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

Science.gov (United States)

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

Energy balance calculations and assessment of two thermochemical sulfur cycles

International Nuclear Information System (INIS)

Leger, D.; Lessart, P.; Manaud, J.P.; Benizri, R.; Courvoisier, P.

1978-01-01

Thermochemical cyclic processes which include the highly endothermal decomposition of sulphuric acid are promising for hydrogen production by water-splitting. Our study is directed toward two cycles of this family, each involving the formation and decomposition of sulphuric acid and including other reactions using iron sulphide for the first and oxides and bromides of copper and magnesium for the second. Thermochemical analyses of the two cycles are undertaken. Thermodynamic studies of the reactions are carried out, taking into account possible side-reactions. The concentration of reactants, products and by-products resulting from simultaneous equilibria are calculated, the problems of separation thoroughly studied and the flow-diagrams of the processes drawn up. Using as heat source the helium leaving a 3000 MWth high temperature nuclear reactor and organizing internal heat exchange the enthalpy diagrams are drawn up and the net energy balances evaluated. The overall thermal efficiencies are about 28%, a value corresponding to non-optimized process schemes. Possible improvements aiming at energy-saving and increased efficiency are indicated

Assessment of thermochemical hydrogen production. Project 61010 (formerly 8994) final report, July 1, 1977-March 31, 1979

Energy Technology Data Exchange (ETDEWEB)

Dafler, J.R.; Foh, S.E.; Lee, T.S.; Schreiber, J.D.

1979-05-01

The Institute of Gas Technology's (IGT) assessment of thermochemical water-splitting processes is given. Eight tasks were performed: evaluation of load-line efficiencies; hydrogen bromide electrolysis; maximum attainable thermal efficiency on a specific bromide hybrid cycle; development of electrolyzer elements for H/sub 2/SO/sub 3/; feasibility of high-temperature reference-state thermochemical cycles; interfacing characteristics - solar high-temperature heat sources; analysis of solar and solar hybrid heat sources; and laboratory assessment of cycle with high-temperature step. Engineering analyses were done on two thermochemical hydrogen production cycles - IGT's cycles B-1 and H-5. The load line efficiency for B-1 was 18.1% and for H-5 37.4%. The electrolysis of HBr (aq) on three substrates: platinum, porous graphite, and vitreous graphite was investigated. Platinum proved to be the most efficient electrode surface, with vitreous graphite showing no promise, and porous graphite showing only slightly better results. On platinum, cell voltages of under 1.0 volt were obtained at current densities up to 200 mA/cm/sup 2/. Five new members of the metal-metal oxide class of cycles were derived. The maximum attainable efficiencies of these high-temperature, two-step cycles range from 64 to 86%. Six high-temperature metal oxide-metal sulfate cycles were derived. Performance and capital costs data for a wide range of solar primary heat sources were tabulated.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

1999-01-01

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

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

1981-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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)

Remarks on the thermochemical production of hydrogen from water using heat from the high temperature reactor

International Nuclear Information System (INIS)

Barnert, H.

1980-06-01

In this report, some aspects of the production of hydrogen from water using heat from the High Temperature Reactor has been studied. These aspects are: the theoretical potential for economic competitivness, the application of hydrogen in the Heat Market, the size of the market potential in the Federal Republic of Germany and the extent of research and development work. In addition another novel proposal for a thermochemical cycle has been studied. For the description of the theoretical potential for economic competitivness, a definition of the 'coupling', has been introduced, which is thermodynamicaly developed; the thermochemical cycle is compared with the thermochemical cycle. Using the coupling, it becomes possible to describe a relation between thermodynamical parameters and the ecomomical basic data of capital costs. Reasons are given from the theoretical point of view for the application of hydrogen as an energy carrier of high exergetic value in the heat market. The discussion of energy problems as 'questions of global survival' leads here to a proposal for the introduction of the term 'extropy'. The market potential in the Federal Republic of Germany is estimated. A further novel proposal for a thermochemical cycle is the 'hydrocarbon-hybrid-process'. The extent of research and development work is explained. (orig.) [de

Design and reliability assessment of control systems for a nuclear-based hydrogen production plant with copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Al-Dabbagh, Ahmad W. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada); Lu, Lixuan [Faculty of Energy Systems and Nuclear Science, Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada)

2010-02-15

The thermochemical Copper-Chlorine (Cu-Cl) cycle is an emerging new method of nuclear-based hydrogen production. In the process, water is decomposed into hydrogen and oxygen through several physical and chemical processes. In this paper, a Distributed Control System (DCS) is designed for the thermochemical Cu-Cl cycle. The architecture and the communication networks of the DCS are discussed. Reliability of the DCS is assessed using fault trees. In the assessment, the impact of the malfunction of the actuators, sensors, controllers and communication networks on the overall system reliability is investigated. This provides key information for the selection of control system components, and determination of their inspection frequency and maintenance strategy. The hydrogen reactor unit, which is one of the major components in the thermochemical Cu-Cl cycle, is used to demonstrate the detailed design and analysis. (author)

Bimetallic catalysts for HI decomposition in the iodine-sulfur thermochemical cycle

International Nuclear Information System (INIS)

Wang Laijun; Hu Songzhi; Xu Lufei; Li Daocai; Han Qi; Chen Songzhe; Zhang Ping; Xu Jingming

2014-01-01

Among the different kinds of thermochemical water-splitting cycles, the iodine-sulfur (IS) cycle has attracted more and more interest because it is one of the promising candidates for economical and massive hydrogen production. However, there still exist some science and technical problems to be solved before industrialization of the IS process. One such problem is the catalytic decomposition of hydrogen iodide. Although the active carbon supported platinum has been verified to present the excellent performance for HI decomposition, it is very expensive and easy to agglomerate under the harsh condition. In order to decrease the cost and increase the stability of the catalysts for HI decomposition, a series of bimetallic catalysts were prepared and studied at INET. This paper summarized our present research advances on the bimetallic catalysts (Pt-Pd, Pd-Ir and Pt-Ir) for HI decomposition. In the course of the study, the physical properties, structure, and morphology of the catalysts were characterized by specific surface area, X-ray diffractometer; and transmission electron microscopy, respectively. The catalytic activity for HI decomposition was investigated in a fixed bed reactor under atmospheric pressure. The results show that due to the higher activity and better stability, the active carbon supported bimetallic catalyst is more potential candidate than mono metallic Pt catalyst for HI decomposition in the IS thermochemical cycle. (author)

Membranes for H2 generation from nuclear powered thermochemical cycles

International Nuclear Information System (INIS)

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

2006-01-01

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 2 SO 4 into O 2 , SO 2 , and H 2 O at temperatures around 850 C. In-situ removal of O 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 x Sr 1-x Co 1-y B y O 3-δ (A=La, Y; B=Cr-Ni), in particular the family La x Sr 1-x Co 1-y Mn y O 3-δ (LSCM), and doped La 2 Ni 1-x M x O 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 2 SO 4 decomposition reactor study (at Sandia), in which our membranes were tested in the actual H 2 SO 4 decomposition step

Thermal integration of SCWR nuclear and thermochemical hydrogen plants

International Nuclear Information System (INIS)

Wang, Z.; Naterer, G.F.; Gabriel, K.S.

2010-01-01

In this paper, the intermediate heat exchange between a Generation IV supercritical water-cooled nuclear reactor (SCWR) and a thermochemical hydrogen production cycle is discussed. It is found that the maximum and range of temperatures of a thermochemical cycle are the dominant parameters that affect the design of its coupling with SCWR. The copper-chlorine (Cu-Cl) thermochemical cycle is a promising cycle that can link with SCWRs. The location of extracting heat from a SCWR to a thermochemical cycle is investigated in this paper. Steam bypass lines downstream of the SCWR core are suggested for supplying heat to the Cu-Cl hydrogen production cycle. The stream extraction location is strongly dependent on the temperature requirements of the chemical steps of the thermochemical cycle. The available quantity of heat exchange at different hours of a day is also studied. It is found that the available heat at most hours of power demand in a day can support an industrial scale steam methane reforming plant if the SCWR power station is operating at full design capacity. (author)

Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

International Nuclear Information System (INIS)

Garcia, L.; Gonzalez, D.

2011-01-01

Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

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

International Nuclear Information System (INIS)

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

1981-01-01

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 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 2 and O 2

Membranes for H2 generation from nuclear powered thermochemical cycles.

Energy Technology Data Exchange (ETDEWEB)

Nenoff, Tina Maria; Ambrosini, Andrea; Garino, Terry J.; Gelbard, Fred; Leung, Kevin; Navrotsky, Alexandra (University of California, Davis, CA); Iyer, Ratnasabapathy G. (University of California, Davis, CA); 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.

Advances in hydrogen production by thermochemical water decomposition: A review

International Nuclear Information System (INIS)

Rosen, Marc A.

2010-01-01

Hydrogen demand as an energy currency is anticipated to rise significantly in the future, with the emergence of a hydrogen economy. Hydrogen production is a key component of a hydrogen economy. Several production processes are commercially available, while others are under development including thermochemical water decomposition, which has numerous advantages over other hydrogen production processes. Recent advances in hydrogen production by thermochemical water decomposition are reviewed here. Hydrogen production from non-fossil energy sources such as nuclear and solar is emphasized, as are efforts to lower the temperatures required in thermochemical cycles so as to expand the range of potential heat supplies. Limiting efficiencies are explained and the need to apply exergy analysis is illustrated. The copper-chlorine thermochemical cycle is considered as a case study. It is concluded that developments of improved processes for hydrogen production via thermochemical water decomposition are likely to continue, thermochemical hydrogen production using such non-fossil energy will likely become commercial, and improved efficiencies are expected to be obtained with advanced methodologies like exergy analysis. Although numerous advances have been made on sulphur-iodine cycles, the copper-chlorine cycle has significant potential due to its requirement for process heat at lower temperatures than most other thermochemical processes.

Renewable hydrogen production via thermochemical/electrochemical coupling

Energy Technology Data Exchange (ETDEWEB)

Ambrosini, Andrea [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Babiniec, Sean Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, James E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

A coupled electrochemical/thermochemical cycle was investigated to produce hydrogen from renewable resources. Like a conventional thermochemical cycle, this cycle leverages chemical energy stored in a thermochemical working material that is reduced thermally by solar energy. However, in this concept, the stored chemical energy only needs to be partially, but not fully, capable of splitting steam to produce hydrogen. To complete the process, a proton-conducting membrane is driven to separate hydrogen as it is produced, thus shifting the thermodynamics toward further hydrogen production. This novel coupled-cycle concept provides several benefits. First, the required oxidation enthalpy of the reversible thermochemical material is reduced, enabling the process to occur at lower temperatures. Second, removing the requirement for spontaneous steam-splitting widens the scope of materials compositions, allowing for less expensive/more abundant elements to be used. Lastly, thermodynamics calculations suggest that this concept can potentially reach higher efficiencies than photovoltaic-to-electrolysis hydrogen production methods. This Exploratory Express LDRD involved assessing the practical feasibility of the proposed coupled cycle. A test stand was designed and constructed and proton-conducting membranes were synthesized. While the full proof of concept was not achieved, the individual components of the experiment were validated and new capabilities that can be leveraged by a variety of programs were developed.

Thermoeconomic analysis of a copper-chlorine thermochemical cycle for nuclear-based hydrogen production

International Nuclear Information System (INIS)

Orhan, Mehmet F.; Dincer, Ibrahim; Rosen, Marc A.

2010-01-01

Thermochemical water splitting with a copper-chlorine (Cu-Cl) cycle is a promising process that could be linked with nuclear reactors to decompose water into its constituents, oxygen and hydrogen, through intermediate copper and chlorine compounds. In this paper, a comprehensive exergoeconomic analysis of the Cu-Cl cycle is reported to evaluate the production costs as a function of the amount and quality of the energy used for hydrogen production, as well as the costs of the exergy losses and the exergoeconomic improvement potential of the equipment used in the process. An additional objective is to determine changes in the design parameters of the Cu-Cl cycle that improve the cost effectiveness of the overall system. (orig.)

Thermochemical cycles based on metal oxides for solar hydrogen production; Ciclos termoquimicos basados en oxidos metalicos para produccion de hidrogeno solar

Energy Technology Data Exchange (ETDEWEB)

Fernandez Saavedra, R.; Quejido Cabezas, J.

2012-11-01

The growing demand for energy requires the development and optimization of alternative energy sources. One of the options currently being investigated is solar hydrogen production with thermochemical cycles. This process involves the use of concentrated solar radiation as an energy source to dissociate water through a series of endothermic and exothermic chemical reactions, for the purpose of obtaining hydrogen on a sustainable basis. Of all the thermochemical cycles that have been evaluated, the most suitable ones for implementation with solar energy are those based on metal oxides. (Author) 20 refs.

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

Science.gov (United States)

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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

System and process for producing fuel with a methane thermochemical cycle

Science.gov (United States)

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.

Ceramic carbon electrode-based anodes for use in the Cu-Cl thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, Santhanam; Easton, E. Bradley [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada)

2010-05-15

We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. CCE-based electrodes vastly outperform a bare carbon electrode. Optimization of the organosilicate loading revealed maximum electrode performance was achieved with 36 wt% and was explained in terms of the optimal balance of active area and anion transport properties. (author)

Exergy analysis of a system using a chemical heat pump to link a supercritical water-cooled nuclear reactor and a thermochemical water splitting cycle

International Nuclear Information System (INIS)

Granovskii, M.; Dincer, I.; Rosen, M. A.; Pioro, I

2007-01-01

The power generation efficiency of nuclear plants is mainly determined by the permissible temperatures and pressures of the nuclear reactor fuel and coolants. These parameters are limited by materials properties and corrosion rates and their effect on nuclear reactor safety. The advanced materials for the next generation of CANDU reactors, which employ steam as a coolant and heat carrier, permit the increased steam parameters (outlet temperature up to 625 degree C and pressure of about 25 MPa). Supercritical water-cooled (SCW) nuclear power plants are expected to increase the power generation efficiency from 35 to 45%. Supercritical water-cooled nuclear reactors can be linked to thermochemical water splitting cycles for hydrogen production. An increased steam temperature from the nuclear reactor makes it also possible to utilize its energy in thermochemical water splitting cycles. These cycles are considered by many as one of the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require a heat supply at the temperatures over 550-600 degree C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump which increases the temperature the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. A high temperature chemical heat pump which employs the reversible catalytic methane conversion reaction is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with a SCW nuclear plant on one side and thermochemical water splitting cycle on the other, increases the temperature level of the 'nuclear' heat and, thus, the intensity of

Life cycle assessment of nuclear-based hydrogen production via thermochemical water splitting using a copper-chlorine (Cu-Cl) cycle

Science.gov (United States)

Ozbilen, Ahmet Ziyaettin

The energy carrier hydrogen is expected to solve some energy challenges. Since its oxidation does not emit greenhouse gases (GHGs), its use does not contribute to climate change, provided that it is derived from clean energy sources. Thermochemical water splitting using a Cu-Cl cycle, linked with a nuclear super-critical water cooled reactor (SCWR), which is being considered as a Generation IV nuclear reactor, is a promising option for hydrogen production. In this thesis, a comparative environmental study is reported of the three-, four- and five-step Cu-Cl thermochemical water splitting cycles with various other hydrogen production methods. The investigation uses life cycle assessment (LCA), which is an analytical tool to identify and quantify environmentally critical phases during the life cycle of a system or a product and/or to evaluate and decrease the overall environmental impact of the system or product. The LCA results for the hydrogen production processes indicate that the four-step Cu-Cl cycle has lower environmental impacts than the three- and five-step Cu-Cl cycles due to its lower thermal energy requirement. Parametric studies show that acidification potentials (APs) and global warming potentials (GWPs) for the four-step Cu-Cl cycle can be reduced from 0.0031 to 0.0028 kg SO2-eq and from 0.63 to 0.55 kg CO2-eq, respectively, if the lifetime of the system increases from 10 to 100 years. Moreover, the comparative study shows that the nuclear-based S-I and the four-step Cu-Cl cycles are the most environmentally benign hydrogen production methods in terms of AP and GWP. GWPs of the S-I and the four-step Cu-Cl cycles are 0.412 and 0.559 kg CO2-eq for reference case which has a lifetime of 60 years. Also, the corresponding APs of these cycles are 0.00241 and 0.00284 kg SO2-eq. It is also found that an increase in hydrogen plant efficiency from 0.36 to 0.65 decreases the GWP from 0.902 to 0.412 kg CO 2-eq and the AP from 0.00459 to 0.00209 kg SO2-eq for the

Thermochemical water-splitting cycle, bench-scale investigations and process engineering. Annual report, October 1, 1978-September 30, 1979

Energy Technology Data Exchange (ETDEWEB)

Caprioglio, G.; McCorkle, K.H.; Besenbruch, G.E.; Rode, J.S.

1980-03-01

A program to investigate thermochemical water splitting has been under way at General Atomic Company (GA) since October 1972. This document is an annual progress report of Department of Energy (DOE) sponsored process development work on the GA sulfur-iodine thermochemical water splitting cycle. The work consisted of laboratory bench-scale investigations, demonstration of the process in a closed-loop cycle demonstrator, and process engineering design studies. A bench-scale system, consisting of three subunits, has been designed to study the cycle under continuous flow conditions. The designs of subunit I, which models the main solution reaction and product separation, and subunit II, which models the concentration and decomposition of sulfuric acid, were presented in an earlier annual report. The design of subunit III, which models the purification and decomposition of hydrogen iodide, is given in this report. Progress on the installation and operation of subunits I and II is described. A closed-loop cycle demonstrator was installed and operated based on a DOE request. Operation of the GA sulfur-iodine cycle was demonstrated in this system under recycle conditions. The process engineering addresses the flowsheet design of a large-scale production process consisting of four chemical sections (I through IV) and one helium heat supply section (V). The completed designs for sections I through V are presented. The thermal efficiency of the process calculated from the present flowsheet is 47%.

A hybrid mammalian cell cycle model

Directory of Open Access Journals (Sweden)

Vincent Noël

2013-08-01

Full Text Available Hybrid modeling provides an effective solution to cope with multiple time scales dynamics in systems biology. Among the applications of this method, one of the most important is the cell cycle regulation. The machinery of the cell cycle, leading to cell division and proliferation, combines slow growth, spatio-temporal re-organisation of the cell, and rapid changes of regulatory proteins concentrations induced by post-translational modifications. The advancement through the cell cycle comprises a well defined sequence of stages, separated by checkpoint transitions. The combination of continuous and discrete changes justifies hybrid modelling approaches to cell cycle dynamics. We present a piecewise-smooth version of a mammalian cell cycle model, obtained by hybridization from a smooth biochemical model. The approximate hybridization scheme, leading to simplified reaction rates and binary event location functions, is based on learning from a training set of trajectories of the smooth model. We discuss several learning strategies for the parameters of the hybrid model.

Solar Hydrogen Production via a Samarium Oxide-Based Thermochemical Water Splitting Cycle

Directory of Open Access Journals (Sweden)

Rahul Bhosale

2016-04-01

Full Text Available The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and water splitting steps are determined. The effect of oxygen partial pressure in the inert flushing gas on the thermal reduction temperature (TH is examined. An analysis based on the second law of thermodynamics is performed to determine the cycle efficiency (ηcycle and solar-to-fuel energy conversion efficiency (ηsolar−to−fuel attainable with and without heat recuperation. The results indicate that ηcycle and ηsolar−to−fuel both increase with decreasing TH, due to the reduction in oxygen partial pressure in the inert flushing gas. Furthermore, the recuperation of heat for the operation of the cycle significantly improves the solar reactor efficiency. For instance, in the case where TH = 2280 K, ηcycle = 24.4% and ηsolar−to−fuel = 29.5% (without heat recuperation, while ηcycle = 31.3% and ηsolar−to−fuel = 37.8% (with 40% heat recuperation.

Thermal tests of a multi-tubular reactor for hydrogen production by using mixed ferrites thermochemical cycle

Science.gov (United States)

Gonzalez-Pardo, Aurelio; Denk, Thorsten; Vidal, Alfonso

2017-06-01

The SolH2 project is an INNPACTO initiative of the Spanish Ministry of Economy and Competitiveness, with the main goal to demonstrate the technological feasibility of solar thermochemical water splitting cycles as one of the most promising options to produce H2 from renewable sources in an emission-free way. A multi-tubular solar reactor was designed and build to evaluate a ferrite thermochemical cycle. At the end of this project, the ownership of this plant was transferred to CIEMAT. This paper reviews some additional tests with this pilot plant performed in the Plataforma Solar de Almería with the main goal to assess the thermal behavior of the reactor, evaluating the evolution of the temperatures inside the cavity and the relation between supplied power and reached temperatures. Previous experience with alumina tubes showed that they are very sensitive to temperature and flux gradients, what leads to elaborate an aiming strategy for the heliostat field to achieve a uniform distribution of the radiation inside the cavity. Additionally, the passing of clouds is a phenomenon that importantly affects all the CSP facilities by reducing their efficiency. The behavior of the reactor under these conditions has been studied.

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

International Nuclear Information System (INIS)

Werner, R.W.

1982-01-01

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 2 SO 4 -H 2 O system

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, S.; Easton, E.B. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Science

2009-07-01

A thermochemical cycle is a process by which water is decomposed into hydrogen and oxygen through a series of chemical reactions. The chemicals that are used in these reactions are regenerated and recycled during the process. Sol-gel chemistry is becoming more common for the synthesis of electrode materials. The sol-gel reaction can be conducted in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together through the ceramic binder, which can also promote ion transport. The CCE structure also has a high active surface area and is chemically and thermally robust. This paper presented an investigation of CCE materials prepared using 3-aminopropyl trimethoxysilane. Several electrochemical experiments including cyclic voltammetry and electrochemical impedance spectroscopy were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the copper-chlorine thermochemical cycle. Subsequent experiments included the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements were also presented. Specifically, the paper presented the experiment with particular reference to the CCE preparation; electrochemical experiments; thermal analysis; and scanning electron microscopy. Results were also provided. These included TGA analysis; scanning electron microscopy analysis; electrochemical characterization; and anodic polarization. Characterization of these CCE material demonstrated that they had good thermal stability, could be used at high temperatures, and were therefore, very promising anode materials. 15 refs., 7 figs.

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

Energy Technology Data Exchange (ETDEWEB)

Werner, R.W. (ed.)

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)

Performance comparison of two low-CO2 emission solar/methanol hybrid combined cycle power systems

International Nuclear Information System (INIS)

Li, Yuanyuan; Zhang, Na; Lior, Noam

2015-01-01

Highlights: • Two novel solar hybrid combined cycle systems have been proposed and analyzed. • The power systems integrate solar-driven thermo-chemical conversion and CO 2 capture. • Exergy efficiency of about 55% and specific CO 2 emissions of 34 g/kW h are predicted. • Systems CO 2 emissions are 36.8% lower compared to a combined cycle with CO 2 capture. • The fossil fuel demand is ∼30% lower with a solar share of ∼20%. - Abstract: Two novel hybrid combined cycle power systems that use solar heat and methanol, and integrate CO 2 capture, are proposed and analyzed, one based on solar-driven methanol decomposition and the other on solar-driven methanol reforming. The high methanol conversion rates at relatively low temperatures offer the advantage of using the solar heat at only 200–300 °C to drive the syngas production by endothermic methanol conversions and its conversion to chemical energy. Pre-combustion decarbonization is employed to produce CO 2 -free fuel from the fully converted syngas, which is then burned to produce heat at the high temperature for power generation in the proposed advanced combined cycle systems. To improve efficiency, the systems’ configurations were based on the principle of cascade use of multiple heat sources of different temperatures. The thermodynamic performance of the hybrid power systems at its design point is simulated and evaluated. The results show that the hybrid systems can attain an exergy efficiency of about 55%, and specific CO 2 emissions as low as 34 g/kW h. Compared to a gas/steam combined cycle with flue gas CO 2 capture, the proposed solar-assisted system CO 2 emissions are 36.8% lower, and a fossil fuel saving ratio of ∼30% is achievable with a solar thermal share of ∼20%. The system integration predicts high efficiency conversion of solar heat and low-energy-penalty CO 2 capture, with the additional advantage that solar heat is at relatively low temperature where its collection is cheaper and

Capabilities to Support Thermochemical Hydrogen Production Technology Development

Energy Technology Data Exchange (ETDEWEB)

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.

Thermodynamic of the associated cycle and application to the assembly of thermochemical iodine sulphur cycle and a nuclear engine for the hydrogen production

International Nuclear Information System (INIS)

Dumont, Y.

2008-01-01

This thesis is devoted to the design of an assembly of a hydrogen production process by the thermochemical iodine-sulphur cycle and a nuclear reactor. The suggested coupling network uses a power cycle which produces a work which is directly used for the heat pump running. The purpose of this thermodynamic cycle association is to recover the rejected energy at low temperature of a process to provide the energy needs of this same process at high temperature. This association is applied to the studied coupling. The construction of the energy distribution network is designed by the pinch analysis. In the case of a conventional coupling, the efficiency of hydrogen production is 22.0%. By integrating the associated cycles into the coupling, the efficiency of production is 42.6%. The exergetic efficiency, representative of the energy using quality, increases from 58.7% to 85.4%. (author) [fr

Entropy Analysis of Solar Two-Step Thermochemical Cycles for Water and Carbon Dioxide Splitting

Directory of Open Access Journals (Sweden)

Matthias Lange

2016-01-01

Full Text Available The present study provides a thermodynamic analysis of solar thermochemical cycles for splitting of H2O or CO2. Such cycles, powered by concentrated solar energy, have the potential to produce fuels in a sustainable way. We extend a previous study on the thermodynamics of water splitting by also taking into account CO2 splitting and the influence of the solar absorption efficiency. Based on this purely thermodynamic approach, efficiency trends are discussed. The comprehensive and vivid representation in T-S diagrams provides researchers in this field with the required theoretical background to improve process development. Furthermore, results about the required entropy change in the used redox materials can be used as a guideline for material developers. The results show that CO2 splitting is advantageous at higher temperature levels, while water splitting is more feasible at lower temperature levels, as it benefits from a great entropy change during the splitting step.

Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

Energy Technology Data Exchange (ETDEWEB)

Petrov, Miroslav P.

2002-02-01

Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

Hydrogen production by the iodine-sulphur thermochemical cycle. Total and partial pressure measurements

International Nuclear Information System (INIS)

D Doizi; V Dauvois; J L Roujou; V Delanne; P Fauvet; B Larousse; O Hercher; P Carles; C Moulin

2006-01-01

The iodine sulphur thermochemical cycle appears to be one of the most promising candidate for the massive production of hydrogen using nuclear energy. The key step in this cycle is the HI distillation section which must be optimized to get a good efficiency of the overall cycle. The concept of reactive versus extractive distillation of HI has been proposed because of its potentiality. The design and the optimization of the reactive distillation column requires the knowledge of the liquid vapour equilibrium over the ternary HI-I 2 -H 2 O mixtures up to 300 C and 100 bars. A general methodology based on three experimental devices imposed by the very corrosive and concentrated media will be described: 1) I1 for the total pressure measurement versus different ternary compositions. 2) I2 for the partial and total pressure measurements around 130 C and 2 bars to validate the choice of the analytical optical 'online' techniques we have proposed. 3) I3 for the partial and total pressures measurements in the process domain. The results obtained on pure samples, binary mixtures HI-H 2 O and ternary mixtures using an experimental design analysis in the experimental device I2 will be discussed. (authors)

Thermodynamic analysis of the use a chemical heat pump to link a supercritical water-cooled nuclear reactor and a thermochemical water-splitting cycle for hydrogen production

International Nuclear Information System (INIS)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.; Pioro, Igor

2008-01-01

Increases in the power generation efficiency of nuclear power plants (NPPs) are mainly limited by the permissible temperatures in nuclear reactors and the corresponding temperatures and pressures of the coolants in reactors. Coolant parameters are limited by the corrosion rates of materials and nuclear-reactor safety constraints. The advanced construction materials for the next generation of CANDU reactors, which employ supercritical water (SCW) as a coolant and heat carrier, permit improved 'steam' parameters (outlet temperatures up to 625degC and pressures of about 25 MPa). An increase in the temperature of steam allows it to be utilized in thermochemical water splitting cycles to produce hydrogen. These methods are considered by many to be among the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require an intensive heat supply at temperatures higher than 550-600degC. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump, which increases the temperature of the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. Here, a high-temperature chemical heat pump, which employs the reversible catalytic methane conversion reaction, is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with the second steam cycle of a SCW nuclear power generation plant on one side and a thermochemical water splitting cycle on the other, increases the temperature of the 'nuclear' heat and, consequently, the intensity of heat transfer into the water splitting cycle. A comparative preliminary thermodynamic analysis is conducted of

Probing cycle stability and reversibility in thermochemical energy storage – CaC_2O_4·H_2O as perfect match?

International Nuclear Information System (INIS)

Knoll, Christian; Müller, Danny; Artner, Werner; Welch, Jan M.; Werner, Andreas; Harasek, Michael; Weinberger, Peter

2017-01-01

Highlights: • CaC_2O_4·H_2O dehydration is fully reversible between 25 °C and 200 °C. • Isothermal cycling between hydrate and anhydrate phase can be triggered by the water vapour concentration. • High reaction rates and full reversibility demonstrated over 100 cycles. • Material shows no ageing effects or reactivity decrease. - Abstract: The dehydration and subsequent rehydration of calcium oxalate monohydrate has yet to find application in thermochemical energy storage. Unlike for many other salt hydrates, complete reversibility of the dehydration-rehydration reaction was observed. Additionally, it was found that the rehydration temperature is strongly affected by the water vapour concentration: Full reversibility is not only achieved at room-temperature, but, depending on the water vapour concentration, at up to 200 °C. This allows isothermal switching of the material between charging and discharging by a change of the H_2O-partial pressure. Cycle stability of the material was tested by a long-term stress experiment involving 100 charging and discharging cycles. No signs of material fatigue or reactivity loss were found. In-situ powder X-ray diffraction showed complete rehydration of the material within 300 s. The experimental findings indicate that the CaC_2O_4·H_2O/CaC_2O_4 system is perfectly suited for technical application as a thermochemical energy storage medium.

Assessment of a closed thermochemical energy storage using energy and exergy methods

International Nuclear Information System (INIS)

Abedin, Ali Haji; Rosen, Marc A.

2012-01-01

Highlights: ► Thermodynamics assessments are reported for a general closed thermochemical thermal energy storage system. ► Energy and exergy efficiencies of various processes in a closed thermochemical TES are evaluated and compared. ► Understanding is enhanced of thermochemical TES technologies and their potential implementations. ► Exergy analysis is observed to be useful when applied to thermochemical TES, with or in place of energy analysis. - Abstract: Thermal energy storage (TES) is an important technology for achieving more efficient and environmentally benign energy systems. Thermochemical TES is a type of TES with the potential for high energy density and is only recently being considered intensively. To improve understanding of thermochemical TES systems and their implementation, energy and exergy analyses are beneficial. Here, thermodynamics assessments are presented for a general closed thermochemical TES system, including assessments and comparisons of the efficiencies of the overall thermochemical TES cycle and its charging, storing and discharging processes. Locations and causes of thermodynamic losses in thermochemical TES systems are being specified using exergy analysis. The analytical methodology applied in this study identifies that energy and exergy efficiencies differ for thermochemical TESs, e.g. the energy efficiency for a case study is approximately 50% while the exergy efficiency is about 10%. Although the focus is to evaluate thermodynamic efficiencies, other design parameters such as cost, and environmental impact also need to be examined in assessing thermochemical storage. The efficiencies for thermochemical TES provided here should be helpful for designing these energy systems and enhancing their future prospects.

Thermophysical properties of copper compounds in copper-chlorine thermochemical water splitting cycles

International Nuclear Information System (INIS)

Zamfirescu, C.; Dincer, I.; Naterer, G.F.

2009-01-01

This paper examines the relevant thermophysical properties of compounds of chlorine and copper that are found in thermochemical water splitting cycles. There are four variants of such Cu-Cl cycles that use heat and electricity to split the water molecule and produce H 2 and O 2 . Since the energy input is mainly in the form of thermal energy, the Cu-Cl water splitting cycle is much more efficient than water electrolysis, if the electricity generation efficiency for electrolysis is taken into account. A number of copper compounds (Cu 2 OCl 2 , CuO, CuCl 2 , CuCl) and other chemicals (Cu, HCl) are recycled within the plant, while the overall effect is splitting of the water molecule. The system includes a number of chemical reactors, heat exchangers, spray dryer and electrochemical cell. This paper identifies the available experimental data for properties of copper compounds relevant to the Cu-Cl cycle analysis and design. It also develops new regression formulas to correlate the properties, which include: specific heat, enthalpy, entropy, Gibbs free energy, density, formation enthalpy and free energy. No past literature data is available for the viscosity and thermal conductivity of molten CuCl, so estimates are provided. The properties are evaluated at 1 bar and a range of temperatures from ambient to 675-1000K, which are consistent with the operating conditions of the cycle. Updated calculations of chemical exergies are provided as follows: 21.08, 6.268, 82.474, and 75.0 kJ/mol for Cu 2 OCl 2 , CuO, CuCl 2 and CuCl, respectively. For molten CuCl, the estimated viscosity varies from 2.6 to 1.7mPa.s. (author)

CHOOSING DRIVING CYCLE OF HYBRID VEHICLE

Directory of Open Access Journals (Sweden)

A. Vorona

2011-01-01

Full Text Available The analysis of existing driving cycles was performed. After comparing some of the cycles, one specific driving cycle was selected for the hybrid vehicle as the most reliable in representing the real moving of the vehicle in operating conditions and which may be reproduced at experimental tests at the modeling roller stand.

A general survey of the potential and the main issues associated with the sulfur-iodine thermochemical cycle for hydrogen production using nuclear heat

International Nuclear Information System (INIS)

Vitart, Xavier; Carles, Philippe; Anzieu, Pascal

2008-01-01

The thermochemical sulfur-iodine cycle is studied by CEA with the objective of massive hydrogen production using nuclear heat at high temperature. The challenge is to acquire by the end of 2008 the necessary decision elements, based on a scientific and validated approach, to choose the most promising way to produce hydrogen using a generation IV nuclear reactor. Amongst the thermochemical cycles, the sulfur-iodine process remains a very promising solution in matter of efficiency and cost, versus its main competitor, conventional electrolysis. The sulfur-iodine cycle is a very versatile process, which allows lot of variants for each section which can be adjusted in synergy in order to optimise the whole process. The main part of CEA's program is devoted to the study of the basic processes: new thermodynamics data acquisition, optimisation of water and iodine quantity, optimisation of temperature and pressure in each unit of the flow-sheet and survey of innovative solutions (membrane separations for instance). This program also includes optimisation of a detailed flow-sheet and studies for a hydrogen production plant (design, scale, first evaluations of safety issues and technico-economic questions). This program interacts strongly with other teams, in the framework of international collaborations (Europe, USA for instance). (author)

A general survey of the potential and the main issues associated with the sulfur-iodine thermochemical cycle for hydrogen production using nuclear heat

International Nuclear Information System (INIS)

Vitart, X.; Carles, P.; Anzieu, P.

2008-01-01

The thermochemical sulfur-iodine cycle is studied by CEA with the objective of massive hydrogen production using nuclear heat at high temperature. The challenge is to acquire by the end of 2008 the necessary decision elements, based on a scientific and validated approach, to choose the most promising way to produce hydrogen using a generation IV nuclear reactor. Amongst the thermochemical cycles, the sulfur-iodine process remains a very promising solution in matter of efficiency and cost, versus its main competitor, conventional electrolysis. The sulfur-iodine cycle is a very versatile process, which allows lot of variants for each section which can be adjusted in synergy in order to optimise the whole process. The main part of CEA's program is devoted to the study of the basic processes: new thermodynamics data acquisition, optimisation of water and iodine quantity, optimisation of temperature and pressure in each unit of the flow-sheet and survey of innovative solutions (membrane separations for instance). This program also includes optimisation of a detailed flow-sheet and studies for a hydrogen production plant (design, scale, first evaluations of safety issues and technico-economic questions). This program interacts strongly with other teams, in the framework of international collaborations (Europe, USA for instance). (authors)

Achievement report for 1st phase (fiscal 1974-80) Sunshine Program research and development - Hydrogen energy. Research on hydrogen production technology using thermochemical process (Research on cycles of Fe systems etc.); 1974-1980 nendo suiso energy seika hokokusho. Netsu kagakuho ni yoru suiso seizo gijutsu no kenkyu (tetsukei cycle nado no kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

Collected in this report are the results of efforts of the Government Industrial Research Institute, Osaka, in the 7-year period that began in fiscal 1974. The Institute, after looking for basic reactions in thermochemical cycles which are promising, has come to propose a new cycle in which iron and bromine are the reactants. In the research, the Fe-Br reaction is divided into a hydrogen generating loop and an oxygen generating loop, both to be developed into devices. Problems in developing them into a cycle are isolated, and solved. In the hydrogen generating loop, the use of a molten salt is contrived for the prevention of reduction in the reactivity of the Fe{sub 3}O{sub 4} to be generated, and now it is expected that the problem will be solved. No problem is detected in the oxygen generating loop. The process is now accepted as a superb one. As for the materials for the Fe-Br-based cycle apparatus, important tasks have to be undertaken since existing materials cannot be used as is. Besides, thermal efficiency etc. are estimated for a new As-Br-based hybrid cycle and the Fe-Br-based cycle. (NEDO)

A hybrid multi-effect distillation and adsorption cycle

KAUST Repository

Thu, Kyaw

2013-04-01

This paper describes the development of a simple hybrid desalination system of a Multi-Effect Distillation (MED) and an adsorption (AD) cycle operating at sub-atmospheric pressures and temperatures. By hybridizing the conventional MED with an AD cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent\\'s regeneration temperature and this extended the usage of thermal energy emanating from the brine heater and (ii) the vapor extraction from the last MED stage by AD cycle which provides the effect of lowering saturation temperatures of all MED stages to the extent of 5°C, resulting in scavenging of heat leaks into the MED stages from the ambient. The combined effects of the hybrid cycles increase the water production capacity of the desalination plant by nearly twofolds.In this paper, we demonstrate a hybrid cycle by simulating an 8-stage MED cycle which is coupled to an adsorption cycle for direct vapor extraction from the last MED stage. The sorption properties of silica gel is utilized (acting as a mechanical vapor compressor) to reduce the saturation temperatures of MED stages. The modeling utilizes the adsorption isotherms and kinetics of the adsorbent. +. adsorbate (silica-gel. +. water) pair along with the governing equations of mass, energy and concentration. For a 8-stage MED and AD cycles operating at assorted temperatures of 65-90°C, the results show that the water production rate increases from 60% to twofolds when compared to the MED alone. The performance ratio (PR) and gain output ratio (GOR) also improve significantly. © 2012 Elsevier Ltd.

Natural gas usage as a heat source for integrated SMR and thermochemical hydrogen production technologies

International Nuclear Information System (INIS)

Jaber, O.; Naterer, G.F.; Dincer, I.

2010-01-01

This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl cycle out-performs the other conventional methods with respect to fuel requirements, carbon dioxide emissions and total cost of production. (author)

Analysis of sulfur-iodine thermochemical cycle for solar hydrogen production. Part 1: decomposition of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Huang, Cunping; T-Raissi, Ali [Central Florida Univ., Florida Solar Energy Center, Cocoa, FL (United States)

2005-05-01

The sulfur-iodine (S-I) thermochemical water splitting cycle is one of the most studied cycles for hydrogen (H{sub 2}) production. S-I cycle consists of four sections: (I) acid production and separation and oxygen purification, (II) sulfuric acid concentration and decomposition, (III) hydroiodic acid (HI) concentration, and (IV) HI decomposition and H{sub 2} purification. Section II of the cycle is an endothermic reaction driven by the heat input from a high temperature source. Analysis of the S-I cycle in the past thirty years have been focused mostly on the utilization of nuclear power as the high temperature heat source for the sulfuric acid decomposition step. Thermodynamic as well as kinetic considerations indicate that both the extent and rate of sulfuric acid decomposition can be improved at very high temperatures (in excess of 1000 deg C) available only from solar concentrators. The beneficial effect of high temperature solar heat for decomposition of sulfuric acid in the S-I cycle is described in this paper. We used Aspen Technologies' HYSYS chemical process simulator (CPS) to develop flowsheets for sulfuric acid (H{sub 2}SO{sub 4}) decomposition that include all mass and heat balances. Based on the HYSYS analyses, two new process flowsheets were developed. These new sulfuric acid decomposition processes are simpler and more stable than previous processes and yield higher conversion efficiencies for the sulfuric acid decomposition and sulfur dioxide and oxygen formation. (Author)

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

International Nuclear Information System (INIS)

Krikorian, O.H.

1982-01-01

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

Thermochemical recuperative combined cycle with methane-steam reforming combustion; Tennengasu kaishitsu nensho ni yoru konbaindo saikuru hatsuden no kokoritsuka oyobi denryoku fuka heijunka taio

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, R.; Essaki, K.; Tsutsumi, A. [The University of Tokyo, Tokyo (Japan). Dept. of Chemical System Engineering; Kaganoi, S.; Kurimura, H. [Teikoku Sekiyu Co., Tokyo (Japan); Sasaki, T.; Ogawa, T. [Toshiba Co., Tokyo (Japan)

2000-03-10

Thermochemical recuperative combined cycles with methane-steam reforming are proposed for improving their thermal efficiency and for peak-load leveling. For targeting higher thermal efficiency, a cycle with methane-steam reforming reaction heated by gas turbine exhaust was analyzed. The inlet temperature of gas turbine was set at 1,350 degree C. Low-pressure steam extracted from a steam turbine is mixed with methane, and then this mixture is heated by part of the gas turbine exhaust to promote a reforming reaction. The rest of the exhaust heat is used to produce steam, which drives steam turbines to generate electricity. The effect of steam-to-methane ratio (S/C) on thermal efficiency of the cycle, as well as on methane conversion, is investigated by using the ASPEN Plus process simulator. The methane feed rate was fixed at constant and S/C ratio was varied from 2.25 to 4.75. Methane conversion shows an increasing trend toward the ratio and has a maximum value of 17.9 % at S/C=4.0. Thermal efficiency for the system is about 51 % higher than that calculated for a conventional 1,300 degree C class combined cycle under similar conditions. A thermochemical recuperative combined cycle is designed for peak-load leveling. In night-time operation from 20 : 00 to 8 : 00 it stores hydrogen produced by methane steam reforming at S/C=3.9 to save power generation. The gas turbine inlet temperature is 1,330 degree C. In daytime operation from 8 : 00 to 20 : 00 the chemically recuperated combined cycle operated at S/C=2.0 is driven by the mixture of a combined cycle operated at constant load with the same methane feed rate, whereas daytime operation generated power 1.26 times larger than that of the combined cycle. (author)

An experimental investigation on MEDAD hybrid desalination cycle

KAUST Repository

Shahzad, Muhammad Wakil; Thu, Kyaw; Kim, Yong-deuk; Ng, Kim Choon

2015-01-01

This paper presents an advanced desalination cycle called "MEDAD" desalination which is a hybrid of the conventional multi-effect distillation (MED) and an adsorption cycle (AD). The combined cycles allow some of MED stages to operate below ambient

Limit Cycle Analysis in a Class of Hybrid Systems

Directory of Open Access Journals (Sweden)

Antonio Favela-Contreras

2016-01-01

Full Text Available Hybrid systems are those that inherently combine discrete and continuous dynamics. This paper considers the hybrid system model to be an extension of the discrete automata associating a continuous evolution with each discrete state. This model is called the hybrid automaton. In this work, we achieve a mathematical formulation of the steady state and we show a way to obtain the initial conditions region to reach a specific limit cycle for a class of uncoupled and coupled continuous-linear hybrid systems. The continuous-linear term is used in the sense of the system theory and, in this sense, continuous-linear hybrid automata will be defined. Thus, some properties and theorems that govern the hybrid automata dynamic behavior to evaluate a limit cycle existence have been established; this content is explained under a theoretical framework.

Hybrid cycles for micro generation

International Nuclear Information System (INIS)

Campanari, S.

2000-01-01

This paper deals with the main features of two emerging technologies in the field of small-scale power generation, micro turbines and Solid Oxide Fuel Cells, discussing the extremely high potential of their combination into hybrid cycles and their possible role for distributed cogeneration [it

Efficiency of the sulfur-iodine thermochemical water splitting process for hydrogen production based on ADS

International Nuclear Information System (INIS)

Gonzalez, D.; Garcia, L.; Garcia, C.; Garcia, L.; Brayner, C.

2013-01-01

The current hydrogel production is based on fossil fuels; they have a huge contribution to the atmosphere's pollution. thermochemical water splitting cycles don't present this issue because the required process heat is obtained from nuclear energy and therefore, the environmental impact is smaller than using conventional fuels. One of the promising approaches to produce large quantities of hydrogen in an efficient way using nuclear energy is the sulfur-iodine (S-I) thermochemical water splitting cycle. The nuclear source proposed in this paper is a pebble bed gas cooled transmutation facility. Pebble bed very high temperature advanced systems have great perspectives to assume the future nuclear energy. Software based on Chemical Process Simulation (CPS) can be used to simulate the thermochemical water splitting sulfur-iodine cycle for hydrogen production. In this paper, a model for analyzing the sulfur-iodine process sensibility is developed. Efficiency is also calculated and the influence of different parameters on this value. The behavior of the proposed model before different values of initial reactant's flow is analyzed. (Author)

Numerical investigations of hybrid rocket engines

Science.gov (United States)

Betelin, V. B.; Kushnirenko, A. G.; Smirnov, N. N.; Nikitin, V. F.; Tyurenkova, V. V.; Stamov, L. I.

2018-03-01

Paper presents the results of numerical studies of hybrid rocket engines operating cycle including unsteady-state transition stage. A mathematical model is developed accounting for the peculiarities of diffusion combustion of fuel in the flow of oxidant, which is composed of oxygen-nitrogen mixture. Three dimensional unsteady-state simulations of chemically reacting gas mixture above thermochemically destructing surface are performed. The results show that the diffusion combustion brings to strongly non-uniform fuel mass regression rate in the flow direction. Diffusive deceleration of chemical reaction brings to the decrease of fuel regression rate in the longitudinal direction.

High performance ceramic carbon electrode-based anodes for use in the Cu-Cl thermochemical cycle for hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, Santhanam; Easton, E. Bradley [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario L1H 7K4 (Canada)

2010-02-15

A high performance ceramic carbon electrode (CCE) was fabricated by the sol-gel method to study the CuCl electrolysis in Cu-Cl thermochemical cycle. The electrochemical behavior and stability of the CCE was investigated by polarization experiments at different concentrations of CuCl/HCl system. The CCE displayed excellent anodic performance and vastly outperformed the bare carbon fiber paper (CFP) even at high concentrations of CuCl (0.5 M) and HCl (6 M), which is explained in terms of increased active area and enhanced anion transport properties. Further enhancement of activity was achieved by coating the CCE layer onto both sides of the CFP substrate. (author)

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

International Nuclear Information System (INIS)

Ranganathan, S.; Easton, E.B.

2009-01-01

Sol-gel chemistry is becoming more popular for the synthesis of electrode materials. For example, the sol-gel reaction can be performed in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together via the ceramic binder, which can also promote ion transport. Furthermore, the CCE structure has a high active surface area and is chemical and thermally robust. We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments (cyclic voltammetry, electrochemical impedance spectroscopy) were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. Our initial results have shown that CCE-based electrodes vastly outperform a bare carbon electrode, and thus are highly promising and cost-effective electrode material. Subsequent experiments involved the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements will be presented. (author)

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, S.; Easton, E.B. [Faculty of Science, Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada)], E-mail: ranga@uoit.ca, Brad.Easton@uoit.ca

2009-07-01

Sol-gel chemistry is becoming more popular for the synthesis of electrode materials. For example, the sol-gel reaction can be performed in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together via the ceramic binder, which can also promote ion transport. Furthermore, the CCE structure has a high active surface area and is chemical and thermally robust. We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments (cyclic voltammetry, electrochemical impedance spectroscopy) were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. Our initial results have shown that CCE-based electrodes vastly outperform a bare carbon electrode, and thus are highly promising and cost-effective electrode material. Subsequent experiments involved the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements will be presented. (author)

Assessment of thermochemical hydrogen production. Project 8994 mid-contract progress report, July 1--November 1, 1977. [Iron chloride and copper sulfate cycles

Energy Technology Data Exchange (ETDEWEB)

Dafler, J.R.; Foh, S.E.; Schreiber, J.D.

1977-12-01

We have completed the base-case (first-cut) flowsheet analysis for two thermochemical water-splitting cycles that have been under study at the Institute of Gas Technology: a four-step iron chloride cycle (denoted B-1) and a four-step copper sulfate cycle (denoted H-5). In the case of Cycle B-1, an energy balance has located the worst problem areas in the cycle, and flowsheet modifications have begun. Calculations of equilibrium effects due to the hydrolysis of ferrous chloride at pressures high enough to interface with projected hydrogen transmission systems will, apparently, necessitate higher temperature process heat input for this step. Higher pressure operation of some critical separation processes yields more favorable heat balances. For Cycle H-5, the unmodified (base-case) flowsheet indicates that reaction product separations will be relatively simple with respect to Cycle B-1. Work of Schuetz and others dealing with the electrolysis and thermodynamics of HBr/H/sub 2/O/SO/sub 2/ systems is being extensively reviewed. Work plans for this part of the contract are currently being reviewed.

Assessing the potential of hybrid fossil–solar thermal plants for energy policy making: Brayton cycles

International Nuclear Information System (INIS)

Bernardos, Eva; López, Ignacio; Rodríguez, Javier; Abánades, Alberto

2013-01-01

This paper proposes a first study in-depth of solar–fossil hybridization from a general perspective. It develops a set of useful parameters for analyzing and comparing hybrid plants, it studies the case of hybridizing Brayton cycles with current solar technologies and shows a tentative extrapolation of the results to integrated combined cycle systems (ISCSS). In particular, three points have been analyzed: the technical requirements for solar technologies to be hybridized with Brayton cycles, the temperatures and pressures at which hybridization would produce maximum power per unit of fossil fuel, and their mapping to current solar technologies and Brayton cycles. Major conclusions are that a hybrid plant works in optimum conditions which are not equal to those of the solar or power blocks considered independently, and that hybridizing at the Brayton cycle of a combined cycle could be energetically advantageous. -- Highlights: •We model a generic solar–fossil hybrid Brayton cycle. •We calculate the operating conditions for maximum ratio power/fuel consumption. •Best hybrid plant conditions are not the same as solar or power blocks separately. •We study potential for hybridization with current solar technologies. •Hybridization at the Brayton in a combined cycle may achieve high power/fuel ratio

Communication: The electronic entropy of charged defect formation and its impact on thermochemical redox cycles

Science.gov (United States)

Lany, Stephan

2018-02-01

The ideal material for solar thermochemical water splitting, which has yet to be discovered, must satisfy stringent conditions for the free energy of reduction, including, in particular, a sufficiently large positive contribution from the solid-state entropy. By inverting the commonly used relationship between defect formation energy and defect concentration, it is shown here that charged defect formation causes a large electronic entropy contribution manifesting itself as the temperature dependence of the Fermi level. This result is a general feature of charged defect formation and motivates new materials design principles for solar thermochemical hydrogen production.

