Science.gov

Sample records for dual fuel conversion

  1. Dual-fuel engine conversions evaluated by U.S. Navy

    SciTech Connect

    1996-10-01

    In seeking ways to reduce emissions from two-stroke locomotive type engines, the Navy has evaluated dual-fuel conversions operating on a compression ignition cycle, using up to 94% natural gas and 6% diesel pilot fuel. The Navy has conducted an evaluation and test program under the direction of Dr. Normnn L. Helgeson, at the Naval Facilities Engineering Service Center in Port Hueneme, California. Of the Navy`s many diesel engines, those installed in its MUSE (mobile utility support equipment) units for temporary electrical power were the first Navy off-road engines to be affected by emissions regulations. Most of the units are powered by the EMD 645 engine, and when burning diesel fuel do not meet the emission requirements in many areas of the country. This paper discusses the changes and results of the conversion and shakedown tests.

  2. Develop the dual fuel conversion system for high output, medium speed diesel engines. Quarterly report number 1, September 1--December 31, 1996

    SciTech Connect

    1997-01-08

    Energy Conversions Incorporated has made substantial progress on the EMD-710 dual-fuel test cell in the first quarter of the project. The project is on schedule and has not met with any major roadblocks that would derail the planned timetable. Please note that much of the work done started before the funding arrived, and therefore those items are not included in the financial expenditures for the quarter.

  3. Dual Tank Fuel System

    DOEpatents

    Wagner, Richard William; Burkhard, James Frank; Dauer, Kenneth John

    1999-11-16

    A dual tank fuel system has primary and secondary fuel tanks, with the primary tank including a filler pipe to receive fuel and a discharge line to deliver fuel to an engine, and with a balance pipe interconnecting the primary tank and the secondary tank. The balance pipe opens close to the bottom of each tank to direct fuel from the primary tank to the secondary tank as the primary tank is filled, and to direct fuel from the secondary tank to the primary tank as fuel is discharged from the primary tank through the discharge line. A vent line has branches connected to each tank to direct fuel vapor from the tanks as the tanks are filled, and to admit air to the tanks as fuel is delivered to the engine.

  4. Low conversion ratio fuel studies.

    SciTech Connect

    Smith, M. A.

    2006-02-28

    Recent studies on TRU disposition in fast reactors indicated viable reactor performance for a sodium cooled low conversion ratio reactor design. Additional studies have been initiated to refine the earlier work and consider the feasibility of alternate fuel forms such as nitride and oxide fuel (rather than metal fuel). These alternate fuel forms may have significant impacts upon the burner design and the safety behavior. The work performed thus far has focused on compiling the necessary fuel form property information and refinement of the physics models. For this limited project, the burner design and performance using nitride fuel will be assessed.

  5. Develop the dual fuel conversion system for high output, medium speed diesel engines. Quarterly report number 5, November 1997--January 1998

    SciTech Connect

    1998-02-23

    This quarter has the authors starting out with the engine mapped out in its standard dual fuel configuration. This means that the engine is configured to be exactly what the have been selling in the past. They have worked to install the new style gas injectors, Hydraulic power unit, control lines, gas lines and associated hardware. This hardware has been tested and is operational. They have been able to start at installing the spark ignition system but have been held up because of other more pressing work.

  6. Vehicle conversion to hybrid gasoline/alternative fuel operation

    NASA Astrophysics Data System (ADS)

    Donakowski, T. D.

    1982-11-01

    The alternative fuels considered are compressed natural gas (CNG), liquefied natural gas (LNG), liquid petroleum gas (LPG), and methanol; vehicles were required to operate in a hybrid or dual-fuel gasoline/alternative fuel mode. Economic feasibility was determined by comparing the costs of continued use of gasoline fuel with the use of alternative fuel and retrofitted equipment. Differences in the amounts of future expenditures are adjusted by means of a total life-cycle costing. All fuels studied are technically feasible to allow a retrofit conversion to hybrid gasoline/alternative fuel operation except for methanol. Conversion to LPG is not recommended for vehicles with more than 100,000 km (60,000 miles) of prior use. Methanol conversion is not recommended for vehicles with more than 50,00 km (30,000 miles).

  7. Vehicle conversion to hybrid gasoline/alternative fuel operation

    NASA Technical Reports Server (NTRS)

    Donakowski, T. D.

    1982-01-01

    The alternative fuels considered are compressed natural gas (CNG), liquefied natural gas (LNG), liquid petroleum gas (LPG), and methanol; vehicles were required to operate in a hybrid or dual-fuel gasoline/alternative fuel mode. Economic feasibility was determined by comparing the costs of continued use of gasoline fuel with the use of alternative fuel and retrofitted equipment. Differences in the amounts of future expenditures are adjusted by means of a total life-cycle costing. All fuels studied are technically feasible to allow a retrofit conversion to hybrid gasoline/alternative fuel operation except for methanol. Conversion to LPG is not recommended for vehicles with more than 100,000 km (60,000 miles) of prior use. Methanol conversion is not recommended for vehicles with more than 50,00 km (30,000 miles).

  8. Enhanced catalyst for conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, P.K.; Rabo, J.A.

    1985-12-03

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C[sub 5][sup +] hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising a SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  9. Enhanced conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.; Rabo, Jule A.

    1986-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  10. Enhanced catalyst for conversion of syngas to liquid motor fuels

    DOEpatents

    Coughlin, Peter K.; Rabo, Jule A.

    1985-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

  11. Conversion of raw carbonaceous fuels

    DOEpatents

    Cooper, John F.

    2007-08-07

    Three configurations for an electrochemical cell are utilized to generate electric power from the reaction of oxygen or air with porous plates or particulates of carbon, arranged such that waste heat from the electrochemical cells is allowed to flow upwards through a storage chamber or port containing raw carbonaceous fuel. These configurations allow combining the separate processes of devolatilization, pyrolysis and electrochemical conversion of carbon to electric power into a single unit process, fed with raw fuel and exhausting high BTU gases, electric power, and substantially pure CO.sub.2 during operation.

  12. Biomass conversion processes for energy and fuels

    NASA Astrophysics Data System (ADS)

    Sofer, S. S.; Zaborsky, O. R.

    The book treats biomass sources, promising processes for the conversion of biomass into energy and fuels, and the technical and economic considerations in biomass conversion. Sources of biomass examined include crop residues and municipal, animal and industrial wastes, agricultural and forestry residues, aquatic biomass, marine biomass and silvicultural energy farms. Processes for biomass energy and fuel conversion by direct combustion (the Andco-Torrax system), thermochemical conversion (flash pyrolysis, carboxylolysis, pyrolysis, Purox process, gasification and syngas recycling) and biochemical conversion (anaerobic digestion, methanogenesis and ethanol fermentation) are discussed, and mass and energy balances are presented for each system.

  13. Natural Gas for Advanced Dual-Fuel Combustion Strategies

    NASA Astrophysics Data System (ADS)

    Walker, Nicholas Ryan

    Natural gas fuels represent the next evolution of low-carbon energy feedstocks powering human activity worldwide. The internal combustion engine, the energy conversion device widely used by society for more than one century, is capable of utilizing advanced combustion strategies in pursuit of ultra-high efficiency and ultra-low emissions. Yet many emerging advanced combustion strategies depend upon traditional petroleum-based fuels for their operation. In this research the use of natural gas, namely methane, is applied to both conventional and advanced dual-fuel combustion strategies. In the first part of this work both computational and experimental studies are undertaken to examine the viability of utilizing methane as the premixed low reactivity fuel in reactivity controlled compression ignition, a leading advanced dual-fuel combustion strategy. As a result, methane is shown to be capable of significantly extending the load limits for dual-fuel reactivity controlled compression ignition in both light- and heavy-duty engines. In the second part of this work heavy-duty single-cylinder engine experiments are performed to research the performance of both conventional dual-fuel (diesel pilot ignition) and advanced dual-fuel (reactivity controlled compression ignition) combustion strategies using methane as the premixed low reactivity fuel. Both strategies are strongly influenced by equivalence ratio; diesel pilot ignition offers best performance at higher equivalence ratios and higher premixed methane ratios, whereas reactivity controlled compression ignition offers superior performance at lower equivalence ratios and lower premixed methane ratios. In the third part of this work experiments are performed in order to determine the dominant mode of heat release for both dual-fuel combustion strategies. By studying the dual-fuel homogeneous charge compression ignition and single-fuel spark ignition, strategies representative of autoignition and flame propagation

  14. Dual fuel low NOx burner

    SciTech Connect

    Shyhching Yang; Bortz, S.J.

    1993-08-31

    A dual fuel burner is described comprising: a divergent quarl having an entrance, and exit downstream from said entrance, and a plurality of axially extending staging air ports equally spaced around said exit; a wind pipe coaxially connected to said entrance of said quarl; a swirl generator coaxially received in said wind pipe, said swirl generator having a plurality of vanes and a center hole; a gas gun including a tube and a gas nozzle, said tube having an upstream end and a downstream end and being coaxially positioned within said center hole of said swirl generator said gas nozzle being mounted to said downstream end of said tube and positioned in the vicinity of said entrance of said quarl, said gas nozzle having a plurality of passageways having center lines that diverge in the downstream direction and are inclined at an angle of about 15 to 40 degrees with respect to the centerline of said quarl; an oil gun including an oil tube, an oil nozzle, and a high pressure air tube, said oil gun tube having an upstream end and a downstream end, said oil gun tube being coaxially positioned within said gas gun tube, said oil nozzle being mounted to said downstream end of said oil gun tube and positioned in the vicinity of said entrance of said quarl, said oil nozzle including a plurality of passageways having center lines that diverge in the downstream direction and are inclined at an angle of about 15 to 40 degrees with respect to the centerline of said quarl; said high pressure tube provided within said oil gun tube, said high pressure tube being in fluid communication with said oil nozzle passageways.

  15. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel...

  16. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Dual fuel vehicle incentive. 538.9 Section 538.9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel...

  17. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles... 49 Transportation 6 2014-10-01 2014-10-01 false Dual fuel vehicle incentive. 538.9 Section...

  18. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles... 49 Transportation 6 2010-10-01 2010-10-01 false Dual fuel vehicle incentive. 538.9 Section...

  19. 49 CFR 538.9 - Dual fuel vehicle incentive.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION MANUFACTURING INCENTIVES FOR ALTERNATIVE FUEL VEHICLES § 538.9 Dual fuel vehicle incentive. The application of 49 U.S.C. 32905(b) and (d) to qualifying dual fuel vehicles... 49 Transportation 6 2012-10-01 2012-10-01 false Dual fuel vehicle incentive. 538.9 Section...

  20. Dual fuel gradients in uranium silicide plates

    SciTech Connect

    Pace, B.W.

    1997-08-01

    Babcock & Wilcox has been able to achieve dual gradient plates with good repeatability in small lots of U{sub 3}Si{sub 2} plates. Improvements in homogeneity and other processing parameters and techniques have allowed the development of contoured fuel within the cladding. The most difficult obstacles to overcome have been the ability to evaluate the bidirectional fuel loadings in comparison to the perfect loading model and the different methods of instilling the gradients in the early compact stage. The overriding conclusion is that to control the contour of the fuel, a known relationship between the compact, the frames and final core gradient must exist. Therefore, further development in the creation and control of dual gradients in fuel plates will involve arriving at a plausible gradient requirement and building the correct model between the compact configuration and the final contoured loading requirements.

  1. Develop the dual fuel conversion system for high output, medium speed diesel engines. Quarterly report number 4, July--September, 1997

    SciTech Connect

    1997-09-23

    This quarter started out with fresh ability to perform sustained engine operation on gas because of the successful operation of the gas compressor last quarter. The authors have completed baseline tests recording emissions and efficiency numbers. This gives the authors data that they have never before been able to acquire in the facility. In addition to the baseline data they have recorded data with a host of additional engine variables. These variables include the adjustments of ignition timing, air fuel ratio, air inlet temperatures and some propane seeding of the injected gas. With the background data on record they will be able to properly measure the level of positive impact that the port gas injection system provides. The remaining time in this quarter has been focused on completing the application of the port style gas injection system. The next steps in this project all pivot on the application of this port injection system. They have also progressed in the evaluation of the cylinder/engine monitoring system.

  2. Combustion system for dual fuel engine

    SciTech Connect

    Schaub, F.S.; Smith, J.G.

    1990-10-30

    This patent describes in an dual gas-liquid fuel four cycle engine having cylinders and wherein each cylinder is operatively connected thereto and each cylinder has a piston, two inlet valves, two exhaust valves and a first liquid fuel injector. It comprises: at least one fuel torch cell operatively connected to at least one cylinder, the torch cell having a torch cell nozzle at one end thereof and the other end having appropriate means to connect the torch cell to a fuel supply, a second fuel injector mounted in the torch cell at a predetermined angle to an axis of the torch cell, the torch cell defining an auto-ignition chamber, the second fuel injector being in operative communication with the auto-ignition chamber by an injector nozzle passageway, the injector nozzle passageway entering the auto-ignition chamber at a predetermined angle relative to the axis, and a torch nozzle passage connecting the auto-ignition chamber with the cylinder at a predetermined angle to a top inner portion of a cylinder head.

  3. Fuel cell having dual electrode anode or cathode

    DOEpatents

    Findl, E.

    1984-04-10

    A fuel cell that is characterized by including a dual electrode anode that is operable to simultaneously electro-oxidize a gaseous fuel and a liquid fuel. In alternative embodiments, a fuel cell having a single electrode anode is provided with a dual electrode cathode that is operable to simultaneously reduce a gaseous oxidant and a liquid oxidant to electro-oxidize a fuel supplied to the cell.

  4. Fuel cell having dual electrode anode or cathode

    DOEpatents

    Findl, Eugene

    1985-01-01

    A fuel cell that is characterized by including a dual electrode anode that is operable to simultaneously electro-oxidize a gaseous fuel and a liquid fuel. In alternative embodiments, a fuel cell having a single electrode anode is provided with a dual electrode cathode that is operable to simultaneously reduce a gaseous oxidant and a liquid oxidant to electro-oxidize a fuel supplied to the cell.

  5. Conversion of wood residues to diesel fuel

    SciTech Connect

    Kuester, J.L.

    1981-01-01

    The basic approach is indirect liquefaction, i.e., thermal gasification followed by catalytic liquefaction. The indirect approach results in separation of the oxygen in the biomass feedstock, i.e., oxygenated compounds do not appear in the liquid hydrocarbon fuel product. The general conversion scheme is shown. The process is capable of accepting a wide variety of feedstocks. Potential products include medium quality gas, normal propanol, paraffinic fuel and/or high octane gasoline. A flow diagram of the continuous laboratory unit is shown. A fluidized bed pyrolysis system is used for gasification. Capacity is about 10 lbs/h of feedstock. The pyrolyzer can be fluidized with recycle pyrolysis gas, steam or recycle liquefaction system off gas or some combination thereof. Tars are removed in a wet scrubber. Unseparated pyrolysis gases are utilized as feed to a modified Fischer-Tropsch reactor. The liquid condensate from the reactor consists of a normal propanol-water phase and a paraffinic hydrocarbon phase. The reactor can be operated to optimize for either product. If a high octane gasoline is desired, the paraffinic fuel is passed through a conventional catalytic reformer. The normal propanol could be used as a fuel extender if blended with the hydrocarbon fuel products. Off gases from the downstream reactors are of high quality due to the accumulation of low molecular weight paraffins.

  6. 76 FR 19829 - Clean Alternative Fuel Vehicle and Engine Conversions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... include conversions of conventional gasoline or diesel vehicles to hybrid-electric vehicles, and conversions from hybrid-electric vehicles to plug-in hybrid electric vehicles. Since alternative fuel... Parts Manufacturing. 336322 Other Motor Vehicle Electrical and Electronic Equipment...

  7. Fossil fuel conversion -- Measurement and modeling

    SciTech Connect

    Solomon, P.R.; Smoot, L.D.; Serio, M.A.; Hamblen, D.G.; Brewster, B.S.; Radulovic, P.T.

    1995-11-01

    The main objective of this program is to understand the chemical and physical mechanisms in coal conversion processes and incorporate this knowledge in computer-aided reactor engineering technology for the purposes of development, evaluation, design, scale up, simulation, control and feedstock evaluation in advanced coal conversion devices. To accomplish this objective, this program will: (1) provide critical data on the physical and chemical processes in fossil fuel gasifier and combustors; (2) further develop a set of comprehensive codes; and (3) apply these codes to model various types of combustors and gasifier (fixed-bed, transport reactor, and fluidized-bed for coal and gas turbines for natural gas). Results are presented on the devolatilization of large coal particles; transport reactor modeling; fluidized bed model; nitrogen evolution from small and large coal particles; modeling of hydrogen cyanide and ammonia release during coal pyrolysis; oxidation rates for large coal particles at high pressures; advanced fixed-bed model development and evaluation; application of ACERC combustion and gasification codes to AFR diagnostic capabilities to systems of interest to METC; and submodel for lean premixed combustion of natural gas in industrial gas turbines.

  8. Dual-Fuel Truck Fleet: Start-Up Experience

    SciTech Connect

    NREL

    1998-09-30

    Although dual-fuel engine technology has been in development and limited use for several years, it has only recently moved toward full-scale operational capability for heavy-duty truck applications. Unlike a bifuel engine, which has two separate fuel systems that are used one at a time, a dual-fuel engine uses two fuel systems simultaneously. One of California's South Coast Air Quality Management District (SCAQMD) current programs is a demonstration of dual-fuel engine technology in heavy-duty trucks. These trucks are being studied as part of the National Renewable Energy Laboratory's (NREL's) Alternative Fuel Truck Program. This report describes the start-up experience from the program.

  9. Garbage to hydrocarbon fuel conversion system

    SciTech Connect

    Gould, W.A.

    1986-07-15

    A garbage to hydrocarbon fuel conversion system is described which consists of: (a) a source of combustible garbage; (b) means for pulverizing the garbage; (c) a furnace to burn the garbage; (d) means for transporting the pulverized garbage to the furnace which comprises a motor operated worm feed automatic stoker; (e) a steam generating coil inside the furnace which supplies live steam to power a turbine which in turn powers an alternating current generator; and a condenser which returns remaining the steam to a liquid state for re-circulation through the steam generating coils; (f) means for collecting incompletely combusted waste gases from the furnace; precipitating out dust and light oil for re-combustion in the furnace; and, extracting hydrocarbon gas; where in the means for precipitating out dust and light oil for re-combustion in the furnace comprise a cottrell precipitator wherein oil from an external source is mixed with fine dust received from the exhaust port, wherein an electrostatic charge helps to precipitate the dust; a dust and light oil mixer which provides a homogeneous mixture; and, an oil burner mounted to the furnace whose heat output is supplied to the furnace to add energy thereto; and (g) means for burning trapped heavy gases and removing waste ash from the furnace for disposal.

  10. Direct Carbon Conversion: Application to the Efficient Conversion of Fossil Fuels to Electricity

    SciTech Connect

    Cooper, J F; Cherepy, N; Berry, G; Pasternak, A; Surles, T; Steinberg, M

    2001-03-07

    We introduce a concept for efficient conversion of fossil fuels to electricity that entails the decomposition of fossil-derived hydrocarbons into carbon and hydrogen, and electrochemical conversion of these fuels in separate fuel cells. Carbon/air fuel cells have the advantages of near zero entropy change and associated heat production (allowing 100% theoretical conversion efficiency). The activities of the C fuel and CO{sub 2} product are invariant, allowing constant EMF and full utilization of fuel in single pass mode of operation. System efficiency estimates were conducted for several routes involving sequential extraction of a hydrocarbon from the fossil resource by (hydro) pyrolysis followed by thermal decomposition. The total energy conversion efficiencies of the processes were estimated to be (1) 80% for direct conversion of petroleum coke; (2) 67% HHV for CH{sub 4}; (3) 72% HHV for heavy oil (modeled using properties of decane); (4) 75.5% HHV (83% LHV) for natural gas conversion with a Rankine bottoming cycle for the H{sub 2} portion; and (5) 69% HHV for conversion of low rank coals and lignite through hydrogenation and pyrolysis of the CH{sub 4} intermediate. The cost of carbon fuel is roughly $7/GJ, based on the cost of the pyrolysis step in the industrial furnace black process. Cell hardware costs are estimated to be less than $500/kW.

  11. Effects of mixing system and pilot fuel quality on diesel-biogas dual fuel engine performance.

    PubMed

    Bedoya, Iván Darío; Arrieta, Andrés Amell; Cadavid, Francisco Javier

    2009-12-01

    This paper describes results obtained from CI engine performance running on dual fuel mode at fixed engine speed and four loads, varying the mixing system and pilot fuel quality, associated with fuel composition and cetane number. The experiments were carried out on a power generation diesel engine at 1500 m above sea level, with simulated biogas (60% CH(4)-40% CO(2)) as primary fuel, and diesel and palm oil biodiesel as pilot fuels. Dual fuel engine performance using a naturally aspirated mixing system and diesel as pilot fuel was compared with engine performance attained with a supercharged mixing system and biodiesel as pilot fuel. For all loads evaluated, was possible to achieve full diesel substitution using biogas and biodiesel as power sources. Using the supercharged mixing system combined with biodiesel as pilot fuel, thermal efficiency and substitution of pilot fuel were increased, whereas methane and carbon monoxide emissions were reduced. PMID:19683439

  12. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, B.D.; Confer, G.L.; Zujing Shen; Hapeman, M.J.; Flynn, P.L.

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slurry, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure. 19 figures.

  13. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, Bertrand D.; Confer, Gregory L.; Shen, Zujing; Hapeman, Martin J.; Flynn, Paul L.

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slutty, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure.

  14. 75 FR 29605 - Clean Alternative Fuel Vehicle and Engine Conversions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-26

    ... of conventional gasoline or diesel vehicles to hybrid-electric vehicles, and conversions from hybrid-electric vehicles to plug-in hybrid electric vehicles. Since alternative fuel conversion activity often... Manufacturing. 336322 Other Motor Vehicle Electrical and Electronic Equipment Manufacturing. 336399 All...

  15. Toward Solar Fuels: Photocatalytic Conversion of Carbon Dioxide to Hydrocarbons

    SciTech Connect

    Roy, SC; Varghese, OK; Paulose, M; Grimes, CA

    2010-03-01

    The past several decades have seen a significant rise in atmospheric carbon dioxide levels resulting from the combustion of hydrocarbon fuels. A solar energy based technology to recycle carbon dioxide into readily transportable hydrocarbon fuel (i.e., a solar fuel) would help reduce atmospheric CO2 levels and partly fulfill energy demands within the present hydrocarbon based fuel infrastructure. We review the present status of carbon dioxide conversion techniques, with particular attention to a recently developed photocatalytic process to convert carbon dioxide and water vapor into hydrocarbon fuels using sunlight.

  16. THERMOCHEMICAL CONVERSION OF FERMENTATION-DERIVED OXYGENATES TO FUELS

    SciTech Connect

    Ramasamy, Karthikeyan K.; Wang, Yong

    2013-06-01

    At present ethanol generated from renewable resources through fermentation process is the dominant biofuel. But ethanol suffers from undesirable fuel properties such as low energy density and high water solubility. The production capacity of fermentation derived oxygenates are projected to rise in near future beyond the current needs. The conversion of oxygenates to hydrocarbon compounds that are similar to gasoline, diesel and jet fuel is considered as one of the viable option. In this chapter the thermo catalytic conversion of oxygenates generated through fermentation to fuel range hydrocarbons will be discussed.

  17. Indirect-fired gas turbine dual fuel cell power cycle

    DOEpatents

    Micheli, Paul L.; Williams, Mark C.; Sudhoff, Frederick A.

    1996-01-01

    A fuel cell and gas turbine combined cycle system which includes dual fuel cell cycles combined with a gas turbine cycle wherein a solid oxide fuel cell cycle operated at a pressure of between 6 to 15 atms tops the turbine cycle and is used to produce CO.sub.2 for a molten carbonate fuel cell cycle which bottoms the turbine and is operated at essentially atmospheric pressure. A high pressure combustor is used to combust the excess fuel from the topping fuel cell cycle to further heat the pressurized gas driving the turbine. A low pressure combustor is used to combust the excess fuel from the bottoming fuel cell to reheat the gas stream passing out of the turbine which is used to preheat the pressurized air stream entering the topping fuel cell before passing into the bottoming fuel cell cathode. The CO.sub.2 generated in the solid oxide fuel cell cycle cascades through the system to the molten carbonate fuel cell cycle cathode.

  18. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  19. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2012-01-24

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  20. Carbon Fuel Particles Used in Direct Carbon Conversion Fuel Cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2008-10-21

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  1. Carbon fuel particles used in direct carbon conversion fuel cells

    DOEpatents

    Cooper, John F.; Cherepy, Nerine

    2011-08-16

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  2. Biological conversion of methane to liquid fuels: status and opportunities.

    PubMed

    Ge, Xumeng; Yang, Liangcheng; Sheets, Johnathon P; Yu, Zhongtang; Li, Yebo

    2014-12-01

    Methane is the main component of natural gas and biogas. As an abundant energy source, methane is crucial not only to meet current energy needs but also to achieve a sustainable energy future. Conversion of methane to liquid fuels provides energy-dense products and therefore reduces costs for storage, transportation, and distribution. Compared to thermochemical processes, biological conversion has advantages such as high conversion efficiency and using environmentally friendly processes. This paper is a comprehensive review of studies on three promising groups of microorganisms (methanotrophs, ammonia-oxidizing bacteria, and acetogens) that hold potential in converting methane to liquid fuels; their habitats, biochemical conversion mechanisms, performance in liquid fuels production, and genetic modification to enhance the conversion are also discussed. To date, methane-to-methanol conversion efficiencies (moles of methanol produced per mole methane consumed) of up to 80% have been reported. A number of issues that impede scale-up of this technology, such as mass transfer limitations of methane, inhibitory effects of H2S in biogas, usage of expensive chemicals as electron donors, and lack of native strains capable of converting methane to liquid fuels other than methanol, are discussed. Future perspectives and strategies in addressing these challenges are also discussed. PMID:25281583

  3. Fuel Economy and Emissions of a Vehicle Equipped with an Aftermarket Flexible-Fuel Conversion Kit

    SciTech Connect

    Thomas, John F; Huff, Shean P; West, Brian H

    2012-04-01

    The U.S. Environmental Protection Agency (EPA) grants Certificates of Conformity for alternative fuel conversion systems and also offers other forms of premarket registration of conversion kits for use in vehicles more than two model years old. Use of alternative fuels such as ethanol, natural gas, and propane are encouraged by the Energy Policy Act of 1992. Several original equipment manufacturers (OEMs) produce emissions-certified vehicles capable of using alternative fuels, and several alternative fuel conversion system manufacturers produce EPA-approved conversion systems for a variety of alternative fuels and vehicle types. To date, only one manufacturer (Flex Fuel U.S.) has received EPA certifications for ethanol fuel (E85) conversion kits. This report details an independent evaluation of a vehicle with a legal installation of a Flex Fuel U.S. conversion kit. A 2006 Dodge Charger was baseline tested with ethanol-free certification gasoline (E0) and E20 (gasoline with 20 vol % ethanol), converted to flex-fuel operation via installation of a Flex Box Smart Kit from Flex Fuel U.S., and retested with E0, E20, E50, and E81. Test cycles included the Federal Test Procedure (FTP or city cycle), the highway fuel economy test (HFET), and the US06 test (aggressive driving test). Averaged test results show that the vehicle was emissions compliant on E0 in the OEM condition (before conversion) and compliant on all test fuels after conversion. Average nitrogen oxide (NOx) emissions exceeded the Tier 2/Bin 5 intermediate life NO{sub X} standard with E20 fuel in the OEM condition due to two of three test results exceeding this standard [note that E20 is not a legal fuel for non-flexible-fuel vehicles (non-FFVs)]. In addition, one E0 test result before conversion and one E20 test result after conversion exceeded the NOX standard, although the average result in these two cases was below the standard. Emissions of ethanol and acetaldehyde increased with increasing ethanol

  4. Dual-water mixture fuel burner

    DOEpatents

    Brown, Thomas D.; Reehl, Douglas P.; Walbert, Gary F.

    1986-08-05

    A coal-water mixture (CWM) burner includes a conically shaped rotating cup into which fuel comprised of coal particles suspended in a slurry is introduced via a first, elongated inner tube coupled to a narrow first end portion of the cup. A second, elongated outer tube is coaxially positioned about the first tube and delivers steam to the narrow first end of the cup. The fuel delivery end of the inner first tube is provided with a helical slot on its lateral surface for directing the CWM onto the inner surface of the rotating cup in the form of a uniform, thin sheet which, under the influence of the cup's centrifugal force, flows toward a second, open, expanded end portion of the rotating cup positioned immediately adjacent to a combustion chamber. The steam delivered to the rotating cup wets its inner surface and inhibits the coal within the CWM from adhering to the rotating cup. A primary air source directs a high velocity air flow coaxially about the expanded discharge end of the rotating cup for applying a shear force to the CWM in atomizing the fuel mixture for improved combustion. A secondary air source directs secondary air into the combustion chamber adjacent to the outlet of the rotating cup at a desired pitch angle relative to the fuel mixture/steam flow to promote recirculation of hot combustion gases within the ignition zone for increased flame stability.

  5. Coal conversion and synthetic-fuel production

    NASA Technical Reports Server (NTRS)

    Bradford, R.; Atkins, W. T.; Bass, R. M.; Dascher, R.; Dunkin, J.; Luce, N.; Seward, W.; Warren, D.

    1980-01-01

    Report evaluates potential coal gasification and synthetic-fuel production technologies for 1985 to 1990. Book includes overview of present and future technical and economic potential, ways of evaluating gasification facility designs, discussion of promising processes, characterization of potential markets, and list of available gasification systems.

  6. FUEL DECOMPOSITION AND FLAME REACTIONS IN CONVERSION OF FUEL NITROGEN TO NOX

    EPA Science Inventory

    The report describes an experimental and analytical research program conducted to provide information on the chemical phenomena involved in the conversion of air and fuel nitrogen to NOx. Under Task 1, Fuel Decomposition, early (preflame) reactions of fuel nitrogen species were i...

  7. Dual-fuel engine developments at MAN B&W

    SciTech Connect

    Albrecht, A.

    1995-10-01

    MAN B&W in Augsburg, Germany has further developed its dual-fuel line of engines with the 32/40 DG engine family. These engines, with prechamber injection, augment the company`s spark-ignited gas and dual-fuel engines based on its four-stroke diesel engines. MAN B&W`s power range is between 400 and 16200 kW. Based on the well-proven 32/ 40 engine, the 32/40 DG dual-fuel engine was developed mainly for stationary applications in cogeneration plants and power stations, covering an output range from 2.4 to 7.2 MW. The engine line (bore 320 x stroke 400 mm) has a cylinder output of 400 kW at 750 r/min and a bmep of 19.9 bar with a maximum efficiency of 44.4%. The development focused on meeting TA Luft limits for NO{sub x} emissions of less than 500 mg/m{sup 3} NO{sub x}. This level was targeted without catalytic exhaust after treatment (SCR) and retaining high efficiency and high mean effective pressure similar to that of the diesel engine. To meet the development goals, a combustion system is used with two injection systems, one for the pilot injection into a prechamber and another for the main injection volume under diesel fuel operation.

  8. 49 CFR 536.10 - Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... vehicles—consistency with 49 CFR part 538. (a) Statutory alternative fuel and dual-fuel vehicle fuel... manufacturer must calculate the fuel economy of dual fueled vehicles in accordance with 40 CFR 600.510-12(c... 49 Transportation 6 2014-10-01 2014-10-01 false Treatment of dual-fuel and alternative...

  9. 49 CFR 536.10 - Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... vehicles—consistency with 49 CFR part 538. (a) Statutory alternative fuel and dual-fuel vehicle fuel... manufacturer must calculate the fuel economy of dual fueled vehicles in accordance with 40 CFR 600.510-12(c... 49 Transportation 6 2013-10-01 2013-10-01 false Treatment of dual-fuel and alternative...

  10. Gas Conversion Systems Reclaim Fuel for Industry

    NASA Technical Reports Server (NTRS)

    2015-01-01

    A human trip to Mars will require astronauts to utilize resources on the Red Planet to generate oxygen and fuel for the ride home, among other things. Lakewood, Colorado-based Pioneer Energy has worked under SBIR agreements with Johnson Space Center to develop technology for those purposes, and now uses a commercialized version of the technology to recover oil and gas that would otherwise be wasted at drilling sites.

  11. Conversion of waste plastics to fuel oil

    NASA Astrophysics Data System (ADS)

    Roaper, R. B.; Bhatia, J.

    1981-10-01

    Most of the plastics in use in the world today are produced from crude oil. This increased use of plastics results in an increased generation of discard and waste. In the case of thermoplastics, the types which constitute the bulk of the plastics in high volume use, it is theoretically possible to recycle discard and waste into virgin plastics. However, due to type incompatibility, and contamination with foreign materials, this approach has not proven economically feasible except for a smal quantity of the discard and waste stream. A pyrolysis process was successfully demonstrated which converted atactic polypropylene, APP, to fuel oil and a small fraction of fuel gas. In the current program, a commercial plant, with capacity of 17,000,000 lb/year feedstock, was designed for the pyrolysis of APP waste to fuel oil. In addition, the feasibility of this approach was extended to waste or discarded isotactic polypropylene, PP, and low density polyethylene, LDPE, through pilot plant work, process design, and economic considerations.

  12. High-Temperature, Dual-Atmosphere Corrosion of Solid-Oxide Fuel Cell Interconnects

    NASA Astrophysics Data System (ADS)

    Gannon, Paul; Amendola, Roberta

    2012-12-01

    High-temperature corrosion of ferritic stainless steel (FSS) surfaces can be accelerated and anomalous when it is simultaneously subjected to different gaseous environments, e.g., when separating fuel (hydrogen) and oxidant (air) streams, in comparison with single-atmosphere exposures, e.g., air only. This so-called "dual-atmosphere" exposure is realized in many energy-conversion systems including turbines, boilers, gasifiers, heat exchangers, and particularly in intermediate temperature (600-800°C) planar solid-oxide fuel cell (SOFC) stacks. It is generally accepted that hydrogen transport through the FSS (plate or tube) and its subsequent integration into the growing air-side surface oxide layer can promote accelerated and anomalous corrosion—relative to single-atmosphere exposure—via defect chemistry changes, such as increased cation vacancy concentrations, decreased oxygen activity, and steam formation within the growing surface oxide layers. Establishment of a continuous and dense surface oxide layer on the fuel side of the FSS can inhibit hydrogen transport and the associated effects on the air side. Minor differences in FSS composition, microstructure, and surface conditions can all have dramatic influences on dual-atmosphere corrosion behaviors. This article reviews high-temperature, dual-atmosphere corrosion phenomena and discusses implications for SOFC stacks, related applications, and future research.

  13. Enzymantic Conversion of Coal to Liquid Fuels

    SciTech Connect

    Richard Troiano

    2011-01-31

    The work in this project focused on the conversion of bituminous coal to liquid hydrocarbons. The major steps in this process include mechanical pretreatment, chemical pretreatment, and finally solubilization and conversion of coal to liquid hydrocarbons. Two different types of mechanical pretreatment were considered for the process: hammer mill grinding and jet mill grinding. After research and experimentation, it was decided to use jet mill grinding, which allows for coal to be ground down to particle sizes of 5 {mu}m or less. A Fluid Energy Model 0101 JET-O-MIZER-630 size reduction mill was purchased for this purpose. This machine was completed and final testing was performed on the machine at the Fluid Energy facilities in Telford, PA. The test results from the machine show that it can indeed perform to the required specifications and is able to grind coal down to a mean particle size that is ideal for experimentation. Solubilization and conversion experiments were performed on various pretreated coal samples using 3 different approaches: (1) enzymatic - using extracellular Laccase and Manganese Peroxidase (MnP), (2) chemical - using Ammonium Tartrate and Manganese Peroxidase, and (3) enzymatic - using the live organisms Phanerochaete chrysosporium. Spectral analysis was used to determine how effective each of these methods were in decomposing bituminous coal. After analysis of the results and other considerations, such as cost and environmental impacts, it was determined that the enzymatic approaches, as opposed to the chemical approaches using chelators, were more effective in decomposing coal. The results from the laccase/MnP experiments and Phanerochaete chrysosporium experiments are presented and compared in this final report. Spectra from both enzymatic methods show absorption peaks in the 240nm to 300nm region. These peaks correspond to aromatic intermediates formed when breaking down the coal structure. The peaks then decrease in absorbance over time

  14. Emission of a Dual-Fuel Turbocharged Compression Ignition Engine

    NASA Astrophysics Data System (ADS)

    Rózycki, Andrzej

    2012-02-01

    The paper describes the results of a four-cylinder dual fuel turbocharged compression ignition engine. The aim of the study was to determine the maximum CNG share in thefuel mixture delivered into the cylinder. Analysis of the investigation results showed that the CNG energy share in the fuel charge delivered into the cylinder can reach 45%. At that level of CNG energy share a 15% reduction in maximum torque is achieved in comparison with the standard fuelling. The unburnt hydrocarbon emission increases significantly. Emissions of other principal pollutants reach values comparable with those obtained at standard fuelling.

  15. Conversion of olefins to liquid motor fuels

    DOEpatents

    Rabo, Jule A.; Coughlin, Peter K.

    1988-01-01

    Linear and/or branched claim C.sub.2 to C.sub.12 olefins are converted to hydrocarbon mixtures suitable for use as liquid motor fuels by contact with a catalyst capable of ensuring the production of desirable products with only a relatively minor amount of heavy products boiling beyond the diesel oil range. The catalyst having desirable stability during continuous production operations, comprises a steam stabilized zeolite Y catalyst of hydrophobic character, desirably in aluminum-extracted form. The olefins such as propylene, may be diluted with inerts, such as paraffins or with water, the latter serving to moderate the acidity of the catalyst, or to further moderate the activity of the aluminum-extracted catalyst, so as to increase the effective life of the catalyst.

  16. Cyclic Combustion Variations in Dual Fuel Partially Premixed Pilot-Ignited Natural Gas Engines

    SciTech Connect

    Srinivasan, K. K.; Krishnan, S. R.

    2012-05-09

    Dual fuel pilot ignited natural gas engines are identified as an efficient and viable alternative to conventional diesel engines. This paper examines cyclic combustion fluctuations in conventional dual fuel and in dual fuel partially premixed low temperature combustion (LTC). Conventional dual fueling with 95% (energy basis) natural gas (NG) substitution reduces NOx emissions by almost 90%t relative to straight diesel operation; however, this is accompanied by 98% increase in HC emissions, 10 percentage points reduction in fuel conversion efficiency (FCE) and 12 percentage points increase in COVimep. Dual fuel LTC is achieved by injection of a small amount of diesel fuel (2-3 percent on an energy basis) to ignite a premixed natural gas–air mixture to attain very low NOx emissions (less than 0.2 g/kWh). Cyclic variations in both combustion modes were analyzed by observing the cyclic fluctuations in start of combustion (SOC), peak cylinder pressures (Pmax), combustion phasing (Ca50), and the separation between the diesel injection event and Ca50 (termed “relative combustion phasing”). For conventional dual fueling, as % NG increases, Pmax decreases, SOC and Ca50 are delayed, and cyclic variations increase. For dual fuel LTC, as diesel injection timing is advanced from 20° to 60°BTDC, the relative combustion phasing is identified as an important combustion parameter along with SoC, Pmax, and CaPmax. For both combustion modes, cyclic variations were characterized by alternating slow and fast burn cycles, especially at high %NG and advanced injection timings. Finally

  17. Process review of lignocellulose biochemical conversion to fuel ethanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review is meant to give a general technical review of the state-of-the-art in process technology for the biochemical conversion of lignocellulose to fuel ethanol. The proceeding details the chemical structure of biomass and basic process steps needed for extracting carbohydrates as sugars and ...

  18. Alcohol fuel conversion apparatus for internal combustion engines

    SciTech Connect

    Carroll, B.I.

    1987-01-13

    An alcohol fuel conversion apparatus is described for internal combustion engines comprising: fuel storage means containing an alcohol fuel; primary heat exchanger means in fluid communication with the fuel storage means for transferring heat to pressurized alcohol contained within the heat exchanger means; a heat source for heating the heat exchange means; pressure relief valve means, in closed fluid communication with the primary heat exchange means, operable to release heated pressurized alcohol into an expansion chamber; converter means, including the expansion chamber, in fluid communication with the pressure relief valve means for receiving the heated pressurized alcohol and for the vaporization of the alcohol; carburetor means in fluid communication with the converter means for metering and mixing vaporized alcohol with air for proper combustion and for feeding the mixture to an internal combustion engine; and pump means for pressurized pumping of alcohol from the fuel storage means to the heat exchanger means, converter means, carburetor means, and to the engine.

  19. LIEKKI and JALO: Combustion and fuel conversion

    NASA Astrophysics Data System (ADS)

    Grace, Thomas M.; Renz, Ulrich; Sarofim, Adel F.

    LIEKKI and JALO are well conceived and structured programs designed to strengthen Finland's special needs in combustion and gasification to utilize a diversity of fuels, increase the ratio of electrical to heat output, and to support the export market. Started in 1988, these two programs provide models of how universities, Technical research center's laboratories (VTT's), and industry can collaborate successfully in order to achieve national goals. The research is focused on long term goals in certain targeted niche areas. This is an effective way to use limited resources. The niche areas were chosen in a rational manner and appear to be appropriate for Finland. The LIEKKl and JALO programs have helped pull together research efforts that were previously more fragmented. For example, the combustion modeling area still appears fragmented. Individual project objectives should be tied to program goals at a very early stage to provide sharper focusing to the research. Both the LIEKKl and JALO programs appear to be strongly endorsed by industry. Industrial members of the Executive Committees were very supportive of these programs. There are good mechanisms for technology transfer in place, and the programs provide opportunities to establish good interfaces between industrial people and the individual researchers. The interest of industry is shown by the large number of applied projects that are supported by industry. This demonstrates the relevancy of the programs. There is a strong interaction between the JALO program and industry in black liquor gasification.

  20. Dual Development of Conversational and Narrative Discourse: Mother and Child Interactions during Narrative Co-Construction

    ERIC Educational Resources Information Center

    Kelly, Kimberly Reynolds; Bailey, Alison L.

    2013-01-01

    We investigated longitudinally the co-constructed narratives of 31 mother-child dyads collected when the children were 3-, 4-, and 5-years old, examining the dual development of child conversational and narrative discourse skills and the impact of maternal verbal assistance. Linear mixed-model analysis revealed that children's developmental…

  1. Fleet Conversion in Local Government: Determinants of Driver Fuel Choice for Bi-Fuel Vehicles

    ERIC Educational Resources Information Center

    Johns, Kimberly D.; Khovanova, Kseniya M.; Welch, Eric W.

    2009-01-01

    This study evaluates the conversion of one local government's fleet from gasoline to bi-fuel E-85, compressed natural gas, and liquid propane gas powered vehicles at the midpoint of a 10-year conversion plan. This study employs a behavioral model based on the theory of reasoned action to explore factors that influence an individual's perceived and…

  2. Dual mode fuel injection system and fuel injector for same

    SciTech Connect

    Lawrence, Keith E.; Tian, Ye

    2005-09-20

    A fuel injection system has the ability to produce two different spray patterns depending on the positioning of a needle control valve member. Positioning of the needle control valve member determines which of the two needle control chambers are placed in a low pressure condition. First and second needle valve members have closing hydraulic surfaces exposed to fluid pressure in the two needle control chambers. The injector preferably includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by the first and second needle valve members.

  3. Econometric comparisons of liquid rocket engines for dual-fuel advanced earth-to-orbit shuttles

    NASA Technical Reports Server (NTRS)

    Martin, J. A.

    1978-01-01

    Econometric analyses of advanced Earth-to-orbit vehicles indicate that there are economic benefits from development of new vehicles beyond the space shuttle as traffic increases. Vehicle studies indicate the advantage of the dual-fuel propulsion in single-stage vehicles. This paper shows the economic effect of incorporating dual-fuel propulsion in advanced vehicles. Several dual-fuel propulsion systems are compared to a baseline hydrogen and oxygen system.

  4. Serial biological conversion of coal to liquid fuels

    SciTech Connect

    Not Available

    1991-02-01

    Water soluble coal products produced by the action of coal solubilizing organisms LSC and H12 were obtained and used in a second biological process for conversion to alcohol fuels. Several sources of natural inocula were screened and studied for their ability to produce fuels from solubilized coal. Alcohols and organic acids were produced from cultures obtained from sewage sludge and sheep and rumen fluid. The sheep rumen culture, in addition to producing alcohols and acids, was capable of totally eliminating color from the culture medium indicating significant breakdown of the solubilized coal. 12 refs., 9 figs., 59 tabs.

  5. Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion

    SciTech Connect

    Brown, N. R.; Brown, N. R.; Baek, J. S; Hanson, A. L.; Cuadra, A.; Cheng, L. Y.; Diamond, D. J.

    2014-04-30

    It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-Enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size-Plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). A summary of the methodology to obtain these results is presented. Fuel element tolerance assumptions and hot channel factors used in the safety analysis are also given.

  6. 26 CFR 48.4041-7 - Dual use of taxable liquid fuel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Dual use of taxable liquid fuel. 48.4041-7... taxable liquid fuel. Tax applies to all taxable liquid fuel sold for use or used as a fuel in the motor... liquid fuel sold for this use or so used, whether or not the special equipment is mounted on the...

  7. 26 CFR 48.4041-7 - Dual use of taxable liquid fuel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Dual use of taxable liquid fuel. 48.4041-7... taxable liquid fuel. Tax applies to all taxable liquid fuel sold for use or used as a fuel in the motor... liquid fuel sold for this use or so used, whether or not the special equipment is mounted on the...

  8. 26 CFR 48.4041-7 - Dual use of taxable liquid fuel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Dual use of taxable liquid fuel. 48.4041-7... taxable liquid fuel. Tax applies to all taxable liquid fuel sold for use or used as a fuel in the motor... liquid fuel sold for this use or so used, whether or not the special equipment is mounted on the...

  9. 26 CFR 48.4041-7 - Dual use of taxable liquid fuel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Dual use of taxable liquid fuel. 48.4041-7... taxable liquid fuel. Tax applies to all taxable liquid fuel sold for use or used as a fuel in the motor... liquid fuel sold for this use or so used, whether or not the special equipment is mounted on the...

  10. Catalysts for conversion of syngas to liquid motor fuels

    DOEpatents

    Rabo, Jule A.; Coughlin, Peter K.

    1987-01-01

    Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst composition capable of ensuring the production of only relatively minor amounts of heavy products boiling beyond the diesel oil range. The catalyst composition, having desirable stability during continuous production operation, employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component. The latter component is a steam-stabilized zeolite Y catalyst of hydrophobic character, desirably in acid-extracted form.

  11. Core conversion of the Portuguese research reactor to LEU fuel

    SciTech Connect

    Marques, J.G.; Ramos, A.R.; Kocher, A.

    2008-07-15

    Core conversion of the Portuguese Research Reactor (RPI) to LEU fuel is being performed within IAEA's Technical Cooperation project POR/4/016, with financial support from the US and Portugal. CERCA was selected as manufacturer of the LEU assemblies by the IAEA after an international call for bids. CERCA provided a comprehensive package to the RPI which included the mechanical verification of the design of the assemblies, their manufacture and arrangements for a joint inspection of the finished assemblies. The LEU fuel assemblies were manufactured within 8 months upon final approval of the design. The safety analyses for the core conversion to LEU fuel were made with the assistance of the RERTR program and were submitted for review by the IAEA and by Portuguese authorities in January 2007. Revised documents were submitted in June 2007 addressing the issues raised during review. Regulatory approval was received in early August and core conversion was done in early September. All measured safety parameters are within the defined acceptance limits. Operation at full power is expected by the end of October. (author)

  12. Syngas Conversion to Hydrocarbon Fuels through Mixed Alcohol Intermediates

    SciTech Connect

    Dagle, Robert A.; Lebarbier, Vanessa M.; Albrecht, Karl O.; Li, Jinjing; Taylor, Charles E.; Bao, Xinhe; Wang, Yong

    2013-05-13

    Synthesis gas (syngas) can be used to synthesize a variety of fuels and chemicals. Domestic transportation and military operational interests have driven continued focus on domestic syngas-based fuels production. Liquid transportation fuels may be made from syngas via four basic processes: 1) higher alcohols, 2) Fischer-Tropsch (FT), 3) methanol-to-gasoline (MTG), and 4) methanol-to-olefins (MTO) and olefins-to-gasoline/distillate (MOGD). Compared to FT and higher alcohols, MTG and MTO-MOGD have received less attention in recent years. Due to the high capital cost of these synthetic fuel plants, the production cost of the finished fuel cannot compete with petroleum-derived fuel. Pacific Northwest National Laboratory has recently evaluated one way to potentially reduce capital cost and overall production cost for MTG by combining the methanol and MTG syntheses in a single reactor. The concept consists of mixing the conventional MTG catalyst (i.e. HZSM-5) with an alcohol synthesis catalyst. It was found that a methanol synthesis catalyst, stable at high temperature (i.e. Pd/ZnO/Al2O3) [1], when mixed with ZSM-5, was active for syngas conversion. Relatively high syngas conversion can be achieved as the equilibrium-driven conversion limitations for methanol and dimethyl ether are removed as they are intermediates to the final hydrocarbon product. However, selectivity control was difficult to achieve as formation of undesirable durene and light hydrocarbons was problematic [2]. The objective of the present study was thus to evaluate other potential composite catalyst systems and optimize the reactions conditions for the conversion of syngas to hydrocarbon fuels, through the use of mixed alcohol intermediates. Mixed alcohols are of interest as they have recently been reported to produce higher yields of gasoline compared to methanol [3]. 1. Lebarbier, V.M., Dagle, R.A., Kovarik, L., Lizarazo-Adarme, J.A., King, D.L., Palo, D.R., Catalyst Science & Technology, 2012, 2

  13. Near-Optimal Operation of Dual-Fuel Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.; Chou, H. C.; Bowles, J. V.

    1996-01-01

    A near-optimal guidance law for the ascent trajectory from earth surface to earth orbit of a fully reusable single-stage-to-orbit pure rocket launch vehicle is derived. Of interest are both the optimal operation of the propulsion system and the optimal flight path. A methodology is developed to investigate the optimal throttle switching of dual-fuel engines. The method is based on selecting propulsion system modes and parameters that maximize a certain performance function. This function is derived from consideration of the energy-state model of the aircraft equations of motion. Because the density of liquid hydrogen is relatively low, the sensitivity of perturbations in volume need to be taken into consideration as well as weight sensitivity. The cost functional is a weighted sum of fuel mass and volume; the weighting factor is chosen to minimize vehicle empty weight for a given payload mass and volume in orbit.

  14. Alternative fuel information: Facts about CNG and LPG conversion

    SciTech Connect

    O`Connor, K.

    1994-06-01

    As new environmental and energy related laws begin to take effect, increasing numbers of alternative fuel vehicles (AFVs) will be required in federal, state, municipal, and private fleets across the country. The National Energy Policy Act of 1992 and the Clean Air Act Amendments of 1990, along with several new state and local laws, will require fleet managers to either purchase original equipment manufacturer (OEM) vehicles, which are produced by automakers, or convert existing vehicles to run on alternative fuels. Because there is a limited availability and selection of OEM vehicles, conversions are seen as a transition to the time when automakers will produce more AFVs for public sale. A converted vehicle is any vehicle that originally was designed to operate on gasoline, and has been altered to run on an alternative fuel such as compressed natural gas (CNG) or propane (liquefied petroleum gas -- LPG), the two most common types of fuel conversions. In the United States, more than 25,000 vehicles already have been converted to COG, and 300,000 have been converted to LPG.

  15. Conversion of Pentose-Derived Furans into Hydrocarbon Fuels

    SciTech Connect

    Moens, L.; Johnson, D. K.

    2012-01-01

    We are interested in the conversion of biomass-derived hemicellulose into hydrocarbon molecules that can be used in the formulation of 'drop-in' fuels such as gasoline (C5-12), diesel (C10-20) and jet fuel (C9-16). Our focus lies on the use of furfuryl alcohol as a starting material since that is already produced commercially from hemicellulose-derived pentoses. The steps required to convert the latter into hydrocarbons are 1) oligomerization of furfuryl alcohol to form dimers (C10) and trimers (C15), and 2) hydrotreatment of the dimers and trimers to produce a mixture of linear hydrocarbons with carbon chain lengths in the range of diesel and jet fuels. However, furfuryl alcohol readily polymerizes to form resins in the presence of an acid catalyst, and the exothermic oligomerization must be carried out under reaction control. This presentation will discuss our progress in the development of this sugar-to-hydrocarbon pathway.

  16. Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion

    SciTech Connect

    Brown N. R.; Brown,N.R.; Baek,J.S; Hanson, A.L.; Cuadra,A.; Cheng,L.Y.; Diamond, D.J.

    2013-03-31

    It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. . The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). In addition, a summary of the methodology to obtain these results is presented.

  17. Conversion of microalgae to jet fuel: process design and simulation.

    PubMed

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming. PMID:24997379

  18. Microbial conversion of coals to clean fuel forms

    SciTech Connect

    Barik, S.; Isbister, J.; Hawley, B.; Forgacs, T.; Reed, L.; Anspach, G.; Middaugh, T.

    1988-01-01

    Anaerobic cultures have been used for the production of methane and alcohols from coal. Cultures were adapted from natural inocula collected from sources such as sewage sludge and horse manure. A 1% (w/v) slurry of leonardite, lignite, or subbituminous coal was used in the incubations. Methane was produced from all cultures, including some untreated coals, to a greater extent than in control cultures. Over several months of adaptation, methane production capacity increased considerably. Volatile fatty acids (VFAs) were identified as intermediates in the conversion of coal to methane. A proposed scheme for the conversion is breakdown of the coal polymer by a series of organisms and metabolism of the fragments to methane precursors such as VFAs. A mixture of short chain alcohols was produced by cultures grown in the presence of methane inhibitors. These cultures after prolonged adaptation show potential for use in larger scale bioreactors for the production of gaseous and liquid fuels.

  19. Adding value to coal conversion`s char: A strategy for lower-priced fuels

    SciTech Connect

    Kruse, C.W.; Fatemi, M.; Feizoulof, C.

    1994-12-31

    Coal`s low hydrogen to carbon ratio gives coal physical properties that are not the most desired in fuel markets. The problem is dealt with in conversion technologies designed to upgrade coal to more desirable fuels by either: (1) chemically adding hydrogen, as in liquefaction or high-BTU gasification, or (2) the production of char, as in mild gasification. The first option is neither cost-effective nor environmentally sound. Liquefaction results in the production of one mole of carbon dioxide for each mole of hydrogen needed. The result is that despite the preferred hydrogen to carbon ratio in the fuel, carbon dioxide is produced in greater quantities than it would be by simply burning the coal. The depressed market value of char is the primary drawback of coal utilization technologies exercising the second option. Making value-added, non-fuel products from char could significantly improve the economics of overall operations and result in competitively-priced premium hydrocarbon fuels. The research goal of a growing number of groups, including ours, is to produce and describe carbon products which will command higher prices than the carbon (coal) from which they were produced.

  20. 49 CFR 536.10 - Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... vehicles—consistency with 49 CFR part 538. (a) Statutory alternative fuel and dual-fuel vehicle fuel... 49 Transportation 6 2012-10-01 2012-10-01 false Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538. 536.10 Section 536.10 Transportation Other Regulations...

  1. 49 CFR 536.10 - Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... vehicles—consistency with 49 CFR part 538. (a) Statutory alternative fuel and dual-fuel vehicle fuel... 49 Transportation 6 2011-10-01 2011-10-01 false Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538. 536.10 Section 536.10 Transportation Other Regulations...

  2. 49 CFR 536.10 - Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... vehicles—consistency with 49 CFR part 538. (a) Statutory alternative fuel and dual-fuel vehicle fuel... 49 Transportation 6 2010-10-01 2010-10-01 false Treatment of dual-fuel and alternative fuel vehicles-consistency with 49 CFR part 538. 536.10 Section 536.10 Transportation Other Regulations...

  3. Analyses for conversion of the Georgia Tech Research Reactor from HEU to LEU fuel

    SciTech Connect

    Matos, J.E.; Mo, S.C.; Woodruff, W.L.

    1992-09-01

    This document presents information concerning: analyses for conversion of the Georgia Tech Research Reactor from HEU to LEU; changes to technical specifications mandated by the conversion of the GTRR to low enrichment fuel; changes in the Safety Analysis Report mandated by the conversion of the GTRR to low enrichment fuel; and copies of all changed pages of the SAR and the technical specifications.

  4. Complete polarization conversion using one crystal with dual transverse Pockels effect.

    PubMed

    Li, Changsheng

    2008-05-01

    Based on dual transverse Pockels effect, complete polarization conversion can be achieved by using only one electro-optic crystal and its two externally applied voltages. The electro-optic phase retardation and the azimuth angle of the field-induced principal dielectric axes of the crystal can be independently and linearly controlled by the amplitude and direction of the applied electric field, and the formulas for this correlation are deduced for arbitrary input and output polarization states. The candidate crystals mainly include the uniaxial crystals of 3 m, 62 m, and 32 symmetry groups, and the cubic crystals of 43 m and 23 symmetry groups. Theoretical analysis demonstrates that one crystal exhibiting both dual transverse Pockels effect and optical activity can also be used for complete polarization converter. The continuous polarization rotation of a linearly polarized light from 0 degrees to 180 degrees has been performed experimentally by use of single lithium niobate crystal with four lateral electrodes. In addition the light beam position-dependent polarization conversion by using a bulk electro-optic crystal is also measured in the experiment. This new type of polarization converter will have potential applications in many fields due to its simple configuration, explicit control logic of polarization conversion, and lower power consumption. PMID:18449288

  5. Dual-fueling of a prechamber diesel engine with natural gas

    SciTech Connect

    Song, S.; Hill, P.G.

    1985-10-01

    The feasibility of dual-fuel operation with natural gas in a prechamber diesel engine was studied with special emphasis on fuel consumption and cylinder pressure development. The effects of air restriction, pilot diesel flow rate, and injection timing were also investigated. Near full load the fuel energy consumption rate was close to that of straight diesel operation though at part load (in the absence of air restriction) the fuel energy consumption rate was relatively high. In the absence of injection timing adjustment the maximum power output of dual-fuel operation was severely limited by the maximum cylinder pressure. Retarding the injection timing is effective in reducing the maximum cylinder pressure to a safe level. The analysis of apparent energy release indicates the differences in combustion mechanism between auto-ignition of diesel fuel in straight diesel operation and propagation of flame fronts in dual-fuel operation.

  6. Dual-fuel natural gas/diesel engines: Technology, performance, and emissions

    NASA Astrophysics Data System (ADS)

    Turner, S. H.; Weaver, C. S.

    1994-11-01

    An investigation of current dual-fuel natural gas/diesel engine design, performance, and emissions was conducted. The most pressing technological problems associated with dual-fuel engine use were identified along with potential solutions. It was concluded that dual-fuel engines can achieve low NO(sub x) and particulate emissions while retaining fuel-efficiency and BMEP levels comparable to those of diesel engines. The investigation also examined the potential economic impact of dual-fuel engines in diesel-electric locomotives, marine vessels, farm equipment, construction, mining, and industrial equipment, and stand-alone electricity generation systems. Recommendations for further additional funding to support research, development, and demonstration in these applications were then presented.

  7. Review of solar fuel-producing quantum conversion processes

    NASA Astrophysics Data System (ADS)

    Peterson, D. B.; Biddle, J. R.; Fujita, T.

    1984-05-01

    The status and potential of fuel-producing solar photochemical processes are discussed. Research focused on splitting water to produce dihydrogen and is at a relatively early stage of development. Current emphasis is primarily directed toward understanding the basic chemistry underlying such quantum conversion processes. Theoretical analyses by various investigators predict a limiting thermodynamic efficiency of 31% for devices with a single photosystem operating with unfocused sunlight at 300 K. When non-idealities are included, it appears unlikely that actual devices will have efficiencies greater than 12 to 15%. Observed efficiencies are well below theoretical limits. Cyclic homogeneous photochemical processes for splitting water have efficiencies considerably less than 1%. Efficiency can be significantly increased by addition of a sacrificial reagent; however, such systems are no longer cyclic and it is doubtful that they would be economical on a commercial scale. The observed efficiencies for photoelectrochemical processes are also low but such systems appear more promising than homogeneous photochemical systems. Operating and systems options, including operation at elevated temperature and hybrid and coupled quantum-thermal conversion processes, are also considered.

  8. Review of solar fuel-producing quantum conversion processes

    NASA Technical Reports Server (NTRS)

    Peterson, D. B.; Biddle, J. R.; Fujita, T.

