 g kWh-1 compared to 7.14 and 6.97 g kWh-1 of DFH, and XYH, and PM EF of 2.09 g kWh-1 compared to 0.14 and 0.04 g kWh-1 of DFH, and XYH. Average emission factors for all pollutants except sulfur dioxide in the low-engine-power engineering vessel (HH) were significantly higher than that of the previous studies (such as 30.2 g kg-1 fuel of CO EF compared to 2.17 to 19.5 g kg-1 fuel in previous studies, 115 g kg-1 fuel of NOx EF compared to 22.3 to 87 g kg-1 fuel in previous studies and 9.40 g kg-1 fuel of PM EF compared to 1.2 to 7.6 g kg-1 fuel in previous studies), while for the two higher-engine-power vessels (DFH and XYH), most of the average emission factors for pollutants were comparable to the results of the previous studies, engine type was one of the most important influence factors for the differences. Emission factors for all three vessels were significantly different during different operating modes. Organic carbon and elemental carbon were the main components of particulate matter, while water-soluble ions and elements were present in trace amounts. The test inland ships and some test offshore vessels in China always had higher EFs for CO, NOx, and PM than previous studies. Besides, due to the significant influence of engine type on shipping emissions and that no accurate local EFs could be used in inventory calculation, much more measurement data for different vessels in China are still in urgent need. Best-fit engine speeds during actual operation should be based on both emission factors and economic costs.

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.

Automobiles and global warming: Alternative fuels and other options for carbon dioxide emissions reduction

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

Sagar, A.D.

Automobiles are a source of considerable pollution at the global level, including a significant fraction of the total greenhouse gas emissions. Alternative fuels have received some attention as potential options to curtail the carbon dioxide emissions from motor vehicles. This article discusses the feasibility and desirability (from a technical as well as a broader environmental perspective) of the large-scale production and use of alternative fuels as a strategy to mitigate automotive carbon dioxide emissions. Other options such as improving vehicle efficiency and switching to more efficient modes of passenger transportation are also discussed. These latter options offer an effective andmore » immediate way to tackle the greenhouse and other pollutant emission from automobiles, especially as the limitations of currently available alternative fuels and the technological and other constraints for potential future alternatives are revealed.« less

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.

State Carbon Dioxide Emissions Data

EIA Publications

2017-01-01

These estimates of energy-related carbon dioxide (CO2) are based on the State Energy Data System. The state data include a summary table with total energy-related CO2 by state beginning in 1990, tables with emissions by all fuels and sectors in 2015, and additional tables for each fuel and sector with history going back to 1980

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

Wackett, LP

The current biofuels landscape is chaotic. It is controlled by the rules imposed by economic forces and driven by the necessity of finding new sources of energy, particularly motor fuels. The need is bringing forth great creativity in uncovering new candidate fuel molecules that can be made via metabolic engineering. These next generation fuels include long-chain alcohols, terpenoid hydrocarbons, and diesel-length alkanes. Renewable fuels contain carbon derived from carbon dioxide. The carbon dioxide is derived directly by a photosynthetic fuel-producing organism(s) or via intermediary biomass polymers that were previously derived from carbon dioxide. To use the latter economically, biomass depolymerizationmore » processes must improve and this is a very active area of research. There are competitive approaches with some groups using enzyme based methods and others using chemical catalysts. With the former, feedstock and end-product toxicity loom as major problems. Advances chiefly rest on the ability to manipulate biological systems. Computational and modular construction approaches are key. For example, novel metabolic networks have been constructed to make long-chain alcohols and hydrocarbons that have superior fuel properties over ethanol. A particularly exciting approach is to implement a direct utilization of solar energy to make a usable fuel. A number of approaches use the components of current biological systems, but re-engineer them for more direct, efficient production of fuels.« less

Fission product palladium-silicon carbide interaction in htgr fuel particles

NASA Astrophysics Data System (ADS)

Minato, Kazuo; Ogawa, Toru; Kashimura, Satoru; Fukuda, Kousaku; Shimizu, Michio; Tayama, Yoshinobu; Takahashi, Ishio

1990-07-01

Interaction of fission product palladium (Pd) with the silicon carbide (SiC) layer was observed in irradiated Triso-coated uranium dioxide particles for high temperature gas-cooled reactors (HTGR) with an optical microscope and electron probe microanalyzers. The SiC layers were attacked locally or the reaction product formed nodules at the attack site. Although the main element concerned with the reaction was palladium, rhodium and ruthenium were also detected at the corroded areas in some particles. Palladium was detected on both the hot and cold sides of the particles, but the corroded areas and the palladium accumulations were distributed particularly on the cold side of the particles. The observed Pd-SiC reaction depths were analyzed on the assumption that the release of palladium from the fuel kernel controls the whole Pd-SiC reaction.

Energy-Related Carbon Dioxide Emissions at the State Level, 2000-2014

EIA Publications

2017-01-01

This analysis examines some of the factors that influence state-level carbon dioxide emissions from the consumption of fossil fuels. These factors include: the fuel mix — especially in the generation of electricity; the state climate; the population density of the state; the industrial makeup of the state and whether the state is a net exporter or importer of electricity.

Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site

NASA Astrophysics Data System (ADS)

Buss, Joshua A.; Agapie, Theodor

2016-01-01

Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide, further deoxygenative coupling of carbon monoxide to generate useful multicarbon products is challenging. Molybdenum and vanadium nitrogenases are capable of converting carbon monoxide into hydrocarbons under mild conditions, using discrete electron and proton sources. Electrocatalytic reduction of carbon monoxide on copper catalysts also uses a combination of electrons and protons, while the industrial Fischer-Tropsch process uses dihydrogen as a combined source of electrons and electrophiles for carbon monoxide coupling at high temperatures and pressures. However, these enzymatic and heterogeneous systems are difficult to probe mechanistically. Molecular catalysts have been studied extensively to investigate the elementary steps by which carbon monoxide is deoxygenated and coupled, but a single metal site that can efficiently induce the required scission of carbon-oxygen bonds and generate carbon-carbon bonds has not yet been documented. Here we describe a molybdenum compound, supported by a terphenyl-diphosphine ligand, that activates and cleaves the strong carbon-oxygen bond of carbon monoxide, enacts carbon-carbon coupling, and spontaneously dissociates the resulting fragment. This complex four-electron transformation is enabled by the terphenyl-diphosphine ligand, which acts as an electron reservoir and exhibits the coordinative flexibility needed to stabilize the different intermediates involved in the overall reaction sequence. We anticipate that these design elements might help in the development of efficient catalysts for converting carbon monoxide to chemical fuels, and should prove useful in the broader context of performing complex multi-electron transformations at a single metal site.

40 CFR 86.1524 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Emission Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Light-Duty Trucks; Idle...

Power Satellites, Carbon Dioxide, Synthetic Fuel, Sequestering Carbon as Synthetic Oil and Fresh Water from Seawater

NASA Astrophysics Data System (ADS)

Keith Henson, H.

2010-05-01

A small number of people have been working for the past year on ways to reduce the cost of power from space to the point that it could entirely displace fossil fuels and even put carbon dioxide back in empty oil fields as synthetic oil. The challenging part is reducing the cost of transport to GEO by a factor of ˜200 discussed in another paper in this volume. Given low cost power, synthetic fuels, carbon sequestration, and fresh water from seawater become economical.

Alternative fossil-based transportation fuels

DOT National Transportation Integrated Search

2008-01-01

"Alternative fuels derived from oil sands and from coal liquefaction can cost-effectively diversify fuel supplies, but neither type significantly reduces U.S. carbon-dioxide emissions enough to arrest long-term climate change".

CARBON DIOXIDE FIXATION.

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

FUJITA,E.

2000-01-12

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

Analysis of high-purity germanium dioxide by ETV-ICP-AES with preliminary concentration of trace elements.

PubMed

Medvedev, Nickolay S; Shaverina, Anastasiya V; Tsygankova, Alphiya R; Saprykin, Anatoly I

2016-08-01

The paper presents a combined technique of germanium dioxide analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) with preconcentration of trace elements by distilling off matrix and electrothermal (ETV) introduction of the trace elements concentrate into the ICP. Evaluation of metrological characteristics of the developed technique of high-purity germanium dioxide analysis was performed. The limits of detection (LODs) for 25 trace elements ranged from 0.05 to 20ng/g. The accuracy of proposed technique is confirmed by "added-found" («or spiking») experiment and comparing the results of ETV-ICP-AES and ICP-AES analysis of high purity germanium dioxide samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling the UO2 ex-AUC pellet process and predicting the fuel rod temperature distribution under steady-state operating condition

NASA Astrophysics Data System (ADS)

Hung, Nguyen Trong; Thuan, Le Ba; Thanh, Tran Chi; Nhuan, Hoang; Khoai, Do Van; Tung, Nguyen Van; Lee, Jin-Young; Jyothi, Rajesh Kumar

2018-06-01

Modeling uranium dioxide pellet process from ammonium uranyl carbonate - derived uranium dioxide powder (UO2 ex-AUC powder) and predicting fuel rod temperature distribution were reported in the paper. Response surface methodology (RSM) and FRAPCON-4.0 code were used to model the process and to predict the fuel rod temperature under steady-state operating condition. Fuel rod design of AP-1000 designed by Westinghouse Electric Corporation, in these the pellet fabrication parameters are from the study, were input data for the code. The predictive data were suggested the relationship between the fabrication parameters of UO2 pellets and their temperature image in nuclear reactor.

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.

The effects of battlefield contaminants on PEMFC performance

NASA Astrophysics Data System (ADS)

Moore, Jon M.; Adcock, Paul L.; Lakeman, J. Barry; Mepsted, Gary O.

The effects of contaminants on the performance of an air breathing proton exchange membrane fuel cell (PEMFC) were investigated, by introduction into oxidant air fed to the fuel cell. The impact of the common pollutants sulphur dioxide, nitrogen dioxide, carbon monoxide, propane and benzene and the chemical warfare agents, sarin, sulphur mustard, cyanogen chloride (CNCl) and hydrogen cyanide (HCN) were assessed. At the concentrations studied, the common contaminants had either no effect on performance or caused a reversible depression. The chemical warfare agents all seriously compromised the performance of the fuel cells in an irreversible manner.

Method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2000-01-01

A method for converting hydrocarbon fuel into hydrogen gas and carbon dioxide within a reformer 10 is disclosed. According to the method, a stream including an oxygen-containing gas is directed adjacent to a first vessel 18 and the oxygen-containing gas is heated. A stream including unburned fuel is introduced into the oxygen-containing gas stream to form a mixture including oxygen-containing gas and fuel. The mixture of oxygen-containing gas and unburned fuel is directed tangentially into a partial oxidation reaction zone 24 within the first vessel 18. The mixture of oxygen-containing gas and fuel is further directed through the partial oxidation reaction zone 24 to produce a heated reformate stream including hydrogen gas and carbon monoxide. Steam may also be mixed with the oxygen-containing gas and fuel, and the reformate stream from the partial oxidation reaction zone 24 directed into a steam reforming zone 26. High- and low-temperature shift reaction zones 64,76 may be employed for further fuel processing.

Alternative Anodes for the Electrolytic Reduction of Uranium Dioxide

NASA Astrophysics Data System (ADS)

Merwin, Augustus

Reprocessing of spent nuclear fuel is an essential step in closing the nuclear fuel cycle. In order to consume current stockpiles, ceramic uranium dioxide spent nuclear fuel will be subjected to an electrolytic reduction process. The current reduction process employs a platinum anode and a stainless steel alloy 316 cathode in a molten salt bath consisting of LiCl-2wt% Li 2O and occurs at 700°C. A major shortcoming of the existing process is the degradation of the platinum anode under the severely oxidizing conditions encountered during electrolytic reduction. This work investigates alternative anode materials for the electrolytic reduction of uranium oxide. The high temperature and extreme oxidizing conditions encountered in these studies necessitated a unique set of design constraints on the system. Thus, a customized experimental apparatus was designed and constructed. The electrochemical experiments were performed in an electrochemical reactor placed inside a furnace. This entire setup was housed inside a glove box, in order to maintain an inert atmosphere. This study investigates alternative anode materials through accelerated corrosion testing. Surface morphology was studied using scanning electron microscopy. Surface chemistry was characterized using energy dispersive spectroscopy and Raman spectroscopy. Electrochemical behavior of candidate materials was evaluated using potentiodynamic polarization characteristics. After narrowing the number of candidate electrode materials, ferrous stainless steel alloy 316, nickel based Inconel 718 and elemental tungsten were chosen for further investigation. Of these materials only tungsten was found to be sufficiently stable at the anodic potential required for electrolysis of uranium dioxide in molten salt. The tungsten anode and stainless steel alloy 316 cathode electrode system was studied at the required reduction potential for UO2 with varying lithium oxide concentrations. Electrochemical impedance spectroscopy showed mixed (kinetic and diffusion) control and an overall low impedance due to extreme corrosion. It was observed that tungsten is sufficiently stable in LiCl - 2wt% Li 2O at 700°C at the required anodic potential for the reduction of uranium oxide. This study identifies tungsten to be a superior anode material to platinum for the electrolytic reduction of uranium oxide, both in terms of superior corrosion behavior and reduced cost, and thus recommends that tungsten be further investigated as an alternative anode for the electrolytic reduction of uranium dioxide.

40 CFR 60.43 - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Fossil-Fuel... from liquid fossil fuel or liquid fossil fuel and wood residue. (2) 520 ng/J heat input (1.2 lb/MMBtu) derived from solid fossil fuel or solid fossil fuel and wood residue, except as provided in paragraph (e...

40 CFR 60.43 - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Fossil-Fuel... from liquid fossil fuel or liquid fossil fuel and wood residue. (2) 520 ng/J heat input (1.2 lb/MMBtu) derived from solid fossil fuel or solid fossil fuel and wood residue, except as provided in paragraph (e...

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

Code of Federal Regulations, 2013 CFR

2013-07-01

... sulfur oxides. (iii) Fossil fuel means natural gas, refinery fuel gas, coke oven gas, petroleum, coal and any form of solid, liquid, or gaseous fuel derived from such materials. (iv) Fossil fuel-fired steam generating unit means a furnace or boiler used in the process of burning fossil fuel for the purpose of...

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

Code of Federal Regulations, 2014 CFR

2014-07-01

... sulfur oxides. (iii) Fossil fuel means natural gas, refinery fuel gas, coke oven gas, petroleum, coal and any form of solid, liquid, or gaseous fuel derived from such materials. (iv) Fossil fuel-fired steam generating unit means a furnace or boiler used in the process of burning fossil fuel for the purpose of...

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

Code of Federal Regulations, 2010 CFR

2010-07-01

... sulfur oxides. (iii) Fossil fuel means natural gas, refinery fuel gas, coke oven gas, petroleum, coal and any form of solid, liquid, or gaseous fuel derived from such materials. (iv) Fossil fuel-fired steam generating unit means a furnace or boiler used in the process of burning fossil fuel for the purpose of...

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

Code of Federal Regulations, 2012 CFR

2012-07-01

... sulfur oxides. (iii) Fossil fuel means natural gas, refinery fuel gas, coke oven gas, petroleum, coal and any form of solid, liquid, or gaseous fuel derived from such materials. (iv) Fossil fuel-fired steam generating unit means a furnace or boiler used in the process of burning fossil fuel for the purpose of...

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

Code of Federal Regulations, 2011 CFR

2011-07-01

... sulfur oxides. (iii) Fossil fuel means natural gas, refinery fuel gas, coke oven gas, petroleum, coal and any form of solid, liquid, or gaseous fuel derived from such materials. (iv) Fossil fuel-fired steam generating unit means a furnace or boiler used in the process of burning fossil fuel for the purpose of...

Unconventional fossil-based fuels : economic and environmental trade-offs

DOT National Transportation Integrated Search

2008-01-01

Both high import payments for petroleum motor fuels and concerns regarding emissions of carbon dioxide (CO2) are motivating interest in possible fuel substitutes. In this report, RAND researchers assess the potential future production levels, product...

Thermal expansion of the nuclear fuel-sodium reaction product Na3(U0.84(2),Na0.16(2))O4 - Structural mechanism and comparison with related sodium-metal ternary oxides

NASA Astrophysics Data System (ADS)

Illy, Marie-Claire; Smith, Anna L.; Wallez, Gilles; Raison, Philippe E.; Caciuffo, Roberto; Konings, Rudy J. M.

2017-07-01

Na3.16(2)UV,VI0.84(2)O4 is obtained from the reaction of sodium with uranium dioxide under oxygen potential conditions typical of a sodium-cooled fast nuclear reactor. In the event of a breach of the steel cladding, it would be the dominant reaction product forming at the rim of the mixed (U,Pu)O2 fuel pellets. High-temperature X-ray diffraction measurements show that a distortion of the uranium environment in Na3.16(2)UV,VI0.84(2)O4 results in a strongly anisotropic thermal expansion. A comparison with several related sodium metallates Nan-2Mn+On-1 - including Na3SbO4 and Na3TaO4, whose crystal structures are reported for the first time - has allowed us to assess the role played in the lattice expansion by the Mn+ cation radius and the Na/M ratio. On this basis, the thermomechanical behavior of the title compound is discussed, along with those of several related double oxides of sodium and actinide elements, surrogate elements, or fission products.

The Impact of Pollution Charges, Ash Handling and Carbon Dioxide on the Cost Competitiveness of the Fuel Sources Used for Energy Production in Estonia

NASA Astrophysics Data System (ADS)

Latisov, Eduard; Kleesmaa, Juri; Siirde, Andres

2010-01-01

The goal of this paper is to estimate the effects of pollution charges, ash handling and of the carbon dioxide quota trade on the competitiveness of natural gas, oil shale, peat and wood chips in Estonia for 2010 and 2015. The pollution charges and levels are calculated based on the Environmental Charges Act, and Regulations No 99/2004 and No 94/2004 of the Estonian Minister of the Environment. The calculations show a considerable change in the cost competitiveness of fuels. Fuel related costs of the fossil fuels with high CO2 emission factors and other environmental impacts may be doubled.

Emission measurements from a crude oil tanker at sea.

PubMed

Agrawal, Harshit; Welch, William A; Miller, J Wayne; Cockert, David R

2008-10-01

This work presents an all-inclusive set of regulated and nonregulated emission factors for the main propulsion engine (ME), auxiliary engine (AE) and an auxiliary boiler on a Suezmax class tanker while operating at sea. The data include criteria pollutants (carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter), a greenhouse gas (carbon dioxide), the principal speciated hydrocarbons needed for human health risk assessments, and a detailed analysis of the PM into its primary constituents (ions, elements, organic, and elemental carbon). Measurements followed ISO 8178-1 methods with modifications described in the paper. The vessel burned two fuels: a heavy fuel oil in the ME and boiler and a distillate fuel in the AE. The weighted NO(x) emissions for the ME and AE are 19.87 +/- 0.95 and 13.57 +/- 0.31 g/kWh, respectively. The weighted PM mass emissions factor is 1.60 +/- 0.08 g/kWh for the ME and 0.141 +/- 0.005 g/kWh for the AE, with the sulfate content of the PM being the root cause for the difference. For the ME, sulfate with associated water is about 75% of total PM mass, and the organic carbon ranges from 15 to 25% of the PM mass. A deeper analysis showed that the conversion of fuel sulfur to sulfate in the ME ranged from 1.4to 5%. This article also provides emission factors for selected polycyclic aromatic hydrocarbons, heavy alkanes, carbonyls, light hydrocarbon species, metals, and ions for the ME, AE, and the boiler.

HYNOL PROCESS EVALUATION

EPA Science Inventory

The report examines process alternatives for the optimal use of natural gas and biomass for production of fuel-cell vehicle fuel, emphasizing maximum displacement of petroleum and maximum reduction of overall fuel-cycle carbon dioxide (CO2) emissions at least cost. Three routes a...

Advanced dry head-end reprocessing of light water reactor spent nuclear fuel

DOEpatents

Collins, Emory D; Delcul, Guillermo D; Hunt, Rodney D; Johnson, Jared A; Spencer, Barry B

2013-11-05

A method for reprocessing spent nuclear fuel from a light water reactor includes the step of reacting spent nuclear fuel in a voloxidation vessel with an oxidizing gas having nitrogen dioxide and oxygen for a period sufficient to generate a solid oxidation product of the spent nuclear fuel. The reacting step includes the step of reacting, in a first zone of the voloxidation vessel, spent nuclear fuel with the oxidizing gas at a temperature ranging from 200-450.degree. C. to form an oxidized reaction product, and regenerating nitrogen dioxide, in a second zone of the voloxidation vessel, by reacting oxidizing gas comprising nitrogen monoxide and oxygen at a temperature ranging from 0-80.degree. C. The first zone and the second zone can be separate. A voloxidation system is also disclosed.

Advanced dry head-end reprocessing of light water reactor spent nuclear fuel

DOEpatents

Collins, Emory D.; Delcul, Guillermo D.; Hunt, Rodney D.; Johnson, Jared A.; Spencer, Barry B.

2014-06-10

A method for reprocessing spent nuclear fuel from a light water reactor includes the step of reacting spent nuclear fuel in a voloxidation vessel with an oxidizing gas having nitrogen dioxide and oxygen for a period sufficient to generate a solid oxidation product of the spent nuclear fuel. The reacting step includes the step of reacting, in a first zone of the voloxidation vessel, spent nuclear fuel with the oxidizing gas at a temperature ranging from 200-450.degree. C. to form an oxidized reaction product, and regenerating nitrogen dioxide, in a second zone of the voloxidation vessel, by reacting oxidizing gas comprising nitrogen monoxide and oxygen at a temperature ranging from 0-80.degree. C. The first zone and the second zone can be separate. A voloxidation system is also disclosed.

40 CFR 60.43 - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Fossil-Fuel.../J heat input (0.80 lb/MMBtu) derived from liquid fossil fuel or liquid fossil fuel and wood residue. (2) 520 ng/J heat input (1.2 lb/MMBtu) derived from solid fossil fuel or solid fossil fuel and wood...

40 CFR 60.43 - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Fossil-Fuel.../J heat input (0.80 lb/MMBtu) derived from liquid fossil fuel or liquid fossil fuel and wood residue. (2) 520 ng/J heat input (1.2 lb/MMBtu) derived from solid fossil fuel or solid fossil fuel and wood...

40 CFR 60.43 - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Fossil-Fuel.../J heat input (0.80 lb/MMBtu) derived from liquid fossil fuel or liquid fossil fuel and wood residue. (2) 520 ng/J heat input (1.2 lb/MMBtu) derived from solid fossil fuel or solid fossil fuel and wood...

Greening the Mixture: An Evaluation of the Department of Defense’s Alternative Aviation Fuel Strategy

DTIC Science & Technology

2012-06-08

process begins with gasification of feedstocks such as coal, natural gas, or biomass towards the production of alternative fuels. With adequate carbon...Barrels per day CBTL Coal and Biomass to Liquid CCS Carbon Dioxide Capture and Sequestration CTL Coal to Liquid DARPA Defense Advanced Research...sequestration. Captured carbon dioxide from coal-to-liquid (CTL) or coal and biomass -to-liquid (CBTL) production could be readily injected into the

Mars methane engine

NASA Technical Reports Server (NTRS)

Bui, Hung; Coletta, Chris; Debois, Alain

1994-01-01

The feasibility of an internal combustion engine operating on a mixture of methane, carbon dioxide, and oxygen has been verified by previous design groups for the Mars Methane Engine Project. Preliminary stoichiometric calculations examined the theoretical fuel-air ratios needed for the combustion of methane. Installation of a computer data acquisition system along with various ancillary components will enable the performance of the engine, running on the described methane mixture, to be optimized with respect to minimizing excess fuel. Theoretical calculations for stoichiometric combustion of methane-oxygen-carbon dioxide mixtures yielded a ratio of 1:2:4.79 for a methane-oxygen-carbon dioxide mixture. Empirical data shows the values to be closer to 1:2.33:3.69 for optimum operation.

Boron coating on boron nitride coated nuclear fuels by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Durmazuçar, Hasan H.; Gündüz, Güngör

2000-12-01

Uranium dioxide-only and uranium dioxide-gadolinium oxide (5% and 10%) ceramic nuclear fuel pellets which were already coated with boron nitride were coated with thin boron layer by chemical vapor deposition to increase the burn-up efficiency of the fuel during reactor operation. Coating was accomplished from the reaction of boron trichloride with hydrogen at 1250 K in a tube furnace, and then sintering at 1400 and 1525 K. The deposited boron was identified by infrared spectrum. The morphology of the coating was studied by using scanning electron microscope. The plate, grainy and string (fiber)-like boron structures were observed.

Sustainable Transportation Fuels from Natural Gas (H{sub 2}), Coal and Biomass

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

Huffman, Gerald

2012-12-31

This research program is focused primarily on the conversion of coal, natural gas (i.e., methane), and biomass to liquid fuels by Fischer-Tropsch synthesis (FTS), with minimum production of carbon dioxide. A complementary topic also under investigation is the development of novel processes for the production of hydrogen with very low to zero production of CO{sub 2}. This is in response to the nation's urgent need for a secure and environmentally friendly domestic source of liquid fuels. The carbon neutrality of biomass is beneficial in meeting this goal. Several additional novel approaches to limiting carbon dioxide emissions are also being explored.

40 CFR 60.44c - Compliance and performance test methods and procedures for sulfur dioxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and procedures for sulfur dioxide. 60.44c Section 60.44c Protection of Environment ENVIRONMENTAL... Compliance and performance test methods and procedures for sulfur dioxide. (a) Except as provided in... operator seeks to demonstrate compliance with the fuel oil sulfur limits under § 60.42c based on shipment...

40 CFR 60.44c - Compliance and performance test methods and procedures for sulfur dioxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and procedures for sulfur dioxide. 60.44c Section 60.44c Protection of Environment ENVIRONMENTAL... Compliance and performance test methods and procedures for sulfur dioxide. (a) Except as provided in... operator seeks to demonstrate compliance with the fuel oil sulfur limits under § 60.42c based on shipment...

40 CFR 60.44c - Compliance and performance test methods and procedures for sulfur dioxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and procedures for sulfur dioxide. 60.44c Section 60.44c Protection of Environment ENVIRONMENTAL... Compliance and performance test methods and procedures for sulfur dioxide. (a) Except as provided in... operator seeks to demonstrate compliance with the fuel oil sulfur limits under § 60.42c based on shipment...

40 CFR 60.44c - Compliance and performance test methods and procedures for sulfur dioxide.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and procedures for sulfur dioxide. 60.44c Section 60.44c Protection of Environment ENVIRONMENTAL... Compliance and performance test methods and procedures for sulfur dioxide. (a) Except as provided in... operator seeks to demonstrate compliance with the fuel oil sulfur limits under § 60.42c based on shipment...

Chemical recycling of carbon dioxide to methanol and dimethyl ether: from greenhouse gas to renewable, environmentally carbon neutral fuels and synthetic hydrocarbons.

PubMed

Olah, George A; Goeppert, Alain; Prakash, G K Surya

2009-01-16

Nature's photosynthesis uses the sun's energy with chlorophyll in plants as a catalyst to recycle carbon dioxide and water into new plant life. Only given sufficient geological time can new fossil fuels be formed naturally. In contrast, chemical recycling of carbon dioxide from natural and industrial sources as well as varied human activities or even from the air itself to methanol or dimethyl ether (DME) and their varied products can be achieved via its capture and subsequent reductive hydrogenative conversion. The present Perspective reviews this new approach and our research in the field over the last 15 years. Carbon recycling represents a significant aspect of our proposed Methanol Economy. Any available energy source (alternative energies such as solar, wind, geothermal, and atomic energy) can be used for the production of needed hydrogen and chemical conversion of CO(2). Improved new methods for the efficient reductive conversion of CO(2) to methanol and/or DME that we have developed include bireforming with methane and ways of catalytic or electrochemical conversions. Liquid methanol is preferable to highly volatile and potentially explosive hydrogen for energy storage and transportation. Together with the derived DME, they are excellent transportation fuels for internal combustion engines (ICE) and fuel cells as well as convenient starting materials for synthetic hydrocarbons and their varied products. Carbon dioxide thus can be chemically transformed from a detrimental greenhouse gas causing global warming into a valuable, renewable and inexhaustible carbon source of the future allowing environmentally neutral use of carbon fuels and derived hydrocarbon products.

CONSTRUCTION OF NUCLEAR FUEL ELEMENTS

DOEpatents

Weems, S.J.

1963-09-24

>A rib arrangement and an end construction for nuclearfuel elements laid end to end in a coolant tube are described. The rib arrangement is such that each fuel element, when separated from other fuel elements, fits loosely in the coolant tube and so can easily be inserted or withdrawn from the tube. The end construction of the fuel elements is such that the fuel elements when assembled end to end are keyed against relative rotation, and the ribs of each fuel element cooperate with the ribs of the adjacent fuel elements to give the assembled fuel elements a tight fit with the coolant tube. (AEC)

A method for phenomenological and chemical kinetics study of autocatalytic reactive dissolution by optical microscopy. The case of uranium dioxide dissolution in nitric acid media

NASA Astrophysics Data System (ADS)

Marc, Philippe; Magnaldo, Alastair; Godard, Jérémy; Schaer, Éric

2018-03-01

Dissolution is a milestone of the head-end of hydrometallurgical processes, as the stabilization rates of the chemical elements determine the process performance and hold-up. This study aims at better understanding the chemical and physico-chemical phenomena of uranium dioxide dissolution reactions in nitric acid media in the Purex process, which separates the reusable materials and the final wastes of the spent nuclear fuels. It has been documented that the attack of sintering-manufactured uranium dioxide solids occurs through preferential attack sites, which leads to the development of cracks in the solids. Optical microscopy observations show that in some cases, the development of these cracks leads to the solid cleavage. It is shown here that the dissolution of the detached fragments is much slower than the process of the complete cleavage of the solid, and occurs with no disturbing phenomena, like gas bubbling. This fact has motivated the measurement of dissolution kinetics using optical microscopy and image processing. By further discriminating between external resistance and chemical reaction, the "true" chemical kinetics of the reaction have been measured, and the highly autocatalytic nature of the reaction confirmed. Based on these results, the constants of the chemical reactions kinetic laws have also been evaluated.

Monitoring arrangement for vented nuclear fuel elements

DOEpatents

Campana, Robert J.

1981-01-01

In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180.degree. rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements.

40 CFR 49.129 - Rule for limiting emissions of sulfur dioxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., incinerator, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, open burning, process source, reference method, refuse, residual fuel oil, solid fuel, stack, standard conditions...

40 CFR 49.129 - Rule for limiting emissions of sulfur dioxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., incinerator, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, open burning, process source, reference method, refuse, residual fuel oil, solid fuel, stack, standard conditions...

Record annual increase of carbon dioxide observed at Mauna Loa for 2015 |

Science.gov Websites

related to atmospheric change since the 1950's. The annual growth rate of atmospheric carbon dioxide year. Continued high emissions from fossil fuel consumption are driving the underlying growth rate over

A study of extractive and remote-sensing sampling and measurement of emissions from military aircraft engines

NASA Astrophysics Data System (ADS)

Cheng, Meng-Dawn; Corporan, Edwin

2010-12-01

Aircraft emissions contribute to the increased atmospheric burden of particulate matter (PM) that plays an important role in air quality, human health, visibility, contrail formation and climate change. Sampling and measurement of modern aircraft emissions at the engine exhaust plane (EEP) for engine and fuel certification remains challenging, as no agency-certified method is available. In this paper we summarize the results of three recent field studies devoted to investigate the consistency and applicability of "extractive" and "optical remote-sensing" (ORS) technologies in the sampling and measurement of gaseous and PM emitted by a number of military aircraft engines. Three classes of military engines were investigated; these include T56, TF33, and T700 & T701C types of engines, which consume 70-80% of the military aviation fuel each year. JP-8 and Fischer-Tropsch (FT)-derived paraffinic fuels were used to study the effect of fuels. It was found that non-volatile particles in the engine emissions were in the 20 nm range for the low power condition of new helicopter engines to 80 nm for the high power condition of legacy engines. Elemental analysis indicated little metals were present on particles, while most of the materials on the exhaust particles were carbon and sulfate based. Alkanes, carbon monoxide, carbon dioxide, nitrogen oxides, sulfur dioxide, formaldehyde, ethylene, acetylene and propylene were detected. The last five species were most noticeable only under low engine power. The emission indices calculated based on the ORS data deviate significantly from those based on the extractive data. Nevertheless, the ORS techniques were useful in the sense that it provided non-intrusive real-time detection of species in the exhaust plume, which warrants further development. The results obtained in this program help validate sampling methodology and measurement techniques used for non-volatile PM aircraft emissions as described in the SAE AIR6037 (2009).

40 CFR 52.536 - Original identification of plan section.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Florida Department of Pollution Control. (15) Revised limits on sulfur dioxide emissions from fossil-fuel... specific Fossil Fuel Steam Generators, submitted on November 6, 1978, and February 3, 1979, by the Florida..., fossil fuel steam generators-visible emissions, submitted on October 19, 1979; revision describing...

40 CFR 52.536 - Original identification of plan section.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Florida Department of Pollution Control. (15) Revised limits on sulfur dioxide emissions from fossil-fuel... specific Fossil Fuel Steam Generators, submitted on November 6, 1978, and February 3, 1979, by the Florida..., fossil fuel steam generators-visible emissions, submitted on October 19, 1979; revision describing...

40 CFR 52.536 - Original identification of plan section.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Florida Department of Pollution Control. (15) Revised limits on sulfur dioxide emissions from fossil-fuel... specific Fossil Fuel Steam Generators, submitted on November 6, 1978, and February 3, 1979, by the Florida..., fossil fuel steam generators-visible emissions, submitted on October 19, 1979; revision describing...

40 CFR 52.536 - Original identification of plan section.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Florida Department of Pollution Control. (15) Revised limits on sulfur dioxide emissions from fossil-fuel... specific Fossil Fuel Steam Generators, submitted on November 6, 1978, and February 3, 1979, by the Florida..., fossil fuel steam generators-visible emissions, submitted on October 19, 1979; revision describing...

Affordable Development and Demonstration of a Small NTR Engine and Stage: A Preliminary NASA, DOE, and Industry Assessment

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg, Abraham; Joyner, Claude R.

2015-01-01

The Nuclear Thermal Rocket (NTR) represents the next evolutionary step in cryogenic liquid rocket engines. Deriving its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core, the NTR can generate high thrust at a specific impulse of approx. 900 seconds or more - twice that of today's best chemical rockets. In FY'11, as part of the AISP project, NASA proposed a Nuclear Thermal Propulsion (NTP) effort that envisioned two key activities - "Foundational Technology Development" followed by system-level "Technology Demonstrations". Five near-term NTP activities identified for Foundational Technology Development became the basis for the NCPS project started in FY'12 and funded by NASA's AES program. During Phase 1 (FY'12-14), the NCPS project was focused on (1) Recapturing fuel processing techniques and fabricating partial length "heritage" fuel elements for the two candidate fuel forms identified by NASA and the DOE - NERVA graphite "composite" and the uranium dioxide (UO2) in tungsten "cermet". The Phase 1 effort also included: (2) Engine Conceptual Design; (3) Mission Analysis and Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable and Sustainable NTP Development Strategy. During FY'14, a preliminary plan for DDT&E was outlined by GRC, the DOE and industry for NASA HQ that involved significant system-level demonstration projects that included GTD tests at the NNSS, followed by a FTD mission. To reduce development costs, the GTD and FTD tests use a small, low thrust (approx. 7.5 or 16.5 klbf) engine. Both engines use graphite composite fuel and a "common" fuel element design that is scalable to higher thrust (approx. 25 klbf) engines by increasing the number of elements in a larger diameter core that can produce greater thermal power output. To keep the FTD mission cost down, a simple "1-burn" lunar flyby mission was considered along with maximizing the use of existing and flight proven liquid rocket and stage hardware (e.g., from the RL10-B2 engine and Delta Cryogenic Second Stage) to further ensure affordability. This paper provides a preliminary NASA, DOE and industry assessment of what is required - the key DDT&E activities, development options, and the associated schedule - to affordably build, ground test and fly a small NTR engine and stage within a 10-year timeframe.

Transportation fuels and vehicles.

DOT National Transportation Integrated Search

1999-06-24

Environmental concerns are currently the primary driver of innovation in the area of Transportation Fuels and Vehicles. Road vehicle emissions are a significant determinant of urban air quality and produce a very substantial quantity of carbon dioxid...

40 CFR 49.130 - Rule for limiting sulfur in fuels.

Code of Federal Regulations, 2010 CFR

2010-07-01

... burned at stationary sources within the Indian reservation to control emissions of sulfur dioxide (SO2..., gaseous fuel, marine vessel, mobile sources, motor vehicle, nonroad engine, nonroad vehicle, owner or...

Performance of nickel-based oxygen carrier produced using renewable fuel aloe vera

NASA Astrophysics Data System (ADS)

Afandi, NF; Devaraj, D.; Manap, A.; Ibrahim, N.

2017-04-01

Consuming and burning of fuel mainly fossil fuel has gradually increased in this upcoming era due to high-energy demand and causes the global warming. One of the most effective ways to reduce the greenhouse gases is by capturing carbon dioxide (CO2) during the combustion process. Chemical looping combustion (CLC) is one of the most effective methods to capture the CO2 without the need of an energy intensive air separation unit. This method uses oxygen carrier to provide O2 that can react with fuel to form CO2 and H2O. This research focuses on synthesizing NiO/NiAl2O4 as an oxygen carrier due to its properties that can withstand high temperature during CLC application. The NiO/NiAl2O4 powder was synthesized using solution combustion method with plant extract renewable fuel, aloe vera as the fuel. In order to optimize the performance of the particles that can be used in CLC application, various calcination temperatures were varied at 600°C, 800°C, 1050°C and 1300°C. The phase and morphology of obtained powders were characterized using X-ray diffraction (XRD) and Field Emission Microscopy (FESEM) respectively together with the powder elements. In CLC application, high reactivity can be achieved by using smaller particle size of oxygen carrier. This research succeeded in producing nano-structured powder with high crystalline structure at temperature 1050°C which is suitable to be used in CLC application.

Fuel Cells | Climate Neutral Research Campuses | NREL

Science.gov Websites

to develop fuel cells on campus. Does your campus support telecommunications networks where there is captures waste heat to generate hot water. Additionally, the exhaust carbon dioxide is routed to an energy conversion calculation methodologies. U.S. Department of Energy - Fuel Cell Animation: Provides an

FUEL ELEMENT SUPPORT

DOEpatents

Wyman, W.L.

1961-06-27

The described cylindrical fuel element has longitudinally spaced sets of short longitudinal ribs circumferentially spaced from one another. The ribs support the fuel element in a coolant tube so that there is an annular space for coolant flow between the fuel element and the interior of the coolant tube. If the fuel element grows as a result of reactor operation, the circumferential distribution of the ribs maintains the uniformity of the annular space between the coolant tube and the fuel element, and the collapsibility of the ribs prevents the fuel element from becoming jammed in the coolant tube.

Thermal breeder fuel enrichment zoning

DOEpatents

Capossela, Harry J.; Dwyer, Joseph R.; Luce, Robert G.; McCoy, Daniel F.; Merriman, Floyd C.

1992-01-01

A method and apparatus for improving the performance of a thermal breeder reactor having regions of higher than average moderator concentration are disclosed. The fuel modules of the reactor core contain at least two different types of fuel elements, a high enrichment fuel element and a low enrichment fuel element. The two types of fuel elements are arranged in the fuel module with the low enrichment fuel elements located between the high moderator regions and the high enrichment fuel elements. Preferably, shim rods made of a fertile material are provided in selective regions for controlling the reactivity of the reactor by movement of the shim rods into and out of the reactor core. The moderation of neutrons adjacent the high enrichment fuel elements is preferably minimized as by reducing the spacing of the high enrichment fuel elements and/or using a moderator having a reduced moderating effect.

Carbon dioxide recycling

EPA Science Inventory

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

University coal research/historically black colleges and universities and other minority institutions contractors review meeting

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

NONE

2006-07-01

A variety of papers/posters were presented on topics concerning power generation, including solid oxide fuel cells, hydrogen production, mercury as a combustion product, carbon dioxide separation from flue gas. A total of 31 presentations in slide/overview/viewgraph form and with a separate abstract are available online (one in abstract form only) and 24 poster papers (text). In addition 41 abstracts only are available. Papers of particular interest include: Hydrogen production from hydrogen sulfide in IGCC power plants; Oxidation of mercury in products of coal combustion; Computer aided design of advanced turbine aerofoil alloys for industrial gas turbines in coal fired environments;more » Developing engineered fuel using flyash and biomass; Conversion of hydrogen sulfide in coal gases to elemental sulfur with monolithic catalysts; Intelligent control via wireless sensor networks for advanced coal combustion systems; and Investment of fly ash and activated carbon obtained from pulverized coal boilers (poster).« less

Irradiation of TZM: Uranium dioxide fuel pin at 1700 K

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1973-01-01

A fuel pin clad with TZM and containing solid pellets of uranium dioxide was fission heated in a static helium-cooled capsule at a maximum surface temperature of 1700 K for approximately 1000 hr and to a total burnup of 2.0 percent of the uranium-235. The results of the postirradiation examination indicated: (1) A transverse, intergranular failure of the fuel pin occurred when the fuel pin reached 2.0-percent burnup. This corresponds to 1330 kW-hr/cu cm, where the volume is the sum of the fuel, clad, and void volumes in the fuel region. (2) The maximum swelling of the fuel pin was less than 1.5 percent on the fuel-pin diameter. (3) There was no visible interaction between the TZM clad and the UO2. (4) Irradiation at 1700 K produced a course-grained structure, with an average grain diameter of 0.02 centimeter and with some of the grains extending one-half of the thickness of the clad. (5) Below approximately 1500 K, the irradiation of the clad produced a moderately fine-grained structure, with an average grain diameter of 0.004 centimeter.