Thorium--uranium cycle ICF hybrid concept

International Nuclear Information System (INIS)

Frank, T.G.

1978-01-01

The results of preliminary studies of a laser-driven fusion-fission hybrid concept utilizing the 232 Th- 233 U breeding cycle are reported. Neutron multiplication in the breeding blanket is provided by a region containing 238 UO 2 and the equilibrium concentration of 239 PuO 2 . Established fission reactor technology is utilized to determine limits on operating conditions for high-temperature fuels and structures. The implications of nonproliferation policies for the operation of fusion-fission hybrid reactors are discussed

A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

Science.gov (United States)

Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

2016-05-01

The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from "purely" sensible to "hybrid" sensible/ thermochemical one, via coating the porous heat exchange modules with oxides of multivalent metals for which their reduction/oxidation reactions are accompanied by significant heat effects, or by manufacturing them entirely of such oxides. In this way solar heat produced during on-sun operation can be used (in addition to sensibly heating the porous solid) to power the endothermic reduction of the oxide from its state with the higher metal valence to that of the lower; the thermal energy can be entirely recovered by the reverse exothermic oxidation reaction (in addition to sensible heat) during off-sun operation. Such sensible and thermochemical storage concepts were tested on a solar-irradiated receiver- heat storage module cascade for the first time. Parametric studies performed so far involved the comparison of three different SiC-based receivers with respect to their capability of supplying solar-heated air at temperatures sufficient for the reduction of the oxides, the effect of air flow rate on the temperatures achieved within the storage module, as well as the comparison of different porous storage media made of cordierite with respect to their sensible storage capacity.

Reaction modelling of Iron Oxide Bromination in the UT-3 thermochemical cycle for Hydrogen production from water

International Nuclear Information System (INIS)

Amir-Rusli

1996-01-01

Analysis modelling of the iron oxide bromination had been carried out using experiment data from the iron oxide bromination in the UT-3 thermochemical cycle. Iron oxide in the form of pellets were made of the calcination of the mixture of iron oxide, silica, graphite and cellulose at 1473 K. Thermobalance reactor was used to study the kinetic reactions of the iron oxide bromination at a temperature of 473 K for 2 - 6 hours. The data collected from the experiments were used as input for the common models. However, none of these models could not explain the result of the experiments. A new model, a combination of two kinetic reactions : exposed particle and coated particle was created and worked successfully

Solar Thermochemical Hydrogen Production Research (STCH)

Energy Technology Data Exchange (ETDEWEB)

Perret, Robert [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

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.

Thermochemical reactivity of 5–15 mol% Fe, Co, Ni, Mn-doped cerium oxides in two-step water-splitting cycle for solar hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Gokon, Nobuyuki, E-mail: ngokon@eng.niigata-u.ac.jp [Center for Transdisciplinary Research, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Suda, Toshinori [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan); Kodama, Tatsuya [Department of Chemistry & Chemical Engineering, Faculty of Engineering, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan)

2015-10-10

Highlights: • 5–15 mol% M-doped ceria are examined for thermochemical two-step water-splitting. • 5 mol% Fe- and Co-doped ceria have stoichiometric production of oxygen and hydrogen. • 10–15 mol% Fe- and Mn-doped ceria showed near-stoichiometric production. - Abstract: The thermochemical two-step water-splitting cycle using transition element-doped cerium oxide (M–CeO{sub 2−δ}; M = Fe, Co, Ni, Mn) powders was studied for hydrogen production from water. The oxygen/hydrogen productivity and repeatability of M–CeO{sub 2−δ} materials with M doping contents in the 5–15 mol% range were examined using a thermal reduction (TR) temperature of 1500 °C and water decomposition (WD) temperatures in the 800–1150 °C range. The temperature, steam partial pressure, and steam flow rate in the WD step had an impact on the hydrogen productivity and production rate. 5 mol% Fe- and Co-doped CeO{sub 2−δ} enhances hydrogen productivity by up to 25% on average compared to undoped CeO{sub 2}, and shows stable repeatability of stoichiometric oxygen and hydrogen production for the cyclic thermochemical two-step water-splitting reaction. In addition, 5 mol% Mn-doped CeO{sub 2−δ}, 10 and 15 mol% Fe- and Mn-doped CeO{sub 2−δ} show near stoichiometric reactivities.

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

International Nuclear Information System (INIS)

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 3 Decomposition Reactor. The technical, economic, and safety tradeoffs that arise are discussed

An experimental investigation on MEDAD hybrid desalination cycle

KAUST Repository

Shahzad, Muhammad Wakil

2015-04-02

This paper presents an advanced desalination cycle called "MEDAD" desalination which is a hybrid of the conventional multi-effect distillation (MED) and an adsorption cycle (AD). The combined cycles allow some of MED stages to operate below ambient temperature, as low as 5. °C in contrast to the conventional MED. The MEDAD cycle results in a quantum increase of distillate production at the same top-brine condition. Being lower than the ambient temperature for the bottom stages of hybrid cycle, ambient energy can now be scavenged by the MED processes whilst the AD cycle is powered by low temperature waste heat from exhaust or renewable sources. In this paper, we present the experiments of a 3-stage MED and MEDAD plants. These plants have been tested at assorted heat source temperatures from 15. °C to 70. °C and with portable water as a feed. All system states are monitored including the distillate production and power consumption and the measured results are expressed in terms of performance ratio (PR). It is observed that the synergetic matching of MEDAD cycle led to a quantum increase in distillate production, up to 2.5 to 3 folds vis-a-vis to a conventional MED of the same rating. © 2015 Elsevier Ltd.

Low CO2-emissions hybrid solar combined-cycle power system with methane membrane reforming

International Nuclear Information System (INIS)

Li, Yuanyuan; Zhang, Na; Cai, Ruixian

2013-01-01

Based on the principle of cascade utilization of multiple energy resources, a gas-steam combined cycle power system integrated with solar thermo-chemical fuel conversion and CO 2 capture has been proposed and analyzed. The collected solar heat at 550 °C drives the endothermic methane reforming and is converted to the produced syngas chemical exergy, and then released as high-temperature thermal energy via combustion for power generation, achieving its high-efficiency heat-power conversion. The reforming reaction is integrated with a hydrogen separation membrane, which continuously withdraws hydrogen from the reaction zone and enables nearly full methane conversion. The CO 2 enriched gas being concentrated in the retentate zone is collected and processed with pre-combustion decarbonization. The system is thermodynamically simulated using the ASPEN PLUS code. The results show that with 91% CO 2 captured, the specific CO 2 emission is 25 g/kWh. An exergy efficiency of 58% and thermal efficiency of 51.6% can be obtained. A fossil fuel saving ratio of 31.2% is achievable with a solar thermal share of 28.2%, and the net solar-to-electricity efficiency based on the gross solar heat incident on the collector is about 36.4% compared with the same gas-steam combined cycle system with an equal CO 2 removal ratio obtained by post-combustion decarbonization. - Highlights: ► A solar-assisted hybrid combined cycle power system has been proposed and analyzed. ► The system integrates power generation with solar-driven reforming and CO 2 capture. ► solar heat upgrading and high-efficiency heat-to-power conversion are achieved. ► membrane reforming enables high CH 4 conversion and pre-combustion CO 2 capture. ► The system thermodynamic performances have been investigated and compared

CFD Studies on Biomass Thermochemical Conversion

Directory of Open Access Journals (Sweden)

Lifeng Yan

2008-06-01

Full Text Available 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.

Local hybrid functionals: An assessment for thermochemical kinetics

International Nuclear Information System (INIS)

Kaupp, Martin; Bahmann, Hilke; Arbuznikov, Alexei V.

2007-01-01

Local hybrid functionals with position-dependent exact-exchange admixture are a new class of exchange-correlation functionals in density functional theory that promise to advance the available accuracy in many areas of application. Local hybrids with different local mixing functions (LMFs) governing the position dependence are validated for the heats of formation of the extended G3/99 set, and for two sets of barriers of hydrogen-transfer and heavy-atom transfer reactions (HTBH38 and NHTBH38 databases). A simple local hybrid Lh-SVWN with only Slater and exact exchange plus local correlation and a one-parameter LMF, g(r)=b(τ W (r)/τ(r)), performs best and provides overall mean absolute errors for thermochemistry and kinetics that are a significant improvement over standard state-of-the-art global hybrid functionals. In particular, this local hybrid functional does not suffer from the systematic deterioration that standard functionals exhibit for larger molecules. In contrast, local hybrids based on generalized gradient approximation exchange tend to give rise to nonintuitive LMFs, and no improved functionals have been obtained along this route. The LMF is a real-space function and thus can be analyzed in detail. We use, in particular, graphical analyses to rationalize the performance of different local hybrids for thermochemistry and reaction barriers

A hydrogen production experiment by the thermo-chemical and electrolytic hybrid hydrogen production in lower temperature range. System viability and preliminary thermal efficiency estimation

International Nuclear Information System (INIS)

Takai, Toshihide; Nakagiri, Toshio; Inagaki, Yoshiyuki

2008-10-01

A new experimental apparatus by the thermo-chemical and electrolytic Hybrid-Hydrogen production in Lower Temperature range (HHLT) was developed and hydrogen production experiment was performed to confirm the system operability. Hydrogen production efficiency was estimated and technical problems were clarified through the experimental results. Stable operation of the SO 3 electrolysis cell and the sulfur dioxide solution electrolysis cell were confirmed during experimental operation and any damage which would be affected solid operation was not detected under post operation inspection. To improve hydrogen production efficiency, it was found that the reduction of sulfuric acid circulation and the decrease in the cell voltage were key issues. (author)

Thermochemical surface engineering of steels

DEFF Research Database (Denmark)

Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

Nuclear-produced hydrogen by a thermochemical Cu-Cl plant for passenger hydrogen trains

International Nuclear Information System (INIS)

Marin, G.; Naterer, G.; Gabriel, K.

2010-01-01

This paper compares the technical and economic aspects of electrification of a passenger-train operation in Ontario Canada, versus operation with hydrogen trains using nuclear-produced hydrogen. A local GO Transit diesel operation in Ontario has considered electrification as an alternative to reduce greenhouse gas emissions of passenger trains in the Toronto area. Hydrogen production from nuclear energy via a thermo-chemical Copper-Chlorine (Cu-Cl) cycle for train operation is shown to have lower emissions than direct electrification. It significantly reduces the greenhouse gas emissions compared to diesel operation. A bench-mark reference case used for the nuclear thermo-chemical Cu-Cl cycle is the Sulfur-Iodine (S-I) cycle, under investigation in the USA, Japan, and France, among others. The comparative study in this paper considers a base case of diesel operated passenger trains, within the context of a benefits case analysis for train electrification, for GO Transit operations in Toronto, and the impact of each cost component is discussed. The cost analysis includes projected prices of fuel cell trains, with reference to studies performed by train operators. (author)

Ultimate refrigerating conditions, behavior turning and a thermodynamic analysis for absorption–compression hybrid refrigeration cycle

International Nuclear Information System (INIS)

Zheng Danxing; Meng Xuelin

2012-01-01

Highlights: ► Two novel fundamental concepts of the absorption refrigeration cycle were proposed. ► The interaction mechanism of compressor pressure increasing with other key-parameters was investigated. ► A set of optimal operating condition of hybrid refrigeration cycle was found. ► A simulation and investigation for R134a-DMF hybrid refrigeration cycle was performed. - Abstract: The absorption–compression hybrid refrigeration cycle has been considered as an effective approach to reduce the mechanical work consumption by using low-grade heat, such as solar energy. This work aims at studying the thermodynamic mechanism of the hybrid refrigeration cycle. Two fundamental concepts have been proposed, which are the ultimate refrigerating temperature (or the ultimate temperature lift) and the behavior turning. On the basis of that, the interaction mechanism of compressor pressure increasing with other key-parameters and the impact of compressor pressure increasing on the cycle performance have been investigated. The key-parameters include the concentration difference, the circulation ratio of working fluid, etc. The work points out that the hybrid refrigeration cycle performance varies with the change of compressor outlet pressure and depends on which one achieves dominance in the hybrid refrigeration cycle, the absorption sub-system or the compression sub-system. The behavior turning point during parameters changing corresponds to a maximum value of the heat powered coefficient of performance. In this case, the hybrid refrigeration cycle performance is optimal because the low-grade heat utilization is the most effective. In addition, to validate the theoretical analysis, a solar hybrid refrigeration cycle with R134a–DMF as working pair was simulated. The Peng–Robinson equation of state was adopted to calculate thermophysical properties when the reliability assessment of the prediction models on the available literature data of R134a–DMF system had been

Thermodynamic analysis of SCW NPP cycles with thermo-chemical co-generation of hydrogen

International Nuclear Information System (INIS)

Naidin, N.; Mokry, S.; Monichan, R.; Chophla, K.; Pioro, I.; Naterer, G.; Gabriel, K.

2009-01-01

Research activities are currently conducted worldwide to develop Generation IV nuclear reactor concepts with the objective of improving thermal efficiency and increasing economic competitiveness of Generation IV Nuclear Power Plants (NPPs) compared to modern thermal power plants. The Super-Critical Water-cooled Reactor (SCWR) concept is one of the six Generation IV options chosen for further investigation and development in several countries including Canada and Russia. Water-cooled reactors operating at subcritical pressures (10 - 16 MPa) have provided a significant amount of electricity production for the past 50 years. However, the thermal efficiency of the current NPPs is not very high (30 - 35%). As such, more competitive designs, with higher thermal efficiencies, which will be close to that of modern thermal power plants (45 - 50%), need to be developed and implemented. Super-Critical Water (SCW) NPPs will have much higher operating parameters compared to current NPPs (i.e., steam pressures of about 25 MPa and steam outlet temperatures up to 625 o C). Furthermore, SCWRs operating at higher temperatures can facilitate an economical co-generation of hydrogen through thermochemical cycles (particularly, the copper-chlorine cycle) or direct high-temperature electrolysis. The two SCW NPP cycles proposed by this paper are based on direct, regenerative, no-reheat and single-reheat configurations. As such, the main parameters and performance in terms of thermal efficiency of the SCW NPP concepts mentioned above are being analyzed. The cycles are generally comprised of: an SCWR, a SC turbine, one deaerator, ten feedwater heaters, and pumps. The SC turbine of the no-reheat cycle consists of one High-Pressure (HP) cylinder and two Low-Pressure (LP) cylinders. Alternatively, the SC turbine for the single-reheat cycle is comprised of one High-Pressure (HP) cylinder, one Intermediate-Pressure (IP) cylinder and two Low-Pressure (LP) cylinders. Since the single-reheat option

Screening analysis of solar thermochemical hydrogen concepts.

Energy Technology Data Exchange (ETDEWEB)

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.

Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2014-01-01

A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...... other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle....

Biomass Thermochemical Conversion Program: 1986 annual report

Energy Technology Data Exchange (ETDEWEB)

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.

Conceptual design of SO3 decomposer for thermo-chemical iodine-sulfur process pilot plant

International Nuclear Information System (INIS)

Akihiro Kanagawa; Seiji Kasahara; Atsuhiko Terada; Shinji Kubo; Ryutaro Hino; Yoshiyuki Kawahara; Masaharu Watabe; Hiroshi Fukui; Kazuo Ishino; Toshio Takahashi

2005-01-01

Thermo-chemical water-splitting cycle is a method to make an effective use of the high temperature nuclear heat for hydrogen production. Japan Atomic Energy Research Institute (JAERI) has been conducting R and D on HTGR and also on thermo-chemical hydrogen production by using a thermo-chemical iodine-sulfur cycle (IS process). Based on the test results and know-how obtained through a bench-scale tests of hydrogen production of about 30 NL/hr, JAERI has a plan to construct a pilot test plant heated by high temperature helium gas, which has a hydrogen production performance of 30 Nm 3 /hr and will be operated under the high pressure up to 2 MPa. One of the key components of the pilot test plant is a SO 3 decomposer under high temperature conditions up to 850 degree C and high pressure up to 2 MPa. In this paper, a concept of the SO 3 decomposer for the pilot test plant fabricated with SiC ceramics, a corrosion-resistant material is investigated. Preliminary analyses on temperature and flow-rate distributions in the SO 3 decomposer and on thermal stress were carried out. A SO 3 decomposer model was experimentally manufactured. (authors)

Efficiency of the sulfur–iodine thermochemical water splitting process for hydrogen production based on ADS (accelerator driven system)

International Nuclear Information System (INIS)

García, Lázaro; González, Daniel; García, Carlos; García, Laura; Brayner, Carlos

2013-01-01

The current hydrogen production is based on fossil fuels; they have a huge contribution to the atmosphere's pollution. Thermochemical water splitting cycles don't present this issue because the required process heat is obtained from nuclear energy and therefore, the environmental impact is smaller than using conventional fuels. Although, solar hydrogen production could be also used for practical applications because it's lower environmental impact. One of the promising approaches to produce large quantities of hydrogen in an efficient way using nuclear energy is the sulfur–iodine (S–I) thermochemical water splitting cycle. The nuclear source proposed in this paper is a pebble bed gas cooled transmutation facility. Pebble bed very high temperature advanced systems have great perspectives to assume the future nuclear energy. Softwares based on CPS (chemical process simulation) can be used to simulate the thermochemical water splitting sulfur-iodine cycle for hydrogen production. In this paper, a model for analyzing the sulfur-iodine process sensibility respect to the thermodynamics parameters: temperature, pressure and mass flow is developed. Efficiency is also calculated and the influence of different parameters on this value. The behavior of the proposed model for different values of initial reactant's flow, is analyzed. - Highlights: • Chemical Process Simulation (CPS) of the complete sulfur iodine cycle. • Conceptual design of an accelerator driven system for hydrogen production. • Radial and axial temperature profile for the end of stationary cycle (EOC). • Thermal stability of the sulfuric and hydriodic acid sections determination. • Sulfur iodine cycle efficiency analyses for different heat flow from the ADS

Analysis of alternative flow sheets for the hybrid chlorine cycle

Energy Technology Data Exchange (ETDEWEB)

Gooding, Charles H. [Department of Chemical and Biomolecular Engineering, 209 Earle Hall, Clemson University, Clemson, SC 29634-0909 (United States)

2009-05-15

This paper reports the results of the most complete conceptual study conducted to date on hydrogen production using the hybrid chlorine cycle. Three alternative process flow sheets were developed, each capable of producing hydrogen at 35 C (308 K) and 21 bar. The alternative approaches differ primarily in the way HCl is isolated and converted to hydrogen and chlorine gases. Aspen Plus trademark simulation software was used to model the unit processes, supplemented where necessary by custom Excel spreadsheets. Major equipment was sized for a 200-million kg/yr plant; feasible materials of construction were identified; fixed capital investments and variable costs were estimated. Estimated net thermal efficiencies of the flow sheets range from 30% to 36%, based on the lower heating value of the hydrogen produced. With electrical power valued at $0.05/kWh, the cost of hydrogen produced by the hybrid chlorine cycle would be at least $3/kg. These results indicate that direct electrolysis of water is a more attractive way to produce hydrogen than any presently conceived version of the hybrid chlorine cycle. (author)

Hybrid solar central receiver for combined cycle power plant

Science.gov (United States)

Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

1995-01-01

A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

Thermodynamic consideration on the constitution of multi-thermochemical water splitting process

International Nuclear Information System (INIS)

Tagawa, Hiroaki

1976-03-01

The multi-thermochemical water splitting cycle comprises individual chemical reactions which are generalized as hydrolysis, hydrogen generation, oxygen generation and regeneration of the circulating materials. The circulating agents are required for the constitution of the cycle, but the guiding principle of selecting them is not available yet. In the present report, thermodynamic properties, especially Gibbs free energies for formation, of the agents are examined as a function of temperature. Oxides, sulfo-oxides, chlorides, bromides and iodides are chosen as the compounds. The chemical reactions for hydrolysis, hydrogen generation and oxygen generation are reviewed in detail. The general formulas for the three step splitting cycle are represented with discussion. (auth.)

Solar hydrogen project - Thermochemical process design

Energy Technology Data Exchange (ETDEWEB)

Allen, D.J.; Ng, L.F.; Rao, M.S.M.; Wu, S.F.; Zoschak, R.J.

1984-08-01

The thermochemical decomposition of water using solar energy offers an elegant way of combining solar and chemical technologies to produce a high quality fuel. The DOE has sponsored Foster Wheeler to develop a process design for a solar water-splitting process based on the sulfuric acid/iodine cycle. The study has centered around the design of a sulfuric acid decomposition reactor and the central receiver. Materials' properties impose severe constraints upon the design of decomposition reactor. In this paper, the constraints imposed on the design are specified and a reactor and receiver design is presented together with a preliminary design of the balance of plant.

High Efficiency Solar Thermochemical Reactor for Hydrogen Production.

Energy Technology Data Exchange (ETDEWEB)

McDaniel, Anthony H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-09-30

This research and development project is focused on the advancement of a technology that produces hydrogen at a cost that is competitive with fossil-based fuels for transportation. A twostep, solar-driven WS thermochemical cycle is theoretically capable of achieving an STH conversion ratio that exceeds the DOE target of 26% at a scale large enough to support an industrialized economy [1]. The challenge is to transition this technology from the laboratory to the marketplace and produce hydrogen at a cost that meets or exceeds DOE targets.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Thermodynamic analysis of a combined-cycle solar thermal power plant with manganese oxide-based thermochemical energy storage

Science.gov (United States)

Lei, Qi; Bader, Roman; Kreider, Peter; Lovegrove, Keith; Lipiński, Wojciech

2017-11-01

We explore the thermodynamic efficiency of a solar-driven combined cycle power system with manganese oxide-based thermochemical energy storage system. Manganese oxide particles are reduced during the day in an oxygen-lean atmosphere obtained with a fluidized-bed reactor at temperatures in the range of 750-1600°C using concentrated solar energy. Reduced hot particles are stored and re-oxidized during night-time to achieve continuous power plant operation. The steady-state mass and energy conservation equations are solved for all system components to calculate the thermodynamic properties and mass flow rates at all state points in the system, taking into account component irreversibilities. The net power block and overall solar-to-electric energy conversion efficiencies, and the required storage volumes for solids and gases in the storage system are predicted. Preliminary results for a system with 100 MW nominal solar power input at a solar concentration ratio of 3000, designed for constant round-the-clock operation with 8 hours of on-sun and 16 hours of off-sun operation and with manganese oxide particles cycled between 750 and 1600°C yield a net power block efficiency of 60.0% and an overall energy conversion efficiency of 41.3%. Required storage tank sizes for the solids are estimated to be approx. 5-6 times smaller than those of state-of-the-art molten salt systems.

Experimental investigation of molten salt droplet quenching and solidification processes of heat recovery in thermochemical hydrogen production

International Nuclear Information System (INIS)

Ghandehariun, S.; Wang, Z.; Naterer, G.F.; Rosen, M.A.

2015-01-01

Highlights: • Thermal efficiency of a thermochemical cycle of hydrogen production is improved. • Direct contact heat recovery from molten salt is analyzed. • Falling droplets quenched into water are investigated experimentally. - Abstract: This paper investigates the heat transfer and X-ray diffraction patterns of solidified molten salt droplets in heat recovery processes of a thermochemical Cu–Cl cycle of hydrogen production. It is essential to recover the heat of the molten salt to enhance the overall thermal efficiency of the copper–chlorine cycle. A major portion of heat recovery within the cycle can be achieved by cooling and solidifying the molten salt exiting an oxygen reactor. Heat recovery from the molten salt is achieved by dispersing the molten stream into droplets. In this paper, an analytical study and experimental investigation of the thermal phenomena of a falling droplet quenched into water is presented, involving the droplet surface temperature during descent and resulting composition change in the quench process. The results show that it is feasible to quench the molten salt droplets for an efficient heat recovery process without introducing any material imbalance for the overall cycle integration.

Copper oxide--copper sulfate water-splitting cycle

Energy Technology Data Exchange (ETDEWEB)

Foh, S. E.; Schreiber, J. D.; Dafler, J. R.

1978-08-01

A hybrid copper oxide--copper sulfate thermochemical water-splitting cycle, IGT's H-5, has been demonstrated in the laboratory with recycled materials. The optimum configuration and operating conditions for the electrolytic hydrogen-producing step have not yet been defined. With cooperative funding (A.G.A./G.R.I./DOE) a conceptual flowsheet was developed for this cycle and a load-line efficiency of about 37% calculated. This figure is the result of a single iteration on the original base case flow sheet and compares well with the values calculated for other processes at this stage of development. An iterative optimization of process conditions would improve efficiency. The data required to perform an economic analysis are not yet available and the electrolysis step must be more fully defined. An attractive process efficiency, relatively few corrosive materials, and few gas-phase separations are attributes of Cycle H-5 that lead us to believe hydrogen costs (to be developed during future analyses) would be improved significantly over similar processes analyzed to date.

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

International Nuclear Information System (INIS)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia

2011-01-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia, E-mail: dgr@instec.cu, E-mail: lgarcia@instec.cu [Departamento de Ingenieria Nuclear, Instituto Superior de Ciencias y Tecnologias Aplicadas, La Habana (Cuba)

2011-07-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

Research on Fuel Consumption of Hybrid Bulldozer under Typical Duty Cycle

Science.gov (United States)

Song, Qiang; Wang, Wen-Jun; Jia, Chao; Yao, You-Liang; Wang, Sheng-Bo

The hybrid drive bulldozer adopts a dual-motor independent drive system with engine-generator assembly as its power source. The mathematical model of the whole system is constructed on the software platform of MATLAB/Simulink. And then according to the velocity data gained from a real test experiment, a typical duty cycle is build up. Finally the fuel consumption of the bulldozer is calculated under this duty-cycle. Simulation results show that, compared with the traditional mechanical one, the hybrid electric drive system can save fuel up to 16% and therefore indicates great potential for lifting up fuel economy.

Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

Energy Technology Data Exchange (ETDEWEB)

None

1979-11-01

This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

Biomass thermochemical conversion program: 1987 annual report

Energy Technology Data Exchange (ETDEWEB)

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.

Biomass thermochemical conversion program. 1985 annual report

Energy Technology Data Exchange (ETDEWEB)

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.

Hybrid Automotive Engine Using Ethanol-Burning Miller Cycle

Science.gov (United States)

Weinstein, Leonard

2004-01-01

A proposed hybrid (internal-combustion/ electric) automotive engine system would include as its internal-combustion subsystem, a modified Miller-cycle engine with regenerative air preheating and with autoignition like that of a Diesel engine. The fuel would be ethanol and would be burned lean to ensure complete combustion. Although the proposed engine would have a relatively low power-to-weight ratio compared to most present engines, this would not be the problem encountered if this engine were used in a non-hybrid system since hybrid systems require significantly lower power and thus smaller engines than purely internal-combustion-engine-driven vehicles. The disadvantage would be offset by the advantages of high fuel efficiency, low emission of nitrogen oxides and particulate pollutants, and the fact that ethanol is a renewable fuel. The original Miller-cycle engine, named after its inventor, was patented in the 1940s and is the basis of engines used in some modern automobiles, but is not widely known. In somewhat oversimplified terms, the main difference between a Miller-cycle engine and a common (Otto-cycle) automobile engine is that the Miller-cycle engine has a longer expansion stroke while retaining the shorter compression stroke. This is accomplished by leaving the intake valve open for part of the compression stroke, whereas in the Otto cycle engine, the intake valve is kept closed during the entire compression stroke. This greater expansion ratio makes it possible to extract more energy from the combustion process without expending more energy for compression. The net result is greater efficiency. In the proposed engine, the regenerative preheating would be effected by running the intake air through a heat exchanger connected to the engine block. The regenerative preheating would offer two advantages: It would ensure reliable autoignition during operation at low ambient temperature and would help to cool the engine, thereby reducing the remainder of the

Thermodynamic analysis of a combined-cycle solar thermal power plant with manganese oxide-based thermochemical energy storage

Directory of Open Access Journals (Sweden)

Lei Qi

2017-01-01

Full Text Available We explore the thermodynamic efficiency of a solar-driven combined cycle power system with manganese oxide-based thermochemical energy storage system. Manganese oxide particles are reduced during the day in an oxygen-lean atmosphere obtained with a fluidized-bed reactor at temperatures in the range of 750–1600°C using concentrated solar energy. Reduced hot particles are stored and re-oxidized during night-time to achieve continuous power plant operation. The steady-state mass and energy conservation equations are solved for all system components to calculate the thermodynamic properties and mass flow rates at all state points in the system, taking into account component irreversibilities. The net power block and overall solar-to-electric energy conversion efficiencies, and the required storage volumes for solids and gases in the storage system are predicted. Preliminary results for a system with 100 MW nominal solar power input at a solar concentration ratio of 3000, designed for constant round-the-clock operation with 8 hours of on-sun and 16 hours of off-sun operation and with manganese oxide particles cycled between 750 and 1600°C yield a net power block efficiency of 60.0% and an overall energy conversion efficiency of 41.3%. Required storage tank sizes for the solids are estimated to be approx. 5–6 times smaller than those of state-of-the-art molten salt systems.

Design of GA thermochemical water-splitting process for the Mirror Advanced Reactor System

International Nuclear Information System (INIS)

Brown, L.C.

1983-04-01

GA interfaced the sulfur-iodine thermochemical water-splitting cycle to the Mirror Advanced Reactor System (MARS). The results of this effort follow as one section and part of a second section to be included in the MARS final report. This section describes the process and its interface to the reactor. The capital and operating costs for the hydrogen plant are described

US work on technical and economic aspects of electrolytic, thermochemical, and hybrid processes for hydrogen production at temperatures below 550 deg. C

International Nuclear Information System (INIS)

Petri, M.C.; Yyldyz, B.; Klickman, A.E.

2006-01-01

Hydrogen demand is increasing, but there are few options for affordable hydrogen production free of greenhouse gas emissions. Nuclear power is one of the most promising options. Most research is focused on high-temperature electrolytic and thermochemical processes for nuclear-generated hydrogen, but it will be many years before very high temperature reactors become commercially available. For light water reactors or supercritical reactors, low-temperature water electrolysis is a currently available technology for hydrogen production. Higher efficiencies may be gained through thermo-electrochemical hydrogen production cycles, but there are only a limited number that have heat requirements consistent with the lower temperatures of light-water reactor technology. Indeed, active research is ongoing for only three such cycles in the USA. Reductions in electricity and system costs would be needed (or the imposition of a carbon tax) for low-temperature water electrolysis to compete with today's costs for steam methane reformation. The interactions between hydrogen and electricity markets and hydrogen and electricity producers are complex and will evolve as the markets evolve. (author)

Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

Energy Technology Data Exchange (ETDEWEB)

Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

2014-10-01

This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

Development of a seasonal thermochemical storage system

NARCIS (Netherlands)

Cuypers, R.; Maraz, N.; Eversdijk, J.; Finck, C.J.; Henquet, E.M.P.; Oversloot, H.P.; Spijker, J.C. van 't; Geus, A.C. de

2012-01-01

In our laboratories, a seasonal thermochemical storage system for dwellings and offices is being designed and developed. Based on a thermochemical sorption reaction, space heating, cooling and generation of domestic hot water will be achieved with up to 100% renewable energy, by using solar energy

Thermochemical evaluation and preparation of cesium uranates

International Nuclear Information System (INIS)

Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku; Sato, Seichi; Ohashi, Hiroshi.

1997-03-01

Two kinds of cesium uranates, Cs 2 UO 4 and Cs 2 U 2 O 7 , which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U 3 O 8 and Cs 2 CO 3 for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs 2 UO 4 and Cs 2 U 2 O 7 were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs 2 UO 4 and Cs 2 U 2 O 7 were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D. [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac No. 8532, Col. Progreso, C.P. 62550, Jiutepec, Morelos (Mexico)

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)

The hybrid two stage anticlockwise cycle for ecological energy conversion

Directory of Open Access Journals (Sweden)

Cyklis Piotr

2016-01-01

Full Text Available The anticlockwise cycle is commonly used for refrigeration, air conditioning and heat pumps applications. The application of refrigerant in the compression cycle is within the temperature limits of the triple point and the critical point. New refrigerants such as 1234yf or 1234ze have many disadvantages, therefore natural refrigerants application is favourable. The carbon dioxide and water can be applied only in the hybrid two stages cycle. The possibilities of this solutions are shown for refrigerating applications, as well some experimental results of the adsorption-compression double stages cycle, powered with solar collectors are shown. As a high temperature cycle the adsorption system is applied. The low temperature cycle is the compression stage with carbon dioxide as a working fluid. This allows to achieve relatively high COP for low temperature cycle and for the whole system.

Thermochemical and thermophysical properties of minor actinide compounds

International Nuclear Information System (INIS)

Minato, Kazuo; Takano, Masahide; Otobe, Haruyoshi; Nishi, Tsuyoshi; Akabori, Mitsuo; Arai, Yasuo

2009-01-01

Burning or transmutation of minor actinides (MA: Np, Am, Cm) that are classified as the high-level radioactive waste in the current nuclear fuel cycle is an option for the advanced nuclear fuel cycle. Although the thermochemical and thermophysical properties of minor actinide compounds are essential for the design of MA-bearing fuels and analysis of their behavior, the experimental data on minor actinide compounds are limited. To support the research and development of the MA-bearing fuels, the property measurements were carried out on minor actinide nitrides and oxides. The lattice parameters and their thermal expansions were measured by high-temperature X-ray diffractometry. The specific heat capacities were measured by drop calorimetry and the thermal diffusivities by laser-flash method. The thermal conductivities were determined by the specific heat capacities, thermal diffusivities and densities. The oxygen potentials were measured by electromotive force method.

Uranium-thorium fuel cycle in a very high temperature hybrid system

International Nuclear Information System (INIS)

Hernandez, C.R.G.; Oliva, A.M.; Fajardo, L.G.; Garcia, J.A.R.; Curbelo, J.P.; Abadanes, A.

2011-01-01

Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. Therefore, Thorium fuels can complement Uranium fuels and ensure long term sustainability of nuclear power. The main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a Uranium-Thorium (U + Th) fuel cycle are shown in this paper. Once-through and two step U + Th fuel cycle was evaluated. With this goal, a preliminary conceptual design of a hybrid system formed by a Graphite Moderated Gas-Cooled Very High Temperature Reactor and two ADSs is proposed. The main parameters related to the neutronic behavior of the system in a deep burn scheme are optimized. The parameters that describe the nuclear fuel breeding and Minor Actinide stockpile are compared with those of a simple Uranium fuel cycle. (author)

Maximizing Efficiency in Two-step Solar-thermochemical Fuel Production

Energy Technology Data Exchange (ETDEWEB)

Ermanoski, I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-05-01

Widespread solar fuel production depends on its economic viability, largely driven by the solar-to-fuel conversion efficiency. In this paper, the material and energy requirements in two-step solar-thermochemical cycles are considered.The need for advanced redox active materials is demonstrated, by considering the oxide mass flow requirements at a large scale. Two approaches are also identified for maximizing the efficiency: optimizing reaction temperatures, and minimizing the pressure in the thermal reduction step by staged thermal reduction. The results show that each approach individually, and especially the two in conjunction, result in significant efficiency gains.

A hybrid Rankine cycle (HyRC) with ambient pressure combustion (APC)

International Nuclear Information System (INIS)

Wu, Lijun; Thimsen, David; Clements, Bruce; Zheng, Ligang; Pomalis, Richard

2014-01-01

The main losses in thermal power generation include heat in exhaust flue gas, heat rejected through steam condensation of low-pressure turbine, and exergy destruction in heat exchange process etc. To the extent that the heat losses are significantly greater in temperature than either air or water coolant resources, these losses also represent exergy losses which might be exploited to improve plant capacity and efficiency. This paper presents a hybrid Rankine cycle (HyRC) with an ambient pressure combustion (APC) boiler to address the recovery potential of these losses within the steam Rankine cycle (SRC). The APC–HyRC concept employs an organic Rankine cycle (ORC) to supplement SRC and to reduce cycle energy losses to the atmosphere since organic fluids are capable of lowering cycle condensation temperature when a very low temperature heat sink is available. The case studies based on a 399 MW SRC unit show that the APC–HyRC configurations have better thermodynamic performance than its base case SRC at a cycle condensation temperature of 30 °C and below. The best APC–HyRC configuration generates up to 14% more power than the baseline steam cycle which is a 5.45% increase in overall gross efficiency with a cycle condensation temperature at 4 °C. - Highlights: • A hybrid Rankine cycle with water and organic fluid is presented. • Heat losses in exhaust flue gas and exhaust steam are reduced. • Exergy losses in regeneration process are reduced. • Efficiency improvements are made to the conventional steam Rankine cycle. • Issues in design/construction of greenfield and repowering project are discussed

Hydrogen Production From Water By Thermo-Chemical Methods (UT-3): Evaluation of Side Reactions By Simulation Process

International Nuclear Information System (INIS)

Rusli, A.

1997-01-01

Hydogen fuel with its advantages will be able to replace all the positions of fossil fuels post o il and gas or migas . Among the advantages of hydrogen fuel are pollution free, abundant of raw material in the form of water molecule, flexible in application, able to stroge and transport as well as fossil energy sources (oil and gas). Hydogen could be produced from water by means of thermochemical, thermolysis, photolysis and electrolysis. Nuclear heat (HTGR), solar heat or waste heat from steel industry can be used as energy source for these processes. In case of thermochemical method, some problems realated to production process should be studied and evaluated. Simulation is considered can be applied to study the effects of side reactions and also to resolve its problems in hydrogen production process. In this paper is reported the evalution results of hydrogen production process by thermochemical (UT-3) through both of the experimental and computer simulation. It has been proposed a new flow chart of hydrogen production to achieve the hydrogen production continuously. A simulator has been developed based on experimental data and related mathematical equations. This simulator can be used to scle-up the UT-3 thermochemical cycle for hydrogen production process

Thermochemical evaluation and preparation of cesium uranates

Energy Technology Data Exchange (ETDEWEB)

Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sato, Seichi; Ohashi, Hiroshi

1997-03-01

Two kinds of cesium uranates, Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7}, which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U{sub 3}O{sub 8} and Cs{sub 2}CO{sub 3} for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

Microencapsulation of salts for enhanced thermochemical storage materials

NARCIS (Netherlands)

Cuypers, R.; Jong, A.J. de; Eversdijk, J.; Spijker, J.C. van 't; Oversloot, H.P.; Ingenhut, B.L.J.; Cremers, R.K.H.; Papen-Botterhuis, N.E.

2013-01-01

Thermochemical storage is a new and emerging long-term thermal storage for residential use (cooling, heating & domestic hot water generation), offering high thermal storage density without the need for thermal insulation during storage (Fig. 1). However, existing materials for thermochemical storage

Estimation of formation enthalpies of vanadates by Born-Gaber cycle method

International Nuclear Information System (INIS)

Golovkin, B.G.

1993-01-01

Principle possibility of calculating Gibbs energy of ionic compound formation as a function of thermochemical radii of component ions of temperature and pressure is shown. Formula for determination of thermochemical radii of polyatomic ions is suggested. Enthalpies of formation of 81 vanadates were estimated with the use of Kapustinsky equation and Born-Gaber cycle

Hydrogen and oxygen production with nuclear heat

International Nuclear Information System (INIS)

Barnert, H.

1979-09-01

After some remarks on the necessity of producing secondary energy sources for the heat market, the thermodynamic fundamentals of the processes for producing hydrogen and oxygen from water on the basis of nuclear thermal energy are briefly explained. These processes are summarized as one class of the 'thermochemical cycle process' for the conversion of thermal into chemical energy. A number of thermochemical cycle processes are described. The results of the design work so far are illustrated by the example of the 'sulphuric acid hybrid process'. The nuclear heat source of the thermochemical cycle process is the high-temperature reactor. Statements concerning rentability are briefly commented upon, and the research and development efforts and expenditure required are sketched. (orig.) 891 GG/orig. 892 MB [de

Thermochemical Surface Engineering: A Playground for Science and Innovation

DEFF Research Database (Denmark)

Christiansen, Thomas Lundin; Dahl, Kristian Vinter; Jellesen, Morten Stendahl

2017-01-01

Surface engineering by thermochemical processing is the intentional change of the composition of a material at elevated temperature with the purpose to improve materials performance. In thermochemical processing components from the starting material are essential in the development of the phases...... at the surface. Current research and innovation activities are used to exemplify thermochemical surface engineering and the interplay of science and innovation. The examples given encompass aspects of the synthesis of extremely porous materials, low temperature surface hardening of stainless steel, surface...

Fuel economy and life-cycle cost analysis of a fuel cell hybrid vehicle

Science.gov (United States)

Jeong, Kwi Seong; Oh, Byeong Soo

The most promising vehicle engine that can overcome the problem of present internal combustion is the hydrogen fuel cell. Fuel cells are devices that change chemical energy directly into electrical energy without combustion. Pure fuel cell vehicles and fuel cell hybrid vehicles (i.e. a combination of fuel cell and battery) as energy sources are studied. Considerations of efficiency, fuel economy, and the characteristics of power output in hybridization of fuel cell vehicle are necessary. In the case of Federal Urban Driving Schedule (FUDS) cycle simulation, hybridization is more efficient than a pure fuel cell vehicle. The reason is that it is possible to capture regenerative braking energy and to operate the fuel cell system within a more efficient range by using battery. Life-cycle cost is largely affected by the fuel cell size, fuel cell cost, and hydrogen cost. When the cost of fuel cell is high, hybridization is profitable, but when the cost of fuel cell is less than 400 US$/kW, a pure fuel cell vehicle is more profitable.

Thermochemical transformations of anthracite fractions

Energy Technology Data Exchange (ETDEWEB)

Belkina, T.V.; Privalov, V.E.; Stepanenko, atM.A.

1979-08-01

Research on the nature of thermochemical transformations of anthracite fractions and the possibility of increasing their activity and identifying conditions for their use in the electrode pitch process is described. From research done on different anthracite fractions processed at varying temperatures it was concluded that accumulations of condensates from heating anthracite fractions occur significantly slower in comparison with pitch. As a result the electrode pitch process is prolonged. Thermal treatment of an anthracite fraction causes the formation and accumulation of condensates and promotes thermochemical transformations. Lastly, the use of thermally treated anthracite fractions apparently intensifies the electrode pitch process and improves its quality. (16 refs.) (In Russian)

Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

International Nuclear Information System (INIS)

Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

2016-01-01

A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77. �

Achievement report on research and development in the Sunshine Project in fiscal 1976. Research and development of water decomposition by using a hybrid cycle composed of thermo-chemistry and photo-chemistry; 1976 nendo netsukagaku oyobi hikari kagaku hybrid cycle ni yoru mizu bunkai no kenkyu kahatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-03-01

This paper describes water decomposition by using a hybrid cycle composed of thermo-chemistry and photo-chemistry. Ferric sulfate and HI are obtained from ferrous sulfate and iodine via photo-chemical reaction. This is an endothermic reaction of 10.8 kcal. Then, the photo-chemically reacted aqueous solution is electrolysed to separate HI, while Fe{sup 3+} (ferric ion) is reduced and converted into Fe{sup 2+} (ferrous ion). Oxygen is generated at this time. Since mixed potential is made from iron oxidation and reduction potential and iodine potential, the electrolytic efficiency is greatly influenced by electrode materials. Ideally, an electrode material that causes only the reduction of Fe{sup 3+}, but not other reactions is preferable. The HI is decomposed into hydrogen and iodine by electrolysis. Research is continuing to acquire hydrogen from HI thermo-chemically. Endothermic reaction heat of 7 to 8 kcal has been obtained in photo-chemical reaction, the heat quantity being close to the theoretical value of 10.8. A result close to the theoretical value may be expected if the electrode material problem is solved. The basic research will be continued for a high possibility of linking the research to a pilot plant in the future. (NEDO)

Novel separation process of gaseous mixture of SO2 and O2 with ionic liquid for hydrogen production in thermochemical sulfur-iodine water splitting cycle

International Nuclear Information System (INIS)

Kim, Chang Soo; Gong, Gyeong Taek; Yoo, Kye Sang; Kim, Honggon; Lee, Byoung Gwon; Ahn, Byoung Sung; Jung, Kwang Deog; Lee, Ki Yong; Song, Kwang Ho

2007-01-01

Sulfur-Iodine cycle is the most promising thermochemical cycle for water splitting to produce hydrogen which can replace the fossil fuels in the future. As a sub-cycle in the thermochemical Sulfur-Iodine water splitting cycle, sulfuric acid (H 2 SO 4 ) decomposes into oxygen (O 2 ) and sulfur dioxide (SO 2 ) which should be separated for the recycle of SO 2 into the sulfuric acid generation reaction (Bunsen Reaction). In this study, absorption and desorption process of SO 2 by ionic liquid which is useful for the recycle of SO 2 into sulfuric acid generation reaction after sulfuric acid decomposition in the thermochemical Sulfur-Iodine cycle is investigated. At first, the operability as an absorbent for the SO 2 absorption and desorption at high temperature without the volatilization of absorbents which is not suitable for the recycle of absorbent-free SO 2 after the absorption process. The temperature range of operability is determined by TGA and DTA analysis. Most of ionic liquids investigated are applicable at high temperature desorption without volatility around 300 deg. C except [BMIm] Cl, and [BMIm] OAc which show the decomposition of ionic liquids. To evaluate the capability of SO 2 absorption, each ionic liquid is located in the absorption tube and gaseous SO 2 is bubbled into the ionic liquid. During the bubbling, the weight of the system is measured and converted into the absorbed SO 2 amount at each temperature controlled by the heater. Saturated amounts of absorbed SO 2 by ionic liquids at 50 deg. C are presented. The effect of anions for the SO 2 absorption capability is shown in the order of Cl, OAc, MeSO 3 , BF 4 , MeSO 4 , PF 6 , and HSO 4 when they are combined with [BMIm] cation. [BMIm]Cl has the largest amount of SO 2 absorbed which can be the most promising absorbent; however, from the point of operability at high temperature which includes desorption process, [BMIm]Cl is vulnerable to high temperature around 250 deg. C based on the TGA

Performance analysis of hybrid solid oxide fuel cell and gas turbine cycle: Application of alternative fuels

International Nuclear Information System (INIS)

Zabihian, Farshid; Fung, Alan S.

2013-01-01

Highlights: • Variation of the stream properties in the syngas-fueled hybrid SOFC–GT cycle. • Detailed analysis of the operation of the methane-fueled SOFC–GT cycle. • Investigate effects of inlet fuel type and composition on performance of cycle. • Comparison of system operation when operated with and without anode recirculation. - Abstract: In this paper, the hybrid solid oxide fuel cell (SOFC) and gas turbine (GT) model was applied to investigate the effects of the inlet fuel type and composition on the performance of the cycle. This type of analysis is vital for the real world utilization of manufactured fuels in the hybrid SOFC–GT system due to the fact that these fuel compositions depends on the type of material that is processed, the fuel production process, and process control parameters. In the first part of this paper, it is shown that the results of a limited number of studies on the utilization of non-conventional fuels have been published in the open literature. However, further studies are required in this area to investigate all aspects of the issue for different configurations and assumptions. Then, the results of the simulation of the syngas-fueled hybrid SOFC–GT cycle are employed to explain the variation of the stream properties throughout the cycle. This analysis can be very helpful in understanding cycle internal working and can provide some interesting insights to the system operation. Then, the detailed information of the operation of the methane-fueled SOFC–GT cycle is presented. For both syngas- and methane-fueled cycles, the operating conditions of the equipment are presented and compared. Moreover, the comparison of the characteristics of the system when it is operated with two different schemes to provide the required steam for the cycle, with anode recirculation and with an external source of water, provides some interesting insights to the system operation. For instance, it was shown that although the physical

Performance analysis of an integrated energy storage and energy upgrade thermochemical solid–gas sorption system for seasonal storage of solar thermal energy

International Nuclear Information System (INIS)

Li, Tingxian; Wang, Ruzhu; Kiplagat, Jeremiah K.; Kang, YongTae

2013-01-01

An innovative dual-mode thermochemical sorption energy storage method is proposed for seasonal storage of solar thermal energy with little heat losses. During the charging phase in summer, solar thermal energy is stored in form of chemical bonds resulting from thermochemical decomposition process, which enables the stored energy to be kept several months at ambient temperature. During the discharging phase in winter, the stored thermal energy is released in the form of chemical reaction heat resulting from thermochemical synthesis process. Thermodynamic analysis showed that the advanced dual-mode thermochemical sorption energy storage is an effective method for the long-term seasonal storage of solar energy. A coefficient of performance (COP h ) of 0.6 and energy density higher than 1000 kJ/kg of salt can be attained from the proposed system. During the discharging phase at low ambient temperatures, the stored thermal energy can be upgraded by use of a solid–gas thermochemical sorption heat transformer cycle. The proposed thermochemical sorption energy storage has distinct advantages over the conventional sensible heat and latent heat storage, such as higher energy storage density, little heat losses, integrated energy storage and energy upgrade, and thus it can contribute to improve the seasonal utilization of solar thermal energy. - Highlights: ► A dual-mode solid thermochemical sorption is proposed for seasonal solar thermal energy storage. ► Energy upgrade techniques into the energy storage system are integrated. ► Performance of the proposed seasonal energy storage system is evaluated. ► Energy density and COP h from the proposed system are as high as 1043 kJ/kg of salt and 0.60, respectively

Influence of driving patterns on life cycle cost and emissions of hybrid and plug-in electric vehicle powertrains

International Nuclear Information System (INIS)

Karabasoglu, Orkun; Michalek, Jeremy

2013-01-01

We compare the potential of hybrid, extended-range plug-in hybrid, and battery electric vehicles to reduce lifetime cost and life cycle greenhouse gas emissions under various scenarios and simulated driving conditions. We find that driving conditions affect economic and environmental benefits of electrified vehicles substantially: Under the urban NYC driving cycle, hybrid and plug-in vehicles can cut life cycle emissions by 60% and reduce costs up to 20% relative to conventional vehicles (CVs). In contrast, under highway test conditions (HWFET) electrified vehicles offer marginal emissions reductions at higher costs. NYC conditions with frequent stops triple life cycle emissions and increase costs of conventional vehicles by 30%, while aggressive driving (US06) reduces the all-electric range of plug-in vehicles by up to 45% compared to milder test cycles (like HWFET). Vehicle window stickers, fuel economy standards, and life cycle studies using average lab-test vehicle efficiency estimates are therefore incomplete: (1) driver heterogeneity matters, and efforts to encourage adoption of hybrid and plug-in vehicles will have greater impact if targeted to urban drivers vs. highway drivers; and (2) electrified vehicles perform better on some drive cycles than others, so non-representative tests can bias consumer perception and regulation of alternative technologies. We discuss policy implications. - Highlights: • Electrified vehicle life cycle emissions and cost depend on driving conditions. • GHGs can triple in NYC conditions vs. highway (HWFET), cost +30%. • Under NYC conditions hybrid and plug-in vehicles cut GHGs up to 60%, cost 20%. • Under HWFET conditions they offer few GHG reductions at higher costs. • Federal tests for window labels and CAFE standards favor some technologies over others

The Conceptual Design of an Integrated Nuclearhydrogen Production Plant Using the Sulfur Cycle Water Decomposition System

Science.gov (United States)

Farbman, G. H.