    1984-01-01

    The status and potential of fuel-producing solar photochemical processes are discussed. Research focused on splitting water to produce dihydrogen and is at a relatively early stage of development. Current emphasis is primarily directed toward understanding the basic chemistry underlying such quantum conversion processes. Theoretical analyses by various investigators predict a limiting thermodynamic efficiency of 31% for devices with a single photosystem operating with unfocused sunlight at 300 K. When non-idealities are included, it appears unlikely that actual devices will have efficiencies greater than 12 to 15%. Observed efficiencies are well below theoretical limits. Cyclic homogeneous photochemical processes for splitting water have efficiencies considerably less than 1%. Efficiency can be significantly increased by addition of a sacrificial reagent; however, such systems are no longer cyclic and it is doubtful that they would be economical on a commercial scale. The observed efficiencies for photoelectrochemical processes are also low but such systems appear more promising than homogeneous photochemical systems. Operating and systems options, including operation at elevated temperature and hybrid and coupled quantum-thermal conversion processes, are also considered.

  9. Initial Test Results of a Dual Closed-Brayton-Cycle Power Conversion System

    NASA Technical Reports Server (NTRS)

    Johnson, Paul K.; Mason, Lee S.

    2007-01-01

    The dual Brayton power conversion system constructed for NASA Glenn Research Center (GRC) was acceptance tested April 2007 at Barber-Nichols, Inc., Arvada, Colorado. This uniquely configured conversion system is built around two modified commercial Capstone C30 microturbines and employs two closed-Brayton-cycle (CBC) converters sharing a common gas inventory and common heat source. Because both CBCs share the gas inventory, behavior of one CBC has an impact on the performance of the other CBC, especially when one CBC is standby or running at a different shaft speed. Testing performed to date includes the CBCs operating at equal and unequal shaft speeds. A test was also conducted where one CBC was capped off and the other was operated as a single CBC converter. The dual Brayton configuration generated 10.6 kWe at 75 krpm and a turbine inlet temperature of 817 K. Single Brayton operation generated 14.8 kWe at 90 krpm and a turbine inlet temperature of 925 K.

  10. Plasmolysis for efficient CO2 -to-fuel conversion

    NASA Astrophysics Data System (ADS)

    van Rooij, Gerard

    2015-09-01

    The strong non-equilibrium conditions provided by the plasma phase offer the opportunity to beat traditional thermal process energy efficiencies via preferential excitation of molecular vibrational modes. It is therefore a promising option for creating artificial solar fuels from CO2as raw material using (intermittently available) sustainable energy surpluses, which can easily be deployed within the present infrastructure for conventional fossil fuels. In this presentation, a common microwave reactor approach is evaluated experimentally with Rayleigh scattering and Fourier transform infrared spectroscopy to assess gas temperatures and conversion degrees, respectively. The results are interpreted on basis of estimates of the plasma dynamics obtained with electron energy distribution functions calculated with a Boltzmann solver. It indicates that the intrinsic electron energies are higher than is favourable for preferential vibrational excitation due to dissociative excitation, which causes thermodynamic equilibrium chemistry still to dominate the initial experiments. Novel reactor approaches are proposed to tailor the plasma dynamics to achieve the non-equilibrium in which vibrational excitation is dominant. In collaboration with Dirk van den Bekerom, Niek den Harder, Teofil Minea, Dutch Institute For Fundamental Energy Research, Eindhoven, Netherlands; Gield Berden, Institute for Molecules and Materials, FELIX facility, Radboud University, Nijmegen, Netherlands; Richard Engeln, Applied Physics, Plasma en Materials Processing, Eindhoven University of Technology; and Waldo Bongers, Martijn Graswinckel, Erwin Zoethout, Richard van de Sanden, Dutch Institute For Fundamental Energy Research, Eindhoven, Netherlands.

  11. Low enrichment fuel conversion for Iowa State University

    SciTech Connect

    Rohach, A.F.; Hendrickson, R.A.

    1990-08-01

    Work during the reported period was centered primarily in preparation for receiving the LEU fuel and the shipping of the HEU fuel. The LEU fuel has not been received. The HEU fuel assemblies for the UTR-10 reactor will not fit into any current research reactor shipping containers; therefore, the fuel assemblies must be disassembled and the fuel shipped as fuel plates. Procedures and practices have been developed so that the fuel assemblies will be disassembled in a shielded environment.

  12. Wavelength conversion of 544-Gbit/s dual-carrier PDM-16QAM signal based on the co-polarized dual-pump scheme.

    PubMed

    Li, Xinying; Yu, Jianjun; Dong, Ze; Chi, Nan

    2012-09-10

    Due to its relative low baud rate as well as simple and cost-efficient implementation, dual-carrier polarization-division-multiplexing 16-ary quadrature amplitude modulation (PDM-16QAM) is a promising candidate for the next generation optical systems and networks at 400Gb/s per channel. The co-polarized dual-pump scheme, based on four-wave mixing (FWM) in a 1-km high nonlinear fiber (HNLF), can realize the all-optical wavelength conversion (AOWC) of the dual-carrier PDM-16QAM signal with spectral non-inversion and polarization insensitivity. We first experimentally demonstrated AOWC of the 544-Gbit/s dual-carrier PDM-16QAM signal based on the co-polarized dual-pump scheme. We investigated the conversion efficiency (CE) and optical signal-to-noise ratio (OSNR) of the converted signal at different pump spacing and pump power. We measured that the OSNR penalty is 0.6 dB due to AOWC when the bit-error ratio (BER) and pump spacing is 2 x 10-2 and 200 GHz, respectively. PMID:23037255

  13. Conversion and evaluation of the THOR reactor core to TRIGA fuel elements

    SciTech Connect

    Li, S.-H.; Shiau, L.-C.

    1990-07-01

    The THOR reactor is a pool type 1 MW research reactor and has been operated since 1961. The original MTR fuel elements have been gradually replaced by TRIGA fuel elements since 1977 and the conversion completed in 1987. The calculations were performed for various core configurations by using computer codes, WIMS/CITATION. The computing results have been evaluated and compared with the core measurements after the fuel conversion. The analysis results are in good correspondence with the measurements. (author)

  14. Feasibility study on AFR-100 fuel conversion from uranium-based fuel to thorium-based fuel

    SciTech Connect

    Heidet, F.; Kim, T.; Grandy, C.

    2012-07-30

    Although thorium has long been considered as an alternative to uranium-based fuels, most of the reactors built to-date have been fueled with uranium-based fuel with the exception of a few reactors. The decision to use uranium-based fuels was initially made based on the technology maturity compared to thorium-based fuels. As a result of this experience, lot of knowledge and data have been accumulated for uranium-based fuels that made it the predominant nuclear fuel type for extant nuclear power. However, following the recent concerns about the extent and availability of uranium resources, thorium-based fuels have regained significant interest worldwide. Thorium is more abundant than uranium and can be readily exploited in many countries and thus is now seen as a possible alternative. As thorium-based fuel technologies mature, fuel conversion from uranium to thorium is expected to become a major interest in both thermal and fast reactors. In this study the feasibility of fuel conversion in a fast reactor is assessed and several possible approaches are proposed. The analyses are performed using the Advanced Fast Reactor (AFR-100) design, a fast reactor core concept recently developed by ANL. The AFR-100 is a small 100 MW{sub e} reactor developed under the US-DOE program relying on innovative fast reactor technologies and advanced structural and cladding materials. It was designed to be inherently safe and offers sufficient margins with respect to the fuel melting temperature and the fuel-cladding eutectic temperature when using U-10Zr binary metal fuel. Thorium-based metal fuel was preferred to other thorium fuel forms because of its higher heavy metal density and it does not need to be alloyed with zirconium to reduce its radiation swelling. The various approaches explored cover the use of pure thorium fuel as well as the use of thorium mixed with transuranics (TRU). Sensitivity studies were performed for the different scenarios envisioned in order to determine the

  15. CONVERSION OF LIGNOCELLULOSIC MATERIAL TO CHEMICALS AND FUELS

    SciTech Connect

    Edwin S. Olson

    2001-06-30

    A direct conversion of cellulosic wastes, including resin-bonded furniture and building waste, to levulinate esters is being investigated with the view to producing fuels, solvents, and chemical intermediates as well as other useful by-products in an inexpensive process. The acid-catalyzed reaction of cellulosic materials with ethanol or methanol at 200 C gives good yields of levulinate and formate esters, as well as useful by-products, such as a solid residue (charcoal) and a resinous lignin residue. An initial plant design showed reasonable rates of return for production of purified ethyl levulinate and by-products. In this project, investigations have been performed to identify and develop reactions that utilize esters of levulinic acid produced during the acid-catalyzed ethanolysis reaction. We wish to develop uses for levulinate esters that allow their marketing at prices comparable to inexpensive polymer intermediates. These prices will allow a sufficient rate of return to justify building plants for utilizing the waste lignocellulosics. If need is demonstrated for purified levulinate, the initial plant design work may be adequate, at least until further pilot-scale work on the process is performed.

  16. Dual fuel Russian urban transit buses: Economical reduced emissions. Export trade information

    SciTech Connect

    1998-01-01

    This study, conducted by Caterpillar, was funded by the US Trade and Development Agency. The scope of this project was to examine the financial and environmental aspects of introducing new alternative fuel engines to the buses of Russia`s public transportation system. The report consists of the following: (1) executive summary; (2) background/overview; (3) 3306 design, development, test; (4) electronic governed engines; (5) Moscow bus testing; (6) conclusions; (7) appendices. The appendices include: (1) Caterpillar emissions lab report; (2) dyno tests -- dual fuel data sheets; (3) 3360 horizontal engine lub tilt test; (4) 1000 hour endurance test -- engine operator sheets; (5) 1000 hour endurance test -- 250 hour check; (6) Caterpillar dual fuel electronic engines; (7) product description -- dual fuel electronic governed engines; (8) California Environmental Protection Agency -- certification of caterpillar electronic governed engines; (9) annual payback data.

  17. Experimental and Analytical Performance of a Dual Brayton Power Conversion System

    NASA Technical Reports Server (NTRS)

    Lavelle, Thomas A.; Hervol, David S.; Briggs, Maxwell; Owen, A. Karl

    2009-01-01

    The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using the Dual Brayton Power Conversion System (DBPCS) and analytically using the Closed- Cycle System Simulation (CCSS) computer code. Selected operating modes include steady-state operation at equal and unequal shaft speeds and various start-up scenarios. Equal shaft speed steady-state tests were conducted for heater exit temperatures of 840 to 950 K and speeds of 50 to 90 krpm, providing a system performance map. Unequal shaft speed steady-state testing over the same operating conditions shows that the power produced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory. Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy. Although the DBPCS is not considered a flight-like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.

  18. Conversion of atactic polypropylene waste to fuel oil. Final report

    SciTech Connect

    Bhatia, J.

    1981-04-01

    A stable, convenient thermal pyrolysis process was demonstrated on a large scale pilot plant. The process successfully converted high viscosity copolymer atactic polypropylene to predominantly liquid fuels which could be burned in commercial burners. Energy yield of the process was very high - in excess of 93% including gas phase heating value. Design and operating data were obtained to permit design of a commercial size atactic conversion plant. Atactic polypropylene can be cracked at temperatures around 850/sup 0/F and residence time of 5 minutes. The viscosity of the cracked product increases with decrease in time/temperature. A majority of the pyrolysis was carried out at a pressure of 50 psig. Thermal cracking of atactic polypropylene is seen to result in sigificant coke formation (0.4% to 0.8% on a weight of feed basis) although the coke levels were of an order of magnitude lower than those obtained during catalytic cracking. The discrepancy between batch and continuous test data can be atrributed to lowered heat transfer and diffusion rates. Oxidative pyrolysis is not seen as a viable commercial alternative due to a significant amount of water formation. However, introduction of controlled quantities of oxygen at lower temperatures to affect change in feedstock viscosity could be considered. It is essential to have a complete characterization of the polymer composition and structure in order to obtain useful and duplicable data because the pyrolysis products and probably the pyrolysis kinetics are affected by introduction of abnormalities into the polymer structure during polymerization. The polymer products from continuous testing contained an olefinic content of 80% or higher. This suggests that the pyrolysis products be investigated for use as olefinic raw materials. Catalytic cracking does not seem to result in any advantage over the Thermal Cracking process in terms of reaction rates or temperature of operation.

  19. Neutronic study on conversion of SAFARI-1 to LEU silicide fuel

    SciTech Connect

    Ball, G.; Pond, R.; Hanan, N.; Matos, J.

    1995-02-01

    This paper marks the initial study into the technical and economic feasibility of converting the SAFARI-1 reactor in South Africa to LEU silicide fuel. Several MTR assembly geometries and LEU uranium densities have been studied and compared with MEU and HEU fuels. Two factors of primary importance for conversion of SAFARI-1 to LEU fuel are the economy of the fuel cycle and the performance of the incore and excore irradiation positions.

  20. Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.

    PubMed

    Stettler, Marc E J; Midgley, William J B; Swanson, Jacob J; Cebon, David; Boies, Adam M

    2016-02-16

    Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles. PMID:26757000

  1. Analyses for conversion of the Georgia Tech Research Reactor from HEU to LEU fuel

    SciTech Connect

    Matos, J.E.; Mo, S.C.; Woodruff, W.L.

    1992-01-01

    The 5 MW Georgia Tech Research Reactor (GTRR) is a heterogeneous, heavy water moderated and cooled reactor, fueled with highly-enriched uranium aluminum alloy fuel plates. The GTRR is required to convert to low enrichment (LEU) fuel in accordance with USNRC policy. Results of design and safety analyses performed by the RERTR Program at the Argonne National Laboratory for LEU conversion of the GTRR are summarized. Only those parameters which could change as a result of replacing the fuel are addressed. The performance of the reactor and all safety margins with LEU fuel are expected to be about the same as those with the current HEU fuel.

  2. Analyses for conversion of the Georgia Tech Research Reactor from HEU to LEU fuel

    SciTech Connect

    Matos, J.E.; Mo, S.C.; Woodruff, W.L.

    1992-12-31

    The 5 MW Georgia Tech Research Reactor (GTRR) is a heterogeneous, heavy water moderated and cooled reactor, fueled with highly-enriched uranium aluminum alloy fuel plates. The GTRR is required to convert to low enrichment (LEU) fuel in accordance with USNRC policy. Results of design and safety analyses performed by the RERTR Program at the Argonne National Laboratory for LEU conversion of the GTRR are summarized. Only those parameters which could change as a result of replacing the fuel are addressed. The performance of the reactor and all safety margins with LEU fuel are expected to be about the same as those with the current HEU fuel.

  3. SYMPOSIUM PROCEEDINGS: ENVIRONMENTAL ASPECTS OF FUEL CONVERSION TECHNOLOGY, IV (APRIL 1979, HOLLYWOOD, FL)

    EPA Science Inventory

    The proceedings document presentations made at the symposium on Environmental Aspects of Fuel Conversion Technology. The symposium acted as a colloquium for discussion of environmentally related information on coal gasification and liquefaction. The program included sessions on p...

  4. Changes on degree of conversion of dual-cure luting light-cured with blue LED

    NASA Astrophysics Data System (ADS)

    Bandéca, M. C.; El-Mowafy, O.; Saade, E. G.; Rastelli, A. N. S.; Bagnato, V. S.; Porto-Neto, S. T.

    2009-05-01

    The indirect adhesive procedures constitute recently a substantial portion of contemporary esthetic restorative treatments. The resin cements have been used to bond tooth substrate and restorative materials. Due to recently introduction of the self-bonding resin luting cement based on a new monomer, filler and initiation technology has become important to study the degree of conversion of these new materials. In the present work the polymerization reaction and the filler content of dual-cured dental resin cements were studied by means of infra-red spectroscopy (FT-IR) and thermogravimetry (TG). Twenty specimens were made in a metallic mold (8 mm diameter × 1 mm thick) from each of 2 cements, Panavia® F2.0 (Kuraray) and RelyX™ Unicem Applicap (3M/ESPE). Each specimen was cured with blue LED with power density of 500 mW/cm2 for 30 s. Immediately after curing, 24 and 48 h, and 7 days DC was determined. For each time interval 5 specimens were pulverized, pressed with KBr and analyzed with FT-IR. The TG measurements were performed in Netzsch TG 209 under oxygen atmosphere and heating rate of 10°C/min from 25 to 700°C. A two-way ANOVA showed DC (%) mean values statistically significance differences between two cements ( p < 0.05). The Tukey’s test showed no significant difference only for the 24 and 48 h after light irradiation for both resin cements ( p > 0.05). The Relx-Y™ Unicem mean values were significantly higher than Panavia® F 2.0. The degree of conversion means values increasing with the storage time and the filler content showed similar for both resin cements.

  5. MAN B&W Diesel extends dual-fuel engine range up to 16 MW

    SciTech Connect

    Schaaf, H.

    1996-04-01

    In 1995, MAN B&W Diesel launched a dual-fuel version of the successful L + V (in-line and vee) configurations of the 32/40 diesel engine series, covering a power range between 2.4 and 7.2 MW. In 1996, the company is launching a dual-fuel version of the L + V 48/60 engine series, moving the power range of dual-fuel engines to 16.2 MW. With its new dual fuel type 32/40 DG and 48/60 DG engines, MAN B&W Diesel has designed prime movers offering a high efficiency at low operating costs, while simultaneously meeting the most stringent NO{sub x} emission limits without any exhaust gas after-treatment. These engines are based on the successful HFO-operated four-stroke diesel engines. They offer environment-friendly and, operating at high mean effective pressures, simultaneously cost effective propulsion alternatives, especially if natural gas is used as a fuel. Extension of the compatibility to permit further kinds of gas such as sewage gas to be used is being developed.

  6. Comparison of Propane and Methane Performance and Emissions in a Turbocharged Direct Injection Dual Fuel Engine

    SciTech Connect

    Gibson, C. M.; Polk, A. C.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2011-01-01

    With increasingly restrictive NO x and particulate matter emissions standards, the recent discovery of new natural gas reserves, and the possibility of producing propane efficiently from biomass sources, dual fueling strategies have become more attractive. This paper presents experimental results from dual fuel operation of a four-cylinder turbocharged direct injection (DI) diesel engine with propane or methane (a natural gas surrogate) as the primary fuel and diesel as the ignition source. Experiments were performed with the stock engine control unit at a constant speed of 1800 rpm, and a wide range of brake mean effective pressures (BMEPs) (2.7-11.6 bars) and percent energy substitutions (PESs) of C 3 H 8 and CH 4. Brake thermal efficiencies (BTEs) and emissions (NO x, smoke, total hydrocarbons (THCs), CO, and CO 2) were measured. Maximum PES levels of about 80-95% with CH 4 and 40-92% with C 3 H 8 were achieved. Maximum PES was limited by poor combustion efficiencies and engine misfire at low loads for both C 3 H 8 and CH 4, and the onset of knock above 9 bar BMEP for C 3 H 8. While dual fuel BTEs were lower than straight diesel BTEs at low loads, they approached diesel BTE values at high loads. For dual fuel operation, NO x and smoke reductions (from diesel values) were as high as 66-68% and 97%, respectively, but CO and THC emissions were significantly higher with increasing PES at all engine loads

  7. Indirect-fired gas turbine dual fuel cell power cycle

    SciTech Connect

    Micheli, P.L.; Williams, M.C.; Sudhoff, F.A.

    1998-04-01

    The present invention relates generally to an integrated fuel cell power plant, and more specifically to a combination of cycles wherein a first fuel cell cycle tops an indirect-fired gas turbine cycle and a second fuel cell cycle bottoms the gas turbine cycle so that the cycles are thermally integrated in a tandem operating arrangement. The United States Government has rights in this invention pursuant to the employer-employee relationship between the United States Department of Energy and the inventors.

  8. Mixed core conversion study with HEU and LEU fuels

    SciTech Connect

    Matos, J.E.; Freese, K.E.

    1984-01-01

    The results of a mixed core study are presented for gradual replacement of HEU fuel with LEU fuel using the IAEA generic 10 MW reactor as an example. The key parameters show that the transition can be accomplished safely and economically.

  9. Low enrichment fuel conversion for Iowa State University

    SciTech Connect

    Rohach, A.F.

    1992-08-01

    This report discusses the UTR-10 reactor at Iowa State University which went critical on low enriched uranium (LEU) fuel on August 14, 1991. However, subsequent to the criticality experiments the fuel plates started to discolor. In addition, roll pins used to lift the fuel assemblies were discovered to be cracked. It was determined that these problems were due to chemical agents in the primary coolant water. The roll pins were replaced by solid stainless steel pins. The primary coolant was replaced and the reactor is currently in operation. Surveillance specimens will be used to monitor any possible future discoloration. The high enriched fuel (HEU) is being prepared for eventual shipment to a high enriched fuel receiving facility.

  10. Use of alcohol fuel: engine-conversion demonstration. Final report

    SciTech Connect

    Marsh, W.K.

    1982-01-01

    The use of ethanol as a fuel extender when mixed with gasoline, and the use of both hydrated and anhydrous ethanol as a fuel in gasoline and diesel engines are discussed. Required engine modifications for efficient use of ethanol are described, and include engine compression alterations, carburetor adjustments, and arrangement for fuel preheating. In 1981 and 1982 a demonstration of ethanol use in spark ignition engines was conducted at a major public park in South Carolina. The demonstration included a controlled road test with a pick-up truck and a demonstration of ethanol use in small, air cooled gasoline engines. One problem that was identified was that of contaminated fuel that clogged the fuel system after a few days' operation. (LEW)

  11. BioFacts: Fueling a stronger economy, thermochemical conversion of biomass

    NASA Astrophysics Data System (ADS)

    1994-12-01

    A primary mission of the US DOE is to stimulate the development, acceptance, and use of transportation fuels made from plants and wastes called biomass. Through the National Renewable Energy Laboratory (NREL), DOE is developing and array of biomass conversion technologies that can be easily integrated into existing fuel production and distribution systems. The variety of technology options being developed should enable individual fuel producers to select and implement the most cost-effective biomass conversion process suited to their individual needs. Current DOE biofuels research focuses on the separate and tandem uses of biochemical and thermochemical conversion processes. This overview specifically addresses NREL's thermochemical conversion technologies, which are largely based on existing refining processes.

  12. BioFacts: Fueling a stronger economy, Thermochemical conversion of biomass

    SciTech Connect

    1994-12-01

    A primary mission of the US DOE is to stimulate the development, acceptance, and use of transportation fuels made from plants and wastes called biomass. Through the National Renewable Energy Laboratory (NREL), Doe is developing and array of biomass conversion technologies that can be easily integrated into existing fuel production and distribution systems. The variety of technology options being developed should enable individual fuel producers to select and implement the most cost-effective biomass conversion process suited to their individual needs. Current DOE biofuels research focuses on the separate and tandem uses of biochemical and thermochemical conversion processes. This overview specifically addresses NREL`s thermochemical conversion technologies, which are largely based on existing refining processes.

  13. Conversion of hydrocarbon fuel in thermal protection reactors of hypersonic aircraft

    NASA Astrophysics Data System (ADS)

    Kuranov, A. L.; Mikhaylov, A. M.; Korabelnikov, A. V.

    2016-07-01

    Thermal protection of heat-stressed surfaces of a high-speed vehicle flying in dense layers of atmosphere is one of the topical issues. Not of a less importance is also the problem of hydrocarbon fuel combustion in a supersonic air flow. In the concept under development, it is supposed that in the most high-stressed parts of airframe and engine, catalytic thermochemical reactors will be installed, wherein highly endothermic processes of steam conversion of hydrocarbon fuel take place. Simultaneously with heat absorption, hydrogen generation will occur in the reactors. This paper presents the results of a study of conversion of hydrocarbon fuel in a slit reactor.

  14. Ten-percent solar-to-fuel conversion with nonprecious materials

    PubMed Central

    Cox, Casandra R.; Lee, Jungwoo Z.; Nocera, Daniel G.; Buonassisi, Tonio

    2014-01-01

    Direct solar-to-fuels conversion can be achieved by coupling a photovoltaic device with water-splitting catalysts. We demonstrate that a solar-to-fuels efficiency (SFE) > 10% can be achieved with nonprecious, low-cost, and commercially ready materials. We present a systems design of a modular photovoltaic (PV)–electrochemical device comprising a crystalline silicon PV minimodule and low-cost hydrogen-evolution reaction and oxygen-evolution reaction catalysts, without power electronics. This approach allows for facile optimization en route to addressing lower-cost devices relying on crystalline silicon at high SFEs for direct solar-to-fuels conversion. PMID:25225379

  15. Ten-percent solar-to-fuel conversion with nonprecious materials.

    PubMed

    Cox, Casandra R; Lee, Jungwoo Z; Nocera, Daniel G; Buonassisi, Tonio

    2014-09-30

    Direct solar-to-fuels conversion can be achieved by coupling a photovoltaic device with water-splitting catalysts. We demonstrate that a solar-to-fuels efficiency (SFE) > 10% can be achieved with nonprecious, low-cost, and commercially ready materials. We present a systems design of a modular photovoltaic (PV)-electrochemical device comprising a crystalline silicon PV minimodule and low-cost hydrogen-evolution reaction and oxygen-evolution reaction catalysts, without power electronics. This approach allows for facile optimization en route to addressing lower-cost devices relying on crystalline silicon at high SFEs for direct solar-to-fuels conversion. PMID:25225379

  16. Preliminary neutronics calculations for conversion of the Tehran research reactor core from HEU to LEU fuel

    SciTech Connect

    Nejat, S.M.R. . Dept. of Engineering Physics.)

    1993-08-01

    The 5-MW highly enriched uranium (HEU)-fueled Tehran Research Reactor is considered for conversion to high-density, low-enriched uranium (LEU) fuel. A preliminary neutronics calculation is performed as part of the conversion goal. In this study, two cores are considered: the HEU reference core and a proposed LEU core similar to the reference core, and a proposed LEU core similar to the reference core, using standardized U[sub 3]Si[sub 2] plates with the option of different [sup 235]U loadings. Various possibilities are investigated for the conversion of HEU to LEU fuel elements with 20% enriched [sup 235]U loadings of 207 to 297 g [sup 235]U/element. For the same equilibrium cycle length, the fuels are compared for flux, power distribution, burnup, and reactivity.

  17. A Metal-Nitride Nanowire Dual-Photoelectrode Device for Unassisted Solar-to-Hydrogen Conversion under Parallel Illumination.

    PubMed

    AlOtaibi, B; Fan, S; Vanka, S; Kibria, M G; Mi, Z

    2015-10-14

    A dual-photoelectrode device, consisting of a photoanode and photocathode with complementary energy bandgaps, has long been perceived as an ideal scheme for achieving high efficiency, unassisted solar-driven water splitting. Previously reported 2-photon tandem devices, however, generally exhibit an extremely low efficiency (<0.1%), which has been largely limited by the incompatibility between the two photoelectrode materials. Here we show that the use of metal-nitride nanowire photoelectrodes, together with the scheme of parallel illumination by splitting the solar spectrum spatially and spectrally, can break the efficiency bottleneck of conventional 2-photon tandem devices. We have first investigated a dual-photoelectrode device consisting of a GaN nanowire photoanode and an InGaN nanowire photocathode, which exhibited an open circuit potential of 1.3 V and nearly 20-fold enhancement in the power conversion efficiency under visible light illumination (400-600 nm), compared to the individual photoelectrodes in 1 mol/L HBr. We have further demonstrated a dual-photoelectrode device consisting of parallel-connected metal-nitride nanowire photoanodes and a Si/InGaN nanowire photocathode, which can perform unassisted, direct solar-to-hydrogen conversion. A power conversion efficiency of 2% was measured under AM1.5G 1 sun illumination. PMID:26360182

  18. Knock prediction for dual fuel engines by using a simplified combustion model.

    PubMed

    Fei, Shao-mei; Liu, Zhen-tao; Yan, Zhao-da

    2003-01-01

    The present work used a methane-air mixture chemical kinetics scheme consisting of 119 elementary reaction steps and 41 chemical species to develop a simplified combustion model for prediction of the knock in dual fuel engines. Calculated values by the model for natural gas operation showed good agreement with corresponding experimental values over a broad range of operating conditions. PMID:12958720

  19. REDUCTION OF USE OF PETROLEUM ENERGY RESOURCES BY CONVERSION OF WASTE COOKING OILS INTO DIESEL FUEL

    EPA Science Inventory

    This project has a dual objective of providing hands-on experience to undergraduate engineering students and producing biodiesel fuel from a used cooking oil feedstock. The project consists of three phases: Phase I - process development and construction of a pilot plant; Phase...

  20. Delays hit conversion to low enriched uranium fuel

    NASA Astrophysics Data System (ADS)

    Allen, Michael

    2016-03-01

    Eliminating highly enriched uranium (HEU) fuel from civilian research reactors around the world will take a lot longer than anticipated, according to a new study by the US National Academies of Sciences, Engineering and Medicine.

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

    SciTech Connect

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

    2010-07-15

    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{sub 2} levels by 3% in comparison with current thermal power plants.

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

    PubMed

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

    2010-07-01

    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. PMID:20207531

  3. POLLUTION CONTROL PRACTICES--FUEL CONVERSION AND ITS ENVIRONMENTAL EFFECTS

    EPA Science Inventory

    The paper examines water-related effects that could be expected from siting specific conversion plants at given locations in the major coal and oil shale bearing regions of the U.S. A total of 90 plant/site combinations were studied: 48 in the Central and Eastern U.S., and 42 in ...

  4. Catalytic conversion of biomass to monofunctional hydrocarbons and targeted liquid-fuel classes.

    PubMed

    Kunkes, Edward L; Simonetti, Dante A; West, Ryan M; Serrano-Ruiz, Juan Carlos; Gärtner, Christian A; Dumesic, James A

    2008-10-17

    It is imperative to develop more efficient processes for conversion of biomass to liquid fuels, such that the cost of these fuels would be competitive with the cost of fuels derived from petroleum. We report a catalytic approach for the conversion of carbohydrates to specific classes of hydrocarbons for use as liquid transportation fuels, based on the integration of several flow reactors operated in a cascade mode, where the effluent from the one reactor is simply fed to the next reactor. This approach can be tuned for production of branched hydrocarbons and aromatic compounds in gasoline, or longer-chain, less highly branched hydrocarbons in diesel and jet fuels. The liquid organic effluent from the first flow reactor contains monofunctional compounds, such as alcohols, ketones, carboxylic acids, and heterocycles, that can also be used to provide reactive intermediates for fine chemicals and polymers markets. PMID:18801970

  5. Dual phase MgO-ZrO 2 ceramics for use in LWR inert matrix fuel

    NASA Astrophysics Data System (ADS)

    Medvedev, P. G.; Frank, S. M.; O'Holleran, T. P.; Meyer, M. K.

    2005-06-01

    To address the low thermal conductivity of the ZrO 2-based inert matrix fuel and the instability in water of the MgO-based inert matrix fuel, the dual-phase MgO-ZrO 2 ceramics are proposed as a matrix for light water reactor fuel for actinide transmutation and Pu burning. It is envisioned that in a dual-phase system MgO will act as efficient heat conductor while ZrO 2 will provide protection from the coolant attack. This paper describes results of fabrication, characterization and hydration testing of MgO-ZrO 2 ceramics containing 30-70 wt% of MgO.

  6. Formate Formation and Formate Conversion in Biological Fuels Production

    PubMed Central

    Crable, Bryan R.; Plugge, Caroline M.; McInerney, Michael J.; Stams, Alfons J. M.

    2011-01-01

    Biomethanation is a mature technology for fuel production. Fourth generation biofuels research will focus on sequestering CO2 and providing carbon-neutral or carbon-negative strategies to cope with dwindling fossil fuel supplies and environmental impact. Formate is an important intermediate in the methanogenic breakdown of complex organic material and serves as an important precursor for biological fuels production in the form of methane, hydrogen, and potentially methanol. Formate is produced by either CoA-dependent cleavage of pyruvate or enzymatic reduction of CO2 in an NADH- or ferredoxin-dependent manner. Formate is consumed through oxidation to CO2 and H2 or can be further reduced via the Wood-Ljungdahl pathway for carbon fixation or industrially for the production of methanol. Here, we review the enzymes involved in the interconversion of formate and discuss potential applications for biofuels production. PMID:21687599

  7. A survey of Opportunities for Microbial Conversion of Biomass to Hydrocarbon Compatible Fuels

    SciTech Connect

    Jovanovic, Iva; Jones, Susanne B.; Santosa, Daniel M.; Dai, Ziyu; Ramasamy, Karthikeyan K.; Zhu, Yunhua

    2010-09-01

    Biomass is uniquely able to supply renewable and sustainable liquid transportation fuels. In the near term, the Biomass program has a 2012 goal of cost competitive cellulosic ethanol. However, beyond 2012, there will be an increasing need to provide liquid transportation fuels that are more compatible with the existing infrastructure and can supply fuel into all transportation sectors, including aviation and heavy road transport. Microbial organisms are capable of producing a wide variety of fuel and fuel precursors such as higher alcohols, ethers, esters, fatty acids, alkenes and alkanes. This report surveys liquid fuels and fuel precurors that can be produced from microbial processes, but are not yet ready for commercialization using cellulosic feedstocks. Organisms, current research and commercial activities, and economics are addressed. Significant improvements to yields and process intensification are needed to make these routes economic. Specifically, high productivity, titer and efficient conversion are the key factors for success.

  8. Conversion system overview assessment. Volume III. Solar thermal/coal or biomass derived fuels

    SciTech Connect

    Copeland, R. J.

    1980-02-01

    The three volumes of this report cover three distinct areas of solar energy research: solar thermoelectrics, solar-wind hybrid systems, and synthetic fuels derived with solar thermal energy. Volume III deals with the conversion of synthetic fuels with solar thermal heat. The method is a hybrid combination of solar energy with either coal or biomass. A preliminary assessment of this technology is made by calculating the cost of fuel produced as a function of the cost of coal and biomass. It is shown that within the projected ranges of coal, biomass, and solar thermal costs, there are conditions when solar synthetic fuels with solar thermal heat will become cost-competitive.

  9. Task 3.3: Warm Syngas Cleanup and Catalytic Processes for Syngas Conversion to Fuels Subtask 3: Advanced Syngas Conversion to Fuels

    SciTech Connect

    Lebarbier Dagel, Vanessa M.; Li, J.; Taylor, Charles E.; Wang, Yong; Dagle, Robert A.; Deshmane, Chinmay A.; Bao, Xinhe

    2014-03-31

    activity was to develop methods and enabling materials for syngas conversion to SNG with readily CO2 separation. Suitable methanation catalyst and CO2 sorbent materials were developed. Successful proof-of-concept for the combined reaction-sorption process was demonstrated, which culminated in a research publication. With successful demonstration, a decision was made to switch focus to an area of fuels research of more interest to all three research institutions (CAS-NETL-PNNL). Syngas-to-Hydrocarbon Fuels through Higher Alcohol Intermediates There are two types of processes in syngas conversion to fuels that are attracting R&D interest: 1) syngas conversion to mixed alcohols; and 2) syngas conversion to gasoline via the methanol-to-gasoline process developed by Exxon-Mobil in the 1970s. The focus of this task was to develop a one-step conversion technology by effectively incorporating both processes, which is expected to reduce the capital and operational cost associated with the conversion of coal-derived syngas to liquid fuels. It should be noted that this work did not further study the classic Fischer-Tropsch reaction pathway. Rather, we focused on the studies for unique catalyst pathways that involve the direct liquid fuel synthesis enabled by oxygenated intermediates. Recent advances made in the area of higher alcohol synthesis including the novel catalytic composite materials recently developed by CAS using base metal catalysts were used.

  10. DIRECT THERMOCHEMICAL CONVERSION OF SEWAGE SLUDGE TO FUEL OIL

    EPA Science Inventory

    A disposal method for primary sewage sludge and industrial sludges which generates boiler fuel as a product and is energy self sufficient or energy-generating is described. The method involves direct liquefaction in a mild aqueous alkali above 250 degs. C and was demonstrated for...

  11. Fault tree analysis of fire and explosion accidents for dual fuel (diesel/natural gas) ship engine rooms

    NASA Astrophysics Data System (ADS)

    Guan, Yifeng; Zhao, Jie; Shi, Tengfei; Zhu, Peipei

    2016-07-01

    In recent years, China's increased interest in environmental protection has led to a promotion of energy-efficient dual fuel (diesel/natural gas) ships in Chinese inland rivers. A natural gas as ship fuel may pose dangers of fire and explosion if a gas leak occurs. If explosions or fires occur in the engine rooms of a ship, heavy damage and losses will be incurred. In this paper, a fault tree model is presented that considers both fires and explosions in a dual fuel ship; in this model, dual fuel engine rooms are the top events. All the basic events along with the minimum cut sets are obtained through the analysis. The primary factors that affect accidents involving fires and explosions are determined by calculating the degree of structure importance of the basic events. According to these results, corresponding measures are proposed to ensure and improve the safety and reliability of Chinese inland dual fuel ships.

  12. Conversion of Biomass-Derived Furans into Hydrocarbon Fuels

    SciTech Connect

    Moens, L.; Johnson, D. K.

    2013-01-01

    One of the most studied chemical transformations of carbohydrates is their thermocatalytic dehydration to form furans. Cellulose-derived glucose is thereby converted into 5-hydroxymethylfurfuraldehyde (5-HMF), while the hemicellulose-derived pentoses (e.g., xylose, arabinose) form furfuraldehyde. Our objective is to identify new pathways to convert furfuryl alcohol into a mixture of aliphatic hydrocarbons that can be used as drop-in fuels for diesel (C10-20) and jet fuel (C9-16) blends. Furfuryl alcohol is produced commercially through hydrogenation of furfuraldehyde that is derived from hemicellulose-derived pentoses via acid-catalyzed dehydration. The steps that we are currently pursuing to convert furfuryl alcohol into hydrocarbons are 1) oligomerization of furfuryl alcohol to form dimers (C10) and trimers (C15), and 2) hydrotreatment of the dimers and trimers to produce a mixture of linear hydrocarbons with carbon chain lengths in the range of diesel and jet fuels. This presentation will discuss our progress in the development of this pathway.

  13. Catalytic conversion of lignocellulosic biomass to fine chemicals and fuels.

    PubMed

    Zhou, Chun-Hui; Xia, Xi; Lin, Chun-Xiang; Tong, Dong-Shen; Beltramini, Jorge

    2011-11-01

    Lignocellulosic biomass is the most abundant and bio-renewable resource with great potential for sustainable production of chemicals and fuels. This critical review provides insights into the state-of the-art accomplishments in the chemocatalytic technologies to generate fuels and value-added chemicals from lignocellulosic biomass, with an emphasis on its major component, cellulose. Catalytic hydrolysis, solvolysis, liquefaction, pyrolysis, gasification, hydrogenolysis and hydrogenation are the major processes presently studied. Regarding catalytic hydrolysis, the acid catalysts cover inorganic or organic acids and various solid acids such as sulfonated carbon, zeolites, heteropolyacids and oxides. Liquefaction and fast pyrolysis of cellulose are primarily conducted over catalysts with proper acidity/basicity. Gasification is typically conducted over supported noble metal catalysts. Reaction conditions, solvents and catalysts are the prime factors that affect the yield and composition of the target products. Most of processes yield a complex mixture, leading to problematic upgrading and separation. An emerging technique is to integrate hydrolysis, liquefaction or pyrolysis with hydrogenation over multifunctional solid catalysts to convert lignocellulosic biomass to value-added fine chemicals and bio-hydrocarbon fuels. And the promising catalysts might be supported transition metal catalysts and zeolite-related materials. There still exist technological barriers that need to be overcome (229 references). PMID:21863197

  14. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    SciTech Connect

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  15. Catalytic conversion wood syngas to synthetic aviation turbine fuels over a multifunctional catalyst.

    PubMed

    Yan, Qiangu; Yu, Fei; Liu, Jian; Street, Jason; Gao, Jinsen; Cai, Zhiyong; Zhang, Jilei

    2013-01-01

    A continuous process involving gasification, syngas cleaning, and Fischer-Tropsch (FT) synthesis was developed to efficiently produce synthetic aviation turbine fuels (SATFs). Oak-tree wood chips were first gasified to syngas over a commercial pilot plant downdraft gasifier. The raw wood syngas contains about 47% N(2), 21% CO, 18% H(2), 12% CO(2,) 2% CH(4) and trace amounts of impurities. A purification reaction system was designed to remove the impurities in the syngas such as moisture, oxygen, sulfur, ammonia, and tar. The purified syngas meets the requirements for catalytic conversion to liquid fuels. A multi-functional catalyst was developed and tested for the catalytic conversion of wood syngas to SATFs. It was demonstrated that liquid fuels similar to commercial aviation turbine fuels (Jet A) was successfully synthesized from bio-syngas. PMID:23131653

  16. Conversion and standardization of US university reactor fuels using LEU, status 1989

    SciTech Connect

    Brown, K.R.; Matos, J.E.; Argonne National Lab., IL )

    1989-01-01

    In 1986, the US Department of Energy initiated a program to change the fuel used in most of the US university research reactors using HEU (93%) to LEU({lt}20{percent}) in order to minimize the risk of theft or diversion of this weapons-useable material. An important consideration in the LEU conversion planning process has been the desire to standardize the fuels that are used and to enhance the performance and utilization of the reactors. This paper describes the current status of this conversion process and the plans and schedules to complete an orderly transition from HEU to LEU fuel in most of these reactors. To date, three university reactors have been converted to LEU fuel, completed safety documentation for three reactors is being evaluated by the USNRC, and work on the safety documentation for six reactors is in progress. 13 refs., 9 tabs.

  17. Energy conversion and fuel production from electrochemical interfaces

    NASA Astrophysics Data System (ADS)

    Markovic, Nenad

    2012-02-01

    Design and synthesis of energy efficient and stable electrochemical interfaces (materials and double layer components) with tailor properties for accelerating and directing chemical transformations is the key to developing new alternative energy systems -- fuel cells, electrolizers and batteries. In aqueous electrolytes, depending on the nature of the reacting species, the supporting electrolyte, and the metal electrodes, two types of interactions have traditionally been considered: (i) direct -- covalent - bond formation between adsorbates and electrodes, involving chemisorption, electron transfer, and release of the ion hydration shell; and (ii) relatively weak non-covalent metal-ion forces that may affect the concentration of ions in the vicinity of the electrode but do not involve direct metal-adsorbate bonding. The range of physical phenomena associated with these two classes of bonds is unusually broad, and are of paramount importance to understand activity of both metal-electrolyte two phase interfaces and metal-Nafion-electrolyte three phase interfaces. Furthermore, in the past, researcher working in the field of fuel cells (converting hydrogen and oxygen into water) and electrolyzers (splitting water back to H2 and O2) ) seldom focused on understanding the electrochemical compliments of these reactions in battery systems, e.g., the lithium-air system. In this lecture, we address the importance of both covalent and non-covalent interactions in controlling catalytic activity at the two-phase and three-phase interfaces. Although the field is still in its infancy, a great deal has already been learned and trends are beginning to emerge that give new insight into the relationship between the nature of bonding interactions and catalytic activity/stability of electrochemical interfaces. In addition, to bridge the gap between the ``water battery'' (fuel cell <-> electrolyzer) and the Li-air battery systems we demonstrate that this would require fundamentally new

  18. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    SciTech Connect

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; Larry Chick

    2004-05-07

    The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.

  19. Conversion and standardization of university reactor fuels using low-enrichment uranium - options and costs

    SciTech Connect

    Harris, D.R.; Matos, J.E.; Young, H.H.

    1985-01-01

    The highly-enriched uranium (HEU) fuel used in twenty United States university reactors can be viewed as contributing to the risk of theft or diversion of weapons-useable material. The US Nuclear Regulatory Commission has issued a policy statement expressing its concern and has published a proposed rule on limiting the use of HEU in NRC-licensed non-power reactors. The fuel options, functional impacts, licensing, and scheduling of conversion and standardization of these reactor fuels to use of low-enrichment uranium (LEU) have been assessed. The university reactors span a wide range in form and function, from medium-power intense neutron sources where HEU fuel may be required, to low-power training and research facilities where HEU fuel is unnecessary. Conversion provides an opportunity to standardize university reactor fuels and improve reactor utilization in some cases. The entire program is estimated to cost about $10 million and to last about five years. Planning for conversion and standardization is facilitated by the US Department of Energy. 20 refs., 1 tab.

  20. Dual mode fuel injector with one piece needle valve member

    DOEpatents

    Lawrence, Keith E.; Hinrichsen, Michael H.; Buckman, Colby

    2005-01-18

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively by inner and outer needle value members. The homogenous charged nozzle outlet set is defined by an outer needle value member that is moveably positioned in an injector body, which defines the conventional nozzle outlet set. The inner needle valve member is positioned in the outer needle valve member. The outer needle valve member is a piece component that includes at least one external guide surface, an external value surface and an internal valve seat.

  1. Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) for dual mode applications

    NASA Astrophysics Data System (ADS)

    Malloy, John; Jacox, Michael; Zubrin, Robert

    1992-07-01

    The Small Externally Fueled Heat-Pipe Thermionic Reactor (SEHPTR) is described in the context of applications as a dual-mode nuclear power source for satellites. The SEHPTR is a thermionic power system based on a reactor with modular fuel elements around cylindrical thermionic heat-pipe modules with diodes for heat rejection. The SEHPTR concept is theorized to be suitable for directly heating hydrogen gas in the core to increase propulsion and reduce orbit-transfer times. The advantages of dual-mode operation of the SEHPTR are listed including enhanced mission safety and performance at relatively low costs. The SEHPTR could provide direct thermal thrust and an integrated stage that symbiotically utilizes electric power, direct thrust, and hydrogen arcjets. The system is argued to be more effective than a nuclear power system designed solely for electrical power production.

  2. Fretting wear behaviors of a dual-cooled nuclear fuel rod under a simulated rod vibration

    SciTech Connect

    Lee, Young-Ho; Kim, Hyung-Kyu; Kang, Heung-Seok; Yoon, Kyung-Ho; Kim, Jae-Yong; Lee, Kang-Hee

    2012-06-06

    Recently, a dual-cooled fuel (i.e., annular fuel) that is compatible with current operating PWR plants has been proposed in order to realize both a considerable amount of power uprating and an increase of safety margins. As the design concept should be compatible with current operating PWR plants, however, it shows a narrow gap between the fuel rods when compared with current solid nuclear fuel arrays and needs to modify the spacer grid shapes and their positions. In this study, fretting wear tests have been performed to evaluate the wear resistance of a dual-cooled fuel by using a proposed spring and dimple of spacer grids that have a cantilever type and hemispherical shape, respectively. As a result, the wear volume of the spring specimen gradually increases as the contact condition is changed from a certain gap, just contact to positive force. However, in the dimple specimen, just contact condition shows a large wear volume. In addition, a circular rod motion at upper region of contact surface is gradually increased and its diametric size depends on the wear depth increase. Based on the test results, the fretting wear resistance of the proposed spring and dimple is analyzed by comparing the wear measurement results and rod motion in detail.

  3. Fretting wear behaviors of a dual-cooled nuclear fuel rod under a simulated rod vibration

    NASA Astrophysics Data System (ADS)

    Lee, Young-Ho; Kim, Hyung-Kyu; Kang, Heung-Seok; Yoon, Kyung-Ho; Kim, Jae-Yong; Lee, Kang-Hee

    2012-06-01

    Recently, a dual-cooled fuel (i.e., annular fuel) that is compatible with current operating PWR plants has been proposed in order to realize both a considerable amount of power uprating and an increase of safety margins. As the design concept should be compatible with current operating PWR plants, however, it shows a narrow gap between the fuel rods when compared with current solid nuclear fuel arrays and needs to modify the spacer grid shapes and their positions. In this study, fretting wear tests have been performed to evaluate the wear resistance of a dual-cooled fuel by using a proposed spring and dimple of spacer grids that have a cantilever type and hemispherical shape, respectively. As a result, the wear volume of the spring specimen gradually increases as the contact condition is changed from a certain gap, just contact to positive force. However, in the dimple specimen, just contact condition shows a large wear volume. In addition, a circular rod motion at upper region of contact surface is gradually increased and its diametric size depends on the wear depth increase. Based on the test results, the fretting wear resistance of the proposed spring and dimple is analyzed by comparing the wear measurement results and rod motion in detail.

  4. Method and apparatus for conversion of carbonaceous materials to liquid fuel

    DOEpatents

    Lux, Kenneth W.; Namazian, Mehdi; Kelly, John T.

    2015-12-01

    Embodiments of the invention relates to conversion of hydrocarbon material including but not limited to coal and biomass to a synthetic liquid transportation fuel. The invention includes the integration of a non-catalytic first reaction scheme, which converts carbonaceous materials into a solid product that includes char and ash and a gaseous product; a non-catalytic second reaction scheme, which converts a portion of the gaseous product from the first reaction scheme to light olefins and liquid byproducts; a traditional gas-cleanup operations; and the third reaction scheme to combine the olefins from the second reaction scheme to produce a targeted fuel like liquid transportation fuels.

  5. ATMOSPHERIC CHEMISTRY OF POTENTIAL EMISSIONS FROM FUEL CONVERSION FACILITIES. A SMOG CHAMBER STUDY

    EPA Science Inventory

    The atmospheric chemistry of chemical species that may be emitted from fuel conversion facilities were studied in smog chambers. Of 17 compounds assessed for ozone-forming potential, 6 compounds were selected along with a control species, propylene, for testing in the presence of...

  6. SYMPOSIUM PROCEEDINGS: ENVIRONMENTAL ASPECTS OF FUEL CONVERSION TECHNOLOGY, V (SEPTEMBER 1980, ST. LOUIS, MO)

    EPA Science Inventory

    The report documents presentations at the fifth EPA-sponsored symposium on the environmental aspects of fuel conversion technology, in St. Louis, MO, 9/16-19/80. The symposium served as a colloquium on environmental information related to coal gasification, indirect liquefaction,...

  7. Fuel processor for fuel cell power system. [Conversion of methanol into hydrogen

    DOEpatents

    Vanderborgh, N.E.; Springer, T.E.; Huff, J.R.

    1986-01-28

    A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

  8. Radiation-initiated conversion of paraffins to engine fuel: Direct and indirect initiation

    NASA Astrophysics Data System (ADS)

    Metreveli, A. K.; Ponomarev, A. V.

    2016-07-01

    Formation of gasoline and diesel fuel has been investigated using three various radiation-induced ways: (1) cracking of wax, (2) synthesis from methane, (3) high-temperature conversion of wax dilute solution in methane. The wax, synthesized by Fischer-Tropsch method, initially contained a mixture of C17-C120 linear paraffins. The yield of wax conversion to liquid mixture (C4-C27 alkenes and 61.5% alkanes) via mode (1) was 0.83±0.09 μmole/J, whereas yield of gas conversion to liquid mixture (C5-C13 alkanes) via mode (2) was 0.95±0.02 μmole/J. In the dilute solution wax underwent indirect action of radiation. In comparison with (1) the mode (3) produces similar amount of lighter fuel containing 80% of alkanes (C5-C15). At the same time degree of methane fixation is almost three times higher.

  9. Effective conversion of biomass tar into fuel gases in a microwave reactor

    NASA Astrophysics Data System (ADS)

    Anis, Samsudin; Zainal, Z. A.

    2016-06-01

    This work deals with conversion of naphthalene (C10H8) as a biomass tar model compound by means of thermal and catalytic treatments. A modified microwave oven with a maximum output power of 700 W was used as the experimental reactor. Experiments were performed in a wide temperature range of 450-1200°C at a predetermined residence time of 0.24-0.5 s. Dolomite and Y-zeolite were applied to convert naphthalene catalytically into useful gases. Experimental results on naphthalene conversion showed that conversion efficiency and yield of gases increased significantly with the increase of temperature. More than 90% naphthalene conversion efficiency was achieved by thermal treatment at 1200°C and 0.5 s. Nevertheless, this treatment was unfavorable for fuel gases production. The main product of this treatment was soot. Catalytic treatment provided different results with that of thermal treatment in which fuel gases formation was found to be the important product of naphthalene conversion. At a high temperature of 900°C, dolomite had better conversion activity where almost 40 wt.% of naphthalene could be converted into hydrogen, methane and other hydrocarbon gases.

  10. Neutronic Analyses for HEU to LEU fuel conversion of the Massachusetts Institute of Technology.

    SciTech Connect

    Wilson, E. H.; Newton, T. H.; Bergeron, A.; Horelik, N.; Stevens, J. G

    2011-03-02

    The Massachusetts Institute of Technology (MIT) reactor (MITR-II), based in Cambridge, Massachusetts, is a research reactor designed primarily for experiments using neutron beam and in-core irradiation facilities. It delivers a neutron flux comparable to current LWR power reactors in a compact 6 MW core using Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most research and test reactors both domestic and international have started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on a mixture of uranium and molybdenum (UMo) is expected to allow the conversion of compact high performance reactors like the MITR-II. This report presents the results of steady state neutronic safety analyses for conversion of MITR-II from the use of HEU fuel to the use of U-Mo LEU fuel. The objective of this work was to demonstrate that the safety analyses meet current requirements for an LEU core replacement of MITR-II.

  11. Status of core conversion with LEU silicide fuel in JRR-4

    SciTech Connect

    Nakajima, Teruo; Ohnishi, Nobuaki; Shirai, Eiji

    1997-08-01

    Japan Research Reactor No.4 (JRR-4) is a light water moderated and cooled, 93% enriched uranium ETR-type fuel used and swimming pool type reactor with thermal output of 3.5MW. Since the first criticality was achieved on January 28, 1965, JRR-4 has been used for shielding experiments, radioisotope production, neutron activation analyses, training for reactor engineers and so on for about 30 years. Within the framework of the RERTR Program, the works for conversion to LEU fuel are now under way, and neutronic and thermal-hydraulic calculations emphasizing on safety and performance aspects are being carried out. The design and evaluation for the core conversion are based on the Guides for Safety Design and Evaluation of research and testing reactor facilities in Japan. These results show that the JRR-4 will be able to convert to use LEU fuel without any major design change of core and size of fuel element. LEU silicide fuel (19.75%) will be used and maximum neutron flux in irradiation hole would be slightly decreased from present neutron flux value of 7x10{sup 13}(n/cm{sup 2}/s). The conversion works are scheduled to complete in 1998, including with upgrade of the reactor building and utilization facilities.

  12. Recent Developments on the Production of Transportation Fuels via Catalytic Conversion of Microalgae: Experiments and Simulations

    SciTech Connect

    Shi, Fan; Wang, Ping; Duan, Yuhua; Link, Dirk; Morreale, Bryan

    2012-08-02

    Due to continuing high demand, depletion of non-renewable resources and increasing concerns about climate change, the use of fossil fuel-derived transportation fuels faces relentless challenges both from a world markets and an environmental perspective. The production of renewable transportation fuel from microalgae continues to attract much attention because of its potential for fast growth rates, high oil content, ability to grow in unconventional scenarios, and inherent carbon neutrality. Moreover, the use of microalgae would minimize “food versus fuel” concerns associated with several biomass strategies, as microalgae do not compete with food crops in the food chain. This paper reviews the progress of recent research on the production of transportation fuels via homogeneous and heterogeneous catalytic conversions of microalgae. This review also describes the development of tools that may allow for a more fundamental understanding of catalyst selection and conversion processes using computational modelling. The catalytic conversion reaction pathways that have been investigated are fully discussed based on both experimental and theoretical approaches. Finally, this work makes several projections for the potential of various thermocatalytic pathways to produce alternative transportation fuels from algae, and identifies key areas where the authors feel that computational modelling should be directed to elucidate key information to optimize the process.

  13. Recent developments in the production of liquid fuels via catalytic conversion of microalgae: experiments and simulations

    SciTech Connect

    Shi,Fan; Wang, Pin; Duan, Yuhua; Link, Dirk; Morreale, Bryan

    2012-01-01

    Due to continuing high demand, depletion of non-renewable resources and increasing concerns about climate change, the use of fossil fuel-derived transportation fuels faces relentless challenges both from a world markets and an environmental perspective. The production of renewable transportation fuel from microalgae continues to attract much attention because of its potential for fast growth rates, high oil content, ability to grow in unconventional scenarios, and inherent carbon neutrality. Moreover, the use of microalgae would minimize ‘‘food versus fuel’’ concerns associated with several biomass strategies, as microalgae do not compete with food crops in the food chain. This paper reviews the progress of recent research on the production of transportation fuels via homogeneous and heterogeneous catalytic conversions of microalgae. This review also describes the development of tools that may allow for a more fundamental understanding of catalyst selection and conversion processes using computational modelling. The catalytic conversion reaction pathways that have been investigated are fully discussed based on both experimental and theoretical approaches. Finally, this work makes several projections for the potential of various thermocatalytic pathways to produce alternative transportation fuels from algae, and identifies key areas where the authors feel that computational modelling should be directed to elucidate key information to optimize the process.

  14. High conversion Th-U{sup 233} fuel assembly for current generation of PWRs

    SciTech Connect

    Baldova, D.; Fridman, E.

    2012-07-01

    This paper presents a preliminary design of a high conversion Th-U{sup 233} fuel assembly applicable for current generation of Pressurized Water Reactor (PWRs). The considered fuel assembly has a typical 17 x 17 PWR lattice. However in order to increase the conversion of Th{sup 232} to U{sup 233}, the assembly was subdivided into the two regions called seed and blanket. The central seed region has a higher than blanket U{sup 233} content and acts as a neutron source for the peripheral blanket region. The latest acts as a U{sup 233} breeder. While the seed fuel pins have a standard dimensions the blanket fuel radius was increased in order to reduce the moderation and to facilitate the resonance neutron absorption in blanket Th{sup 232}. The U{sup 233} content in the seed and blanket regions was optimized to achieve maximal initial to discharged fissile inventory ratio (FIR) taking into account the target fuel cycle length of 12 months with 3-batch reloading scheme. In this study the neutronic calculations were performed on the fuel assembly level using Helios deterministic lattice transport code. The fuel cycle length and the core k{sub eff} were estimated by applying the Non Linear Reactivity Model. The applicability of the HELIOS code for the analysis of the Th-based high conversion designs was confirmed with the help of continuous-energy Monte-Carlo code SERPENT. The results of optimization studies show that for the heterogeneous seed and blanket (SB) fuel assembly the FIR of about 0.95 can be achieved. (authors)

  15. Rationale for continuing R&D in direct coal conversion to produce high quality transportation fuels

    SciTech Connect

    Srivastava, R.D.; McIlvried, H.G.; Gray, D.

    1995-12-31

    For the foreseeable future, liquid hydrocarbon fuels will play a significant role in the transportation sector of both the United States and the world. Factors favoring these fuels include convenience, high energy density, and the vast existing infrastructure for their production and use. At present the U.S. consumes about 26% of the world supply of petroleum, but this situation is expected to change because of declining domestic production and increasing competition for imports from countries with developing economies. A scenario and time frame are developed in which declining world resources will generate a shortfall in petroleum supply that can be allieviated in part by utilizing the abundant domestic coal resource base. One option is direct coal conversion to liquid transportation fuels. Continued R&D in coal conversion technology will results in improved technical readiness that can significantly reduce costs so that synfuels can compete economically in a time frame to address the shortfall.

  16. Development of the new MAN B and W 32/40 dual fuel engine

    SciTech Connect

    Schiffgens, H.J.; Brandt, D.; Dier, L.; Glauber, R.

    1996-12-31

    Based on the tried and proven 32/40 diesel engine MAN B and W Diesel AG has developed a dual fuel gas engine covering a rate from 2.4 to 7.2 MW for stationary application in cogeneration and power stations. This paper reports the salient points of the 32/40 DG development project from the concept phase through to prototype testing. To reach the targets a dual fuel prechamber combustion system was developed using an externally arranged, cylinder individual gas admission for the main combustion chamber and a pilot fuel injection to the prechamber. Due to the high thermal and mechanical load sustaining capability of the strong-built heavy fuel diesel engine, bmep (19.9 bar) and efficiency (42.6%) in excess of the targets were achieved with a more than satisfactory life of components. Moreover, the NO{sub x} limit of 500 mg/m{sup 3} as specified in the German TA Luft was successfully met.

  17. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Conversion Pathway: Biological Conversion of Sugars to Hydrocarbons The 2017 Design Case

    SciTech Connect

    Kevin Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J Bonner; Garold L. Gresham; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2013-09-01

    The U.S. Department of Energy promotes the production of a range of liquid fuels and fuel blendstocks from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass collection, conversion, and sustainability. As part of its involvement in this program, the Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL conducted a campaign to quantify the economics and sustainability of moving biomass from standing in the field or stand to the throat of the biomass conversion process. The goal of this program was to establish the current costs based on conventional equipment and processes, design improvements to the current system, and to mark annual improvements based on higher efficiencies or better designs. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $35/dry ton. This goal was successfully achieved in 2012 by implementing field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. Looking forward to 2017, the programmatic target is to supply biomass to the conversion facilities at a total cost of $80/dry ton and on specification with in-feed requirements. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, abundant, low-cost feedstock. If this goal is not achieved, biofuel plants are destined to be small and/or clustered in select regions of the country that have a lock on low-cost feedstock. To put the 2017 cost target into perspective of past accomplishments of the cellulosic ethanol pathway, the $80 target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all

  18. Preliminary Multiphysics Analyses of HFIR LEU Fuel Conversion using COMSOL

    SciTech Connect

    Freels, James D; Bodey, Isaac T; Arimilli, Rao V; Curtis, Franklin G; Ekici, Kivanc; Jain, Prashant K

    2011-06-01

    4 of this report. The HFIR LEU conversion project has also obtained the services of Dr. Prashant K. Jain of the Reactor & Nuclear Systems Division (RNSD) of ORNL. Prashant has quickly adapted to the COMSOL tools and has been focusing on thermal-structure interaction (TSI) issues and development of alternative 3D model approaches that could yield faster-running solutions. Prashant is the primary contributor to Section 5 of the report. And finally, while incorporating findings from all members of the COMSOL team (i.e., the team) and contributing as the senior COMSOL leader and advocate, Dr. James D. Freels has focused on the 3D model development, cluster deployment, and has contributed primarily to Section 3 and overall integration of this report. The team has migrated to the current release of COMSOL at version 4.1 for all the work described in this report, except where stated otherwise. Just as in the performance of the research, each of the respective sections has been originally authored by the respective authors. Therefore, the reader will observe a contrast in writing style throughout this document.