Corrigendum to "Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields" [J. Power Sources 268 (5 December 2014) 439-442

NASA Astrophysics Data System (ADS)

Majidi, Pasha; Pickup, Peter G.

2016-09-01

The authors regret that Equation (5) is incorrect and has resulted in errors in Fig. 4 and the efficiencies stated on p. 442. The corrected equation, figure and text are presented below. In addition, the title should be 'Sinusoidal potential cycling operation of a direct ethanol fuel cell to improve carbon dioxide yields', and the reversible cell potential quoted on p. 441 should be 1.14 V. The authors would like to apologise for any inconvenience caused.

PROCESS OF MAKING SHAPED FUEL FOR NUCLEAR REACTORS

DOEpatents

O'Leary, W.J.; Fisher, E.A.

1964-02-11

A process for making uranium dioxide fuel of great strength, density, and thermal conductivity by mixing it with 0.1 to 1% of a densifier oxide (tin, aluminum, zirconium, ferric, zinc, chromium, molybdenum, titanium, or niobium oxide) and with a plasticizer (0.5 to 3% of bentonite and 0.05 to 2% of methylcellulose, propylene glycol alginate, or ammonium alginate), compacting the mixture obtained, and sintering the bodies in an atmosphere of carbon monoxide or carbon dioxide, with or without hydrogen, or of a nitrogen-hydrogen mixture is described. (AEC)

A Comparison of Materials Issues for Cermet and Graphite-Based NTP Fuels

NASA Technical Reports Server (NTRS)

Stewart, Mark E.; Schnitzler, Bruce G.

2013-01-01

This paper compares material issues for cermet and graphite fuel elements. In particular, two issues in NTP fuel element performance are considered here: ductile to brittle transition in relation to crack propagation, and orificing individual coolant channels in fuel elements. Their relevance to fuel element performance is supported by considering material properties, experimental data, and results from multidisciplinary fluid/thermal/structural simulations. Ductile to brittle transition results in a fuel element region prone to brittle fracture under stress, while outside this region, stresses lead to deformation and resilience under stress. Poor coolant distribution between fuel element channels can increase stresses in certain channels. NERVA fuel element experimental results are consistent with this interpretation. An understanding of these mechanisms will help interpret fuel element testing results.

Low temperature chemical processing of graphite-clad nuclear fuels

DOEpatents

Pierce, Robert A.

2017-10-17

A reduced-temperature method for treatment of a fuel element is described. The method includes molten salt treatment of a fuel element with a nitrate salt. The nitrate salt can oxidize the outer graphite matrix of a fuel element. The method can also include reduced temperature degradation of the carbide layer of a fuel element and low temperature solubilization of the fuel in a kernel of a fuel element.

Heterogeneous catalytic process for alcohol fuels from syngas

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

Minahan, D.M.; Nagaki, D.A.

1995-12-31

This project is focused on the discovery and evaluation of novel heterogeneous catalyst for the production of oxygenated fuel enhancers from synthesis gas. Catalysts have been studied and optimized for the production of methanol and isobutanol mixtures which may be used for the downstream synthesis of MTBE or related oxygenates. Higher alcohols synthesis (HAS) from syngas was studied; the alcohols that are produced in this process may be used for the downstream synthesis of MTBE or related oxygenates. This work has resulted in the discovery of a catalyst system that is highly selective for isobutanol compared with the prior art.more » The catalysts operate at high temperature (400{degrees}C), and consist of a spinel oxide support (general formula AB{sub 2}O{sub 4}, where A=M{sup 2+} and B = M{sup 3+}), promoted with various other elements. These catalysts operate by what is believed to be an aldol condensation mechanism, giving a product mix of mainly methanol and isobutanol. In this study, the effect of product feed/recycle (methanol, ethanol. n-propanol, isopropanol, carbon dioxide and water) on the performance of 10-DAN-55 (spinel oxide based catalyst) at 400{degrees}C, 1000 psi, GHSV = 12,000 and syngas (H{sub 2}/CO) ratio = 1:2 (alcohol addition) and 1:1 (carbon dioxide and water addition) was studied. The effect of operation at high temperatures and pressures on the performance of an improved catalyst formulation was also examined.« less

The use of renewable energy in the form of methane via electrolytic hydrogen generation using carbon dioxide as the feedstock

NASA Astrophysics Data System (ADS)

Hashimoto, Koji; Kumagai, Naokazu; Izumiya, Koichi; Takano, Hiroyuki; Shinomiya, Hiroyuki; Sasaki, Yusuke; Yoshida, Tetsuya; Kato, Zenta

2016-12-01

The history reveals the continuous increase in world energy consumption and carbon emissions. For prevention of intolerable global warming and complete exhaustion of fossil fuels we need complete conversion from fossil fuel consumption to renewable energy. We have been performing the research and development of global carbon dioxide recycling for more than 25 years to supply renewable energy to the world in the form of methane produced by the reaction of carbon dioxide captured from chimney with hydrogen generated electrolytically using electricity generated by renewable energy. We created the cathode and anode for electrolytic hydrogen generation and the catalyst for carbon dioxide methanation by the reaction with hydrogen. The methane formation from renewable energy will be the most convenient and efficient key technology for the use of renewable energy by storage of intermittent and fluctuating electricity generated from renewable energy and by regeneration of stable electricity. Domestic and international cooperation of companies for industrialization is in progress.

The removal of sulfur dioxide from flue gases

PubMed Central

Kettner, Helmut

1965-01-01

The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost. PMID:14315714

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.

Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields

NASA Astrophysics Data System (ADS)

Majidi, Pasha; Pickup, Peter G.

2014-12-01

A direct ethanol fuel cell has been operated under sinusoidal (AC) potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At 80 °C, faradaic yields of CO2 as high as 25% have been achieved with a PtRu anode catalyst, while the maximum CO2 production at constant potential was 13%. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO. These results will be important in the optimization of operating conditions for direct ethanol fuel cells, where the benefits of potential cycling are projected to increase as catalysts that produce CO2 more efficiently are implemented.

77 FR 5418 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-03

... aft fuel system 40 micron fuel filter element with a 10 micron fuel filter element. This proposed AD... fuel filter element, part number (P/N) 52-0505-2 or 52-01064-1. This proposed AD would require replacing each forward and aft fuel system 40 micron fuel filter element with a 10 micron fuel filter...

Platinum Monolayer Shell on Non-Noble Metal Core Electrocatalysts for the Hydrogen Oxidation Reaction

NASA Astrophysics Data System (ADS)

Teeluck, Krishani Malini

According to the United States Environmental Protection Agency, as of 2015, transportation accounted for 32% of the carbon dioxide emissions in the United States (and all carbon dioxide emissions in the U.S. accounted for 82.2% of all greenhouse gases from human activity). A hydrogen fuel cell is a device that efficiently produces electrical energy directly from a chemical reaction, with zero carbon emissions, and therefore holds great promise in alleviating our dependence on harmful use of energy sources. Due to their clean emissions and high efficiencies, there has been focus on the hydrogen fuel cell for vehicle applications using proton exchange membrane and alkaline fuel cells. Although the proton exchange membrane fuel cell is currently being used in vehicles, their high cost limits their feasibility in the market. This has inspired the development of the alkaline fuel cell whose efficiency and simplicity suggest the possibility of manufacturing high power fuel cell vehicles at a low cost, since the electrocatalysts in the alkaline fuel cell can be made from non-noble metals. Although the hydrogen oxidation reaction is one of the fastest electrochemical reactions in acidic media, it is two orders of magnitude slower in alkaline media, which hinders the overall efficiency of the alkaline fuel cell. Pure platinum is currently the best catalyst for the hydrogen oxidation reaction, but platinum’s high cost and rarity yields economic issues, rendering the technology futile if it cannot be commercialized. Furthermore, platinum’s hydrogen binding energy is slightly stronger than the optimal hydrogen binding energy. As the hydrogen oxidation reaction happens only on the surface of the catalyst, there is no need for platinum content beyond the exterior. Since tungsten and nickel are cheap, as well as abundant, they are ideal elements to replace the core of the catalyst with, while leaving a platinum shell surrounding this core. The activity of the hydrogen oxidation reaction when using a platinum monolayer shell on a nickel tungsten core electrocatalyst is explored, and it was found that the novel catalyst created here exhibits kinetics that rival pure platinum, but at less than half the platinum content, suggesting that nickel and tungsten modify the electronic properties of platinum in a way that enhances its activity for the hydrogen oxidation reaction. Furthermore, the hydrogen binding energy of this novel electrocatalyst was found to be weaker than the optimal binding energy (rather than stronger, as seen in pure platinum), indicating the possibility of modifying the electronic properties of platinum for a more optimal hydrogen binding energy.

Neutron Radiation Characteristics of Plutonium Dioxide Fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, reactions with low Z impurities in the fuel, and reactions with O-18. For spontaneous fission neutrons a value of (1.95 plus or minus 0.07) X 1,000 n/s/q PuO2 is obtained. The neutron yield from (alpha, neutron) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.42 plus or minus 0.32) X 10,000 n/s/q PuO2. The neutron yield from (alpha, neutron) reactions with low Z impurities in the fuel is presented in tabular form for one part per million of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

76 FR 80747 - Approval and Promulgation of Implementation Plans; Oregon: New Source Review/Prevention of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... 340-228--Requirements for Fuel Burning Equipment and Fuel Sulfur Content 0020 Definitions 11/8/2007 0200 General Emission Standards for Fuel 11/8/2007 Burning Equipment, Sulfur Dioxide Standards. 0210... reduced sulfur (TRS) emission-related definitions. 0100 Wigwam Waste Burners, Wigwam Waste Burners 11/8...

Indoor concentrations of nitrogen dioxide and sulfur dioxide from burning solid fuels for cooking and heating in Yunnan Province, China.

PubMed

Seow, W J; Downward, G S; Wei, H; Rothman, N; Reiss, B; Xu, J; Bassig, B A; Li, J; He, J; Hosgood, H D; Wu, G; Chapman, R S; Tian, L; Wei, F; Caporaso, N E; Vermeulen, R; Lan, Q

2016-10-01

The Chinese national pollution census has indicated that the domestic burning of solid fuels is an important contributor to nitrogen dioxide (NO2 ) and sulfur dioxide (SO2 ) emissions in China. To characterize indoor NO2 and SO2 air concentrations in relation to solid fuel use and stove ventilation in the rural counties of Xuanwei and Fuyuan, in Yunnan Province, China, which have among the highest lung cancer rates in the nation, a total of 163 participants in 30 selected villages were enrolled. Indoor 24-h NO2 and SO2 samples were collected in each household over two consecutive days. Compared to smoky coal, smokeless coal use was associated with higher NO2 concentrations [geometric mean (GM) = 132 μg/m(3) for smokeless coal and 111 μg/m(3) for smoky coal, P = 0.065] and SO2 [limit of detection = 24 μg/m(3) ; percentage detected (%Detect) = 86% for smokeless coal and 40% for smoky coal, P < 0.001]. Among smoky coal users, significant variation of NO2 and SO2 air concentrations was observed across different stove designs and smoky coal sources in both counties. Model construction indicated that the measurements of both pollutants were influenced by stove design. This exposure assessment study has identified high levels of NO2 and SO2 as a result of burning solid fuels for cooking and heating. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

NUCLEAR REACTOR FUEL ELEMENT

DOEpatents

Wheelock, C.W.; Baumeister, E.B.

1961-09-01

A reactor fuel element utilizing fissionable fuel materials in plate form is described. This fuel element consists of bundles of fuel-bearing plates. The bundles are stacked inside of a tube which forms the shell of the fuel element. The plates each have longitudinal fins running parallel to the direction of coolant flow, and interspersed among and parallel to the fins are ribs which position the plates relative to each other and to the fuel element shell. The plate bundles are held together by thin bands or wires. The ex tended surface increases the heat transfer capabilities of a fuel element by a factor of 3 or more over those of a simple flat plate.

Low cost, lightweight fuel cell elements

NASA Technical Reports Server (NTRS)

Kindler, Andrew (Inventor)

2001-01-01

New fuel cell elements for use in liquid feed fuel cells are provided. The elements including biplates and endplates are low in cost, light in weight, and allow high efficiency operation. Electrically conductive elements are also a part of the fuel cell elements.

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.

NUCLEAR REACTOR

DOEpatents

Treshow, M.

1958-08-19

A neuclear reactor is described of the heterogeneous type and employing replaceable tubular fuel elements and heavy water as a coolant and moderator. A pluraltty of fuel tubesa having their axes parallel, extend through a tank type pressure vessel which contatns the liquid moderator. The fuel elements are disposed within the fuel tubes in the reaetive portion of the pressure vessel during normal operation and the fuel tubes have removable plug members at each end to permit charging and discharging of the fuel elements. The fuel elements are cylindrical strands of jacketed fissionable material having helical exterior ribs. A bundle of fuel elements are held within each fuel tube with their longitudinal axes parallel, the ribs serving to space them apart along their lengths. Coolant liquid is circulated through the fuel tubes between the spaced fuel elements. Suitable control rod and monitoring means are provided for controlling the reactor.

Nuclear reactor composite fuel assembly

DOEpatents

Burgess, Donn M.; Marr, Duane R.; Cappiello, Michael W.; Omberg, Ronald P.

1980-01-01

A core and composite fuel assembly for a liquid-cooled breeder nuclear reactor including a plurality of elongated coextending driver and breeder fuel elements arranged to form a generally polygonal bundle within a thin-walled duct. The breeder elements are larger in cross section than the driver elements, and each breeder element is laterally bounded by a number of the driver elements. Each driver element further includes structure for spacing the driver elements from adjacent fuel elements and, where adjacent, the thin-walled duct. A core made up of the fuel elements can advantageously include fissile fuel of only one enrichment, while varying the effective enrichment of any given assembly or core region, merely by varying the relative number and size of the driver and breeder elements.

Method of locating a leaking fuel element in a fast breeder power reactor

DOEpatents

Honekamp, John R.; Fryer, Richard M.

1978-01-01

Leaking fuel elements in a fast reactor are identified by measuring the ratio of .sup.134 Xe to .sup.133 Xe in the reactor cover gas following detection of a fuel element leak, this ratio being indicative of the power and burnup of the failed fuel element. This procedure can be used to identify leaking fuel elements in a power breeder reactor while continuing operation of the reactor since the ratio measured is that of the gases stored in the plenum of the failed fuel element. Thus, use of a cleanup system for the cover gas makes it possible to identify sequentially a multiplicity of leaking fuel elements without shutting the reactor down.

Trash to Gas: Converting Space Waste into Useful Supply Products

NASA Technical Reports Server (NTRS)

Tsoras, Alexandra

2013-01-01

The cost of sending mass into space with current propulsion technology is very expensive, making every item a crucial element of the space mission. It is essential that all materials be used to their fullest potential. Items like food, packaging, clothing, paper towels, gloves, etc., normally become trash and take up space after use. These waste materials are currently either burned up upon reentry in earth's atmosphere or sent on cargo return vehicles back to earth: a very wasteful method. The purpose of this project was to utilize these materials and create useful products like water and methane gas, which is used for rocket fuel, to further supply a deep space mission. The system used was a thermal degradation reactor with the configuration of a down-draft gasifier. The reactor was loaded with approximately 100g of trash simulant and heated with two external ceramic heaters with separate temperature control in order to create pyrolysis and gasification in one zone and incineration iri a second zone simultaneously. Trash was loaded into the top half of the reactor to undergo pyrolysis while the downdraft gas experienced gasification or incineration to treat tars and maximize the production of carbon dioxide. Minor products included carbon monoxide, methane, and other hydrocarbons. The carbon dioxide produced can be sent to a Sabatier reactor to convert the gas into methane, which can be used as rocket propellant. In order to maximize the carbon dioxide and useful gases produced, and minimize the unwanted tars and leftover ashen material, multiple experiments were performed with altered parameters such as differing temperatures, flow rates, and location of inlet air flow. According to the data received from these experiments, the process will be further scaled up and optimized to ultimately create a system that reduces trash buildup while at the same time providing enough useful gases to potentially fill a methane tank that could fuel a lunar ascent vehicle or other deep space mission.

40 CFR 86.224-94 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1994 and Later Model Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.224-94 Carbon dioxide...

Catalytic Combustion for Ultra-Low NOx Hydrogen Turbines

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

Etemad, Shahrokh; Baird, Benjamin; Alavandi, Sandeep

2011-06-30

Precision Combustion, Inc., (PCI) in close collaboration with Solar Turbines, Incorporated, has developed and demonstrated a combustion system for hydrogen fueled turbines that reduces NOx to low single digit level while maintaining or improving current levels of efficiency and eliminating emissions of carbon dioxide. Full scale Rich Catalytic Hydrogen (RCH1) injector was developed and successfully tested at Solar Turbines, Incorporated high pressure test facility demonstrating low single digit NOx emissions for hydrogen fuel in the range of 2200F-2750F. This development work was based on initial subscale development for faster turnaround and reduced cost. Subscale testing provided promising results for 42%more » and 52% H2 with NOx emissions of less than 2 ppm with improved flame stability. In addition, catalytic reactor element testing for substrate oxidation, thermal cyclic injector testing to simulate start-stop operation in a gas turbine environment, and steady state 15 atm. operation testing were performed successfully. The testing demonstrated stable and robust catalytic element component life for gas turbine conditions. The benefit of the catalytic hydrogen combustor technology includes capability of delivering near-zero NOx without costly post-combustion controls and without requirement for added sulfur control. In addition, reduced acoustics increase gas turbine component life. These advantages advances Department of Energy (DOE’s) objectives for achievement of low single digit NOx emissions, improvement in efficiency vs. postcombustion controls, fuel flexibility, a significant net reduction in Integrated Gasification Combined Cycle (IGCC) system net capital and operating costs, and a route to commercialization across the power generation field from micro turbines to industrial and utility turbines.« less

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

Sublette, K.L.

With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans andmore » have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.« less

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.

Fossil-Fuel C02 Emissions Database and Exploration System

NASA Astrophysics Data System (ADS)

Krassovski, M.; Boden, T.

2012-04-01

Fossil-Fuel C02 Emissions Database and Exploration System Misha Krassovski and Tom Boden Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) quantifies the release of carbon from fossil-fuel use and cement production each year at global, regional, and national spatial scales. These estimates are vital to climate change research given the strong evidence suggesting fossil-fuel emissions are responsible for unprecedented levels of carbon dioxide (CO2) in the atmosphere. The CDIAC fossil-fuel emissions time series are based largely on annual energy statistics published for all nations by the United Nations (UN). Publications containing historical energy statistics make it possible to estimate fossil-fuel CO2 emissions back to 1751 before the Industrial Revolution. From these core fossil-fuel CO2 emission time series, CDIAC has developed a number of additional data products to satisfy modeling needs and to address other questions aimed at improving our understanding of the global carbon cycle budget. For example, CDIAC also produces a time series of gridded fossil-fuel CO2 emission estimates and isotopic (e.g., C13) emissions estimates. The gridded data are generated using the methodology described in Andres et al. (2011) and provide monthly and annual estimates for 1751-2008 at 1° latitude by 1° longitude resolution. These gridded emission estimates are being used in the latest IPCC Scientific Assessment (AR4). Isotopic estimates are possible thanks to detailed information for individual nations regarding the carbon content of select fuels (e.g., the carbon signature of natural gas from Russia). CDIAC has recently developed a relational database to house these baseline emissions estimates and associated derived products and a web-based interface to help users worldwide query these data holdings. Users can identify, explore and download desired CDIAC fossil-fuel CO2 emissions data. This presentation introduces the architecture and design of the new relational database and web interface, summarizes the present state and functionality of the Fossil-Fuel CO2 Emissions Database and Exploration System, and highlights future plans for expansion of the relational database and interface.

A Jacobian-free Newton Krylov method for mortar-discretized thermomechanical contact problems

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

Hansen, Glen, E-mail: Glen.Hansen@inl.gov

2011-07-20

Multibody contact problems are common within the field of multiphysics simulation. Applications involving thermomechanical contact scenarios are also quite prevalent. Such problems can be challenging to solve due to the likelihood of thermal expansion affecting contact geometry which, in turn, can change the thermal behavior of the components being analyzed. This paper explores a simple model of a light water reactor nuclear fuel rod, which consists of cylindrical pellets of uranium dioxide (UO{sub 2}) fuel sealed within a Zircalloy cladding tube. The tube is initially filled with helium gas, which fills the gap between the pellets and cladding tube. Themore » accurate modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel performance, including cladding stress and behavior under irradiated conditions, which are factors that affect the lifetime of the fuel. The thermomechanical contact approach developed here is based on the mortar finite element method, where Lagrange multipliers are used to enforce weak continuity constraints at participating interfaces. In this formulation, the heat equation couples to linear mechanics through a thermal expansion term. Lagrange multipliers are used to formulate the continuity constraints for both heat flux and interface traction at contact interfaces. The resulting system of nonlinear algebraic equations are cast in residual form for solution of the transient problem. A Jacobian-free Newton Krylov method is used to provide for fully-coupled solution of the coupled thermal contact and heat equations.« less

A Jacobian-Free Newton Krylov Method for Mortar-Discretized Thermomechanical Contact Problems

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

Glen Hansen

2011-07-01

Multibody contact problems are common within the field of multiphysics simulation. Applications involving thermomechanical contact scenarios are also quite prevalent. Such problems can be challenging to solve due to the likelihood of thermal expansion affecting contact geometry which, in turn, can change the thermal behavior of the components being analyzed. This paper explores a simple model of a light water reactor nuclear reactor fuel rod, which consists of cylindrical pellets of uranium dioxide (UO2) fuel sealed within a Zircalloy cladding tube. The tube is initially filled with helium gas, which fills the gap between the pellets and cladding tube. Themore » accurate modeling of heat transfer across the gap between fuel pellets and the protective cladding is essential to understanding fuel performance, including cladding stress and behavior under irradiated conditions, which are factors that affect the lifetime of the fuel. The thermomechanical contact approach developed here is based on the mortar finite element method, where Lagrange multipliers are used to enforce weak continuity constraints at participating interfaces. In this formulation, the heat equation couples to linear mechanics through a thermal expansion term. Lagrange multipliers are used to formulate the continuity constraints for both heat flux and interface traction at contact interfaces. The resulting system of nonlinear algebraic equations are cast in residual form for solution of the transient problem. A Jacobian-free Newton Krylov method is used to provide for fully-coupled solution of the coupled thermal contact and heat equations.« less

Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes

DTIC Science & Technology

2013-06-25

membranes (AEMs) are being developed for potential use in fuel cell systems which include portable power applications. In a fuel cell , these membranes...Alkaline Anion Exchange Membranes Report Title ABSTRACT Anion exchange membranes (AEMs) are being developed for potential use in fuel cell systems which...include portable power applications. In a fuel cell , these membranes transport hydroxide ions from the cathode to the anode. If carbon dioxide is

Analyzing the impact of reactive transport on the repository performance of TRISO fuel

NASA Astrophysics Data System (ADS)

Schmidt, Gregory

One of the largest determiners of the amount of electricity generated by current nuclear reactors is the efficiency of the thermodynamic cycle used for power generation. Current light water reactors (LWR) have an efficiency of 35% or less for the conversion of heat energy generated by the reactor to electrical energy. If this efficiency could be improved, more power could be generated from equivalent volumes of nuclear fuel. One method of improving this efficiency is to use a coolant flow that operates at a much higher temperature for electricity production. A reactor design that is currently proposed to take advantage of this efficiency is a graphite-moderated, helium-cooled reactor known as a High Temperature Gas Reactor (HTGR). There are significant differences between current LWR's and the proposed HTGR's but most especially in the composition of the nuclear fuel. For LWR's, the fuel elements consist of pellets of uranium dioxide or plutonium dioxide that are placed in long tubes made of zirconium metal alloys. For HTGR's, the fuel, known as TRISO (TRIstructural-ISOtropic) fuel, consists of an inner sphere of fissile material, a layer of dense pyrolytic carbon (PyC), a ceramic layer of silicon carbide (SiC) and a final dense outer layer of PyC. These TRISO particles are then compacted with graphite into fuel rods that are then placed in channels in graphite blocks. The blocks are then arranged in an annular fashion to form a reactor core. However, this new fuel form has unanswered questions on the environmental post-burn-up behavior. The key question for current once-through fuel operations is how these large irradiated graphite blocks with spent fuel inside will behave in a repository environment. Data in the literature to answer this question is lacking, but nevertheless this is an important question that must be answered before wide-spread adoption of HTGR's could be considered. This research has focused on answering the question of how the large quantity of graphite surrounding the spent HTGR fuel will impact the release of aqueous uranium from the TRISO fuel. In order to answer this question, the sorption and partitioning behavior of uranium to graphite under a variety of conditions was investigated. Key systematic variables that were analyzed include solution pH, dissolved carbonate concentration, uranium metal concentration and ionic strength. The kinetics and desorption characteristics of uranium/graphite partitioning were studied as well. The graphite used in these experiments was also characterized by a variety of techniques and conclusions are drawn about the relevant surface chemistry of graphite. This data was then used to generate a model for the reactive transport of uranium in a graphite matrix. This model was implemented with the software code CXTFIT and validated through the use of column studies mirroring the predicted system.

Light-Duty Vehicle CO2 and Fuel Economy Trends

EPA Pesticide Factsheets

This report provides data on the fuel economy, carbon dioxide (CO2) emissions, and technology trends of new light-duty vehicles (cars, minivans, sport utility vehicles, and pickup trucks) for model years 1975 to present in the United States.

CONCENTRIC TUBE FUEL ELEMENT SPRING ALIGNMENT SPACER DEVICE

DOEpatents

Weems, S.J.

1963-09-24

A rib construction for a nuclear-fuel element is described, in which one of three peripherally spaced ribs adjacent to each end of the fuel element is mounted on a radially yielding spring that embraces the fuel element. This spring enables the fuel element to have a good fit with a coolant tube and yet to be easily inserted in and withdrawn from the tube. (AEC)

Occupational exposures to emissions from combustion of diesel and alternative fuels in underground mining--a simulated pilot study.

PubMed

Lutz, Eric A; Reed, Rustin J; Lee, Vivien S T; Burgess, Jefferey L

2015-01-01

Diesel fuel is commonly used for underground mining equipment, yet diesel engine exhaust is a known human carcinogen. Alternative fuels, including biodiesel, and a natural gas/diesel blend, offer the potential to reduce engine emissions and associated health effects. For this pilot study, exposure monitoring was performed in an underground mine during operation of a load-haul-dump vehicle. Use of low-sulfur diesel, 75% biodiesel/25% diesel blend (B75), and natural gas/diesel blend (GD) fuels were compared. Personal samples were collected for total and respirable diesel particulate matter (tDPM and rDPM, respectively) and total and respirable elemental and organic carbon (tEC, rEC, tOC, rOC, respectively), as well as carbon monoxide (CO), formaldehyde, acetaldehyde, naphthalene, nitric oxide (NO), and nitrogen dioxide (NO2). Compared to diesel, B75 use was associated with a 33% reduction in rDPM, reductions in rEC, tEC, and naphthalene, increased tDPM, tOC, and NO, and no change in rOC, CO, and NO2. Compared to diesel, GD was associated with a 66% reduction in rDPM and a reduction in all other exposures except CO. The alternative fuels tested both resulted in reduced rDPM, which is the basis for the current Mine Safety and Health Administration (MSHA) occupational exposure standard. Although additional study is needed with a wider variety of equipment, use of alternative fuels have the promise of reducing exposures from vehicular exhaust in underground mining settings.

STUDIES OF FAST REACTOR FUEL ELEMENT BEHAVIOR UNDER TRANSIENT HEATING TO FAILURE. I. INITIAL EXPERIMENTS ON METALLIC SAMPLES IN THE ABSENCE OF COOLANT

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

Dickerman, C. E.; Sowa, E. S.; Okrent, D.

1961-08-01

Meltdown tests on single metallic unirradiated fuel elements in TREAT are described. The fuel elements (EBRII Mark I fuel pins, EBR-II fuel pins with retractory Nb or Ta cladding, and Fermi-I fuel pins) are tested in an inert atmosphere, with no coolant. The fuel elements are exposed to reactor power bursts of 200 msec to 25 sec duration, under conditions simulating fast reactor operations. For these tests, the type of power burst, the integrated power, the fuel enrichment, the maximum cladding temperature, and the effects of the test on the fuel element are recorded. ( T.F.H.)

Effects of FAME biodiesel and HVORD on emissions from an older-technology diesel engine.

PubMed

Bugarski, A D; Hummer, J A; Vanderslice, S E

2017-12-01

The results of laboratory evaluations were used to compare the potential of two alternative, biomass-derived fuels as a control strategy to reduce the exposure of underground miners to aerosols and gases emitted by diesel-powered equipment. The effects of fatty acid methyl ester (FAME) biodiesel and hydrotreated vegetable oil renewable diesel (HVORD) on criteria aerosol and gaseous emissions from an older-technology, naturally aspirated, mechanically controlled engine equipped with a diesel oxidation catalytic converter were compared with those of widely used petroleum-derived, ultralow-sulfur diesels (ULSDs). The emissions were characterized for four selected steady-state conditions. When fueled with FAME biodiesel and HVORD, the engine emitted less aerosols by total particulate mass, total carbon mass, elemental carbon mass and total number than when it was fueled with ULSDs. Compared with ULSDs, FAME biodiesel and HVORD produced aerosols that were characterized by single modal distributions, smaller count median diameters, and lower total and peak concentrations. For the majority of test cases, FAME biodiesel and HVORD favorably affected nitric oxide (NO) and adversely affected nitrogen dioxide (NO 2 ) generation. Therefore, the use of these alternative fuels appears to be a viable tool for the underground mining industry to address the issues related to emissions from diesel engines, and to transition toward more universal solutions provided by advanced engines with integrated exhaust after treatment technologies.

Effects of FAME biodiesel and HVORD on emissions from an older-technology diesel engine

PubMed Central

Bugarski, A.D.; Hummer, J.A.; Vanderslice, S.E.

2017-01-01

The results of laboratory evaluations were used to compare the potential of two alternative, biomass-derived fuels as a control strategy to reduce the exposure of underground miners to aerosols and gases emitted by diesel-powered equipment. The effects of fatty acid methyl ester (FAME) biodiesel and hydrotreated vegetable oil renewable diesel (HVORD) on criteria aerosol and gaseous emissions from an older-technology, naturally aspirated, mechanically controlled engine equipped with a diesel oxidation catalytic converter were compared with those of widely used petroleum-derived, ultralow-sulfur diesels (ULSDs). The emissions were characterized for four selected steady-state conditions. When fueled with FAME biodiesel and HVORD, the engine emitted less aerosols by total particulate mass, total carbon mass, elemental carbon mass and total number than when it was fueled with ULSDs. Compared with ULSDs, FAME biodiesel and HVORD produced aerosols that were characterized by single modal distributions, smaller count median diameters, and lower total and peak concentrations. For the majority of test cases, FAME biodiesel and HVORD favorably affected nitric oxide (NO) and adversely affected nitrogen dioxide (NO2) generation. Therefore, the use of these alternative fuels appears to be a viable tool for the underground mining industry to address the issues related to emissions from diesel engines, and to transition toward more universal solutions provided by advanced engines with integrated exhaust after treatment technologies. PMID:29348698

NUCLEAR REACTOR FUEL-BREEDER FUEL ELEMENT

DOEpatents

Currier, E.L. Jr.; Nicklas, J.H.

1962-08-14

A fuel-breeder fuel element was developed for a nuclear reactor wherein discrete particles of fissionable material are dispersed in a matrix of fertile breeder material. The fuel element combines the advantages of a dispersion type and a breeder-type. (AEC)

15. VIEW OF DUMMY FUEL ELEMENT ON FUEL ELEMENT HOLDER. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW OF DUMMY FUEL ELEMENT ON FUEL ELEMENT HOLDER. SHOWS AIR FORCE MAN AT EDGE OF TANK. INEL PHOTO NUMBER 65-6176, TAKEN NOVEMBER 10, 1965. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

Nano-spike Catalysts Convert Carbon Dioxide Directly into Ethanol

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

Rondinone, Adam

2016-10-12

In a new twist to waste-to-fuel technology, scientists at the Department of Energy’s Oak Ridge National Laboratory have developed an electrochemical process that uses tiny spikes of carbon and copper to turn carbon dioxide, a greenhouse gas, into ethanol. Their finding, which involves nanofabrication and catalysis science, was serendipitous.

Analysis of Emission Reduction Strategies for Power Boilers in the US Pulp and Paper Industry.

EPA Science Inventory

The U.S. pulp and paper industry utilizes a variety of fuels to provide energy for process needs. Energy production results in air emissions of sulfur dioxide (SO2), nitrogen oxides (NOX), particulate matter (PM), and greenhouse gases such as carbon dioxide (CO2). Air emissions f...

Mixed uranium dicarbide and uranium dioxide microspheres and process of making same

DOEpatents

Stinton, David P.

1983-01-01

Nuclear fuel microspheres are made by sintering microspheres containing uranium dioxide and uncombined carbon in a 1 mole percent carbon monoxide/99 mole percent argon atmosphere at 1550.degree. C. and then sintering the microspheres in a 3 mole percent carbon monoxide/97 mole percent argon atmosphere at the same temperature.

Neutron radiation characteristics of plutonium dioxide fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, (alpha, n) reactions with low Z impurities in the fuel, and (alpha, n) reactions with O-18. For spontaneous fission neutrons a value of (1.95 + or - 0.07) X 1,000 n/s/g PuO2 is obtained. The neutron yield from (alpha, n) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha-particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.14 + or - 0.26) X 10,000 n/s/g PuO2. The neutron yield from (alpha, n) reactions with low Z impurities in the fuel is presented in tabular form for one part part per million of each impurity. The total neutron yield due to the combined effects of all the impurities depends upon the fractional weight concentration of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

Transition Core Properties during Conversion of the NBSR from HEU to LEU Fuel

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

Hanson, A. L.; Diamond, D.

2013-10-31

The transition of the NBSR from HEU to LEU fuel is challenging due to reactivity constraints and the need to maintain an uninterrupted science program, the mission of the NBSR. The transition cannot occur with a full change of HEU to LEU fuel elements since the excess reactivity would be large enough that the NBSR would violate the technical specification for shutdown margin. Manufacturing LEU fuel elements to represent irradiated fuel elements would be cost prohibitive since 26 one-of-a-kind fuel elements would need to be manufactured. For this report a gradual transition from the present HEU fuel to the proposedmore » LEU fuel was studied. The gradual change approach would follow the present fuel management scheme and replace four HEU fuel elements with four LEU fuel elements each cycle. This manuscript reports the results of a series of calculations to predict the neutronic characteristics and how the neutronics will change during the transition from HEU to LEU in the NBSR.« less

New Concepts for Compact Space Reactor Power Systems for Space Based Radar Applications: A Feasibility Study

DTIC Science & Technology

1989-12-01

SPENT FUEL REPROCESSING COULD ALSO BE EMPLOYED IRRADIATION EXPERIENCE - EXTREMELY LIMITED - JOINT US/UK PROGRAM (ONGOING) - TUI/KFK PROGRAM (CANCELED...only the use of off-the-shelf technologies. For example, conventional fuel technology (uranium dioxide), conventional thermionic conversion...advanced fuel (Americium oxide, A1TI2O3) and advanced thermionic conversion. Concept C involves use of an advanced fuel (Americium oxide, Arri203

Dry syngas purification process for coal gas produced in oxy-fuel type integrated gasification combined cycle power generation with carbon dioxide capturing feature.

PubMed

Kobayashi, Makoto; Akiho, Hiroyuki

2017-12-01

Electricity production from coal fuel with minimizing efficiency penalty for the carbon dioxide abatement will bring us sustainable and compatible energy utilization. One of the promising options is oxy-fuel type Integrated Gasification Combined Cycle (oxy-fuel IGCC) power generation that is estimated to achieve thermal efficiency of 44% at lower heating value (LHV) base and provide compressed carbon dioxide (CO 2 ) with concentration of 93 vol%. The proper operation of the plant is established by introducing dry syngas cleaning processes to control halide and sulfur compounds satisfying tolerate contaminants level of gas turbine. To realize the dry process, the bench scale test facility was planned to demonstrate the first-ever halide and sulfur removal with fixed bed reactor using actual syngas from O 2 -CO 2 blown gasifier for the oxy-fuel IGCC power generation. Design parameter for the test facility was required for the candidate sorbents for halide removal and sulfur removal. Breakthrough test was performed on two kinds of halide sorbents at accelerated condition and on honeycomb desulfurization sorbent at varied space velocity condition. The results for the both sorbents for halide and sulfur exhibited sufficient removal within the satisfactory short depth of sorbent bed, as well as superior bed conversion of the impurity removal reaction. These performance evaluation of the candidate sorbents of halide and sulfur removal provided rational and affordable design parameters for the bench scale test facility to demonstrate the dry syngas cleaning process for oxy-fuel IGCC system as the scaled up step of process development. Copyright © 2017 Elsevier Ltd. All rights reserved.

77 FR 22391 - Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources: Electric...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-13

... dioxide (CO 2 ) for new affected fossil fuel-fired electric utility generating units (EGUs). The EPA is proposing these requirements because CO 2 is a greenhouse gas (GHG) and fossil fuel-fired power plants are... new fossil fuel-fired EGUs greater than 25 megawatt electric (MWe) to meet an output-based standard of...

The Increasing Concentrations of Atmospheric CO2: How Much, When and Why?

DOE Data Explorer

Marland, Gregg [Environmental Sciences Division, Oak Ridge National Laboratory (ORNL); Boden, Tom [Environmental Sciences Division, Oak Ridge National Laboratory (ORNL)

2009-01-01

There is now a sense that the world community has achieved a broad consensus that: 1.) the atmospheric concentration of carbon dioxide (CO2) is increasing, 2.) this increase is due largely to the combustion of fossil fuels, and 3.) this increase is likely to lead to changes in the global climate. This consensus is sufficiently strong that virtually all countries are involved in trying to achieve a functioning agreement on how to confront, and mitigate, these changes in climate. This paper reviews the first two of these components in a quantitative way. We look at the data on the atmospheric concentration of carbon dioxide and on the magnitude of fossil-fuel combustion, and we examine the trends in both. We review the extent to which cause and effect can be demonstrated between the trends in fossil-fuel burning and the trends in atmospheric CO2 concentration. Finally, we look at scenarios for the future use of fossil fuels and what these portend for the future of atmospheric chemistry. Along the way we examine how and where fossil fuels are used on the Earth and some of the issues that are raised by any effort to reduce fossil-fuel use.

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.

Aerosols emitted in underground mine air by diesel engine fueled with biodiesel.

PubMed

Bugarski, Aleksandar D; Cauda, Emanuele G; Janisko, Samuel J; Hummer, Jon A; Patts, Larry D

2010-02-01

Using biodiesel in place of petroleum diesel is considered by several underground metal and nonmetal mine operators to be a viable strategy for reducing the exposure of miners to diesel particulate matter. This study was conducted in an underground experimental mine to evaluate the effects of soy methyl ester biodiesel on the concentrations and size distributions of diesel aerosols and nitric oxides in mine air. The objective was to compare the effects of neat and blended biodiesel fuels with those of ultralow sulfur petroleum diesel. The evaluation was performed using a mechanically controlled, naturally aspirated diesel engine equipped with a muffler and a diesel oxidation catalyst. The effects of biodiesel fuels on size distributions and number and total aerosol mass concentrations were found to be strongly dependent on engine operating conditions. When fueled with biodiesel fuels, the engine contributed less to elemental carbon concentrations for all engine operating modes and exhaust configurations. The substantial increases in number concentrations and fraction of organic carbon (OC) in total carbon over the baseline were observed when the engine was fueled with biodiesel fuels and operated at light-load operating conditions. Size distributions for all test conditions were found to be single modal and strongly affected by engine operating conditions, fuel type, and exhaust configuration. The peak and total number concentrations as well as median diameter decreased with an increase in the fraction of biodiesel in the fuels, particularly for high-load operating conditions. The effects of the diesel oxidation catalyst, commonly deployed to counteract the potential increase in OC emissions due to use of biodiesel, were found to vary depending upon fuel formulation and engine operating conditions. The catalyst was relatively effective in reducing aerosol number and mass concentrations, particularly at light-load conditions, but also showed the potential for an increase in nitrogen dioxide concentrations at high-load modes.

