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Sample records for bromine thermochemical cycle

  1. Thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

    1975-01-01

    The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

  2. Molten-Phase Hydrolysis Stage Analysis and Experiments for the Calcium Bromine Thermochemical Cycle

    SciTech Connect

    Doctor, Richard D.; Panchal, C.B.; Lottes, Steven A.; Lyczkowski, Robert W.; Yang, Jianhong

    2007-07-01

    The goal of the United States Department of Energy Nuclear Hydrogen Initiative as linked with the Generation IV Nuclear Energy Systems Initiative for Gas Reactor Deployment is to develop a cost-effective, proliferation-resistant, low-greenhouse-gas emissions, and sustainable, nuclear-based energy supply system. The calcium-bromine cycle under development at Argonne National Laboratory combines both experimental and modeling studies of a novel continuous 'hybrid' cycle for hydrogen production, where 'hybrid' means that both nuclear heat and electricity are employed. Engineering the calcium-bromine cycle for continuous operation should facilitate its practical development since there will be an inherent advantage to using components and materials which will operate in a constant, non-cycling chemical and thermal environment. This paper focuses on the first and important calcium bromide hydrolysis stage to generate hydrogen bromide, which when split by electrolysis, produces hydrogen. (authors)

  3. Studies of thermochemical water-splitting cycles

    NASA Technical Reports Server (NTRS)

    Remick, R. J.; Foh, S. E.

    1980-01-01

    Higher temperatures and more isothermal heat profiles of solar heat sources are developed. The metal oxide metal sulfate class of cycles were suited for solar heat sources. Electrochemical oxidation of SO2 and thermochemical reactions are presented. Electrolytic oxidation of sulfur dioxide in dilute sulfuric acid solutions were appropriate for metal oxide metal sulfate cycles. The cell voltage at workable current densities required for the oxidation of SO2 was critical to the efficient operation of any metal oxide metal sulfate cycle. A sulfur dioxide depolarized electrolysis cell for the splitting of water via optimization of the anode reaction is discussed. Sulfuric acid concentrations of 30 to 35 weight percent are preferred. Platinized platinum or smooth platinum gave the best anode kinetics at a given potential of the five materials examined.

  4. Development of the Hybrid Sulfur Thermochemical Cycle

    SciTech Connect

    Summers, William A.; Steimke, John L

    2005-09-23

    The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

  5. Bromine

    USGS Publications Warehouse

    Ober, Joyce A.

    2011-01-01

    All U.S. production of bromine in 2010 came from underground brines in Arkansas. It was the leading mineral commodity produced in the state in terms of value. Albemarle Corp. and Chemtura Corp. recovered bromine.

  6. Bromine

    USGS Publications Warehouse

    Ober, Joyce A.

    2012-01-01

    The element bromine is found principally as a dissolved species in seawater, evaporitic (salt) lakes and underground brines associated with petroleum deposits. Seawater contains about 65 parts per million of bromine or an estimated 100 Tt (110 trillion st). In the Middle East, the highly saline waters of the Dead Sea are estimated to contain 1 Gt (1.1billion st) of bromine. Bromine is also recovered from seawater as a coproduct during evaporation to produce salt.

  7. Bromine

    USGS Publications Warehouse

    Ober, J.A.

    2013-01-01

    The element bromine is found principally as a dissolved species in seawater, evaporitic (salt) lakes and underground brines associated with petroleum deposits. Seawater contains about 65 parts per million of bromine or an estimated 907 Gt (100 trillion st). In the Middle East, the highly saline waters of the Dead Sea are estimated to contain 907 Mt (1 billion st) of bromine. Bromine also may be recovered from seawater as a coproduct during evaporation to produce salt.

  8. Bromine

    USGS Publications Warehouse

    Apodaca, Lori E.

    2010-01-01

    The entire U.S. production of bromine in 2009 came from underground brines in Arkansas, where it was the leading mineral commodity produced in terms of value. Two companies, Albermarle Corp. and Chemtura Corp., were responsible for bromine recovery. Worldwide, the United States is still the leading producer. However, U.S. dominance has decreased, as countries like China, Israel, Japan and Jordan have strengthened their positions as world producers of elemental bromine.

  9. Thermochemical cycle analysis using linked CECS72 and HYDRGN computer programs

    NASA Technical Reports Server (NTRS)

    Donovan, L. F.

    1977-01-01

    A combined thermochemical cycle analysis computer program was designed. Input to the combined program is the same as input to the thermochemical cycle analysis program except that the extent of the reactions need not be specified. The combined program is designed to be run interactively from a computer time-sharing terminal. This mode of operation allows correction or modification of the cycle to take place during cycle analysis. A group of 13 thermochemical cycles was used to test the combined program.

  10. Interfacing primary heat sources and cycles for thermochemical hydrogen production

    SciTech Connect

    Bowman, M.G.

    1980-01-01

    Advantages cited for hydrogen production from water by coupling thermochemical cycles with primary heat include the possibility of high efficiencies. These can be realized only if the cycle approximates the criteria required to match the characteristics of the heat source. Different types of cycles may be necessary for fission reactors, for fusion reactors or for solar furnaces. Very high temperature processes based on decomposition of gaseous H/sub 2/O or CO/sub 2/ appear impractical even for projected solar technology. Cycles based on CdO decomposition are potentially quite efficient and require isothermal heat at temperatures that may be available from solar furnaces of fusion reactors. Sulfuric acid and solid sulfate cycles are potentially useful at temperatures available from each heat source. Solid sulfate cycles offer advantages for isothermal heat sources. All cycles under development include concentration and drying steps. Novel methods for improving such operations would be beneficial.

  11. ALTERNATIVE FLOWSHEETS FOR THE SULFUR-IODINE THERMOCHEMICAL HYDROGEN CYCLE

    SciTech Connect

    BROWN,LC; LENTSCH,RD; BESENBRUCH,GE; SCHULTZ,KR; FUNK,JE

    2003-02-01

    OAK-B135 A hydrogen economy will need significant new sources of hydrogen. Unless large-scale carbon sequestration can be economically implemented, use of hydrogen reduces greenhouse gases only if the hydrogen is produced with non-fossil energy sources. Nuclear energy is one of the limited options available. One of the promising approaches to produce large quantities of hydrogen from nuclear energy efficiently is the Sulfur-Iodine (S-I) thermochemical water-splitting cycle, driven by high temperature heat from a helium Gas-Cooled Reactor. They have completed a study of nuclear-driven thermochemical water-splitting processes. The final task of this study was the development of a flowsheet for a prototype S-I production plant. An important element of this effort was the evaluation of alternative flowsheets and selection of the reference design.

  12. Advanced Electrochemical Technologies for Hydrogen Production by Alternative Thermochemical Cycles

    SciTech Connect

    Lvov, Serguei; Chung, Mike; Fedkin, Mark; Lewis, Michele; Balashov, Victor; Chalkova, Elena; Akinfiev, Nikolay; Stork, Carol; Davis, Thomas; Gadala-Maria, Francis; Stanford, Thomas; Weidner, John; Law, Victor; Prindle, John

    2011-01-06

    Hydrogen fuel is a potentially major solution to the problem of climate change, as well as addressing urban air pollution issues. But a key future challenge for hydrogen as a clean energy carrier is a sustainable, low-cost method of producing it in large capacities. Most of the world's hydrogen is currently derived from fossil fuels through some type of reforming processes. Nuclear hydrogen production is an emerging and promising alternative to the reforming processes for carbon-free hydrogen production in the future. This report presents the main results of a research program carried out by a NERI Consortium, which consisted of Penn State University (PSU) (lead), University of South Carolina (USC), Tulane University (TU), and Argonne National Laboratory (ANL). Thermochemical water decomposition is an emerging technology for large-scale production of hydrogen. Typically using two or more intermediate compounds, a sequence of chemical and physical processes split water into hydrogen and oxygen, without releasing any pollutants externally to the atmosphere. These intermediate compounds are recycled internally within a closed loop. While previous studies have identified over 200 possible thermochemical cycles, only a few have progressed beyond theoretical calculations to working experimental demonstrations that establish scientific and practical feasibility of the thermochemical processes. The Cu-Cl cycle has a significant advantage over other cycles due to lower temperature requirements – around 530 °C and below. As a result, it can be eventually linked with the Generation IV thermal power stations. Advantages of the Cu-Cl cycle over others include lower operating temperatures, ability to utilize low-grade waste heat to improve energy efficiency, and potentially lower cost materials. Another significant advantage is a relatively low voltage required for the electrochemical step (thus low electricity input). Other advantages include common chemical agents and

  13. Bromine isotope analysis - a tool for investigating biogeochemical cycle of bromine-containing organic and inorganic compounds in the environment

    NASA Astrophysics Data System (ADS)

    Gelman, F.; Bernstein, A.; Levin, E.; Ronen, Z.; Halicz, L.

    2012-04-01

    Bromine naturally occurs mainly in the form of bromide and is usually considered as a conservative tracer in the groundwater system. However, nowadays many synthetically produced organobromine compounds are introduced into the environment by humans. Due to a possible toxic effect of these compounds, investigation of their fate in the nature is of the utmost importance. In this sense, examination of isotopic composition of inorganic and organic bromine may serve as a powerful tool for understanding Br geochemical cycle. Due to a relatively small mass difference between the isotopes 81Br and 79Br, bromine isotope fractionation originating from biotic and abiotic processes is expected to be in the range of several permille. Therefore, a highly precise technique for the bromine isotope ratio analysis is required. This work presents a new methodology for the precise determination of bromine isotope ratio in inorganic bromides and individual organic compounds by MC-ICPMS. Attained external precision (2σ) up to 0.1‰ allowed employment of the developed technique for determination of the bromine isotope composition in organic and inorganic bromides and Br KIE in biogeochemical processes.

  14. Present and future status of thermochemical cycles applied to fusion energy sources

    SciTech Connect

    Booth, L.A.; Cox, K.E.; Krakowski, R.A.; Pendergrass, J.H.

    1980-01-01

    This paper reviews the status of current research on thermochemical hydrogen production cycles and identifies the needs for advanced cycles and materials research. The Los Alamos Scientific Laboratory (LASL) bismuth sulfate thermochemical cycle is characterized, and fusion reactor blanket concepts for both inertial and magnetic confinement schemes are presented as thermal energy sources for process heat applications.

  15. Methane-methanol cycle for the thermochemical production of hydrogen

    DOEpatents

    Dreyfuss, Robert M.; Hickman, Robert G.

    1976-01-01

    A thermochemical reaction cycle for the generation of hydrogen from water comprising the following sequence of reactions wherein M represents a metal: CH.sub.4 + H.sub.2 O .fwdarw. CO + 3H.sub.2 (1) co + 2h.sub.2 .fwdarw. ch.sub.3 oh (2) ch.sub.3 oh + so.sub.2 + mo .fwdarw. mso.sub.4 + ch.sub.4 (3) mso.sub.4 .fwdarw. mo + so.sub.2 + 1/2o.sub.2 (4) the net reaction is the decomposition of water into hydrogen and oxygen.

  16. Membranes for H2 generation from nuclear powered thermochemical cycles.

    SciTech Connect

    Nenoff, Tina Maria; Ambrosini, Andrea; Garino, Terry J.; Gelbard, Fred; Leung, Kevin; Navrotsky, Alexandra; Iyer, Ratnasabapathy G.; Axness, Marlene

    2006-11-01

    In an effort to produce hydrogen without the unwanted greenhouse gas byproducts, high-temperature thermochemical cycles driven by heat from solar energy or next-generation nuclear power plants are being explored. The process being developed is the thermochemical production of Hydrogen. The Sulfur-Iodide (SI) cycle was deemed to be one of the most promising cycles to explore. The first step of the SI cycle involves the decomposition of H{sub 2}SO{sub 4} into O{sub 2}, SO{sub 2}, and H{sub 2}O at temperatures around 850 C. In-situ removal of O{sub 2} from this reaction pushes the equilibrium towards dissociation, thus increasing the overall efficiency of the decomposition reaction. A membrane is required for this oxygen separation step that is capable of withstanding the high temperatures and corrosive conditions inherent in this process. Mixed ionic-electronic perovskites and perovskite-related structures are potential materials for oxygen separation membranes owing to their robustness, ability to form dense ceramics, capacity to stabilize oxygen nonstoichiometry, and mixed ionic/electronic conductivity. Two oxide families with promising results were studied: the double-substituted perovskite A{sub x}Sr{sub 1-x}Co{sub 1-y}B{sub y}O{sub 3-{delta}} (A=La, Y; B=Cr-Ni), in particular the family La{sub x}Sr{sub 1-x}Co{sub 1-y}Mn{sub y}O{sub 3-{delta}} (LSCM), and doped La{sub 2}Ni{sub 1-x}M{sub x}O{sub 4} (M = Cu, Zn). Materials and membranes were synthesized by solid state methods and characterized by X-ray and neutron diffraction, SEM, thermal analyses, calorimetry and conductivity. Furthermore, we were able to leverage our program with a DOE/NE sponsored H{sub 2}SO{sub 4} decomposition reactor study (at Sandia), in which our membranes were tested in the actual H{sub 2}SO{sub 4} decomposition step.

  17. Commercial Alloys for Sulfuric Acid Vaporization in Thermochemical Hydrogen Cycles

    SciTech Connect

    Thomas M. Lillo; Karen M. Delezene-Briggs

    2005-10-01

    Most thermochemical cycles being considered for producing hydrogen include a processing stream in which dilute sulfuric acid is concentrated, vaporized and then decomposed over a catalyst. The sulfuric acid vaporizer is exposed to highly aggressive conditions. Liquid sulfuric acid will be present at a concentration of >96 wt% (>90 mol %) H2SO4 and temperatures exceeding 400oC [Brown, et. al, 2003]. The system will also be pressurized, 0.7-3.5 MPa, to keep the sulfuric acid in the liquid state at this temperature and acid concentration. These conditions far exceed those found in the commercial sulfuric acid generation, regeneration and handling industries. Exotic materials, e.g. ceramics, precious metals, clad materials, etc., have been proposed for this application [Wong, et. al., 2005]. However, development time, costs, reliability, safety concerns and/or certification issues plague such solutions and should be considered as relatively long-term, optimum solutions. A more cost-effective (and relatively near-term) solution would be to use commercially-available metallic alloys to demonstrate the cycle and study process variables. However, the corrosion behavior of commercial alloys in sulfuric acid is rarely characterized above the natural boiling point of concentrated sulfuric acid (~250oC at 1 atm). Therefore a screening study was undertaken to evaluate the suitability of various commercial alloys for concentration and vaporization of high-temperature sulfuric acid. Initially alloys were subjected to static corrosion tests in concentrated sulfuric acid (~95-97% H2SO4) at temperatures and exposure times up to 200oC and 480 hours, respectively. Alloys with a corrosion rate of less than 5 mm/year were then subjected to static corrosion tests at a pressure of 1.4 MPa and temperatures up to 375oC. Exposure times were shorter due to safety concerns and ranged from as short as 5 hours up to 144 hours. The materials evaluated included nickel-, iron- and cobalt

  18. Materials study supporting thermochemical hydrogen cycle sulfuric acid decomposer design

    NASA Astrophysics Data System (ADS)

    Peck, Michael S.

    Increasing global climate change has been driven by greenhouse gases emissions originating from the combustion of fossil fuels. Clean burning hydrogen has the potential to replace much of the fossil fuels used today reducing the amount of greenhouse gases released into the atmosphere. The sulfur iodine and hybrid sulfur thermochemical cycles coupled with high temperature heat from advanced nuclear reactors have shown promise for economical large-scale hydrogen fuel stock production. Both of these cycles employ a step to decompose sulfuric acid to sulfur dioxide. This decomposition step occurs at high temperatures in the range of 825°C to 926°C dependent on the catalysis used. Successful commercial implementation of these technologies is dependent upon the development of suitable materials for use in the highly corrosive environments created by the decomposition products. Boron treated diamond film was a potential candidate for use in decomposer process equipment based on earlier studies concluding good oxidation resistance at elevated temperatures. However, little information was available relating the interactions of diamond and diamond films with sulfuric acid at temperatures greater than 350°C. A laboratory scale sulfuric acid decomposer simulator was constructed at the Nuclear Science and Engineering Institute at the University of Missouri-Columbia. The simulator was capable of producing the temperatures and corrosive environments that process equipment would be exposed to for industrialization of the sulfur iodide or hybrid sulfur thermochemical cycles. A series of boron treated synthetic diamonds were tested in the simulator to determine corrosion resistances and suitability for use in thermochemical process equipment. These studies were performed at twenty four hour durations at temperatures between 600°C to 926°C. Other materials, including natural diamond, synthetic diamond treated with titanium, silicon carbide, quartz, aluminum nitride, and Inconel

  19. Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

    SciTech Connect

    Werner, R.W.; Ribe, F.L.

    1981-01-21

    This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units. (MOW)

  20. An analysis of hydrogen production via closed-cycle schemes. [thermochemical processings from water

    NASA Technical Reports Server (NTRS)

    Chao, R. E.; Cox, K. E.

    1975-01-01

    A thermodynamic analysis and state-of-the-art review of three basic schemes for production of hydrogen from water: electrolysis, thermal water-splitting, and multi-step thermochemical closed cycles is presented. Criteria for work-saving thermochemical closed-cycle processes are established, and several schemes are reviewed in light of such criteria. An economic analysis is also presented in the context of energy costs.

  1. Materials considerations for the coupling of thermochemical hydrogen cycles to tandem mirror reactors

    SciTech Connect

    Krikorian, O.H.

    1980-10-10

    Candidate materials are discussed and initial choices made for the critical elements in a liquid Li-Na Cauldron Tandem Mirror blanket and the General Atomic Sulfur-Iodine Cycle for thermochemical hydrogen production. V and Ti alloys provide low neutron activation, good radiation damage resistance, and good chemical compatibility for the Cauldron design. Aluminide coated In-800H and siliconized SiC are materials choices for heat exchanger components in the thermochemical cycle interface.

  2. Carbonate thermochemical cycle for the production of hydrogen

    DOEpatents

    Collins, Jack L [Knoxville, TN; Dole, Leslie R [Knoxville, TN; Ferrada, Juan J [Knoxville, TN; Forsberg, Charles W [Oak Ridge, TN; Haire, Marvin J [Oak Ridge, TN; Hunt, Rodney D [Oak Ridge, TN; Lewis, Jr, Benjamin E [Knoxville, TN; Wymer, Raymond G [Oak Ridge, TN

    2010-02-23

    The present invention is directed to a thermochemical method for the production of hydrogen from water. The method includes reacting a multi-valent metal oxide, water and a carbonate to produce an alkali metal-multi-valent metal oxide compound, carbon dioxide, and hydrogen.

  3. Carbonate Thermochemical Cycle for the Production of Hydrogen

    SciTech Connect

    Ferrada, Juan J; Collins, Jack Lee; Dole, Leslie Robert; Forsberg, Charles W; Haire, Marvin Jonathan; Hunt, Rodney Dale; Lewis Jr, Benjamin E; Wymer, Raymond; Ladd-Lively, Jennifer L

    2009-01-01

    The present invention is directed to a thermochemical method for the production of hydrogen from water. The method includes reacting a multi-valent metal oxide, water and a carbonate to produce an alkali metal-multi-valent metal oxide compound, carbon dioxide, and hydrogen.

  4. Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water

    NASA Technical Reports Server (NTRS)

    Ota, K.; Conger, W. L.

    1977-01-01

    The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

  5. A thermochemical data bank for cycle analysis. [water decomposition for hydrogen production

    NASA Technical Reports Server (NTRS)

    Carty, R.; Funk, J.; Conger, W.; Soliman, M.; Cox, K.

    1976-01-01

    The use of the computer program PAC-2 to produce a thermodynamic data bank for various materials used in water-splitting cycles is described. The sources of raw data and a listing of 439 materials for which data are presently available are presented. This paper also discusses the use of the data bank in conjunction with two other programs, CEC-72 and HYDRGN. The integration of these three programs implement an evaluation procedure for thermochemical water splitting cycles. CEC-72 is a program used to predict the equilibrium composition of the various chemical reactions in the cycle. HYDRGN is a program which is used to calculate changes in thermodynamic properties, work of separation, amount of recycle, internal heat regeneration, total thermal energy and process thermal efficiency for a thermochemical cycle.

  6. Hydrogen production by water decomposition using a combined electrolytic-thermochemical cycle

    NASA Technical Reports Server (NTRS)

    Farbman, G. H.; Brecher, L. E.

    1976-01-01

    A proposed dual-purpose power plant generating nuclear power to provide energy for driving a water decomposition system is described. The entire system, dubbed Sulfur Cycle Water Decomposition System, works on sulfur compounds (sulfuric acid feedstock, sulfur oxides) in a hybrid electrolytic-thermochemical cycle; performance superior to either all-electrolysis systems or presently known all-thermochemical systems is claimed. The 3345 MW(th) graphite-moderated helium-cooled reactor (VHTR - Very High Temperature Reactor) generates both high-temperature heat and electric power for the process; the gas stream at core exit is heated to 1850 F. Reactor operation is described and reactor innards are illustrated. A cost assessment for on-stream performance in the 1990's is optimistic.

  7. Synfuels from fusion: using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

    SciTech Connect

    Werner, R.W.

    1982-11-01

    This study is concerned with the following area: (1) the tandem mirror reactor and its physics; (2) energy balance; (3) the lithium oxide canister blanket system; (4) high-temperature blanket; (5) energy transport system-reactor to process; (6) thermochemical hydrogen processes; (7) interfacing the GA cycle; (8) matching power and temperature demands; (9) preliminary cost estimates; (10) synfuels beyond hydrogen; and (11) thermodynamics of the H/sub 2/SO/sub 4/-H/sub 2/O system. (MOW)

  8. Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion

    NASA Astrophysics Data System (ADS)

    Mu, Dongyan; Seager, Thomas; Rao, P. Suresh; Zhao, Fu

    2010-10-01

    Lignocellulosic biomass can be converted into ethanol through either biochemical or thermochemical conversion processes. Biochemical conversion involves hydrolysis and fermentation while thermochemical conversion involves gasification and catalytic synthesis. Even though these routes produce comparable amounts of ethanol and have similar energy efficiency at the plant level, little is known about their relative environmental performance from a life cycle perspective. Especially, the indirect impacts, i.e. emissions and resource consumption associated with the production of various process inputs, are largely neglected in previous studies. This article compiles material and energy flow data from process simulation models to develop life cycle inventory and compares the fossil fuel consumption, greenhouse gas emissions, and water consumption of both biomass-to-ethanol production processes. The results are presented in terms of contributions from feedstock, direct, indirect, and co-product credits for four representative biomass feedstocks i.e., wood chips, corn stover, waste paper, and wheat straw. To explore the potentials of the two conversion pathways, different technological scenarios are modeled, including current, 2012 and 2020 technology targets, as well as different production/co-production configurations. The modeling results suggest that biochemical conversion has slightly better performance on greenhouse gas emission and fossil fuel consumption, but that thermochemical conversion has significantly less direct, indirect, and life cycle water consumption. Also, if the thermochemical plant operates as a biorefinery with mixed alcohol co-products separated for chemicals, it has the potential to achieve better performance than biochemical pathway across all environmental impact categories considered due to higher co-product credits associated with chemicals being displaced. The results from this work serve as a starting point for developing full life cycle

  9. Revisiting the BaO2/BaO redox cycle for solar thermochemical energy storage.

    PubMed

    Carrillo, A J; Sastre, D; Serrano, D P; Pizarro, P; Coronado, J M

    2016-03-21

    The barium peroxide-based redox cycle was proposed in the late 1970s as a thermochemical energy storage system. Since then, very little attention has been paid to such redox couples. In this paper, we have revisited the use of reduction-oxidation reactions of the BaO2/BaO system for thermochemical heat storage at high temperatures. Using thermogravimetric analysis, reduction and oxidation reactions were studied in order to find the main limitations associated with each process. Furthermore, the system was evaluated through several charge-discharge stages in order to analyse its possible degradation after repeated cycling. Through differential scanning calorimetry the heat stored and released were also determined. Oxidation reaction, which was found to be slower than reduction, was studied in more detail using isothermal tests. It was observed that the rate-controlling step of BaO oxidation follows zero-order kinetics, although at high temperatures a deviation from Arrhenius behaviour was observed probably due to hindrances to anionic oxygen diffusion caused by the formation of an external layer of BaO2. This redox couple was able to withstand several redox cycles without deactivation, showing reaction conversions close to 100% provided that impurities are previously eliminated through thermal pre-treatment, demonstrating the feasibility of this system for solar thermochemical heat storage. PMID:26922970

  10. Status of the DOE /STOR/-sponsored national program on hydrogen production from water via thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Baker, C. E.

    1977-01-01

    A pure thermochemical cycle is a system of linked regenerative chemical reactions which accepts only water and heat and produces hydrogen. Thermochemical cycles are potentially a more efficient and cheaper means of producing hydrogen from water than is the generation of electricity followed by electrolysis. The Energy Storage Systems Division of the Department of Energy is currently funding a national program on thermochemical hydrogen production. The National Aeronautics and Space Administration is responsible for the technical management of this program. The goal is to develop a cycle which can potentially operate with an efficiency greater than 40% using a heat source providing a maximum available temperature of 1150 K. A closed bench-scale demonstration of such a cycle would follow. This cycle would be labeled a 'reference cycle' and would serve as a baseline against which future cycles would be compared.

  11. Synfuels from fusion: producing hydrogen with the tandem mirror reactor and thermochemical cycles

    SciTech Connect

    Ribe, F.L.; Werner, R.W.

    1981-01-21

    This report examines, for technical merit, the combination of a fusion reactor driver and a thermochemical plant as a means for producing synthetic fuel in the basic form of hydrogen. We studied: (1) one reactor type - the Tandem Mirror Reactor - wishing to use to advantage its simple central cell geometry and its direct electrical output; (2) two reactor blanket module types - a liquid metal cauldron design and a flowing Li/sub 2/O solid microsphere pellet design so as to compare the technology, the thermal-hydraulics, neutronics and tritium control in a high-temperature operating mode (approx. 1200 K); (3) three thermochemical cycles - processes in which water is used as a feedstock along with a high-temperature heat source to produce H/sub 2/ and O/sub 2/.