  19. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 3: Energy conversion subsystems and components. Part 3: Gasification, process fuels, and balance of plant

    NASA Technical Reports Server (NTRS)

    Boothe, W. A.; Corman, J. C.; Johnson, G. G.; Cassel, T. A. V.

    1976-01-01

    Results are presented of an investigation of gasification and clean fuels from coal. Factors discussed include: coal and coal transportation costs; clean liquid and gas fuel process efficiencies and costs; and cost, performance, and environmental intrusion elements of the integrated low-Btu coal gasification system. Cost estimates for the balance-of-plant requirements associated with advanced energy conversion systems utilizing coal or coal-derived fuels are included.

  20. EDITORIAL: Non-thermal plasma-assisted fuel conversion for green chemistry Non-thermal plasma-assisted fuel conversion for green chemistry

    NASA Astrophysics Data System (ADS)

    Nozaki, Tomohiro; Gutsol, Alexander

    2011-07-01

    This special issue is based on the symposium on Non-thermal Plasma Assisted Fuel Conversion for Green Chemistry, a part of the 240th ACS National Meeting & Exposition held in Boston, MA, USA, 22-26 August 2010. Historically, the Division of Fuel Chemistry of the American Chemical Society (ACS) has featured three plasma-related symposia since 2000, and has launched special issues in Catalysis Today on three occasions: 'Catalyst Preparation using Plasma Technologies', Fall Meeting, Washington DC, USA, 2000. Special issue in Catalysis Today 72 (3-4) with 12 peer-reviewed articles. 'Plasma Technology and Catalysis', Spring Meeting, New Orleans, LA, USA, 2003. Special issue in Catalysis Today 89 (1-2) with more than 30 peer-reviewed articles. 'Utilization of Greenhouse Gases II' (partly focused on plasma-related technologies), Spring Meeting, Anaheim, CA, USA, 2004. Special issue in Catalysis Today 98 (4) with 25 peer-reviewed articles. This time, selected presentations are published in this Journal of Physics D: Applied Physics special issue. An industrial material and energy conversion technology platform is established on thermochemical processes including various catalytic reactions. Existing industry-scale technology is already well established; nevertheless, further improvement in energy efficiency and material saving has been continuously demanded. Drastic reduction of CO2 emission is also drawing keen attention with increasing recognition of energy and environmental issues. Green chemistry is a rapidly growing research field, and frequently highlights renewable bioenergy, bioprocesses, solar photocatalysis of water splitting, and regeneration of CO2 into useful chemicals. We would also like to emphasize 'plasma catalysis' of hydrocarbon resources as an important part of the innovative next-generation green technologies. The peculiarity of non-thermal plasma is that it can generate reactive species almost independently of reaction temperature. Plasma

  1. Effect of Operating Parameters on a Dual-Stage High Velocity Oxygen Fuel Thermal Spray System

    NASA Astrophysics Data System (ADS)

    Khan, Mohammed N.; Shamim, Tariq

    2014-08-01

    High velocity oxygen fuel (HVOF) thermal spray systems are being used to apply coatings to prevent surface degradation. The coatings of temperature sensitive materials such as titanium and copper, which have very low melting points, cannot be applied using a single-stage HVOF system. Therefore, a dual-stage HVOF system has been introduced and modeled computationally. The dual-spray system provides an easy control of particle oxidation by introducing a mixing chamber. In addition to the materials being sprayed, the thermal spray coating quality depends to a large extent on flow behavior of reacting gases and the particle dynamics. The present study investigates the influence of various operating parameters on the performance of a dual-stage thermal spray gun. The objective is to develop a predictive understanding of various parameters. The gas flow field and the free jet are modeled by considering the conservation of mass, momentum, and energy with the turbulence and the equilibrium combustion sub models. The particle phase is decoupled from the gas phase due to very low particle volume fractions. The results demonstrate the advantage of a dual-stage system over a single-stage system especially for the deposition of temperature sensitive materials.

  2. A novel thin film solid oxide fuel cell for microscale energy conversion

    SciTech Connect

    Jankowiski, A F; Morse, J D

    1999-05-01

    A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, mainfold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by codeposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting interfacial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thickness on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600--1000 C), thereby rendering this fuel cell system suitable for miniaturization. Scaling towards miniaturization is accomplished by utilizing novel micromaching approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable.

  3. Analysis of ignition behavior in a turbocharged direct injection dual fuel engine using propane and methane as primary fuels

    SciTech Connect

    Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2011-10-05

    This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (Ω pilot ∼ 0.2-0.6 and Ω overall ∼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant Ω pilot (> 0.5), increasing Ω overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing Ω overall (at constant Ω pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

  4. Decentralized conversion of biomass to energy, fuels and electricity with fuel cells

    SciTech Connect

    Grimes, P.

    1996-12-31

    Fuel cells, new processes, advanced equipment and total system approaches will allow biomass to become a larger source of energy to make electricity, fuel and chemicals. These innovative new approaches allow smaller scale operations and allow decentralization of biomass to energy. The pivotal role of biomass will change and expand. Biomass will become a significant near term and a long term energy source.

  5. SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

    SciTech Connect

    Nguyen Minh; Jim Powers

    2003-10-01

    This report summarizes the work performed for April 2003--September 2003 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U.S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid oxide Fuel Cell Program''. During this reporting period, the conceptual system design activity was completed. The system design, including strategies for startup, normal operation and shutdown, was defined. Sealant and stack materials for the solid oxide fuel cell (SOFC) stack were identified which are capable of meeting the thermal cycling and degradation requirements. A cell module was tested which achieved a stable performance of 0.238 W/cm{sup 2} at 95% fuel utilization. The external fuel processor design was completed and fabrication begun. Several other advances were made on various aspects of the SOFC system, which are detailed in this report.

  6. Application of High Performance Computing for Simulating Cycle-to-Cycle Variation in Dual-Fuel Combustion Engines

    DOE PAGESBeta

    Jupudi, Ravichandra S.; Finney, Charles E.A.; Primus, Roy; Wijeyakulasuriya, Sameera; Klingbeil, Adam E.; Tamma, Bhaskar; Stoyanov, Miroslav K.

    2016-04-05

    Interest in operational cost reduction is driving engine manufacturers to consider lower-cost fuel substitution in heavy-duty diesel engines. These dual-fuel (DF) engines could be operated either in diesel-only mode or operated with premixed natural gas (NG) ignited by a pilot flame of compression-ignited direct-injected diesel fuel. One promising application is that of large-bore, medium-speed engines such as those used in locomotives. With realistic natural gas substitution levels in the fleet of locomotives currently in service, such fuel substitution could result in billions of dollars of savings annually in the US alone. However, under certain conditions, dual-fuel operation can result inmore » increased cycle-to-cycle variability (CCV) during combustion, resulting in variations in cylinder pressure and work extraction. In certain situations, the CCV of dual-fuel operation can be notably higher than that of diesel-only combustion under similar operating conditions. Excessive CCV can limit the NG substitution rate and operating range of a dual-fuel engine by increasing emissions and reducing engine stability, reliability and fuel efficiency via incomplete natural-gas combustion. Running multiple engine cycles in series to simulate CCV can be quite time consuming. Hence innovative modelling techniques and large computing resources are needed to investigate the factors affecting CCV in dual-fuel engines. This paper discusses the use of the High Performance Computing resource Titan, at the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory, to investigate cycle-to-cycle combustion variability of a dual-fuel engine. The CONVERGE CFD software was used to simulate multiple, parallel single cycles of dual-fuel combustion with perturbed operating parameters and boundary conditions. These perturbations are imposed according to a sparse grids sampling of the parameter space. The sampling scheme chosen is similar to a design of experiments method

  7. Scaled-up dual anode/cathode microbial fuel cell stack for actual ethanolamine wastewater treatment.

    PubMed

    An, Byung-Min; Heo, Yoon; Maitlo, Hubdar-Ali; Park, Joo-Yang

    2016-06-01

    The aim of this work was to develop the scale-up microbial fuel cell technology for actual ethanolamine wastewater treatment, dual anode/cathode MFC stacks connected in series to achieve any desired current, treatment capacity, and volume capacity. However, after feeding actual wastewater into the MFC, maximum power density decreased while the corresponding internal resistance increased. With continuous electricity production, a stack of eight MFCs in series achieved 96.05% of COD removal and 97.30% of ammonia removal at a flow rate of 15.98L/d (HRT 12h). The scaled-up dual anode/cathode MFC stack system in this research was demonstrated to treat actual ETA wastewater with the added benefit of harvesting electricity energy. PMID:26888335

  8. Dual-band polarization conversion based on non-twisted Q-shaped metasurface

    NASA Astrophysics Data System (ADS)

    Cao, Hailin; Liang, Jianshuo; Wu, Xiaodong; Pi, Yuwei; Xu, Hang; Liu, Junjie; Meng, Zhenya; Zhang, Yongliang

    2016-07-01

    In this paper, we theoretically and experimentally report an achiral dual-band metasurface with linear birefringence. The unit cell of the achiral metasurface consists of non-twisted Q-shape metallic ring resonators with a stub breaking the rotational symmetry. Moreover, due to the presence of the stub, we find the proposed metasurface emits dual-band circularly polarized wave with low transmission loss and high polarization extinction for a normal incident y-direction linearly polarized wave. We also systematically investigate the dependence of the electromagnetic response of the proposed structure on the geometric parameters. It is hoped that the proposed simple, easily fabricated model of achiral metasurface can be used in further polarization control applications

  9. The Rhode Island Nuclear Science Center conversion from HEU to LEU fuel

    SciTech Connect

    Tehan, Terry

    2000-09-27

    The 2-MW Rhode Island Nuclear Science Center (RINSC) open pool reactor was converted from 93% UAL-High Enriched Uranium (HEU) fuel to 20% enrichment U3Si2-AL Low Enriched Uranium (LEU) fuel. The conversion included redesign of the core to a more compact size and the addition of beryllium reflectors and a beryllium flux trap. A significant increase in thermal flux level was achieved due to greater neutron leakage in the new compact core configuration. Following the conversion, a second cooling loop and an emergency core cooling system were installed to permit operation at 5 MW. After re-licensing at 2 MW, a power upgrade request will be submitted to the NRC.

  10. CONVERSION OF RUSSIAN WEAPON-GRADE PLUTONIUM INTO OXIDE FOR MIXED OXIDE (MOX) FUEL FABRICATION.

    SciTech Connect

    Glagovski, E.; Kolotilov, Y.; Glagolenko, Y.; Zygmunt, Stanley J.; Mason, C. F. V.; Hahn, W. K.; Durrer, R. E.; Thomas, S.; Sicard, B.; Herlet, N.; Fraize, G.; Villa, A.

    2001-01-01

    Progress has been made in the Russian Federation towards the conversion of weapons-grade plutonium (w-Pu) into plutonium oxide (PuO{sub 2}) suitable for further manufacture into mixed oxide (MOX) fuels. This program is funded both by French Commissariat x 1'Energie Atomique (CEA) and the US National Nuclear Security Administration (NNSA). The French program was started as a way to make available their expertise gained from manufacturing MOX fuel. The US program was started in 1998 in response to US proliferation concerns and the acknowledged international need to decrease available w-Pu. Russia has selected both the conversion process and the manufacturing site. This paper discusses the present state of development towards fulfilling this mission: the demonstration plant designed to process small amounts of Pu and validate all process stages and the industrial plant that will process up to 5 metric tons of Pu per year.

  11. Direct electrochemical conversion of carbon anode fuels in molton salt media

    SciTech Connect

    Cherepy, N; Krueger, R; Cooper, J F

    2001-01-17

    We are conducting research into the direct electrochemical conversion of reactive carbons into electricity--with experimental evidence of total efficiencies exceeding 80% of the heat of combustion of carbon. Together with technologies for extraction of reactive carbons from broad based fossil fuels, direct carbon conversion addresses the objectives of DOE's ''21st Century Fuel Cell'' with exceptionally high efficiency (>70% based on standard heat of reaction, {Delta}H{sub std}), as well as broader objectives of managing CO{sub 2} emissions. We are exploring the reactivity of a wide range of carbons derived from diverse sources, including pyrolyzed hydrocarbons, petroleum cokes, purified coals and biochars, and relating their electrochemical reactivity to nano/microstructural characteristics.

  12. Performance and economics of advanced energy conversion systems for coal and coal-derived fuels

    NASA Technical Reports Server (NTRS)

    Corman, J. C.; Fox, G. R.

    1978-01-01

    The desire to establish an efficient Energy Conversion System to utilize the fossil fuel of the future - coal - has produced many candidate systems. A comparative technical/economic evaluation was performed on the seven most attractive advanced energy conversion systems. The evaluation maintains a cycle-to-cycle consistency in both performance and economic projections. The technical information base can be employed to make program decisions regarding the most attractive concept. A reference steam power plant was analyzed to the same detail and, under the same ground rules, was used as a comparison base. The power plants were all designed to utilize coal or coal-derived fuels and were targeted to meet an environmental standard. The systems evaluated were two advanced steam systems, a potassium topping cycle, a closed cycle helium system, two open cycle gas turbine combined cycles, and an open cycle MHD system.

  13. High Conversion of Coal to Transportation Fuels for the Future With Low HC Gas Production

    SciTech Connect

    Alex G. Oblad; Wendell H. Wiser

    1996-07-01

    An announced objective of the Department of Energy in funding this work, and other current research in coal liquefaction, is to produce a synthetic crude from coal at a cost lower than $30.00 per barrel (Task A). A second objective, reflecting a recent change in direction in the synthetic fuels effort of DOE, is to produce a fuel which is low in aromatics, yet of sufficiently high octane number for use in the gasoline- burning transportation vehicles of today. To meet this second objective, research was proposed, and funding awarded, for conversion of the highly-aromatic liquid product from coal conversion to a product high in isoparaffins, which compounds in the gasoline range exhibit a high octane number (Task B).

  14. Heterogeneous Catalytic Conversion of Biobased Chemicals into Liquid Fuels in the Aqueous Phase.

    PubMed

    Wu, Kejing; Wu, Yulong; Chen, Yu; Chen, Hao; Wang, Jianlong; Yang, Mingde

    2016-06-22

    Different biobased chemicals are produced during the conversion of biomass into fuels through various feasible technologies (e.g., hydrolysis, hydrothermal liquefaction, and pyrolysis). The challenge of transforming these biobased chemicals with high hydrophilicity is ascribed to the high water content of the feedstock and the inevitable formation of water. Therefore, aqueous-phase processing is an interesting technology for the heterogeneous catalytic conversion of biobased chemicals. Different reactions, such as dehydration, isomerization, aldol condensation, ketonization, and hydrogenation, are applied for the conversion of sugars, furfural/hydroxymethylfurfural, acids, phenolics, and so on over heterogeneous catalysts. The activity, stability, and reusability of the heterogeneous catalysts in water are summarized, and deactivation processes and several strategies are introduced to improve the stability of heterogeneous catalysts in the aqueous phase. PMID:27158985

  15. Fuel Cycle System Analysis Implications of Sodium-Cooled Metal-Fueled Fast Reactor Transuranic Conversion Ratio

    SciTech Connect

    Steven J. Piet; Edward A. Hoffman; Samuel E. Bays; Gretchen E. Matthern; Jacob J. Jacobson; Ryan Clement; David W. Gerts

    2013-03-01

    If advanced fuel cycles are to include a large number of fast reactors (FRs), what should be the transuranic (TRU) conversion ratio (CR)? The nuclear energy era started with the assumption that they should be breeder reactors (CR > 1), but the full range of possible CRs eventually received attention. For example, during the recent U.S. Global Nuclear Energy Partnership program, the proposal was burner reactors (CR < 1). Yet, more recently, Massachusetts Institute of Technology's "Future of the Nuclear Fuel Cycle" proposed CR [approximately] 1. Meanwhile, the French company EDF remains focused on breeders. At least one of the reasons for the differences of approach is different fuel cycle objectives. To clarify matters, this paper analyzes the impact of TRU CR on many parameters relevant to fuel cycle systems and therefore spans a broad range of topic areas. The analyses are based on a FR physics parameter scan of TRU CR from 0 to [approximately]1.8 in a sodium-cooled metal-fueled FR (SMFR), in which the fuel from uranium-oxide-fueled light water reactors (LWRs) is recycled directly to FRs and FRs displace LWRs in the fleet. In this instance, the FRs are sodium cooled and metal fueled. Generally, it is assumed that all TRU elements are recycled, which maximizes uranium ore utilization for a given TRU CR and waste radiotoxicity reduction and is consistent with the assumption of used metal fuel separated by electrochemical means. In these analyses, the fuel burnup was constrained by imposing a neutron fluence limit to fuel cladding to the same constant value. This paper first presents static, time-independent measures of performance for the LWR [right arrow] FR fuel cycle, including mass, heat, gamma emission, radiotoxicity, and the two figures of merit for materials for weapon attractiveness developed by C. Bathke et al. No new fuel cycle will achieve a static equilibrium in the foreseeable future. Therefore, additional analyses are shown with dynamic, time

  16. Low-Enriched Uranium Fuel Conversion Activities for the High Flux Isotope Reactor, Annual Report for FY 2011

    SciTech Connect

    Renfro, David G; Cook, David Howard; Freels, James D; Griffin, Frederick P; Ilas, Germina; Sease, John D; Chandler, David

    2012-03-01

    This report describes progress made during FY11 in ORNL activities to support converting the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. Conversion from HEU to LEU will require a change in fuel form from uranium oxide to a uranium-molybdenum (UMo) alloy. With both radial and axial contouring of the fuel foil and an increase in reactor power to 100 MW, calculations indicate that the HFIR can be operated with LEU fuel with no degradation in performance to users from the current levels achieved with HEU fuel. Studies are continuing to demonstrate that the fuel thermal safety margins can be preserved following conversion. Studies are also continuing to update other aspects of the reactor steady state operation and accident response for the effects of fuel conversion. Technical input has been provided to Oregon State University in support of their hydraulic testing program. The HFIR conversion schedule was revised and provided to the GTRI program. In addition to HFIR conversion activities, technical support was provided directly to the Fuel Fabrication Capability program manager.

  17. Digital Compensation of IQ Imbalance for Dual-Carrier Double Conversion Receivers

    NASA Astrophysics Data System (ADS)

    Park, Chester Sungchung; Park, Fitzgerald Sungkyung

    A receiver architecture and a digital IQ imbalance compensation method for dual-carrier reception are newly proposed. The impact of IQ imbalance on the baseband signal is mathematically analyzed. Based on the analysis, IQ imbalance parameters are estimated and the coupling effect of IQ imbalance is compensated using digital baseband processing alone. Simulation results show that the proposed IQ imbalance compensation successfully removes IQ imbalance. The deviation from the ideal performance is less than 1dB when it is applied to the 3GPP-LTE carrier aggregation.

  18. Degree of conversion of two dual-cured resin cements light-irradiated through zirconia ceramic disks

    PubMed Central

    Kim, Min-Jeong; Kim, Kyo-Han; Kim, Young-Kyung

    2013-01-01

    PURPOSE The aim of this Fourier transform infrared (FTIR) spectroscopic study was to measure the degree of conversion (DC) of dual-cured resin cements light-irradiated through zirconia ceramic disks with different thicknesses using various light-curing methods. MATERIALS AND METHODS Zirconia ceramic disks (KT12) with three different thicknesses (1.0, 2.0, and 4.0 mm) were prepared. The light transmittance of the disks was measured using ultraviolet visible near-infrared spectroscopy. Four different light-curing protocols were used by combining two curing light modes (Elipar TriLight (standard mode) and bluephase G2 (high power mode)) with light-exposure times of 40 and 120 seconds. The DCs of the two dual-cured resin cements (Duo-Link and Panavia F2.0) light-irradiated through the disks was analyzed at three time intervals (3, 7, and 10 minutes) by FTIR spectroscopy. The data was analyzed using repeated measures ANOVA (α=.05).Two-way ANOVA and Tukey post hoc test were used to analyze the 10 minute DC results. RESULTS The 1.0 mm thick disk exhibited low light transmittance (<25%), and the transmittance decreased considerably with increasing disk thickness. All groups exhibited significantly higher 10 minute DC values than the 3 or 7 minute values (P<.05), but some exceptions were observed in Duo-Link. Two-way ANOVA revealed that the influence of the zirconia disk thickness on the 10 minute DC was dependent on the light-curing methods (P<.001). This finding was still valid even at 4.0 mm thickness, where substantial light attenuation took place. CONCLUSION The curing of the dual-cured resin cements was affected significantly by the light-curing technique, even though the additional chemical polymerization mechanism worked effectively. PMID:24353887

  19. Development of a Dual-Fuel Gas Turbine Engine of Liquid and Low-Calorific Gas

    NASA Astrophysics Data System (ADS)

    Koyama, Masamichi; Fujiwara, Hiroshi

    We developed a dual-fuel single can combustor for the Niigata Gas Turbine (NGT2BC), which was developed as a continuous-duty gas turbine capable of burning both kerosene and digester gas. The output of the NGT2BC is 920kW for continuous use with digester gas and 1375kW for emergency use with liquid fuel. Digester gas, obtained from sludge processing at sewage treatment plants, is a biomass energy resource whose use reduces CO2 emissions and take advantage of an otherwise wasted energy source. Design features for good combustion with digester gas include optimized the good matching of gas injection and swirl air and reduced reference velocity. The optimal combination of these parameters was determined through CFD analysis and atmospheric rig testing.

  20. Analysis of magma-thermal conversion of biomass to gaseous fuel

    SciTech Connect

    Gerlach, T.M.

    1982-02-01

    A wide range of magma types and pluton geometries believed to occur within the upper 10 km of the crust provide suitable sources of thermal energy for conversion of water-biomass mixtures to higher quality gaseous fuel. Gaseous fuel can be generated within a magma body, within the hot subsolidus margins of a magma body, or within surface reaction vessels heated by thermal energy derived from a magma body. The composition, amount, and energy content of the fuel gases generated from water-biomass mixtures are not sensitive to the type, age, depth, or temperature of a magma body thermal source. The amount and energy content of the generated fuel is almost entirely a function of the proportion of biomass in the starting mixture. CH/sub 4/ is the main gas that can be generated in important quantities by magma thermal energy under most circumstances. CO is never an important fuel product, and H/sub 2/ generation is very limited. The rates at which gaseous fuels can be generated are strongly dependent on magma type. Fuel generation rates for basaltic magmas are at least 2 to 3 times those for andesitic magmas and 5 to 6 times those for rhyolitic magmas. The highest fuel generation rates, for any particular magma body, will be achieved at the lowest possible reaction vessel operating temperature that does not cause graphite deposition from the water-biomass starting mixture. The energy content of the biomass-derived fuels is considerably greater than that consumed in the generation and refinement process.

  1. Conversion of vegetable oils and animal fats into paraffinic cetane enhancers for diesel fuels

    SciTech Connect

    Wong, A.; Feng, Y.; Hogan, E.

    1995-11-01

    The two principal methods of producing biodiesel fuels are (a) transesterification of vegetable oils and animal fats with a monohydric alcohol, and (b) direct hydrotreating of tree oils, vegetable oils and animal fats. The patented hydrotreating technology is based on the catalytic processing of biomass oils and fats with hydrogen, under elevated temperature and pressure conditions. The typical mix of hydrotreated products is as follows: 5-15% light distillate (naphta), 40-60% middle distillate (cetane), 5-15% heavy distillate and 5-10% burner gas. The naptha fraction may be used as a gasoline supplement. The middle distillate is designed for use as a cetane booster for diesel fuels. Both heavy distillate and light hydrocarbon gases are usable as power boiler fuels. Typically, the cetane enhancer would be admixed with diesel fuel in the range of 5 to 30% by volume. This new diesel blend meets the essential quality characteristics of the basic diesel fuel, for direct use in diesel engines without any modifications. The basic hydrotreatment technology has been evaluated further in the laboratory on degummed soya oil, yellow grease and animal tallow. The preliminary findings suggest that the technology can provide efficient conversion of these materials into cetane enhancers for diesel fuels.

  2. Progress made on the University of Missouri research reactor HEU to LEU fuel conversion feasibility study

    SciTech Connect

    McKibben, J. Charles; Kutikkad, Kiratadas; Foyto, Leslie P.

    2008-07-15

    The University of Missouri Research Reactor (MURR), the highest-powered University-owned research reactor in the U.S. designed to operate at a maximum steady-state power level of 10 MW{sub th}, is one of five U.S. high performance research reactors that use HEU fuel that is actively th collaborating with the U.S. Department of Energy to find a suitable LEU fuel replacement. A conversion feasibility study, using U-10Mo monolithic LEU fuel, is currently being performed at MURR. At first, broad scoping studies where conducted using the transport code MCNP, where the core water-to-metal ratio was varied by altering the thickness or width of the plate cladding, fuel meat, and coolant channel gaps, and varying the number of fuel plates. From these studies, an optimal LEU core design was chosen based on the following calculated parameters: power peaking factors, excess reactivity, and the fast and thermal fluxes available to the experimental facilities. Fuel burnup calculations are now being performed using the 3-D diffusion theory code REBUS. Also included in this paper are some preliminary safety analyses, including parametric studies using the reactivity transient code PARET-ANL and hydraulic calculations using the light- and heavy-water thermal-hydraulic transient code RELAP5/MOD3.3. (author)

  3. Experimental and theoretical study of a dual-layer gas diffusion layer in PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Park, Sehkyu

    2008-07-01

    The gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs) functions as a diffuser and a current collector. The GDL typically consists of the microporous layer (MPL) and the macroporous substrate (MPS). The MPL reduces the ohmic losses and facilitates water removal in the MEA. In this study, a novel method was developed to prepare a dual-layer GDL that enhances the catalyst utilization and the overall fuel cell performance. Several characterization techniques, including mercury porosimetry, water permeation measurement, electrochemical polarization and ac impedance spectroscopy were performed to investigate how carbon loading (or MPL thickness) and PTFE content in the MPL and in the MPS control the water management in PEM fuel cells. An experimental study on carbon loading in the MPL showed that a relatively low carbon loading (0.5 mg cm-2 in this study) results in a balancing of water saturations in the catalyst layer and the GDL, thus improving the oxygen diffusion kinetics. Experimental studies on PTFE content in the MPL and in the MPS indicated that effective water management is attributed to the trade-off between the pore volume and the hydrophobic property of each diffusion layer. A theoretical study of a dual-layer GDL in PEM fuel cells demonstrated that saturation in the MPS is intimately coupled with both the fraction of hydrophilic surface and the average pore diameter. A thin and more hydrophobic MPL altered the pore geometry and the hydrophobic property of a MPS, resulting in better mass transport of reactants and products in the MEA.

  4. Comparative study on power generation of dual-cathode microbial fuel cell according to polarization methods.

    PubMed

    Lee, Kang-yu; Ryu, Wyan-seuk; Cho, Sung-il; Lim, Kyeong-ho

    2015-11-01

    Microbial fuel cells (MFCs) exist in various forms depending on the type of pollutant to be removed and the expected performance. Dual-cathode MFCs, with their simple structure, are capable of removing both organic matter and nitrogen. Moreover, various methods are available for the collection of polarization data, which can be used to calculate the maximum power density, an important factor of MFCs. Many researchers prefer the method of varying the external resistance in a single-cycle due to the short measurement time and high accuracy. This study compared power densities of dual-cathode MFCs in a single-cycle with values calculated over multi-cycles to determine the optimal polarization method. External resistance was varied from high to low and vice versa in the single-cycle, to calculate power density. External resistance was organized in descending order with initial start-up at open circuit voltage (OCV), and then it was organized in descending order again after the initial start-up at 1000 Ω. As a result, power density was underestimated at the anoxic cathode when the external resistance was varied from low to high, and overestimated at the aerobic cathode and anoxic cathode when external resistance at OCV was reduced following initial start-up. In calculating the power densities of dual-cathode MFCs, this paper recommends the method of gradually reducing the external resistance after initial start-up with high external resistance. PMID:26210028

  5. Conversion of alcohols to enantiopure amines through dual enzyme hydrogen-borrowing cascades

    PubMed Central

    Mutti, Francesco G.; Knaus, Tanja; Scrutton, Nigel S.; Breuer, Michael; Turner, Nicholas J.

    2016-01-01

    α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds on industrial scale. Here we present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on the combination of an alcohol dehydrogenase (ADHs from Aromatoleum sp., Lactobacillus sp. and Bacillus sp.) enzyme operating in tandem with an amine dehydrogenase (AmDHs engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols (up to 96% conversion and 99% enantiomeric excess). Furthermore, primary alcohols are aminated with high conversion (up to 99%). This redox self-sufficient network possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. PMID:26404833

  6. Dual lithium insertion and conversion mechanisms in a titanium-based mixed-anion nanocomposite.

    PubMed

    Dambournet, Damien; Chapman, Karena W; Chupas, Peter J; Gerald, Rex E; Penin, Nicolas; Labrugere, Christine; Demourgues, Alain; Tressaud, Alain; Amine, Khalil

    2011-08-31

    The electrochemical reaction of lithium with a vacancy-containing titanium hydroxyfluoride was studied. On the basis of pair distribution function analysis, NMR, and X-ray photoelectron spectroscopy, we propose that the material undergoes partitioning upon initial discharge to form a nanostructured composite containing crystalline Li(x)TiO(2), surrounded by a Ti(0) and LiF layer. The Ti(0) is reoxidized upon reversible charging to an amorphous TiF(3) phase via a conversion reaction. The crystalline Li(x)TiO(2) is involved in an insertion reaction. The resulting composite electrode, Ti(0)-LiF/Li(x)TiO(2) ⇔ TiF(3)/ Li(y)TiO(2), allows reaction of more than one Li per Ti, providing a route to higher capacities while improving the energy efficiency compared to pure conversion chemistries. PMID:21809881

  7. Separation of Corn Fiber and Conversion to Fuels and Chemicals Phase II: Pilot-scale Operation

    SciTech Connect

    Abbas, Charles; Beery, Kyle; Orth, Rick; Zacher, Alan

    2007-09-28

    The purpose of the Department of Energy (DOE)-supported corn fiber conversion project, “Separation of Corn Fiber and Conversion to Fuels and Chemicals Phase II: Pilot-scale Operation” is to develop and demonstrate an integrated, economical process for the separation of corn fiber into its principal components to produce higher value-added fuel (ethanol and biodiesel), nutraceuticals (phytosterols), chemicals (polyols), and animal feed (corn fiber molasses). This project has successfully demonstrated the corn fiber conversion process on the pilot scale, and ensured that the process will integrate well into existing ADM corn wet-mills. This process involves hydrolyzing the corn fiber to solubilize 50% of the corn fiber as oligosaccharides and soluble protein. The solubilized fiber is removed and the remaining fiber residue is solvent extracted to remove the corn fiber oil, which contains valuable phytosterols. The extracted oil is refined to separate the phytosterols and the remaining oil is converted to biodiesel. The de-oiled fiber is enzymatically hydrolyzed and remixed with the soluble oligosaccharides in a fermentation vessel where it is fermented by a recombinant yeast, which is capable of fermenting the glucose and xylose to produce ethanol. The fermentation broth is distilled to remove the ethanol. The stillage is centrifuged to separate the yeast cell mass from the soluble components. The yeast cell mass is sold as a high-protein yeast cream and the remaining sugars in the stillage can be purified to produce a feedstock for catalytic conversion of the sugars to polyols (mainly ethylene glycol and propylene glycol) if desirable. The remaining materials from the purification step and any materials remaining after catalytic conversion are concentrated and sold as a corn fiber molasses. Additional high-value products are being investigated for the use of the corn fiber as a dietary fiber sources.

  8. Dual bed reactor for the study of catalytic biomass tars conversion

    SciTech Connect

    Ammendola, P.; Piriou, B.; Lisi, L.; Ruoppolo, G.; Chirone, R.; Russo, G.

    2010-04-15

    A dual fixed bed laboratory scale set up has been used to compare the activity of a novel Rh/LaCoO{sub 3}/Al{sub 2}O{sub 3} catalyst to that of dolomite, olivine and Ni/Al{sub 2}O{sub 3}, typical catalysts used in fluidized bed biomass gasification, to convert tars produced during biomass devolatilization stage. The experimental apparatus allows the catalyst to be operated under controlled conditions of temperature and with a real gas mixture obtained by the pyrolysis of the biomass carried out in a separate fixed bed reactor operated under a selected and controlled heating up rate. The proposed catalyst exhibits much better performances than conventional catalysts tested. It is able to completely convert tars and also to strongly decrease coke formation due to its good redox properties. (author)

  9. Scan-less, line-field confocal microscopy by combination of wavelength/space conversion with dual optical comb

    NASA Astrophysics Data System (ADS)

    Yasui, Takeshi; Hase, Eiji; Miyamoto, Shuji; Hsieh, Yi-Da; Minamikawa, Takeo; Yamamoto, Hirotsugu

    2016-03-01

    Optical frequency comb (OFC) has attracted attentions for optical frequency metrology in visible and infrared regions because the mode-resolved OFC spectrum can be used as a precise frequency ruler due to both characteristics of broadband radiation and narrow-line CW radiation. Furthermore, the absolute accuracy of all frequency modes in OFC is secured by phase-locking a repetition frequency frep and a carrier-envelope-offset frequency fceo to a frequency standard. However, application fields of OFC other than optical frequency metrology are still undeveloped. One interesting aspect of OFC except for the frequency ruler is optical carrier having a huge number of discrete frequency channels because OFC is composed of a series of frequency spikes regularly separated by frep in the broad spectral range. If a certain quantity to be measured is encoded on each comb mode by dimensional conversion, a huge number of data for the measured quantity can be obtained from a single mode-resolved spectrum of OFC. In this paper, we encode the confocal microscopic line-image of a sample on the mode-resolved OFC spectrum by the dimensional conversion between wavelength and 1D-space. The resulting image-encoded OFC spectrum is acquired by an optical spectrum analyzer or dual comb spectrometer. Finally, the line image of the sample is decoded from the spectral amplitude of the mode-resolved OFC spectrum. The combination of OFC with the dimensional conversion enables to establish both confocal modality and line-field imaging under the scan-less condition.

  10. Prospects for conversion of solar energy into chemical fuels: the concept of a solar fuels industry.

    PubMed

    Harriman, Anthony

    2013-08-13

    There is, at present, no solar fuels industry anywhere in the world despite the well-publicized needs to replace our depleting stock of fossil fuels with renewable energy sources. Many obstacles have to be overcome in order to store sunlight in the form of chemical potential, and there are severe barriers to surmount in order to produce energy on a massive scale, at a modest price and in a convenient form. It is also essential to allow for the intermittent nature of sunlight, its diffusiveness and variability and to cope with the obvious need to use large surface areas for light collection. Nonetheless, we have no alternative but to devise viable strategies for storage of sunlight as biomass or chemical feedstock. Simple alternatives, such as solar heating, are attractive in terms of quick demonstrations but are not the answer. Photo-electrochemical devices might serve as the necessary machinery by which to generate electronic charge but the main problem is to couple these charges to the multi-electron catalysis needed to drive energy-storing chemical reactions. Several potential fuels (CO, H₂, HCOOH, NH₃, O₂, speciality organics, etc.) are possible, but the photochemical reduction of CO₂ deserves particular mention because of ever-growing concerns about overproduction of greenhouse gases. The prospects for achieving these reactions under ambient conditions are considered herein. PMID:23816906

  11. Development of Hydrothermal Liquefaction and Upgrading Technologies for Lipid-Extracted Algae Conversion to Liquid Fuels

    SciTech Connect

    Zhu, Yunhua; Albrecht, Karl O.; Elliott, Douglas C.; Hallen, Richard T.; Jones, Susanne B.

    2013-10-01

    Bench-scale tests were performed for lipid-extracted microalgae (LEA) conversion to liquid fuels via hydrotreating liquefaction (HTL) and upgrading processes. Process simulation and economic analysis for a large-scale LEA HTL and upgrading system were developed based on the best available test results. The system assumes an LEA feed rate of 608 dry metric ton/day and that the feedstock is converted to a crude HTL bio-oil and further upgraded via hydrotreating and hydrocracking to produce liquid hydrocarbon fuels, mainly alkanes. Performance and cost results demonstrate that HTL would be an effective option to convert LEA to liquid fuel. The liquid fuels annual yield was estimated to be 26.9 million gallon gasoline-equivalent and the overall energy efficiency at higher heating value basis was estimated to be 69.5%. The minimum fuel selling price (MFSP) was estimated to be $0.75/L with LEA feedstock price at $33.1 metric ton at dry basis and 10% internal rate of return. A sensitivity analysis indicated that the largest effects to production cost would come from the final products yields and the upgrading equipments cost. The impact of plant scale on MFSP was also investigated.

  12. Chemical analysis and ozone formation potential of exhaust from dual-fuel (liquefied petroleum gas/gasoline) light duty vehicles

    NASA Astrophysics Data System (ADS)

    Adam, T. W.; Astorga, C.; Clairotte, M.; Duane, M.; Elsasser, M.; Krasenbrink, A.; Larsen, B. R.; Manfredi, U.; Martini, G.; Montero, L.; Sklorz, M.; Zimmermann, R.; Perujo, A.

    2011-06-01

    Measures must be undertaken to lower the transport sector's contribution to anthropogenic emissions. Vehicles powered by liquefied petroleum gas (LPG) are an option due to their reduced emissions of air pollutants compared to engines with conventional fuels. In the present study, ten different dual-fuel LPG/gasoline light duty vehicles were tested, which all complied with European emission level legislation EURO-4. Tests with LPG and gasoline were performed on a chassis dynamometer by applying the New European Driving Cycle (NEDC) and emission factors and ozone formation potentials of both kinds of fuels were compared. The components investigated comprised regulated compounds, CO 2, volatile hydrocarbons and carbonyls. On-line analysis of aromatic species was carried out by resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry (REMPI-TOFMS). We demonstrate that utilization of LPG can entail some environmental benefits by reducing emissions. However, for dual-fuel LPG/gasoline vehicles running on LPG the benefits are less than expected. The main reason is that dual-fuel vehicles usually start the engine up on gasoline even when LPG is selected as fuel. This cold-start phase is crucial for the quality of the emissions. Moreover, we demonstrate an influence on the chemical composition of emissions of vehicle performance, fuel and the evaporative emission system of the vehicles.

  13. Accident Analysis for the NIST Research Reactor Before and After Fuel Conversion

    SciTech Connect

    Baek J.; Diamond D.; Cuadra, A.; Hanson, A.L.; Cheng, L-Y.; Brown, N.R.

    2012-09-30

    Postulated accidents have been analyzed for the 20 MW D2O-moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analysis has been carried out for the present core, which contains high enriched uranium (HEU) fuel and for a proposed equilibrium core with low enriched uranium (LEU) fuel. The analyses employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron transport calculations were performed with the MCNPX code to determine homogenized fuel compositions in the lower and upper halves of each fuel element and to determine the resulting neutronic properties of the core. The accident analysis employed a model of the primary loop with the RELAP5 code. The model includes the primary pumps, shutdown pumps outlet valves, heat exchanger, fuel elements, and flow channels for both the six inner and twenty-four outer fuel elements. Evaluations were performed for the following accidents: (1) control rod withdrawal startup accident, (2) maximum reactivity insertion accident, (3) loss-of-flow accident resulting from loss of electrical power with an assumption of failure of shutdown cooling pumps, (4) loss-of-flow accident resulting from a primary pump seizure, and (5) loss-of-flow accident resulting from inadvertent throttling of a flow control valve. In addition, natural circulation cooling at low power operation was analyzed. The analysis shows that the conversion will not lead to significant changes in the safety analysis and the calculated minimum critical heat flux ratio and maximum clad temperature assure that there is adequate margin to fuel failure.

  14. A guide to the emissions certification procedures for alternative fuel aftermarket conversions

    SciTech Connect

    1998-01-01

    Emissions certification is still relatively new to the aftermarket vehicle conversion industry. Many in the industry think that as soon as a vehicle is converted to operate on compressed natural gas (CNG) or liquefied petroleum gas (LFG), it automatically runs as clean as or cleaner than it did on the conventional fuel. However, recent studies have shown that aftermarket conversions may not always reduce emissions. To achieve emissions benefits, the conversion equipment must be designed and calibrated specifically for the engine and emissions control system on which it has been installed, and the installation and setup must be performed so as to not adversely affect the vehicle`s original emissions performance. The reason for certification, then, is to ensure that these criteria are met, that the vehicle continues to perform properly, and that it continues to satisfy all appropriate emissions standards throughout its useful life. The authors have prepared this guide to help equipment manufacturers, distributors, and installers understand the emissions certification process for aftermarket conversions. The guide gives an overview of the certification requirements established by the US EPA and by the state of California.

  15. Two-stage thermal conversion of inedible lipid feedstocks to renewable chemicals and fuels.

    PubMed

    Asomaning, Justice; Mussone, Paolo; Bressler, David C

    2014-04-01

    The aim of this work was to study the conversion of inedible, low cost lipid feedstocks to renewable hydrocarbons using a two stage thermal hydrolysis-pyrolysis method. Beef tallow, yellow grease, brown grease and cold pressed camelina oil were first hydrolyzed and the fatty acids produced were recovered and pyrolyzed in batch reactors. The pyrolysis products were identified and quantified using gas chromatography and mass spectrometry. The pyrolysis product yields were similar for all the feedstock used with the organic liquid fraction (OLF) accounting for 76-80% of the product. The OLF consisted predominantly of n-alkanes. Approximately 30% OLF constituted a gasoline-equivalent fraction and 50% a diesel fraction. Other fuel property test showed that the OLF met the specifications set out by the Canadian general standards board. This research demonstrated a novel two-stage thermal hydrolysis-pyrolysis conversion method for producing OLF from inedible and low-value lipids. PMID:24583215

  16. Radioactive Waste Management at the New Conversion Facility of 'TVEL'{sup R} Fuel Company - 13474

    SciTech Connect

    Indyk, S.I.; Volodenko, A.V.; Tvilenev, K.A.; Tinin, V.V.; Fateeva, E.V.

    2013-07-01

    The project on the new conversion facility construction is being implemented by Joint Stock Company (JSC) 'Siberian Group of Chemical Enterprises' (SGChE) within TVEL{sup R} Fuel Company. The objective is to construct the up-to-date facility ensuring the industrial and environmental safety with the reduced impact on the community and environment in compliance with the Russian new regulatory framework on radioactive waste (RW) management. The history of the SGChE development, as well as the concepts and approaches to RW management implemented by now are shown. The SGChE future image is outlined, together with its objectives and concept on RW management in compliance with the new act 'On radioactive waste management' adopted in Russia in 2011. Possible areas of cooperation with international companies are discussed in the field of RW management with the purpose of deploying the best Russian and world practices on RW management at the new conversion facility. (authors)

  17. Direct conversion of spent fuel to High-Level-Waste (HLW) glass

    SciTech Connect

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Rudolph, J.

    1994-09-20

    The Glass Material Oxidation and Dissolution System (GMODS) is a recently invented process for the direct, single-step conversion of spent nuclear fuel (SNF) to high-level waste (HLW) glass. GMODS converts metals, ceramics, organics, and amorphous solids to glass in a single step. Conventional vitrification technology can not accept feeds containing metals or carbon. The GMODS has the potential to solve several issues associated with the disposal of various US Department of Energy (DOE) miscellaneous SNFs: (1) chemical forms unacceptable for repository disposal; (2) high cost of qualifying small quantities of particular SNFs for disposal; (3) limitations imposed by high-enriched SNF in a repository because of criticality and safeguards issues; and (4) classified design information. Conversion of such SNFs to glass eliminates these concerns. A description of the GMODS, {open_quotes}strawman{close_quotes} product criteria, experimental work to date, and product characteristics are included herein.

  18. Temporal mode sorting using dual-stage quantum frequency conversion by asymmetric Bragg scattering.

    PubMed

    Christensen, Jesper B; Reddy, Dileep V; McKinstrie, C J; Rottwitt, K; Raymer, M G

    2015-09-01

    The temporal shape of single photons provides a high-dimensional basis of temporal modes, and can therefore support quantum computing schemes that go beyond the qubit. However, the lack of linear optical components to act as quantum gates has made it challenging to efficiently address specific temporal-mode components from an arbitrary superposition. Recent progress towards realizing such a "quantum pulse gate," has been proposed using nonlinear optical signal processing to add coherently the effect of multiple stages of quantum frequency conversion. This scheme, called temporal-mode interferometry [D. V. Reddy, Phys. Rev. A 91, 012323 (2015)], has been shown in the case of three-wave mixing to promise near-unity mode-sorting efficiency. Here we demonstrate that it is also possible to achieve high mode-sorting efficiency using four-wave mixing, if one pump pulse is long and the other short - a configuration we call asymmetrically-pumped Bragg scattering. PMID:26368430

  19. Conversion of TRIGA research reactors from high-enriched- to low-enriched-uranium fuels: owner/operator view

    SciTech Connect

    Feltz, D.E.

    1986-01-01

    In June 1985, the US Nuclear Regulatory Commission (NRC) commissioners issued a four-point directive to the NRC staff concerning the conversion of research reactors from the use of high-enriched-uranium (HEU) to low-enriched-uranium (LEU) fuels. As a result of this directive, the earlier concerns of the research reactor community that were presented to the NRC during the comment period of the 1984 proposed rule on HEU-LEU conversion must be dealt with now. This paper discusses the items of most concern to HEU TRIGA owner/operators for conversion to LEU fuel.

  20. Graphene-based electrochemical energy conversion and storage: fuel cells, supercapacitors and lithium ion batteries.

    PubMed

    Hou, Junbo; Shao, Yuyan; Ellis, Michael W; Moore, Robert B; Yi, Baolian

    2011-09-14

    Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems. PMID:21799983

  1. Graphene-based Electrochemical Energy Conversion and Storage: Fuel cells, Supercapacitors and Lithium Ion Batteries

    SciTech Connect

    Hou, Junbo; Shao, Yuyan; Ellis, Michael A.; Moore, Robert; Yi, Baolian

    2011-09-14

    Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems.

  2. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-02-01

    Light hydrocarbon gases could be reacted with low cost alkaline earth metal oxide (CaO, MgO) in high-temperature plasma reactor to achieve very high ([le]100%) gas conversion to H[sub 2], CO, and the corresponding metal carbides. These carbides could be stored, transported, and hydrolyzed to acetylene or methyl acetylene, which in turn could be upgraded to a wide range of chemicals and premium liquid hydrocarbon fuels. An electric arc discharge reactor was built for converting methane. Literature reviews were made.

  3. SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

    SciTech Connect

    Unknown

    2003-06-01

    This report summarizes the progress made during the September 2001-March 2002 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program''. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. The overall objective of the program is to demonstrate a modular SOFC system that can be configured to create highly efficient, cost-competitive, and environmentally benign power plants tailored to specific markets. When fully developed, the system will meet the efficiency, performance, life, and cost goals for future commercial power plants.

  4. One-pot catalytic conversion of cellulose and of woody biomass solids to liquid fuels.

    PubMed

    Matson, Theodore D; Barta, Katalin; Iretskii, Alexei V; Ford, Peter C

    2011-09-01

    Efficient methodologies for converting biomass solids to liquid fuels have the potential to reduce dependence on imported petroleum while easing the atmospheric carbon dioxide burden. Here, we report quantitative catalytic conversions of wood and cellulosic solids to liquid and gaseous products in a single stage reactor operating at 300-320 °C and 160-220 bar. Little or no char is formed during this process. The reaction medium is supercritical methanol (sc-MeOH) and the catalyst, a copper-doped porous metal oxide, is composed of earth-abundant materials. The major liquid product is a mixture of C(2)-C(6) aliphatic alcohols and methylated derivatives thereof that are, in principle, suitable for applications as liquid fuels. PMID:21806029

  5. International Atomic Energy Agency support of research reactor highly enriched uranium to low enriched uranium fuel conversion projects

    SciTech Connect

    Bradley, E.; Adelfang, P.; Goldman, I.N.

    2008-07-15

    The IAEA has been involved for more than twenty years in supporting international nuclear non- proliferation efforts associated with reducing the amount of highly enriched uranium (HEU) in international commerce. IAEA projects and activities have directly supported the Reduced Enrichment for Research and Test Reactors (RERTR) programme, as well as directly assisted efforts to convert research reactors from HEU to LEU fuel. HEU to LEU fuel conversion projects differ significantly depending on several factors including the design of the reactor and fuel, technical needs of the member state, local nuclear infrastructure, and available resources. To support such diverse endeavours, the IAEA tailors each project to address the relevant constraints. This paper presents the different approaches taken by the IAEA to address the diverse challenges involved in research reactor HEU to LEU fuel conversion projects. Examples of conversion related projects in different Member States are fully detailed. (author)

  6. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    SciTech Connect

    Skok, A.J.; Abueg, R.Z.; Schwartz, P.

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  7. 10 CFR 830 Major Modification Determination for Advanced Test Reactor LEU Fuel Conversion

    SciTech Connect

    Boyd D. Christensen; Michael A. Lehto; Noel R. Duckwitz

    2012-05-01

    The Advanced Test Reactor (ATR), located in the ATR Complex of the Idaho National Laboratory (INL), was constructed in the 1960s for the purpose of irradiating reactor fuels and materials. Other irradiation services, such as radioisotope production, are also performed at ATR. The ATR is fueled with high-enriched uranium (HEU) matrix (UAlx) in an aluminum sandwich plate cladding. The National Nuclear Security Administration Global Threat Reduction Initiative (GTRI) strategic mission includes efforts to reduce and protect vulnerable nuclear and radiological material at civilian sites around the world. Converting research reactors from using HEU to low-enriched uranium (LEU) was originally started in 1978 as the Reduced Enrichment for Research and Test Reactors (RERTR) Program under the U.S. Department of Energy (DOE) Office of Science. Within this strategic mission, GTRI has three goals that provide a comprehensive approach to achieving this mission: The first goal, the driver for the modification that is the subject of this determination, is to convert research reactors from using HEU to LEU. Thus the mission of the ATR LEU Fuel Conversion Project is to convert the ATR and Advanced Test Reactor Critical facility (ATRC) (two of the six U.S. High-Performance Research Reactors [HPRR]) to LEU fuel by 2017. The major modification criteria evaluation of the project pre-conceptual design identified several issues that lead to the conclusion that the project is a major modification.

  8. Life-cycle-assessment of fuel-cells-based landfill-gas energy conversion technologies

    NASA Astrophysics Data System (ADS)

    Lunghi, P.; Bove, R.; Desideri, U.

    Landfill-gas (LFG) is produced as result of the biological reaction of municipal solid waste (MSW). This gas contains about 50% of methane, therefore it cannot be released into the atmosphere as it is because of its greenhouse effect consequences. The high percentage of methane encouraged researchers to find solutions to recover the related energy content for electric energy production. The most common technologies used at the present time are internal combustion reciprocating engines and gas turbines. High conversion efficiency guaranteed by fuel cells (FCs) enable to enhance the energy recovery process and to reduce emissions to air, such as NO x and CO. In any case, in order to investigate the environmental advantages associated with the electric energy generation using fuel cells, it is imperative to consider the whole "life cycle" of the system, "from cradle-to-grave". In fact, fuel cells are considered to be zero-emission devices, but, for example, emissions associated with their manufacture or for hydrogen production must be considered in order to evaluate all impacts on the environment. In the present work a molten carbonate fuel cell (MCFC) system for LFG recovery is considered and a life cycle assessment (LCA) is conducted for an evaluation of environmental consequences and to provide a guide for further environmental impact reduction.

  9. Valorization of food waste into hydroxymethylfurfural: Dual role of metal ions in successive conversion steps.

    PubMed

    Yu, Iris K M; Tsang, Daniel C W; Yip, Alex C K; Chen, Season S; Ok, Yong Sik; Poon, Chi Sun

    2016-11-01

    This study aimed to transform food waste into a value-added chemical, hydroxymethylfurfural (HMF), and unravel the tangled effects induced by the metal catalysts on each single step of the successive conversion pathway. The results showed that using cooked rice and bread crust as surrogates of starch-rich food waste, yields of 8.1-9.5% HMF and 44.2-64.8% glucose were achieved over SnCl4 catalyst. Protons released from metal hydrolysis and acidic by-products rendered Brønsted acidity to catalyze fructose dehydration and hydrolysis of glycosidic bond. Lewis acid site of metals could facilitate both fructose dehydration and glucose isomerization via promoting the rate-limiting internal hydride shift, with the catalytic activity determined by its electronegativity, electron configuration, and charge density. Lewis acid site of a higher valence also enhanced hydrolysis of polysaccharide. However, the metals also catalyzed undesirable polymerization possibly by polarizing the carbonyl groups of sugars and derivatives, which should be minimized by process optimization. PMID:27498014

  10. Demonstration of Caterpillar C-10 dual-fuel engines in MCI 102DL3 commuter buses

    SciTech Connect

    2000-02-28

    The purpose of this program was to demonstrate the Caterpillar C-10 Dual-Fuel Natural Gas (DFNG) engine in an over-the-road bus application. Three new Motor Coach Industries (MCI) 102DL3 buses, equipped with Caterpillar C-10 DFNG engines, and one bus, equipped with a Caterpillar C-10 diesel engine, were operated side by side on similar fixed-route revenue service for a 12-month demonstration period (February 1998 to January 1999). The buses were used as part of the Clean Air Express Commuter Bus Program in Santa Barbara County, California. The performance and reliability of the DFNG engines were similar to that of the diesel engine, but the emissions results were mixed.

  11. Dual application of duckweed and azolla plants for wastewater treatment and renewable fuels and petrochemicals production

    PubMed Central

    2014-01-01

    Background Shortages in fresh water supplies today affects more than 1 billion people worldwide. Phytoremediation strategies, based on the abilities of aquatic plants to recycle nutrients offer an attractive solution for the bioremediation of water pollution and represents one of the most globally researched issues. The subsequent application of the biomass from the remediation for the production of fuels and petrochemicals offers an ecologically friendly and cost-effective solution for water pollution problems and production of value-added products. Results In this paper, the feasibility of the dual application of duckweed and azolla aquatic plants for wastewater treatment and production of renewable fuels and petrochemicals is explored. The differences in absorption rates of the key wastewater nutrients, ammonium and phosphorus by these aquatic macrophytes were used as the basis for optimization of the composition of wastewater effluents. Analysis of pyrolysis products showed that azolla and algae produce a similar range of bio-oils that contain a large spectrum of petrochemicals including straight-chain C10-C21 alkanes, which can be directly used as diesel fuel supplement, or a glycerin-free component of biodiesel. Pyrolysis of duckweed produces a different range of bio-oil components that can potentially be used for the production of “green” gasoline and diesel fuel using existing techniques, such as catalytic hydrodeoxygenation. Conclusions Differences in absorption rates of the key wastewater nutrients, ammonium and phosphorus by different aquatic macrophytes can be used for optimization of composition of wastewater effluents. The generated data suggest that the composition of the petrochemicals can be modified in a targeted fashion, not only by using different species, but also by changing the source plants’ metabolic profile, by exposing them to different abiotic or biotic stresses. This study presents an attractive, ecologically friendly and cost

  12. Enzymatic conversion of unusual cellulosic wastes to alcohol fuel. Alcohol-Fuels Grant Program

    SciTech Connect

    Pye, E.K.

    1983-02-01

    Samples of unusual cellulosic wastes from a Sulfite pulp mill, spent mushroom compost and wastes from a cellophane manufacturing plant were collected and analyzed for saccharide content. This analysis showed that the pulp mill wastes (fines) had the greatest cellulose content (approx. 78%), while the cellophane wastes contained up to 40% cellulose and the mushroom compost only 20 to 25% cellulose. The mushroom compost could not be used both technically and economically as a substrate for ethanol production. The cellulose in the pulp mill waste was readily hydrolyzed to cellobiose by the extracellular enzymes of Thermomonospora fusca YX but required substantial quantities of ..beta..-glucosidase activity in order to generate glucose. The glucose produced could be easily fermented by both Saccharmoyces yeast and Thermoanaerobacter ethanolicus. The use of T. ethanolicus eliminated the need for ..beta..-glucosidase additions but gave low yields and low conversions. Under the best of circumstances, 60 to 70% of the cellulose was hydrolyzed and converted to ethanol. However, ethanol concentrations greater than 1% w/v were rarely achieved, thus leading to high recovery costs for ethanol. To overcome these problems two process recommendations have been made. One is a novel design for high temperature enzymatic saccharification of cellulose in a countercurrent tower design, followed by fermentation of the sugar stream in a thermophilic fermentation in a packed bed containing immobilized Thermoanaerobacter ethanolicus. This design should reduce the need for costly enzyme and provide a continuous process. The second design is more conventional and uses a sulfur dioxide catalyzed hydrolysis of cellulose followed by yeast fermentation.

  13. Quantum confined colloidal nanorod heterostructures for solar-to-fuel conversion.

    PubMed

    Wu, Kaifeng; Lian, Tianquan

    2016-07-11

    Solar energy conversion, particularly solar-driven chemical fuel formation, has been intensely studied in the past decades as a potential approach for renewable energy generation. Efficient solar-to-fuel conversion requires artificial photosynthetic systems with strong light absorption, long-lived charge separation and efficient catalysis. Colloidal quantum confined nanoheterostructures have emerged as promising materials for this application because of the ability to tailor their properties through size, shape and composition. In particular, colloidal one-dimensional (1D) semiconductor nanorods (NRs) offer the opportunity to simultaneously maintain quantum confinement in radial dimensions for tunable light absorptions and bulk like carrier transport in the axial direction for long-distance charge separations. In addition, the versatile chemistry of colloidal NRs enables the formation of semiconductor heterojunctions (such as CdSe/CdS dot-in-rod NRs) to separate photogenerated electron-hole pairs and deposition of metallic domains to accept charges and catalyze redox reactions. In this review, we summarize research progress on colloidal NR heterostructures and their applications for solar energy conversion, emphasizing mechanistic insights into the working principle of these systems gained from spectroscopic studies. Following a brief overview of synthesis of various NRs and heterostructures, we introduce their electronic structures and dynamics of exciton and carrier transport and interfacial transfer. We discuss how these exciton and carrier dynamics are controlled by their structures and provide key mechanistic understanding on their photocatalytic performance, including the photo-reduction of a redox mediator (methyl viologen) and light driven H2 generation. We discuss the solar-driven H2 generation mechanism, key efficiency limiting steps, and potential approaches for rational improvement in semiconductor NR/metal heterostructures (such as Pt tipped Cd

  14. Direct Conversion of Carbon Fuels in a Molten Carbonate Fuel Cell

    SciTech Connect

    Cherepy, N J; Fiet, K J; Krueger, R; Jankowski, A F; Cooper, J F

    2004-01-28

    Anodes of elemental carbon may be discharged in a galvanic cell using a molten carbonate electrolyte, a nickel-foam anode-current collector, and a porous nickel air cathode to achieve power densities of 40-100 mW/cm{sup 2}. We report cell and anode polarization, surface area, primary particle size and a crystallization index for nine particulate carbon samples derived from fuel oil, methane, coal, charred biological material and petroleum coke. At 800 C, current densities of 50-125 mA/cm{sup 2} were measured at a representative cell voltage of 0.8 V. Power densities for cells with two carbon-anode materials were found to be nearly the same on scales of 2.8- and 60 cm{sup 2} active area. Constant current operation of a small cell was accompanied by constant voltage during multiple tests of 10-30 hour duration. Cell voltage fell off after the carbon inventory was consumed. Three different cathode structures are compared, indicating that an LLNL fabricated porous nickel electrode with <10 {micro}m pores provides improved rates compared with nickel foam with 100-300 {micro}m pores. Petroleum coke containing substantial sulfur and ash discharges at a slightly lower rate than purified petroleum coke. The sulfur leads to degradation of the anode current collector over time. A conceptual model for electrochemical reactivity of carbon is presented which indicates the importance of (1) bulk lattice disorder, which continually provides surface reactive sites during anodic dissolution and (2) electrical conductivity, which lowers the ohmic component of anode polarization.