Isolation, Preliminary Characterization and Preliminary Assessment of Scale-Up Potential of Photosynthetic Microalgae for the Production of Both Biofuels and Bio-Active Molecules in the U.S. and Canada: Cooperative Research and Development Final Report, CRADA Number CRD-10-372

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

Pienkos, P.

2012-09-01

Combustion flue gases are a major contributor to carbon dioxide emissions into the Earth's atmosphere, a factor that has been linked to the possible global climate change. It is, therefore, critical to begin thinking seriously about ways to reduce this influx into the atmosphere. Using carbon dioxide from fossil fuel combustion as a feedstock for the growth, photosynthetic microorganisms can provide a large sink for carbon assimilation as well as a feedstock for the production of significant levels of biofuels. Combining microalgal farming with fossil fuel energy production has great potential to diminish carbon dioxide releases into the atmosphere, asmore » well as contribute to the production of biofuels (e.g., biodiesel, renewable diesel and gasoline and jet fuel) as well as valuable co-products such as animal feeds and green chemicals. CO2 capture may be a regulatory requirement in future new coal or natural gas power plants and will almost certainly become an opportunity for commerce, the results of such studies may provide industries in the US and Canada with both regulatory relief and business opportunities as well as the ability to meet environmental and regulatory requirements, and to produce large volumes of fuels and co-products.« less

NEUTRONIC REACTOR

DOEpatents

Ohlinger, L.A.; Wigner, E.P.; Weinberg, A.M.; Young, G.J.

1958-09-01

This patent relates to neutronic reactors of the heterogeneous water cooled type, and in particular to a fuel element charging and discharging means therefor. In the embodiment illustrated the reactor contains horizontal, parallel coolant tubes in which the fuel elements are disposed. A loading cart containing a magnzine for holding a plurality of fuel elements operates along the face of the reactor at the inlet ends of the coolant tubes. The loading cart is equipped with a ram device for feeding fuel elements from the magazine through the inlot ends of the coolant tubes. Operating along the face adjacent the discharge ends of the tubes there is provided another cart means adapted to receive irradiated fuel elements as they are forced out of the discharge ends of the coolant tubes by the incoming new fuel elements. This cart is equipped with a tank coataining a coolant, such as water, into which the fuel elements fall, and a hydraulically operated plunger to hold the end of the fuel element being discharged. This inveation provides an apparatus whereby the fuel elements may be loaded into the reactor, irradiated therein, and unloaded from the reactor without stopping the fiow of the coolant and without danger to the operating personnel.

Nuclear reactor

DOEpatents

Thomson, Wallace B.

2004-03-16

A nuclear reactor comprising a cylindrical pressure vessel, an elongated annular core centrally disposed within and spaced from the pressure vessel, and a plurality of ducts disposed longitudinally of the pressure vessel about the periphery thereof, said core comprising an annular active portion, an annular reflector just inside the active portion, and an annular reflector just outside the active a portion, said annular active portion comprising rectangular slab, porous fuel elements radially disposed around the inner reflector and extending the length of the active portion, wedge-shaped, porous moderator elements disposed adjacent one face of each fuel element and extending the length of the fuel element, the fuel and moderator elements being oriented so that the fuel elements face each other and the moderator elements do likewise, adjacent moderator elements being spaced to provide air inlet channels, and adjacent fuel elements being spaced to provide air outlet channels which communicate with the interior of the peripheral ducts, and means for introducing air into the air inlet channels which passes through the porous moderator elements and porous fuel elements to the outlet channel.

CWEX (Crop/Wind-Energy Experiment): Measurements of the interaction between crop agriculture and wind power

NASA Astrophysics Data System (ADS)

Rajewski, Daniel Andrew

The current expansion of wind farms in the U.S. Midwest promotes an alternative renewable energy portfolio to conventional energy sources derived from fossil fuels. The construction of wind turbines and large wind farms within several millions of cropland acres creates a unique interaction between two unlike energy sources: electric generation by wind and bio-fuel production derived from crop grain and plant tissues. Wind turbines produce power by extracting mean wind speed and converting a portion of the flow to turbulence downstream of each rotor. Turbine-scale turbulence modifies fluxes of momentum, heat, moisture, and other gaseous constituents (e.g. carbon dioxide) between the crop canopy and the atmospheric boundary layer. Conversely, crop surfaces and tillage elements produce drag on the hub-height wind resource, and the release of sensible and latent heat flux from the canopy or soil influences the wind speed profile. The Crop-Wind Energy Experiment (CWEX) measured momentum, energy, and CO2 fluxes at several locations within the leading line of turbines in a large operational wind farm, and overall turbines promote canopy mixing of wind speed, temperature, moisture, and carbon dioxide in both the day and night. Turbine-generated perturbations of these fluxes are dependent on several factors influencing the turbine operation (e.g. wind speed, wind direction, stability, orientation of surrounding turbines within a wind park) and the cropland surface (e.g. crop type and cultivar, planting density, chemical application, and soil composition and drainage qualities). Additional strategies are proposed for optimizing the synergy between crop and wind power.

40 CFR 86.135-90 - Dynamometer procedure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and methanol-fueled Otto-cycle vehicles. The dynamometer run consists of two tests, a “cold” start... analyzed for hydrocarbon, carbon monoxide, carbon dioxide, and oxides of nitrogen. Methanol and formaldehyde samples (exhaust and dilution air) are collected and analyzed for methanol-fueled vehicles (a...

40 CFR 86.135-90 - Dynamometer procedure.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and methanol-fueled Otto-cycle vehicles. The dynamometer run consists of two tests, a “cold” start... analyzed for hydrocarbon, carbon monoxide, carbon dioxide, and oxides of nitrogen. Methanol and formaldehyde samples (exhaust and dilution air) are collected and analyzed for methanol-fueled vehicles (a...

Petroleum Plantations for Fuel and Materials.

ERIC Educational Resources Information Center

Calvin, Melvin

1979-01-01

Several alternatives to long-range fuel production are given. The carbon dioxide problem resulting from the burning of coal is discussed. Emphasis is given to the topic of hydrocarbon producing plants, such as those in the genus Euphorbia, and the economics of oil production from them. (SA)

Light-duty automotive technology and fuel economy trends : 1975 through 2008

DOT National Transportation Integrated Search

2009-11-01

This report summarizes key trends in carbon dioxide (CO2) emissions, fuel economy and technology usage related to model year (MY) 1975 through 2009 light-duty vehicles sold in the United States. Light-duty vehicles are those vehicles that EPA classif...

Performance of diesel engine using diesel B3 mixed with crude palm oil.

PubMed

Namliwan, Nattapong; Wongwuttanasatian, Tanakorn

2014-01-01

The objective of this study was to test the performance of diesel engine using diesel B3 mixed with crude palm oil in ratios of 95 : 5, 90 : 10, and 85 : 15, respectively, and to compare the results with diesel B3. According to the tests, they showed that the physical properties of the mixed fuel in the ratio of 95 : 5 were closest to those of diesel B3. The performance of the diesel engine that used mixed fuels had 5-17% lower torque and power than that of diesel B3. The specific fuel consumption of mixed fuels was 7-33% higher than using diesel B3. The components of gas emissions by using mixed fuel had 1.6-52% fewer amount of carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), and oxygen (O2) than those of diesel B3. On the other hand, nitric oxide (NO) and nitrogen oxides (NO X ) emissions when using mixed fuels were 10-39% higher than diesel B3. By comparing the physical properties, the performance of the engine, and the amount of gas emissions of mixed fuel, we found out that the 95 : 5 ratio by volume was a suitable ratio for agricultural diesel engine (low-speed diesel engine).

Advanced coal gasifier-fuel cell power plant systems design

NASA Technical Reports Server (NTRS)

Heller, M. E.

1983-01-01

Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

Comparison of different vehicle power trains

NASA Astrophysics Data System (ADS)

Mizsey, Peter; Newson, Esmond

Four different alternatives of mobile power train developments (hybrid diesel, fuel cell operating with hydrogen produced on a petrochemical basis, methanol reformer-fuel cell system, gasoline reformer-fuel cell system), are compared with the gasoline internal combustion engine (ICE), for well-to-wheel efficiencies, CO 2 emissions, and investment costs. Although the ICE requires the lowest investment cost, it is not competitive in well-to-wheel efficiencies and less favourable than the above alternatives for CO 2 emissions. The hybrid diesel power train has the highest well-to-wheel efficiency (30%), but its well-to-wheel carbon dioxide emission is similar to that of the fuel cell power train operated with compressed hydrogen produced on a centralised petrochemical basis. This latter case, however, has the advantage over the hybrid diesel power train that the carbon dioxide emission is concentrated and easier to control than the several point-like sources of emissions. Among the five cases studied only the on-board reforming of methanol offers the possibility of using a renewable energy source (biomass).

Neutronic fuel element fabrication

DOEpatents

Korton, George

2004-02-24

This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure by encompassing the sides of the fuel element between the header plates.

Grafted functional groups on expanded tetrafluoroethylene (ePTFE) support for fuel cell and water transport membranes

DOEpatents

Fuller, Timothy J.; Jiang, Ruichun

2017-01-24

A method for forming a modified solid polymer includes a step of contacting a solid fluorinated polymer with a sodium sodium-naphthalenide solution to form a treated fluorinated solid polymer. The treated fluorinated solid polymer is contacted with carbon dioxide, sulfur dioxide, or sulfur trioxide to form a solid grafted fluorinated polymer. Characteristically, the grafted fluorinated polymer includes appended CO.sub.2H or SO.sub.2H or SO.sub.3H groups. The solid grafted fluorinated polymer is advantageously incorporated into a fuel cell as part of the ion-conducting membrane or a water transport membrane in a humidifier.

System and process for producing fuel with a methane thermochemical cycle

DOEpatents

Diver, Richard B.

2015-12-15

A thermochemical process and system for producing fuel are provided. The thermochemical process includes reducing an oxygenated-hydrocarbon to form an alkane and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. Another thermochemical process includes reducing a metal oxide to form a reduced metal oxide, reducing an oxygenated-hydrocarbon with the reduced metal oxide to form an alkane, and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. The system includes a reformer configured to perform a thermochemical process.

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

DOEpatents

Huffman, Gerald P

2012-09-18

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

Constraints to commercialization of algal fuels.

PubMed

Chisti, Yusuf

2013-09-10

Production of algal crude oil has been achieved in various pilot scale facilities, but whether algal fuels can be produced in sufficient quantity to meaningfully displace petroleum fuels, has been largely overlooked. Limitations to commercialization of algal fuels need to be understood and addressed for any future commercialization. This review identifies the major constraints to commercialization of transport fuels from microalgae. Algae derived fuels are expensive compared to petroleum derived fuels, but this could change. Unfortunately, improved economics of production are not sufficient for an environmentally sustainable production, or its large scale feasibility. A low-cost point supply of concentrated carbon dioxide colocated with the other essential resources is necessary for producing algal fuels. An insufficiency of concentrated carbon dioxide is actually a major impediment to any substantial production of algal fuels. Sustainability of production requires the development of an ability to almost fully recycle the phosphorous and nitrogen nutrients that are necessary for algae culture. Development of a nitrogen biofixation ability to support production of algal fuels ought to be an important long term objective. At sufficiently large scale, a limited supply of freshwater will pose a significant limitation to production even if marine algae are used. Processes for recovering energy from the algal biomass left after the extraction of oil, are required for achieving a net positive energy balance in the algal fuel oil. The near term outlook for widespread use of algal fuels appears bleak, but fuels for niche applications such as in aviation may be likely in the medium term. Genetic and metabolic engineering of microalgae to boost production of fuel oil and ease its recovery, are essential for commercialization of algal fuels. Algae will need to be genetically modified for improved photosynthetic efficiency in the long term. Copyright © 2013 Elsevier B.V. All rights reserved.

Catalyst for the reduction of sulfur dioxide to elemental sulfur

DOEpatents

Jin, Y.; Yu, Q.; Chang, S.G.

1996-02-27

The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h{sup {minus}1}. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications. 21 figs.

Catalyst for the reduction of sulfur dioxide to elemental sulfur

DOEpatents

Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

1996-01-01

The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h.sup.-1. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications.

Relative importance of thermal versus carbon dioxide induced warming from fossil-fuel combustion

NASA Astrophysics Data System (ADS)

Zhang, X.; Caldeira, K.

2015-12-01

The Earth is heated both when reduced carbon is oxidized to carbon dioxide and when outgoing longwave radiation is trapped by carbon dioxide in the atmosphere (CO2 greenhouse effect). The purpose of this study is to improve our understanding of time scales and relative magnitudes of climate forcing increase over time from pulse, continuous, and historical CO2 and thermal emissions. To estimate the amount of global warming that would be produced by thermal and CO2 emissions from fossil fuel combustion, we calculate thermal emissions with thermal contents of fossil fuels and estimate CO2 emissions with emission factors from Intergovernmental Panel on Climate Change (IPCC) AR5. We then use a schematic climate model mimicking Coupled Model Intercomparison Project Phase 5 to investigate the climate forcing and the time-integrated climate forcing. We show that, considered globally, direct thermal forcing from fossil fuel combustion is about 1.71% the radiative forcing from CO2 that has accumulated in the atmosphere from past fossil fuel combustion. When a new power plant comes on line, the radiative forcing from the accumulation of released CO2 exceeds the thermal emissions from the power plant in less than half a year (and about 3 months for coal plants). Due to the long lifetime of CO2 in the atmosphere, CO2 radiative forcing greatly overwhelms direct thermal forcing on longer time scales. Ultimately, the cumulative radiative forcing from the CO2 exceeds the direct thermal forcing by a factor of ~100,000.

Thermal exploitation of wastes with lignite for energy production.

PubMed

Grammelis, Panagiotis; Kakaras, Emmanuel; Skodras, George

2003-11-01

The thermal exploitation of wastewood with Greek lignite was investigated by performing tests in a laboratory-scale fluidized bed reactor, a 1-MW(th) semi-industrial circulating fluidized bed combustor, and an industrial boiler. Blends of natural wood, demolition wood, railroad sleepers, medium-density fiberboard residues, and power poles with lignite were used, and the co-combustion efficiency and the effect of wastewood addition on the emitted pollutants were investigated. Carbon monoxide, sulfur dioxide, and oxides of nitrogen emissions were continuously monitored, and, during the industrial-scale tests, the toxic emissions (polychlorinated dibenzodioxins and dibenzofurans and heavy metals) were determined. Ash samples were analyzed for heavy metals in an inductively coupled plasma-atomic emission spectroscopy spectrophotometer. Problems were observed during the preparation of wastewood, because species embedded with different compounds, such as railway sleepers and demolition wood, were not easily treated. All wastewood blends were proven good fuels; co-combustion proceeded smoothly and homogeneous temperature and pressure profiles were obtained. Although some fluctuations were observed, low emissions of gaseous pollutants were obtained for all fuel blends. The metal element emissions (in the flue gases and the solid residues) were lower than the legislative limits. Therefore, wastewood co-combustion with lignite can be realized, provided that the fuel handling and preparation can be practically performed in large-scale installations.

Aerial sampling of emissions from biomass pile burns in ...

EPA Pesticide Factsheets

Emissions from burning piles of post-harvest timber slash in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5 µm), black carbon, ultraviolet absorbing PM, elemental/organic carbon, semi-volatile organics (polycyclic aromatic hydrocarbons and polychlorinated dibenzodioxins/dibenzofurans), filter-based metals, and volatile organics were sampled for determination of emission factors. The effect on emissions from covering or not covering piles with polyethylene sheets to prevent fuel wetting was determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emissions of volatile organic compounds. Results for other pollutants will also be discussed. This work determined the emissions from open burning of forest slash wood, with and without plastic sheeting. The foresters advocate the use of plastic to keep the slash wood dry and aid in the controlled combustion of the slash to reduce fuel loading. Concerns about the emissions from the burning plastic prompted this work which conducted an extensive characterization of dry, wet, and dry with plastic slash pile emissions.

Application of Argonne's Glass Furnace Model to longhorn glass corporation oxy-fuel furnace for the production of amber glass.

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

Golchert, B.; Shell, J.; Jones, S.

2006-09-06

The objective of this project is to apply the Argonne National Laboratory's Glass Furnace Model (GFM) to the Longhorn oxy-fuel furnace to improve energy efficiency and to investigate the transport of gases released from the batch/melt into the exhaust. The model will make preliminary estimates of the local concentrations of water, carbon dioxide, elemental oxygen, and other subspecies in the entire combustion space as well as the concentration of these species in the furnace exhaust gas. This information, along with the computed temperature distribution in the combustion space may give indications on possible locations of crown corrosion. An investigation intomore » the optimization of the furnace will be performed by varying several key parameters such as the burner firing pattern, exhaust number/size, and the boost usage (amount and distribution). Results from these parametric studies will be analyzed to determine more efficient methods of operating the furnace that reduce crown corrosion. Finally, computed results from the GFM will be qualitatively correlated to measured values, thus augmenting the validation of the GFM.« less

Nuclear reactor control

DOEpatents

Cawley, William E.; Warnick, Robert F.

1982-01-01

1. In a nuclear reactor incorporating a plurality of columns of tubular fuel elements disposed in horizontal tubes in a mass of graphite wherein water flows through the tubes to cool the fuel elements, the improvement comprising at least one control column disposed in a horizontal tube including fewer fuel elements than in a normal column of fuel elements and tubular control elements disposed at both ends of said control column, and means for varying the horizontal displacement of the control column comprising a winch at the upstream end of the control column and a cable extending through the fuel and control elements and attached to the element at the downstream end of the column.

Optimization of Environmental Conditions to Maximize Carbon Dioxide Sequestration Through Algal Growth

DTIC Science & Technology

2010-03-01

this would complete the fossil fuel cycle, as algae are understood to be the progenitors of our current oil based fossil fuel stocks. As primary... oil . However, considering the scope of the world’s energy uses, these sources cannot possibly replace the fossil fuels currently in use. Some...122 Jatropha 1892 140 77 Coconut 2689 99 54 Oil Palm 5950 45 24 * For meeting 50% of transport fuel requirements in the United States

Sulfur control in ion-conducting membrane systems

DOEpatents

Stein, VanEric Edward; Richards, Robin Edward; Brengel, David Douglas; Carolan, Michael Francis

2003-08-05

A method for controlling the sulfur dioxide partial pressure in a pressurized, heated, oxygen-containing gas mixture which is contacted with an ion-conducting metallic oxide membrane which permeates oxygen ions. The sulfur dioxide partial pressure in the oxygen-depleted non-permeate gas from the membrane module is maintained below a critical sulfur dioxide partial pressure, p.sub.SO2 *, to protect the membrane material from reacting with sulfur dioxide and reducing the oxygen flux of the membrane. Each ion-conducting metallic oxide material has a characteristic critical sulfur dioxide partial pressure which is useful in determining the required level of sulfur removal from the feed gas and/or from the fuel gas used in a direct-fired feed gas heater.

Solar electricity and solar fuels

NASA Astrophysics Data System (ADS)

Spiers, David J.

1989-04-01

The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

Further Sensitivity Analysis of Hypothetical Policies to Limit Energy-Related Carbon Dioxide Emissions

EIA Publications

2013-01-01

This analysis supplements the Annual Energy Outlook 2013 alternative cases which imposed hypothetical carbon dioxide emission fees on fossil fuel consumers. It offers further cases that examine the impacts of fees placed only on the emissions from electric power facilities, impacts of returning potential revenues to consumers, and two cap-and-trade policies.

Nano-spike Catalysts Convert Carbon Dioxide Directly into Ethanol

ScienceCinema

Rondinone, Adam

2018-06-12

In a new twist to waste-to-fuel technology, scientists at the Department of Energy’s Oak Ridge National Laboratory have developed an electrochemical process that uses tiny spikes of carbon and copper to turn carbon dioxide, a greenhouse gas, into ethanol. Their finding, which involves nanofabrication and catalysis science, was serendipitous.

SOA FORMATION FROM THE IRRADIATION OF A-PINENE-NOX IN THE ABSENCE AND PRESENCE OF SULFUR DIOXIDE

EPA Science Inventory

Sulfur dioxide (SO2) is an important constituent in the polluted atmosphere. It is emitted from combustion sources using fuels that contain sulfur. Emissions of SO2 in the United States were reportedly 17 Tg in 1996 with most coming from coal and petroleum combustion. The pr...

ISRU Technologies for Mars Life Support

NASA Technical Reports Server (NTRS)

Finn, John E.; Kliss, Mark; Sridhar, K. R.; Iacomini, Christie

2001-01-01

Life support systems can take advantage of elements in the atmosphere of Mars to provide for necessary consumables such as oxygen and buffer gas for makeup of leakage. In situ consumables production (ISCP) can be performed effectively in conjunction with in situ propellant production, in which oxygen and methane are manufactured for rocket fuel. This project considers ways of achieving the optimal system objectives from the two sometimes competing objectives of ISPP and ISCP. In previous years we worked on production of a nitrogen-argon buffer gas as a by- product of the CO2 acquisition and compression system. Recently we have been focusing on combined electrolysis of water vapor and carbon dioxide. Combined electrolysis of water vapor and carbon dioxide is essential for reducin,o the complexity of a combined ISPP/ISCP plant. Using a solid oxide electrolysis cell (SOEC) for this combined process would be most advantageous for it allows mainly gas phase reactions, O2 gas delivered from the electrolyzer is free of any H2O vapor, and SOE is already a proven technology for pure CO2 electrolysis. Combined SOEC testing is conducted at The University of Arizona in the Space Technologies Laboratory (STL) of the Aerospace and Mechanical Engineering Department.

Nuclear Power’s Role in Generating Electricity

DTIC Science & Technology

2008-05-01

and Without EPAct Incentives 9 2-1. Historical Volatility in Fuel Prices 20 2-2. Carbon Dioxide Emissions of Base-Load Technologies for Generating...options using that fuel would operate at their maximum capacity factor.CBO 20 NUCLEAR POWER’S ROLE IN GENERATING ELECTRICITY CBOFigure 2-1. Historical ... Volatility in Fuel Prices (Percentage change) Source: Congressional Budget Office based on data from the Energy Information Administration (EIA

77 FR 16868 - Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-22

... Fuel Elements for Use in Research and Test Reactors AGENCY: Nuclear Regulatory Commission. ACTION... Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test Reactors.'' This guide describes... plate-type uranium-aluminum fuel elements used in research and test reactors (RTRs). DATES: Submit...

Abilities of helium immobilization by the UO2 surface using the “ab initio” method

NASA Astrophysics Data System (ADS)

Dąbrowski, Ludwik; Szuta, Marcin

2016-09-01

We present density functional theory calculation results concerning the uranium dioxide crystals with a helium atom incorporated in the octahedral sites on a nano superficial layer of UO2 fuel element. In order to quantify the capability of helium immobilization we propose a quantum model of adsorption and desorption which we compare with the classical model of Langmuir. Significant differences between the models are maintained in a wide temperature range including high temperatures of the order of 1000 K. By the proposed method of quantum isotherms it was established that the octahedral positions near the metal surface are good traps for helium atoms. While in a temperature close to 1089 K it predicts an intensive release of helium, which is consistent with the experimental results.

Titanium dioxide in dental enamel as a trace element and its variation with bleaching

PubMed Central

Durán-Sedó, Randall; Herrera-Sancho, Óscar-Andrey

2018-01-01

Background Titanium is a less studied trace element in dental enamel. Literature relates an increased Titanium concentration with a decreased enamel crystal domain size, which in turn is related to a higher color value. The aim of our study was to analyze the effect of tooth bleaching agents on its concentration in dental enamel by means of confocal Raman spectroscopy. Material and Methods Human teeth were randomly distributed in six experimental groups (n=10) and submitted to different bleaching protocols according to the manufacturer´s instructions. Confocal Raman spectroscopy was carried out in order to identify and quantify the presence of titanium dioxide molecules in enamel prior to and during whitening. Statistical analysis included repeated measures analysis of variance (p≤0.05) and Bonferroni pairwise comparisons. Results Titanium dioxide concentration was negatively affected by the longer bleaching protocols (at-home bleaching gels). All in-office whitening products increased significantly the studied molecule (p≤0,05). Conclusions All dental specimens depicted the presence of titanium dioxide as a trace element in dental enamel. Bleaching gels that have to be applied at higher concentrations but for shorter periods of time increase the concentration of titanium dioxide, whilst at-home whitening gels used for longer periods of time despite the lower concentration caused a loss in titanium. Key words:Bleaching, whitening, hydrogen peroxide, carbamide peroxide, Raman spectroscopy, titanium dioxide. PMID:29930771

Titanium dioxide in dental enamel as a trace element and its variation with bleaching.

PubMed

Vargas-Koudriavtsev, Tatiana; Durán-Sedó, Randall; Herrera-Sancho, Óscar-Andrey

2018-06-01

Titanium is a less studied trace element in dental enamel. Literature relates an increased Titanium concentration with a decreased enamel crystal domain size, which in turn is related to a higher color value. The aim of our study was to analyze the effect of tooth bleaching agents on its concentration in dental enamel by means of confocal Raman spectroscopy. Human teeth were randomly distributed in six experimental groups (n=10) and submitted to different bleaching protocols according to the manufacturer´s instructions. Confocal Raman spectroscopy was carried out in order to identify and quantify the presence of titanium dioxide molecules in enamel prior to and during whitening. Statistical analysis included repeated measures analysis of variance ( p ≤0.05) and Bonferroni pairwise comparisons. Titanium dioxide concentration was negatively affected by the longer bleaching protocols (at-home bleaching gels). All in-office whitening products increased significantly the studied molecule ( p ≤0,05). All dental specimens depicted the presence of titanium dioxide as a trace element in dental enamel. Bleaching gels that have to be applied at higher concentrations but for shorter periods of time increase the concentration of titanium dioxide, whilst at-home whitening gels used for longer periods of time despite the lower concentration caused a loss in titanium. Key words: Bleaching, whitening, hydrogen peroxide, carbamide peroxide, Raman spectroscopy, titanium dioxide.

Fuel pumping system and method

DOEpatents

Shafer, Scott F [Morton, IL; Wang, Lifeng ,

2006-12-19

A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

Fuel Pumping System And Method

DOEpatents

Shafer, Scott F.; Wang, Lifeng

2005-12-13

A fuel pumping system that includes a pump drive is provided. A first pumping element is operatively connected to the pump drive and is operable to generate a first flow of pressurized fuel. A second pumping element is operatively connected to the pump drive and is operable to generate a second flow of pressurized fuel. A first solenoid is operatively connected to the first pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the first flow of pressurized fuel. A second solenoid is operatively connected to the second pumping element and is operable to vary at least one of a fuel pressure and a fuel flow rate of the second flow of pressurized fuel.

Determination of Combustion Product Radicals in a Hydrocarbon Fueled Rocket Exhaust Plume

NASA Technical Reports Server (NTRS)

Langford, Lester A.; Allgood, Daniel C.; Junell, Justin C.

2007-01-01

The identification of metallic effluent materials in a rocket engine exhaust plume indicates the health of the engine. Since 1989, emission spectroscopy of the plume of the Space Shuttle Main Engine (SSME) has been used for ground testing at NASA's Stennis Space Center (SSC). This technique allows the identification and quantification of alloys from the metallic elements observed in the plume. With the prospect of hydrocarbon-fueled rocket engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from the hydrocarbon fuels are of great interest. The effect of several diatomic molecular radicals, such as Carbon Dioxide , Carbon Monoxide, Molecular Carbon, Methylene Radical, Cyanide or Cyano Radical, and Nitric Oxide, needs to be identified and the effects of their band systems on the spectral region from 300 nm to 850 nm determined. Hydrocarbon-fueled rocket engines will play a prominent role in future space exploration programs. Although hydrogen fuel provides for higher engine performance, hydrocarbon fuels are denser, safer to handle, and less costly. For hydrocarbon-fueled engines using RP-1 or CH4 , the plume is different from a hydrogen fueled engine due to the presence of several other species, such as CO2, C2, CO, CH, CN, and NO, in the exhaust plume, in addition to the standard H2O and OH. These species occur as intermediate or final combustion products or as a result of mixing of the hot plume with the atmosphere. Exhaust plume emission spectroscopy has emerged as a comprehensive non-intrusive sensing technology which can be applied to a wide variety of engine performance conditions with a high degree of sensitivity and specificity. Stennis Space Center researchers have been in the forefront of advancing experimental techniques and developing theoretical approaches in order to bring this technology to a more mature stage.

Thermodynamic calculations of oxygen self-diffusion in mixed-oxide nuclear fuels

DOE PAGES

Parfitt, David C.; Cooper, Michael William; Rushton, Michael J.D.; ...

2016-07-29

Mixed-oxide fuels containing uranium with thorium and/or plutonium may play an important part in future nuclear fuel cycles. There are, however, significantly less data available for these materials than conventional uranium dioxide fuel. In the present study, we employ molecular dynamics calculations to simulate the elastic properties and thermal expansivity of a range of mixed oxide compositions. These are then used to support equations of state and oxygen self-diffusion models to provide a self-consistent prediction of the behaviour of these mixed oxide fuels at arbitrary compositions.

Nitrogen Deposition: A Component of Global Change Analyses

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

Norby, Richard J.

1997-12-31

The global cycles of carbon and nitrogen are being perturbed by human activities that increase the transfer from large pools of nonreactive forms of the elements to reactive forms that are essential to the functioning of the terrestrial biosphere. The cycles are closely linked at all scales, and global change analyses must consider carbon and nitrogen cycles together. The increasing amount of nitrogen originating from fossil fuel combustion and deposited to terrestrial ecosystems as nitrogen oxides could increase the capacity of ecosystems to sequester carbon thereby removing some of the excess carbon dioxide from the atmosphere and slowing the developmentmore » of greenhouse warming. Several global and ecosystem models have calculated the amount of carbon sequestration that can be attributed to nitrogen deposition based on assumptions about the allocation of nitrogen among ecosystem components with different carbon-nitrogen ratios. They support the premise that nitrogen deposition is responsible for a an increasing terrestrial carbon sink since industrialization began, but there are large uncertainties related to the continued capacity of ecosystems to retain exogenous nitrogen. Whether terrestrial ecosystems continue to sequester additional carbon will depend in part on their response to increasing atmospheric carbon dioxide concentrations, which is widely thought to be constrained by limited nitrogen availability. Ecosystem models generally support the conclusion that the responses of ecosystems to increasing concentrations of carbon dioxide will be larger, and the range of possible responses will be wider, in ecosystems with increased nitrogen inputs originating as atmospheric deposition.« less

CARBON DIOXIDE FROM FOSSIL FUELS: ADAPTING TO UNCERTAINTY

EPA Science Inventory

The paper discusses the general effect and control of CO2. The world is likely to experience noticeable global warming by the beginning of the next century if high annual growth rates of fossil fuel energy use continue. Only with optimistic assumptions and low growth rates will C...

Effects of elevated carbon dioxide concentrations on broiler chicken performance from 28 to 49 days

USDA-ARS?s Scientific Manuscript database

Improvements in modern broiler housing have substantially reduced air leakage, making proper operation of ventilation systems critical to maintaining a suitable environment. Fuel prices have increased in recent years, leading to reduced minimum ventilation in order to conserve fuel which increases ...

40 CFR 73.20 - Phase II early reduction credits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... utility, including generators that are not fossil fuel-fired) that has decreased its total coal-fired... quality of fuel being burned. (c) Initial certification of eligibility. The designated representative of a... reductions in sulfur dioxide emissions; and (2) A report listing all units in the utility system, each fossil...

Means for supporting fuel elements in a nuclear reactor

DOEpatents

Andrews, Harry N.; Keller, Herbert W.

1980-01-01

A grid structure for a nuclear reactor fuel assembly comprising a plurality of connecting members forming at least one longitudinally extending opening peripheral and inner fuel element openings through each of which openings at least one nuclear fuel element extends, said connecting members forming wall means surrounding said each peripheral and inner fuel element opening, a pair of rigid projections longitudinally spaced from one another extending from a portion of said wall means into said each peripheral and inner opening for rigidly engaging said each fuel element, respectively, yet permit individual longitudinal slippage thereof, and resilient means formed integrally on and from said wall means and positioned in said each peripheral and inner opening in opposed relationship with said projections and located to engage said fuel element to bias the latter into engagement with said rigid projections, respectively

Fuel assembly for nuclear reactors

DOEpatents

Creagan, Robert J.; Frisch, Erling

1977-01-01

A new and improved fuel assembly is formed to minimize the amount of parasitic structural material wherein a plurality of hollow tubular members are juxtaposed to the fuel elements of the assembly. The tubular members may serve as guide tubes for control elements and are secured to a number of longitudinally spaced grid members along the fuel assembly. The grid members include means thereon engaging each of the fuel elements to laterally position the fuel elements in a predetermined array. Openings in the bottom of each hollow member serve as a shock absorber to cushion shock transmitted to the structure when the control elements are rapidly inserted in their corresponding tubular members.

Reducing Actinide Production Using Inert Matrix Fuels

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

Deinert, Mark

2017-08-23

The environmental and geopolitical problems that surround nuclear power stem largely from the longlived transuranic isotopes of Am, Cm, Np and Pu that are contained in spent nuclear fuel. New methods for transmuting these elements into more benign forms are needed. Current research efforts focus largely on the development of fast burner reactors, because it has been shown that they could dramatically reduce the accumulation of transuranics. However, despite five decades of effort, fast reactors have yet to achieve industrial viability. A critical limitation to this, and other such strategies, is that they require a type of spent fuel reprocessingmore » that can efficiently separate all of the transuranics from the fission products with which they are mixed. Unfortunately, the technology for doing this on an industrial scale is still in development. In this project, we explore a strategy for transmutation that can be deployed using existing, current generation reactors and reprocessing systems. We show that use of an inert matrix fuel to recycle transuranics in a conventional pressurized water reactor could reduce overall production of these materials by an amount that is similar to what is achievable using proposed fast reactor cycles. Furthermore, we show that these transuranic reductions can be achieved even if the fission products are carried into the inert matrix fuel along with the transuranics, bypassing the critical separations hurdle described above. The implications of these findings are significant, because they imply that inert matrix fuel could be made directly from the material streams produced by the commercially available PUREX process. Zirconium dioxide would be an ideal choice of inert matrix in this context because it is known to form a stable solid solution with both fission products and transuranics.« less

FUEL ELEMENT FOR NUCLEAR REACTORS

DOEpatents

Dickson, J.J.

1963-09-24

A method is described whereby fuel tubes or pins are cut, loaded with fuel pellets and a heat transfer medium, sealed at each end with slotted fittings, and assembled into a rectangular tube bundle to form a fuel element. The tubes comprising the fuel element are laterally connected between their ends by clips and tabs to form a linear group of spaced parallel tubes, which receive their vertical support by resting on a grid. The advantages of this method are that it permits elimination of structural material (e.g., fuel-element cans) within the reactor core, and removal of at least one fuel pin from an element and replacement thereof so that a burnable poison may be utilized during the core lifetime. (AEC)

Sustainable Carbon Dioxide Sequestration as Soil Carbon to Achieve Carbon Neutral Status for DoD Lands

DTIC Science & Technology

2017-10-01

e.g., when burned) or sinks (when growing) for carbon, depending upon its state. Fossil fuels (coal, oil, and gas) are formed over long periods of...world (Solar Energy Industries Association (SEIA) 2013). Most of the DoD’s energy comes from fossil fuels. In 2011, it was estimated that the DoD...energy consumption and fossil fuel use. Lowering carbon emissions can be equated to lower fuel consumption, reducing costs, and making DoD entities less

Analysis of Consequences of Using Gas Fuels for Running Auxiliary Ship Boilers in the Light of Contemporary Environmental Protection Requirements

NASA Astrophysics Data System (ADS)

Adamkiewicz, Andrzej; Bartoszewski, Marek; Kendra, Martin

2016-09-01

The article justifies the application of gas fuels for supplying auxiliary ship boilers. It presents legal regulations on maritime environmental protection areas and their requirements which are in power. It shows the chronology of introduced limitations on sulphur and nitrogen dioxide emissions and thresholds of carbon dioxide emission reduction expressed by EEDI (Energy Efficiency Design Indicator) and EEOI (Energy Efficiency Operational Indicator). Ways to decrease the values of EEDI and EEOI in the ship energy effectiveness management have been shown. Consequences of replacing marine fuels with LNG for running auxiliary ship boilers have been considered thoroughly, taking into account ecological, constructional, operational, procedural and logistic limitations as well as economic consequences. The summary shows the influence of particular consequences of using LNG for running boilers on the methods of maintenance of auxiliary boilers.

Grooved Fuel Rings for Nuclear Thermal Rocket Engines

NASA Technical Reports Server (NTRS)

Emrich, William

2009-01-01

An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants. The grooved ring fuel design attempts to retain the best features of the particle bed fuel element while eliminating most of its design deficiencies. In the grooved ring design, the hydrogen propellant enters the fuel element in a manner similar to that of the Particle Bed Reactor (PBR) fuel element.

Fuel combustion adds to anxiety over CO/sub 2/ buildup

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

Sleeper, D.

1979-08-01

In the past 20 y, the annual rate of increase of atmosphreic carbon dioxide has grown sharply because of increased fossil fuel combustion. Most scientists agree that CO/sub 2/ buildup in the atmosphere is causing a greenhouse effect, slowly warming the earth's climate. Large-scale production of synthetic fuels that could be combusted without releasing CO/sub 2/ is examined as a possible solution. 31 references, 1 figure.

Behavior or Nonmetallic Materials in Shale Oil Derived Jet Fuels and in High Aromatic and High Sulfur Petroleum Fuels

DTIC Science & Technology

1978-07-01

degrades thermal stability and forms undesirable sulfur dioxide emissions . Although the original premises for controlling total sulfur may not still...eliminate corrosive trace contamination, presence of surfactants which deactivate filter/ separators, carry-over of refinery processing materials, and...increase raw vapor emissions from ground fuel handling facilities and during refueling operations. Controlling raw vapor emissions is difficult at 3

Current status of the development of high density LEU fuel for Russian research reactors

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

Vatulin, A.; Dobrikova, I.; Suprun, V.

2008-07-15

One of the main directions of the Russian RERTR program is to develop U-Mo fuel and fuel elements/FA with this fuel. The development is carried out both for existing reactors, and for new advanced designs of reactors. Many organizations in Russia, i.e. 'TVEL', RDIPE, RIAR, IRM, NPCC participate in the work. Two fuels are under development: dispersion and monolithic U-Mo fuel, as well two types of FA to use the dispersion U-Mo fuel: with tubular type fuel elements and with pin type fuel elements. The first stage of works was successfully completed. This stage included out-pile, in-pile and post irradiationmore » examinations of U-Mo dispersion fuel in experimental tubular and pin fuel elements under parameters similar to operation conditions of Russian design pool-type research reactors. The results received both in Russia and abroad enabled to go on to the next stage of development which includes irradiation tests both of full-scale IRT pin-type and tube-type fuel assemblies with U-Mo dispersion fuel and of mini-fuel elements with modified U-Mo dispersion fuel and monolithic fuel. The paper gives a generalized review of the results of U-Mo fuel development accomplished by now. (author)« less

Effect of energy taxation on fuel choice and emissions (Energiaverojen vaikutus polttoainevalintoihin ja paeaestoeihin). Research notes (in English;Finnish)

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

Leino, P.; Kosunen, P.; Rauhamaeki, J.

1997-05-01

The aim of the project was to study how various tax models for power plant fuels affect the fuel consumption and emissions of particles, sulphur dioxide (SO{sup 2}), nitrogen oxide (NOx) and carbon dioxide (CO{sup 2}). First, the development of Finnish energy taxation is discussed, followed by a survey of the energy production structure for 1994. For this purpose, it was necessary to prepare a large boiler database, which covers about 95% of the fuel consumption of Finnish energy production. The boiler database was used to calculate the emissions of particles, SO{sup 2}, NOx and CO{sup 2} in 1994. Themore » year 2010 selected under review is the year by which the Ministry of Trade and Industry has prepared their primary energy consumption estimates. Four different alternatives were studied as future tax models. In the first alternative taxation would be as it in years 1995--1996 and in the second alternative taxation would be as 1 January 1997. In the third alternative the Finnish application of EU taxes would be in force in full, i.e., the tax on heavy fuel oil would be 10 US dollars a barrel. In the fourth alternative there would be no taxes on fuels.« less

Thermal-Hydraulic Transient Analysis of a Packed Particle Bed Reactor Fuel Element

DTIC Science & Technology

1990-06-01

long fuel elements, arranged to form a core , were analyzed for an up-power transient from 0 MWt to approximately 18 MWt. The simple model significantly...VARIATIONS IN FUEL ELEMENT GEOMETRY ............. 60 4.4 VARIATIONS IN THE MANNER OF TRANSIENT CONTROL ..... 62 4.5 CORE REPRESENTATION BY MULTIPLE FUEL ...the HTGR , however, the PBR packs small fuel particles between inner and outer retention elements, designated as frits. The PBR is appropriate for a

Nuclear fuel elements and method of making same

DOEpatents

Schweitzer, Donald G.