  12. Status of the DOE (STOR)-sponsored national program on hydrogen production from water via thermochemical cycles

    NASA Technical Reports Server (NTRS)

    Baker, C. E.

    1977-01-01

    The program structure is presented. The activities of the thermochemical cycles program are grouped according to the following categories: (1) specific cycle development, (2) support research and technology, (3) cycle evaluation. Specific objectives and status of on-going activities are discussed. Chemical reaction series for the production of hydrogen are presented. Efficiency and economic evaluations are also discussed.

  13. Corrosive Resistant Diamond Coatings for the Acid Based Thermo-Chemical Hydrogen Cycles

    SciTech Connect

    Mark A. Prelas

    2009-06-25

    This project was designed to test diamond, diamond-like and related materials in environments that are expected in thermochemical cycles. Our goals were to build a High Temperature Corrosion Resistance (HTCR) test stand and begin testing the corrosive properties of barious materials in a high temperature acidic environment in the first year. Overall, we planned to test 54 samples each of diamond and diamond-like films (of 1 cm x 1 cm area). In addition we use a corrosion acceleration method by treating the samples at a temperature much larger than the expected operating temperature. Half of the samples will be treated with boron using the FEDOA process.

  14. The evaluation of alternative thermochemical cycles-Part II the down selection process.

    SciTech Connect

    Lewis, M. A.; Masin, J. G.; Chemical Sciences and Engineering Division

    2009-01-01

    The Nuclear Hydrogen Initiative (NHI) of the U.S. Department of Energy's Office of Nuclear Energy Science and Technology is supporting an effort to reevaluate thermochemical cycles reported in the literature as having both promising efficiencies and proof-of-concept results. Nine cycles were identified. A group of universities was tasked with the evaluation of these cycles using the NHI consistent methodology for calculating efficiency and for recommending and conducting critical research needed to help in the down-selection process. Argonne National Laboratory coordinated these activities. This paper provides an overview of the program and summarizes the results of the down-selection process. Individual papers that contain the details of the research are provided by the universities.

  15. Cycle Evaluations of Reversible Chemical Reactions for Solar Thermochemical Energy Storage in Support of Concentrating Solar Power Generation Systems

    SciTech Connect

    Krishnan, Shankar; Palo, Daniel R.; Wegeng, Robert S.

    2010-07-25

    The production and storage of thermochemical energy is a possible route to increase capacity factors and reduce the Levelized Cost of Electricity from concentrated solar power generation systems. In this paper, we present the results of cycle evaluations for various thermochemical cycles, including a well-documented ammonia closed-cycle along with open- and closed-cycle versions of hydrocarbon chemical reactions. Among the available reversible hydrocarbon chemical reactions, catalytic reforming-methanation cycles are considered; specifically, various methane-steam reforming cycles are compared to the ammonia cycle. In some cases, the production of an intermediate chemical, methanol, is also included with some benefit being realized. The best case, based on overall power generation efficiency and overall plant capacity factor, was found to be an open cycle including methane-steam reforming, using concentrated solar energy to increase the chemical energy content of the reacting stream, followed by combustion to generate heat for the heat engine.

  16. Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

    SciTech Connect

    Brown, L.C.; Funk, J.F.; Showalter, S.K.

    1999-12-15

    OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study.

  17. Life cycle assessment of microalgae to biofuel: Thermochemical processing through hydrothermal liquefaction or pyrolysis

    NASA Astrophysics Data System (ADS)

    Bennion, Edward P.

    Microalgae are currently being investigated as a renewable transportation fuel feedstock based on various advantages that include high annual yields, utilization of poor quality land, does not compete with food, and can be integrated with various waste streams. This study focuses on directly assessing the impact of two different thermochemical conversion technologies on the microalgae-to-biofuel process through life cycle assessment. A system boundary of a "well to pump" (WTP) is defined and includes sub-process models of the growth, dewatering, thermochemical bio-oil recovery, bio-oil stabilization, conversion to renewable diesel, and transport to the pump. Models were validated with experimental and literature data and are representative of an industrial-scale microalgae-to-biofuel process. Two different thermochemical bio-oil conversion systems are modeled and compared on a systems level, hydrothermal liquefaction (HTL) and pyrolysis. The environmental impact of the two pathways were quantified on the metrics of net energy ratio (NER), defined here as energy consumed over energy produced, and greenhouse gas (GHG) emissions. Results for WTP biofuel production through the HTL pathway were determined to be 1.23 for the NER and GHG emissions of -11.4 g CO2 eq (MJ renewable diesel)-1. WTP biofuel production through the pyrolysis pathway results in a NER of 2.27 and GHG emissions of 210 g CO2 eq (MJ renewable diesel)-1. The large environmental impact associated with the pyrolysis pathway is attributed to feedstock drying requirements and combustion of co-products to improve system energetics. Discussion focuses on a detailed breakdown of the overall process energetics and GHGs, impact of modeling at laboratory-scale compared to industrial-scale, environmental impact sensitivity to engineering systems input parameters for future focused research and development, and a comparison of results to literature.

  18. Solar Thermochemical Fuels Production: Solar Fuels via Partial Redox Cycles with Heat Recovery

    SciTech Connect

    2011-12-19

    HEATS Project: The University of Minnesota is developing a solar thermochemical reactor that will efficiently produce fuel from sunlight, using solar energy to produce heat to break chemical bonds. The University of Minnesota is envisioning producing the fuel by using partial redox cycles and ceria-based reactive materials. The team will achieve unprecedented solar-to-fuel conversion efficiencies of more than 10% (where current state-of-the-art efficiency is 1%) by combined efforts and innovations in material development, and reactor design with effective heat recovery mechanisms and demonstration. This new technology will allow for the effective use of vast domestic solar resources to produce precursors to synthetic fuels that could replace gasoline.

  19. Thermochemical cycles for energy storage: Thermal decomposition of ZnCO sub 4 systems

    SciTech Connect

    Wentworth, W.E. )

    1992-04-01

    The overall objective of our research has been to develop thermochemical cycles that can be used for energy storage. A specific cycle involving ammonium hydrogen sulfate (NH{sub 4}HSO{sub 4}) has been proposed. Each reaction in the proposed cycle has been examined experimentally. Emphasis has been placed on the basic chemistry of these reactions. In the concluding phase of this research, reported herein, we have shown that when NH{sub 4}HSO{sub 4} is mixed with ZnO and decomposed, the resulting products can be released stepwise (H{sub 2}A{sub (g)} at {approximately}163{degrees}C, NH{sub 3(g)} at 365--418{degrees}C, and a mixture of SO{sub 2(g)} and SO{sub 3(g)} at {approximately}900{degrees}C) and separated by controlling the reaction temperature. Side reactions do not appear to be significant and the respective yields are high as would be required for the successful use of this energy storage reaction in the proposed cycle. Thermodynamic, kinetic, and other reaction parameters have been measured for the various steps of the reaction. Finally we have completed a detailed investigation of one particular reaction: the thermal decomposition of zinc sulfate (ZnSO{sub 4}). We have demonstrated that this reaction can be accelerated and the temperature required reduced by the addition of excess ZnO, V{sub 2}A{sub 5} and possibly other metal oxides.

  20. System and process for producing fuel with a methane thermochemical cycle

    SciTech Connect

    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.

  1. Solar Metal Sulfate-Ammonia Based Thermochemical Water Splitting Cycle for Hydrogen Production

    NASA Technical Reports Server (NTRS)

    Huang, Cunping (Inventor); T-Raissi, Ali (Inventor); Muradov, Nazim (Inventor)

    2014-01-01

    Two classes of hybrid/thermochemical water splitting processes for the production of hydrogen and oxygen have been proposed based on (1) metal sulfate-ammonia cycles (2) metal pyrosulfate-ammonia cycles. Methods and systems for a metal sulfate MSO.sub.4--NH3 cycle for producing H2 and O2 from a closed system including feeding an aqueous (NH3)(4)SO3 solution into a photoctalytic reactor to oxidize the aqueous (NH3)(4)SO3 into aqueous (NH3)(2)SO4 and reduce water to hydrogen, mixing the resulting aqueous (NH3)(2)SO4 with metal oxide (e.g. ZnO) to form a slurry, heating the slurry of aqueous (NH4)(2)SO4 and ZnO(s) in the low temperature reactor to produce a gaseous mixture of NH3 and H2O and solid ZnSO4(s), heating solid ZnSO4 at a high temperature reactor to produce a gaseous mixture of SO2 and O2 and solid product ZnO, mixing the gaseous mixture of SO2 and O2 with an NH3 and H2O stream in an absorber to form aqueous (NH4)(2)SO3 solution and separate O2 for aqueous solution, recycling the resultant solution back to the photoreactor and sending ZnO to mix with aqueous (NH4)(2)SO4 solution to close the water splitting cycle wherein gaseous H2 and O2 are the only products output from the closed ZnSO4--NH3 cycle.

  2. Conceptual design study FY 1981: synfuels from fusion - using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

    SciTech Connect

    Krikorian, O.H.

    1982-02-09

    This report represents the second year's effort of a scoping and conceptual design study being conducted for the express purpose of evaluating the engineering potential of producing hydrogen by thermochemical cycles using a tandem mirror fusion driver. The hydrogen thus produced may then be used as a feedstock to produce fuels such as methane, methanol, or gasoline. The main objective of this second year's study has been to obtain some approximate cost figures for hydrogen production through a conceptual design study.

  3. Stability of Supported Platinum Sulfuric Acid Decomposition Catalysts for use in Thermochemical Water Splitting Cycles

    SciTech Connect

    Daniel M. Ginosar; Lucia M. Petkovic; Anne W. Glenn; Kyle C. Burch

    2007-03-01

    The activity and stability of several metal oxide supported platinum catalysts were explored for the sulfuric acid decomposition reaction. The acid decomposition reaction is common to several sulfur based thermochemical water splitting cycles. Reactions were carried out using a feed of concentrated liquid sulfuric acid (96 wt%) at atmospheric pressure at temperatures between 800 and 850 °C and a weight hour space velocity of 52 g acid/g catalyst/hr. Reactions were run at these high space velocities such that variations in kinetics were not masked by surplus catalyst. The influence of exposure to reaction conditions was explored for three catalysts; 0.1-0.2 wt% Pt supported on alumina, zirconia and titania. The higher surface area Pt/Al2O3 and Pt/ZrO2 catalysts were found to have the highest activity but deactivated rapidly. A low surface area Pt/TiO2 catalyst was found to have good stability in short term tests, but slowly lost activity for over 200 hours of continuous operation.

  4. Advances in Acid Concentration Membrane Technology for the Sulfur-Iodine Thermochemical Cycle

    SciTech Connect

    Frederick F. Stewart; Christopher J. Orme

    2006-11-01

    One of the most promising cycles for the thermochemical generation of hydrogen is the Sulfur-Iodine (S-I) process, where aqueous HI is thermochemically decomposed into H2 and I2 at approximately 350 degrees Celsius. Regeneration of HI is accomplished by the Bunsen reaction (reaction of SO2, water, and iodine to generate H2SO4 and HI). Furthermore, SO2 is regenerated from the decomposition of H2SO4 at 850 degrees Celsius yielding the SO2 as well as O2. Thus, the cycle actually consists of two concurrent oxidation-reduction loops. As HI is regenerated, co-produced H2SO4 must be separated so that each may be decomposed. Current flowsheets employ a large amount (~83 mol% of the entire mixture) of elemental I2 to cause the HI and the H2SO4 to separate into two phases. To aid in the isolation of HI, which is directly decomposed into hydrogen, water and iodine must be removed. Separation of iodine is facilitated by removal of water. Sulfuric acid concentration is also required to facilitate feed recycling to the sulfuric acid decomposer. Decomposition of the sulfuric acid is an equilibrium limited process that leaves a substantial portion of the acid requiring recycle. Distillation of water from sulfuric acid involves significant corrosion issues at the liquid-vapor interface. Thus, it is desirable to concentrate the acid without boiling. Recent efforts at the INL have concentrated on applying pervaporation through Nafion-117, Nafion-112, and sulfonated poly(etheretherketone) (S-PEEK) membranes for the removal of water from HI/water and HI/Iodine/water feedstreams. In pervaporation, a feed is circulated at low pressure across the upstream side of the membrane, while a vacuum is applied downstream. Selected permeants sorb into the membrane, transport through it, and are vaporized from the backside. Thus, a concentration gradient is established, which provides the driving force for transport. In this work, membrane separations have been performed at temperatures as high as

  5. Chemical equilibria involved in the oxygen-releasing step of manganese ferrite water-splitting thermochemical cycle

    SciTech Connect

    Seralessandri, L.; Bellusci, M.; Alvani, C.; La Barbera, A.; Padella, F.; Varsano, F.

    2008-08-15

    Sodium ferrimanganite carbonatation reaction was investigated at different temperatures/carbon dioxide partial pressures to evaluate the feasibility of the thermochemical water-splitting cycle based on the MnFe{sub 2}O{sub 4}/Na{sub 2}CO{sub 3}/Na(Mn{sub 1/3}Fe{sub 2/3})O{sub 2} system. After thermal treatments in selected experimental conditions, the obtained powder samples were investigated by using the X-ray diffraction (XRD) technique and Rietveld analysis. Two different lamellar Na{sub 1-x}Mn{sub 1/3}Fe{sub 2/3}O{sub 2-{delta}} phases were observed together with the expected MnFe{sub 2}O{sub 4}/Na{sub 2}CO{sub 3} mixture. Different equilibrium regions among sodium-depleted lamellar phases, manganese ferrite and sodium carbonate were found as a function of the different reaction conditions. A hypothesis concerning the regeneration mechanism of the initial compounds is proposed. Chemical equilibrium between stoichiometric and sub-stoichiometric forms of sodium ferrimanganite and sodium carbonate formation/dissociation appears to be essential factors governing the oxygen-releasing step of the manganese ferrite thermochemical cycle. - Graphical abstract: Na(Mn{sub 1/3}Fe{sub 2/3})O{sub 2} disproportion reaction in the presence of CO{sub 2} was studied. Chemical equilibria among Na{sub 1-x}(Mn{sub 1/3}Fe{sub 2/3})O{sub 2}, MnFe{sub 2}O{sub 4} and Na{sub 2}CO{sub 3} compounds were evidenced and studied by means of Rietveld analysis performed on XRD patterns. Two different sodium-depleted lamellar structures were identified. The role of sodium carbonate formation/dissociation equilibrium in the oxygen-releasing step of the manganese ferrite thermochemical cycle has been highlighted.

  6. Commercial Activated Carbon for the Catalytic Production of Hydrogen via the Sulfur-Iodine Thermochemical Water Splitting Cycle

    SciTech Connect

    Daniel M. Ginosar; Lucia M. Petkovic; Kyle C. Burch

    2011-07-01

    Eight activated carbon catalysts were examined for their catalytic activity to decompose hydroiodic acid (HI) to produce hydrogen; a key reaction in the sulfur-iodine (S-I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773 K. No statistically significant correlation was found between catalyst sample properties and catalytic activity. Four of the eight samples were examined for one week of continuous operation at 723 K. All samples appeared to be stable over the period of examination.

  7. Bioenergy co-products derived from microalgae biomass via thermochemical conversion--life cycle energy balances and CO2 emissions.

    PubMed

    Khoo, H H; Koh, C Y; Shaik, M S; Sharratt, P N

    2013-09-01

    An investigation of the potential to efficiently convert lipid-depleted residual microalgae biomass using thermochemical (gasification at 850 °C, pyrolysis at 550 °C, and torrefaction at 300 °C) processes to produce bioenergy derivatives was made. Energy indicators are established to account for the amount of energy inputs that have to be supplied to the system in order to gain 1 MJ of bio-energy output. The paper seeks to address the difference between net energy input-output balances based on a life cycle approach, from "cradle-to-bioenergy co-products", vs. thermochemical processes alone. The experimental results showed the lowest results of Net Energy Balances (NEB) to be 0.57 MJ/MJ bio-oil via pyrolysis, and highest, 6.48 MJ/MJ for gas derived via torrefaction. With the complete life cycle process chain factored in, the energy balances of NEBLCA increased to 1.67 MJ/MJ (bio-oil) and 7.01 MJ/MJ (gas). Energy efficiencies and the life cycle CO2 emissions were also calculated. PMID:23810951

  8. Kinetics of Thermochemical Reactions Important in the Venus Atmospheric Sulfur Cycle

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.

    1997-01-01

    The purpose of this project was to experimentally measure the rates of several thermochemical gas-solid reactions between sulfur gases in the Venus atmosphere and reactive minerals on the hot Venus surface. Despite the great importance of these reactions for the maintenance of significant amounts of sulfur gases (and thus for the maintenance of the global cloud cover) in the atmosphere of Venus, essentially no kinetic data are currently available for them.

  9. Kinetics of thermochemical gas-solid reactions important in the Venus sulfur cycle

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.

    1988-01-01

    The thermochemical net reaction CaCO3 + SO2 yields CaSO4 + CO is predicted to be an important sink for incorporation of SO2 into the Venus crust. The reaction rate law was established to understand the dependence of rate on experimental variables such as temperature and partial pressure of SO2, CO2, and O2. The experimental approach was a variant of the thermogravimetric method often employed to study the kinetics of thermochemical gas-solid reactions. Clear calcite crystals were heated at constant temperature in SO2-bearing gas streams for varying time periods. Reaction rate was determined by three independent methods. A weighted linear least squares fit to all rate data yielded a rate equation. Based on the Venera 13, 14 and Vega 2 observations of CaO content of the Venus atmosphere, SO2 at the calculated rate would be removed from the Venus atmosphere in about 1,900,00 years. The most plausible endogenic source of the sulfur needed to replenish atmospheric SO2 is volcanism. The annual amount of erupted material needed for the replenishment depends on sulfur content; three ratios are used to calculate rates ranging from 0.4 to 11 cu km/year. This geochemically derived volcanism rate can be used to test if geophysically derived rates are correct. The work also suggests that Venus is less volcanically active than the Earth.

  10. Pt/TiO2 (Rutile) Catalysts for Sulfuric Acid Decomposition in Sulfur-Based Thermochemical Water-Splitting Cycles

    SciTech Connect

    L. M. Petkovic; D. M. Ginosar; H. W. Rollins; K. C. Burch; P. J. Pinhero; H. H. Farrell

    2008-04-01

    Thermochemical cycles consist of a series of chemical reactions to produce hydrogen from water at lower temperatures than by direct thermal decomposition. All the sulfur-based cycles for water splitting employ the sulfuric acid decomposition reaction. This work reports the studies performed on platinum supported on titania (rutile) catalysts to investigate the causes of catalyst deactivation under sulfuric acid decomposition reaction conditions. Samples of 1 wt% Pt/TiO2 (rutile) catalysts were submitted to flowing concentrated sulfuric acid at 1123 K and atmospheric pressure for different times on stream (TOS) between 0 and 548 h. Post-operation analyses of the spent catalyst samples showed that Pt oxidation and sintering occurred under reaction conditions and some Pt was lost by volatilization. Pt loss rate was higher at initial times but total loss appeared to be independent of the gaseous environment. Catalyst activity showed an initial decrease that lasted for about 66 h, followed by a slight recovery of activity between 66 and 102 h TOS, and a period of slower deactivation after 102 h TOS. Catalyst sulfation did not seem to be detrimental to catalyst activity and the activity profile suggested that a complex dynamical situation involving platinum sintering, volatilization, and oxidation, along with TiO2 morphological changes affected catalyst activity in a non-monotonic way.

  11. Thermochemical CO2 splitting via redox cycling of ceria reticulated foam structures with dual-scale porosities.

    PubMed

    Furler, Philipp; Scheffe, Jonathan; Marxer, Daniel; Gorbar, Michal; Bonk, Alexander; Vogt, Ulrich; Steinfeld, Aldo

    2014-06-14

    Efficient heat transfer of concentrated solar energy and rapid chemical kinetics are desired characteristics of solar thermochemical redox cycles for splitting CO2. We have fabricated reticulated porous ceramic (foam-type) structures made of ceria with dual-scale porosity in the millimeter and micrometer ranges. The larger void size range, with dmean = 2.5 mm and porosity = 0.76-0.82, enables volumetric absorption of concentrated solar radiation for efficient heat transfer to the reaction site during endothermic reduction, while the smaller void size range within the struts, with dmean = 10 μm and strut porosity = 0-0.44, increases the specific surface area for enhanced reaction kinetics during exothermic oxidation with CO2. Characterization is performed via mercury intrusion porosimetry, scanning electron microscopy, and thermogravimetric analysis (TGA). Samples are thermally reduced at 1773 K and subsequently oxidized with CO2 at temperatures in the range 873-1273 K. On average, CO production rates are ten times higher for samples with 0.44 strut porosity than for samples with non-porous struts. The oxidation rate scales with specific surface area and the apparent activation energy ranges from 90 to 135.7 kJ mol(-1). Twenty consecutive redox cycles exhibited stable CO production yield per cycle. Testing of the dual-scale RPC in a solar cavity-receiver exposed to high-flux thermal radiation (3.8 kW radiative power at 3015 suns) corroborated the superior performance observed in the TGA, yielding a shorter cycle time and a mean solar-to-fuel energy conversion efficiency of 1.72%. PMID:24736455

  12. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    SciTech Connect

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  13. Life cycle assessment of hydrogen production from S-I thermochemical process coupled to a high temperature gas reactor

    SciTech Connect

    Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D.

    2012-07-01

    The purpose of this paper is to quantify the greenhouse gas (GHG) emissions associated to the hydrogen produced by the sulfur-iodine thermochemical process, coupled to a high temperature nuclear reactor, and to compare the results with other life cycle analysis (LCA) studies on hydrogen production technologies, both conventional and emerging. The LCA tool was used to quantify the impacts associated with climate change. The product system was defined by the following steps: (i) extraction and manufacturing of raw materials (upstream flows), (U) external energy supplied to the system, (iii) nuclear power plant, and (iv) hydrogen production plant. Particular attention was focused to those processes where there was limited information from literature about inventory data, as the TRISO fuel manufacture, and the production of iodine. The results show that the electric power, supplied to the hydrogen plant, is a sensitive parameter for GHG emissions. When the nuclear power plant supplied the electrical power, low GHG emissions were obtained. These results improve those reported by conventional hydrogen production methods, such as steam reforming. (authors)

  14. Activated Carbon Catalysts for the Production of Hydrogen for the Sulfur-Iodine Thermochemical Water Splitting Cycle

    SciTech Connect

    Lucia M. Petkovic; Daniel M. Ginosar; Harry W. Rollins; Kyle C Burch; Cristina Deiana; Hugo S. Silva; Maria F. Sardella; Dolly Granados

    2009-05-01

    Seven activated carbon catalysts obtained from a variety of raw material sources and preparation methods were examined for their catalytic activity to decompose hydroiodic acid (HI) to produce hydrogen; a key reaction in the sulfur-iodine (S-I) thermochemical water splitting cycle. Activity was examined under a temperature ramp from 473 to 773 K. Within the group of ligno-cellulosic steam-activated carbon catalysts, activity increased with surface area. However, both a mineral-based steam-activated carbon and a ligno-cellulosic chemically-activated carbon displayed activities lower than expected based on their higher surface areas. In general, ash content was detrimental to catalytic activity while total acid sites, as determined by Bohem’s titrations, seemed to favor higher catalytic activity within the group of steam-activated carbons. These results suggest, one more time, that activated carbon raw materials and preparation methods may have played a significant role in the development of surface characteristics that eventually dictated catalyst activity and stability as well.

  15. Thermochemical breakthroughs

    SciTech Connect

    Schiefelbein, G.F.

    1985-08-01

    Biomass is an important energy resource at present and offers excellent potential for increased energy impact in the future. Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion to higher valued energy products. Thermochemical processes are well suited for conversion of these materials. In this paper, research sponsored by the US Department of Energy's Biomass Thermochemical Conversion Program to convert biomass into higher valued energy forms is discussed. Pacific Northwest Laboratory serves as the Field Management Office for the Biomass Thermochemical Conversion Program. 20 refs., 10 figs., 2 tabs.

  16. Solar Thermochemical Energy Storage Through Carbonation Cycles of SrCO3/SrO Supported on SrZrO3.

    PubMed

    Rhodes, Nathan R; Barde, Amey; Randhir, Kelvin; Li, Like; Hahn, David W; Mei, Renwei; Klausner, James F; AuYeung, Nick

    2015-11-01

    Solar thermochemical energy storage has enormous potential for enabling cost-effective concentrated solar power (CSP). A thermochemical storage system based on a SrO/SrCO3 carbonation cycle offers the ability to store and release high temperature (≈1200 °C) heat. The energy density of SrCO3/SrO systems supported by zirconia-based sintering inhibitors was investigated for 15 cycles of exothermic carbonation at 1150 °C followed by decomposition at 1235 °C. A sample with 40 wt % of SrO supported by yttria-stabilized zirconia (YSZ) shows good energy storage stability at 1450 MJ m(-3) over fifteen cycles at the same cycling temperatures. After further testing over 45 cycles, a decrease in energy storage capacity to 1260 MJ m(-3) is observed during the final cycle. The decrease is due to slowing carbonation kinetics, and the original value of energy density may be obtained by lengthening the carbonation steps. PMID:26435332

  17. Brominated dibenzofurans

    Integrated Risk Information System (IRIS)

    Brominated dibenzofurans ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  18. Bromine Safety

    SciTech Connect

    Meyers, B

    2001-04-09

    The production and handling in 1999 of about 200 million kilograms of bromine plus substantial derivatives thereof by Great Lakes Chemical Corp. and Albemarle Corporation in their southern Arkansas refineries gave OSHA Occupational Injury/Illness Rates (OIIR) in the range of 0.74 to 1.60 reportable OIIRs per 200,000 man hours. OIIRs for similar industries and a wide selection of other U.S. industries range from 1.6 to 23.9 in the most recent OSHA report. Occupational fatalities for the two companies in 1999 were zero compared to a range in the U.S.of zero for all computer manufacturing to 0.0445 percent for all of agriculture, forestry and fishing in the most recent OSHA report. These results show that bromine and its compounds can be considered as safe chemicals as a result of the bromine safety standards and practices at the two companies. The use of hydrobromic acid as an electrical energy storage medium in reversible PEM fuel cells is discussed. A study in 1979 of 20 megawatt halogen working fluid power plants by Oronzio de Nora Group found such energy to cost 2 to 2.5 times the prevailing base rate at that time. New conditions may reduce this relative cost. The energy storage aspect allows energy delivery at maximum demand times where the energy commands premium rates. The study also found marginal cost and performance advantages for hydrobromic acid over hydrochloric acid working fluid. Separate studies in the late 70s by General Electric also showed marginal performance advantages for hydrobromic acid.