  15. Power-law relationships for estimating mass, fuel consumption and costs of energy conversion equipments.

    PubMed

    Caduff, Marloes; Huijbregts, Mark A J; Althaus, Hans-Joerg; Hendriks, A Jan

    2011-01-15

    To perform life-cycle assessment studies, data on the production and use of the products is required. However, often only few data or measurements are available. Estimation of properties can be performed by applying scaling relationships. In many disciplines, they are used to either predict data or to search for underlying patterns, but they have not been considered in the context of product assessments hitherto. The goal of this study was to explore size scaling for commonly used energy conversion equipment, that is, boilers, engines, and generators. The variables mass M, fuel consumption Q, and costs C were related to power P. The established power-law relationships were M = 10(0.73.. 1.89)P(0.64.. 1.23) (R(2) ≥ 0.94), Q = 10(0.06.. 0.68)P(0.82.. 1.02) (R(2) ≥ 0.98) and C = 10(2.46.. 2.86)P(0.83.. 0.85) (R(2) ≥ 0.83). Mass versus power and costs versus power showed that none of the equipment types scaled isometrically, that is, with a slope of 1. Fuel consumption versus power scaled approximately isometrically for steam boilers, the other equipments scaled significantly lower than 1. This nonlinear scaling behavior induces a significant size effect. The power laws we established can be applied to scale the mass, fuel consumption and costs of energy conversion equipments up or down. Our findings suggest that empirical scaling laws can be used to estimate properties, particularly relevant in studies focusing on early product development for which generally only little information is available. PMID:21133374

  16. Power production and wastewater treatment simultaneously by dual-chamber microbial fuel cell technique.

    PubMed

    Izadi, Paniz; Rahimnejad, Mostafa; Ghoreyshi, Ali

    2015-01-01

    Microbial fuel cell (MFC) is a novel technology that is able to convert the chemical energy of organic and inorganic substrates to electrical energy directly. The use of fossil fuels and recent energy crisis bring increasing attention to this technology. Besides electricity generation, wastewater treatment is another application of MFCs. Sulfide is a hazardous ion that is common in wastes. In this article, dual-chamber MFC was fabricated and a mixed culture of microorganisms was used as an active biocatalyst in an anaerobic anodic chamber to convert substrate to electricity. The obtained experimental results indicate that this MFC can successfully alter sulfide to elementary sulfur and power generation. The initial concentration of sulfide in wastewater was 1.5 g L(-1) , and it was removed after 10 days of MFC operation. Maximum produced power and current density were 48.68 mW⋅m(-2) and 231.47 mA⋅m(-2) , respectively. Besides, the influences of a biocathode were investigated and accordingly the data obtained for power and current density were increased to 372.27 mW⋅m(-2) and 1,665.15 mA⋅m(-2) , respectively. PMID:25640146

  17. Numerical Simulation of Vitiation Effects on a Hydrogen-Fueled Dual-Mode Scramjet

    NASA Technical Reports Server (NTRS)

    Vyas, Manan A.; Engblom, William A.; Georgiadis, Nicholas J.; Trefny, Charles J.; Bhagwandin, Vishal A.

    2010-01-01

    The Wind-US computational fluid dynamics (CFD) flow solver was used to simulate dual-mode direct-connect ramjet/scramjet engine flowpath tests conducted in the University of Virginia (UVa) Supersonic Combustion Facility (SCF). The objective was to develop a computational capability within Wind-US to aid current hypersonic research and provide insight to flow as well as chemistry details that are not resolved by instruments available. Computational results are compared with experimental data to validate the accuracy of the numerical modeling. These results include two fuel-off non-reacting and eight fuel-on reacting cases with different equivalence ratios, split between one set with a clean (non-vitiated) air supply and the other set with a vitiated air supply (12 percent H2O vapor). The Peters and Rogg hydrogen-air chemical kinetics model was selected for the scramjet simulations. A limited sensitivity study was done to investigate the choice of turbulence model and inviscid flux scheme and led to the selection of the k-epsilon model and Harten, Lax and van Leer (for contact waves) (HLLC) scheme for general use. Simulation results show reasonably good agreement with experimental data and the overall vitiation effects were captured.

  18. Degradation modeling of high temperature proton exchange membrane fuel cells using dual time scale simulation

    NASA Astrophysics Data System (ADS)

    Pohl, E.; Maximini, M.; Bauschulte, A.; vom Schloß, J.; Hermanns, R. T. E.

    2015-02-01

    HT-PEM fuel cells suffer from performance losses due to degradation effects. Therefore, the durability of HT-PEM is currently an important factor of research and development. In this paper a novel approach is presented for an integrated short term and long term simulation of HT-PEM accelerated lifetime testing. The physical phenomena of short term and long term effects are commonly modeled separately due to the different time scales. However, in accelerated lifetime testing, long term degradation effects have a crucial impact on the short term dynamics. Our approach addresses this problem by applying a novel method for dual time scale simulation. A transient system simulation is performed for an open voltage cycle test on a HT-PEM fuel cell for a physical time of 35 days. The analysis describes the system dynamics by numerical electrochemical impedance spectroscopy. Furthermore, a performance assessment is performed in order to demonstrate the efficiency of the approach. The presented approach reduces the simulation time by approximately 73% compared to conventional simulation approach without losing too much accuracy. The approach promises a comprehensive perspective considering short term dynamic behavior and long term degradation effects.

  19. Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program

    SciTech Connect

    Nguyen Minh

    2006-07-31

    This report summarizes the work performed for Phase I (October 2001 - August 2006) under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled 'Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program'. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. During Phase I of the program significant progress has been made in the area of SOFC technology. A high-efficiency low-cost system was designed and supporting technology developed such as fuel processing, controls, thermal management, and power electronics. Phase I culminated in the successful demonstration of a prototype system that achieved a peak efficiency of 41%, a high-volume cost of $724/kW, a peak power of 5.4 kW, and a degradation rate of 1.8% per 500 hours. . An improved prototype system was designed, assembled, and delivered to DOE/NETL at the end of the program. This prototype achieved an extraordinary peak efficiency of 49.6%.

  20. Conceptual Design Parameters for HFIR LEU U-Mo Fuel Conversion Experimental Irradiations

    SciTech Connect

    Renfro, David G; Cook, David Howard; Chandler, David; Ilas, Germina; Jain, Prashant K

    2013-03-01

    The High Flux Isotope Reactor (HFIR) is a versatile research reactor that is operated at the Oak Ridge National Laboratory (ORNL). The HFIR core is loaded with high-enriched uranium (HEU) and operates at a power level of 85 MW. The primary scientific missions of the HFIR include cold and thermal neutron scattering, materials irradiation, and isotope production. An engineering design study of the conversion of the HFIR from HEU to low-enriched uranium (LEU) fuel is ongoing at the Oak Ridge National Laboratory. The LEU fuel considered is based on a uranium-molybdenum alloy that is 10 percent by weight molybdenum (U-10Mo) with a 235U enrichment of 19.75 wt %. The LEU core design discussed in this report is based on the design documented in ORNL/TM-2010/318. Much of the data reported in Sections 1 and 2 of this document was derived from or taken directly out of ORNL/TM-2010/318. The purpose of this report is to document the design parameters for and the anticipated normal operating conditions of the conceptual HFIR LEU fuel to aid in developing requirements for HFIR irradiation experiments.

  1. Biochemical Conversion Processes of Lignocellulosic Biomass to Fuels and Chemicals - A Review.

    PubMed

    Brethauer, Simone; Studer, Michael H

    2015-01-01

    Lignocellulosic biomass - such as wood, agricultural residues or dedicated energy crops - is a promising renewable feedstock for production of fuels and chemicals that is available at large scale at low cost without direct competition for food usage. Its biochemical conversion in a sugar platform biorefinery includes three main unit operations that are illustrated in this review: the physico-chemical pretreatment of the biomass, the enzymatic hydrolysis of the carbohydrates to a fermentable sugar stream by cellulases and finally the fermentation of the sugars by suitable microorganisms to the target molecules. Special emphasis in this review is put on the technology, commercial status and future prospects of the production of second-generation fuel ethanol, as this process has received most research and development efforts so far. Despite significant advances, high enzyme costs are still a hurdle for large scale competitive lignocellulosic ethanol production. This could be overcome by a strategy termed 'consolidated bioprocessing' (CBP), where enzyme production, enzymatic hydrolysis and fermentation is integrated in one step - either by utilizing one genetically engineered superior microorganism or by creating an artificial co-culture. Insight is provided on both CBP strategies for the production of ethanol as well as of advanced fuels and commodity chemicals. PMID:26598400

  2. Enhancement of conversion efficiency of extreme ultraviolet radiation from a liquid aqueous solution microjet target by use of dual laser pulses

    NASA Astrophysics Data System (ADS)

    Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Kawasaki, Keita; Sasaki, Wataru; Kubodera, Shoichi

    2006-03-01

    We demonstrated a debris-free, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO II) nano-particles. By using a low SnO II concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris.

  3. Develop the dual fuel conversion system for high output, medium speed diesel engines. Final report

    SciTech Connect

    1998-07-16

    The original plan for the project involved design modifications to an existing system to enhance its performance and increase the limit of power that was achieved by the original design and to apply the higher performance product to the full sized engine and test its performance. The new system would also be applied to a different engine model. The specific work would include the redesign of gas injectors, piston configurations and two types of igniters, engine instrumentation, monitoring and testing.

  4. Steady-State Thermal-Hydraulics Analyses for the Conversion of BR2 to Low Enriched Uranium Fuel

    SciTech Connect

    Licht, J.; Bergeron, A.; Dionne, B.; Van den Branden, G; Kalcheva, S; Sikik, E; Koonen, E

    2015-01-01

    The code PLTEMP/ANL version 4.2 was used to perform the steady-state thermal-hydraulic analyses of the BR2 research reactor for conversion from Highly-Enriched to Low Enriched Uranium fuel (HEU and LEU, respectively). Calculations were performed to evaluate different fuel assemblies with respect to the onset of nucleate boiling (ONB), flow instability (FI), critical heat flux (CHF) and fuel temperature at beginning of cycle conditions. The fuel assemblies were characteristic of fresh fuel (0% burnup), highest heat flux (16% burnup), highest power (32% burnup) and highest burnup (46% burnup). Results show that the high heat flux fuel element is limiting for ONB, FI, and CHF, for both HEU and LEU fuel, but that the high power fuel element produces similar margin in a few cases. The maximum fuel temperature similarly occurs in both the high heat flux and high power fuel assemblies for both HEU and LEU fuel. A sensitivity study was also performed to evaluate the variation in fuel temperature due to uncertainties in the thermal conductivity degradation associated with burnup.

  5. Conversion of the energy-subtracted CT number to electron density based on a single linear relationship: an experimental verification using a clinical dual-source CT scanner.

    PubMed

    Tsukihara, Masayoshi; Noto, Yoshiyuki; Hayakawa, Takahide; Saito, Masatoshi

    2013-05-01

    In radiotherapy treatment planning, the conversion of the computed tomography (CT) number to electron density is one of the main processes that determine the accuracy of patient dose calculations. However, in general, the CT number and electron density of tissues cannot be interrelated using a simple one-to-one correspondence. This study aims to experimentally verify the clinical feasibility of an existing novel conversion method proposed by the author of this note, which converts the energy-subtracted CT number (ΔHU) to the relative electron density (ρe) via a single linear relationship by using a dual-energy CT (DECT). The ΔHU-ρe conversion was performed using a clinical second-generation dual-source CT scanner operated in the dual-energy mode with tube potentials of 80 kV and 140 kV with and without an additional tin filter. The ΔHU-ρe calibration line was obtained from the DECT image acquisition for tissue substitutes in an electron density phantom. In addition, the effect of object size on ΔHU-ρe conversion was also experimentally investigated. The plot of the measured ΔHU versus nominal ρe values exhibited a single linear relationship over a wide ρe range from 0.00 (air) to 2.35 (aluminum). The ΔHU-ρe conversion performed with the tin filter yielded a lower dose and more reliable ρe values that were less affected by the object-size variation when compared to the corresponding values obtained for the case without the tin filter. PMID:23571116

  6. Conversion of the energy-subtracted CT number to electron density based on a single linear relationship: an experimental verification using a clinical dual-source CT scanner

    NASA Astrophysics Data System (ADS)

    Tsukihara, Masayoshi; Noto, Yoshiyuki; Hayakawa, Takahide; Saito, Masatoshi

    2013-05-01

    In radiotherapy treatment planning, the conversion of the computed tomography (CT) number to electron density is one of the main processes that determine the accuracy of patient dose calculations. However, in general, the CT number and electron density of tissues cannot be interrelated using a simple one-to-one correspondence. This study aims to experimentally verify the clinical feasibility of an existing novel conversion method proposed by the author of this note, which converts the energy-subtracted CT number (ΔHU) to the relative electron density (ρe) via a single linear relationship by using a dual-energy CT (DECT). The ΔHU-ρe conversion was performed using a clinical second-generation dual-source CT scanner operated in the dual-energy mode with tube potentials of 80 kV and 140 kV with and without an additional tin filter. The ΔHU-ρe calibration line was obtained from the DECT image acquisition for tissue substitutes in an electron density phantom. In addition, the effect of object size on ΔHU-ρe conversion was also experimentally investigated. The plot of the measured ΔHU versus nominal ρe values exhibited a single linear relationship over a wide ρe range from 0.00 (air) to 2.35 (aluminum). The ΔHU-ρe conversion performed with the tin filter yielded a lower dose and more reliable ρe values that were less affected by the object-size variation when compared to the corresponding values obtained for the case without the tin filter.

  7. A study of spin isomer conversion kinetics in supercritical fluid hydrogen for cyrogenic fuel storage technologies

    NASA Astrophysics Data System (ADS)

    Matthews, Manyalibo J.; Petitpas, Guillaume; Aceves, Salvador M.

    2011-08-01

    A detailed kinetic study of para-ortho hydrogen conversion under supercritical conditions using rotational Raman scattering is presented. Isochoric measurements of initially low ortho concentrations over temperatures 32 < T < 280 K and densities 0.014 < ρ < 0.060 g/cm3 were used to derive kinetic rate constants k(ρ, T) by solving an autocatalytic kinetic rate equation. At low ortho concentrations and T < 100 K, k is found to be ˜2× higher than previous results based on thermal conductivity measurements, decreasing weakly with temperature, similar to Wigner's original paramagnetic theory. Accurate modeling of k(ρ, T) is critical in predicting cryogenic hydrogen fuel tank dormancy performance for hydrogen-power vehicles.

  8. COMSOL-based Multiphysics Simulations to Support HFIR s Conversion to LEU Fuel

    SciTech Connect

    Jain, Prashant K; Freels, James D; Cook, David Howard

    2011-01-01

    In this paper, development of at least one form of the COMSOL-based modeling framework for the HFIR is presented, key simulation steps are identified and several milestones achieved towards a coupled multi-physics capability are highlighted. COMSOL-based multi-physics simulation capability is able to answer the need for predictive 3D simulations of HFIR s involute plate and channels. Step-by-step development and analyses of the COMSOL models for the single and multi-channels will lead towards the desired full-core simulation capability for the HFIR. With very few experiments planned to support the conversion process, these 3D simulations will become the basis for the nuclear safety analysis of the HFIR s LEU fuel core.

  9. Technician's Perspective on an Ever-Changing Research Environment: Catalytic Conversion of Biomass to Fuels

    SciTech Connect

    Thibodeaux, J.; Hensley, J.

    2013-01-01

    The biomass thermochemical conversion platform at the National Renewable Energy Laboratory (NREL) develops and demonstrates processes for the conversion of biomass to fuels and chemicals including gasification, pyrolysis, syngas clean-up, and catalytic synthesis of alcohol and hydrocarbon fuels. In this talk, I will discuss the challenges of being a technician in this type of research environment, including handling and working with catalytic materials and hazardous chemicals, building systems without being given all of the necessary specifications, pushing the limits of the systems through ever-changing experiments, and achieving two-way communication with engineers and supervisors. I will do this by way of two examples from recent research. First, I will describe a unique operate-to-failure experiment in the gasification of chicken litter that resulted in the formation of a solid plug in the gasifier, requiring several technicians to chisel the material out. Second, I will compare and contrast bench scale and pilot scale catalyst research, including instances where both are conducted simultaneously from common upstream equipment. By way of example, I hope to illustrate the importance of researchers 1) understanding the technicians' perspective on tasks, 2) openly communicating among all team members, and 3) knowing when to voice opinions. I believe the examples in this talk will highlight the crucial role of a technical staff: skills attained by years of experience to build and operate research and production systems. The talk will also showcase the responsibilities of NREL technicians and highlight some interesting behind-the-scenes work that makes data generation from NREL's thermochemical process development unit possible.

  10. Direct conversion of methane to C sub 2 's and liquid fuels

    SciTech Connect

    Warren, B.K.; Campbell, K.D.

    1989-11-22

    Objectives of the project are to discover and evaluate novel catalytic systems for the conversion of methane or by-product light hydrocarbon gases either indirectly (through intermediate light gases rich in C{sub 2}'s) or directly to liquid hydrocarbon fuels, and to evaluate, from an engineering perspective, different conceptualized schemes. The approach is to carry out catalyst testing on several specific classes of potential catalysts for the conversion of methane selectively to C{sub 2} products. Promoted metal oxide catalysts were tested. Several of these exhibited similar high ethylene to ethane ratios and low carbon dioxide to carbon monoxide ratios observed for the NaCl/{alpha}-alumina catalyst system reported earlier. Research on catalysts containing potentially activated metals began with testing of metal molecular sieves. Silver catalysts were shown to be promising as low temperature catalysts. Perovskites were tested as potential methane coupling catalysts. A layered perovskite (K{sub 2}La{sub 2}Ti{sub 3}O{sub 10}) gave the highest C{sub 2} yield. Work continued on the economic evaluation of a hypothetical process converting methane to ethylene. An engineering model of the methane coupling system has been prepared. 47 refs., 17 figs., 57 tabs.

  11. Biotechnological research and development for biomass conversion to chemicals and fuels

    SciTech Connect

    Villet, R.

    1980-08-01

    It is likely that a growing need to produce chemicals and fuels from renewable resources will stimulate the development of biotechnology as a commerical enterprise of considerable potential. The purpose of the analysis and the development structure that could lead to establishing this new technology are presented. Two general goals are recommended: (i) in the near term, to revive the older fermentation industry and, by the addition of sophisticated technology, to make it competitive; (ii) in the longer term, to develop a new biotechnology largely based on lignocellulose. Specific research projects are outlined in these two areas and also for the following: microbial formation of hydrocarbons; methane from anaerobic digestion; lignin; methanol. For cellulose conversion to ethanol the relative merits of using added cellulases or, alternatively, direct fermentation with anaerobic thermophiles, are discussed. In selecting suitable feedstocks for biotechnological processes there is a need to use a production-extraction-conversion system as a basis for evaluation. An effective research workforce for developing biotechnology must be pluridisciplinary. The strategy adopted at the Solar Energy Research Institute is to design the Biotechnology Branch as an integrated set of three Groups: Biochemistry and Molecular Genetics; Microbiology; Chemical and Biochemical Engineering.

  12. Molecular Breeding Algae For Improved Traits For The Conversion Of Waste To Fuels And Commodities.

    SciTech Connect

    Bagwell, C.

    2015-10-14

    This Exploratory LDRD aimed to develop molecular breeding methodology for biofuel algal strain improvement for applications in waste to energy / commodity conversion technologies. Genome shuffling technologies, specifically protoplast fusion, are readily available for the rapid production of genetic hybrids for trait improvement and have been used successfully in bacteria, yeast, plants and animals. However, genome fusion has not been developed for exploiting the remarkable untapped potential of eukaryotic microalgae for large scale integrated bio-conversion and upgrading of waste components to valued commodities, fuel and energy. The proposed molecular breeding technology is effectively sexual reproduction in algae; though compared to traditional breeding, the molecular route is rapid, high-throughput and permits selection / improvement of complex traits which cannot be accomplished by traditional genetics. Genome fusion technologies are the cutting edge of applied biotechnology. The goals of this Exploratory LDRD were to 1) establish reliable methodology for protoplast production among diverse microalgal strains, and 2) demonstrate genome fusion for hybrid strain production using a single gene encoded trait as a proof of the concept.

  13. Direct conversion of methane to C sub 2 's and liquid fuels

    SciTech Connect

    Warren, B.K.; Campbell, K.D.; Matherne, J.L.; Kinkade, N.E.

    1990-03-12

    The objectives of the project are to discover and evaluate novel catalytic systems for the conversion of methane or by-product light hydrocarbon gases either indirectly (through intermediate light gases rich in C{sub 2}'s) or directly to liquid hydrocarbon fuels, and to evaluate, from an engineering perspective, different conceptualized schemes. The approach is to carry out catalyst testing on several specific classes of potential catalysts for the conversion of methane selectively to C{sub 2} products. The behavior of alkaline earth/metal oxide/halide catalysts containing strontium was found to be different from the behavior of catalysts containing barium. Two approaches were pursued to avoid the heterogeneous/homogeneous mechanism in order to achieve higher C{sub 2} selectivity/methane conversion combinations. One approach was to eliminate or minimize the typical gas phase combustion chemistry and make more of the reaction occur on the surface of the catalyst by using silver. Another approach was to change the gas phase chemistry to depart from the typical combustion reaction network by using vapor-phase catalysts. The layered perovskite K{sub 2}La{sub 2}Ti{sub 3}O{sub 10} was further studied. Modifications of process and catalyst variables for LaCaMnCoO{sub 6} catalysts resulted in catalysts with superior performance. Results obtained with a literature catalyst Na{sub 2}CO{sub 3}/Pr{sub 6}O{sub 11} were better than those obtained with NaCO{sub 3}/Pr-Ce oxide or Na{sub 2}CO{sub 3}/Ag-Pr-Ce oxide. 52 refs., 15 figs., 9 tabs.

  14. Conversion of solar energy into electricity by using duckweed in Direct Photosynthetic Plant Fuel Cell.

    PubMed

    Hubenova, Yolina; Mitov, Mario

    2012-10-01

    In the present study we demonstrate for the first time the possibility for conversion of solar energy into electricity on the principles of Direct Photosynthetic Plant Fuel Cell (DPPFC) technology by using aquatic higher plants. Lemna minuta duckweed was grown autotrophically in specially constructed fuel cells under sunlight irradiation and laboratory lighting. Current and power density up to 1.62±0.10 A.m(-2) and 380±19 mW.m(-2), respectively, were achieved under sunlight conditions. The influence of the temperature, light intensity and day/night sequencing on the current generation was investigated. The importance of the light intensity was demonstrated by the higher values of generated current (at permanently connected resistance) during daytime than those through the nights, indicating the participation of light-dependent photosynthetic processes. The obtained DPPFC outputs in the night show the contribution of light-independent reactions (respiration). The electron transfer in the examined DPPFCs is associated with a production of endogenous mediator, secreted by the duckweed. The plants' adaptive response to the applied polarization is also connected with an enhanced metabolism resulting in an increase of the protein and carbohydrate intracellular content. Further investigations aiming at improvement of the DPPFC outputs and elucidation of the electron transfer mechanism are required for practical application. PMID:22445768

  15. Study of CNG/diesel dual fuel engine's emissions by means of RBF neural network.

    PubMed

    Liu, Zhen-tao; Fei, Shao-mei

    2004-08-01

    Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission performance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFEmain performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx, emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data. PMID:15473052

  16. Determination of Optimal Parameters for Dual-Layer Cathode of Polymer Electrolyte Fuel Cell Using Computational Intelligence-Aided Design

    PubMed Central

    Chen, Yi; Huang, Weina; Peng, Bei

    2014-01-01

    Because of the demands for sustainable and renewable energy, fuel cells have become increasingly popular, particularly the polymer electrolyte fuel cell (PEFC). Among the various components, the cathode plays a key role in the operation of a PEFC. In this study, a quantitative dual-layer cathode model was proposed for determining the optimal parameters that minimize the over-potential difference and improve the efficiency using a newly developed bat swarm algorithm with a variable population embedded in the computational intelligence-aided design. The simulation results were in agreement with previously reported results, suggesting that the proposed technique has potential applications for automating and optimizing the design of PEFCs. PMID:25490761

  17. Hexavalent chromium reduction and energy recovery by using dual-chambered microbial fuel cell.

    PubMed

    Gangadharan, Praveena; Nambi, Indumathi M

    2015-01-01

    Microbial fuel cell (MFC) technology is utilized to treat hexavalent chromium (Cr(VI)) from wastewater and to generate electricity simultaneously. The Cr(VI) is bioelectrochemically reduced to non-toxic Cr(III) form in the presence of an organic electron donor in a dual-chambered MFC. The Cr(VI) as catholyte and artificial wastewater inoculated with anaerobic sludge as anolyte, Cr(VI) at 100 mg/L was completely removed within 48 h (initial pH value 2.0). The total amount of Cr recovered was 99.87% by the precipitation of Cr(III) on the surface of the cathode. In addition to that 78.4% of total organic carbon reduction was achieved at the anode chamber within 13 days of operation. Furthermore, the maximum power density of 767.01 mW/m² (2.08 mA/m²) was achieved by MFCs at ambient conditions. The present work has successfully demonstrated the feasibility of using MFCs for simultaneous energy production from wastewater and reduction of toxic Cr(VI) to non-toxic Cr(III). PMID:25714633

  18. Converting hazardous organics into clean energy using a solar responsive dual photoelectrode photocatalytic fuel cell.

    PubMed

    Li, Jianyong; Li, Jinhua; Chen, Quanpeng; Bai, Jing; Zhou, Baoxue

    2013-11-15

    Direct discharging great quantities of organics into water-body not only causes serious environmental pollution but also wastes energy sources. In this paper, a solar responsive dual photoelectrode photocatalytic fuel cell (PFC(2)) based on TiO2/Ti photoanode and Cu2O/Cu photocathode was designed for hazardous organics treatment with simultaneous electricity generation. Under solar irradiation, the interior bias voltage produced for the Fermi level difference between photoelectrodes drives photoelectrons of TiO2/Ti photoanode to combine with photoholes of Cu2O/Cu photocathode through external circuit thus generating electricity. In the meantime, organics are decomposed by photoholes remained at TiO2/Ti photoanode. By using various hazardous organics including azo dyes as model pollutants, the PFC showed high converting performance of organics into electricity. For example, in 0.05 M phenol solution, a short-circuit current density 0.23 mA cm(-2), open-circuit voltage 0.49 V, maximum power output 0.3610(-4)W cm(-2) was achieved. On the other hand, removal rate of chroma reached 67%, 87% and 63% in 8h for methyl orange, methylene blue, Congo red, respectively. PMID:24051045

  19. Study of neutron physics: conversion of the University of Missouri-Rolla reactor to low-enriched fuel

    SciTech Connect

    Straka, M.; Covington, L.

    1987-01-01

    A detailed study of a fuel conversion (using LEU) has been undertaken for the University of Missouri-Rolla reactor. Results achieved with the available code package have been compared with the measured data whenever possible. The neutronic codes LEOPARD and 2DB-UM provided adequate results in most cases examined.

  20. Using Fermentation and Catalysis to Make Fuels and Products: Biochemical Conversion

    SciTech Connect

    2010-09-01

    Information about the Biomass Program's collaborative projects to improve processing routes for biochemical conversion, which entails breaking down biomass to make the carbohydrates available for conversion into sugars.

  1. Synthesis of Mesoporous Single Crystal Co(OH)2 Nanoplate and Its Topotactic Conversion to Dual-Pore Mesoporous Single Crystal Co3O4.

    PubMed

    Jia, Bao-Rui; Qin, Ming-Li; Li, Shu-Mei; Zhang, Zi-Li; Lu, Hui-Feng; Chen, Peng-Qi; Wu, Hao-Yang; Lu, Xin; Zhang, Lin; Qu, Xuan-Hui

    2016-06-22

    A new class of mesoporous single crystalline (MSC) material, Co(OH)2 nanoplates, is synthesized by a soft template method, and it is topotactically converted to dual-pore MSC Co3O4. Most mesoporous materials derived from the soft template method are reported to be amorphous or polycrystallined; however, in our synthesis, Co(OH)2 seeds grow to form single crystals, with amphiphilic block copolymer F127 colloids as the pore producer. The single-crystalline nature of material can be kept during the conversion from Co(OH)2 to Co3O4, and special dual-pore MSC Co3O4 nanoplates can be obtained. As the anode of lithium-ion batteries, such dual-pore MSC Co3O4 nanoplates possess exceedingly high capacity as well as long cyclic performance (730 mAh g(-1) at 1 A g(-1) after the 350th cycle). The superior performance is because of the unique hierarchical mesoporous structure, which could significantly improve Li(+) diffusion kinetics, and the exposed highly active (111) crystal planes are in favor of the conversion reaction in the charge/discharge cycles. PMID:27250515

  2. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels Conversion Pathway: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway "The 2017 Design Case"

    SciTech Connect

    Kevin L. Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J. Bonner; Garold L. Gresham; J. Richard Hess; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2014-01-01

    The U.S. Department of Energy promotes the production of liquid fuels from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass sustainable supply, logistics, conversion, and overall system sustainability. As part of its involvement in this program, Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL quantified and the economics and sustainability of moving biomass from the field or stand to the throat of the conversion process using conventional equipment and processes. All previous work to 2012 was designed to improve the efficiency and decrease costs under conventional supply systems. The 2012 programmatic target was to demonstrate a biomass logistics cost of $55/dry Ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model.

  3. Micropower chemical fuel-to-electric conversion : a "regenerative flip" hydrogen concentration cell promising near carnot efficiency.

    SciTech Connect

    Wally, Karl

    2006-05-01

    Although battery technology is relatively mature, power sources continue to impose serious limitations for small, portable, mobile, or remote applications. A potentially attractive alternative to batteries is chemical fuel-to-electric conversion. Chemical fuels have volumetric energy densities 4 to 10 times those of batteries. However, realizing this advantage requires efficient chemical fuel-to-electric conversion. Direct electrochemical conversion would be the ideal, but, for most fuels, is generally not within the state-of-the-science. Next best, chemical-to-thermal-to-electric conversion can be attractive if efficiencies can be kept high. This small investigative project was an exploration into the feasibility of a novel hybrid (i.e., thermal-electrochemical) micropower converter of high theoretical performance whose demonstration was thought to be within near-term reach. The system is comprised of a hydrogen concentration electrochemical cell with physically identical hydrogen electrodes as anode and cathode, with each electrode connected to physically identical hydride beds each containing the same low-enthalpy-of-formation metal hydride. In operation, electrical power is generated by a hydrogen concentration differential across the electrochemical cell. This differential is established via coordinated heating and passive cooling of the corresponding hydride source and sink. Heating is provided by the exothermic combustion (i.e., either flame combustion or catalytic combustion) of a chemical fuel. Upon hydride source depletion, the role of source and sink are reversed, heating and cooling reversed, electrodes commutatively reversed, cell operation reversed, while power delivery continues unchanged. This 'regenerative flip' of source and sink hydride beds can be cycled continuously until all available heating fuel is consumed. Electricity is efficiently generated electrochemically, but hydrogen is not consumed, rather the hydrogen is regeneratively cycled as

  4. Catalytic Conversion of Carbon-Containing Compounds into Valuable Chemicals and Fuels

    NASA Astrophysics Data System (ADS)

    Cheng, Zhuo

    Conversion of carbon-containing compounds, especially C1 compounds such as carbon dioxide and methane, to valuable chemicals and fuels will hopefully address concerns over decreasing supplies of fossil fuels and mitigate the eects of greenhouse gas emissions on global climate change. Many challenges, however, remain to be addressed before these technologies may be adopted on an industrial scale. Chiefly, catalysts must be developed to activate carbon-containing compounds from their thermodynamically stable ground states, using hydrogen, electrons, or heat as energy sources. We chose as model catalytic systems: 1) Metathesis of ethene and 2-butene; 2) Methane dehydrogenation and carbon dioxide hydrogenation. We developed three computational methodologies to study these processes across a range of length and time scales. First, we investigated how electronic structure affects the properties and reactivity of these catalyst systems; by computing the partial electronic density of states, electronic localization function, and excess spin density, we showed how redox supports, such as ceria, promote electron transfer reactions. We applied this to the studies of methane activation and carbon dioxide activation. Second, we developed a non-equilibrium thermodynamics approach to calculate energies of activation at nite temperatures, based on the Bronsted-Evans-Polanyi principle and the Nudged Elastic Band method. Third, we developed an approach to numerically compute heat capacities and other thermodynamic properties on extended catalytic systems that are comparable in accuracy and precision to methods that have been well-developed for gas-phase molecules. We applied these to the studies of metathesis propagation and carbon dioxide hydrogenation. We gained mechanistic, thermodynamic, and kinetic insight into the elementary steps that comprise larger reaction networks of interest to the broader catalysis community. Ultimately, these theoretical and computational predictions

  5. Conversion of orange peel waste biomass to bioelectricity using a mediator-less microbial fuel cell.

    PubMed

    Miran, Waheed; Nawaz, Mohsin; Jang, Jiseon; Lee, Dae Sung

    2016-03-15

    Microorganisms have the potential to become a game-changer in sustainable energy production in the coming generations. Microbial fuel cells (MFCs) as an alternative renewable technology can capture bioenergy (electricity) from carbon-based sources by utilizing microorganisms as biocatalysts. This study demonstrated that MFC technology can be explored for bioelectricity production from orange peel waste (OPW), an agricultural byproduct and an organic substrate, without any chemical pretreatment or the addition of extra mediators. A maximum voltage generation of 0.59 ± 0.02 V (at 500 Ω) was achieved in a dual chamber MFC during stable voltage generation stages. The maximum power density and current density obtained were 358.8 ± 15.6 mW/m(2) and 847 ± 18.4 mA/m(2), respectively. Key components of OPW, namely pectin and cellulose, were also tested in their pure form, with pectin giving a stable current, while no significant current generation was achieved using cellulose alone as the substrate, thus demonstrating the absence of cellulose-degrading bacteria. Maximum pectinase and polygalacturonase enzyme activities of 18.55 U/g and 9.04 U/g (per gram of substrate), respectively were achieved during orange peel degradation in MFCs. Bacterial identification using 16S rRNA analysis of the initial inoculum fed to the MFC, the biofilm attached to the anode, and the anode suspension, showed significant diversity in community composition. A well-known exoelectrogen, Pseudomonas, was present among the predominant genera in the anode biofilm. PMID:26780146

  6. Fuel nitrogen conversion and release of nitrogen oxides during coal gangue calcination.

    PubMed

    Zhang, Yingyi; Ge, Xinlei; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-05-01

    The pollution emission during the widespread utilization of coal gangue in construction industry has long been neglected. In present study, the NO x release behaviors in a simulation experiment of coal gangue calcination in construction industry were systematically investigated. The corresponding evolution of nitrogen functionalities in coal gangue was also discussed. Results showed that pyrrolic (N-5) and pyridine N-oxide (N-6-O) forms nitrogen were relatively abundant in the raw gangue. During calcination, the N-5 and N-6-O form nitrogen greatly decreased and converted to quaternary nitrogen (N-Q). It was found that NO2 was formed under slowly heating-up condition and at 600 °C under isothermal condition, while only NO was detected with further increase of temperature. From 600 to 1000 °C, the conversion ratio of fuel nitrogen to NO x increased from 8 to 12 %. The char nitrogen was found greatly contribute to NO formation, which may bring difficulty to the abatement of NO x emission during coal gangue calcination. PMID:25501860

  7. Highly active and stable iron Fischer-Tropsch catalyst for synthesis gas conversion to liquid fuels

    SciTech Connect

    Bukur, D.B.; Lang, X.

    1999-09-01

    A precipitated iron Fischer-Tropsch (F-T) catalyst (100 Fe/3 Cu/4 K/16 SiO{sub 2} on mass basis) was tested in a stirred tank slurry reactor under reaction conditions representative of industrial practice using CO-rich synthesis gas (260 C, 1.5--2.2 MPa, H{sub 2}/CO = 2/3). Repeatability of performance and reproducibility of catalyst preparation procedure were successfully demonstrated on a laboratory scale. Catalyst productivity was increased by operating at higher synthesis pressure while maintaining a constant contact time in the reactor and through the use of different catalyst pretreatment procedures. In one of the tests (run SA-2186), the catalyst productivity was 0.86 (g hydrocarbons/g Fe/h) at syngas conversion of 79%, methane selectivity of 3% (weight percent of total hydrocarbons produced), and C{sub 5}+ hydrocarbon selectivity of 83 wt %. This represents a substantial improvement in productivity in comparison to state-of-the-art iron F-T catalysts. This catalyst is ideally suited for production of high-quality diesel fuels and C{sub 2}-c{sub 4} olefins from a coal-derived synthesis gas.

  8. One-pot conversions of lignocellulosic and algal biomass into liquid fuels.

    PubMed

    De, Sudipta; Dutta, Saikat; Saha, Basudeb

    2012-09-01

    The one-pot conversion of lignocellulosic and algal biomass into a liquid fuel, 2,5-dimethylfuran (DMF), has been achieved by using a multicomponent catalytic system comprising [DMA]⁺ [CH₃SO₃]⁻ (DMA=N,N-dimethylacetamide), Ru/C, and formic acid. The synthesis of DMF from all substrates was carried out under mild reaction conditions. The reaction progressed via 5-hydroxyemthylfurfural (HMF) in the first step followed by hydrogenation and hydrogenolysis of HMF with the Ru/C catalyst and formic acid as a hydrogen source. This report discloses the effectiveness of the Ru/C catalyst for the first time for DMF synthesis from inexpensive and readily abundant biomass sources, which gives a maximum yield of 32 % DMF in 1 h. A reaction route involving 5-(formyloxymethyl)furfural (FMF) as an intermediate has been elucidated based on the ¹H and ¹³C NMR spectroscopic data. Another promising biofuel, 5-ethoxymethylfurfural (EMF), was also synthesized with high selectivity from polymeric carbohydrate-rich biomass substrates by using a Brønsted acidic ionic liquid catalyst, that is [DMA]⁺ [CH₃SO₃]⁻, by etherification of HMF in ethanol. PMID:22639414

  9. Catalyst and feedstock effects in the thermochemical conversion of biomass to liquid transportation fuels

    SciTech Connect

    Rejai, B.; Agblevor, F.A.; Evans, R.J.; Wang, D.

    1992-05-01

    The thermochemical conversion of biomass feedstocks to liquid transportation fuels can be accomplished by three processes, namely gasification, high-pressure liquefaction, and pyrolysis. In this study, the pyrolysis option is selected which is followed by the catalytic upgrading of pyrolysis vapors to aromatic and olefinic hydrocarbons (PYROCAT process). The aromatics constitute a high-octane gasoline blend, while the olefins can be utilized as feedstocks for various chemicals. The PYROCAT process has been studied in a laboratory-scale fixed-bed catalytic reactor. Consecutive biomass samples were pyrolyzed rapidly in steam at 550{degree}C and atmospheric pressure, and then the pyrolysis vapors were passed over a zeolite catalyst. The catalytic upgrading products were monitored in real-time using molecular-beam mass-spectrometry (MBMS). The yields of major products were estimated from mass-spectral data. Several zeolite catalysts were screened in the upgrading process and promising catalysts with high yields were identified. Feedstocks studied included: the woody biomass species aspen (Populus tremuloides), basswood (Tilia americana), and willow (Salix alba); the three isolated components of wood lignin, xylan and cellulose; and the herbaceous species bagasse (Saccharum spp. hybrid), wheat straw (Triticum aestivum), and Sericea lespedeza (Lespedeza cuneata). 17 refs.

  10. Regenerative Fuel Cells for Space Power and Energy Conversion (NaBH4/H2O2 Fuel Cell Development)

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas I.; Miley, George H.; Luo, Nie; Burton, Rodney; Mather, Joseph; Hawkins, Glenn; Byrd, Ethan; Gu, Lifeng; Shrestha, Prajakti Joshi

    2006-01-01

    A viewgraph presentation describing hydrogen peroxide and sodium borohydride development is shown. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Fuel Cell Comparisons; 4) MEA Optimization; 5) 500-Watt Stack Testing; 6) System Modeling: Fuel Cell Power Source for Lunar Rovers; and 7) Conclusions

  11. Biochemical Conversion: Using Enzymes, Microbes, and Catalysis to Make Fuels and Chemicals

    SciTech Connect

    2013-07-26

    This fact sheet describes the Bioenergy Technologies Office's biochemical conversion work and processes. BETO conducts collaborative research, development, and demonstration projects to improve several processing routes for the conversion of cellulosic biomass.

  12. Method and system for low-NO.sub.x dual-fuel combustion of liquid and/or gaseous fuels

    DOEpatents

    Gard, Vincent; Chojnacki, Dennis A; Rabovitser, Ioseph K

    2014-12-02

    A method and apparatus for combustion in which a pressurized preheated liquid fuel is atomized and a portion thereof flash vaporized, creating a mixture of fuel vapor and liquid droplets. The mixture is mixed with primary combustion oxidant, producing a fuel/primary oxidant mixture which is then injected into a primary combustion chamber in which the fuel/primary oxidant mixture is partially combusted, producing a secondary gaseous fuel containing hydrogen and carbon oxides. The secondary gaseous fuel is mixed with a secondary combustion oxidant and injected into the second combustion chamber wherein complete combustion of the secondary gaseous fuel is carried out. The resulting second stage flue gas containing very low amounts of NO.sub.x is then vented from the second combustion chamber.

  13. Extended set of activation monitors for NCT beam characterization and spectral conditions of the beam after reactor fuel conversion.

    PubMed

    Marek, Milan; Vins, Miroslav; Lahodova, Zdena; Viererbl, Ladislav; Koleska, Michal

    2014-06-01

    Since 2010 the LVR-15 reactor has been gradually converted from highly enriched fuel (36wt% (235)U) to low enriched fuel with the enrichment of 19.75wt% (235)U. Paper presents influence of the core pattern changes on the neutron characteristics of the epithermal beam. The determination of neutron spectrum free in the beam was done with a set of neutron activation monitors. After the reactor conversion the change in neutron spectrum is not provable as differences are in the range of measurement errors. PMID:24369892

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

    SciTech Connect

    Hanson A. L.; Diamond D.

    2013-10-31

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

  15. Dual-enhanced photothermal conversion properties of reduced graphene oxide-coated gold superparticles for light-triggered acoustic and thermal theranostics

    NASA Astrophysics Data System (ADS)

    Lin, Li-Sen; Yang, Xiangyu; Niu, Gang; Song, Jibin; Yang, Huang-Hao; Chen, Xiaoyuan

    2016-01-01

    A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the plasmonic coupling of the self-assembled gold nanoparticles and the interaction between GSPs and rGO endow rGO-GSPs with enhanced photothermal conversion properties, allowing rGO-GSPs to be used for sensitive photoacoustic detection and efficient photothermal ablation of tumours in vivo. This study provides a facile approach to prepare colloidal superparticles-graphene hybrid nanostructures and will pave the way toward the design and optimization of photothermal nanomaterials with improved properties for theranostic applications.A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the

  16. Ruthenium nanoparticles supported on carbon nanotubes as efficient catalysts for selective conversion of synthesis gas to diesel fuel.

    PubMed

    Kang, Jincan; Zhang, Shuli; Zhang, Qinghong; Wang, Ye

    2009-01-01

    Diesel do nicely: The title system is a highly selective Fischer-Tropsch catalyst for the production of C(10)-C(20) hydrocarbons (diesel fuel). The C(10)-C(20) selectivity strongly depends on the mean size of the Ru nanoparticles. Nanoparticles with a mean size around 7 nm exhibit the highest C(10)-C(20) selectivity (ca. 65%) and a relatively higher turnover frequency for CO conversion. PMID:19248073

  17. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 1: Executive summary. [using coal or coal derived fuels

    NASA Technical Reports Server (NTRS)

    Corman, J. C.

    1976-01-01

    A data base for the comparison of advanced energy conversion systems for utility applications using coal or coal-derived fuels was developed. Estimates of power plant performance (efficiency), capital cost, cost of electricity, natural resource requirements, and environmental intrusion characteristics were made for ten advanced conversion systems. Emphasis was on the energy conversion system in the context of a base loaded utility power plant. All power plant concepts were premised on meeting emission standard requirements. A steam power plant (3500 psig, 1000 F) with a conventional coal-burning furnace-boiler was analyzed as a basis for comparison. Combined cycle gas/steam turbine system results indicated competitive efficiency and a lower cost of electricity compared to the reference steam plant. The Open-Cycle MHD system results indicated the potential for significantly higher efficiency than the reference steam plant but with a higher cost of electricity.

  18. Conversion of Mixed Oxygenates Generated from Synthesis Gas to Fuel Range Hydrocarbon

    SciTech Connect

    Ramasamy, Karthikeyan K.; Gerber, Mark A.; Lilga, Michael A.; Flake, Matthew D.

    2012-08-19

    The growing dependence in the U.S. on foreign crude oil supplies and increased concerns regarding greenhouse gas emission has generated considerable interest in research to develop renewable and environmentally friendly liquid hydrocarbon transportation fuels. One of the strategies for achieving this is to produce intermediate compounds such as alcohols and other simple oxygenates from biomass generated synthesis gas (mixture of carbon monoxide and hydrogen) and further convert them into liquid hydrocarbons. The focus of this research is to investigate the effects of mixed oxygenates intermediate product compositions on the conversion step to produce hydrocarbon liquids. A typical mixed oxygenate stream is expected to contain water (around 50%), alcohols, such as methanol and ethanol (around 35%), and smaller quantities of oxygenates such as acetaldehyde, acetic acid and ethyl acetate. However the ratio and the composition of the mixed oxygenate stream generated from synthesis gas vary significantly depending on the catalyst used and the process conditions. Zeolite catalyzed deoxygenation of methanol accompanied by chain growth is well understood under Methanol-to-Gasoline (MTG) like reaction conditions using an H-ZSM-5 zeolite as the catalyst6-8. Research has also been conducted to a limited extent in the past with higher alcohols, but not with other oxygenates present9-11. Also there has been little experimental investigation into mixtures containing substantial amounts of water. The latter is of particular interest because water separation from the hydrocarbon product would be less energy intensive than first removing it from the oxygenate intermediate stream prior to hydrocarbon synthesis, potentially reducing overall processing costs.

  19. Modifying woody plants for efficient conversion to liquid and gaseous fuels

    SciTech Connect

    Dinus, R.J.; Dimmel, D.R.; Feirer, R.P.; Johnson, M.A.; Malcolm, E.W. )

    1990-07-01

    The Short Rotation Woody Crop Program (SRWCP), Department of Energy, is developing woody plant species as sources of renewable energy. Much progress has been made in identifying useful species, and testing site adaptability, stand densities, coppicing abilities, rotation lengths, and harvesting systems. Conventional plant breeding and intensive cultural practices have been used to increase above-ground biomass yields. Given these and foreseeable accomplishments, program leaders are now shifting attention to prospects for altering biomass physical and chemical characteristics, and to ways for improving the efficiency with which biomass can be converted to gaseous and liquid fuels. This report provides a review and synthesis of literature concerning the quantity and quality of such characteristics and constituents, and opportunities for manipulating them via conventional selection and breeding and/or molecular biology. Species now used by SRWCP are emphasized, with supporting information drawn from others as needed. Little information was found on silver maple (Acer saccharinum), but general comparisons (Isenberg 1981) suggest composition and behavior similar to those of the other species. Where possible, conclusions concerning means for and feasibility of manipulation are given, along with expected impacts on conversion efficiency. Information is also provided on relationships to other traits, genotype X environment interactions, and potential trade-offs or limitations. Biomass productivity per se is not addressed, except in terms of effects that may by caused by changes in constituent quality and/or quantity. Such effects are noted to the extent they are known or can be estimated. Likely impacts of changes, however effected, on suitability or other uses, e.g., pulp and paper manufacture, are notes. 311 refs., 4 figs., 9 tabs.

  20. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid-and Carbohydrate-Derived Fuel Products

    SciTech Connect

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E. C. D.; Laurens, L. M. L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-11

    The U.S. Department of Energy (DOE) promotes the production of a range of liquid fuels and fuel blendstocks from biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass production, conversion, and sustainability. As part of its involvement in this program, the National Renewable Energy Laboratory (NREL) investigates the conceptual production economics of these fuels. This includes fuel pathways from lignocellulosic (terrestrial) biomass, as well as from algal (aquatic) biomass systems.

  1. Biofuels and biomass-to-liquid fuels in the biorefinery: catalytic conversion of lignocellulosic biomass using porous materials.

    PubMed

    Stöcker, Michael

    2008-01-01

    At a time when the focus is on global warming, CO(2) emission, secure energy supply, and less consumption of fossil-based fuels, the use of renewable energy resources is essential. Various biomass resources are discussed that can deliver fuels, chemicals, and energy products. The focus is on the catalytic conversion of biomass from wood. The challenges involved in the processing of lignocellulose-rich materials will be highlighted, along with the application of porous materials as catalysts for the biomass-to-liquids (BTL) fuels in biorefineries. The mechanistic understanding of the complex reactions that take place, the development of catalysts and processes, and the product spectrum that is envisaged will be discussed, along with a sustainable concept for biorefineries based on lignocellulose. Finally, the current situation with respect to upgrading of the process technology (pilot and commercial units) will be addressed. PMID:18937235

  2. EVALUATION OF CORE PHYSICS ANALYSIS METHODS FOR CONVERSION OF THE INL ADVANCED TEST REACTOR TO LOW-ENRICHMENT FUEL

    SciTech Connect

    Mark DeHart; Gray S. Chang

    2012-04-01

    Computational neutronics studies to support the possible conversion of the ATR to LEU are underway. Simultaneously, INL is engaged in a physics methods upgrade project to put into place modern computational neutronics tools for future support of ATR fuel cycle and experiment analysis. A number of experimental measurements have been performed in the ATRC in support of the methods upgrade project, and are being used to validate the new core physics methods. The current computational neutronics work is focused on performance of scoping calculations for the ATR core loaded with a candidate LEU fuel design. This will serve as independent confirmation of analyses that have been performed previously, and will evaluate some of the new computational methods for analysis of a candidate LEU fuel for ATR.

  3. Dual-enhanced photothermal conversion properties of reduced graphene oxide-coated gold superparticles for light-triggered acoustic and thermal theranostics.

    PubMed

    Lin, Li-Sen; Yang, Xiangyu; Niu, Gang; Song, Jibin; Yang, Huang-Hao; Chen, Xiaoyuan

    2016-01-28

    A rational design of highly efficient photothermal agents that possess excellent light-to-heat conversion properties is a fascinating topic in nanotheranostics. Herein, we present a facile route to fabricate size-tunable reduced graphene oxide (rGO)-coated gold superparticles (rGO-GSPs) and demonstrate their dual-enhanced photothermal conversion properties for photoacoustic imaging and photothermal therapy. For the first time, graphene oxide (GO) was directly used as an emulsifying agent for the preparation of gold superparticles (GSPs) with near-infrared absorption by the emulsion method. Moreover, GO spontaneously deposited on the surface of GSPs could also act as the precursor of the rGO shell. Importantly, both the plasmonic coupling of the self-assembled gold nanoparticles and the interaction between GSPs and rGO endow rGO-GSPs with enhanced photothermal conversion properties, allowing rGO-GSPs to be used for sensitive photoacoustic detection and efficient photothermal ablation of tumours in vivo. This study provides a facile approach to prepare colloidal superparticles-graphene hybrid nanostructures and will pave the way toward the design and optimization of photothermal nanomaterials with improved properties for theranostic applications. PMID:26726809

  4. Magnesium carbide synthesis from methane and magnesium oxide - a potential methodology for natural gas conversion to premium fuels and chemicals

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.

    1995-12-31

    Diversification of the raw materials base for manufacturing premium fuels and chemicals offers U.S. and international consumers economic and strategic benefits. Extensive reserves of natural gas in the world provide a valuable source of clean gaseous fuel and chemical feedstock. Assuming the availability of suitable conversion processes, natural gas offers the prospect of improving flexibility in liquid fuels and chemicals manufacture, and thus, the opportunity to complement, supplement, or displace petroleum-based production as economic and strategic considerations require. The composition of natural gas varies from reservoir to reservoir but the principal hydrocarbon constituent is always methane (CH{sub 4}). With its high hydrogen-to-carbon ratio, methane has the potential to produce hydrogen or hydrogen-rich products. However, methane is a very chemically stable molecule and, thus, is not readily transformed to other molecules or easily reformed to its elements (H{sub 2} and carbon). In many cases, further research is needed to augment selectivity to desired product(s), increase single-pass conversions, or improve economics (e.g. there have been estimates of $50/bbl or more for liquid products) before the full potential of these methodologies can be realized on a commercial scale. With the trade-off between gas conversion and product selectivity, a major challenge common to many of these technologies is to simultaneously achieve high methane single-pass conversions and high selectivity to desired products. Based on the results of the scoping runs, there appears to be strong indications that a breakthrough has finally been achieved in that synthesis of magnesium carbides from MgO and methane in the arc discharge reactor has been demonstrated.

  5. One-step catalytic conversion of biomass-derived carbohydrates to liquid fuels

    DOEpatents

    Sen, Ayusman; Yang, Weiran

    2014-03-18

    The invention relates to a method for manufacture of hydrocarbon fuels and oxygenated hydrocarbon fuels such as alkyl substituted tetrahydrofurans such as 2,5-dimethyltetrahydrofuran, 2-methyltetrahydrofuran, 5-methylfurfural and mixtures thereof. The method generally entails forming a mixture of reactants that includes carbonaceous material, water, a metal catalyst and an acid reacting that mixture in the presence of hydrogen. The reaction is performed at a temperature and for a time sufficient to produce a furan type hydrocarbon fuel. The process may be adapted to provide continuous manufacture of hydrocarbon fuels such as a furan type fuel.

  6. Biochemical conversions of lignocellulosic biomass for sustainable fuel-ethanol production in the upper Midwest

    NASA Astrophysics Data System (ADS)

    Brodeur-Campbell, Michael J.

    Biofuels are an increasingly important component of worldwide energy supply. This research aims to understand the pathways and impacts of biofuels production, and to improve these processes to make them more efficient. In Chapter 2, a life cycle assessment (LCA) is presented for cellulosic ethanol production from five potential feedstocks of regional importance to the upper Midwest — hybrid poplar, hybrid willow, switchgrass, diverse prairie grasses, and logging residues — according to the requirements of Renewable Fuel Standard (RFS). Direct land use change emissions are included for the conversion of abandoned agricultural land to feedstock production, and computer models of the conversion process are used in order to determine the effect of varying biomass composition on overall life cycle impacts. All scenarios analyzed here result in greater than 60% reduction in greenhouse gas emissions relative to petroleum gasoline. Land use change effects were found to contribute significantly to the overall emissions for the first 20 years after plantation establishment. Chapter 3 is an investigation of the effects of biomass mixtures on overall sugar recovery from the combined processes of dilute acid pretreatment and enzymatic hydrolysis. Biomass mixtures studied were aspen, a hardwood species well suited to biochemical processing; balsam, a high-lignin softwood species, and switchgrass, an herbaceous energy crop with high ash content. A matrix of three different dilute acid pretreatment severities and three different enzyme loading levels was used to characterize interactions between pretreatment and enzymatic hydrolysis. Maximum glucose yield for any species was 70% of theoretical for switchgrass, and maximum xylose yield was 99.7% of theoretical for aspen. Supplemental β-glucosidase increased glucose yield from enzymatic hydrolysis by an average of 15%, and total sugar recoveries for mixtures could be predicted to within 4% by linear interpolation of the pure

  7. In vitro observation of the stage conversion of transgenic Toxoplasma gondii RH strain expressing dual fluorescent proteins.

    PubMed

    Song, Qijun; Sun, Ximeng; Ji, Yongsheng; Yan, Xinlei; Zou, Jun; Zhao, Shiyun; Suo, Xun; Zhu, Xingquan; Liu, Xianyong

    2016-09-01

    Toxoplasma gondii converts from tachyzoites to bradyzoites after acute infection and thus survives the attack of the host immune responses. In this study, we observed the conversion of tachyzoites to bradyzoites in cell cultures using a transgenic T. gondii RH strain. The transgenic parasites continuously express yellow fluorescent protein (YFP) but only express red fluorescent protein (RFP) at the bradyzoite stage. Red fluorescent bradyzoite-containing cysts were found in transgenic parasite infected cells cultured with atmospheric CO2 supply, indicating the successful induction of the stage conversion. In cell culture with alkalic medium (pH 8.1) and atmospheric CO2 supply, only part of the YFP-expressing parasites in a cyst express RFP marker, suggesting the asynchronous development of T. gondii in vitro. This study provides a possibility for further studies of the gene expression profile during stage conversion and the genes involved. PMID:27447207

  8. Investigation of the Performance of D2O-Cooled High-Conversion Reactors for Fuel Cycle Calculations

    SciTech Connect

    Hikaru Hiruta; Gilles Youinou

    2013-09-01

    This report presents FY13 activities for the analysis of D2O cooled tight-pitch High-Conversion PWRs (HCPWRs) with U-Pu and Th-U fueled cores aiming at break-even or near breeder conditions while retaining the negative void reactivity. The analyses are carried out from several aspects which could not be covered in FY12 activities. SCALE 6.1 code system is utilized, and a series of simple 3D fuel pin-cell models are developed in order to perform Monte Carlo based criticality and burnup calculations. The performance of U-Pu fueled cores with axial and internal blankets is analyzed in terms of their impact on the relative fissile Pu mass balance, initial Pu enrichment, and void coefficient. In FY12, Pu conversion performances of D2O-cooled HCPWRs fueled with MOX were evaluated with small sized axial/internal DU blankets (approximately 4cm of axial length) in order to ensure the negative void reactivity, which evidently limits the conversion performance of HCPWRs. In this fiscal year report, the axial sizes of DU blankets are extended up to 30 cm in order to evaluate the amount of DU necessary to reach break-even and/or breeding conditions. Several attempts are made in order to attain the milestone of the HCPWR designs (i.e., break-even condition and negative void reactivity) by modeling of HCPWRs under different conditions such as boiling of D2O coolant, MOX with different 235U enrichment, and different target burnups. A similar set of analyses are performed for Th-U fueled cores. Several promising characteristics of 233U over other fissile like 239Pu and 235U, most notably its higher fission neutrons per absorption in thermal and epithermal ranges combined with lower ___ in the fast range than 239Pu allows Th-U cores to be taller than MOX ones. Such an advantage results in 4% higher relative fissile mass balance than that of U-Pu fueled cores while retaining the negative void reactivity until the target burnup of 51 GWd/t. Several other distinctions between U-Pu and

  9. Converting oil shale to liquid fuels: energy inputs and greenhouse gas emissions of the Shell in situ conversion process.

    PubMed

    Brandt, Adam R

    2008-10-01

    Oil shale is a sedimentary rock that contains kerogen, a fossil organic material. Kerogen can be heated to produce oil and gas (retorted). This has traditionally been a CO2-intensive process. In this paper, the Shell in situ conversion process (ICP), which is a novel method of retorting oil shale in place, is analyzed. The ICP utilizes electricity to heat the underground shale over a period of 2 years. Hydrocarbons are produced using conventional oil production techniques, leaving shale oil coke within the formation. The energy inputs and outputs from the ICP, as applied to oil shales of the Green River formation, are modeled. Using these energy inputs, the greenhouse gas (GHG) emissions from the ICP are calculated and are compared to emissions from conventional petroleum. Energy outputs (as refined liquid fuel) are 1.2-1.6 times greater than the total primary energy inputs to the process. In the absence of capturing CO2 generated from electricity produced to fuel the process, well-to-pump GHG emissions are in the range of 30.6-37.1 grams of carbon equivalent per megajoule of liquid fuel produced. These full-fuel-cycle emissions are 21%-47% larger than those from conventionally produced petroleum-based fuels. PMID:18939591

  10. Prospects for the development of independent power supply systems on the basis of solid fuel thermal conversion technology

    NASA Astrophysics Data System (ADS)

    Sultanguzin, I. A.; Fedyukhin, A. V.; Kurzanov, S. Yu.; Gyulmaliev, A. M.; Stepanova, T. A.; Tumanovsky, V. A.; Titov, D. P.

    2015-05-01

    Theoretical principles of using solid fuel for organizing independent power supply to small settlements and industrial consumers are considered. Thermogravimetric experiments have been carried out for a few types of wood with determining the universal kinetic parameters characterizing the pyrolysis process. A procedure for describing the solid fuel thermal decomposition process has been proposed that is based on writing the equations of four independent parallel thermal decomposition reactions for each component of the initial raw material. A software package has been developed using which the calorific value, composition, and volume of the gas produced in the thermal conversion of solid fuels can be estimated. The impact of operating parameters on the synthesis gas composition has been evaluated. It has been found that increasing the thermal conversion temperature results in a higher calorific value of the obtained gas per unit weight of the feedstock. A qualitative and quantitative comparison of the computational model and the results obtained during experimental studies on the existing gasifier has been carried out. It is shown that the parameters of gas obtained on the test bench are consistent with the calculated ones in both the amount of gas and its chemical energy. The combined-cycle power plant flow chart involving the biomass gasification process has been numerically simulated in the Aspen Plus computer program, and calculations aimed at determining the optimal operating parameters of different thermal process circuit components and of the entire CCP system were performed.

  11. Direct conversion of surplus fissile materials, spent nuclear fuel, and other materials to high-level-waste glass

    SciTech Connect

    Forsberg, C.W.; Elam, K.R.