1992-01-01

A nuclear fuel element for a high temperature gas nuclear reactor that has an average operating temperature in excess of 2000.degree. C., and a method of making such a fuel element. The fuel element is characterized by having fissionable fuel material localized and stabilized within pores of a carbon or graphite member by melting the fissionable material to cause it to chemically react with the carbon walls of the pores. The fissionable fuel material is further stabilized and localized within the pores of the graphite member by providing one or more coatings of pyrolytic carbon or diamond surrounding the porous graphite member so that each layer defines a successive barrier against migration of the fissionable fuel from the pores, and so that the outermost layer of pyrolytic carbon or diamond forms a barrier between the fissionable material and the moderating gases used in an associated high temperature gas reactor. The method of the invention provides for making such new elements either as generally spherically elements, or as flexible filaments, or as other relatively small-sized fuel elements that are particularly suited for use in high temperature gas reactors.

78 FR 17591 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... aft fuel system 40 micron fuel filter element with a 10 micron nominal (40 micron absolute) fuel filter element. This AD was prompted by a National Transportation Safety Board (NTSB) review of in... helicopters with a fuel system 40 micron fuel filter element, part number (P/N) 52-0505-2 or 52-01064-1. That...

International Energy Outlook

EIA Publications

2017-01-01

This report presents international energy projections through 2050, prepared by the Energy Information Administration, including outlooks for major energy fuels and associated carbon dioxide emissions.

Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel.

PubMed

Ristovski, Z D; Jayaratne, E R; Morawska, L; Ayoko, G A; Lim, M

2005-06-01

A comprehensive study of the particle and carbon dioxide emissions from a fleet of six dedicated liquefied petroleum gas (LPG) powered and five unleaded petrol (ULP) powered new Ford Falcon Forte passenger vehicles was carried out on a chassis dynamometer at four different vehicle speeds--0 (idle), 40, 60, 80 and 100 km h(-1). Emission factors and their relative values between the two fuel types together with a statistical significance for any difference were estimated for each parameter. In general, LPG was found to be a 'cleaner' fuel, although in most cases, the differences were not statistically significant owing to the large variations between emissions from different vehicles. The particle number emission factors ranged from 10(11) to 10(13) km(-1) and was over 70% less with LPG compared to ULP. Corresponding differences in particle mass emission factor between the two fuels were small and ranged from the order of 10 microg km(-1) at 40 to about 1000 microg km(-1) at 100 km h(-1). The count median particle diameter (CMD) ranged from 20 to 35 nm and was larger with LPG than with ULP in all modes except the idle mode. Carbon dioxide emission factors ranged from about 300 to 400 g km(-1) at 40 km h(-1), falling with increasing speed to about 200 g km(-1) at 100 km h(-1). At all speeds, the values were 10% to 18% greater with ULP than with LPG.

Assessing global radiative forcing due to regional emissions of tropospheric ozone precursors: a step towards climate credit for ozone reductions

NASA Astrophysics Data System (ADS)

Mauzerall, D. L.; Naik, V.; Horowitz, L. W.; Schwarzkopf, D.; Ramaswamy, V.; Oppenheimer, M.

2005-05-01

Carbon dioxide emissions from fossil-fuel consumption are presented for the five Asian countries that are among the global leaders in anthropogenic carbon emissions: China (13% of global total), Japan (5% of global total), India (5% of global total), South Korea (2% of global total), and Indonesia (1% of global total). Together, these five countries represent over a quarter of the world's fossil-fuel based carbon emissions. Moreover, these countries are rapidly developing and energy demand has grown dramatically in the last two decades. A method is developed to estimate the spatial and seasonal flux of fossil-fuel consumption, thereby greatly improving the temporal and spatial resolution of anthropogenic carbon dioxide emissions. Currently, only national annual data for anthropogenic carbon emissions are available, and as such, no understanding of seasonal or sub-national patterns of emissions are possible. This methodology employs fuel distribution data from representative sectors of the fossil-fuel market to determine the temporal and spatial patterns of fuel consumption. These patterns of fuel consumption are then converted to patterns of carbon emissions. The annual total emissions estimates produced by this method are consistent to those maintained by the United Nations. Improved estimates of temporal and spatial resolution of the human based carbon emissions allows for better projections about future energy demands, carbon emissions, and ultimately the global carbon cycle.

Performance of Diesel Engine Using Diesel B3 Mixed with Crude Palm Oil

PubMed Central

Namliwan, Nattapong; Wongwuttanasatian, Tanakorn

2014-01-01

The objective of this study was to test the performance of diesel engine using diesel B3 mixed with crude palm oil in ratios of 95 : 5, 90 : 10, and 85 : 15, respectively, and to compare the results with diesel B3. According to the tests, they showed that the physical properties of the mixed fuel in the ratio of 95 : 5 were closest to those of diesel B3. The performance of the diesel engine that used mixed fuels had 5–17% lower torque and power than that of diesel B3. The specific fuel consumption of mixed fuels was 7–33% higher than using diesel B3. The components of gas emissions by using mixed fuel had 1.6–52% fewer amount of carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), and oxygen (O2) than those of diesel B3. On the other hand, nitric oxide (NO) and nitrogen oxides (NOX) emissions when using mixed fuels were 10–39% higher than diesel B3. By comparing the physical properties, the performance of the engine, and the amount of gas emissions of mixed fuel, we found out that the 95 : 5 ratio by volume was a suitable ratio for agricultural diesel engine (low-speed diesel engine). PMID:24688402

One dimensional modeling of a diesel-CNG dual fuel engine

NASA Astrophysics Data System (ADS)

Azman, Putera Adam; Fawzi, Mas; Ismail, Muammar Mukhsin; Osman, Shahrul Azmir

2017-04-01

Some of the previous studies have shown that the use of compressed natural gas (CNG) in diesel engines potentially produce engine performance improvement and exhaust gas emission reduction, especially nitrogen oxides, unburned hydrocarbons, and carbon dioxide. On the other hand, there are other researchers who claimed that the use of CNG increases exhaust gas emissions, particularly nitrogen oxides. In this study, a one-dimensional model of a diesel-CNG dual fuel engine was made based on a 4-cylinder 2.5L common rail direct injection diesel engine. The software used is GT-Power, and it was used to analyze the engine performance and exhaust gas emissions of several diesel-CNG dual fuel blend ratios, i.e. 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. The effect of 100%, 75%, 50% engine loads on the exhaust gas emissions were also studied. The result shows that all diesel-CNG fuel blends produces higher brake torque and brake power at engine speed of 2000-3000 rpm compared with 100% diesel. The 50:50 diesel-CNG blend produces the highest brake torque and brake power, but also has the highest brake specific fuel consumption. As a higher percentage of CNG added to the dual fuel blend, unburned hydrocarbons and carbon monoxide emission increased while carbon dioxide emission decreased. The nitrogen oxides emission concentration is generally unaffected by any change of the dual fuel ratio.

NEUTRONIC REACTOR AND FUEL ELEMENT THEREFOR

DOEpatents

Szilard, L.; Young, G.J.

1958-03-01

This patent relates to a reactor design of the type which employs solid fuel elements disposed in channels within the moderator through which channels and around the fuel elements is conveyed a coolant fiuid. The coolant channels are comprised of aluminum tubes extending through a solid moderator such as graphite and the fuel elements are comprised of an elongated solid body of natural uranium jacketed in an aluminum jacket with the ends thereof closed by aluminum caps of substantially greater thickness than the jacket was and in good thermal contact with the fuel material to facilitate the conduction of heat from the central portion of said ends to the coolant surrounding the fuel element to prevent overheating of said central portion.

Evaluating measurements of carbon dioxide emissions using a precision source--A natural gas burner.

PubMed

Bryant, Rodney; Bundy, Matthew; Zong, Ruowen

2015-07-01

A natural gas burner has been used as a precise and accurate source for generating large quantities of carbon dioxide (CO2) to evaluate emissions measurements at near-industrial scale. Two methods for determining carbon dioxide emissions from stationary sources are considered here: predicting emissions based on fuel consumption measurements-predicted emissions measurements, and direct measurement of emissions quantities in the flue gas-direct emissions measurements. Uncertainty for the predicted emissions measurement was estimated at less than 1%. Uncertainty estimates for the direct emissions measurement of carbon dioxide were on the order of ±4%. The relative difference between the direct emissions measurements and the predicted emissions measurements was within the range of the measurement uncertainty, therefore demonstrating good agreement. The study demonstrates how independent methods are used to validate source emissions measurements, while also demonstrating how a fire research facility can be used as a precision test-bed to evaluate and improve carbon dioxide emissions measurements from stationary sources. Fossil-fuel-consuming stationary sources such as electric power plants and industrial facilities account for more than half of the CO2 emissions in the United States. Therefore, accurate emissions measurements from these sources are critical for evaluating efforts to reduce greenhouse gas emissions. This study demonstrates how a surrogate for a stationary source, a fire research facility, can be used to evaluate the accuracy of measurements of CO2 emissions.

The carbon footprint of Australian ambulance operations.

PubMed

Brown, Lawrence H; Canyon, Deon V; Buettner, Petra G; Crawford, J Mac; Judd, Jenni

2012-12-01

To determine the greenhouse gas emissions associated with the energy consumption of Australian ambulance operations, and to identify the predominant energy sources that contribute to those emissions. A two-phase study of operational and financial data from a convenience sample of Australian ambulance operations to inventory their energy consumption and greenhouse gas emissions for 1 year. State- and territory-based ambulance systems serving 58% of Australia's population and performing 59% of Australia's ambulance responses provided data for the study. Emissions for the participating systems totalled 67 390 metric tons of carbon dioxide equivalents. For ground ambulance operations, emissions averaged 22 kg of carbon dioxide equivalents per ambulance response, 30 kg of carbon dioxide equivalents per patient transport and 3 kg of carbon dioxide equivalents per capita. Vehicle fuels accounted for 58% of the emissions from ground ambulance operations, with the remainder primarily attributable to electricity consumption. Emissions from air ambulance transport were nearly 200 times those for ground ambulance transport. On a national level, emissions from Australian ambulance operations are estimated to be between 110 000 and 120 000 tons of carbon dioxide equivalents each year. Vehicle fuels are the primary source of emissions for ground ambulance operations. Emissions from air ambulance transport are substantially higher than those for ground ambulance transport. © 2012 The Authors. EMA © 2012 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Nitrogen dioxide exposures inside ice skating rinks.

PubMed Central

Brauer, M; Spengler, J D

1994-01-01

OBJECTIVES. The common operation of fuel-powered resurfacing equipment in enclosed ice skating rinks has the potential for producing high concentrations of carbon monoxide and nitrogen dioxide. Exposures to these gaseous combustion products may adversely affect the health of those inside the rink. Little information is available on pollutant concentrations under normal operating conditions. METHODS. One-week average nitrogen dioxide concentrations in 70 northeastern US rinks were measured with passive samplers during normal winter season conditions. RESULTS. The median nitrogen dioxide level inside rinks was 180 ppb, more than 10 times higher than the median outdoor concentration. One-week average nitrogen dioxide concentrations above 1000 ppb were measured in 10% of the rinks. CONCLUSIONS. Considering that short-term peak concentrations were likely to have reached two to five times the measured 1-week averages, our results suggest that nitrogen dioxide levels were well above short-term air quality guidelines and constitute a public health concern of considerable magnitude. PMID:8129060

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.

Modeling Seasonality in Carbon Dioxide Emissions From Fossil Fuel Consumption

NASA Astrophysics Data System (ADS)

Gregg, J. S.; Andres, R. J.

2004-05-01

Using United States data, a method is developed to estimate the monthly consumption of solid, liquid and gaseous fossil fuels using monthly sales data to estimate the relative monthly proportions of the total annual national fossil fuel use. These proportions are then used to estimate the total monthly carbon dioxide emissions for each state. From these data, the goal is to develop mathematical models that describe the seasonal flux in consumption for each type of fuel, as well as the total emissions for the nation. The time series models have two components. First, the general long-term yearly trend is determined with regression models for the annual totals. After removing the general trend, two alternatives are considered for modeling the seasonality. The first alternative uses the mean of the monthly proportions to predict the seasonal distribution. Because the seasonal patterns are fairly consistent in the United States, this is an effective modeling technique. Such regularity, however, may not be present with data from other nations. Therefore, as a second alternative, an ordinary least squares autoregressive model is used. This model is chosen for its ability to accurately describe dependent data and for its predictive capacity. It also has a meaningful interpretation, as each coefficient in the model quantifies the dependency for each corresponding time lag. Most importantly, it is dynamic, and able to adapt to anomalies and changing patterns. The order of the autoregressive model is chosen by the Akaike Information Criterion (AIC), which minimizes the predicted variance for all models of increasing complexity. To model the monthly fuel consumption, the annual trend is combined with the seasonal model. The models for each fuel type are then summed together to predict the total carbon dioxide emissions. The prediction error is estimated with the root mean square error (RMSE) from the actual estimated emission values. Overall, the models perform very well, with relative RMSE less than 10% for all fuel types, and under 5% for the national total emissions. Development of successful models is important to better understand and predict global environmental impacts from fossil fuel consumption.

Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

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

Montierth, Leland M.

2016-07-19

The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element designmore » for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition, as part of a fuel meat thickness optimization effort for reactor performance, other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B, that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.« less

Life cycle analysis of vehicles powered by a fuel cell and by internal combustion engine for Canada

NASA Astrophysics Data System (ADS)

Zamel, Nada; Li, Xianguo

The transportation sector is responsible for a great percentage of the greenhouse gas emissions as well as the energy consumption in the world. Canada is the second major emitter of carbon dioxide in the world. The need for alternative fuels, other than petroleum, and the need to reduce energy consumption and greenhouse gases emissions are the main reasons behind this study. In this study, a full life cycle analysis of an internal combustion engine vehicle (ICEV) and a fuel cell vehicle (FCV) has been carried out. The impact of the material and fuel used in the vehicle on energy consumption and carbon dioxide emissions is analyzed for Canada. The data collected from the literature shows that the energy consumption for the production of 1 kg of aluminum is five times higher than that of 1 kg of steel, although higher aluminum content makes vehicles lightweight and more energy efficient during the vehicle use stage. Greenhouse gas regulated emissions and energy use in transportation (GREET) software has been used to analyze the fuel life cycle. The life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting, and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extraction of hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that the use of coal to obtain hydrogen generates the highest emissions and consumes the highest energy. Comparing the overall life cycle of an ICEV and a FCV, the total emissions of an FCV are 49% lower than an ICEV and the energy consumption of FCV is 87% lower than that of ICEV. Further, CO 2 emissions during the hydrogen fuel production in a central plant can be easily captured and sequestrated. The comparison carried out in this study between FCV and ICEV is extended to the use of recycled material. It is found that using 100% recycled material can reduce energy consumption by 45% and carbon dioxide emissions by 42%, mainly due to the reduced use of electricity during the manufacturing of the material.

FUEL-BREEDER FUEL ELEMENT FOR NUCLEAR REACTOR

DOEpatents

Abbott, W.E.; Balent, R.

1958-09-16

A fuel element design to facilitate breeding reactor fuel is described. The fuel element is comprised of a coatainer, a central core of fertile material in the container, a first bonding material surrounding the core, a sheet of fissionable material immediately surrounding the first bonding material, and a second bonding material surrounding the fissionable material and being in coniact with said container.

Evaluation of the finite element fuel rod analysis code (FRANCO)

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

Lee, K.; Feltus, M.A.

1994-12-31

Knowledge of temperature distribution in a nuclear fuel rod is required to predict the behavior of fuel elements during operating conditions. The thermal and mechanical properties and performance characteristics are strongly dependent on the temperature, which can vary greatly inside the fuel rod. A detailed model of fuel rod behavior can be described by various numerical methods, including the finite element approach. The finite element method has been successfully used in many engineering applications, including nuclear piping and reactor component analysis. However, fuel pin analysis has traditionally been carried out with finite difference codes, with the exception of Electric Powermore » Research Institute`s FREY code, which was developed for mainframe execution. This report describes FRANCO, a finite element fuel rod analysis code capable of computing temperature disrtibution and mechanical deformation of a single light water reactor fuel rod.« less

Radial flow nuclear thermal rocket (RFNTR)

DOEpatents

Leyse, Carl F.

1995-11-07

A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

Radial flow nuclear thermal rocket (RFNTR)

DOEpatents

Leyse, Carl F.

1995-01-01

A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

Why do we conduct energy research in Alabama?

NASA Astrophysics Data System (ADS)

Hills, D. J.

2017-12-01

The purpose of the Energy Investigations Program (EIP) at the Geological Survey of Alabama is to research all geological topics related to energy that would affect the state. The state of Alabama has a rich history of coal, oil, and natural gas production. These traditional fuels are still a necessary part of power production, even as other energy sources are being developed. EIP helps assess the remaining reserves of these hydrocarbons, both from areas that have had extensive production as well as new regions that have yet to have viable production. Our research helps people decide how (or even if) they want to develop the resource. Even so, the research in EIP is not all about fossil fuels. We also investigate how carbon dioxide produced from burning these traditional fuels might be captured and then either used or stored permanently. The same types of geology that are good for producing oil and gas are also often good for geologic storage of carbon dioxide permanently. Carbon dioxide can also be used to produce more oil and gas from an older, less productive field, as it can be used to push more of the hydrocarbon out of the rock. This type of research can lead to job development and economic stability or growth within the state.

40 CFR 86.111-94 - Exhaust gas analytical system.

Code of Federal Regulations, 2012 CFR

2012-07-01

... systems for analysis of total hydrocarbon (THC) (hydrocarbon plus methanol in the case of methanol-fueled...), carbon dioxide (CO2), and oxides of nitrogen (NOX). The schematic diagram of the continuous THC analysis train (and for THC plus methanol for methanol-fueled diesel-cycle vehicles) is shown as part of Figure...

40 CFR 86.111-94 - Exhaust gas analytical system.

Code of Federal Regulations, 2013 CFR

2013-07-01

... systems for analysis of total hydrocarbon (THC) (hydrocarbon plus methanol in the case of methanol-fueled...), carbon dioxide (CO2), and oxides of nitrogen (NOX). The schematic diagram of the continuous THC analysis train (and for THC plus methanol for methanol-fueled diesel-cycle vehicles) is shown as part of Figure...

40 CFR 86.111-94 - Exhaust gas analytical system.

Code of Federal Regulations, 2014 CFR

2014-07-01

... systems for analysis of total hydrocarbon (THC) (hydrocarbon plus methanol in the case of methanol-fueled...), carbon dioxide (CO2), and oxides of nitrogen (NOX). The schematic diagram of the continuous THC analysis train (and for THC plus methanol for methanol-fueled diesel-cycle vehicles) is shown as part of Figure...

Multidisciplinary Simulation of Graphite-Composite and Cermet Fuel Elements for NTP Point of Departure Designs

NASA Technical Reports Server (NTRS)

Stewart, Mark E.; Schnitzler, Bruce G.

2015-01-01

This paper compares the expected performance of two Nuclear Thermal Propulsion fuel types. High fidelity, fluid/thermal/structural + neutronic simulations help predict the performance of graphite-composite and cermet fuel types from point of departure engine designs from the Nuclear Thermal Propulsion project. Materials and nuclear reactivity issues are reviewed for each fuel type. Thermal/structural simulations predict thermal stresses in the fuel and thermal expansion mis-match stresses in the coatings. Fluid/thermal/structural/neutronic simulations provide predictions for full fuel elements. Although NTP engines will utilize many existing chemical engine components and technologies, nuclear fuel elements are a less developed engine component and introduce design uncertainty. Consequently, these fuel element simulations provide important insights into NTP engine performance.

Results of Uranium Dioxide-Tungsten Irradiation Test and Post-Test Examination

NASA Technical Reports Server (NTRS)

Collins, J. F.; Debogdan, C. E.; Diianni, D. C.

1973-01-01

A uranium dioxide (UO2) fueled capsule was fabricated and irradiated in the NASA Plum Brook Reactor Facility. The capsule consisted of two bulk UO2 specimens clad with chemically vapor deposited tungsten (CVD W) 0.762 and 0.1016 cm (0.030-and 0.040-in.) thick, respectively. The second specimen with 0.1016-cm (0.040-in.) thick cladding was irradiated at temperature for 2607 hours, corresponding to an average burnup of 1.516 x 10 to the 20th power fissions/cu cm. Postirradiation examination showed distortion in the bottom end cap, failure of the weld joint, and fracture of the central vent tube. Diametral growth was 1.3 percent. No evidence of gross interaction between CVD tungsten or arc-cast tungsten cladding and the UO2 fuel was observed. Some of the fission gases passed from the fuel cavity to the gas surrounding the fuel specimen via the vent tube and possibly the end-cap weld failure. Whether the UO2 loss rates through the vent tube were within acceptable limits could not be determined in view of the end-cap weld failure.

A comparison of emissions from vehicles fueled with diesel or compressed natural gas.

PubMed

Hesterberg, Thomas W; Lapin, Charles A; Bunn, William B

2008-09-01

A comprehensive comparison of emissions from vehicles fueled with diesel or compressed natural gas (CNG) was developed from 25 reports on transit buses, school buses, refuse trucks, and passenger cars. Emissions for most compounds were highest for untreated exhaust emissions and lowest for treated exhaust CNG buses without after-treatment had the highest emissions of carbon monoxide, hydrocarbons, nonmethane hydrocarbons (NMHC), volatile organic compounds (VOCs; e.g., benzene, butadiene, ethylene, etc.), and carbonyl compounds (e.g., formaldehyde, acetaldehyde, acrolein). Diesel buses without after-treatment had the highest emissions of particulate matter and polycyclic aromatic hydrocarbons (PAHs). Exhaust after-treatments reduced most emissions to similar levels in diesel and CNG buses. Nitrogen oxides (NO(x)) and carbon dioxide (CO2) emissions were similar for most vehicle types, fuels, and exhaust after-treatments with some exceptions. Diesel school buses had higher CO2 emissions than the CNG bus. CNG transit buses and passenger cars equipped with three-way catalysts had lower NO(x) emissions. Diesel buses equipped with traps had higher nitrogen dioxide emissions. Fuel economy was best in the diesel buses not equipped with exhaust after-treatment.

Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

NASA Astrophysics Data System (ADS)

Degueldre, Claude; Cozzo, Cedric; Martin, Matthias; Grolimund, Daniel; Mieszczynski, Cyprian

2013-06-01

Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg-1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (˜0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13- coordination environment (e.g. >90%) and no (<10%) Am(IV) or (V) can be detected in the rim zone. The occurrence of americium dioxide is avoided by the redox buffering activity of the uranium dioxide matrix.

Visible light-harvesting photoanodes for solar energy conversion: A comparison of anchoring groups to titanium dioxide

NASA Astrophysics Data System (ADS)

Martini, Lauren A.

Environmental concerns related to climate change and geopolitical issues related to energy security have led to a widespread pursuit of alternative, non-fossil fuel energy sources capable of meeting our increasing global energy demands. Solar energy, which strikes the earth's surface at a rate vastly exceeding our current worldwide power demand, presents itself as a promising source of clean, abundant and renewable energy. The capture and conversion of solar energy into electricity as well as storable, transportable chemical fuels has therefore become major area of chemical research. Inspired by photosynthesis in nature, in which plants and algae convert sunlight, water, and carbon dioxide into oxygen and stored chemical fuel in the form of sugars, recent work has focused on visible light-driven water-splitting technologies for the production of solar fuels. Honda and Fujishima reported the first example of photoelectrochemical water oxidation in 1972. In their system, an inexpensive titanium dioxide semiconductor irradiated with ultraviolet light produced oxygen at the photoanode surface and hydrogen at the surface of a platinum counter electrode. In attempt to harness visible light instead, titanium dioxide and other inexpensive wide band gap photoanodes have been functionalized with visible light-absorbing molecular dyes. These dye-sensitized photoanodes have been used successfully to convert solar energy into electrical current, as in dye-sensitized solar cells, and to drive chemical processes like water oxidation, as in photocatalytic cells. In both systems, a long-lived charge separation is established upon illumination of the photoanode surface when a photoexcited molecular chromophore transfers an electron to the semiconductor conduction band. Following this electron injection process, a nearby redox-active species is oxidized and refills the hole left behind on the molecular chromophore. While the steps of this scheme are relatively straightforward, the integration of efficient visible-light absorption, ultrafast forward electron transfer, and stable charge separation is quite complicated. The work presented here is devoted to the design, synthesis, spectroscopy, and computational study of dye-sensitized photoanodes. In particular, we explore the relative stability and performance of different anchoring groups for the surface attachment of light-harvesting molecular dyes to titanium dioxide. Here we present the first systematic study that directly compares carboxylate, phosphonate, acetylacetonate, and hydroxamate anchors using the same molecular chromophore framework. We discuss a number of novel methods for the incorporation of anchoring group functionalities on each chromophore framework. We also assess the relative water stability of each of the anchoring groups on titanium dioxide as well as the relative efficiency of electron transfer from photoexcited molecular chromophores through each anchoring group into the conduction band of titanium dioxide. We hope that the work presented here will contribute to the rational design of better photoanodes for light-driven water splitting.

Selective sulfur dioxide adsorption on crystal defect sites on an isoreticular metal organic framework series

PubMed Central

Rodríguez-Albelo, L. Marleny; López-Maya, Elena; Hamad, Said; Ruiz-Salvador, A. Rabdel; Calero, Sofia; Navarro, Jorge A.R.

2017-01-01

The widespread emissions of toxic gases from fossil fuel combustion represent major welfare risks. Here we report the improvement of the selective sulfur dioxide capture from flue gas emissions of isoreticular nickel pyrazolate metal organic frameworks through the sequential introduction of missing-linker defects and extra-framework barium cations. The results and feasibility of the defect pore engineering carried out are quantified through a combination of dynamic adsorption experiments, X-ray diffraction, electron microscopy and density functional theory calculations. The increased sulfur dioxide adsorption capacities and energies as well as the sulfur dioxide/carbon dioxide partition coefficients values of defective materials compared to original non-defective ones are related to the missing linkers enhanced pore accessibility and to the specificity of sulfur dioxide interactions with crystal defect sites. The selective sulfur dioxide adsorption on defects indicates the potential of fine-tuning the functional properties of metal organic frameworks through the deliberate creation of defects. PMID:28198376

NUCLEAR REACTOR FUEL ELEMENT ASSEMBLY

DOEpatents

Stengel, F.G.

1963-12-24

A method of fabricating nuclear reactor fuel element assemblies having a plurality of longitudinally extending flat fuel elements in spaced parallel relation to each other to form channels is presented. One side of a flat side plate is held contiguous to the ends of the elements and a welding means is passed along the other side of the platertransverse to the direction of the longitudinal extension of the elements. The setting and speed of travel of the welding means is set to cause penetration of the side plate with welds at bridge the gap in each channel between adjacent fuel elements with a weld-through bubble of predetermined size. The fabrication of a high strength, dependable fuel element is provided, and the reduction of distortion and high production costs are facilitated by this method. (AEC)

Joint DoD/DoE Shale Oil Project. Volume 3. Testing of Refined Shale Oil Fuels.

DTIC Science & Technology

1983-12-01

inches displacement NO Nitric oxide CLR Cooperative Lubrication Research NOX Oxides of nitrogen CO Carbon monoxide CO2 Carbon dioxide cSt Centistokes... composition and properties, and evaluation of toxicity. This report summarizes the results of these test and evalua- tion studies. The Paraho/Sohio effort...TABLE 11-1. DOE ALTERNATIVE FUELS PROGRAM DIESEL ENGINE TESTS WITH SHALE FUELS ............................... 11-11 TABLE 11-2. COMPOSITION OF

Synergetic and inhibition effects in carbon dioxide gasification of blends of coals and biomass fuels of Indian origin.

PubMed

Satyam Naidu, V; Aghalayam, P; Jayanti, S

2016-06-01

The present study investigates the enhancement of CO2 gasification reactivity of coals due to the presence of catalytic elements in biomass such as K2O, CaO, Na2O and MgO. Co-gasification of three Indian coal chars with two biomass chars has been studied using isothermal thermogravimetric analysis (TGA) in CO2 environment at 900, 1000 and 1100°C. The conversion profiles have been used to establish synergetic or inhibitory effect on coal char reactivity by the presence of catalytic elements in biomass char by comparing the 90% conversion time with and without biomass. It is concluded that both biomasses exhibit synergistic behavior when blended with the three coals with casuarina being more synergetic than empty fruit bunch. Some inhibitory effect has been noted for the high ash coal at the highest temperature with higher 90% conversion time for the blend over pure coal, presumably due to diffusional control of the conversion rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal Hydraulic Analysis of a Packed Bed Reactor Fuel Element

DTIC Science & Technology

1989-05-25

Engineer and Master of Science in Nuclear Engineering. ABSTRACT A model of the behavior of a packed bed nuclear reactor fuel element is developed . It...RECOMMENDATIONS FOR FURTHER INVESTIGATION .................... 150 APPENDIX A FUEL ELEMENT MODEL PROGRAM DESIGN AND OPERA- T IO N...follow describe the details of the packed bed reactor and then discuss the development of the mathematical representations of the fuel element. These are

METHOD AND APPARATUS FOR CONTROLLING NEUTRON DENSITY

DOEpatents

Wigner, E.P.; Young, G.J.; Weinberg, A.M.

1961-06-27

A neutronic reactor comprising a moderator containing uniformly sized and spaced channels and uniformly dimensioned fuel elements is patented. The fuel elements have a fissionable core and an aluminum jacket. The cores and the jackets of the fuel elements in the central channels of the reactor are respectively thinner and thicker than the cores and jackets of the fuel elements in the remainder of the reactor, producing a flattened flux.

FUEL ELEMENT FOR NUCLEAR REACTORS

DOEpatents

Bassett, C.H.

1961-05-16

A fuel element particularly adapted for use in nuclear reactors of high power density is offered. It has fissionable fuel pellet segments mounted in a tubular housing and defining a central passage in the fuel element. A burnable poison element extends through the central passage, which is designed to contain more poison material at the median portion than at the end portions thereby providing a more uniform hurnup and longer reactivity life.

Theoretical analysis of swelling characteristics of cylindrical uranium dioxide fuel pins with a niobium - 1-percent-zirconium clad

NASA Technical Reports Server (NTRS)

Saltsman, J. F.

1973-01-01

The relations between clad creep strain and fuel volume swelling are shown for cylindrical UO2 fuel pins with a Nb-1Zr clad. These relations were obtained by using the computer code CYGRO-2. These clad-strain - fuel-volume-swelling relations may be used with any fuel-volume-swelling model, provided the fuel volume swelling is isotropic and independent of the clad restraints. The effects of clad temperature (over a range from 118 to 1642 K (2010 to 2960 R)), pin diameter, clad thickness and central hole size in the fuel have been investigated. In all calculations the irradiation time was 500 hours. The burnup rate was varied.

Spent nuclear fuel assembly inspection using neutron computed tomography

NASA Astrophysics Data System (ADS)

Pope, Chad Lee

The research presented here focuses on spent nuclear fuel assembly inspection using neutron computed tomography. Experimental measurements involving neutron beam transmission through a spent nuclear fuel assembly serve as benchmark measurements for an MCNP simulation model. Comparison of measured results to simulation results shows good agreement. Generation of tomography images from MCNP tally results was accomplished using adapted versions of built in MATLAB algorithms. Multiple fuel assembly models were examined to provide a broad set of conclusions. Tomography images revealing assembly geometric information including the fuel element lattice structure and missing elements can be obtained using high energy neutrons. A projection difference technique was developed which reveals the substitution of unirradiated fuel elements for irradiated fuel elements, using high energy neutrons. More subtle material differences such as altering the burnup of individual elements can be identified with lower energy neutrons provided the scattered neutron contribution to the image is limited. The research results show that neutron computed tomography can be used to inspect spent nuclear fuel assemblies for the purpose of identifying anomalies such as missing elements or substituted elements. The ability to identify anomalies in spent fuel assemblies can be used to deter diversion of material by increasing the risk of early detection as well as improve reprocessing facility operations by confirming the spent fuel configuration is as expected or allowing segregation if anomalies are detected.

SLUG HANDLING DEVICES

DOEpatents

Gentry, J.R.

1958-09-16

A device is described for handling fuel elements of a neutronic reactor. The device consists of two concentric telescoped contalners that may fit about the fuel element. A number of ratchet members, equally spaced about the entrance to the containers, are pivoted on the inner container and spring biased to the outer container so thnt they are forced to hear against and hold the fuel element, the weight of which tends to force the ratchets tighter against the fuel element. The ratchets are released from their hold by raising the inner container relative to the outer memeber. This device reduces the radiation hazard to the personnel handling the fuel elements.

FUEL ELEMENTS FOR NUCLEAR REACTORS

DOEpatents

Blainey, A.; Lloyd, H.

1961-07-11

A method of sheathing a tubular fuel element for a nuclear reactor is described. A low melting metal core member is centered in a die, a layer of a powdered sheathing substance is placed on the bottom of the die, the tubular fuel element is inserted in the die, the space between the tubular fuel element and the die walls and core member is filled with the same powdered sheathing substance, a layer of the same substance is placed over the fissile material, and the charge within the die is subjected to pressure in the direction of the axis of the fuel element at the sintering temperature of the protective substance.

Recapturing Graphite-Based Fuel Element Technology for Nuclear Thermal Propulsion

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

Trammell, Michael P; Jolly, Brian C; Miller, James Henry

ORNL is currently recapturing graphite based fuel forms for Nuclear Thermal Propulsion (NTP). This effort involves research and development on materials selection, extrusion, and coating processes to produce fuel elements representative of historical ROVER and NERVA fuel. Initially, lab scale specimens were fabricated using surrogate oxides to develop processing parameters that could be applied to full length NTP fuel elements. Progress toward understanding the effect of these processing parameters on surrogate fuel microstructure is presented.

Fuel element concept for long life high power nuclear reactors

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.; Rom, F. E.

1969-01-01

Nuclear reactor fuel elements have burnups that are an order of magnitude higher than can currently be achieved by conventional design practice. Elements have greater time integrated power producing capacity per unit volume. Element design concept capitalizes on known design principles and observed behavior of nuclear fuel.

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.

NEUTRONIC REACTOR FUEL ELEMENT

DOEpatents

Shackleford, M.H.

1958-12-16

A fuel element possessing good stability and heat conducting properties is described. The fuel element comprises an outer tube formed of material selected from the group consisting of stainhess steel, V, Ti. Mo. or Zr, a fuel tube concentrically fitting within the outer tube and containing an oxide of an isotope selected from the group consisting of U/sup 235/, U/sup 233/, and Pu/sup 239/, and a hollow, porous core concentrically fitting within the fuel tube and formed of an oxide of an element selected from the group consisting of Mg, Be, and Zr.

35. DETAILS AND SECTIONS OF FUEL ELEMENT SUPPORT PLATFORM, FUEL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. DETAILS AND SECTIONS OF FUEL ELEMENT SUPPORT PLATFORM, FUEL ELEMENT HOLDER, TRIP MECHANISM COVER, AND OTHER DETAILS. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-S-3. INEL INDEX CODE NUMBER: 075 0701 60 851 151977. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

Possible consequences of operation with KIVN fuel elements in K Zircaloy process tubes

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

Carlson, P.A.

1963-08-06

From considerations of the results of experimental simulations of non-axial placement of fuel elements in process tubes and in-reactor experience, it is concluded that the ultimate outcome of a charging error which results in operation with one or more unsupported fuel elements in a K Zircaloy-2 process tube would be multiple fuel failure and failure of the process tube. The outcome of the accident is determined by the speed with which the fuel failure is detected and the reactor is shut down. The release of fission products would be expected to be no greater than that which has occurred followingmore » severe fuel failure incidents. The highest probability for fission product release occurs during the discharge of failed fuel elements, when a small fraction of the exposed uranium of the fuel element may be oxidized when exposed to air before the element falls into the water-filled discharge chute. The confinement and fog spray facilities were installed to reduce the amount of fission products which might escape from the reactor building after such an event.« less

Rack for storing spent nuclear fuel elements

DOEpatents

Rubinstein, Herbert J.; Clark, Philip M.; Gilcrest, James D.

1978-06-20

A rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed fuel elements. The enclosures are fixed at the lower ends thereof to a base. Pockets are formed between confronting walls of adjacent enclosures for receiving high absorption neutron absorbers, such as Boral, cadmium, borated stainless steel and the like for the closer spacing of spent fuel elements.

METHOD OF OPERATING NUCLEAR REACTORS

DOEpatents

Untermyer, S.

1958-10-14

A method is presented for obtaining enhanced utilization of natural uranium in heavy water moderated nuclear reactors by charging the reactor with an equal number of fuel elements formed of natural uranium and of fuel elements formed of uranium depleted in U/sup 235/ to the extent that the combination will just support a chain reaction. The reactor is operated until the rate of burnup of plutonium equals its rate of production, the fuel elements are processed to recover plutonium, the depleted uranium is discarded, and the remaining uranium is formed into fuel elements. These fuel elements are charged into a reactor along with an equal number of fuel elements formed of uranium depleted in U/sup 235/ to the extent that the combination will just support a chain reaction, and reuse of the uranium is continued as aforesaid until it wlll no longer support a chain reaction when combined with an equal quantity of natural uranium.

Nuclear fuel element with axially aligned fuel pellets and fuel microspheres therein

DOEpatents

Sease, J.D.; Harrington, F.E.

1973-12-11

Elongated single- and multi-region fuel elements are prepared by replacing within a cladding container a coarse fraction of fuel material which includes plutonium and uranium in the appropriate regions of the fuel element and then infiltrating with vibration a fine-sized fraction of uranium-containing microspheres throughout all interstices in the coarse material in a single loading. The fine, rigid material defines a thin annular layer between the coarse fraction and the cladding to reduce adverse mechanical and chemical interactions. (Official Gazette)

Impact of trace element additives on anaerobic digestion of sewage sludge with in-situ carbon dioxide sequestration

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

Linville, Jessica L.; Shen, Yanwen; Schoene, Robin P.

Anaerobic digestion (AD) of sludge at wastewater treatment plants can benefit from addition of essential trace metals such as iron, nickel and cobalt to increase biogas production for utilization in combined heat and power systems, fed into natural gas pipelines or as a vehicle fuel. This study evaluated the impact and benefits of Ni/Co and olivine addition to the digester at mesophilic temperatures. These additions supplement previously reported research in which iron-rich olivine (MgSiO4) was added to sequester CO2 in-situ during batch AD of sludge. Trace element addition has been shown to stimulate and stabilize biogas production and have amore » synergistic effect on the mineral carbonation process. AD with 5% w/v olivine and 1.5 mg/L Ni/Co addition had a 17.3% increase in methane volume, a 6% increase in initial exponential methane production rate and a 56% increase in methane yield (mL CH4/g CODdegraded) compared to the control due to synergistic trace element and olivine addition while maintaining 17.7% CO2 sequestration from olivine addition. Both first-order kinetic modeling and response surface methodology modeling confirmed the combined benefit of the trace elements and olivine addition. These results were significantly higher than previously reported results with olivine addition alone [1].« less

Design Evolutuion of Hot Isotatic Press Cans for NTP Cermet Fuel Fabrication

NASA Technical Reports Server (NTRS)

Mireles, O. R.; Broadway, J.; Hickman, R.

2014-01-01

Nuclear Thermal Propulsion (NTP) is under consideration for potential use in deep space exploration missions due to desirable performance properties such as a high specific impulse (> 850 seconds). Tungsten (W)-60vol%UO2 cermet fuel elements are under development, with efforts emphasizing fabrication, performance testing and process optimization to meet NTP service life requirements [1]. Fuel elements incorporate design features that provide redundant protection from crack initiation, crack propagation potentially resulting in hot hydrogen (H2) reduction of UO2 kernels. Fuel erosion and fission product retention barriers include W coated UO2 fuel kernels, W clad internal flow channels and fuel element external W clad resulting in a fully encapsulated fuel element design as shown.

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.

Use of Elemental Sulfur or Selenium in a Novel One-Pot Copper-Catalyzed Tandem Cyclization of Functionalized Ynamides Leading to Benzosultams.

PubMed

Siva Reddy, Alla; Kumara Swamy, K C

2015-06-19

A novel and efficient [Cu]-catalyzed one-pot regio- and stereospecific synthesis of benzo[1,4,2]dithiazine 1,1-dioxides and benzo[1,4,2]thiaselenazine 1,1-dioxides by cyclization of functionalized ynamides with elemental sulfur/selenium has been developed. Its generality is elegantly illustrated by extension to benzodithiazepines and benzothiaselenazepines. Involvement of water in the reaction is demonstrated by the incorporation of (2)D at the olefinic site by using D2O in place of water. Selective oxidation at sulfur in benzo[1,4,2]dithiazine 1,1-dioxide by using mCPBA as the oxidizing agent is also described.

The legacy of fossil fuels.

PubMed

Armaroli, Nicola; Balzani, Vincenzo

2011-03-01

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Real-world energy use and emission rates for idling long-haul trucks and selected idle reduction technologies.