  19. Bromination of Phenol

    ERIC Educational Resources Information Center

    Talbot, Christopher

    2013-01-01

    This "Science note" examines the bromination of phenol, a reaction that is commonly taught at A-level and IB (International Baccalaureate) as an example of electrophilic substitution. Phenol undergoes bromination with bromine or bromine water at room temperature. A white precipitate of 2,4,6-tribromophenol is rapidly formed. This…

  20. Cesium Neonide: Molecule or Thermochemical Exercise?

    ERIC Educational Resources Information Center

    Blake, P. G.; Clack, D. W.

    1982-01-01

    Thermochemical cycles are used to decide which hypothetical compounds might exist and, if not, what is the factor that condemns them to non-existence. Hypothetical compounds of rare gases provide examples of the approach with added historical interest that thermochemical considerations led to prediction and demonstration that XePtF-6 was stable.…

  1. Thermochemical cycles for energy storage: Thermal decomposition of ZnCO{sub 4} systems. Final topical report, January 1, 1982--December 31, 1984

    SciTech Connect

    Wentworth, W.E.

    1992-04-01

    The overall objective of our research has been to develop thermochemical cycles that can be used for energy storage. A specific cycle involving ammonium hydrogen sulfate (NH{sub 4}HSO{sub 4}) has been proposed. Each reaction in the proposed cycle has been examined experimentally. Emphasis has been placed on the basic chemistry of these reactions. In the concluding phase of this research, reported herein, we have shown that when NH{sub 4}HSO{sub 4} is mixed with ZnO and decomposed, the resulting products can be released stepwise (H{sub 2}A{sub (g)} at {approximately}163{degrees}C, NH{sub 3(g)} at 365--418{degrees}C, and a mixture of SO{sub 2(g)} and SO{sub 3(g)} at {approximately}900{degrees}C) and separated by controlling the reaction temperature. Side reactions do not appear to be significant and the respective yields are high as would be required for the successful use of this energy storage reaction in the proposed cycle. Thermodynamic, kinetic, and other reaction parameters have been measured for the various steps of the reaction. Finally we have completed a detailed investigation of one particular reaction: the thermal decomposition of zinc sulfate (ZnSO{sub 4}). We have demonstrated that this reaction can be accelerated and the temperature required reduced by the addition of excess ZnO, V{sub 2}A{sub 5} and possibly other metal oxides.

  2. 49 CFR 173.228 - Bromine pentafluoride or bromine trifluoride.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Bromine pentafluoride or bromine trifluoride. 173... Class 1 and Class 7 § 173.228 Bromine pentafluoride or bromine trifluoride. (a) Bromine pentafluoride and bromine trifluoride are authorized in packagings as follows: (1) Specification 3A150,...

  3. 49 CFR 173.228 - Bromine pentafluoride or bromine trifluoride.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Bromine pentafluoride or bromine trifluoride. 173... Class 1 and Class 7 § 173.228 Bromine pentafluoride or bromine trifluoride. (a) Bromine pentafluoride and bromine trifluoride are authorized in packagings as follows: (1) Specification 3A150,...

  4. 49 CFR 173.228 - Bromine pentafluoride or bromine trifluoride.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bromine pentafluoride or bromine trifluoride. 173... Class 1 and Class 7 § 173.228 Bromine pentafluoride or bromine trifluoride. (a) Bromine pentafluoride and bromine trifluoride are authorized in packagings as follows: (1) Specification 3A150,...

  5. 49 CFR 173.228 - Bromine pentafluoride or bromine trifluoride.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Bromine pentafluoride or bromine trifluoride. 173... Class 1 and Class 7 § 173.228 Bromine pentafluoride or bromine trifluoride. (a) Bromine pentafluoride and bromine trifluoride are authorized in packagings as follows: (1) Specification 3A150,...

  6. 49 CFR 173.228 - Bromine pentafluoride or bromine trifluoride.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Bromine pentafluoride or bromine trifluoride. 173... Class 1 and Class 7 § 173.228 Bromine pentafluoride or bromine trifluoride. (a) Bromine pentafluoride and bromine trifluoride are authorized in packagings as follows: (1) Specification 3A150,...

  7. Enhanced hydrogen production by doping Pr into Ce0.9Hf0.1O2 for thermochemical two-step water-splitting cycle

    NASA Astrophysics Data System (ADS)

    Meng, Qing-Long; Tamaura, Yutaka

    2014-03-01

    We synthesized (Ce0.9Hf0.1)1-xPrxO2-δ (x=0, 0.05 and 0.1) using the polymerized complex method. The synthesized samples, as well as the samples after thermochemical two-step water-splitting cycles have a fluorite structure and Pr exists in the solid solutions with both trivalent and tetravalent states, as suggested by powder X-ray Diffraction (XRD) Patterns. The reduction fraction of Ce4+ in redox cycles (oxidation step in air) and two-step water-splitting cycles (oxidation step in steam) indicates that the addition of Pr into Ce-Hf oxide solid solution cannot improve the reduction fraction of Ce4+ during the redox cycles but both the reduction fraction of Ce4+ and H2 yield are significantly enhanced during two-step water-splitting cycles. The chemical composition of 10 mol% Pr doped Ce0.9Hf0.1O2 exhibits the highest reactivity for hydrogen production in H2-generation step by yielding an average amount of 5.72 ml g-1 hydrogen gas, which is much higher than that evolved by Ce0.9Hf0.1O2 (4.50 ml g-1). The enhancement effect of doping Pr on the performance during two-step water-splitting cycles is because of the multivalent properties of Pr, which can: (1) reduce the amount of Ce3+ oxidized by contamination air (contamination air eliminated by partial oxidation of Pr3+ to Pr4+) in H2-generation step; (2) enhance the reaction rate in H2-generation step by improving the ionic conductivity (extrinsic oxygen vacancies created by the substitution of Ce4+ by Pr3+).

  8. Thermochemical generation of hydrogen

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Petersen, G. R. (Inventor)

    1982-01-01

    The direct fluid contact heat exchange with H2SO4 at about 330 C prior to high temperature decomposition at about 830 C in the oxygen release step of several thermochemical cycles for splitting water into hydrogen and oxygen provides higher heat transfer rates, savings in energy and permits use of cast vessels rather than expensive forged alloy indirect heat exchangers. Among several candidate perfluorocarbon liquids tested, only perfluoropropylene oxide polymers having a degree of polymerization from about 10 to 60 were chemically stable, had low miscibility and vapor pressure when tested with sulfuric acid at temperatures from 300 C to 400 C.

  9. Thermochemical Production of Hydrogen from Water.

    ERIC Educational Resources Information Center

    Bamberger, C. E.; And Others

    1978-01-01

    Discusses the possible advantages of decomposing water by means of thermochemical cycles. Explains that, if energy consumption can be minimized, this method is capable of producing hydrogen more efficiently than electrolysis. (GA)

  10. Innovative solar thermochemical water splitting.

    SciTech Connect

    Hogan, Roy E. Jr.; Siegel, Nathan P.; Evans, Lindsey R.; Moss, Timothy A.; Stuecker, John Nicholas; Diver, Richard B., Jr.; Miller, James Edward; Allendorf, Mark D.; James, Darryl L.

    2008-02-01

    Sandia National Laboratories (SNL) is evaluating the potential of an innovative approach for splitting water into hydrogen and oxygen using two-step thermochemical cycles. Thermochemical cycles are heat engines that utilize high-temperature heat to produce chemical work. Like their mechanical work-producing counterparts, their efficiency depends on operating temperature and on the irreversibility of their internal processes. With this in mind, we have invented innovative design concepts for two-step solar-driven thermochemical heat engines based on iron oxide and iron oxide mixed with other metal oxides (ferrites). The design concepts utilize two sets of moving beds of ferrite reactant material in close proximity and moving in opposite directions to overcome a major impediment to achieving high efficiency--thermal recuperation between solids in efficient counter-current arrangements. They also provide inherent separation of the product hydrogen and oxygen and are an excellent match with high-concentration solar flux. However, they also impose unique requirements on the ferrite reactants and materials of construction as well as an understanding of the chemical and cycle thermodynamics. In this report the Counter-Rotating-Ring Receiver/Reactor/Recuperator (CR5) solar thermochemical heat engine and its basic operating principals are described. Preliminary thermal efficiency estimates are presented and discussed. Our ferrite reactant material development activities, thermodynamic studies, test results, and prototype hardware development are also presented.

  11. Purified Brominated Indole Derivatives from Dicathais orbita Induce Apoptosis and Cell Cycle Arrest in Colorectal Cancer Cell Lines

    PubMed Central

    Esmaeelian, Babak; Benkendorff, Kirsten; Johnston, Martin R.; Abbott, Catherine A.

    2013-01-01

    Dicathais orbita is a large Australian marine gastropod known to produce bioactive compounds with anticancer properties. In this research, we used bioassay guided fractionation from the egg mass extract of D. orbita using flash column chromatography and identified fractions containing tyrindoleninone and 6-bromoisatin as the most active against colon cancer cells HT29 and Caco-2. Liquid chromatography coupled with mass spectrometry (LCMS) and 1H NMR were used to characterize the purity and chemical composition of the isolated compounds. An MTT assay was used to determine effects on cell viability. Necrosis and apoptosis induction using caspase/LDH assay and flow cytometry (PI/Annexin-V) and cell cycle analysis were also investigated. Our results show that semi-purified 6-bromoisatin had the highest anti-cancer activity by inhibiting cell viability (IC50 = ~100 µM) and increasing caspase 3/7 activity in both of the cell lines at low concentration. The fraction containing 6-bromoisatin induced 77.6% apoptosis and arrested 25.7% of the cells in G2/M phase of cell cycle in HT29 cells. Tyrindoleninone was less potent but significantly decreased the viability of HT29 cells at IC50 = 390 µM and induced apoptosis at 195 µM by increasing caspase 3/7 activity in these cells. This research will facilitate the development of these molluscan natural products as novel complementary medicines for colorectal cancer. PMID:24152558

  12. Thermochemical water-splitting cycle, bench-scale investigations, and process engineering. Final report, February 1977-December 31, 1981

    SciTech Connect

    Norman, J.H.; Besenbruch, G.E.; Brown, L.C.; O'Keefe, D.R.; Allen, C.L.

    1982-05-01

    The sulfur-iodine water-splitting cycle is characterized by the following three reactions: 2H/sub 2/O + SO/sub 2/ + I/sub 2/ ..-->.. H/sub 2/SO/sub 4/ + 2HI; H/sub 2/SO/sub 4/ ..-->.. H/sub 2/O + SO/sub 2/ + 1/2 O/sub 2/; and 2HI ..-->.. H/sub 2/ + I/sub 2/. This cycle was developed at General Atomic after several critical features in the above reactions were discovered. These involved phase separations, catalytic reactions, etc. Estimates of the energy efficiency of this economically reasonable advanced state-of-the-art processing unit produced sufficiently high values (to approx.47%) to warrant cycle development effort. The DOE contract was largely directed toward the engineering development of this cycle, including a small demonstration unit (CLCD), a bench-scale unit, engineering design, and costing. The work has resulted in a design that is projected to produce H/sub 2/ at prices not yet generally competitive with fossil-fuel-produced H/sub 2/ but are projected to be favorably competitive with respect to H/sub 2/ from fossil fuels in the future.

  13. Hydrolysis of CuCl{sub 2} in the Cu-Cl thermochemical cycle for hydrogen production : experimental studies using a spray reactor with an ultrasonic atomizer.

    SciTech Connect

    Ferrandon, M. S.; Lewis, M. A.; Alvarez, F.; Shafirovich, E.; Chemical Sciences and Engineering Division; Univ. of Texas at El Paso

    2010-03-01

    The Cu-Cl thermochemical cycle is being developed as a hydrogen production method. Prior proof-of-concept experimental work has shown that the chemistry is viable while preliminary modeling has shown that the efficiency and cost of hydrogen production have the potential to meet DOE's targets. However, the mechanisms of CuCl{sub 2} hydrolysis, an important step in the Cu-Cl cycle, are not fully understood. Although the stoichiometry of the hydrolysis reaction, 2CuCl{sub 2} + H{sub 2}O {leftrightarrow} Cu{sub 2}OCl{sub 2} + 2HCl, indicates a necessary steam-to-CuCl{sub 2} molar ratio of 0.5, a ratio as high as 23 has been typically required to obtain near 100% conversion of the CuCl{sub 2} to the desired products at atmospheric pressure. It is highly desirable to conduct this reaction with less excess steam to improve the process efficiency. Per Le Chatelier's Principle and according to the available equilibrium-based model, the needed amount of steam can be decreased by conducting the hydrolysis reaction at a reduced pressure. In the present work, the experimental setup was modified to allow CuCl{sub 2} hydrolysis in the pressure range of 0.4-1 atm. Chemical and XRD analyses of the product compositions revealed the optimal steam-to-CuCl{sub 2} molar ratio to be 20-23 at 1 atm pressure. The experiments at 0.4 atm and 0.7 atm showed that it is possible to lower the steam-to-CuCl{sub 2} molar ratio to 15, while still obtaining good yields of the desired products. An important effect of running the reaction at reduced pressure is the significant decrease of CuCl concentration in the solid products, which was not predicted by prior modeling. Possible explanations based on kinetics and residence times are suggested.

  14. Hydrogen/bromine cell

    SciTech Connect

    Hohne, K.; Starbeck, G.

    1985-05-28

    Described herein is an energy storage device which utilizes a hydrogen/bromine cell. The cell includes a bromine electrode and a hydrogen electrode. The cell is light weight, resists corrosion caused by bromine or hydrobromic acid and uses both an electrolysis and a fuel cell reaction to store or discharge electrical energy. The cell frame is made of graphite and has a pyrographite coating on at least the portion facing the bromine electrode. This cell is therefore very useful in matching varying energy supplies with varying energy demands and allows for decentralization of energy storage.

  15. Thermochemical production of hydrogen

    DOEpatents

    Dreyfuss, Robert M.

    1976-07-13

    A thermochemical reaction cycle for the generation of hydrogen from water comprising the following sequence of reactions wherein M represents a metal and Z represents a metalloid selected from the arsenic-antimony-bismuth and selenium-tellurium subgroups of the periodic system: 2MO + Z + SO.sub.2 .fwdarw. MZ + MSO.sub.4 (1) mz + h.sub.2 so.sub.4 .fwdarw. mso.sub.4 + h.sub.2 z (2) 2mso.sub.4 .fwdarw. 2mo + so.sub.2 + so.sub.3 + 1/20.sub.2 (3) h.sub.2 z .fwdarw. z + h.sub.2 (4) h.sub.2 o + so.sub.3 .fwdarw. h.sub.2 so.sub.4 (5) the net reaction is the decomposition of water into hydrogen and oxygen.

  16. Measurements of stratospheric bromine

    NASA Technical Reports Server (NTRS)

    Sedlacek, W. A.; Lazrus, A. L.; Gandrud, B. W.

    1984-01-01

    From 1974 to 1977, molecules containing acidic bromine were sampled in the stratosphere by using tetrabutyl ammonium hydroxide impregnated filters. Sampling was accomplished by WB-57F aircraft and high-altitude balloons, spanning latitudes from the equator to 75 deg N and altitudes up to 36.6 km. Analytical results are reported for 4 years of measurements and for laboratory simulations that determined the filter collection efficiencies for a number of brominated species. Mass mixing ratios for the collected bromine species in air average about 27 pptm in the stratosphere. Seasonal variability seems to be small.

  17. Solid bromine complexers

    DOEpatents

    Grimes, Patrick G.

    1987-01-20

    The cell of the invention comprises a housing, a zinc or cadmium anode, a chemically non-reactive counterelectrode and cathodic halogen. The cathodic halogen is selected from chlorine and bromine, and preferably is bromine. The cell also is provided with an aqueous metal halide containing electrolyte in which the metal ions are of the same metal as the metal of the anode and halide anions are of the same halogen as the cathodic halogen material. Importantly, in the present invention, anion exchange resins provide a convenient means for storing the halogen generated during charging of the cell and providing a source of halogen to be used in the discharge of the cell.

  18. Brominated Flame Retardants

    EPA Science Inventory

    Brominated flame retardants (BFRs) belong to a large class of compounds known as organohalogens. BFRs are currently the largest marketed flame retardant group due to their high performance efficiency and low cost. In the commercial market, more than 75 different BFRs are recogniz...

  19. Capabilities to Support Thermochemical Hydrogen Production Technology Development

    SciTech Connect

    Daniel M. Ginosar

    2009-05-01

    This report presents the results of a study to determine if Idaho National Laboratory (INL) has the skilled staff, instrumentation, specialized equipment, and facilities required to take on work in thermochemical research, development, and demonstration currently being performed by the Nuclear Hydrogen Initiative (NHI). This study outlines the beneficial collaborations between INL and other national laboratories, universities, and industries to strengthen INL's thermochemical efforts, which should be developed to achieve the goals of the NHI in the most expeditious, cost effective manner. Taking on this work supports INL's long-term strategy to maintain leadership in thermochemical cycle development. This report suggests a logical path forward to accomplish this transition.

  20. Bromine-Chlorine Coupling in the Antarctic Ozone Hole

    NASA Technical Reports Server (NTRS)

    Danilin, Michael Y.; Sze, Nien-Dak; Ko, Malcolm K. W.; Rodriquez, Jose M.; Prather, Michael J.

    1996-01-01

    The contribution from the chlorine and bromine species in the formation of the Antarctic ozone hole is evaluated. Since chlorine and bromine compounds are of different industrial origin, it is desirable, from a policy point of view, to be able to attribute chlorine-catalyzed loss of ozone with those reactions directly involving chlorine species, and likewise for bromine-catalyzed loss. In the stratosphere, however, most of the chemical families are highly coupled, and, for example, changes in the chlorine abundance will alter the partitioninig in other families and thus the rate of ozone loss. This modeling study examines formation of the Antarctic ozone hole for a wide range of bromine concentrations (5 - 25 pptv) and for chlorine concentrations typical of the last two decades (1.5, 2.5 and 3.5 ppbv). We follow the photochemical evolution of a single parcel of air, typical of the inner Antarctic vortex (50 mbar, 70 deg. S, NO(sub y) = 2 ppbv, with Polar Stratospheric Clouds(PSC)) from August 1 to November 1. For all of these ranges of chlorine and bromine loading, we would predict a substantial ozone hole (local depletion greater than 90%) within the de-nitrified, PSC- perturbed vortex. The contributions of the different catalytic cycles responsible for ozone loss are tabulated. The deep minimum in ozone is driven primarily by the chlorine abundance. As bromine levels decrease, the magnitude of the chlorine-catalyzed ozone loss increases to take up the slack. This is because bromine suppresses ClO by accelerating the conversion of ClO an Cl2O2 back to HCI. For this range of conditions, the local relative efficiency of ozone destruction per bromine atom to that per chlorine atom (alpha-factor) ranges from 33 to 55, decreasing with increase of bromine.

  1. Bromination of marine particulate organic matter through oxidative mechanisms

    NASA Astrophysics Data System (ADS)

    Leri, Alessandra C.; Mayer, Lawrence M.; Thornton, Kathleen R.; Ravel, Bruce

    2014-10-01

    Although bromine (Br) is considered conservative in seawater, it exhibits a well established correlation with organic carbon in marine sediments. This carbon-bromine association was recently attributed to covalent bonding, with organobromine in sinking particulates providing a putative link between sedimentary organobromine and organic matter cycling in surface waters. We hypothesized that phytoplankton detritus, a major precursor of sedimentary organic matter, would be susceptible to bromination through oxidative attack. Through a series of model experiments, we demonstrate incorporation of Br into algal particulate detritus through peroxidative and photochemical mechanisms. Peroxidative bromination was enhanced by addition of exogenous bromoperoxidase, but the enzyme was not required for the reaction. Fenton-like reaction conditions also promoted bromination, especially under solar irradiation, implicating radical mechanisms in the euphotic zone as another abiotic source of brominated particulates. These reactions produced aliphatic and aromatic forms of organobromine, suggesting that lipid- and protein-rich components of algal membranes provide suitable substrates for bromination. Biogenic organobromines in certain genera of phytoplankton also appeared in both aliphatic and aromatic forms. Experimental evidence and samples from oceanic midwater sediment traps imply that the aromatic fraction is more stable than the aliphatic. These experiments establish Br as a versatile oxidant in the transformation of planktonic organic matter through both enzymatic and abiotic mechanisms. Organobromine may serve as a marker of oxidative breakdown of marine organic detritus, with the metastable component providing a short-lived indicator of early-stage oxidation. By altering the stability of aliphatic and aromatic moieties, bromination may affect the availability of organic matter to organisms, with consequences for the preservation and degradation of marine organic carbon.

  2. Bromine function in halite geochemistry

    SciTech Connect

    Billo, S.M. )

    1991-06-01

    Of the halogens or salt formers, bromine is the only nonmetal which occurs naturally as a poisonous liquid much denser than water. The power of its atoms, expressed by a valence of 1 and 5, makes it unite directly with a large number of metallic elements to form salts. As a rare and strongly electronegative element of group VII in the periodic table, bromine exists in seawater and evaporitic brines as bromide with a ratio to chlorinity of 0.00348. Most water detains only about 1 ppm bromide for each 300 ppm of chloride. The most abundant source of bromine is ocean water (65 ppm Br), but richer peps occur in salt deposits and primarily in mineral brines. Atomic absorption spectrophotometric resolutions of Permian Castile halites exposed low values of bromine compared with its higher quantities in modern oceans like the Mediterranean. Bromine analyses of the two petrographically distinct forms of halite that characterize many ancient evaporite deposits, as in the Elk Point basin fields of Alberta, imply they crystallized from brines of noticeably different concentrations. Bromine in halite has been used as a paleosalinity indicator and a stratigraphic marker. Bromine liquid, with an atomic weight of 79.904 and atomic number 35, is used in producing gasoline antiknock mixtures, fumigants, photographic chemicals, drilling fluids, and fire retardants. It is also highly toxic and corrosive as bromine gas. Bromine contents greater than 1 ppm may be unsafe in the atmosphere, and a dose of 500 ppm can lead to death in less than an hour.

  3. Thermochemical seasonal energy storage for solar thermal power

    SciTech Connect

    Barnhart, J.S.

    1984-01-01

    During the many years that thermochemical energy storage has been under investigation, the concept has been plagued with two persistent problems: high capital cost and poor efficiency. Literally hundreds of chemical reactions have also been carried out. For short-term storage, thermochemical systems suffer in comparison with highly efficient sensible storage media such as molten salts. Long-term storage, on the other hand, is not cost-competitive with systems employing fossil backup power. Thermochemical storage will play a significant role in solar thermal electric conversion only under highly select circumstances. The portion of electric demand served by solar plants must be sufficiently high that the balance of the grid cannot fully supplant seasonal storage. High fossil fuel costs must preclude the use of gas turbines for backup power. Significant breakthroughs in the development of one or more chemical reaction systems must occur. Ingeniously integrated systems must be employed to enhance the efficiency and cost-effectiveness of thermochemical storage. A promising integration scheme discussed herein consists of using sensible storage for diurnal cycling in parallel with thermochemical seasonal storage. Under the most favorable circumstances, thermochemical storage can be expected to play a small but perhaps vital role in supplying baseload energy from solar thermal electric conversion plants.

  4. Thermochemical water decomposition processes

    NASA Technical Reports Server (NTRS)

    Chao, R. E.

    1974-01-01

    Thermochemical processes which lead to the production of hydrogen and oxygen from water without the consumption of any other material have a number of advantages when compared to other processes such as water electrolysis. It is possible to operate a sequence of chemical steps with net work requirements equal to zero at temperatures well below the temperature required for water dissociation in a single step. Various types of procedures are discussed, giving attention to halide processes, reverse Deacon processes, iron oxide and carbon oxide processes, and metal and alkali metal processes. Economical questions are also considered.

  5. INTRODUCTION TO BROMINATED FLAME RETARDANTS

    EPA Science Inventory

    Brominated flame retardants (BFRs) are a large and diverse class of major industrial products used to provide fire safety. Tetrabromobisphenol A (TBBPA), Hexabromocylocodecane (HBCD), and Polybrominated Diphenyl Ethers (PBDEs) are the major commercial compounds. TBBPA is a react...

  6. Towards graphene bromide: bromination of graphite oxide

    NASA Astrophysics Data System (ADS)

    Jankovský, O.; Šimek, P.; Klimová, K.; Sedmidubský, D.; Matějková, S.; Pumera, M.; Sofer, Z.

    2014-05-01

    Halogenated graphene derivatives are interesting for their outstanding physical and chemical properties. In this paper, we present various methods for the synthesis of brominated graphene derivatives by the bromination of graphite oxides. Graphite oxides, prepared according to either the Hummers or Hofmann method, were brominated using bromine or hydrobromic acid under reflux or in an autoclave at elevated temperatures and pressures. The influence of both graphite oxide precursors on the resulting brominated graphenes was investigated by characterization of the graphenes, which was carried out using various techniques, including SEM, SEM-EDS, high-resolution XPS, FTIR, STA and Raman spectroscopy. In addition, the resistivity of the brominated graphenes was measured and the electrochemical properties were investigated by cyclic voltammetry. Although the brominated graphenes were structurally similar, they had remarkably different bromine concentrations. The most highly brominated graphene (bromine concentration above 26 wt%) exhibited a C/O ratio above 44 and partial hydrogenation. Brominated graphenes with such properties could be used for reversible bromine storage or as a starting material for further chemical modifications.Halogenated graphene derivatives are interesting for their outstanding physical and chemical properties. In this paper, we present various methods for the synthesis of brominated graphene derivatives by the bromination of graphite oxides. Graphite oxides, prepared according to either the Hummers or Hofmann method, were brominated using bromine or hydrobromic acid under reflux or in an autoclave at elevated temperatures and pressures. The influence of both graphite oxide precursors on the resulting brominated graphenes was investigated by characterization of the graphenes, which was carried out using various techniques, including SEM, SEM-EDS, high-resolution XPS, FTIR, STA and Raman spectroscopy. In addition, the resistivity of the brominated

  7. Screening analysis of solar thermochemical hydrogen concepts.

    SciTech Connect

    Diver, Richard B., Jr.; Kolb, Gregory J.