    1995-01-31

    With the end of the cold war the United States, Russia, and other countries have excess plutonium and other materials from the reductions in inventories of nuclear weapons. The United States Academy of Sciences (NAS) has recommended that these surplus fissile materials (SFMs) be processed so they are no more accessible than plutonium in spent nuclear fuel (SNF). This spent fuel standard, if adopted worldwide, would prevent rapid recovery of SFMs for the manufacture of nuclear weapons. The NAS recommended investigation of three sets of options for disposition of SFMs while meeting the spent fuel standard: (1) incorporate SFMs with highly radioactive materials and dispose of as waste, (2) partly burn the SFMs in reactors with conversion of the SFMs to SNF for disposal, and (3) dispose of the SFMs in deep boreholes. The US Government is investigating these options for SFM disposition. A new method for the disposition of SFMs is described herein: the simultaneous conversion of SFMs, SNF, and other highly radioactive materials into high-level-waste (HLW) glass. The SFMs include plutonium, neptinium, americium, and {sup 233}U. The primary SFM is plutonium. The preferred SNF is degraded SNF, which may require processing before it can be accepted by a geological repository for disposal.

  12. Effect of Light Intensity on the Degree of Conversion of Dual-cured Resin Cement at Different Depths with the use of Translucent Fiber Posts

    PubMed Central

    Bahari, Mahmoud; Savadi Oskoee, Siavash; Kimyai, Soodabeh; Mohammadi, Narmin; Saati Khosroshahi, Elmira

    2014-01-01

    Objectives: To evaluate the effect of different light intensities on the degree of conversion (DC) of dual-cured resin cement at different depths of translucent fiber posts. Materials and Methods: Thirty translucent fiber posts were randomly assigned into three (n=10) groups. They were cemented in the simulated canal spaces using Duo-Link dual-cured resin cement. The cement was light-cured under 600, 800 and 1100 mW/cm2 light intensities for 40 seconds. DC of the resin cement was calculated at cervical, middle and apical thirds using the spectra of FT-Raman spectrometer. Data were analyzed by repeated measurement ANOVA and Tukey’s post hoc tests (α=0.05). Results: In all the groups, the least DC was obtained at the apical region. There were no significant differences in the DC with different light intensities between the cervical and middle regions (p>0.05). However, in the apical region, the DC in both 800 and 1100 mw/cm2 was similar (p>0.05), but greater with 600 mW/cm2 light intensity (p=0.02 and p<0.001, respectively). Conclusion: In comparison with the light intensity of 600 mW/cm2, the light intensity of 800 mW/cm2 significantly increased the DC of dual-cured resin cement in the apical region. However, DC was not significantly different between 800 and 1100 mw/cm2 light intensities. If the resin cement, especially in the apical areas is not sufficiently cured, microleakage might increase and post retention might be jeopardized. In comparison with 600 mW/cm2 light intensity, 800 mW/cm2 significantly increases DC at the apical third that might be clinically beneficial. PMID:25628659

  13. Conversion of arterial input functions for dual pharmacokinetic modeling using Gd-DTPA/MRI and 18F-FDG/PET.

    PubMed

    Poulin, Eric; Lebel, Réjean; Croteau, Etienne; Blanchette, Marie; Tremblay, Luc; Lecomte, Roger; Bentourkia, M'hamed; Lepage, Martin

    2013-03-01

    Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (ν(e)), and the blood volume fraction (ν(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models. PMID:22570280

  14. Biotechnological research and development for biomass conversion to chemicals and fuels

    NASA Astrophysics Data System (ADS)

    Villet, R.

    1980-08-01

    Revitalization of the older fermentation industry and development of biotechnology largely based on lignocellulose are proposed. Specific research projects are outlined in these two areas and also for the following: microbial formation of hydrocarbons; methane from anaerobic digestion; lignin; methanol. For cellulose conversion to ethanol the relative merits using added cellulases or, alternatively, direct fermentation with anaerobic thermophiles, are discussed. In selecting suitable feedstocks for biotechnological processes there is a need to use a production extraction conversion system as a basis for evaluation.

  15. Genetic parameters of growth, feed intake, feed conversion and carcass composition of dual-purpose bulls in performance testing.

    PubMed

    Jensen, J; Mao, I L; Andersen, B B; Madsen, P

    1991-03-01

    Genetic parameters for growth, total energy intake, feed conversion ratio, average daily energy intake and carcass composition were estimated in an experiment with 650 bull calves from 31 half-sib groups of Holstein Friesian or Brown Swiss sires. All traits analyzed had an amount of additive genetic variance that allows for considerable response to selection. No interaction between genotype (sire group) and proportion of roughage in the diet was found. Daily gain was strongly correlated negatively with feed conversion ratio but positively correlated with daily energy intake. Results indicate that genetic selection for either daily gain or average daily energy intake would decrease carcass fatness at a constant slaughter weight. However, the environmental correlation between daily energy intake and carcass fatness was positive. PMID:2061263

  16. Engineering an iridium-containing metal-organic molecular capsule for induced-fit geometrical conversion and dual catalysis.

    PubMed

    Li, Xuezhao; Wu, Jinguo; Chen, Liyong; Zhong, Xiaoming; He, Cheng; Zhang, Rong; Duan, Chunying

    2016-08-11

    By introducing photoactive fac-tris(2-phenylpyridine)iridium moieties as a ligand backbone to constrain the coordination geometry of cobalt ions, a multifunctional Ir2Co3-type capsule was achieved and showed induced-fit capsule-capsule conversion by cooperative binding one carbonate anion with the equatorial Co(ii) centers. The capsule combined photocatalysis and transition metal activation synergistically and exhibited efficient catalytic ability on visible light-activated α-trichloromethylation. PMID:27320443

  17. Initial measurements of BN-350 spent fuel in dry storage casks using the dual slab verification detonator

    SciTech Connect

    Santi, Peter Angelo; Browne, Michael C; Freeman, Corey R; Parker, Robert F; Williams, Richard B

    2010-01-01

    The Dual Slab Verification Detector (DSVD) has been developed, built, and characterized by Los Alamos National Laboratory in cooperation with the International Atomic Energy Agency (IAEA) as part of the dry storage safeguards system for the spent fuel from the BN-350 fast reactor. The detector consists of two rows of 3He tubes embedded in a slab of polyethylene which has been designed to be placed on the outer surface of the dry storage cask. By performing DSVD measurements at several different locations around the outer surface of the DUC, a signature 'fingerprint' can be established for each DUC based on the neutron flux emanating from inside the dry storage cask. The neutron fingerprint for each individual DUC will be dependent upon the spatial distribution of nuclear material within the cask, thus making it sensitive to the removal of a certain amount of material from the cask. An initial set of DSVD measurements have been performed on the first set of dry storage casks that have been loaded with canisters of spent fuel and moved onto the dry storage pad to both establish an initial fingerprint for these casks as well as to quantify systematic uncertainties associated with these measurements. The results from these measurements will be presented and compared with the expected results that were determined based on MCNPX simulations of the dry storage facility. The ability to safeguard spent nuclear fuel is strongly dependent on the technical capabilities of establishing and maintaining continuity of knowledge (COK) of the spent fuel as it is released from the reactor core and either reprocessed or packaged and stored at a storage facility. While the maintenance of COK is often done using continuous containment and surveillance (C/S) on the spent fuel, it is important that the measurement capabilities exist to re-establish the COK in the event of a significant gap in the continuous CIS by performing measurements that independently confirm the presence and content

  18. High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

    PubMed

    Liu, Wei; Mu, Wei; Deng, Yulin

    2014-12-01

    Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. PMID:25283435

  19. Low enrichment fuel conversion for Iowa State University. Progress report, August 1, 1991--July 31, 1992

    SciTech Connect

    Rohach, A.F.

    1992-08-01

    This report discusses the UTR-10 reactor at Iowa State University which went critical on low enriched uranium (LEU) fuel on August 14, 1991. However, subsequent to the criticality experiments the fuel plates started to discolor. In addition, roll pins used to lift the fuel assemblies were discovered to be cracked. It was determined that these problems were due to chemical agents in the primary coolant water. The roll pins were replaced by solid stainless steel pins. The primary coolant was replaced and the reactor is currently in operation. Surveillance specimens will be used to monitor any possible future discoloration. The high enriched fuel (HEU) is being prepared for eventual shipment to a high enriched fuel receiving facility.

  20. Recovery Act. Demonstration of a Pilot Integrated Biorefinery for the Efficient, Direct Conversion of Biomass to Diesel Fuel

    SciTech Connect

    Schuetzle, Dennis; Tamblyn, Greg; Caldwell, Matt; Hanbury, Orion; Schuetzle, Robert; Rodriguez, Ramer; Johnson, Alex; Deichert, Fred; Jorgensen, Roger; Struble, Doug

    2015-05-12

    The Renewable Energy Institute International, in collaboration with Greyrock Energy and Red Lion Bio-Energy (RLB) has successfully demonstrated operation of a 25 ton per day (tpd) nameplate capacity, pilot, pre-commercial-scale integrated biorefinery (IBR) plant for the direct production of premium, “drop-in”, synthetic fuels from agriculture and forest waste feedstocks using next-generation thermochemical and catalytic conversion technologies. The IBR plant was built and tested at the Energy Center, which is located in the University of Toledo Medical Campus in Toledo, Ohio.

  1. Feasibility analyses for HEU to LEU fuel conversion of the LAUE Langivin Institute (ILL) High Flux Reactor (RHF).

    SciTech Connect

    Stevens, J.; Tentner. A.; Bergeron, A.; Nuclear Engineering Division

    2010-08-19

    The High Flux Reactor (RHF) of the Laue Langevin Institute (ILL) based in Grenoble, France is a research reactor designed primarily for neutron beam experiments for fundamental science. It delivers one of the most intense neutron fluxes worldwide, with an unperturbed thermal neutron flux of 1.5 x 10{sup 15} n/cm{sup 2}/s in its reflector. The reactor has been conceived to operate at a nuclear power of 57 MW but currently operates at 52 MW. The reactor currently uses a Highly Enriched Uranium (HEU) fuel. In the framework of its non-proliferation policies, the international community presently aims to minimize the amount of nuclear material available that could be used for nuclear weapons. In this geopolitical context, most worldwide research and test reactors have already started a program of conversion to the use of Low Enriched Uranium (LEU) fuel. A new type of LEU fuel based on a mixture of uranium and molybdenum (UMo) is expected to allow the conversion of compact high performance reactors like the RHF. This report presents the results of reactor design, performance and steady state safety analyses for conversion of the RHF from the use of HEU fuel to the use of UMo LEU fuel. The objective of this work was to show that is feasible, under a set of manufacturing assumptions, to design a new RHF fuel element that could safely replace the HEU element currently used. The new proposed design has been developed to maximize performance, minimize changes and preserve strong safety margins. Neutronics and thermal-hydraulics models of the RHF have been developed and qualified by benchmark against experiments and/or against other codes and models. The models developed were then used to evaluate the RHF performance if LEU UMo were to replace the current HEU fuel 'meat' without any geometric change to the fuel plates. Results of these direct replacement analyses have shown a significant degradation of the RHF performance, in terms of both neutron flux and cycle length

  2. Concurrent Phosphorus Recovery and Energy Generation in Mediator-Less Dual Chamber Microbial Fuel Cells: Mechanisms and Influencing Factors

    PubMed Central

    Almatouq, Abdullah; Babatunde, Akintunde O.

    2016-01-01

    This study investigated the mechanism and key factors influencing concurrent phosphorus (P) recovery and energy generation in microbial fuel cells (MFC) during wastewater treatment. Using a mediator-less dual chamber microbial fuel cell operated for 120 days; P was shown to precipitate as struvite when ammonium and magnesium chloride solutions were added to the cathode chamber. Monitoring data for chemical oxygen demand (COD), pH, oxidation reduction potential (ORP) and aeration flow rate showed that a maximum 38% P recovery was achieved; and this corresponds to 1.5 g/L, pH > 8, −550 ± 10 mV and 50 mL/min respectively, for COD, pHcathode, ORP and cathode aeration flow rate. More importantly, COD and aeration flow rate were shown to be the key influencing factors for the P recovery and energy generation. Results further show that the maximum P recovery corresponds to 72 mW/m2 power density. However, the energy generated at maximum P recovery was not the optimum; this shows that whilst P recovery and energy generation can be concurrently achieved in a microbial fuel cell, neither can be at the optimal value. PMID:27043584

  3. Concurrent Phosphorus Recovery and Energy Generation in Mediator-Less Dual Chamber Microbial Fuel Cells: Mechanisms and Influencing Factors.

    PubMed

    Almatouq, Abdullah; Babatunde, Akintunde O

    2016-04-01

    This study investigated the mechanism and key factors influencing concurrent phosphorus (P) recovery and energy generation in microbial fuel cells (MFC) during wastewater treatment. Using a mediator-less dual chamber microbial fuel cell operated for 120 days; P was shown to precipitate as struvite when ammonium and magnesium chloride solutions were added to the cathode chamber. Monitoring data for chemical oxygen demand (COD), pH, oxidation reduction potential (ORP) and aeration flow rate showed that a maximum 38% P recovery was achieved; and this corresponds to 1.5 g/L, pH > 8, -550 ± 10 mV and 50 mL/min respectively, for COD, pH(cathode), ORP and cathode aeration flow rate. More importantly, COD and aeration flow rate were shown to be the key influencing factors for the P recovery and energy generation. Results further show that the maximum P recovery corresponds to 72 mW/m² power density. However, the energy generated at maximum P recovery was not the optimum; this shows that whilst P recovery and energy generation can be concurrently achieved in a microbial fuel cell, neither can be at the optimal value. PMID:27043584

  4. A novel dual-screw coal feeder for production of low sulfur fuel

    SciTech Connect

    Lin, L.; Khang, S.J.; Keener, T.C.

    1993-06-15

    In this project, the following tasks have been performed: (1) Setting up the Dual-Screw feeder reactor. (2) Determination of the pyrolysis product and the sulfur distribution in char, tar and gas based on experimental data. (3) Study of the devolatilization and the desulfurization kinetics and obtaining the basic kinetic parameters. (4) Study of the sulfur removal efficiency of lime pellets fed into the outer tube of the dual-screw feeder reactor. (5) Study of the effect of the coal particle size on pyrolysis and desulfurization. (6) Study of the coal pyrolysis using a TGA (Thermal Gravimetric Analyzer). (7) Study of the coal desulfurization using a tube oven. (8) Setting up a combustor. (9) Study of the combustion characteristics of the pyrolysis products from the dual-screw feeder reactor. (10) Process simulation of the dual-screw feeder reactor. The experimental results of devolatilization and desulfurization of an Ohio {number_sign}8 coal demonstrate that an increasing the temperature in mild coal pyrolysis leads to the increase of both the devolatilization yield and the desulfurization yield. Under the experimental conditions, mainly the organic sulfur releases in the form of H{sub 2}S. Both the devolatilization and the desulfurization processes can be described by using the first-order-reaction model which gives the activation energy values for pyrolysis and desulfurization of 170,021 kJ/mol and 78,783 kJ/mol, indicating the sulfur is easier to release than volatiles. The outer screw region of CaO pellets also demonstrated almost a complete removal of hydrogen sulfide from volatiles. At a temperature of 475{degree}C and a residence time of 6 minutes, 73.1% of the organic sulfur was removed in the screw feeder reactor. The investigation of the combustion characteristics of the pyrolysis products showed a negligible reduction of the total heating value of the char and volatile products.

  5. Status and future opportunities for conversion of synthesis gas to liquid energy fuels: Final report

    SciTech Connect

    Mills, G

    1993-05-01

    The manufacture of liquid energy fuels from syngas (a mixture of H{sub 2} and CO, usually containing CO{sub 2}) is of growing importance and enormous potential because: (1) Abundant US supplies of coal, gas, and biomass can be used to provide the needed syngas. (2) The liquid fuels produced, oxygenates or hydrocarbons, can help lessen environmental pollution. Indeed, oxygenates are required to a significant extent by the Clean Air Act Amendments (CAAA) of 1990. (3) Such liquid synfuels make possible high engine efficiencies because they have high octane or cetane ratings. (4) There is new, significantly improved technology for converting syngas to liquid fuels and promising opportunities for further improvements. This is the subject of this report. The purpose of this report is to provide an account and evaluative assessment of advances in the technology for producing liquid energy fuels from syngas and to suggest opportunities for future research deemed promising for practical processes. Much of the improved technology for selective synthesis of desired fuels from syngas has resulted from advances in catalytic chemistry. However, novel process engineering has been particularly important recently, utilizing known catalysts in new configurations to create new catalytic processes. This report is an update of the 1988 study Catalysts for Fuels from Syngas: New Directions for Research (Mills 1988), which is included as Appendix A. Technology for manufacture of syngas is not part of this study. The manufacture of liquid synfuels is capital intensive. Thus, in evaluating advances in fuels technology, focus is on the potential for improved economics, particularly on lowering plant investment costs. A second important criteria is the potential for environmental benefits. The discussion is concerned with two types of hydrocarbon fuels and three types of oxygenate fuels that can be synthesized from syngas. Seven alternative reaction pathways are involved.

  6. Neutronic optimization in high conversion Th-{sup 233}U fuel assembly with simulated annealing

    SciTech Connect

    Kotlyar, D.; Shwageraus, E.

    2012-07-01

    This paper reports on fuel design optimization of a PWR operating in a self sustainable Th-{sup 233}U fuel cycle. Monte Carlo simulated annealing method was used in order to identify the fuel assembly configuration with the most attractive breeding performance. In previous studies, it was shown that breeding may be achieved by employing heterogeneous Seed-Blanket fuel geometry. The arrangement of seed and blanket pins within the assemblies may be determined by varying the designed parameters based on basic reactor physics phenomena which affect breeding. However, the amount of free parameters may still prove to be prohibitively large in order to systematically explore the design space for optimal solution. Therefore, the Monte Carlo annealing algorithm for neutronic optimization is applied in order to identify the most favorable design. The objective of simulated annealing optimization is to find a set of design parameters, which maximizes some given performance function (such as relative period of net breeding) under specified constraints (such as fuel cycle length). The first objective of the study was to demonstrate that the simulated annealing optimization algorithm will lead to the same fuel pins arrangement as was obtained in the previous studies which used only basic physics phenomena as guidance for optimization. In the second part of this work, the simulated annealing method was used to optimize fuel pins arrangement in much larger fuel assembly, where the basic physics intuition does not yield clearly optimal configuration. The simulated annealing method was found to be very efficient in selecting the optimal design in both cases. In the future, this method will be used for optimization of fuel assembly design with larger number of free parameters in order to determine the most favorable trade-off between the breeding performance and core average power density. (authors)

  7. Status and future opportunities for conversion of synthesis gas to liquid energy fuels: Final report

    SciTech Connect

    Mills, G. . Center for Catalytic Science and Technology)

    1993-05-01

    The manufacture of liquid energy fuels from syngas (a mixture of H[sub 2] and CO, usually containing CO[sub 2]) is of growing importance and enormous potential because: (1) Abundant US supplies of coal, gas, and biomass can be used to provide the needed syngas. (2) The liquid fuels produced, oxygenates or hydrocarbons, can help lessen environmental pollution. Indeed, oxygenates are required to a significant extent by the Clean Air Act Amendments (CAAA) of 1990. (3) Such liquid synfuels make possible high engine efficiencies because they have high octane or cetane ratings. (4) There is new, significantly improved technology for converting syngas to liquid fuels and promising opportunities for further improvements. This is the subject of this report. The purpose of this report is to provide an account and evaluative assessment of advances in the technology for producing liquid energy fuels from syngas and to suggest opportunities for future research deemed promising for practical processes. Much of the improved technology for selective synthesis of desired fuels from syngas has resulted from advances in catalytic chemistry. However, novel process engineering has been particularly important recently, utilizing known catalysts in new configurations to create new catalytic processes. This report is an update of the 1988 study Catalysts for Fuels from Syngas: New Directions for Research (Mills 1988), which is included as Appendix A. Technology for manufacture of syngas is not part of this study. The manufacture of liquid synfuels is capital intensive. Thus, in evaluating advances in fuels technology, focus is on the potential for improved economics, particularly on lowering plant investment costs. A second important criteria is the potential for environmental benefits. The discussion is concerned with two types of hydrocarbon fuels and three types of oxygenate fuels that can be synthesized from syngas. Seven alternative reaction pathways are involved.

  8. A new fabrication route for SFR fuel using (U, Pu)O2 powder obtained by oxalic co-conversion

    NASA Astrophysics Data System (ADS)

    Vaudez, Stéphane; Belin, Renaud C.; Aufore, Laurence; Sornay, Philippe; Grandjean, Stéphane

    2013-11-01

    The standard powder metallurgy preparation of SFR (Sodium Fast Reactor) oxide fuel involves UO2 and PuO2 co-milling. An alternative route, using a solid-solution of mixed oxide obtained by oxalic co-conversion as the starting material, is presented. It was used to manufacture nuclear fuels for the "COPIX" irradiation conducted in the Phenix SFR. Two processes using co-converted powders were tested to elaborate fuel pellets: (1) the Direct Process that consists in pressing and sintering the mixed oxide with the final Pu content and (2) the Dilution Process, which involves the dilution of a high Pu content mixed oxide with UO2. After studying the structural and microstructural evolution with temperature of these innovative raw materials, the elaboration parameters were adjusted to obtain final pellets in accordance with the Phenix fuel specifications. This study demonstrates the feasibility of such new fabrication route at laboratory scale and, from a more fundamental prospect, allows a better understanding of the underlying phenomena involved during sintering.

  9. Dual-Fuel Combustion Turbine Provides Reliable Power to U.S. Navy Submarine Base New London in Groton, Connecticut

    SciTech Connect

    Halverson, Mark A. )

    2002-01-01

    In keeping with a long-standing tradition of running Base utilities as a business, the U.S. Navy Submarine Base New London installed a dual-fuel combustion turbine with a heat recovery boiler. The 5-megawatt (MW) gas- and oil-fired combustion turbine sits within the Lower Base area, just off the shores of the Thames River. The U.S. Navy owns, operates, and maintains the combined heat and power (CHP) plant, which provides power to the Navy?s nuclear submarines when they are in port and to the Navy?s training facilities at the Submarine Base. Heat recovered from the turbine is used to produce steam for use in Base housing, medical facilities, and laundries. In FY00, the Navy estimates that it will save over $500,000 per year as a result of the combined heat and power unit.

  10. Development of anode zone using dual-anode system to reduce organic matter crossover in membraneless microbial fuel cells.

    PubMed

    Kim, Jisu; Kim, Bongkyu; An, Junyeong; Lee, Yoo Seok; Chang, In Seop

    2016-08-01

    To prevent the occurrence of the organic crossover in membraneless microbial fuel cells (ML-MFCs), dual-anode MFC (DA-MFC) was designed from multi-anode concept to ensure anode zone. The anode zone addressed increase the utilization of organic matter in ML-MFCs, as the result, the organic crossover was prevented and performance of MFCs were enhanced. The maximum power of the DA-MFC was 0.46mW, which is about 1.56 times higher than the ML-MFC (0.29mW). Furthermore, the DA-MFC had advantage in correlation of organic substance concentration and dissolved oxygen concentration, and even electric over-potential. In addition, in terms of cathode fouling, the DA-MFC showed clearer surface. Hence, the anode zone should be considered in the advanced ML-MFC for practically use in wastewater treatment process, and also for scale-up of MFCs. PMID:26972026

  11. Dual-Doped Molybdenum Trioxide Nanowires: A Bifunctional Anode for Fiber-Shaped Asymmetric Supercapacitors and Microbial Fuel Cells.

    PubMed

    Yu, Minghao; Cheng, Xinyu; Zeng, Yinxiang; Wang, Zilong; Tong, Yexiang; Lu, Xihong; Yang, Shihe

    2016-06-01

    A novel in situ N and low-valence-state Mo dual doping strategy was employed to significantly improve the conductivity, active-site accessibility, and electrochemical stability of MoO3 , drastically boosting its electrochemical properties. Consequently, our optimized N-MoO3-x nanowires exhibited exceptional performances as a bifunctional anode material for both fiber-shaped asymmetric supercapacitors (ASCs) and microbial fuel cells (MFCs). The flexible fiber-shaped ASC and MFC device based on the N-MoO3-x anode could deliver an unprecedentedly high energy density of 2.29 mWh cm(-3) and a remarkable power density of 0.76 μW cm(-1) , respectively. Such a bifunctional fiber-shaped N-MoO3-x electrode opens the way to integrate the electricity generation and storage for self-powered sources. PMID:27097987

  12. A solar light driven dual photoelectrode photocatalytic fuel cell (PFC) for simultaneous wastewater treatment and electricity generation.

    PubMed

    Bai, Jing; Wang, Rui; Li, Yunpo; Tang, Yuanyuan; Zeng, Qingyi; Xia, Ligang; Li, Xuejin; Li, Jinhua; Li, Caolong; Zhou, Baoxue

    2016-07-01

    In this paper, a novel dual heterojunction Photocatalytic Fuel Cell (PFC) system based on BiVO4/TiO2 nanotubes/FTO photoanode and ZnO/CuO nanowires/FTO photocathode has been designed. Compared with the electrodes in PFCs reported in earlier literatures, the proposed heterojunction not only enhances the visible light absorption but also offers a higher photoconversion efficiency. In addition, the nanostructured heterojunction owns a large surface area that ensures a large amount of active sites for organics degradation. The performance of the PFC base on the dual photoelectrodes was also studied herein. The results indicated that the PFC in ths paper exhibits a superior performance and its JV(max) reached 0.116 mw cm(-2), which is higher than that in most of reported PFCs with a Pt-free photocathode. When hazardous organic compounds such as methyl orange, Congo red and methylene blue were decomposed, the degradation rates obtained is to be 76%, 83%, and 90% respectively after 80 mins reaction. The proposed heterojunction photoelectrodes provided great potential for cost-effective and high-efficiency organic pollutants degradation and electricity generation in a PFC system. PMID:26954476

  13. Cellulose-derived nitrogen and phosphorus dual-doped carbon as high performance oxygen reduction catalyst in microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Liu, Qin; Zhou, Yan; Chen, Shuiliang; Wang, Zejie; Hou, Haoqing; Zhao, Feng

    2015-01-01

    Microbial fuel cells (MFCs) couple functions of waste removal and electricity generation. The future success of MFCs inevitably depends on the increase of performance at decrease of material cost. Therefore, the use of renewable and sustainable materials, e.g. cellulose, to prepare high performance materials for MFCs would be an inevitable trend. In this communication, nitrogen and phosphorus dual-doped carbons were prepared by pyrolysis of cellulose using ammonium phosphate as doping source and employed as oxygen reduction reaction (ORR) catalyst in air-cathode of MFCs. A maximum power density of 2293 ± 50 mW m-2 was generated by the air-cathode using the dual-doped carbon catalyst, which was higher than the air-cathode using Pt/C catalyst with Pt load of 0.5 mg cm-2 (1680 ± 32 mW m-2). This study provided a facile and sustainable way to prepare low-cost and high-efficient ORR catalyst for scaled-up MFC applications.

  14. Conversion of crop seed oils to jet fuel and associated methods

    DOEpatents

    Ginosar, Daniel M.; Petkovic, Lucia M.; Thompson, David N.

    2010-05-18

    Aspects of the invention include methods to produce jet fuel from biological oil sources. The method may be comprised of two steps: hydrocracking and reforming. The process may be self-sufficient in heat and hydrogen.

  15. Techno-economic Analysis for the Thermochemical Conversion of Biomass to Liquid Fuels

    SciTech Connect

    Zhu, Yunhua; Tjokro Rahardjo, Sandra A.; Valkenburt, Corinne; Snowden-Swan, Lesley J.; Jones, Susanne B.; Machinal, Michelle A.

    2011-06-01

    ). This study is part of an ongoing effort within the Department of Energy to meet the renewable energy goals for liquid transportation fuels. The objective of this report is to present a techno-economic evaluation of the performance and cost of various biomass based thermochemical fuel production. This report also documents the economics that were originally developed for the report entitled “Biofuels in Oregon and Washington: A Business Case Analysis of Opportunities and Challenges” (Stiles et al. 2008). Although the resource assessments were specific to the Pacific Northwest, the production economics presented in this report are not regionally limited. This study uses a consistent technical and economic analysis approach and assumptions to gasification and liquefaction based fuel production technologies. The end fuels studied are methanol, ethanol, DME, SNG, gasoline and diesel.

  16. Analysis of LOCA Scenarios in the NIST Research Reactor Before and After Fuel Conversion

    SciTech Connect

    Baek, J. S.; Cheng, L. Y.; Diamond, D.

    2015-08-30

    An analysis has been done of hypothetical loss-of-coolant-accidents (LOCAs) in the research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The purpose of the analysis is to determine if the peak clad temperature remains below the Safety Limit, which is the blister temperature for the fuel. The configuration of the NBSR considered in the analysis is that projected for the future when changes will be made so that shutdown pumps do not operate when a LOCA signal is detected. The analysis was done for the present core with high-enriched uranium (HEU) fuel and with the proposed low-enriched uranium (LEU) fuel that would be used when the NBSR is converted from one to the other. The analysis consists of two parts. The first examines how the water would drain from the primary system following a break and the possibility for the loss of coolant from within the fuel element flow channels. This work is performed using the TRACE system thermal-hydraulic code. The second looks at the fuel clad temperature as a function of time given that the water may have drained from many of the flow channels and the water in the vessel is in a quasi-equilibrium state. The temperature behavior is investigated using the three-dimensional heat conduction code HEATING7.3. The results in all scenarios considered for both HEU and LEU fuel show that the peak clad temperature remains below the blister temperature.

  17. Teamwork in microbial fuels cells: symbiotic conversion of sugars into electricity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A binary culture of Lactococcus lactis and Shewanella oneidensis was studied for an efficient conversion of glucose into electricity in a continuously-operated chemostatic electrochemical reactor. The homolactic fermentation bacterium L. lactis fermented glucose almost exclusively to lactate – the ...

  18. WATER-RELATED ENVIRONMENTAL EFFECTS IN FUEL CONVERSION. VOLUME I. SUMMARY

    EPA Science Inventory

    The report gives results of an examination of water-related effects that can be expected from siting conversion plants in the major U.S. coal and oil shale bearing regions. Ninety plant-site combinations were studied: 48 in the Central and Eastern U.S. and 42 in the Western. Synt...

  19. WATER-RELATED ENVIRONMENTAL EFFECTS IN FUEL CONVERSION: VOLUME II. APPENDICES

    EPA Science Inventory

    The report gives results of an examination of water-related effects that can be expected from siting conversion plants in the major U.S. coal and oil shale bearing regions. Ninety plant-site combinations were studied: 48 in the Central and Eastern U.S. and 42 in the Western. Synt...

  20. Scale-up of wheat straw conversion to fuel ethanol at 100 liter scale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat straw can serve as low cost feedstock for conversion to ethanol. Pretreatment is crucial prior to enzymatic hydrolysis. We have used dilute H2SO4 pretreatment at a high temperature for pretreatment of wheat straw. The pretreated hydrolyzate was bioabated using a novel fungal strain able to ...

  1. Catalytic Conversion of Biomass to Fuels and Chemicals Using Ionic Liquids

    SciTech Connect

    Liu, Wei; Zheng, Richard; Brown, Heather; Li, Joanne; Holladay, John; Cooper, Alan; Rao, Tony

    2012-04-13

    This project provides critical innovations and fundamental understandings that enable development of an economically-viable process for catalytic conversion of biomass (sugar) to 5-hydroxymethylfurfural (HMF). A low-cost ionic liquid (Cyphos 106) is discovered for fast conversion of fructose into HMF under moderate reaction conditions without any catalyst. HMF yield from fructose is almost 100% on the carbon molar basis. Adsorbent materials and adsorption process are invented and demonstrated for separation of 99% pure HMF product and recovery of the ionic liquid from the reaction mixtures. The adsorbent material appears very stable in repeated adsorption/regeneration cycles. Novel membrane-coated adsorbent particles are made and demonstrated to achieve excellent adsorption separation performances at low pressure drops. This is very important for a practical adsorption process because ionic liquids are known of high viscosity. Nearly 100% conversion (or dissolution) of cellulose in the catalytic ionic liquid into small molecules was observed. It is promising to produce HMF, sugars and other fermentable species directly from cellulose feedstock. However, several gaps were identified and could not be resolved in this project. Reaction and separation tests at larger scales are needed to minimize impacts of incidental errors on the mass balance and to show 99.9% ionic liquid recovery. The cellulose reaction tests were troubled with poor reproducibility. Further studies on cellulose conversion in ionic liquids under better controlled conditions are necessary to delineate reaction products, dissolution kinetics, effects of mass and heat transfer in the reactor on conversion, and separation of final reaction mixtures.

  2. Nitric Oxide PLIF Visualization of Simulated Fuel-Air Mixing in a Dual-Mode Scramjet

    NASA Technical Reports Server (NTRS)

    Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Bathel, Brett F.; Danehy, Paul M.; Rockwell, Robert D.; Goyne, Christopher P.; McDaniel, James C.

    2015-01-01

    Nitric oxide (NO) planar induced laser fluorescence (PLIF) measurements have been performed in a small scale scramjet combustor at the University of Virginia Aerospace Research Laboratory at nominal simulated Mach 5 flight. A mixture of NO and N2 was injected at the upstream end of the inlet isolator as a surrogate for ethylene fuel, and the mixing of this fuel simulant was studied with and without a shock train. The shock train was produced by an air throttle, which simulated the blockage effects of combustion downstream of the cavity flame holder. NO PLIF signal was imaged in a plane orthogonal to the freestream at the leading edge of the cavity. Instantaneous planar images were recorded and analyzed to identify the most uniform cases, which were achieved by varying the location of the fuel injection and shock train. This method was used to screen different possible fueling configurations to provide optimized test conditions for follow-on combustion measurements using ethylene fuel. A theoretical study of the selected NO rotational transitions was performed to obtain a LIF signal that is linear with NO mole fraction and approximately independent of pressure and temperature.

  3. Techno-economic analysis of biomass to fuel conversion via the MixAlco process.

    PubMed

    Pham, Viet; Holtzapple, Mark; El-Halwagi, Mahmoud

    2010-11-01

    MixAlco is a robust process that converts biomass to fuels and chemicals. A key feature of the MixAlco process is the fermentation, which employs a mixed culture of acid-forming microorganisms to convert biomass components (carbohydrates, proteins, and fats) to carboxylate salts. Subsequently, these intermediate salts are chemically converted to hydrocarbon fuels (gasoline, jet fuel, and diesel). This work focuses on process synthesis, simulation, integration, and cost estimation of the MixAlco process. For the base-case capacity of 40 dry tonne feedstock per hour, the total capital investment is US $5.54/annual gallon of hydrocarbon fuels (US $3.79/annual gallon of ethanol equivalent), and the minimum selling price [with 10% return on investment (ROI), internal hydrogen production, and US $60/tonne biomass] is US $2.56/gal hydrocarbon, which is equivalent to US $1.75/gal ethanol. If plant capacity is increased to 400 tph, the minimum selling price of biomass-derived hydrocarbon fuels is US $1.76/gal hydrocarbon (US $1.20/gal ethanol equivalent), which can compete without subsidies with petroleum-derived hydrocarbons when crude oil sells for about US $65/bbl. At 40 tph, using the average tipping fee for municipal solid waste (US $45/dry tonne) and current price of external hydrogen (US $1/kg), the minimum selling price is only US $1.24/gal hydrocarbon (US $0.85/gal ethanol equivalent). PMID:20596882

  4. Dual membrane hollow fiber fuel cell and method of operating same

    NASA Technical Reports Server (NTRS)

    Ingham, J. D.; Lawson, D. D. (Inventor)

    1978-01-01

    A gaseous fuel cell is described which includes a pair of electrodes formed by open-ended, ion-exchange hollow fibers, each having a layer of metal catalyst deposited on the inner surface and large surface area current collectors such as braided metal mesh in contact with the metal catalyst layer. A fuel cell results when the electrodes are immersed in electrolytes and electrically connected. As hydrogen and oxygen flow through the bore of the fibers, oxidation and reduction reactions develop an electrical potential. Since the hollow fiber configuration provides large electrode area per unit volume and intimate contact between fuel and oxidizer at the interface, and due to the low internal resistance of the electrolyte, high power densities can be obtained.

  5. Conversion and standardization of university reactor fuels using low-enrichment uranium: Plans and schedules

    SciTech Connect

    Young, H.H.; Brown, K.R.; Matos, J.E.

    1986-01-01

    The highly-enriched uranium (HEU) fuel used in twenty United States university reactors can be viewed as contributing to the risk of theft or diversion of weapons-useable material. To minimize this risk, the US Nuclear Regulatory Commission issued its final rule on ''Limiting the Use of Highly Enriched Uranium in Domestically Licensed Research and Test Reactors,'' in February 1986. This paper describes the plans and schedules developed by the US Department of Energy to coordinate an orderly transition from HEU to LEU fuel in most of these reactors. An important element in the planning process has been the desire to standardize the LEU fuels used in US university reactors and to enhance the performance and utilization of a number of these reactors. The program is estimated to cost about $10 million and to last about five years.

  6. Dual-Fuel Fluidized Bed Combustor Prototype for Residential Heating: Steady-State and Dynamic Behavior

    NASA Astrophysics Data System (ADS)

    Cammarota, Antonio; Chirone, Riccardo; Miccio, Michele; Sollmene, Roberto; Urcluohr, Massimo

    Fluidized bed combustion of biogenic fuels can be recognized as an attractive option for an ecologically sustainable use of biofuels in residential applications. Nevertheless, biomass combustion in fluidized bed reactors presents some drawbacks that are mainly related to mixing/segregation of fuel particles/volatile matter during devolatilization inside the bed and in the freeboard or to bed agglomeration. A prototype of a 30-50 kWth fluidized bed boiler for residential heating has been designed to burn either a gaseous combustible or a solid biomass fuel or both fuels at the same time. The prototype has been equipped with a gas burner located in the wind-box to optimize the start-up stage of the boiler and with a fluidized bed characterized by a conical geometry ("Gulf Stream" circulation) to improve the mixing of the fuel particles during both devolatilization and char burn-out. The operation of the combustor adopting wood pellets as fuel has been investigated to evaluate their use in residential combustion applications. Steady-state thermally stable regimes of operation have been recognized analyzing both boiler temperatures and gaseous emissions. The optimization of the steady-state operation of the boiler in terms of gaseous emissions has been achieved by varying the nominal thermal power and air excess. An ad-hoc experimental campaign has been carried out to analyze the dynamic performance of the prototype as a response to changes of the demanded thermal power. On the basis of the experimental data, an interpretation of the dynamic behavior of the fluidized bed boiler has been proposed.

  7. Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines

    DOE PAGESBeta

    Lucachick, Glenn; Curran, Scott; Storey, John Morse; Prikhodko, Vitaly Y.; Northrop, William F.

    2016-03-10

    Our work explores the volatility of particles produced from two diesel low temperature combustion (LTC) modes proposed for high-efficiency compression ignition engines. It also explores mechanisms of particulate formation and growth upon dilution in the near-tailpipe environment. Moreover, the number distribution of exhaust particles from low- and mid-load dual-fuel reactivity controlled compression ignition (RCCI) and single-fuel premixed charge compression ignition (PPCI) modes were experimentally studied over a gradient of dilution temperature. Particle volatility of select particle diameters was investigated using volatility tandem differential mobility analysis (V-TDMA). Evaporation rates for exhaust particles were compared with V-TDMA results for candidate pure n-alkanesmore » to identify species with similar volatility characteristics. The results show that LTC particles are mostly comprised of material with volatility similar to engine oil alkanes. V-TDMA results were used as inputs to an aerosol condensation and evaporation model to support the finding that smaller particles in the distribution are comprised of lower volatility material than large particles under primary dilution conditions. Although the results show that saturation levels are high enough to drive condensation of alkanes onto existing particles under the dilution conditions investigated, they are not high We conclude that observed particles from LTC operation must grow from low concentrations of highly non-volatile compounds present in the exhaust.« less

  8. A dual-chambered microbial fuel cell with Ti/nano-TiO2/Pd nano-structure cathode

    NASA Astrophysics Data System (ADS)

    Hosseini, Mir Ghasem; Ahadzadeh, Iraj

    2012-12-01

    In this research, Ti/nano-TiO2/Pd nano-structure electrode is prepared, characterized and applied as cathode electrode in a dual-chambered microbial fuel cell with graphite anode and Flemion cation exchange membrane. Prepared nano-structured electrode morphology and mixed-culture biofilm formed on the anode are studied by scanning electron microscopy (SEM). Cell performance is investigated by polarization, cyclic voltammetery (CV) and electrochemical impedance spectroscopy (EIS) methods. Results show that Ti/nano-TiO2/Pd electrode exhibits satisfactory long term performance as a cathode to reduce water dissolved oxygen. The maximum output power of the cell is about 200 mW m-2 normalized to the cathode surface area. Open circuit potential (OCP) of the cell is about 480 mV and value of the short circuit current is 0.21 mA cm-2 of the cathode geometric surface area. Thus this nano-structure cathode can produce comparable output power to that of platinum-based cathodes such as Pt-doped carbon paper; therefore due to the ease of preparation and low cost, this electrode can be applied as alternative to platinum-based cathodes in microbial fuel cells.

  9. Enzymatic conversion of waste cooking oils into alternative fuel--biodiesel.

    PubMed

    Chen, Guanyi; Ying, Ming; Li, Weizhun

    2006-01-01

    Production of biodiesel from pure oils through chemical conversion may not be applicable to waste oils/fats. Therefore, enzymatic conversion using immobilized lipase based on Rhizopus orzyae is considered in this article. This article studies this technological process, focusing on optimization of several process parameters, including the molar ratio of methanol to waste oils, biocatalyst load, and adding method, reaction temperature, and water content. The results indicate that methanol/oils ratio of 4, immobilized lipase/oils of 30 wt% and 40 degrees C are suitable for waste oils under 1 atm. The irreversible inactivation of the lipase is presumed and a stepwise addition of methanol to reduce inactivation of immobilized lipases is proposed. Under the optimum conditions the yield of methyl esters is around 88-90%. PMID:16915699

  10. Conversion of the University of Virginia reactor to low-enrichment fuel

    SciTech Connect

    Rydin, R.A.; Freeman, D.W.; Fehr, M.K.

    1989-01-01

    The University of Virginia is using the LEOPARD-LINX-TWODB computational package to assist in converting the 2-MW(thermal) University of Virginia Reactor (UVAR) to low-enrichment uranium fuel (LEU). Recent efforts have been focused on designing an upgraded LEU replacement core. The UVAR is unique in that anywhere from 16 to 27 fuel elements have been used over the years in a variety of geometrical arrangements. However, a compact and fixed core arrangement offers significant operational and experimental advantages over past practice, including a higher and more temporally constant thermal flux. The authors have concentrated on relative burnup comparisons between representative 4 {times} 4, 4 {times} 5, and 5 {times} 5 cores using 18 curved-plant/element HEU (HEU-18) and 18 and 22 flat-plate/element LEU (LEU-18 and LEU-22) fuel. It is concluded that the UVAR should be supplied with LEU-22 fuel. The authors have also explored the reactivity and power-peaking effects of separately varying the reflector compositions on various reactor faces from light water to heavy water to graphite. Thermal-hydraulic behavior has also been analyzed with a combination of the PARET and THERHYD codes, which indicates the LEU cores will be acceptable with only small modifications in UVAR safety system settings.

  11. 40 CFR 600.206-93 - Calculation and use of fuel economy values for gasoline-fueled, diesel-fueled, electric, alcohol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... values for gasoline-fueled, diesel-fueled, electric, alcohol-fueled, natural gas-fueled, alcohol dual fuel, and natural gas dual fuel vehicle configurations. 600.206-93 Section 600.206-93 Protection of... gasoline-fueled, diesel-fueled, electric, alcohol-fueled, natural gas-fueled, alcohol dual fuel,...

  12. Dual-Layer Nanostructured Flexible Thin-Film Amorphous Silicon Solar Cells with Enhanced Light Harvesting and Photoelectric Conversion Efficiency.

    PubMed

    Lin, Yinyue; Xu, Zhen; Yu, Dongliang; Lu, Linfeng; Yin, Min; Tavakoli, Mohammad Mahdi; Chen, Xiaoyuan; Hao, Yuying; Fan, Zhiyong; Cui, Yanxia; Li, Dongdong

    2016-05-01

    Three-dimensional (3-D) structures have triggered tremendous interest for thin-film solar cells since they can dramatically reduce the material usage and incident light reflection. However, the high aspect ratio feature of some 3-D structures leads to deterioration of internal electric field and carrier collection capability, which reduces device power conversion efficiency (PCE). Here, we report high performance flexible thin-film amorphous silicon solar cells with a unique and effective light trapping scheme. In this device structure, a polymer nanopillar membrane is attached on top of a device, which benefits broadband and omnidirectional performances, and a 3-D nanostructure with shallow dent arrays underneath serves as a back reflector on flexible titanium (Ti) foil resulting in an increased optical path length by exciting hybrid optical modes. The efficient light management results in 42.7% and 41.7% remarkable improvements of short-circuit current density and overall efficiency, respectively. Meanwhile, an excellent flexibility has been achieved as PCE remains 97.6% of the initial efficiency even after 10 000 bending cycles. This unique device structure can also be duplicated for other flexible photovoltaic devices based on different active materials such as CdTe, Cu(In,Ga)Se2 (CIGS), organohalide lead perovskites, and so forth. PMID:27052357

  13. Ultra-broad band and dual-band highly efficient polarization conversion based on the three-layered chiral structure

    NASA Astrophysics Data System (ADS)

    Xu, Kai-kai; Xiao, Zhong-yin; Tang, Jing-yao; Liu, De-jun; Wang, Zi-hua

    2016-07-01

    In the paper, a novel three-layered chiral structure is proposed and investigated, which consists of a split-ring resonator sandwiched between two layers of sub-wavelength gratings. This designed structure can achieve simultaneously asymmetric transmission with an extremely broad bandwidth and high amplitude as well as multi-band 90° polarization rotator with very low dispersion. Numerical simulations adopted two kinds of softwares with different algorithms demonstrate that asymmetric parameter can reach a maximum of 0.99 and over than 0.8 from 4.6 to 16.8 GHz, which exhibit magnitude and bandwidth improvement over previous chiral metamaterials in microwave bands (S, C, X and Ku bands). Specifically, the reason of high amplitude is analyzed in detail based on the Fabry-perot like resonance. Subsequently, the highly efficient polarization conversion with very low dispersion between two orthogonal linearly polarized waves is also analyzed by the optical activity and ellipticity. Finally, the electric fields are also investigated and further demonstrate the correctness of the simulated and calculated results.

  14. Evaluation of UF{sub 6}-to-UO{sub 2} conversion capability at commercial nuclear fuel fabrication facilities.

    SciTech Connect

    Ranek, N. L.; Monette, F. A.

    2001-06-08

    This report examines the capabilities of existing commercial nuclear fuel fabrication facilities to convert depleted uranium hexafluoride (UF{sub 6}) to uranium oxide (UO{sub 2}). The U.S. Department of Energy (DOE) needs this information to determine whether using such capacity to convert DOE's inventory of depleted UF{sub 6} to a more stable form is a reasonable alternative that should be considered in the site-specific environmental impact statement for construction and operation of depleted UF{sub 6} conversion facilities. Publicly available information sources were consulted to ascertain the information summarized in this report. For domestic facilities, the information summarized includes currently operating capacity to convert depleted UF{sub 6} to UO{sub 2}; transportation distances from depleted UF{sub 6} storage locations near Oak Ridge, Tennessee, Portsmouth, Ohio, and Paducah, Kentucky, to the facilities; and regulatory requirements applicable to nuclear fuel fabrication and transportation of depleted UF{sub 6}. The report concludes that the total currently operating capability of U.S. commercial nuclear fuel fabricators to convert UF{sub 6} to UO{sub 2} is approximately 5,200 metric tons of UF{sub 6} per annum (tUF{sub 6}/a). This total includes 666 tUF{sub 6}/a scheduled for shutdown by the end of 2001. However, only about 300 tUF{sub 6}/a of this capacity could be confirmed as being possibly available to DOE. The report also provides some limited descriptions of the capabilities of foreign fuel fabrication plants to convert UF{sub 6} to uranium oxide forms.

  15. Rare-Earth-Based Nanoparticles with Simultaneously Enhanced Near-Infrared (NIR)-Visible (Vis) and NIR-NIR Dual-Conversion Luminescence for Multimodal Imaging.

    PubMed

    Ma, Dandan; Xu, Xiang; Hu, Min; Wang, Jing; Zhang, Zhenxi; Yang, Jian; Meng, Lingjie

    2016-04-01

    Multifunctional NaGdF4 :Yb(3+) ,Er(3+) ,Nd(3+) @NaGdF4 :Nd(3+) core-shell nanoparticles (called Gd:Yb(3+) ,Er(3+) ,Nd(3+) @Gd:Nd(3+) NPs) with simultaneously enhanced near-infrared (NIR)-visible (Vis) and NIR-NIR dual-conversion (up and down) luminescence (UCL/DCL) properties were successfully synthesized. The resulting core-shell NPs simultaneously emitted enhanced UCL at 522, 540, and 660 nm and DCL at 980 and 1060 nm under the excitation of a 793 nm laser. The enhanced UCL and DCL can be explained by complex energy-transfer processes, Nd(3+) →Yb(3+) →Er(3+) and Nd(3+) →Yb(3+) , respectively. The effects of Nd(3+) concentration and shell thickness on the UCL/DCL properties were systematically investigated. The UCL and DCL properties of NPs were observed under the optimal conditions: a shell Nd(3+) content of 20 % and a shell thickness of approximately 5 nm. Moreover, the Gd:Yb(3+) ,Er(3+) ,Nd(3+) @Gd:20 % Nd(3+) NPs exhibited remarkable magnetic resonance imaging (MRI) properties similar to that of a clinical agent, Omniscan. Thus, the core-shell NPs with excellent UCL/DCL/magnetic resonance imaging (MRI) properties have great potential for both in vitro and in vivo multimodal bioimaging. PMID:26788691

  16. Energy conversion with solid oxide fuel cell systems: A review of concepts amd outlooks for the short- and long-term

    SciTech Connect

    Adams, II, Thomas A.; Nease, Jake; Tucker, David; Barton, Paul I.

    2013-01-01

    A review of energy conversion systems which use solid oxide fuel cells (SOFCs) as their primary electricity generation component is presented. The systems reviewed are largely geared for development and use in the short- and long-term future. These include systems for bulk power generation, distributed power generation, and systems integrated with other forms of energy conversion such as fuel production. The potential incorporation of CO{sub 2} capture and sequestration technologies and the influences of potential government policies are also discussed.

  17. Earth--abundant water--splitting catalysts coupled to silicon solar cells for solar--to--fuels conversion

    NASA Astrophysics Data System (ADS)

    Cox, Casandra R.

    Direct solar--to--fuels conversion can be achieved by coupling semiconductors with water--splitting catalysts. A 10% or higher solar to fuels conversion is minimally necessary for the realization of a robust future technology. Many water--splitting devices have been proposed but due to expensive designs and/or materials, none have demonstrated the necessary efficiency at low--cost that is a requisite for large--scale implementation. In this thesis, a modular approach is used to couple water--splitting catalysts with crystalline silicon (c--Si) photovoltaics, with ultimate goal of demonstrating a stand--alone and direct solar-to-fuels water--splitting device comprising all non--precious, technology ready, materials. Since the oxygen evolution reaction is the key efficiency--limiting step for water--splitting, we first focus on directly interfacing oxygen evolution catalysts with c--Si photovoltaics. Due to the instability of silicon under oxidizing conditions, a protective interface between the PV and OER catalyst is required. This coupling of catalyst to Si semiconductor thus requires optimization of two interfaces: the silicon|protective layer interface; and, the protective layer|catalyst interface. A modular approach allows for the independent optimization and analysis of these two interfaces. A stand--alone water--splitting device based on c--Si is created by connecting multiple single junction c-Si solar cells in series. Steady--state equivalent circuit analysis allows for a targeted solar--to--fuels efficiency to be designed within a predictive framework for a series--connected c--Si solar cells and earth--abundant water--splitting catalysts operating at neutral pH. Guided by simulation and modeling, a completely modular, stand--alone water--splitting device possessing a 10% SFE is demonstrated. Importantly, the modular approach enables facile characterization and trouble--shooting for each component of the solar water--splitting device. Finally, as direct

  18. Parallel-burn options for dual-fuel single-stage orbital transports

    NASA Technical Reports Server (NTRS)

    Martin, J. A.

    1978-01-01

    A parallel-burn version of a single-stage vehicle for transport from the earth to low-earth orbit using two fuels and rocket propulsion is considered. New engine results were incorporated in vehicle performance and design studies. The results indicate that a hydrogen-cooled gas generator cycle engine provides attractive vehicle performance and that there is little incentive for increasing the chamber pressure beyond 27 MPa.

  19. Thermal conversion of biomass to valuable fuels, chemical feedstocks and chemicals

    DOEpatents

    Peters, William A.; Howard, Jack B.; Modestino, Anthony J.; Vogel, Fredreric; Steffin, Carsten R.

    2009-02-24

    A continuous process for the conversion of biomass to form a chemical feedstock is described. The biomass and an exogenous metal oxide, preferably calcium oxide, or metal oxide precursor are continuously fed into a reaction chamber that is operated at a temperature of at least 1400.degree. C. to form reaction products including metal carbide. The metal oxide or metal oxide precursor is capable of forming a hydrolizable metal carbide. The reaction products are quenched to a temperature of 800.degree. C. or less. The resulting metal carbide is separated from the reaction products or, alternatively, when quenched with water, hydolyzed to provide a recoverable hydrocarbon gas feedstock.

  20. Structured catalyst bed and method for conversion of feed materials to chemical products and liquid fuels

    DOEpatents

    Wang, Yong , Liu; Wei

    2012-01-24

    The present invention is a structured monolith reactor and method that provides for controlled Fischer-Tropsch (FT) synthesis. The invention controls mass transport limitations leading to higher CO conversion and lower methane selectivity. Over 95 wt % of the total product liquid hydrocarbons obtained from the monolithic catalyst are in the carbon range of C.sub.5-C.sub.18. The reactor controls readsorption of olefins leading to desired products with a preselected chain length distribution and enhanced overall reaction rate. And, liquid product analysis shows readsorption of olefins is reduced, achieving a narrower FT product distribution.

  1. Nature-Inspired Design of Artificial Solar-to-Fuel Conversion Systems based on Copper Phosphate Microflowers.

    PubMed

    Wang, Jing; Zhu, Ting; Ho, Ghim Wei

    2016-07-01

    Phosphates play significant roles in plant photosynthesis by mediating electron transportation and furnishing energy for CO2 reduction. Motivated by this, we demonstrate herein an artificial solar-to-fuel conversion system, involving versatile copper phosphate microflowers as template and titanium dioxide nanoparticles as host photocatalyst. The elaborate flowerlike architectures, coupled with a unique proton-reduction cycle from interchangeability of different species of orthophosphate ions, not only offer a 2D nanosheet platform for an optimal heterostructure interface but also effectively augment charge-carrier transfer, thereby contributing to enhanced photoactivity and hydrogen generation. These nature-inspired, phosphate-derived nanocomposites advance the synthesis of a large variety of functional materials, which holds great potential for photochemical, photoelectric and catalytic applications. PMID:27225314

  2. Evaluation of research in plant biomass production for liquid fuel conversion: The case of India, Brazil and Japan

    SciTech Connect

    Thomas, S.M. )

    1992-01-01

    The aims of this study were to identify research activities in the field of plant biomass production for liquid fuel conversion and to evaluate research in areas outside the USA and EEC. Results are presented for three countries: Japan, India and Brazil. Research groups were identified from a range of information sources. Data were collected by interview and related to funding, information access, staffing, publication policy and degree of awareness of other research groups in the field. Bibliometric analysis and peer review were used as indicators in an attempt to assess research output. The findings are discussed in relation to agro-industrial policy in Japan, the use of marginal land in India and the Proalcohol program in Brazil.

  3. Genome and Transcriptome of Clostridium phytofermentans, Catalyst for the Direct Conversion of Plant Feedstocks to Fuels

    DOE PAGESBeta

    Petit, Elsa; Coppi, Maddalena V.; Hayes, James C.; Tolonen, Andrew C.; Warnick, Thomas; Latouf, William G.; Amisano, Danielle; Biddle, Amy; Mukherjee, Supratim; Ivanova, Natalia; et al

    2015-06-02

    Clostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of our present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C. phytofermentans is reflected in a diversity of genes encoding ATP-binding cassette sugar transporters and glycoside hydrolases, many of which may have been acquired through horizontal gene transfer.more » These genes are frequently organized as operons that may be controlled individually by the many transcriptional regulators identified in the genome. Preferential ethanol production may be due to high levels of expression of multiple ethanol dehydrogenases and additional pathways maximizing ethanol yield. The genome also encodes three different proteinaceous bacterial microcompartments with the capacity to compartmentalize pathways that divert fermentation intermediates to various products. Lastly, these characteristics make C. phytofermentans an attractive resource for improving the efficiency and speed of biomass conversion to biofuels.« less

  4. Genome and Transcriptome of Clostridium phytofermentans, Catalyst for the Direct Conversion of Plant Feedstocks to Fuels

    SciTech Connect

    Petit, Elsa; Coppi, Maddalena V.; Hayes, James C.; Tolonen, Andrew C.; Warnick, Thomas; Latouf, William G.; Amisano, Danielle; Biddle, Amy; Mukherjee, Supratim; Ivanova, Natalia; Lykidis, Athanassios; Land, Miriam; Hauser, Loren; Kyrpides, Nikos; Henrissat, Bernard; Lau, Joanne; Schnell, Danny J.; Church, George M.; Leschine, Susan B.; Blanchard, Jeffrey L.

    2015-06-02

    Clostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of our present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C. phytofermentans is reflected in a diversity of genes encoding ATP-binding cassette sugar transporters and glycoside hydrolases, many of which may have been acquired through horizontal gene transfer. These genes are frequently organized as operons that may be controlled individually by the many transcriptional regulators identified in the genome. Preferential ethanol production may be due to high levels of expression of multiple ethanol dehydrogenases and additional pathways maximizing ethanol yield. The genome also encodes three different proteinaceous bacterial microcompartments with the capacity to compartmentalize pathways that divert fermentation intermediates to various products. Lastly, these characteristics make C. phytofermentans an attractive resource for improving the efficiency and speed of biomass conversion to biofuels.

  5. Genome and Transcriptome of Clostridium phytofermentans, Catalyst for the Direct Conversion of Plant Feedstocks to Fuels

    PubMed Central

    Petit, Elsa; Coppi, Maddalena V.; Hayes, James C.; Tolonen, Andrew C.; Warnick, Thomas; Latouf, William G.; Amisano, Danielle; Biddle, Amy; Mukherjee, Supratim; Ivanova, Natalia; Lykidis, Athanassios; Land, Miriam; Hauser, Loren; Kyrpides, Nikos; Henrissat, Bernard; Lau, Joanne; Schnell, Danny J.; Church, George M.; Leschine, Susan B.; Blanchard, Jeffrey L.

    2015-01-01

    Clostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of the present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C. phytofermentans is reflected in a diversity of genes encoding ATP-binding cassette sugar transporters and glycoside hydrolases, many of which may have been acquired through horizontal gene transfer. These genes are frequently organized as operons that may be controlled individually by the many transcriptional regulators identified in the genome. Preferential ethanol production may be due to high levels of expression of multiple ethanol dehydrogenases and additional pathways maximizing ethanol yield. The genome also encodes three different proteinaceous bacterial microcompartments with the capacity to compartmentalize pathways that divert fermentation intermediates to various products. These characteristics make C. phytofermentans an attractive resource for improving the efficiency and speed of biomass conversion to biofuels. PMID:26035711

  6. Selective conversion of methane to synthetic fuels using dielectric barrier discharge contacting liquid film

    NASA Astrophysics Data System (ADS)

    Nozaki, Tomohiro; Goujard, Valentin; Yuzawa, Shuhei; Moriyama, Shota; Ağıral, Anıl; Okazaki, Ken

    2011-07-01

    This paper presents the reaction mechanism of single-step methane partial oxidation to methanol at room temperature using non-thermal plasma microreactor. Macroscopic quantities of hydrogen peroxide (H2O2) and methyl hydroperoxide (CH3OOH) are produced when methane is partially oxidized at room temperature (about 5 °C). CH3OOH is known to be the principle intermediate of incomplete methane oxidation product such as CH3OH and HCHO, but has not been demonstrated experimentally so far. H2O2 promotes post-plasma oxidation of oxygenates in the condensed plasma-synthesized liquid. At an early stage of in-liquid oxidation, H2O2 oxidizes HCHO into HCOOH preferentially; subsequently, HCOOH is fully oxidized to CO2 and H2O. Depending upon the concentration of oxygenates and H2O2, electrical conductivity of the plasma solution dramatically increased, which detrimentally influences plasma properties. Methane partial oxidation with air was also investigated from a practical viewpoint. Generation of active nitrogen species (ANS) is the key to promoting overall methane conversion in the presence of oxygen; however, fragile oxygenates were also decomposed by ANS, thus selectivity for useful oxygenates was degraded in the presence of nitrogen. When oxygen is fully consumed, CH4 conversion is also terminated and water gas shift reaction (CO + H2O = CO2 + H2) becomes predominant.