PubMed

Frey, H Christopher; Kuo, Po-Yao

2009-07-01

Long-haul freight trucks typically idle for 2000 or more hours per year, motivating interest in reducing idle fuel use and emissions using auxiliary power units (APUs) and shore-power (SP). Fuel-use rates are estimated based on electronic control unit (ECU) data for truck engines and measurements for APU engines. Engine emission factors were measured using a portable emission measurement system. Indirect emissions from SP were based on average utility grid emission factors. Base engine fuel use and APU and SP electrical load were analyzed for 20 trucks monitored for more than 1 yr during 2.76 million mi of activity within 42 U.S. states. The average base engine fuel use varied from 0.46 to 0.65 gal/hr. The average APU fuel use varied from 0.24 to 0.41 gal/hr. Fuel-use rates are typically lowest in mild weather, highest in hot or cold weather, and depend on engine speed (revolutions per minute [RPM]). Compared with the base engine, APU fuel use and emissions of carbon dioxide (CO2) and sulfur dioxide (SO2) are lower by 36-47%. Oxides of nitrogen (NO(x)) emissions are lower by 80-90%. Reductions in particulate matter (PM), carbon monoxide (CO), and hydrocarbon emissions vary from approximately 10 to over 50%. SP leads to more substantial reductions, except for SO2. The actual achievable reductions will be lower because only a fraction of base engine usage will be replaced by APUs, SP, or both. Recommendations are made for reducing base engine fuel use and emissions, accounting for variability in fuel use and emissions reductions, and further work to quantify real-world avoided fuel use and emissions.

NREL Produces Ethylene via Photosynthesis | News | NREL

Science.gov Websites

process, by contrast, produces ethylene by using carbon dioxide, which is food for the bacteria. That three tons that would be emitted by tapping fossil fuels and another three tons absorbed by the bacteria currently hitting plants, algae and bacteria capable of producing fuels directly. Ten years ago, a group of

The Feasibility and Current Estimated Capital Costs of Producing Jet Fuel at Sea Using Carbon Dioxide and Hydrogen

DTIC Science & Technology

2010-09-29

emission of sulfur and nitrogen compounds that are produced from the combustion of petroleum derived fossil fuel. 2.0 INTRODUCTION A costlbenefit and...Thermal Energy from Oceans. Enviro . Sci. & Eng. 2007,4,35. 13. Avery, W. H.; Wu, C. Renewable Energy From The Ocean; Oxford University Press: New York

A mathematical model of a large open fire

NASA Technical Reports Server (NTRS)

Harsha, P. T.; Bragg, W. N.; Edelman, R. B.

1981-01-01

A mathematical model capable of predicting the detailed characteristics of large, liquid fuel, axisymmetric, pool fires is described. The predicted characteristics include spatial distributions of flame gas velocity, soot concentration and chemical specie concentrations including carbon monoxide, carbon dioxide, water, unreacted oxygen, unreacted fuel and nitrogen. Comparisons of the predictions with experimental values are also given.

40 CFR 60.42c - Standard for sulfur dioxide (SO2).

Code of Federal Regulations, 2010 CFR

2010-07-01

....2 lb/MMBtu) heat input. If coal is combusted with other fuels, the affected facility shall neither... excess of 520 ng/J (1.2 lb/MMBtu) heat input. If coal is fired with coal refuse, the affected facility.../MMBtu) heat input. If coal is combusted with other fuels, the affected facility is subject to the 50...

Anti-air pollution & energy conservation system for automobiles using leaded or unleaded gasoline, diesel or alternate fuel

DOEpatents

Bose, Ranendra K.

2002-06-04

Exhaust gases from an internal combustion engine operating with leaded or unleaded gasoline or diesel or natural gas, are used for energizing a high-speed gas turbine. The convoluting gas discharge causes a first separation stage by stratifying of heavier and lighter exhaust gas components that exit from the turbine in opposite directions, the heavier components having a second stratifying separation in a vortex tube to separate combustible pollutants from non-combustible components. The non-combustible components exit a vortex tube open end to atmosphere. The lighter combustible, pollutants effected in the first separation are bubbled through a sodium hydroxide solution for dissolving the nitric oxide, formaldehyde impurities in this gas stream before being piped to the engine air intake for re-combustion, thereby reducing the engine's exhaust pollution and improving its fuel economy. The combustible, heavier pollutants from the second separation stage are piped to air filter assemblies. This gas stream convoluting at a high-speed through the top stator-vanes of the air filters, centrifugally separates the coalescent water, aldehydes, nitrogen dioxides, sulfates, sulfur, lead particles which collect at the bottom of the bowl, wherein it is periodically released to the roadway. Whereas, the heavier hydrocarbon, carbon particles are piped through the air filter's porous element to the engine air intake for re-combustion, further reducing the engine's exhaust pollution and improving its fuel economy.

Development of Nanomaterials for Nuclear Energetics

NASA Astrophysics Data System (ADS)

Petrunin, V. F.

Structure and properties peculiarities of the nanocrystalline powders give the opportunity to design new and to develop a modernization of nuclear energy industry materials. It was shown experimentally, that addition of 5-10% uranium dioxide nanocrystalline powder to traditional coarse powder allows to decrease the sintering temperature or to increase the fuel tablets size of grain. Similar perspectives for the technology of neutron absorbing tablets of control-rod modernization are shown by nanopowder of dysprosium hafnate changing instead now using boron carbide. It is powders in nanocrystalline state get an opportunity to sinter them and to receive compact tablet with 8,2-8,4 g/cm2 density for automatic defence system of nuclear reactor. Resource of dysprosium hafnate ceramics can be 18-20 years instead 4-5 years for boron carbide. To step up the radiation-damage stability of fuel element jacket material was suggested to strengthen a heat-resistant ferrite-martensite steel by Y2O3 nanocrystalline powder addition. Nanopowder with size of particles 560 nm and crystallite size 9 nm was prepeared by chemical coprecipitation method. To make lighter the container for transport and provisional disposal of exposed fuel from nuclear reactor a new boron-aluminium alloy called as boral was developed. This composite armed with nanopowders of boron-containing materials and heavy metals oxides can replace succesburnt-up corrosion-resistant steels.

Preparation of high temperature gas-cooled reactor fuel element

DOEpatents

Bradley, Ronnie A.; Sease, John D.

1976-01-01

This invention relates to a method for the preparation of high temperature gas-cooled reactor (HTGR) fuel elements wherein uncarbonized fuel rods are inserted in appropriate channels of an HTGR fuel element block and the entire block is inserted in an autoclave for in situ carbonization under high pressure. The method is particularly applicable to remote handling techniques.

Nuclear fuel element

DOEpatents

Zocher, Roy W.

1991-01-01

A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

Electrocatalytic process for carbon dioxide conversion

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

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

An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and a Helper Polymer in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said carbon dioxide reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. The reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH,more » C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2, and CF.sub.3COOH.« less

Influence of test fuel properties and composition on UNECE R101 CO2 and fuel economy valuation

NASA Astrophysics Data System (ADS)

Parker, A.

2015-12-01

CO2 emission and fuel consumption of passenger cars is now assessed by using a simplistic procedure measuring the emission during a test performed without any control of the fuel properties and computing the fuel consumption through an unsophisticated formula. As pump gasoline and diesel fuels are refinery products mixture of many different hydrocarbons, and in case of gasoline may also contain a significant amount of oxygenates, the fuel properties, including the density, carbon and energy content may strongly vary from one pump fuel to the other. Being the specific test fuels carefully selected by the car manufacturers and everything but randomly chosen pump fuels, the claimed CO2 emission and fuel economy figures may differ largely from the certification values. I show from the analysis of the 2014 UK government data for 2358 diesel and 2103 petrol vehicles how same volumes of only theoretically same pump fuels used during the certification test by the cars manufacturers unfortunately do not produce the same carbon dioxide emission, and very likely do not have the same energy content. The CO2 emission per liter of diesel fuel is shown to oscillate froma maximum of 3049 g to a minimum of 2125 g, with an average of 2625 g, froma +16.13% to a -19.06% of the average. TheCO2 emission per liter of petrol fuel is shown to oscillate even more from a maximum of 3735 g to a minimum of 1767 g with an average of 2327 g, from a +60.48% to a -24.05% of the average. The proposed solution is to center the assessment on the energy demand by measuring with accuracy the mass of fuel consumed and the fuel properties of the test fuel starting from the lower heating. The corrected fuel consumption and the corrected carbon dioxide emission to mention from the test are then computed by using pure hydrocarbon reference fuels for diesel and petrol having a given lower heating value and a given hydrocarbon composition. Alternatively, exactly the same test fuel should be used by all the manufacturers.

Producing liquid fuels from biomass

NASA Astrophysics Data System (ADS)

Solantausta, Yrjo; Gust, Steven

The aim of this survey was to compare, on techno-economic criteria, alternatives of producing liquid fuels from indigenous raw materials in Finland. Another aim was to compare methods under development and prepare a proposal for steering research related to this field. Process concepts were prepared for a number of alternatives, as well as analogous balances and production and investment cost assessments for these balances. Carbon dioxide emissions of the alternatives and the price of CO2 reduction were also studied. All the alternatives for producing liquid fuels from indigenous raw materials are utmost unprofitable. There are great differences between the alternatives. While the production cost of ethanol is 6 to 9 times higher than the market value of the product, the equivalent ratio for substitute fuel oil produced from peat by pyrolysis is 3 to 4. However, it should be borne in mind that the technical uncertainties related to the alternatives are of different magnitude. Production of ethanol from barley is of commercial technology, while biomass pyrolysis is still under development. If the aim is to reach smaller carbon dioxide emissions by using liquid biofuels, the most favorable alternative is pyrolysis oil produced from wood. Fuels produced from cultivated biomass are more expensive ways of reducing CO2 emissions. Their potential of reducing CO2 emissions in Finland is insignificant. Integration of liquid fuel production to some other production line is more profitable.

Energy consumption habits and human health nexus in Sub-Saharan Africa.

PubMed

Hanif, Imran

2018-05-22

This study explores the impact of fossil fuels consumption, solid fuels consumption for cooking purposes, economic growth, and carbon emissions on human health, with a key emphasis on the occurrence of tuberculosis and the high mortality rate in Sub-Saharan Africa. For its practical insights, the study develops a system Generalized Method of Moment (GMM) for a panel of 34 middle- and lower-middle-income countries from 1995 to 2015. The study adopts a flexible methodology to tackle endogeneity in the variables. The robust results report that the use of solid fuels (charcoal, peat, wood, wood pellets, crop residues) for cooking purposes and the consumption of fossil fuels (oil, coal, gas) are significantly increasing the occurrence of tuberculosis. In addition, the results highlight that the consumption of both solid fuels and fossil fuels has adverse affects on life expectancy by increasing the mortality rate in Sub-Saharan African countries. Results report that renewable energy sources like sun, wind, and water (all with potential to prevent households from direct exposure to particulate matters and harmful gases) as well as a rise in economic growth serve as helping factors to control the occurrence of tuberculosis and to decrease the mortality rate. Moreover, the use of renewable energy sources is serving to lessen emissions of carbon dioxide, nitrogen dioxides, and particulate matters, which can ultimately decrease the mortality rate and extend the life expectancy in Sub-Saharan Africa.

Optical sensing elements for nitrogen dioxide (NO.sub.2) gas detection, a sol-gel method for making the sensing elements and fiber optic sensors incorporating nitrogen dioxide gas optical sensing elements

DOEpatents

Mechery, Shelly John [Mississippi State, MS; Singh, Jagdish P [Starkville, MS

2007-07-03

A sensing element, a method of making a sensing element, and a fiber optic sensor incorporating the sensing element are described. The sensor can be used for the quantitative detection of NO.sub.2 in a mixture of gases. The sensing element can be made by incorporating a diazotizing reagent which reacts with nitrous ions to produce a diazo compound and a coupling reagent which couples with the diazo compound to produce an azo dye into a sol and allowing the sol to form an optically transparent gel. The sensing element changes color in the presence of NO.sub.2 gas. The temporal response of the absorption spectrum at various NO.sub.2 concentrations has also been recorded and analyzed. Sensors having different design configurations are described. The sensing element can detect NO.sub.2 gas at levels of parts per billion.

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

Konyashov, Vadim V.; Krasnov, Alexander M.

Results are provided of the experimental investigation of radioactive fission product (RFP) release, i.e., krypton, xenon, and iodine radionuclides from fuel elements with initial defects during long-term (3 to 5 yr) irradiation under low linear power (5 to 12 kW/m) and during special experiments in the VK-50 vessel-type boiling water reactor.The calculation model for the RFP release from the fuel-to-cladding gap of the defective fuel element into coolant was developed. It takes into account the convective transport in the fuel-to-cladding gap and RFP sorption on the internal cladding surface and is in good agreement with the available experimental data. Anmore » approximate analytical solution of the transport equation is given. The calculation dependencies of the RFP release coefficients on the main parameters such as defect size, fuel-to-cladding gap, temperature of the internal cladding surface, and radioactive decay constant were analyzed.It is shown that the change of the RFP release from the fuel elements with the initial defects during long-term irradiation is, mainly, caused by fuel swelling followed by reduction of the fuel-to-cladding gap and the fuel temperature. The calculation model for the RFP release from defective fuel elements applicable to light water reactors (LWRs) was developed. It takes into account the change of the defective fuel element parameters during long-term irradiation. The calculation error according to the program does not exceed 30% over all the linear power change range of the LWR fuel elements (from 5 to 26 kW/m)« less

Fire Extinguishing Agents for Rocket Fuels

DTIC Science & Technology

1951-09-01

Fl&saable Are© for Mixtures of ’Hydrogen? Carbon Dioxid© and Air - - - - —*_-*.«. r. ----- . Flesnablo Area for Mixtures of...MÜxturesof Ammonia,~ Carbon "- Dioxide"" aad" 25 15 16 Flammable Afea for: Mixtures of Ammonia, Methyl. Bromide aad Air...at 6«,7°C. This compound was Obtained from Carbide and Carbon Chemicals Corporation end was purified by rectification. ^ . ’ ’Ethanol (G2HBOH

Improve Your Boiler's Combustion Efficiency: Office of Industrial Technologies (OIT) Steam Energy Tips No.4

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

Not Available

2002-03-01

Operating your boiler with an optimum amount of excess air will minimize heat loss up the stack and improve combustion efficiency. Combustion efficiency is a measure of how effectively the heat content of a fuel is transferred into usable heat. The stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency. Given complete mixing, a precise or stoichiometric amount of air is required to completely react with a given quantity of fuel. In practice, combustion conditions are never ideal, and additional or ''excess'' air must be supplied to completely burn the fuel. The correctmore » amount of excess air is determined from analyzing flue gas oxygen or carbon dioxide concentrations. Inadequate excess air results in unburned combustibles (fuel, soot, smoke, and carbon monoxide) while too much results in heat lost due to the increased flue gas flow--thus lowering the overall boiler fuel-to-steam efficiency. The table relates stack readings to boiler performance. On well-designed natural gas-fired systems, an excess air level of 10% is attainable. An often stated rule of thumb is that boiler efficiency can be increased by 1% for each 15% reduction in excess air or 40 F reduction in stack gas temperature.« less

Effects of Beryllium and Compaction Pressure on the Thermal Diffusivity of Uranium Dioxide Fuel Pellets

NASA Astrophysics Data System (ADS)

Camarano, D. M.; Mansur, F. A.; Santos, A. M. M.; Ferraz, W. B.; Ferreira, R. A. N.

2017-09-01

In nuclear reactors, the performance of uranium dioxide (UO2) fuel is strongly dependent on the thermal conductivity, which directly affects the fuel pellet temperature, the fission gas release and the fuel rod mechanical behavior during reactor operation. The use of additives to improve UO2 fuel performance has been investigated, and beryllium oxide (BeO) appears as a suitable additive because of its high thermal conductivity and excellent chemical compatibility with UO2. In this paper, UO2-BeO pellets were manufactured by mechanical mixing, pressing and sintering processes varying the BeO contents and compaction pressures. Pellets with BeO contents of 2 wt%, 3 wt%, 5 wt% and 7 wt% BeO were pressed at 400 MPa, 500 MPa and 600 MPa. The laser flash method was applied to determine the thermal diffusivity, and the results showed that the thermal diffusivity tends to increase with BeO content. Comparing thermal diffusivity results of UO2 with UO2-BeO pellets, it was observed that there was an increase in thermal diffusivity of at least 18 % for the UO2-2 wt% BeO pellet pressed at 400 MPa. The maximum relative expanded uncertainty (coverage factor k = 2) of the thermal diffusivity measurements was estimated to be 9 %.

The Complex Sol-Gel Process for producing small ThO2 microspheres

NASA Astrophysics Data System (ADS)

Brykala, Marcin; Rogowski, Marcin

2016-05-01

Thorium based fuels offer several benefits compared to uranium based fuels thus they might be an attractive alternative to conventional fuel types. This study is devoted to the synthesis and the characterization of small thorium dioxide microspheres (Ø <50 μm). Their application involves using powder-free process, called the Complex Sol-Gel Process. The source sols used for the processes were prepared by the method where in the starting ascorbic acid solution the solid thorium nitrate was dissolved and partially neutralized by aqueous ammonia under pH control. The microspheres of thorium-ascorbate gel were obtained using the ICHTJ Process (INCT in English). Studies allowed to determine an optimal heat treatment with calcination temperature of 700 °C and temperature rate not higher than 2 °C/min which enabled us to obtain a crack-free surface of microspheres. The main parameters which have a strong influence on the synthesis method and features of the spherical particles of thorium dioxide are described in this article.

Photographic combustion characterization of LOX/Hydrocarbon type propellants

NASA Technical Reports Server (NTRS)

Judd, D. C.

1980-01-01

One hundred twenty-seven tests were conducted over a chamber pressure range of 125-1500 psia, a fuel temperature range of -245 F to 158 F, and a fuel velocity range of 48-707 ft/sec to demonstrate the advantages and limitations of using high speed photography to identify potential combustion anomalies such as pops, fuel freezing, reactive stream separation and carbon formations. Combustion evaluation criteria were developed to guide selection of the fuels, injector elements, and operating conditions for testing. Separate criteria were developed for fuel and injector element selection and evaluation. The photographic test results indicated conclusively that injector element type and design directly influence carbon formation. Unlike spray fan, impingement elements reduce carbon formation because they induce a relatively rapid near zone fuel vaporization rate. Coherent jet impingement elements, on the other hand, exhibit increased carbon formation.

VENTED FUEL ELEMENT FOR GAS-COOLED NEUTRONIC REACTORS

DOEpatents

Furgerson, W.T.

1963-12-17

A hollow, porous-walled fuel element filled with fissionable fuel and provided with an outlet port through its wall is described. In operation in a gas-cooled reactor, the element is connected, through its outlet port, to the vacuum side of a pump that causes a portion of the coolant gas flowing over the exterior surface of the element to be drawn through the porous walls thereof and out through the outlet port. This continuous purging gas flow sweeps away gaseous fission products as they are released by the fissioning fuel. (AEC) A fuel element for a nuclear reactor incorporating a body of metal of melting point lower than the temperature of operation of the reactor and a nuclear fuel in finely divided form dispersed in the body of metal as a settled slurry is presented. (AEC)

NEUTRONIC REACTOR CHARGING AND DISCHARGING

DOEpatents

Zinn, W.H.

1959-07-14

A method and arrangement is presented for removing a fuel element from a neutronic reactor tube through which a liquid coolant is being circulaled. The fuel element is moved into a section of the tube beyond the reactor proper, and then the coolant in the tube between the fuel element and the reactor proper is frozen, so that the fuel element may be removed from the tube without loss of the coolant therein. The method is particularly useful in the case of a liquid metal- cooled reactor.

Nuclear Rocket Ceramic Metal Fuel Fabrication Using Tungsten Powder Coating and Spark Plasma Sintering

NASA Technical Reports Server (NTRS)

Barnes, M. W.; Tucker, D. S.; Hone, L.; Cook, S.

2017-01-01

Nuclear thermal propulsion is an enabling technology for crewed Mars missions. An investigation was conducted to evaluate spark plasma sintering (SPS) as a method to produce tungsten-depleted uranium dioxide (W-dUO2) fuel material when employing fuel particles that were tungsten powder coated. Ceramic metal fuel wafers were produced from a blend of W-60vol% dUO2 powder that was sintered via SPS. The maximum sintering temperatures were varied from 1,600 to 1,850 C while applying a 50-MPa axial load. Wafers exhibited high density (>95% of theoretical) and a uniform microstructure (fuel particles uniformly dispersed throughout tungsten matrix).

Fuel handling apparatus for a nuclear reactor

DOEpatents

Hawke, Basil C.

1987-01-01

Fuel handling apparatus for transporting fuel elements into and out of a nuclear reactor and transporting them within the reactor vessel extends through a penetration in the side of the reactor vessel. A lateral transport device carries the fuel elements laterally within the vessel and through the opening in the side of the vessel, and a reversible lifting device raises and lowers the fuel elements. In the preferred embodiment, the lifting device is supported by a pair of pivot arms.

Trade, transport, and sinks extend the carbon dioxide responsibility of countries: An editorial essay

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

Peters, Glen P; Marland, Gregg; Hertwich, Edgar G.

2009-01-01

Globalization and the dynamics of ecosystem sinks need be considered in post-Kyoto climate negotiations as they increasingly affect the carbon dioxide concentration in the atmosphere. Currently, the allocation of responsibility for greenhouse gas mitigation is based on territorial emissions from fossil-fuel combustion, process emissions and some land-use emissions. However, at least three additional factors can significantly alter a country's impact on climate from carbon dioxide emissions. First, international trade causes a separation of consumption from production, reducing domestic pollution at the expense of foreign producers, or vice versa. Second, international transportation emissions are not allocated to countries for the purposemore » of mitigation. Third, forest growth absorbs carbon dioxide and can contribute to both carbon sequestration and climate change protection. Here we quantify how these three factors change the carbon dioxide emissions allocated to China, Japan, Russia, USA, and European Union member countries. We show that international trade can change the carbon dioxide currently allocated to countries by up to 60% and that forest expansion can turn some countries into net carbon sinks. These factors are expected to become more dominant as fossil-fuel combustion and process emissions are mitigated and as international trade and forest sinks continue to grow. Emission inventories currently in wide-spread use help to understand the global carbon cycle, but for long-term climate change mitigation a deeper understanding of the interaction between the carbon cycle and society is needed. Restructuring international trade and investment flows to meet environmental objectives, together with the inclusion of forest sinks, are crucial issues that need consideration in the design of future climate policies. And even these additional issues do not capture the full impact of changes in the carbon cycle on the global climate system.« less

Drying results of K-Basin fuel element 1990 (Run 1)

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

Marschman, S.C.; Abrefah, J.; Klinger, G.S.

1998-06-01

The water-filled K-Basins in the Hanford 100-Area have been used to store N-Reactor spent nuclear fuel (SNF) since the 1970s. Because some leaks in the basins have been detected and some of the fuel is breached due to handling damage and corrosion, efforts are underway to remove the fuel elements from wet storage. An Integrated Process Strategy (IPS) has been developed to package, dry, transport, and store these metallic uranium fuels in an interim storage facility on the Hanford Site (WHC 1995). Information required to support the development of the drying processes, and the required safety analyses, is being obtainedmore » from characterization tests conducted on fuel elements removed from the K-Basins. A series of whole element drying tests (reported in separate documents, see Section 8.0) have been conducted by Pacific Northwest National Laboratory (PNNL) on several intact and damaged fuel elements recovered from both the K-East and K-West Basins. This report documents the results of the first of those tests (Run 1), which was conducted on an N-Reactor inner fuel element (1990) that had been stored underwater in the K-West Basin (see Section 2.0). This fuel element was subjected to a combination of low- and high-temperature vacuum drying treatments that were intended to mimic, wherever possible, the fuel treatment strategies of the IPS. The testing was conducted in the Whole Element Furnace Testing System, described in Section 3.0, located in the Postirradiation Testing Laboratory (PTL, 327 Building). The test conditions and methodology are given in Section 4.0, and the experimental results provided in Section 5.0. These results are further discussed in Section 6.0.« less

FUEL ELEMENT FOR NEUTRONIC REACTORS

DOEpatents

Evans, T.C.; Beasley, E.G.

1961-01-17

A fuel element for neutronic reactors, particularly the gas-cooled type of reactor, is described. The element comprises a fuel-bearing plate rolled to form a cylinder having a spiral passageway passing from its periphery to its center. In operation a coolant is admitted to the passageway at the periphery of the element, is passed through the spiral passageway, and emerges into a central channel defined by the inner turn of the rolled plate. The advantage of the element is that the fully heated coolant (i.e., coolant emerging into the central channel) is separated and thus insulated from the periphery of the element, which may be in contact with a low-temperature moderator, by the intermediate turns of the spiral fuel element.

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

Beam heated linear theta-pinch device for producing hot plasmas

DOEpatents

Bohachevsky, Ihor O.

1981-01-01

A device for producing hot plasmas comprising a single turn theta-pinch coil, a fast discharge capacitor bank connected to the coil, a fuel element disposed along the center axis of the coil, a predetermined gas disposed within the theta-pinch coil, and a high power photon, electron or ion beam generator concentrically aligned to the theta-pinch coil. Discharge of the capacitor bank generates a cylindrical plasma sheath within the theta-pinch coil which heats the outer layer of the fuel element to form a fuel element plasma layer. The beam deposits energy in either the cylindrical plasma sheath or the fuel element plasma layer to assist the implosion of the fuel element to produce a hot plasma.

Development of a tunable Fabry-Perot interferometer UV camera for monitoring sulfur dioxide emissions

NASA Astrophysics Data System (ADS)

Tamminen, J.; Kujanpää, J.; Ojanen, H.; Saari, H.; Näkki, I.; Tukiainen, S.; Kyrölä, E.

2017-12-01

We present a novel UV camera for sulfur dioxide emission monitoring.The camera is equipped with a piezo-actuated Fabry-Perot interferometer allowing thefilter transmission to be tuned to match the differential absorption features ofsulfur dioxide in the wavelength region 305-320 nm. The differential absorption structuresare exploited to reduce the interfering effects of weakly wavelength dependent absorbers, suchas aerosols and black carbon, present in the exhaust gas. A data processing algorithm basedon two air gaps of the filter is presented allowing collection of a sufficient signal-to-noise ratio fordetecting sulfur dioxide in the ship plumes even in the designated emission control areas, such as the Baltic Seawhere the sulfur content limit of fuel oil is 0.1 %. First field tests performed inLänsisatama harbour, Helsinki Finland, indicate that sulfur dioxide can be detectedin ship plumes. The camera is light-weight and can be mounted to a drone.

Glycerol conversion into value added chemicals over bimetallic catalysts in supercritical carbon dioxide

NASA Astrophysics Data System (ADS)

Hidayati, Luthfiana N.; Sudiyarmanto, Adilina, Indri B.

2017-01-01

Development of alternative energy from biomass encourage the experiments and production of biodiesel lately. Biodiesel industries widely expand because biodiesel as substitute of fossil fuel recognized as promising renewable energy. Glycerol is a byproduct of biodiesel production, which is resulted 10% wt average every production. Meanwhile, carbon dioxide is a gas that is very abundant amount in the atmosphere. Glycerol and carbon dioxide can be regarded as waste, possibly will produce value-added chemical compounds through chemically treated. In this preliminary study, conversion of glycerol and carbon dioxide using bimetallic catalyst Ni-Sn with various catalyst supports : MgO, γ-Al2O3, and hydrotalcite. Catalysts which have been prepared, then physically characterized by XRD, surface area and porosity analysis, and thermal gravity analysis. Catalytic test performance using supercritical carbon dioxide conditions. Furthermore, the products were analyzed by GC. The final product mostly contained of propylene glycol and glycerol carbonate.

Interactions between CO2, minerals, and toxic ions: Implications for CO2 leakage from deep geological storage (Invited)

NASA Astrophysics Data System (ADS)

Renard, F.; Montes-Hernandez, G.

2013-12-01

The long-term injection of carbon dioxide into geological underground reservoirs may lead to leakage events that will enhance fluid-rock interactions and question the safety of these repositories. If injection of carbon dioxide into natural reservoirs has been shown to mobilize some species into the pore fluid, including heavy metals and other toxic ions, the detailed interactions remain still debated because two main processes could interact and modify fluid composition: on the one hand dissolution/precipitation reactions may release/incorporate trace elements, and on the other hand adsorption/desorption reactions on existing mineral surfaces may also mobilize or trap these elements. We analyze here, through laboratory experiments, a scenario of a carbon dioxide reservoir that leaks into a fresh water aquifer through a localized leakage zone such as a permeable fault zone localized in the caprock and enhance toxic ions mobilization. Our main goal is to evaluate the potential risks on potable water quality. In a series of experiments, we have injected carbon dioxide into a fresh water aquifer-like medium that contained carbonate and/or iron oxide particles, pure water, and various concentrations of trace elements (copper, arsenic, cadmium, and selenium, in various states of oxidation). This analogue and simplified medium has been chosen because it contains two minerals (calcite, goethite) widespread found in freshwater aquifers. The surface charge of these minerals may vary with pH and therefore control how trace elements are adsorbed or desorbed, depending on fluid composition. Our experiments show that these minerals could successfully prevent the remobilization of adsorbed Cu(II), Cd(II), Se(IV), and As(V) if carbon dioxide is intruded into a drinking water aquifer. Furthermore, a decrease in pH resulting from carbon dioxide intrusion could reactivate the adsorption of Se(IV) and As(V) if goethite and calcite are sufficiently available in the aquifer. Our results also suggest that adsorption of cadmium and copper could be promoted by calcite dissolution. These ions adsorbed on calcite are not remobilized when carbon dioxide is intruded into the system, even if calcite dissolution is intensified. On the other hand, arsenite As(III), significantly adsorbed on goethite, is partially remobilized by carbon dioxide intrusion. These results show that carbon dioxide may, in some case remobilize some toxic ions in the pore fluid, but the pH effect may also enhance adsorption of other toxic ione on calcite and goethite particles.

Assessment of current atomic scale modelling methods for the investigation of nuclear fuels under irradiation: Example of uranium dioxide

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

Bertolus, Marjorie; Krack, Matthias; Freyss, Michel

Multiscale approaches are developed to build more physically based kinetic and mechanical mesoscale models to enhance the predictive capability of fuel performance codes and increase the efficiency of the development of the safer and more innovative nuclear materials needed in the future. Atomic scale methods, and in particular electronic structure and empirical potential methods, form the basis of this multiscale approach. It is therefore essential to know the accuracy of the results computed at this scale if we want to feed them into higher scale models. We focus here on the assessment of the description of interatomic interactions in uraniummore » dioxide using on the one hand electronic structure methods, in particular in the density functional theory (DFT) framework and on the other hand empirical potential methods. These two types of methods are complementary, the former enabling to get results from a minimal amount of input data and further insight into the electronic and magnetic properties, while the latter are irreplaceable for studies where a large number of atoms needs to be considered. We consider basic properties as well as specific ones, which are important for the description of nuclear fuel under irradiation. These are especially energies, which are the main data passed to higher scale models. We limit ourselves to uranium dioxide.« less

Simulation on reactor TRIGA Puspati core kinetics fueled with thorium (Th) based fuel element

NASA Astrophysics Data System (ADS)

Mohammed, Abdul Aziz; Pauzi, Anas Muhamad; Rahman, Shaik Mohmmed Haikhal Abdul; Zin, Muhamad Rawi Muhammad; Jamro, Rafhayudi; Idris, Faridah Mohamad

2016-01-01

In confronting global energy requirement and the search for better technologies, there is a real case for widening the range of potential variations in the design of nuclear power plants. Smaller and simpler reactors are attractive, provided they can meet safety and security standards and non-proliferation issues. On fuel cycle aspect, thorium fuel cycles produce much less plutonium and other radioactive transuranic elements than uranium fuel cycles. Although not fissile itself, Th-232 will absorb slow neutrons to produce uranium-233 (233U), which is fissile. By introducing Thorium, the numbers of highly enriched uranium fuel element can be reduced while maintaining the core neutronic performance. This paper describes the core kinetic of a small research reactor core like TRIGA fueled with a Th filled fuel element matrix using a general purpose Monte Carlo N-Particle (MCNP) code.

Simulation on reactor TRIGA Puspati core kinetics fueled with thorium (Th) based fuel element

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

Mohammed, Abdul Aziz, E-mail: azizM@uniten.edu.my; Rahman, Shaik Mohmmed Haikhal Abdul; Pauzi, Anas Muhamad, E-mail: anas@uniten.edu.my

2016-01-22

In confronting global energy requirement and the search for better technologies, there is a real case for widening the range of potential variations in the design of nuclear power plants. Smaller and simpler reactors are attractive, provided they can meet safety and security standards and non-proliferation issues. On fuel cycle aspect, thorium fuel cycles produce much less plutonium and other radioactive transuranic elements than uranium fuel cycles. Although not fissile itself, Th-232 will absorb slow neutrons to produce uranium-233 ({sup 233}U), which is fissile. By introducing Thorium, the numbers of highly enriched uranium fuel element can be reduced while maintainingmore » the core neutronic performance. This paper describes the core kinetic of a small research reactor core like TRIGA fueled with a Th filled fuel element matrix using a general purpose Monte Carlo N-Particle (MCNP) code.« less

BOILER-SUPERHEATED REACTOR

DOEpatents

Heckman, T.P.

1961-05-01

A nuclear power reactor of the type in which a liquid moderator-coolant is transformed by nuclear heating into a vapor that may be used to drive a turbo- generator is described. The core of this reactor comprises a plurality of freely suspended tubular fuel elements, called fuel element trains, within which nonboiling pressurized liquid moderator-coolant is preheated and sprayed through orifices in the walls of the trains against the outer walls thereof to be converted into vapor. Passage of the vapor ovcr other unwetted portions of the outside of the fuel elements causes the steam to be superheated. The moderatorcoolant within the fuel elements remains in the liqUid state, and that between the fuel elements remains substantiaily in the vapor state. A unique liquid neutron-absorber control system is used. Advantages expected from the reactor design include reduced fuel element failure, increased stability of operation, direct response to power demand, and circulation of a minimum amount of liquid moderatorcoolant. (A.G.W.)

Reactive Shear Layer Mixing and Growth Rate Effects on Afterburning Properties for Axisymetric Rocket Engine Plumes

DTIC Science & Technology

2006-09-01

water, carbon monoxide and carbon dioxide . The ratio of specific heats is reduced as the number of atoms in the molecule increases and as the...The flow of the jet is faster than the surrounding air, and since gas turbine engines run fuel lean, the exhaust products have generally fully reacted...previous types by several characteristics. The core of the rocket exhaust flowfield is fuel rich, and unlike gas turbine engines, which burn fuel

FUEL ELEMENT FOR NUCLEAR REACTORS

DOEpatents

Bassett, C.H.

1961-11-21

A fuel element is designed which is particularly adapted for reactors of high power density used to generate steam for the production of electricity. The fuel element consists of inner and outer concentric tubes forming an annular chamber within which is contained fissionable fuel pellet segments, wedge members interposed between the fuel segments, and a spring which, acting with wedge members, urges said fuel pellets radially into contact against the inner surface of the outer tube. The wedge members may be a fertile material convertible into fissionable fuel material by absorbing neutrons emitted from the fissionable fuel pellet segments. The costly grinding of cylindrical fuel pellets to close tolerances for snug engagement is reduced because the need to finish the exact size is eliminated. (AEC)

40 CFR 60.46c - Emission monitoring for sulfur dioxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... potential SO2 emission rate of the fuel combusted, and the span value of the SO2 CEMS at the outlet from the SO2 control device shall be 50 percent of the maximum estimated hourly potential SO2 emission rate of... estimated hourly potential SO2 emission rate of the fuel combusted. (d) As an alternative to operating a...

Stability of solid oxide fuel cell materials

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

Armstrong, T.R.; Bates, J.L.; Chick, L.A.

1996-04-01

Interconnection materials in a solid oxide fuel cell are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. The thermal expansion characteristics of substituted lanthanum and yttrium chromite interconnect materials were evaluated by dilatometry as a function of oxygen partial pressures from 1 atm to 10{sup -18} atm, controlled using a carbon dioxide/hydrogen buffer.

40 CFR 60.44c - Compliance and performance test methods and procedures for sulfur dioxide.

Code of Federal Regulations, 2010 CFR

2010-07-01

... = Fraction of the total heat input from fuel combustion derived from coal and oil, as determined by... total heat input from fuel combustion derived from coal and oil, as determined by applicable procedures... generating unit load during the 30-day period does not have to be the maximum design heat input capacity, but...

Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

DOEpatents

Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

2010-10-19

An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

Enhanced Low-Enriched Uranium Fuel Element for the Advanced Test Reactor

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

Pope, M. A.; DeHart, M. D.; Morrell, S. R.

2015-03-01

Under the current US Department of Energy (DOE) policy and planning scenario, the Advanced Test Reactor (ATR) and its associated critical facility (ATRC) will be reconfigured to operate on low-enriched uranium (LEU) fuel. This effort has produced a conceptual design for an Enhanced LEU Fuel (ELF) element. This fuel features monolithic U-10Mo fuel foils and aluminum cladding separated by a thin zirconium barrier. As with previous iterations of the ELF design, radial power peaking is managed using different U-10Mo foil thicknesses in different plates of the element. The lead fuel element design, ELF Mk1A, features only three fuel meat thicknesses,more » a reduction from the previous iterations meant to simplify manufacturing. Evaluation of the ELF Mk1A fuel design against reactor performance requirements is ongoing, as are investigations of the impact of manufacturing uncertainty on safety margins. The element design has been evaluated in what are expected to be the most demanding design basis accident scenarios and has met all initial thermal-hydraulic criteria.« less

Neutron source, linear-accelerator fuel enricher and regenerator and associated methods

DOEpatents

Steinberg, Meyer; Powell, James R.; Takahashi, Hiroshi; Grand, Pierre; Kouts, Herbert

1982-01-01

A device for producing fissile material inside of fabricated nuclear elements so that they can be used to produce power in nuclear power reactors. Fuel elements, for example, of a LWR are placed in pressure tubes in a vessel surrounding a liquid lead-bismuth flowing columnar target. A linear-accelerator proton beam enters the side of the vessel and impinges on the dispersed liquid lead-bismuth columns and produces neutrons which radiate through the surrounding pressure tube assembly or blanket containing the nuclear fuel elements. These neutrons are absorbed by the natural fertile uranium-238 elements and are transformed to fissile plutonium-239. The fertile fuel is thus enriched in fissile material to a concentration whereby they can be used in power reactors. After use in the power reactors, dispensed depleted fuel elements can be reinserted into the pressure tubes surrounding the target and the nuclear fuel regenerated for further burning in the power reactor.

Performance of Charcoal Cookstoves for Haiti, Part 2: Results from the Controlled Cooking Test

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

Lask, Kathleen; Jones, Jennifer; Booker, Kayje

2011-11-30

Five charcoal cookstoves were tested using a Controlled Cooking Test (CCT) developed from cooking practices in Haiti. Cookstoves were tested for total burn time, specific fuel consumption, and emissions of carbon monoxide (CO), carbon dioxide (CO 2), and the ratio of carbon monoxide to carbon dioxide (CO/CO 2). These results are presented in this report along with LBNL testers’ observations regarding the usability of the stoves.

Calculation of Heat-Bearing Agent’s Steady Flow in Fuel Bundle

NASA Astrophysics Data System (ADS)

Amosova, E. V.; Guba, G. G.

2017-11-01

This paper introduces the result of studying the heat exchange in the fuel bundle of the nuclear reactor’s fuel magazine. The article considers the fuel bundle of the infinite number of fuel elements, fuel elements are considered in the checkerboard fashion (at the tops of a regular triangle a fuel element is a plain round rod. The inhomogeneity of volume energy release in the rod forms the inhomogeneity of temperature and velocity fields, and pressure. Computational methods for studying hydrodynamics in magazines and cores with rod-shape fuel elements are based on a significant simplification of the problem: using basic (averaged) equations, isobaric section hypothesis, porous body model, etc. This could be explained by the complexity of math description of the three-dimensional fluid flow in the multi-connected area with the transfer coefficient anisotropy, curved boundaries and technical computation difficulties. Thus, calculative studying suggests itself as promising and important. There was developed a method for calculating the heat-mass exchange processes of inter-channel fuel element motions, which allows considering the contribution of natural convection to the heat-mass exchange based on the Navier-Stokes equations and Boussinesq approximation.

International energy outlook, 2010

DOT National Transportation Integrated Search

2010-07-01

This report presents international energy projections through 2035, : prepared by the U.S. Energy Information Administration, including outlooks : for major energy fuels and associated carbon dioxide emissions. The International Energy Outlook 2010 (...

Respiratory Issues in OI

MedlinePlus

Respiratory Issues in Osteogenesis Imperfecta \\ Introduction The respiratory system’s job is to bring oxygen into the body and remove carbon dioxide, the waste product of breathing. Because oxygen is the fuel ...

Greenhouse gases: low methane leakage from gas pipelines.