1976-01-01

A hydrogen production plant was designed based on a hybrid electrolytic-thermochemical process for decomposing water. The sulfur cycle water decomposition system is driven by a very high temperature nuclear reactor that provides 1,283 K helium working gas. The plant is sized to approximately ten million standard cubic meters per day of electrolytically pure hydrogen and has an overall thermal efficiently of 45.2 percent. The economics of the plant were evaluated using ground rules which include a 1974 cost basis without escalation, financing structure and other economic factors. Taking into account capital, operation, maintenance and nuclear fuel cycle costs, the cost of product hydrogen was calculated at $5.96/std cu m for utility financing. These values are significantly lower than hydrogen costs from conventional water electrolysis plants and competitive with hydrogen from coal gasification plants.

Energy Management Strategy Based on the Driving Cycle Model for Plugin Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Xiaoling Fu

2014-01-01

Full Text Available The energy management strategy (EMS for a plugin hybrid electric vehicle (PHEV is proposed based on the driving cycle model and dynamic programming (DP algorithm. A driving cycle model is constructed by collecting and processing the driving data of a certain school bus. The state of charge (SOC profile can be obtained by the DP algorithm for the whole driving cycle. In order to optimize the energy management strategy in the hybrid power system, the optimal motor torque control sequence can be calculated using the DP algorithm for the segments between the traffic intersections. Compared with the traditional charge depleting-charge sustaining (CDCS strategy, the test results on the ADVISOR platform show a significant improvement in fuel consumption using the EMS proposed in this paper.

Gasoline-powered serial hybrid cars cause lower life cycle carbon emissions than battery cars

Science.gov (United States)

Meinrenken, Christoph J.; Lackner, Klaus S.

2011-04-01

Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available serial hybrid technology achieves the well known efficiency gains from regenerative breaking, lack of gearbox, and light weighting - even if the electricity is generated onboard, from conventional fuels. Here, we analyze emissions for commercially available, state-of the-art battery cars (e.g. Nissan Leaf) and those of commercially available serial hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that serial hybrid cars driven on (fossil) gasoline cause fewer life cycle GHG emissions (126g CO2e per km) than battery cars driven on current US grid electricity (142g CO2e per km). We attribute this novel finding to the significant incremental life cycle emissions from battery cars from losses during grid transmission, battery dis-/charging, and larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

Solar Thermochemical Hydrogen Production via Terbium Oxide Based Redox Reactions

Directory of Open Access Journals (Sweden)

Rahul Bhosale

2016-01-01

Full Text Available The computational thermodynamic modeling of the terbium oxide based two-step solar thermochemical water splitting (Tb-WS cycle is reported. The 1st step of the Tb-WS cycle involves thermal reduction of TbO2 into Tb and O2, whereas the 2nd step corresponds to the production of H2 through Tb oxidation by water splitting reaction. Equilibrium compositions associated with the thermal reduction and water splitting steps were determined via HSC simulations. Influence of oxygen partial pressure in the inert gas on thermal reduction of TbO2 and effect of water splitting temperature (TL on Gibbs free energy related to the H2 production step were examined in detail. The cycle (ηcycle and solar-to-fuel energy conversion (ηsolar-to-fuel efficiency of the Tb-WS cycle were determined by performing the second-law thermodynamic analysis. Results obtained indicate that ηcycle and ηsolar-to-fuel increase with the decrease in oxygen partial pressure in the inert flushing gas and thermal reduction temperature (TH. It was also realized that the recuperation of the heat released by the water splitting reactor and quench unit further enhances the solar reactor efficiency. At TH=2280 K, by applying 60% heat recuperation, maximum ηcycle of 39.0% and ηsolar-to-fuel of 47.1% for the Tb-WS cycle can be attained.

Thermochemical production of hydrogen from water

International Nuclear Information System (INIS)

Funk, J.E.; Conger, W.L.; Carty, R.H.; Barker, R.E.

1975-01-01

A review of recent developments in the selection and evaluation of multi-step thermochemical water-splitting cycles is presented. A computerized and thermodynamic and chemical engineering analysis procedure is discussed with calculates, among other things, the thermal efficiency of the process which is defined to be the ratio of the enthalpy change for water decomposition to the total thermal energy required by the process. Changes in the thermodynamic state in each step of the process are also determined. Engineering considerations such as the effect of approach to equilibrium in the chemical reaction steps on the work of separation, and the magnitude of the recycle streams are included. Important practical matters such as thermal regeneration in the product and reactant streams are dealt with in some detail. The effect of reaction temperature on thermal efficiency is described and the use of the analysis procedure is demonstrated by applying it to several processes. (author)

Economics analysis of fuel cycle cost of fusion–fission hybrid reactors based on different fuel cycle strategies

Energy Technology Data Exchange (ETDEWEB)

Zu, Tiejun, E-mail: tiejun@mail.xjtu.edu.cn; Wu, Hongchun; Zheng, Youqi; Cao, Liangzhi

2015-01-15

Highlights: • Economics analysis of fuel cycle cost of FFHRs is carried out. • The mass flows of different fuel cycle strategies are established based on the equilibrium fuel cycle model. • The levelized fuel cycle costs of different fuel cycle strategies are calculated, and compared with current once-through fuel cycle. - Abstract: The economics analysis of fuel cycle cost of fusion–fission hybrid reactors has been performed to compare four fuel cycle strategies: light water cooled blanket burning natural uranium (Strategy A) or spent nuclear fuel (Strategy B), sodium cooled blanket burning transuranics (Strategy C) or minor actinides (Strategy D). The levelized fuel cycle costs (LFCC) which does not include the capital cost, operation and maintenance cost have been calculated based on the equilibrium mass flows. The current once-through (OT) cycle strategy has also been analyzed to serve as the reference fuel cycle for comparisons. It is found that Strategy A and Strategy B have lower LFCCs than OT cycle; although the LFCC of Strategy C is higher than that of OT cycle when the uranium price is at its nominal value, it would become comparable to that of OT cycle when the uranium price reaches its historical peak value level; Strategy D shows the highest LFCC, because it needs to reprocess huge mass of spent nuclear fuel; LFCC is sensitive to the discharge burnup of the nuclear fuel.

Lifecycle assessment of microalgae to biofuel: Comparison of thermochemical processing pathways

International Nuclear Information System (INIS)

Bennion, Edward P.; Ginosar, Daniel M.; Moses, John; Agblevor, Foster; Quinn, Jason C.

2015-01-01

Highlights: • Well to pump environmental assessment of two thermochemical processing pathways. • NER of 1.23 and GHG emissions of −11.4 g CO 2-eq (MJ) −1 for HTL pathway. • HTL represents promising conversion pathway based on use of wet biomass. • NER of 2.27 and GHG emissions of 210 g CO 2-eq (MJ) −1 for pyrolysis pathway. • Pyrolysis pathway: drying microalgae feedstock dominates environmental impact. - Abstract: Microalgae is 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 environmental impact of two different thermochemical conversion technologies for the microalgae-to-biofuel process through life cycle assessment. A system boundary of “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 CO 2-eq (MJ renewable diesel) −1 . Biofuel production through the pyrolysis pathway results in a NER of 2.27 and GHG emissions of 210 g CO 2-eq (MJ renewable diesel) −1 . The large environmental impact associated with the pyrolysis pathway is attributed to feedstock drying

Thermochemical data for reactor materials

International Nuclear Information System (INIS)

Ronchi, C.; Turrini, F.

1990-01-01

This report describes a computer database of thermochemical properties of nuclear reactor materials to be used for source term calculations in reactor accident codes. In the first part, the structure and the content of the computer file is described. In the second part a set of thermochemical data is presented pertaining to chemical reactions occurring during severe nuclear reactor accidents and involving fuel (uranium dioxide), fission products and structural materials. These data are complementary to those collected in the databook recently published by Cordfunke and Potter after a study supported by the Commission of the European Communities. The present data were collected from review articles and databanks and follow a discussion on the uncertainties and errors involved in the calculation of complex chemical equilibria in the extrapolated temperature range

Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

KAUST Repository

Ng, Kim Choon

2015-01-01

The energy, water and environment nexus is a crucial factor when considering the future development of desalination plants or industry in the water-stressed economies. New generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increase around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available thermally-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent of MED with AD cycles, or simply called the MEDAD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-steam at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60 and 80. °C. In this paper, the authors have reported their pioneered research on aspects of AD and related hybrid MEDAD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concept, the authors examined the cost apportionment of fuel cost by the quality or exergy of working steam for such cogeneration configurations.

Thermochemical performance analysis of solar driven CO_2 methane reforming

International Nuclear Information System (INIS)

Fuqiang, Wang; Jianyu, Tan; Huijian, Jin; Yu, Leng

2015-01-01

Increasing CO_2 emission problems create urgent challenges for alleviating global warming, and the capture of CO_2 has become an essential field of scientific research. In this study, a finite volume method (FVM) coupled with thermochemical kinetics was developed to analyze the solar driven CO_2 methane reforming process in a metallic foam reactor. The local thermal non-equilibrium (LTNE) model coupled with radiative heat transfer was developed to provide more temperature information. A joint inversion method based on chemical process software and the FVM coupled with thermochemical kinetics was developed to obtain the thermochemical reaction parameters and guarantee the calculation accuracy. The detailed thermal and thermochemical performance in the metal foam reactor was analyzed. In addition, the effects of heat flux distribution and porosity on the solar driven CO_2 methane reforming process were analyzed. The numerical results can serve as theoretical guidance for the solar driven CO_2 methane reforming application. - Highlights: • Solar driven CO_2 methane reforming process in metal foam reactor is analyzed. • FVM with chemical reactions was developed to analyze solar CO_2 methane reforming. • A joint inversion method was developed to obtain thermochemical reaction parameters. • Results can be a guidance for the solar driven CO_2 methane reforming application.

Standard GAX versus hybrid GAX absorption refrigeration cycle: From the view point of thermoeconomics

International Nuclear Information System (INIS)

Mehr, A.S.; Zare, V.; Mahmoudi, S.M.S.

2013-01-01

Highlights: • The SGAX cycle is found to be thermoeconomically efficient compared to HGAX cycle. • The HGAX cycle has higher COP and exergy efficiency compared to SGAX cycle. • Minimum product cost is found 180.5 $/GJ and 159.1 $/GJ for HGAX and SGAX, respectively. - Abstract: The main goal of this research is to compare thermoeconomic performance of a GAX absorption cycle and a hybrid GAX absorption cycle in which a compressor is employed to raise the absorber pressure. In order to do this, the ammonia–water standard GAX (SGAX) and hybrid GAX (HGAX) absorption refrigeration cycles are investigated and optimized from the viewpoints of thermodynamics and economics. Parametric studies are carried out and with the help of genetic algorithm (GA), the cycles’ performance is optimized based on the COP and exergy efficiency as well as the cost of unit product. Results indicate that although, compared to the GAX cycle, the HGAX cycle demonstrates a better performance from the view points of both the first and second laws of thermodynamics, the unit product cost for the HGAX cycle is higher. At the optimum operating conditions, the cost of unit product for the HGAX cycle is calculated as 180.5 $/GJ while the corresponding value for the SGAX cycle is obtained as 159.1 $/GJ. Also, the exergoeconomic analyses unfold that the condenser has the lowest exergoeconomic factor, f, in both the systems. In addition, inspired from nature, a new graphical plot is proposed to illustrate the fuel cost, product cost, capital investment and operating and maintenance cost and cost rates associated with the exergy destruction and losses within the system’s components

Sizing for fuel cell/supercapacitor hybrid vehicles based on stochastic driving cycles

International Nuclear Information System (INIS)

Feroldi, Diego; Carignano, Mauro

2016-01-01

Highlights: • A sizing procedure based on the fulfilment of real driving conditions is proposed. • A methodology to generate long-term stochastic driving cycles is proposed. • A parametric optimization of the real-time EMS is conducted. • A trade-off design is adopted from a Pareto front. • A comparison with optimal consumption via Dynamic Programming is performed. - Abstract: In this article, a methodology for the sizing and analysis of fuel cell/supercapacitor hybrid vehicles is presented. The proposed sizing methodology is based on the fulfilment of power requirements, including sustained speed tests and stochastic driving cycles. The procedure to generate driving cycles is also presented in this paper. The sizing algorithm explicitly accounts for the Equivalent Consumption Minimization Strategy (ECMS). The performance is compared with optimal consumption, which is found using an off-line strategy via Dynamic Programming. The sizing methodology provides guidance for sizing the fuel cell and the supercapacitor number. The results also include analysis on oversizing the fuel cell and varying the parameters of the energy management strategy. The simulation results highlight the importance of integrating sizing and energy management into fuel cell hybrid vehicles.

Are the lessons of the techno-economic studies on the sulphur-iodine cycle applicable to the other cycles?

International Nuclear Information System (INIS)

Werkoff, F.; Mansilla, C.

2007-01-01

Further advances in nuclear energy system design can broaden the opportunities for the use of nuclear energy. To explore these opportunities, several countries are involved in a forum on the development of next generation nuclear energy systems known as 'Generation IV'. Six concepts have been chosen by the forum, to be studied. The Very High Temperature Reactor (VHTR) offers perspectives for producing electricity and hydrogen with high efficiencies. Nuclear production of hydrogen by thermochemical means is one of the prime candidates for powering the hydrogen economy without producing green house gases. Among them, the Sulphur-Iodine (S-I) thermochemical cycle appeared well fitted with the VHTR, due to the temperature needed for the decomposition of the sulphuric acid. It was invented in the 1970's and it benefits from a revival of interest in the framework of Generation IV. In the last past years, assessments of the S-I process, coupled with a VHTR have been carried out. It appeared that these assessments have to be considered, looking with a particular care to the recommendations of the Generation IV crosscutting economics group [1]: a Generation IV system will: 1. Have a clear life-cost advantage over other energy systems. 2. Have a level of financial risk comparable to other energy projects. The experience gained from techno-economic studies [2, 3] which consider the S-I cycle, indicates that the choice of alternatives cycles to the S-I one must be driven by the characteristic of a previously selected nuclear reactor, mainly the temperature at the nuclear core outlet. Moreover, the net efficiency of the thermochemical cycle must be higher than a reference value defined from the alkaline electrolysis fed by the electricity produced from the selected reactor. Besides, the technical feasibility of the thermochemical processes is not yet established and the production cost of hydrogen from these processes is the result of the sum of several cost factors which are

Free-Standing Hybrid Graphene Paper Encapsulating Nanostructures for High Cycle-Life Supercapacitors.

Science.gov (United States)

Jiao, Xinyan; Hao, Qingli; Xia, Xifeng; Lei, Wu; Ouyang, Yu; Ye, Haitao; Mandler, Daniel

2018-03-09

The incorporation of spacers between graphene sheets has been investigated as an effective method to improve the electrochemical performance of graphene papers (GPs) for supercapacitors. Here, we report the design of free-standing GP@NiO and GP@Ni hybrid GPs in which NiO nanoclusters and Ni nanoparticles are encapsulated into graphene sheets through electrostatic assembly and subsequent vacuum filtration. The encapsulated NiO nanoclusters and Ni nanoparticles can mitigate the restacking of graphene sheets, providing sufficient spaces for high-speed ion diffusion and electron transport. In addition, the spacers strongly bind to graphene sheets, which can efficiently improve the electrochemical stability. Therefore, at a current density of 0.5 A g -1 , the GP@NiO and GP@Ni electrodes exhibit higher specific capacitances of 306.9 and 246.1 F g -1 than the GP electrode (185.7 F g -1 ). The GP@NiO and GP@Ni electrodes exhibit capacitance retention of 98.7 % and 95.6 % after 10000 cycles, demonstrating an outstanding cycling stability. Additionally, the GP@NiO∥GP@Ni delivers excellent cycling stability (93.7 % after 10 000 cycles) and high energy density. These free-standing encapsulated hybrid GPs have great potential as electrode for high-performance supercapacitors. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Life cycle energy metrics and CO 2 credit analysis of a hybrid photovoltaic/thermal greenhouse dryer

OpenAIRE

P. Barnwal; G. N. Tiwari

2008-01-01

In this paper, life cycle energy metrics, such as energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE), and mitigation of CO 2 emissions for a hybrid photovoltaic/thermal (PV/T) greenhouse dryer have been analyzed. The hybrid PV/T greenhouse (roof type even span) dryer, designed and constructed at Solar Energy Park, Indian Institute of Technology, New Delhi (28°35′N, 77°12′E, 216 m above MSL), India, has a 2.50 m × 2.60 m floor area, 1.80 m ce...

Combined cycle solar central receiver hybrid power system study. Volume III. Appendices. Final technical report

Energy Technology Data Exchange (ETDEWEB)

None

1979-11-01

A design study for a 100 MW gas turbine/steam turbine combined cycle solar/fossil-fuel hybrid power plant is presented. This volume contains the appendices: (a) preconceptual design data; (b) market potential analysis methodology; (c) parametric analysis methodology; (d) EPGS systems description; (e) commercial-scale solar hybrid power system assessment; and (f) conceptual design data lists. (WHK)

Current hybrid-electric powertrain architectures: Applying empirical design data to life cycle assessment and whole-life cost analysis

International Nuclear Information System (INIS)

Hutchinson, Tim; Burgess, Stuart; Herrmann, Guido

2014-01-01

Highlights: • Design data for 44 hybrid cars available in the US has been gathered and analysed. • An empirical life cycle assessment of greenhouse gas emissions is performed. • Empirical whole-life cost modelling is used to evaluate powertrain architectures. • The value to be seen in each architecture is highly dependent on its application. • Mild, HSD and Plug-in HSD powertrains are the most likely architectures to dominate. - Abstract: The recent introduction of hybrid-electric powertrain technology has disrupted the automotive industry, causing significant powertrain design divergence. As this radical powertrain innovation matures, will hybrid vehicles dominate the future automotive market and does this represent a positive shift in the environmental impact of the industry? The answer to this question is sought within this paper. It seeks to take advantage of the position that the industry has reached, replacing previous theoretical studies with the first extensive empirical models of life cycle emissions and whole-life costing. A comprehensive snapshot of today’s hybrid market is presented, with detailed descriptions of the various hybrid powertrain architectures. Design data has been gathered for 44 hybrid passenger cars currently available in the US. The empirical data is used to explore the relative life cycle greenhouse gas emissions and whole-life costing of different hybrid powertrain architectures. Potential dominant designs are identified and their emissions are shown to be reduced. However, both the emissions and economic competitiveness of different hybrid powertrains are shown to vary significantly depending on how the vehicle is used

Catalytic performance and durability of Ni/AC for HI decomposition in sulfur–iodine thermochemical cycle for hydrogen production

International Nuclear Information System (INIS)

Fu, Guangshi; He, Yong; Zhang, Yanwei; Zhu, Yanqun; Wang, Zhihua; Cen, Kefa

2016-01-01

Highlights: • The relation between Ni content and Ni particle dispersion were disclosed. • The effect of Ni content on the catalytic activity of Ni/AC catalyst was revealed. • The optimal content of Ni for Ni/AC catalysts in HI decomposition was found. - Abstract: This work reports the Ni content effect on the Ni/AC catalytic performance in the HI decomposition reaction of the sulfur–iodine (SI) thermochemical cycle for hydrogen production and the Ni/AC catalyst durability in a long-term test. Accordingly, five catalysts with the Ni content ranging from 5% to 15% were prepared by an incipient-wetness impregnation method. The activity of all catalysts was examined under the temperature range of 573–773 K. The catalytic performance evaluation suggests that Ni content plays a significant role in the Ni dispersion, Ni particle size, and eventually the catalytic activity in HI decomposition. 12% is the optimal Ni content for Ni/AC catalysts in HI decomposition which is balanced between poor dispersion of Ni particles and increasing active center. The results of 24 h durability test, which incorporated with BET and TEM investigations of the 12%Ni/AC catalyst before and after the reaction, indicate that establishing a better Ni particle dispersion pattern and improving the stability of Ni particles on the support should be considered in the future.

Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

KAUST Repository

Ng, Kim Choon; Thu, Kyaw; Oh, Seungjin; Ang, Li; Shahzad, Muhammad Wakil; Ismail, Azhar Bin

2015-01-01

-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent

Development of a hybrid energy storage sizing algorithm associated with the evaluation of power management in different driving cycles

International Nuclear Information System (INIS)

Masoud, Masih Tehrani; Mohammad Reza, Ha'iri Yazdi; Esfahanian, Vahid; Sagha, Hossein

2012-01-01

In this paper, a hybrid energy storage sizing algorithm for electric vehicles is developed to achieve a semi optimum cost effective design. Using the developed algorithm, a driving cycle is divided into its micro-trips and the power and energy demands in each micro trip are determined. The battery size is estimated because the battery fulfills the power demands. Moreover, the ultra capacitor (UC) energy (or the number of UC modules) is assessed because the UC delivers the maximum energy demands of the different micro trips of a driving cycle. Finally, a design factor, which shows the power of the hybrid energy storage control strategy, is utilized to evaluate the newly designed control strategies. Using the developed algorithm, energy saving loss, driver satisfaction criteria, and battery life criteria are calculated using a feed forward dynamic modeling software program and are utilized for comparison among different energy storage candidates. This procedure is applied to the hybrid energy storage sizing of a series hybrid electric city bus in Manhattan and to the Tehran driving cycle. Results show that a higher aggressive driving cycle (Manhattan) requires more expensive energy storage system and more sophisticated energy management strategy

Construction apparatus for thermochemical hydrogen production process

Energy Technology Data Exchange (ETDEWEB)

Kubo, S.; Nakajima, H.; Higashi, S.; Onuki, K.; Akino, S.S.N. [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan). Nuclear Heat Utilization Engineering Lab

2001-06-01

Studies have been carried out at the Japan Atomic Energy Research Institute (JAERI) on hydrogen production through thermochemical processes such as water-splitting. These studies are classified with iodine-sulphur cycle studies using heat from high temperature gas-cooled reactors. An experimental apparatus was constructed with fluorine resin, glass and quartz. It can produce hydrogen at a rate of 50 litres per hour. Electricity provides the heat required for the operation. The closed chemical process requires special control techniques. The process flow diagram for the apparatus was designed based on the results of previous studies including one where hydrogen production was successfully achieved at a rate of one liter per hour for 48 hours. Experimental operations under atmospheric pressure will be carried out for the next four years to develop the process. The data will be used in the next research and development programs aimed at designing a bench-scale apparatus. 7 refs., 1 tab., 8 figs.

OPTIMIZED WTE CONVERSION OF MUNICIPAL SOLID WASTE IN SHANGHAI APPLYING THERMOCHEMICAL TECHNOLOGIES

OpenAIRE

Dai, Siyang

2016-01-01

Thermochemical technologies have been proven effective in treating municipal solid waste (MSW) for many years. China, with a rapid increase of MSW, plans to implement more environmental friendly ways to treat MSW than landfill, which treats about 79 % of total MSW currently. The aim of this master thesis was to find out a suitable thermochemical technology to treat MSW in Shanghai, China. Several different thermochemical technologies are compared in this thesis and plasma gasification was sel...

Thermochemical storage for CSP via redox structured reactors/heat exchangers: The RESTRUCTURE project

Science.gov (United States)

Karagiannakis, George; Pagkoura, Chrysoula; Konstandopoulos, Athanasios G.; Tescari, Stefania; Singh, Abhishek; Roeb, Martin; Lange, Matthias; Marcher, Johnny; Jové, Aleix; Prieto, Cristina; Rattenbury, Michael; Chasiotis, Andreas

2017-06-01

The present work provides an overview of activities performed in the framework of the EU-funded collaborative project RESTRUCTURE, the main goal of which was to develop and validate a compact structured reactor/heat exchanger for thermochemical storage driven by 2-step high temperature redox metal oxide cycles. The starting point of development path included redox materials qualification via both theoretical and lab-scale experimental studies. Most favorable compositions were cobalt oxide/alumina composites. Preparation of small-scale structured bodies included various approaches, ranging from perforated pellets to more sophisticated honeycomb geometries, fabricated by extrusion and coating. Proof-of-concept of the proposed novel reactor/heat exchanger was successfully validated in small-scale structures and the next step included scaling up of redox honeycombs production. Significant challenges were identified for the case of extruded full-size bodies and the final qualified approach related to preparation of cordierite substrates coated with cobalt oxide. The successful experimental evaluation of the pilot reactor/heat exchanger system constructed motivated the preliminary techno-economic evaluation of the proposed novel thermochemical energy storage concept. Taking into account experimental results, available technologies and standard design aspects a model for a 70.5 MWe CSP plant was defined. Estimated LCOE costs were calculated to be in the range of reference values for Combined Cycle Power Plants operated by natural gas. One of main cost contributors was the storage system itself, partially due to relatively high cost of cobalt oxide. This highlighted the need to identify less costly and equally efficient to cobalt oxide redox materials.

Integrated gasification and Cu-Cl cycle for trigeneration of hydrogen, steam and electricity

Energy Technology Data Exchange (ETDEWEB)

Aghahosseini, S; Dincer, I; Naterer, G F [University of Ontario, Oshawa, ON (Canada). Institute of Technology

2011-02-15

This paper develops and analyzes an integrated process model of an Integrated Gasification Combined Cycle (IGCC) and a thermochemical copper-chlorine (Cu-Cl) cycle for trigeneration of hydrogen, steam and electricity. The process model is developed with Aspen HYSYS software. By using oxygen instead of air for the gasification process, where oxygen is provided by the integrated Cu-Cl cycle, it is found that the hydrogen content of produced syngas increases by about 20%, due to improvement of the gasification combustion efficiency and reduction of syngas NOx emissions. Moreover, about 60% of external heat required for the integrated Cu-Cl cycle can be provided by the IGCC plant, with minor modifications of the steam cycle, and a slight decrease of IGCC overall efficiency. Integration of gasification and thermochemical hydrogen production can provide significant improvements in the overall hydrogen, steam and electricity output, when compared against the processes each operating separately and independently of each other.

Thermochemical Heat Storage: from Reaction Storage Density to System Storage Density

NARCIS (Netherlands)

Jong, A.J. de; Vliet, L.D. van; Hoegaerts, C.L.G.; Roelands, C.P.M.; Cuypers, R.

2016-01-01

Long-term and compact storage of solar energy is crucial for the eventual transition to a 100% renewable energy economy. For this, thermochemical materials provide a promising solution. The compactness of a long-term storage system is determined by the thermochemical reaction, operating conditions,

The control system of the ecological hybrid two stages refrigerating cycle

Directory of Open Access Journals (Sweden)

Cyklis Piotr

2016-01-01

Full Text Available The compression anticlockwise cycle is mostly used for refrigeration. However due to the environmental regulations, the use of classic refrigerants: F-gases is limited by international agreements. Therefore the combined compression-adsorption hybrid cycle with natural liquids: water/carbon dioxide working as the energy carriers is a promising solution. This allows to utilize the solar or waste energy for the refrigeration purpose. In this paper application of the solar collectors as the energy source for the adsorption cycle, coupled with the low temperature (LT refrigerating carbon dioxide compression cycle is shown. The control of the system is an essential issue to reduce the electric power consumption. The control of the solar heat supply and water sprayed cooling tower, for the adsorption cycle re-cooling, is presented in this paper. The designed control system and algorithm is related to the LT compression cycle, which operates according to the need of cold for the refrigeration chamber. The results of the laboratory investigations of the full system, showing the reduction of the energy consumption and maximum utilization of the solar heat for different control methods are presented.

A demand-centered, hybrid life-cycle methodology for city-scale greenhouse gas inventories.

Science.gov (United States)

Ramaswami, Anu; Hillman, Tim; Janson, Bruce; Reiner, Mark; Thomas, Gregg

2008-09-01

Greenhouse gas (GHG) accounting for individual cities is confounded by spatial scale and boundary effects that impact the allocation of regional material and energy flows. This paper develops a demand-centered, hybrid life-cycle-based methodology for conducting city-scale GHG inventories that incorporates (1) spatial allocation of surface and airline travel across colocated cities in larger metropolitan regions, and, (2) life-cycle assessment (LCA) to quantify the embodied energy of key urban materials--food, water, fuel, and concrete. The hybrid methodology enables cities to separately report the GHG impact associated with direct end-use of energy by cities (consistent with EPA and IPCC methods), as well as the impact of extra-boundary activities such as air travel and production of key urban materials (consistent with Scope 3 protocols recommended by the World Resources Institute). Application of this hybrid methodology to Denver, Colorado, yielded a more holistic GHG inventory that approaches a GHG footprint computation, with consistency of inclusions across spatial scale as well as convergence of city-scale per capita GHG emissions (approximately 25 mt CO2e/person/year) with state and national data. The method is shown to have significant policy impacts, and also demonstrates the utility of benchmarks in understanding energy use in various city sectors.

Synfuel (hydrogen) production from fusion power

International Nuclear Information System (INIS)

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

1979-01-01

A potential use of fusion energy for the production of synthetic fuel (hydrogen) is described. The hybrid-thermochemical bismuth-sulfate cycle is used as a vehicle to assess the technological and economic merits of this potential nonelectric application of fusion power

Gasoline-powered series hybrid cars cause lower life cycle carbon emissions than battery cars

Science.gov (United States)

Meinrenken, Christoph; Lackner, Klaus S.

2012-02-01

Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available series hybrid technology achieves the well known efficiency gains in electric drivetrains (regenerative breaking, lack of gearbox) even if the electricity is generated onboard, from conventional fuels. Here, we analyze life cycle GHG emissions for commercially available, state-of the-art plug-in battery cars (e.g. Nissan Leaf) and those of commercially available series hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that series hybrid cars driven on (fossil) gasoline cause fewer emissions (126g CO2eq per km) than battery cars driven on current US grid electricity (142g CO2eq per km). We attribute this novel finding to the significant incremental emissions from plug-in battery cars due to losses during grid transmission and battery dis-/charging, and manufacturing larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

Thermochemical data for reactor materials and fission products: The ECN database

International Nuclear Information System (INIS)

Cordfunke, E.H.P.; Konings, R.J.M.

1993-02-01

The activities of the authors regarding the compilation of a database of thermochemical properties for reactor materials and fission products is reviewed. The evaluation procedures and techniques are outlined and examples are given. In addition, examples of the use of thermochemical data for the application in the field of Nuclear Technology are given. (orig.)

A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

OpenAIRE

Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

2016-01-01

The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from “purely” sensible to “hybrid” sensible/ thermochemical one, via coating...

Thermochemical nitrate reduction

International Nuclear Information System (INIS)

Cox, J.L.; Lilga, M.A.; Hallen, R.T.

1992-09-01

A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with ∼3 wt% NO 3 - solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200 degrees C to 350 degrees C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia ∼ methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics

Hybrid System Modeling and Full Cycle Operation Analysis of a Two-Stroke Free-Piston Linear Generator

Directory of Open Access Journals (Sweden)

Peng Sun

2017-02-01

Full Text Available Free-piston linear generators (FPLGs have attractive application prospects for hybrid electric vehicles (HEVs owing to their high-efficiency, low-emissions and multi-fuel flexibility. In order to achieve long-term stable operation, the hybrid system design and full-cycle operation strategy are essential factors that should be considered. A 25 kW FPLG consisting of an internal combustion engine (ICE, a linear electric machine (LEM and a gas spring (GS is designed. To improve the power density and generating efficiency, the LEM is assembled with two modular flat-type double-sided PM LEM units, which sandwich a common moving-magnet plate supported by a middle keel beam and bilateral slide guide rails to enhance the stiffness of the moving plate. For the convenience of operation processes analysis, the coupling hybrid system is modeled mathematically and a full cycle simulation model is established. Top-level systemic control strategies including the starting, stable operating, fault recovering and stopping strategies are analyzed and discussed. The analysis results validate that the system can run stably and robustly with the proposed full cycle operation strategy. The effective electric output power can reach 26.36 kW with an overall system efficiency of 36.32%.

2009 Thermochemical Conversion Platform Review Report

Energy Technology Data Exchange (ETDEWEB)

Ferrell, John [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

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.

Internet Enabled Remote Driving of a Combat Hybrid Electric Power System for Duty Cycle Measurement

National Research Council Canada - National Science Library

Goodell, Jarrett; Compere, Marc; Smith, Wilford; Holtz, Dale; Brudnak, Mark; Pozolo, Mike; Paul, Victor; Mohammad, Syed; Mortsfield, Todd; Shvartsman, Andrey

2007-01-01

This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware, both of which were used to measure the duty cycle of a combat vehicle in a virtual...

Performance Analysis of Hybrid Electric Vehicle over Different Driving Cycles

Science.gov (United States)

Panday, Aishwarya; Bansal, Hari Om

2017-02-01

Article aims to find the nature and response of a hybrid vehicle on various standard driving cycles. Road profile parameters play an important role in determining the fuel efficiency. Typical parameters of road profile can be reduced to a useful smaller set using principal component analysis and independent component analysis. Resultant data set obtained after size reduction may result in more appropriate and important parameter cluster. With reduced parameter set fuel economies over various driving cycles, are ranked using TOPSIS and VIKOR multi-criteria decision making methods. The ranking trend is then compared with the fuel economies achieved after driving the vehicle over respective roads. Control strategy responsible for power split is optimized using genetic algorithm. 1RC battery model and modified SOC estimation method are considered for the simulation and improved results compared with the default are obtained.

Study of emissions and fuel economy for parallel hybrid versus conventional vehicles on real world and standard driving cycles

Directory of Open Access Journals (Sweden)

Ahmed Al-Samari

2017-12-01

Full Text Available Parallel hybrid electric vehicles (PHEVs increasing rapidly in the automobile markets. However, the benefits out of using this kind of vehicles are still concerned a lot of costumers. This work investigated the expected benefits (such as decreasing emissions and increasing fuel economy from using the parallel HEV in comparison to the conventional vehicle model of the real-world and standard driving cycles. The software Autonomie used in this study to simulate the parallel HEV and conventional models on these driving cycles.The results show that the fuel economy (FE can be improved significantly up to 68% on real-world driving cycle, which is represented mostly city activities. However, the FE improvement was limited (10% on the highway driving cycle, and this is expected since the using of brake system was infrequent. Moreover, the emissions from parallel HEV decreased about 40% on the real-world driving cycle, and decreased 11% on the highway driving cycle. Finally, the engine efficiency, improved about 12% on the real-world driving cycle, and about 7% on highway driving cycle. Keywords: Emissions, Hybrid electric vehicles, Fuel economy, Real-world driving cycle

Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

International Nuclear Information System (INIS)

Zhou, Z.; Yang, Y.; Xu, H.

2011-01-01

This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

Review of the direct thermochemical conversion of lignocellulosic biomass for liquid fuels

Directory of Open Access Journals (Sweden)

Jianchun JIANG,Junming XU,Zhanqian SONG

2015-03-01

Full Text Available Increased demand for liquid transportation fuels, environmental concerns and depletion of petroleum resources requires the development of efficient conversion technologies for production of second-generation biofuels from non-food resources. Thermochemical approaches hold great potential for conversion of lignocellulosic biomass into liquid fuels. Direct thermochemical processes convert biomass into liquid fuels in one step using heat and catalysts and have many advantages over indirect and biological processes, such as greater feedstock flexibility, integrated conversion of whole biomass, and lower operation costs. Several direct thermochemical processes are employed in the production of liquid biofuels depending on the nature of the feedstock properties: such as fast pyrolysis/liquefaction of lignocellulosic biomass for bio-oil, including upgrading methods, such as catalytic cracking and hydrogenation. Owing to the substantial amount of liquid fuels consumed by vehicular transport, converting biomass into drop-in liquid fuels may reduce the dependence of the fuel market on petroleum-based fuel products. In this review, we also summarize recent progress in technologies for large-scale equipment for direct thermochemical conversion. We focus on the technical aspects critical to commercialization of the technologies for production of liquid fuels from biomass, including feedstock type, cracking catalysts, catalytic cracking mechanisms, catalytic reactors, and biofuel properties. We also discuss future prospects for direct thermochemical conversion in biorefineries for the production of high grade biofuels.

Hydrogen production using the sulfur-iodine cycle coupled to a VHTR: An overview

International Nuclear Information System (INIS)

Vitart, X.; Le Duigou, A.; Carles, P.

2006-01-01

The sulfur-iodine thermo-chemical cycle is considered to be one of the most promising routes for massive hydrogen production, using high temperature heat from a Generation IV VHTR. We propose here a brief overview of the main questions raised by this cycle, along with the general lines of French CEA's program

Life-cycle private costs of hybrid electric vehicles in the current Chinese market

International Nuclear Information System (INIS)

Lin, Chengtao; Wu, Tian; Ou, Xunmin; Zhang, Qian; Zhang, Xu; Zhang, Xiliang

2013-01-01

Understanding the life-cycle private cost (LCPC) of the hybrid electric vehicle (HEV) is important for market feasibility analysis. An HEV LCPC model was established to evaluate HEV market prospects in China compared with traditional internal combustion engine vehicles (ICEV). The Kluger HV, a full-hybrid HEV sports utility vehicle (SUV), aimed at the Chinese market, was simulated as the 2010 model's technology details were well publicized. The LCPC of the Kluger HV was roughly the same (about 1.06 times) as that of its comparable ICEV (Highlander SUV). This aligns with other compact and midsize HEV cars (e.g., Toyota Prius, Honda Civic and Toyota Camry HEV) in China. With oil prices predicted to rise in the long-term, the advantage of HEVs energy saving will partly compensate the high manufacturing costs associated with their additional motor/battery components. Besides supporting technology development, enabling policy should be implemented to introduce HEV technology into taxi fleets and business cars. This technology's cost-competitiveness, compared with traditional ICEVs, is advantageous for these higher mileage vehicles. - Highlights: ► A model is set up to evaluate the life-cycle private cost of HEVs. ► Life-cycle private costs of HEVs are higher than conventional cars in China. ► HEVs become competitive when the oil price rises

Parametric analysis of blade configurations for a small-scale nitrogen axial expander with hybrid open-Rankine cycle

International Nuclear Information System (INIS)

Khalil, Khalil M.; Mahmoud, S.; Al- Dadah, R.K.; AL-Mousawi, Fadhel

2017-01-01

Highlights: • Develop cryogenic energy storage and efficient recovery technologies. • Integrate small scale closed and cryogenic open-Rankine cycles. • Investigate blade configuration on small-scale axial expander performance. • Use mean line and 3D CFD simulation for expander robust design procedure. • Predict effects of expander efficiency on hybrid open-Rankine cycle efficiency. - Abstract: During the last few decades, low-grade energy sources such as solar energy and wind energy have enhanced the efficiency of the advanced renewable technologies such as the combined Rankine. Furthermore, these heat sources have contributed to a reduction in CO2 emissions. To address the problem of the intermittent nature of such renewable sources, energy storage technologies have been used to balance the power demand and smooth out energy production. In this study, the direct expansion cycle (open Rankine cycle) is combined with a closed loop Rankine cycle to generate power more efficiently and address the problem of discontinuous renewable sources. The topping cycle of this system is a closed looped Rankine cycle and propane is used as a hydrocarbon fluid, while the direct expansion cycle is considered to be the bottoming cycle utilizing nitrogen as cryogen fluid. Small-scale expanders are the most important parts in many thermal power cycles, such as the Rankine cycle, due to the significant impact on the overall cycle’s efficiency. This work investigated the effect of using a number of blade configurations on the cycle’s performance using a small-scale axial expander. A three-dimensional Computational Fluid Dynamic (CFD) simulation was used to examine four proposed blade configurations (lean, sweep, twist, bowl) with three hub- tip ratios (0.83, 0.75, 0.66). In addition, a numerical simulation model of the hybrid open expansion- Rankine cycle was designed and modeled in order to estimate the cycle’s performance. The results show that when the expander�

Extension of a reactive distillation process design methodology: application to the hydrogen production through the Iodine-Sulfur thermochemical cycle; Generalisation d'une approche de conception de procedes de distillation reactive: application a la production d'hydrogene par le cycle thermochimique I-S

Energy Technology Data Exchange (ETDEWEB)

Belaissaoui, B

2006-02-15

Reactive distillation is a promising way to improve classical processes. This interest has been comforted by numerous successful applications involving reactive systems in liquid phase but never in vapour phase. In this context, general design tools have been developed for the analysis of reactive distillation processes whatever the reactive phase. A general model for open condensation and evaporation of vapour or liquid reactive systems in chemical equilibrium has been written and applied to extend the feasibility analysis, synthesis and design methods of the sequential design methodology of R. Thery (2002). The extended design methodology is applied to the industrial production of hydrogen through the iodine-sulphur thermochemical cycle by vapour phase reactive distillation. A column configuration is proposed with better performance formerly published configuration. (author)

OECD/NEA thermochemical database

Energy Technology Data Exchange (ETDEWEB)

Byeon, Kee Hoh; Song, Dae Yong; Shin, Hyun Kyoo; Park, Seong Won; Ro, Seung Gy

1998-03-01

This state of the art report is to introduce the contents of the Chemical Data-Service, OECD/NEA, and the results of survey by OECD/NEA for the thermodynamic and kinetic database currently in use. It is also to summarize the results of Thermochemical Database Projects of OECD/NEA. This report will be a guide book for the researchers easily to get the validate thermodynamic and kinetic data of all substances from the available OECD/NEA database. (author). 75 refs.

Multi-state system in a fault tree analysis of a nuclear based thermochemical hydrogen plant

International Nuclear Information System (INIS)

Zhang, Y.

2008-01-01

Nuclear-based hydrogen generation is a promising way to supply hydrogen for this large market in the future. This thesis focuses on one of the most promising methods, a thermochemical Cu-Cl cycle, which is currently under development by UOIT, Atomic Energy of Canada Limited (AECL) and the Argonne National Laboratory (ANL). The safety issues of the Cu-Cl cycle are addressed in this thesis. An investigation of major accident scenarios shows that potential tragedies can be avoided with effective risk analysis and safety management programs. As a powerful and systematic tool, fault tree analysis (FTA) is adapted to the particular needs of the Cu-Cl system. This thesis develops a new method that combines FTA with a reliability analysis tool, multi-state system (MSS), to improve the accuracy of FTA and also improve system reliability. (author)

Life cycle cost analysis of single slope hybrid (PV/T) active solar still

International Nuclear Information System (INIS)

Kumar, Shiv; Tiwari, G.N.

2009-01-01

This paper presents the life cycle cost analysis of the single slope passive and hybrid photovoltaic (PV/T) active solar stills, based on the annual performance at 0.05 m water depth. Effects of various parameters, namely interest rate, life of the system and the maintenance cost have been taken into account. The comparative cost of distilled water produced from passive solar still (Rs. 0.70/kg) is found to be less than hybrid (PV/T) active solar still (Rs. 1.93/kg) for 30 years life time of the systems. The payback periods of the passive and hybrid (PV/T) active solar still are estimated to be in the range of 1.1-6.2 years and 3.3-23.9 years, respectively, based on selling price of distilled water in the range of Rs. 10/kg to Rs. 2/kg. The energy payback time (EPBT) has been estimated as 2.9 and 4.7 years, respectively. (author)

Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

International Nuclear Information System (INIS)

Haro, P.; Ollero, P.; Villanueva Perales, A.L.; Gómez-Barea, A.

2013-01-01

Highlights: ► A thermochemical biorefinery based on bio-DME as intermediate is studied. ► The assessed concepts (12) lead to multi-product generation (polygeneration). ► In all concepts DME is converted by carbonylation or hydrocarbonylation. ► Rates of return are similar to or higher than plants producing a single product. -- Abstract: Thermochemical biorefinery based on dimethyl ether (DME) as an intermediate is studied. DME is converted into methyl acetate, which can either be hydrogenated to ethanol or sold as a co-product. Considering this option together with a variety of technologies for syngas upgrading, 12 different process concepts are analyzed. The considered products are ethanol, methyl acetate, H 2 , DME and electricity. The assessment of each alternative includes biomass pretreatment, gasification, syngas clean-up and conditioning, DME synthesis and conversion, product separation, and heat and power integration. A plant size of 500 MW th processing poplar chips is taken as a basis. The resulting energy efficiency to products ranges from 34.9% to 50.2%. The largest internal rate of return (28.74%) corresponds to a concept which produces methyl acetate, DME and electricity (exported to grid). A sensitivity analysis with respect to total plant investment (TPI), total operation costs (TOC) and market price of products was carried out. The overall conclusion is that, despite its greater complexity, this kind of thermochemical biorefinery is more profitable than thermochemical bioprocesses oriented to a single product.

Thermochemical stability of Soviet macroporous sulfonated cation-exchangers

Energy Technology Data Exchange (ETDEWEB)

Rukhlyada, N.N.; Plotnikova, V.P.; Roginskaya, B.S.; Znamenskii, Yu.P.; Zavodovskaya, A.S.; Dobrova, E.I.

1988-10-20

The purpose of this work was to study the influence of macroporosity on the thermochemical stability of sulfonated cation-exchangers. The investigations were carried out on commercial macroporous sulfonated cation-exchangers based on styrene-divinylbenzene copolymers. Study of the thermochemical stability of macroporous sulfonated cation-exchangers in dilute hydrogen peroxide solutions showed that the type of macroporosity has virtually no influence on their stability. The determining factor in thermal stability of macroporous cation-exchangers, as of the gel type, is the degree of cross-linking of the polymer matrix. The capacity loss of macroporous cation-exchangers during oxidative thermolysis is caused by destruction of the macromolecular skeleton and elution of fragments of polar chains containing sulfo groups into the solution.

Quantitative Thermochemical Measurements in High-Pressure Gaseous Combustion

Science.gov (United States)

Kojima, Jun J.; Fischer, David G.

2012-01-01

We present our strategic experiment and thermochemical analyses on combustion flow using a subframe burst gating (SBG) Raman spectroscopy. This unconventional laser diagnostic technique has promising ability to enhance accuracy of the quantitative scalar measurements in a point-wise single-shot fashion. In the presentation, we briefly describe an experimental methodology that generates transferable calibration standard for the routine implementation of the diagnostics in hydrocarbon flames. The diagnostic technology was applied to simultaneous measurements of temperature and chemical species in a swirl-stabilized turbulent flame with gaseous methane fuel at elevated pressure (17 atm). Statistical analyses of the space-/time-resolved thermochemical data provide insights into the nature of the mixing process and it impact on the subsequent combustion process in the model combustor.

Effects of thermo-chemical pre-treatment on anaerobic biodegradability and hydrolysis of lignocellulosic biomass

NARCIS (Netherlands)

Fernandes, T.; Klaasse Bos, G.J.; Zeeman, G.; Sanders, J.P.M.; Lier, van J.B.

2009-01-01

The effects of different thermo-chemical pre-treatment methods were determined on the biodegradability and hydrolysis rate of lignocellulosic biomass. Three plant species, hay, straw and bracken were thermo-chemically pre-treated with calcium hydroxide, ammonium carbonate and maleic acid. After

2011 Biomass Program Platform Peer Review. Thermochemical Conversion

Energy Technology Data Exchange (ETDEWEB)

Grabowski, Paul E. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

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.

Preliminary design and analysis on nuclear fuel cycle for fission-fusion hybrid spent fuel burner

International Nuclear Information System (INIS)

Chen Yan; Wang Minghuang; Jiang Jieqiong

2012-01-01

A wet-processing-based fuel cycle and a dry-processing were designed for a fission-fusion hybrid spent fuel burner (FDS-SFB). Mass flow of SFB was preliminarily analyzed. The feasibility analysis of initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing were preliminarily evaluated. The results of mass flow of FDS-SFB demonstrated that the initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing of nuclear fuel cycle of FDS-SFB is preliminarily feasible. (authors)

Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle

Science.gov (United States)

Liberatore, Raffaele; Ferrara, Mariarosaria; Lanchi, Michela; Turchetti, Luca

2017-06-01

It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographical location and plant sizing criteria. The use of a sulfur burner, which can serve both as thermal backup and SO2 source for the open cycle, is also considered.

Life cycle assessment of greenhouse gas emissions from plug-in hybrid vehicles: implications for policy.

Science.gov (United States)

Samaras, Constantine; Meisterling, Kyle

2008-05-01

Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a role in reducing greenhouse gas (GHG) emissions from the transport sector. However, meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. We assess life cycle GHG emissions from PHEVs and find that they reduce GHG emissions by 32% compared to conventional vehicles, but have small reductions compared to traditional hybrids. Batteries are an important component of PHEVs, and GHGs associated with lithium-ion battery materials and production account for 2-5% of life cycle emissions from PHEVs. We consider cellulosic ethanol use and various carbon intensities of electricity. The reduced liquid fuel requirements of PHEVs could leverage limited cellulosic ethanol resources. Electricity generation infrastructure is long-lived, and technology decisions within the next decade about electricity supplies in the power sector will affectthe potential for large GHG emissions reductions with PHEVs for several decades.

Hybrid nuclear cycles for nuclear fission sustainability

International Nuclear Information System (INIS)

Piera, M.; Martinez-Val, M. M.

2007-01-01

resources could be exploited with such a cycle, using very safe reactors. This percentage is much higher than the actual value for the once-through cycle (0.5 %) and the value for multiple Pu recycling in the MOX scheme (1 %). Moreover, thorium could also be exploited through fertile conversion into U-233 in the subcritical breeders. The separation between energy production (to be done in LWR) and nuclear breeding (to be done in subcritical hybrids) presents a scenario with very appealing safety features and a high potential for an efficient utilization of all natural resources of uranium and thorium, that account for 10 2 4 J, i.e., 25 Gtoe, which is 35,000 times as large as the annual production of Nuclear Energy nowadays, and about 2,500 times as large as the total annual energy consumption all over the globe

A complete geothermal energy cycle with heat pumps and hybrid HVAC systems for the city of Denizli, Turkey

Energy Technology Data Exchange (ETDEWEB)

Eltez, M. [Ege Univ., Izmir (Turkey). Mechanical Engineering Dept.; Kilkis, I.B. [Heatway Radiant Floors and Snowmelting, Springfield, MO (United States)]|[Middle East Technical Univ., Ankara (Turkey)

1995-12-31

This paper discusses general aspects of maximizing geofluid effectiveness by employing hybrid cycle plants coupled to district HVAC systems. Alternative and new techniques in space heating and cooling are also discussed. A case study is presented for the district HVAC system for the city of Denizli in Turkey. Results are compared with an open-cycle, open-loop system.

A stable organic-inorganic hybrid layer protected lithium metal anode for long-cycle lithium-oxygen batteries

Science.gov (United States)

Zhu, Jinhui; Yang, Jun; Zhou, Jingjing; Zhang, Tao; Li, Lei; Wang, Jiulin; Nuli, Yanna

2017-10-01

A stable organic-inorganic hybrid layer (OIHL) is direct fabricated on lithium metal surface by the interfacial reaction of lithium metal foil with 1-chlorodecane and oxygen/carbon dioxide mixed gas. This favorable OIHL is approximately 30 μm thick and consists of lithium alkyl carbonate and lithium chloride. The lithium-oxygen batteries with OIHL protected lithium metal anode exhibit longer cycle life (340 cycles) than those with bare lithium metal anode (50 cycles). This desirable performance can be ascribed to the robust OIHL which prevents the growth of lithium dendrites and the corrosion of lithium metal.

Sorting through the many total-energy-cycle pathways possible with early plug-in hybrids

International Nuclear Information System (INIS)

Gaines, L.; Burnham, A.; Rousseau, A.; Santini, D.