    2008-03-01

    A screening analysis was performed to identify concentrating solar power (CSP) concepts that produce hydrogen with the highest efficiency. Several CSP concepts were identified that have the potential to be much more efficient than today's low-temperature electrolysis technology. They combine a central receiver or dish with either a thermochemical cycle or high-temperature electrolyzer that operate at temperatures >600 C. The solar-to-hydrogen efficiencies of the best central receiver concepts exceed 20%, significantly better than the 14% value predicted for low-temperature electrolysis.

  8. Probing the tropical tropopause layer for organic and inorganic bromine

    NASA Astrophysics Data System (ADS)

    Werner, Bodo; Pfeilsticker, Klaus; Atlas, Elliot; Cheung, Ross; Chipperfield, Martyn; Colosimo, Fedele; Deutschmann, Tim; Elkins, Jim; Fahey, David; Feng, Wu; Festa, James; Gao, Ru-Shan; Hossaini, Ryan; Navarro, Maria; Raecke, Rasmus; Scalone, Lisa; Spolaor, Max; Thornberry, Troy; Tsai, Catalina; Stutz, Jochen

    2016-04-01

    Bromine chemistry impacts the levels of ozone in the upper troposphere and the stratosphere. An accurate quantitative understanding of the sources, sinks, and chemical transformation of bromine species is thus important to understand the photochemistry and budget of bromine in the tropical upper troposphere, tropopause layer and lowermost stratosphere (UT/TTL/LS). These regions are also known to serve as a gateway for delivery of ozone depleting gases to the stratosphere. CH3Br, halons, short-lived organic bromine precursors (VSLS), such as CHBr3, CH2Br2, and possibly inorganic product gases have been identified as the main bromine gases delivered to the stratosphere. However, many important details of the transport and delivery of VSLS and inorganic bromine compounds through the TTL are still uncertain. Moreover, a number of chemical processes, including the transformation of the source gases and cycling of inorganic bromine species at low ambient temperature and on ice particles are also poorly understood. The presentation reports measurements of CH4, O3, NO2, and BrO performed by different instruments and techniques during the 2013 NASA-ATTREX flights in the TTL and LS. The interpretation of our measurements is supported by chemical transport model (SLIMCAT) simulations. SLIMCAT results, in conjunction with extensive radiative transfer calculations using the Monte Carlo model McArtim, also are used to improve retrieval of O3, NO2, and BrO concentrations from limb scattered sunlight measurements made with the Differential Optical Absorption Spectroscopy (DOAS) technique during ATTREX. The chemical transport model also allows us to attribute observed concentration variations to transport and to photochemical processes. When properly accounting for the transport-related concentration variations in methane and ozone, we find that measured BrO mostly agrees with model simulations. An exception are regions where the contribution of the short-lived CH2Br2 or the

  9. MTCI/Thermochem stream reforming process for biomass

    SciTech Connect

    Mansour, M.N.; Durai-Swamy, K.; Voelker, G.

    1995-11-01

    Manufacturing and Technology Conversion International, Inc. (MTCI) has developed a novel technology to convert solid fuels including biomass, coal, municipal solid waste (MSW) and wastewater sludges into usable syngas by steam reforming in an indirectly heated, fluid-bed reactor. MTCI has licensed and patented the technology to ThermoChem, Inc. Both MTCI and ThermoChem have built two modular commercial-scale demonstration units: one for recycle paper mill rejects (similar to refuse-derived fuel [RDF]), and another for chemical recovery of black liquor. ThermoChem has entered into an agreement with Ajinkyatara Cooperative Sugar Factory, India, for building a 10 MW combined cycle power generation facility based on bagasse & agro-residue gasification.

  10. Bromine heterogenous chemistry in the troposhere

    SciTech Connect

    Abbatt, J.P.D.

    1996-10-01

    Motivated by the observations of boundary layer ozone loss which is correlated with high levels of bromine in the Arctic springtime, we have studied a number of heterogeneous interactions of tropospheric bromine species. The goal of this work is both to better define the source of inorganic bromine during this time of year and to determine the primary mechanism which keeps bromine in a photochemically active form.

  11. Solar Thermochemical Hydrogen Production Research (STCH)

    SciTech Connect

    Perret, Robert

    2011-05-01

    Eight cycles in a coordinated set of projects for Solar Thermochemical Cycles for Hydrogen production (STCH) were self-evaluated for the DOE-EERE Fuel Cell Technologies Program at a Working Group Meeting on October 8 and 9, 2008. This document reports the initial selection process for development investment in STCH projects, the evaluation process meant to reduce the number of projects as a means to focus resources on development of a few most-likely-to-succeed efforts, the obstacles encountered in project inventory reduction and the outcomes of the evaluation process. Summary technical status of the projects under evaluation is reported and recommendations identified to improve future project planning and selection activities.

  12. High Performance Electrolyzers for Hybrid Thermochemical Cycles

    SciTech Connect

    Dr. John W. Weidner

    2009-05-10

    Extensive electrolyzer testing was performed at the University of South Carolina (USC). Emphasis was given to understanding water transport under various operating (i.e., temperature, membrane pressure differential and current density) and design (i.e., membrane thickness) conditions when it became apparent that water transport plays a deciding role in cell voltage. A mathematical model was developed to further understand the mechanisms of water and SO2 transport, and to predict the effect of operating and design parameters on electrolyzer performance.

  13. Thermochemical cycles for the production of hydrogen

    DOEpatents

    Steinberg, M.; Dang, V.D.

    Two-step processes for the preparation of hydrogen are described: CrCl/sub 3/(g) ..-->.. CrCl/sub 2/(g) + 1/2Cl/sub 2/(g) and CrCl/sub 2/(s) + HCl(g) reversible CrCl/sub 3/(s) + 1/2H/sub 2/(g); UCl/sub 4/(g) ..-->.. UCl/sub 3/(g) + 1/2Cl/sub 2/(g) and UCl/sub 3/(s) + HCl(g) ..-->.. UCl/sub 4/(s) + 1/2H/sub 2/(g); and CaSO/sub 4/(s) ..-->.. CaO(s) + SO/sub 2/(g) + 1/2O/sub 2/(g) and CaO(s) + SO/sub 2/(g) + H/sub 2/O(l) ..-->.. CaSO/sub 4/(s) + H/sub 2/(g). The high temperature available from solar collectors, high temperature gas reactors or fusion reactors is utilized in the first step in which the reaction is endothermic. The efficiency is at least 60% and with process heat recovery, the efficiency may be increased up to 74.4%. An apparatus fr carrying out the process in conjunction with a fusion reactor, is described.

  14. Zinc-bromine battery design for electric vehicles

    NASA Astrophysics Data System (ADS)

    Bellows, R. J.; Grimes, P.; Einstein, H.; Kantner, E.; Malachesky, P.; Newby, K.

    1983-02-01

    Design projections for zinc-bromine batteries are attractive for electric vehicle applications in terms of low manufacturing costs ($28/kWh) and good performance characteristics. Zinc-bromine battery projections (60-80 Wh/kg, 130-200 W/kg) compare favorably to both current lead acid batteries and proposed advanced battery candidates. The performance of recently developed battery components with 1200 sq/cm electrodes in a 120V, 10 kWh module is described. Similarly constructed smaller scale (600 sq/cm) components have shown lifetimes exceeding 400 cycles and the ability to follow both regenerative braking (J227aD) and random cycling regimes. Initial dynamometer evaluations of full scale 20 kWh batteries is expected in early 1984.

  15. Electronic properties of bromine-doped carbon nanotubes

    SciTech Connect

    Jhi, Seung-Hoon; Louie, Steven G.; Cohen, Marvin L.

    2002-07-15

    Intercalation of bromine molecules (Br2) into single-wall carbon nanotube (SWNT) ropes is studied using the ab initio pseudopotential density functional method. Electronic and vibrational properties of the SWNT and Br2 are studied for various bromine concentrations. A drastic change in the charge transfer, bromine stretching-mode, and bromine bond-length is observed when the bromine-bromine distance decreases. Calculated electronic structures show that, at high bromine concentrations, the bromine ppsigma level broadens due to the interbromine interaction. These states overlap with the electronic bands of the SWNT near the Fermi level which results in a substantial charge transfer from carbon to bromine.

  16. Solar Thermochemical Production of Fuels

    SciTech Connect

    Wegeng, Robert S.; TeGrotenhuis, Ward E.; Mankins, John C.

    2007-06-25

    [Abstract] If cost and efficiency targets can be achieved, Solar Thermochemical Plants – occupying a few square kilometers each – can potentially generate substantial quantities of transportation fuels, therefore enabling reductions in imports of foreign petroleum and emissions of carbon dioxide. This paper describes the results of a comparative evaluation of various solar thermochemical approaches for producing chemical fuels. Common to each approach is the concentration of solar and/or other radiant energy so that high temperature heat is provided for thermochemical processes including chemical reactors, heat exchangers and separators. The study includes the evaluation of various feedstock chemicals as input to the Solar Thermochemical Plant: natural gas, biomass and zero-energy chemicals (water and carbon dioxide); the effect of combusting natural gas or concentrating beamed radiant energy from an orbiting platform (e.g., space solar power) as supplemental energy sources that support high plant capacity factors; and the production of either hydrogen or long-chain hydrocarbons (i.e., Fischer-Tropsch fuels) as the Solar Fuel product of the plant.

  17. Hydrogen-Bromine Secondary Battery

    NASA Technical Reports Server (NTRS)

    England, C. (Inventor)

    1975-01-01

    A secondary battery is described utilizing hydrogen and halogen as primary reactants. It comprises inert anode and cathode initially contacting an aqueous solution of an acid and an alkali metal bromide. The hydrogen generated during charging of the cell is stored as gas, while the bromine becomes dissolved predominantly in the lower layers of the acid electrolyte. Preferred components are phosphoric acid and lithium bromide.

  18. Inorganic bromine in the marine boundary layer: a critical review

    NASA Astrophysics Data System (ADS)

    Sander, R.; Keene, W. C.; Pszenny, A. A. P.; Arimoto, R.; Ayers, G. P.; Baboukas, E.; Cainey, J. M.; Crutzen, P. J.; Duce, R. A.; Hönninger, G.; Huebert, B. J.; Maenhaut, W.; Mihalopoulos, N.; Turekian, V. C.; van Dingenen, R.

    2003-09-01

    The cycling of inorganic bromine in the marine boundary layer (mbl) has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is substantially depleted in bromine (often exceeding 50%) relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that the supermicrometer depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. Mechanisms for the submicrometer enrichments are not well understood. Currently available techniques cannot reliably quantify many Br containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans outside the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion) can be of local importance. Transport of degradation products of long-lived Br containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic

  19. Inorganic bromine in the marine boundary layer: a critical review

    NASA Astrophysics Data System (ADS)

    Sander, R.; Keene, W. C.; Pszenny, A. A. P.; Arimoto, R.; Ayers, G. P.; Baboukas, E.; Cainey, J. M.; Crutzen, P. J.; Duce, R. A.; Hönninger, G.; Huebert, B. J.; Maenhaut, W.; Mihalopoulos, N.; Turekian, V. C.; van Dingenen, R.

    2003-06-01

    The cycling of inorganic bromine in the marine boundary layer (mbl) has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is depleted in bromine by about 50% relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that these depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. However, currently available techniques cannot reliably quantify many \\chem{Br}-containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans, excluding the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion) can be of local importance. Transport of degradation products of long-lived Br-containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic Br and Cl. Subsequent transformations can destroy tropospheric ozone, oxidize

  20. Process for the thermochemical production of hydrogen

    DOEpatents

    Norman, John H.; Russell, Jr., John L.; Porter, II, John T.; McCorkle, Kenneth H.; Roemer, Thomas S.; Sharp, Robert

    1978-01-01

    Hydrogen is thermochemically produced from water in a cycle wherein a first reaction produces hydrogen iodide and H.sub.2 SO.sub.4 by the reaction of iodine, sulfur dioxide and water under conditions which cause two distinct aqueous phases to be formed, i.e., a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. After separation of the two phases, the heavier phase containing most of the hydrogen iodide is treated, e.g., at a high temperature, to decompose the hydrogen iodide and recover hydrogen and iodine. The H.sub.2 SO.sub.4 is pyrolyzed to recover sulfur dioxide and produce oxygen.

  1. Stability of Bromine Intercalated Graphite Fibers

    NASA Technical Reports Server (NTRS)

    Gaier, J. R.

    1984-01-01

    Previous evidence suggested that bromine intercalation compounds of crystalline graphite spontaneously deintercalate when the bromine atmosphere is removed. However, results show that bromine intercalated P-100 graphite fibers are stable for long periods of time. They are stable under vacuum conditions, high humidity, and current densities up to 24,000 A/sq cm. They are thermally stable to 200 C, and at temperatures as high as 400 C still retain 80 percent of the conductivity gained by intercalation. At temperatures greater than 300 C, there is significant oxidative degradation of the fibers. The environmental stability shown by the bromine compound makes it a promising candidate for practical applications in aerospace technology.

  2. Sensitivity of Ozone to Bromine in the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Salawitch, R. J.; Weisenstein, D. K.; Kovalenko, L. J.; Sioris, C. E.; Wennberg, P. O.; Chance, K.; Ko, M. K. W.; McLinden, C. A.

    2005-01-01

    Measurements of BrO suggest that inorganic bromine (Br(sub y)) at and above the tropopause is 4 to 8 ppt greater than assumed in models used in past ozone trend assessment studies. This additional bromine is likely carried to the stratosphere by short-lived biogenic compounds and their decomposition products, including tropospheric BrO. Including this additional bromine in an ozone trend simulation increases the computed ozone depletion over the past approx.25 years, leading to better agreement between measured and modeled ozone trends. This additional Br(sub y) (assumed constant over time) causes more ozone depletion because associated BrO provides a reaction partner for ClO, which increases due to anthropogenic sources. Enhanced Br(sub y) causes photochemical loss of ozone below approx.14 km to change from being controlled by HO(sub x) catalytic cycles (primarily HO2+O3) to a situation where loss by the BrO+HO2 cycle is also important.

  3. Brominated carbon black: An EDXD study

    SciTech Connect

    Carbone, Marilena; Gontrani, Lorenzo

    2014-06-19

    An energy dispersive X-Ray study of pure and brominated carbon black was carried out. The analysis of the diffraction patterns reveals that the low bromine load (ca.1% mol) is trapped into the structure, without significantly modifying it. This allows the application of the difference methods, widely tested for electrolyte solutions, inorganic matrices containing metals and isomorphic substitutions.

  4. Mineral resource of the month: bromine

    USGS Publications Warehouse

    U.S. Geological Survey

    2009-01-01

    The article offers information on bromine, a natural element considered as a dissolved species in seawater, saltwater lakes and underground brines linked with petroleum deposits. Bromine belongs to the halogen group of elements and is characterized with brownish-red color and beach-like odor. It is commonly used in flame retardants, agriculture and drilling.

  5. Enhanced water management using bromine chemistry

    SciTech Connect

    Sergent, R.H.

    1986-01-01

    This paper focuses on bromine chemistry and some of its unique properties, with regard to providing solutions to new and changing problems. Bromine Chemistry offers many unique properties for enhancing a water management program. Regardless of the method used to generate a residual, hypobromous acid delivers faster kill rates than an equimolar concentration of hypochlorous acid at an elevated pH or in the presence of ammonia or nitrogenous materials. In addition, the faster degradation of most bromine compounds relative to their chlorinated analogs increases the environmental acceptability of most brominated effluents relative to chlorination. Based on these advantages, the application of bromine chemistry to water treatment requirements has moved out of the speculative research phase and has moved into the sphere of a practical, commercial reality.

  6. Thermochemical differentiation and intermittent convection of the Earth's mantle

    NASA Astrophysics Data System (ADS)

    Kotelkin, Vycheslav; Lobkovsky, Leopold

    2010-05-01

    The numerical experiments are based on the thermochemical model of mantle convection. The model includes the description of the endothermic phase transition at the upper/lower mantle boundary. The aim of this work is the influence of thermochemical processes on mantle convection. As regards the thermochemical differentiation takes place near the mantle boundaries. The differentiation in the D" layer is due to melting with the rise in temperature and the descent of molten iron-bearing components of mantle material into the core. This process generates the lighter fraction, particularly produces the lower mantle plums. It takes place only if the current temperature exceeds the melting temperature. The differentiation near the outer mantle boundary is due to extracting the lighter mantle components into the crust. These thermochemical processes take place when the hot substance is lifting and the pressure falls. The growth of the continental crust on the outer surface is modeling. The oceanic crust returns into mantle throw the subducting zones. The modeling includes the "gabbro-eclogite" transition of oceanic crust. As regards the generation of heavy eclogitic material is located at the depths 80-100 km. Seismic tomography of deep mantle layers showed that the mantle really contains large inclusions of heavy, supposedly eclogitic material. The numerical experiments give a strong nonlinear interaction (either accelerating or slowing down) between the thermochemical processes and mantle convection. It leads to an impulsive character of geodynamics and promotes the formation of different cycles in the evolutionary process. Periods of gradual evolution are interrupted by the geodynamic activity outbursts. These peaks of geodynamic activity play a key role in the geological history of the Earth. Analogous oscillations of geodynamic process produce interaction heavy and light density inhomogeneities with the endothermic phase transition. When convection is layered then the

  7. Solar thermochemical process interface study

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The design and analyses of a subsystem of a hydrogen production process are described. The process is based on solar driven thermochemical reactions. The subject subsystem receives sulfuric acid of 60% concentration at 100 C, 1 atm pressure. The acid is further concentrated, vaporized, and decomposed (at a rate of 122 g moles/sec H2SO4) into SO2, O2, and water. The produce stream is cooled to 100 C. Three subsystem options, each being driven by direct solar energy, were designed and analyzed. The results are compared with a prior study case in which solar energy was provided indirectly through a helium loop.

  8. System for thermochemical hydrogen production

    DOEpatents

    Werner, R.W.; Galloway, T.R.; Krikorian, O.H.

    1981-05-22

    Method and apparatus are described for joule boosting a SO/sub 3/ decomposer using electrical instead of thermal energy to heat the reactants of the high temperature SO/sub 3/ decomposition step of a thermochemical hydrogen production process driven by a tandem mirror reactor. Joule boosting the decomposer to a sufficiently high temperature from a lower temperature heat source eliminates the need for expensive catalysts and reduces the temperature and consequent materials requirements for the reactor blanket. A particular decomposer design utilizes electrically heated silicon carbide rods, at a temperature of 1250/sup 0/K, to decompose a cross flow of SO/sub 3/ gas.

  9. CFD studies on biomass thermochemical conversion.

    PubMed

    Wang, Yiqun; Yan, Lifeng

    2008-06-01

    Thermochemical conversion of biomass offers an efficient and economically process to provide gaseous, liquid and solid fuels and prepare chemicals derived from biomass. Computational fluid dynamic (CFD) modeling applications on biomass thermochemical processes help to optimize the design and operation of thermochemical reactors. Recent progression in numerical techniques and computing efficacy has advanced CFD as a widely used approach to provide efficient design solutions in industry. This paper introduces the fundamentals involved in developing a CFD solution. Mathematical equations governing the fluid flow, heat and mass transfer and chemical reactions in thermochemical systems are described and sub-models for individual processes are presented. It provides a review of various applications of CFD in the biomass thermochemical process field. PMID:19325848

  10. CFD Studies on Biomass Thermochemical Conversion

    PubMed Central

    Wang, Yiqun; Yan, Lifeng

    2008-01-01

    Thermochemical conversion of biomass offers an efficient and economically process to provide gaseous, liquid and solid fuels and prepare chemicals derived from biomass. Computational fluid dynamic (CFD) modeling applications on biomass thermochemical processes help to optimize the design and operation of thermochemical reactors. Recent progression in numerical techniques and computing efficacy has advanced CFD as a widely used approach to provide efficient design solutions in industry. This paper introduces the fundamentals involved in developing a CFD solution. Mathematical equations governing the fluid flow, heat and mass transfer and chemical reactions in thermochemical systems are described and sub-models for individual processes are presented. It provides a review of various applications of CFD in the biomass thermochemical process field. PMID:19325848

  11. Biomass Thermochemical Conversion Program: 1986 annual report

    SciTech Connect

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1987-01-01

    Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion, and thermochemical processes are well suited for conversion of these materials. Thermochemical conversion processes can generate a variety of products such as gasoline hydrocarbon fuels, natural gas substitutes, or heat energy for electric power generation. The US Department of Energy is sponsoring research on biomass conversion technologies through its Biomass Thermochemical Conversion Program. Pacific Northwest Laboratory has been designated the Technical Field Management Office for the Biomass Thermochemical Conversion Program with overall responsibility for the Program. This report briefly describes the Thermochemical Conversion Program structure and summarizes the activities and major accomplishments during fiscal year 1986. 88 refs., 31 figs., 5 tabs.

  12. Comparative environmental analysis of waste brominated plastic thermal treatments

    SciTech Connect

    Bientinesi, M. Petarca, L.

    2009-03-15

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste.

  13. Comparative environmental analysis of waste brominated plastic thermal treatments.

    PubMed

    Bientinesi, M; Petarca, L

    2009-03-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of "fossil fuels" and "climate change". Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste. PMID:18829288

  14. Hydrogen peroxide thermochemical oscillator as driver for primordial RNA replication

    PubMed Central

    Ball, Rowena; Brindley, John

    2014-01-01

    This paper presents and tests a previously unrecognized mechanism for driving a replicating molecular system on the prebiotic earth. It is proposed that cell-free RNA replication in the primordial soup may have been driven by self-sustained oscillatory thermochemical reactions. To test this hypothesis, a well-characterized hydrogen peroxide oscillator was chosen as the driver and complementary RNA strands with known association and melting kinetics were used as the substrate. An open flow system model for the self-consistent, coupled evolution of the temperature and concentrations in a simple autocatalytic scheme is solved numerically, and it is shown that thermochemical cycling drives replication of the RNA strands. For the (justifiably realistic) values of parameters chosen for the simulated example system, the mean amount of replicant produced at steady state is 6.56 times the input amount, given a constant supply of substrate species. The spontaneous onset of sustained thermochemical oscillations via slowly drifting parameters is demonstrated, and a scheme is given for prebiotic production of complementary RNA strands on rock surfaces. PMID:24647902

  15. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    NASA Astrophysics Data System (ADS)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2015-09-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favored the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  16. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    NASA Astrophysics Data System (ADS)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2016-02-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  17. Brominated Flame Retardants and Perfluorinated Chemicals

    EPA Science Inventory

    Brominated flame retardants (BFRs) and perfluorinated chemicals (PFCs) belong to a large class of chemicals known as organohalogens. It is believed that both BFRs and PFCs saved lives by reducing flammability of materials commonly used and bactericidal (biocidal) properties. Thes...

  18. PCBs, PBBs and Brominated Flame Retardants

    EPA Science Inventory

    This chapter introduces selected organohalogen chemicals such as polychlorinated biphenyls (PCB5), polychiorinated biphenyls (PBBs), and brominated flame retardants (BFRs) with emphasis on the background, physicochemical properties, environmental levels, health effects and possib...

  19. Polyfunctional epoxies. I - Rubber-toughened brominated and nonbrominated formulations for graphite composites. II - Nonrubber versus rubber-toughened brominated formulations for graphite composites

    NASA Technical Reports Server (NTRS)

    Nir, Z.; Gilwee, W. J.; Kourtides, D. A.; Parker, J. A.

    1985-01-01

    A new trifunctional epoxy resin, Tris-(hydroxyphenyl) methane triglycidyl ether, is compared to a state-of-the-art tetraglycidyl 4,4'-diaminodiphenyl methane (TGDDM), in graphite composites. Rubber-toughened brominated formulations of the epoxy resin are compared to nonbrominated ones in terms of their mechanical performance, environmental stability, thermochemical behavior, and flame retardancy. It is shown that the new resin performs almost the same way as the TGDDM does, but has improved glass transition temperature and environmental properties. Brominated polymeric additives (BPA) of different molecular weights are tested as a Br source to flame retardant graphite epoxy composites. The optimal molecular weight of the BPA and its polymeric backbone length are derived and compared with a 10 percent rubber-toughened formulation of the epoxy resin. Results indicate that when the Br content in the graphite composite is increased without the use of rubber, the mechanical properties improved. The use of BPAs as tougheners for graphite composites is also considered.

  20. Biomass thermochemical conversion program: 1987 annual report

    SciTech Connect

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1988-01-01

    The objective of the Biomass Thermochemical Conversion Program is to generate a base of scientific data and conversion process information that will lead to establishment of cost-effective processes for conversion of biomass resources into clean fuels. To accomplish this objective, in fiscal year 1987 the Thermochemical Conversion Program sponsored research activities in the following four areas: Liquid Hydrocarbon Fuels Technology; Gasification Technology; Direct Combustion Technology; Program Support Activities. In this report an overview of the Thermochemical Conversion Program is presented. Specific research projects are then described. Major accomplishments for 1987 are summarized.

  1. Biomass thermochemical conversion program. 1985 annual report

    SciTech Connect

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1986-01-01

    Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion, and thermochemical processes are well suited for conversion of these materials. The US Department of Energy (DOE) is sponsoring research on this conversion technology for renewable energy through its Biomass Thermochemical Conversion Program. The Program is part of DOE's Biofuels and Municipal Waste Technology Division, Office of Renewable Technologies. This report briefly describes the Thermochemical Conversion Program structure and summarizes the activities and major accomplishments during fiscal year 1985. 32 figs., 4 tabs.

  2. The development of the General Atomic thermochemical water-splitting process

    NASA Astrophysics Data System (ADS)

    Besenbruch, G. E.; Allen, C. L.; Brown, L. C.; McCorkle, K.; Rode, Y. S.; Norman, Y. H.; Trester, P.; Sharp, R.

    1981-03-01

    Thermochemical water splitting was investigated. The main advantages of the cycle are that it can be conducted as an all liquid and gas phase process and that its unit operations are simple, industry-developed processes like distillation, vaporization, and phase separation.