  7. Conversion of solvent refined lignite into premium liquid fuels. Annual report, January-December, 1980

    SciTech Connect

    Baltisberger, R.J.; Stenberg, V.I.; Klabunde, K.J.; Woolsey, N.F.

    1981-04-01

    Comparison of three preasphaltene samples separated from three lignite derived samples obtained from GFETC prepared at 404, 460 and 480/sup 0/C shows that increased temperature tends to produce higher molecular weight preasphaltene fractions containing more aromatic carbons with fewer acid (phenolic) sites per molecule. Ether cleavage studies of the model compounds; diphenyl ether, bibenzothiophene, dibenzofuran and anisole, show that partial or complete ether cleavage was obtained with sodium in hexamethyl phosphoramide solvent. Thus a careful consideration of acidity before and after cleavage can now give a measure of the diaryl ether content of a mixture. This reaction may be useful in coal liquid analysis. Denitrification of N,N-Dimethylamine without aromatic ring reduction occurs with CO-H/sub 2/O and H/sub 2/ at 425/sup 0/C in about 13% conversion. The optimum of 21 conditions gave a 19% conversion which occurs at 150 psi H/sub 2/S and 750 psi H/sub 2/. Thus, H/sub 2/S enhances nitrogen removal from this model compound. Using ESR dispersion techniques we have shown the presence of a second CO radical species on MgO, probably CO-.. observed by ESR, treatment of carbon monoxide radical species on both CO and MgO with CO/sub 2/ or H/sub 2/O causes a destruction of one of the radical species at a rate greater than that of the other.

  8. A dual model HU conversion from MRI intensity values within and outside of bone segment for MRI-based radiotherapy treatment planning of prostate cancer

    SciTech Connect

    Korhonen, Juha; Kapanen, Mika; Keyriläinen, Jani; Seppälä, Tiina; Tenhunen, Mikko

    2014-01-15

    Purpose: The lack of electron density information in magnetic resonance images (MRI) poses a major challenge for MRI-based radiotherapy treatment planning (RTP). In this study the authors convert MRI intensity values into Hounsfield units (HUs) in the male pelvis and thus enable accurate MRI-based RTP for prostate cancer patients with varying tissue anatomy and body fat contents. Methods: T{sub 1}/T{sub 2}*-weighted MRI intensity values and standard computed tomography (CT) image HUs in the male pelvis were analyzed using image data of 10 prostate cancer patients. The collected data were utilized to generate a dual model HU conversion technique from MRI intensity values of the single image set separately within and outside of contoured pelvic bones. Within the bone segment local MRI intensity values were converted to HUs by applying a second-order polynomial model. This model was tuned for each patient by two patient-specific adjustments: MR signal normalization to correct shifts in absolute intensity level and application of a cutoff value to accurately represent low density bony tissue HUs. For soft tissues, such as fat and muscle, located outside of the bone contours, a threshold-based segmentation method without requirements for any patient-specific adjustments was introduced to convert MRI intensity values into HUs. The dual model HU conversion technique was implemented by constructing pseudo-CT images for 10 other prostate cancer patients. The feasibility of these images for RTP was evaluated by comparing HUs in the generated pseudo-CT images with those in standard CT images, and by determining deviations in MRI-based dose distributions compared to those in CT images with 7-field intensity modulated radiation therapy (IMRT) with the anisotropic analytical algorithm and 360° volumetric-modulated arc therapy (VMAT) with the Voxel Monte Carlo algorithm. Results: The average HU differences between the constructed pseudo-CT images and standard CT images of each

  9. OH PLIF Visualization of a Premixed Ethylene-fueled Dual-Mode Scramjet Combustor

    NASA Technical Reports Server (NTRS)

    Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.; Johansen, Craig T.; Rockwell, Robert D.; Goyne, Christopher P.; McDaniel, James C.

    2016-01-01

    Hydroxyl radical (OH) planar induced laser fluorescence (PLIF) measurements have been performed in a small-scale scramjet combustor at the University of Virginia Aerospace Research Laboratory at nominal simulated Mach 5 enthalpy. OH lines were carefully chosen to have fluorescent signal that is independent of pressure and temperature but linear with mole fraction. The OH PLIF signal was imaged in planes orthogonal to and parallel to the freestream flow at different equivalence ratios. Flameout limits were tested and identified. Instantaneous planar images were recorded and analyzed to compare the results with width increased dual-pump enhanced coherent anti-Stokes Raman spectroscopy (WIDECARS) measurements in the same facility and large eddy simulation/Reynolds average Navier-Stokes (LES/RANS) numerical simulation. The flame angle was found to be approximately 10 degrees for several different conditions, which is in agreement with numerical predictions and measurements using WIDECARS. Finally, a comparison between NO PLIF non-combustion cases and OH PLIF combustion cases is provided: the comparison reveals that the dominant effect of flame propagation is freestream turbulence rather than heat release and concentration gradients.

  10. Study on an environmental-friendly and high-efficient fuel cell energy conversion system.

    PubMed

    Yu, Li-Jun; Cao, Guang-Yi; Zhu, Xin-Jian; Jiang, An-Zhong; Tian, Zi-Ping

    2003-01-01

    The kinds and the distribution of the coal in China are investigated. The results indicated that the 80% coal in China is used by the method of the coal gasification. The possibility of utilization and development of the fuel cell power plant in China is analyzed. A combined cycle generation system is designed. Its net electrical efficiency is about 55% (LHV), which is higher than that of the fire power plant. So it is environmental-friendly and high-efficient generation mode. PMID:12602611

  11. Conversion of cellulosic wastes to liquid hydrocarbon fuels. Progress report, January-February 1981

    SciTech Connect

    Kuester, J.L.

    1981-01-01

    The following materials were processed thru gasification: sugarcane bagasse, smooth sumac, coralberry, wild bergamot, pokeweed, cornstarch, Portugese oak cork and hog fuel. A data summary is given. The high H/sub 2//CO ratio at low temperature for pokeweed is of significance (>T, >H/sub 2/). Also the high olefin content of Portugese oak cork (commercial cork) is of major interest. The most promising feedstock to date with regard to synthesis gas composition has been guayule cork. A comparison of data for the two cork materials is given. A detailed breakdown for corn starch is given revealing an exceptionally high methane content (35.50 mole %). (MHR)

  12. LDRD final report on "fundamentals of synthetic conversion of CO2 to simple hydrocarbon fuels" (LDRD 113486).

    SciTech Connect

    Maravelias, Christos T.; Kemp, Richard Alan; Mavrikakis, Manos; Miller, James Edward; Stewart, Constantine A.

    2009-11-01

    Energy production is inextricably linked to national security and poses the danger of altering the environment in potentially catastrophic ways. There is no greater problem than sustainable energy production. Our purpose was to attack this problem by examining processes, technology, and science needed for recycling CO{sub 2} back into transportation fuels. This approach can be thought of as 'bio-inspired' as nature employs the same basic inputs, CO{sub 2}/energy/water, to produce biomass. We addressed two key deficiencies apparent in current efforts. First, a detailed process analysis comparing the potential for chemical and conventional engineering methods to provide a route for the conversion of CO{sub 2} and water to fuel has been completed. No apparent 'showstoppers' are apparent in the synthetic route. Opportunities to improve current processes have also been identified and examined. Second, we have also specifically addressed the fundamental science of the direct production of methanol from CO{sub 2} using H{sub 2} as a reductant.

  13. Direct conversion of methane to C sub 2 's and liquid fuels

    SciTech Connect

    Warren, B.K.; Campbell, K.D.; Matherne, J.L.

    1990-02-14

    Research on promoted metal oxide catalysts has continued with the study of alkaline earth/metal oxide halide catalysts. A barium bromide/alumina catalyst was comparable in methane conversion and selectivity to C{sub 2}'s to barium chloride/alumina catalysts. The effects of varying methane to oxygen feed ratios were explored for one of the best alkaline earth catalysts and one of the best literature catalysts (Li/MgO). A significant decrease in the selectivity to C{sub 2}'s is observed upon addition of ethane to the feed gas (feed gas methane/ethane ratio of 3). This observation demonstrates that a significant amount of ethane should not be recycled during methane oxidation over these types of catalysts under process conditions used. Methane oxidation over barium carbonate alone results in high enough selectivities and methane conversions to suggest an oxidized barium species may be responsible for methane oxidation on barium/metal oxide catalysts. Methane coupling studies have continued using layered perovskite catalysts in the cofeed mode and double perovskite catalysts in the sequential mode. Addition of sodium to the double perovskite LaCaMnCoO{sub 6} resulted in a catalyst with improved selectivity over the one without sodium. A reactor system containing two reactors in under construction. These reactors will be used to study different feed diluents, including steam. One reactor will be used to study the effects of pressure on the reaction. Process economics were explored for a hypothetical methane coupling scheme employing a feed mixture of 7/2/1 nitrogen/methane/oxygen. Economic evaluations of the first two of a series of cases based on extrapolations of Union Carbide methane coupling results have been completed. 33 refs., 17 figs., 2 tabs.

  14. Conversion of waste polypropylene to liquid fuel using acid-activated kaolin.

    PubMed

    Panda, Achyut K; Singh, R K

    2014-10-01

    Waste polypropylene was subjected to thermal degradation in the presence of kaolin and acid-treated kaolin, with different catalyst-to-plastics ratios, in a semi-batch reactor at a temperature range of 400-550°C to obtain optimized process conditions for the production of liquid fuels. The effects of process temperature, catalyst and feed composition on yield and quality of the oil were determined. For a thermal decomposition reaction at up to 450°C, the major product is volatile oil; and the major products at a higher temperature (475-550°C) are either viscous liquid or wax. The highest yield of condensed fraction in the thermal reaction is 82.85% by weight at 500°C. Use of kaolin and acid-treated kaolin as a catalyst decreased the reaction time and increased the yield of liquid fraction. The major product of catalysed degradation at all temperatures is highly volatile liquid oil. The maximum oil yield using kaolin and acid-treated kaolin is 87.5% and 92%, respectively, at 500°C. The oil obtained was characterized using GC-MS for its composition and different fuel properties by IS methods. PMID:25135440

  15. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2002-01-01

    Boise Cascade Corporation and the Gas Technology Institute (GTI) are cooperating to develop, demonstrate and place in continuous operation an advanced biomass gasification-based power generation system suitable for near-term commercial deployment in the Forest Products Industry. The system will be used in conjunction with, rather than in place of, existing wood waste fired boilers and flue gas cleanup systems. The novel system will include three advanced technological components based on GTI's RENUGAS{reg_sign} and METHANE de-NOX{reg_sign} technologies, and a gas turbine-based power generation concept developed in DOE's High Performance Power System (HIPPS) program. The system has, as its objective, to avoid the major hurdles of high-pressure gasification, i.e., high-pressure fuel feeding and ash removal, and hot gas cleaning that are typical for conventional IGCC power generation. It aims to also minimize capital intensity and technology risks. The system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as fuel resources.

  16. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2002-10-01

    Boise Paper Solutions and the Gas Technology Institute (GTI) are cooperating to develop, demonstrate and place in continuous operation an advanced biomass gasification-based power generation system suitable for near-term commercial deployment in the Forest Products Industry. The system will be used in conjunction with, rather than in place of, existing wood waste fired boilers and flue gas cleanup systems. The novel system will include three advanced technological components based on GTI's RENUGAS{reg_sign} and three-stage stoker combustion technologies, and a gas turbine-based power generation concept developed in DOE's High Performance Power System (HIPPS) program. The system has, as its objective, to avoid the major hurdles of high-pressure gasification, i.e., high-pressure fuel feeding and ash removal, and hot gas cleaning that are typical for conventional IGCC power generation. It aims to also minimize capital intensity and technology risks. The system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as fuel resources. The overall objective of this project is to demonstrate the commercial applicability of an advanced biomass gasification-based power generation system at Boise Paper Solutions' pulp and paper mill located at DeRidder, Louisiana.

  17. Photocatalytic conversion of CO2 into value-added and renewable fuels

    NASA Astrophysics Data System (ADS)

    Yuan, Lan; Xu, Yi-Jun

    2015-07-01

    The increasing energy crisis and the worsening global climate caused by the excessive utilization of fossil fuel have boosted tremendous research activities about CO2 capture, storage and utilization. Artificial photosynthesis that uses solar light energy to convert CO2 to form value-added and renewable fuels such as methane or methanol has been consistently drawing increasing attention. It is like killing two birds with one stone since it can not only reduce the greenhouse effects caused by CO2 emission but also produce value added chemicals for alternative energy supplying. This review provides a brief introduction about the basic principles of artificial photosynthesis of CO2 and the progress made in exploring more efficient photocatalysts from the viewpoint of light harvesting and photogenerated charge carriers boosting. Moreover, the undergoing mechanisms of CO2 photoreduction are discussed with selected examples, in terms of adsorption of reactants, CO2 activation as well as the possible reaction pathways. Finally, perspectives on future research directions and open issues in CO2 photoreduction are outlined.

  18. 40 CFR 600.206-93 - Calculation and use of fuel economy values for gasoline-fueled, diesel-fueled, electric, alcohol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... values for gasoline-fueled, diesel-fueled, electric, alcohol-fueled, natural gas-fueled, alcohol dual fuel, and natural gas dual fuel vehicle configurations. 600.206-93 Section 600.206-93 Protection of... for gasoline-fueled, diesel-fueled, electric, alcohol-fueled, natural gas-fueled, alcohol dual...

  19. Facile electrochemical polymerization of polypyrrole film applied as cathode material in dual rotating disk photo fuel cell

    NASA Astrophysics Data System (ADS)

    Li, Kan; Zhang, Hongbo; Tang, Tiantian; Tang, Yanping; Wang, Yalin; Jia, Jinping

    2016-08-01

    Polypyrrole (PPy) film is synthesized on Ti substrate through electrochemical polymerization method and is applied as cathode material in a TiO2 NTs-PPy dual rotating disk photo fuel cell (PFC). The optimized PPy electrochemical polymerization is carried out using linear sweep voltammetry from 0 V to 1.2 V (vs. SCE) with scan rate of 0.1 V s-1, 100 circles. Sixty milliliter real textile wastewater with the initial COD and conductivity of 408 ± 6 mgO2 L-1 and 20180 μS cm-1 is treated in this PFC under UV irradiation. About 0.46 V open-circuit voltage (VOC) and 1.8-2.2 mA short-circuit current (JSC) are obtained. Due to the effective electron-hole separation effect, the COD removal rate is as high as 0.0055 min-1. Stable current and COD removal can be obtained at different output voltage. Two influence factors including rotating speed and pH are investigated. Better electricity generation performance and COD removal activity are achieved at high rotating speed and in acidic condition. In comparison with platinized cathode, though VOC is lower, similar JSC is measured. Considering the high cost of Pt, PPy is a promising alternative cathode material in PFC that can also generate electricity efficiently and stably.

  20. Facile electrochemical polymerization of polypyrrole film applied as cathode material in dual rotating disk photo fuel cell

    NASA Astrophysics Data System (ADS)

    Li, Kan; Zhang, Hongbo; Tang, Tiantian; Tang, Yanping; Wang, Yalin; Jia, Jinping

    2016-08-01

    Polypyrrole (PPy) film is synthesized on Ti substrate through electrochemical polymerization method and is applied as cathode material in a TiO2 NTs-PPy dual rotating disk photo fuel cell (PFC). The optimized PPy electrochemical polymerization is carried out using linear sweep voltammetry from 0 V to 1.2 V (vs. SCE) with scan rate of 0.1 V s-1, 100 circles. Sixty milliliter real textile wastewater with the initial COD and conductivity of 408 ± 6 mgO2 L-1 and 20180 μS cm-1 is treated in this PFC under UV irradiation. About 0.46 V open-circuit voltage (VOC) and 1.8-2.2 mA short-circuit current (JSC) are obtained. Due to the effective electron-hole separation effect, the COD removal rate is as high as 0.0055 min-1. Stable current and COD removal can be obtained at different output voltage. Two influence factors including rotating speed and pH are investigated. Better electricity generation performance and COD removal activity are achieved at high rotating speed and in acidic condition. In comparison with platinized cathode, though VOC is lower, similar JSC is measured. Considering the high cost of Pt, PPy is a promising alternative cathode material in PFC that can also generate electricity efficiently and stably.

  1. Dual-Carbon sources fuel the OCS deep-reef Community, a stable isotope investigation

    USGS Publications Warehouse

    Sulak, Kenneth J.; Berg, J.; Randall, Michael; Dennis, George D., III; Brooks, R.A.

    2008-01-01

    The hypothesis that phytoplankton is the sole carbon source for the OCS deep-reef community (>60 m) was tested. Trophic structure for NE Gulf of Mexico deep reefs was analyzed via carbon and nitrogen stable isotopes. Carbon signatures for 114 entities (carbon sources, sediment, fishes, and invertebrates) supported surface phytoplankton as the primary fuel for the deep reef. However, a second carbon source, the macroalga Sargassum, with its epiphytic macroalgal associate, Cladophora liniformis, was also identified. Macroalgal carbon signatures were detected among 23 consumer entities. Most notably, macroalgae contributed 45 % of total carbon to the 13C isotopic spectrum of the particulate-feeding reef-crest gorgonian Nicella. The discontinuous spatial distribution of some sessile deep-reef invertebrates utilizing pelagic macroalgal carbon may be trophically tied to the contagious distribution of Sargassum biomass along major ocean surface features.

  2. The characteristics of American coals in relation to their conversion into clean-energy fuels

    NASA Astrophysics Data System (ADS)

    Spackman, W.; Davis, A.; Walker, P. L.; Lovell, H. L.; Vastola, F. J.; Given, P. H.; Suhr, N. H.; Jenkins, R. G.

    1982-06-01

    The Sample Bank for characterization of coal includes full seam channel samples as well as samples of lithotypes, seam benches, and subseam sections. The data include: proximate analysis, ultimate analysis, sulfur froms analysis, calorific value, maceral analysis, vitrinite reflectance analysis, ash fusion analysis, free-swelling index determination, Gray-King coke type determination, Hardgrove grindability determination, Vicker's microhardness determination, major and minor element analysis, trace element analysis, and mineral species analysis. The pyrolysis of coal was studied the reactivity of chars, produced from all ranks of American coals, was studied for reactivity to air, CO2, H2 and steam. The catalytic effect of minerals and various cations on the gasification processes was examined. Combustion of chars, low volatile fuels, coal-oil-water-air emulsions and other subjects of research are reported.

  3. Thermochemical Conversion of Woody Biomass to Fuels and Chemicals Final Report

    SciTech Connect

    Pendse, Hemant P.

    2015-09-30

    Maine and its industries identified more efficient utilization of biomass as a critical economic development issue. In Phase I of this implementation project, a research team was assembled, research equipment was implemented and expertise was demonstrated in pyrolysis, hydrodeoxygenation of pyrolysis oils, catalyst synthesis and characterization, and reaction engineering. Phase II built upon the infrastructure to innovate reaction pathways and process engineering, and integrate new approaches for fuels and chemical production within pulp and paper and other industries within the state. This research cluster brought together chemists, engineers, physicists and students from the University of Maine, Bates College, and Bowdoin College. The project developed collaborations with Oak Ridge National Laboratory and Brookhaven National Laboratory. The specific research projects within this proposal were of critical interest to the DoE - in particular the biomass program within EERE and the catalysis/chemical transformations program within BES. Scientific and Technical Merit highlights of this project included: (1) synthesis and physical characterization of novel size-selective catalyst/supports using engineered mesoporous (1-10 nm diameter pores) materials, (2) advances in fundamental knowledge of novel support/ metal catalyst systems tailored for pyrolysis oil upgrading, (3) a microcalorimetric sensing technique, (4) improved methods for pyrolysis oil characterization, (5) production and characterization of woody biomass-derived pyrolysis oils, (6) development of two new patented bio oil pathways: thermal deoxygenation (TDO) and formate assisted pyrolysis (FASP), and (7) technoeconomics of pyrolysis of Maine forest biomass. This research cluster has provided fundamental knowledge to enable and assess pathways to thermally convert biomass to hydrocarbon fuels and chemicals.

  4. Catalytic conversion of isophorone to jet-fuel range aromatic hydrocarbons over a MoO(x)/SiO2 catalyst.

    PubMed

    Chen, Fang; Li, Ning; Wang, Wentao; Wang, Aiqin; Cong, Yu; Wang, Xiaodong; Zhang, Tao

    2015-07-28

    For the first time, jet fuel range C8-C9 aromatic hydrocarbons were synthesized in high carbon yield (∼80%) by the catalytic conversion of isophorone over MoO(x)/SiO2 at atmospheric pressure. A possible reaction pathway was proposed according to the control experiments and the intermediates generated during the reaction. PMID:26110372

  5. Study concerning the utilization of the ocean spreading center environment for the conversion of biomass to a liquid fuel. (Includes Appendix A: hydrothermal petroleum genesis). [Supercritical water

    SciTech Connect

    Steverson, M.; Stormberg, G.

    1985-01-01

    This document contains a report on the feasibility of utilizing energy obtained from ocean spreading centers as process heat for the conversion of municipal solid wastes to liquid fuels. The appendix contains a paper describing hydrothermal petroleum genesis. Both have been indexed separately for inclusion in the Energy Data Base. (DMC)

  6. TU-F-18C-02: Increasing Amorphous Selenium Thickness in Direct Conversion Flat-Panel Imagers for Contrast-Enhanced Dual-Energy Breast Imaging

    SciTech Connect

    Scaduto, DA; Hu, Y-H; Zhao, W

    2014-06-15

    Purpose: Contrast-enhanced (CE) breast imaging using iodinated contrast agents requires imaging with x-ray spectra at energies greater than those used in mammography. Optimizing amorphous selenium (a-Se) flat panel imagers (FPI) for this higher energy range may increase lesion conspicuity. Methods: We compare imaging performance of a conventional FPI with 200 μm a-Se conversion layer to a prototype FPI with 300 μm a-Se layer. Both detectors are evaluated in a Siemens MAMMOMAT Inspiration prototype digital breast tomosynthesis (DBT) system using low-energy (W/Rh 28 kVp) and high-energy (W/Cu 49 kVp) x-ray spectra. Detectability of iodinated lesions in dual-energy images is evaluated using an iodine contrast phantom. Effects of beam obliquity are investigated in projection and reconstructed images using different reconstruction methods. The ideal observer signal-to-noise ratio is used as a figure-of-merit to predict the optimal a-Se thickness for CE lesion detectability without compromising conventional full-field digital mammography (FFDM) and DBT performance. Results: Increasing a-Se thickness from 200 μm to 300 μm preserves imaging performance at typical mammographic energies (e.g. W/Rh 28 kVp), and improves the detective quantum efficiency (DQE) for high energy (W/Cu 49 kVp) by 30%. While the more penetrating high-energy x-ray photons increase geometric blur due to beam obliquity in the FPI with thicker a-Se layer, the effect on lesion detectability in FBP reconstructions is negligible due to the reconstruction filters employed. Ideal observer SNR for CE objects shows improvements in in-plane detectability with increasing a-Se thicknesses, though small lesion detectability begins to degrade in oblique projections for a-Se thickness above 500 μm. Conclusion: Increasing a-Se thickness in direct conversion FPI from 200 μm to 300 μm improves lesion detectability in CE breast imaging with virtually no cost to conventional FFDM and DBT. This work was partially

  7. ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

    SciTech Connect

    Joseph Rabovitser; Bruce Bryan

    2003-04-01

    The objective of this project is the development and commercial demonstration of an advanced biomass gasification-based power generation system at Boise Cascade Corporation's pulp and paper mill in DeRidder, Louisiana. The advanced power generation system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as the primary fuel resource. The novel system is based on three advanced technology components: GTI's RENUGAS{reg_sign} and 3-stage solid fuels combustion technologies coupled with one of the power generation approaches used in DOE's HIPPS program. Phase 1 of the project is a technical and economic evaluation of the system at the DeRidder site. A Continuation Application will be submitted at the conclusion of Phase 1 for authorization to proceed to testing and design in Phase 2. Phase 2 includes pilot-scale verification of selected system components and preparation of a detailed engineering design and cost estimate for retrofit of the advanced power system at the DeRidder mill. Phase 3 will complete procurement and construction of the system at the DeRidder site along with all required permitting activities. Phase 4 of the project will included plant commissioning, startup and demonstration operations. Design information for the Gasification Island was completed during the quarter. Two vendor quotations were received for the bark/hog fuel dryers. A final layout plan for the major equipment was developed and submitted to DeRidder for review and approval. The Institute of Paper Science and Technology (IPST) completed a subcontract for a laboratory study on VOC emissions from wood waste drying using bark from the DeRidder mill. Samples of DeRidder's lime mud and green liquor dregs were collected and analyzed in GTI's laboratory. It was determined that lime mud is far too fine to be utilized as inert bed material in the

  8. Specialty applications offer added options to transportation fuel outlets for Fischer-Tropsch conversion

    SciTech Connect

    Oukaci, R.; Singleton, A.H.

    1998-12-31

    In the past decade estimated global reserves of natural gas have increased by more than 30 percent to more than 5,300 trillion standard cubic feet (TCF). Of the current total, about 2,800 TCF are surplus to any current or anticipated demand. This ``overhand`` of natural gas availability has precipitated the development of various forms of the Fischer-Tropsch process for converting this resource to liquid hydrocarbons having premium value as transportation fuel feedstocks. The Williams Companies has been active in this field through the development of the GasCat process that focuses on supported cobalt catalysts and the slurry bubble column reactor applied to reserves capable of producing 500 million SCFD and higher quantities of natural gas, converting this into liquids production of 50,000 barrels/day and greater. In the course of the development of the GasCat process, an evaluation has been made of certain specialty applications of the hydrocarbons that can be produced. The high normal paraffin content (98%+), high purity (no S-, N-, O-compounds, aromatics, or metal inclusions) of the liquid products, as well as their low or no odor, generally difficult to achieve with petroleum products, make these F-T products exceptionally valuable solvents for a wide range of specialty applications. Similarly, the normal paraffinic nature and high purity of the F-T waxes provide the latter with outstanding properties that may result in a gradual displacement of petroleum waxes in many applications. An extensive evaluation of F-T products upgrading processes for redirection of F-T product slate to higher value specialty chemicals and waxes was carried out using F-T reactor effluents collected during some long catalyst performance runs. The specialty products were evaluated by GC, FTIR, NMR and a number of ASTM methods to determine their composition and physical properties. The results suggest that the smaller but higher value specialty applications may beneficially influence

  9. Conversion of lignocellulosic biomass to green fuel oil over sodium based catalysts.

    PubMed

    Nguyen, T S; Zabeti, M; Lefferts, L; Brem, G; Seshan, K

    2013-08-01

    Upgrading of biomass pyrolysis vapors over 20 wt.% Na2CO3/γ-Al2O3 catalyst was studied in a lab-scale fix-bed reactor at 500°C. Characterization of the catalyst using SEM and XRD has shown that sodium carbonate is well-dispersed on the support γ-Al2O3. TGA and (23)Na MAS NMR suggested the formation of new hydrated sodium phase, which is likely responsible for the high activity of the catalyst. Catalytic oil has much lower oxygen content (12.3 wt.%) compared to non-catalytic oil (42.1 wt.%). This comes together with a tremendous increase in the energy density (37 compared to 19 MJ kg(-1)). Decarboxylation of carboxylic acids was favoured on the catalyst, resulting to an oil almost neutral (TAN=3.8mg KOH/g oil and pH=6.5). However, the mentioned decarboxylation resulted in the formation of carbonyls, which correlates to low stability of the oil. Catalytic pyrolysis results in a bio-oil which resembles a fossil fuel oil in its properties. PMID:23747447

  10. Fossil fuel and hydrocarbon conversion using hydrogen-rich plasmas. Topical report February 1994--February 1995

    SciTech Connect

    1995-02-01

    Experiments were made on use of H and CH plasmas for converting waste materials and heavy oils to H-rich transportation fuels. Batch and continuous experiments were conducted with an industrial microwave generator and a commercial microwave oven. A continuously circulating reactor was constructed for conducting experiments on flowing oils. Experiments on decomposition of scrap tires showed that microwave plasmas can be used to decompose scrap tires into potentially useful liquid products. In a batch experiment using a commercial microwave oven, about 20% of the tire was converted to liquid products in about 9 minutes. Methane was decomposed in a microwave plasma to yield a liquid products composed of various compound types; GC/MS analyses identified unsaturated compounds including benzene, toluene, ethyl benzene, methyl and ethyl naphthalene, small amounts of larger aromatic rings, and olefinic compounds. Experiments on a crude oil in a continuously flowing reactor showed that distillate materials are produced using H and CH plasmas. Also, the recycle oils had an overall carbon aromaticity lower than that of starting feed material, indicating that some hydrogenation and methanation had taken place in the recycle oils.

  11. The first molecular level monitoring of carbohydrate conversion to 5-hydroxymethylfurfural in ionic liquids. B2O3--an efficient dual-function metal-free promoter for environmentally benign applications.

    PubMed

    Khokhlova, Elena A; Kachala, Vadim V; Ananikov, Valentine P

    2012-04-01

    The mechanistic nature of the conversion of carbohydrates to the sustainable platform chemical 5-hydroxymethylfurfural (5-HMF) was revealed at the molecular level. A detailed study of the key sugar units involved in the biomass conversion process has shown that the simple dissolution of fructose in the ionic liquid 1-butyl-3-methylimidazolium chloride significantly changes the anomeric composition and favors the formation of the open fructoketose form. A special NMR approach was developed for the determination of molecular structures and monitoring of chemical reactions directly in ionic liquids. The transformation of glucose to 5-HMF has been followed in situ through the detection of intermediate species. A new environmentally benign, easily available, metal-free promoter with a dual functionality (B(2)O(3)) was developed for carbohydrate conversion to 5-HMF. PMID:22359390

  12. Local production of agricultural fuel: conversion of alfalfa to ethanol. Final report

    SciTech Connect

    Nelson, D.; Tjostem, J.; Koeltzow, D.E.

    1981-09-01

    Initial project goals were to determine the economic and technological feasibility of producing fuel grade ethanol from the sugars contained in alfalfa and other legumes using a small-scale, single-farm production facility. These data indicate that alfalfa from the field does have reducing sugar present before any breakdown due to the presence of the mold. There is also plenty of natural bacterial contamination which quickly depletes the sugar supply. However, if the alfalfa is autoclaved prior to incubation, the number of bacteria present in the samples is greatly reduced. There was no difference between the flasks which contained an inoculum of Tricoderma reesei and those that did not. Analysis of these solutions failed to show any trace of cellulase activity even after 288 hours (12 days). Therefore, one can also conclude that the Tricoderma reesei strain QM9414 does not grow on alfalfa under these conditions. Future experiments will involve different conditions of temperature and pH. Acid insoluble lignin levels in our 3rd cutting alfalfa samples range from 16.8% to 19.77% with an average of 18.3%. This agrees well with the levels of 13.8% and 15.9% reported by Linder, et al. Results of lipid, water, protein, lignin and cellulose analysis of alfalfa are given. Over 80% of the cellulose in alfalfa can be converted into glucose. Subsequent fermentation by S. carlisbergenois produced near theoretical yields of ethanol. However, the cost of the hay was $440.00; the market value of the ethanol was $120.00. The poor economics results since only 13.1% of the alfalfa contains cellulose. Results show that while production of ethanol from legume-type plants is technically possible, it is not economically feasible.

  13. Impact of the High Flux Isotope Reactor HEU to LEU Fuel Conversion on Cold Source Nuclear Heat Generation Rates

    SciTech Connect

    Chandler, David

    2014-03-01

    Under the sponsorship of the US Department of Energy National Nuclear Security Administration, staff members at the Oak Ridge National Laboratory have been conducting studies to determine whether the High Flux Isotope Reactor (HFIR) can be converted from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. As part of these ongoing studies, an assessment of the impact that the HEU to LEU fuel conversion has on the nuclear heat generation rates in regions of the HFIR cold source system and its moderator vessel was performed and is documented in this report. Silicon production rates in the cold source aluminum regions and few-group neutron fluxes in the cold source moderator were also estimated. Neutronics calculations were performed with the Monte Carlo N-Particle code to determine the nuclear heat generation rates in regions of the HFIR cold source and its vessel for the HEU core operating at a full reactor power (FP) of 85 MW(t) and the reference LEU core operating at an FP of 100 MW(t). Calculations were performed with beginning-of-cycle (BOC) and end-of-cycle (EOC) conditions to bound typical irradiation conditions. Average specific BOC heat generation rates of 12.76 and 12.92 W/g, respectively, were calculated for the hemispherical region of the cold source liquid hydrogen (LH2) for the HEU and LEU cores, and EOC heat generation rates of 13.25 and 12.86 W/g, respectively, were calculated for the HEU and LEU cores. Thus, the greatest heat generation rates were calculated for the EOC HEU core, and it is concluded that the conversion from HEU to LEU fuel and the resulting increase of FP from 85 MW to 100 MW will not impact the ability of the heat removal equipment to remove the heat deposited in the cold source system. Silicon production rates in the cold source aluminum regions are estimated to be about 12.0% greater at BOC and 2.7% greater at EOC for the LEU core in comparison to the HEU core. Silicon is aluminum s major transmutation product and

  14. Cross section generation and physics modeling in a feasibility study of the conversion of the high flux isotope reactor core to use low-enriched uranium fuel

    SciTech Connect

    Ellis, R. J.; Gehin, J. C.; Primm Iii, R. T.

    2006-07-01

    A computational study has been initiated at ORNL to examine the feasibility of converting the High Flux Isotope Reactor (HFIR) from highly enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. The current study is limited to steady-state, nominal operation and are focused on the determination of the fuel requirements, primarily density, that are required to maintain the performance of the reactor. Reactor physics analyses are reported for a uranium-molybdenum alloy that would be substituted for the current fuel - U{sub 3}O{sub 8} mixed with aluminum. An LEU core design has been obtained and requires an increase in {sup 235}U loading of a factor of 1.9 over the current HEU fuel. These initial results indicate that the conversion from HEU to LEU results in a reduction of the thermal fluxes in the central flux trap region of approximately 9 % and in the outer beryllium reflector region of approximately 15%. Ongoing work is being performed to improve upon this initial design to further minimize the impact of conversion to LEU fuel. (authors)

  15. Hybrid photocathodes for solar fuel production: coupling molecular fuel-production catalysts with solid-state light harvesting and conversion technologies

    PubMed Central

    Cedeno, Diana; Krawicz, Alexandra; Moore, Gary F.

    2015-01-01

    Artificial photosynthesis is described as the great scientific and moral challenge of our time. We imagine a future where a significant portion of our energy is supplied by such technologies. However, many scientific, engineering and policy challenges must be addressed for this realization. Scientific challenges include the development of effective strategies to couple light absorption, electron transfer and catalysis for efficient conversion of light energy to chemical energy as well as the construction and study of structurally diverse assemblies to carry out these processes. In this article, we review recent efforts from our own research to develop a modular approach to interfacing molecular fuel-production catalysts to visible-light-absorbing semiconductors and discuss the role of the interfacing material as a protection layer for the catalysts as well as the underpinning semiconductor. In concluding, we briefly discuss the potential benefits of a globally coordinated project on artificial photosynthesis that interfaces teams of scientists, engineers and policymakers. Further, we offer cautions that such a large interconnected organization should consider. This article is inspired by, and draws largely from, an invited presentation given by the corresponding author at the Royal Society at Chicheley Hall, home of the Kavli Royal Society International Centre, Buckinghamshire on the themed meeting topic: ‘Do we need a global project on artificial photosynthesis?’ PMID:26052422

  16. Hybrid photocathodes for solar fuel production: coupling molecular fuel-production catalysts with solid-state light harvesting and conversion technologies.

    PubMed

    Cedeno, Diana; Krawicz, Alexandra; Moore, Gary F

    2015-06-01

    Artificial photosynthesis is described as the great scientific and moral challenge of our time. We imagine a future where a significant portion of our energy is supplied by such technologies. However, many scientific, engineering and policy challenges must be addressed for this realization. Scientific challenges include the development of effective strategies to couple light absorption, electron transfer and catalysis for efficient conversion of light energy to chemical energy as well as the construction and study of structurally diverse assemblies to carry out these processes. In this article, we review recent efforts from our own research to develop a modular approach to interfacing molecular fuel-production catalysts to visible-light-absorbing semiconductors and discuss the role of the interfacing material as a protection layer for the catalysts as well as the underpinning semiconductor. In concluding, we briefly discuss the potential benefits of a globally coordinated project on artificial photosynthesis that interfaces teams of scientists, engineers and policymakers. Further, we offer cautions that such a large interconnected organization should consider. This article is inspired by, and draws largely from, an invited presentation given by the corresponding author at the Royal Society at Chicheley Hall, home of the Kavli Royal Society International Centre, Buckinghamshire on the themed meeting topic: 'Do we need a global project on artificial photosynthesis?' PMID:26052422

  17. Angular-resolution and material-characterization measurements for a dual-particle imaging system with mixed-oxide fuel

    NASA Astrophysics Data System (ADS)

    Poitrasson-Rivière, Alexis; Polack, J. Kyle; Hamel, Michael C.; Klemm, Dietrich D.; Ito, Kai; McSpaden, Alexander T.; Flaska, Marek; Clarke, Shaun D.; Pozzi, Sara A.; Tomanin, Alice; Peerani, Paolo

    2015-10-01

    A dual-particle imaging (DPI) system, capable of simultaneously imaging fast neutrons and gamma rays, has been operated in the presence of mixed-oxide (MOX) fuel to assess the system's angular resolution and material-characterization capabilities. The detection principle is based on the scattering physics of neutrons (elastic scattering) and gamma rays (Compton scattering) in organic and inorganic scintillators. The detection system is designed as a combination of a two-plane Compton camera and a neutron-scatter camera. The front plane consists of EJ-309 liquid scintillators and the back plane consists of interleaved EJ-309 and NaI(Tl) scintillators. MCNPX-PoliMi was used to optimize the geometry of the system and the resulting prototype was built and tested using a Cf-252 source as an SNM surrogate. A software package was developed to acquire and process data in real time. The software was used for a measurement campaign to assess the angular resolution of the imaging system with MOX samples. Measurements of two MOX canisters of similar isotopics and intensity were performed for 6 different canister separations (from 5° to 30°, corresponding to distances of 21 cm and 131 cm, respectively). The measurements yielded a minimum separation of 20° at 2.5 m (86-cm separation) required to see 2 separate hot spots. Additionally, the results displayed good agreement with MCNPX-PoliMi simulations. These results indicate an angular resolution between 15° and 20°, given the 5° step. Coupled with its large field of view, and its capability to differentiate between spontaneous fission and (α,n) sources, the DPI system shows its potential for nuclear-nonproliferation applications.

  18. Basic mechanisms of photosynthesis and applications to improved production and conversion of biomass to fuels and chemical products

    SciTech Connect

    El-Sayed, M.; Greenbaum, E.; Wasielewski, M.

    1996-09-01

    Natural photosynthesis, the result of 3.5 billion years of evolutionary experimentation, is the best proven, functional solar energy conversion technology. It is responsible for filling the vast majority of humanity`s energy, nutritional, and materials needs. Understanding the basic physical chemical principles underlying photosynthesis as a working model system is vital to further exploitation of this natural technology. These principles can be used to improve or modify natural photosynthesis so that it is more efficient or so that it can produce unusual products such as hydrogen, methane, methanol, ethanol, diesel fuel substitutes, biodegradable materials, or other high value chemical products. Principles garnered from the natural process can also be used to design artificial photosynthetic devices that employ analogs of natural antenna and reaction center function, self-assembly and repair concepts, photoinduced charge transfer processes, photoprotection, and dark reactions that facilitate catalytic action to convert light into, useful chemical or electrical energy. The present broad understanding of many structural and functional aspects of photosynthesis has resulted from rapid recent research progress. X-ray structures of several key photosynthetic reaction centers and antenna systems are available, and the overall principles controlling photoinduced energy and electron transfer are being established.

  19. Conversion of residual organics in corn stover-derived biorefinery stream to bioenergy via microbial fuel cell

    SciTech Connect

    Borole, Abhijeet P; Hamilton, Choo Yieng; Schell, Daniel J

    2012-01-01

    A biorefinery process typically uses about 4-10 times as much water as the amount of biofuel generated. The wastewater produced in a biorefinery process contains residual sugars, 5-furfural, phenolics, and other pretreatment and fermentation byproducts. Treatment of the wastewater can reduce the need for fresh water and potentially add to the environmental benefits of the process. Use of microbial fuel cells (MFCs) for conversion of the various organics present in a post-fermentation biorefinery stream is reported here. The organic loading was varied over a wide range to assess removal efficiency, coulombic efficiency and power production. A coulombic efficiency of 40% was observed for a low loading of 1% (0.66 g/L) and decreased to 1.8% for the undiluted process stream (66.4 g/L organic loading). A maximum power density of 1180 mW/m2 was observed at a loading of 8%. Excessive loading was found to result in poor electrogenic performance. The results indicate that operation of an MFC at an intermediate loading using dilution and recirculation of the process stream can enable effective treatment with bioenergy recovery.

  20. Conversion of a micro, glow-ignition, two-stroke engine from nitromethane-methanol blend fuel to military jet propellant (JP-8)

    NASA Astrophysics Data System (ADS)

    Wiegand, Andrew L.

    The goal of the thesis "Conversion of a Micro, Glow-Ignition, Two-Stroke Engine from Nitromethane-Methanol Blend Fuel to Military Jet Propellant (JP-8)" was to demonstrate the ability to operate a small engine on JP-8 and was completed in two phases. The first phase included choosing, developing a test stand for, and baseline testing a nitromethane-methanol-fueled engine. The chosen engine was an 11.5 cc, glow-ignition, two-stroke engine designed for remote-controlled helicopters. A micro engine test stand was developed to load and motor the engine. Instrumentation specific to the low flow rates and high speeds of the micro engine was developed and used to document engine behavior. The second phase included converting the engine to operate on JP-8, completing JP-8-fueled steady-state testing, and comparing the performance of the JP-8-fueled engine to the nitromethane-methanol-fueled engine. The conversion was accomplished through a novel crankcase heating method; by heating the crankcase for an extended period of time, a flammable fuel-air mixture was generated in the crankcase scavenged engine, which greatly improved starting times. To aid in starting and steady-state operation, yttrium-zirconia impregnated resin (i.e. ceramic coating) was applied to the combustion surfaces. This also improved the starting times of the JP-8-fueled engine and ultimately allowed for a 34-second starting time. Finally, the steady-state data from both the nitromethane-methanol and JP-8-fueled micro engine were compared. The JP-8-fueled engine showed signs of increased engine friction while having higher indicated fuel conversion efficiency and a higher overall system efficiency. The minimal ability of JP-8 to cool the engine via evaporative effects, however, created the necessity of increased cooling air flow. The conclusion reached was that JP-8-fueled micro engines could be viable in application, but not without additional research being conducted on combustion phenomenon and

  1. Electrochemical, interfacial, and surface studies of the conversion of carbon dioxide to liquid fuels on tin electrodes

    NASA Astrophysics Data System (ADS)

    Wu, Jingjie

    The electrochemical reduction of carbon dioxide (CO2) into liquid fuels especially coupling with the intermittent renewable electricity offers a promising means of storing electricity in chemical form, which reduces the dependence on fossil fuels and mitigates the negative impact of anthropogenic CO2 emissions on the planet. Although converting CO2 to fuels is not in itself a new concept, the field has not substantially advanced in the last 30 years primarily because of the challenge of discovery of structural electrocatalysts and the development of membrane architectures for efficient collection of reactants and separation of products. An efficient catalyst for the electrochemical conversion of CO2 to fuels must be capable of mediating a proton-coupled electron transfer reaction at low overpotentials, reducing CO2 in the presence of water, selectively converting CO 2 to desirable chemicals, and sustaining long-term operations (Chapter 1). My Ph.D. research was an investigation of the electroreduction of CO2 on tin-based electrodes and development of an electrochemical cell to convert CO2 to liquid fuels. The initial study focused on understanding the CO2 reduction reaction chemistry in the electrical double layer with an emphasis on the effects of electrostatic adsorption of cations, specific adsorption of anion and electrolyte concentration on the potential and proton concentration at outer Helmholtz plane at which reduction reaction occurs. The variation of potential and proton concentration at outer Helmholtz plane accounts for the difference in activity and selectivity towards CO2 reduction when using different electrolytes (Chapter 2). Central to the highly efficient CO2 reduction is an optimum microstructure of catalyst layer in the Sn gas diffusion electrode (GDE) consisting of 100 nm Sn nanoparticles to facilitate gas diffusion and charge transfer. This microstructure in terms of the proton conductor fraction and catalyst layer thickness was optimized to

  2. Conversion and Evaluation of the University of Massachusetts Lowell Research Reactor From High-Enriched To Low-Enriched Uranium Fuel

    SciTech Connect

    Leo M. Bobek

    2003-11-19

    The process for converting the University of Massachusetts Lowell Research Reactor (UMLRR) from high-enrichment uranium (HEU) fuel to low-enrichment uranium (LEU) fuel began in 1988. Several years of design reviews, computational modeling, and thermal hydraulic analyses resulted in a preliminary reference core design and configuration based on 20 standard, MTR-type, flat-plate, 19.75% enriched, uranium silicide (u3Si2) fuel elements. A final safety analysis for the fuel conversion was submitted to the Nuclear Regulatory Commission (NRC) in 1993. The NRC made two additional requests for additional information and supplements were submitted in 1994 and 1997. The new UMLRR Reactor Supervisor initiated an effort to change the LEU reference core configuration to eliminate a complicated control rod modification needed for the smaller core.

  3. Inhibition of CO poisoning on Pt catalyst coupled with the reduction of toxic hexavalent chromium in a dual-functional fuel cell.

    PubMed

    Chung, Dong Young; Kim, Hyoung-il; Chung, Young-Hoon; Lee, Myeong Jae; Yoo, Sung Jong; Bokare, Alok D; Choi, Wonyong; Sung, Yung-Eun

    2014-01-01

    We propose a method to enhance the fuel cell efficiency with the simultaneous removal of toxic heavy metal ions. Carbon monoxide (CO), an intermediate of methanol oxidation that is primarily responsible for Pt catalyst deactivation, can be used as an in-situ reducing agent for hexavalent chromium (Cr (VI)) with reactivating the CO-poisoned Pt catalyst. Using electro-oxidation measurements, the oxidation of adsorbed CO molecules coupled with the concurrent conversion of Cr (VI) to Cr (III) was confirmed. This concept was also successfully applied to a methanol fuel cell to enhance its performance efficiency and to remove toxic Cr (VI) at the same time. PMID:25502744

  4. Inhibition of CO poisoning on Pt catalyst coupled with the reduction of toxic hexavalent chromium in a dual-functional fuel cell

    NASA Astrophysics Data System (ADS)

    Chung, Dong Young; Kim, Hyoung-Il; Chung, Young-Hoon; Lee, Myeong Jae; Yoo, Sung Jong; Bokare, Alok D.; Choi, Wonyong; Sung, Yung-Eun

    2014-12-01

    We propose a method to enhance the fuel cell efficiency with the simultaneous removal of toxic heavy metal ions. Carbon monoxide (CO), an intermediate of methanol oxidation that is primarily responsible for Pt catalyst deactivation, can be used as an in-situ reducing agent for hexavalent chromium (Cr (VI)) with reactivating the CO-poisoned Pt catalyst. Using electro-oxidation measurements, the oxidation of adsorbed CO molecules coupled with the concurrent conversion of Cr (VI) to Cr (III) was confirmed. This concept was also successfully applied to a methanol fuel cell to enhance its performance efficiency and to remove toxic Cr (VI) at the same time.

  5. Inhibition of CO poisoning on Pt catalyst coupled with the reduction of toxic hexavalent chromium in a dual-functional fuel cell

    PubMed Central

    Chung, Dong Young; Kim, Hyoung-il; Chung, Young-Hoon; Lee, Myeong Jae; Yoo, Sung Jong; Bokare, Alok D.; Choi, Wonyong; Sung, Yung-Eun

    2014-01-01

    We propose a method to enhance the fuel cell efficiency with the simultaneous removal of toxic heavy metal ions. Carbon monoxide (CO), an intermediate of methanol oxidation that is primarily responsible for Pt catalyst deactivation, can be used as an in-situ reducing agent for hexavalent chromium (Cr (VI)) with reactivating the CO-poisoned Pt catalyst. Using electro-oxidation measurements, the oxidation of adsorbed CO molecules coupled with the concurrent conversion of Cr (VI) to Cr (III) was confirmed. This concept was also successfully applied to a methanol fuel cell to enhance its performance efficiency and to remove toxic Cr (VI) at the same time. PMID:25502744

  6. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products

    SciTech Connect

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E.; Laurens, L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-01

    Beginning in 2013, NREL began transitioning from the singular focus on ethanol to a broad slate of products and conversion pathways, ultimately to establish similar benchmarking and targeting efforts. One of these pathways is the conversion of algal biomass to fuels via extraction of lipids (and potentially other components), termed the 'algal lipid upgrading' or ALU pathway. This report describes in detail one potential ALU approach based on a biochemical processing strategy to selectively recover and convert select algal biomass components to fuels, namely carbohydrates to ethanol and lipids to a renewable diesel blendstock (RDB) product. The overarching process design converts algal biomass delivered from upstream cultivation and dewatering (outside the present scope) to ethanol, RDB, and minor coproducts, using dilute-acid pretreatment, fermentation, lipid extraction, and hydrotreating.

  7. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 12: Fuel cells. [energy conversion efficiency of, for use in electric power plants

    NASA Technical Reports Server (NTRS)

    Warde, C. J.; Ruka, R. J.; Isenberg, A. O.

    1976-01-01

    A parametric assessment of four fuel cell power systems -- based on phosphoric acid, potassium hydroxide, molten carbonate, and stabilized zirconia -- has shown that the most important parameters for electricity-cost reduction and/or efficiency improvement standpoints are fuel cell useful life and power density, use of a waste-heat recovery system, and fuel type. Typical capital costs, overall energy efficiencies (based on the heating value of the coal used to produce the power plant fuel), and electricity costs are: phosphoric acid $350-450/kWe, 24-29%, and 11.7 to 13.9 mills/MJ (42 to 50 mills/kWh); alkaline $450-700/kWe, 26-31%, and 12.8 to 16.9 mills/MJ (46 to 61 mills/kWh); molten carbonate $480-650/kWe, 32-46%, and 10.6 to 19.4 mills/MJ (38 to 70 mills/kWh), stabilized zirconia $420-950/kWe, 26-53%, and 9.7 to 16.9 mills/MJ (35 to 61 mills/kWh). Three types of fuel cell power plants -- solid electrolytic with steam bottoming, molten carbonate with steam bottoming, and solid electrolyte with an integrated coal gasifier -- are recommended for further study.

  8. Experimental study on the effect of varying syngas composition on the emissions of dual fuel CI engine operating at various engine speeds

    NASA Astrophysics Data System (ADS)

    Mahgoub, B. K. M.; Sulaiman, S. A.; Karim, Z. A. A.; Hagos, F. Y.

    2015-12-01

    Using syngas as a supplement fuel of diesel in dual fuel mode is a proposed solution in the effort to protect the environment and control the serious threats posed by greenhouse gas emissions from compression ignition engines. The objective of this study was to experimentally examine the effect of syngas composition on the exhaust emission of dual fuel compression ignition (CI) engine at various engine speeds, and to compare the operating ranges of imitated syngas versus pure diesel. The study was conducted using a naturally aspirated, two strokes, single cylinder 3.7 kW diesel engine operated at speeds of 1200, 2000 and 3000 rpm. The engine was tested with three different syngas compositions. Diesel fuel was partially substituted by syngas through the air inlet. The test results disclose the impact of using syngas in CI engines on emission of CO2, NOx, unburned hydrocarbons and carbon monoxide. The experimental measurements confirmed that all syngas compositions are capable of reducing the emissions of CO2 and NOX compared with diesel fuel. Wide range of diesel replacement ratios (up to 72%) was attained without any penalty. Syngas with composition of 49% N2, 12% CO2, 25% CO, 10% H2, and 4% CH4 reduced the emissions of CO2 and NOx at engine speed of 1200 rpm up to 1% and 108 ppm, respectively. The lowest emission of UHC and NOx was emitted when the engine was operating at speed of 2000 rpm and 3000 rpm, respectively with composition of 38% N2, 8% Co2, 29% CO, 19% H2, and 6% CH4. Therefore, syngas could be a promising technique for controlling NOx emissions in CI engines. However, hydrogen content in syngas is important parameter that needs to be further investigation for its effect.

  9. High conversion of coal to transportation fuels for the future with low HC gas production. Progress report No. 11, April 1--June 30, 1995

    SciTech Connect

    Wiser, W.H.; Oblad, A.G.

    1995-07-01

    The objectives of this research are: (1) produce a synthetic crude from coal at a cost lower than $30.00 per barrel; and (2) produce a fuel which is low in aromatics, yet of sufficiently high octane number for use in the gasoline-burning transportation vehicles of today. To meet this second objective, research was proposed, and funding awarded, for conversion of the highly-aromatic liquid product from coal conversion to a product high in isoparaffins, which compounds in the gasoline range exhibit a high octane number. Experimental coal liquefaction studies conducted in a batch microreactor in our laboratory have demonstrated potential for high conversions of coal to liquids with low yield of hydrocarbon (HC) gases, hence small consumption of hydrogen in the primary liquefaction step. Ratios of liquids/HC gases as high as 30/1, at liquid yields as high as 82% of the coal by weight, have been achieved. The principal objective of this work is to examine how nearly we may approach these results in a continuous-flow system, at a size sufficient to evaluate the process concept for production of transportation fuels from coal. A continuous-flow reactor system is to be designed, constructed and operated. The system is to be computer-operated for process control and data logging, and is to be fully instrumented. The primary liquid products will be characterized by GC, FTIR, and GC/MS, to determine the types and quantities of the principal components produced under conditions of high liquids production with high ratios of liquids/HC gases, hydrogen consumption for the conversion to primary liquids will be calculated. Conversion of the aromatics of this liquid product to isoparrafins will be investigated, to examine the potential for producing a transportation fuel from coal with satisfactory octane rating but low in aromatic content. Progress to date is described.

  10. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway

    SciTech Connect

    Jones, Susanne B.; Meyer, Pimphan A.; Snowden-Swan, Lesley J.; Padmaperuma, Asanga B.; Tan, Eric; Dutta, Abhijit; Jacobson, Jacob; Cafferty, Kara

    2013-11-01

    This report describes a proposed thermochemical process for converting biomass into liquid transportation fuels via fast pyrolysis followed by hydroprocessing of the condensed pyrolysis oil. As such, the analysis does not reflect the current state of commercially-available technology but includes advancements that are likely, and targeted to be achieved by 2017. The purpose of this study is to quantify the economic impact of individual conversion targets to allow a focused effort towards achieving cost reductions.

  11. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Fast Pyrolysis and Hydrotreating Bio-oil Pathway

    SciTech Connect

    Jones, S.; Meyer, P.; Snowden-Swan, L.; Padmaperuma, A.; Tan, E.; Dutta, A.; Jacobson, J.; Cafferty, K.

    2013-11-01

    This report describes a proposed thermochemical process for converting biomass into liquid transportation fuels via fast pyrolysis followed by hydroprocessing of the condensed pyrolysis oil. As such, the analysis does not reflect the current state of commercially-available technology but includes advancements that are likely, and targeted to be achieved by 2017. The purpose of this study is to quantify the economic impact of individual conversion targets to allow a focused effort towards achieving cost reductions.

  12. Initial Neutronics Analyses for HEU to LEU Fuel Conversion of the Transient Reactor Test Facility (TREAT) at the Idaho National Laboratory

    SciTech Connect

    Kontogeorgakos, D.; Derstine, K.; Wright, A.; Bauer, T.; Stevens, J.

    2013-06-01

    The purpose of the TREAT reactor is to generate large transient neutron pulses in test samples without over-heating the core to simulate fuel assembly accident conditions. The power transients in the present HEU core are inherently self-limiting such that the core prevents itself from overheating even in the event of a reactivity insertion accident. The objective of this study was to support the assessment of the feasibility of the TREAT core conversion based on the present reactor performance metrics and the technical specifications of the HEU core. The LEU fuel assembly studied had the same overall design, materials (UO2 particles finely dispersed in graphite) and impurities content as the HEU fuel assembly. The Monte Carlo N–Particle code (MCNP) and the point kinetics code TREKIN were used in the analyses.

  13. The joint Australia/Federal Republic of Germany feasibility study on the conversion of Australian coals into liquid fuels in Australia

    NASA Astrophysics Data System (ADS)

    Imhausen, K. H.

    1982-08-01

    The IG hydrogenation process used commercially in Germany up to 1945, was improved. Pilot plants in Germany are presently under construction or in the start-up phase. A technical concept for the conversion of Australian bituminous coals and/or Australian brown coals into automotive fuels, using coal hydrogenation, gasification and Fisher-Tropsch synthesis was developed. Development of technology, consumption figures and of expenditure/investment for a complete plant, producing about 3 million tons of automotive fuels per year, was also attempted. The results show that standard automotive fuels are produced from bituminous coal, using a combination of high pressure coal hydrogenation and of Fisher-Tropsch synthesis, and from brown coal, using high pressure coal hydrogenation only. Under the assumption that crude oil prices increase 3% more rapidly than yearly inflation, and the raw material cost are staying at a low level, commercial plants are planned.

  14. Engineering Bacteria for Efficient Fuel Production: Novel Biological Conversion of Hydrogen and Carbon Dioxide Directly into Free Fatty Acids

    SciTech Connect

    2010-07-12

    Electrofuels Project: OPX Biotechnologies is engineering a microorganism currently used in industrial biotechnology to directly produce a liquid fuel from hydrogen and carbon dioxide (CO2). The microorganism has the natural ability to use hydrogen and CO2 for growth. OPX Biotechnologies is modifying the microorganism to divert energy and carbon away from growth and towards the production of liquid fuels in larger, commercially viable quantities. The microbial system will produce a fuel precursor that can be chemically upgraded to various hydrocarbon fuels.

  15. Effect of Particle and Injection Parameters on the Performance of a Dual-Stage High-Velocity Oxygen Fuel Thermal Spray System

    NASA Astrophysics Data System (ADS)

    Khan, Mohammed N.; Shamim, Tariq

    2015-06-01

    For temperature-sensitive material (such as titanium) coatings, recently developed high-velocity oxygen fuel dual-stage thermal spray systems offer better control of particle oxidation and production of various coating structures. These advantages of the dual-stage thermal system are significantly influenced by the state of the coating particles being injected. Hence, the objective of the present study is to investigate the effects of particle size, shape, injection velocity, and injection angle on a dual-stage thermal spray system by employing a comprehensive mathematical model. The results demonstrate that the particle size, shape, injection velocity, and injection angle affect the particle velocity and temperature, which in turn may affect the coating quality. The results show that smaller particles have higher temperatures and velocities owing to decrease in particle thermal and mass inertia. Spherical particles have higher temperature and lower velocity than the non-spherical particles because of lower drag. The particle velocity and temperature also increase with the increase of the injection velocity. Similarly, the particles injection angle also plays an important role. Higher particle temperatures and velocities outside of the barrel are obtained if the particles are injected at oblique angles to the main gaseous flow.

  16. A dual-structured anode/Ni-mesh current collector hollow fibre for micro-tubular solid oxide fuel cells (SOFCs)

    NASA Astrophysics Data System (ADS)

    Li, Tao; Wu, Zhentao; Li, K.

    2014-04-01

    In this study, a unique dual-structured hollow fibre design has been developed for micro-tubular solid oxide fuel cells (MT-SOFCs), using a single-step phase-inversion assisted co-extrusion technique. The dual-structured design consists of an outer anode layer and an inner anodic current collecting layer that are formed simultaneously during fabrication. Meanwhile, a plurality of micro-channels initiating from the exterior surface of the anode layer penetrate through the two layers, forming a highly asymmetric anode and a mesh current collecting layer, which significantly facilitates the gas transport. With the increasing thickness of the current collecting layer (approximately 15-60 μm), electrical conductivity increases from 1.9 × 104 S cm-1 to 4.0 × 104 S cm-1, while the mechanical strength drops slightly from approximately 168-113 MPa due to its 'dragging effect' during co-sintering. The benefits of improved current collection may potentially overweigh the reduced mechanical property, especially when dual-structured hollow fibres of this type are bundled together to form a stack. Moreover, benefiting from this innovative design, sustainable development of a larger scale of MT-SOFC stack or system becomes less challenging, since technical issues, such as concentration polarization and efficient current collection, hampering the MT-SOFC system design, can be completely overcome.