2008-01-01

Using the 'total energy cycle' methodology, we compare U.S. near term (to ∼2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), and conventional vehicles (CVs). For PHEVs, we present total energy-per-unit-of-VKT information two ways (1) energy from the grid during charge depletion (CD); (2) energy from stored on-board fossil fuel when charge sustaining (CS). We examine 'incremental sources of supply of liquid fuel such as (a) oil sands from Canada, (b) Fischer-Tropsch diesel via natural gas imported by LNG tanker, and (c) ethanol from cellulosic biomass. We compare such fuel pathways to various possible power converters producing electricity, including (i) new coal boilers, (ii) new integrated, gasified coal combined cycle (IGCC), (iii) existing natural gas fueled combined cycle (NGCC), (iv) existing natural gas combustion turbines, (v) wood-to-electricity, and (vi) wind/solar. We simulate a fuel cell HEV and also consider the possibility of a plug-in hybrid fuel cell vehicle (FCV). For the simulated FCV our results address the merits of converting some fuels to hydrogen to power the fuel cell vs. conversion of those same fuels to electricity to charge the PHEV battery. The investigation is confined to a U.S. compact sized car (i.e. a world passenger car). Where most other studies have focused on emissions (greenhouse gases and conventional air pollutants), this study focuses on identification of the pathway providing the most vehicle kilometers from each of five feedstocks examined. The GREET 1.7 fuel cycle model and the new GREET 2.7 vehicle cycle model were used as the foundation for this study. Total energy, energy by fuel type, total greenhouse gases (GHGs), volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO x ), fine particulate (PM2.5) and sulfur oxides (SO x ) values are presented. We also isolate the PHEV emissions contribution from varying k

Generation of H2 and CO by solar thermochemical splitting of H2O and CO2 by employing metal oxides

International Nuclear Information System (INIS)

Rao, C.N.R.; Dey, Sunita

2016-01-01

Generation of H 2 and CO by splitting H 2 O and CO 2 respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H 2 O or CO 2 over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H 2 O or CO 2 . While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites of the type Ln 1−x A x Mn 1−y M y O 3 (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H 2 and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y 0.5 Sr 0.5 MnO 3 which releases 483 µmol/g of O 2 at 1673 K and produces 757 µmol/g of CO from CO 2 at 1173 K. The production of H 2 from H 2 O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H 2 based on the Mn 3 O 4 /NaMnO 2 cycle briefly. - Graphical abstract: Ln 0.5 A 0.5 Mn 1−x M x O 3 (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO 2 and H 2 O for the generation of CO and H 2 . - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO 2 and H 2 O. • In Ln 1−x A x MnO 3 perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles in the thermochemical process. • H 2 O splitting is also achieved by the use of the Mn 3 O 4 -sodium carbonate system. • Thermochemical splitting of CO 2 and H

A control-oriented cycle-life model for hybrid electric vehicle lithium-ion batteries

International Nuclear Information System (INIS)

Suri, Girish; Onori, Simona

2016-01-01

In this paper, a semi-empirical Lithium-iron phosphate-graphite battery aging model is identified over data mimicking actual cycling conditions that a hybrid electric vehicle battery encounters under real driving scenarios. The aging model is then used to construct the severity factor map, used to characterize relative aging of the battery under different operating conditions. This is used as a battery degradation criterion within a multi-objective optimization problem where battery aging minimization is to be achieved along with fuel consumption minimization. The method proposed is general and can be applied to other battery chemistry as well as different vehicular applications. Finally, simulations conducted using a hybrid electric vehicle simulator show how the two modeling tools developed in this paper, i.e., the severity factor map and the aging model, can be effectively used in a multi-objective optimization problem to predict and control battery degradation. - Highlights: • Battery aging model for hybrid electric vehicles using real driving conditions data. • Development of a modeling tool to assess battery degradation for real time optimization. • "3"1P NMR analysis of an enzyme-treated extract showed expected hydrolysis of P forms. • Development of an energy management strategy to minimize battery degradation. • Simulation results from hybrid electric vehicle simulator.

TEA: A CODE CALCULATING THERMOCHEMICAL EQUILIBRIUM ABUNDANCES

Energy Technology Data Exchange (ETDEWEB)

Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver, E-mail: jasmina@physics.ucf.edu [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States)

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 and Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows and 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.

TEA: A CODE CALCULATING THERMOCHEMICAL EQUILIBRIUM ABUNDANCES

International Nuclear Information System (INIS)

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

2016-01-01

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 and Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows and 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.

The Hybrid Automobile and the Atkinson Cycle

Science.gov (United States)

Feldman, Bernard J.

2008-01-01

The hybrid automobile is a strikingly new automobile technology with a number of new technological features that dramatically improve energy efficiency. This paper will briefly describe how hybrid automobiles work; what are these new technological features; why the Toyota Prius hybrid internal combustion engine operates on the Atkinson cycle…

Studies on closed-cycle processes for hydrogen production, 3

International Nuclear Information System (INIS)

Sato, Shoichi; Ikezoe, Yasumasa; Shimizu, Saburo; Nakajima, Hayato; Kobayashi, Toshiaki

1978-10-01

Studies made in fiscal 1977 on the thermochemical and radiation chemical processes for hydrogen production are reported. In the thermochemical process, cerium (III) carbonate was used as an intermediate, and a workable process was found, which consisted of eight reaction steps. In other feasible processes, carbon dioxide was made to react with iron (II) chloride or iodide at high temperature to form carbon monoxide, and three or four reaction steps ensued. Also, an improved process of the sulfur cycle was studied. In this process, nickel salts were separated by solvent extraction. Estimated thermal efficiency (HHV) of the process was 30 - 40%, assuming 70 - 80% heat recovery. In the radiation chemical process, carbon dioxide was added with propane or nitrogen dioxide and radiolyzed: reaction mechanisms are discussed. (author)

The effects of hybrid cycle training in inactive people with long-term spinal cord injury : design of a multicenter randomized controlled trial

NARCIS (Netherlands)

Bakkum, Arjan J. T.; de Groot, Sonja; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

2013-01-01

Purpose: Physical activity in people with long-term spinal cord injury (SCI) is important to stay fit and healthy. The purpose of this study is to evaluate the effects of hybrid cycle training (hand cycling in combination with functional electrical stimulation-induced leg cycling) on fitness,

Thermochemical treatment of the pay zone in the well RK-3

Energy Technology Data Exchange (ETDEWEB)

Labudovic, V

1970-02-01

The elements are given for the calculation of the thermochemical treatment of the Well RK-3. From the diagram, the Mg and HCl reaction velocity vs. pressure and the temperature vs. the quantity of the reacted CaCO/sub 3/ can be read out. These are important elements for the calculation of a thermochemical treatment. A comparison of calculated and measured temperatures and the factors influencing the heat conductivity of the formation rock is given. The heating range at formation depths is calculated. The relation quantity of warm acid vs. injection pressure also is given.

Feasibility of Thorium Fuel Cycles in a Very High Temperature Pebble-Bed Hybrid System

Directory of Open Access Journals (Sweden)

L.P. Rodriguez

2015-08-01

Full Text Available Nuclear energy presents key challenges to be successful as a sustainable energy source. Currently, the viability of the use thorium-based fuel cycles in an innovative nuclear energy generation system is being investigated in order to solve these key challenges. In this work, the feasibility of three thorium-based fuel cycles (232Th-233U, 232Th-239Pu, and 232Th-U in a hybrid system formed by a Very High Temperature Pebble-Bed Reactor (VHTR and two Pebble-Bed Accelerator Driven Systems (ADSs was evaluated using parameters related to the neutronic behavior such as nuclear fuel breeding, minor actinide stockpile, the energetic contribution of each fissile isotope, and the radiotoxicity of the long lived wastes. These parameters were used to compare the fuel cycles using the well-known MCNPX ver. 2.6e computational code. The results obtained confirm that the 232Th-233U fuel cycle is the best cycle for minimizing the production of plutonium isotopes and minor actinides. Moreover, the inclusion of the second stage in the ADSs demonstrated the possibility of extending the burnup cycle duration and reducing the radiotoxicity of the discharged fuel from the VHTR.

SUNgas: Thermochemical Approaches to Solar Fuels

Science.gov (United States)

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

Effects of key factors on solar aided methane steam reforming in porous medium thermochemical reactor

International Nuclear Information System (INIS)

Wang, Fuqiang; Tan, Jianyu; Ma, Lanxin; Leng, Yu

2015-01-01

Highlights: • Effects of key factors on chemical reaction for solar methane reforming are studied. • MCRT and FVM method coupled with UDFs is used to establish numerical model. • Heat and mass transfer model coupled with thermochemical reaction is established. • LTNE model coupled with P1 approximation is used for porous matrix solar reactor. • A formula between H 2 production and conductivity of porous matrix is put forward. - Abstract: With the aid of solar energy, methane reforming process can save up to 20% of the total methane consumption. Monte Carlo Ray Tracing (MCRT) method and Finite Volume Method (FVM) combined method are developed to establish the heat and mass transfer model coupled with thermochemical reaction kinetics for porous medium solar thermochemical reactor. In order to provide more temperature information, local thermal non-equilibrium (LTNE) model coupled with P1 approximation is established to investigate the thermal performance of porous medium solar thermochemical reaction. Effects of radiative heat loss and thermal conductivity of porous matrix on temperature distribution and thermochemical reaction for solar driven steam methane reforming process are numerically studied. Besides, the relationship between hydrogen production and thermal conductivity of porous matrix are analyzed. The results illustrate that hydrogen production shows a 3 order polynomial relation with thermal conductivity of porous matrix

Effective Heat and Mass Transport Properties of Anisotropic Porous Ceria for Solar Thermochemical Fuel Generation

Directory of Open Access Journals (Sweden)

Sophia Haussener

2012-01-01

Full Text Available High-resolution X-ray computed tomography is employed to obtain the exact 3D geometrical configuration of porous anisotropic ceria applied in solar-driven thermochemical cycles for splitting H2O and CO2. The tomography data are, in turn, used in direct pore-level numerical simulations for determining the morphological and effective heat/mass transport properties of porous ceria, namely: porosity, specific surface area, pore size distribution, extinction coefficient, thermal conductivity, convective heat transfer coefficient, permeability, Dupuit-Forchheimer coefficient, and tortuosity and residence time distributions. Tailored foam designs for enhanced transport properties are examined by means of adjusting morphologies of artificial ceria samples composed of bimodal distributed overlapping transparent spheres in an opaque medium.

New applications with time-dependent thermochemical simulation

Energy Technology Data Exchange (ETDEWEB)

Koukkari, P. [VTT Chemical Technology, Espoo (Finland); Laukkanen, L. [VTT Automation, Espoo (Finland); Penttilae, K. [Kemira Engineering Oy, Helsinki (Finland)

1996-12-31

A new method (RATEMIX) to calculate multicomponent chemical reaction mixtures as a series of sequential thermochemical states was recently introduced. The procedure combines multicomponent thermodynamics with chemical kinetics and may be used to simulate the multicomponent reactors as a thermochemical natural process. The method combines the desired reaction rates sequentially with constrained Gibbs energy minimization. The reactant concentrations are determined by the experimental (Arrhenius) rate laws. During the course of the given reaction the subsequent side reactions are supposed to occur reversibly. At every sequential stage of the given reaction the temperature and composition of the reaction mixture are calculated by a thermodynamic subroutine, which minimizes the Gibbs energy of the system and takes into account the heat transfer between the system and its surroundings. The extents of reaction are included as algorithmic constraints in the Gibbs energy minimization procedure. Initially, the reactants are introduced to the system as inert copies to match both the mass and energy balance of the reactive system. During the calculation the copies are sequentially interchanged to the actual reactants which allows one to simulate the time-dependent reaction route by using the thermochemical procedure. For each intermediate stage, the temperature and composition are calculated and as well numerical estimates of the thermodynamic functions are obtained. The method is applicable in processes where the core thermodynamic and kinetic data of the system are known and the time-dependent heat transfer data can either be measured or estimated by calculation. The method has been used to simulate e.g. high temperature flame reactions, zinc vapour oxidation and a counter-current rotary drum with chemical reactions. The procedure has today been tested with SOLGASMIX, CHEMSAGE and HSC programs. (author)

New applications with time-dependent thermochemical simulation

Energy Technology Data Exchange (ETDEWEB)

Koukkari, P [VTT Chemical Technology, Espoo (Finland); Laukkanen, L [VTT Automation, Espoo (Finland); Penttilae, K [Kemira Engineering Oy, Helsinki (Finland)

1997-12-31

A new method (RATEMIX) to calculate multicomponent chemical reaction mixtures as a series of sequential thermochemical states was recently introduced. The procedure combines multicomponent thermodynamics with chemical kinetics and may be used to simulate the multicomponent reactors as a thermochemical natural process. The method combines the desired reaction rates sequentially with constrained Gibbs energy minimization. The reactant concentrations are determined by the experimental (Arrhenius) rate laws. During the course of the given reaction the subsequent side reactions are supposed to occur reversibly. At every sequential stage of the given reaction the temperature and composition of the reaction mixture are calculated by a thermodynamic subroutine, which minimizes the Gibbs energy of the system and takes into account the heat transfer between the system and its surroundings. The extents of reaction are included as algorithmic constraints in the Gibbs energy minimization procedure. Initially, the reactants are introduced to the system as inert copies to match both the mass and energy balance of the reactive system. During the calculation the copies are sequentially interchanged to the actual reactants which allows one to simulate the time-dependent reaction route by using the thermochemical procedure. For each intermediate stage, the temperature and composition are calculated and as well numerical estimates of the thermodynamic functions are obtained. The method is applicable in processes where the core thermodynamic and kinetic data of the system are known and the time-dependent heat transfer data can either be measured or estimated by calculation. The method has been used to simulate e.g. high temperature flame reactions, zinc vapour oxidation and a counter-current rotary drum with chemical reactions. The procedure has today been tested with SOLGASMIX, CHEMSAGE and HSC programs. (author)

Carbon footprint evaluation at industrial park level: A hybrid life cycle assessment approach

International Nuclear Information System (INIS)

Dong, Huijuan; Geng, Yong; Xi, Fengming; Fujita, Tsuyoshi

2013-01-01

Industrial parks have become the effective strategies for government to promote sustainable economic development due to the following advantages: shared infrastructure and concentrated industrial activities within planned areas. However, due to intensive energy consumption and dependence on fossil fuels, industrial parks have become the main areas for greenhouse gas emissions. Therefore, it is critical to quantify their carbon footprints so that appropriate emission reduction policies can be raised. The objective of this paper is to seek an appropriate method on evaluating the carbon footprint of one industrial park. The tiered hybrid LCA method was selected due to its advantages over other methods. Shenyang Economic and Technological Development Zone (SETDZ), a typical comprehensive industrial park in China, was chosen as a case study park. The results show that the total life cycle carbon footprint of SETDZ was 15.29 Mt, including 6.81 Mt onsite (direct) carbon footprint, 8.47 Mt upstream carbon footprint, and only 3201 t downstream carbon footprint. Analysis from industrial sector perspectives shows that chemical industry and manufacture of general purpose machinery and special purposes machinery sector were the two largest sectors for life cycle carbon footprint. Such a sector analysis may be useful for investigation of appropriate emission reduction policies. - Highlights: ► A hybrid LCA model was employed to calculate industrial park carbon footprint. ► A case study on SETDZ is done. ► Life cycle carbon footprint of SETDZ is 15.29 Mt. ► Upstream and onsite carbon footprints account for 55.40% and 44.57%, respectively. ► Chemical industry and machinery manufacturing sectors are the two largest sectors

Evaluation of chemical, thermobaric and thermochemical pre-treatment on anaerobic digestion of high-fat cattle slaughterhouse waste.

Science.gov (United States)

Harris, Peter W; Schmidt, Thomas; McCabe, Bernadette K

2017-11-01

This work aimed to enhance the anaerobic digestion of fat-rich dissolved air flotation (DAF) sludge through chemical, thermobaric, and thermochemical pre-treatment methods. Soluble chemical oxygen demand was enhanced from 16.3% in the control to 20.84% (thermobaric), 40.82% (chemical), and 50.7% (thermochemical). Pre-treatment altered volatile fatty acid concentration by -64% (thermobaric), 127% (chemical) and 228% (thermochemical). Early inhibition was reduced by 20% in the thermochemical group, and 100% in the thermobaric group. Specific methane production was enhanced by 3.28% (chemical), 8.32% (thermobaric), and 8.49% (thermochemical) as a result of pre-treatment. Under batch digestion, thermobaric pre-treatment demonstrated the greatest improvement in methane yield with respect to degree of pre-treatment applied. Thermobaric pre-treatment was also the most viable for implementation at slaughterhouses, with potential for heat-exchange to reduce pre-treatment cost. Further investigation into long-term impact of pre-treatments in semi-continuous digestion experiments will provide additional evaluation of appropriate pre-treatment options for high-fat slaughterhouse wastewater. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prototype thermochemical heat storage with open reactor system

NARCIS (Netherlands)

Zondag, H.A.; Kikkert, B.; Smeding, S.F.; Boer, de R.; Bakker, M.

2013-01-01

Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage system has been realized at

A systematic multi-step screening of numerous salt hydrates for low temperature thermochemical energy storage

International Nuclear Information System (INIS)

N’Tsoukpoe, Kokouvi Edem; Schmidt, Thomas; Rammelberg, Holger Urs; Watts, Beatriz Amanda; Ruck, Wolfgang K.L.

2014-01-01

Highlights: • We report an evaluation of the potential of salt hydrates for thermochemical storage. • Both theoretical calculations and experimental measurements using TGA/DSC are used. • Salt hydrates offer very low potential for thermochemical heat storage. • The efficiency of classical processes using salt hydrates is very low: typically 25%. • New processes are needed for the use of salt hydrates in thermochemical heat storage. - Abstract: In this paper, the potential energy storage density and the storage efficiency of salt hydrates as thermochemical storage materials for the storage of heat generated by a micro-combined heat and power (micro-CHP) have been assessed. Because salt hydrates used in various thermochemical heat storage processes fail to meet the expectations, a systematic evaluation of the suitability of 125 salt hydrates has been performed in a three-step approach. In the first step general issues such as toxicity and risk of explosion have been considered. In the second and third steps, the authors implement a combined approach consisting of theoretical calculations and experimental measurements using Thermogravimetric Analysis (TGA). Thus, application-oriented comparison criteria, among which the net energy storage density of the material and the thermal efficiency, have been used to evaluate the potential of 45 preselected salt hydrates for a low temperature thermochemical heat storage application. For an application that requires a discharging temperature above 60 °C, SrBr 2 ·6H 2 O and LaCl 3 ·7H 2 O appear to be the most promising, only from thermodynamic point of view. However, the maximum net energy storage density including the water in the water storage tank that they offer (respectively 133 kW h m −3 and 89 kW h m −3 ) for a classical thermochemical heat storage process are not attractive for the intended application. Furthermore, the thermal efficiency that would result from the storage process based on salt hydrates

The NREL Biochemical and Thermochemical Ethanol Conversion Processes: Financial and Environmental Analysis Comparison

Directory of Open Access Journals (Sweden)

Jesse Sky Daystar

2015-07-01

Full Text Available The financial and environmental performance of the National Renewable Energy Lab’s (NREL thermochemical and biochemical biofuel conversion processes are examined herein with pine, eucalyptus, unmanaged hardwood, switchgrass, and sweet sorghum. The environmental impacts of the process scenarios were determined by quantifying greenhouse gas (GHG emissions and TRACI impacts. Integrated financial and environmental performance metrics were introduced and used to examine the biofuel production scenarios. The thermochemical and biochemical conversion processes produced the highest financial performance and lowest environmental impacts when paired with pine and sweet sorghum, respectively. The high ash content of switchgrass and high lignin content of loblolly pine lowered conversion yields, resulting in the highest environmental impacts and lowest financial performance for the thermochemical and biochemical conversion processes, respectively. Biofuel produced using the thermochemical conversion process resulted in lower TRACI single score impacts and somewhat lower GHG emissions per megajoule (MJ of fuel than using the biochemical conversion pathway. The cost of carbon mitigation resulting from biofuel production and corresponding government subsidies was determined to be higher than the expected market carbon price. In some scenarios, the cost of carbon mitigation was several times higher than the market carbon price, indicating that there may be other more cost-effective methods of reducing carbon emissions.

Numerical investigation of a straw combustion boiler – Part I: Modelling of the thermo-chemical conversion of straw

Directory of Open Access Journals (Sweden)

Dernbecher Andrea

2016-01-01

Full Text Available In the framework of a European project, a straw combustion boiler in conjunction with an organic Rankine cycle is developed. One objective of the project is the enhancement of the combustion chamber by numerical methods. A comprehensive simulation of the combustion chamber is prepared, which contains the necessary submodels for the thermo-chemical conversion of straw and for the homogeneous gas phase reactions. Part I introduces the modelling approach for the thermal decomposition of the biomass inside the fuel bed, whereas part II deals with the simulation of the gas phase reactions in the freeboard.

PLUG-IN HYBRID ELECTRIC VEHICLE AND HYBRID ELECTRIC VEHICLE EMISSIONS UNDER FTP AND US06 CYCLES AT HIGH, AMBIENT, AND LOW TEMPERATURES

Energy Technology Data Exchange (ETDEWEB)

Seidman, M.R.; Markel, T.

2008-01-01

The concept of a Plug-in Hybrid Electric Vehicle (PHEV) is to displace consumption of gasoline by using electricity from the vehicle’s large battery pack to power the vehicle as much as possible with minimal engine operation. This paper assesses the PHEV emissions and operation. Currently, testing of vehicle emissions is done using the federal standard FTP4 cycle on a dynamometer at ambient (75°F) temperatures. Research was also completed using the US06 cycle. Furthermore, research was completed at high (95°F) and low (20°F) temperatures. Initial dynamometer testing was performed on a stock Toyota Prius under the standard FTP4 cycle, and the more demanding US06 cycle. Each cycle was run at 95°F, 75°F, and 20°F. The testing was repeated with the same Prius retrofi tted with an EnergyCS Plug-in Hybrid Electric system. The results of the testing confi rm that the stock Prius meets Super-Ultra Low Emission Vehicle requirements under current testing procedures, while the PHEV Prius under current testing procedures were greater than Super-Ultra Low Emission Vehicle requirements, but still met Ultra Low Emission Vehicle requirements. Research points to the catalyst temperature being a critical factor in meeting emission requirements. Initial engine emissions pass through with minimal conversion until the catalyst is heated to typical operating temperatures of 300–400°C. PHEVs also have trouble maintaining the minimum catalyst temperature throughout the entire test because the engine is turned off when the battery can support the load. It has been observed in both HEVs and PHEVs that the catalyst is intermittently unable to reduce nitrogen oxide emissions, which causes further emission releases. Research needs to be done to combat the initial emission spikes caused by a cold catalyst. Research also needs to be done to improve the reduction of nitrogen oxides by the catalyst system.

Solar High Temperature Water-Splitting Cycle with Quantum Boost

Energy Technology Data Exchange (ETDEWEB)

Taylor, Robin [SAIC; Davenport, Roger [SAIC; Talbot, Jan [UCSD; Herz, Richard [UCSD; Genders, David [Electrosynthesis Co.; Symons, Peter [Electrosynthesis Co.; Brown, Lloyd [TChemE

2014-04-25

A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are

The calculation of specific heats for some important solid components in hydrogen production process based on CuCl cycle

Directory of Open Access Journals (Sweden)

Avsec Jurij

2014-01-01

Full Text Available Hydrogen is one of the most promising energy sources of the future enabling direct production of power and heat in fuel cells, hydrogen engines or furnaces with hydrogen burners. One of the last remainder problems in hydrogen technology is how to produce a sufficient amount of cheap hydrogen. One of the best options is large scale thermochemical production of hydrogen in combination with nuclear power plant. copper-chlorine (CuCl cycle is the most promissible thermochemical cycle to produce cheap hydrogen.This paper focuses on a CuCl cycle, and the describes the models how to calculate thermodynamic properties. Unfortunately, for many components in CuCl cycle the thermochemical functions of state have never been measured. This is the reason that we have tried to calculate some very important thermophysical properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure substances and their mixtures such as CuCl, HCl, Cu2OCl2 important in CuCl hydrogen production in their fluid and solid phase with an aid of statistical thermodynamics. For the solid phase, we have developed the mathematical model for the calculation of thermodynamic properties for polyatomic crystals. In this way, we have used Debye functions and Einstein function for acoustical modes and optical modes of vibrations to take into account vibration of atoms. The influence of intermolecular energy we have solved on the basis of Murnaghan equation of state and statistical thermodynamics.

Thermodynamic limits on the performance of a solar thermochemical energy storage system

Energy Technology Data Exchange (ETDEWEB)

Lovegrove, K [Australian National Univ., Canberra (Australia). Energy Research Centre

1993-12-01

General expressions for the exergetic and work recovery efficiencies of thermochemical storage systems have been developed by assuming that the reaction process is the only source irreversibility within the closed-loop system. These have been used to plot contours of constant efficiency for the ammonia-based thermochemical system. The effect of spontaneous separation of mixtures due to the preferential condensation of ammonia has been examined analytically and graphically. The analysis presented represents a necessary prerequisite for the optimization of system efficiencies by reactor design. (author)

Decomposition analysis of cupric chloride hydrolysis in the Cu-Cl cycle of hydrogen production

International Nuclear Information System (INIS)

Daggupati, V.N.; Naterer, G.F.; Gabriel, K.S.; Gravelsins, R.; Wang, Z.

2009-01-01

This paper examines cupric chloride solid conversion during hydrolysis in a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. The hydrolysis reaction is a challenging step, in terms of the excess steam requirement and the decomposition of cupric chloride (CuCl 2 ) into cuprous chloride (CuCl) and chlorine (Cl 2 ). The hydrolysis and decomposition reactions are analyzed with respect to the chemical equilibrium constant. The effects of operating parameters are examined, including the temperature, pressure, excess steam and equilibrium conversion. A maximization of yield and selectivity are very important. Rate constants for the simultaneous reaction steps are determined using a uniform reaction model. A shrinking core model is used to determine the rate coefficients and predict the solid conversion time, with diffusional and reaction control. These new results are useful for scale-up of the engineering equipment in the thermochemical Cu-Cl cycle for hydrogen production. (author)

Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass

International Nuclear Information System (INIS)

Facchinetti, Emanuele; Gassner, Martin; D’Amelio, Matilde; Marechal, François; Favrat, Daniel

2012-01-01

Due to its suitability for using wet biomass, hydrothermal gasification is a promising process for the valorization of otherwise unused waste biomass to synthesis gas and biofuels. Solid oxide fuel cell (SOFC) based hybrid cycles are considered as the best candidate for a more efficient and clean conversion of (bio) fuels. A significant potential for the integration of the two technologies is expected since hydrothermal gasification requires heat at 673–773 K, whereas SOFC is characterized by heat excess at high temperature due to the limited electrochemical fuel conversion. This work presents a systematic process integration and optimization of a SOFC-gas turbine (GT) hybrid cycle fueled with hydrothermally gasified waste biomass. Several design options are systematically developed and compared through a thermodynamic optimization approach based on First Law and exergy analysis. The work demonstrates the considerable potential of the system that allows for converting wet waste biomass into electricity at a First Law efficiency of up to 63%, while simultaneously enabling the separation of biogenic carbon dioxide for further use or sequestration. -- Highlights: ► Hydrothermal gasification is a promising process for the valorization of waste wet biomass. ► Solid Oxide Fuel Cell – Gas Turbine hybrid cycle emerges as the best candidates for conversion of biofuels. ► A systematic process integration and optimization of a SOFC-GT hybrid cycle fuelled with hydrothermally gasified biomass is presented. ► The system may convert wet waste biomass to electricity at a First Law efficiency of 63% while separating the biogenic carbon dioxide. ► The process integration enables to improve the First Law efficiency of around 4% with respect to a non-integrated system.

Towards the renewal of the NEA Thermochemical Database

International Nuclear Information System (INIS)

Ragoussi, Maria-Eleni; Costa, Davide; Bossant, Manuel

2015-01-01

The Thermochemical Database (TDB) Project was created three decades ago as a joint undertaking of the NEA Radioactive Waste Management Committee and the NEA Data Bank. The project involves the collection of high-quality and traceable thermochemical data for a set of elements (mainly minor actinides and fission products) relevant to geophysical modelling of deep geological repositories. Funding comes from 15 participating organisations, primarily national nuclear waste authorities and research institutions. The quantities that are stored in the TDB database are: the standard molar Gibbs energy and enthalpy of formation, the standard molar entropy and, when available, the heat capacity at constant pressure, together with their uncertainty intervals. Reaction data are also provided: equilibrium constant of reaction, molar Gibbs energy of reaction, molar enthalpy of reaction and molar entropy of reaction. Data assessment is carried out by teams of expert reviewers through an in-depth analysis of the available scientific literature, following strict guidelines defined by the NEA to ensure the accuracy and self-consistency of the adopted datasets. Thermochemical data that has been evaluated and selected over the years have been published in the 13 volumes of the Chemical Thermodynamics series. They are also stored in a database that is updated each time the study of a new element is completed. The TDB selected data are made available to external third parties through the NEA web site where data extracted from the database can be displayed and downloaded as plain text files. Following recent recommendations of the Task Force on the Future Programme of the NEA Data Bank to enhance scientific expertise and user services, a renewal of the software managing the TDB database is being undertaken. The software currently used was designed 20 years ago and is becoming obsolete. Redesigning the application will provide an opportunity to correct current shortcomings and to develop

Economic assessment and energy model scenarios of municipal solid waste incineration and gas turbine hybrid dual-fueled cycles in Thailand

International Nuclear Information System (INIS)

Udomsri, Seksan; Martin, Andrew R.; Fransson, Torsten H.

2010-01-01

Finding environmentally benign methods related to sound municipal solid waste (MSW) management is of highest priority in Southeast Asia. It is very important to study new approaches which can reduce waste generation and simultaneously enhance energy recovery. One concrete example of particular significance is the concept of hybrid dual-fuel power plants featuring MSW and another high-quality fuel like natural gas. The hybrid dual-fuel cycles provide significantly higher electrical efficiencies than a composite of separate single-fuel power plant (standalone gas turbine combined cycle and MSW incineration). Although hybrid versions are of great importance for energy conversion from MSW, an economic assessment of these systems must be addressed for a realistic appraisal of these technologies. This paper aims to further examine an economic assessment and energy model analysis of different conversion technologies. Energy models are developed to further refine the expected potential of MSW incineration with regards to energy recovery and environmental issues. Results show that MSW incineration can play role for greenhouse gas reduction, energy recovery and waste management. In Bangkok, the electric power production via conventional incineration and hybrid power plants can cover 2.5% and 8% of total electricity consumption, respectively. The hybrid power plants have a relative short payback period (5 years) and can further reduce the CO 2 levels by 3% in comparison with current thermal power plants.

Thermochemical study of MoS2 oxidation

International Nuclear Information System (INIS)

Filimonov, D.S.; Topor, N.D.; Kesler, Ya.A.

1990-01-01

Thermochemical studies of oxidation processes of metallic molybdenum, sulfur, molybdenum disulfide under different conditions in microcalorimeter are conducted. Values of thermal effects which are used to calculate standard formation enthalpy of MoS 2 and which correlate well are obtained. Δ f H 0 (MoS 2 ,298.15 K) recommended value constitutes (-223.0±16.7) kJ/mol

Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

International Nuclear Information System (INIS)

Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel; Velasco, Abanades

2013-01-01

Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U 233 , Th+Pu 239 and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel, E-mail: dperez@instec.cu, E-mail: cgh@instec.cu, E-mail: dmilian@instec.cu [Higher Institute of Technologies and Applied Sciences, Havana (Cuba); Velasco, Abanades, E-mail: abanades@etsii.upm.es [Department of Simulation of Thermo Energy Systems, Polytechnic University of Madrid (Spain)

2013-07-01

Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U{sup 233}, Th+Pu{sup 239} and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

Global warming potential of the sulfur-iodine process using life cycle assessment methodology

International Nuclear Information System (INIS)

Lattin, William C.; Utgikar, Vivek P.

2009-01-01

A life cycle assessment (LCA) of one proposed method of hydrogen production - thermochemical water-splitting using the sulfur-iodine cycle couple with a very high-temperature nuclear reactor - is presented in this paper. Thermochemical water-splitting theoretically offers a higher overall efficiency than high-temperature electrolysis of water because heat from the nuclear reactor is provided directly to the hydrogen generation process, instead of using the intermediate step of generating electricity. The primary heat source for the S-I cycle is an advanced nuclear reactor operating at temperatures corresponding to those required by the sulfur-iodine process. This LCA examines the environmental impact of the combined advanced nuclear and hydrogen generation plants and focuses on quantifying the emissions of carbon dioxide per kilogram of hydrogen produced. The results are presented in terms of global warming potential (GWP). The GWP of the system is 2500 g carbon dioxide-equivalent (CO 2 -eq) per kilogram of hydrogen produced. The GWP of this process is approximately one-sixth of that for hydrogen production by steam reforming of natural gas, and is comparable to producing hydrogen from wind- or hydro-electric conventional electrolysis. (author)

Dynamic hybrid life cycle assessment of energy and carbon of multicrystalline silicon photovoltaic systems.

Science.gov (United States)

Zhai, Pei; Williams, Eric D

2010-10-15

This paper advances the life cycle assessment (LCA) of photovoltaic systems by expanding the boundary of the included processes using hybrid LCA and accounting for the technology-driven dynamics of embodied energy and carbon emissions. Hybrid LCA is an extended method that combines bottom-up process-sum and top-down economic input-output (EIO) methods. In 2007, the embodied energy was 4354 MJ/m(2) and the energy payback time (EPBT) was 2.2 years for a multicrystalline silicon PV system under 1700 kWh/m(2)/yr of solar radiation. These results are higher than those of process-sum LCA by approximately 60%, indicating that processes excluded in process-sum LCA, such as transportation, are significant. Even though PV is a low-carbon technology, the difference between hybrid and process-sum results for 10% penetration of PV in the U.S. electrical grid is 0.13% of total current grid emissions. Extending LCA from the process-sum to hybrid analysis makes a significant difference. Dynamics are characterized through a retrospective analysis and future outlook for PV manufacturing from 2001 to 2011. During this decade, the embodied carbon fell substantially, from 60 g CO(2)/kWh in 2001 to 21 g/kWh in 2011, indicating that technological progress is realizing reductions in embodied environmental impacts as well as lower module price.

Hydrogen production via thermochemical water-splitting by lithium redox reaction

International Nuclear Information System (INIS)

Nakamura, Naoya; Miyaoka, Hiroki; Ichikawa, Takayuki; Kojima, Yoshitsugu

2013-01-01

Highlights: •Hydrogen production via water-splitting by lithium redox reactions possibly proceeds below 800 °C. •Entropy control by using nonequilibrium technique successfully reduces the reaction temperature. •The operating temperature should be further reduced by optimizing the nonequilibrium condition to control the cycle. -- Abstracts: Hydrogen production via thermochemical water-splitting by lithium redox reactions was investigated as energy conversion technique. The reaction system consists of three reactions, which are hydrogen generation by the reaction of lithium and lithium hydroxide, metal separation by thermolysis of lithium oxide, and oxygen generation by hydrolysis of lithium peroxide. The hydrogen generation reaction completed at 500 °C. The metal separation reaction is thermodynamically difficult because it requires about 3400 °C in equilibrium condition. However, it was indicated from experimental results that the reaction temperature was drastically reduced to 800 °C by using nonequilibrium technique. The hydrolysis reaction was exothermic reaction, and completed by heating up to 300 °C. Therefore, it was expected that the water-splitting by lithium redox reactions was possibly operated below 800 °C under nonequilibrium condition

700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

Science.gov (United States)

Ruan, Dianbo; Kim, Myeong-Seong; Yang, Bin; Qin, Jun; Kim, Kwang-Bum; Lee, Sang-Hyun; Liu, Qiuxiang; Tan, Lei; Qiao, Zhijun

2017-10-01

To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g-1), good rate capabilities (148 mAhh g-1 at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg-1, a maximum power density of 2466 W kg-1, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.

Thermochemical treatment of radioactive waste by using powder metal fuels

International Nuclear Information System (INIS)

Dmitriev, S.A.; Ojovan, M.I.; Karlina, O.K.

2001-01-01

Full text: A thermochemical approach was suggested for treating and conditioning specific streams of radioactive wastes for example spent ion exchange resins, mixed, organic or chlorine-containing radioactive waste as well as in order to decontaminate heavily contaminated surfaces. Conventional treatment methods of such waste encounters serious problems concerning complete destruction of organic molecules and possible emissions of radionuclides, heavy metals and chemically hazardous species or in case of contaminated materials - complete removal of contamination from surface. The thermochemical treatment of radioactive waste uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. Thermochemical treatment technologies use the energy of chemical reactions in the mixture of waste with PMF to sustain both decomposition and synthesis processes as well as processes of isomorphic substitutions of hazardous elements into stable mineral forms. The composition of the PMF is designed in such a way as to minimise the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the mineral or glass like final products. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. Thermochemical treatment technologies are very efficient, easy to apply, they have low capital investment and can be used both at large and small facilities. An advantage of thermochemical technologies is their autonomy. Thus these technologies can be successfully applied in order to treat small amount of waste without usage of complex and expensive equipment. They can be used also in emergency situations. Currently the thermochemical treatment technologies were developed and demonstrated to be feasible as follows: 1. Decontamination of surfaces; 2. Processing of organic waste; 3. Vitrification of dusty

Comprehensive characterisation of sewage sludge for thermochemical conversion processes - Based on Singapore survey.

Science.gov (United States)

Chan, Wei Ping; Wang, Jing-Yuan

2016-08-01

Recently, sludge attracted great interest as a potential feedstock in thermochemical conversion processes. However, compositions and thermal degradation behaviours of sludge were highly complex and distinctive compared to other traditional feedstock led to a need of fundamental research on sludge. Comprehensive characterisation of sludge specifically for thermochemical conversion was carried out for all existing Water Reclamation Plants in Singapore. In total, 14 sludge samples collected based on the type, plant, and batch categorisation. Existing characterisation methods for physical and chemical properties were analysed and reviewed using the collected samples. Qualitative similarities and quantitative variations of different sludge samples were identified and discussed. Oxidation of inorganic in sludge during ash forming analysis found to be causing significant deviations on proximate and ultimate analysis. Therefore, alternative parameters and comparison basis including Fixed Residues (FR), Inorganic Matters (IM) and Total Inorganics (TI) were proposed for better understanding on the thermochemical characteristics of sludge. Copyright © 2016 Elsevier Ltd. All rights reserved.

New high expansion ratio gasoline engine for the TOYOTA hybrid system. Improving engine efficiency with high expansion ratio cycle; Hybrid system yo kobochohi gasoline engine. Kobochohi cycle ni yoru engine no kokoritsuka

Energy Technology Data Exchange (ETDEWEB)

Hirose, K; Takaoka, T; Ueda, T; Kobayashi, Y [Toyota Motor Corp., Aichi (Japan)

1997-10-01

50% reduction of CO2 and fuel consumption have been achieved with the newly developed gasoline engine for the Toyota Hybrid System. This is achieved due to the combination of electric motors and the internal combustion engine which is optimized in the size, swept volume and heat cycle. By delaying the intake valve close timing a high expansion ratio (13.5:1) cycle has been realized. Electricmotor assist enable to cut the maximum engine speed, and friction loss. A best fuel consumption figure better than 230 g/kWh has been achieved. Elimination of lightload firing, motor assisted quick start and improvement of catalyst warm up makes to achieve the clean emission level such as 1/10 of Japanese `78 regulation limit. 10 refs., 16 figs., 1 tab.

The NAGRA/PSI thermochemical database: new developments

International Nuclear Information System (INIS)

Hummel, W.; Berner, U.; Thoenen, T.; Pearson, F.J.Jr.

2000-01-01

The development of a high quality thermochemical database for performance assessment is a scientifically fascinating and demanding task, and is not simply collecting and recording numbers. The final product can by visualised as a complex building with different storeys representing different levels of complexity. The present status report illustrates the various building blocks which we believe are integral to such a database structure. (authors)

The NAGRA/PSI thermochemical database: new developments

Energy Technology Data Exchange (ETDEWEB)

Hummel, W.; Berner, U.; Thoenen, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Pearson, F.J.Jr. [Ground-Water Geochemistry, New Bern, NC (United States)

2000-07-01

The development of a high quality thermochemical database for performance assessment is a scientifically fascinating and demanding task, and is not simply collecting and recording numbers. The final product can by visualised as a complex building with different storeys representing different levels of complexity. The present status report illustrates the various building blocks which we believe are integral to such a database structure. (authors)

Thermochemical structure of the Earth's mantle and continental crust

DEFF Research Database (Denmark)

Guerri, Mattia

A detailed knowledge of the Earth's thermal structure and chemical composition is fundamental in order to understand the processes driving the planet ormation and evolution. The inaccessibility of most of the Earth's interior makes the determination of its thermo-chemical conditions a challenging...

Energy storage technologies and hybrid architectures for specific diesel-driven rail duty cycles: Design and system integration aspects

International Nuclear Information System (INIS)

Meinert, M.; Prenleloup, P.; Schmid, S.; Palacin, R.

2015-01-01

Highlights: • We assessed integration of energy storage systems into hybrid system architectures. • We considered mechanical and electrical energy storage systems. • Potential of different combinations has been analyzed by standardized duty cycles. • Most promising are diesel-driven suburban, regional and shunting operations. • Double-layer capacitors and Lithium-ion batteries have the highest potential. - Abstract: The use of diesel-driven traction is an intrinsic part of the functioning of railway systems and it is expected to continue being so for the foreseeable future. The recent introduction of more restrictive greenhouse gas emission levels and other legislation aiming at the improvement of the environmental performance of railway systems has led to the need of exploring alternatives for cleaner diesel rolling stock. This paper focuses on assessing energy storage systems and the design of hybrid system architectures to determine their potential use in specific diesel-driven rail duty cycles. Hydrostatic accumulators, flywheels, Lithium-ion batteries and double-layer capacitors have been assessed and used to design hybrid system architectures. The potential of the different technology combinations has been analyzed using standardized duty cycles enhanced with gradient profiles related to suburban, regional and shunting operations. The results show that double-layer capacitors and Lithium-ion batteries have the highest potential to be successfully integrated into the system architecture of diesel-driven rail vehicles. Furthermore, the results also suggest that combining these two energy storage technologies into a single hybridisation package is a highly promising design that draws on their strengthens without any significant drawbacks.

A hybrid system using a regenerative electrochemical cycle to harvest waste heat from the proton exchange membrane fuel cell

International Nuclear Information System (INIS)

Long, Rui; Li, Baode; Liu, Zhichun; Liu, Wei

2015-01-01

A new hybrid system consisting of a PEMFC (proton exchange membrane fuel cell) subsystem and a TREC (thermally regenerative electrochemical cycle) subsystem is proposed to convert the waste heat produced by the PEMFC system into electricity. The performance of the hybrid system and its corresponding subsystems is analyzed. Results reveal that there exists optimal current densities of the PEMFC and TREC systems leading to the maximum power output of the hybrid system. With the maximum power output as the objective function, an optimization of the hybrid system based on genetic algorithm method is conducted under different operating temperatures of the PEMFC subsystem. The power output of the hybrid system is 6.85%–20.59% larger than that of the PEMFC subsystem. And the total electrical efficiency is improved by 2.74%–8.27%. The corresponding electrical efficiency of the TREC is 4.56%–13.81%. The hybrid system proposed in this paper could contribute to utilizing the fuel energy more efficiently and sufficiently. - Highlights: • A hybrid power system consisting of a PEMFC and a TREC subsystems is proposed. • Parameters' impacts on performance of the hybrid system have been analyzed. • The maximum power output of the hybrid system is investigated based on genetic algorithm. • Total power output of the hybrid system is 7.63%–18.84% larger than that of the PEMFC subsystem.

Biomass thermochemical gasification: Experimental studies and modeling

Science.gov (United States)

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

REITP3-Hazard evaluation program for heat release based on thermochemical calculation

Energy Technology Data Exchange (ETDEWEB)

Akutsu, Yoshiaki.; Tamura, Masamitsu. [The University of Tokyo, Tokyo (Japan). School of Engineering; Kawakatsu, Yuichi. [Oji Paper Corp., Tokyo (Japan); Wada, Yuji. [National Institute for Resources and Environment, Tsukuba (Japan); Yoshida, Tadao. [Hosei University, Tokyo (Japan). College of Engineering

1999-06-30

REITP3-A hazard evaluation program for heat release besed on thermochemical calculation has been developed by modifying REITP2 (Revised Estimation of Incompatibility from Thermochemical Properties{sup 2)}. The main modifications are as follows. (1) Reactants are retrieved from the database by chemical formula. (2) As products are listed in an external file, the addition of products and change in order of production can be easily conducted. (3) Part of the program has been changed by considering its use on a personal computer or workstation. These modifications will promote the usefulness of the program for energy hazard evaluation. (author)

An optimized Fuzzy Logic Controller by Water Cycle Algorithm for power management of Stand-alone Hybrid Green Power generation

International Nuclear Information System (INIS)

Sarvi, Mohammad; Avanaki, Isa Nasiri

2015-01-01

Highlights: • A new method to improve the performance of renewable power management is proposed. • The proposed method is based on Fuzzy Logic optimized by the Water Cycle Algorithm. • The proposed method characteristics are compared with two other methods. • The comparisons confirm that the proposed method is robust and effectiveness one. - Abstract: This paper aims to improve the power management system of a Stand-alone Hybrid Green Power generation based on the Fuzzy Logic Controller optimized by the Water Cycle Algorithm. The proposed Stand-alone Hybrid Green Power consists of wind energy conversion and photovoltaic systems as primary power sources and a battery, fuel cell, and Electrolyzer as energy storage systems. Hydrogen is produced from surplus power generated by the wind energy conversion and photovoltaic systems of Stand-alone Hybrid Green Power and stored in the hydrogen storage tank for fuel cell later using when the power generated by primary sources is lower than load demand. The proposed optimized Fuzzy Logic Controller based power management system determines the power that is generated by fuel cell or use by Electrolyzer. In a hybrid system, operation and maintenance cost and reliability of the system are the important issues that should be considered in studies. In this regard, Water Cycle Algorithm is used to optimize membership functions in order to simultaneously minimize the Loss of Power Supply Probability and operation and maintenance. The results are compared with the particle swarm optimization and the un-optimized Fuzzy Logic Controller power management system to prove that the proposed method is robust and effective. Reduction in Loss of Power Supply Probability and operation and maintenance, are the most advantages of the proposed method. Moreover the level of the State of Charge of the battery in the proposed method is higher than other mentioned methods which leads to increase battery lifetime.

Analysis of hot spots in boilers of organic Rankine cycle units during transient operation

DEFF Research Database (Denmark)

Benato, A.; Kærn, Martin Ryhl; Pierobon, Leonardo

2015-01-01

This paper is devoted to the investigation of critical dynamic events causing thermochemical decompositionof the working fluid in organic Rankine cycle power systems. The case study is the plant of an oiland gas platform where one of the three gas turbines is combined with an organic Rankine cycle...... and fluid decomposition. It is demonstrated thatthe use of a spray attemperator can mitigate the problems of local overheating of the organic compound.As a practical consequence, this paper provides guidelines for safe and reliable operation of organicRankine cycle power modules on offshore installations....

Probabilistic thermo-chemical analysis of a pultruded composite rod

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study the deterministic thermo-chemical pultrusion simulation of a composite rod taken from the literature [7] is used as a validation case. The predicted centerline temperature and cure degree profiles of the rod match well with those in the literature [7]. Following the validation...

Thermochemical conversion of microalgal biomass into biofuels: a review.

Science.gov (United States)

Chen, Wei-Hsin; Lin, Bo-Jhih; Huang, Ming-Yueh; Chang, Jo-Shu

2015-05-01

Following first-generation and second-generation biofuels produced from food and non-food crops, respectively, algal biomass has become an important feedstock for the production of third-generation biofuels. Microalgal biomass is characterized by rapid growth and high carbon fixing efficiency when they grow. On account of potential of mass production and greenhouse gas uptake, microalgae are promising feedstocks for biofuels development. Thermochemical conversion is an effective process for biofuel production from biomass. The technology mainly includes torrefaction, liquefaction, pyrolysis, and gasification. Through these conversion technologies, solid, liquid, and gaseous biofuels are produced from microalgae for heat and power generation. The liquid bio-oils can further be upgraded for chemicals, while the synthesis gas can be synthesized into liquid fuels. This paper aims to provide a state-of-the-art review of the thermochemical conversion technologies of microalgal biomass into fuels. Detailed conversion processes and their outcome are also addressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

A hybrid life cycle and multi-criteria decision analysis approach for identifying sustainable development strategies of Beijing's taxi fleet

International Nuclear Information System (INIS)

Cai, Yanpeng; Applegate, Scott; Yue, Wencong; Cai, Jianying; Wang, Xuan; Liu, Gengyuan; Li, Chunhui

2017-01-01

To identify and evaluate sustainable strategies of taxi fleet in Beijing in terms of economic, policy, and environmental implications, a hybrid approach was developed through incorporating multi-criteria decision analysis (MCDA) methods within a general life-cycle analysis (LCA) framework. The approach can (a) help comprehensive evaluate environmental impacts of multiple types of vehicles, (b) facilitate analysis of environmental, economic and policy features of such vehicles, and (c) identify desirable taxi fleet development strategies for the city. The developed approach represented an improvement of the decision-making capability for taxi implementation based on multiple available technologies and their performance that can be specifically tailored to Beijing. The results demonstrated that the proposed approach could comprehensively reflect multiple implications of strategies for the taxi fleet in Beijing to reduce air pollution in the city. The results also indicated that the electric vehicle powered with the year 2020 electricity projections would be the ideal solution, outranking the other alternatives. The conventional vehicle ranked the lowest among the alternatives. The plug-in hybrid vehicle powered by 2020 electricity projects ranked the third, followed by the plug-in hybrid vehicle ranking the fourth, and the hybrid vehicle ranking the fifth. - Highlights: • An hybrid approach was proposed for evaluating sustainable strategies of Beijing's taxi fleet. • This approach was based on the combination of multi-criteria decision analysis methods and life-cycle assessment. • Environmental, economic and policy performances of multiple strategies were compared. • Detailed responses of taxi drivers and local residents were interviewed. • The electric vehicle would be the ideal solution for Beijing Taxi fleet.

A synergetic hybridization of adsorption cycle with the multi-effect distillation (MED)

KAUST Repository

Thu, K.