  3. Bromine accumulation in acidic black colluvial soils

    NASA Astrophysics Data System (ADS)

    Cortizas, Antonio Martínez; Vázquez, Cruz Ferro; Kaal, Joeri; Biester, Harald; Casais, Manuela Costa; Rodríguez, Teresa Taboada; Lado, Luis Rodríguez

    2016-02-01

    Recent investigations showed that bromine is incorporated to soil organic matter (SOM), its content increasing with humification. But few research was done on its long-term accumulation and the role played by pedogenetic processes, as those involved in organic matter stabilization. We investigated bromine content and distribution in four deep, acidic, organic-rich, Holocene soils from an oceanic area of Western Europe. Bromine concentrations (93-778 μg g-1) in the silt + clay (<50 μm) fraction were on average 3-times higher than those (17-250 μg g-1) in the fine earth (<2 mm), the former containing almost all bromine (90 ± 5%). Inventories were between 148 and 314 g m-2, indicating a rather large variability in a small area, and total estimated retention was low (6-16%). The degree of SOM bromination, expressed as the Br/C molar ratio, varied between 0.03 and 1.20 mmol Br/mol C. The ratio was highly correlated (n = 23, r2 0.88, p < 0.01) with the age of the SOM for the last ∼12 ka. Partial least squares modeling indicates that bromine concentration depends on the amount of organic matter stabilized as aluminium-OM associations, and to a lesser extent on soil acidity (pH) and iron-OM associations. Thus, at scales of thousands of years, bromine accumulation in acidic soils is linked to the pool of metal-clay-stabilized organic matter.

  4. Abiotic Bromination of Soil Organic Matter.

    PubMed

    Leri, Alessandra C; Ravel, Bruce

    2015-11-17

    Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic activity of decomposer organisms. Building on a recent finding that naturally produced organobromine is ubiquitous in SOM, we hypothesized that inorganic bromide could be subject to abiotic oxidations resulting in bromination of SOM. Through lab-based degradation treatments of plant material and soil humus, we have shown that abiotic bromination of particulate organic matter occurs in the presence of a range of inorganic oxidants, including hydrogen peroxide and assorted forms of ferric iron, producing both aliphatic and aromatic forms of organobromine. Bromination of oak and pine litter is limited primarily by bromide concentration. Fresh plant material is more susceptible to bromination than decayed litter and soil humus, due to a labile pool of mainly aliphatic compounds that break down during early stages of SOM formation. As the first evidence of abiotic bromination of particulate SOM, this study identifies a mechanistic source of the natural organobromine in humic substances and the soil organic horizon. Formation of organobromine through oxidative treatments of plant material also provides insights into the relative stability of aromatic and aliphatic components of SOM. PMID:26468620

  5. The milling of pristine and brominated P-100 graphite fibers

    NASA Technical Reports Server (NTRS)

    Dillehay, M. E.; Gaier, J. R.

    1986-01-01

    Techniques were developed for the ball milling of pristine and brominated P-100 graphite fibers. Because of the lubrication properties of graphite, large ball loads (50 percent by volume) were required. Use of 2-propanol as a milling medium enhanced the efficiency of the process. Milled brominated P-100 fibers had resistivities which were indistinguishable from milled pristine P-100 fibers. Apparent loss of bromine from the brominated fibers suggests that bromine would not be the intercalate of choice in applications where milled fibers of this type are required. Other intercalates which do not degas may be more appropriate for a milled fiber application. These same results, however, do provide evidence that bromine molecules leave the fiber surface when removed from overpressure of bromine. While exploring possible solvent media for milling purposes, it was found that brominated fibers are stable in a wide variety of organic solvents.

  6. SUNgas: Thermochemical Approaches to Solar Fuels

    NASA Astrophysics Data System (ADS)

    Davidson, Jane

    2013-04-01

    Solar energy offers an intelligent solution to reduce anthropogenic emissions of greenhouse gases and to meet an expanding global demand for energy. A transformative change from fossil to solar energy requires collection, storage, and transport of the earth's most abundant but diffuse and intermittent source of energy. One intriguing approach for harvest and storage of solar energy is production of clean fuels via high temperature thermochemical processes. Concentrated solar energy is the heat source and biomass or water and carbon dioxide are the feedstocks. Two routes to produce fuels using concentrated solar energy and a renewable feed stock will be discussed: gasification of biomass or other carbonaceous materials and metal oxide cycles to produce synthesis gas. The first and most near term route to solar fuels is to gasify biomass. With conventional gasification, air or oxygen is supplied at fuel-rich levels to combust some of the feedstock and in this manner generate the energy required for conversion to H2 and CO. The partial-combustion consumes up to 40% of the energetic value of the feedstock. With air combustion, the product gas is diluted by high levels of CO2 and N2. Using oxygen reduces the product dilution, but at the expense of adding an oxygen plant. Supplying the required heat with concentrated solar radiation eliminates the need for partial combustion of the biomass feedstock. As a result, the product gas has an energetic value greater than that of the feedstock and it is not contaminated by the byproducts of combustion. The second promising route to solar fuels splits water and carbon dioxide. Two-step metal-oxide redox cycles hold out great potential because they the temperature required to achieve a reasonable degree of dissociation is lower than direct thermal dissociation and O2 and the fuel are produced in separate steps. The 1^st step is the endothermic thermal dissociation of the metal oxide to the metal or lower-valence metal oxide. The 2

  7. 40 CFR 721.3420 - Brominated arylalkyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Brominated arylalkyl ether. 721.3420... Substances § 721.3420 Brominated arylalkyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated arylalkyl ether (P-83-906)...

  8. 21 CFR 180.30 - Brominated vegetable oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Brominated vegetable oil. 180.30 Section 180.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Brominated vegetable oil. The food additive brominated vegetable oil may be safely used in accordance...

  9. 21 CFR 180.30 - Brominated vegetable oil.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Brominated vegetable oil. 180.30 Section 180.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Brominated vegetable oil. The food additive brominated vegetable oil may be safely used in accordance...

  10. 21 CFR 180.30 - Brominated vegetable oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Brominated vegetable oil. 180.30 Section 180.30... Requirements for Certain Food Additives § 180.30 Brominated vegetable oil. The food additive brominated vegetable oil may be safely used in accordance with the following prescribed conditions: (a) The...

  11. 21 CFR 180.30 - Brominated vegetable oil.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brominated vegetable oil. 180.30 Section 180.30 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Brominated vegetable oil. The food additive brominated vegetable oil may be safely used in accordance...

  12. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic ester. 721.2925... Substances § 721.2925 Brominated aromatic ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a brominated aromatic ester (PMN...

  13. 40 CFR 721.3085 - Brominated phthalate ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Brominated phthalate ester. 721.3085... Substances § 721.3085 Brominated phthalate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated phthalate ester (PMN P-90-581)...

  14. 40 CFR 721.2925 - Brominated aromatic ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Brominated aromatic ester. 721.2925... Substances § 721.2925 Brominated aromatic ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a brominated aromatic ester (PMN...

  15. 40 CFR 721.10124 - Brominated polyaromatic compound (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Brominated polyaromatic compound... Specific Chemical Substances § 721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance... brominated polyaromatic compound (PMN P-06-617) is subject to reporting under this section for...

  16. 40 CFR 721.10124 - Brominated polyaromatic compound (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Brominated polyaromatic compound... Specific Chemical Substances § 721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance... brominated polyaromatic compound (PMN P-06-617) is subject to reporting under this section for...

  17. 40 CFR 721.10124 - Brominated polyaromatic compound (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Brominated polyaromatic compound... Specific Chemical Substances § 721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance... brominated polyaromatic compound (PMN P-06-617) is subject to reporting under this section for...

  18. 40 CFR 721.10124 - Brominated polyaromatic compound (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated polyaromatic compound... Specific Chemical Substances § 721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance... brominated polyaromatic compound (PMN P-06-617) is subject to reporting under this section for...

  19. 40 CFR 721.10124 - Brominated polyaromatic compound (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated polyaromatic compound... Specific Chemical Substances § 721.10124 Brominated polyaromatic compound (generic). (a) Chemical substance... brominated polyaromatic compound (PMN P-06-617) is subject to reporting under this section for...

  20. Biodegradation of brominated and organophosphorus flame retardants.

    PubMed

    Waaijers, Susanne L; Parsons, John R

    2016-04-01

    Brominated flame retardants account for about 21% of the total production of flame retardants and many of these have been identified as persistent, bioaccumulative and toxic. Nevertheless, debromination of these chemicals under anaerobic conditions is well established, although this can increase their toxicity. Consequently, the production and use of these chemicals has been restricted and alternative products have been developed. Many of these are brominated compounds and share some of the disadvantages of the chemicals they are meant to replace. Therefore, other, nonbrominated, flame retardants such as organophosphorus compounds are also being used in increasing quantities, despite the fact that knowledge of their biodegradation and environmental fate is often lacking. PMID:26748263

  1. Bromine and Chlorine Go Separate Ways

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph shows the relative concentrations of bromine and chlorine at various locations on Earth and Mars. Typically, bromine and chlorine stick together in a fixed ratio, as in martian meteorites and Earth seawater. But sometimes the elements split apart and their relative quantities diverge. This separation is usually caused by evaporation processes, as in the Dead Sea on Earth. On Mars, at Meridiani Planum and Gusev Crater, this split has been observed to an even greater degree than seen on Earth. This puzzling result is currently being further explored by Mars Exploration Rover scientists. Data for the Mars locations were taken by the rover's alpha particle X-ray spectrometer.

  2. Optically pumped molecular bromine laser. Master's thesis

    SciTech Connect

    Morrison, J.W.

    1990-12-01

    An optically pumped molecular bromine laser was studied to investigate the quenching kinetics state of Br2. This included characterization of the pressure dependence of the laser output power. The approach was to excite molecular bromine in a sealed cell with a Nd:YAG pumped dye laser. Unresolved side fluorescence and amplified stimulated emission (ASE) spectra were recorded. ASE offered the advantage of a simpler optical system with no externally induced wavelength dependencies. Stimulated emission as a signal monitor offered greater resolution than side fluorescence spectra and facilitated spectroscopic assignment. (JS)

  3. A Substitute Foe "Bromine in Carbon Tetrachloride"

    ERIC Educational Resources Information Center

    Daley, Joshua M.; Landolt, Robert G.

    2005-01-01

    The addition of a dilute solution of bromine in carbon tetrachloride to a compound to test for carbon-carbon multiple bonds, which is one of the widely cited qualitative tests employed in organic chemistry is presented. Major advantages of this approach include the ease and rapidness of the procedure, the stability of the test solution over time,…

  4. HEALTH ASPECTS OF BROMINATED FLAME RETARDANTS (BFRS)

    EPA Science Inventory

    In order to reduce the societal costs of fires, flammability standards have been set for consumer products and equipment. Flame retardants containing bromine have constituted the largest share of this market due both to their efficiency and cost. While there are at least 75 dif...

  5. Brominated flame retardants as food contaminants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter reviews analytical methods for the three major brominated flame retardant (BFR) classes in use today, tetrabromobisphenol-A (TBBP-A), hexabromocyclododecanes (HBCDs), and polybrominated diphenyl ethers (PBDEs), a "legacy" BFR no longer in use, polybrominated biphenyls (PBBs), and a...

  6. Structure and functionality of bromine doped graphite.

    PubMed

    Hamdan, Rashid; Kemper, A F; Cao, Chao; Cheng, H P

    2013-04-28

    First-principles calculations are used to study the enhanced in-plane conductivity observed experimentally in Br-doped graphite, and to study the effect of external stress on the structure and functionality of such systems. The model used in the numerical calculations is that of stage two doped graphite. The band structure near the Fermi surface of the doped systems with different bromine concentrations is compared to that of pure graphite, and the charge transfer between carbon and bromine atoms is analyzed to understand the conductivity change along different high symmetry directions. Our calculations show that, for large interlayer separation between doped graphite layers, bromine is stable in the molecular form (Br2). However, with increased compression (decreased layer-layer separation) Br2 molecules tend to dissociate. While in both forms, bromine is an electron acceptor. The charge exchange between the graphite layers and Br atoms is higher than that with Br2 molecules. Electron transfer to the Br atoms increases the number of hole carriers in the graphite sheets, resulting in an increase of conductivity. PMID:23635160

  7. BROMINATED FLAME RETARDANTS: CAUSE FOR CONCERN?

    EPA Science Inventory

    Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades in a successful effort to reduce fire-related injury and property damage. Recently, concern for this emerging class of chemicals has risen due to the occurrence of several class...

  8. BROMINATED FLAME RETARDANTS: WHY DO WE CARE?

    EPA Science Inventory

    Brominated flame retardants (BFRs) save lives and property by preventing the spread of fires or delaying the time of flashover, enhancing the time people have to escape. The worldwide production of BFRs exceeded 200,000 metric tons in 2003 placing them in the high production vol...

  9. Structure and functionality of bromine doped graphite

    SciTech Connect

    Hamdan, Rashid; Kemper, A. F.; Cao Chao; Cheng, H. P.

    2013-04-28

    First-principles calculations are used to study the enhanced in-plane conductivity observed experimentally in Br-doped graphite, and to study the effect of external stress on the structure and functionality of such systems. The model used in the numerical calculations is that of stage two doped graphite. The band structure near the Fermi surface of the doped systems with different bromine concentrations is compared to that of pure graphite, and the charge transfer between carbon and bromine atoms is analyzed to understand the conductivity change along different high symmetry directions. Our calculations show that, for large interlayer separation between doped graphite layers, bromine is stable in the molecular form (Br{sub 2}). However, with increased compression (decreased layer-layer separation) Br{sub 2} molecules tend to dissociate. While in both forms, bromine is an electron acceptor. The charge exchange between the graphite layers and Br atoms is higher than that with Br{sub 2} molecules. Electron transfer to the Br atoms increases the number of hole carriers in the graphite sheets, resulting in an increase of conductivity.

  10. HEALTH EFFECTS OF BROMINATED FLAME RETARDANTS (BFRS)

    EPA Science Inventory

    Abstract Brominated flame retardant use has increased dramatically in order to provide fire safety to consumers. However, there is growing concern about widespread environmental contamination and potential health risks from some of these products. The most used products...

  11. Brominated organic species in the arctic atmosphere

    NASA Technical Reports Server (NTRS)

    Berg, W. W.; Heidt, L. E.; Pollock, W.; Sperry, P. D.; Cicerone, R. J.; Gladney, E. S.

    1984-01-01

    Measurements are reported of four gas-phase, brominated organic species found in the Arctic atmosphere during March and April 1983. Volume mixing ratios for CH3Br, CH2BrCH2Br, CHBr3, and CH2Br2 were determined by gas chromatography/mass spectrometry analysis from samples taken Arctic wide, including at the geographic North Pole and during a tropopause folding event over Baffin Bay near Thule, Greenland. Methyl bromide mixing ratios were reasonably constant at 11 plus or minus 4 pptv, while the other three brominated organics showed a high degree of variability. Bromoform (2 to 46 pptv) was found to be the dominant contributor to gaseous organic bromine to the Arctic troposphere at 38 plus or minus 10 percent followed by CH2Br2 (3 to 60 pptv) at 29 plus or minus 6 percent. Both CH3Br and CH2BrCH2Br (1 to 37 pptv) reservoirs contained less than 20 percent of the organically bound bromine. Stratospheric samples, taken during a tropopause folding event, showed mixing ratios for all four species at levels high enough to support a stratospheric total volume mixing ratio of 249 pptv Br (888 ngBr/SCM).

  12. Bromination of selected pharmaceuticals in water matrices.

    PubMed

    Benitez, F Javier; Acero, Juan L; Real, Francisco J; Roldan, Gloria; Casas, Francisco

    2011-11-01

    The bromination of five selected pharmaceuticals (metoprolol, naproxen, amoxicillin, phenacetin, and hydrochlorothiazide) was studied with these compounds individually dissolved in ultra-pure water. The apparent rate constants for the bromination reaction were determined as a function of the pH, obtaining the sequence amoxicillin>naproxen>hydrochlorothiazide≈phenacetin≈metoprolol. A kinetic mechanism specifying the dissociation reactions and the species formed for each compound according to its pK(a) value and the pH allowed the intrinsic rate constants to be determined for each elementary reaction. There was fairly good agreement between the experimental and calculated values of the apparent rate constants, confirming the goodness of the proposed reaction mechanism. In a second stage, the bromination of the selected pharmaceuticals simultaneously dissolved in three water matrices (a groundwater, a surface water from a public reservoir, and a secondary effluent from a WWTP) was investigated. The pharmaceutical elimination trend agreed with the previously determined rate constants. The influence of the main operating conditions (pH, initial bromine dose, and characteristics of the water matrix) on the degradation of the pharmaceuticals was established. An elimination concentration profile for each pharmaceutical in the water matrices was proposed based on the use of the previously evaluated apparent rate constants, and the theoretical results agreed satisfactorily with experiment. Finally, chlorination experiments performed in the presence of bromide showed that low bromide concentrations slightly accelerate the oxidation of the selected pharmaceuticals during chlorine disinfection. PMID:21906777

  13. Graphite fiber intercalation: Dynamics of the bromine intercalation process

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Zinolabedini, R.

    1985-01-01

    The resistance of pitch-based graphite fibers was monitored, in situ, during a series of bromine intercalation experiments. The threshold pressure for the bromine intercalation of pitch-based fibers was estimated to be 102 torr. When the bromine atmosphere was removed from the reaction chamber, the resistivity of the intercalated graphite fibers increased consistently. This increase was attributed to loss of bromine from the perimeter of the fiber. The loss was confirmed by mapping the bromine concentration across the diameter of single intercalated fibers with either energy dispersive spectroscopy or scanning Auger microscopy. A statistical study comparing fibers intercalated in bromine vapor with fibers intercalated in bromine liquid showed that similar products were obtained with both methods of intercalation.

  14. Preparation of ionic membranes for zinc/bromine storage batteries

    NASA Astrophysics Data System (ADS)

    Assink, R. A.; Arnold, C., Jr.

    Zinc/bromine flow batteries are being developed for vehicular and utility load leveling applications. During charge, an aqueous zinc bromide salt is electrolyzed to zinc metal and molecular bromine. During discharge, the zinc and bromine react to again form the zinc bromide salt. One serious disadvantage of the microporous separators presently used in the zinc/bromine battery is that modest amounts of bromine and negatively charged bromine moieties permeate through these materials and react with the zinc anode. This results in partial self-discharge of the battery and low coulombic efficiencies. Our approach to this problem is to impregnate the microporous separators with a soluble cationic polyelectrolyte. In laboratory screening tests a sulfonated polysulfone resin and fully fluorinated sulfonic acid polymer substantially reduced bromine permeation with only modest increases in the area resistance.

  15. Development of rechargeable lithium-bromine batteries with lithium ion conducting solid electrolyte

    NASA Astrophysics Data System (ADS)

    Takemoto, Koshin; Yamada, Hirotoshi

    2015-05-01

    Electrochemical performances of a prototype lithium-bromine battery (LBB) employing a solid electrolyte is investigated. The discharge capacity decreases with repeating charge/discharge cycles. Electrochemical impedance analysis reveals that the capacity fading is mainly due to increase in the interfacial resistance between an aqueous active material solution and a solid electrolyte. Based on the results of symmetric cells and structural analysis of the surface of the solid electrolyte immersed in Br2 solutions, it is suggested that a Li+-depletion layer is formed on the surface of the solid electrolyte as a result of contact with bromine. Addition of tetraethylammonium bromide (TEABr) depresses the interfacial resistance, which results in improved cycleability. LBB with 1.0 M LiBr and 0.25 M TEABr shows discharge capacity of 139 mAh/g-LiBr and Coulombic efficiency of 99.6% at 5th cycle.

  16. Search for Possible Stratospheric Bromine Reservoir Species: Theoretical Study of the Photostability of Mono-, Tri-, and Pentacoordinated Bromine Compounds

    NASA Technical Reports Server (NTRS)

    Lee, TImothy J.; Mejia, Cesar N.; Beran, J. O.; Head-Gordon, Martin

    2004-01-01

    Previous work has shown that pentacoordinated bromine compounds have their lowest excited electronic states shifted to the blue relative to monocoordinated bromine molecules, and that this shift may be large enough to render them photostable in the lower stratosphere. Our earlier work has also shown that certain pentacoordinated bromine compounds are thermodynamically stable relative to their mono- or tricoordinated isomers, suggesting that if a bromine stratospheric reservoir species exists, then it is most likely a pentacoordinated compound. In this study we have examined the singlet excited electronic states of several bromine compounds in order to assess their photostability excited states in mono-, tri-, and pentacoordinated bromine molecules. Due to the strong spin-orbit mixing in bromine, we have also examined the lowest triplet excited state.

  17. Study of the liquid vapor equilibrium in the bromine-hydrobromic acid-water system

    NASA Technical Reports Server (NTRS)

    Benizri, R.; Lessart, P.; Courvoisier, P.

    1984-01-01

    A glass ebullioscope was built and at atmospheric pressure, liquid-vapor equilibria relative to the Br2-HBr-H2O system, in the concentration range of interest for evaluation of the Mark 13 cycle was studied. Measurements were performed for the brome-azeotrope (HBr-H2O) pseudo-binary system and for the ternary system at temperatures lower than 125 C and in the bromine concentration range up to 13% wt.

  18. Process for thermochemically producing hydrogen

    DOEpatents

    Bamberger, Carlos E.; Richardson, Donald M.

    1976-01-01

    Hydrogen is produced by the reaction of water with chromium sesquioxide and strontium oxide. The hydrogen producing reaction is combined with other reactions to produce a closed chemical cycle for the thermal decomposition of water.

  19. Thermochemical characteristics of chitosan-polylactide copolymers

    NASA Astrophysics Data System (ADS)

    Goruynova, P. E.; Larina, V. N.; Smirnova, N. N.; Tsverova, N. E.; Smirnova, L. A.

    2016-05-01

    The energies of combustion of chitosan and its block-copolymers with different polylactide contents are determined in a static bomb calorimeter. Standard enthalpies of combustion and formation are calculated for these substances. The dependences of the thermochemical characteristics on block-copolymer composition are determined and discussed.

  20. Intro to NREL's Thermochemical Pilot Plant

    SciTech Connect

    Magrini, Kim

    2013-09-27

    NREL's Thermochemical Pilot Plant converts biomass into higher hydrocarbon fuels and chemicals.NREL is researching biomass pyrolysis. The lab is examining how to upgrade bio-oils via stabilization. Along with this, NREL is developing the engineering system requirements for producing these fuels and chemicals at larger scales.

  1. 1982 annual report: Biomass Thermochemical Conversion Program

    SciTech Connect

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1983-01-01

    This report provides a brief overview of the Thermochemical Conversion Program's activities and major accomplishments during fiscal year 1982. The objective of the Biomass Thermochemical Conversion Program is to generate scientific data and fundamental biomass converison process information that, in the long term, could lead to establishment of cost effective processes for conversion of biomass resources into clean fuels and petrochemical substitutes. The goal of the program is to improve the data base for biomass conversion by investigating the fundamental aspects of conversion technologies and exploring those parameters which are critical to these conversion processes. To achieve this objective and goal, the Thermochemical Conversion Program is sponsoring high-risk, long-term research with high payoff potential which industry is not currently sponsoring, nor is likely to support. Thermochemical conversion processes employ elevated temperatures to convert biomass materials into energy. Process examples include: combustion to produce heat, steam, electricity, direct mechanical power; gasification to produce fuel gas or synthesis gases for the production of methanol and hydrocarbon fuels; direct liquefaction to produce heavy oils or distillates; and pyrolysis to produce a mixture of oils, fuel gases, and char. A bibliography of publications for 1982 is included.

  2. Biomass for thermochemical conversion: targets and challenges.

    PubMed

    Tanger, Paul; Field, John L; Jahn, Courtney E; Defoort, Morgan W; Leach, Jan E

    2013-01-01

    Bioenergy will be one component of a suite of alternatives to fossil fuels. Effective conversion of biomass to energy will require the careful pairing of advanced conversion technologies with biomass feedstocks optimized for the purpose. Lignocellulosic biomass can be converted to useful energy products via two distinct pathways: enzymatic or thermochemical conversion. The thermochemical pathways are reviewed and potential biotechnology or breeding targets to improve feedstocks for pyrolysis, gasification, and combustion are identified. Biomass traits influencing the effectiveness of the thermochemical process (cell wall composition, mineral and moisture content) differ from those important for enzymatic conversion and so properties are discussed in the language of biologists (biochemical analysis) as well as that of engineers (proximate and ultimate analysis). We discuss the genetic control, potential environmental influence, and consequences of modification of these traits. Improving feedstocks for thermochemical conversion can be accomplished by the optimization of lignin levels, and the reduction of ash and moisture content. We suggest that ultimate analysis and associated properties such as H:C, O:C, and heating value might be more amenable than traditional biochemical analysis to the high-throughput necessary for the phenotyping of large plant populations. Expanding our knowledge of these biomass traits will play a critical role in the utilization of biomass for energy production globally, and add to our understanding of how plants tailor their composition with their environment. PMID:23847629

  3. Intro to NREL's Thermochemical Pilot Plant

    ScienceCinema

    Magrini, Kim

    2014-06-10

    NREL's Thermochemical Pilot Plant converts biomass into higher hydrocarbon fuels and chemicals.NREL is researching biomass pyrolysis. The lab is examining how to upgrade bio-oils via stabilization. Along with this, NREL is developing the engineering system requirements for producing these fuels and chemicals at larger scales.

  4. 2009 Thermochemical Conversion Platform Review Report

    SciTech Connect

    Ferrell, John

    2009-12-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass Program’s Thermochemical Conversion platform review meeting, held on April 14-16, 2009, at the Sheraton Denver Downtown, Denver, Colorado.

  5. Biomass for thermochemical conversion: targets and challenges

    PubMed Central

    Tanger, Paul; Field, John L.; Jahn, Courtney E.; DeFoort, Morgan W.; Leach, Jan E.