  17. The Bacterial Flagellar Type III Export Gate Complex Is a Dual Fuel Engine That Can Use Both H+ and Na+ for Flagellar Protein Export

    PubMed Central

    Minamino, Tohru; Morimoto, Yusuke V.; Hara, Noritaka; Aldridge, Phillip D.; Namba, Keiichi

    2016-01-01

    The bacterial flagellar type III export apparatus utilizes ATP and proton motive force (PMF) to transport flagellar proteins to the distal end of the growing flagellar structure for self-assembly. The transmembrane export gate complex is a H+–protein antiporter, of which activity is greatly augmented by an associated cytoplasmic ATPase complex. Here, we report that the export gate complex can use sodium motive force (SMF) in addition to PMF across the cytoplasmic membrane to drive protein export. Protein export was considerably reduced in the absence of the ATPase complex and a pH gradient across the membrane, but Na+ increased it dramatically. Phenamil, a blocker of Na+ translocation, inhibited protein export. Overexpression of FlhA increased the intracellular Na+ concentration in the presence of 100 mM NaCl but not in its absence, suggesting that FlhA acts as a Na+ channel. In wild-type cells, however, neither Na+ nor phenamil affected protein export, indicating that the Na+ channel activity of FlhA is suppressed by the ATPase complex. We propose that the export gate by itself is a dual fuel engine that uses both PMF and SMF for protein export and that the ATPase complex switches this dual fuel engine into a PMF-driven export machinery to become much more robust against environmental changes in external pH and Na+ concentration. PMID:26943926

  18. Proceedings of the 33. intersociety energy conversion engineering conference

    SciTech Connect

    Anghaie, S.

    1998-07-01

    These papers were presented at the Intersociety Energy Conversion Engineering Conference, August of 1998. The topics of the papers included aerospace power analyses and simulation, space energy conversion, applications and requirements for space power systems, space solar power, terrestrial energy, aerospace batteries, aerospace power management, aerospace power electronics, aircraft power, dual use technologies, electric propulsion, wireless energy transmission, terrestrial thermoelectric, heat pumps, innovative concepts, stirling engine and heat pump applications, stirling engines and components, stirling analysis, magnetohydrodynamics, thermionics, AMTEC advanced modular power systems, advanced cycles, co-generation and heat engines, alkali batteries, other batteries, terrestrial fuel cells, fuel cells in distributed generation systems, fuel cells in buildings applications, systems modeling and analysis of fuel cells, polymer electrolyte fuel cells, fuel processing for fuel cells, alternative fuel vehicles, clean energy options, electric vehicles, energy and the environment, thermal storage, building energy systems, concepts in cold fusion, power systems control, electric power systems, simulation and modeling, nuclear power systems, fossil fuels, energy policy, deregulation of electric utilities, photovoltaic energy technology, modeling and simulation, advanced solar house and building, wind energy, hydrogen energy systems, energy from waste and biomass, geothermal, cryogenic heat transfer, heat pipes, loop heat pipes, and capillary pumped loops, spacecraft and aircraft thermal control, numerical analysis and code verification, two phase heat and mass transfer.

  19. Study of combustion and emission characteristics of fuel derived from waste plastics by various waste to energy (W-t-E) conversion processes

    NASA Astrophysics Data System (ADS)

    Hazrat, M. A.; Rasul, M. G.; Khan, M. M. K.

    2016-07-01

    Reduction of plastic wastes by means of producing energy can be treated as a good investment in the waste management and recycling sectors. In this article, conversion of plastics into liquid fuel by two thermo-chemical processes, pyrolysis and gasification, are reviewed. The study showed that the catalytic pyrolysis of homogenous waste plastics produces better quality and higher quantity of liquefied fuel than that of non-catalytic pyrolysis process at a lower operating temperature. The syngas produced from gasification process, which occurs at higher temperature than the pyrolysis process, can be converted into diesel by the Fischer-Tropsch (FT) reaction process. Conducive bed material like Olivine in the gasification conversion process can remarkably reduce the production of tar. The waste plastics pyrolysis oil showed brake thermal efficiency (BTE) of about 27.75%, brake specific fuel consumption (BSFC) of 0.292 kg/kWh, unburned hydrocarbon emission (uHC) of 91 ppm and NOx emission of 904 ppm in comparison with the diesel for BTE of 28%, BSFC of 0.276 kg/kWh, uHC of 57 ppm and NOx of 855 ppm. Dissolution of Polystyrene (PS) into biodiesel also showed the potential of producing alternative transport fuel. It has been found from the literature that at higher engine speed, increased EPS (Expanded Polystyrene) quantity based biodiesel blends reduces CO, CO2, NOx and smoke emission. EPS-biodiesel fuel blend increases the brake thermal efficiency by 7.8%, specific fuel consumption (SFC) by 7.2% and reduces brake power (Pb) by 3.2%. More study using PS and EPS with other thermoplastics is needed to produce liquid fuel by dissolving them into biodiesel and to assess their suitability as a transport fuel. Furthermore, investigation to find out most suitable W-t-E process for effective recycling of the waste plastics as fuel for internal combustion engines is necessary to reduce environmental pollution and generate revenue which will be addressed in this article.

  20. Copper-palladium core-shell as an anode in a multi-fuel membraneless nanofluidic fuel cell: toward a new era of small energy conversion devices.

    PubMed

    Maya-Cornejo, J; Ortiz-Ortega, E; Álvarez-Contreras, L; Arjona, N; Guerra-Balcázar, M; Ledesma-García, J; Arriaga, L G

    2015-02-14

    A membraneless nanofluidic fuel cell with flow-through electrodes that works with several fuels (individually or mixed): methanol, ethanol, glycerol and ethylene-glycol in alkaline media is presented. For this application, an efficient Cu@Pd electrocatalyst was synthesized and tested, resulting outstanding performance until now reported, opening the possibility of power nano-devices for multi-uses purposes, regardless of fuel re-charge employed. PMID:25566986

  1. Early direct-injection, low-temperature combustion of diesel fuel in an optical engine utilizing a 15-hole, dual-row, narrow-included-angle nozzle.

    SciTech Connect

    Gehrke, Christopher R.; Radovanovic, Michael S.; Milam, David M.; Martin, Glen C.; Mueller, Charles J.

    2008-04-01

    Low-temperature combustion of diesel fuel was studied in a heavy-duty, single-cylinder optical engine employing a 15-hole, dual-row, narrow-included-angle nozzle (10 holes x 70/mD and 5 holes x 35/mD) with 103-/gmm-diameter orifices. This nozzle configuration provided the spray targeting necessary to contain the direct-injected diesel fuel within the piston bowl for injection timings as early as 70/mD before top dead center. Spray-visualization movies, acquired using a high-speed camera, show that impingement of liquid fuel on the piston surface can result when the in-cylinder temperature and density at the time of injection are sufficiently low. Seven single- and two-parameter sweeps around a 4.82-bar gross indicated mean effective pressure load point were performed to map the sensitivity of the combustion and emissions to variations in injection timing, injection pressure, equivalence ratio, simulated exhaust-gas recirculation, intake temperature, intake boost pressure, and load. High-speed movies of natural luminosity were acquired by viewing through a window in the cylinder wall and through a window in the piston to provide quasi-3D information about the combustion process. These movies revealed that advanced combustion phasing resulted in intense pool fires within the piston bowl, after the end of significant heat release. These pool fires are a result of fuel-films created when the injected fuel impinged on the piston surface. The emissions results showed a strong correlation with pool-fire activity. Smoke and NO/dx emissions rose steadily as pool-fire intensity increased, whereas HC and CO showed a dramatic increase with near-zero pool-fire activity.

  2. Biomass Thermochemical Conversion Program. 1984 annual report

    SciTech Connect

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

    1985-01-01

    The objective of the program is to generate scientific data and conversion process information that will lead to establishment of cost-effective process for converting biomass resources into clean fuels. The goal of the program is to develop the data base for biomass thermal conversion by investigating the fundamental aspects of conversion technologies and by exploring those parameters that are critical to the conversion processes. The research activities can be divided into: (1) gasification technology; (2) liquid fuels technology; (3) direct combustion technology; and (4) program support activities. These activities are described in detail in this report. Outstanding accomplishments during fiscal year 1984 include: (1) successful operation of 3-MW combustor/gas turbine system; (2) successful extended term operation of an indirectly heated, dual bed gasifier for producing medium-Btu gas; (3) determination that oxygen requirements for medium-Btu gasification of biomass in a pressurized, fluidized bed gasifier are low; (4) established interdependence of temperature and residence times on biomass pyrolysis oil yields; and (5) determination of preliminary technical feasibility of thermally gasifying high moisture biomass feedstocks. A bibliography of 1984 publications is included. 26 figs., 1 tab.

  3. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates.

    SciTech Connect

    Lyons, J.E.

    1992-07-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  4. Light alkane conversion processes - Suprabiotic catalyst systems for selective oxidation of light alkane gases to fuel oxygenates

    SciTech Connect

    Lyons, J.E.

    1992-01-01

    The objective of the work presented in this paper is to develop new, efficient catalysts for the selective transformation of the light alkanes in natural gas to alcohols for use as liquid transportation fuels, fuel precursors and chemical products. There currently exists no DIRECT one-step catalytic air-oxidation process to convert these substrates to alcohols. Such a one-step route would represent superior useful technology for the utilization of natural gas and similar refinery-derived light hydrocarbon streams. Processes for converting natural gas or its components (methane, ethane, propane, and the butanes) to alcohols for use as motor fuels, fuel additives or fuel precursors will not only add a valuable alternative to crude oil but will produce a clean-burning, high octane alternative to conventional gasoline.

  5. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals. Quarterly technical status report, October 1--December 31, 1992

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-02-01

    Light hydrocarbon gases could be reacted with low cost alkaline earth metal oxide (CaO, MgO) in high-temperature plasma reactor to achieve very high ({le}100%) gas conversion to H{sub 2}, CO, and the corresponding metal carbides. These carbides could be stored, transported, and hydrolyzed to acetylene or methyl acetylene, which in turn could be upgraded to a wide range of chemicals and premium liquid hydrocarbon fuels. An electric arc discharge reactor was built for converting methane. Literature reviews were made.

  6. PREPARING THE HIGH FLUX ISOTOPE REACTOR FOR CONVERSION TO LOW ENRICHED URANIUM FUEL ? RETURN TO 100 MW

    SciTech Connect

    Smith, Kevin Arthur; Primm, Trent

    2009-01-01

    The feasibility of low-enriched uranium (LEU) fuel as a replacement for the current, high enriched uranium (HEU) fuel for the High Flux Isotope Reactor (HFIR) has been under study since 2006. Reactor performance studies have been completed for conceptual plate designs and show that maintaining reactor performance while converting to LEU fuel requires returning the reactor power to 100 MW from 85 MW. The analyses required to up-rate the reactor power and the methods to perform these analyses are discussed. Comments regarding the regulatory approval process are provided along with a conceptual schedule.

  7. Compliant alkali silicate sealing glass for solid oxide fuel cell applications: the effect of protective YSZ coating on electrical stability in dual environment

    SciTech Connect

    Chou, Y. S.; Thomsen, Edwin C.; Choi, Jung-Pyung; Stevenson, Jeffry W.

    2012-03-15

    Recently, compliant sealing glass has been proposed as a potential candidate sealant for solid oxide fuel cell (SOFC) applications. In a previous paper, the thermal stability and chemical compatibility were reported for a compliant alkali-containing silicate glass sealed between anode supported YSZ bi-layer and YSZ-coated stainless steel interconnect. In this paper, we will report the electrical stability of the compliant glass under a DC load and dual environment at 700-800 degrees C. Apparent electrical resistivity was measured with a 4-point method for the glass sealed between two plain SS441 metal coupons or YSZ-coated aluminized substrates. The results showed instability with plain SS441 at 800 degrees C, but stable behavior of increasing resistivity with time was observed with the YSZ coated SS441. In addition, results of interfacial microstructure analysis with scanning electron microscopy will be correlated with the measured resistivity results. Overall, the YSZ coating demonstrated chemically stability with the alkali-containing compliant silicate sealing glass under electrical field and dual environments.

  8. Process for the conversion of and aqueous biomass hydrolyzate into fuels or chemicals by the selective removal of fermentation inhibitors

    DOEpatents

    Hames, Bonnie R.; Sluiter, Amie D.; Hayward, Tammy K.; Nagle, Nicholas J.

    2004-05-18

    A process of making a fuel or chemical from a biomass hydrolyzate is provided which comprises the steps of providing a biomass hydrolyzate, adjusting the pH of the hydrolyzate, contacting a metal oxide having an affinity for guaiacyl or syringyl functional groups, or both and the hydrolyzate for a time sufficient to form an adsorption complex; removing the complex wherein a sugar fraction is provided, and converting the sugar fraction to fuels or chemicals using a microorganism.

  9. Acceleration of Enzymatic conversion of Agricultural Waste Biomass into Bio-fuels by Low Intensity Uniform Ultrasound Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most critical stages of conversion of agricultural waste biomass into biofuels employs hydrolysis reactions between highly specific enzymes and matching substrates (e.g. corn stover cellulose with cellulase) that produce soluble sugars, which then could be converted into ethanol. Despite ...

  10. Single junction inverted polymer solar cell reaching power conversion efficiency 10.31% by employing dual-doped zinc oxide nano-film as cathode interlayer.

    PubMed

    Liao, Sih-Hao; Jhuo, Hong-Jyun; Yeh, Po-Nan; Cheng, Yu-Shan; Li, Yi-Lun; Lee, Yu-Hsuan; Sharma, Sunil; Chen, Show-An

    2014-01-01

    We present high efficiency and stable inverted PSCs (i-PSC) by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) (denoted as InZnO-BisC60) film as cathode interlayer and PTB7-Th:PC71BM as the active layer (where PTB7-Th is a low bandgap polymer we proposed previously). This dual-doped ZnO, InZnO-BisC60, film shows dual and opposite gradient dopant concentration profiles, being rich in fullerene derivative at the cathode surface in contact with active layer and rich in In at the cathode surface in contact with the ITO surface. Such doping in ZnO not only gives improved surface conductivity by a factor of 270 (from 0.015 to 4.06 S cm(-1)) but also provides enhanced electron mobility by a factor of 132 (from 8.25*10(-5) to 1.09*10(-2) cm(2) V(-1) s(-1)). The resulting i-PSC exhibits the improved PCE 10.31% relative to that with ZnO without doping 8.25%. This PCE 10.31% is the best result among the reported values so far for single junction PSC. PMID:25351472

  11. Single Junction Inverted Polymer Solar Cell Reaching Power Conversion Efficiency 10.31% by Employing Dual-Doped Zinc Oxide Nano-Film as Cathode Interlayer

    NASA Astrophysics Data System (ADS)

    Liao, Sih-Hao; Jhuo, Hong-Jyun; Yeh, Po-Nan; Cheng, Yu-Shan; Li, Yi-Lun; Lee, Yu-Hsuan; Sharma, Sunil; Chen, Show-An

    2014-10-01

    We present high efficiency and stable inverted PSCs (i-PSC) by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) (denoted as InZnO-BisC60) film as cathode interlayer and PTB7-Th:PC71BM as the active layer (where PTB7-Th is a low bandgap polymer we proposed previously). This dual-doped ZnO, InZnO-BisC60, film shows dual and opposite gradient dopant concentration profiles, being rich in fullerene derivative at the cathode surface in contact with active layer and rich in In at the cathode surface in contact with the ITO surface. Such doping in ZnO not only gives improved surface conductivity by a factor of 270 (from 0.015 to 4.06 S cm-1) but also provides enhanced electron mobility by a factor of 132 (from 8.25*10-5 to 1.09*10-2 cm2 V-1 s-1). The resulting i-PSC exhibits the improved PCE 10.31% relative to that with ZnO without doping 8.25%. This PCE 10.31% is the best result among the reported values so far for single junction PSC.

  12. Single Junction Inverted Polymer Solar Cell Reaching Power Conversion Efficiency 10.31% by Employing Dual-Doped Zinc Oxide Nano-Film as Cathode Interlayer

    PubMed Central

    Liao, Sih-Hao; Jhuo, Hong-Jyun; Yeh, Po-Nan; Cheng, Yu-Shan; Li, Yi-Lun; Lee, Yu-Hsuan; Sharma, Sunil; Chen, Show-An

    2014-01-01

    We present high efficiency and stable inverted PSCs (i-PSC) by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) (denoted as InZnO-BisC60) film as cathode interlayer and PTB7-Th:PC71BM as the active layer (where PTB7-Th is a low bandgap polymer we proposed previously). This dual-doped ZnO, InZnO-BisC60, film shows dual and opposite gradient dopant concentration profiles, being rich in fullerene derivative at the cathode surface in contact with active layer and rich in In at the cathode surface in contact with the ITO surface. Such doping in ZnO not only gives improved surface conductivity by a factor of 270 (from 0.015 to 4.06 S cm−1) but also provides enhanced electron mobility by a factor of 132 (from 8.25*10−5 to 1.09*10−2 cm2 V−1 s−1). The resulting i-PSC exhibits the improved PCE 10.31% relative to that with ZnO without doping 8.25%. This PCE 10.31% is the best result among the reported values so far for single junction PSC. PMID:25351472

  13. Technical Support to SBIR Phase II Project: Improved Conversion of Cellulose Waste to Ethanol Using a Dual Bioreactor System: Cooperative Research and Development Final Report, CRADA Number CRD-08-310

    SciTech Connect

    Zhang, M.

    2013-04-01

    Over-dependence on fossil fuel has spurred research on alternative energy. Inedible plant materials such as grass and corn stover represent abundant renewable natural resources that can be transformed into biofuel. Problems in enzymatic conversion of biomass to sugars include the use of incomplete synergistic enzymes, end-product inhibition, and adsorption and loss of enzymes necessitating their use in large quantities. Technova Corporation will develop a defined consortium of natural microorganisms that will efficiently break down biomass to energy-rich soluble sugars, and convert them to cleaner-burning ethanol fuel. The project will also develop a novel biocatalytic hybrid reactor system dedicated to this bioprocess, which embodies recent advances in nanotechnology. NREL will participate to develop a continuous fermentation process.

  14. Carbonaceous Aerosols Emitted from Light-Duty Vehicles Operating on Ethanol Fuel Blends

    EPA Science Inventory

    Air pollution is among the many environmental and public health concerns associated with increased ethanol use in vehicles. Jacobson [2007] showed for the U.S. market that full conversion to e85 ([85% ethanol, 15% gasoline]—the maximum standard blend used in modern dual fuel veh...

  15. Evaluation of environmental-control technologies for commercial nuclear fuel-conversion (UF/sub 6/) facilities

    SciTech Connect

    Perkins, B.L.

    1982-10-01

    At present in the United States, there are two commercial conversion facilities. These facilities process uranium concentrate into UF/sub 6/ for shipment to the enrichment facilities. One conversion facility uses a dry hydrofluor process, whereas the other facility uses a process known as the wet solvent extraction-fluorination process. Because of the different processes used in the two plants, waste characteristics, quantities, and treatment practices differ at each facility. Wastes and effluent streams contain impurities found in the concentrate (such as uranium daughters, vanadium, molybdenum, selenium, arsenic, and ammonia) and process chemicals used in the circuit (including fluorine, nitrogen, and hydrogen), as well as small quantities of uranium. Studies of suitable disposal options for the solid wastes and sludges generated at the facilities and the long-term effects of emissions to the ambient environment are needed. 30 figures, 34 tables.

  16. Energy conversion alternatives study

    NASA Technical Reports Server (NTRS)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  17. Building biomass into the utility fuel mix at NYSEG: System conversion and testing results for Greenidge Station

    SciTech Connect

    Benjamin, W.

    1996-12-31

    NYSEG is in the second phase of developing resources and systems for cofiring biomass with coal. In the first phase, stoker boilers were fired with biomass (typically wood waste products). Encouraged by positive results at the older stokers, NYSEG decided to develop the process for its pulverized coal boilers beginning with Greenidge Station, a 108-MW pulverized coal (PC) unit with a General Electric turbine generator and a 665,000-lb Combustion Engineering, tangentially fired boiler. Greenidge Station is in the center of New York, surrounded by farms, forests, vineyards, and orchards. The test bums at Greenidge Station demonstrated that a parallel fuel feed system can effectively provide wood products to a PC unit. Emission results were promising but inconclusive. Additional testing, for longer durations, at varied loads and with different woods needs to be conducted to clarify and establish relationships between the percent wood fired at varying moisture contents. Loads need to be varied to develop continuous emission monitor emission data that can be compared to coal-only data. Economic analysis indicates that it will be beneficial to further refine the equipment and systems. Refinements may include chipping and drying equipment, plus installation of fuel storage and feed systems with permanent boiler penetration. NYSEG will attempt to identify the problems associated with cofiring by direct injection, compared to cofiring a biomass/coal mixture through the existing fuel handling system. Specifically, an examination will be made of fuel size criteria and the system modifications necessary for minimal impacts on coal-fired operation.

  18. CONVERSION OF WIND POWER TO HYDROGEN FUEL: DESIGN OF AN ALTERNATIVE ENERGY SYSTEM FOR AN INJECTION MOLDING FACILITY

    EPA Science Inventory

    Injection molding plants are large consumers of electricity. At its current level of operations, Harbec Plastics (Ontario, NY) uses about 2,000,000 kilowatt-hours of electricity per year. Based on the US average fuel mix, approximately 1.5 pounds of CO2

  19. Efficient Conversion of Lignin to Electricity Using a Novel Direct Biomass Fuel Cell Mediated by Polyoxometalates at Low Temperatures.

    PubMed

    Zhao, Xuebing; Zhu, J Y

    2016-01-01

    A novel polyoxometalates (POMs) mediated direct biomass fuel cell (DBFC) was used in this study to directly convert lignin to electricity at low temperatures with high power output and Faradaic efficiency. When phosphomolybdic acid H3 PMo12 O40 (PMo12) was used as the electron and proton carrier in the anode solution with a carbon electrode, and O2 was directly used as the final electron acceptor under the catalysis of Pt, the peak power density reached 0.96 mW cm(-2), 560 times higher than that of phenol-fueled microbial fuel cells (MFCs). When the cathode reaction was catalyzed by PMo12, the power density could be greatly enhanced to 5 mW cm(-2). Continuous operation demonstrated that this novel fuel cell was promising as a stable electrochemical power source. Structure analysis of the lignin indicated that the hydroxyl group content was reduced whereas the carbonyl group content increased. Both condensation and depolymerization takes place during the PMo12 oxidation of lignin. PMID:26692572

  20. Advanced reactors and novel reactions for the conversion of triglyceride based oils into high quality renewable transportation fuels

    NASA Astrophysics Data System (ADS)

    Linnen, Michael James

    Sustainable energy continues to grow more important to all societies, leading to the research and development of a variety of alternative and renewable energy technologies. Of these, renewable liquid transportation fuels may be the most visible to consumers, and this visibility is further magnified by the long-term trend of increasingly expensive petroleum fuels that the public consumes. While first-generation biofuels such as biodiesel and fuel ethanol have been integrated into the existing fuel infrastructures of several countries, the chemical differences between them and their petroleum counterparts reduce their effectiveness. This gives rise to the development and commercialization of second generation biofuels, many of which are intended to have equivalent properties to those of their petroleum counterparts. In this dissertation, the primary reactions for a second-generation biofuel process, known herein as the University of North Dakota noncatalytic cracking process (NCP), have been studied at the fundamental level and improved. The NCP is capable of producing renewable fuels and chemicals that are virtually the same as their petroleum counterparts in performance and quality (i.e., petroleum-equivalent). In addition, a novel analytical method, FIMSDIST was developed which, within certain limitations, can increase the elution capabilities of GC analysis and decrease sample processing times compared to other high resolution methods. These advances are particularly useful for studies of highly heterogeneous fuel and/or organic chemical intermediates, such as those studied for the NCP. However the data from FIMSDIST must be supplemented with data from other methods such as for certain carboxylic acid, to provide accurate, comprehensive results, From a series of TAG cracking experiments that were performed, it was found that coke formation during cracking is most likely the result of excessive temperature and/or residence time in a cracking reactor. Based on this

  1. Carboxylic acid reductase is a versatile enzyme for the conversion of fatty acids into fuels and chemical commodities.

    PubMed

    Akhtar, M Kalim; Turner, Nicholas J; Jones, Patrik R

    2013-01-01

    Aliphatic hydrocarbons such as fatty alcohols and petroleum-derived alkanes have numerous applications in the chemical industry. In recent years, the renewable synthesis of aliphatic hydrocarbons has been made possible by engineering microbes to overaccumulate fatty acids. However, to generate end products with the desired physicochemical properties (e.g., fatty aldehydes, alkanes, and alcohols), further conversion of the fatty acid is necessary. A carboxylic acid reductase (CAR) from Mycobacterium marinum was found to convert a wide range of aliphatic fatty acids (C(6)-C(18)) into corresponding aldehydes. Together with the broad-substrate specificity of an aldehyde reductase or an aldehyde decarbonylase, the catalytic conversion of fatty acids to fatty alcohols (C(8)-C(16)) or fatty alkanes (C(7)-C(15)) was reconstituted in vitro. This concept was applied in vivo, in combination with a chain-length-specific thioesterase, to engineer Escherichia coli BL21(DE3) strains that were capable of synthesizing fatty alcohols and alkanes. A fatty alcohol titer exceeding 350 mg·L(-1) was obtained in minimal media supplemented with glucose. Moreover, by combining the CAR-dependent pathway with an exogenous fatty acid-generating lipase, natural oils (coconut oil, palm oil, and algal oil bodies) were enzymatically converted into fatty alcohols across a broad chain-length range (C(8)-C(18)). Together with complementing enzymes, the broad substrate specificity and kinetic characteristics of CAR opens the road for direct and tailored enzyme-catalyzed conversion of lipids into user-ready chemical commodities. PMID:23248280

  2. Carboxylic acid reductase is a versatile enzyme for the conversion of fatty acids into fuels and chemical commodities

    PubMed Central

    Akhtar, M. Kalim; Turner, Nicholas J.; Jones, Patrik R.

    2013-01-01

    Aliphatic hydrocarbons such as fatty alcohols and petroleum-derived alkanes have numerous applications in the chemical industry. In recent years, the renewable synthesis of aliphatic hydrocarbons has been made possible by engineering microbes to overaccumulate fatty acids. However, to generate end products with the desired physicochemical properties (e.g., fatty aldehydes, alkanes, and alcohols), further conversion of the fatty acid is necessary. A carboxylic acid reductase (CAR) from Mycobacterium marinum was found to convert a wide range of aliphatic fatty acids (C6–C18) into corresponding aldehydes. Together with the broad-substrate specificity of an aldehyde reductase or an aldehyde decarbonylase, the catalytic conversion of fatty acids to fatty alcohols (C8–C16) or fatty alkanes (C7–C15) was reconstituted in vitro. This concept was applied in vivo, in combination with a chain-length-specific thioesterase, to engineer Escherichia coli BL21(DE3) strains that were capable of synthesizing fatty alcohols and alkanes. A fatty alcohol titer exceeding 350 mg·L−1 was obtained in minimal media supplemented with glucose. Moreover, by combining the CAR-dependent pathway with an exogenous fatty acid-generating lipase, natural oils (coconut oil, palm oil, and algal oil bodies) were enzymatically converted into fatty alcohols across a broad chain-length range (C8–C18). Together with complementing enzymes, the broad substrate specificity and kinetic characteristics of CAR opens the road for direct and tailored enzyme-catalyzed conversion of lipids into user-ready chemical commodities. PMID:23248280

  3. Synergistic Effects in Nanoengineered HNb3O8/Graphene Hybrids with Improved Photocatalytic Conversion Ability of CO2 into Renewable Fuels.

    PubMed

    Liu, He; Zhang, Haitao; Shen, Peng; Chen, Feixiong; Zhang, Suojiang

    2016-01-12

    Layered HNb3O8/graphene hybrids with numerous heterogeneous interfaces and hierarchical pores were fabricated via the reorganization of exfoliated HNb3O8 nanosheets with graphene nanosheets (GNs). Numerous interfaces and pores were created by the alternative stacking of HNb3O8 nanosheets with limited size and GNs with a buckling and folding feature. The photocatalytic conversation of CO2 into renewable fuels by optimized HNb3O8/G hybrids yields 8.0-fold improvements in CO evolution amounts than that of commercial P25 and 8.6-fold improvements than that of HNb3O8 bulk powders. The investigation on the relationships between microstructures and improved photocatalytic performance demonstrates that the improved photocatalytic performance is attributed to the exotic synergistic effects via the combination of enhanced specific BET surface area, increased strong acid sites and strong acid amounts, narrowed band gap energy, depressed electron-hole recombination rate, and heterogeneous interfaces. PMID:26695348

  4. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels. Thermochemical Research Pathways with In Situ and Ex Situ Upgrading of Fast Pyrolysis Vapors

    SciTech Connect

    Dutta, Abhijit; Sahir, Asad; Tan, Eric; Humbird, David; Snowden-Swan, Lesley J.; Meyer, Pimphan; Ross, Jeff; Sexton, Danielle; Yap, Raymond; Lukas, John Lukas

    2015-03-01

    This report was developed as part of the U.S. Department of Energy’s Bioenergy Technologies Office’s efforts to enable the development of technologies for the production of infrastructurecompatible, cost-competitive liquid hydrocarbon fuels from biomass. Specifically, this report details two conceptual designs based on projected product yields and quality improvements via catalyst development and process integration. It is expected that these research improvements will be made within the 2022 timeframe. The two conversion pathways detailed are (1) in situ and (2) ex situ upgrading of vapors produced from the fast pyrolysis of biomass. While the base case conceptual designs and underlying assumptions outline performance metrics for feasibility, it should be noted that these are only two of many other possibilities in this area of research. Other promising process design options emerging from the research will be considered for future techno-economic analysis.

  5. Simultaneous Measurements of Temperature and Major Species Concentration in a Hydrocarbon-Fueled Dual Mode Scramjet Using WIDECARS

    NASA Astrophysics Data System (ADS)

    Gallo, Emanuela Carolina Angela

    Width increased dual-pump enhanced coherent anti-Stokes Raman spectroscopy (WIDECARS) measurements were conducted in a McKenna air-ethylene premixed burner, at nominal equivalence ratio range between 0.55 and 2.50 to provide quantitative measurements of six major combustion species (C2H 4, N2, O2, H2, CO, CO2) concentration and temperature simultaneously. The purpose of this test was to investigate the uncertainties in the experimental and spectral modeling methods in preparation for an subsequent scramjet C2H4/air combustion test at the University of Virginia-Aerospace Research Laboratory. A broadband Pyrromethene (PM) PM597 and PM650 dye laser mixture and optical cavity were studied and optimized to excite the Raman shift of all the target species. Two hundred single shot recorded spectra were processed, theoretically fitted and then compared to computational models, to verify where chemical equilibrium or adiabatic condition occurred, providing experimental flame location and formation, species concentrations, temperature, and heat losses inputs to computational kinetic models. The Stark effect, temperature, and concentration errors are discussed. Subsequently, WIDECARS measurements of a premixed air-ethylene flame were successfully acquired in a direct connect small-scale dual-mode scramjet combustor, at University of Virginia Supersonic Combustion Facility (UVaSCF). A nominal Mach 5 flight condition was simulated (stagnation pressure p0 = 300 kPa, temperature T0 = 1200 K, equivalence ratio range ER = 0.3 -- 0.4). The purpose of this test was to provide quantitative measurements of the six major combustion species concentration and temperature. Point-wise measurements were taken by mapping four two-dimensional orthogonal planes (before, within, and two planes after the cavity flame holder) with respect to the combustor freestream direction. Two hundred single shot recorded spectra were processed and theoretically fitted. Mean flow and standard deviation are

  6. Two-stage conversion of crude glycerol to energy using dark fermentation linked with microbial fuel cell or microbial electrolysis cell.

    PubMed

    Chookaew, Teera; Prasertsan, Poonsuk; Ren, Zhiyong Jason

    2014-03-25

    Crude glycerol is a main byproduct of the biodiesel industry, and the beneficial use of waste glycerol has been a major challenge. This study characterises the conversion of crude glycerol into bioenergy such as H2 and electricity using a two-stage process linking dark fermentation with a microbial fuel cell (MFC) or microbial electrolysis cell (MEC). The results showed that fermentation achieved a maximum H2 rate of 332 mL/L and a yield of 0.55 mol H2/mol glycerol, accompanied by 20% of organic removal. Fed with the raw fermentation products with an initial COD of 7610 mg/L, a two-chamber MFC produced 92 mW/m(2) in power density and removed 50% of COD. The Columbic efficiency was 14%. When fed with 50% diluted fermentation product, a similar power output (90m W/m(2)) and COD removal (49%) were obtained, but the CE doubled to 27%. Similar substrates were used to produce H2 in two-chamber MECs, and the diluted influent had a higher performance, with the highest yield at 106 mL H2/g COD and a CE of 24%. These results demonstrate that dark fermentation linked with MFC/MEC can be a feasible option for conversion of waste glycerol into bioenergy. PMID:24380781

  7. Dual-fuel production from restaurant grease trap waste: bio-fuel oil extraction and anaerobic methane production from the post-extracted residue.

    PubMed

    Kobayashi, Takuro; Kuramochi, Hidetoshi; Maeda, Kouji; Tsuji, Tomoya; Xu, Kaiqin

    2014-10-01

    An effective way for restaurant grease trap waste (GTW) treatment to generate fuel oil and methane by the combination of physiological and biological processes was investigated. The heat-driven extraction could provide a high purity oil equivalent to an A-grade fuel oil of Japanese industrial standard with 81-93 wt% of extraction efficiency. A post-extracted residue was treated as an anaerobic digestion feedstock, and however, an inhibitory effect of long chain fatty acid (LCFA) was still a barrier for high-rate digestion. From the semi-continuous experiment fed with the residual sludge as a single substrate, it can be concluded that the continuous addition of calcium into the reactor contributed to reducing LCFA inhibition, resulting in the long-term stable operation over one year. Furthermore, the anaerobic reactor performed well with 70-80% of COD reduction and methane productivity under an organic loading rate up to 5.3g-COD/L/d. PMID:25043346

  8. Hydrothermal synthesis of nanocubes of sillenite type compounds for photovoltaic applications and solar energy conversion of carbon dioxide to fuels

    DOEpatents

    Subramanian, Vaidyanathan; Murugesan, Sankaran

    2014-04-29

    The present invention relates to formation of nanocubes of sillenite type compounds, such as bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, via a hydrothermal synthesis process, with the resulting compound(s) having multifunctional properties such as being useful in solar energy conversion, environmental remediation, and/or energy storage, for example. In one embodiment, a hydrothermal method is disclosed that transforms nanoparticles of TiO.sub.2 to bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, optionally loaded with palladium nanoparticles. The method includes reacting titanium dioxide nanotubes with a bismuth salt in an acidic bath at a temperature sufficient and for a time sufficient to form bismuth titanate crystals, which are subsequently annealed to form bismuth titanate nanocubes. After annealing, the bismuth titanate nanocubes may be optionally loaded with nano-sized metal particles, e.g., nanosized palladium particles.

  9. Effect of electric impulse for improved energy generation in mediatorless dual chamber microbial fuel cell through electroevolution of Escherichia coli.

    PubMed

    Nandy, Arpita; Kumar, Vikash; Kundu, Patit P

    2016-05-15

    The main emphasis of this study is to understand the electroactive behavior of a microbe in microbial fuel cell (MFC) under specific selection pressure. This study explores potential of a non-electrogenic microbe for power production in a mediatorless MFC under the influence of a specific stress. Electric pulse of specific magnitude has been applied to Escherichia coli cells in a MFC and compared the results with unpulsed (control) MFC. Maximum power density of 187.77 mW/m(2) and 284.44 mW/m(2) for the control and experimental MFC has been observed at corresponding current density of 1444.44 mA/m(2) and 1777.77 mA/m(2). The results show improved performance for the pulsed (experimental) system, despite of initial downfall with respect to the control system. This suggests bacterial adaptation against electrical pulses which leads to evolution of an efficient electrogen. This observation is further confirmed by analyzing the results of Cyclic Voltammetry (CV), Scanning Electron Microscopy (SEM) Electrochemical Impedence Spectroscopy (EIS), enlightening different attributes like electrochemical property, bacterial morphology and impedance. The study is focused on development of a microbial fuel cell catalysed by E. coli, through triggering electroactive property in the microbe by exposing it to external stress. This study is unique in nature as it is mediatorless, economical and describes about a new method of natural bacterial evolution. PMID:26774096

  10. Development of a conditioning system for the dual-purpose transport and storage cask for spent nuclear fuel from decommissioned Russian submarines

    SciTech Connect

    Dyer, R.S.; Barnes, E.; Snipes, R.L.; Guskov, V.; Makarchuk, T.

    2007-07-01

    Russia, stores large quantities of spent nuclear fuel (SNF) from submarine and ice-breaker nuclear powered naval vessels. This high-level radioactive material presents a significant threat to the Arctic and marine environments. Much of the SNF from decommissioned Russian nuclear submarines is stored either onboard the submarines or in floating storage vessels in Northwest and Far East Russia. Some of the SNF is damaged, stored in an unstable condition, or of a type that cannot currently be reprocessed. In many cases, the existing Russian transport infrastructure and reprocessing facilities cannot meet the requirements for moving and reprocessing all of this fuel from remote locations. Additional transport and storage options are required. Some of the existing storage facilities being used in Russia do not meet health and safety and physical security requirements. The U.S. has assisted Russia in the development of a new dual-purpose metal-concrete transport and storage cask (TUK-108/1) for their military SNF and assisted them in building several new facilities for off-loading submarine SNF and storing these TUK-108/1 casks. These efforts have reduced the technical, ecological, and security challenges for removal, handling, interim storage, and shipment of this submarine fuel. Currently, Russian licensing limits the storage period of the TUK-108/1 casks to no more than two years before the fuel must be shipped for reprocessing. In order to extend this licensed storage period, a system is required to condition the casks by removing residual water and creating an inert storage environment by backfilling the internal canisters with a noble gas such as argon. The U.S. has assisted Russia in the development of a mobile cask conditioning system for the TUK-108/1 cask. This new conditioning system allows the TUK 108/1 casks to be stored for up to five years after which the license may be considered for renewal for an additional five years or the fuel will be shipped to

  11. The public health benefits of reducing fine particulate matter through conversion to cleaner heating fuels in New York City.

    PubMed

    Kheirbek, Iyad; Haney, Jay; Douglas, Sharon; Ito, Kazuhiko; Caputo, Steven; Matte, Thomas

    2014-12-01

    In recent years, both New York State and City issued regulations to reduce emissions from burning heating oil. To assess the benefits of these programs in New York City, where the density of emissions and vulnerable populations vary greatly, we simulated the air quality benefits of scenarios reflecting no action, partial, and complete phase-out of high-sulfur heating fuels using the Community MultiScale Air Quality (CMAQ) model conducted at a high spatial resolution (1 km). We evaluated the premature mortality and morbidity benefits of the scenarios within 42 city neighborhoods and computed benefits by neighborhood poverty status. The complete phase-out scenario reduces annual average fine particulate matter (PM2.5) by an estimated 0.71 μg/m(3) city-wide (average of 1 km estimates, 10-90th percentile: 0.1-1.6 μg/m(3)), avoiding an estimated 290 premature deaths, 180 hospital admissions for respiratory and cardiovascular disease, and 550 emergency department visits for asthma each year. The largest improvements were seen in areas of highest building and population density and the majority of benefits have occurred through the partial phase out of high-sulfur heating fuel already achieved. While emissions reductions were greatest in low-poverty neighborhoods, health benefits are estimated to be greatest in high-poverty neighborhoods due to higher baseline morbidity and mortality rates. PMID:25365783

  12. Conversion of Biomass Derivatives to Electricity in Photo Fuel Cells using Undoped and Tungsten-doped Bismuth Vanadate Photoanodes.

    PubMed

    Zhang, Bingqing; Shi, Jingying; Ding, Chunmei; Chong, Ruifeng; Zhang, Bao; Wang, Zhiliang; Li, Ailong; Liang, Zhenxing; Liao, Shijun; Li, Can

    2015-12-01

    The photo fuel cell (PFC) is a promising technology for simultaneously converting solar energy and bioenergy into electricity. Here, we present a miniature air-breathing PFC that uses either BiVO4 or W-doped BiVO4 as the photoanode and a Pt/C catalyst as the air-breathing cathode. The PFC exhibited excellent performance under solar illumination and when fed with several types of biomaterial. We found the PFC performance could be significantly enhanced using W-doping into the BiVO4 photoanode. With glucose as the fuel and simulated sunlight (AM 1.5 G) as the light source, the open-circuit voltage increased from 0.74 to 0.92 V, the short-circuit current density rose from 0.46 to 1.62 mA cm(-2) , and the maximum power density was boosted from 0.05 to 0.38 mW cm(-2) , compared to a PFC using undoped BiVO4 as the anode. PMID:26609790

  13. Simultaneous pH self-neutralization and bioelectricity generation in a dual bioelectrode microbial fuel cell under periodic reversion of polarity

    NASA Astrophysics Data System (ADS)

    Li, Wanjun; Sun, Jian; Hu, Yongyou; Zhang, Yaping; Deng, Feng; Chen, Jie

    2014-12-01

    In order to overcome pH membrane gradient and minimize dosage of buffer, a dual bioelectrode microbial fuel cell (MFC) with periodic reversion of polarity is conducted. The performances of the MFC before and after polarity reversion are compared to the MFC without polarity reversion and the mechanisms of the polarity reversion are investigated using electrochemical impedance spectroscopy and cyclic voltammetry. The MFC has been run continuously and stably for more than four months under periodic reversion of polarity with extreme low phosphate buffer of 5 mM. The accumulated proton in the anode and hydroxyl in the cathode are neutralized after polarity reversion but the acidification of the anode more serious than the alkalization of the cathode. Polarity reversion improve the anodic and cathodic performance due to in situ use of the accumulated proton and hydroxyl in the same electrode chamber which result in 58.3% and 36.0% increases in power density as compared to that produced before polarity reversion and by the MFC without polarity reversion, respectively. Cathode performance can be adversely affected by residual soluble organic carbons during polarity reversion due to oxygen consumption by heterotrophic bacteria in the presence of residual soluble organic carbons.

  14. Compliant alkali silicate sealing glass for solid oxide fuel cell applications: the effect of protective alumina coating on electrical stability in dual environment

    SciTech Connect

    Chou, Y. S.; Choi, Jung-Pyung; Stevenson, Jeffry W.

    2012-12-01

    An alkali-containing silicate glass was recently proposed as a potential sealant for solid oxide fuel cells (SOFC). The glass contains appreciable amount of alkalis and retains its glassy microstructure at elevated temperatures over time. It is more compliant as compared to conventional glass-ceramics sealants and could potentially heal cracks during thermal cycling. In previous papers the thermal cycle stability, thermal stability and chemical compatibility were reported with yttria-stabilized zirconia (YSZ) electrolyte and YSZ-coated ferritic stainless steel interconnect. In this paper, we report the electrical stability of the compliant glass with aluminized AISI441 interconnect material under DC load in dual environment at 700-800oC. Apparent electrical resistivity was measured with a 4-point method for the glass sealed between two aluminized AISI441 metal coupons as well as plain AISI441 substrates. The results showed good electrical stability with the aluminized AISI441 substrate, while unstable behavior was observed for un-coated substrates. In addition, interfacial microstructure was examined with scanning electron microscopy and correlated with the measured resistivity results. Overall, the alumina coating demonstrated good chemical stability with the alkali-containing silicate sealing glass under DC loading.

  15. Electrical Stability of a Novel Refractory Sealing Glass in a Dual Environment for Solid Oxide Fuel Cell Applications

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.; Meinhardt, Kerry D.

    2010-03-01

    A novel refractory alkaline-earth silicate (Sr-Ca-Y-B-Si) sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was sealed between two metallic interconnect plates and tested for electrical stability at elevated temperatures and duel environments under DC loading. The isothermal aging results showed very stable electrical resistivity with values 5-9 orders of magnititudes higher than typical SOFC function materials at 850 degrees C for ~700 hr. For comparison, the state-of-the-art sealing glass (G18, Ba-Ca-Al-B-Si) was also evaluated in a similar condition and showed less stable in accelerated tests at 830 degrees C for ~100 hr. Interfacial microstruicture was characterized and possible reactions were discussed.

  16. Light to liquid fuel: theoretical and realized energy conversion efficiency of plants using crassulacean acid metabolism (CAM) in arid conditions.

    PubMed

    Davis, Sarah C; LeBauer, David S; Long, Stephen P

    2014-07-01

    There has been little attention paid to crassulacean acid metabolism (CAM) as a mechanism for bioenergy crop tolerance to water limitation, in part, because potential yields of CAM plants have been assumed to be lower than those of most commonly studied bioenergy crops. The photochemical efficiency, water-use efficiency (WUE), biomass production, and fuel yield potentials of CAM, C3, and C4 plants that are considered or already in use for bioenergy are reviewed here. The theoretical photosynthetic efficiency of CAM plants can be similar to or greater than other photosynthetic pathways. In arid conditions, the greater WUE of CAM species results in theoretical biomass yield potentials that are 147% greater than C4 species. The realized yields of CAM plants are similar to the theoretical yields that account for water-limiting conditions. CAM plants can potentially be viable commercial bioenergy crops, but additional direct yield measurements from field trials of CAM species are still needed. PMID:24744431

  17. Using of TiN-nanotubes and Cu-nanoparticles for conversion of CO2 to hydrocarbon fuels.

    PubMed

    Mahdavian, Leila

    2015-07-01

    In this study, conversion of CO2 and H2O to CH3OH or CH4 on Cu-nanoparticles in TiN- nanotubes was optimized by density functional theory (DFT) methods. DFT optimized the intermediates and transient states using the GAMESS program package, but the structures, total energy, and thermodynamic properties were calculated by semi-empirical methods using ZINDO/1 at room temperature. The results show a sensitivity enhancement in resistance and capacitance when CO2 and H2O are converted to CH3OH and other products. TiN-nanotubes use photo-catalytic reactivity for the reduction of CO2 and H2O to form CH3OH or CH4 at 298 K. The endohedral location of interaction of these reactants in TiN-nanotubes with Cu-nanoparticles was investigated. Calculations show that these processes were endothermic, thus the reactions need solar or other energies in the presence of visible light to progress favorably. PMID:26142907

  18. Metagenomic Analyses Reveal the Involvement of Syntrophic Consortia in Methanol/Electricity Conversion in Microbial Fuel Cells

    PubMed Central

    Yamamuro, Ayaka; Kouzuma, Atsushi; Abe, Takashi; Watanabe, Kazuya

    2014-01-01

    Methanol is widely used in industrial processes, and as such, is discharged in large quantities in wastewater. Microbial fuel cells (MFCs) have the potential to recover electric energy from organic pollutants in wastewater; however, the use of MFCs to generate electricity from methanol has not been reported. In the present study, we developed single-chamber MFCs that generated electricity from methanol at the maximum power density of 220 mW m−2 (based on the projected area of the anode). In order to reveal how microbes generate electricity from methanol, pyrosequencing of 16S rRNA-gene amplicons and Illumina shotgun sequencing of metagenome were conducted. The pyrosequencing detected in abundance Dysgonomonas, Sporomusa, and Desulfovibrio in the electrolyte and anode and cathode biofilms, while Geobacter was detected only in the anode biofilm. Based on known physiological properties of these bacteria, it is considered that Sporomusa converts methanol into acetate, which is then utilized by Geobacter to generate electricity. This speculation is supported by results of shotgun metagenomics of the anode-biofilm microbes, which reconstructed relevant catabolic pathways in these bacteria. These results suggest that methanol is anaerobically catabolized by syntrophic bacterial consortia with electrodes as electron acceptors. PMID:24852573

  19. High-efficiency intermediate temperature solid oxide electrolyzer cells for the conversion of carbon dioxide to fuels

    SciTech Connect

    Yan , Jingbo; Chen, Hao; Dogdibegovic, Emir; Stevenson, Jeffry W.; Cheng, Mojie; Zhou, Xiao-Dong

    2014-04-15

    Electrochemical reduction of carbon dioxide in the intermediate temperature region was investigated by utilizing a reversible solid oxide electrolysis cell (SOEC). The current potential (i-V) curve exhibited a nonlinear characteristic at low current density. Differentiation of i-V curves revealed that the cell area specific resistance (ASR) was current-dependent and had its maximum in electrolysis mode and minimum in fuel cell mode. Impedance measurements were performed under different current densities and gas compositions, and the results were analyzed by calculating the distribution of relaxation times. The ASR variation resulted from the difference in electrochemical reactions occurring on the Ni-YSZ electrode, i.e., Ni-YSZ is a better electrode for CO oxidation than for CO2 reduction. Coke formation on Ni-YSZ played a crucial role in affecting its electrolysis performance in the intermediate temperature region. The ASR apex was associated with a decrease in cell temperature during electrolysis due to the endothermic nature of CO2 reduction reaction. It was postulated that such a decrease in temperature and rise in CO concentration led to coke formation. As a consequence, higher temperature (>700 degrees C), higher CO2 concentration (>50%), and the presence of hydrogen or steam are recommended for efficient CO2 reduction in solid oxide electrochemical cells. (C) 2013 Elsevier B.V. All rights reserved

  20. Comparison of adsorbents for H2S and D4 removal for biogas conversion in a solid oxide fuel cell.

    PubMed

    Sigot, Léa; Ducom, Gaëlle; Benadda, Belkacem; Labouré, Claire

    2016-01-01

    Biogas contains trace compounds detrimental for solid oxide fuel cell (SOFC) application, especially sulphur-containing compounds and volatile organic silicon compounds (VOSiCs). It is therefore necessary to remove these impurities from the biogas for fuelling an SOFC. In this paper, dynamic lab-scale adsorption tests were performed on synthetic polluted gas to evaluate the performance of a polishing treatment to remove hydrogen sulphide (H2S - sulphur compound) and octamethylcyclotetrasiloxane (D4 - VOSiC). Three kinds of adsorbents were tested: an activated carbon, a silica gel (SG) and a zeolite (Z). Z proved to be the best adsorbent for H2S removal, with an adsorbed quantity higher than [Formula: see text] at the SOFC tolerance limit. However, as concerns D4 removal, SG was the most efficient adsorbent, with an adsorbed quantity of about 184 mgD4/gSG at the SOFC tolerance limit. These results could not be explained by structural characteristics of the adsorbents, but they were partly explained by chemical interactions between the adsorbate and the adsorbent. In these experiments, internal diffusion was the controlling step, Knudsen diffusion being predominant to molecular diffusion. As Z was also a good adsorbent for D4 removal, competition phenomena were investigated with Z for the simultaneous removal of H2S and D4. It was shown that H2S retention was dramatically decreased in the presence of D4, probably due to D4 polymerization resulting in pore blocking. PMID:26183696

  1. New nanostructured silica incorporated with isolated Ti material for the photocatalytic conversion of CO2 to fuels

    NASA Astrophysics Data System (ADS)

    Akhter, Parveen; Hussain, Murid; Saracco, Guido; Russo, Nunzio

    2014-04-01

    In this work, new nanoporous silica (Korea Advanced Institute of Science and Technology-6 (KIT-6)-dried or KIT-6-calcined) incorporated with isolated Ti materials with different Si/Ti ratios (Si/Ti = 200, 100, and 50) has been synthesized and investigated to establish photocatalytic reduction of CO2 in the presence of H2O vapors. The properties of the materials have been characterized through N2 adsorption/desorption, UV-vis, TEM, FT-IR, and XPS analysis techniques. The intermediate amount of the isolated Ti (Si/Ti = 100) has resulted to be more uniformly distributed on the surface and within the three-dimensional pore structure of the KIT-6 material, without its structure collapsing, than the other two ratios (Si/Ti = 200 and 50). However, titania agglomerates have been observed to have formed due to the increased Ti content (Si/Ti = 50). The Ti-KIT-6 (calcined) materials in the reaction showed higher activity than the Ti-KIT-6 (dried) materials, which produced CH4, H2, CO, and CH3OH (vapors) as fuel products. The Ti-KIT-6 (Si/Ti = 100) material also showed more OH groups, which are useful to obtain a higher production rate of the products, particularly methane, which was even higher than the rate of the best commercial TiO2 (Aeroxide P25, Evonik Industries AG, Essen, Germany) photocatalyst.

  2. New nanostructured silica incorporated with isolated Ti material for the photocatalytic conversion of CO2 to fuels

    PubMed Central

    2014-01-01

    In this work, new nanoporous silica (Korea Advanced Institute of Science and Technology-6 (KIT-6)-dried or KIT-6-calcined) incorporated with isolated Ti materials with different Si/Ti ratios (Si/Ti = 200, 100, and 50) has been synthesized and investigated to establish photocatalytic reduction of CO2 in the presence of H2O vapors. The properties of the materials have been characterized through N2 adsorption/desorption, UV-vis, TEM, FT-IR, and XPS analysis techniques. The intermediate amount of the isolated Ti (Si/Ti = 100) has resulted to be more uniformly distributed on the surface and within the three-dimensional pore structure of the KIT-6 material, without its structure collapsing, than the other two ratios (Si/Ti = 200 and 50). However, titania agglomerates have been observed to have formed due to the increased Ti content (Si/Ti = 50). The Ti-KIT-6 (calcined) materials in the reaction showed higher activity than the Ti-KIT-6 (dried) materials, which produced CH4, H2, CO, and CH3OH (vapors) as fuel products. The Ti-KIT-6 (Si/Ti = 100) material also showed more OH groups, which are useful to obtain a higher production rate of the products, particularly methane, which was even higher than the rate of the best commercial TiO2 (Aeroxide P25, Evonik Industries AG, Essen, Germany) photocatalyst. PMID:24690396

  3. High-efficiency intermediate temperature solid oxide electrolyzer cells for the conversion of carbon dioxide to fuels

    NASA Astrophysics Data System (ADS)

    Yan, Jingbo; Chen, Hao; Dogdibegovic, Emir; Stevenson, Jeffry W.; Cheng, Mojie; Zhou, Xiao-Dong

    2014-04-01

    Electrochemical reduction of carbon dioxide in the intermediate temperature region was investigated by utilizing a reversible solid oxide electrolysis cell (SOEC). The current-potential (i-V) curve exhibited a nonlinear characteristic at low current density. Differentiation of i-V curves revealed that the cell area specific resistance (ASR) was current-dependent and had its maximum in electrolysis mode and minimum in fuel cell mode. Impedance measurements were performed under different current densities and gas compositions, and the results were analyzed by calculating the distribution of relaxation times. The ASR variation resulted from the difference in electrochemical reactions occurring on the Ni-YSZ electrode, i.e., Ni-YSZ is a better electrode for CO oxidation than for CO2 reduction. Coke formation on Ni-YSZ played a crucial role in affecting its electrolysis performance in the intermediate temperature region. The ASR apex was associated with a decrease in cell temperature during electrolysis due to the endothermic nature of CO2 reduction reaction. It was postulated that such a decrease in temperature and rise in CO concentration led to coke formation. As a consequence, higher temperature (>700 °C), higher CO2 concentration (>50%), and the presence of hydrogen or steam are recommended for efficient CO2 reduction in solid oxide electrochemical cells.

  4. Dual-resonance converse magnetoelectric and voltage step-up effects in laminated composite of long-type 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 piezoelectric single-crystal transformer and Tb0.3Dy0.7Fe1.92 magnetostrictive alloy bars

    NASA Astrophysics Data System (ADS)

    Ming Leung, Chung; Wing Or, Siu; Wang, Feifei; Ho, S. L.

    2011-05-01

    We report a dual-resonance converse magnetoelectric effect and a dual-resonance voltage step-up effect in a laminated composite made by sandwiching the output (or secondary) section of a long-type 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) piezoelectric single-crystal transformer having a longitudinal-longitudinal polarization between two Tb0.3Dy0.7Fe1.92 (Terfenol-D) magnetostrictive alloy bars having a longitudinal magnetization. The reported converse magnetoelectric effect originates from the mechanically mediated resonance converse piezoelectric effect in the PMN-PT transformer and resonance converse magnetostrictive effect in the Terfenol-D bars. The additional voltage step-up effect results from the mechanically mediated resonance converse and direct piezoelectric effects in the PMN-PT transformer. The composite shows two sharp resonance peaks of 0.39 and 0.54 G/V in converse magnetoelectric coefficient (αB = dB/dVin) and of 1.4 and 2.1 in voltage step-up ratio (Vout/Vin) at about 54 and 120 kHz, corresponding to the half- and full-wavelength longitudinal mode resonances, respectively. The measured magnetic induction (B) exhibits good linear relationships to the applied ac voltage (Vin) with amplitude varying from 10 to 100 V in both resonance and nonresonance conditions. These dual-resonance effects make the composite great promise for coil-free electromagnetic device applications.

  5. Contribution to Conversion of CO2 to fuel by electro-photo-catalytic reduction in hydro-genocarbonated aqueous solution tion

    NASA Astrophysics Data System (ADS)

    Nezzal, Ghania; Benammar, Souad; Hamouni, Samia; Meziane, Dalila; Naama, Sabrina; Abdessemed, Djamel

    2015-04-01

    Referring to the last World Conference COPENHAGEN (2010), endorsed by the United Nations,to '' RISKS OF CLIMATE CHANGES ', states had not reached an agreement to work fairly, in an international program, to limit Carbon dioxide emissions into the atmosphere, to put off it, to the next (in 2015), the right decisions, despite the recommendations of the 'IPCC'. Based on the natural reaction of photosynthesis, which converts carbon dioxide in the presence of water and sun, to '' OSA'' ', it is natural that scientists believe to implement an artificial conversion of CO2 in a renewable energy faster. Our contribution focuses on the same goals, by a different line. In this perspective, nano-materials, catalysts, pervaporation membranes, pervaporation unit, and a photo-reactor prototype, have been made. A summary of the preliminary results presented: For example, are given the concentrations of the various species present in a aqueous solution of sodium hydrogen carbonate, 0.5M, saturated with CO2, at standard temperature and pressure: (CO2) = 1M; (H2CO3) = 0,038M; (HCO3-) = 0,336M; (CO3 --) = 0,34M; pH = 7.33, an overall concentration = 1,714M, more than three times that of the initial solution. It is in such conditions that the conversion of carbon dioxide by the hydrogen produced in situ by electrolysis, in fuel, must be done in the presence of catalyst, under UV radiation. For electrodes, a nano-porous layer was formed on their surface to receive the suitable catalyst. These lats prepared, are made of porous supports (montmorillonite, aluminum and silicon oxides) into which are inserted the metal precursor, by impregnation interactive, in Iron, cobalt, nickel salt solutions, cobalt, nickel. Their performance has been identified by the reduction of para- nitrophenol, to para-aminophenol in aqueous medium in the presence of sodium borohydride. This is the catalyst 'Cobalt supported by SiO2'' that gave the best conversion, 99.5% instead of 99.7%, for a platinum catalyst

  6. Dual-Mode Combustor

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  7. Reactor Physics Methods and Preconceptual Core Design Analyses for Conversion of the Advanced Test Reactor to Low-Enriched Uranium Fuel Annual Report for Fiscal Year 2012

    SciTech Connect

    David W. Nigg; Sean R. Morrell

    2012-09-01

    several obsolete components of the current analytical tool set used for ATR neutronics support. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). It will also greatly facilitate the LEU conversion effort, since the upgraded computational capabilities are now at a stage where they can be, and in fact have been, used for the required physics analysis from the beginning. In this context, extensive scoping neutronics analyses were completed for six preconceptual candidate LEU fuel element designs for the ATR (and for its companion critical facility, ATRC). Of these, four exhibited neutronics performance in what is believed to be an acceptable range. However, there are currently some concerns with regard to fabricability and mechanical performance that have emerged for one of the four latter concepts. Thus three concepts have been selected for more comprehensive conceptual design analysis during the upcoming fiscal year.

  8. Research and development of rapid hydrogenation for coal conversion to synthetic motor fuels (riser cracking of coal). Final report, April 1, 1976-September 30, 1980

    SciTech Connect

    Duncan, D. A.; Beeson, J. L.; Oberle, R. D.

    1981-02-01

    The objective of the program described was to develop a noncatalytic process for the hydropyrolysis of lignite and coal to produce high-octane blending gasoline constituents, methane, ethane, and carbon oxides. The process would operate in a balanced plant mode, using spent char to generate process hydrogen by steam-oxygen gasification. The technical program included the construction and operating of a bench-scale unit (5-10 lb/hr), the design, construction, and operation of a process development unit (PDU) (100 lb/hr), and a final technical and economic assessment of the process, called Riser Cracking of Coal. In the bench-scale unit program, 143 runs were made investigating the effects of pressure, temperature, heating rate, residence time, and particle size, processing North Dakota lignite in hydrogen. Some runs were made in which the hydrogen was preheated to pyrolysis temperatures prior to contact with the coal, and, also, in which steam was substituted for half of the hydrogen. Attempts to operate the bench-scale unit at 1200 psig and 1475/sup 0/F were not successful. Depth of carbon conversion was found to be influenced by hydrogen pressure, hydrogen-to-coal ratio, and the severity of the thermal treatment. The composition of hydrocarbon liquids produced was found to change with severity. At low severity, the liquids contained sizable fractions of phenols and cresols. At high severity, the fraction of phenols and cresols was much reduced, with an attendant increase in BTX. In operating the PDU, it was necessary to use more oxygen than was planned to achieve pyrolysis temperatures because of heat losses, and portions of hydrocarbon products were lost through combustion with a large increase in carbon oxide yields. Economic studies, however, showed that selling prices for gasoline blending stock, fuel oil, and fuel gas are competitive in current markets, so that the process is held to warrant further development.