2014-01-01

Multi-effect distillation (MED) systems are proven and energy efficient thermally-driven desalination systems for handling harsh seawater feed in the Gulf region. The high cycle efficiency is markedly achieved by latent energy re-use with minimal stage temperature-difference across the condensing steam and the evaporating saline seawater in each stage. The efficacies of MED system are (i) its low stage-temperature-difference between top brine temperature (TBT) and final condensing temperature, (ii) its robustness to varying salinity and ability to handle harmful algae Blooming (HABs) and (iii) its compact foot-print per unit water output. The practical TBT of MED systems, hitherto, is around 65 C for controllable scaling and fouling with the ambient-limited final condenser temperature, usually from 30 to 45 C. The adsorption (ADC) cycles utilize low-temperature heat sources (typically below 90 C) to produce useful cooling power and potable water. Hybridizing MED with AD cycles, they synergistically improve the water production rates at the same energy input whilst the AD cycle is driven by the recovered waste heat. We present a practical AD + MED combination that can be retrofitted to existing MEDs: The cooling energy of AD cycle through the water vapor uptake by the adsorbent is recycled internally, providing lower temperature condensing environment in the effects whilst the final condensing temperature of MED is as low as 5-10 C, which is below ambient. The increase in the temperature difference between TBT and final condensing temperature accommodates additional MED stages. A detailed numerical model is presented to capture the transient behaviors of heat and mass interactions in the combined AD + MED cycles and the results are presented in terms of key variables. It is observed that the water production rates of the combined cycle increase to give a GOR of 8.8 from an initial value of 5.9. © 2013 Elsevier Ltd. All rights reserved.

Overview of recent advances in thermo-chemical conversion of biomass

International Nuclear Information System (INIS)

Zhang Linghong; Xu Chunbao; Champagne, Pascale

2010-01-01

Energy from biomass, bioenergy, is a perspective source to replace fossil fuels in the future, as it is abundant, clean, and carbon dioxide neutral. Biomass can be combusted directly to generate heat and electricity, and by means of thermo-chemical and bio-chemical processes it can be converted into bio-fuels in the forms of solid (e.g., charcoal), liquid (e.g., bio-oils, methanol and ethanol), and gas (e.g., methane and hydrogen), which can be used further for heat and power generation. This paper provides an overview of the principles, reactions, and applications of four fundamental thermo-chemical processes (combustion, pyrolysis, gasification, and liquefaction) for bioenergy production, as well as recent developments in these technologies. Some advanced thermo-chemical processes, including co-firing/co-combustion of biomass with coal or natural gas, fast pyrolysis, plasma gasification and supercritical water gasification, are introduced. The advantages and disadvantages, potential for future applications and challenges of these processes are discussed. The co-firing of biomass and coal is the easiest and most economical approach for the generation of bioenergy on a large-sale. Fast pyrolysis has attracted attention as it is to date the only industrially available technology for the production of bio-oils. Plasma techniques, due to their high destruction and reduction efficiencies for any form of waste, have great application potential for hazardous waste treatment. Supercritical water gasification is a promising approach for hydrogen generation from biomass feedstocks, especially those with high moisture contents.

Application of Thermochemical Modeling to Assessment/Evaluation of Nuclear Fuel Behavior

Energy Technology Data Exchange (ETDEWEB)

Besmann, Theodore M [University of South Carolina, Columbia; McMurray, Jake W [ORNL; Simunovic, Srdjan [ORNL

2016-01-01

The combination of new fuel compositions and higher burn-ups envisioned for the future means that representing fuel properties will be much more important, and yet more complex. Behavior within the oxide fuel rods will be difficult to model owing to the high temperatures, and the large number of elements generated and their significant concentrations that are a result of fuels taken to high burn-up. This unprecedented complexity offers an enormous challenge to the thermochemical understanding of these systems and opportunities to advance solid solution models to describe these materials. This paper attempts to model and simulate that behavior using an oxide fuels thermochemical description to compute the equilibrium phase state and oxygen potential of LWR fuel under irradiation.

Ceria-based electrospun fibers for renewable fuel production via two-step thermal redox cycles for carbon dioxide splitting.

Science.gov (United States)

Gibbons, William T; Venstrom, Luke J; De Smith, Robert M; Davidson, Jane H; Jackson, Gregory S

2014-07-21

Zirconium-doped ceria (Ce(1-x)Zr(x)O2) was synthesized through a controlled electrospinning process as a promising approach to cost-effective, sinter-resistant material structures for high-temperature, solar-driven thermochemical redox cycles. To approximate a two-step redox cycle for solar fuel production, fibrous Ce(1-x)Zr(x)O2 with relatively low levels of Zr-doping (0 rates of O2 release during reduction and CO production during reoxidation and by assessing post-cycling fiber crystallite sizes and surface areas. Sintering increases with reduction temperature but occurs primarily along the fiber axes. Even after 108 redox cycles with reduction at 1400 °C and oxidation with CO2 at 800 °C, the fibers maintain their structure with surface areas of ∼0.3 m(2) g(-1), higher than those observed in the literature for other ceria-based structures operating at similarly high temperature conditions. Total CO production and peak production rate stabilize above 3.0 mL g(-1) and 13.0 mL min(-1) g(-1), respectively. The results show the potential for electrospun oxides as sinter-resistant material structures with adequate surface area to support rapid CO2 splitting in solar thermochemical redox cycles.

Thermochemical properties of the alkali hydroxides: A review

International Nuclear Information System (INIS)

Konings, R.J.M.; Cordfunke, E.H.P.

1989-01-01

The formation of volatile alkali hydroxides as a result of high-temperature steam corrosion plays an important role in nuclear technology. For the modeling of the volatilization processes, reliable thermodynamic data are required. In the present paper recent physico-chemical experiments by the authors will be discussed and the thermochemical properties of the alkali hydroxide series will be evaluated. (orig.)

Enhancements to the hybrid pressurized air receiver (HPAR) concept in the SUNDISC cycle

Science.gov (United States)

Heller, Lukas; Hoffmann, Jaap

2017-06-01

A dual-pressure air receiver has previously been proposed as part of a hybrid receiver system preheating pressurized air in a solarized gas turbine and providing hot non-pressurized air to power the bottoming cycle of a combined cycle CSP plant. The receiver, based on a bundle of metallic tubular absorbers, was found to not be able to provide the non-pressurized air at the required temperature. Three enhancements to the basic design are presented and thermally modeled: (a) Finned absorber tubes to increase the convective heat transfer, (b) quartz glass elements to alleviate convective losses and improve the flow inside the tube bundle as well as (c) additional absorber elements behind the tube bundle. It could be shown that finned absorber tubes as well as the additional absorber elements have potential to improve the thermal performance of the receiver while a quartz glass window and flow-enhancing quartz elements could be indispensable additions to either of the other enhancements.

Solar thermochemical processing system and method

Science.gov (United States)

Wegeng, Robert S.; Humble, Paul H.; Krishnan, Shankar; Leith, Steven D.; Palo, Daniel R.; Dagle, Robert A.

2018-04-24

A solar thermochemical processing system is disclosed. The system includes a first unit operation for receiving concentrated solar energy. Heat from the solar energy is used to drive the first unit operation. The first unit operation also receives a first set of reactants and produces a first set of products. A second unit operation receives the first set of products from the first unit operation and produces a second set of products. A third unit operation receives heat from the second unit operation to produce a portion of the first set of reactants.

Water Footprint and Land Requirement of Solar Thermochemical Jet-Fuel Production.

Science.gov (United States)

Falter, Christoph; Pitz-Paal, Robert

2017-11-07

The production of alternative fuels via the solar thermochemical pathway has the potential to provide supply security and to significantly reduce greenhouse gas emissions. H 2 O and CO 2 are converted to liquid hydrocarbon fuels using concentrated solar energy mediated by redox reactions of a metal oxide. Because attractive production locations are in arid regions, the water footprint and the land requirement of this fuel production pathway are analyzed. The water footprint consists of 7.4 liters per liter of jet fuel of direct demand on-site and 42.4 liters per liter of jet fuel of indirect demand, where the dominant contributions are the mining of the rare earth oxide ceria, the manufacturing of the solar concentration infrastructure, and the cleaning of the mirrors. The area-specific productivity is found to be 33 362 liters per hectare per year of jet fuel equivalents, where the land coverage is mainly due to the concentration of solar energy for heat and electricity. The water footprint and the land requirement of the solar thermochemical fuel pathway are larger than the best power-to-liquid pathways but an order of magnitude lower than the best biomass-to-liquid pathways. For the production of solar thermochemical fuels arid regions are best-suited, and for biofuels regions of a moderate and humid climate.

Geometric optimization of a solar cubic-cavity multi-tubular thermochemical reactor using a Monte Carlo-finite element radiative transfer model

International Nuclear Information System (INIS)

Valades-Pelayo, P.J.; Romero-Paredes, H.; Arancibia-Bulnes, C.A.; Villafán-Vidales, H.I.

2016-01-01

In the present study, the optimization of a multi-tubular solar thermochemical cavity reactor is carried out. The reactor consists of a cubic cavity made of woven graphite, housing nine 2.54 cm diameter tungsten tubes. A heat transfer model is developed and implemented considering high-temperature radiative transfer at steady state. The temperature distribution on the receiver tubes is determined by using a hybrid Monte Carlo-finite volume approach. The optimization aims at maximizing average tube temperature by varying tube locations. Optimal tube distributions are explored by using a custom-made stochastic, multi-parameter, global optimization algorithm. A considerable increase in average temperature as well as improvement on temperature uniformity is found in the optimized tube arrays. Patterns among the different optimal distributions are found, and general features are discussed.

Analysis of environmental effect of hybrid solar-assisted desalination cycle in Sirdarya Thermal Power Plant, Uzbekistan

International Nuclear Information System (INIS)

Alikulov, Khusniddin; Xuan, Tran Dang; Higashi, Osamu; Nakagoshi, Nobukazu; Aminov, Zarif

2017-01-01

Highlights: • A hybrid solar-assisted desalination cycle was designed and stimulated. • Maximum of 21,064.00 kW effective solar heat can be achieved. • The use of parabolic-trough collectors in the Multi Effect Distillation is potential. • The cycle can be applied in other regions with high Direct Normal Irradiation. - Abstract: This study was to investigate possible reduction of fossil fuel consumption and carbon dioxide emission in one of energy sectors of Sirdarya Thermal Power Plant (TPP), Uzbekistan. A hybrid solar-assisted desalination cycle has been designed and simulated for partially supplying saturated steam with 200 °C, 8 bar, and 32 t/h parameters to a Multi Effect Distillation (MED) process in the Sirdarya Thermal Power Plant. The outcome of the parental design model stated that maximum, 21,064.00 kW effective solar heat can be achieved, which is equivalent to 31.76 t/h of saturated steam with 200 °C and 8 bar parameters. Total saved fossil fuel in each month proved that it is possible to reduce fossil fuel (heavy oil and natural gas) consumption with 59.64, 95.24, 389.96, and 298.26 tons during available Direct Normal Irradiation (DNI) by using parabolic-trough collectors. Moreover, the above-mentioned fossil fuel savings accounted for CO_2 reduction with amounts of 182.50, 255.46, 1045.87 & 799.96 tons per each consistent month. Findings proved that integration of parabolic-trough collectors into the MED process is feasible in terms of high DNI availability and demand for retrofitting old existing heat-consuming facilities in Sirdarya Thermal Power Plant. Besides, the cycle also can be applied in other regions of Uzbekistan with high DNI for generating solar heat. Therefore, conducted study is eligible to be applied on the research site by taking into account of sufficient meteorological data and required steam parameters.

Integrated laboratory scale demonstration experiment of the hybrid sulphur cycle and preliminary scale-up

International Nuclear Information System (INIS)

Leybros, J.; Rivalier, P.; Saturnin, A.; Charton, S.

2010-01-01

The hybrid sulphur cycle is today one of the most promising processes to produce hydrogen on a massive scale within the scope of high temperature nuclear reactors development. Thus, the Fuel Cycle Technology Department at CEA Marcoule is involved in studying the hybrid sulphur process from a technical and economical performance standpoint. Based on mass and energy balance calculations, a ProsimPlus TM flow sheet and a commercial plant design were prepared. This work includes a study on sizing of the main equipment. The capital cost has been estimated using the major characteristics of main equipment based upon formulae and charts published in literature. A specific approach has been developed for electrolysers. Operational costs are also proposed for a plant producing 1000 mol/s H 2 . Bench scale and pilot experiments must focus on the electrochemical step due to limited experimental data. Thus, a pilot plant with a hydrogen capacity of 100 NL/h was built with the aim of acquiring technical and technological data for electrolysis. This pilot plant was designed to cover a wide range of operating conditions: sulphuric acid concentrations up to 60 wt.%, temperatures up to 100 deg. C and pressures up to 10 bar. New materials and structures recently developed for fuel cells, which are expected to yield significant performance improvements when applied to classical electrochemical processes, will be tested. All experiments will be coupled with phenomenological simulation tools developed jointly with the experimental programme. (authors)

Multiple Origins and Nested Cycles of Hybridization Result in High Tetraploid Diversity in the Monocot Prospero.

Science.gov (United States)

Jang, Tae-Soo; Parker, John S; Emadzade, Khatere; Temsch, Eva M; Leitch, Andrew R; Weiss-Schneeweiss, Hanna

2018-01-01

Polyploidy is a major driving force in angiosperm evolution, but our understanding of establishment and early diversification processes following allo- vs. auto-polyploidy is limited. An excellent system to address such questions is the monocot plant Prospero autumnale , as it comprises several genomically and chromosomally distinct diploid cytotypes and their auto- and allotetraploid derivatives. To infer origins and evolutionary trajectories of the tetraploids, we use genome size data, in situ hybridization with parental genomic DNAs and specific probes (satDNA, rDNAs), as well as molecular-phylogenetic analyses. Thus, we demonstrate that an astounding range of allotetraploid lineages has been formed recurrently by chromosomal re-patterning, interactions of chromosomally variable parental genomes and nested cycles of extensive hybridization, whereas autotetraploids have originated at least twice and are cytologically stable. During the recurrent formation and establishment across wide geographic areas hybridization in some populations could have inhibited lineage diversification and nascent speciation of such a hybrid swarm. However, cytotypes that became fixed in populations enhanced the potential for species diversification, possibly exploiting the extended allelic base, and fixed heterozygosity that polyploidy confers. The time required for polyploid cytotype fixation may in part reflect the lag phase reported for polyploids between their formation and species diversification.

Multiple Origins and Nested Cycles of Hybridization Result in High Tetraploid Diversity in the Monocot Prospero

Directory of Open Access Journals (Sweden)

Tae-Soo Jang

2018-04-01

Full Text Available Polyploidy is a major driving force in angiosperm evolution, but our understanding of establishment and early diversification processes following allo- vs. auto-polyploidy is limited. An excellent system to address such questions is the monocot plant Prospero autumnale, as it comprises several genomically and chromosomally distinct diploid cytotypes and their auto- and allotetraploid derivatives. To infer origins and evolutionary trajectories of the tetraploids, we use genome size data, in situ hybridization with parental genomic DNAs and specific probes (satDNA, rDNAs, as well as molecular-phylogenetic analyses. Thus, we demonstrate that an astounding range of allotetraploid lineages has been formed recurrently by chromosomal re-patterning, interactions of chromosomally variable parental genomes and nested cycles of extensive hybridization, whereas autotetraploids have originated at least twice and are cytologically stable. During the recurrent formation and establishment across wide geographic areas hybridization in some populations could have inhibited lineage diversification and nascent speciation of such a hybrid swarm. However, cytotypes that became fixed in populations enhanced the potential for species diversification, possibly exploiting the extended allelic base, and fixed heterozygosity that polyploidy confers. The time required for polyploid cytotype fixation may in part reflect the lag phase reported for polyploids between their formation and species diversification.

Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany

International Nuclear Information System (INIS)

Henssler, Martin

2015-01-01

According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO 2eq -reduction compared to the fossil reference fuel (83.8 g CO 2eq /MJ fuel /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO 2eq -savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H 2 ) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V registered -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H 2 ). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H 2 -production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO 2eq -saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO 2eq -saving is between 72 (H 2 ) and 95 % (Fischer-Tropsch-diesel or -gasoline). When the production costs of the

Utilization of salt ammoniacates in fluidized beds in energy conversion thermochemical systems

International Nuclear Information System (INIS)

Romero, Jesus

1984-01-01

This research thesis notably reports the design and development of a thermochemical storage device involving equilibria of thermal decomposition of ammoniacates of strontium chlorides and calcium chloride in fluidized beds. The experimental study of this device allowed operating conditions and the most important concomitant effects of fluidization to be highlighted. The measured thermal exchange coefficient is about twenty times the measured value in equivalent devices using fixed beds. An irreversibility of the operation has been noticed, and seems to be associated with the irreversible change of grain size of solids. The author also reports a study of the properties of ammoniacates of metallic salts, and of the influence of fluidization on the performance of energy conversion thermochemical systems [fr

Thermochemical equilibrium in a kernel of a UN TRISO coated fuel particle

International Nuclear Information System (INIS)

Kim, Young Min; Jo, C. K.; Lim, H. S.; Cho, M. S.; Lee, W. J.

2012-01-01

A coated fuel particle (CFP) with a uranium mononitride (UN) kernel has been recently considered as an advanced fuel option, such as in fully ceramic micro encapsulated (FCM) replacement fuel for light water reactors (LWRs). In FCM fuel, a large number of tri isotropic coated fuel particles (TRISOs) are embedded in a silicon carbide (SiC) matrix. Thermochemical equilibrium calculations can predict the chemical behaviors of a kernel in a TRISO of FCM fuel during irradiation. They give information on the kind and quantity of gases generated in a kernel during irradiation. This study treats the quantitative analysis of thermochemical equilibrium in a UN TRISO of FCM LWR fuel using HSC software

Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies.

Science.gov (United States)

Gallagher, Patricia M; Spatari, Sabrina; Cucura, Jeffrey

2013-04-15

Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental "systems-level" decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier. Copyright © 2013 Elsevier B.V. All rights reserved.

Life cycle cost of a hybrid forward osmosis – low pressure reverse osmosis system for seawater desalination and wastewater recovery

KAUST Repository

Valladares Linares, Rodrigo; Li, Z.; Yangali-Quintanilla, V.; Ghaffour, NorEddine; Amy, Gary L.; Leiknes, TorOve; Vrouwenvelder, Johannes S.

2015-01-01

-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality

Solar thermochemical production of ammonia from water, air and sunlight: Thermodynamic and economic analyses

International Nuclear Information System (INIS)

Michalsky, Ronald; Parman, Bryon J.; Amanor-Boadu, Vincent; Pfromm, Peter H.

2012-01-01

Ammonia is an important input into agriculture and is used widely as base chemical for the chemical industry. It has recently been proposed as a sustainable transportation fuel and convenient one-way hydrogen carrier. Employing typical meteorological data for Palmdale, CA, solar energy is considered here as an inexpensive and renewable energy alternative in the synthesis of NH 3 at ambient pressure and without natural gas. Thermodynamic process analysis shows that a molybdenum-based solar thermochemical NH 3 production cycle, conducted at or below 1500 K, combined with solar thermochemical H 2 production from water may operate at a net-efficiency ranging from 23 to 30% (lower heating value of NH 3 relative to the total energy input). Net present value optimization indicates ecologically and economically sustainable NH 3 synthesis at above about 160 tons NH 3 per day, dependent primarily on heliostat costs (varied between 90 and 164 dollars/m 2 ), NH 3 yields (ranging from 13.9 mol% to stoichiometric conversion of fixed and reduced nitrogen to NH 3 ), and the NH 3 sales price. Economically feasible production at an optimum plant capacity near 900 tons NH 3 per day is shown at relative conservative technical assumptions and at a reasonable NH 3 sales price of about 534 ± 28 dollars per ton NH 3 . -- Highlights: ► Conceptual reactant and process improvements of solar-driven NH 3 synthesis at 1 bar. ► Thermodynamic underpinnings of a Molybdenum reactant. ► Process analysis determining energy and materials requirements and the net-efficiency. ► Net present value analysis accounting for yield, investment, and sales price variations.

Energy Efficiency Comparison between Hydraulic Hybrid and Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Jia-Shiun Chen

2015-05-01

Full Text Available Conventional vehicles tend to consume considerable amounts of fuel, which generates exhaust gases and environmental pollution during intermittent driving cycles. Therefore, prospective vehicle designs favor improved exhaust emissions and energy consumption without compromising vehicle performance. Although pure electric vehicles feature high performance and low pollution characteristics, their limitations are their short driving range and high battery costs. Hybrid electric vehicles (HEVs are comparatively environmentally friendly and energy efficient, but cost substantially more compared with conventional vehicles. Hydraulic hybrid vehicles (HHVs are mainly operated using engines, or using alternate combinations of engine and hydraulic power sources while vehicles accelerate. When the hydraulic system accumulator is depleted, the conventional engine reengages; concurrently, brake-regenerated power is recycled and reused by employing hydraulic motor–pump modules in circulation patterns to conserve fuel and recycle brake energy. This study adopted MATLAB Simulink to construct complete HHV and HEV models for backward simulations. New European Driving Cycles were used to determine the changes in fuel economy. The output of power components and the state-of-charge of energy could be retrieved. Varying power component models, energy storage component models, and series or parallel configurations were combined into seven different vehicle configurations: the conventional manual transmission vehicle, series hybrid electric vehicle, series hydraulic hybrid vehicle, parallel hybrid electric vehicle, parallel hydraulic hybrid vehicle, purely electric vehicle, and hydraulic-electric hybrid vehicle. The simulation results show that fuel consumption was 21.80% lower in the series hydraulic hybrid vehicle compared to the series hybrid electric vehicle; additionally, fuel consumption was 3.80% lower in the parallel hybrid electric vehicle compared to the

Electrifying Australian transport: Hybrid life cycle analysis of a transition to electric light-duty vehicles and renewable electricity

International Nuclear Information System (INIS)

Wolfram, Paul; Wiedmann, Thomas

2017-01-01

Highlights: •This research assesses life-cycle carbon impacts of different powertrains. •We illustrate a transition to low-carbon vehicles in a hybrid IO-LCA model. •Different electricity and transport scenarios are integrated in the model. •With Australia’s current grid-mix, electric vehicles offer no mitigation potential. •Using renewable energy, electric vehicle carbon footprints can be cut by 66%. -- Abstract: Recent life cycle assessments confirmed the greenhouse gas emission reduction potential of renewable electricity and electric vehicle technologies. However, each technology is usually assessed separately and not within a consistent macro-economic, multi-sectoral framework. Here we present a multi-regional input-output based hybrid approach with integrated scenarios to facilitate the carbon footprint assessment of all direct and indirect effects of a transition to low-emission transportation and electricity generation technologies in Australia. The work takes into account on-road energy consumption values that are more realistic than official drive-cycle energy consumption figures used in previous work. Accounting for these factors as well as for Australia’s grid electricity, which heavily relies on coal power, electric vehicles are found to have a higher carbon footprint than conventional vehicles, whereas hybrid electric vehicles have the lowest. This means that – from a carbon footprint perspective – powertrain electrification is beneficial only to a certain degree at the current stage. This situation can be changed by increasing shares of renewable electricity in the grid. In our best-case scenario, where renewable energy accounts for 96% of the electricity mix in 2050, electric vehicle carbon footprints can be cut by 66% by 2050 relative to 2009. In the business-as-usual scenario (36% renewable electricity share by 2050), electric vehicles can reach a 56% reduction if fossil fuel power plants significantly increase their efficiencies

Fusion as a source of synthetic fuels

International Nuclear Information System (INIS)

Powell, J.R.; Fillo, J.A.; Steinberg, M.

1981-01-01

In the near-term, coal derived synthetic fuels will be used; but in the long-term, resource depletion and environmental effects will mandate synthetic fuels from inexhaustible sources - fission, fusion, and solar. Of the three sources, fusion appears uniquely suited for the efficient production of hydrogen-based fuels, due to its ability to directly generate very high process temperatures (up to approx. 2000 0 C) for water splitting reactions. Fusion-based water splitting reactions include high temperature electrolysis (HTE) of steam, thermochemical cycles, hybrid electrochemical/thermochemical, and direct thermal decomposition. HTE appears to be the simplest and most efficient process with efficiencies of 50 to 70% (fusion to hydrogen chemical energy), depending on process conditions

Fuels production by the thermochemical transformation of the biomass

International Nuclear Information System (INIS)

Claudet, G.

2005-01-01

The biomass is a local and renewable energy source, presenting many advantages. This paper proposes to examine the biomass potential in France, the energy valorization channels (thermochemical chains of thermolysis and gasification) with a special interest for the hydrogen production and the research programs oriented towards the agriculture and the forest. (A.L.B.)

Thermochemical investigations on uranyl phosphates and arsenates

International Nuclear Information System (INIS)

Barten, H.

1986-11-01

The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

Integrated economic and life cycle assessment of thermochemical production of bioethanol to reduce production cost by exploiting excess of greenhouse gas savings

International Nuclear Information System (INIS)

Reyes Valle, C.; Villanueva Perales, A.L.; Vidal-Barrero, F.; Ollero, P.

2015-01-01

Highlights: • Assessment of economics and sustainability of thermochemical ethanol production. • Exploitation of excess CO 2 saving by either importing fossil energy or CO 2 trading. • Significant increase in alcohol production by replacing biomass with natural gas. • CO 2 emission trading is not cost-competitive versus import of fossil energy. • Lowest ethanol production cost for partial oxidation as reforming technology. - Abstract: In this work, two options are investigated to enhance the economics of the catalytic production of bioethanol from biomass gasification by exploiting the excess of CO 2 emission saving: (i) to import fossil energy, in the form of natural gas and electricity or (ii) to trade CO 2 emissions. To this end, an integrated life cycle and economic assessment is carried out for four process configurations, each using a different light hydrocarbon reforming technology: partial oxidation, steam methane reforming, tar reforming and autothermal reforming. The results show that for all process configurations the production of bioethanol and other alcohols significantly increases when natural gas displaces biomass, maintaining the total energy content of the feedstock. The economic advantage of the partial substitution of biomass by natural gas depends on their prices and this is explored by carrying out a sensitivity analysis, taking historical prices into account. It is also concluded that the trade of CO 2 emissions is not cost-competitive compared to the import of natural gas if the CO 2 emission price remains within historical European prices. The CO 2 emission price would have to double or even quadruple the highest CO 2 historical price for CO 2 emission trading to be a cost-competitive option

A process for the thermochemical poduction of H2

International Nuclear Information System (INIS)

Norman, J.H.; Russell, J.L. Jr.; Porter, J.T. II; McCorkl, K.H.; Roemer, T.S.; Sharp, Robert.

1976-01-01

A process is described for the thermochemical production of H 2 from water. HI 3 and H 2 SO 4 are prepared by chemical reaction between I 2 , SO 2 and H 2 O. Then HI 3 is heated and decomposed into H 2 and I 2 . The heat is produced by a nuclear reactor [fr

Genomic divergence and lack of introgressive hybridization between two 13-year periodical cicadas support life cycle switching in the face of climate change.

Science.gov (United States)

Koyama, Takuya; Ito, Hiromu; Fujisawa, Tomochika; Ikeda, Hiroshi; Kakishima, Satoshi; Cooley, John R; Simon, Chris; Yoshimura, Jin; Sota, Teiji

2016-11-01

Life history evolution spurred by post-Pleistocene climatic change is hypothesized to be responsible for the present diversity in periodical cicadas (Magicicada), but the mechanism of life cycle change has been controversial. To understand the divergence process of 13-year and 17-year cicada life cycles, we studied genetic relationships between two synchronously emerging, parapatric 13-year periodical cicada species in the Decim group, Magicicada tredecim and M. neotredecim. The latter was hypothesized to be of hybrid origin or to have switched from a 17-year cycle via developmental plasticity. Phylogenetic analysis using restriction-site-associated DNA sequences for all Decim species and broods revealed that the 13-year M. tredecim lineage is genomically distinct from 17-year Magicicada septendecim but that 13-year M. neotredecim is not. We detected no significant introgression between M. tredecim and M. neotredecim/M. septendecim thus refuting the hypothesis that M. neotredecim are products of hybridization between M. tredecim and M. septendecim. Further, we found that introgressive hybridization is very rare or absent in the contact zone between the two 13-year species evidenced by segregation patterns in single nucleotide polymorphisms, mitochondrial lineage identity and head width and abdominal sternite colour phenotypes. Our study demonstrates that the two 13-year Decim species are of independent origin and nearly completely reproductively isolated. Combining our data with increasing observations of occasional life cycle change in part of a cohort (e.g. 4-year acceleration of emergence in 17-year species), we suggest a pivotal role for developmental plasticity in Magicicada life cycle evolution. © 2016 John Wiley & Sons Ltd.

Thermochemical investigation of lithium-vanadium bronzes

International Nuclear Information System (INIS)

Filippova, S.E.; Kesler, Ya.A.; Tret'yakov, Yu.D.; Gordeev, I.V.

1979-01-01

A thermochemical investigation was carried out of lithium-vanadium bronzes. The enthalpies of solution and the standard enthalpies of formation of the bronzes β-Lisub(x)Vsub(2)Osub(5) were determined. Investigated was the dependence of the enthalpy of mixing bronzes on the composition; a linear character of the dependence evidences of negligibly small, as compared to the experimental error, energy variations of the matrix V 2 O 5 on introduction of lithium. The variation was calculated of the partial molar enthalpy of lithium in the formation of β-Lisub(x)Vsub(2)Osub(5)

Electric and Hybrid Vehicle System Research and Development Project: Hybrid Vehicle Potential Assessment. Volume VI. Cost analysis

Energy Technology Data Exchange (ETDEWEB)

Hardy, K.S.

1979-09-30

The purpose of the cost analysis is to determine the economic feasibility of a variety of hybrid vehicles with respect to conventional vehicles specifically designed for the same duty cycle defined by the mission analysis. Several different hybrid configurations including parallel, parallel-flywheel, and series vehicles were evaluated. The ramifications of incorporating examples of advanced batteries, these being the advanced lead-acid, nickel-zinc, and sodium sulfur were also investigated. Vehicles were specifically designed with these batteries and for the driving cycles specified by the mission. Simulated operation on the missions yielded the energy consumption (petroleum and/or electricity) over the driving cycles. It was concluded that: in the event that gasoline prices reach $2.50 to $3.00/gal, hybrid vehicles in many applications will become economically competitive with conventional vehicles without subsidization; in some commercial applications hybrid vehicles could be economically competitive, when the gasoline price ranges from $1.20 to $1.50/gal. The cost per kWh per cycle of the advanced batteries is much more important economically than the specific energy; the series hybrid vehicles were found to be more expensive in comparison to the parallel or parallel-flywheel hybrids when designed as passenger vehicles; and hybrid vehicles designed for private use could become economically competitive and displace up to 50% of the fuel normally used on that mission if subsidies of $500 to $2000 were supplied to the owner/operator. (LCL)

Generation of H{sub 2} and CO by solar thermochemical splitting of H{sub 2}O and CO{sub 2} by employing metal oxides

Energy Technology Data Exchange (ETDEWEB)

Rao, C.N.R., E-mail: cnrrao@jncasr.ac.in; Dey, Sunita

2016-10-15

Generation of H{sub 2} and CO by splitting H{sub 2}O and CO{sub 2} respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H{sub 2}O or CO{sub 2} over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H{sub 2}O or CO{sub 2}. While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites of the type Ln{sub 1−x}A{sub x}Mn{sub 1−y}M{sub y}O{sub 3} (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H{sub 2} and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y{sub 0.5}Sr{sub 0.5}MnO{sub 3} which releases 483 µmol/g of O{sub 2} at 1673 K and produces 757 µmol/g of CO from CO{sub 2} at 1173 K. The production of H{sub 2} from H{sub 2}O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H{sub 2} based on the Mn{sub 3}O{sub 4}/NaMnO{sub 2} cycle briefly. - Graphical abstract: Ln{sub 0.5}A{sub 0.5}Mn{sub 1−x}M{sub x}O{sub 3} (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO{sub 2} and H{sub 2}O for the generation of CO and H{sub 2}. - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO{sub 2} and H{sub 2}O. • In Ln{sub 1−x}A{sub x}MnO{sub 3} perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles

Preparation and thermochemical stability of uranium-zirconium-carbonitrides

International Nuclear Information System (INIS)

Kouhsen, C.

1975-08-01

This investigation deals with the preparation and the thermochemical stability of uranium-zirconium-carbonitrides as well as with the mechanism of (U,Zr) (C,N)-preparation by carbothermic reduction of uranium-zirconium-oxide. Single-phase (U,Zr) (C,N)-solid solutions with U:Zr-propertions of 3:1, 1:1, and 1:3 were prepared from oxide powder. The thermochemical stability of the (U,Zr) (C,N)-solid solutions against carbon was measured for varying Zr- and N-contents and for several temperatures; the results indicate an increase of the uranium carbide stability potential by the formation of (U,Zr) (C,N)-solid solutions. The thermodynamic properties ΔG 0 , ΔH 0 , and ΔS 0 were calculated and the correlation between the M(C,N)-lattice constant and the N-content was evaluated. Through an intensive investigation of the reaction mechanism, several different reaction paths were found; for each of them the characteristical diffusion of matter was explained by means of the microsections. It was shown that the Zr-concentration of the oxide reactant and the heating rate during the carbothermic reduction influence the species of the reaction product, especially the homogeneity of the (U,Zr) (C,N)-solid solution. (orig.) [de

Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures

Science.gov (United States)

Barmina, I.; Kolmickovs, A.; Valdmanis, R.; Vostrikovs, S.; Zake, M.

2018-05-01

Thermo-chemical conversion of microwave activated wheat straw mixtures with wood or peat pellets is studied experimentally with the aim to provide more effective application of wheat straw for heat energy production. Microwave pre-processing of straw pellets is used to provide a partial decomposition of the main constituents of straw and to activate the thermo-chemical conversion of wheat straw mixtures with wood or peat pellets. The experimental study includes complex measurements of the elemental composition of biomass pellets (wheat straw, wood, peat), DTG analysis of their thermal degradation, FTIR analysis of the composition of combustible volatiles entering the combustor, the flame temperature, the heat output of the device and composition of the products by comparing these characteristics for mixtures with unprocessed and mw pre-treated straw pellets. The results of experimental study confirm that mw pre-processing of straw activates the thermal decomposition of mixtures providing enhanced formation of combustible volatiles. This leads to improvement of the combustion conditions in the flame reaction zone, completing thus the combustion of volatiles, increasing the flame temperature, the heat output from the device, the produced heat energy per mass of burned mixture and decreasing at the same time the mass fraction of unburned volatiles in the products.

Traffic sounds and cycling safety : the use of electronic devices by cyclists and the quietness of hybrid and electric cars.

NARCIS (Netherlands)

Stelling-Konczak, A. Hagenzieker, M.P. & Wee, B. van

2015-01-01

The growing popularity of electric devices and the increasing number of hybrid and electric cars have recently raised concerns about the use of auditory signals by vulnerable road users. This paper consolidates current knowledge about the two trends in relation to cycling safety. Both a literature

Tomato second cycle hybrids as a source of genetic variability for fruit quality traits

Directory of Open Access Journals (Sweden)

Pereira da Costa JH

2016-11-01

Full Text Available The objective of this study was to investigate the phenotypic and molecular variability in a F2 generation derived from a SCH (Second Cycle Hybrid in order to detect QTLs for some fruit traits of tomato. Genome coverage at different levels was achieved by three types of molecular markers (polypeptides, sequence-related amplified polymorphism-SRAP and amplified restriction fragment polymorphism - AFLP. Different degrees of polymorphism were detected by SRAP and AFLP at the DNA structure level and also by polypeptides at the DNA expression level. The first two markers, associated with phenotypic variation, detected QTLs involved in important agronomic traits such as fruit shelf life, soluble solids content, pH, and titratable acidity. New gene blocks originated by recombination during the first cycle of crossing were detected. This study confirmed that the observed phenotypic differences represent a new gene rearrangement and that these new gene blocks are responsible for the presence of the genetic variability detected for these traits.

Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure

Science.gov (United States)

Manure storages, and in particular those storing digested manure, are a source of ammonia (NH3) emissions. Permeable manure storage covers can reduce NH3 emissions, however performance can decline as they degrade. Thermochemical conversion of biomass through pyrolysis and steam treatment could incre...

Carbon and energy footprints of electric delivery trucks:a hybrid multi-regional input-output life cycle assessment

OpenAIRE

Zhao, Yang; Onat, Nuri Cihat; Küçükvar, Murat; Tatari, Ömer

2016-01-01

Due to frequent stop-and-go operation and long idling periods when driving in congested urban areas, the electrification of commercial delivery trucks has become an interesting topic nationwide. In this study, environmental impacts of various alternative delivery trucks including battery electric, diesel, diesel-electric hybrid, and compressed natural gas trucks are analyzed. A novel life cycle assessment method, an environmentally-extended multi-region input-output analysis, is utilized to c...

Cascading pressure reactor and method for solar-thermochemical reactions

Science.gov (United States)

Ermanoski, Ivan

2017-11-14

Reactors and methods for solar thermochemical reactions are disclosed. The reactors and methods include a cascade of reduction chambers at successively lower pressures that leads to over an order of magnitude pressure decrease compared to a single-chambered design. The resulting efficiency gains are substantial, and represent an important step toward practical and efficient solar fuel production on a large scale.

Life-Cycle Assessment of a Distributed-Scale Thermochemical Bioenergy Conversion System

Science.gov (United States)

Hongmei Gu; Richard Bergman

2016-01-01

Expanding bioenergy production from woody biomass has the potential to decrease net greenhouse gas (GHG) emissions and improve the energy security of the United States. Science-based and internationally accepted life-cycle assessment (LCA) is an effective tool for policy makers to make scientifically informed decisions on expanding renewable energy production from...

Life-cycle Economic and Environmental Effects of Green, Gray and Hybrid Stormwater Infrastructure

Science.gov (United States)

Stokes-Draut, J. R.; Taptich, M. N.; Horvath, A.

2016-12-01

Cities throughout the U.S. are seeking efficient ways to manage stormwater for many reasons, including flood control, pollution management, water supply augmentation and to prepare for a changing climate. Traditionally, cities have relied primarily on gray infrastructure, namely sewers, storage and treatment facilities. In these systems, urban runoff, its volume increasing as impervious surfaces expand, is channeled to a wastewater plant where it is mixed with raw sewage prior to treatment or it is discharged, generally untreated, to local water bodies. These facilities are inflexible and expensive to build and maintain. Many systems are deteriorating and/or approaching, if not exceeding, their design capacity. Increasingly, more innovative approaches that integrate stormwater management into the natural environment and that make sense at both local and regional scales are sought. Identifying the best stormwater solution will require evaluating the life-cycle economic costs associated with these alternatives, including costs associated with construction, operation, and maintenance including regulatory and permitting costs, financing, as well as other indirect costs (e.g., avoided wastewater processing or system capacity expansion, increased property value) and non-economic co-benefits (i.e, aesthetics, habitat provision). Beyond conventional life-cycle costing, applying life-cycle assessment (LCA) will contribute to more holistic and sustainable decision-making. LCA can be used to quantitatively track energy use, greenhouse gas emissions, and other environmental effects associated with constructing, operating, and maintaining green and gray infrastructure, including supply chain contributions. We will present the current state of knowledge for implementing life-cycle costing and LCA into stormwater management decisions for green, gray and hybrid infrastructure.

On the thermo-chemical origin of the stratified region at the top of the Earth's core

Science.gov (United States)

Nakagawa, Takashi

2018-03-01

I developed a combined model of the thermal and chemical evolution of the Earth's core and investigated its influence on a thermochemically stable region beneath the core-mantle boundary (CMB). The chemical effects of the growing stable region are caused by the equilibrium chemical reaction between silicate and the metallic core. The thermal effects can be characterized by the growth of the sub-isentropic shell, which may have a rapid growth rate compared to that of the chemically stable region. When the present-day CMB heat flow was varied, the origin of the stable region changed from chemical to thermochemical to purely thermal because the rapid growth of the sub-isentropic shell can replace the chemically stable region. Physically reasonable values of the present-day CMB heat flow that can maintain the geodynamo action over 4 billion years should be between 8 and 11 TW. To constrain the thickness of the thermochemically stable region beneath the CMB, the chemical diffusivity is important and should be ∼O(10-8) m2/s to obtain a thickness of the thermochemically stable region beneath the CMB consistent with that inferred from geomagnetic secular variations (140 km). However, the strength of the stable region found in this study is too high to be consistent with the constraint on the stability of the stable region inferred from geomagnetic secular variations.

A Hybrid Algorithm for Solving the Economic Lot and Delivery Scheduling Problem in the Common Cycle Case

DEFF Research Database (Denmark)

Ju, Suquan; Clausen, Jens

2004-01-01

The ELDSP problem is a combined lot sizing and sequencing problem. A supplier produces and delivers components of different component types to a consumer in batches. The task is to determine the cycle time, i.e. that time between deliveries, which minimizes the total cost per time unit. This incl......The ELDSP problem is a combined lot sizing and sequencing problem. A supplier produces and delivers components of different component types to a consumer in batches. The task is to determine the cycle time, i.e. that time between deliveries, which minimizes the total cost per time unit....... This includes the determination of the production sequence of the component types within each cycle. We investigate the computational behavior of two published algorithms, a heuristic and an optimal algorithm. With large number of component types, the optimal algorithm has long running times. We devise a hybrid...

Haemolytic activity of uranium compounds haemolysis by thermochemical derivatives of ammonium uranate

International Nuclear Information System (INIS)

Stuart, W.I.; Tucker, A.D.; Adams, R.B.

1975-01-01

A study has been made of the haemolytic action on human erythrocytes by ammonium uranate (AU) and various thermochemical products of AU. These products were obtained by heating AU in hydrogen at 5 0 C min -1 to various temperatures. Haemolysis has been interpreted in terms of a diffusion model which for each product yields a single parameter Ksub(N), the haemolytic activity factor. The magnitude of Ksub(N) is a convenient measure of the ability of a powder to damage erythrocytes. The haemolytic activity of certain thermochemical derivatives indicates an exceptionally high potential for damage to erythrocytes. Infrared and thermoanalytical measurements have shown that the high activity of these products derives principally from a self-reduction reaction, induced by heating AU to 400-420 0 C in hydrogen. (author)

Development of a Thermo-chemical Non-equilibrium Solver for Hypervelocity Flows

Science.gov (United States)

Balasubramanian, R.; Anandhanarayanan, K.

2015-04-01

In the present study, a three dimensional flowsolver is indigenously developed to numerically simulate hypervelocity thermal and chemical non equilibrium reactive air flow past flight vehicles. The two-temperature, five species, seventeen reactions, thermo-chemical non equilibrium, non-ionizing, air-chemistry model of Park is implemented in a compressible viscous code CERANS and solved in the finite volume framework. The energy relaxation is addressed by a conservation equation for the vibrational energy of the gas mixture resulting in the evaluation of its vibrational temperature. The AUSM-PW+ numerical flux function has been used for modeling the convective fluxes and a central differencing approximation is used for modeling the diffusive fluxes. The flowsolver had been validated for specifically chosen test cases with inherent flow complexities of non-ionizing hypervelocity thermochemical nonequilibrium flows and results obtained are in good agreement with results available in open literature.

Hybrid Life Cycle Assessment of Low, Mid and High-Rise Multi-Family Dwellings

Directory of Open Access Journals (Sweden)

Kimberly Bawden

2015-04-01

Full Text Available We undertake Life Cycle Assessment (LCA of the cumulative energy demand (CED and global warming potential (GWP for a portfolio of 10 multi-family residences in the U.S. We argue that prior LCA studies of buildings use an inconsistent boundary for processes to be included in the supply chain: The operational phase includes all energy use in a building, but supply chains for the production of appliances, equipment and consumables associated with activities done in the building are neglected. We correct this by starting the analysis with an explicit definition of a functional unit, providing climate controlled space, and including processes associated with this functional unit. Using a hybrid LCA approach, the CED for low, mid and high-rise multi-family residences is found to increase from 30, 34, to 39 GJ/m2, respectively. This increase is due to the need for energy-intensive structural materials such as concrete and steel in taller buildings. With our approach, the share of materials and construction of total life cycle energy doubles to 26%, compared with a 13% share that would be obtained with inconsistent system boundaries used in prior studies. We thus argue that explicit definition of functional unit leads to an increase in the contribution of supply chains to building energy life cycles.

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

Energy Technology Data Exchange (ETDEWEB)

Ferrandon, Magali S.; Lewis, Michele A. [Argonne National Laboratory, Chemical Sciences and Engineering Division, 9700 S. Cass Ave., Argonne, IL 60439 (United States); Alvarez, Francisco; Shafirovich, Evgeny [The University of Texas at El Paso, Mechanical Engineering Department, 500 W. University Ave., El Paso, TX 79968 (United States)

2010-03-15

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 <-> 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. (author)

Exploring the Influence of Attitudes to Walking and Cycling on Commute Mode Choice Using a Hybrid Choice Model

Directory of Open Access Journals (Sweden)

Chuan Ding

2017-01-01

Full Text Available Transport-related problems, such as automobile dependence, traffic congestion, and greenhouse emissions, lead to a great burden on the environment. In developing countries like China, in order to improve the air quality, promoting sustainable travel modes to reduce the automobile usage is gradually recognized as an emerging national concern. Though there are many studies related to the physically active modes (e.g., walking and cycling, the research on the influence of attitudes to active modes on travel behavior is limited, especially in China. To fill up this gap, this paper focuses on examining the impact of attitudes to walking and cycling on commute mode choice. Using the survey data collected in China cities, an integrated discrete choice model and the structural equation model are proposed. By applying the hybrid choice model, not only the role of the latent attitude played in travel mode choice, but also the indirect effects of social factors on travel mode choice are obtained. The comparison indicates that the hybrid choice model outperforms the traditional model. This study is expected to provide a better understanding for urban planners on the influential factors of green travel modes.

Hybrid Electric Vehicle Testing | Transportation Research | NREL

Science.gov (United States)

Hybrid Electric Vehicle Evaluations Hybrid Electric Vehicle Evaluations How Hybrid Electric Vehicles Work Hybrid electric vehicles combine a primary power source, an energy storage system, and an is used to propel the vehicle during normal drive cycles. The batteries supply additional power for

Observations of Circumstellar Thermochemical Equilibrium: The Case of Phosphorus

Science.gov (United States)

Milam, Stefanie N.; Charnley, Steven B.

2011-01-01

We will present observations of phosphorus-bearing species in circumstellar envelopes, including carbon- and oxygen-rich shells 1. New models of thermochemical equilibrium chemistry have been developed to interpret, and constrained by these data. These calculations will also be presented and compared to the numerous P-bearing species already observed in evolved stars. Predictions for other viable species will be made for observations with Herschel and ALMA.

Biomass Program 2007 Program Peer Review - Thermochemical Conversion Platform Summary

Energy Technology Data Exchange (ETDEWEB)

none,

2009-10-27

This document discloses the comments provided by a review panel at the U.S. Department of Energy Office of the Biomass Program Peer Review held on November 15-16, 2007 in Baltimore, MD and the Biomass Program Peer Review for the Thermochemical Platform, held on July 9th and 10th in Golden, Colorado.

Hydrogen production from fusion reactors coupled with high temperature electrolysis

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

Balance and saving of GHG emissions in thermochemical biorefineries

International Nuclear Information System (INIS)

Haro, Pedro; Aracil, Cristina; Vidal-Barrero, Fernando; Ollero, Pedro

2015-01-01

Highlights: • A simplified methodology for the balance and saving of GHG emissions is provided. • The GHG balance has a physical meaning and does not depend on the fossil reference. • The GHG saving depends on regulation of energy carriers. • The impact of Bio-CCS incorporation and multiproduction is analyzed. • The co-production of chemicals needs to be included in future regulation. - Abstract: In this study, a simplified methodology for the calculation of the balance of greenhouse gas (GHG) emissions and corresponding saving compared with the fossil reference is presented. The proposed methodology allows the estimation of the anthropogenic GHG emissions of thermochemical biorefineries (net emitted to the atmosphere). In the calculation of the GHG balance, all relevant factors have been identified and analyzed including multiproduction, emissions from biogenic carbon capture and storage (Bio-CCS), co-feeding of fossil fuels (secondary feedstock) and possible carbon storage in biomass-derived products (chemicals). Therefore, it is possible to calculate the balance of GHG emissions of a hypothetical thermochemical biorefinery considering different alternatives of land-use, biomass feedstock, co-feeding of fossil fuels, Bio-CCS incorporation and final use of the products. The comparison of the estimated GHG balance with the corresponding fossil reference for each product is of special relevance in the methodology since it is the parameter used in European regulation for the fulfillment of sustainability criteria in biomass-derived fuels and liquids. The proposed methodology is tested using a previously assessed set of different process concepts of thermochemical biorefineries (techno-economic analysis). The resulting GHG balance and saving are analyzed to identify uncertainties and provide recommendations for future regulation. In all process concepts, the GHG savings are above the minimum requirement of GHG emissions for 2018. In the case of incorporating

A review on the properties of salt hydrates for thermochemical storage

NARCIS (Netherlands)

Trausel, F.; Jong, A.J. de; Cuypers, R.

2014-01-01

Solar energy is capable of supplying enough energy to answer the total demand of energy in dwellings. However, because of the discrepancy between energy supply and energy demand, an efficient way of storing thermal energy is crucial. Thermochemical storage of heat in salt hydrates provides an

Thermochemical nonequilibrium analysis of O2+Ar based on state-resolved kinetics

International Nuclear Information System (INIS)

Kim, Jae Gang; Boyd, Iain D.

2015-01-01

Highlights: • Thermochemical nonequilibrium studies for three lowest lying electronic states of O 2 . • The complete sets of the rovibrational state-to-state transition rates of O 2 +Ar. • Rovibrational relaxations and coupled chemical reactions of O 2 . • Nonequilibrium reaction rates of O 2 derived from the quasi-steady state assumption. - Abstract: The thermochemical nonequilibrium of the three lowest lying electronic states of molecular oxygen, O 2 (X 3 Σ g - ,a 1 Δ g ,b 1 Σ g + ), through interactions with argon is studied in the present work. The multi-body potential energy surfaces of O 2 +Ar are evaluated from the semi-classical RKR potential of O 2 in each electronic state. The rovibrational states and energies of each electronic state are calculated by the quantum mechanical method based on the present inter-nuclear potential of O 2 . Then, the complete sets of the rovibrational state-to-state transition rate coefficients of O 2 +Ar are calculated by the quasi-classical trajectory method including the quasi-bound states. The system of master equations constructed by the present state-to-state transition rate coefficients are solved to analyze the thermochemical nonequilibrium of O 2 +Ar in various heat bath conditions. From these studies, it is concluded that the vibrational relaxation and coupled chemical reactions of each electronic state needs to be treated as a separate nonequilibrium process, and rotational nonequilibrium needs to be considered at translational temperatures above 10,000 K

Zn/V2O5 Aqueous Hybrid-Ion Battery with High Voltage Platform and Long Cycle Life.

Science.gov (United States)

Hu, Ping; Yan, Mengyu; Zhu, Ting; Wang, Xuanpeng; Wei, Xiujuan; Li, Jiantao; Zhou, Liang; Li, Zhaohuai; Chen, Lineng; Mai, Liqiang

2017-12-13

Aqueous zinc-ion batteries attract increasing attention due to their low cost, high safety, and potential application in stationary energy storage. However, the simultaneous realization of high cycling stability and high energy density remains a major challenge. To tackle the above-mentioned challenge, we develop a novel Zn/V 2 O 5 rechargeable aqueous hybrid-ion battery system by using porous V 2 O 5 as the cathode and metallic zinc as the anode. The V 2 O 5 cathode delivers a high discharge capacity of 238 mAh g -1 at 50 mA g -1 . 80% of the initial discharge capacity can be retained after 2000 cycles at a high current density of 2000 mA g -1 . Meanwhile, the application of a "water-in-salt" electrolyte results in the increase of discharge platform from 0.6 to 1.0 V. This work provides an effective strategy to simultaneously enhance the energy density and cycling stability of aqueous zinc ion-based batteries.