    2013-01-01

    Bioenergy will be one component of a suite of alternatives to fossil fuels. Effective conversion of biomass to energy will require the careful pairing of advanced conversion technologies with biomass feedstocks optimized for the purpose. Lignocellulosic biomass can be converted to useful energy products via two distinct pathways: enzymatic or thermochemical conversion. The thermochemical pathways are reviewed and potential biotechnology or breeding targets to improve feedstocks for pyrolysis, gasification, and combustion are identified. Biomass traits influencing the effectiveness of the thermochemical process (cell wall composition, mineral and moisture content) differ from those important for enzymatic conversion and so properties are discussed in the language of biologists (biochemical analysis) as well as that of engineers (proximate and ultimate analysis). We discuss the genetic control, potential environmental influence, and consequences of modification of these traits. Improving feedstocks for thermochemical conversion can be accomplished by the optimization of lignin levels, and the reduction of ash and moisture content. We suggest that ultimate analysis and associated properties such as H:C, O:C, and heating value might be more amenable than traditional biochemical analysis to the high-throughput necessary for the phenotyping of large plant populations. Expanding our knowledge of these biomass traits will play a critical role in the utilization of biomass for energy production globally, and add to our understanding of how plants tailor their composition with their environment. PMID:23847629

  6. Thermochemical Conversion Pilot Plant (Fact Sheet)

    SciTech Connect

    Not Available

    2013-06-01

    The state-of-the-art thermochemical conversion pilot plant includes several configurable, complementary unit operations for testing and developing various reactors, filters, catalysts, and other unit operations. NREL engineers and scientists as well as clients can test new processes and feedstocks in a timely, cost-effective, and safe manner to obtain extensive performance data on processes or equipment.

  7. Brominated flame retardants: cause for concern?

    PubMed Central

    Birnbaum, Linda S; Staskal, Daniele F

    2004-01-01

    Brominated flame retardants (BFRs) have routinely been added to consumer products for several decades in a successful effort to reduce fire-related injury and property damage. Recently, concern for this emerging class of chemicals has risen because of the occurrence of several classes of BFRs in the environment and in human biota. The widespread production and use of BFRs; strong evidence of increasing contamination of the environment, wildlife, and people; and limited knowledge of potential effects heighten the importance of identifying emerging issues associated with the use of BFRs. In this article, we briefly review scientific issues associated with the use of tetrabromobisphenol A, hexabromocyclododecane, and three commercial mixtures of polybrominated diphenyl ethers and discuss data gaps. Overall, the toxicology database is very limited; the current literature is incomplete and often conflicting. Available data, however, raise concern over the use of certain classes of brominated flame retardants. PMID:14698924

  8. Bromine-containing source gases during EASOE

    SciTech Connect

    Fabian, P. ); Borchers, R.; Kourtidis, K. )

    1994-06-22

    The authors report three different vertical profile measurements of three bromine containing gases which are thought to be the major sources of active bromine in the stratosphere. These gases are CBrClF[sub 2] (Halon-1211), CBrF[sub 3] (Halon-1301) and methyl bromide (CH[sub 3]Br). They were sampled using cryogenic samplers from balloon borne flights from Kiruna during January, February and March 1992. The two halons are of anthropogenic origin, while methyl bromide is thought to have a relatively large natural origin. Consistent with the decrease in concentration of these gases with altitude was an increase in the density of BrO[sub x] with altitude.

  9. Marine bacterial degradation of brominated methanes

    USGS Publications Warehouse

    Goodwin, K.D.; Lidstrom, M.E.; Oremland, R.S.

    1997-01-01

    Brominated methanes are ozone-depleting compounds whose natural sources include marine algae such as kelp. Brominated methane degradation by bacteria was investigated to address whether bacterial processes might effect net emission of these compounds to the atmosphere. Bacteria in seawater collected from California kelp beds degraded CH2Br2 but not CHBr3. Specific inhibitors showed that methanotrophs and nitrifiers did not significantly contribute to CH2Br2 removal. A seawater enrichment culture oxidized 14CH2Br2 to 14CO2 as well as 14CH3Br to 14CO2. The rates of CH2Br2 degradation in laboratory experiments suggest that bacterial degradation of CH2Br2 in a kelp bed accounts for <1% of the CH2Br2 produced by the kelp. However, the half-life of CH2Br2 due to bacterial removal appears faster than hydrolysis and within an order of magnitude of volatilization to the atmosphere.Brominated methanes are ozone-depleting compounds whose natural sources include marine algae such as kelp. Brominated methane degradation by bacteria was investigated to address whether bacterial processes might effect net emission of these compounds to the atmosphere. Bacteria in seawater collected from California kelp beds degraded CH2Br2 but not CHBr3. Specific inhibitors showed that methanotrophs and nitrifiers did not significantly contribute to CH2Br2 removal. A seawater enrichment culture oxidized 14CH2Br2 to 14CO2 as well as 14CH3Br to 14CO2. The rates of CH2Br2 degradation in laboratory experiments suggest that bacterial degradation of CH2Br2 in a kelp bed accounts for <1% of the CH2Br2 produced by the kelp. However, the half-life of CH2Br2 due to bacterial removal appears faster than hydrolysis and within an order of magnitude of volatilization to the atmosphere.

  10. Chemical engineering challenges in driving thermochemical hydrogen processes with the tandem mirror reactor

    SciTech Connect

    Galloway, T.R.; Werner, R.W.

    1980-01-01

    The Tandem Mirror Reactor is described and compared with Tokamaks, both from a basic physics viewpoint and from the suitability of the respective reactor for synfuel production. Differences and similarities between the TMR as an electricity producer or a synfuel producer are also cited. The Thermochemical cycle chosen to link with the fusion energy source is the General Atomic Sulfur-Iodine Cycle, which is a purely thermal-driven process with no electrochemical steps. There are real chemical engineering challenges of getting this high quality heat into the large thermochemical plant in an efficient manner. We illustrate with some of our approaches to providing process heat via liquid sodium to drive a 1050 K, highly-endothermic, catalytic and fluidized-bed SO/sub 3/ Decomposition Reactor. The technical, economic, and safety tradeoffs that arise are discussed.

  11. Moving bed reactor for solar thermochemical fuel production

    DOEpatents

    Ermanoski, Ivan

    2013-04-16

    Reactors and methods for solar thermochemical reactions are disclosed. Embodiments of reactors include at least two distinct reactor chambers between which there is at least a pressure differential. In embodiments, reactive particles are exchanged between chambers during a reaction cycle to thermally reduce the particles at first conditions and oxidize the particles at second conditions to produce chemical work from heat. In embodiments, chambers of a reactor are coupled to a heat exchanger to pre-heat the reactive particles prior to direct exposure to thermal energy with heat transferred from reduced reactive particles as the particles are oppositely conveyed between the thermal reduction chamber and the fuel production chamber. In an embodiment, particle conveyance is in part provided by an elevator which may further function as a heat exchanger.

  12. Course of bromination of thiazole and 2-methylthiazole

    SciTech Connect

    Gol'dfarb, Ya. L.; Belen'kii, L.I.; Gromova, G.P.

    1986-12-01

    Bromination of thiazole by bromine in the presence of aluminum chloride in neutral solvent or without solvent takes place at the 2-position. Such an orientation contradicts the traditional addition-cleavage mechanism, and agrees with the ylid mechanism of electrophilic substitution. 2-Methylthiazole brominates at the 5-position, and the reaction is impeded in the presence of aluminum chloride; this is due to heterocycle deactivation by complexation with the Lewis acid at the nitrogen atom.

  13. Hydrogen-bromine fuel cell advance component development

    NASA Technical Reports Server (NTRS)

    Charleston, Joann; Reed, James

    1988-01-01

    Advanced cell component development is performed by NASA Lewis to achieve improved performance and longer life for the hydrogen-bromine fuel cells system. The state-of-the-art hydrogen-bromine system utilizes the solid polymer electrolyte (SPE) technology, similar to the SPE technology developed for the hydrogen-oxygen fuel cell system. These studies are directed at exploring the potential for this system by assessing and evaluating various types of materials for cell parts and electrode materials for Bromine-hydrogen bromine environment and fabricating experimental membrane/electrode-catalysts by chemical deposition.

  14. A web service infrastructure for thermochemical data.

    PubMed

    Paolini, Christopher P; Bhattacharjee, Subrata

    2008-07-01

    W3C standardized Web Services are becoming an increasingly popular middleware technology used to facilitate the open exchange of chemical data. While several projects in existence use Web Services to wrap existing commercial and open-source tools that mine chemical structure data, no Web Service infrastructure has yet been developed to compute thermochemical properties of substances. This work presents an infrastructure of Web Services for thermochemical data retrieval. Several examples are presented to demonstrate how our Web Services can be called from Java, through JavaScript using an AJAX methodology, and within commonly used commercial applications such as Microsoft Excel and MATLAB for use in computational work. We illustrate how a JANAF table, widely used by chemists and engineers, can be quickly reproduced through our Web Service infrastructure. PMID:18543903

  15. Brominated thiophenes as precursors in the preparation of brominated and arylated anthraquinones.

    PubMed

    Thiemann, Thies; Tanaka, Yasuko; Iniesta, Jesus

    2009-01-01

    Brominated anthraquinones can be synthesized directly from bromothiophenes when these are reacted with 1,4-naphthoquinones in the presence of meta-chloroperoxybenzoic acid. The bromoanthraquinones are versatile building blocks in the preparation of arylated anthraquinones and of extended pi-systems with interspersed anthraquinone units. PMID:19305356

  16. Electrochemical & Thermochemical Behavior of Cerium(IV) Oxide delta

    NASA Astrophysics Data System (ADS)

    Chueh, William C.

    reoxidized to form H2, CO, and/or CH4. Analysis of gas evolution rates confirms that the kinetics of ceria oxidation by H2O and CO2 are dominated by surface reactions, rather than by ambipolar oxygen diffusion. Temperature-programmed oxidation experiments revealed that, even under thermodynamically favored conditions, carbonaceous species do not form on the surface of neat ceria, thereby giving a high CO selectivity when dissociating CO2. A scaled-up ceria-based solar reactor was designed and tested to demonstrate the feasibility of solar fuel production via thermochemical cycling.

  17. Thermochemical Modeling of the Uranium-Cerium-Oxygen System

    SciTech Connect

    Voit, Stewart L; Besmann, Theodore M

    2010-10-01

    The objective of the Fuel Cycle R&D Program, Advanced Fuels campaign is to provide the research and development necessary to develop low loss, high quality nuclear fuels for ultra-high burnup reactor operation. Primary work in this area will be focused on the ceramic and metallic fuel systems. The goal of the current work is to enhance the understanding of ceramic nuclear fuel thermochemistry to support fuel research and development efforts. The thermochemical behavior of oxide nuclear fuel under irradiation is dependent on the oxygen to metal ratio (O:M). In fluorite-structured fuel, the actinide metal cation is bonded with {approx}2 oxygen atoms on a crystal lattice and as the metal atoms fission, fission fragments and free oxygen are created. The resulting fission fragments will contain some oxide forming elements, however these are insufficient to bind to all the liberated oxygen and therefore, there is an average increase in O:M with fuel burnup. Some of the fission products also form species that will migrate to and react with the cladding surface in a phenomenon known as Fuel Clad Chemical Interaction (FCCI). Cladding corrosion is life-limiting so it is desirable to understand influencing factors, such as oxide thermochemistry, which can be used to guide the design and fabrication of higher burn up fuel. A phased oxide fuel thermochemical model development effort is underway within the Advanced Fuels Campaign. First models of binary oxide systems are developed. For nuclear fuel system this means U-O and transuranic systems such as Pu-O, Np-O and Am-O. Next, the binary systems will be combined to form pseudobinary systems such as U-Pu-O, etc. The model development effort requires the use of data to allow optimization based on known thermochemical parameters as a function of composition and temperature. Available data is mined from the literature and supplemented by experimental work as needed. Due to the difficulty of performing fuel fabrication development

  18. The Addition of Bromine to 1,2-Diphenylethene

    ERIC Educational Resources Information Center

    Amburgey-Peters, Judith C.; Haynes, Leroy W.

    2005-01-01

    The bromination of 1,2-diphenylethene, using a variety of solvents and brominating agents, can be used in both introductory and advanced organic chemistry courses. The reactions can be used to illustrate the effects of changing solvents and reagents, as well as to reveal interesting aspects of organic reaction mechanisms.

  19. 40 CFR 721.10534 - Brominated aliphatic alcohol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Brominated aliphatic alcohol (generic... Specific Chemical Substances § 721.10534 Brominated aliphatic alcohol (generic). (a) Chemical substance and... aliphatic alcohol (PMN P-12-260) is subject to reporting under this section for the significant new...

  20. 40 CFR 721.10534 - Brominated aliphatic alcohol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Brominated aliphatic alcohol (generic... Specific Chemical Substances § 721.10534 Brominated aliphatic alcohol (generic). (a) Chemical substance and... aliphatic alcohol (PMN P-12-260) is subject to reporting under this section for the significant new...

  1. The BRomine, Ozone, and Mercury EXperiment (BROMEX)

    NASA Astrophysics Data System (ADS)

    Nghiem, S. V.; Shepson, P. B.; Simpson, W. R.; Perovich, D. K.; Sturm, M.; Douglas, T. A.; Rigor, I. G.; Clemente-Colon, P.; Burrows, J. P.; Richter, A.; Bottenheim, J. W.; Steffen, A.; Barber, D. G.; Kaleschke, L.; Hall, D. K.; Markus, T.; Eicken, H.; Neumann, G.

    2011-12-01

    In the decade of the 2000s, Arctic perennial (multi-year) sea ice has diminished drastically, whereas seasonal (first-year) sea ice has become the dominant ice class. This change effectively increases the overall surface salinity of the sea ice cover and in the overlying snowpack. Satellite results in 2010 and 2011 show the extent of perennial sea ice remains minimal with significant bromine explosions in the springtime. Key science questions still remain to be answered to understand the impact of the Arctic perennial sea ice reduction on low-atmospheric physical and chemical processes. Of the highest priority is to investigate the impact on bromine explosion events that lead to depletion of ozone and gaseous elementary mercury in the atmosphere. With that objective, we present the development of the BRomine, Ozone, and Mercury EXperiment in (BROMEX) in spring 2012 around Barrow, extending out to 200 km offshore and inland. In BROMEX, chemical, sea ice, snow, and ocean measurements will be made across sea ice leads both upwind and downwind areas of newly opened leads. Chemical-measurement buoys and other types of buoys will be deployed with helicopter flights to both sides of the leads. Various flight patterns of aircraft carrying ozone and bromine-measuring sensors will be used to characterize the chemical distribution over sea ice, land, and mountainous regions. Our approach will use data from multiple satellite instruments including MODIS, AMSR-E, QuikSCAT, GOME-2, SCIAMACHY, OMI, RADARSAT-2, Envisat ASAR, TerraSAR-X, TanDEM-X, SMOS, CryoSat-2 altimeter, and Oceansat-2 scatterometer. Moreover, results from recent field campaigns such as the IPY OASIS, INCATPA, CFL, SALT, and IceBridge, from sea ice and snow products generated by the U.S. Naval and National Ice Center, from NASA cryospheric observations, and from surface observation networks such as SIZONet will be utilized together with new measurements from BROMEX. Further collaborations with the international

  2. Effects of milling brominated P-100 graphite fibers

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Dillehay, Michael E.; Hambourger, Paul D.

    1987-01-01

    Preliminary procedures have been developed for the ball milling of pristine and brominated P-100 graphite fibers. Because of the lubricative properties of graphite, large ball loads (50 percent by volume) are required. Use of 2-propanol as a milling medium enhances the efficiency of the process. The fibers, when allowed to settle from the milling medium, tend to be preferentially aligned with rather few fibers standing up. Milled, brominated P-100 fibers have resistivities that are indistinguishable from their pristine counterparts, apparently because of loss of bromine. This suggests that bromine would not be the intercalate of choice in applications where milled fibers of this type are required. It was found that brominated graphite fibers are stable in a wide variety of organic solvents.

  3. Toxic effects of brominated indoles and phenols on zebrafish embryos.

    PubMed

    Kammann, U; Vobach, M; Wosniok, W

    2006-07-01

    Organobromine compounds in the marine environment have been the focus of growing attention in past years. In contrast to anthropogenic brominated flame retardants, other brominated compounds are produced naturally, e.g., by common polychaete worms and algae. Brominated phenols and indoles assumed to be of biogenic origin have been detected in water and sediment extracts from the German Bight. These substances as well as some of their isomers have been tested with the zebrafish embryo test and were found to cause lethal as well as nonlethal malformations. The zebrafish test was able to detect a log K(OW)-related toxicity for bromophenols, suggesting nonpolar narcosis as a major mode of action. Different effect patterns could be observed for brominated indoles and bromophenols. The comparison of effective concentrations in the zebrafish embryo test with the concentrations determined in water samples suggests the possibility that brominated indoles may affect early life stages of marine fish species in the North Sea. PMID:16418895

  4. Ammonia synthesis for producing supercritical steam in the context of solar thermochemical energy storage

    NASA Astrophysics Data System (ADS)

    Chen, Chen; Aryafar, Hamarz; Warrier, Gopinath; Lovegrove, Keith M.; Lavine, Adrienne S.

    2016-05-01

    In ammonia-based solar thermochemical energy storage systems, the stored energy is released when the hydrogen (H2) and nitrogen (N2) react exothermically to synthesize ammonia (NH3), providing thermal energy to a power block for electricity generation. However, ammonia synthesis has not yet been shown to reach temperatures consistent with the highest performance modern power blocks. Two similar ammonia synthesis reactors with different lengths have been used to study the ammonia synthesis reaction at high temperature and pressure and to begin the process of model improvement and validation. With the longer reactor, supercritical steam with flow rate up to 0.09 g/s has been heated from less than 350°C to ˜650°C. This result shows the technical feasibility of using ammonia-based thermochemical energy storage in a CSP plant with a supercritical steam Rankine cycle power block.

  5. Thermochemical energy storage with ammonia: Aiming for the sunshot cost target

    NASA Astrophysics Data System (ADS)

    Lavine, Adrienne S.; Lovegrove, Keith M.; Jordan, Joshua; Anleu, Gabriela Bran; Chen, Chen; Aryafar, Hamarz; Sepulveda, Abdon

    2016-05-01

    Thermochemical energy storage has the potential to reduce the cost of concentrating solar thermal power. This paper presents recent advances in ammonia-based thermochemical energy storage (TCES), supported by an award from the U.S. Dept. of Energy SunShot program. Advances have been made in three areas: identification of promising approaches for underground containment of the gaseous products of the dissociation reaction, demonstration that ammonia synthesis can be used to generate steam for a supercritical-steam Rankine cycle, and a preliminary design for integration of the endothermic reactors within a tower receiver. Based on these advances, ammonia-based TCES shows promise to meet the 15/kWht SunShot cost target.

  6. CuC1 thermochemical cycle for hydrogen production

    DOEpatents

    Fan, Qinbai; Liu, Renxuan

    2012-01-03

    An electrochemical cell for producing copper having a dense graphite anode electrode and a dense graphite cathode electrode disposed in a CuCl solution. An anion exchange membrane made of poly(ethylene vinyl alcohol) and polyethylenimine cross-linked with a cross-linking agent selected from the group consisting of acetone, formaldehyde, glyoxal, glutaraldehyde, and mixtures thereof is disposed between the two electrodes.

  7. Design and construction of a cascading pressure reactor prototype for solar-thermochemical hydrogen production

    NASA Astrophysics Data System (ADS)

    Ermanoski, Ivan; Grobbel, Johannes; Singh, Abhishek; Lapp, Justin; Brendelberger, Stefan; Roeb, Martin; Sattler, Christian; Whaley, Josh; McDaniel, Anthony; Siegel, Nathan P.

    2016-05-01

    Recent work regarding the efficiency maximization for solar thermochemical fuel production in two step cycles has led to the design of a new type of reactor—the cascading pressure reactor—in which the thermal reduction step of the cycle is completed in multiple stages, at successively lower pressures. This approach enables lower thermal reduction pressures than in single-staged reactors, and decreases required pump work, leading to increased solar to fuel efficiencies. Here we report on the design and construction of a prototype cascading pressure reactor and testing of some of the key components. We especially focus on the technical challenges particular to the design, and their solutions.

  8. New infrared spectroscopic database for bromine nitrate

    NASA Astrophysics Data System (ADS)

    Wagner, Georg; Birk, Manfred

    2016-08-01

    Fourier transform infrared measurements of bromine nitrate have been performed in the spectral region 675-1400 cm-1 at 0.014 cm-1 spectral resolution. Absorption cross sections were derived from 38 spectra covering the temperature range from 203 to 296 K and air pressure range from 0 to 190 mbar. For line-by-line analysis, further spectra were recorded at 0.00094 cm-1 spectral resolution at 223 and 293 K. The sample was synthesized from ClONO2 and Br2. Band strengths of the bands ν3 around 803 cm-1 and ν2 around 1286 cm-1 were determined from three pure BrONO2 measurements at different temperatures and pressures. Number densities in the absorption cell were derived from pressure measurements of the purified sample taking into account small amounts of impurities determined spectroscopically. Resulting band strengths are Sν3 = 2.872(52) × 10-17 cm2 molec-1 cm-1 and Sν2 = 3.63(15) × 10-17 cm2 molec-1 cm-1. Absorption cross sections of all measurements were scaled to these band strengths. Further data reduction was achieved with an interpolation scheme based on two-dimensional polynomials in ln(pressure) and temperature. The database is well-suited for remote-sensing application and should reduce the atmospheric bromine nitrate error budget substantially.

  9. Heterogeneous processing of bromine compounds by atmospheric aerosols: Relation to the ozone budget

    SciTech Connect

    Robinson, J.M.; Henson, B.F.; Dubey, M.K.; Casson, J.L.; Johal, M.S.; Wilson, K.R.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The depletion of ozone, particularly above Antarctica, has been investigated extensively to formulate public policy on the use of halocarbons. While it has been shown that heterogeneous reactions of chlorine compounds on stratospheric particulates cause the ozone hole, little is known of the analogous bromine mechanisms, even though it has been recognized for two decades that catalytic destruction of ozone by bromine could be more efficient than chlorine. Furthermore, field measurements and modeling calculations suggest that these heterogeneous (gas/surface) reactions are not restricted to the Antarctic regions but occur globally. The authors have performed laboratory measurements of the uptake of bromine compounds and other halogens on simulated stratospheric aerosols to help elucidate their role in catalytic ozone destruction cycles. Their studies contribute to the data base required to make assessments of the effects of human activities on global change, including the Montreal Protocol.

  10. Thermochemical Process Development Unit: Researching Fuels from Biomass, Bioenergy Technologies (Fact Sheet)

    SciTech Connect

    Not Available

    2009-01-01

    The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a unique facility dedicated to researching thermochemical processes to produce fuels from biomass.

  11. 40 CFR 415.290 - Applicability; description of the bromine production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... bromine production subcategory. 415.290 Section 415.290 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bromine Production Subcategory § 415.290 Applicability; description of the bromine production... bromine by the brine-mining process and by the Trona process....

  12. 40 CFR 415.290 - Applicability; description of the bromine production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... bromine production subcategory. 415.290 Section 415.290 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bromine Production Subcategory § 415.290 Applicability; description of the bromine production... bromine by the brine-mining process and by the Trona process....

  13. 40 CFR 415.290 - Applicability; description of the bromine production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... bromine production subcategory. 415.290 Section 415.290 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bromine Production Subcategory § 415.290 Applicability; description of the bromine production... bromine by the brine-mining process and by the Trona process....

  14. 40 CFR 415.290 - Applicability; description of the bromine production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... bromine production subcategory. 415.290 Section 415.290 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bromine Production Subcategory § 415.290 Applicability; description of the bromine production... bromine by the brine-mining process and by the Trona process....

  15. 40 CFR 415.290 - Applicability; description of the bromine production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... bromine production subcategory. 415.290 Section 415.290 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bromine Production Subcategory § 415.290 Applicability; description of the bromine production... bromine by the brine-mining process and by the Trona process....

  16. Cyclic Performance Analysis of Hydrogen/Bromine Flow Batteries for Grid-Scale Energy Storage

    SciTech Connect

    Cho, KT; Tucker, MC; Ding, M; Ridgway, P; Battaglia, VS; Srinivasan, V; Weber, AZ

    2014-06-03

    This paper explores the critical factors dominating the cycle performance of the hydrogen/bromine redox flow battery (RFB). Carbon electrode oxidation to CO2 was seen as the dominant side reaction, which can be prevented by operating the cell below 1.4 V. Crossover of bromide species from the positive to the negative electrode, especially during charge, dominates the coulombic efficiency, and can result in dissolution of the Pt catalyst if an adequate hydrogen supply is not maintained. This paper also describes the tradeoffs in voltaic, energy, and coulombic efficiencies during cycling, including the determination of the peak energy efficiency with respect to the HBr concentration and current density. Long-term cycling demonstrates negligible cell-component degradation over 600 cycles (approximate to 3 months), with capacity loss caused by the bromine from the system, which can be mitigated by proper system design. The data and methodologies provided in this paper can be used to understand better the operation of this and other RFBs.