  9. Design, Synthesis, and Mechanistic Evaluation of Iron-Based Catalysis for Synthesis Gas Conversion to Fuels and Chemicals

    SciTech Connect

    Enrique Iglesia; Akio Ishikawa; Manual Ojeda; Nan Yao

    2007-09-30

    A detailed study of the catalyst composition, preparation and activation protocol of Fe-based catalysts for the Fischer-Tropsch Synthesis (FTS) have been carried out in this project. We have studied the effects of different promoters on the catalytic performance of Fe-based catalysts. Specifically, we have focused on how their sequence of addition dramatically influences the performance of these materials in the Fischer-Tropsch synthesis. The resulting procedures have been optimized to improve further upon the already unprecedented rates and C{sub 5+} selectivities of the Fe-based catalysts that we have developed as part of this project. Selectivity to C{sub 5+} hydrocarbon was close to 90 % (CO{sub 2}-free basis) and CO conversion rate was about 6.7 mol h{sup -1} g-at Fe{sup -1} at 2.14 MPa, 508 K and with substoichiometric synthesis gas; these rates were larger than any reported previously for Fe-based FTS catalysts at these conditions. We also tested the stability of Fe-based catalysts during FTS reaction (10 days); as a result, the high hydrocarbon formation rates were maintained during 10 days, though the gradual deactivation was observed. Our investigation has also focused on the evaluation of Fe-based catalysts with hydrogen-poor synthesis gas streams (H{sub 2}/CO=1). We have observed that the Fe-based catalysts prepared in this project display also a high hydrocarbon synthesis rate with substoichiometric synthesis gas (H{sub 2}/CO=1) stream, which is a less desirable reactant mixture than stoichiometric synthesis gas (H{sub 2}/CO=2). We have improved the catalyst preparation protocols and achieved the highest FTS reaction rates and selectivities so far reported at the low temperatures required for selectivity and stability. Also, we have characterized the catalyst structural change and active phases formed, and their catalytic behavior during the activation process to evaluate their influences on FTS reaction. The efforts of this project led to (i

  10. Fuel for Success: Academic Momentum as a Mediator between Dual Enrollment and Educational Outcomes of Two-Year Technical College Students

    ERIC Educational Resources Information Center

    Wang, Xueli; Chan, Hsun-yu; Phelps, L. Allen; Washbon, Janet I.

    2015-01-01

    Objective: Despite the fairly substantial body of literature devoted to understanding whether dual enrollment programs are related to academic success in college, less is known regarding how dual enrollment transmits its potentially positive influence, especially among two-year college students. In this study, we fill this gap by delving into the…

  11. Energy conversion and storage program

    NASA Astrophysics Data System (ADS)

    1990-12-01

    The Energy Conversion and Storage Program applies chemical and chemical engineering principles to solve problems in (1) production of new synthetic fuels; (2) development of high-performance rechargeable batteries and fuel cells; (3) development of advanced thermochemical processes for energy storage; (4) characterization of complex chemical processes; and (5) the application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, and advanced methods of analysis. The following five areas are discussed: electrochemical energy storage and conversion; microstructured materials; biotechnology; fossil fuels; and high temperature superconducting processing. Papers have been processed separately for inclusion on the data base.

  12. Conversion program in Sweden

    SciTech Connect

    Jonsson, E.B.

    1997-08-01

    The conversion of the Swedish 50 MW R2 reactor from HEU to LEU fuel has been successfully accomplished over a 16 cycles long process. The conversion started in January 1991 with the introduction of 6 LEU assemblies in the 8*8 core. The first all LEU core was loaded in March 1993 and physics measurements were performed for the final licensing reports. A total of 142 LEU fuel assemblies have been irradiated up until September 1994 without any fuel incident. The operating licence for the R2 reactor was renewed in mid 1994 taking into account new fuel type. The Swedish Nuclear Inspectorate (SKI) pointed out one crucial problem with the LEU operation, that the back end of the LEU fuel cycle has not yet been solved. For the HEU fuel Sweden had the reprocessing alternative. The country is now relying heavily on the success of the USDOEs Off Site Fuels Policy to take back the spent fuel from the research reactors. They have in the meantime increased their intermediate storage facilities. There is, however, a limit both in time and space for storage of MTR-type of assemblies in water. The penalty of the lower thermal neutron flux in LEU cores has been reduced by improvements of the new irradiation rigs and by fine tuning the core calculations. The Studsvik code package, CASMO-SIMULATE, widely used for ICFM in LWRs has been modified to suit the compact MTR type of core.

  13. Merger-driven fueling of active galactic nuclei: Six dual and of AGNs discovered with Chandra and Hubble Space Telescope observations

    DOE PAGESBeta

    Comerford, Julia M.; Pooley, David; Barrows, R. Scott; Greene, Jenny E.; Zakamska, Nadia L.; Madejski, Greg M.; Cooper, Michael C.

    2015-06-19

    Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS observations of 12 optically selected dual AGN candidates atmore » $$z\\lt 0.34$$, where we use the X-rays to identify AGNs. We also present Hubble Space Telescope/Wide Field Camera 3 observations of 10 of these candidates, which reveal any stellar bulges accompanying the AGNs. We discover a dual AGN system with separation $${\\rm \\Delta }x=2.2$$ kpc, where the two stellar bulges have coincident [O iii] λ5007 and X-ray sources. This system is an extremely minor merger (460:1) that may include a dwarf galaxy hosting an intermediate mass black hole. We also find six single AGNs, and five systems that are either dual or offset AGNs with separations $${\\rm \\Delta }x\\lt 10$$ kpc. Four of the six dual AGNs and dual/offset AGNs are in ongoing major mergers, and these AGNs are 10 times more luminous, on average, than the single AGNs in our sample. This hints that major mergers may preferentially trigger higher luminosity AGNs. Further, we find that confirmed dual AGNs have hard X-ray luminosities that are half of those of single AGNs at fixed [O III] λ5007 luminosity, on average. Lastly, this could be explained by high densities of gas funneled to galaxy centers during mergers, and emphasizes the need for deeper X-ray observations of dual AGN candidates.« less

  14. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Thermochemical Research Pathways with In Situ and Ex Situ Upgrading of Fast Pyrolysis Vapors

    SciTech Connect

    Dutta, Abhijit; Sahir, A. H.; Tan, Eric; Humbird, David; Snowden-Swan, Lesley J.; Meyer, Pimphan A.; Ross, Jeff; Sexton, Danielle; Yap, Raymond; Lukas, John

    2015-03-01

    This report was developed as part of the U.S. Department of Energy’s Bioenergy Technologies Office’s efforts to enable the development of technologies for the production of infrastructure-compatible, cost-competitive liquid hydrocarbon fuels from biomass. Specifically, this report details two conceptual designs based on projected product yields and quality improvements via catalyst development and process integration. It is expected that these research improvements will be made within the 2022 timeframe. The two conversion pathways detailed are (1) in situ and (2) ex situ upgrading of vapors produced from the fast pyrolysis of biomass. While the base case conceptual designs and underlying assumptions outline performance metrics for feasibility, it should be noted that these are only two of many other possibilities in this area of research. Other promising process design options emerging from the research will be considered for future techno-economic analysis. Both the in situ and ex situ conceptual designs, using the underlying assumptions, project MFSPs of approximately $3.5/gallon gasoline equivalent (GGE). The performance assumptions for the ex situ process were more aggressive with higher distillate (diesel-range) products. This was based on an assumption that more favorable reaction chemistry (such as coupling) can be made possible in a separate reactor where, unlike in an in situ upgrading reactor, one does not have to deal with catalyst mixing with biomass char and ash, which pose challenges to catalyst performance and maintenance. Natural gas was used for hydrogen production, but only when off gases from the process was not sufficient to meet the needs; natural gas consumption is insignificant in both the in situ and ex situ base cases. Heat produced from the burning of char, coke, and off-gases allows for the production of surplus electricity which is sold to the grid allowing a reduction of approximately 5¢/GGE in the MFSP.

  15. A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements

    NASA Technical Reports Server (NTRS)

    Otugen, M. Volkan

    1997-01-01

    Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of

  16. Solar energy conversion.

    SciTech Connect

    Crabtree, G. W.; Lewis, N. S.

    2008-03-01

    If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience. The Sun has the enormous untapped potential to supply our growing energy needs. The barrier to greater use of the solar resource is its high cost relative to the cost of fossil fuels, although the disparity will decrease with the rising prices of fossil fuels and the rising costs of mitigating their impact on the environment and climate. The cost of solar energy is directly related to the low conversion efficiency, the modest energy density of solar radiation, and the costly materials currently required. The development of materials and methods to improve solar energy conversion is primarily a scientific challenge: Breakthroughs in fundamental understanding ought to enable marked progress. There is plenty of room for improvement, since photovoltaic conversion efficiencies for inexpensive organic and dye-sensitized solar cells are currently about 10% or less, the conversion efficiency of photosynthesis is less than 1%, and the best solar thermal efficiency is 30%. The theoretical limits suggest that we can do much better. Solar conversion is a young science. Its major growth began in the 1970s, spurred by the oil crisis that highlighted the pervasive importance of energy to our personal, social, economic, and political lives. In contrast, fossil-fuel science has developed over more than 250 years, stimulated by the Industrial Revolution and the promise of abundant fossil fuels. The science of thermodynamics, for example, is intimately intertwined with the development of the steam engine. The Carnot cycle, the mechanical equivalent of heat, and entropy all played starring roles in the development of thermodynamics and the technology of heat engines. Solar-energy science faces

  17. WASTEWATER TREATMENT IN COAL CONVERSION

    EPA Science Inventory

    The report describes water treatment control technology specific to fuel conversion plant sites in the western U.S. Most plants converting coal to other fuels use a large quantity of clean water (as stream) and put out a large quantity of dirty water that is condensed when the pr...

  18. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals. Quarterly technical status report, April 1--June 30, 1993

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.; Peters, W.A.

    1993-08-01

    Previous work at MIT indicates that essentially stoichiometric, rather than catalytic, reactions with alkaline earth metal oxides offer technical and economic promise as an innovative approach to upgrading natural gas to premium products such as liquid hydrocarbon fuels and chemicals. In this approach, methane would be reacted with relatively low cost and recyclable alkaline earth metal oxides, such as CaO and MgO, at high temperatures (>1500{degrees}C) to achieve very high (i.e. approaching 100%) gas conversions to H{sub 2}, CO and the corresponding alkaline earth metal carbides. These carbides exist stably in solid form at dry ambient conditions and show promise for energy storage and long distance transport. The overall objective of the proposed research is to develop new scientific and engineering knowledge bases for further assessment of the approach by performing laboratory-scale experiments and thermodynamic and thermochemical kinetics calculations. Work on this project will be performed according to two tasks. Under Task 1 (Industrial Chemistry), a laboratory-scale electric arc discharge plasma reactor is being constructed and will be used to assess the technical feasibility of producing Mg{sub 2}C{sub 3} from MgO and methane, and to identify the operating conditions of interest for the commercial production of Mg{sub 2}C{sub 3} and/or CaC{sub 2} from MgO and/or CaO and methane. Under Task 2 (Mechanistic Foundations), preliminary thermodynamic calculations were performed for the Ca-C-H-O and Mg-C-H-O systems using the Chemkin program. A scoping run with CaO in an electrical screen heater reactor under reduced methane pressure was also conducted. No appreciable quantity of acetylene was detected upon hydrolysis of the solid residue. This can be attributed to the very small quantity of methane at the very low pressure coupled with inadequate contacting of whatever methane was present with the CaO powder.

  19. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    SciTech Connect

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-04-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles close-in to the target

  20. Dual-Mode Combustion

    NASA Technical Reports Server (NTRS)

    Goyne, Christopher P.; McDaniel, James C.

    2002-01-01

    The Department of Mechanical and Aerospace Engineering at the University of Virginia has conducted an investigation of the mixing and combustion processes in a hydrogen fueled dual-mode scramjet combustor. The experiment essentially consisted of the "direct connect" continuous operation of a Mach 2 rectangular combustor with a single unswept ramp fuel injector. The stagnation enthalpy of the test flow simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and laser based diagnostics. These diagnostics included, pressure and wall temperature measurements, Fuel Plume Imaging (FPI) and Particle Image Velocimetry (PIV). A schematic of the combustor configuration and a summary of the measurements obtained are presented. The experimental work at UVa was parallel by Computational Fluid Dynamics (CFD) work at NASA Langley. The numerical and experiment results are compared in this document.

  1. Mini-cavity plasma core reactors for dual-mode space nuclear power/propulsion systems. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Chow, S.

    1976-01-01

    A mini-cavity plasma core reactor is investigated for potential use in a dual-mode space power and propulsion system. In the propulsive mode, hydrogen propellant is injected radially inward through the reactor solid regions and into the cavity. The propellant is heated by both solid driver fuel elements surrounding the cavity and uranium plasma before it is exhausted out the nozzle. The propellant only removes a fraction of the driver power, the remainder is transferred by a coolant fluid to a power conversion system, which incorporates a radiator for heat rejection. Neutronic feasibility of dual mode operation and smaller reactor sizes than those previously investigated are shown to be possible. A heat transfer analysis of one such reactor shows that the dual-mode concept is applicable when power generation mode thermal power levels are within the same order of magnitude as direct thrust mode thermal power levels.

  2. Advanced bioreactor concepts for gaseous substrates: Conversion of synthesis gas to liquid fuels and removal of SO{sub x} and NO{sub x} from coal combustion gases. CRADA final report

    SciTech Connect

    Kaufman, E.N.; Selvaraj, P.T.

    1997-10-01

    The purpose of the proposed research program was the development and demonstration of a new generation of gaseous substrate-based bioreactors for the production of liquid fuels from coal synthesis gas and the removal of NO{sub x} and SO{sub x} species from coal combustion flue gas. This study addressed the further investigation of optimal bacterial strains, growth media and kinetics for the biocatalytic conversion of coal synthesis gas to liquid fuel such as ethanol and the reduction of gaseous flue gas constituents. The primary emphasis was on the development of advanced bioreactor systems coupled with innovative biocatalytic systems that will provide increased productivity under controlled conditions. It was hoped that this would result in bioprocessing options that have both technical and economic feasibility, thus, ensuring early industrial use. Predictive mathematical models were formulated to accommodate hydrodynamics, mass transport, and conversion kinetics, and provide the data base for design and scale-up. The program was separated into four tasks: (1) Optimization of Biocatalytic Kinetics; (2) Development of Well-mixed and Columnar Reactors; (3) Development of Predictive Mathematical Models; and (4) Industrial Demonstration. Research activities addressing both synthesis gas conversion and flue gas removal were conducted in parallel by BRI and ORNL respectively.

  3. Dual-Laser-Pulse Ignition

    NASA Technical Reports Server (NTRS)

    Trinh, Huu; Early, James W.; Thomas, Matthew E.; Bossard, John A.

    2006-01-01

    A dual-pulse laser (DPL) technique has been demonstrated for generating laser-induced sparks (LIS) to ignite fuels. The technique was originally intended to be applied to the ignition of rocket propellants, but may also be applicable to ignition in terrestrial settings in which electric igniters may not be suitable.

  4. Biomass thermochemical conversion program: 1987 annual report

    SciTech Connect

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

    1988-01-01

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

  5. Conversion of deoxynivalenol to 3-acetyldeoxynivlenol in barley derived fuel ethanol co-products with yeast expressing trichothecene 3-0-acetyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The trichothecene mycotoxin deoxynivalenol (DON) may be concentrated in dried distillers grains with solubles (DDGS), a co-product of fuel ethanol fermentation, when grain containing DON is used to produce fuel ethanol. Even low levels of DON (less than 5ppm) in DDGS sold as feed pose a significant ...

  6. Steam reforming of fuel to hydrogen in fuel cell

    DOEpatents

    Young, J.E.; Fraioli, A.V.

    1983-07-13

    A fuel cell is described capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

  7. Steam reforming of fuel to hydrogen in fuel cells

    DOEpatents

    Fraioli, Anthony V.; Young, John E.

    1984-01-01

    A fuel cell capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

  8. Cost-savings possible with Air Force conversion to JP-8 as its primary fuel. Summary report, January-April 1987

    SciTech Connect

    Martel, C.R.

    1987-05-01

    JP-4 has been the primary fuel for the USAF since 1951. However, in 1979 the USAF converted to JP-8 as its primary jet fuel for its operations in Great Britain. Recently, the North Atlantic Treaty Organization (NATO) began the switch from JP-4 (F40) to JP-8 (F34) as its primary jet fuel. However, JP-4 continues to be the primary USAF jet fuel within the continental United States. The cost and manpower savings possible by converting from JP-4 to JP-8, as the primary jet fuel for the Air Force, are identified and estimated. The much lower volatility of JP-8, as compared to JP-4, accounts for the anticipated savings. For example, aircraft fuel systems must be purged prior to maintenance, and purging aircraft fuel systems that have contained JP-4 can take hours to days. With JP-8 purging may not even be necessary under most ambient temperatures. Another major savings is the reduced evaporation of JP-8, as compared to the more volatile JP-4. Finally, reduced fatalities and casualty losses resulting from ground and flight accidents are estimated.

  9. Dual Spark Plugs For Stratified-Charge Rotary Engine

    NASA Technical Reports Server (NTRS)

    Abraham, John; Bracco, Frediano V.

    1996-01-01

    Fuel efficiency of stratified-charge, rotary, internal-combustion engine increased by improved design featuring dual spark plugs. Second spark plug ignites fuel on upstream side of main fuel injector; enabling faster burning and more nearly complete utilization of fuel.

  10. Energy Conversion in Natural and Artificial Photosynthesis

    PubMed Central

    McConnell, Iain; Li, Gonghu; Brudvig, Gary W.

    2010-01-01

    Summary Modern civilization is dependent upon fossil fuels, a nonrenewable energy source originally provided by the storage of solar energy. Fossil fuel dependence has severe consequences including energy security issues and greenhouse gas emissions. The consequences of fossil fuel dependence could be avoided by fuel-producing artificial systems that mimic natural photosynthesis, directly converting solar energy to fuel. This review describes the three key components of solar energy conversion in photosynthesis: light harvesting, charge separation, and catalysis. These processes are compared in natural and artificial systems. Such a comparison can assist in understanding the general principles of photosynthesis and in developing working devices including photoelectrochemical cells for solar energy conversion. PMID:20534342

  11. Metric Conversion

    Atmospheric Science Data Center

    2013-03-12

    ... 1,000,000 1,000,000 micrometers nano- 1,000,000,000 1,000,000,000 nanometers ... conversions, see the National Institute of Standards and Technology (NIST) Special Publications: NIST Guide to SI Units: ...

  12. Technical Aspects of Acceleration of Enzymatic Conversion of Corn Stover Biomass into Bio-fuels by Low Intensity, Uniform Ultrasound Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most critical stages of conversion of plant biomass into biofuels employs hydrolysis reactions between highly specific enzymes and matching substrates (e.g. corn stover cellulose with cellulase) that produce soluble sugars, which then could be converted into ethanol. Important benefits of...

  13. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals. Quarterly technical status report, July 1, 1995--September 30, 1995

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.

    1995-11-01

    Two final scoping runs were conducted to test the experimental protocol for methane conversion to alkaline earth metal carbides in the thermal plasma reactor and to refine the techniques for carbide analysis. Having demonstrated the adequacy of the experimental protocol, the systematic study of metal carbide synthesis from methane and MgO commenced. Initial runs with MgO/CH{sub 4} gave surprisingly low methane conversions (<2%) to magnesium carbides, despite high conversions (65-90%) to hydrogen. An X-ray diffraction analysis showed the presence of a significant amount of elemental magnesium, a finding supported by the observation of bright lights upon hydrolysis of the solid products in the open air. The high conversion to hydrogen and the presence of elemental Mg in the solid products suggest that the plasma effluent is not being quenched rapidly enough and any magnesium carbides formed may be decomposing into the elements. To test this hypothesis, attempts to increase quench rates were made including lowering the arc power level, decreasing the anode nozzle-to-probe distance and introducing more quench gas.

  14. Utilization of a fuel cell power plant for the capture and conversion of gob well gas. Final report, June--December, 1995

    SciTech Connect

    Przybylic, A.R.; Haynes, C.D.; Haskew, T.A.; Boyer, C.M. II; Lasseter, E.L.

    1995-12-01

    A preliminary study has been made to determine if a 200 kW fuel cell power plant operating on variable quality coalbed methane can be placed and successfully operated at the Jim Walter Resources No. 4 mine located in Tuscaloosa County, Alabama. The purpose of the demonstration is to investigate the effects of variable quality (50 to 98% methane) gob gas on the output and efficiency of the power plant. To date, very little detail has been provided concerning the operation of fuel cells in this environment. The fuel cell power plant will be located adjacent to the No. 4 mine thermal drying facility rated at 152 M British thermal units per hour. The dryer burns fuel at a rate of 75,000 cubic feet per day of methane and 132 tons per day of powdered coal. The fuel cell power plant will provide 700,000 British thermal units per hour of waste heat that can be utilized directly in the dryer, offsetting coal utilization by approximately 0.66 tons per day and providing an avoided cost of approximately $20 per day. The 200 kilowatt electrical power output of the unit will provide a utility cost reduction of approximately $3,296 each month. The demonstration will be completely instrumented and monitored in terms of gas input and quality, electrical power output, and British thermal unit output. Additionally, real-time power pricing schedules will be applied to optimize cost savings. 28 refs., 35 figs., 13 tabs.

  15. High efficiency chemical energy conversion system based on a methane catalytic decomposition reaction and two fuel cells. Part II. Exergy analysis

    NASA Astrophysics Data System (ADS)

    Liu, Qinghua; Tian, Ye; Li, Hongjiao; Jia, Lijun; Xia, Chun; Thompson, Levi T.; Li, Yongdan

    A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%.

  16. Review of betavoltaic energy conversion

    NASA Technical Reports Server (NTRS)

    Olsen, Larry C.

    1993-01-01

    Betavoltaic energy conversion refers to the generation of power by coupling a beta source to a semiconductor junction device. The theory of betavoltaic energy conversion and some past studies of the subject are briefly reviewed. Calculations of limiting efficiencies for semiconductor cells versus bandgap are presented along with specific studies for Pm-147 and Ni-63 fueled devices. The approach used for fabricating Pm-147 fueled batteries by the author in the early 1970's is reviewed. Finally, the potential performance of advanced betavoltaic power sources is considered.

  17. Design of a dual-layer ceramic interconnect based on perovskite oxides for segmented-in-series solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Park, Beom-Kyeong; Kim, Dae-Wi; Song, Rak-Hyun; Lee, Seung-Bok; Lim, Tak-Hyoung; Park, Seok-Joo; Park, Chong-Ook; Lee, Jong-Won

    2015-12-01

    A segmented-in series (SIS) SOFC consists of segmented unit cells connected in electrical series and shows improved stack efficiency over conventional SOFCs. In this design, a thin interconnect film provides both electrical contact and sealing between the anode of one cell and the cathode of the next; thus, it should have high conductivity and chemical/structural stability in both reducing and oxidizing atmospheres as well as impermeability to gases. Here, we report a dual-layer interconnect film for SIS-SOFCs comprising perovskite-type oxides, Sr0.7La0.2TiO3 (exposed to a reducing atmosphere) and La0.8Sr0.2FeO3 (exposed to an oxidizing atmosphere). The interconnect film is not only very dense but also highly conductive and stable under SOFC operating conditions; in particular, it shows an area-specific resistance of 19.6 mΩ cm2 at 800 °C, which is much lower than the generally accepted limit for SOFCs. A flat-tubular SIS-SOFC fabricated using these interconnect films exhibits a power density as high as 340 mW cm-2, which proves the feasibility of the dual-layer interconnect design.

  18. Coal conversion processes and analysis methodologies for synthetic fuels production. [technology assessment and economic analysis of reactor design for coal gasification

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Information to identify viable coal gasification and utilization technologies is presented. Analysis capabilities required to support design and implementation of coal based synthetic fuels complexes are identified. The potential market in the Southeast United States for coal based synthetic fuels is investigated. A requirements analysis to identify the types of modeling and analysis capabilities required to conduct and monitor coal gasification project designs is discussed. Models and methodologies to satisfy these requirements are identified and evaluated, and recommendations are developed. Requirements for development of technology and data needed to improve gasification feasibility and economies are examined.

  19. NSF presentation. [summary on energy conversion research program

    NASA Technical Reports Server (NTRS)

    Morse, F. H.

    1973-01-01

    Wind energy conversion research is considered in the framework of the national energy problem. Research and development efforts for the practical application of solar energy -- including wind energy -- as alternative energy supplies are assessed in: (1) Heating and cooling of buildings; (2) photovoltaic energy conversion; (3) solar thermal energy conversion; (4) wind energy conversion; (5) ocean thermal energy conversion; (6) photosynthetic production of organic matter; and (7) conversion of organic matter into fuels.

  20. Energy Conversion and Storage Program

    SciTech Connect

    Cairns, E.J.

    1992-03-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering principles applicable to electrochemical energy storage and conversion. Chemical Applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing waste streams from synfuel plants and coal gasifiers. Other research projects seek to identify and characterize the constituents of liquid fuel-system streams and to devise energy-efficient means for their separation. Materials Applications research includes the evaluation of the properties of advanced materials, as well as the development of novel preparation techniques. For example, the use of advanced techniques, such as sputtering and laser ablation, are being used to produce high-temperature superconducting films.

  1. An intensified π-hole in beryllium-doped boron nitride meshes: its determinant role in CO2 conversion into hydrocarbon fuels.

    PubMed

    Azofra, Luis Miguel; MacFarlane, Douglas R; Sun, Chenghua

    2016-02-28

    DFT investigations on beryllium-doped boron nitride meshes or sheets (BNs) predict the existence of a very reactive kind of novel material capable of spontaneously reducing the first hydrogenation step in the CO2 conversion mechanism. This impressive behaviour appears as a result of the very deep π-hole generated by the beryllium moieties, and also determines its selectivity towards the production of CH4. PMID:26841973

  2. State of Practice for Emerging Waste Conversion Technologies

    EPA Science Inventory

    New technologies to convert municipal and other waste streams into fuels and chemical commodities, termed conversion technologies, are rapidly developing. Conversion technologies are garnering increasing interest and demand due primarily to alternative energy initiatives. These t...

  3. Conversation Classes.

    ERIC Educational Resources Information Center

    Xia, Jiang

    1998-01-01

    Describes an activity for use in the conversational English-as-a-foreign-language classroom. The activity involves having each student say one or two sentences that continues a story being made up as the activity goes along. Students were positive about the activity, because saying only one or two sentences helped them not to feel pressured or…

  4. Assumptions and Criteria for Performing a Feasability Study of the Conversion of the High Flux Isotope Reactor Core to Use Low-Enriched Uranium Fuel

    SciTech Connect

    Primm, R.T., III; Ellis, R.J.; Gehin, J.C.; Moses, D.L.; Binder, J.L.; Xoubi, N.

    2006-02-01

    A computational study will be initiated during fiscal year 2006 to examine the feasibility of converting the High Flux Isotope Reactor from highly enriched uranium fuel to low-enriched uranium. The study will be limited to steady-state, nominal operation, reactor physics and thermal-hydraulic analyses of a uranium-molybdenum alloy that would be substituted for the current fuel powder--U{sub 3}O{sub 8} mixed with aluminum. The purposes of this document are to (1) define the scope of studies to be conducted, (2) define the methodologies to be used to conduct the studies, (3) define the assumptions that serve as input to the methodologies, (4) provide an efficient means for communication with the Department of Energy and American research reactor operators, and (5) expedite review and commentary by those parties.

  5. Liquid Fuel from Heat-Loving Microorganisms: H2-Dependent Conversion of CO2 to Liquid Electrofuels by Extremely Thermophilic Archaea

    SciTech Connect

    2010-07-01

    Electrofuels Project: NC State is working with the University of Georgia to create Electrofuels from primitive organisms called extremophiles that evolved before photosynthetic organisms and live in extreme, hot water environments with temperatures ranging from 167-212 degrees Fahrenheit The team is genetically engineering these microorganisms so they can use hydrogen to turn carbon dioxide directly into alcohol-based fuels. High temperatures are required to distill the biofuels from the water where the organisms live, but the heat-tolerant organisms will continue to thrive even as the biofuels are being distilled—making the fuel-production process more efficient. The microorganisms don’t require light, so they can be grown anywhere—inside a dark reactor or even in an underground facility.

  6. Cellulosic Biomass Sugars to Advantage Jet Fuel: Catalytic Conversion of Corn Stover to Energy Dense, Low Freeze Point Paraffins and Naphthenes: Cooperative Research and Development Final Report, CRADA Number CRD-12-462

    SciTech Connect

    Elander, Rick

    2015-08-04

    NREL will provide scientific and engineering support to Virent Energy Systems in three technical areas: Process Development/Biomass Deconstruction; Catalyst Fundamentals; and Technoeconomic Analysis. The overarching objective of this project is to develop the first fully integrated process that can convert a lignocellulosic feedstock (e.g., corn stover) efficiently and cost effectively to a mix of hydrocarbons ideally suited for blending into jet fuel. The proposed project will investigate the integration of Virent Energy System’s novel aqueous phase reforming (APR) catalytic conversion technology (BioForming®) with deconstruction technologies being investigated by NREL at the 1-500L scale. Corn stover was chosen as a representative large volume, sustainable feedstock.

  7. Durability of PEM Fuel Cell Membranes

    NASA Astrophysics Data System (ADS)

    Huang, Xinyu; Reifsnider, Ken

    Durability is still a critical limiting factor for the commercialization of polymer electrolyte membrane (PEM) fuel cells, a leading energy conversion technology for powering future hydrogen fueled automobiles, backup power systems (e.g., for base transceiver station of cellular networks), portable electronic devices, etc. Ionic conducting polymer (ionomer) electrolyte membranes are the critical enabling materials for the PEM fuel cells. They are also widely used as the central functional elements in hydrogen generation (e.g., electrolyzers), membrane cell for chlor-alkali production, etc. A perfluorosulfonic acid (PFSA) polymer with the trade name Nafion® developed by DuPont™ is the most widely used PEM in chlor-alkali cells and PEM fuel cells. Similar PFSA membranes have been developed by Dow Chemical, Asahi Glass, and lately Solvay Solexis. Frequently, such membranes serve the dual function of reactant separation and selective ionic conduction between two otherwise separate compartments. For some applications, the compromise of the "separation" function via the degradation and mechanical failure of the electrolyte membrane can be the life-limiting factor; this is particularly the case for PEM in hydrogen/oxygen fuel cells.

  8. Energy Conversion and Storage Program

    NASA Astrophysics Data System (ADS)

    Cairns, E. J.

    1993-06-01

    This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Chemical applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing product and waste streams from synfuel plants, coal gasifiers, and biomass conversion processes. Materials applications research includes evaluation of the properties of advanced materials, as well as development of novel preparation techniques. For example, techniques such as sputtering, laser ablation, and poised laser deposition are being used to produce high-temperature superconducting films.

  9. Advanced bioreactor systems for gaseous substrates: Conversion of synthesis gas to liquid fuels and removal of SO{sub x} and NO{sub x} from coal combustion gases

    SciTech Connect

    Selvaraj, P.T.; Kaufman, E.N.

    1995-06-01

    The purpose of the proposed research program is the development and demonstration of a new generation of gaseous substrate-based bioreactors for the production of liquid fuels from coal synthesis gas and the removal of NO{sub x} and SO{sub x} species from combustion flue gas. Coal is thermochemically converted to synthesis gas consisting of carbon monoxide, hydrogen, and carbon dioxide. Conventional catalytic upgrading of coal synthesis gas into alcohols or other oxychemicals is subject to several processing problems such as interference of the other constituents in the synthesis gases, strict CO/H{sub 2} ratios required to maintain a particular product distribution and yield, and high processing cost due to the operation at high temperatures and pressures. Recently isolated and identified bacterial strains capable of utilizing CO as a carbon source and coverting CO and H{sub 2} into mixed alcohols offer the potential of performing synthesis gas conversion using biocatalysts. Biocatalytic conversion, though slower than the conventional process, has several advantages such as decreased interference of the other constituents in the synthesis gases, no requirement for strict CO/H{sub 2} ratios, and decreased capital and oeprating costs as the biocatalytic reactions occur at ambient temperatures and pressures.

  10. Conversational sensing

    NASA Astrophysics Data System (ADS)

    Preece, Alun; Gwilliams, Chris; Parizas, Christos; Pizzocaro, Diego; Bakdash, Jonathan Z.; Braines, Dave

    2014-05-01

    Recent developments in sensing technologies, mobile devices and context-aware user interfaces have made it pos- sible to represent information fusion and situational awareness for Intelligence, Surveillance and Reconnaissance (ISR) activities as a conversational process among actors at or near the tactical edges of a network. Motivated by use cases in the domain of Company Intelligence Support Team (CoIST) tasks, this paper presents an approach to information collection, fusion and sense-making based on the use of natural language (NL) and controlled nat- ural language (CNL) to support richer forms of human-machine interaction. The approach uses a conversational protocol to facilitate a ow of collaborative messages from NL to CNL and back again in support of interactions such as: turning eyewitness reports from human observers into actionable information (from both soldier and civilian sources); fusing information from humans and physical sensors (with associated quality metadata); and assisting human analysts to make the best use of available sensing assets in an area of interest (governed by man- agement and security policies). CNL is used as a common formal knowledge representation for both machine and human agents to support reasoning, semantic information fusion and generation of rationale for inferences, in ways that remain transparent to human users. Examples are provided of various alternative styles for user feedback, including NL, CNL and graphical feedback. A pilot experiment with human subjects shows that a prototype conversational agent is able to gather usable CNL information from untrained human subjects.

  11. Conversational sensemaking

    NASA Astrophysics Data System (ADS)

    Preece, Alun; Webberley, Will; Braines, Dave

    2015-05-01

    Recent advances in natural language question-answering systems and context-aware mobile apps create opportunities for improved sensemaking in a tactical setting. Users equipped with mobile devices act as both sensors (able to acquire information) and effectors (able to act in situ), operating alone or in collectives. The currently- dominant technical approaches follow either a pull model (e.g. Apple's Siri or IBM's Watson which respond to users' natural language queries) or a push model (e.g. Google's Now which sends notifications to a user based on their context). There is growing recognition that users need more flexible styles of conversational interaction, where they are able to freely ask or tell, be asked or told, seek explanations and clarifications. Ideally such conversations should involve a mix of human and machine agents, able to collaborate in collective sensemaking activities with as few barriers as possible. Desirable capabilities include adding new knowledge, collaboratively building models, invoking specific services, and drawing inferences. As a step towards this goal, we collect evidence from a number of recent pilot studies including natural experiments (e.g. situation awareness in the context of organised protests) and synthetic experiments (e.g. human and machine agents collaborating in information seeking and spot reporting). We identify some principles and areas of future research for "conversational sensemaking".

  12. Classification of biodiesel and fuel blends using gas chromatography - differential mobility spectrometry with cluster analysis and isolation of C18:3 me by dual ion filtering.

    PubMed

    Pasupuleti, Dedeepya; Eiceman, Gary A; Pierce, Karisa M

    2016-08-01

    Fatty acid alkyl esters (FAAEs) were determined at 10-100mg/L in biodiesel and blends with petrodiesel without sample pre-treatment using gas chromatography with a tandem differential mobility detector. Selectivity was provided through chromatographic separations and atmospheric pressure chemical ionization reactions in the detector with mobility characterization of gas ions. Limits of detection were ~0.5ng with an average of 2.98% RSD for peak area precision, ≤1.3% RSD for retention time precision, and ≤9.2% RSD for compensation voltage precision. Biodiesel blends were classified using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Unsupervised cluster analysis captured 52.72% of variance in a single PC while supervised analysis captured 71.64% of variance using Fisher ratio feature selection. Test set predictions showed successful clustering according to source or feedstock when regressed onto the training set model. Detection of the regulated substance methyl linolenate (C18:3 me) was achieved in 6-10s with a 1m long capillary column using dual ion filtering in the tandem differential mobility detector. PMID:27216685

  13. Double-shelled plasmonic Ag-TiO2 hollow spheres toward visible light-active photocatalytic conversion of CO2 into solar fuel

    NASA Astrophysics Data System (ADS)

    Feng, Shichao; Wang, Meng; Zhou, Yong; Li, Ping; Tu, Wenguang; Zou, Zhigang

    2015-10-01

    Double-shelled hollow hybrid spheres consisting of plasmonic Ag and TiO2 nanoparticles were successfully synthesized through a simple reaction process. The analysis reveals that Ag nanoparticles were dispersed uniformly in the TiO2 nanoparticle shell. The plasmonic Ag-TiO2 hollow sphere proves to greatly enhance the photocatalytic activity toward reduction of CO2 into renewable hydrocarbon fuel (CH4) in the presence of water vapor under visible-light irradiation. The possible formation mechanism of the hollow sphere and related plasmon-enhanced photocatalytic performance were also briefly discussed.

  14. Double-shelled plasmonic Ag-TiO{sub 2} hollow spheres toward visible light-active photocatalytic conversion of CO{sub 2} into solar fuel

    SciTech Connect

    Feng, Shichao; Wang, Meng; Li, Ping; Tu, Wenguang; Zhou, Yong; Zou, Zhigang

    2015-10-01

    Double-shelled hollow hybrid spheres consisting of plasmonic Ag and TiO{sub 2} nanoparticles were successfully synthesized through a simple reaction process. The analysis reveals that Ag nanoparticles were dispersed uniformly in the TiO{sub 2} nanoparticle shell. The plasmonic Ag-TiO{sub 2} hollow sphere proves to greatly enhance the photocatalytic activity toward reduction of CO{sub 2} into renewable hydrocarbon fuel (CH{sub 4}) in the presence of water vapor under visible-light irradiation. The possible formation mechanism of the hollow sphere and related plasmon-enhanced photocatalytic performance were also briefly discussed.

  15. Advanced bioreactor systems for gaseous substrates: Conversion of synthesis gas to liquid fuels and removal of SO{sub X} and NO{sub X} from coal combustion gases

    SciTech Connect

    Selvaraj, P.T.; Kaufman, E.N.

    1996-06-01

    The purpose of this research program is the development and demonstration of a new generation of gaseous substrate based bioreactors for the production of liquid fuels from coal synthesis gas and the removal of NO{sub x} and SO{sub x} species from combustion flue gas. This R&D program is a joint effort between the staff of the Bioprocessing Research and Development Center (BRDC) of ORNL and the staff of Bioengineering Resources, Inc. (BRI) under a Cooperative Research and Development Agreement (CRADA). The Federal Coordinating Council for Science, Engineering, and Technology report entitled {open_quotes}Biotechnology for the 21st Century{close_quotes} and the recent Energy Policy Act of 1992 emphasizes research, development, and demonstration of the conversion of coal to gaseous and liquid fuels and the control of sulfur and nitrogen oxides in effluent streams. This R&D program presents an innovative approach to the use of bioprocessing concepts that will have utility in both of these identified areas.

  16. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model). Quarterly technical progress report, November 1, 1979-January 31, 1980

    SciTech Connect

    Ahn, Y.K.; Chen, Y.C.; Chen, H.T.; Helm, R.W.; Nelson, E.T.; Shields, K.J.; Stringer, R.P.; Bailie, R.C.

    1980-01-01

    The biomass allocation model has been developed and is undergoing testing. Data bases for biomass feedstock and thermochemical products are complete. Simulated data on process efficiency and product costs are being used while more accurate data are being developed. Market analyses data are stored for the biomass allocation model. The modeling activity will assist in providing process efficiency information required for the allocation model. Process models for entrained bed and fixed bed gasifiers based on coal have been adapted to biomass. Fuel product manufacturing costs will be used as inputs for the data banks of the biomass allocations model. Conceptual economics have been generated for seven of the fourteen process configurations via a biomass economic computer program. The PDU studies are designed to demonstrate steady state thermochemical conversions of biomass to fuels in fluidized, moving and entrained bed reactor configurations. Pulse tests in a fluidized bed to determine the effect of particle size on reaction rates and product gas composition have been completed. Two hour shakedown tests using peanut hulls and wood as the biomass feedstock and the fluidized bed reactor mode have been carried out. A comparison was made of the gas composition using air and steam - O/sub 2/. Biomass thermal profiles and biomass composition information shall be provided. To date approximately 70 biomass types have been collected. Chemical characterization of this material has begun. Thermal gravimetric, pyrogaschromatographic and effluent gas analysis has begun on pelletized samples of these biomass species.

  17. Mode conversion in ITER

    NASA Astrophysics Data System (ADS)

    Jaeger, E. F.; Berry, L. A.; Myra, J. R.

    2006-10-01

    Fast magnetosonic waves in the ion cyclotron range of frequencies (ICRF) can convert to much shorter wavelength modes such as ion Bernstein waves (IBW) and ion cyclotron waves (ICW) [1]. These modes are potentially useful for plasma control through the generation of localized currents and sheared flows. As part of the SciDAC Center for Simulation of Wave-Plasma Interactions project, the AORSA global-wave solver [2] has been ported to the new, dual-core Cray XT-3 (Jaguar) at ORNL where it demonstrates excellent scaling with the number of processors. Preliminary calculations using 4096 processors have allowed the first full-wave simulations of mode conversion in ITER. Mode conversion from the fast wave to the ICW is observed in mixtures of deuterium, tritium and helium3 at 53 MHz. The resulting flow velocity and electric field shear will be calculated. [1] F.W. Perkins, Nucl. Fusion 17, 1197 (1977). [2] E.F. Jaeger, L.A. Berry, J.R. Myra, et al., Phys. Rev. Lett. 90, 195001-1 (2003).

  18. Thermally resistant polymers for fuel tank sealants

    NASA Technical Reports Server (NTRS)

    Webster, J. A.

    1972-01-01

    Conversion of fluorocarbon dicarboxylic acid to intermediates whose terminal functional groups permit polymerization is discussed. Resulting polymers are used as fuel tank sealers for jet fuels at elevated temperatures. Stability and fuel resistance of the prototype polymers is explained.

  19. Aluminum oxide as a dual-functional modifier of Ni-based anodes of solid oxide fuel cells for operation on simulated biogas

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Wang, Wei; Ran, Ran; Tade, Moses O.; Shao, Zongping

    2014-12-01

    Al2O3 and SnO2 additives are introduced into the Ni-YSZ cermet anode of solid oxide fuel cells (SOFCs) for operation on simulated biogas. The effects of incorporating Al2O3/SnO2 on the electrical conductivity, morphology, coking resistance and catalytic activity for biogas reforming of the cermet anode are systematically studied. The electrochemical performance of the internal reforming SOFC is enhanced by introducing an appropriate amount of Al2O3 into the anode, but it becomes worse with excess alumina addition. For SnO2, a negative effect on the electrochemical performance is demonstrated, although the coking resistance of the anode is improved. For fuel cells operating on biogas, stable operation under a polarization current for 130 h at 750 °C is achieved for a cell with an Al2O3-modified anode, while cells with unmodified or SnO2-modified Ni-YSZ anodes show much poorer stability under the same conditions. The improved performance of the cell with the Al2O3-modified anode mainly results from the suppressed coking and sintering of the anode and from the formation of NiAl2O4 in the unreduced anode. In sum, modifying the anode with Al2O3 may be a useful and facile way to improve the coking resistance and electrochemical performance of the nickel-based cermet anodes for SOFCs.

  20. Alternative Motor Fuel Use Model

    Energy Science and Technology Software Center (ESTSC)

    1992-11-16

    AMFU is a tool for the analysis and prediction of motor fuel use by highway vehicles. The model advances the art of vehicle stock modeling by including a representation of the choice of motor fuel for flexible and dual fuel vehicles.

  1. Coal conversion products Industrial applications

    NASA Technical Reports Server (NTRS)

    Warren, D.; Dunkin, J.

    1980-01-01

    The synfuels economic evaluation model was utilized to analyze cost and product economics of the TVA coal conversion facilities. It is concluded that; (1) moderate yearly future escalations ( 6%) in current natural gas prices will result in medium-Btu gas becoming competitive with natural gas at the plant boundary; (2) utilizing DRI price projections, the alternate synfuel products, except for electricity, will be competitive with their counterparts; (3) central site fuel cell generation of electricity, utilizing MBG, is economically less attractive than the other synthetic fuels, given projected price rises in electricity produced by other means; and (4) because of estimated northern Alabama synfuels market demands, existing conventional fuels, infrastructure and industrial synfuels retrofit problems, a diversity of transportable synfuels products should be produced by the conversion facility.

  2. Optimized energy conversion efficiency in solid-oxide fuel cells implementing SrMo1-xFexO3-δ perovskites as anodes

    NASA Astrophysics Data System (ADS)

    Martínez-Coronado, R.; Alonso, J. A.; Aguadero, A.; Fernández-Díaz, M. T.

    2012-06-01

    Oxides of composition SrMo1-xFexO3-δ (x = 0.1, 0.2) have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers close to 900 mW cm-2 at 850 °C with pure H2 as a fuel. This excellent performance is accounted for the results of an “in situ” neutron powder diffraction experiment, at the working temperature of the SOFC, showing the presence of a sufficiently high oxygen deficiency, with large displacement factors for oxygen atoms that suggest a large lability and mobility, combined with a huge metal-like electronic conductivity, as high as 340 S cm-1 at T = 50 °C for x = 0.1. The magnitude of the electronic conductivity decreases with increasing Fe-doping content. An adequate thermal expansion coefficient, reversibility upon cycling in oxidizing-reducing atmospheres and chemical compatibility with the electrolyte make these oxides good candidates for anodes in intermediate-temperature SOFC (IT-SOFCs).

  3. Catalytic conversion of cellulose to liquid hydrocarbon fuels by progressive removal of oxygen to facilitate separation processes and achieve high selectivities

    DOEpatents

    Dumesic, James A.; Ruiz, Juan Carlos Serrano; West, Ryan M.

    2012-04-03

    Described is a method to make liquid chemicals, such as functional intermediates, solvents, and liquid fuels from biomass-derived cellulose. The method is cascading; the product stream from an upstream reaction can be used as the feedstock in the next downstream reaction. The method includes the steps of deconstructing cellulose to yield a product mixture comprising levulinic acid and formic acid, converting the levulinic acid to .gamma.-valerolactone, and converting the .gamma.-valerolactone to pentanoic acid. Alternatively, the .gamma.-valerolactone can be converted to a mixture of n-butenes. The pentanoic acid so formed can be further reacted to yield a host of valuable products. For example, the pentanoic acid can be decarboxylated yield 1-butene or ketonized to yield 5-nonanone. The 5-nonanone can be hydrodeoxygenated to yield nonane, or 5-nonanone can be reduced to yield 5-nonanol. The 5-nonanol can be dehydrated to yield nonene, which can be dimerized to yield a mixture of C.sub.9 and C.sub.18 olefins, which can be hydrogenated to yield a mixture of alkanes. Alternatively, the nonene may be isomerized to yield a mixture of branched olefins, which can be hydrogenated to yield a mixture of branched alkanes. The mixture of n-butenes formed from .gamma.-valerolactone can also be subjected to isomerization and oligomerization to yield olefins in the gasoline, jet and Diesel fuel ranges.

  4. 1982 annual report: Biomass Thermochemical Conversion Program

    SciTech Connect

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

    1983-01-01

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

  5. Biomass thermal conversion research at SERI

    SciTech Connect

    Milne, T. A.; Desrosiers, R. E.; Reed, T. B.

    1980-09-01

    SERI's involvement in the thermochemical conversion of biomass to fuels and chemicals is reviewed. The scope and activities of the Biomass Thermal Conversion and Exploratory Branch are reviewed. The current status and future plans for three tasks are presented: (1) Pyrolysis Mechanisms; (2) High Pressure O/sub 2/ Gasifier; and (3) Gasification Test Facility.

  6. A fast spectrum dual path flow cermet reactor

    SciTech Connect

    Anghaie, S.; Feller, G.J. ); Peery, S.D.; Parsley, R.C. )

    1993-01-15

    A cermet fueled, dual path fast reactor for space nuclear propulsion applications is conceptually designed. The reactor utilizes an outer annulus core and an inner cylindrical core with radial and axial reflector. The dual path flow minimizes the impact of power peaking near the radial reflector. Basic neutronics and core design aspects of the reactor are discussed. The dual path reactor is integrated into a 25000 lbf thrust nuclear rocket.

  7. Conversion of light hydrocarbon gases to metal carbides for production of liquid fuels and chemicals. Quarterly technical status report, April 1, 1995--June 30, 1995

    SciTech Connect

    Diaz, A.F.; Modestino, A.J.; Howard, J.B.

    1995-08-01

    Upgrading of the experimental apparatus was necessitated by problems encountered in the previous scoping runs with CH{sub 4}/MgO. To further improve plasma stability, a pressure controller was installed on the cooling chamber to maintain the chamber pressure constant at 1 atm and a mass flow controller was installed on the main plasma gas inlet line. With a fully functional data acquisition and control system, there is now the capability to record arc voltage, arc current, chamber pressure, feed gas mass flow, and cooling water and gas temperatures during the relatively short experimental runs. With this system, an improved sampling protocol can also be implemented whereby gas and solid sampling are initiated only when fully developed flowrates of methane and MgO are established in the plasma. Solid products from a scoping run under conditions of excess MgO above the stoichiometric requirement for 100% conversion of the methane exhibited intense reactivity in the open atmosphere, indicating high concentrations of magnesium carbide in the product. The hypothesis is that reaction begins with hydrolysis of the carbide by atmospheric moisture giving acetylene and/or methylacetylene which then, because of the intense local heating (possibly due to the fine particle sizes of the recently formed carbides), are ignited to produce flaming combustion.

  8. Converse Piezoelectricity

    NASA Astrophysics Data System (ADS)

    Springborg, Michael; Kirtman, Bernard

    2013-03-01

    Piezoelectricity results from a coupling between responses to mechanical and electric perturbations and leads to changes in the polarization due to strain or stress or, alternatively, the occurrence of strain as a function of an applied external, electrostatic field (i.e., converse piezoelectricity). Theoretical studies of those properties for extended systems require accordingly that their dipole moment or polarization can be calculated. However, whereas the definition of the operator for the dipole moment for any finite system is trivial, it is only within the last 2 decades that the expressions for the equivalent operator in the independent-particle approximation for the infinite and periodic system have been presented. Here, we demonstrate that the so called branch dependence of the polarization for the infinite, periodic system is related to physical observables in contrast to what often is assumed. This is related to the finding that converse piezoelectric properties depend both on the surfaces of the samples of interest even for samples with size well above the thermodynamic limit. However, we shall demonstrate that these properties can be calculated without explicitly taking the surfaces into account. Both the foundations and results for real system shall be presented.

  9. A tunable dual frequency dye laser - dual frequency oscillator design

    NASA Technical Reports Server (NTRS)

    Abury, Y.

    1983-01-01

    The pulsed dye laser offers a tunable oscillator, followed by three amplifiers. It is pumped by a dual frequency Nd:YAG laser. Tuning and spectral width are controlled by a holographic network connected to a high power telescope. The modified two wavelength dye laser allows for absorption lidar techniques for remote sensing of the atmosphere. Line switching is achieved by electrooptical commutation. A feasibility experiment was performed with the original oscillator. A model was then built, and tested with different dyes. After a few modifications were made to improve the conversion efficiency, this oscillator was inserted in the laser to check whether the amplifier stages were correctly adjusted.

  10. Energy Conversion & Storage Program, 1993 annual report

    SciTech Connect

    Cairns, E.J.

    1994-06-01

    The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in: production of new synthetic fuels; development of high-performance rechargeable batteries and fuel cells; development of high-efficiency thermochemical processes for energy conversion; characterization of complex chemical processes and chemical species; and the study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis.

  11. Thermionic energy conversion technology - Present and future

    NASA Technical Reports Server (NTRS)

    Shimada, K.; Morris, J. F.

    1977-01-01

    Aerospace and terrestrial applications of thermionic direct energy conversion and advances in direct energy conversion (DEC) technology are surveyed. Electrode materials, the cesium plasma drop (the difference between the barrier index and the collector work function), DEC voltage/current characteristics, conversion efficiency, and operating temperatures are discussed. Attention is centered on nuclear reactor system thermionic DEC devices, for in-core or out-of-core operation. Thermionic fuel elements, the radiation shield, power conditions, and a waste heat rejection system are considered among the thermionic DEC system components. Terrestrial applications include topping power systems in fossil fuel and solar power generation.

  12. Conversion of polyethylene into gasoline-range fuels by two-stage catalytic degradation using silica-alumina and HZSM-5 zeolite

    SciTech Connect

    Uemichi, Yoshio; Nakamura, Junko; Itoh, Toshihiro; Sugioka, Masatoshi; Garforth, A.A.; Dwyer, J.

    1999-02-01

    A two-stage catalytic degradation of polyethylene using amorphous silica-alumina and HZSM-5 zeolite catalysts in series has been developed for converting the polymer into high-quality gasoline-range fuels. Compared with the one-stage degradation over each catalyst, the two-stage method provides some advantages. They are an improved gasoline yield and a high octane number despite low aromatics content. Significant results were obtained when silica-alumina and HZSM-5 were used in a weight ratio of 9:1 as upper and lower catalysts, respectively, in a flow reactor. The reverse sequence of catalysts showed no advantage. It was suggested that large pores and moderate acidity of the silica-alumina loaded in the upper layer operated favorably to catalyze the degradation of polyethylene into liquid hydrocarbons. The resulting oils showed low quality, and they were transformed into high-quality gasoline on the strongly acidic sites of the HZSM-5 loaded in the lower layer at the expense of oil yield. Increases in concentration of isoparaffins and aromatics contributed to the upgrading.

  13. Layer-by-layer self-assembly in the development of electrochemical energy conversion and storage devices from fuel cells to supercapacitors.

    PubMed

    Xiang, Yan; Lu, Shanfu; Jiang, San Ping

    2012-11-01

    As one of the most effective synthesis tools, layer-by-layer (LbL) self-assembly technology can provide a strong non-covalent integration and accurate assembly between homo- or hetero-phase compounds or oppositely charged polyelectrolytes, resulting in highly-ordered nanoscale structures or patterns with excellent functionalities and activities. It has been widely used in the developments of novel materials and nanostructures or patterns from nanotechnologies to medical fields. However, the application of LbL self-assembly in the development of highly efficient electrocatalysts, specific functionalized membranes for proton exchange membrane fuel cells (PEMFCs) and electrode materials for supercapacitors is a relatively new phenomenon. In this review, the application of LbL self-assembly in the development and synthesis of key materials of PEMFCs including polyelectrolyte multilayered proton-exchange membranes, methanol-blocking Nafion membranes, highly uniform and efficient Pt-based electrocatalysts, self-assembled polyelectrolyte functionalized carbon nanotubes (CNTs) and graphenes will be reviewed. The application of LbL self-assembly for the development of multilayer nanostructured materials for use in electrochemical supercapacitors will also be reviewed and discussed (250 references). PMID:22945597

  14. Energetic conversion of European semi-natural grassland silages through the integrated generation of solid fuel and biogas from biomass: energy yields and the fate of organic compounds.

    PubMed

    Hensgen, Frank; Bühle, Lutz; Donnison, Iain; Heinsoo, Katrin; Wachendorf, Michael

    2014-02-01

    Twelve European habitat types were investigated to determine the influence of the IFBB technique (integrated generation of biogas and solid fuel from biomass) on the fate of organic compounds and energy yields of semi-natural grassland biomass. Concentration of organic compounds in silage and IFBB press cake (PC), mass flows within that system and methane yields of IFBB press fluids (PF) were determined. The gross energy yield of the IFBB technique was calculated in comparison to hay combustion (HC) and whole crop digestion (WCD). The IFBB treatment increased fibre and organic matter (OM) concentrations and lowered non-fibre carbohydrates and crude protein concentrations. The PF was highly digestible irrespective of habitat types, showing mean methane yields between 312.1 and 405.0 LN CH4 kg(-1) VS. Gross energy yields for the IFBB system (9.75-30.19MWh ha(-1)) were in the range of HC, outperformed WCD and were influenced by the habitat type. PMID:24393744

  15. Biomass Thermochemical Conversion Program: 1986 annual report

    SciTech Connect

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

    1987-01-01

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

  16. Energy conversion

    SciTech Connect

    Woodall, J.M.

    1982-02-16

    Energy conversion capable of receiving input energy in thermal or radiant form at a variable rate and releasing energy in thermal, radiant or electrical form independent of rate is accomplished by providing a buffer member of a material that has three criteria: a melting temperature above 1300/sup degree/ K, a thermal conductance greater than 0.1 in calories per square centimeter per centimeter per degree per second and a latent heat of fusion of the order of 1 kilocalorie per mole. The converter can absorb energy of multiple types, store it and then release it in a form compatible with the prospective use. Sunlight of daylight duration and varying intensity is converted to steady 24 hour a day electrical output.

  17. Introduction to Solar Photon Conversion

    SciTech Connect

    Nozik, Arthur J; Miller, John

    2010-11-10

    This Thematic Issue on Solar Photon Conversion will provide a review by leading researchers on the present status and prognosis of the science and technology of direct solar photoconversion to electricity and fuels. The topics covered include advanced and novel concepts for low-cost photovoltaic (PV) energy based on chemistry (dye-sensitized photoelectrodes, organic and molecular PV, multiple exciton generation in quantum dots, singlet fission), solar water splitting, redox catalysis for water oxidation and reduction, the role of nanoscience and nanocrystals in solar photoconversion, photoelectrochemical energy conversion, and photoinduced electron transfer.

  18. Characteristics of American coals in relation to their conversion into clean-energy fuels. Final report. [1150 samples of US coals

    SciTech Connect

    Spackman, W.; Davis, A.; Walker, P.L.; Lovell, H.L.; Vastola, F.J.; Given, P.H.; Suhr, N.H.; Jenkins, R.G.

    1982-06-01

    To further characterize the Nation's coals, the Penn State Coal Sample Bank and Data Base were expanded to include a total of 1150 coal samples. The Sample Bank includes full-seam channel samples as well as samples of lithotypes, seam benches, and sub-seam sections. To the extent feasible and appropriate basic compositional data were generated for each sample and validated and computerized. These data include: proximate analysis, ultimate analysis, sulfur forms analysis, calorific value, maceral analysis, vitrinite reflectance analysis, ash fusion analysis, free-swelling index determination, Gray-King coke type determination, Hardgrove grindability determination, Vicker's microhardness determination, major and minor element analysis, trace element analysis, and mineral species analysis. During the contract period more than 5000 samples were prepared and distributed. A theoretical and experimental study of the pyrolysis of coal has been completed. The reactivity of chars, produced from all ranks of American coals, has been studied with regard to reactivity to air, CO/sub 2/, H/sub 2/ and steam. Another area research has concerned the catalytic effect of minerals and various cations on the gasification processes. Combustion of chars, low volatile fuels, coal-oil-water-air emulsions and other subjects of research are reported here. The products of this research can be found in 23 DOE Technical Research Reports and 49 published papers. As another mechanism of technology transfer, the results have been conveyed via more than 70 papers presented at a variety of scientific meetings. References to all of these are contained in this report.

  19. LEU conversion status of US research reactors, September 1996

    SciTech Connect

    Matos, J.E.

    1996-10-07

    This paper summarizes the conversion status of research and test reactors in the United States from the use of fuels containing highly- enriched uranium (HEU, greater than or equal to 20%) to the use of fuels containing low-enriched uranium (LEU, < 20%). Estimates of the uranium densities required for conversion are made for reactors with power levels greater than or equal to 1 MW that are not currently involved in the LEU conversion process.

  20. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    SciTech Connect

    H.C. Maru; M. Farooque

    2002-02-01

    The carbonate fuel cell promises highly efficient, cost-effective and environmentally superior power generation from pipeline natural gas, coal gas, biogas, and other gaseous and liquid fuels. FuelCell Energy, Inc. has been engaged in the development of this unique technology, focusing on the development of the Direct Fuel Cell (DFC{reg_sign}). The DFC{reg_sign} design incorporates the unique internal reforming feature which allows utilization of a hydrocarbon fuel directly in the fuel cell without requiring any external reforming reactor and associated heat exchange equipment. This approach upgrades waste heat to chemical energy and thereby contributes to a higher overall conversion efficiency of fuel energy to electricity with low levels of environmental emissions. Among the internal reforming options, FuelCell Energy has selected the Indirect Internal Reforming (IIR)--Direct Internal Reforming (DIR) combination as its baseline design. The IIR-DIR combination allows reforming control (and thus cooling) over the entire cell area. This results in uniform cell temperature. In the IIR-DIR stack, a reforming unit (RU) is placed in between a group of fuel cells. The hydrocarbon fuel is first fed into the RU where it is reformed partially to hydrogen and carbon monoxide fuel using heat produced by the fuel cell electrochemical reactions. The reformed gases are then fed to the DIR chamber, where the residual fuel is reformed simultaneously with the electrochemical fuel cell reactions. FuelCell Energy plans to offer commercial DFC power plants in various sizes, focusing on the subMW as well as the MW-scale units. The plan is to offer standardized, packaged DFC power plants operating on natural gas or other hydrocarbon-containing fuels for commercial sale. The power plant design will include a diesel fuel processing option to allow dual fuel applications. These power plants, which can be shop-fabricated and sited near the user, are ideally suited for distributed power