Impact of Spanish electricity mix, over the period 2008–2030, on the Life Cycle energy consumption and GHG emissions of Electric, Hybrid Diesel-Electric, Fuel Cell Hybrid and Diesel Bus of the Madrid Transportation System

International Nuclear Information System (INIS)

García Sánchez, Juan Antonio; López Martínez, José María; Lumbreras Martín, Julio; Flores Holgado, María Nuria; Aguilar Morales, Hansel

2013-01-01

Highlights: • We assess the performance of 4 buses that run on different alternative fuel types and technologies. • The buses assessed are Fuel Cell-Hybrid Bus, Hybrid Diesel-Electric Bus, Battery Electric Bus, and a Diesel Bus. • We examine the environmental impact caused by the Life Cycle of each vehicle technology, fossil fuel and energy carrier. • Life Cycle of Battery Electric Bus shows that it has a big potential of improvement in terms of environmental impact. - Abstract: In spite of the advanced research in automotive technology, and the improvement of fuels, the road transport sector continues to be an environmental concern, since the increase in transport demand is offsetting the effects of these technological improvements. Therefore, this poses the following question: what combination of technology and fuel is more efficient in terms of energy consumption and green house gas (GHG) emissions? To fully address this question it is necessary to carry out a Life Cycle Assessment (LCA). This paper presents a global LCA of 4 buses that run on the following fuel types and technologies: (1) Fuel Cell- Hybrid Bus, (2) Hybrid Diesel-Electric Bus (series configuration), (3) Battery Electric Bus and (4) Combustion Ignition Engine Bus. The impact categories assessed are: primary energy consumption, fossil energy and GHG emissions. Among the principal results, we can conclude that the Global LCA of buses (3) and (1) (which are the more sensitive pathways to the electricity mix variation) have for the 2008–2030 period a room for improvement of 25.62% and 28.16% in terms of efficiency of fossil energy consumption and a potential GHG emission reduction of 28.70% and 30.88% respectively

Overview of current biological and thermo-chemical treatment technologies for sustainable sludge management.

Science.gov (United States)

Zhang, Linghong; Xu, Chunbao Charles; Champagne, Pascale; Mabee, Warren

2014-07-01

Sludge is a semi-solid residue produced from wastewater treatment processes. It contains biodegradable and recalcitrant organic compounds, as well as pathogens, heavy metals, and other inorganic constituents. Sludge can also be considered a source of nutrients and energy, which could be recovered using economically viable approaches. In the present paper, several commonly used sludge treatment processes including land application, composting, landfilling, anaerobic digestion, and combustion are reviewed, along with their potentials for energy and product recovery. In addition, some innovative thermo-chemical techniques in pyrolysis, gasification, liquefaction, and wet oxidation are briefly introduced. Finally, a brief summary of selected published works on the life cycle assessment of a variety of sludge treatment and end-use scenarios is presented in order to better understand the overall energy balance and environmental burdens associated with each sludge treatment pathway. In all scenarios investigated, the reuse of bioenergy and by-products has been shown to be of crucial importance in enhancing the overall energy efficiency and reducing the carbon footprint. © The Author(s) 2014.

Explore the performance limit of a solar PV – thermochemical power generation system

International Nuclear Information System (INIS)

Li, Wenjia; Hao, Yong

2017-01-01

Highlights: •Theoretical net solar-to-electric efficiency of 51.5% is attainable. •Design of efficient PVT systems is governed by at least 5 key considerations. •Concentration ratio has the most pronounced influence on PVT system efficiency. •Efficient PV, low emissivity and high concentration deliver the best performance. -- Abstract: Performance limit of a solar hybrid power generation system integrating efficient photovoltaic (PV) cells and methanol thermal (T) decomposition is explored from a thermodynamic perspective within the capability of state-of-the-art technologies. This type of PVT system features potentially high “net solar-to-electric efficiency” in general, primarily resulting from a key difference in the design of the thermal part compared with conventional PVT systems, i.e. replacing heat engines by a thermochemical power generation module for thermal energy utilization. Key design parameters of the system, including PV cell type, emissivity, solar concentration ratio and solar concentrator type, are individually studied. A system combining all such optimized aspects is projected to achieve net solar-to-electric efficiencies up to 51.5%, after taking all major (e.g. optical, radiative) losses into consideration. This study reveals important insights and enriches understanding on design principles of efficient PVT systems aimed at comprehensive and effective utilization of solar energy.

Multi effect desalination and adsorption desalination (MEDAD): A hybrid desalination method

KAUST Repository

Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw; Saha, Bidyut Baran; Chun, Wongee

2014-01-01

This paper presents an advanced desalination cycle that hybridizes a conventional multi-effect distillation (MED) and an emerging yet low-energy adsorption cycle (AD). The hybridization of these cycles, known as MED + AD or MEDAD in short, extends

Revisiting dibenzothiophene thermochemical data: Experimental and computational studies

International Nuclear Information System (INIS)

Freitas, Vera L.S.; Gomes, Jose R.B.; Ribeiro da Silva, Maria D.M.C.

2009-01-01

Thermochemical data of dibenzothiophene were studied in the present work by experimental techniques and computational calculations. The standard (p 0 =0.1MPa) molar enthalpy of formation, at T = 298.15 K, in the gaseous phase, was determined from the enthalpy of combustion and sublimation, obtained by rotating bomb calorimetry in oxygen, and by Calvet microcalorimetry, respectively. This value was compared with estimated data from G3(MP2)//B3LYP computations and also with the other results available in the literature.

Effects of Hybrid Cycle and Handcycle Exercise on Cardiovascular Disease Risk Factors in People with Spinal Cord Injury : A Randomized Controlled Trial

NARCIS (Netherlands)

Bakkum, Arjan J. T.; Paulson, Thomas A. W.; Bishop, Nicolette C.; Goosey-Tolfrey, Victoria L.; Stolwijk-Swuste, Janneke M.; van Kuppevelt, Dirk J.; de Groot, Sonja; Janssen, Thomas W. J.

Objective: To examine the effects of a 16-week exercise programme, using either a hybrid cycle or a handcycle, on cardiovascular disease risk factors in people with spinal cord injury. Participants: Nineteen individuals with spinal cord injury >= 8 years. Design: Multicentre randomized controlled

Exergy analysis of thermochemical ethanol production via biomass gasification and catalytic synthesis

NARCIS (Netherlands)

van der Heijden, H.H.J.L.; Ptasinski, K.J.

2012-01-01

In this paper an exergy analysis of thermochemical ethanol production from biomass is presented. This process combines a steam-blown indirect biomass gasification of woody feedstock, with a subsequent conversion of produced syngas into ethanol. The production process involves several process

Thermochemical Erosion Modeling of the 25-MM M242/M791 Gun System

National Research Council Canada - National Science Library

Sopok, Samuel

1997-01-01

The MACE gun barrel thermochemical erosion modeling code addresses wall degradations due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 25-mm M242/M791 gun system...

An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul; Ganjehkaviri, A.

2015-01-01

Highlights: • 40% of energy demand of Malaysia could be supplied by thermochemical process of PSR. • SCWG of PSR is preferable thermochemical process due to char and tar elimination. • Potential of H 2 production from SCWG of PSR is 1.05 × 10 10 kgH 2 per year in Malaysia. • Highly moisturized PSR could be used in hydrogen production by SCWG process. - Abstract: Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO 2 ) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 10 10 kgH 2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from

1D Ni-Co oxide and sulfide nanoarray/carbon aerogel hybrid nanostructures for asymmetric supercapacitors with high energy density and excellent cycling stability.

Science.gov (United States)

Hao, Pin; Tian, Jian; Sang, Yuanhua; Tuan, Chia-Chi; Cui, Guanwei; Shi, Xifeng; Wong, C P; Tang, Bo; Liu, Hong

2016-09-15

The fabrication of supercapacitor electrodes with high energy density and excellent cycling stability is still a great challenge. A carbon aerogel, possessing a hierarchical porous structure, high specific surface area and electrical conductivity, is an ideal backbone to support transition metal oxides and bring hope to prepare electrodes with high energy density and excellent cycling stability. Therefore, NiCo 2 S 4 nanotube array/carbon aerogel and NiCo 2 O 4 nanoneedle array/carbon aerogel hybrid supercapacitor electrode materials were synthesized by assembling Ni-Co precursor needle arrays on the surface of the channel walls of hierarchical porous carbon aerogels derived from chitosan in this study. The 1D nanostructures grow on the channel surface of the carbon aerogel vertically and tightly, contributing to the enhanced electrochemical performance with ultrahigh energy density. The energy density of NiCo 2 S 4 nanotube array/carbon aerogel and NiCo 2 O 4 nanoneedle array/carbon aerogel hybrid asymmetric supercapacitors can reach up to 55.3 Wh kg -1 and 47.5 Wh kg -1 at a power density of 400 W kg -1 , respectively. These asymmetric devices also displayed excellent cycling stability with a capacitance retention of about 96.6% and 92% over 5000 cycles.

Electric/Hybrid Vehicle Simulation

Science.gov (United States)

Slusser, R. A.; Chapman, C. P.; Brennand, J. P.

1985-01-01

ELVEC computer program provides vehicle designer with simulation tool for detailed studies of electric and hybrid vehicle performance and cost. ELVEC simulates performance of user-specified electric or hybrid vehicle under user specified driving schedule profile or operating schedule. ELVEC performs vehicle design and life cycle cost analysis.

Third millenium ideal gas and condensed phase thermochemical database for combustion (with update from active thermochemical tables).

Energy Technology Data Exchange (ETDEWEB)

Burcat, A.; Ruscic, B.; Chemistry; Technion - Israel Inst. of Tech.

2005-07-29

The thermochemical database of species involved in combustion processes is and has been available for free use for over 25 years. It was first published in print in 1984, approximately 8 years after it was first assembled, and contained 215 species at the time. This is the 7th printed edition and most likely will be the last one in print in the present format, which involves substantial manual labor. The database currently contains more than 1300 species, specifically organic molecules and radicals, but also inorganic species connected to combustion and air pollution. Since 1991 this database is freely available on the internet, at the Technion-IIT ftp server, and it is continuously expanded and corrected. The database is mirrored daily at an official mirror site, and at random at about a dozen unofficial mirror and 'finger' sites. The present edition contains numerous corrections and many recalculations of data of provisory type by the G3//B3LYP method, a high-accuracy composite ab initio calculation. About 300 species are newly calculated and are not yet published elsewhere. In anticipation of the full coupling, which is under development, the database started incorporating the available (as yet unpublished) values from Active Thermochemical Tables. The electronic version now also contains an XML file of the main database to allow transfer to other formats and ease finding specific information of interest. The database is used by scientists, educators, engineers and students at all levels, dealing primarily with combustion and air pollution, jet engines, rocket propulsion, fireworks, but also by researchers involved in upper atmosphere kinetics, astrophysics, abrasion metallurgy, etc. This introductory article contains explanations of the database and the means to use it, its sources, ways of calculation, and assessments of the accuracy of data.

COMPARISON OF PARALLEL AND SERIES HYBRID POWERTRAINS FOR TRANSIT BUS APPLICATION

Energy Technology Data Exchange (ETDEWEB)

Gao, Zhiming [ORNL; Daw, C Stuart [ORNL; Smith, David E [ORNL; Jones, Perry T [ORNL; LaClair, Tim J [ORNL; Parks, II, James E [ORNL

2016-01-01

The fuel economy and emissions of both conventional and hybrid buses equipped with emissions aftertreatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicate that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar CO and HC tailpipe emissions but were also predicted to have reduced NOx tailpipe emissions compared to the conventional bus in higher speed cycles. For the New York bus cycle (NYBC), which has the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus, while the parallel hybrid bus had significantly lower tailpipe emissions. All three bus powertrains were found to require periodic active DPF regeneration to maintain PM control. Plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed due to the relatively large battery capacity that is typical of the series hybrid configuration.

Effects of Hybrid Cycle and Handcycle Exercise on Cardiovascular Disease Risk Factors in People with Spinal Cord Injury: a Randomized Controlled Trial

NARCIS (Netherlands)

Bakkum, A.J.T.; Paulson, T.A.W.; Bishop, N.C.; Goosey-Tolfrey, V.L.; Stolwijk-Swuste, J.M.; van Kuppevelt, D.J.; de Groot, S.; Janssen, T.W.J.

2015-01-01

Objective: To examine the effects of a 16-week exercise programme, using either a hybrid cycle or a handcycle, on cardiovascular disease risk factors in people with spinal cord injury. Participants: Nineteen individuals with spinal cord injury ≥ 8 years. Design: Multicentre randomized controlled

Cyclic thermochemical process for producing hydrogen using cerium-titanium compounds

Science.gov (United States)

Bamberger, C.E.

A thermochemical cyclic process for producing hydrogen employs the reaction between ceric oxide and titanium dioxide to form cerium titanate and oxygen. The titanate is treated with an alkali metal hydroxide to give hydrogen, ceric oxide, an alkali metal titanate and water. Alkali metal titanate and water are boiled to give titanium dioxide which, along with ceric oxide, is recycled.

Materials-Related Aspects of Thermochemical Water and Carbon Dioxide Splitting: A Review

Directory of Open Access Journals (Sweden)

Robert Pitz-Paal

2012-10-01

Full Text Available Thermochemical multistep water- and CO2-splitting processes are promising options to face future energy problems. Particularly, the possible incorporation of solar power makes these processes sustainable and environmentally attractive since only water, CO2 and solar power are used; the concentrated solar energy is converted into storable and transportable fuels. One of the major barriers to technological success is the identification of suitable active materials like catalysts and redox materials exhibiting satisfactory durability, reactivity and efficiencies. Moreover, materials play an important role in the construction of key components and for the implementation in commercial solar plants. The most promising thermochemical water- and CO2-splitting processes are being described and discussed with respect to further development and future potential. The main materials-related challenges of those processes are being analyzed. Technical approaches and development progress in terms of solving them are addressed and assessed in this review.

Applicability test of glass lining material for high-temperature acidic solutions of sulfuric acid in thermochemical water-splitting IS process

International Nuclear Information System (INIS)

Iwatsuki, Jin; Tanaka, Nobuyuki; Terada, Atsuhiko; Onuki, Kaoru; Watanabe, Yutaka

2010-01-01

A key issue for realizing the thermochemical IS process for hydrogen production is the selection of materials for working with high-temperature acidic solutions of sulfuric acid and hydriodic acid. Glass lining material is a promising candidate, which is composed of steel having good strength and glass having good corrosion resistance. Since the applicability of glass lining material depends strongly on the service condition, corrosion tests using glass used in glass lining material and heat cycle tests using glass lining piping were carried out to examine the possibility of using the glass lining material with high-temperature acidic solutions of sulfuric acid. It was confirmed that the glass lining materials exhibited sufficient corrosion resistance and heat resistance in high-temperature sulfuric acid of the IS process. (author)

Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies

Energy Technology Data Exchange (ETDEWEB)

Gallagher, Patricia M., E-mail: pmg24@drexel.edu [Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19038 (United States); Spatari, Sabrina; Cucura, Jeffrey [Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19038 (United States)

2013-04-15

Highlights: ► We use LCA to study environmental impacts of grouting techniques for site remediation. ► We consider colloidal silica permeation grouting and cement jet grouting. ► Manufacturing and transportation contribute significantly in all impact categories. ► Activity outside of direct site activity is important in assessing impacts. ► LCA can be used to consider sustainability criteria for remediation decisions. -- Abstract: Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental “systems-level” decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required

Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies

International Nuclear Information System (INIS)

Gallagher, Patricia M.; Spatari, Sabrina; Cucura, Jeffrey

2013-01-01

Highlights: ► We use LCA to study environmental impacts of grouting techniques for site remediation. ► We consider colloidal silica permeation grouting and cement jet grouting. ► Manufacturing and transportation contribute significantly in all impact categories. ► Activity outside of direct site activity is important in assessing impacts. ► LCA can be used to consider sustainability criteria for remediation decisions. -- Abstract: Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental “systems-level” decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required

Solar fuel processing efficiency for ceria redox cycling using alternative oxygen partial pressure reduction methods

International Nuclear Information System (INIS)

Lin, Meng; Haussener, Sophia

2015-01-01

Solar-driven non-stoichiometric thermochemical redox cycling of ceria for the conversion of solar energy into fuels shows promise in achieving high solar-to-fuel efficiency. This efficiency is significantly affected by the operating conditions, e.g. redox temperatures, reduction and oxidation pressures, solar irradiation concentration, or heat recovery effectiveness. We present a thermodynamic analysis of five redox cycle designs to investigate the effects of working conditions on the fuel production. We focused on the influence of approaches to reduce the partial pressure of oxygen in the reduction step, namely by mechanical approaches (sweep gassing or vacuum pumping), chemical approaches (chemical scavenger), and combinations thereof. The results indicated that the sweep gas schemes work more efficient at non-isothermal than isothermal conditions, and efficient gas phase heat recovery and sweep gas recycling was important to ensure efficient fuel processing. The vacuum pump scheme achieved best efficiencies at isothermal conditions, and at non-isothermal conditions heat recovery was less essential. The use of oxygen scavengers combined with sweep gas and vacuum pump schemes further increased the system efficiency. The present work can be used to predict the performance of solar-driven non-stoichiometric redox cycles and further offers quantifiable guidelines for system design and operation. - Highlights: • A thermodynamic analysis was conducted for ceria-based thermochemical cycles. • Five novel cycle designs and various operating conditions were proposed and investigated. • Pressure reduction method affects optimal operating conditions for maximized efficiency. • Chemical oxygen scavenger proves to be promising in further increasing efficiency. • Formulation of quantifiable design guidelines for economical competitive solar fuel processing

JAEA’s R&D on the Thermochemical Hydrogen Production IS Process

International Nuclear Information System (INIS)

Kasahara, Seiji; Tanaka, Nobuyuki; Noguchi, Hiroki; Iwatsuki, Jin; Takegami, Hiroaki; Yan, Xing L.; Kubo, Shinji

2014-01-01

Japan Atomic Energy Agency (JAEA) has studied iodine-sulfur (IS) process, a thermochemical cycle to produce hydrogen by water splitting. This process is a candidate application of high temperature heat from high temperature gas-cooled reactors. This paper outlines the IS process study in JAEA, in particular recent situation of the R&D. Reactor components and a total process facility are tested to evaluate their integrity. A Bunsen reactor, a H_2SO_4 decomposer and a HI decomposer made of industrial materials such as SiC ceramic, fluoroplastic and lining materials have been examined separately as reactor components. A semibatch test and a thermal cycle test were operated in the Bunsen reactor. H_2SO_4 decomposition test is in a bayonet type reactor and HI decomposition test in an adiabatic radial flow type reactor are now under way. On the basis of a demonstration of continuous hydrogen production of 31 NL/h by a glass apparatus, an experimental apparatus of the total IS process has just been constructed to verify integrity of process components of industrial materials, H_2 production scale of which is 200 NL/h. Electro-electrodialysis (EED) cells to concentrate HI before distillation and a SiC-made bayonet type H_2SO_4 decomposer are applied in the facility. Process data of EED cells has been collected aiming to improve H_2 production thermal efficiency. Influence of temperature, composition in solution and existence of impurities on the cell properties has been investigated. Reduction of heat input to a HI separation step by applying the results of the study was shown. (author)

Thermochemical aspects of fuel-cladding and fuel-coolant interactions in LMFBR oxide fuel pins

International Nuclear Information System (INIS)

Adamson, M.G.; Aitken, E.A.; Caputi, R.W.; Potter, P.E.; Mignanelli, M.A.

1979-01-01

This paper examines several thermochemical aspects of the fuel-cladding, fuel-coolant and fuel-fission product interactions that occur in LMFBR austenitic stainless steel-clad mixed (U,Pu)-oxide fuel pins during irradiation under normal operating conditions. Results are reported from a variety of high temperature EMF cell experiments in which continuous oxygen activity measurements on reacting and equilibrium mixtures of metal oxides and (excess) liquid alkali metal (Na, K, Cs) were performed. Oxygen potential and 0:M thresholds for Na-fuel reactions are re-evaluated in the light of new measurements and newly-assessed thermochemical data, and the influence on oxygen potential of possible U-Pu segregation between oxide and urano-plutonate (equilibrium) phases has been analyzed. (orig./RW) [de

Fuel cell hybrid taxi life cycle analysis

Energy Technology Data Exchange (ETDEWEB)

Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

2011-09-15

A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

Fuel cell hybrid taxi life cycle analysis

International Nuclear Information System (INIS)

Baptista, Patricia; Ribau, Joao; Bravo, Joao; Silva, Carla; Adcock, Paul; Kells, Ashley

2011-01-01

A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO 2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO 2 emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: → A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. → The hydrogen powered vehicles have the lowest energy consumption and CO 2 emissions results. → A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

Neutralization and Acid Dissociation of Hydrogen Carbonate Ion: A Thermochemical Approach

Science.gov (United States)

Koga, Nobuyoshi; Shigedomi, Kana; Kimura, Tomoyasu; Tatsuoka, Tomoyuki; Mishima, Saki

2013-01-01

A laboratory inquiry into the thermochemical relationships in the reaction between aqueous solutions of NaHCO[subscript 3] and NaOH is described. The enthalpy change for this reaction, delta[subscript r]H, and that for neutralization of strong acid and NaOH(aq), delta[subscript n]H, are determined calorimetrically; the explanation for the…

Thermo-chemical simulation of a composite offshore vertical axis wind turbine blade

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study three dimensional steady state thermo-chemical simulation of a pultrusion process is investigated by using the finite element/nodal control volume (FE/NCV) technique. Pultrusion simulation of a composite having a C-shaped cross section is performed as a validation case. The o...

Thermo-chemical simultion of a composite offshore vertical axis wind turbine blade

NARCIS (Netherlands)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study three dimensional steady state thermo-chemical simulation of a pultrusion process is investigated by using the finite element/nodal control volume (FE/NCV) technique. Pultrusion simulation of a composite having a C-shaped cross section is performed as a validation case. The

Analysis of a diesel-electric hybrid urban bus system

Science.gov (United States)

Marr, W. W.; Sekar, R. R.; Ahlheim, M. C.

A hybrid bus powered by a diesel engine and a battery pack was analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, were evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

The hybrid electric vehicle revolution, off road

Energy Technology Data Exchange (ETDEWEB)

Wood, B.E. [ePower Technologies (United States)

2004-07-01

In this presentation the author presents concepts and details of hybrid vehicles in general, including their benefits, then describes off-road hybrid vehicles. Hybrid vehicles have been experimented with for over a century. Demonstrator vehicles include a diesel-electric tractor, an electric lawn tractor, a hybrid snow thrower, and a hybrid wheel loader. A duty cycle for the loader is shown with battery-assisted acceleration, and regenerative braking. Both of these keep the size of the engine small, the loads on it less variable, thus improving fuel economy. A hybrid excavator and its duty cycle is shown. A fuel cell lift truck that is currently in design is illustrated. The author then describes the possibilities of the hydrogen economy where sourcing and infrastructure are yet to be demonstrated on a commercial scale. The author predicts that off-road hydrogen fuel cell vehicles will be commercially viable five years before on-road applications. The author predicts hydrogen sourced from biogas, photovoltaics, and wind power. tabs, figs.

Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird.

Science.gov (United States)

Duckworth, Renée A; Semenov, Georgy A

2017-10-01

Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and, if so, has long-lasting consequences. Here, we summarize 30 years of survey data across 10 populations to show that in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover. Despite mixed pairing occurring only during early succession, genetic data showed presence of hybrids at both early and late successional stages. Moreover, hybrids showed novel patterns of variation in morphology and behavior, emphasizing that even ephemeral contexts for hybridization can have important evolutionary consequences. Our results suggest that because ecological succession often brings together closely related competitors in disparate numbers but lasts for only a brief period of time, it may be a widespread but underappreciated context for hybridization.

Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury: a 16-week randomized controlled trial.

Science.gov (United States)

Bakkum, A J T; de Groot, S; Stolwijk-Swüste, J M; van Kuppevelt, D J; van der Woude, L H V; Janssen, T W J

2015-05-01

This is an open randomized controlled trial. The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI). The study was conducted in two rehabilitation centers with a specialized SCI unit. Twenty individuals (SCI⩾8 years) were randomly assigned to a hybrid cycle (voluntary arm exercise combined with functional electrical stimulation (FES)-induced leg exercise) or a handcycle group. During 16 weeks, both groups trained twice a week for 30 min at 65-75% heart rate reserve. Outcome measures obtained before, during and after the program were fitness (peak power output, peak oxygen consumption), submaximal VO2 and heart rate (HR), resting HR, wheelchair skill performance time score) and physical activity (distance travelled in wheelchair and Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) score). Changes were examined using a two-factor mixed-measures analysis of variance. For all fitness parameters, except for submaximal VO2, no interaction effects were found. The hybrid cycle group showed a decrease in VO2 over time in contrast to the handcycle group (P=0.045). An overall reduction in HRrest (5±2 b.p.m.; P=0.03) and overall increase in PASIPD score (6.5±2.1; P=0.002) were found after 16 weeks of training. No overall training effects were found for the other fitness and activity outcome measures. In the current study, hybrid cycling and handcycling showed similar effects on fitness and physical activity, indicating that there seem to be no additional benefits of the FES-induced leg exercise over handcycle training alone.

A hybrid life cycle assessment of the vehicle-to-grid application in light duty commercial fleet

International Nuclear Information System (INIS)

Zhao, Yang; Tatari, Omer

2015-01-01

The vehicle-to-grid system is an approach utilizing the idle battery capacity of electric vehicles while they are parked to provide supplementary energy to the power grid. As electrification continues in light duty vehicle fleets, the application of vehicle-to-grid systems for commercial delivery truck fleets can provide extra revenue for fleet owners, and also has significant potential for reducing greenhouse gas emissions from the electricity generation sector. In this study, an economic input–output based hybrid life cycle assessment is conducted to analyze the potential greenhouse gas emissions emission savings from the use of the vehicle-to-grid system, as well as the possible emission impacts caused by battery degradation. A Monte Carlo simulation was performed to address the uncertainties that lie in the electricity exchange amount of the vehicle-to-grid service as well as the battery life of the electric vehicles. The results of this study showed that extended range electric vehicles and battery electric vehicles are both viable regulation service providers for saving greenhouse gas emissions from electricity generation if the battery wear-out from regulation services is assumed to be minimal, but the vehicle-to-grid system becomes less attractive at higher battery degradation levels. - Highlights: • The commercial delivery trucks are studied as vehicle-to-grid service providers. • Hybrid life cycle assessment is conducted to evaluate emission mitigation. • Battery degradation level and corresponding emissions and cost are evaluated. • Vehicle-to-grid service is shown to have significant emission saving effect.

Effect of multiple-feedstock strategy on the economic and environmental performance of thermochemical ethanol production under extreme weather conditions

International Nuclear Information System (INIS)

Kou, Nannan; Zhao, Fu

2011-01-01

Current US transportation sector mainly relies on liquid hydrocarbons derived from petroleum and about 60% of the petroleum consumed is from areas where supply may be disturbed by regional instability. This has led to serious concerns on energy security and global warming. To address these issues, numerous alternative energy carriers have been proposed. Among them, second generation biofuel is one of the most promising technologies. Gasification-based thermochemical conversion will bring flexibility to both feedstock and production sides of a plant, thus presents an attractive technical route to address both the energy security and global warming concerns. In this paper, thermochemical ethanol production using multiple-feedstock (corn stover, municipal solid waste, and wood chips) is simulated using Aspen Plus and compared with the single-feedstock scenario, in terms of economic performances, life cycle greenhouse gas (GHG) emissions and survivability under extreme weather conditions. For a hypothetical facility in southwest Indiana it is found that multiple-feedstock strategy improves the net present value by 18% compared to single-feedstock strategy. This margin is increased to 57% when effects of extreme weather conditions on feedstock supply are considered. Moreover, multiple-feedstock fuel plant has no potential risk of bankruptcy during the payback period, while single-feedstock fuel plant has a 75% chance of bankruptcy. Although the multiple-feedstock strategy has 26% more GHG emission per liter of ethanol produced than the single-feedstock strategy, the trend is reversed if feedstock supply disruption is taken into account. Thus the idea of multiple-feedstock strategy is proposed to the future thermo chemical biofuel plants.

Recommended Ideal-Gas Thermochemical Functions for Heavy Water and its Substituent Isotopologues

Czech Academy of Sciences Publication Activity Database

Simkó, I.; Furtenbacher, T.; Hrubý, Jan; Zobov, N. F.; Polyansky, O. L.; Tennyson, J.; Gamache, R. R.; Szidarovszky, T.; Dénes, N.; Császár, A. G.

2017-01-01

Roč. 46, č. 2 (2017), č. článku 023104. ISSN 0047-2689 R&D Projects: GA ČR GA16-02647S Institutional support: RVO:61388998 Keywords : heavy water * ideal-gas thermochemical functions * partition function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 4.204, year: 2016

An overview of R and D activities for the Cu-Cl, cycle with emphasis on the hydrolysis reaction

International Nuclear Information System (INIS)

Lewis, M.A.; Ferrandon, M.S.; Tatterson, D.F.

2010-01-01

This paper describes the status of the development effort for the Cu-Cl thermochemical cycle. Most of the recent work has been focused on the hydrolysis reaction, which is challenging because of the need for excess steam to achieve high yields. Two types of spray reactors were tested and the ultrasonic nozzle gave excellent results. The conceptual process design for the overall process now includes a spray reactor. Engineering methods to increase efficiency are proposed. Preliminary values for the efficiency and capital costs for producing hydrogen using the Cu-Cl cycle have been calculated. (authors)

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

2015-01-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

Numerical and experimental analyses of different magnetic thermodynamic cycles with an active magnetic regenerator

International Nuclear Information System (INIS)

Plaznik, Uroš; Tušek, Jaka; Kitanovski, Andrej; Poredoš, Alojz

2013-01-01

We have analyzed the influence of different magnetic thermodynamic cycles on the performance of a magnetic cooling device with an active magnetic regenerator (AMR) based on the Brayton, Ericsson and Hybrid Brayton–Ericsson cycles. Initially, a numerical simulation was performed using a 1D, time-dependent, numerical model. Then a comparison was made with respect to the cooling power and the COP for different temperature spans. We showed that applying the Ericsson or the Hybrid Brayton–Ericsson cycle with an AMR, instead of the standard Brayton cycle, can increase the efficiency of the selected cooling device. Yet, in the case of the Ericsson cycle, the cooling power was decreased compared to the Hybrid and especially compared to the Brayton cycle. Next, an experimental analysis was carried out using a linear-type magnetic cooling device. Again, the Brayton, Ericsson and Hybrid Brayton–Ericsson cycles with an AMR were compared with respect to the cooling power and the COP for different temperature spans. The results of the numerical simulation were confirmed. The Hybrid Brayton–Ericsson cycle with an AMR showed the best performance if a no-load temperature span was considered as a criterion. -- Highlights: • New thermodynamic cycles with an active magnetic regenerator (AMR) are presented. • Three different thermodynamic cycles with an AMR were analyzed. • Numerical and experimental analyses were carried out. • The best overall performance was achieved with the Hybrid Brayton–Ericsson cycle. • With this cycle the temperature span of test device was increased by almost 10%

IS process for thermochemical hydrogen production

International Nuclear Information System (INIS)

Onuki, Kaoru; Nakajima, Hayato; Ioka, Ikuo; Futakawa, Masatoshi; Shimizu, Saburo

1994-11-01

The state-of-the-art of thermochemical hydrogen production by IS process is reviewed including experimental data obtained at JAERI on the chemistry of the Bunsen reaction step and on the corrosion resistance of the structural materials. The present status of laboratory scale demonstration at JAERI is also included. The study on the chemistry of the chemical reactions and the products separations has identified feasible methods to function the process. The flowsheeting studies revealed a process thermal efficiency higher than 40% is achievable under efficient process conditions. The corrosion resistance of commercially available structural materials have been clarified under various process conditions. The basic scheme of the process has been realized in a laboratory scale apparatus. R and D requirements to proceed to the engineering demonstration coupled with HTTR are briefly discussed. (author)

Method for thermochemical decomposition of water

Science.gov (United States)

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.

Non-equilibrium thermochemical heat storage in porous media: Part 1 – Conceptual model

International Nuclear Information System (INIS)

Nagel, T.; Shao, H.; Singh, A.K.; Watanabe, N.; Roßkopf, C.; Linder, M.; Wörner, A.; Kolditz, O.

2013-01-01

Thermochemical energy storage can play an important role in the establishment of a reliable renewable energy supply and can increase the efficiency of industrial processes. The application of directly permeated reactive beds leads to strongly coupled mass and heat transport processes that also determine reaction kinetics. To advance this technology beyond the laboratory stage requires a thorough theoretical understanding of the multiphysics phenomena and their quantification on a scale relevant to engineering analyses. Here, the theoretical derivation of a macroscopic model for multicomponent compressible gas flow through a porous solid is presented along with its finite element implementation where solid–gas reactions occur and both phases have individual temperature fields. The model is embedded in the Theory of Porous Media and the derivation is based on the evaluation of the Clausius–Duhem inequality. Special emphasis is placed on the interphase coupling via mass, momentum and energy interaction terms and their effects are partially illustrated using numerical examples. Novel features of the implementation of the described model are verified via comparisons to analytical solutions. The specification, validation and application of the full model to a calcium hydroxide/calcium oxide based thermochemical storage system are the subject of part 2 of this study. - Highlights: • Rigorous application of the Theory of Porous Media and the 2nd law of thermodynamics. • Thermodynamically consistent model for thermochemical heat storage systems. • Multicomponent gas; modified Fick's and Darcy's law; thermal non-equilibrium; solid–gas reactions. • Clear distinction between source and production terms. • Open source finite element implementation and benchmarks

Burn cycle requirements comparison of pulsed and steady-state tokamak reactors

International Nuclear Information System (INIS)

Brooks, J.N.; Ehst, D.A.

1983-12-01

Burn cycle parameters and energy transfer system requirements were analyzed for an 8-m commercial tokamak reactor using four types of cycles: conventional, hybrid, internal transformer, and steady state. Not surprisingly, steady state is the best burn mode if it can be achieved. The hybrid cycle is a promising alternative to the conventional. In contrast, the internal transformer cycle does not appear attractive for the size tokamak in question

To Error Problem Concerning Measuring Concentration of Carbon Oxide by Thermo-Chemical Sen

Directory of Open Access Journals (Sweden)

V. I. Nazarov

2007-01-01

Full Text Available The paper gives additional errors in respect of measuring concentration of carbon oxide by thermo-chemical sensors. A number of analytical expressions for calculation of error data and corrections for environmental factor deviations from admissible ones have been obtained in the paper

Thermochemical and thermophysical properties of alkaline-earth perovskites

International Nuclear Information System (INIS)

Yamanaka, Shinsuke; Kurosaki, Ken; Maekawa, Takuji; Matsuda, Tetsushi; Kobayashi, Shin-ichi; Uno, Masayoshi

2005-01-01

In order to contribute to safety evaluation of high burnup oxide fuels, we studied the thermochemical and thermophysical properties of alkaline-earth perovskites known as oxide inclusions. Polycrystalline samples of alkaline-earth perovskites, BaUO 3 , BaZrO 3 , BaCeO 3 , BaMoO 3 , SrTiO 3 , SrZrO 3 , SrCeO 3 , SrMoO 3 , SrHfO 3 and SrRuO 3 , were prepared and the thermal expansion coefficient, melting temperature, elastic moduli, Debye temperature, microhardness, heat capacity, and thermal conductivity were measured. The relationship between some physical properties was studied

Importance of the correlation contribution for local hybrid functionals: range separation and self-interaction corrections.

Science.gov (United States)

Arbuznikov, Alexei V; Kaupp, Martin

2012-01-07

Local hybrid functionals with their position-dependent exact-exchange admixture are a conceptually simple and promising extension of the concept of a hybrid functional. Local hybrids based on a simple mixing of the local spin density approximation (LSDA) with exact exchange have been shown to be successful for thermochemistry, reaction barriers, and a range of other properties. So far, the combination of this generation of local hybrids with an LSDA correlation functional has been found to give the most favorable results for atomization energies, for a range of local mixing functions (LMFs) governing the exact-exchange admixture. Here, we show that the choice of correlation functional to be used with local hybrid exchange crucially influences the parameterization also of the exchange part as well as the overall performance. A novel ansatz for the correlation part of local hybrids is suggested based on (i) range-separation of LSDA correlation into short-range (SR) and long-range (LR) parts, and (ii) partial or full elimination of the one-electron self-correlation from the SR part. It is shown that such modified correlation functionals allow overall larger exact exchange admixture in thermochemically competitive local hybrids than before. This results in improvements for reaction barriers and for other properties crucially influenced by self-interaction errors, as demonstrated by a number of examples. Based on the range-separation approach, a fresh view on the breakdown of the correlation energy into dynamical and non-dynamical parts is suggested.

Laser thermal effect on silicon nitride ceramic based on thermo-chemical reaction with temperature-dependent thermo-physical parameters

International Nuclear Information System (INIS)

Pan, A.F.; Wang, W.J.; Mei, X.S.; Wang, K.D.; Zhao, W.Q.; Li, T.Q.

2016-01-01

Highlights: • A two-dimensional thermo-chemical reaction model is creatively built. • Thermal conductivity and heat capacity of β-Si_3N_4 are computed accurately. • The appropriate thermo-chemical reaction rate is fitted and reaction element length is set to assure the constringency. • The deepest ablated position was not the center of the ablated area due to plasma absorption. • The simulation results demonstrate the thermo-chemical process cant be simplified to be physical phase transition. - Abstract: In this study, a two-dimensional thermo-chemical reaction model with temperature-dependent thermo-physical parameters on Si_3N_4 with 10 ns laser was developed to investigate the ablated size, volume and surface morphology after single pulse. For model parameters, thermal conductivity and heat capacity of β-Si_3N_4 were obtained from first-principles calculations. Thermal-chemical reaction rate was fitted by collision theory, and then, reaction element length was deduced using the relationship between reaction rate and temperature distribution. Furthermore, plasma absorption related to energy loss was approximated as a function of electron concentration in Si_3N_4. It turned out that theoretical ablated volume and radius increased and then remained constant with increasing laser energy, and the maximum ablated depth was not in the center of the ablated zone. Moreover, the surface maximum temperature of Si_3N_4 was verified to be above 3000 K within pulse duration, and it was much higher than its thermal decomposition temperature of 1800 K, which indicated that Si_3N_4 was not ablated directly above the thermal decomposition temperature. Meanwhile, the single pulse ablation of Si_3N_4 was performed at different powers using a TEM_0_0 10 ns pulse Nd:YAG laser to validate the model. The model showed a satisfactory consistence between the experimental data and numerical predictions, presenting a new modeling technology that may significantly increase the

Benchmarking the DFT+U method for thermochemical calculations of uranium molecular compounds and solids.

Science.gov (United States)

Beridze, George; Kowalski, Piotr M

2014-12-18

Ability to perform a feasible and reliable computation of thermochemical properties of chemically complex actinide-bearing materials would be of great importance for nuclear engineering. Unfortunately, density functional theory (DFT), which on many instances is the only affordable ab initio method, often fails for actinides. Among various shortcomings, it leads to the wrong estimate of enthalpies of reactions between actinide-bearing compounds, putting the applicability of the DFT approach to the modeling of thermochemical properties of actinide-bearing materials into question. Here we test the performance of DFT+U method--a computationally affordable extension of DFT that explicitly accounts for the correlations between f-electrons - for prediction of the thermochemical properties of simple uranium-bearing molecular compounds and solids. We demonstrate that the DFT+U approach significantly improves the description of reaction enthalpies for the uranium-bearing gas-phase molecular compounds and solids and the deviations from the experimental values are comparable to those obtained with much more computationally demanding methods. Good results are obtained with the Hubbard U parameter values derived using the linear response method of Cococcioni and de Gironcoli. We found that the value of Coulomb on-site repulsion, represented by the Hubbard U parameter, strongly depends on the oxidation state of uranium atom. Last, but not least, we demonstrate that the thermochemistry data can be successfully used to estimate the value of the Hubbard U parameter needed for DFT+U calculations.

A gas dynamic and thermochemical model of steam/sodium microleak phenomena

International Nuclear Information System (INIS)

Perkins, R.; Airey, R.; Daniels, L.C.

1985-06-01

Conflicting findings have been reported by 3 UK laboratories for the blockage or rapid escalation of steam/sodium microleaks. In an earlier paper it was shown that this discrepancy could be resolved through the influence on the steam flow of the geometry of the leak paths; the geometry being dependent upon the method of manufacture. The application of gas dynamics and thermochemical methods could account for the rapid escalation of some leaks in terms of the presence of shock waves in the gas flow within the leak path. In this paper the gas dynamic and thermochemical theories are re-stated and a series of leak experiments conducted to test the validity of the theory is described. The theory predicts that for some leaks of variable area of cross-section the blockage/escalation behaviour is determined by small changes in the sodium-side pressure; this effect was found and is discussed as a validation of the theory. Other aspects of leak phenomena are discussed and conclusions are drawn with emphasis on implications for further programmes of leak study and for leaks in LMFBR steam generators in service. (author)

A pilot test plan of the thermochemical water-splitting iodine-sulfur process

International Nuclear Information System (INIS)

Kubo, Shinji; Kasahara, Seiji; Okuda, Hiroyuki; Terada, Atsuhiko; Tanaka, Nobuyuki; Inaba, Yoshitomo; Ohashi, Hirofumi; Inagaki, Yoshiyuki; Onuki, Kaoru; Hino, Ryutaro

2004-01-01

Research and development (R and D) of hydrogen production systems using high-temperature gas-cooled reactors (HTGR) are being conducted by the Japan Atomic Research Institute (JAERI). To develop the systems, superior hydrogen production methods are essential. The thermochemical hydrogen production cycle, the IS (iodine-sulfur) process, is a prospective candidate, in which heat supplied by HTGR can be consumed for the thermal driving load. With this attractive feature, JAERI will conduct pilot-scale tests, aiming to establish technical bases for practical plant designs using HTGR. The hydrogen will be produced at a maximum rate of 30 m 3 /h, continuously using high-temperature helium gas supplied by a helium gas loop, with an electric heater of about 400 kW. The plant will employ an advanced hydroiodic acid-processing device for efficient hydrogen production, and the usefulness of the device was confirmed from mass and heat balance analysis. Through design works and the hydrogen production tests, valuable data for construction and operation will be acquired to evaluate detailed process performance for practical systems. After completing the pilot-scale tests, JAERI will move onto the next R and D step, which will be demonstrations of the IS process to which heat is supplied from a high-temperature engineering test reactor (HTTR)

Fusion-Fission Hybrid for Fissile Fuel Production without Processing

Energy Technology Data Exchange (ETDEWEB)

Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

2012-01-02

Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in

Final Report for project titled "New fluoroionomer electrolytes with high conductivity and low SO2 crossover for use in electrolyzers being developed for hydrogen production from nuclear power plants"

Energy Technology Data Exchange (ETDEWEB)

Dennis W. Smith; Stephen Creager

2012-09-13

Thermochemical water splitting cycles, using the heat of nuclear power plants, offer an alternate highly efficient route for the production of hydrogen. Among the many possible thermochemical cycles for the hydrogen production, the sulfur-based cycles lead the competition in overall energy efficiency. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process, which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce hydrogen. The Savannah River National Laboratory (SRNL) selected the fuel cell MEA design concept for the SDE in the HyS process since the MEA concept provides a much smaller cell footprint than conventional parallel plate technology. The electrolyzer oxidizes sulfur dioxide to form sulfuric acid at the anode and reduces protons to form hydrogen at the cathode. The overall electrochemical cell reaction consists of the production of H{sub 2}SO{sub 4} and H{sub 2}. There is a significant need to provide the membrane materials that exhibit reduced sulfur dioxide transport characteristics without sacrificing other important properties such as high ionic conductivity and excellent chemical stability in highly concentrated sulfuric acid solutions saturated with sulfur dioxide. As an alternative membrane, sulfonated Perfluorocyclobutyl aromatic ether polymer (sPFCB) were expected to posses low SO2 permeability due to their stiff backbones as well as high proton conductivity, improved mechanical properties. The major accomplishments of this project were the synthesis, characterizations, and optimizations of suitable electrolyzers for good SDE performance and higher chemical stability against sulfuric acid. SDE performance results of developed sPFCB polyelectrolytes have shown that these membranes exhibit good chemical stability against H{sub 2}SO{sub 4}.

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

Science.gov (United States)

Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

2015-04-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model.

Science.gov (United States)

Cressman, Erik N K; Shenoi, Mithun M; Edelman, Theresa L; Geeslin, Matthew G; Hennings, Leah J; Zhang, Yan; Iaizzo, Paul A; Bischof, John C

2012-01-01

To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.

Towards improved local hybrid functionals by calibration of exchange-energy densities

International Nuclear Information System (INIS)

Arbuznikov, Alexei V.; Kaupp, Martin

2014-01-01

A new approach for the calibration of (semi-)local and exact exchange-energy densities in the context of local hybrid functionals is reported. The calibration functions are derived from only the electron density and its spatial derivatives, avoiding spatial derivatives of the exact-exchange energy density or other computationally unfavorable contributions. The calibration functions fulfill the seven more important out of nine known exact constraints. It is shown that calibration improves substantially the definition of a non-dynamical correlation energy term for generalized gradient approximation (GGA)-based local hybrids. Moreover, gauge artifacts in the potential-energy curves of noble-gas dimers may be corrected by calibration. The developed calibration functions are then evaluated for a large range of energy-related properties (atomization energies, reaction barriers, ionization potentials, electron affinities, and total atomic energies) of three sets of local hybrids, using a simple one-parameter local-mixing. The functionals are based on (a) local spin-density approximation (LSDA) or (b) Perdew-Burke-Ernzerhof (PBE) exchange and correlation, and on (c) Becke-88 (B88) exchange and Lee-Yang-Parr (LYP) correlation. While the uncalibrated GGA-based functionals usually provide very poor thermochemical data, calibration allows a dramatic improvement, accompanied by only a small deterioration of reaction barriers. In particular, an optimized BLYP-based local-hybrid functional has been found that is a substantial improvement over the underlying global hybrids, as well as over previously reported LSDA-based local hybrids. It is expected that the present calibration approach will pave the way towards new generations of more accurate hyper-GGA functionals based on a local mixing of exchange-energy densities

Effects of ultrasonic and thermo-chemical pre-treatments on methane production from fat, oil and grease (FOG) and synthetic kitchen waste (KW) in anaerobic co-digestion.

Science.gov (United States)

Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

2013-02-01

The effects of ultrasonic and thermo-chemical pre-treatments on the methane production potential of anaerobic co-digestion with synthetic kitchen waste (KW) or fat, oil and grease (FOG) were investigated. Non-linear regressions were fitted to accurately assess and compare the methane production from co-digestion under the various pre-treatment conditions and to achieve representative simulations and predictions. Ultrasonic pre-treatment was not found to improve methane production effectively from either FOG co-digestion or KW co-digestions. Thermo-chemical pre-treatment could increase methane production yields from both FOG and KW co-digestions. COD solubilization was found to effectively represent the effects of pre-treatment. A comprehensive evaluation indicated that the thermo-chemical pre-treatments of pH=10, 55°C and pH=8, 55°C provided the best conditions to increase methane production from FOG and KW co-digestions, respectively. The most effective enhancement of biogas production (288±0.85mLCH(4)/g TVS) was achieved from thermo-chemically pre-treated FOG co-digestion, which was 9.9±1.5% higher than FOG co-digestion without thermo-chemical pre-treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hybrid fuel cells technologies for electrical microgrids

Energy Technology Data Exchange (ETDEWEB)

San Martin, Jose Ignacio; Zamora, Inmaculada; San Martin, Jose Javier; Aperribay, Victor; Eguia, Pablo [Department of Electrical Engineering, University of the Basque Country, Alda. de Urquijo, s/n, 48013 Bilbao (Spain)

2010-09-15

Hybrid systems are characterized by containing two or more electrical generation technologies, in order to optimize the global efficiency of the processes involved. These systems can present different operating modes. Besides, they take into account aspects that not only concern the electrical and thermal efficiencies, but also the reduction of pollutant emissions. There is a wide range of possible configurations to form hybrid systems, including hydrogen, renewable energies, gas cycles, vapour cycles or both. Nowadays, these technologies are mainly used for energy production in electrical microgrids. Some examples of these technologies are: hybridization processes of fuel cells with wind turbines and photovoltaic plants, cogeneration and trigeneration processes that can be configured with fuel cell technologies, etc. This paper reviews and analyses the main characteristics of electrical microgrids and the systems based on fuel cells for polygeneration and hybridization processes. (author)

Thermochemical hydrogen production studies at LLNL: a status report

International Nuclear Information System (INIS)

Krikorian, O.H.

1982-01-01

Currently, studies are underway at the Lawrence Livermore National Laboratory (LLNL) on thermochemical hydrogen production based on magnetic fusion energy (MFE) and solar central receivers as heat sources. These areas of study were described earlier at the previous IEA Annex I Hydrogen Workshop (Juelich, West Germany, September 23-25, 1981), and a brief update will be given here. Some basic research has also been underway at LLNL on the electrolysis of water from fused phosphate salts, but there are no current results in that area, and the work is being terminated

Achievement report for fiscal 1976 on Sunshine Program. Research and development of hydrogen production technology using thermochemical method; 1976 nendo netsukagakuho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-03-01

The research and development centers on the details of the Fe-Cu-Cl-based cycle. The items studied in this connection are (1) the development of a process simulator, (2) an experimental study of the Fe-Cu-Cl-based cycle, and (3) the recapitulation of the Fe-Cl-based cycle. The outcome of the comparison of Fe-Cl-based cycles widely conducted in the past enables a conclusion that the Fe-Cu-Cl-based cycle is at present is the most practical, technologically as well as in the way of thermal efficiency. The achievement on the first reaction (hydrolysis of ferrous chloride) of fiscal 1975, and then what is reported in literature on the fifth reaction (reverse Deacon process), are incorporated into the experiment of fiscal 1976, and this completes the acquisition of basic data necessary to develop the Fe-Cu-Cl-based cycle into an application process. Using optimum conditions chosen out of these basic data, a flowchart is compiled and the details of the process are calculated. As the result, a thermal efficiency of 30-33% is obtained, and the figures are deemed to indicate that the thermochemical method is sufficiently superior to the electrolytic method. (NEDO)

Water conservation implications for decarbonizing non-electric energy supply: A hybrid life-cycle analysis.