PubMed

Lelieveld, J; Lechtenböhmer, S; Assonov, S S; Brenninkmeijer, C A M; Dienst, C; Fischedick, M; Hanke, T

2005-04-14

Using natural gas for fuel releases less carbon dioxide per unit of energy produced than burning oil or coal, but its production and transport are accompanied by emissions of methane, which is a much more potent greenhouse gas than carbon dioxide in the short term. This calls into question whether climate forcing could be reduced by switching from coal and oil to natural gas. We have made measurements in Russia along the world's largest gas-transport system and find that methane leakage is in the region of 1.4%, which is considerably less than expected and comparable to that from systems in the United States. Our calculations indicate that using natural gas in preference to other fossil fuels could be useful in the short term for mitigating climate change.

THE MANUFACTURE OF FUEL ELEMENTS OF THE ARGONAUT TYPE

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

Kittl, J.; Machado, R.E.; Mazza, J.A.

1958-06-10

The conditions required for the manufacture of the RA-1 Argonant type fuel elements are investigated. The fuel elements are in the form of a plate which is manufactured by the extrusion of a presintered mass of U/sub 3/O/sub 8/ (20% enriched) in an aluminum matrix. Steps in the investigation were obtention and specification of U/sub 3/O/sub 8/ and Al in powder form for testing, filling, and extrusion tests, finishing of the fuel elements, and computation of U/sub 3/O/sub 8/ content. (W.D.M.)

Multiphysics Modeling of a Single Channel in a Nuclear Thermal Propulsion Grooved Ring Fuel Element

NASA Technical Reports Server (NTRS)

Kim, Tony; Emrich, William J., Jr.; Barkett, Laura A.; Mathias, Adam D.; Cassibry, Jason T.

2013-01-01

In the past, fuel rods have been used in nuclear propulsion applications. A new fuel element concept that reduces weight and increases efficiency uses a stack of grooved discs. Each fuel element is a flat disc with a hole on the interior and grooves across the top. Many grooved ring fuel elements for use in nuclear thermal propulsion systems have been modeled, and a single flow channel for each design has been analyzed. For increased efficiency, a fuel element with a higher surface-area-to-volume ratio is ideal. When grooves are shallower, i.e., they have a lower surface area, the results show that the exit temperature is higher. By coupling the physics of turbulence with those of heat transfer, the effects on the cooler gas flowing through the grooves of the thermally excited solid can be predicted. Parametric studies were done to show how a pressure drop across the axial length of the channels will affect the exit temperatures of the gas. Geometric optimization was done to show the behaviors that result from the manipulation of various parameters. Temperature profiles of the solid and gas showed that more structural optimization is needed to produce the desired results. Keywords: Nuclear Thermal Propulsion, Fuel Element, Heat Transfer, Computational Fluid Dynamics, Coupled Physics Computations, Finite Element Analysis

40 CFR 79.56 - Fuel and fuel additive grouping system.

Code of Federal Regulations, 2010 CFR

2010-07-01

... further testing under the provisions of Tier 3 or to support regulatory decisions affecting that fuel or... elements or classes of compounds other than those permitted in the base fuel for the respective fuel family... all of the following criteria: (1) Contain no elements other than carbon, hydrogen, oxygen, nitrogen...

Fischer-Tropsch synthesis in supercritical phase carbon dioxide: Recycle rates

NASA Astrophysics Data System (ADS)

Soti, Madhav

With increasing oil prices and attention towards the reduction of anthropogenic CO2, the use of supercritical carbon dioxide for Fischer Tropsch Synthesis (FTS) is showing promise in fulfilling the demand of clean liquid fuels. The evidence of consumption of carbon dioxide means that it need not to be removed from the syngas feed to the Fischer Tropsch reactor after the gasification process. Over the last five years, research at SIUC have shown that FTS in supercritical CO2reduces the selectivities for methane, enhances conversion, reduces the net CO2produces in the coal to liquid fuels process and increase the life of the catalyst. The research has already evaluated the impact of various operating and feed conditions on the FTS for the once through process. We believe that the integration of unreacted feed recycle would enhance conversion, increase the yield and throughput of liquid fuels for the same reactor size. The proposed research aims at evaluating the impact of recycle of the unreacted feed gas along with associated product gases on the performance of supercritical CO2FTS. The previously identified conditions will be utilized and various recycle ratios will be evaluated in this research once the recycle pump and associated fittings have been integrated to the supercritical CO2FTS. In this research two different catalysts (Fe-Zn-K, Fe-Co-Zn-K) were analyzed under SC-FTS in different recycle rate at 350oC and 1200 psi. The use of recycle was found to improve conversion from 80% to close to 100% with both catalysts. The experiment recycle rate at 4.32 and 4.91 was clearly surpassing theoretical recycle curve. The steady state reaction rate constant was increased to 0.65 and 0.8 min-1 for recycle rate of 4.32 and 4.91 respectively. Carbon dioxide selectivity was decreased for both catalyst as it was converting to carbon monoxide. Carbon dioxide consumption was increased from 0.014 to 0.034 mole fraction. This concluded that CO2is being used in the system and converting which created the concentration of the feed gas higher inside the reactor. The research has provided the best conditions for the enhanced conversion while minimizing CO2formation. Though this research was not able to provide the optimal recycle rate it have created the path for the future research to proceed in the right direction. This reduction and utilization of CO2will help to reduce the cost of carbon dioxide removal and saves the environment from carbon dioxide emission.

Electrical heating tests of uranium dioxide external fuel configuration at emitter temperature of 1900 K

NASA Technical Reports Server (NTRS)

Diianni, D. C.; Mayer, J. T.

1974-01-01

Testing of two fuel clad specimens for thermionic reactor application is described. The annular UO2 fuel was clad on both sides with tungsten; heat rejection was radially inward. The tests were intended to study inner clad stability, fuel redistribution, and fuel melting problems. The specimens were tested in a vacuum chamber using electron bombardment heating. Fuel structural changes were studied using periodic gammagraphs and posttest metallography. The first specimen test was terminated at 50 hours because of a braze failure. The second specimen was tested for 240 hours when an outer clad leak developed due to a tungsten-water reaction. The fuel developed numerous cracks on cooldown but the inner clad remained dimensionally stable. The fuel cover gas did not impede the rate of fuel redistribution. Posttest examination showed the fuel had not melted during operation.

Occupational health and safety assessment of exposure to jet fuel combustion products in air medical transport.

PubMed

MacDonald, Russell D; Thomas, Laura; Rusk, Frederick C; Marques, Shauna D; McGuire, Dan

2010-01-01

Transport medicine personnel are potentially exposed to jet fuel combustion products. Setting-specific data are required to determine whether this poses a risk. This study assessed exposure to jet fuel combustion products, compared various engine ignition scenarios, and determined methods to minimize exposure. The Beechcraft King Air B200 turboprop aircraft equipped with twin turbine engines, using a kerosene-based jet fuel (Jet A-1), was used to measure products of combustion during boarding, engine startup, and flight in three separate engine start scenarios ("shielded": internal engine start, door closed; "exposed": ground power unit start, door open; and "minimized": ground power unit right engine start, door open). Real-time continuous monitoring equipment was used for oxygen, carbon dioxide, carbon monoxide, nitrogen dioxide, hydrogen sulfide, sulfur dioxide, volatile organic compounds, and particulate matter. Integrated methods were used for aldehydes, polycyclic aromatic hydrocarbons, volatile organic compounds, and aliphatic hydrocarbons. Samples were taken in the paramedic breathing zone for approximately 60 minutes, starting just before the paramedics boarded the aircraft. Data were compared against regulated time-weighted exposure thresholds to determine the presence of potentially harmful products of combustion. Polycyclic aromatic hydrocarbons, aldehydes, volatile organic compounds, and aliphatic hydrocarbons were found at very low concentrations or beneath the limits of detection. There were significant differences in exposures to particulates, carbon monoxide, and total volatile organic compound between the "exposed" and "minimized" scenarios. Elevated concentrations of carbon monoxide and total volatile organic compounds were present during the ground power unit-assisted dual-engine start. There were no appreciable exposures during the "minimized" or "shielded" scenarios. Air medical personnel exposures to jet fuel combustion products were generally low and did not exceed established U.S. or Canadian health and safety exposure limits. Avoidance of ground power unit-assisted dual-engine starts and closing the hangar door prior to start minimize or eliminate the occupational exposure.

Dioxin and trace metal emissions from combustion of carbonized RDF slurry fuels

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

Klosky, M.; Fisher, M.; Singhania, A.

1997-12-01

In 1994, the U.S. generated approximately 209 million tons of Municipal Solid Waste (MSW), with 61% landfilled, 24% recycled, and 15% processed through Municipal Waste Combustion (MWC). In order to divert a larger portion of this generated MSW from landfills, MWC will have to play a growing role in MSW disposal. However, recently promulgated New Source Performance Standards (NSPS) for MWC will add an additional financial burden, through mandated emission reductions and air pollution control technologies, to an already financially pressured MWC marketplace. In the past, Refuse Derived Fuel (RDF), a solid fuel produced from MSW, has been fired inmore » industrial and coal boilers as an alternative means of MWC. While lower sulfur dioxide (SO{sub 2}) emissions provided the impetus, firing RDF in industrial and coal boilers frequently suffered from several disadvantages including increased solids handling, increased excess air requirements, increased air emissions, increased slag formation in the boiler, and higher fly ash resistivity. This paper summarizes the latest emissions and combustion tests with the carbonized RDF slurry fuel. With EnerTech`s SlurryCarb{trademark} process, a pumpable slurry of RDF is continuously pressurized with a pump to between 1200 and 2500 psi. The RDF slurry is pressurized above the saturated steam curve to maintain a liquid state when the slurry is heated to approximately 480-660{degrees}F. Slurry pressure and temperature then are maintained for less than 30 minutes in plug-flow reactors. At this temperature and pressure, oxygen functional groups in the molecular structure of the RDF are split off as carbon dioxide gas. This evolved carbon dioxide gas comprises a significant weight percentage of the feed RDF, but only a minimal percentage of the heating value.« less

HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS

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

Sell, D. A.; Baily, C. E.; Malewitz, T. J.

2016-09-01

A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium aftermore » the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.« less

Rate Theory Modeling and Simulations of Silicide Fuel at LWR Conditions

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

Miao, Yinbin; Ye, Bei; Mei, Zhigang

Uranium silicide (U 3Si 2) fuel has higher thermal conductivity and higher uranium density, making it a promising candidate for the accident-tolerant fuel (ATF) used in light water reactors (LWRs). However, previous studies on the fuel performance of U 3Si 2, including both experimental and computational approaches, have been focusing on the irradiation conditions in research reactors, which usually involve low operation temperatures and high fuel burnups. Thus, it is important to examine the fuel performance of U 3Si 2 at typical LWR conditions so as to evaluate the feasibility of replacing conventional uranium dioxide fuel with this silicide fuelmore » material. As in-reactor irradiation experiments involve significant time and financial cost, it is appropriate to utilize modeling tools to estimate the behavior of U 3Si 2 in LWRs based on all those available research reactor experimental references and state-of-the-art density functional theory (DFT) calculation capabilities at the early development stage. Hence, in this report, a comprehensive investigation of the fission gas swelling behavior of U 3Si 2 at LWR conditions is introduced. The modeling efforts mentioned in this report was based on the rate theory (RT) model of fission gas bubble evolution that has been successfully applied for a variety of fuel materials at devious reactor conditions. Both existing experimental data and DFT-calculated results were used for the optimization of the parameters adopted by the RT model. Meanwhile, the fuel-cladding interaction was captured by the coupling of the RT model with simplified mechanical correlations. Therefore, the swelling behavior of U 3Si 2 fuel and its consequent interaction with cladding in LWRs was predicted by the rate theory modeling, providing valuable information for the development of U 3Si 2 fuel as an accident-tolerant alternative for uranium dioxide.« less

Converting environmentally hazardous materials into clean energy using a novel nanostructured photoelectrochemical fuel cell

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

Gan, Yong X., E-mail: yong.gan@utoledo.edu; Gan, Bo J.; Clark, Evan

2012-09-15

Highlights: ► A photoelectrochemical fuel cell has been made from TiO{sub 2} nanotubes. ► The fuel cell decomposes environmentally hazardous materials to produce electricity. ► Doping the anode with a transition metal oxide increases the visible light sensitivity. ► Loading the anode with a conducting polymer enhances the visible light absorption. -- Abstract: In this work, a novel photoelectrochemical fuel cell consisting of a titanium dioxide nanotube array photosensitive anode and a platinum cathode was made for decomposing environmentally hazardous materials to produce electricity and clean fuel. Titanium dioxide nanotubes (TiO{sub 2} NTs) were prepared via electrochemical oxidation of puremore » Ti in an ammonium fluoride and glycerol-containing solution. Scanning electron microscopy was used to analyze the morphology of the nanotubes. The average diameter, wall thickness and length of the as-prepared TiO{sub 2} NTs were determined. The photosensitive anode made from the highly ordered TiO{sub 2} NTs has good photo-catalytic property, as proven by the decomposition tests on urea, ammonia, sodium sulfide and automobile engine coolant under ultraviolet (UV) radiation. To improve the efficiency of the fuel cell, doping the TiO{sub 2} NTs with a transition metal oxide, NiO, was performed and the photosensitivity of the doped anode was tested under visible light irradiation. It is found that the NiO-doped anode is sensitive to visible light. Also found is that polyaniline-doped photosensitive anode can harvest photon energy in the visible light spectrum range much more efficiently than the NiO-doped one. It is concluded that the nanostructured photoelectrochemical fuel cell can generate electricity and clean fuel by decomposing hazardous materials under sunlight.« less

Indoor air pollution and the health of children in biomass- and fossil-fuel users of Bangladesh: situation in two different seasons

PubMed Central

Khalequzzaman, Md.; Sakai, Kiyoshi; Hoque, Bilqis Amin; Nakajima, Tamie

2010-01-01

Objectives Indoor air pollution levels are reported to be higher with biomass fuel, and a number of respiratory diseases in children are associated with pollution from burning such fuel. However, little is known about the situation in developing countries. The aim of the study was to compare indoor air pollution levels and prevalence of symptoms in children between biomass- and fossil-fuel-using households in different seasons in Bangladesh. Methods We conducted a cross-sectional study among biomass- (n = 42) and fossil-fuel (n = 66) users having children <5 years in Moulvibazar and Dhaka, Bangladesh. Health-related information of one child from each family was retrieved once in winter (January 2008) and once in summer (June 2008). The measured pollutants were carbon monoxide (CO), carbon dioxide (CO2), dust particles, volatile organic compounds (VOCs), and nitrogen dioxide. Results Mean concentration of dust particles and geometric mean concentrations of VOCs such as benzene, toluene, and xylene, which were significantly higher in biomass- than fossil-fuel-users’ kitchens (p < 0.05), were significantly higher in winter than in summer (p < 0.05). Levels of CO and CO2, which were significantly higher in biomass than fossil-fuel users (p < 0.05), were significantly higher in summer than winter (p < 0.05). However, no significant difference was found in the occurrence of symptoms between biomass- and fossil-fuel users either in winter or in summer. Conclusions It was suggested that the measured indoor air pollution did not directly result in symptoms among children. Other factors may be involved. PMID:21432551

Indoor air pollution and the health of children in biomass- and fossil-fuel users of Bangladesh: situation in two different seasons.

PubMed

Khalequzzaman, Md; Kamijima, Michihiro; Sakai, Kiyoshi; Hoque, Bilqis Amin; Nakajima, Tamie

2010-07-01

Indoor air pollution levels are reported to be higher with biomass fuel, and a number of respiratory diseases in children are associated with pollution from burning such fuel. However, little is known about the situation in developing countries. The aim of the study was to compare indoor air pollution levels and prevalence of symptoms in children between biomass- and fossil-fuel-using households in different seasons in Bangladesh. We conducted a cross-sectional study among biomass- (n = 42) and fossil-fuel (n = 66) users having children <5 years in Moulvibazar and Dhaka, Bangladesh. Health-related information of one child from each family was retrieved once in winter (January 2008) and once in summer (June 2008). The measured pollutants were carbon monoxide (CO), carbon dioxide (CO(2)), dust particles, volatile organic compounds (VOCs), and nitrogen dioxide. Mean concentration of dust particles and geometric mean concentrations of VOCs such as benzene, toluene, and xylene, which were significantly higher in biomass- than fossil-fuel-users' kitchens (p < 0.05), were significantly higher in winter than in summer (p < 0.05). Levels of CO and CO(2), which were significantly higher in biomass than fossil-fuel users (p < 0.05), were significantly higher in summer than winter (p < 0.05). However, no significant difference was found in the occurrence of symptoms between biomass- and fossil-fuel users either in winter or in summer. It was suggested that the measured indoor air pollution did not directly result in symptoms among children. Other factors may be involved.

Processing of uranium dioxide nuclear fuel pellets using spark plasma sintering

NASA Astrophysics Data System (ADS)

Ge, Lihao

Uranium dioxide (UO2), one of the most common nuclear fuels, has been applied in most of the nuclear plant these days for electricity generation. The main objective of this research is to introduce a novel method for UO 2 processing using spark plasma sintering technique (SPS). Firstly, an investigation into the influence of processing parameters on densification of UO2 powder during SPS is presented. A broad range of sintering temperatures, hold time and heating rates have been systematically varied to investigate their influence on the sintered pellet densification process. The results revealed that up to 96% theoretical density (TD) pellets can be obtained at a sintering temperature of 1050 °C for 30s hold time and a total run time of only 10 minutes. A systematic study is performed by varying the sintering temperature between 750°C to 1450°C and hold time between 0.5 min to 20 min to obtain UO2 pellets with a range of densities and grain sizes. The microstructure development in terms of grain size, density and porosity distribution is investigated. The Oxygen/Uranium (O/U) ratio of the resulting pellets is found to decrease after SPS. The mechanical and thermal properties of UO2 are evaluated. For comparable density and grain size, Vickers hardness and Young's modulus are in agreement with the literature value. The thermal conductivity of UO2 increases with the density but the grain size in the investigated range has no significant influence. Overall, the mechanical and thermal properties of UO2 are comparable with the one made using conventional sintering methods. Lastly, the influence of chromium dioxide (Cr2O3) and zirconium diboride (ZrB2) on the grain size of doped UO 2 fuel pellet is performed to investigate the feasibility of producing large-grain-size nuclear fuel using SPS. The benefits of using SPS over the conventional sintering of UO2 are summarized. The future work of designing macro-porous UO2 pellet and thorium dioxide (ThO 2) cored UO2 pellet is also proposed.

Fuel assembly for the production of tritium in light water reactors

DOEpatents

Cawley, W.E.; Trapp, T.J.

1983-06-10

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Fuel assembly for the production of tritium in light water reactors

DOEpatents

Cawley, William E.; Trapp, Turner J.

1985-01-01

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Nuclear fuel elements having a composite cladding

DOEpatents

Gordon, Gerald M.; Cowan, II, Robert L.; Davies, John H.

1983-09-20

An improved nuclear fuel element is disclosed for use in the core of nuclear reactors. The improved nuclear fuel element has a composite cladding of an outer portion forming a substrate having on the inside surface a metal layer selected from the group consisting of copper, nickel, iron and alloys of the foregoing with a gap between the composite cladding and the core of nuclear fuel. The nuclear fuel element comprises a container of the elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel material retaining means positioned in the cavity. The metal layer of the composite cladding prevents perforations or failures in the cladding substrate from stress corrosion cracking or from fuel pellet-cladding interaction or both. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy.

40 CFR 63.6620 - What performance tests and other procedures must I use?

Code of Federal Regulations, 2011 CFR

2011-07-01

... based on the ratio of oxygen volume to the ultimate CO2 volume produced by the fuel at zero percent... volume of CO2 produced to the gross calorific value of the fuel from Method 19, dsm3/J (dscf/106 Btu... equivalent percent carbon dioxide (CO2). If pollutant concentrations are to be corrected to 15 percent oxygen...

40 CFR 63.6620 - What performance tests and other procedures must I use?

Code of Federal Regulations, 2012 CFR

2012-07-01

... based on the ratio of oxygen volume to the ultimate CO2 volume produced by the fuel at zero percent... volume of CO2 produced to the gross calorific value of the fuel from Method 19, dsm3/J (dscf/106 Btu... equivalent percent carbon dioxide (CO2). If pollutant concentrations are to be corrected to 15 percent oxygen...

An evaluation of the carbon balance technique for estimating emission factors and fuel consumption in forest fires

Treesearch

Nelson, Jr. Ralph M.

1982-01-01

Eighteen experimental fires were used to compare measured and calculated values for emission factors and fuel consumption to evaluate the carbon balance technique. The technique is based on a model for the emission factor of carbon dioxide, corrected for the production of other emissions, and which requires measurements of effluent concentrations and air volume in the...

Initial Operation of the Nuclear Thermal Rocket Element Environmental Simulator

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.; Pearson, J. Boise; Schoenfeld, Michael P.

2015-01-01

The Nuclear Thermal Rocket Element Environmental Simulator (NTREES) facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The NTREES facility has recently been upgraded such that the power capabilities of the facility have been increased significantly. At its present 1.2 MW power level, more prototypical fuel element temperatures nay now be reached. The new 1.2 MW induction heater consists of three physical units consisting of a transformer, rectifier, and inverter. This multiunit arrangement facilitated increasing the flexibility of the induction heater by more easily allowing variable frequency operation. Frequency ranges between 20 and 60 kHz can accommodated in the new induction heater allowing more representative power distributions to be generated within the test elements. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during testing In this new higher power configuration, NTREES will be capable of testing fuel elements and fuel materials at near-prototypic power densities. As checkout testing progressed and as higher power levels were achieved, several design deficiencies were discovered and fixed. Most of these design deficiencies were related to stray RF energy causing various components to encounter unexpected heating. Copper shielding around these components largely eliminated these problems. Other problems encountered involved unexpected movement in the coil due to electromagnetic forces and electrical arcing between the coil and a dummy test article. The coil movement and arcing which were encountered during the checkout testing effectively destroyed the induction coil in use at the time and resulted in NTREES being out of commission for a couple of months while a new stronger coil was procured. The new coil includes several additional pieces of support structure to prevent coil movement in the future. In addition, new insulating test article support components have been fabricated to prevent unexpected arcing to the test articles. Additional activities are also now underway to address ways in which the radial temperature profiles across test articles may be controlled such that they are more prototypical of what they would encounter in an operating nuclear engine. The causes of the temperature distribution problem are twofold. First, the fuel element test article is isolated in NTREES as opposed to being in the midst of many other mostly identical fuel elements in a nuclear engine. As a result, the fuel element heat flux boundary conditions in NTREES are far from adiabatic as would normally be the case in a reactor. Second, induction heating skews the power distribution such that power is preferentially deposited near the outside of the fuel element. Nuclear heating, conversely, deposits its power much more uniformly throughout the fuel element. Current studies are now looking at various schemes to adjust the amount of thermal radiation emitted from the fuel element surface so as to essentially vary the thermal boundary conditions on the test article. It is hoped that by properly adjusting the thermal boundary conditions on the fuel element test article, it may be possible to substantially correct for the inappropriate radial power distributions resulting from the induction heating so as to yield a more nearly correct temperature distribution throughout the fuel element.

Analysis of Accidents at the Pakistan Research Reactor-1 Using Proposed Mixed-Fuel (HEU and LEU) Core

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

Bokhari, Ishtiaq H.

2004-12-15

The Pakistan Research Reactor-1 (PARR-1) was converted from highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel in 1991. The reactor is running successfully, with an upgraded power level of 10 MW. To save money on the purchase of costly fresh LEU fuel elements, the use of less burnt HEU spent fuel elements along with the present LEU fuel elements is being considered. The proposal calls for the HEU fuel elements to be placed near the thermal column to gain the required excess reactivity. In the present study the safety analysis of a proposed mixed-fuel core has been carried outmore » at a calculated steady-state power level of 9.8 MW. Standard computer codes and correlations were employed to compute various parameters. Initiating events in reactivity-induced accidents involve various modes of reactivity insertion, namely, start-up accident, accidental drop of a fuel element on the core, flooding of a beam tube with water, and removal of an in-pile experiment during reactor operation. For each of these transients, time histories of reactor power, energy released, temperature, and reactivity were determined.« less

METHOD AND APPARATUS FOR HANDLING RADIOACTIVE PRODUCTS

DOEpatents

Nicoll, D.

1959-02-24

A device is described for handling fuel elements being discharged from a nuclear reactor. The device is adapted to be disposed beneath a reactor within the storage canal for spent fuel elements. The device is comprised essentially of a cylinder pivotally mounted to a base for rotational motion between a vertical position. where the mouth of the cylinder is in the top portion of the container for receiving a fuel element discharged from a reactor into the cylinder, and a horizontal position where the mouth of the cylinder is remote from the top portion of the container and the fuel element is discharged from the cylinder into the storage canal. The device is operated by hydraulic pressure means and is provided with a means to prevent contaminated primary liquid coolant in the reactor system from entering the storage canal with the spent fuel element.

CO(2) fixation through hydrogenation by chemical or enzymatic methods.

PubMed

Beller, Matthias; Bornscheuer, Uwe T

2014-04-25

Two birds with one stone: The simulaneous fixation of the greenhouse gas carbon dioxide and storage of the alternative fuel hydrogen can be accomplished with the formation of formic acid. In principle, this is now possible either with an enzymatic system based on a newly discovered bacterial hydrogen-dependent carbon dioxide reductase or by using organometallic catalysts at room temperature and ambient pressure. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmental Compliance Assessment and Management Program (ECAMP)

DTIC Science & Technology

1994-06-01

square yard mg milligram yr year mi mile Chemicals CO carbon monoxide NO 2 nitrogen dioxide CO2 carbon dioxide NOx nitrogen oxides Hg mercury SO2 sulfur...installation intentionally shielded themselves from information which would have revealed a leak. (!)(3X)5)(7)(8) A.77. Facilities on Verify that facilities...released from the largest tank within the diked area, assuming a fuel tank. Verify that walls of diked areas are of earth , concrete, steel, or solid

Novel Application of Carbonate Fuel Cell for Capturing Carbon Dioxide from Flue Gas Streams

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

Jolly, Stephen; Ghezel-Ayagh, Hossein; Willman, Carl

To address concerns about climate change resulting from emission of CO2 by coal-fueled power plants, FuelCell Energy, Inc. has developed the Combined Electric Power and Carbon-dioxide Separation (CEPACS) system concept. The CEPACS system utilizes Electrochemical Membrane (ECM) technology derived from the Company’s Direct FuelCell® products. The system separates the CO2 from the flue gas of other plants and produces electric power using a supplementary fuel. FCE is currently evaluating the use of ECM to cost effectively separate CO2 from the flue gas of Pulverized Coal (PC) power plants under a U.S. Department of Energy contract. The overarching objective of themore » project is to verify that the ECM can achieve at least 90% CO2 capture from the flue gas with no more than 35% increase in the cost of electricity. The project activities include: 1) laboratory scale operational and performance tests of a membrane assembly, 2) performance tests of the membrane to evaluate the effects of impurities present in the coal plant flue gas, in collaboration with Pacific Northwest National Laboratory, 3) techno-economic analysis for an ECM-based CO2 capture system applied to a 550 MW existing PC plant, in partnership with URS Corporation, and 4) bench scale (11.7 m2 area) testing of an ECM-based CO2 separation and purification system.« less

Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels.

PubMed

Singh, Meenesh R; Clark, Ezra L; Bell, Alexis T

2015-11-10

Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32-42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0-0.9 V, 0.9-1.95 V, and 1.95-3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

NASA Astrophysics Data System (ADS)

Singh, Meenesh R.; Clark, Ezra L.; Bell, Alexis T.

2015-11-01

Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32-42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0-0.9 V, 0.9-1.95 V, and 1.95-3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

Gases and trace elements in soils at the North Silver Bell deposit, Pima County, Arizona

USGS Publications Warehouse

Hinkle, M.E.; Dilbert, C.A.

1984-01-01

Soil samples were collected over the North Silver Bell porphyry copper deposit near Tucson, Arizona. Volatile elements and compounds in gases derived from the soils and metallic elements in the soils were analyzed in order: (1) to see which volatile constituents of the soils might be indicative of the ore body or the alteration zones; and (2) to distinguish the ore and alteration zones by comparison of trace elements in the soil. Plots of analytical data on trace elements in soils indicated a typical distribution pattern for metals around a porphyry copper deposit, with copper, molybdenum, and arsenic concentrations higher over the ore body, and zinc, lead, and silver concentrations higher over the alteration zones. Higher than average concentrations of helium, carbon disulfide, and sulfur dioxide adsorbed on soils were found over the ore body, whereas higher concentrations of carbon dioxide and carbonyl sulfide were found over the alteration zones. ?? 1984.

Calculation of Distribution Dynamics of Inhomogeneous Temperature Field in Range of Fuel Elements by Using FreeFem++

NASA Astrophysics Data System (ADS)

Amosova, E. V.; Shishkin, A. V.

2017-11-01

This article introduces the result of studying the heat exchange in the fuel element of the nuclear reactor fuel magazine. Fuel assemblies are completed as a bundle of cylindrical fuel elements located at the tops of a regular triangle. Uneven distribution of fuel rods in a nuclear reactor’s core forms the inhomogeneity of temperature fields. This article describes the developed method for heat exchange calculation with the account for impact of an inhomogeneous temperature field on the thermal-physical properties of materials and unsteady effects. The acquired calculation results are used for evaluating the tolerable temperature levels in protective case materials.

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

Balashov, Victor N.; Brantley, Susan L.; Guthrie, George D.

One idea for mitigating the increase in fossil- fuel generated carbon dioxide (CO 2) in the atmosphere is to inject CO 2 into subsurface saline sandstone reservoirs, thereby storing it in those geologic formations and out of the atmosphere.

Differential Die-Away Instrument: Report on Fuel Assembly Mock-up Measurements with Neutron Generator

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

Goodsell, Alison Victoria; Swinhoe, Martyn Thomas; Henzl, Vladimir

2014-09-18

Fresh fuel experiments for the differential die-away (DDA) project were performed using a DT neutron generator, a 15x15 PWR fuel assembly, and nine 3He detectors in a water tank inside of a shielded cell at Los Alamos National Laboratory (LANL). Eight different fuel enrichments were created using low enriched (LEU) and depleted uranium (DU) dioxide fuel rods. A list-mode data acquisition system recorded the time-dependent signal and analysis of the DDA signal die-away time was performed. The die-away time depended on the amount of fissile material in the fuel assembly and the position of the detector. These experiments were performedmore » in support of the spent nuclear fuel Next Generation Safeguards Initiative DDA project. Lessons learned from the fresh fuel DDA instrument experiments and simulations will provide useful information to the spent fuel project.« less

Fuel cell elements with improved water handling capacity

NASA Technical Reports Server (NTRS)

Kindler, Andrew (Inventor); Lee, Albany (Inventor)

2001-01-01

New fuel cell components for use in liquid feed fuel cell systems are provided. The components include biplates and endplates, having a hydrophilic surface and allow high efficiency operation. Conductive elements and a wicking device also form a part of the fuel cell components of the invention.

Phase characteristics of rare earth elements in metallic fuel for a sodium-cooled fast reactor by injection casting

NASA Astrophysics Data System (ADS)

Kuk, Seoung Woo; Kim, Ki Hwan; Kim, Jong Hwan; Song, Hoon; Oh, Seok Jin; Park, Jeong-Yong; Lee, Chan Bock; Youn, Young-Sang; Kim, Jong-Yun

2017-04-01

Uranium-zirconium-rare earth (U-Zr-RE) fuel slugs for a sodium-cooled fast reactor were manufactured using a modified injection casting method, and investigated with respect to their uniformity, distribution, composition, and phase behavior according to RE content. Nd, Ce, Pr, and La were chosen as four representative lanthanide elements because they are considered to be major RE components of fuel ingots after pyroprocessing. Immiscible layers were found on the top layers of the melt-residue commensurate with higher fuel slug RE content. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) data showed that RE elements in the melt-residue were distributed uniformly throughout the fuel slugs. RE element agglomeration did not contaminate the fuel slugs but strongly affected the RE content of the slugs.

78 FR 33132 - Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-03

... Fuel Elements for Use in Research and Test Reactors AGENCY: Nuclear Regulatory Commission. ACTION... Research and Test Reactors.'' This guide describes a method that the staff of the NRC considers acceptable... assurance program for verifying the quality of plate-type uranium-aluminum fuel elements used in research...

NEUTRONIC REACTOR

DOEpatents

Metcalf, H.E.

1957-10-01

A reactor of the type which preferably uses plutonium as the fuel and a liquid moderator, preferably ordinary water, and which produces steam within the reactor core due to the heat of the chain reaction is described. In the reactor shown the fuel elements are essentially in the form of trays and are ventically stacked in spaced relationship. The water moderator is continuously supplied to the trays to maintain a constant level on the upper surfaces of the fuel element as it is continually evaporated by the heat. The steam passes out through the spaces between the fuel elements and is drawn off at the top of the core. The fuel elements are clad in aluminum to prevent deterioration thereof with consequent contamimation of the water.

Synergism of He-3 acquisition with lunar base evolution

NASA Technical Reports Server (NTRS)

Crabb, T. M.; Jacobs, M. K.

1992-01-01

Researchers have discovered that the lunar surface contains a valuable fusion fuel element that is relatively scarce on Earth. This element, He-3, originates from the solar wind that has bombarded the surface of the Moon over geologic time. Mining operations to recover this resource would allow the by-product acquisition of hydrogen, water, carbon dioxide, carbon monoxide, methane, and nitrogen from the lunar surface with relatively minimal additional resource investment when compared to the costs to supply these resources from Earth. Two configurations for the He-3 mining system are discussed, and the impacts of these mining operations on a projected lunar base scenario are assessed. We conclude that the acquisition of He-3 is feasible with minimal advances in current state-of-the-art technologies and could support a terrestrial nuclear fusion power economy with the lowest hazard risk of any nuclear reaction known. Also, the availability of the by-products of He-3 acquisition from the Moon could significantly reduce the operational requirements of a lunar base and increase the commercialization potential of the base through consumable resupply of the lunar base itself, other components of the space infrastructure, and other space missions.

Uranium dioxide fuel cladding strain investigation with the use of CYGRO-2 computer program

NASA Technical Reports Server (NTRS)

Smith, J. R.

1973-01-01

Previously irradiated UO2 thermionic fuel pins in which gross fuel-cladding strain occurred were modeled with the use of a computer program to define controlling parameters which may contribute to cladding strain. The computed strain was compared with measured strain, and the computer input data were studied in an attempt to get agreement with measured strain. Because of the limitations of the program and uncertainties in input data, good agreement with measured cladding strain was not attained. A discussion of these limitations is presented.

Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

DOEpatents

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2012-05-15

A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

Electron Correlation and Tranport Properties in Nuclear Fuel Materials

NASA Astrophysics Data System (ADS)

Yin, Quan; Haule, Kristjan; Kotliar, Gabriel; Savrasov, Sergey; Pickett, Warren

2011-03-01

Using first principle LDA+DMFT method, we conduct a systematic study on the correlated electronic structures and transport properties of select actinide carbides, nitrides, and oxides, many of which are nuclear fuel materials. Our results capture the metal--insulator Mott transition within the studied systems, and the appearance of the Zhang-Rice state in uranium dioxide. More importantly, by understanding the physics underlying their transport properties, we suggest ways to improve the efficiency of currently used fuels. This work is supported by the DOE Nuclear Energy University Program, contract No. 00088708.

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

PubMed

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

2013-06-01

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

FETC Programs for Reducing Greenhouse Gas Emissions

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

Ruether, J.A.

1998-02-01

Mark Twain once quipped that everyone talks about the weather but no one does anything about it. With interest in global climate change on the rise, researchers in the fossil-energy sector are feeling the heat to provide new technology to permit continued use of fossil fuels but with reduced emissions of so-called `greenhouse gases.` Three important greenhouse gases, carbon dioxide, methane, and nitrous oxide, are released to the atmosphere in the course of recovering and combusting fossil fuels. Their importance for trapping radiation, called forcing, is in the order given. In this report, we briefly review how greenhouse gases causemore » forcing and why this has a warming effect on the Earth`s atmosphere. Then we discuss programs underway at FETC that are aimed at reducing emissions of methane and carbon dioxide.« less

Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

DOEpatents

Huffman, Gerald P.

2012-11-13

A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

Characterization of fuels for second-generation PFBC

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

Zevenhoven, C.A.P.; Hupa, M.

1997-12-31

In second-generation PFBC technology a solid fuel is partly converted in a devolatilization step (in a carbonizer) to produce a char and a pressurized fuel gas, followed by PFB combustion of the char. The fuel gas is led to the combustion chamber of a gas turbine after it is mixed with the PFBC off-gas, thus increasing the temperature at the inlet of the expansion turbine. Clearly, the optimization of the carbonizer design and operation is essential to the process. Detailed information on the behavior of solid fuels under pressurized conditions is, however, largely limited to steam and/or carbon dioxide gasificationmore » reactivities, obtained at a different combination of process parameters, such as temperature, pressure, heating rate, particle size and gas atmosphere. In the present work, the effect of temperature, pressure and heating rates on the yields of volatiles and char residue reactivity has been measured for a set of fuels ranging from bituminous coal to wood. Laboratory conditions were typical for the carbonizer and combustion reactors in a second-generation PFBC system. A pressurized thermogravimetric reactor (PTGR) operated at heating rates of around 250 K/s and a pressurized grid heater (PGH) operated at heating rates up to 3,000 K/s were used to analyze fuel devolatilization and char reactivity against carbon dioxide or steam at temperatures between 800 and 1,100 C, and 1, 10 or 25 bar total pressure. For comparison, a few experiments were repeated without a separate devolatilization step. The behavior of the various fuels were compared and related to proximate and ultimate fuel analysis. Several empirical, engineering equations are given. A simple 2-parameter model which separates intrinsic surface reactivity and physical, structure effects, very well describes the time-conversion data of the char. It was found that the fuel O/C molar ratio is a very good index for char reactivity, when the char O/C ratio itself is unknown.« less

Determination of the emissions from an aircraft auxiliary power unit (APU) during the Alternative Aviation Fuel Experiment (AAFEX).

PubMed

Kinsey, John S; Timko, Michael T; Herndon, Scott C; Wood, Ezra C; Yu, Zhenhong; Miake-Lye, Richard C; Lobo, Prem; Whitefield, Philip; Hagen, Donald; Wey, Changlie; Anderson, Bruce E; Beyersdorf, Andreas J; Hudgins, Charles H; Thornhill, K Lee; Winstead, Edward; Howard, Robert; Bulzan, Dan I; Tacina, Kathleen B; Knighton, W Berk

2012-04-01

The emissions from a Garrett-AiResearch (now Honeywell) Model GTCP85-98CK auxiliary power unit (APU) were determined as part of the National Aeronautics and Space Administration's (NASA's) Alternative Aviation Fuel Experiment (AAFEX) using both JP-8 and a coal-derived Fischer Tropsch fuel (FT-2). Measurements were conducted by multiple research organizations for sulfur dioxide (SO2, total hydrocarbons (THC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), speciated gas-phase emissions, particulate matter (PM) mass and number, black carbon, and speciated PM. In addition, particle size distribution (PSD), number-based geometric mean particle diameter (GMD), and smoke number were also determined from the data collected. The results of the research showed PM mass emission indices (EIs) in the range of 20 to 700 mg/kg fuel and PM number EIs ranging from 0.5 x 10(15) to 5 x 10(15) particles/kg fuel depending on engine load and fuel type. In addition, significant reductions in both the SO2 and PM EIs were observed for the use of the FT fuel. These reductions were on the order of approximately 90% for SO2 and particle mass EIs and approximately 60% for the particle number EI, with similar decreases observed for black carbon. Also, the size of the particles generated by JP-8 combustion are noticeably larger than those emitted by the APU burning the FT fuel with the geometric mean diameters ranging from 20 to 50 nm depending on engine load and fuel type. Finally, both particle-bound sulfate and organics were reduced during FT-2 combustion. The PM sulfate was reduced by nearly 100% due to lack of sulfur in the fuel, with the PM organics reduced by a factor of approximately 5 as compared with JP-8.

Solid recovered fuels in the steel industry.

PubMed

Kepplinger, Werner L; Tappeiner, Tamara

2012-04-01

By using waste materials as alternative fuels in metallurgical plants it is possible to minimize the traditionally used reducing agents, such as coke, coal, oil or natural gas. Moreover, by using waste materials in the metallurgical industry it is feasible to recover these materials as far as possible. This also represents another step towards environmental protection because carbon dioxide emissions can be reduced, if the H(2) content of the waste material is greater in comparison with that of the substituted fuel and the effects of global warming can therefore be reduced. In the present article various solid recovered fuels and their applications in the metallurgical industry are detailed.

Carbon-13 and proton nuclear magnetic resonance analysis of shale-derived refinery products and jet fuels and of experimental referee broadened-specification jet fuels

NASA Technical Reports Server (NTRS)

Dalling, D. K.; Bailey, B. K.; Pugmire, R. J.