  17. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER

    SciTech Connect

    PROJECT STAFF

    2011-10-31

    Thermal energy storage (TES) is an integral part of a concentrated solar power (CSP) system. It enables plant operators to generate electricity beyond on sun hours and supply power to the grid to meet peak demand. Current CSP sensible heat storage systems employ molten salts as both the heat transfer fluid and the heat storage media. These systems have an upper operating temperature limit of around 400 C. Future TES systems are expected to operate at temperatures between 600 C to 1000 C for higher thermal efficiencies which should result in lower electricity cost. To meet future operating temperature and electricity cost requirements, a TES concept utilizing thermochemical cycles (TCs) based on multivalent solid oxides was proposed. The system employs a pair of reduction and oxidation (REDOX) reactions to store and release heat. In the storage step, hot air from the solar receiver is used to reduce the oxidation state of an oxide cation, e.g. Fe3+ to Fe2+. Heat energy is thus stored as chemical bonds and the oxide is charged. To discharge the stored energy, the reduced oxide is re-oxidized in air and heat is released. Air is used as both the heat transfer fluid and reactant and no storage of fluid is needed. This project investigated the engineering and economic feasibility of this proposed TES concept. The DOE storage cost and LCOE targets are $15/kWh and $0.09/kWh respectively. Sixteen pure oxide cycles were identified through thermodynamic calculations and literature information. Data showed the kinetics of re-oxidation of the various oxides to be a key barrier to implementing the proposed concept. A down selection was carried out based on operating temperature, materials costs and preliminary laboratory measurements. Cobalt oxide, manganese oxide and barium oxide were selected for developmental studies to improve their REDOX reaction kinetics. A novel approach utilizing mixed oxides to improve the REDOX kinetics of the selected oxides was proposed. It partially

  18. Thermochemical property estimation of hydrogenated silicon clusters.

    PubMed

    Adamczyk, Andrew J; Broadbelt, Linda J

    2011-08-18

    The thermochemical properties for selected hydrogenated silicon clusters (Si(x)H(y), x = 3-13, y = 0-18) were calculated using quantum chemical calculations and statistical thermodynamics. Standard enthalpy of formation at 298 K and standard entropy and constant pressure heat capacity at various temperatures, i.e., 298-6000 K, were calculated for 162 hydrogenated silicon clusters using G3//B3LYP. The hydrogenated silicon clusters contained ten to twenty fused Si-Si bonds, i.e., bonds participating in more than one three- to six-membered ring. The hydrogenated silicon clusters in this study involved different degrees of hydrogenation, i.e., the ratio of hydrogen to silicon atoms varied widely depending on the size of the cluster and/or degree of multifunctionality. A group additivity database composed of atom-centered groups and ring corrections, as well as bond-centered groups, was created to predict thermochemical properties most accurately. For the training set molecules, the average absolute deviation (AAD) comparing the G3//B3LYP values to the values obtained from the revised group additivity database for standard enthalpy of formation and entropy at 298 K and constant pressure heat capacity at 500, 1000, and 1500 K were 3.2%, 1.9%, 0.40%, 0.43%, and 0.53%, respectively. Sensitivity analysis of the revised group additivity parameter database revealed that the group parameters were able to predict the thermochemical properties of molecules that were not used in the training set within an AAD of 3.8% for standard enthalpy of formation at 298 K. PMID:21728331

  19. Use of Bromine and Bromo-Organic Compounds in Organic Synthesis.

    PubMed

    Saikia, Indranirekha; Borah, Arun Jyoti; Phukan, Prodeep

    2016-06-22

    Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis. PMID:27199233

  20. Hydrogen-Bromine Flow Battery: Hydrogen Bromine Flow Batteries for Grid Scale Energy Storage

    SciTech Connect

    2010-10-01

    GRIDS Project: LBNL is designing a flow battery for grid storage that relies on a hydrogen-bromine chemistry which could be more efficient, last longer and cost less than today’s lead-acid batteries. Flow batteries are fundamentally different from traditional lead-acid batteries because the chemical reactants that provide their energy are stored in external tanks instead of inside the battery. A flow battery can provide more energy because all that is required to increase its storage capacity is to increase the size of the external tanks. The hydrogen-bromine reactants used by LBNL in its flow battery are inexpensive, long lasting, and provide power quickly. The cost of the design could be well below $100 per kilowatt hour, which would rival conventional grid-scale battery technologies.

  1. Thermochemical energy storage for a lunar base

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Mckissock, Barbara I.; Difilippo, Frank

    1992-01-01

    A thermochemical solar energy storage concept involving the reversible reaction CaO + H2O yields Ca(OH)2 is proposed as a power system element for a lunar base. The operation and components of such a system are described. The CaO/H2O system is capable of generating electric power during both the day and night. Mass of the required amount of CaO is neglected since it is obtained from lunar soil. Potential technical problems, such as reactor design and lunar soil processing, are reviewed.

  2. Bromine content and brominated flame retardants in food and animal feed from the UK.

    PubMed

    Fernandes, A R; Mortimer, D; Rose, M; Smith, F; Panton, S; Garcia-Lopez, M

    2016-05-01

    Current occurrence data for polybrominated diphenyl ethers (PBDE) and hexa-bromocyclododecane (HBCD) measured in most commonly consumed foods (n = 156) and animal feeds (n = 51) sampled in the UK, demonstrates an ongoing ubiquity of these contaminants in human and animal diets. PBDE concentrations for the sum of 17 measured congeners ranged from 0.02 ng/g to 8.91 ng/g whole weight for food, and 0.11 ng/g to 9.63 ng/g whole weight for animal feeds. The highest concentration ranges, and mean values were detected in fish, processed foods and fish feeds. HBCD diastereomers (alpha-HBCD was the most commonly detected) generally occurred at lower concentrations (from <0.01 ng/g to 10.1 ng/g for food and <0.01 ng/g to 0.66 ng/g for animal feed) and less frequently than PBDEs, but tetrabromobisphenol A which was also measured, was rarely detected. The total bromine content of the samples was also determined in an attempt to use a mass balance approach to investigate some of these samples for the occurrence of novel and emerging BFRs. Although the approach was further refined by measuring organic bromine content, the concentrations of bromine were too high (in most cases by orders of magnitude) to allow use of the approach. A selected sub-set of samples was screened by GC-MS, for the presence of novel/emerging brominated flame retardants (PBT, TBX, PBEB, DBHCTD, HCTBPH and OBTMPI) but these were not detected at the higher limits of detection that result from full scan (GC-MS) screening. This data will contribute to the EU wide risk assessment on these contaminants. PMID:26733012

  3. Production of bromoform and dibromomethane by Giant Kelp: Factors affecting release and comparison to anthropogenic bromine sources

    USGS Publications Warehouse

    Goodwin, K.D.; North, W.J.; Lidstrom, M.E.

    1998-01-01

    Macrocystis pyrifera (Giant Kelp), a dominant macroalgal species in southern California, produced 171 ng per g fresh wt (gfwt) per day of CHBr3 and 48 ng gfwt-1 d-1 of CH2Br2 during laboratory incubations of whole blades. Comparable rates were measured during in situ incubations of intact fronds. Release of CHBr3 and CH2Br2 by M. pyrifera was affected by light and algal photosynthetic activity, suggesting that environmental factors influencing kelp physiology can affect halomethane release to the atmosphere. Data from H2O2 additions suggest that brominated methane production during darkness is limited by bromide oxidant supply. A bromine budget constructed for a region of southern California indicated that bromine emitted from the use of CH3Br as a fumigant (1 x 108 g Br yr-1) dominates macroalgal sources (3 x 106 g Br yr-1). Global projections, however, suggest that combined emissions of marine algae (including microalgae) contribute substantial amounts of bromine to the global cycle, perhaps on the same order of magnitude as anthropogenic sources.

  4. Ruthenium-Catalyzed meta-Selective C—H Bromination

    PubMed Central

    Teskey, Christopher J; Lui, Andrew Y W; Greaney, Michael F

    2015-01-01

    The first example of a transition-metal-catalyzed, meta-selective C–H bromination procedure is reported. In the presence of catalytic [{Ru(p-cymene)Cl2}2], tetrabutylammonium tribromide can be used to functionalize the meta C–H bond of 2-phenylpyridine derivatives, thus affording difficult to access products which are highly predisposed to further derivatization. We demonstrate this utility with one-pot bromination/arylation and bromination/alkenylation procedures to deliver meta-arylated and meta-alkenylated products, respectively, in a single step. PMID:26288217

  5. Properties and potential applications of brominated P-100 carbon fibers

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Gaier, J. R.; Hung, C. C.; Banks, B. A.

    1986-01-01

    A review of the properties and potential applications of bromine-intercalated pitch-based carbon fibers is presented. The dynamics of the intercalation reaction are summarized, and characteristics, such as resistivity, density, and stability, are discussed. In addition, the mechanical and electrical properties of bromine-intercalated fiber-epoxy conposites will be addressed. With conductivities comparable to stainless steel, these brominated carbon fibers may be used in a number of composite applications, such as electromagnetic interference shielding containers, large conductive space structures, lightning strike-tolerant aircraft surfaces, and aircraft deicing applications.

  6. Alkaline reforming of brominated fire-retardant plastics: fate of bromine and antimony.

    PubMed

    Onwudili, Jude A; Williams, Paul T

    2009-02-01

    High-impact polystyrene (HIPS) flame retarded with decabromodiphenyl ether (DDE), has been reacted in supercritical water from 380 to 450 degrees C and 21.5 to 31.0 MPa pressure in a batch reactor. Different concentrations of sodium hydroxide additive were used in situ to neutralize the corrosive inorganic bromine species released during the reactions. It appeared that supercritical water conditions lowered the decomposition temperature of both the fire-retardant DDE and HIPS. The reaction products included oils (up to 76 wt%), char (up to 18 wt%) and gas (up to 2.4 wt%) which was mainly methane. The presence of the alkaline water led to up to 97 wt% debromination of the product oil, producing virtually bromine-free oil feedstock. The removal of antimony from the oil product during processing was of the order of 98 wt%. The oil consisted of many single- and multiple-ringed aromatic compounds, many of which had alkyl substituents and/or aliphatic C(n)-bridges (n=1-4). The major single-ringed compounds included toluene, xylenes, ethylbenzene, propylbenzene and alpha-methylstyrene. Bibenzyl (diphenylethane), stilbene, diphenylmethane, diphenylpropane, diphenylcyclopropane, diphenylpropene, diphenylbutane, diphenylbutene and diphenylbuta-1,3-diene were the major C(n)-bridged compounds. Diphenyl ether and acetophenone were the major oxygenated compounds found. The process thus has the potential to produce bromine-free and antimony-free oils from fire-retardant plastics. PMID:19054543

  7. In search of stratospheric bromine oxide

    NASA Technical Reports Server (NTRS)

    Lestrade, John Patrick

    1986-01-01

    The Imaging Spectrometric Observatory (ISO) is capable of recording spectra in the wavelength range of 200 to 12000 Angstroms. Data from a recent Spacelab 1 ATLAS mission has imaged the terrestrial airglow at tangent ray heights of 90 and 150 km. These data contain information about trace atmospheric constituents such as bromine oxide (BrO), hydroxyl (OH), and chlorine dioxide (OClO). The abundances of these species are critical to stratospheric models of catalytic ozone destruction. Heretofore, very few observations were made especially for BrO. Software was developed to purge unwanted solar features from the airglow spectra. The next step is a measure of the strength of the emission features for BrO. The final analysis will yield the scale height of this important compound.

  8. Relevance of BFRs and thermal conditions on the formation pathways of brominated and brominated-chlorinated dibenzodioxins and dibenzofurans.

    PubMed

    Weber, Roland; Kuch, Bertram

    2003-09-01

    The widespread use of brominated flame-retarded products in the last two decades has resulted in an increasing presence of bromine in thermal processes such as waste combustion and accidental fires. Brominated and brominated-chlorinated dibenzodioxins and dibenzofurans (PBDDs/PBDFs, PXDDs/PXDFs) are micropollutants of concern arising from such processes. The present review aims to evaluate the relevance of these compound classes in actual thermal processes. Four categories of thermal processes are discussed in this respect according to their potential for PBDD/PBDF and PXDD/PXDF generation: thermal stress, pyrolysis/gasification, insufficient combustion conditions and controlled combustion conditions. Under thermal stress situations, as they may occur in production or recycling processes, PBDDs/PBDFs precursors like polybrominated diphenylethers (PBDE) can have a relevant potential for PBDD/PBDF formation via a simple elimination. Under insufficient combustion conditions as they are present in, e.g. accidental fires and uncontrolled burning as well as gasification/pyrolysis processes, considerable amounts of PBDDs/PBDFs can be formed from BFRs, preferably via the precursor pathway. In contrast, under controlled combustion conditions, BFRs and PBDDs/PBDFs can be destroyed with high efficiency. The relevance of de novo synthesis of PXDDs/PXDFs is discussed for this condition. Providing a basis for the understanding of PXDD/PXDF formation in actual thermal processes, the present paper also summarises the formation pathways of brominated and brominated-chlorinated PXDDs/PXDFs from brominated flame retardants (BFRs) investigated during laboratory thermolysis experiments. Relevant mechanistic steps for PBDD/PBDF formation from brominated precursors are discussed including elimination reactions, condensation steps and debromination/hydrogenation reactions. In addition, chlorination/bromination and halogen exchange reactions are briefly discussed with respect for their

  9. Existence state of bromine as an indicator of the source of brominated flame retardants in indoor dust.

    PubMed

    Suzuki, Go; Kida, Akiko; Sakai, Shin-ichi; Takigami, Hidetaka

    2009-03-01

    Indoor dust is an important medium for human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). In this study, we used micro X-ray fluorescence spectrometry (XRFS), digital optical microscopy, and gas chromatography-high resolution mass spectrometry to investigate the existence state of bromine as an indicator of the source of BFRs in indoor dusts and in dusts from the interior of televisions collected in Japan. By means of micro XRFS bromine mapping conducted at a 0.5-s dwell time, we were able to detect bromine levels as low as about 0.1% at each point of about a beam diameter of 50 microm across. The presence of fragments containing 1.0% or more bromine was confirmed in 27 of the 48 dust samples tested. Using magnified images of the fragments, we classified them roughly into particulates and fibrous substances. We analyzed PBDEs in the fragments containing high concentrations of bromine (> or = 0.1%) and confirmed that the fragments contained PBDEs, mainly BDE 209. Furthermore, to detect bromine concentrations < or = 0.1% in the dust samples, we analyzed the samples at a dwell time of 100 s to enhance the detection sensitivity of mapping; atthis dwell time, we confirmed the presence of bromine in the dust coating. Our results suggest that bromine is transferred from products to dust matrixes not only through miniaturization and subsequent direct migration into dust as plastic and textile fragments but also through other pathways such as vaporization and airborne transfer of microparticulates. PMID:19350916

  10. Current Research on Thermochemical Conversion of Biomass at the National Renewable Energy Laboratory

    SciTech Connect

    Baldwin, R. M.; Magrini-Bair, K. A.; Nimlos, M. R.; Pepiot, P.; Donohoe, B. S.; Hensley, J. E.; Phillips, S. D.

    2012-04-05

    The thermochemical research platform at the National Bioenergy Center, National Renewable Energy Laboratory (NREL) is primarily focused on conversion of biomass to transportation fuels using non-biological techniques. Research is conducted in three general areas relating to fuels synthesis via thermochemical conversion by gasification: (1) Biomass gasification fundamentals, chemistry and mechanisms of tar formation; (2) Catalytic tar reforming and syngas cleaning; and (3) Syngas conversion to mixed alcohols. In addition, the platform supports activities in both technoeconomic analysis (TEA) and life cycle assessment (LCA) of thermochemical conversion processes. Results from the TEA and LCA are used to inform and guide laboratory research for alternative biomass-to-fuels strategies. Detailed process models are developed using the best available material and energy balance information and unit operations models created at NREL and elsewhere. These models are used to identify cost drivers which then form the basis for research programs aimed at reducing costs and improving process efficiency while maintaining sustainability and an overall net reduction in greenhouse gases.

  11. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  12. CHEETAH: A next generation thermochemical code

    SciTech Connect

    Fried, L.; Souers, P.

    1994-11-01

    CHEETAH is an effort to bring the TIGER thermochemical code into the 1990s. A wide variety of improvements have been made in Version 1.0. We have improved the robustness and ease of use of TIGER. All of TIGER`s solvers have been replaced by new algorithms. We find that CHEETAH solves a wider variety of problems with no user intervention (e.g. no guesses for the C-J state) than TIGER did. CHEETAH has been made simpler to use than TIGER; typical use of the code occurs with the new standard run command. CHEETAH will make the use of thermochemical codes more attractive to practical explosive formulators. We have also made an extensive effort to improve over the results of TIGER. CHEETAH`s version of the BKW equation of state (BKWC) is able to accurately reproduce energies from cylinder tests; something that other BKW parameter sets have been unable to do. Calculations performed with BKWC execute very quickly; typical run times are under 10 seconds on a workstation. In the future we plan to improve the underlying science in CHEETAH. More accurate equations of state will be used in the gas and the condensed phase. A kinetics capability will be added to the code that will predict reaction zone thickness. Further ease of use features will eventually be added; an automatic formulator that adjusts concentrations to match desired properties is planned.

  13. Effect of a surface active agent on performance of zinc/bromine redox flow batteries: Improvement in current efficiency and system stability

    NASA Astrophysics Data System (ADS)

    Yang, Jung Hoon; Yang, Hyeon Sun; Ra, Ho Won; Shim, Joonmok; Jeon, Jae-Deok

    2015-02-01

    A sustained decrease in current efficiency (CE) is a commonly observed phenomenon in a zinc/bromine redox flow battery. To circumvent this problem, that is, to improve the CE and system stability of the redox flow battery, a surface active agent (SAA), polyoxyethylene (20) sorbitan monolaurate, is introduced as an additive. To investigate the effect of this SAA on the cell performance, polarization testing is performed and the electrode surface is observed after 32 cycles of charge-discharge testing. Adding the SAA facilitates catholyte mixing, leading to an effective reduction of bromine during discharging.

  14. Design of efficient Mn-based redox materials for thermochemical heat storage at high temperatures

    NASA Astrophysics Data System (ADS)

    Carrillo, Alfonso J.; Serrano, David P.; Pizarro, P.; Coronado, Juan M.

    2016-05-01

    Mn-based oxides are promising materials for thermochemical heat storage based on redox cycles, since they are abundant materials whose reduction and oxidation reactions take place in the temperature range at which future CSP plants will work. However, sintering processes related to high temperature cycling can lead to a complete material deactivation that eventually will suppose the loss of cyclability. In this work we present two approaches that have been proposed as to overcome such deactivation. In this respect morphological and chemical modifications were studied. Results showed that even if the first cycle oxidation is enhanced by the presence of macroporosity, sintering also affects to that structures causing a decrease on the oxidation rate. Conversely, chemical modifications, namely addition of cations of Cr and Fe can stabilize the oxidation rate over long term cycling. Specially, by incorporating Fe to the Mn oxide structure the oxidation reaction is remarkably stabilized and improved.

  15. The interaction of bromine with micron and submicron aerosols.

    PubMed

    Spatola, J A; Gentry, J W

    1980-11-01

    This study was undertaken to gain a better understanding of the reactions of aerosols with gases and vapors. The experimental system was designed in which both phases were dispersed. A collision-type nebulizer was used to generate monodisperse aerosols of 0.234, 0.500, 0.804, 1.101 and 2.020 microns diameter. Bromine concentrations of 100 and 200 ppm were produced to interact with the aerosolS. A light-scattering optical particle counter was used to determine the particle number concentration. Reacted aerosol collected on Teflon filters was analyzed by energy-dispersive x-ray fluorescence. Two temperature regimes were selected: approximately 26 degrees C and 60 degrees C. Separate runs were also conducted for the extreme case of zero curvature using 25 microns thick polystyrene sheet. Data generated from this study show a strong dependence of bromine levels on particle size. As the particle size increased, the amount of bromine per particle (ng Br/particle) also increased. However, on a weight-to-weight basis (ng Br/ng aerosol), the amount of bromine was found to increase with decreasing particle size. The concentration dependence on particle diameter was more strongly associated with values between d2 and d3. This dependence, together with other experimental data, supports a shrinking-unreacted core physical model for the actual reaction. When Br2 concentration or reaction temperature was increased, higher levels of bromine resulted in the aerosol. Runs where both temperature and concentration were increased showed lower levels of bromine than with an increase in either variable. One possible explanation is that the relative rates of reaction on the surface of the particle and diffusion through the reacted shell may be the influencing factors. Brominated polystyrene sheet material showed substantially lower bromine levels than the aerosols. PMID:7457368

  16. Algicidal Effect of Bromine and Chlorine on Chlorella pyrenoidosa

    PubMed Central

    Kott, Yehuda; Hershkovitz, Galila; Shemtob, A.; Sless, J. B.

    1966-01-01

    Chlorella pyrenoidosa was found to grow rapidly in tap water. Peak growth was reached after 2 to 3 days. Chlorine and bromine, added to such water, were shown to be effective inhibitors of algal growth. Bromine and bromamine were primarily algicidal, whereas chlorine and chloramines were mainly algistatic. It is assumed that the mechanisms of action of these halogens on Chlorella are not the same. PMID:5914499

  17. Development of Bromine-77 from the LAMPF facility

    SciTech Connect

    Mettler, F.A. Jr.

    1982-01-01

    The objective of the work is to conduct the necessary studies required to evaluate the efficacy, potential benefit and role of bromine-77 labelled steroids in the detection and evaluation of treatment for hormone-dependent tumors. The synthetic goals of the project are to prepose estradiol derivatives which are labelled with bromine-77 at specific positions in the steroid nucleus. In addition, animal studies imaging studies, and cooperative studies are being conducted. (KJD)

  18. Atmospheric bromine and ozone perturbations in the lower stratosphere

    NASA Technical Reports Server (NTRS)

    Yung, Y. L.; Pinto, J. P.; Watson, R. T.; Sander, S. P.

    1980-01-01

    The role of bromine compounds in the photochemistry of the natural and perturbed stratosphere has been reexamined using an expanded reaction scheme and the results of recent laboratory studies of several key reactions. The most important finding is that through the reaction BrO + ClO yielding Br + Cl + O2 there is a synergistic effect between bromine and chlorine which results in an efficient catalytic destruction of ozone in the lower stratosphere. One-dimensional photochemical model results indicate that BrO is the major bromine species throughout the stratosphere, followed by BrONO2, HBr, HOBr and Br. It is shown from the foregoing that bromine is more efficient than chlorine as a catalyst for destroying ozone, and the implications for stratospheric ozone of possible future growth in the industrial and agricultural use of bromine are discussed. Bromine concentrations of 20 pptv (2 x 10 to the -11th power), as suggested by recent observations, can decrease the present-day integrated ozone column density by 2.4%, and can enhance ozone depletion from steady-state chlorofluoromethane release at 1973 rates by a factor of 1.1-1.2.

  19. Biomass thermochemical gasification: Experimental studies and modeling

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  20. Integrated solar thermochemical reaction system for steam methane reforming

    SciTech Connect

    Zheng, Feng; Diver, Rich; Caldwell, Dustin D.; Fritz, Brad G.; Cameron, Richard J.; Humble, Paul H.; TeGrotenhuis, Ward E.; Dagle, Robert A.; Wegeng, Robert S.

    2015-06-05

    Solar-aided upgrade of the energy content of fossil fuels, such as natural gas, can provide a near-term transition path towards a future solar-fuel economy and reduce carbon dioxide emission from fossil fuel consumption. Both steam and dry reforming a methane-containing fuel stream have been studied with concentrated solar power as the energy input to drive the highly endothermic reactions but the concept has not been demonstrated at a commercial scale. Under a current project with the U.S. Department of Energy, PNNL is developing an integrated solar thermochemical reaction system that combines solar concentrators with micro- and meso-channel reactors and heat exchangers to accomplish more than 20% solar augment of methane higher heating value. The objective of our three-year project is to develop and prepare for commercialization such solar reforming system with a high enough efficiency to serve as the frontend of a conventional natural gas (or biogas) combined cycle power plant, producing power with a levelized cost of electricity less than 6¢/kWh, without subsidies, by the year 2020. In this paper, we present results from the first year of our project that demonstrated a solar-to-chemical energy conversion efficiency as high as 69% with a prototype reaction system.

  1. Integrated solar thermochemical reaction system for steam methane reforming

    DOE PAGESBeta

    Zheng, Feng; Diver, Rich; Caldwell, Dustin D.; Fritz, Brad G.; Cameron, Richard J.; Humble, Paul H.; TeGrotenhuis, Ward E.; Dagle, Robert A.; Wegeng, Robert S.

    2015-06-05

    Solar-aided upgrade of the energy content of fossil fuels, such as natural gas, can provide a near-term transition path towards a future solar-fuel economy and reduce carbon dioxide emission from fossil fuel consumption. Both steam and dry reforming a methane-containing fuel stream have been studied with concentrated solar power as the energy input to drive the highly endothermic reactions but the concept has not been demonstrated at a commercial scale. Under a current project with the U.S. Department of Energy, PNNL is developing an integrated solar thermochemical reaction system that combines solar concentrators with micro- and meso-channel reactors and heatmore » exchangers to accomplish more than 20% solar augment of methane higher heating value. The objective of our three-year project is to develop and prepare for commercialization such solar reforming system with a high enough efficiency to serve as the frontend of a conventional natural gas (or biogas) combined cycle power plant, producing power with a levelized cost of electricity less than 6¢/kWh, without subsidies, by the year 2020. In this paper, we present results from the first year of our project that demonstrated a solar-to-chemical energy conversion efficiency as high as 69% with a prototype reaction system.« less

  2. Integrated solar reforming for thermochemical energy transport

    NASA Astrophysics Data System (ADS)

    Rozenman, T.

    1987-12-01

    This report presents a design study of two reforming processes as applied to the concept of solar thermochemical energy transport. Conceptual designs were carried out for steam-methane and CO2-methane reforming plants. A solar central receiver reformer was designed as an integrated reactor with the chemical reaction tubes placed inside the receiver cavity. The two plant designs were compared for their energy efficiency and capital cost. The CO2 reforming plant design results in higher energy efficiency but requires a catalyst which is still in an experimental stage of development. A third design was performed as a modification of the steam reforming plant utilizing a Direct Contact system, in which the process steam is generated by utilizing the heat of condensation. This system resulted in the highest energy efficiency. A comparison of the capital cost of these three plant designs shows them to be equivalent within the estimation accuracy of 25 percent.

  3. Plasmadynamic effects in thermochemical nonequilibrium aerobrake flows

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; Shebalin, J. V.

    1992-01-01

    The paper discusses modifications to the governing equations of thermochemical nonequilibrium flow to include plasmadynamic effects. The magnetic field about a 1.1-m nose-radius aerobrake entering the earth's atmosphere at 80-km altitude and traveling 12 km/s is computed. The result of coupling the additional terms into the Langley Aerothermodynamics Upwind Relaxation Algorithm indicate that plasmadynamic effects are negligible for this two-temperature Mars-return aerobraking simulation. By examining the magnitude of the ohmic heating and observing a decrease in this heating when coupling terms are included in the two-temperature solution, it is argued that a three-temperature solution should not produce any different conclusions for aerobraking into the earth's atmosphere.