Science.gov (United States)

Liu, Shiyuan; Wang, Can; Shi, Lei; Cai, Wenjia; Zhang, Lixiao

2018-08-01

Low-carbon transition in the non-electric energy sector, which includes transport and heating energy, is necessary for achieving the 2 °C target. Meanwhile, as non-electric energy accounts for over 60% of total water consumption in the energy supply sector, it is vital to understand future water trends in the context of decarbonization. However, few studies have focused on life-cycle water impacts for non-electric energy; besides, applying conventional LCA methodology to assess non-electric energy has limitations. In this paper, a Multi-Regional Hybrid Life-Cycle Assessment (MRHLCA) model is built to assess total CO 2 emissions and water consumption of 6 non-electric energy technologies - transport energy from biofuel and gasoline, heat supply from natural gas, biogas, coal, and residual biomass, within 7 major emitting economies. We find that a shift to natural gas and residual biomass heating can help economies reduce 14-65% CO 2 and save more than 21% water. However, developed and developing economies should take differentiated technical strategies. Then we apply scenarios from IMAGE model to demonstrate that if economies take cost-effective 2 °C pathways, the water conservation synergy for the whole energy supply sector, including electricity, can also be achieved. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hierarchically porous carbon/polyaniline hybrid for use in supercapacitors.

Science.gov (United States)

Joo, Min Jae; Yun, Young Soo; Jin, Hyoung-Joon

2014-12-01

A hierarchically porous carbon (HPC)/polyaniline (PANI) hybrid electrode was prepared by the polymerization of PANI on the surface of the HPC via rapid-mixing polymerization. The surface morphologies and chemical composition of the HPC/PANI hybrid electrode were characterized using transmission electron microscopy and X-ray photoelectron spectroscopy (XPS), respectively. The surface morphologies and XPS results for the HPC, PANI and HPC/PANI hybrids indicate that PANI is coated on the surface of HPC in the HPC/PANI hybrids which have two different nitrogen groups as a benzenoid amine (-NH-) peak and positively charged nitrogen (N+) peak. The electrochemical performances of the HPC/PANI hybrids were analyzed by performing cyclic voltammetry and galvanostatic charge-discharge tests. The HPC/PANI hybrids showed a better specific capacitance (222 F/g) than HPC (111 F/g) because of effect of pseudocapacitor behavior. In addition, good cycle stabilities were maintained over 1000 cycles.

Thermo-chemical production of hydrogen from water by metal oxides fixed on ceramic substrates

International Nuclear Information System (INIS)

Roeb, M.; Monnerie, N.; Schmitz, M.; Sattler, C.; Konstandopoulos, A.G.; Agrafiotis, C.; Zaspalis, V.T.; Nalbandian, L.; Steele, A.; Stobbe, P.

2006-01-01

In the European project HYDROSOL a simple two-step thermo-chemical cycle process has been developed and investigated. It is based on metal oxide redox pair systems, which can split water molecules by abstracting oxygen atoms and reversibly incorporating them into their lattice. If concentrated solar radiation is used as the heat source one has a promising method in hand to produce hydrogen without any environmentally critical emissions. The basic idea is to combine a support capable of achieving high temperatures when heated by concentrated solar radiation, with a redox pair system suitable for water dissociation and at the same time for regeneration at these temperatures, so that complete operation of the whole process could be achieved by a single solar energy converter. The feasibility of the process has proven possible in a mini-plant scale using concentrated sunlight provided by the solar furnace in Cologne. Suitable redox materials as coatings and a dedicated receiver-reactor have been developed to produce hydrogen with significant conversions by repeating several subsequent water splitting and regeneration steps. In a design study a possible way of operating the process in commercial scale is demonstrated. (authors)

Systematic validation of non-equilibrium thermochemical models using Bayesian inference

KAUST Repository

Miki, Kenji

2015-10-01

© 2015 Elsevier Inc. The validation process proposed by Babuška et al. [1] is applied to thermochemical models describing post-shock flow conditions. In this validation approach, experimental data is involved only in the calibration of the models, and the decision process is based on quantities of interest (QoIs) predicted on scenarios that are not necessarily amenable experimentally. Moreover, uncertainties present in the experimental data, as well as those resulting from an incomplete physical model description, are propagated to the QoIs. We investigate four commonly used thermochemical models: a one-temperature model (which assumes thermal equilibrium among all inner modes), and two-temperature models developed by Macheret et al. [2], Marrone and Treanor [3], and Park [4]. Up to 16 uncertain parameters are estimated using Bayesian updating based on the latest absolute volumetric radiance data collected at the Electric Arc Shock Tube (EAST) installed inside the NASA Ames Research Center. Following the solution of the inverse problems, the forward problems are solved in order to predict the radiative heat flux, QoI, and examine the validity of these models. Our results show that all four models are invalid, but for different reasons: the one-temperature model simply fails to reproduce the data while the two-temperature models exhibit unacceptably large uncertainties in the QoI predictions.

Preconceptual design and assessment of a Tokamak Hybrid Reactor

Energy Technology Data Exchange (ETDEWEB)

Teofilo, V.L.; Leonard, B.R. Jr.; Aase, D.T.

1980-09-01

The preconceptual design of a commercial Tokamak Hybrid Reactor (THR) power plant has been performed. The tokamak fusion driver for this hybrid is operated in the ignition mode. The D-T fusion plasma, which produces 1140 MW of power, has a major radius of 5.4 m and a minor radius of 1.0 m with an elongation of 2.0. Double null poloidal divertors are assumed for impurity control. The confining toroidal field is maintained by D-shaped Nb/sub 3/Sn superconducting magnets with a maximum field of 12T at the coil. Three blankets with four associated fuel cycle alternatives have been combined with the ignited tokamak fusion driver. The engineering, material, and balance of plant design requirements for the THR are briefly described. Estimates of the capital, operating and maintenance, and fuel cycle costs have been made for the various driver/blanket combinations and an assessment of the market penetrability of hybrid systems is presented. An analysis has been made of the nonproliferation aspects of the hybrid and its associated fuel cycles relative to fission reactors. The current and required level of technology for both the fusion and fission components of the hybrid system has been reviewed. Licensing hybrid systems is also considered.

Preconceptual design and assessment of a Tokamak Hybrid Reactor

International Nuclear Information System (INIS)

Teofilo, V.L.; Leonard, B.R. Jr.; Aase, D.T.

1980-09-01

The preconceptual design of a commercial Tokamak Hybrid Reactor (THR) power plant has been performed. The tokamak fusion driver for this hybrid is operated in the ignition mode. The D-T fusion plasma, which produces 1140 MW of power, has a major radius of 5.4 m and a minor radius of 1.0 m with an elongation of 2.0. Double null poloidal divertors are assumed for impurity control. The confining toroidal field is maintained by D-shaped Nb 3 Sn superconducting magnets with a maximum field of 12T at the coil. Three blankets with four associated fuel cycle alternatives have been combined with the ignited tokamak fusion driver. The engineering, material, and balance of plant design requirements for the THR are briefly described. Estimates of the capital, operating and maintenance, and fuel cycle costs have been made for the various driver/blanket combinations and an assessment of the market penetrability of hybrid systems is presented. An analysis has been made of the nonproliferation aspects of the hybrid and its associated fuel cycles relative to fission reactors. The current and required level of technology for both the fusion and fission components of the hybrid system has been reviewed. Licensing hybrid systems is also considered

Experimental investigation and thermochemical assessment of the system Cu-Y-O

International Nuclear Information System (INIS)

Zimmermann, E.; Mohammad, A.; Boudene, A.; Neuschuetz, D.

1995-01-01

Experimental investigations of the thermochemical properties of the phases in the system Cu-Y-O by means of DTA, EMF, TG and calorimetric measurements are reported. The results together with critically selected data from the literature are used for a complete assessment of the Gibbs energies of the ternary phases (based on the Standard Element Reference State, SER). For the binary subsystems critically assessed data from the literature are used. (orig.)

Life cycle environmental assessment of lithium-ion and nickel metal hydride batteries for plug-in hybrid and battery electric vehicles.

Science.gov (United States)

Majeau-Bettez, Guillaume; Hawkins, Troy R; Strømman, Anders Hammer

2011-05-15

This study presents the life cycle assessment (LCA) of three batteries for plug-in hybrid and full performance battery electric vehicles. A transparent life cycle inventory (LCI) was compiled in a component-wise manner for nickel metal hydride (NiMH), nickel cobalt manganese lithium-ion (NCM), and iron phosphate lithium-ion (LFP) batteries. The battery systems were investigated with a functional unit based on energy storage, and environmental impacts were analyzed using midpoint indicators. On a per-storage basis, the NiMH technology was found to have the highest environmental impact, followed by NCM and then LFP, for all categories considered except ozone depletion potential. We found higher life cycle global warming emissions than have been previously reported. Detailed contribution and structural path analyses allowed for the identification of the different processes and value-chains most directly responsible for these emissions. This article contributes a public and detailed inventory, which can be easily be adapted to any powertrain, along with readily usable environmental performance assessments.

Hierarchical porous carbon/MnO2 hybrids as supercapacitor electrodes.

Science.gov (United States)

Lee, Min Eui; Yun, Young Soo; Jin, Hyoung-Joon

2014-12-01

Hybrid electrodes of hierarchical porous carbon (HPC) and manganese oxide (MnO2) were synthesized using a fast surface redox reaction of potassium permanganate under facile immersion methods. The HPC/MnO2 hybrids had a number of micropores and macropores and the MnO2 nanoparticles acted as a pseudocapacitive material. The synergistic effects of electric double-layer capacitor (EDLC)-induced capacitance and pseudocapacitance brought about a better electrochemical performance of the HPC/MnO2 hybrid electrodes compared to that obtained with a single component. The hybrids showed a specific capacitance of 228 F g(-1) and good cycle stability over 1000 cycles.

An investigation on the fuel savings potential of hybrid hydraulic refuse collection vehicles

Energy Technology Data Exchange (ETDEWEB)

Bender, Frank A., E-mail: bender@isys.uni-stuttgart.de; Bosse, Thomas; Sawodny, Oliver

2014-09-15

Highlights: • Driving cycle acquisition in a refuse collection vehicle. • Vehicle modeling and validation for numerical simulations based on the measured driving cycle. • Fuel consumption analysis for a conventional diesel vehicle and a hybrid hydraulic vehicle. - Abstract: Refuse trucks play an important role in the waste collection process. Due to their typical driving cycle, these vehicles are characterized by large fuel consumption, which strongly affects the overall waste disposal costs. Hybrid hydraulic refuse vehicles offer an interesting alternative to conventional diesel trucks, because they are able to recuperate, store and reuse braking energy. However, the expected fuel savings can vary strongly depending on the driving cycle and the operational mode. Therefore, in order to assess the possible fuel savings, a typical driving cycle was measured in a conventional vehicle run by the waste authority of the City of Stuttgart, and a dynamical model of the considered vehicle was built up. Based on the measured driving cycle and the vehicle model including the hybrid powertrain components, simulations for both the conventional and the hybrid vehicle were performed. Fuel consumption results that indicate savings of about 20% are presented and analyzed in order to evaluate the benefit of hybrid hydraulic vehicles used for refuse collection.

An investigation on the fuel savings potential of hybrid hydraulic refuse collection vehicles

International Nuclear Information System (INIS)

Bender, Frank A.; Bosse, Thomas; Sawodny, Oliver

2014-01-01

Highlights: • Driving cycle acquisition in a refuse collection vehicle. • Vehicle modeling and validation for numerical simulations based on the measured driving cycle. • Fuel consumption analysis for a conventional diesel vehicle and a hybrid hydraulic vehicle. - Abstract: Refuse trucks play an important role in the waste collection process. Due to their typical driving cycle, these vehicles are characterized by large fuel consumption, which strongly affects the overall waste disposal costs. Hybrid hydraulic refuse vehicles offer an interesting alternative to conventional diesel trucks, because they are able to recuperate, store and reuse braking energy. However, the expected fuel savings can vary strongly depending on the driving cycle and the operational mode. Therefore, in order to assess the possible fuel savings, a typical driving cycle was measured in a conventional vehicle run by the waste authority of the City of Stuttgart, and a dynamical model of the considered vehicle was built up. Based on the measured driving cycle and the vehicle model including the hybrid powertrain components, simulations for both the conventional and the hybrid vehicle were performed. Fuel consumption results that indicate savings of about 20% are presented and analyzed in order to evaluate the benefit of hybrid hydraulic vehicles used for refuse collection

Energy and exergy analyses of a copper-chlorine thermochemical water decomposition pilot plant for hydrogen production

International Nuclear Information System (INIS)

Orhan, M.F.; Dincer, I.; Rosen, M.A.

2008-01-01

Nuclear-based hydrogen production via thermochemical water decomposition using a copper-chlorine (Cu-Cl) cycle consists of a series of chemical reactions in which water is split into hydrogen and oxygen as the net result. This is accomplished through reactions involving intermediate copper and chlorine compounds, which are recycled. Energy and exergy analyses are reported here of a Cu-Cl pilot plant, including the relevant chemical reactions. The reference environment is taken to be at a temperature of 298.15 K and atmospheric pressure (1 atm). The chemical exergy of a substance, which is the maximum work that can be obtained from it by taking it to chemical equilibrium with the reference environment at constant temperature and pressure, is calculated with property data for the substance and the reference environment, with enthalpy and entropy values calculated using Shomate equations. The reaction heat, exergy destruction and efficiencies in each chemical reaction vary with the reaction temperature and reference-environment temperature. A parametric study with variable reaction and reference-environment temperatures is also presented. (author)

Thermochemical hydrolysis of macroalgae Ulva for biorefinery: Taguchi robust design method

Science.gov (United States)

Jiang, Rui; Linzon, Yoav; Vitkin, Edward; Yakhini, Zohar; Chudnovsky, Alexandra; Golberg, Alexander

2016-06-01

Understanding the impact of all process parameters on the efficiency of biomass hydrolysis and on the final yield of products is critical to biorefinery design. Using Taguchi orthogonal arrays experimental design and Partial Least Square Regression, we investigated the impact of change and the comparative significance of thermochemical process temperature, treatment time, %Acid and %Solid load on carbohydrates release from green macroalgae from Ulva genus, a promising biorefinery feedstock. The average density of hydrolysate was determined using a new microelectromechanical optical resonator mass sensor. In addition, using Flux Balance Analysis techniques, we compared the potential fermentation yields of these hydrolysate products using metabolic models of Escherichia coli, Saccharomyces cerevisiae wild type, Saccharomyces cerevisiae RN1016 with xylose isomerase and Clostridium acetobutylicum. We found that %Acid plays the most significant role and treatment time the least significant role in affecting the monosaccharaides released from Ulva biomass. We also found that within the tested range of parameters, hydrolysis with 121 °C, 30 min 2% Acid, 15% Solids could lead to the highest yields of conversion: 54.134-57.500 gr ethanol kg-1 Ulva dry weight by S. cerevisiae RN1016 with xylose isomerase. Our results support optimized marine algae utilization process design and will enable smart energy harvesting by thermochemical hydrolysis.

Thermochemical hydrolysis of macroalgae Ulva for biorefinery: Taguchi robust design method.

Science.gov (United States)

Jiang, Rui; Linzon, Yoav; Vitkin, Edward; Yakhini, Zohar; Chudnovsky, Alexandra; Golberg, Alexander

2016-06-13

Understanding the impact of all process parameters on the efficiency of biomass hydrolysis and on the final yield of products is critical to biorefinery design. Using Taguchi orthogonal arrays experimental design and Partial Least Square Regression, we investigated the impact of change and the comparative significance of thermochemical process temperature, treatment time, %Acid and %Solid load on carbohydrates release from green macroalgae from Ulva genus, a promising biorefinery feedstock. The average density of hydrolysate was determined using a new microelectromechanical optical resonator mass sensor. In addition, using Flux Balance Analysis techniques, we compared the potential fermentation yields of these hydrolysate products using metabolic models of Escherichia coli, Saccharomyces cerevisiae wild type, Saccharomyces cerevisiae RN1016 with xylose isomerase and Clostridium acetobutylicum. We found that %Acid plays the most significant role and treatment time the least significant role in affecting the monosaccharaides released from Ulva biomass. We also found that within the tested range of parameters, hydrolysis with 121 °C, 30 min 2% Acid, 15% Solids could lead to the highest yields of conversion: 54.134-57.500 gr ethanol kg(-1) Ulva dry weight by S. cerevisiae RN1016 with xylose isomerase. Our results support optimized marine algae utilization process design and will enable smart energy harvesting by thermochemical hydrolysis.

Evaluation of the performance of MP4-based procedures for a wide range of thermochemical and kinetic properties

Energy Technology Data Exchange (ETDEWEB)

Yu, Li-Juan; Wan, Wenchao; Karton, Amir, E-mail: amir.karton@uwa.edu.au

2016-11-30

We evaluate the performance of standard and modified MPn procedures for a wide set of thermochemical and kinetic properties, including atomization energies, structural isomerization energies, conformational energies, and reaction barrier heights. The reference data are obtained at the CCSD(T)/CBS level by means of the Wn thermochemical protocols. We find that none of the MPn-based procedures show acceptable performance for the challenging W4-11 and BH76 databases. For the other thermochemical/kinetic databases, the MP2.5 and MP3.5 procedures provide the most attractive accuracy-to-computational cost ratios. The MP2.5 procedure results in a weighted-total-root-mean-square deviation (WTRMSD) of 3.4 kJ/mol, whilst the computationally more expensive MP3.5 procedure results in a WTRMSD of 1.9 kJ/mol (the same WTRMSD obtained for the CCSD(T) method in conjunction with a triple-zeta basis set). We also assess the performance of the computationally economical CCSD(T)/CBS(MP2) method, which provides the best overall performance for all the considered databases, including W4-11 and BH76.

Thermochemical properties of some alkaline-earth silicates and zirconates. Fission product behaviour during molten core-concrete interactions

International Nuclear Information System (INIS)

Huntelaar, M.E.

1996-01-01

This thesis aims to make a contribution to a better understanding of the chemical processes occurring during an ex-vessel MCCI accident with a western-type of nuclear reactor. Chosen is for a detailed thermochemical study of the silicates and zirconates of barium and strontium. In Chapter one a short introduction in the history of (research in) nuclear safety is given, followed by the state-of-the-art of molten core-concrete interactions in Chapter two. In both Chapters the role of chemical thermodynamics on this particular subject is dealt with. The experimental work on the silicates and zirconates of barium and strontium performed for this thesis, is described in the Chapters three, four, five, six, and parts of eight. In Chapter three the basis for all thermochemical measurements, the sample preparation is given. Because the sample preparation effects the accuracy of the thermodynamic measurements, a great deal of effort is spent in optimizing the synthesis of the silicates which resulted in the TEOS-method widely employed here. In the next Chapters the different thermochemical techniques used, are described: The low-temperature heat capacity measurements and the enthalpy increment measurements in Chapter four, the enthalpy-of-solution measurements in Chapter five, and measurements to determine the crystal structures in Chapter six. (orig.)

Thermochemical properties of some alkaline-earth silicates and zirconates. Fission product behaviour during molten core-concrete interactions

Energy Technology Data Exchange (ETDEWEB)

Huntelaar, M.E.

1996-06-19

This thesis aims to make a contribution to a better understanding of the chemical processes occurring during an ex-vessel MCCI accident with a western-type of nuclear reactor. Chosen is for a detailed thermochemical study of the silicates and zirconates of barium and strontium. In Chapter one a short introduction in the history of (research in) nuclear safety is given, followed by the state-of-the-art of molten core-concrete interactions in Chapter two. In both Chapters the role of chemical thermodynamics on this particular subject is dealt with. The experimental work on the silicates and zirconates of barium and strontium performed for this thesis, is described in the Chapters three, four, five, six, and parts of eight. In Chapter three the basis for all thermochemical measurements, the sample preparation is given. Because the sample preparation effects the accuracy of the thermodynamic measurements, a great deal of effort is spent in optimizing the synthesis of the silicates which resulted in the TEOS-method widely employed here. In the next Chapters the different thermochemical techniques used, are described: The low-temperature heat capacity measurements and the enthalpy increment measurements in Chapter four, the enthalpy-of-solution measurements in Chapter five, and measurements to determine the crystal structures in Chapter six. (orig.).

Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent.

Science.gov (United States)

Mohamed, Sameera; van der Merwe, Elizabet M; Altermann, Wladyslaw; Doucet, Frédéric J

2016-04-01

Mine tailings can represent untapped secondary resources of non-ferrous, ferrous, precious, rare and trace metals. Continuous research is conducted to identify opportunities for the utilisation of these materials. This preliminary study investigated the possibility of extracting major elements from South African tailings associated with the mining of Platinum Group Metals (PGM) at the Two Rivers mine operations. These PGM tailings typically contain four major elements (11% Al2O3; 12% MgO; 22% Fe2O3; 34% Cr2O3), with lesser amounts of SiO2 (18%) and CaO (2%). Extraction was achieved via thermochemical treatment followed by aqueous dissolution, as an alternative to conventional hydrometallurgical processes. The thermochemical treatment step used ammonium sulphate, a widely available, low-cost, recyclable chemical agent. Quantification of the efficiency of the thermochemical process required the development and optimisation of the dissolution technique. Dissolution in water promoted the formation of secondary iron precipitates, which could be prevented by leaching thermochemically-treated tailings in 0.6M HNO3 solution. The best extraction efficiencies were achieved for aluminium (ca. 60%) and calcium (ca. 80%). 35% iron and 32% silicon were also extracted, alongside chromium (27%) and magnesium (25%). Thermochemical treatment using ammonium sulphate may therefore represent a promising technology for extracting valuable elements from PGM tailings, which could be subsequently converted to value-added products. However, it is not element-selective, and major elements were found to compete with the reagent to form water-soluble sulphate-metal species. Further development of this integrated process, which aims at achieving the full potential of utilisation of PGM tailings, is currently underway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Benzoic acid derivatives: Evaluation of thermochemical properties with complementary experimental and computational methods

International Nuclear Information System (INIS)

Verevkin, Sergey P.; Zaitsau, Dzmitry H.; Emeĺyanenko, Vladimir N.; Stepurko, Elena N.; Zherikova, Kseniya V.

2015-01-01

Highlights: • Vapor pressures of benzoic acid derivatives were measured. • Sublimation enthalpies were derived and compared with the literature. • Thermochemical data tested for consistency using additivity rules and computations. • Contradiction between available enthalpies of sublimation was resolved. • Pairwise interactions of substituents on the benzene ring were derived. - Abstract: Molar sublimation enthalpies of the methyl- and methoxybenzoic acids were derived from the transpiration method, static method, and TGA. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpy data and to recommend sets of sublimation and formation enthalpies for the benzoic acid derivatives. Gas-phase enthalpies of formation calculated with the G4 quantum-chemical method were in agreement with the experiment. Pairwise interactions of the methyl, methoxy, and carboxyl substituents on the benzene ring were derived and used for the development of simple group-additivity procedures for estimation of the vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of substituted benzenes.

Benzoic acid derivatives: Evaluation of thermochemical properties with complementary experimental and computational methods

Energy Technology Data Exchange (ETDEWEB)

Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry and Department “Science and Technology of Life, Light and Matter”, University of Rostock, D-18059 Rostock (Germany); Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Zaitsau, Dzmitry H. [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Emeĺyanenko, Vladimir N. [Department of Physical Chemistry and Department “Science and Technology of Life, Light and Matter”, University of Rostock, D-18059 Rostock (Germany); Stepurko, Elena N. [Chemistry Faculty and Research Institute for Physical Chemical Problems, Belarusian State University, 220030 Minsk (Belarus); Zherikova, Kseniya V. [Nikolaev Institute of Inorganic Chemistry of Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation)

2015-12-20

Highlights: • Vapor pressures of benzoic acid derivatives were measured. • Sublimation enthalpies were derived and compared with the literature. • Thermochemical data tested for consistency using additivity rules and computations. • Contradiction between available enthalpies of sublimation was resolved. • Pairwise interactions of substituents on the benzene ring were derived. - Abstract: Molar sublimation enthalpies of the methyl- and methoxybenzoic acids were derived from the transpiration method, static method, and TGA. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpy data and to recommend sets of sublimation and formation enthalpies for the benzoic acid derivatives. Gas-phase enthalpies of formation calculated with the G4 quantum-chemical method were in agreement with the experiment. Pairwise interactions of the methyl, methoxy, and carboxyl substituents on the benzene ring were derived and used for the development of simple group-additivity procedures for estimation of the vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of substituted benzenes.

Clonal evaluation of new ornamental pineapple hybrids to use as cut flowers

Directory of Open Access Journals (Sweden)

Davi Silva Costa Junior

2016-09-01

Full Text Available Embrapa Cassava and Fruits has developed ornamental pineapple hybrids for several categories of ornamental use including cut flowers, potted plants and landscaping. The objective of this study was to carry out a clonal evaluation of two ornamental hybrids using quantitative and qualitative morphological descriptors to recommend these hybrids as new ornamental pineapple cultivars. Twenty plants of each hybrid (PL01 and PL04 were evaluated regarding the response to floral induction as well as the stability and homogeneity of the clones in two production cycles. The descriptive statistics were calculated and analyzed to determine the genetic distance based on the Gower algorithm. Four groups were formed, two using parental data and the other two containing the different hybrids that were evaluated in the two growing cycles. In the floral evaluation, the time from field planting to harvest of the stem as a cut flower was determined to be as long as 17 months in the first cycle and 13.5 months in the second cycle for both hybrids. They were characterized as a novelty in the flower market; they showed genetic stability and homogeneity and can be recommended as new cultivars of ornamental pineapple because they exhibit satisfactory quality and meet the market requirements.

Clean energy and hydrogen for oil sands development with CANDU SCWR nuclear reactors and Cu-Cl cycles

International Nuclear Information System (INIS)

Wang, Z.L.; Naterer, G.F.; Gabriel, K.S.

2010-01-01

In this paper, the unique capabilities and advantages of SCWR technology for cleaner oil sands development are discussed from two perspectives: lower temperature steam generation by supercritical water for steam assisted gravity drainage (SAGD), and hydrogen production for oil sands upgrading by coupling SCWR with the thermochemical copper-chlorine (Cu-Cl) cycle. The heat requirements for bitumen extraction from the oil sands and the hydrogen requirements for bitumen upgrading are evaluated. A conceptual layout of SCWR coupled with oil sands development is presented. The reduction of CO 2 emissions due to the use of SCWR and thermo chemical hydrogen production cycle is also analyzed. (author)

Bioenergy II. Biomass Valorisation by a Hybrid Thermochemical Fractionation Approach

Energy Technology Data Exchange (ETDEWEB)

De Wild, P.J.; Den Uil, H.; Reith, J.H. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands); Lunshof, A.; Hendriks, C.; Van Eck, E. [Radboud University, Nijmegen (Netherlands); Heeres, E. [University of Groningen, Groningen (Netherlands)

2009-11-15

The need for green renewable sources is adamant because of the adverse effects of the increasing use of fossil fuels on our society. Biomass has been considered as a very attractive candidate for green energy carriers, chemicals and materials. The development of cheap and efficient fractionation technology to separate biomass into its main constituents is highly desirable. It enables treatment of each constituent separately, using dedicated conversion technologies to get specific target chemicals. The synergistic combination of aquathermolysis (hot pressurised water treatment) and pyrolysis (thermal degradation in the absence of oxygen) is a promising thermolysis option, integrating fractionation of biomass with production of valuable chemicals. Batch aquathermolysis in an autoclave and subsequent pyrolysis using bubbling fluidised bed reactor technology with beech, poplar, spruce and straw indicate the potential of this hybrid concept to valorise lignocellulosic biomass. Hemicellulose-derived furfural was obtained in yields that ranged from 2 wt% for spruce to 8 wt% for straw. Hydroxymethylfurfural from hemicellulose was obtained in yields from 0.3 wt% for poplar to 3 wt% for spruce. Pyrolysis of the aquathermolised biomass types resulted in 8 wt% (straw) to 11 wt% (spruce) of cellulose-derived levoglucosan. Next to the furfurals and levoglucosan, appreciable amounts of acetic acid were obtained as well from the aquathermolysis step, ranging from 1 wt% for spruce to 5 wt% for straw. To elucidate relations between the chemical changes occurring in the biomass during the integrated process and type and amount of the chemical products formed, a 13C-solid state NMR study has been conducted. Main conclusions are that aquathermolysis results in hemicellulose degradation to lower molecular weight components. Lignin ether bonds are broken, but apart from that, lignin is hardly affected by the aquathermolysis. Cellulose is also retained, although it seems to become more

Real Time Energy Management Control Strategies for Hybrid Powertrains

Science.gov (United States)

Zaher, Mohamed Hegazi Mohamed

In order to improve fuel efficiency and reduce emissions of mobile vehicles, various hybrid power-train concepts have been developed over the years. This thesis focuses on embedded control of hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy for continuous operations. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, or the motion is driven by gravitational force, or load driven. There are three main concepts for regernerative energy storing devices in hybrid vehicles: electric, hydraulic, and flywheel. The real time control challenge is to balance the system power demand from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle, while making optimal use of the energy saving opportunities in a given operational, often repetitive cycle. In the worst case scenario, only engine is used and hybrid system completely disabled. A rule based control is developed and tuned for different work cycles and linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the machine and its position via GPS, and maps them to the gains.

75 FR 42237 - Regulation of Fuels and Fuel Additives: 2011 Renewable Fuel Standards

Science.gov (United States)

2010-07-20

... Based on a Thermochemical Platform 3. Hybrid Thermochemical/Biochemical Processes 4. Pyrolysis and Depolymerization a. Pyrolysis Diesel Fuel and Gasoline b. Catalytic Depolymerization 5. Catalytic Reforming of... result would be that additional volumes of conventional renewable fuel, such as corn-starch ethanol...

Evaluation and Comparison of Environmental Indicators of Hybrid Corn (Zea mays L. Production by Three Different Harvesting Methods in Alborz Province using Life Cycle Assessment

Directory of Open Access Journals (Sweden)

Majid Khanali

2018-02-01

Full Text Available Introduction Agriculture itself serves a dual role as an energy user and also energy supplier in the form of bio-energy. Recently, the energy use in agriculture has been intensified in response to the rising population, the increasing of standards of living and the limitation sources of energy. Efficient use of energy is a possible pathway for reducing the environmental impacts of energy inputs in agriculture, and providing sustainable agricultural production, since it brings financial savings, fossil resources preservation and air pollution reduction. Life cycle assessment (LCA is defined as the compilation and evaluation of the inputs, outputs and potential environmental impacts of a product system throughout its life cycle. Hybrid seed in agriculture is produced by cross-pollinated plants. Hybrid seed production is one of the main contributors to the dramatic rise in agricultural output during the last half of the 20th century. The alternatives to hybridization are open pollination and cloonal propagation. All of the hybrid seeds planted by the farmer will produce similar plants while the seeds of the next generation from those hybrids will not consistently have the desired characteristics. Controlled hybrids provide very uniform characteristics because they are produced by crossing two inbred strains. Materials and Methods The purpose of this study was to compare the energy consumption pattern and environmental consequences caused by the use of agricultural inputs in the production of seed corn harvested by hand, combine and picker husker. Information required was prepared by the questionnaire method in Alborz Province using census the total producers of hybrid corn in the Province. The investigated inputs were labor, agricultural machinery, diesel fuel, chemical pesticides, fertilizers, gas, electricity, water and seed. The energy of each input was calculated by multiplying the amount of that input with its energy equivalent. The ten

Nicotinamides: Evaluation of thermochemical experimental properties

International Nuclear Information System (INIS)

Zhabina, Aleksandra A.; Nagrimanov, Ruslan N.; Emel’yanenko, Vladimir N.; Solomonov, Boris N.; Verevkin, Sergey P.

2016-01-01

Highlights: • Vapor pressures measured by transpiration method. • Enthalpies of solution measured using high-precision solution calorimetry. • Enthalpies of fusion measured by DSC. • Sublimation enthalpies derived from transpiration and solution calorimetry in agreement. • Experimental results evaluated and compared with G4 calculations. - Abstract: Vapor pressures of the isomeric 2-, 3-, and 4-pyridinecarboxamides were measured by using the transpiration method. The enthalpies of sublimation/vaporization of these compounds at 298.15 K were derived from vapor pressure temperature dependences. The enthalpies of solution of the isomeric pyridinecarboxamides were measured with the high-precision solution calorimetry. The enthalpies of sublimation of 3- and 4-pyridinecarboxamides were independently derived with help of the solution calorimetry based procedure. The enthalpies of fusion of the pyridinecarboxamides were measured by the DSC. Thermochemical data isomeric pyridinecarboxamides were collected, evaluated, and tested for internal consistency. The high-level G4 quantum-chemical method was used for mutual validation of the experimental and theoretical gas phase enthalpies of formation successfully.

A hybrid multi-effect distillation and adsorption cycle

KAUST Repository

Thu, Kyaw; Kim, Youngdeuk; Amy, Gary L.; Chun, Wongee; Ng, K. C.

2013-01-01

cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent's regeneration temperature and this extended the usage of thermal energy emanating from the brine heater

Thermochemical ablation therapy of VX2 tumor using a permeable oil-packed liquid alkali metal.

Directory of Open Access Journals (Sweden)

Ziyi Guo

Full Text Available Alkali metal appears to be a promising tool in thermochemical ablation, but, it requires additional data on safety is required. The objective of this study was to explore the effectiveness of permeable oil-packed liquid alkali metal in the thermochemical ablation of tumors.Permeable oil-packed sodium-potassium (NaK was prepared using ultrasonic mixing of different ratios of metal to oil. The thermal effect of the mixture during ablation of muscle tissue ex vivo was evaluated using the Fluke Ti400 Thermal Imager. The thermochemical effect of the NaK-oil mixture on VX2 tumors was evaluated by performing perfusion CT scans both before and after treatment in 10 VX2 rabbit model tumors. VX2 tumors were harvested from two rabbits immediately after treatment to assess their viability using trypan blue and hematoxylin and eosin (H.E. staining.The injection of the NaK-oil mixture resulted in significantly higher heat in the ablation areas. The permeable oil controlled the rate of heat released during the NaK reaction with water in the living tissue. Perfusion computed tomography and its parameter map confirmed that the NaK-oil mixture had curative effects on VX2 tumors. Both trypan blue and H.E. staining showed partial necrosis of the VX2 tumors.The NaK-oil mixture may be used successfully to ablate tumor tissue in vivo. With reference to the controlled thermal and chemical lethal injury to tumors, using a liquid alkali in ablation is potentially an effective and safe method to treat malignant tumors.

Stable graphene-polyoxometalate nanomaterials for application in hybrid supercapacitors.

Science.gov (United States)

Suárez-Guevara, Jullieth; Ruiz, Vanesa; Gómez-Romero, Pedro

2014-10-14

We report the synthesis of hybrid supercapacitor electrodes by a novel reduction of GO with simultaneous incorporation of polyoxometalate. These hybrids show a 30% increase in specific capacitance and excellent stability after 10,000 cycles.

Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

Energy Technology Data Exchange (ETDEWEB)

Eichler, B.; Neuhausen, J

2004-06-01

An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

Thermochemical micro imprinting of single-crystal diamond surface using a nickel mold under high-pressure conditions

Energy Technology Data Exchange (ETDEWEB)

Imoto, Yuji; Yan, Jiwang, E-mail: yan@mech.keio.ac.jp

2017-05-15

Graphical abstract: A Ni mold and thermochemically imprinted microstructures on diamond. - Highlights: • A thermochemical method for micro machining/patterning of diamond is proposed. • Various kinds of microstructures were imprinted on diamond using a Ni mold. • A graphite layer is formed during imprinting which can be removed by acid. • The processing depth depends strongly on pressure and temperature. - Abstract: Single-crystal diamond is an important material for cutting tools, micro electro mechanical systems, optical devices, and semiconductor substrates. However, the techniques for producing microstructures on diamond surface with high efficiency and accuracy have not been established. This paper proposes a thermochemical imprinting method for transferring microstructures from a nickel (Ni) mold onto single-crystal diamond surface. The Ni mold was micro-structured by a nanoindenter and then pressed against the diamond surface under high temperature and pressure in argon atmosphere. Results show that microstructures on the Ni mold were successfully transferred onto the diamond surface, and their depth increased with both pressure and temperature. Laser micro-Raman spectroscopy, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) analyses indicate that a graphite layer was formed over the contact area between diamond and Ni during pressing, and after washing by a mixed acid, the graphite layer could be completely removed. This study demonstrated the feasibility of a cost-efficient fabrication method for large-area microstructures on single-crystal diamond.

Nagra thermochemical data base. II. Supplement data 05/92

International Nuclear Information System (INIS)

Pearson, F.J.; Berner, U.; Hummel, W.

1992-05-01

Chemical thermodynamic data for aqueous species, minerals, and gases are required by Nagra for geochemical modelling. The Nagra thermochemical data base contains core and supplemental data. Core data for well-characterised entities were individually carefully selected and given by Pearson and Berner (1991). Supplemental data are for less common entities and for elements principally of safety assessment concern. They were selected in groups from other data bases for geochemical modelling and did not receive individual scrutiny. This report gives tables with the Nagra thermochemical data as of 5/92. It includes the core data described in the earlier report with supplemental data for the elements aluminium, silicon, iron, and manganese, the actinides thorium, uranium, neptunium, plutonium, and americium, and elements found as fission or activation products in nuclear waste, including nickel, zirconium, niobium, molybdenum, technetium, palladium, tin, selenium and iodine. Aqueous complexes of four representative organic anions are also included. The sources of these supplemental data are described in the text. Other compilations of data were examined during the selection on the supplemental data. These included the data bases used at the Paul Scherrer Institut with the geochemical programs MINEQL as of 3/91, PHREEQE as of 4/91, and the HATCHES 3.0 data base. This report also gives tables comparing selected data in these three data bases with values from the Nagra data base. This data base has not yet been tested for a full range of nuclear waste management applications, although such work is in progress. It should thus be regarded as a reference fixed point for quality assurance purpose and not critically reviewed standard. (author) tabs., refs

An Improved Multi-Evaporator Adsorption Desalination Cycle for GCC Countries

KAUST Repository

Shahzad, Muhammad Wakil

2017-03-29

In Gulf Cooperation Council (GCC) countries, cogeneration based desalination processes consume almost 25% of the total annual energy and it is increasing at 2.2% annually. The high fresh water demand is attributed to high gross domestic product (GDP) growth rate, 24%, and the high water languishes, more than 10%. Over the past two decades, GCC countries have spent tens of billion dollars to expand their present and planned desalination capacities. It is foreseeable that with business-as-usual scenario, the domestic oil consumption of Saudi Arabia may exceed its production capacity by 2040. Innovative and sustainable water production solutions are needed urgently for future water supplies without environment impact. In this paper, a hybrid desalination cycle is proposed by integrating multi cascaded-evaporators (CE) with an adsorption cycle (AD). In this new innovative cycle, AD desorbed vapors are supplied to the CE to exploit the latent condensation energy within the evaporators arranged in both pressures-temperatures cascaded manner to improves the performance ratio (PR) of the cycle. Hybrid cycle shows more than 10 folds water production improvement as compared to conventional AD cycle due to synergetic effect. This concept is demonstrated in a laboratory pilot plant using a 3 cascaded evaporators pilot and simulation of 8 evaporators hybrid cycle.

A Dynamic Control Strategy for Hybrid Electric Vehicles Based on Parameter Optimization for Multiple Driving Cycles and Driving Pattern Recognition

Directory of Open Access Journals (Sweden)

Zhenzhen Lei

2017-01-01

Full Text Available The driving pattern has an important influence on the parameter optimization of the energy management strategy (EMS for hybrid electric vehicles (HEVs. A new algorithm using simulated annealing particle swarm optimization (SA-PSO is proposed for parameter optimization of both the power system and control strategy of HEVs based on multiple driving cycles in order to realize the minimum fuel consumption without impairing the dynamic performance. Furthermore, taking the unknown of the actual driving cycle into consideration, an optimization method of the dynamic EMS based on driving pattern recognition is proposed in this paper. The simulation verifications for the optimized EMS based on multiple driving cycles and driving pattern recognition are carried out using Matlab/Simulink platform. The results show that compared with the original EMS, the former strategy reduces the fuel consumption by 4.36% and the latter one reduces the fuel consumption by 11.68%. A road test on the prototype vehicle is conducted and the effectiveness of the proposed EMS is validated by the test data.

Gasoline-fueled hybrid vs. conventional vehicle emissions and fuel economy.

Energy Technology Data Exchange (ETDEWEB)

Anderson, J.; Bharathan, D.; He, J.; Plotkin, S.; Santini, D.; Vyas, A.

1999-06-18

This paper addresses the relative fuel economy and emissions behavior, both measured and modeled, of technically comparable, contemporary hybrid and conventional vehicles fueled by gasoline, in terms of different driving cycles. Criteria pollutants (hydrocarbons, carbon monoxide, and nitrogen oxides) are discussed, and the potential emissions benefits of designing hybrids for grid connection are briefly considered. In 1997, Toyota estimated that their grid-independent hybrid vehicle would obtain twice the fuel economy of a comparable conventional vehicle on the Japan 10/15 mode driving cycle. This initial result, as well as the fuel economy level (66 mpg), made its way into the U.S. press. Criteria emissions amounting to one-tenth of Japanese standards were cited, and some have interpreted these results to suggest that the grid-independent hybrid can reduce criteria emissions in the U.S. more sharply than can a conventional gasoline vehicle. This paper shows that the potential of contemporary grid-independent hybrid vehicle technology for reducing emissions and fuel consumption under U.S. driving conditions is less than some have inferred. The importance (and difficulty) of doing test and model assessments with comparable driving cycles, comparable emissions control technology, and comparable performance capabilities is emphasized. Compared with comparable-technology conventional vehicles, grid-independent hybrids appear to have no clear criteria pollutant benefits (or disbenefits). (Such benefits are clearly possible with grid-connectable hybrids operating in zero emissions mode.) However, significant reductions in greenhouse gas emissions (i.e., fuel consumption) are possible with hybrid vehicles when they are used to best advantage.

Theoretical studies of a hybrid ejector CO2 compression cooling system for vehicles and preliminary experimental investigations of an ejector cycle

International Nuclear Information System (INIS)

Chen, Xiangjie; Worall, Mark; Omer, Siddig; Su, Yuehong; Riffat, Saffa

2013-01-01

Highlights: ► Waste heat from vehicle exhausted gas was used as heat source for ejector. ► Ejector acts as the main interface between ejector and CO 2 VC sub-system. ► The effect of sub-cooling was analyzed. ► COP of ejector cooling system was measured between 0.2 and 0.5 during experiments. ► Enhanced ejector and vapour compression system. -- Abstract: This paper presents theoretical investigations into a hybrid ejector and CO 2 vapour compression (VC) system for road transport cooling. The purpose is to utilise the waste heat from exhaust gas and the VC sub-system to drive the ejector system, whose cooling effect will be employed to subcool the VC sub-system. Exploitation of the energy consumption ratio between ejector sub-system and CO 2 VC sub-system indicated that the more energy obtained from exhausted gas, the better system performance could be achieved for CO 2 VC sub-system, and hence higher cooling capacity of the VC sub-system at the same compression power. Thermodynamic simulations of two sub-systems and the hybrid system were presented. The results indicated that, at boiler temperature of 120 °C, evaporator temperature of 10 °C, a COP of 0.584 was achieved for hybrid system, with 22% improvement over a single ejector cycle. Preliminary experimental studies were carried out on a single ejector cycle, with boiler temperatures between 115 °C and 130 °C, and evaporator temperatures between 5 °C and 10 °C. The effects of various operation conditions on the overall ejector operation were coherently analysed. The COP of the ejector sub-system from experimental results was approximately 85% compared with simulation results, which showed a good agreement between theoretical analysis and experimental results.

A 2D nickel-based energetic MOFs incorporating 3,5-diamino-1,2,4-triazole and malonic acid: Synthesis, crystal structure and thermochemical study

International Nuclear Information System (INIS)

Yang, Qi; Song, Xiaxia; Ge, Jing; Zhao, Guowei; Zhang, Wendou; Xie, Gang; Chen, Sanping; Gao, Shengli

2016-01-01

Highlights: • An energetic MOFs with dinuclear nickel unit has been synthesized and characterized. • The Arrhenius equation, derived from kinetics analysis, is ln k = 55.89 − 332.01 × 10 3 /RT. • The standard molar enthalpy of formation of the compound is determined by a thermochemical cycle. • The molar heat capacity at T = 298.15 K is determined to be 1.42 ± 0.11 J · K −1 · g −1 . - Abstract: A new energetic MOFs, {[Ni 2 (C 2 H 5 N 5 ) 2 (C 3 H 2 O 4 ) 2 (H 2 O)]·3H 2 O} n (Hdatrz (C 2 H 5 N 5 ) = 3,5-diamino-1,2,4-triazole, H 2 mal (C 3 H 4 O 4 ) = malonic acid), has been synthesized and characterized by element analysis, chemical analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analysis confirmed that the compound featured a 2D layer structure with dinuclear Ni(II) unit. Thermal analysis demonstrated that the compound after dehydration have good thermostability with decomposition temperature up to 633 K. The non-isothermal kinetics for the compound was studied by Kissinger’s and Ozawa’s methods. The Arrhenius equation of initial thermal decomposition process of compound can be expressed as ln k = 55.89 − 332.01 × 10 3 /RT. Furthermore, a reasonable thermochemical cycle was designed based on the preparation reaction of the compound, and standard molar enthalpy of dissolution of reactants and products were measured by RD496-2000 calorimeter. Finally, the standard molar enthalpy of formation of the compound was determined to be −(2766.3 ± 2.3) kJ · mol −1 in accordance with Hess’s law. In addition, the specific heat capacity of the compound at T = 298.15 K was determined to be 1.42 ± 0.11 J · K −1 · g −1 by RD496-2000 calorimeter.

Positronium hydride defects in thermochemically reduced alkaline-Earth oxides

International Nuclear Information System (INIS)

Monge, M.A.; Pareja, R.; Gonzalez, R.; Chen, Y.

1997-01-01

Thermochemical reduction of both hydrogen-doped MgO and CaO single crystals results in large concentrations of hydride (H - ) ions. In MgO crystals, positron lifetime and Doppler broadening experiments show that positrons are trapped at H - centers forming positronium hydride molecules [e + - H - ]. A value of 640 ps is obtained for the lifetime of the PsH states located in an anion vacancy In MgO positrons are also trapped at H 2- sites at low temperatures. The H 2- ions were induced in the crystals by blue light illumination. The formation of PsH states in CaO could not be conclusively established. (orig.)

Laser driven fusion fission hybrids

International Nuclear Information System (INIS)

Hansen, L.F.; Maniscalco, J.A.

1977-11-01

The role of the fusion-fission hybrid reactor (FFHR) as a fissile fuel and/or power producer is discussed. As long range options to supply the world energy needs, hybrid-fueled thermal-burner reactors are compared to liquid metal fast breeder reactors (LMFBR). A discussion of different fuel cycles (thorium, depleted uranium, and spent fuel) is presented in order to compare the energy multiplication, the production of fissile fuel, the laser efficiency and pellet gain requirements of the hybrid reactor. Lawrence Livermore Laboratory (LLL) has collaborated with Bechtel Corporation and with Westinghouse in two engineering design studies of laser fusion driven hybrid power plants. The hybrid designs which have resulted from these two studies are briefly described and analyzed by considering operational parameters, such as energy multiplication, power density, burn-up and plutonium production as a function time

HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.

2011-07-06

Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

Characterisation of agroindustrial solid residues as biofuels and potential application in thermochemical processes.

Science.gov (United States)

Virmond, Elaine; De Sena, Rennio F; Albrecht, Waldir; Althoff, Christine A; Moreira, Regina F P M; José, Humberto J

2012-10-01

In the present work, selected agroindustrial solid residues from Brazil - biosolids from meat processing wastewater treatment and mixture of sawdust with these biosolids; residues from apple and orange juice industries; sugarcane bagasse; açaí kernels (Euterpe oleracea) and rice husk - were characterised as solid fuels and an evaluation of their properties, including proximate and ultimate composition, energy content, thermal behaviour, composition and fusibility of the ashes was performed. The lower heating value of the biomasses ranged from 14.31 MJkg(-1) to 29.14 MJkg(-1), on a dry and ash free basis (daf), all presenting high volatile matter content, varying between 70.57 wt.% and 85.36 wt.% (daf) what improves the thermochemical conversion of the solids. The fouling and slagging tendency of the ashes was predicted based on the fuel ash composition and on the ash fusibility correlations proposed in the literature, which is important to the project and operation of biomass conversion systems. The potential for application of the Brazilian agroindustrial solid residues studied as alternative energy sources in thermochemical processes has been identified, especially concerning direct combustion for steam generation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

Energy Technology Data Exchange (ETDEWEB)

Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

2010-12-15

The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)

Aerobic dive limits of seals with mutant myoglobin using combined thermochemical and physiological data

DEFF Research Database (Denmark)

Dasmeh, Pouria; Davis, Randall W.; Kepp, Kasper Planeta

2013-01-01

This paper presents an integrated model of convective O2-transport, aerobic dive limits (ADL), and thermochemical data for oxygen binding to mutant myoglobin (Mb), used to quantify the impact of mutations in Mb on the dive limits of Weddell seals (Leptonychotes weddellii). We find that wild-type ...... that such conditions are mostly selected upon in seals. The model is capable of roughly quantifying the physiological impact of single-protein mutations and thus bridges an important gap between animal physiology and molecular (protein) evolution.......This paper presents an integrated model of convective O2-transport, aerobic dive limits (ADL), and thermochemical data for oxygen binding to mutant myoglobin (Mb), used to quantify the impact of mutations in Mb on the dive limits of Weddell seals (Leptonychotes weddellii). We find that wild-type Mb...... traits are only superior under specific behavioral and physiological conditions that critically prolong the ADL, action radius, and fitness of the seals. As an extreme example, the mutations in the conserved His-64 reduce ADL up to 14±2 min for routine aerobic dives, whereas many other mutations...

Hybrid lithium-ion capacitor with LiFePO4/AC composite cathode - Long term cycle life study, rate effect and charge sharing analysis

Science.gov (United States)

Shellikeri, A.; Yturriaga, S.; Zheng, J. S.; Cao, W.; Hagen, M.; Read, J. A.; Jow, T. R.; Zheng, J. P.

2018-07-01

Energy storage devices, which can combine the advantages of lithium-ion battery with that of electric double layer capacitor, are of prime interest. Recently, composite cathodes, which combine a battery material with capacitor material, have shown promise in enhancing life cycle and energy/power performances. Lithium-ion capacitor (LIC), with unique charge storage mechanism of combining a pre-lithiated battery anode with a capacitor cathode, is one such device which has the potential to synergistically incorporate the composite cathode to enhance capacity and cycle life. We report here a hybrid LIC consisting of a lithium iron phosphate (LiFePO4-LFP)/Activated Carbon composite cathode in combination with a hard carbon anode, by integrating the cycle life and capacity enhancing strategies of a dry method of electrode fabrication, anode pre-lithiation and a 3:1 anode to cathode capacity ratio, demonstrating a long cycle life, while elaborating on the charge sharing between the faradaic and non-faradaic mechanism in the battery and capacitor materials, respectively in the composite cathode. An excellent cell capacity retention of 94% (1000 cycles at 1C) and 92% (100,000 cycles at 60C) were demonstrated, while retaining 78% (over 6000 cycles at 2.7C) and 67% (over 70,000 cycles at 43C) of the LFP capacity in the composite cathode.

Eighteen-Month Final Evaluation of UPS Second Generation Diesel Hybrid-Electric Delivery Vans

Energy Technology Data Exchange (ETDEWEB)

Lammert, M.; Walkowicz, K.