1984-01-01

A proton and carbon-13 nuclear magnetic resonance (NMR) study was conducted of Ashland shale oil refinery products, experimental referee broadened-specification jet fuels, and of related isoprenoid model compounds. Supercritical fluid chromatography techniques using carbon dioxide were developed on a preparative scale, so that samples could be quantitatively separated into saturates and aromatic fractions for study by NMR. An optimized average parameter treatment was developed, and the NMR results were analyzed in terms of the resulting average parameters; formulation of model mixtures was demonstrated. Application of novel spectroscopic techniques to fuel samples was investigated.

Advances and recent trends in heterogeneous photo(electro)-catalysis for solar fuels and chemicals.

PubMed

Highfield, James

2015-04-15

In the context of a future renewable energy system based on hydrogen storage as energy-dense liquid alcohols co-synthesized from recycled CO2, this article reviews advances in photocatalysis and photoelectrocatalysis that exploit solar (photonic) primary energy in relevant endergonic processes, viz., H2 generation by water splitting, bio-oxygenate photoreforming, and artificial photosynthesis (CO2 reduction). Attainment of the efficiency (>10%) mandated for viable techno-economics (USD 2.00-4.00 per kg H2) and implementation on a global scale hinges on the development of photo(electro)catalysts and co-catalysts composed of earth-abundant elements offering visible-light-driven charge separation and surface redox chemistry in high quantum yield, while retaining the chemical and photo-stability typical of titanium dioxide, a ubiquitous oxide semiconductor and performance "benchmark". The dye-sensitized TiO2 solar cell and multi-junction Si are key "voltage-biasing" components in hybrid photovoltaic/photoelectrochemical (PV/PEC) devices that currently lead the field in performance. Prospects and limitations of visible-absorbing particulates, e.g., nanotextured crystalline α-Fe2O3, g-C3N4, and TiO2 sensitized by C/N-based dopants, multilayer composites, and plasmonic metals, are also considered. An interesting trend in water splitting is towards hydrogen peroxide as a solar fuel and value-added green reagent. Fundamental and technical hurdles impeding the advance towards pre-commercial solar fuels demonstration units are considered.

Multiple regression analysis in modelling of carbon dioxide emissions by energy consumption use in Malaysia

NASA Astrophysics Data System (ADS)

Keat, Sim Chong; Chun, Beh Boon; San, Lim Hwee; Jafri, Mohd Zubir Mat

2015-04-01

Climate change due to carbon dioxide (CO2) emissions is one of the most complex challenges threatening our planet. This issue considered as a great and international concern that primary attributed from different fossil fuels. In this paper, regression model is used for analyzing the causal relationship among CO2 emissions based on the energy consumption in Malaysia using time series data for the period of 1980-2010. The equations were developed using regression model based on the eight major sources that contribute to the CO2 emissions such as non energy, Liquefied Petroleum Gas (LPG), diesel, kerosene, refinery gas, Aviation Turbine Fuel (ATF) and Aviation Gasoline (AV Gas), fuel oil and motor petrol. The related data partly used for predict the regression model (1980-2000) and partly used for validate the regression model (2001-2010). The results of the prediction model with the measured data showed a high correlation coefficient (R2=0.9544), indicating the model's accuracy and efficiency. These results are accurate and can be used in early warning of the population to comply with air quality standards.

Sustainable Mars Sample Return

NASA Technical Reports Server (NTRS)

Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

2011-01-01

The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

Nuclear Cryogenic Propulsion Stage (NCPS) Fuel Element Testing in the Nuclear Thermal Rocket Element Environmental Simulator (NTREES)

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.

2017-01-01

To satisfy the Nuclear Cryogenic Propulsion Stage (NCPS) testing milestone, a graphite composite fuel element using a uranium simulant was received from the Oakridge National Lab and tested in the Nuclear Thermal Rocket Element Environmental Simulator (NTREES) at various operating conditions. The nominal operating conditions required to satisfy the milestone consisted of running the fuel element for a few minutes at a temperature of at least 2000 K with flowing hydrogen. This milestone test was successfully accomplished without incident.

Space shuttle orbit maneuvering engine, reusable thrust chamber program. Task 6: Data dump hot fuel element investigation

NASA Technical Reports Server (NTRS)

Nurick, W. H.

1974-01-01

An evaluation of reusable thrust chambers for the space shuttle orbit maneuvering engine was conducted. Tests were conducted using subscale injector hot-fire procedures for the injector configurations designed for a regenerative cooled engine. The effect of operating conditions and fuel temperature on combustion chamber performance was determined. Specific objectives of the evaluation were to examine the optimum like-doublet element geometry for operation at conditions consistent with a fuel regeneratively cooled engine (hot fuel, 200 to 250 F) and the sensitivity of the triplet injector element to hot fuels.

Tag gas capsule with magnetic piercing device

DOEpatents

Nelson, Ira V.

1976-06-22

An apparatus for introducing a tag (i.e., identifying) gas into a tubular nuclear fuel element. A sealed capsule containing the tag gas is placed in the plenum in the fuel tube between the fuel and the end cap. A ferromagnetic punch having a penetrating point is slidably mounted in the plenum. By external electro-magnets, the punch may be caused to penetrate a thin rupturable end wall of the capsule and release the tag gas into the fuel element. Preferably the punch is slidably mounted within the capsule, which is in turn loaded as a sealed unit into the fuel element.

Metallic tin quantum sheets confined in graphene toward high-efficiency carbon dioxide electroreduction

NASA Astrophysics Data System (ADS)

Lei, Fengcai; Liu, Wei; Sun, Yongfu; Xu, Jiaqi; Liu, Katong; Liang, Liang; Yao, Tao; Pan, Bicai; Wei, Shiqiang; Xie, Yi

2016-09-01

Ultrathin metal layers can be highly active carbon dioxide electroreduction catalysts, but may also be prone to oxidation. Here we construct a model of graphene confined ultrathin layers of highly reactive metals, taking the synthetic highly reactive tin quantum sheets confined in graphene as an example. The higher electrochemical active area ensures 9 times larger carbon dioxide adsorption capacity relative to bulk tin, while the highly-conductive graphene favours rate-determining electron transfer from carbon dioxide to its radical anion. The lowered tin-tin coordination numbers, revealed by X-ray absorption fine structure spectroscopy, enable tin quantum sheets confined in graphene to efficiently stabilize the carbon dioxide radical anion, verified by 0.13 volts lowered potential of hydroxyl ion adsorption compared with bulk tin. Hence, the tin quantum sheets confined in graphene show enhanced electrocatalytic activity and stability. This work may provide a promising lead for designing efficient and robust catalysts for electrolytic fuel synthesis.

The oxygen and carbon dioxide balance in the earth's atmosphere

NASA Technical Reports Server (NTRS)

Johnson, F. S.

1975-01-01

The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

Nuclear reactor fuel element having improved heat transfer

DOEpatents

Garnier, J.E.; Begej, S.; Williford, R.E.; Christensen, J.A.

1982-03-03

A nuclear reactor fuel element having improved heat transfer between fuel material and cladding is described. The element consists of an outer cladding tube divided into an upper fuel section containing a central core of fissionable or mixed fissionable and fertile fuel material, slightly smaller in diameter than the inner surface of the cladding tube and a small lower accumulator section, the cladding tube being which is filled with a low molecular weight gas to transfer heat from fuel material to cladding during irradiation. A plurality of essentially vertical grooves in the fuel section extend downward and communicate with the accumulator section. The radial depth of the grooves is sufficient to provide a thermal gradient between the hot fuel surface and the relatively cooler cladding surface to allow thermal segregation to take place between the low molecular weight heat transfer gas and high molecular weight fission product gases produced by the fuel material during irradiation.

Biologically removing sulfur from dilute gas flows

NASA Astrophysics Data System (ADS)

Ruitenberg, R.; Dijkman, H.; Buisman, C. J. N.

1999-05-01

A biological process has been developed to clean off-gases containing sulfur dioxide from industrial installations. The sulfur dioxide is converted into hydrogen sulfide, which can then be oxidized to elemental sulfur if not used on-site. The process produces no waste products that require disposal and has a low reagent consumption.

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.

40 CFR 600.113-12 - Fuel economy and carbon-related exhaust emission calculations for FTP, HFET, US06, SC03 and cold...

Code of Federal Regulations, 2011 CFR

2011-07-01

... weighted grams/mile values for total hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2); and... input of grams/mile values for nitrous oxide (N2O) and methane (CH4). Emissions shall be determined for...) Calculate the FTP fuel economy. (1) Calculate the weighted grams/mile values for the FTP test for CO2, HC...

Understanding International Environmental Security: A Strategic Military Perspective

DTIC Science & Technology

2000-11-01

remain one of the more fragile organisms on the planet, bound to a relatively constrained set of environmental conditions of landscape, temperature...series of interwoven phenomena including, but not limited to, deforestation, 30 burning of fossil fuels, and industrial pollution. Assessing each of...burning of fossil fuels is the cause. Figure 3-7 shows the trend in carbon dioxide con- centration over the past 300 years with an expanded view since

Chemical Principles of the Biotechnology of the Preparation of Fuel

NASA Astrophysics Data System (ADS)

Varfolomeev, Sergei D.; Kalyuzhnyi, S. V.; Medman, D. Ya

1988-07-01

The chemical aspects of the biotechnology of the preparation of fuels together with the potential resources and possibilities of the biofuel technology are described. The present state of research into the preparation of biogas (mixture of methane and carbon dioxide), ethanol, acetone, butyl alcohol, and hydrogen from the biomass is examined. The technological features and economic aspects of the processes listed above are analysed. The bibliography includes 213 references.

Memory device using movement of protons

DOEpatents

Warren, W.L.; Vanheusden, K.J.R.; Fleetwood, D.M.; Devine, R.A.B.

1998-11-03

An electrically written memory element is disclosed utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element. 19 figs.

Memory device using movement of protons

DOEpatents

Warren, William L.; Vanheusden, Karel J. R.; Fleetwood, Daniel M.; Devine, Roderick A. B.

1998-01-01

An electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element.

Memory device using movement of protons

DOEpatents

Warren, William L.; Vanheusden, Karel J. R.; Fleetwood, Daniel M.; Devine, Roderick A. B.

2000-01-01

An electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element.

Production of CO2 from Fossil Fuel Burning by Fuel Type, 1860-1982

DOE Data Explorer

Rotty, R.M. [Oak Ridge Associated Univ., Oak Ridge, TN (United States); Marland, G. [Oak Ridge Associated Univ., Oak Ridge, TN (United States)

2004-01-01

Global carbon dioxide emissions for 1950 through 1982 were estimated by Marland and Rotty (1984) from fuel production data from the U.N. Energy Statistics Yearbook (1983, 1984). Data before 1950 came from Keeling (1973). Fuel-production data were used in these calculations because they appeared to be more reliable on a global basis than fuel-consumption data. The data given are the year and annual global CO2 emissions (annual global total; cumulative global total since 1860; and annual global emissions from solid fuels, liquid fuels, natural gas, gas flaring, and cement manufacturing). These data provide the only pre-1950 estimates of the amount of carbon emitted to the atmosphere from fossil-fuel burning. The CO2 emission record since 1950 has been updated and revised several times with the most recent estimates being published by Marland et al. (1989).

Fuel-Cell-Powered Electric Motor Drive Analyzed for a Large Airplane

NASA Technical Reports Server (NTRS)

Brown, Gerald V.; Choi, Benjamin B.

2005-01-01

Because of its high efficiency, fuel cell technology may be used to launch a new generation of more-electric aeropropulsion and power systems for future aircraft. Electric-motor-driven airplanes using fuel-cell powerplants would be beneficial to the environment because of fuel savings, low noise, and zero carbon-dioxide emissions. In spite of the fuel cell s efficiency benefit, to produce the same shaft drive power, a fuel cell- powered electric-drive system must be definitely heavier than a turbine-drive system. However, the fuel-cell system s overall efficiency from fuel-to-shaft power is higher than for a turbine-drive system. This means that the fuel consumption rate could be lower than for a conventional system. For heavier, fuel-laden planes for longer flights, we might achieve substantial fuel savings. In the airplane industry, in fact, an efficiency gain of even a few percentage points can make a major economic difference in operating costs.

NEUTRON REACTOR FUEL ELEMENT UTILIZING ZIRCONIUM-BASE ALLOYS

DOEpatents

Saller, H.A.; Keeler, J.R.; Szumachowski, E.R.

1957-11-12

This patent relates to clad fuel elements for use in neutronic reactors and is drawn to such a fuel element which consists of a core of fissionable material, comprised of an alloy of zirconium and U/sup 235/ enriched uranium, encased in a jacket of a binary zirconium-tin alloy in which the tin content ranges between 1 and 15% by weight.

MRT fuel element inspection at Dounreay

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

Gibson, J.

1997-08-01

To ensure that their production and inspection processes are performed in an acceptable manner, ie. auditable and traceable, the MTR Fuel Element Fabrication Plant at Dounreay operates to a documented quality system. This quality system, together with the fuel element manufacturing and inspection operations, has been independently certified to ISO9002-1987, EN29002-1987 and BS5750:Pt2:1987 by Lloyd`s Register Quality Assurance Limited (LRQA). This certification also provides dual accreditation to the relevant German, Dutch and Australian certification bodies. This paper briefly describes the quality system, together with the various inspection stages involved in the manufacture of MTR fuel elements at Dounreay.

Direct carbon fuel cell and stack designs

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

Gorte, Raymond J.; Oh, Tae-Sik

Disclosed are novel configurations of Direct Carbon Fuel Cells (DCFCs), which optionally comprise a liquid anode. The liquid anode comprises a molten salt/metal, preferably Sb, and a fuel, which has significant elemental carbon content (coal, bio-mass, etc.). The supply of fuel is continuously replenished in the anode. In addition, a stack configuration is suggested where combining a large number of planar or tubular fuel elements.

Nuclear breeder reactor fuel element with axial tandem stacking and getter

DOEpatents

Gibby, Ronald L.; Lawrence, Leo A.; Woodley, Robert E.; Wilson, Charles N.; Weber, Edward T.; Johnson, Carl E.

1981-01-01

A breeder reactor fuel element having a tandem arrangement of fissile and fertile fuel with a getter for fission product cesium disposed between the fissile and fertile sections. The getter is effective at reactor operating temperatures to isolate the cesium generated by the fissile material from reacting with the fertile fuel section.

Carbonated Science Cleans Power Plants

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

Rousseau, Roger; Heldebrant, David; Glezakou, Vand

Similar to the properties of soda, liquid solvents can efficiently capture and convert carbon dioxide from coal power plants. Researchers at PNNL explain this process and how this method can turn captured carbon into plastic or fuel.

Carbon capture and sequestration (CCS)

DOT National Transportation Integrated Search

2009-06-19

Carbon capture and sequestration (or storage)known as CCShas attracted interest as a : measure for mitigating global climate change because large amounts of carbon dioxide (CO2) : emitted from fossil fuel use in the United States are potentiall...

Gridded uncertainty in fossil fuel carbon dioxide emission maps, a CDIAC example

DOE PAGES

Andres, Robert J.; Boden, Thomas A.; Higdon, David M.

2016-12-05

Due to a current lack of physical measurements at appropriate spatial and temporal scales, all current global maps and distributions of fossil fuel carbon dioxide (FFCO2) emissions use one or more proxies to distribute those emissions. These proxies and distribution schemes introduce additional uncertainty into these maps. This paper examines the uncertainty associated with the magnitude of gridded FFCO2 emissions. This uncertainty is gridded at the same spatial and temporal scales as the mass magnitude maps. This gridded uncertainty includes uncertainty contributions from the spatial, temporal, proxy, and magnitude components used to create the magnitude map of FFCO2 emissions. Throughoutmore » this process, when assumptions had to be made or expert judgment employed, the general tendency in most cases was toward overestimating or increasing the magnitude of uncertainty. The results of the uncertainty analysis reveal a range of 4–190 %, with an average of 120 % (2 σ) for populated and FFCO2-emitting grid spaces over annual timescales. This paper also describes a methodological change specific to the creation of the Carbon Dioxide Information Analysis Center (CDIAC) FFCO2 emission maps: the change from a temporally fixed population proxy to a temporally varying population proxy.« less

Gridded uncertainty in fossil fuel carbon dioxide emission maps, a CDIAC example

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

Andres, Robert J.; Boden, Thomas A.; Higdon, David M.

Due to a current lack of physical measurements at appropriate spatial and temporal scales, all current global maps and distributions of fossil fuel carbon dioxide (FFCO2) emissions use one or more proxies to distribute those emissions. These proxies and distribution schemes introduce additional uncertainty into these maps. This paper examines the uncertainty associated with the magnitude of gridded FFCO2 emissions. This uncertainty is gridded at the same spatial and temporal scales as the mass magnitude maps. This gridded uncertainty includes uncertainty contributions from the spatial, temporal, proxy, and magnitude components used to create the magnitude map of FFCO2 emissions. Throughoutmore » this process, when assumptions had to be made or expert judgment employed, the general tendency in most cases was toward overestimating or increasing the magnitude of uncertainty. The results of the uncertainty analysis reveal a range of 4–190 %, with an average of 120 % (2 σ) for populated and FFCO2-emitting grid spaces over annual timescales. This paper also describes a methodological change specific to the creation of the Carbon Dioxide Information Analysis Center (CDIAC) FFCO2 emission maps: the change from a temporally fixed population proxy to a temporally varying population proxy.« less

Gridded uncertainty in fossil fuel carbon dioxide emission maps, a CDIAC example

NASA Astrophysics Data System (ADS)

Andres, Robert J.; Boden, Thomas A.; Higdon, David M.

2016-12-01

Due to a current lack of physical measurements at appropriate spatial and temporal scales, all current global maps and distributions of fossil fuel carbon dioxide (FFCO2) emissions use one or more proxies to distribute those emissions. These proxies and distribution schemes introduce additional uncertainty into these maps. This paper examines the uncertainty associated with the magnitude of gridded FFCO2 emissions. This uncertainty is gridded at the same spatial and temporal scales as the mass magnitude maps. This gridded uncertainty includes uncertainty contributions from the spatial, temporal, proxy, and magnitude components used to create the magnitude map of FFCO2 emissions. Throughout this process, when assumptions had to be made or expert judgment employed, the general tendency in most cases was toward overestimating or increasing the magnitude of uncertainty. The results of the uncertainty analysis reveal a range of 4-190 %, with an average of 120 % (2σ) for populated and FFCO2-emitting grid spaces over annual timescales. This paper also describes a methodological change specific to the creation of the Carbon Dioxide Information Analysis Center (CDIAC) FFCO2 emission maps: the change from a temporally fixed population proxy to a temporally varying population proxy.

Two-Dimensional Diffusion Theory Analysis of Reactivity Effects of a Fuel-Plate-Removal Experiment

NASA Technical Reports Server (NTRS)

Gotsky, Edward R.; Cusick, James P.; Bogart, Donald

1959-01-01

Two-dimensional two-group diffusion calculations were performed on the NASA reactor simulator in order to evaluate the reactivity effects of fuel plates removed successively from the center experimental fuel element of a seven- by three-element core loading at the Oak Ridge Bulk Shielding Facility. The reactivity calculations were performed by two methods: In the first, the slowing-down properties of the experimental fuel element were represented by its infinite media parameters; and, in the second, the finite size of the experimental fuel element was recognized, and the slowing-down properties of the surrounding core were attributed to this small region. The latter calculation method agreed very well with the experimented reactivity effects; the former method underestimated the experimental reactivity effects.

NEUTRONIC REACTOR FUEL ELEMENT

DOEpatents

Picklesimer, M.L.; Thurber, W.C.

1961-01-01

A chemically nonreactive fuel composition for incorporation in aluminum- clad, plate type fuel elements for neutronic reactors is described. The composition comprises a mixture of aluminum and uranium carbide particles, the uranium carbide particles containing at least 80 wt.% UC/sub 2/.

Toxicity of irradiated advanced heavy water reactor fuels.

PubMed

Priest, N D; Richardson, R B; Edwards, G W R

2013-02-01

The good neutron economy and online refueling capability of the CANDU® heavy water moderated reactor (HWR) enable it to use many different fuels such as low enriched uranium (LEU), plutonium, or thorium, in addition to its traditional natural uranium (NU) fuel. The toxicity and radiological protection methods for these proposed fuels, unlike those for NU, are not well established. This study uses software to compare the fuel composition and toxicity of irradiated NU fuel against those of two irradiated advanced HWR fuel bundles as a function of post-irradiation time. The first bundle investigated is a CANFLEX® low void reactor fuel (LVRF), of which only the dysprosium-poisoned central element, and not the outer 42 LEU elements, is specifically analyzed. The second bundle investigated is a heterogeneous high-burnup (LEU,Th)O(2) fuelled bundle, whose two components (LEU in the outer 35 elements and thorium in the central eight elements) are analyzed separately. The LVRF central element was estimated to have a much lower toxicity than that of NU at all times after shutdown. Both the high burnup LEU and the thorium fuel had similar toxicity to NU at shutdown, but due to the creation of such inhalation hazards as (238)Pu, (240)Pu, (242)Am, (242)Cm, and (244)Cm (in high burnup LEU), and (232)U and (228)Th (in irradiated thorium), the toxicity of these fuels was almost double that of irradiated NU after 2,700 d of cooling. New urine bioassay methods for higher actinoids and the analysis of thorium in fecal samples are recommended to assess the internal dose from these two fuels.

Nuclear fuel pin scanner

DOEpatents

Bramblett, Richard L.; Preskitt, Charles A.

1987-03-03

Systems and methods for inspection of nuclear fuel pins to determine fiss loading and uniformity. The system includes infeed mechanisms which stockpile, identify and install nuclear fuel pins into an irradiator. The irradiator provides extended activation times using an approximately cylindrical arrangement of numerous fuel pins. The fuel pins can be arranged in a magazine which is rotated about a longitudinal axis of rotation. A source of activating radiation is positioned equidistant from the fuel pins along the longitudinal axis of rotation. The source of activating radiation is preferably oscillated along the axis to uniformly activate the fuel pins. A detector is provided downstream of the irradiator. The detector uses a plurality of detector elements arranged in an axial array. Each detector element inspects a segment of the fuel pin. The activated fuel pin being inspected in the detector is oscillated repeatedly over a distance equal to the spacing between adjacent detector elements, thereby multiplying the effective time available for detecting radiation emissions from the activated fuel pin.

Space reactor fuel element testing in upgraded TREAT

NASA Astrophysics Data System (ADS)

Todosow, M.; Bezler, P.; Ludewig, H.; Kato, W. Y.

The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc.; a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR); NERVA-derivative; and other concepts are discussed. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT reactor. Initial results suggest that full-scale PBR elements could be tested at an average energy deposition of approximately 60-80 MW-s/L in the current TREAT reactor. If the TREAT reactor was upgraded to include fuel elements with a higher temperature limit, average energy deposition of approximately 100 MW/L may be achievable.

Space reactor fuel element testing in upgraded TREAT

NASA Astrophysics Data System (ADS)

Todosow, Michael; Bezler, Paul; Ludewig, Hans; Kato, Walter Y.

1993-01-01

The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., is a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT reactor. Initial results suggests that full-scale PBR elements could be tested at an average energy deposition of ˜60-80 MW-s/L in the current TREAT reactor. If the TREAT reactor was upgraded to include fuel elements with a higher temperture limit, average energy deposition of ˜100 MW/L may be achievable.

REACTOR FUEL ELEMENTS TESTING CONTAINER

DOEpatents

Whitham, G.K.; Smith, R.R.

1963-01-15

This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

Determination of trace elements in automotive fuels by filter furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Anselmi, Anna; Tittarelli, Paolo; Katskov, Dmitri A.

2002-03-01

The determination of Cd, Cr, Cu, Pb and Ni was performed in gasoline and diesel fuel samples by electrothermal atomic absorption spectrometry using the Transverse Heated Filter Atomizer (THFA). Thermal conditions were experimentally defined for the investigated elements. The elements were analyzed without addition of chemical modifiers, using organometallic standards for the calibration. Forty-microliter samples were injected into the THFA. Gasoline samples were analyzed directly, while diesel fuel samples were diluted 1:4 with n-heptane. The following characteristic masses were obtained: 0.8 pg Cd, 6.4 pg Cr, 12 pg Cu, 17 pg Pb and 27 pg Ni. The limits of determination for gasoline samples were 0.13 μg/kg Cd, 0.4 μg/kg Cr, 0.9 μg/kg Cu, 1.5 μg/kg Pb and 2.5 μg/kg Ni. The corresponding limit of determination for diesel fuel samples was approximately four times higher for all elements. The element recovery was performed using the addition of organometallic compounds to gasoline and diesel fuel samples and was between 85 and 105% for all elements investigated.

FUEL ELEMENT

DOEpatents

Bean, R.W.

1963-11-19

A ceramic fuel element for a nuclear reactor that has improved structural stability as well as improved cooling and fission product retention characteristics is presented. The fuel element includes a plurality of stacked hollow ceramic moderator blocks arranged along a tubular raetallic shroud that encloses a series of axially apertured moderator cylinders spaced inwardly of the shroud. A plurality of ceramic nuclear fuel rods are arranged in the annular space between the shroud and cylinders of moderator and appropriate support means and means for directing gas coolant through the annular space are also provided. (AEC)

DART model for irradiation-induced swelling of dispersion fuel elements including aluminum-fuel interaction

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

Rest, J.; Hofman, G.L.

1997-12-01

The Dispersion Analysis Research Tool (DART) contains models for fission-gas-induced fuel swelling, interaction of fuel with the matrix aluminum, for the resultant reaction-product swelling, and for the calculation of the stress gradient within the fuel particle. The effects of an aluminide shell on fuel particle swelling are evaluated. Validation of the model is demonstrated by a comparison of DART calculations of fuel swelling of U{sub 3}SiAl-Al and U{sub 3}Si{sub 2}-Al for various dispersion fuel element designs with the data.

Reduced size fuel cell for portable applications

NASA Technical Reports Server (NTRS)

Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Clara, Filiberto (Inventor); Frank, Harvey A. (Inventor)

2004-01-01

A flat pack type fuel cell includes a plurality of membrane electrode assemblies. Each membrane electrode assembly is formed of an anode, an electrolyte, and an cathode with appropriate catalysts thereon. The anode is directly into contact with fuel via a wicking element. The fuel reservoir may extend along the same axis as the membrane electrode assemblies, so that fuel can be applied to each of the anodes. Each of the fuel cell elements is interconnected together to provide the voltage outputs in series.

Coolant mass flow equalizer for nuclear fuel

DOEpatents

Betten, Paul R.

1978-01-01

The coolant mass flow distribution in a liquid metal cooled reactor is enhanced by restricting flow in sub-channels defined in part by the peripheral fuel elements of a fuel assembly. This flow restriction, which results in more coolant flow in interior sub-channels, is achieved through the use of a corrugated liner positioned between the bundle of fuel elements and the inner wall of the fuel assembly coolant duct. The corrugated liner is expandable to accommodate irradiation induced growth of fuel assembly components.

Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

PubMed Central

Singh, Meenesh R.; Clark, Ezra L.; Bell, Alexis T.

2015-01-01

Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32–42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0–0.9 V, 0.9–1.95 V, and 1.95–3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices. PMID:26504215

Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

DOE PAGES

Singh, Meenesh R.; Clark, Ezra L.; Bell, Alexis T.

2015-10-26

Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32–42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0–0.9 V, 0.9–1.95 V, and 1.95–3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO 2 reduction on silver and coppermore » cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H 2 and CO) and Hythane (H 2 and CH 4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. Finally, we show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C 2H 4 have high profitability indices.« less

Global warming: China’s contribution to climate change

NASA Astrophysics Data System (ADS)

Spracklen, Dominick V.

2016-03-01

Carbon dioxide emissions from fossil-fuel use in China have grown dramatically in the past few decades, yet it emerges that the country's relative contribution to global climate change has remained surprisingly constant. See Letter p.357

MEANS FOR COOLING REACTORS

DOEpatents

Wheeler, J.A.

1957-11-01

A design of a reactor is presented in which the fuel elements may be immersed in a liquid coolant when desired without the necessity of removing them from the reactor structure. The fuel elements, containing the fissionable material are in plate form and are disposed within spaced slots in a moderator material, such as graphite to form the core. Adjacent the core is a tank containing the liquid coolant. The fuel elements are mounted in spaced relationship on a rotatable shaft which is located between the core and the tank so that by rotation of the shaft the fuel elements may be either inserted in the slots in the core to sustain a chain reaction or immersed in the coolant.

Phosphorus-doped glass proton exchange membranes for low temperature direct methanol fuel cells

NASA Astrophysics Data System (ADS)

Prakash, Shruti; Mustain, William E.; Park, SeongHo; Kohl, Paul A.

Phosphorus-doped silicon dioxide thin films were used as ion exchange membranes in low temperature proton exchange membrane fuel cells. Phosphorus-doped silicon dioxide glass (PSG) was deposited via plasma-enhanced chemical vapor deposition (PECVD). The plasma deposition of PSG films allows for low temperature fabrication that is compatible with current microelectronic industrial processing. SiH 4, PH 3 and N 2O were used as the reactant gases. The effect of plasma deposition parameters, substrate temperature, RF power, and chamber pressure, on the ionic conductivity of the PSG films is elucidated. PSG conductivities as high as 2.54 × 10 -4 S cm -1 were realized, which is 250 times higher than the conductivity of pure SiO 2 films (1 × 10 -6 S cm -1) under identical deposition conditions. The higher conductivity films were deposited at low temperature, moderate pressure, limited reactant gas flow rate, and high RF power.

Desulfurization sorbent regeneration

DOEpatents

Jalan, V.M.; Frost, D.G.

1982-07-07

A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

Air quality assessment in Delhi: before and after CNG as fuel.

PubMed

Chelani, Asha B; Devotta, Sukumar

2007-02-01

A number of policy measures have been activated in India in order to control the levels of air pollutants such as particulate matter, sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)). Delhi, which is one of the most polluted cities in the world, is also going through the implementation phase of the control policies. Ambient air quality data monitored during 2000 to 2003, at 10 sites in Delhi, were analyzed to assess the impact of implementation of these measures, specifically fuel change in vehicles. This paper presents the impact of policy measures on ambient air quality levels and also the source apportionment. CO and NO(2) concentration levels in ambient air are found to be associated with the mobile sources. The temporal variation of air quality data shows the significant effect of shift to CNG (Compressed Natural Gas) in vehicles.

Energy Industry Study, AY 2004-2005

DTIC Science & Technology

2005-06-01

produced by burning coal and other fossil fuels contributes to the greenhouse effect by trapping the sun’s heat in the atmosphere and eventually causing... greenhouse effect by trapping the sun’s heat in the atmosphere and eventually causing major changes in the world’s climate. Third, the coal industry faces...possibly human health. Second, many scientists believe that carbon dioxide produced by burning coal and other fossil fuels contributes to the

Apparatus for converting hydrocarbon fuel into hydrogen gas and carbon dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2001-01-01

A hydrocarbon fuel reformer (200) is disclosed suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. The reformer (200) comprises first and second tubes (208,218). The first tube (208) includes a first catalyst (214) and receives a first mixture of steam and a first fuel. The second tube (218) is annularly disposed about the first tube (208) and receives a second mixture of an oxygen-containing gas and a second fuel. In one embodiment, a third tube (224) is annularly disposed about the second tube (218) and receives a first reaction reformate from the first tube (208) and a second reaction reformate from the second tube (218). A catalyst reforming zone (260) annularly disposed about the third tube (224) may be provided to subject reformate constituents to a shift reaction. In another embodiment, a fractionator is provided to distill first and second fuels from a fuel supply source.

Method And Apparatus For Converting Hydrocarbon Fuel Into Hydrogen Gas And Carbon Dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2001-03-27

A hydrocarbon fuel reforming method is disclosed suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. A first mixture of an oxygen-containing gas and a first fuel is directed into a first tube 108 to produce a first reaction reformate. A second mixture of steam and a second fuel is directed into a second tube 116 annularly disposed about the first tube 108 to produce a second reaction reformate. The first and second reaction reformates are then directed into a reforming zone 144 and subject to a catalytic reforming reaction. In another aspect of the method, a first fuel is combusted with an oxygen-containing gas in a first zone 108 to produce a reformate stream, while a second fuel under steam reforming in a second zone 116. Heat energy from the first zone 108 is transferred to the second zone 116.

Improved nuclear fuel assembly grid spacer

DOEpatents

Marshall, John; Kaplan, Samuel

1977-01-01

An improved fuel assembly grid spacer and method of retaining the basic fuel rod support elements in position within the fuel assembly containment channel. The improvement involves attachment of the grids to the hexagonal channel and of forming the basic fuel rod support element into a grid structure, which provides a design which is insensitive to potential channel distortion (ballooning) at high fluence levels. In addition the improved method eliminates problems associated with component fabrication and assembly.

Thermionic nuclear reactor with internal heat distribution and multiple duct cooling

DOEpatents

Fisher, C.R.; Perry, L.W. Jr.

1975-11-01

A Thermionic Nuclear Reactor is described having multiple ribbon-like coolant ducts passing through the core, intertwined among the thermionic fuel elements to provide independent cooling paths. Heat pipes are disposed in the core between and adjacent to the thermionic fuel elements and the ribbon ducting, for the purpose of more uniformly distributing the heat of fission among the thermionic fuel elements and the ducts.

JACKETED FUEL ELEMENT

DOEpatents

Wigner, E.P.; Szilard, L.; Creutz, E.C.

1959-02-01

These fuel elements are comprised of a homogeneous metallic uranium body completely enclosed and sealed in an aluminum cover. The uranium body and aluminum cover are bonded together by a layer of zinc located between them. The bonding layer serves to improve transfer of heat, provides an additional protection against corrosion of the uranium by the coolant, and also localizes any possible corrosion by preventing travel of corrosive material along the surface of the fuel element.

Comprehensive Fuel Spray Modeling and Impacts on Chamber Acoustics in Combustion Dynamics Simulations

DTIC Science & Technology

2013-05-01

multiple swirler configurations and fuel injector locations at atmospheric pressure con- ditions. Both single-element and multiple-element LDI...the swirl number, Reynolds’ number and injector location in the LDI element. Besides the multi-phase flow characteristics, several experimen- tal...region downstream of the fuel injector on account of a sta- ble and compact precessing vortex core. Recent ex- periments conducted by the Purdue group have

FUEL ELEMENTS FOR THERMAL-FISSION NUCLEAR REACTORS

DOEpatents

Flint, O.

1961-01-10

Fuel elements for thermal-fission nuclear reactors are described. The fuel element is comprised of a core of alumina, a film of a metal of the class consisting of copper, silver, and nickel on the outer face of the core, and a coating of an oxide of a metal isotope of the class consisting of Un/sup 235/, U/ sup 233/, and Pu/sup 239/ on the metal f ilm.

CAFE Standards (released in AEO2010)

EIA Publications

2010-01-01

Pursuant to the Presidents announcement of a National Fuel Efficiency Policy, the National Highway Traffic Safety Administration (NHTSA) and the EPA have promulgated nationally coordinated standards for tailpipe Carbon Dioxide (CO2)-equivalent emissions and fuel economy for light-duty vehicles (LDVs), which includes both passenger cars and light-duty trucks. In the joint rulemaking, the Environmental Protection Agency is enacting CO2-equivalent emissions standards under the Clean Air Act (CAA), and NHTSA is enacting companion Corporate Average Fuel Economy standards under the Energy Policy and Conservation Act, as amended by the Energy Independence and Security Act of 2007.

In-pile and out-of-pile testing of a molybdenum-uranium dioxide cermet fueled themionic diode

NASA Technical Reports Server (NTRS)

Diianni, D. C.

1972-01-01

The behavior of Mo-UO2 cermet fuel in a diode for thermionic reactor application was studied. The diode had a Mo-0.5 Ti emitter and niobium collector. Output power ranged from 1.4 to 2.8 W/cm squared at emitter and collector temperatures of 1500 deg and 540 C. Thermionic performance was stable within the limits of the instrumentation sensitivity. Through 1000 hours of in-pile operation the emitter was dimensionally stable. However, some fission gases (15 percent) leaked through an inner clad imperfection that occurred during fuel fabrication.

A new process for converting SO2 to sulfur without generating secondary pollutants through reactions involving CaS and CaSO4.

PubMed

Sohn, H Y; Kim, Byung-Su

2002-07-01

Nonferrous smelters and coal gasification processes generate environmentally harmful sulfur dioxide streams, most of which are treated to produce sulfuric acid with the accompanying problems of market shortage and transportation difficulties. Some sulfur dioxide streams are scrubbed with an alkali solution or a solid substance such as limestone or dolomite, which in turn generates wastes that pose other pollution problems. While the conversion of sulfur dioxide to elemental sulfur has many environmental advantages, no processes exist that are environmentally acceptable and economically viable. A new method for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating solid wastes has been developed. In this process, calcium sulfate pellets as the starting raw material are reduced by a suitable reducing agent such as hydrogen to produce calcium sulfide pellets, which are used to reduce sulfur dioxide producing elemental sulfur vapor and calcium sulfate. The latter is then reduced to regenerate calcium sulfide. Thermodynamic analysis and experimental results indicated that the CaS-SO2 reaction produces mainly sulfur vapor and solid calcium sulfate and that the gaseous product from the CaSO4-H2 reaction is mainly water vapor. The rates of the two reactions are reasonably rapid in the temperature range 1000-1100 K, and, importantly, the physical strengths and reactivities of the pellets are maintained largely unchanged up to the tenth cycle, the last cycle tested in this work. Sulfur dioxide-containing streams from certain sources, such as the regenerator off-gas from an integrated gasification combined cycle desulfurization unit and new sulfide smelting plants, contain much higher partial pressures of SO2. In these cases, the rate of the first reaction is expected to be proportionally higher than in the test conditions reported in this paper.

Understanding trends in electrochemical carbon dioxide reduction rates

DOE PAGES

Liu, Xinyan; Xiao, Jianping; Peng, Hongjie; ...

2017-05-22

Electrochemical carbon dioxide reduction to fuels presents one of the great challenges in chemistry. Herein we present an understanding of trends in electrocatalytic activity for carbon dioxide reduction over different metal catalysts that rationalize a number of experimental observations including the selectivity with respect to the competing hydrogen evolution reaction. We also identify two design criteria for more active catalysts. The understanding is based on density functional theory calculations of activation energies for electrochemical carbon monoxide reduction as a basis for an electrochemical kinetic model of the process. Furthermore, we develop scaling relations relating transition state energies to the carbonmore » monoxide adsorption energy and determine the optimal value of this descriptor to be very close to that of copper.« less

Carbon Dioxide Methanation for Human Exploration of Mars: A Look at Catalyst Longevity and Activity Using Supported Ruthenium

NASA Technical Reports Server (NTRS)

Petersen, Elspeth M.; Meier, Anne J.; Tessonnier, Jean-Philippe

2018-01-01

Overarching Purpose: To design a carbon dioxide methanation/Sabatier reaction catalyst able to withstand variable conditions including fluctuations in bed temperature and feed flow rates for 480 days of remote operation to produce seven tons of methane. Current Study Purpose: Examine supported Ruthenium as a carbon dioxide methanation catalyst to determine the effects support properties have on the active phase by studying activity and selectivity. Objective: The remote operation of the Mars ISRU (In Situ Resources Utilization) lander to produce rocket fuel prior to crew arrival on the planet to power an ascent vehicle. Constraints: Long-term operation (480 days); Variable conditions: Feed gas flow rates, Feed gas flow ratios, Reactor bed temperature.

Understanding trends in electrochemical carbon dioxide reduction rates

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

Liu, Xinyan; Xiao, Jianping; Peng, Hongjie

Electrochemical carbon dioxide reduction to fuels presents one of the great challenges in chemistry. Herein we present an understanding of trends in electrocatalytic activity for carbon dioxide reduction over different metal catalysts that rationalize a number of experimental observations including the selectivity with respect to the competing hydrogen evolution reaction. We also identify two design criteria for more active catalysts. The understanding is based on density functional theory calculations of activation energies for electrochemical carbon monoxide reduction as a basis for an electrochemical kinetic model of the process. Furthermore, we develop scaling relations relating transition state energies to the carbonmore » monoxide adsorption energy and determine the optimal value of this descriptor to be very close to that of copper.« less

Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element

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

Ruggles, A.E.

1990-10-12

The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results aremore » related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.« less

Elements, Compounds & Mixtures. Physical Science in Action[TM]. Schlessinger Science Library. [Videotape].