  4. Method for thermochemical decomposition of water

    DOEpatents

    Abraham, Bernard M.; Schreiner, Felix

    1977-01-11

    Water is thermochemically decomposed to produce hydrogen by the following sequence of reactions: KI, NH.sub.3, CO.sub. 2 and water in an organic solvent such as ethyl or propyl alcohol are reacted to produce KHCO 3 and NH.sub.4 I. The KHCO.sub.3 is thermally decomposed to K.sub.2 CO.sub.3, H.sub.2 O and CO.sub.2, while the NH.sub.4 I is reacted with Hg to produce HgI.sub.2, NH.sub.3 and H.sub.2. The K.sub.2 CO.sub.3 obtained by calcining KHCO.sub.3 is then reacted with HgI.sub.2 to produce Hg, KI, CO and O.sub.2. All products of the reaction are recycled except hydrogen and oxygen.

  5. CHEETAH: A fast thermochemical code for detonation

    SciTech Connect

    Fried, L.E.

    1993-11-01

    For more than 20 years, TIGER has been the benchmark thermochemical code in the energetic materials community. TIGER has been widely used because it gives good detonation parameters in a very short period of time. Despite its success, TIGER is beginning to show its age. The program`s chemical equilibrium solver frequently crashes, especially when dealing with many chemical species. It often fails to find the C-J point. Finally, there are many inconveniences for the user stemming from the programs roots in pre-modern FORTRAN. These inconveniences often lead to mistakes in preparing input files and thus erroneous results. We are producing a modern version of TIGER, which combines the best features of the old program with new capabilities, better computational algorithms, and improved packaging. The new code, which will evolve out of TIGER in the next few years, will be called ``CHEETAH.`` Many of the capabilities that will be put into CHEETAH are inspired by the thermochemical code CHEQ. The new capabilities of CHEETAH are: calculate trace levels of chemical compounds for environmental analysis; kinetics capability: CHEETAH will predict chemical compositions as a function of time given individual chemical reaction rates. Initial application: carbon condensation; CHEETAH will incorporate partial reactions; CHEETAH will be based on computer-optimized JCZ3 and BKW parameters. These parameters will be fit to over 20 years of data collected at LLNL. We will run CHEETAH thousands of times to determine the best possible parameter sets; CHEETAH will fit C-J data to JWL`s,and also predict full-wall and half-wall cylinder velocities.

  6. Brominated flame retardant exposure of aircraft personnel.

    PubMed

    Strid, Anna; Smedje, Greta; Athanassiadis, Ioannis; Lindgren, Torsten; Lundgren, Håkan; Jakobsson, Kristina; Bergman, Åke

    2014-12-01

    The use of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) in aircraft is the result of high fire safety demands. Personnel working in or with aircraft might therefore be exposed to several BFRs. Previous studies have reported PBDE exposure in flight attendants and in passengers. One other group that may be subjected to significant BFR exposure via inhalation, are the aircraft maintenance workers. Personnel exposure both during flights and maintenance of aircraft, are investigated in the present study. Several BFRs were present in air and dust sampled during both the exposure scenarios; PBDEs, hexabromocyclododecane (HBCDD), decabromodiphenyl ethane (DBDPE) and 1,2-bis (2,4,6-tribromophenoxy) ethane. PBDEs were also analyzed in serum from pilots/cabin crew, maintenance workers and from a control group of individuals without any occupational aircraft exposure. Significantly higher concentrations of PBDEs were found in maintenance workers compared to pilots/cabin crew and control subjects with median total PBDE concentrations of 19, 6.8 and 6.6 pmol g(-1) lipids, respectively. Pilots and cabin crew had similar concentrations of most PBDEs as the control group, except for BDE-153 and BDE-154 which were significantly higher. Results indicate higher concentrations among some of the pilots compared to the cabin crew. It is however, evident that the cabin personnel have lower BFR exposures compared to maintenance workers that are exposed to such a degree that their blood levels are significantly different from the control group. PMID:24745557

  7. 2011 Biomass Program Platform Peer Review. Thermochemical Conversion

    SciTech Connect

    Grabowski, Paul E.

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Thermochemical Conversion Platform Review meeting.

  8. Configuring the thermochemical hydrogen sulfuric acid process step for the Tandem Mirror Reactor

    SciTech Connect

    Galloway, T.R.

    1981-05-01

    This paper identifies the sulfuric acid step as the critical part of the thermochemical cycle in dictating the thermal demands and temperature requirements of the heat source. The General Atomic Sulfur-Iodine Cycle is coupled to a Tandem Mirror. The sulfuric acid decomposition process step is focused on specifically since this step can use the high efficiency electrical power of the direct converter together with the other thermal-produced electricity to Joule-heat a non-catalytic SO/sub 3/ decomposer to approximately 1250/sup 0/K. This approach uses concepts originally suggested by Dick Werner and Oscar Krikorian. The blanket temperature can be lowered to about 900/sup 0/K, greatly alleviating materials problems, the level of technology required, safety problems, and costs. A moderate degree of heat has been integrated to keep the cycle efficiency around 48%, but the number of heat exchangers has been limited in order to keep hydrogen production costs within reasonable bounds.

  9. Syngas production by thermochemical conversion of CO2 and H2O mixtures using a high-temperature heat pipe based reactor

    NASA Astrophysics Data System (ADS)

    Pearlman, Howard; Chen, Chien-Hua

    2012-10-01

    The design of a new high-temperature, solar-based reactor for thermochemical production of syngas using water and carbon dioxide will be discussed. The reactor incorporates the use of high-temperature heat pipe(s) that efficiently transfer the heat from a solar collector to a porous metal oxide material. Special attention is given to the thermal characteristics of the reactor, which are key factors affecting the overall system efficiency and amount of fuel produced. The thermochemical cycle that is considered is that for ceria based material. Preliminary data acquired from an early stage reactor, operated at temperatures up to 1100oC, is presented and efforts are now underway to increase the operating temperature of the reactor to 1300oC to further increase the efficiency of the thermochemical fuel production process.

  10. Detection of bromine monoxide in a volcanic plume.

    PubMed

    Bobrowski, N; Hönninger, G; Galle, B; Platt, U

    2003-05-15

    The emission of volcanic gases usually precedes eruptive activity, providing both a warning signal and an indication of the nature of the lava soon to be erupted. Additionally, volcanic emissions are a significant source of gases and particles to the atmosphere, influencing tropospheric and stratospheric trace-gas budgets. Despite some halogen species having been measured in volcanic plumes (mainly HCl and HF), little is known about bromine compounds and, in particular, gas-phase reactive bromine species. Such species are especially important in the stratosphere, as reactive bromine-despite being two orders of magnitude less abundant than chlorine-accounts for about one-third of halogen-catalysed ozone depletion. In the troposphere, bromine-catalysed complete ozone destruction has been observed to occur regularly during spring in the polar boundary layers as well as in the troposphere above the Dead Sea basin. Here we report observations of BrO and SO2 abundances in the plume of the Soufrière Hills volcano (Montserrat) in May 2002 by ground-based multi-axis differential optical absorption spectroscopy. Our estimate of BrO emission leads us to conclude that local ozone depletion and small ozone 'holes' may occur in the vicinity of active volcanoes, and that the amount of bromine emitted from volcanoes might be sufficiently large to play a role not only in the stratosphere, but also in tropospheric chemistry. PMID:12748638

  11. What can bromine in ice cores tell us about Arctic sea ice in the past?

    NASA Astrophysics Data System (ADS)

    Vallelonga, Paul; Spolaor, Andrea; Maffazzoli, Niccolo; Kjær, Helle; Barbante, Carlo; Saiz-Lopez, Alfonso

    2016-04-01

    Bromine is of interest as a potential sea ice proxy due to its role in polar atmospheric chemistry, particularly the photochemical "bromine explosion" events which occur over the seasonal sea ice surface. A growing body of literature has demonstrated that bromine is reliably deposited and preserved in polar ice caps and can be used to investigate variability over timescales varying from seasonal to multimillenial. For sea ice reconstructions, bromine and sodium are usually evaluated with respect to their relative abundances in seawater. Competing processes of bromine enrichment due to the bromine explosion, and bromine depletion due to scavenging and deposition, must be taken into account when comparing results from coastal and inland sampling sites. We will review existing bromine-based sea ice reconstructions and present new data for locations from Svalbard, Severnaya Zemlya, Northwest Greenland (NEEM ice core) and central East Greenland (Renland ice core).

  12. Environmental monitoring of brominated flame retardants

    NASA Astrophysics Data System (ADS)

    Vagula, Mary C.; Kubeldis, Nathan; Nelatury, Charles F.

    2011-06-01

    Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether. The last three are also commonly called PBDEs. BDE-85 and BDE-209 are the two prominent congeners of PBDEs and this study reports the adverse effects of these congeners in rodents. Exposure of rat sciatic nerves to 5 μg/mL and 20 μg/mL of BDE-85 and BDE-209 respectively lead to significant, concentration dependent reduction in nerve conduction function. Glucose absorption in the rat intestinal segments exposed to 5 μg/mL of BDE-85 and BDE-209 was significantly reduced for both the compounds tested. Lastly, mice when exposed to 0.25 mg/kg body weight for four days showed a disruption in oxidant and antioxidant equilibrium. The tissues namely liver and brain have shown increase in the levels of lipid hydroperoxides indicating oxidative stress. Moreover, all the protective enzymes namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, and glutathione S transferase (GST) have shown tissue specific alterations indicating the induction of damaging oxidative stress and setting in of lipid peroxidation in exposed animals. The results indicate monitoring of PBDEs in the environment is essential because levels as low as 5 μg/mL and 0.25 mg/kg body weight were able to cause damage to the functions of rodents.

  13. The bromine content of micrometeorites - Arguments for stratospheric contamination

    NASA Technical Reports Server (NTRS)

    Rietmeijer, Frans J. M.

    1993-01-01

    Bromine-salt nanocrystals are associated with a porous chondritic micrometeorite (W7029E5) that was collected in the lower stratosphere. These salt nanocrystals occur together with volcanic Na and K salt nanocrystals embedded in sulfuric acid droplets that were originally adhered to the particle. These materials were concentrated during hexane rinsing as part of routine curation procedures at the NASA Johnson Space Center Cosmic Dust Curatorial Facility. This observation is fortuitous to the extent that the concentration of nanocrystals and sulfuric acid is an experimental artifact of curation. If bromine is a stratospheric contaminant due to surface adsorption, there should be a positive linear relationship between the mass-normalized residence time and bromine content of individual micrometeorites. I show that the predicted correlation exists using a new model to calculate the stratospheric residence time of individual nonspherical micrometeorites in the slow-settling Wilson-Huang regime of the stratosphere.

  14. The chemistry of atmospheric bromine. [catalyst for ozone destruction

    NASA Technical Reports Server (NTRS)

    Wofsy, S. C.; Mcelroy, M. B.; Yung, Y. L.

    1975-01-01

    Bromine may act as a catalyst for recombination of ozone and could be more efficient than either nitric oxide or chlorine. The lower atmosphere contains small concentrations of gaseous bromine produced in part by marine activity and volatilization of particulate material released during the combustion of leaded gasoline, with an additional contribution due to the use of methyl bromide as an agricultural fumigant. Observations by Lazrus et al., (1975) indicate small concentrations of bromine, about 10 to the -11th power (v/v), in the contemporary stratosphere and appear to imply a reduction of approximately 0.3% in the global budget of O3. Estimates are given for future reductions in O3 which might occur if the use of CH3Br as an agricultural fumigant were to continue to grow at present rates.

  15. Dichlorinated and Brominated Rugulovasines, Ergot Alkaloids Produced by Talaromyces wortmannii.

    PubMed

    de Medeiros, Lívia Soman; da Silva, José Vinícius; Abreu, Lucas Magalhães; Pfenning, Ludwig Heinrich; Silva, Carolina Lúcia; Thomasi, Sérgio Secherrer; Venâncio, Tiago; van Pée, Karl-Heinz; Nielsen, Kristian Fog; Rodrigues-Filho, Edson

    2015-01-01

    UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system. Brominated rugulovasines were also detected when the microbial incubation medium was supplemented with bromine sources. Studies from 1D/2D NMR and HRMS spectroscopy data allowed the structural elucidation of the dichlorinated compounds, while tandem MS/HRMS data analysis supported the rationalization of brominated congeners. Preliminary genetic studies revealed evidence that FADH₂ dependent halogenase can be involved in the biosynthesis of the produced halocompounds. PMID:26404231

  16. Climate Impact and Economic Feasibility of Solar Thermochemical Jet Fuel Production.

    PubMed

    Falter, Christoph; Batteiger, Valentin; Sizmann, Andreas

    2016-01-01

    Solar thermochemistry presents a promising option for the efficient conversion of H2O and CO2 into liquid hydrocarbon fuels using concentrated solar energy. To explore the potential of this fuel production pathway, the climate impact and economic performance are analyzed. Key drivers for the economic and ecological performance are thermochemical energy conversion efficiency, the level of solar irradiation, operation and maintenance, and the initial investment in the fuel production plant. For the baseline case of a solar tower concentrator with CO2 capture from air, jet fuel production costs of 2.23 €/L and life cycle greenhouse gas (LC GHG) emissions of 0.49 kgCO2-equiv/L are estimated. Capturing CO2 from a natural gas combined cycle power plant instead of the air reduces the production costs by 15% but leads to LC GHG emissions higher than that of conventional jet fuel. Favorable assumptions for all involved process steps (30% thermochemical energy conversion efficiency, 3000 kWh/(m(2) a) solar irradiation, low CO2 and heliostat costs) result in jet fuel production costs of 1.28 €/L at LC GHG emissions close to zero. Even lower production costs may be achieved if the commercial value of oxygen as a byproduct is considered. PMID:26641878

  17. Method and apparatus for maintaining the pH in zinc-bromine battery systems

    DOEpatents

    Grimes, Patrick G.

    1985-09-10

    A method and apparatus for maintaining the pH level in a zinc-bromine battery features reacting decomposition hydrogen with bromine in the presence of a catalyst. The catalyst encourages the formation of hydrogen and bromine ions. The decomposition hydrogen is therefore consumed, alloying the pH of the system to remain substantially at a given value.

  18. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  19. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  20. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  1. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  2. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  3. Solar photochemical and thermochemical splitting of water.

    PubMed

    Rao, C N R; Lingampalli, S R; Dey, Sunita; Roy, Anand

    2016-02-28

    Artificial photosynthesis to carry out both the oxidation and the reduction of water has emerged to be an exciting area of research. It has been possible to photochemically generate oxygen by using a scheme similar to the Z-scheme, by using suitable catalysts in place of water-oxidation catalyst in the Z-scheme in natural photosynthesis. The best oxidation catalysts are found to be Co and Mn oxides with the e(1) g configuration. The more important aspects investigated pertain to the visible-light-induced generation of hydrogen by using semiconductor heterostructures of the type ZnO/Pt/Cd1-xZnxS and dye-sensitized semiconductors. In the case of heterostructures, good yields of H2 have been obtained. Modifications of the heterostructures, wherein Pt is replaced by NiO, and the oxide is substituted with different anions are discussed. MoS2 and MoSe2 in the 1T form yield high quantities of H2 when sensitized by Eosin Y. Two-step thermochemical splitting of H2O using metal oxide redox pairs provides a strategy to produce H2 and CO. Performance of the Ln0.5A0.5MnO3 (Ln = rare earth ion, A = Ca, Sr) family of perovskites is found to be promising in this context. The best results to date are found with Y0.5Sr0.5MnO3. PMID:26755752

  4. Active thermochemical tables - thermochemistry for the 21st century.

    SciTech Connect

    Ruscic, B.; Chemistry

    2005-01-01

    Active Thermochemical Tables (ATcT) are a good example of a significant breakthrough in chemical science that is directly enabled by the US DOE SciDAC initiative. ATcT is a new paradigm of how to obtain accurate, reliable, and internally consistent thermochemistry and overcome the limitations that are intrinsic to the traditional sequential approach to thermochemistry. The availability of high-quality consistent thermochemical values is critical in many areas of chemistry, including the development of realistic predictive models of complex chemical environments such as combustion or the atmosphere, or development and improvement of sophisticated high-fidelity electronic structure computational treatments. As opposed to the traditional sequential evolution of thermochemical values for the chemical species of interest, ATcT utilizes the Thermochemical Network (TN) approach. This approach explicitly exposes the maze of inherent interdependencies normally ignored by the conventional treatment, and allows, inter alia, a statistical analysis of the individual measurements that define the TN. The end result is the extraction of the best possible thermochemistry, based on optimal use of all the currently available knowledge, hence making conventional tabulations of thermochemical values obsolete. Moreover, ATcT offer a number of additional features that are neither present nor possible in the traditional approach. With ATcT, new knowledge can be painlessly propagated through all affected thermochemical values. ATcT also allows hypothesis testing and evaluation, as well as discovery of weak links in the TN. The latter provides pointers to new experimental or theoretical determinations that can most efficiently improve the underlying thermochemical body of knowledge.

  5. The metabolism and de-bromination of bromotyrosine in vivo

    PubMed Central

    Mani, Ali R.; Moreno, José C.; Visser, Theo J.; Moore, Kevin P.

    2016-01-01

    During inflammation, leukocyte-derived eosinophil peroxidase catalyses the formation of hypobromous acid, which can brominate tyrosine residues in proteins to form bromotyrosine. Since eosinophils are involved in the pathogenesis of allergic reactions, such as asthma, urinary bromotyrosine level has been used for the assessment of children with asthma. However, little is known about the metabolism and disposition of bromotyrosine in vivo. The aim of this study was to identify the major urinary metabolites formed during bromotyrosine metabolism and to develop mass spectrometric methods for their quantitation. Deuterium-labeled bromotyrosine was synthesized by deuterium exchange. [D3]bromotyrosine (500 nmole) was injected intraperitoneally into Sprague-Dawley rats and urine was collected for 24 h in a metabolic cage. 13C-labeled derivatives of bromotyrosine and its major urinary metabolite were synthesized and used as internal standards for quantitation. Following solid phase extraction, urine samples were derivatized to the pentafluorobenzyl ester, and analyzed using isotope dilution gas chromatography and negative-ion chemical ionization mass spectrometry. A novel brominated metabolite, 3-bromo-4-hydroxyphenylacetic acid (bromo-HPA), was identified as the major brominated metabolite of bromotyrosine. Bromo-HPA only accounted for 0.43±0.04% of infused [D3]bromotyrosine and 0.12±0.02% of infused [D3]bromotyrosine was excreted in the urine unchanged. However, ~1.3% (6.66±1.33 nmole) of infused [D3]bromotyrosine was excreted in the urine as the de-brominated metabolite, [D3]4-hydroxyphenylacetic acid, which is also a urinary metabolite of tyrosine in mammals. We also tested whether or not iodotyrosine dehalogenase can catalyse de-bromination of bromotyrosine and showed that iodotyrosine dehalogenase is able to de-brominate free bromotyrosine in vitro. We identified bromo-HPA as the main brominated urinary metabolite of bromotyrosine in rats. However, de

  6. Indole derivatives. 129. Reaction of 5-vinylindole with brominating agents

    SciTech Connect

    Starostenko, N.E.; Avdeeva, N.O.; Zeiberlikh, F.N.; Kurkovskaya, L.N.; Suvorov, N.N.

    1987-09-01

    The bromination of 5-vinylindole at two reaction centers, viz., the carbon-carbon multiple bond of the vinyl group and the pyrrole ring, was realized. In the case of the reaction with pyridinium bromide perbromide it was shown that the pyrrole ring is the most reactive with respect to electrophilic agents. It was established that the introduction of an electron-acceptor acetyl group into the pyrrole ring leads to a decrease in the reactivity of the pyrrole ring, and bromination takes place at the double bond.

  7. The metabolism and de-bromination of bromotyrosine in vivo.

    PubMed

    Mani, Ali R; Moreno, José C; Visser, Theo J; Moore, Kevin P

    2016-01-01

    During inflammation, leukocyte-derived eosinophil peroxidase catalyses the formation of hypobromous acid, which can brominate tyrosine residues in proteins to form bromotyrosine. Since eosinophils are involved in the pathogenesis of allergic reactions, such as asthma, urinary bromotyrosine level has been used for the assessment of children with asthma. However, little is known about the metabolism and disposition of bromotyrosine in vivo. The aim of this study was to identify the major urinary metabolites formed during bromotyrosine metabolism and to develop mass spectrometric methods for their quantitation. Deuterium-labeled bromotyrosine was synthesized by deuterium exchange. [D3]bromotyrosine (500 nmole) was injected intraperitoneally into Sprague-Dawley rats and urine was collected for 24h in a metabolic cage. (13)C-labeled derivatives of bromotyrosine and its major urinary metabolite were synthesized and used as internal standards for quantitation. Following solid phase extraction, urine samples were derivatized to the pentafluorobenzyl ester, and analyzed using isotope dilution gas chromatography and negative-ion chemical ionization mass spectrometry. A novel brominated metabolite, 3-bromo-4-hydroxyphenylacetic acid (bromo-HPA), was identified as the major brominated metabolite of bromotyrosine. Bromo-HPA only accounted for 0.43 ± 0.04% of infused [D3]bromotyrosine and 0.12 ± 0.02% of infused [D3]bromotyrosine was excreted in the urine unchanged. However, ~1.3% (6.66 ± 1.33 nmole) of infused [D3]bromotyrosine was excreted in the urine as the de-brominated metabolite, [D3]4-hydroxyphenylacetic acid, which is also a urinary metabolite of tyrosine in mammals. We also tested whether or not iodotyrosine dehalogenase can catalyse de-bromination of bromotyrosine and showed that iodotyrosine dehalogenase is able to de-brominate free bromotyrosine in vitro. We identified bromo-HPA as the main brominated urinary metabolite of bromotyrosine in rats. However, de

  8. Levelized cost of energy and sensitivity analysis for the hydrogen-bromine flow battery

    NASA Astrophysics Data System (ADS)

    Singh, Nirala; McFarland, Eric W.

    2015-08-01

    The technoeconomics of the hydrogen-bromine flow battery are investigated. Using existing performance data the operating conditions were optimized to minimize the levelized cost of electricity using individual component costs for the flow battery stack and other system units. Several different configurations were evaluated including use of a bromine complexing agent to reduce membrane requirements. Sensitivity analysis of cost is used to identify the system elements most strongly influencing the economics. The stack lifetime and round-trip efficiency of the cell are identified as major factors on the levelized cost of electricity, along with capital components related to hydrogen storage, the bipolar plate, and the membrane. Assuming that an electrocatalyst and membrane with a lifetime of 2000 cycles can be identified, the lowest cost market entry system capital is 220 kWh-1 for a 4 h discharge system and for a charging energy cost of 0.04 kWh-1 the levelized cost of the electricity delivered is 0.40 kWh-1. With systems manufactured at large scales these costs are expected to be lower.

  9. Polymeric brominated flame retardants: are they a relevant source of emerging brominated aromatic compounds in the environment?

    PubMed

    Gouteux, Bruno; Alaee, Mehran; Mabury, Scott A; Pacepavicius, Grazina; Muir, Derek C G

    2008-12-15

    A purge and trap method was used to study the release of brominated organic compounds from polymeric brominated flame retardants (BFRs), a relatively unknown class of flame retardant materials. Among the volatile brominated organics released, pentabromotoluene (PBTo), pentabromoethylbenzene (PBEB), and hexabromobenzene (HBB) were of particular interest because of their high potential to persist in the environment The impact of a thermal stress on the release of these compounds was assessed by applying different constant temperatures for one hour to a polymeric BFR sample. Release rates ranged between 22 +/- 2.1 ng g(-1) h(-1) for PBEB to 2480 +/- 500 ng g(-1) h(-1) for PBTo at room temperature. These rates of release reached 65 +/- 11 ng g(-1) h(-1) for PBEB and 42400 +/- 4700 ng g(-1) h(-1) for PBTo at 100 degrees C. This suggests that the compounding of thermoplastic polyesters done at high temperatures, up to 290 degrees C, could lead to the release of significant amounts of volatile brominated compounds in the environment when crude polymeric BFRs are used as flame retardants. To assess if this unsuspected source of volatile brominated compounds to the environment was relevant to support air concentrations in the Great Lakes area, air samples collected at Egbert (ON, Canada) were analyzed and PBTo, PBEB, and HBB were detected at low levels in some air samples (<0.01 to 0.09 pg/m3). As a second step, a Level III fugacity model was run using release rates of PBTo, PBEB, and HBB determined in this study. Results of the model indicated that prevailing PBEB and HBB air concentrations were not supported by their release from polymeric BFRs but by the use of these compounds as additive BFRs. However, these model predictions suffered from a lack of information on the actual use of polymeric BFRs. Hence, further work is needed to assess the release of potentially persistent brominated aromatic compounds from polymeric BFRs. PMID:19174868

  10. Sensing and inactivation of Bacillus anthracis Sterne by polymer-bromine complexes.

    PubMed

    D'Angelo, Paola A; Bromberg, Lev; Hatton, T Alan; Wilusz, Eugene

    2016-08-01

    We report on the performance of brominated poly(N-vinylpyrrolidone) (PVP-Br), brominated poly(ethylene glycol) (PEG-Br), and brominated poly(allylamine-co-4-aminopyridine) (PAAm-APy-Br) for their ability to decontaminate Bacillus anthracis Sterne spores in solution while also allowing for the sensing of the spores. The polymers were brominated by bromine using carbon tetrachloride or potassium tribromide as solvents, with bromine loadings ranging from 1.6 to 4.2 mEq/g of polymer. B. anthracis Sterne spores were exposed to increasing concentrations of brominated polymers for 5 min, while the kinetics of the sporicidal activity was assessed. All brominated polymers demonstrated spore log-kills of 8 within 5 min of exposure at 12 mg/mL aqueous polymer concentration. Sensing of spores was accomplished by measuring the release of dipicolinic acid (DPA) from the spore using time-resolved fluorescence. Parent, non-brominated polymers did not cause any release of DPA and the spores remained viable. In contrast, spores exposed to the brominated polymers were inactivated and the release of DPA was observed within minutes of exposure. Also, this release of DPA continued for a long time after spore inactivation as in a controlled release process. The DPA release was more pronounced for spores exposed to brominated PVP and brominated PEG-8000 compared to brominated PAAm-APy and brominated PEG-400. Using time-resolved fluorescence, we detected as low as 2500 B. anthracis spores, with PEG-8000 being more sensitive to low spore numbers. Our results suggest that the brominated polymers may be used effectively as decontamination agents against bacterial spores while also providing the sensing capability. PMID:27087522