2012-09-01

A parallel hybrid-electric diesel delivery van propulsion system was evaluated at a UPS facility in Minneapolis using on-vehicle data logging, fueling, and maintenance records. Route and drive cycle analysis showed different duty cycles for hybrid vs. conventional delivery vans; routes were switched between the study groups to provide a valid comparison. The hybrids demonstrated greater advantage on the more urban routes; the initial conventional vans' routes had less dense delivery zones. The fuel economy of the hybrids on the original conventional group?s routes was 10.4 mpg vs. 9.2 mpg for the conventional group on those routes a year earlier. The hybrid group's fuel economy on the original hybrid route assignments was 9.4 mpg vs. 7.9 mpg for the conventional group on those routes a year later. There was no statistically significant difference in total maintenance cost per mile or for the vehicle total cost of operation per mile. Propulsion-related maintenance cost per mile was 77% higher for the hybrids, but only 52% more on a cost-per-delivery-day basis. Laboratory dynamometer testing demonstrated 13%-36% hybrid fuel economy improvement, depending on duty cycle, and up to a 45% improvement in ton-mi/gal. NOx emissions increased 21%-49% for the hybrids in laboratory testing.

Thermochemical Fragment Energy Method for Biomolecules: Application to a Collagen Model Peptide.

Science.gov (United States)

Suárez, Ernesto; Díaz, Natalia; Suárez, Dimas

2009-06-09

Herein, we first review different methodologies that have been proposed for computing the quantum mechanical (QM) energy and other molecular properties of large systems through a linear combination of subsystem (fragment) energies, which can be computed using conventional QM packages. Particularly, we emphasize the similarities among the different methods that can be considered as variants of the multibody expansion technique. Nevertheless, on the basis of thermochemical arguments, we propose yet another variant of the fragment energy methods, which could be useful for, and readily applicable to, biomolecules using either QM or hybrid quantum mechanical/molecular mechanics methods. The proposed computational scheme is applied to investigate the stability of a triple-helical collagen model peptide. To better address the actual applicability of the fragment QM method and to properly compare with experimental data, we compute average energies by carrying out single-point fragment QM calculations on structures generated by a classical molecular dynamics simulation. The QM calculations are done using a density functional level of theory combined with an implicit solvent model. Other free-energy terms such as attractive dispersion interactions or thermal contributions are included using molecular mechanics. The importance of correcting both the intermolecular and intramolecular basis set superposition error (BSSE) in the QM calculations is also discussed in detail. On the basis of the favorable comparison of our fragment-based energies with experimental data and former theoretical results, we conclude that the fragment QM energy strategy could be an interesting addition to the multimethod toolbox for biomolecular simulations in order to investigate those situations (e.g., interactions with metal clusters) that are beyond the range of applicability of common molecular mechanics methods.

High cycle fatigue behavior of the IN718/M247 hybrid element fabricated by friction welding at elevated temperatures

Directory of Open Access Journals (Sweden)

Tran Hung Tra

2016-12-01

Full Text Available A hybrid element has been fabricated by friction welding, joining two superalloys Inconel 718 and Mar-M247. The high cycle fatigue behavior of this welded element was investigated at 500 °C and 700 °C. The fabrication could obtain excellent fatigue strength in which the fracture is located in the base metal Mar-M247 side and takes place outside the welded zone. The behavior of the joint under loadings is discussed through a simulation by the numerical finite element method.

Definitive Ideal-Gas Thermochemical Functions of the (H2O)-O-16 Molecule

Czech Academy of Sciences Publication Activity Database

Furtenbacher, T.; Szidarovszky, T.; Hrubý, Jan; Kyuberis, A. A.; Zobov, N. F.; Polyansky, O. L.; Tennyson, J.; Császár, A. G.

2016-01-01

Roč. 45, č. 4 (2016), č. článku 043104. ISSN 0047-2689 R&D Projects: GA ČR(CZ) GA16-02647S Institutional support: RVO:61388998 Keywords : ideal-gas thermochemical quantities * ortho- and para-H2 16O * partition function Subject RIV: BJ - Thermodynamics Impact factor: 4.204, year: 2016 http://aip.scitation.org/doi/pdf/10.1063/1.4967723

Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

Science.gov (United States)

Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

2011-09-28

The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

Life cycle cost of a hybrid forward osmosis - low pressure reverse osmosis system for seawater desalination and wastewater recovery.

Science.gov (United States)

Valladares Linares, R; Li, Z; Yangali-Quintanilla, V; Ghaffour, N; Amy, G; Leiknes, T; Vrouwenvelder, J S

2016-01-01

In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis - low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor - reverse osmosis - advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m(3) d(-1) of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m(3) produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

Comparison of second-generation processes for the conversion of sugarcane bagasse to liquid biofuels in terms of energy efficiency, pinch point analysis and Life Cycle Analysis

International Nuclear Information System (INIS)

Petersen, A.M.; Melamu, Rethabi; Knoetze, J.H.; Görgens, J.F.

2015-01-01

Highlights: • Process evaluation of thermochemical and biological routes for bagasse to fuels. • Pinch point analysis increases overall efficiencies by reducing utility consumption. • Advanced biological route increased efficiency and local environmental impacts. • Thermochemical routes have the highest efficiencies and low life cycle impacts. - Abstract: Three alternative processes for the production of liquid transportation biofuels from sugar cane bagasse were compared, on the perspective of energy efficiencies using process modelling, Process Environmental Assessments and Life Cycle Assessment. Bio-ethanol via two biological processes was considered, i.e. Separate Hydrolysis and Fermentation (Process 1) and Simultaneous Saccharification and Fermentation (Process 2), in comparison to Gasification and Fischer Tropsch synthesis for the production of synthetic fuels (Process 3). The energy efficiency of each process scenario was maximised by pinch point analysis for heat integration. The more advanced bio-ethanol process was Process 2 and it had a higher energy efficiency at 42.3%. Heat integration was critical for the Process 3, whereby the energy efficiency was increased from 51.6% to 55.7%. For both the Process Environmental and Life Cycle Assessment, Process 3 had the least potential for detrimental environmental impacts, due to its relatively high energy efficiency. Process 2 had the greatest Process Environmental Impact due to the intensive use of processing chemicals. Regarding the Life Cycle Assessments, Process 1 was the most severe due to its low energy efficiency

Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles.

Science.gov (United States)

Martin, Martin; Enríquez, L López; Fernández-Polanco, M; Villaverde, S; Garcia-Encina, P A

2007-01-01

Abstract Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350-500 mg COD/L, 110-130 mg NKT/L, 90-100 mg NH3-N/L and 12-15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm(-3)d(-1) and 0.16 kg total N m(-3)d(-1). The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

Hybrid gas turbine–organic Rankine cycle for seawater desalination by reverse osmosis in a hydrocarbon production facility

International Nuclear Information System (INIS)

Eveloy, Valérie; Rodgers, Peter; Qiu, Linyue

2015-01-01

Highlights: • Seawater reverse osmosis driven by hybrid gas turbine–organic Rankine power cycle. • High ambient air and seawater temperatures, and high seawater salinity. • Energy–exergy analysis of power and desalination systems for six organic fluids. • Economic viability of waste heat recovery in subsidized utility pricing context. - Abstract: Despite water scarcity, the use of industrial waste heat for seawater desalination has been limited in the Middle East to date. This study evaluates the technical and economic feasibility of integrating on-site gas turbine power generation and reverse osmosis equipment for the production of both electricity and fresh water in a coastal hydrocarbon production facility. Gas turbine exhaust gas waste heat is recovered using an intermediate heat transfer fluid and fed to an organic Rankine cycle evaporator, to generate mechanical power to drive the reverse osmosis high pressure pump. Six candidate organic working fluids are evaluated, namely toluene, benzene, cyclohexane, cyclopentane, n-pentane and R245fa. Thermodynamic and desalination performance are assessed in the harsh climatic and salinity conditions of the Arabian Gulf. The performance metrics considered incorporate electric power and permeate production, thermal and exergy efficiency, specific energy consumption, system size, and permeate quality. Using toluene in the bottoming power cycle, a gain in power generation efficiency of approximately 12% is achieved relative to the existing gas turbine cycle, with an annual average of 2260 m"3/h of fresh water produced. Depending upon the projected evolution of local water prices, the investment becomes profitable after two to four years, with an end-of-life net present value of 220–380 million USD, and internal rate of return of 26–48%.

Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury : a 16-week randomized controlled trial

NARCIS (Netherlands)

Bakkum, A. J. T.; de Groot, S.; Stolwijk-Swuste, J. M.; van Kuppevelt, D. J.; van der Woude, L. H. V.; Janssen, T. W. J.

Study design: This is an open randomized controlled trial. Objective: The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI). Setting: The study

Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury: a 16-week randomized controlled trial

NARCIS (Netherlands)

Bakkum, A.J.T.; de Groot, S.; Stolwijk-Swuste, J.M.; van Kuppevelt, D.J.; van der Woude, L.H.V.; Janssen, T.W.J.

2015-01-01

Study design:This is an open randomized controlled trial.Objective:The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI).Setting:The study was

Hybrid Simulation of Duty Cycle Influences on Pulse Modulated RF SiH4/Ar Discharge

Science.gov (United States)

Wang, Xifeng; Song, Yuanhong; Zhao, Shuxia; Dai, Zhongling; Wang, Younian

2016-04-01

A one-dimensional fluid/Monte-Carlo (MC) hybrid model is developed to describe capacitively coupled SiH4/Ar discharge, in which the lower electrode is applied by a RF source and pulse modulated by a square-wave, to investigate the modulation effects of the pulse duty cycle on the discharge mechanism. An electron Monte Carlo simulation is used to calculate the electron energy distribution as a function of position and time phase. Rate coefficients in chemical reactions can then be obtained and transferred to the fluid model for the calculation of electron temperature and densities of different species, such as electrons, ions, and radicals. The simulation results show that, the electron energy distribution f(ɛ) is modulated evidently within a pulse cycle, with its tail extending to higher energies during the power-on period, while shrinking back promptly in the afterglow period. Thus, the rate coefficients could be controlled during the discharge, resulting in modulation of the species composition on the substrate compared with continuous excitation. Meanwhile, more negative ions, like SiH-3 and SiH-2, may escape to the electrodes owing to the collapse of ambipolar electric fields, which is beneficial to films deposition. Pulse modulation is thus expected to provide additional methods to customize the plasma densities and components. supported by National Natural Science Foundation of China (No. 11275038)

Development program of hydrogen production by thermo-chemical water splitting is process

International Nuclear Information System (INIS)

Ryutaro Hino

2005-01-01

The Japan Atomic Energy Research Institute (JAERI) has been conducting R and D on the HTGR and also on thermo-chemical water splitting hydrogen production by using a iodine-sulfur cycle (IS process) in the HTTR project. The continuous hydrogen production for one week was demonstrated with a bench-scale test apparatus made of glass, and the hydrogen production rare was about 31 NL/h. Based on the test results and know-how obtained through the bench-scale test, a pilot test plant, which has a hydrogen production performance of 30 Nm 3 /h and will be operated under the high pressure up to 2 MPa, is being designed conceptually as the next step of the IS process development aiming to realize a future nuclear hydrogen production coupled with the HTGR. In this paper, we will introduce one-week continuous hydrogen production conducted with the bench-scale test apparatus and the pilot test program including R and D and an analytical system necessary for designing the pilot test plant. MW. Figure 1 shows an overview of the HTTR-IS plant. In this paper, we will introduce latest test results obtained with the bench-scale test apparatus and concepts of key components of the IS process, a sulfuric acid (H 2 SO 4 ) and a sulfur trioxide (SO 3 ) decomposers working under high-temperature corrosive circumstance, are also introduced as well as relating R and D and an analytical system for the pilot plant design. (authors)

Electric vehicle life cycle cost analysis : final research project report.

Science.gov (United States)

2017-02-01

This project compared total life cycle costs of battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), and vehicles with internal combustion engines (ICE). The analysis considered capital and operati...

Efficiency of two-step solar thermochemical non-stoichiometric redox cycles with heat recovery

International Nuclear Information System (INIS)

Lapp, J.; Davidson, J.H.; Lipiński, W.

2012-01-01

Improvements in the effectiveness of solid phase heat recovery and in the thermodynamic properties of metal oxides are the most important paths to achieving unprecedented thermal efficiencies of 10% and higher in non-stoichiometric solar redox reactors. In this paper, the impact of solid and gas phase heat recovery on the efficiency of a non-stoichiometric cerium dioxide-based H 2 O/CO 2 splitting cycle realized in a solar-driven reactor are evaluated in a parametric thermodynamic analysis. Application of solid phase heat recovery to the cycling metal oxide allows for lower reduction zone operating temperatures, simplifying reactor design. An optimum temperature for metal oxide reduction results from two competing phenomena as the reduction temperature is increased: increasing re-radiation losses from the reactor aperture and decreasing heat loss due to imperfect solid phase heat recovery. Additionally, solid phase heat recovery increases the efficiency gains made possible by gas phase heat recovery. -- Highlights: ► Both solid and gas phase heat recovery are essential to achieve high thermal efficiency in non-stoichiometric ceria-based solar redox reactors. ► Solid phase heat recovery allows for lower reduction temperatures and increases the gains made possible by gas phase heat recovery. ► The optimum reduction temperature increases with increasing concentration ratio and decreasing solid phase heat recovery effectiveness. ► Even moderate levels of heat recovery dramatically improve reactor efficiency from 3.5% to 16%.

Investigation of innovative thermochemical energy storage processes and materials for building applications

OpenAIRE

Aydin, Devrim

2016-01-01

In this study, it is aimed to develop an innovative thermochemical energy storage system through material, reactor and process based investigations for building space heating applications. The developed system could be integrated with solar thermal collectors, photovoltaic panels or heat pumps to store any excess energy in the form of heat for later use. Thereby, it is proposed to address the problem of high operational costs and CO2 emissions released by currently used fossil fuel based heat...

The NEA thermochemical database project. 30 years of accomplishments

International Nuclear Information System (INIS)

Ragoussi, Maria-Eleni; Brassinnes, Stephane

2015-01-01

The NEA Thermochemical Database (TDB) Project (www.oecd-nea.org/dbtdb/) provides a database of chemical thermodynamic values treating the most significant elements related to nuclear waste management. The work carried out since the initiation of TDB in 1984 has resulted in the publication of thirteen major reviews and a large set of selected values that have become an international reference in the field, as they are characterized for their accuracy, consistency and high quality. Herein, we describe the basis, scientific principles and organization of the TDB project, together with its evolution from its inception to the present organization as a joint undertaking under Article 5(b) of the Statute of the OECD Nuclear Energy Agency (NEA).

An approach to thermochemical modeling of nuclear waste glass

International Nuclear Information System (INIS)

Besmann, T.M.; Beahm, E.C.; Spear, K.E.

1998-01-01

This initial work is aimed at developing a basic understanding of the phase equilibria and solid solution behavior of the constituents of waste glass. Current, experimentally determined values are less than desirable since they depend on measurement of the leach rate under non-realistic conditions designed to accelerate processes that occur on a geologic time scale. The often-used assumption that the activity of a species is either unity or equal to the overall concentration of the metal can also yield misleading results. The associate species model, a recent development in thermochemical modeling, will be applied to these systems to more accurately predict chemical activities in such complex systems as waste glasses

Efficiency calculations and optimization analysis of a solar reactor for the high temperature step of the zinc/zinc-oxide thermochemical redox cycle

Energy Technology Data Exchange (ETDEWEB)

Haussener, S.

2007-03-15

A solar reactor for the first step of the zinc/zinc-oxide thermochemical redox cycle is analysed and dimensioned in terms of maximization of efficiency and reaction conversion. Zinc-oxide particles carried in an inert carrier gas, in our case argon, enter the reactor in absorber tubes and are heated by concentrated solar radiation mainly due to radiative heat transfer. The particles dissociate and, in case of complete conversion, a gas mixture of argon, zinc and oxygen leaves the reactor. The aim of this study is to find an optimal design of the reactor regarding efficiency, materials and economics. The number of absorber tubes and their dimensions, the cavity dimension and its material as well as the operating conditions should be determined. Therefore 2D and 3D simulations of an 8 kW reactor are implemented. The gases are modeled as ideal gases with temperature-dependent properties. Absorption and scattering of the particle gas mixture are calculated by Mie-theory. Radiative heat transfer is included in the simulation and implemented with the aid of the discrete ordinates (DO) method. The mixture is modeled as ideal mixture and the reaction with an Arrhenius-type ansatz. Temperature distribution, reaction efficiency (heat used for zinc-oxide reaction divided by input) and tube efficiency (heat going into absorber tubes divided by input) as well as reaction conversion are analyzed to find the most promising reactor design. The results show that the most significant factors for efficiencies, conversion and absorber fluid temperature are concentration of the solar incoming radiation, zinc-oxide mass flow, the number of tubes and their dimension. Higher concentration leads to solely positive effects. Zinc-oxide mass flow variations indicate the existence of an optimal flow rate for each reactor design which maximizes efficiencies and conversion. Higher zinc-oxide mass flow leads, on one hand, to higher tube efficiency but on the other hand to lower temperatures in

An investigation on the fuel savings potential of hybrid hydraulic refuse collection vehicles.

Science.gov (United States)

Bender, Frank A; Bosse, Thomas; Sawodny, Oliver

2014-09-01

Refuse trucks play an important role in the waste collection process. Due to their typical driving cycle, these vehicles are characterized by large fuel consumption, which strongly affects the overall waste disposal costs. Hybrid hydraulic refuse vehicles offer an interesting alternative to conventional diesel trucks, because they are able to recuperate, store and reuse braking energy. However, the expected fuel savings can vary strongly depending on the driving cycle and the operational mode. Therefore, in order to assess the possible fuel savings, a typical driving cycle was measured in a conventional vehicle run by the waste authority of the City of Stuttgart, and a dynamical model of the considered vehicle was built up. Based on the measured driving cycle and the vehicle model including the hybrid powertrain components, simulations for both the conventional and the hybrid vehicle were performed. Fuel consumption results that indicate savings of about 20% are presented and analyzed in order to evaluate the benefit of hybrid hydraulic vehicles used for refuse collection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental results of a 3 k Wh thermochemical heat storage module for space heating application

NARCIS (Netherlands)

Finck, C.J.; Henquet, E.M.R.; Soest, C.F.L. van; Oversloot, H.P.; Jong, A.J. de; Cuypers, R.; Spijker, J.C. van 't

2014-01-01

A 3 kWh thermochemical heat storage (TCS) module was built as part of an all-in house system implementation focusing on space heating application at a temperature level of 40 ºC and a temperature lift of 20 K. It has been tested and measurements showed a maximum water circuit temperature span

CONCEPTUAL DESIGN AND ECONOMICS OF THE ADVANCED CO2 HYBRID POWER CYCLE

Energy Technology Data Exchange (ETDEWEB)

A. Nehrozoglu

2004-12-01

Research has been conducted under United States Department of Energy Contract DEFC26-02NT41621 to analyze the feasibility of a new type of coal-fired plant for electric power generation. This new type of plant, called the Advanced CO{sub 2} Hybrid Power Plant, offers the promise of efficiencies nearing 36 percent, while concentrating CO{sub 2} for 100% sequestration. Other pollutants, such as SO{sub 2} and NOx, are sequestered along with the CO{sub 2} yielding a zero emissions coal plant. The CO{sub 2} Hybrid is a gas turbine-steam turbine combined cycle plant that uses CO{sub 2} as its working fluid to facilitate carbon sequestration. The key components of the plant are a cryogenic air separation unit (ASU), a pressurized circulating fluidized bed gasifier, a CO{sub 2} powered gas turbine, a circulating fluidized bed boiler, and a super-critical pressure steam turbine. The gasifier generates a syngas that fuels the gas turbine and a char residue that, together with coal, fuels a CFB boiler to power the supercritical pressure steam turbine. Both the gasifier and the CFB boiler use a mix of ASU oxygen and recycled boiler flue gas as their oxidant. The resulting CFB boiler flue gas is essentially a mixture of oxygen, carbon dioxide and water. Cooling the CFB flue gas to 80 deg. F condenses most of the moisture and leaves a CO{sub 2} rich stream containing 3%v oxygen. Approximately 30% of this flue gas stream is further cooled, dried, and compressed for pipeline transport to the sequestration site (the small amount of oxygen in this stream is released and recycled to the system when the CO{sub 2} is condensed after final compression and cooling). The remaining 70% of the flue gas stream is mixed with oxygen from the ASU and is ducted to the gas turbine compressor inlet. As a result, the gas turbine compresses a mixture of carbon dioxide (ca. 64%v) and oxygen (ca. 32.5%v) rather than air. This carbon dioxide rich mixture then becomes the gas turbine working fluid and

Cea assessment of the sulphur-iodine cycle for hydrogen production

International Nuclear Information System (INIS)

Caries, Ph.; Vitart, X.; Yvon, P.

2010-01-01

The sulphur-iodine cycle is a promising process for hydrogen production using nuclear heat: - it is a purely thermochemical cycle, implying that hydrogen production will scale with volume rather than surface; - it only involves fluids, thus avoiding the often difficult handling of solids; - its heat requirements are well matched to the temperatures available from a Generation IV very/high temperature reactor. These characteristics seem very attractive for high efficiency and low cost massive hydrogen production. On the other hand, the efficiency of the cycle may suffer from the large over-stoichiometries of water and iodine and the very important heat exchanges it involves; furthermore, due to lack of adequate thermodynamic models, its efficiency is difficult to assess with confidence. Besides, the large quantities of chemicals that need to be handled, and the corrosiveness of these chemicals, are factors not to be overlooked in terms of investment and operation costs. In order to assess the actual potential of the sulphur-iodine cycle for massive hydrogen production at a competitive cost, CEA has been conducting an important programme on this cycle, ranging from thermodynamic measurements to hydrogen production cost evaluation, with flow sheet optimisation, component sizing and investment cost estimation as intermediate steps. The paper will present the method used, the status of both efficiency and production cost estimations, and discuss perspectives for improvement. (authors)

Freeway Driving Cycle Construction Based on Real-Time Traffic Information and Global Optimal Energy Management for Plug-In Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Hongwen He

2017-11-01

Full Text Available This paper presents a freeway driving cycle (FDC construction method based on traffic information. A float car collected different type of roads in California and we built a velocity fragment database. We selected a real freeway driving cycle (RFDC and established the corresponding time traffic information tensor model by using the data in California Department of Transportation performance measure system (PeMS. The correlation of road velocity in the time dimension and spatial dimension are analyzed. According to the average velocity of road sections at different times, the kinematic fragments are stochastically selected in the velocity fragment database to construct a real-time FDC of each section. The comparison between construction freeway driving cycle (CFDC and real freeway driving cycle (RFDC show that the CFDC well reflects the RFDC characteristic parameters. Compared to its application in plug-in electric hybrid vehicle (PHEV optimal energy management based on a dynamic programming (DP algorithm, CFDC and RFDC fuel consumption are similar within approximately 5.09% error, and non-rush hour fuel economy is better than rush hour 3.51 (L/100 km at non-rush hour, 4.29 (L/km at rush hour. Moreover, the fuel consumption ratio can be up to 13.17% in the same CFDC at non-rush hour.

Greenhouse gas implications of using coal for transportation: Life cycle assessment of coal-to-liquids, plug-in hybrids, and hydrogen pathways

International Nuclear Information System (INIS)

Jaramillo, Paulina; Samaras, Constantine; Wakeley, Heather; Meisterling, Kyle

2009-01-01

Using coal to produce transportation fuels could improve the energy security of the United States by replacing some of the demand for imported petroleum. Because of concerns regarding climate change and the high greenhouse gas (GHG) emissions associated with conventional coal use, policies to encourage pathways that utilize coal for transportation should seek to reduce GHGs compared to petroleum fuels. This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the emissions of plug-in hybrid electric vehicles (PHEV) powered with coal-based electricity, and to the emissions of a fuel cell vehicle (FCV) that uses coal-based hydrogen. A life cycle approach is used to account for fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. This analysis allows policymakers to better identify benefits or disadvantages of an energy future that includes coal as a transportation fuel. We find that PHEVs could reduce vehicle life cycle GHG emissions by up to about one-half when coal with carbon capture and sequestration is used to generate the electricity used by the vehicles. On the other hand, CTL fuels and coal-based hydrogen would likely lead to significantly increased emissions compared to PHEVs and conventional vehicles using petroleum-based fuels.

Environmental assessment of plug-in hybrid electric vehicles using naturalistic drive cycles and vehicle travel patterns: A Michigan case study

International Nuclear Information System (INIS)

Marshall, Brandon M.; Kelly, Jarod C.; Lee, Tae-Kyung; Keoleian, Gregory A.; Filipi, Zoran

2013-01-01

Plug-in hybrid electric vehicles (PHEVs) use grid electricity as well as on-board gasoline for motive force. These multiple energy sources make prediction of PHEV energy consumption challenging and also complicate evaluation of their environmental impacts. This paper introduces a novel PHEV energy consumption modeling approach and compares it to a second approach from the literature, each using actual trip patterns from the 2009 National Household Travel Survey (NHTS). The first approach applies distance-dependent fuel efficiency and on-road electricity consumption rates based on naturalistic or real world, driving information to determine gasoline and electricity consumption. The second uses consumption rates derived in accordance with government certification testing. Both approaches are applied in the context of a location-specific case study that focuses on the state of Michigan. The two PHEV models show agreement in electricity demand due to vehicle charging, gasoline consumption, and life cycle environmental impacts for this case study. The naturalistic drive cycle approach is explored as a means of extending location-specific driving data to supplement existing PHEV impact assessments methods. - Highlights: • Travel patterns from survey data are combined with naturalistic drive cycles. • More realistic PHEV energy modeling using these synthesized real-world drive cycles. • Methodology is demonstrated for PHEVs in Michigan but applicable for other regions. • Energy and emissions findings have major implications for PHEV standards and policy

Development and applications of GREET 2.7 -- The Transportation Vehicle-Cycle Model

International Nuclear Information System (INIS)

Burnham, A.; Wang, M. Q.; Wu, Y.

2006-01-01

Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results

Development and applications of GREET 2.7 -- The Transportation Vehicle-CycleModel.

Energy Technology Data Exchange (ETDEWEB)

Burnham, A.; Wang, M. Q.; Wu, Y.

2006-12-20

Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results.

Improving Students' Chemical Literacy Levels on Thermochemical and Thermodynamics Concepts through a Context-Based Approach

Science.gov (United States)

Cigdemoglu, Ceyhan; Geban, Omer

2015-01-01

The aim of this study was to delve into the effect of context-based approach (CBA) over traditional instruction (TI) on students' chemical literacy level related to thermochemical and thermodynamics concepts. Four eleventh-grade classes with 118 students in total taught by two teachers from a public high school in 2012 fall semester were enrolled…

Real-Time Energy Management Control for Hybrid Electric Powertrains

Directory of Open Access Journals (Sweden)

Mohamed Zaher

2013-01-01

Full Text Available This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real-time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. There are three main concepts for energy storing devices in hybrid vehicles: electric, hydraulic, and mechanical (flywheel. The real-time control challenge is to balance the system power demands from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle. In the worst-case scenario, only the engine is used and the hybrid system is completely disabled. A rule-based control algorithm is developed and is tuned for different work cycles and could be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work machine and its position via GPS and maps both of them to the gains.

Graphene/MnO2 hybrid nanosheets as high performance electrode materials for supercapacitors

International Nuclear Information System (INIS)

Mondal, Anjon Kumar; Wang, Bei; Su, Dawei; Wang, Ying; Chen, Shuangqiang; Zhang, Xiaogang; Wang, Guoxiu

2014-01-01

Graphene/MnO 2 hybrid nanosheets were prepared by incorporating graphene and MnO 2 nanosheets in ethylene glycol. Scanning electron microscopy and transmission electron microscopy analyses confirmed nanosheet morphology of the hybrid materials. Graphene/MnO 2 hybrid nanosheets with different ratios were investigated as electrode materials for supercapacitors by cyclic voltammetry (CV) and galvanostatic charge–discharge in 1 M Na 2 SO 4 electrolyte. We found that the graphene/MnO 2 hybrid nanosheets with a weight ratio of 1:4 (graphene:MnO 2 ) delivered the highest specific capacitance of 320 F g −1 . Graphene/MnO 2 hybrid nanosheets also exhibited good capacitance retention on 2000 cycles. - Highlights: • Graphene/MnO 2 hybrid nanosheets with different ratios were fabricated. • The specific capacitance is strongly dependent on graphene/MnO 2 ratios. • The graphene/MnO 2 hybrid electrode (1:4) exhibited high specific capacitance. • The electrode retained 84% of the initial specific capacitance after 2000 cycles

Nuclear hybrid energy infrastructure

Energy Technology Data Exchange (ETDEWEB)

Agarwal, Vivek; Tawfik, Magdy S.

2015-02-01

The nuclear hybrid energy concept is becoming a reality for the US energy infrastructure where combinations of the various potential energy sources (nuclear, wind, solar, biomass, and so on) are integrated in a hybrid energy system. This paper focuses on challenges facing a hybrid system with a Small Modular Reactor at its core. The core of the paper will discuss efforts required to develop supervisory control center that collects data, supports decision-making, and serves as an information hub for supervisory control center. Such a center will also be a model for integrating future technologies and controls. In addition, advanced operations research, thermal cycle analysis, energy conversion analysis, control engineering, and human factors engineering will be part of the supervisory control center. Nuclear hybrid energy infrastructure would allow operators to optimize the cost of energy production by providing appropriate means of integrating different energy sources. The data needs to be stored, processed, analyzed, trended, and projected at right time to right operator to integrate different energy sources.

Static Thermochemical Model of COREX Melter Gasifier

Science.gov (United States)

Srishilan, C.; Shukla, Ajay Kumar

2018-02-01

COREX is one of the commercial smelting reduction processes. It uses the finer size ore and semi-soft coal instead of metallurgical coke to produce hot metal from iron ore. The use of top gas with high calorific value as a by-product export gas makes the process economical and green. The predictive thermochemical model of the COREX process presented here enables rapid computation of process parameters such as (1) required amount of ore, coal, and flux; (2) amount of slag and gas generated; and (3) gas compositions (based on the raw material and desired hot metal quality). The model helps in predicting the variations in process parameters with respect to the (1) degree of metallization and (2) post-combustion ratio for given raw material conditions. In general reduction in coal, flux, and oxygen, the requirement is concomitant with an increase in the degree of metallization and post-combustion ratio. The model reported here has been benchmarked using industrial data obtained from the JSW Steel Plant, India.

Thermochemical equilibrium modelling of a gasifying process

International Nuclear Information System (INIS)

Melgar, Andres; Perez, Juan F.; Laget, Hannes; Horillo, Alfonso

2007-01-01

This article discusses a mathematical model for the thermochemical processes in a downdraft biomass gasifier. The model combines the chemical equilibrium and the thermodynamic equilibrium of the global reaction, predicting the final composition of the producer gas as well as its reaction temperature. Once the composition of the producer gas is obtained, a range of parameters can be derived, such as the cold gas efficiency of the gasifier, the amount of dissociated water in the process and the heating value and engine fuel quality of the gas. The model has been validated experimentally. This work includes a parametric study of the influence of the gasifying relative fuel/air ratio and the moisture content of the biomass on the characteristics of the process and the producer gas composition. The model helps to predict the behaviour of different biomass types and is a useful tool for optimizing the design and operation of downdraft biomass gasifiers

GEOTHERMAL / SOLAR HYBRID DESIGNS: USE OF GEOTHERMAL ENERGY FOR CSP FEEDWATER HEATING

Energy Technology Data Exchange (ETDEWEB)

Craig Turchi; Guangdong Zhu; Michael Wagner; Tom Williams; Dan Wendt

2014-10-01

This paper examines a hybrid geothermal / solar thermal plant design that uses geothermal energy to provide feedwater heating in a conventional steam-Rankine power cycle deployed by a concentrating solar power (CSP) plant. The geothermal energy represents slightly over 10% of the total thermal input to the hybrid plant. The geothermal energy allows power output from the hybrid plant to increase by about 8% relative to a stand-alone CSP plant with the same solar-thermal input. Geothermal energy is converted to electricity at an efficiency of 1.7 to 2.5 times greater than would occur in a stand-alone, binary-cycle geothermal plant using the same geothermal resource. While the design exhibits a clear advantage during hybrid plant operation, the annual advantage of the hybrid versus two stand-alone power plants depends on the total annual operating hours of the hybrid plant. The annual results in this draft paper are preliminary, and further results are expected prior to submission of a final paper.

Analysis of Efficiency of the Ship Propulsion System with Thermochemical Recuperation of Waste Heat

Science.gov (United States)

Cherednichenko, Oleksandr; Serbin, Serhiy

2018-03-01

One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources. The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered. It is suggested to conduct the study with the help of mathematical modeling methods. The model takes into account basic physical correlations, material and thermal balances, phase equilibrium, and heat and mass transfer processes. The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel. In such a plant, it is possible to reduce the specific fuel consumption of the diesel engine by 20%. The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6. When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products, the efficiency coefficient of the plant increases by 4-5%.

Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation

NARCIS (Netherlands)

Baran, Ismet; Tutum, Cem C.; Hattel, Jesper H.; Akkerman, Remko

2015-01-01

A novel three dimensional thermo-chemical simulation of the pultrusion process is presented. A simulation is performed for the pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used.

Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2015-01-01

novel three dimensional thermo-chemical simulation of the pultrusion process is presented. A simulation is performed for the pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used. First...

Coupled thermochemical, isotopic evolution and heat transfer simulations in highly irradiated UO{sub 2} nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Piro, M.H.A., E-mail: markuspiro@gmail.com [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Banfield, J. [Nuclear Engineering Department, University of Tennessee, Knoxville, TN (United States); Clarno, K.T., E-mail: clarnokt@ornl.gov [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Simunovic, S. [Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Besmann, T.M. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Lewis, B.J.; Thompson, W.T. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON (Canada)

2013-10-15

Predictive capabilities for simulating irradiated nuclear fuel behavior are enhanced in the current work by coupling thermochemistry, isotopic evolution and heat transfer. Thermodynamic models that are incorporated into this framework not only predict the departure from stoichiometry of UO{sub 2}, but also consider dissolved fission and activation products in the fluorite oxide phase, noble metal inclusions, secondary oxides including uranates, zirconates, molybdates and the gas phase. Thermochemical computations utilize the spatial and temporal evolution of the fission and activation product inventory in the pellet, which is typically neglected in nuclear fuel performance simulations. Isotopic computations encompass the depletion, decay and transmutation of more than 2000 isotopes that are calculated at every point in space and time. These computations take into consideration neutron flux depression and the increased production of fissile plutonium near the fuel pellet periphery (i.e., the so-called “rim effect”). Thermochemical and isotopic predictions are in very good agreement with reported experimental measurements of highly irradiated UO{sub 2} fuel with an average burnup of 102 GW d t(U){sup −1}. Simulation results demonstrate that predictions are considerably enhanced when coupling thermochemical and isotopic computations in comparison to empirical correlations. Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

FY 1974 report on the results of the Sunshine Project. R and D of the hydrogen production technology by the thermochemical method; 1974 nendo netsukagakuho ni yoru suiso seizo gijutsu no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-05-28

In relation to the R and D of the hydrogen production technology by the thermochemical method, the paper summed up the results of the research conducted in FY 1974. The items for study are as follows. (1) Basic model making for process simulator. (2) Type of facility on the assumption of pilot plant size, and rough selection of equipment structural materials. (3) Extraction of engineering study subjects and working-out of study plans. In (1), the basic model of simulator was established, case studies of various Fe-Cl cycles were made, and a calculation method for the balance of the whole process was established. In (2), it was concluded that in the normal pressure reaction experiment, the oxygen emits extremely little in amount in Mark 9 No. 2 reaction, and therefore, it is very doubtful whether the closed cycle will be completed using this reaction. It was also found out that No. 3 reaction is low in reaction completion degree and it is the problem in point of thermal economy. Accordingly, possibilities of reaction were reviewed, and 6 cycles were found as Fe-Cl cycle. For these reaction cycles, a process flow sheet was made. Comparative studies among processes were conducted, and the cycle structural elementary reaction in Fe-Cl process was specified. (NEDO)

Fuel economy of hybrid fuel-cell vehicles

Science.gov (United States)

Ahluwalia, Rajesh K.; Wang, X.; Rousseau, A.

The potential improvement in fuel economy of a mid-size fuel-cell vehicle by combining it with an energy storage system has been assessed. An energy management strategy is developed and used to operate the direct hydrogen, pressurized fuel-cell system in a load-following mode and the energy storage system in a charge-sustaining mode. The strategy places highest priority on maintaining the energy storage system in a state where it can supply unanticipated boost power when the fuel-cell system alone cannot meet the power demand. It is found that downsizing a fuel-cell system decreases its efficiency on a drive cycle which is compensated by partial regenerative capture of braking energy. On a highway cycle with limited braking energy the increase in fuel economy with hybridization is small but on the stop-and-go urban cycle the fuel economy can improve by 27%. On the combined highway and urban drive cycles the fuel economy of the fuel-cell vehicle is estimated to increase by up to 15% by hybridizing it with an energy storage system.

Life cycle cost of a hybrid forward osmosis – low pressure reverse osmosis system for seawater desalination and wastewater recovery

KAUST Repository

Valladares Linares, Rodrigo

2015-10-19

In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis – low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor – reverse osmosis – advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m3 d−1 of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m3 produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

Proceedings of Brookhaven National Laboratory's fusion/synfuel workshop

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.

1979-01-01

The fusion synfuels workshop held at Brookhaven National Laboratory (BNL) on August 27-29, 1979 examined the current status of candidate synfuel processes and the R and D required to develop the capability for fusion synfuel production. Participants divided into five working groups, covering the following areas: (1) economics and applications; (2) high-temperature electrolysis; (3) thermochemical processes (including hybrid thermo-electrochemical); (4) blanket and materials; and (5) high-efficiency power cycles. Each working group presented a summary of their conclusions and recommendations to all participants during the third day of the Workshop. These summaries are given

Improvement in Performance of a Thermochemical Heat Storage System by Implementing an Internal Heat Recovery System

NARCIS (Netherlands)

Gaeini, M.; Saris, L.; Zondag, H.A.; Rindt, C.C.M.

A lab-scale prototype of a thermochemical heat storage system, employing a water-zeolite 13X as the working pair, is designed and optimized for providing hot tap water. During the hydration process, humid air is introduced to the packed bed reactor filled with dehydrated zeolite 13X, and the

Design optimisation of a flywheel hybrid vehicle

Energy Technology Data Exchange (ETDEWEB)

Kok, D.B.

1999-11-04

during the engine start-up and shutdown periods. Correct throttle valve control ensures that hydrocarbon emissions are not critical for legislative emission limits, but the engine's standard lambda control cannot prevent an increase of nitric oxides. In order to improve tailpipe emissions, the thermo-chemical behaviour of the catalytic converter is investigated and adapted for hybrid vehicle application. In cold-start situations, the fuel consumption and exhaust gas emissions of a mechanical driveline with internal combustion engine increase. A detailed numerical investigation of the thermal behaviour of the hybrid driveline showed that the energy-efficient operation of the engine decreases thermal waste energy that is available to warm up driveline components. Therefore, a redesign of the cooling circuitry and thermal management of the driveline was required to improve system warm-up. A computer model has been developed that combines the functional description of the flywheel hybrid vehicle with the calculation of energy losses. Apart from standardised European drive cycles, velocity profiles that represent more realistic vehicle utilisation are used to assess and optimise the hybrid vehicle's fuel economy, exhaust gas emission and acceleration performance. Subdivision of energy consumption enabled the classification of those systems and components that have a major effect on fuel consumption. Of these, the optimised flywheel system, the hydraulic system, and the transmission consume energy of comparable magnitude in city driving. It is shown that the system's fuel economy is mainly a result of the improved engine operation. Regenerative braking has only limited effect on vehicle fuel consumption. Experiments with an early prototype of the hybrid driveline yielded no gains in fuel consumption when compared to a conventional CVT reference vehicle due to high storage losses in the flywheel system. However, the improved prototype of the flywheel hybrid

Electrochemically deposited hybrid nickel-cobalt hexacyanoferrate nanostructures for electrochemical supercapacitors

International Nuclear Information System (INIS)

Safavi, A.; Kazemi, S.H.; Kazemi, H.

2011-01-01

Highlights: → Nanostructured hybrid nickel-cobalt hexacyanoferrate is used in supercapacitors. → A high capacitance (765 F g -1 ) is obtained at a specific current of 0.2 A g -1 . → Long cycle-life and excellent stability are demonstrated during 1000 cycles. - Abstract: This study describes the use of electrodeposited nanostructured hybrid nickel-cobalt hexacyanoferrate in electrochemical supercapacitors. Herein, various compositions of nickel and cobalt hexacyanoferrates (Ni/CoHCNFe) nanostructures are electrodeposited on an inexpensive stainless steel substrate using cyclic voltammetric (CV) method. The morphology of the electrodeposited nanostructures is studied using scanning electron microscopy, while their electrochemical characterizations are investigated using CV, galvanostatic charge and discharge and electrochemical impedance spectroscopy. The results show that the nanostructures of hybrid metal cyanoferrate, shows a much higher capacitance (765 F g -1 ) than those obtained with just nickel hexacyanoferrate (379 F g -1 ) or cobalt hexacyanoferrate (277 F g -1 ). Electrochemical impedance spectroscopy results confirm the favorable capacitive behavior of the electrodeposited materials. The columbic efficiency is approximately 95% based on the charge and discharge experiments. Long cycle-life and excellent stability of the nanostructured materials are also demonstrated during 1000 cycles.

Electrochemically deposited hybrid nickel-cobalt hexacyanoferrate nanostructures for electrochemical supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Safavi, A., E-mail: safavi@chem.susc.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Nanotechnology Research Institute, Shiraz University, Shiraz (Iran, Islamic Republic of); Kazemi, S.H., E-mail: habibkazemi@iasbs.ac.ir [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Kazemi, H. [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

2011-10-30

Highlights: > Nanostructured hybrid nickel-cobalt hexacyanoferrate is used in supercapacitors. > A high capacitance (765 F g{sup -1}) is obtained at a specific current of 0.2 A g{sup -1}. > Long cycle-life and excellent stability are demonstrated during 1000 cycles. - Abstract: This study describes the use of electrodeposited nanostructured hybrid nickel-cobalt hexacyanoferrate in electrochemical supercapacitors. Herein, various compositions of nickel and cobalt hexacyanoferrates (Ni/CoHCNFe) nanostructures are electrodeposited on an inexpensive stainless steel substrate using cyclic voltammetric (CV) method. The morphology of the electrodeposited nanostructures is studied using scanning electron microscopy, while their electrochemical characterizations are investigated using CV, galvanostatic charge and discharge and electrochemical impedance spectroscopy. The results show that the nanostructures of hybrid metal cyanoferrate, shows a much higher capacitance (765 F g{sup -1}) than those obtained with just nickel hexacyanoferrate (379 F g{sup -1}) or cobalt hexacyanoferrate (277 F g{sup -1}). Electrochemical impedance spectroscopy results confirm the favorable capacitive behavior of the electrodeposited materials. The columbic efficiency is approximately 95% based on the charge and discharge experiments. Long cycle-life and excellent stability of the nanostructured materials are also demonstrated during 1000 cycles.

Adsorption desalination—Principles, process design, and its hybrids for future sustainable desalination

KAUST Repository

Shahzad, Muhammad Wakil; Burhan, Muhammad; Ang, Li; Ng, Kim Choon

2018-01-01

The energy, water, and environment nexus is a crucial factor when considering the future development of desalination plants or industry in water-stressed economies. The new generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increases around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available heat-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as an increase in water production can be expected. The advent of MED with AD cycles, or simply called the MED-AD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-stream at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60°C and 80°C. In this chapter, the authors have reported their pioneered research on aspects of AD and related hybrid MED-AD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concepts, the authors examine the cost apportionment of fuel cost by the quality or exergy of the working steam for such cogeneration configurations.

Adsorption desalination—Principles, process design, and its hybrids for future sustainable desalination

KAUST Repository

Shahzad, Muhammad Wakil

2018-05-03

The energy, water, and environment nexus is a crucial factor when considering the future development of desalination plants or industry in water-stressed economies. The new generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increases around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available heat-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as an increase in water production can be expected. The advent of MED with AD cycles, or simply called the MED-AD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-stream at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60°C and 80°C. In this chapter, the authors have reported their pioneered research on aspects of AD and related hybrid MED-AD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concepts, the authors examine the cost apportionment of fuel cost by the quality or exergy of the working steam for such cogeneration configurations.

Optimization of waste to energy routes through biochemical and thermochemical treatment options of municipal solid waste in Hyderabad, Pakistan

International Nuclear Information System (INIS)

Korai, Muhammad Safar; Mahar, Rasool Bux; Uqaili, Muhammad Aslam

2016-01-01

Highlights: • Existing practice of municipal solid waste management of Hyderabad city, Pakistan have been analyzed. • Development of scenarios on basis of nature of waste components for optimizing waste to energy route. • Analyzing the biochemical and thermochemical potential of MSW through various scenarios. • Evaluation of various treatment technologies under scenarios to optimize waste to energy route. - Abstract: Improper disposal of municipal solid waste (MSW) has created many environmental problems in Pakistan and the country is facing energy shortages as well. The present study evaluates the biochemical and thermochemical treatment options of MSW in order to address both the endemic environmental challenges and in part the energy shortage. According to the nature of waste components, a number of scenarios were developed to optimize the waste to energy (WTE) routes. The evaluation of treatment options has been performed by mathematical equations using the special characteristics of MSW. The power generation potential (PGP) of biochemical (anaerobic digestion) has been observed in the range of 5.9–11.3 kW/ton day under various scenarios. The PGP of Refuse Derived Fuel (RDF), Mass Burn Incinerator (MBI), Gasification/Pyrolysis (Gasi./Pyro.) and Plasma Arc Gasification (PAG) have been found to be in the range of 2.7–118.6 kW/ton day, 3.8–164.7 kW/ton day, 4.2–184.5 kW/ton day and 5.2–224 kW/ton day, respectively. The highest values of biochemical and all thermochemical technologies have been obtained through the use of scenarios including the putrescible components (PCs) of MSW such as food and yard wastes, and the non-biodegradable components (NBCs) of MSW such as plastic, rubber, leather, textile and wood respectively. Therefore, routes which include these components are the optimized WTE routes for maximum PGP by biochemical and thermochemical treatments of MSW. The findings of study lead to recommend that socio-economic and environmental

Influence of Mixed Solvent on the Electrochemical Property of Hybrid Capacitor.

Science.gov (United States)

Lee, Byunggwan; Yoon, J R

2015-11-01

The hybrid capacitors (2245 size, cylindrical type) were prepared by using activated carbon cathode and Li4Ti5O12 anode. In order to improve the cell operation at high temperature range, propylene carbonate (PC) was used in combination with acetonitrile (AN) with volume ratio of 7:3, 5:5, and 3:7, respectively. We investigated the electrochemical behavior of the hybrid capacitors that enabled cell operation with stability at high temperature. The organic electrolyte of hybrid capacitor containing PC and AN with a volume ratio 7:3 intended to exhibit highly reversible cycle performance with good capacity retention at 60 degrees C after 2200 cycles. From this study, it has been found that the very strong influence of the solvent nature on the characteristics of hybrid capacitor, and the difference in performance associated with the two solvents.

Small Hybrid Solar Power System

OpenAIRE

Kane, El Hadj Malick; Larrain, Diego; Favrat, Daniel

2001-01-01

This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The wast...

Small Hybrid Solar Power System

OpenAIRE

Kane, El Hadj Malick; Favrat, Daniel; Larrain, Diego; Allani, Yassine

2003-01-01

This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The waste heat from both...

Thermochemical studies on complex of [Sm(o-NBA)_3phen]_2

Institute of Scientific and Technical Information of China (English)

肖圣雄; 张建军; 李旭; 李强国; 任宁; 李环

2010-01-01

A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution enthalpies of SmCl3·6H2O(s), o-HNBA(s) and phen·H2O(s) in mixed solvent (VHCl :VDMF :VDMSO=2:2:1) were determined by calorimetry at 298.15 K. The enthalpy change of the reaction was determined to be rHmΔθ=252.49±1.60 kJ/mol. Using the relevant data in the literature and a thermochemical recycle ...

Symbiosis of near breeder HTR's with hybrid fusion reactors

International Nuclear Information System (INIS)

Seifritz, W.

1978-07-01

In this contribution to INFCE a symbiotic fusion/fission reactor system, consisting of a hybrid beam-driven micro-explosion fusion reactor (HMER) and associated high-temperature gas-cooled reactors (HTR) with a coupled fuel cycle, is proposed. This system is similar to the well known Fast Breeder/Near Breeder HTR symbiosis except that the fast fission breeder - running on the U/Pu-cycle in the core and the axial blankets and breeding the surplus fissile material as U-233 in its radial thorium metal or thorium oxide blankets - is replaced by a hybrid micro-explosion DT fusion reactor

Thermodynamics and performance of the Mg-H-F system for thermochemical energy storage applications.

Science.gov (United States)

Tortoza, Mariana S; Humphries, Terry D; Sheppard, Drew A; Paskevicius, Mark; Rowles, Matthew R; Sofianos, M Veronica; Aguey-Zinsou, Kondo-Francois; Buckley, Craig E

2018-01-24

Magnesium hydride (MgH 2 ) is a hydrogen storage material that operates at temperatures above 300 °C. Unfortunately, magnesium sintering occurs above 420 °C, inhibiting its application as a thermal energy storage material. In this study, the substitution of fluorine for hydrogen in MgH 2 to form a range of Mg(H x F 1-x ) 2 (x = 1, 0.95, 0.85, 0.70, 0.50, 0) composites has been utilised to thermodynamically stabilise the material, so it can be used as a thermochemical energy storage material that can replace molten salts in concentrating solar thermal plants. These materials have been studied by in situ synchrotron X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, temperature-programmed-desorption mass spectrometry and Pressure-Composition-Isothermal (PCI) analysis. Thermal analysis has determined that the thermal stability of Mg-H-F solid solutions increases proportionally with fluorine content, with Mg(H 0.85 F 0.15 ) 2 having a maximum rate of H 2 desorption at 434 °C, with a practical hydrogen capacity of 4.6 ± 0.2 wt% H 2 (theoretical 5.4 wt% H 2 ). An extremely stable Mg(H 0.43 F 0.57 ) 2 phase is formed upon the decomposition of each Mg-H-F composition of which the remaining H 2 is not released until above 505 °C. PCI measurements of Mg(H 0.85 F 0.15 ) 2 have determined the enthalpy (ΔH des ) to be 73.6 ± 0.2 kJ mol -1 H 2 and entropy (ΔS des ) to be 131.2 ± 0.2 J K -1 mol -1 H 2 , which is slightly lower than MgH 2 with ΔH des of 74.06 kJ mol -1 H 2 and ΔS des = 133.4 J K -1 mol -1 H 2 . Cycling studies of Mg(H 0.85 F 0.15 ) 2 over six absorption/desorption cycles between 425 and 480 °C show an increased usable cycling temperature of ∼80 °C compared to bulk MgH 2 , increasing the thermal operating temperatures for technological applications.