ERIC Educational Resources Information Center

2000

The world contains a limited number of elements--the purest form of matter. But when these elements are combined, the possibilities are limitless! Water, carbon dioxide and salt are just a few examples of how elements can be combined to form entirely new substances. Many of these combinations occur naturally, while others are man-made. Students…

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

Sarta, Jose A.; Castiblanco, Luis A

With cooperation of the International Atomic Energy Agency (IAEA) and the Department of Energy (DOE) of the United States, several calculations and tasks related to the waste disposal of spent MTR fuel enriched nominally to 93% were carried out for the conversion of the IAN-R1 Research Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to remove the spent MTR-HEU fuel of the core and store it safely a program was established at the Instituto de Ciencias Nucleares y Energias Alternativas (INEA). This program included training, acquisition of hardware and software, design and construction of a decay pool, transfer ofmore » the spent HEU fuel elements into the decay pool and his final transport to Savannah River in United States. In this paper are presented data of activities calculated for each relevant radionuclide present in spent MTR-HEU fuel elements of the IAN-R1 Research Reactor and the total activity. The total activity calculated takes in consideration contributions of fission, activation and actinides products. The data obtained were the base for shielding calculations for the decay pool concerning the storage of spent MTR-HEU fuel elements and the respective dosimetric evaluations in the transferring operations of fuel elements into the decay pool.« less

Molybdenum dioxide-based anode for solid oxide fuel cell applications

NASA Astrophysics Data System (ADS)

Kwon, Byeong Wan; Ellefson, Caleb; Breit, Joe; Kim, Jinsoo; Grant Norton, M.; Ha, Su

2013-12-01

The present paper describes the fabrication and performance of a molybdenum dioxide (MoO2)-based anode for liquid hydrocarbon/oxygenated hydrocarbon-fueled solid oxide fuel cells (SOFCs). These fuel cells first internally reform the complex liquid fuel into carbon fragments and hydrogen, which are then electrochemically oxidized to produce electrical energy without external fuel processors. The MoO2-based anode was fabricated on to an yttria-stabilized zirconia (YSZ) electrolyte via combined electrostatic spray deposition (ESD) and direct painting methods. The cell performance was measured by directly feeding liquid fuels such as n-dodecane (i.e., a model diesel/kerosene fuel) or biodiesel (i.e., a future biomass-based liquid fuel) to the MoO2-based anode at 850 °C. The maximum initial power densities obtained from our MoO2-based SOFC were 34 mW cm-2 and 45 mW cm-2 using n-dodecane and biodiesel, respectively. The initial power density of the MoO2-based SOFC was improved up to 2500 mW cm-2 by optimizing the porosity of the MoO2-based anode. To test the long-term stability of the MoO2-based anode SOFC against coking, n-dodecane was continuously fed into the cell for 24 h at the open circuit voltage (OCV). During long-term testing, voltage-current density (V-I) plots were periodically obtained and they showed no significant changes over the operation time. Microstructural examination of the tested cells indicated that the MoO2-based anode displayed negligible coke formation, which explains its stability. On the other hand, SOFCs with conventional nickel (Ni)-based anodes under the same operating conditions showed a significant amount of coke formation on the metal surface, which led to a rapid drop in cell performance. Hence, the present work demonstrates that MoO2-based anodes exhibit outstanding tolerance to coke formation. This result opens up the opportunity for more efficiently generating electrical energy from both existing transportation and next generation biomass-derived liquid fuels using liquid hydrocarbon/oxygenated hydrocarbon-fueled SOFCs.

Evaluation of refractory-metal-clad uranium nitride and uranium dioxide fuel pins after irradiation for times up to 10 450 hours at 990 C

NASA Technical Reports Server (NTRS)

Bowles, K. J.; Gluyas, R. E.

1975-01-01

The effects of some materials variables on the irradiation performance of fuel pins for a lithium-cooled space power reactor design concept were examined. The variables studied were UN fuel density, fuel composition, and cladding alloy. All pins were irradiated at about 990 C in a thermal neutron environment to the design fuel burnup. An 85-percent dense UN fuel gave the best overall results in meeting the operational goals. The T-111 cladding on all specimens was embrittled, possibly by hydrogen in the case of the UN fuel and by uranium and oxygen in the case of the UO2 fuel. Tests with Cb-1Zr cladding indicate potential use of this cladding material. The UO2 fueled specimens met the operational goals of less than 1 percent cladding strain, but other factors make UO2 less attractive than low-density UN for the contemplated space power reactor use.

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.

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

Potter, David Charles; Taylor, Craig Michael; Coons, James Elmer

The percent void of the Fort Saint Vrain (FSV) material is estimated to be 21.1% based on the volume of the gap at the top of the drums, the volume of the coolant channels in the FSV fuel element, and the volume of the fuel handling channel in the FSV fuel element.

NEUTRONIC REACTOR FUEL ELEMENT

DOEpatents

Gurinsky, D.H.; Powell, R.W.; Fox, M.

1959-11-24

A nuclear fuel element comprising a plurality of nuclear fuel bearing strips is presented. The strips are folded along their longitudinal axes to an angle of about 60 deg and are secured at each end by ferrule to form an elongated assembly suitable for occupying a cylindrical coolant channel.

A new look at atmospheric carbon dioxide

NASA Astrophysics Data System (ADS)

Hofmann, David J.; Butler, James H.; Tans, Pieter P.

Carbon dioxide is increasing in the atmosphere and is of considerable concern in global climate change because of its greenhouse gas warming potential. The rate of increase has accelerated since measurements began at Mauna Loa Observatory in 1958 where carbon dioxide increased from less than 1 part per million per year (ppm yr -1) prior to 1970 to more than 2 ppm yr -1 in recent years. Here we show that the anthropogenic component (atmospheric value reduced by the pre-industrial value of 280 ppm) of atmospheric carbon dioxide has been increasing exponentially with a doubling time of about 30 years since the beginning of the industrial revolution (˜1800). Even during the 1970s, when fossil fuel emissions dropped sharply in response to the "oil crisis" of 1973, the anthropogenic atmospheric carbon dioxide level continued increasing exponentially at Mauna Loa Observatory. Since the growth rate (time derivative) of an exponential has the same characteristic lifetime as the function itself, the carbon dioxide growth rate is also doubling at the same rate. This explains the observation that the linear growth rate of carbon dioxide has more than doubled in the past 40 years. The accelerating growth rate is simply the outcome of exponential growth in carbon dioxide with a nearly constant doubling time of about 30 years (about 2%/yr) and appears to have tracked human population since the pre-industrial era.

Space reactor fuel element testing in upgraded TREAT

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

Todosow, M.; Bezler, P.; Ludewig, H.

1993-01-14

The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT reactor. initial results suggest that full-scale PBR, elements could be tested at an average energy deposition of {approximately}60--80 MW-s/L in the current TREAT reactor. Ifmore » the TREAT reactor was upgraded to include fuel elements with a higher temperature limit, average energy deposition of {approximately}100 MW/L may be achievable.« less

Space reactor fuel element testing in upgraded TREAT

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

Todosow, M.; Bezler, P.; Ludewig, H.

1993-05-01

The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT reactor. initial results suggest that full-scale PBR, elements could be tested at an average energy deposition of {approximately}60--80 MW-s/L in the current TREAT reactor. Ifmore » the TREAT reactor was upgraded to include fuel elements with a higher temperature limit, average energy deposition of {approximately}100 MW/L may be achievable.« less

Household air pollution and personal exposure to air pollutants in rural China - A review.

PubMed

Du, Wei; Li, Xinyue; Chen, Yuanchen; Shen, Guofeng

2018-06-01

Solid fuels, an important source of severe Household Air Pollution (HAP) linked to many adverse health outcomes, has been widely consumed around the world. China consumes large amounts of solid fuels and suffers from serious indoor and outdoor air pollution. Though global HAP issues had been reviewed in previous literatures, peer-reviewed Chinese publications were seldom included in those reviews. We conducted a literature review on the studies of HAP and personal exposure in rural China with inputs from peer-reviewed publications in both English and Chinese. A total of 36,572 articles were retrieved, 294 were read in full text, of which 92 were included in final data extraction and in-depth analysis. Although HAP is a very serious issue in China, studies on either HAP or personal exposure assessment were very limited. From existing studies, levels of air pollutants including carbon monoxide, sulfur dioxide, particulate matter (PM), organic carbon, elemental carbon, polycyclic aromatic hydrocarbons (PAHs), etc., in indoor and ambient air were analyzed for their temporal and spatial variations, and the differences across different fuel types were compared. The studies showed that PM and PAHs levels in most rural homes exceeded the World Health Organization (WHO) and Chinese National Standards, especially during the heating season in northern China. Replacing traditional fuels with cleaner ones (such as liquid petroleum gas (LPG), biogas or electricity) was considered as the most appropriate way to mitigate HAP. The daily exposure to PM and PAHs from using LPG, biogas or electricity was considerably lower than that from using traditional solid fuels. However, the level was still higher than the guideline values for PM and PAHs set by WHO to protect human health. To achieve a more effective control, the current data gap need to be closed and suggestions for future research were discussed in this review. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrocatalytic process for carbon dioxide conversion

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

Masel, Richard I.; Salehi-Khojin, Amin

2017-01-31

An electrocatalytic process for carbon dioxide conversion includes combining a Catalytically Active Element and Helper Catalyst in the presence of carbon dioxide, allowing a reaction to proceed to produce a reaction product, and applying electrical energy to said reaction to achieve electrochemical conversion of said reactant to said reaction product. The Catalytically Active Element can be a metal in the form of supported or unsupported particles or flakes with an average size between 0.6 nm and 100 nm. the reaction products comprise at least one of CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, (COO.sup.-).sub.2,more » and CF.sub.3COOH.« less

Domestic nitrogen oxide exposure, urinary nitrate, and asthma prevalence in preschool children.

PubMed

Ciuk, J; Volkmer, R E; Edwards, J W

2001-01-01

A South Australian preschool study carried out in 1993 showed that the prevalence of respiratory symptoms was significantly associated with use of unflued gas appliances for cooking and heating. The authors sought to determine an association between domestic exposure to nitrogen dioxide and the excretion of total urinary nitrate and nitrite, and their association with asthma prevalence. The results indicated that the geometric mean concentrations of nitrogen dioxide were much higher in homes that had natural gas appliance(s) and other types of appliances (i.e., electric and solid fuel). Higher levels of nitrogen dioxide were found in homes of suburban areas with higher prevalence of asthma and respiratory symptoms. Nitrogen dioxide levels were lower in the summer, and there was a higher level in kitchens than in bedrooms. Urinary nitrate excretion was evaluated in 1,335 preschool children from the same sampling areas. No association existed between nitrogen dioxide levels and urinary nitrates, nor was there a relationship between urinary nitrates and asthma prevalence. These findings confirm that there is a positive association between nitrogen dioxide exposure from gas appliances and the prevalence of respiratory symptoms, but urinary nitrate is not a useful biomarker of exposure at these levels.

Boiler Briquette Coal versus Raw Coal: Part I-Stack Gas Emissions.

PubMed

Ge, Su; Bai, Zhipeng; Liu, Weili; Zhu, Tan; Wang, Tongjian; Qing, Sheng; Zhang, Junfeng

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM 10 and PM 2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM 10 , 0.38 for PM 25 , 20.7 for SO 2 , and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM 10 , 0.30 for PM 2 5 , 7.5 for SO 2 , and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM 10 , 0.87 for PM 25 , 46.7 for SO 2 , and 15 for CO, while those of the BB-coal were 2.51 for PM 10 , 0.79 for PM 2.5 , 19.9 for SO 2 , and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/ steam conversion factors, were 0.23 for PM 10 , 0.12 for PM 2.5 , 6.4 for SO 2 , and 2.0 for CO, while those of the BB-coal were 0.30 for PM 10 , 0.094 for PM 2.5 , 2.4 for SO 2 , and 1.7 for CO. PM 10 and PM 2.5 elemental compositions are also presented for both types of coal tested in the study.

Boiler briquette coal versus raw coal: Part I--Stack gas emissions.

PubMed

Ge, S; Bai, Z; Liu, W; Zhu, T; Wang, T; Qing, S; Zhang, J

2001-04-01

Stack gas emissions were characterized for a steam-generating boiler commonly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal (R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution source sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance technique. Sulfur dioxide was measured using the standard wet chemistry method. Carbon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion (in kg/hr), determined using the measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, and 5.3 for CO. The fuel-mass-based emission factors (in g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BB-coal were 2.51 for PM10, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The task-based emission factors (in g/ton steam generated) of the R-coal, determined using the fuel-mass-based emission factors and the coal/steam conversion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for CO, while those of the BB-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also presented for both types of coal tested in the study.

Air Pollution

MedlinePlus

... include: Fine particles produced by the burning of fossil fuels (i.e. the coal and petroleum used in energy production) Noxious gases (sulfur dioxide, nitrogen oxides, carbon monoxide, chemical vapors, etc.) Ground-level ozone (a reactive form of oxygen and a primary component of urban ...

A Method for Improving Temporal and Spatial Resolution of Carbon Dioxide Emissions

NASA Astrophysics Data System (ADS)

Gregg, J. S.; Andres, R. J.

2003-12-01

Using United States data, a method is developed to estimate the monthly consumption of solid, liquid and gaseous fossil fuels for each state in the union. This technique employs monthly sales data to estimate the relative monthly proportions of the total annual national fossil fuel use. These proportions are then used to estimate the total monthly carbon dioxide emissions for each state. To assess the success of this technique, the results from this method are compared with the data obtained from other independent methods. To determine the temporal success of the method, the resulting national time series is compared to the model produced by Carbon Dioxide Information Analysis Center (CDIAC) and the current model being developed by T. J. Blasing and C. Broniak at the Oak Ridge National Laboratory (ORNL). The University of North Dakota (UND) method fits well temporally with the results of the CDIAC and current ORNL research. To determine the success of the spatial component, the individual state results are compared to the annual state totals calculated by ORNL. Using ordinary least squares regression, the annual state totals of this method are plotted against the ORNL data. This allows a direct comparison of estimates in the form of ordered pairs against a one-to-one ideal correspondence line, and allows for easy detection of outliers in the results obtained by this estimation method. Analyzing the residuals of the linear regression model for each type of fuel permits an improved understanding of the strengths and shortcomings of the spatial component of this estimation technique. Spatially, the model is successful when compared to the current ORNL research. The primary advantages of this method are its ease of implementation and universal applicability. In general, this technique compares favorably to more labor-intensive methods that rely on more detailed data. The more detailed data is generally not available for most countries in the world. The methodology used here will be applied to other nations in the world to better understand their sub-annual cycle and sub-national spatial distribution of carbon dioxide emissions from fossil fuel consumption. Better understanding of the cycle will lead to better models used for predicting and responding to global environmental changes currently observed and anticipated.

Fuel shipment experience, fuel movements from the BMI-1 transport cask

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

Bauer, Thomas L.; Krause, Michael G

1986-07-01

The University of Texas at Austin received two shipments of irradiated fuel elements from Northrup Aircraft Corporation on April 11 and 16, 1985. A total of 59 elements consisting of standard and instrumented TRIGA fuel were unloaded from the BMI-1 shipping cask. At the time of shipment, the Northrup core burnup was approximately 50 megawatt days with fuel element radiation levels, after a cooling time of three months, of approximately 1.75 rem/hr at 3 feet. In order to facilitate future planning of fuel shipment at the UT facility and other facilities, a summary of the recent transfer process including severalmore » factors which contributed to its success are presented. Numerous color slides were made of the process for future reference by UT and others involved in fuel transfer and handling of the BMI-1 cask.« less

The Finite Element Modelling and Dynamic Characteristics Analysis about One Kind of Armoured Vehicles’ Fuel Tanks

NASA Astrophysics Data System (ADS)

Gao, Yang; Ge, Zhishang; Zhai, Weihao; Tan, Shiwang; Zhang, Feng

2018-01-01

The static and dynamic characteristics of fuel tank are studied for the armoured vehicle in this paper. The CATIA software is applied to build the CAD model of the armoured vehicles’ fuel tank, and the finite element model is established in ANSYS Workbench. The finite element method is carried out to analyze the static and dynamic mechanical properties of the fuel tank, and the first six orders of mode shapes and their frequencies are also computed and given in the paper, then the stress distribution diagram and the high stress areas are obtained. The results of the research provide some references to the fuel tanks’ design improvement, and give some guidance for the installation of the fuel tanks on armoured vehicles, and help to improve the properties and the service life of this kind of armoured vehicles’ fuel tanks.

Aerosol elemental concentrations in the tropopause region from intercontinental flights with the Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container (CARIBIC) platform

NASA Astrophysics Data System (ADS)

Papaspiropoulos, Giorgos; Martinsson, Bengt G.; Zahn, Andreas; Brenninkmeijer, Carl A. M.; Hermann, Markus; Heintzenberg, Jost; Fischer, Herbert; van Velthoven, Peter F. J.

2002-12-01

This study with the Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container (CARIBIC) platform investigates the aerosol elemental concentrations at 9-11 km altitude in the northern hemisphere. Measurements from 31 intercontinental flights over a 2-year period between Germany and Sri Lanka/Maldives in the Indian Ocean are presented. Aerosol samples were collected with an impaction technique and were analyzed for the concentration of 18 elements using particle-induced X-ray emission (PIXE). Additional measurements of particle number concentrations, ozone and carbon monoxide concentrations, and meteorological modeling were included in the interpretation of the aerosol elemental concentrations. Particulate sulphur was found to be by far the most abundant element. Its upper tropospheric concentration increased, on average, by a factor of 2 from the tropics to midlatitudes, with another factor 2 higher concentrations in the lowermost stratosphere over midlatitudes. Correlation patterns and source profiles suggest contributions from crustal sources and biomass burning, but not from meteor ablation. Coinciding latitudinal gradients in particulate sulphur concentrations and emissions suggest that fossil fuel combustion is an important source of the aerosol in the upper troposphere and lowermost stratosphere. The measurements indicate aerosol transport along isentropic surfaces across the tropopause into the lowermost stratosphere. As a result of the prolonged residence time, ageing via oxidation of sulphur dioxide in the lowermost stratosphere was found to be a likely high-altitude, strong source that, along with downward transport of stratospheric air, could explain the vertical gradient of particulate sulphur mass concentration around the extratropical tropopause.

Thermodynamic and kinetic modelling of fuel oxidation behaviour in operating defective fuel

NASA Astrophysics Data System (ADS)

Lewis, operating defective fuel B. J.; Thompson, W. T.; Akbari, F.; Thompson, D. M.; Thurgood, C.; Higgs, J.

2004-07-01

A theoretical treatment has been developed to predict the fuel oxidation behaviour in operating defective nuclear fuel elements. The equilibrium stoichiometry deviation in the hyper-stoichiometric fuel has been derived from thermodynamic considerations using a self-consistent set of thermodynamic properties for the U-O system, which emphasizes replication of solubilities and three-phase invariant conditions displayed in the U-O binary phase diagram. The kinetics model accounts for multi-phase transport including interstitial oxygen diffusion in the solid and gas-phase transport of hydrogen and steam in the fuel cracks. The fuel oxidation model is further coupled to a heat conduction model to account for the feedback effect of a reduced thermal conductivity in the hyper-stoichiometric fuel. A numerical solution has been developed using a finite-element technique with the FEMLAB software package. The model has been compared to available data from several in-reactor X-2 loop experiments with defective fuel conducted at the Chalk River Laboratories. The model has also been benchmarked against an O/U profile measurement for a spent defective fuel element discharged from a commercial reactor.

NEUTRONIC REACTOR FUEL ELEMENT AND CORE SYSTEM

DOEpatents

Moore, W.T.

1958-09-01

This patent relates to neutronic reactors and in particular to an improved fuel element and a novel reactor core system for facilitating removal of contaminating fission products, as they are fermed, from association with the flssionable fuel, so as to mitigate the interferent effects of such fission products during reactor operation. The fuel elements are comprised of tubular members impervious to fluid and contatning on their interior surfaces a thin layer of fissionable material providing a central void. The core structure is comprised of a plurality of the tubular fuel elements arranged in parallel and a closed manifold connected to their ends. In the reactor the core structure is dispersed in a water moderator and coolant within a pressure vessel, and a means connected to said manifuld is provided for withdrawing and disposing of mobile fission product contamination from the interior of the feel tubes and manifold.

REACTOR UNLOADING

DOEpatents

Leverett, M.C.

1958-02-18

This patent is related to gas cooled reactors wherein the fuel elements are disposed in vertical channels extending through the reactor core, the cooling gas passing through the channels from the bottom to the top of the core. The invention is a means for unloading the fuel elements from the core and comprises dump values in the form of flat cars mounted on wheels at the bottom of the core structure which support vertical stacks of fuel elements. When the flat cars are moved, either manually or automatically, for normal unloading purposes, or due to a rapid rise in the reproduction ratio within the core, the fuel elements are permtted to fall by gravity out of the core structure thereby reducing the reproduction ratio or stopping the reaction as desired.

PROTECTIVELY COVERED ARTICLE AND METHOD OF MANUFACTURE

DOEpatents

Plott, R.F.

1958-10-28

A method of casting a protective jacket about a ura nium fuel element that will bond completely to the uranium without the use of stringers or supports that would ordinarily produce gaps in the cast metal coating and bond is presented. Preformed endcaps of alumlnum alloyed with 13% silicon are placed on the ends of the uranium fuel element. These caps will support the fuel element when placed in a mold. The mold is kept at a ing alloy but below that of uranium so the cast metal jacket will fuse with the endcaps forming a complete covering and bond to the fuel element, which would otherwise oxidize at the gaps or discontinuities lefi in the coating by previous casting methods.

Determination of the wine preservative sulphur dioxide with cyclic voltammetry using inkjet printed electrodes.

PubMed

Schneider, Marion; Türke, Alexander; Fischer, Wolf-Joachim; Kilmartin, Paul A

2014-09-15

During winemaking sulphur dioxide is added to prevent undesirable reactions. However, concerns over the harmful effects of sulphites have led to legal limits being placed upon such additives. There is thus a need for simple and selective determinations of sulphur dioxide in wine, especially during winemaking. The simultaneous detection of polyphenols and sulphur dioxide, using cyclic voltammetry at inert electrodes is challenging due to close oxidation potentials. In the present study, inkjet printed electrodes were developed with a suitable voltammetric signal on which the polyphenol oxidation is suppressed and the oxidation peak height for sulphur dioxide corresponds linearly to the concentration. Different types of working electrodes were printed. Electrodes consisting of gold nanoparticles mixed with silver showed the highest sensitivity towards sulphur dioxide. Low cost production of the sensor elements and ultra fast determination of sulphur dioxide by cyclic voltammetry makes this technique very promising for the wine industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Emissions of carbon monoxide and carbon dioxide from uncompressed and pelletized biomass fuel burning in typical household stoves in China

NASA Astrophysics Data System (ADS)

Wei, Wen; Zhang, Wei; Hu, Dan; Ou, Langbo; Tong, Yindong; Shen, Guofeng; Shen, Huizhong; Wang, Xuejun

2012-09-01

Carbon dioxide (CO2) and carbon monoxide (CO) impact climate change and human health. The uncertainties in emissions inventories of CO2 and CO are primarily due to the large variation in measured emissions factors (EFs), especially to the lack of EFs from developing countries. China's goals of reducing CO2 emissions require a maximum utilization of biomass fuels. Pelletized biomass fuels are well suited for the residential biomass market, providing possibilities of more automated and optimized systems with higher modified combustion efficiency (MCE) and less products from incomplete combustion. However, EFs of CO2 and CO from pellet biomass fuels are seldom reported, and a comparison to conventional uncompressed biomass fuels has never been conducted. Therefore, the objectives of this study were to experimentally determine the CO2 and CO EFs from uncompressed biomass (i.e., firewood and crop residues) and biomass pellets (i.e., pine wood pellet and corn straw pellet) under real residential applications and to compare the influences of fuel properties and combustion conditions on CO2 and CO emissions from the two types of biomass fuels. For the uncompressed biomass examples, the CO2 and CO EFs were 1649.4 ± 35.2 g kg-1 and 47.8 ± 8.9 g kg-1, respectively, for firewood and 1503.2 ± 148.5 g kg-1 and 52.0 ± 14.2 g kg-1, respectively, for crop residues. For the pellet biomass fuel examples, the CO2 and CO EFs were 1708.0 ± 3.8 g kg-1 and 4.4 ± 2.4 g kg-1, respectively, for pellet pine and 1552.1 ± 16.3 g kg-1 and 17.9 ± 10.2 g kg-1, respectively, for pellet corn. In rural China areas during 2007, firewood and crop residue burning produced 721.7 and 23.4 million tons of CO2 and CO, respectively.

Experimental Studies of Coal and Biomass Fuel Synthesis and Flame Characterization for Aircraft Engines

DTIC Science & Technology

2010-05-31

near the catalyst bed was about 600 °C. The rest of the reactor, tar/char collector , and transfer hose to the entrance of the condenser were heated to...such as solar and nuclear [2.2-2.3], to reduce carbon dioxide concentrations and to provide heat for the reactions. Carbon dioxide emission may be...assembly Page 27 of 50 AFOSR Grant #FA9 5 5 0-08-1-04 5 6 Final Performance Report Purdue University Ash collector ( pipe end cap) with product aas

NUCLEAR REACTOR

DOEpatents

Moore, R.V.; Bowen, J.H.; Dent, K.H.

1958-12-01

A heterogeneous, natural uranium fueled, solid moderated, gas cooled reactor is described, in which the fuel elements are in the form of elongated rods and are dlsposed within vertical coolant channels ln the moderator symmetrically arranged as a regular lattice in groups. This reactor employs control rods which operate in vertical channels in the moderator so that each control rod is centered in one of the fuel element groups. The reactor is enclosed in a pressure vessel which ls provided with access holes at the top to facilitate loading and unloadlng of the fuel elements, control rods and control rod driving devices.

JACKETED FISSIONABLE MEMBER

DOEpatents

Boller, E.R.; Robinson, J.W.

1960-09-13

A fuel element design for a nuclear reactor is presented. The fuel element comprises a cylindrical fuel body having a portion of smaller diameter at each end thereof with an annular flange at the extreme ends of these portions of smaller diameter. An end cap fits over the ends of the fuel body and has an internal annular groove adapted to receive the flange. The fuel body and end caps are disposed in a cup-shaped jacket, a closure disc completing the enclosure of the fuel body, and tht caps are bonded over their entire periphery to the jacket.

U-Mo Plate Blister Anneal Interim Report

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

Francine J. Rice; Daniel M. Wachs; Adam B. Robinson

2010-10-01

Blister thresholds in fuel elements have been a longstanding performance parameter for fuel elements of all types. This behavior has yet to be fully defined for the RERTR U-Mo fuel types. Blister anneal studies that began in 2007 have been expanded to include plates from more recent RERTR experiments. Preliminary data presented in this report encompasses the early generations of the U-Mo fuel systems and the most recent but still developing fuel system. Included is an overview of relevant dispersion fuel systems for the purposes of comparison.

MERCURY SPECIATION IN COMBUSTION SYSTEMS: STUDIES WITH SIMULATED FLUE GASES AND MODEL FLY ASHES

EPA Science Inventory

The paper gives results of a bench-scale study of the effects of flue gas and fly ash parameters on the oxidation of elemental mercury in simulated flue gases containing hydrogen chloride (HCl), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and water vapor (H2O...

Biogas Laminar Burning Velocity and Flammability Characteristics in Spark Ignited Premix Combustion

NASA Astrophysics Data System (ADS)

Anggono, Willyanto; Wardana, I. N. G.; Lawes, M.; Hughes, K. J.; Wahyudi, Slamet; Hamidi, Nurkholis; Hayakawa, Akihiro

2013-04-01

Spherically expanding flames propagating at constant pressure were employed to determine the laminar burning velocity and flammability characteristics of biogas-air mixtures in premixed combustion to uncover the fundamental flame propagation characteristics of a new alternative and renewable fuel. The results are compared with those from a methane-air flame. Biogas is a sustainable and renewable fuel that is produced in digestion facilities. The composition of biogas discussed in this paper consists of 66.4% methane, 30.6% carbon dioxide and 3% nitrogen. Burning velocity was measured at various equivalence ratios (phi) using a photographic technique in a high pressure fan-stirred bomb, the initial condition being at room temperature and atmospheric pressure. The flame for methane-air mixtures propagates from phi=0.6 till phi=1.3. The flame at phi >= 1.4 does not propagate because the combustion reaction is quenched by the larger mass of fuel. At phi<=0.5, it does not propagate as well since the heat of reaction is insufficient to burn the mixtures. The flame for biogas-air mixtures propagates in a narrower range, that is from phi=0.6 to phi=1.2. Different from the methane flame, the biogas flame does not propagate at phi>=1.3 because the heat absorbed by inhibitors strengthens the quenching effect by the larger mass of fuel. As in the methane flame, the biogas flame at phi<=0.5 does not propagate. This shows that the effect of inhibitors in extremely lean mixtures is small. Compared to a methane-air mixture, the flammability characteristic (flammable region) of biogas becomes narrower in the presence of inhibitors (carbon dioxide and nitrogen) and the presence of inhibitors causes a reduction in the laminar burning velocity. The inhibitor gases work more effectively at rich mixtures because the rich biogas-air mixtures have a higher fraction of carbon dioxide and nitrogen components compared to the lean biogas-air mixtures.

Use of natural gas, methanol, and ethanol fuel emulsions as environmentally friendly energy carriers for mobile heat power plants

NASA Astrophysics Data System (ADS)

Likhanov, V. A.; Lopatin, O. P.

2017-12-01

The need for using environmentally friendly energy carriers for mobile heat power plants (HPPs) is grounded. Ecologically friendly sources of energy, such as natural gas as well as renewable methyl and ethyl alcohols, are investigated. In order to develop, determine, and optimize the composition of environmentally friendly energy carriers for an HPP, the latter has been tested when working on diesel fuel (DF), compressed natural gas (CNG), and methanol and ethanol fuel emulsions (MFE, EFE). It has been experimentally established that, for the application of environmentally friendly energy carriers for a 4Ch 11.0/12.5 diesel engine of a mobile fuel and power plant, it is necessary to maintain the following ratio of components when working on CNG: 80% gas and 20% DF primer portion. When working on an alcohol mixture, emulsions of the following composition were used: 25% alcohol (methanol or ethanol), 0.5% detergent-dispersant additive succinimide C-5A, 7% water, and 67.5% DF. When this diesel passed from oil DF to environmentally friendly energy sources, it allowed for the reduction of the content of exhaust gases (EG) (1) when working on CNG with recirculation of exhaust gases (EGR) (recirculation was used to eliminate the increased amount of nitric oxides by using CNG): carbon black by 5.8 times, carbon dioxide by 45.9%, and carbon monoxide by 23.8%; (2) when working on MFE: carbon black by 6.4 times, nitrogen oxides by 29.6%, carbon dioxide by 10.1%, and carbon oxide by 47.6%; (3) when working on EFE: carbon black by 4.8 times; nitrogen oxides by 40.3%, carbon dioxide by 26.6%, and carbon monoxide by 28.6%. The prospects of use of environmentally friendly energy carriers in diesels of mobile HPPs, such as natural gas, ethanol, and methanol, has been determined.

Summary of Nitrous Oxide Investigations

DTIC Science & Technology

1976-07-01

Decompcsition of Nitrous Oxide," Doklady Akad. Nauk, SSR 132, 1129, 1960. 3. Mitchell, R. C., Arbit, H. A. , and Campbell, D. T., Carbon Monoxide-.Fueled Gas... Carbon Monoxide-Fueled Gas Generator, AFWL-TR-72-185, Air Force Weapons Laboratory, Kirtland AFB, New Mexico, Feb., 1973. 231 AFWL-TR-75-231...Heats of a Gas, Cp/Cv. Part III. Sulphur Dioxide and Nitrous Oxide," Canadian J. of Res., 19 (Sec. A, No. 9)., !Ul, September 1941. Clusius, Hiller, and

Thermionic System Evaluation Test: Ya-21U System Topaz International Program

DTIC Science & Technology

1996-07-01

by enriched uranium dioxide (U02) fuel pellets, as illustrated by Figure 5. The work section of the converter contained 34 TFEs that provided power...power system. This feature permitted transportation of the highly enriched uranium oxide fuel in separate containers from the space power system and...by Figure 8. The radial reflector contained three safety and nine control drums. Each drum contained a section of boron carbide (B4C) neutron poison

Energy and climate impacts of producing synthetic hydrocarbon fuels from CO(2).

PubMed

van der Giesen, Coen; Kleijn, René; Kramer, Gert Jan

2014-06-17

Within the context of carbon dioxide (CO2) utilization there is an increasing interest in using CO2 as a resource to produce sustainable liquid hydrocarbon fuels. When these fuels are produced by solely using solar energy they are labeled as solar fuels. In the recent discourse on solar fuels intuitive arguments are used to support the prospects of these fuels. This paper takes a quantitative approach to investigate some of the claims made in this discussion. We analyze the life cycle performance of various classes of solar fuel processes using different primary energy and CO2 sources. We compare their efficacy with respect to carbon mitigation with ubiquitous fossil-based fuels and conclude that producing liquid hydrocarbon fuels starting from CO2 by using existing technologies requires much more energy than existing fuels. An improvement in life cycle CO2 emissions is only found when solar energy and atmospheric CO2 are used. Producing fuels from CO2 is a very long-term niche at best, not the panacea suggested in the recent public discourse.

Synthesis, characterization and potential utility of doped ceramics based catalysts

NASA Astrophysics Data System (ADS)

Sharma, Ritika; Yadav, Deepshikha; Singh, G. P.; Vyas, G.; Bhojak, N.

2018-05-01

Excessive utilization of petrol, diesel and other fossil fuels, continuous increase in their prices, and the big problem of carbon dioxide mission have encouraged scientists and technologist to find either new sources of energy or to develop technologies for the sustainable utilization of fuel. Biofuels are the only energy technologies that can resolve the problem of carbon dioxide emission in the atmosphere as well as reduce the amount of fossil fuel burned. Bio ethanol and biodiesel are the most common types of biofuel which are being used at present. Biodiesel has become more interesting for all the researchers in present scenario. Various feedstock viz. edible, nonedible oils, waste cooking oil, animal fat, algae etc, are using for the production of biodiesel worldwide according to their availability. Selection of efficient heterogeneous catalysts for biodiesel preparation still needs more attention of researchers. The present investigation deals with determination of synthesis, characterization and applications of doped ceramic based materials in different medium. Two of doped ceramic based catalysts which has been potentially used for the production of biodiesel. The Engine performance of biodiesel samples, made from industrial waste oils and ceramic based catalyst, have also been investigated and found up to satisfactory levels.

Prediction and validation of blowout limits of co-flowing jet diffusion flames -- effect of dilution

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

Karbasi, M.; Wierzba, I.

1996-10-01

The blowout limits of a co-flowing turbulent methane jet diffusion flame with addition of diluent in either jet fuel or surrounding air stream is studied both analytically and experimentally. Helium, nitrogen and carbon dioxide were employed as the diluents. Experiments indicated that an addition of diluents to the jet fuel or surrounding air stream decreased the stability limit of the jet diffusion flames. The strongest effect was observed with carbon dioxide as the diluent followed by nitrogen and then by helium. A model of extinction based on recognized criterion of the mixing time scale to characteristic combustion time scale ratiomore » using experimentally derived correlations is proposed. It is capable of predicting the large reduction of the jet blowout velocity due to a relatively small increase in the co-flow stream velocity along with an increase in the concentration of diluent in either the jet fuel or surrounding air stream. Experiments were carried out to validate the model. The predicted blowout velocities of turbulent jet diffusion flames obtained using this model are in good agreement with the corresponding experimental data.« less

Final Report: Room Temperature Electrochemical Upgrading of Methane to Oxygenate Fuels

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

Mustain, William E.

The overall objective of this project is to discover the nature of the electrochemically active sites and to uncover the mechanisms for the electrocatalytic transformation of small organic molecules to oxygenate products such as methanol, formaldehyde, carbon monoxide and acetylene. Among the feedstocks of interest in this study are: methane, carbon dioxide, and acetic acid. Methane is an incredibly attractive potential feedstock because of the recent discovery of large shale deposits; carbon dioxide is potentially a very available feedstock from carbon capture technologies; acetic acid (as well as CH 4 and CO 2 and ethanol) has potential as a bio-derivedmore » feedstock. This report summarizes the major results to date regarding the electrochemical transformation of CH 4, CO 2 and acetic acid to chemicals and fuels – with a primary focus on methane. Finer details are available in each of the projects annual reports. In addition to the primary objective, the work in this project has led to synergistic discoveries that are advantageous to other fields including: catalyst layer deposition, anion exchange membrane fuel cells, CO 2 capture and li-ion batteries. Those are very briefly discussed as well.« less

CO 2 hydrogenation to formate and methanol as an alternative to photo- and electrochemical CO 2 reduction

DOE PAGES

Wang, Wan -Hui; Himeda, Yuichiro; Muckerman, James T.; ...

2015-09-03

In this study, carbon dioxide is one of the end products of combustion, and is not a benign component of the atmosphere. The concentration of CO 2 in the atmosphere has reached unprecedented levels and continues to increase owing to an escalating rate of fossil fuel combustion, causing concern about climate change and rising sea levels. In view of the inevitable depletion of fossil fuels, a possible solution to this problem is the recycling of carbon dioxide, possibly captured at its point of generation, to fuels. Researchers in this field are using solar energy for CO 2 activation and utilizationmore » in several ways: (i) so-called artificial photosynthesis using photo-induced electrons; (ii) bulk electrolysis of a CO 2 saturated solution using electricity produced by photovoltaics; (iii) CO 2 hydrogenation using solar-produced H 2; and (iv) the thermochemical reaction of metal oxides at extremely high temperature reached by solar collectors. Since the thermodynamics of CO 2 at high temperature (> 1000 ºC) are quite different from those near room temperature, only chemistry below 200 ºC is discussed in this review.« less

Chemicals and energy co-generation from direct hydrocarbons/oxygen proton exchange membrane fuel cell

NASA Astrophysics Data System (ADS)

Li, W. S.; Lu, D. S.; Luo, J. L.; Chuang, K. T.

A proton exchange membrane fuel cell for chemicals and energy co-generation was set up with hydrocarbons ethane, propane and butane as fuels, and the electrochemical performance of the cell was studied by using linear potential sweep, alternating current impedance and gas chromatography. The cell performance can be improved to a great extent by increasing the platinum load in the catalyst, by treating the membrane with phosphoric acid and by elevating temperature. The improvement of cell performance by the increase of platinum load is ascribed to the increase of reaction sites for hydrocarbon oxidation, that by phosphoric acid treatment to the increase of proton conductivity in Nafion membrane, and that by elevating temperature to the improvement in thermodynamic as well as kinetic aspects. Only a small fraction of the hydrocarbon is converted to carbon dioxide in this cell during its power generation. The current efficiency is 5% for the conversion of ethane to carbon dioxide in the ethane/oxygen fuel cell with 20% carbon-supported platinum as catalyst and phosphoric acid-treated membrane as proton exchange membrane at 0.2 V, 80 °C and ambient pressure. The reaction activity of hydrocarbons at the anode is in the order of propane, butane and ethane. The possible chemicals produced from the cell were hydrocarbons with more than six carbons, which are inactive at the anode under cell conditions.

Characterization of carbon dioxide concentrating chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel.

PubMed

Kumar, Manish; Morya, Raj; Gnansounou, Edgard; Larroche, Christian; Thakur, Indu Shekhar

2017-11-01

Proteomics and metabolomics analysis has become a powerful tool for characterization of microbial ability for fixation of Carbon dioxide. Bacterial community of palaeoproterozoic metasediments was enriched in the shake flask culture in the presence of NaHCO 3 . One of the isolate showed resistance to NaHCO 3 (100mM) and was identified as Serratia sp. ISTD04 by 16S rRNA sequence analysis. Carbon dioxide fixing ability of the bacterium was established by carbonic anhydrase enzyme assay along with proteomic analysis by LC-MS/MS. In proteomic analysis 96 proteins were identified out of these 6 protein involved in carbon dioxide fixation, 11 in fatty acid metabolism, indicating the carbon dioxide fixing potency of bacterium along with production of biofuel. GC-MS analysis revealed that hydrocarbons and FAMEs produced by bacteria within the range of C 13 -C 24 and C 11 -C 19 respectively. Presence of 59% saturated and 41% unsaturated organic compounds, make it a better fuel composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials

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

Weber, J. K. R.; Alderman, O. L. G.; Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439

2016-07-15

An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment wasmore » integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.« less

Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials

DOE PAGES

Weber, J. K. R.; Tamalonis, A.; Benmore, C. J.; ...

2016-07-01

We integrated an aerodynamic levitator with carbon dioxide laser beam heating with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. Furthermore, the chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The samplemore » environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. Our system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.« less

A small, 1400 deg Kelvin, reactor for Brayton space power systems

NASA Technical Reports Server (NTRS)

Lantz, E.; Mayo, W.

1972-01-01

A preliminary cost estimate for a small reactor in Brayton space power systems with (u-233)n or (pu-239)n as the fuel in the T-111 fuel elements totaled to about four million dollars; considered is a 22.8 in. diameter reactor with 247 fuel elements.

Fiber optic sensors for gas turbine control

NASA Technical Reports Server (NTRS)

Shu, Emily Yixie (Inventor); Petrucco, Louis Jacob (Inventor); Daum, Wolfgang (Inventor)

2005-01-01

An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

Fiber optic sensors for gas turbine control

NASA Technical Reports Server (NTRS)

Shu, Emily Yixie (Inventor); Brown, Dale Marius (Inventor); Petrucco, Louis Jacob (Inventor); Lovett, Jeffery Allan (Inventor); Daum, Wolfgang (Inventor); Dunki-Jacobs, Robert John (Inventor)

2003-01-01

An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.