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Sample records for high-efficiency steam reformer

  1. Demonstration of a Highly Efficient Solid Oxide Fuel Cell Power System Using Adiabatic Steam Reforming and Anode Gas Recirculation

    SciTech Connect

    Powell, Michael R.; Meinhardt, Kerry D.; Sprenkle, Vincent L.; Chick, Lawrence A.; Mcvay, Gary L.

    2012-05-01

    Solid oxide fuel cells (SOFC) are currently being developed for a wide variety of applications because of their high efficiency at multiple power levels. Applications for SOFCs encompass a large range of power levels including 1-2 kW residential combined heat and power applications, 100-250 kW sized systems for distributed generation and grid extension, and MW-scale power plants utilizing coal. This paper reports on the development of a highly efficient, small-scale SOFC power system operating on methane. The system uses adiabatic steam reforming of methane and anode gas recirculation to achieve high net electrical efficiency. The anode exit gas is recirculated and all of the heat and water required for the endothermic reforming reaction are provided by the anode gas emerging from the SOFC stack. Although the single-pass fuel utilization is only about 55%, because of the anode gas recirculation the overall fuel utilization is up to 93%. The demonstrated system achieved gross power output of 1650 to 2150 watts with a maximum net LHV efficiency of 56.7% at 1720 watts. Overall system efficiency could be further improved to over 60% with use of properly sized blowers.

  2. Supported metal catalysts for alcohol/sugar alcohol steam reforming

    SciTech Connect

    Davidson, Stephen; Zhang, He; Sun, Junming; Wang, Yong

    2014-08-21

    Despite extensive studies on hydrogen production via steam reforming of alcohols and sugar alcohols, catalysts typically suffer a variety of issues from poor hydrogen selectivity to rapid deactivation. Here, we summarize recent advances in fundamental understanding of functionality and structure of catalysts for alcohol/sugar alcohol steam reforming, and provide perspectives on further development required to design highly efficient steam reforming catalysts.

  3. Steam reformer with catalytic combustor

    DOEpatents

    Voecks, Gerald E.

    1990-03-20

    A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

  4. Steam reformer with catalytic combustor

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor)

    1990-01-01

    A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

  5. Steam Hydrocarbon Cracking and Reforming

    ERIC Educational Resources Information Center

    Golombok, Michael

    2004-01-01

    The interactive methods of steam hydrocarbon reforming and cracking of the oil and chemical industries are scrutinized, with special focus on their resemblance and variations. The two methods are illustrations of equilibrium-controlled and kinetically-controlled processes, the analysis of which involves theories, which overlap and balance each…

  6. Steam Hydrocarbon Cracking and Reforming

    ERIC Educational Resources Information Center

    Golombok, Michael

    2004-01-01

    The interactive methods of steam hydrocarbon reforming and cracking of the oil and chemical industries are scrutinized, with special focus on their resemblance and variations. The two methods are illustrations of equilibrium-controlled and kinetically-controlled processes, the analysis of which involves theories, which overlap and balance each…

  7. Method of steam reforming methanol to hydrogen

    DOEpatents

    Beshty, Bahjat S.

    1990-01-01

    The production of hydrogen by the catalyzed steam reforming of methanol is accomplished using a reformer of greatly reduced size and cost wherein a mixture of water and methanol is superheated to the gaseous state at temperatures of about 800.degree. to about 1,100.degree. F. and then fed to a reformer in direct contact with the catalyst bed contained therein, whereby the heat for the endothermic steam reforming reaction is derived directly from the superheated steam/methanol mixture.

  8. Steam reforming catalyst

    DOEpatents

    Kramarz, Kurt W.; Bloom, Ira D.; Kumar, Romesh; Ahmed, Shabbir; Wilkenhoener, Rolf; Krumpelt, Michael

    2001-01-01

    A method of forming a hydrogen rich gas from a source of hydrocarbon fuel. A vapor of the hydrocarbon fuel and steam is brought in contact with a two-part catalyst having a dehydrogenation powder portion and an oxide-ion conducting powder portion at a temperature not less than about 770.degree.C. for a time sufficient to generate the hydrogen rich. The H.sub.2 content of the hydrogen gas is greater than about 70 percent by volume. The dehydrogenation portion of the catalyst includes a group VIII metal, and the oxide-ion conducting portion is selected from a ceramic oxide from the group crystallizing in the fluorite or perovskite structure and mixtures thereof. The oxide-ion conducting portion of the catalyst is a ceramic powder of one or more of ZrO.sub.2, CeO.sub.2, Bi.sub.2 O.sub.3, (BiVO).sub.4, and LaGaO.sub.3.

  9. Steam Reformer With Fibrous Catalytic Combustor

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.

    1987-01-01

    Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

  10. Fuel cell integrated with steam reformer

    DOEpatents

    Beshty, Bahjat S.; Whelan, James A.

    1987-01-01

    A H.sub.2 -air fuel cell integrated with a steam reformer is disclosed wherein a superheated water/methanol mixture is fed to a catalytic reformer to provide a continuous supply of hydrogen to the fuel cell, the gases exhausted from the anode of the fuel cell providing the thermal energy, via combustion, for superheating the water/methanol mixture.

  11. Methanol Steam Reforming for Hydrogen Production

    SciTech Connect

    Palo, Daniel R.; Dagle, Robert A.; Holladay, Jamie D.

    2007-09-11

    Review article covering developments in methanol steam reforming in the context of PEM fuel cell power systems. Subjects covered include methanol background, use, and production, comparison to other fuels, power system considerations, militrary requirements, competing technologies, catalyst development, and reactor and system development and demonstration.

  12. Hierarchically structured catalysts for cascade and selective steam reforming/hydrodeoxygenation reactions

    SciTech Connect

    Sun, Junming; Karim, Ayman M.; Li, Xiaohong S.; Rainbolt, James E.; Kovarik, Libor; Shin, Yongsoon; Wang, Yong

    2015-09-29

    We report a hierarchically structured catalyst with steam reforming and hydrodeoxygenation functionalities being deposited in the micropores and macropores, respectively. The catalyst is highly efficient to upgrade the pyrolysis vapors of pine forest product residual, resulting in a dramatically decreased acid content and increased hydrocarbon yield without external H2 supply.

  13. Catalytic glycerol steam reforming for hydrogen production

    NASA Astrophysics Data System (ADS)

    Dan, Monica; Mihet, Maria; Lazar, Mihaela D.

    2015-12-01

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H2. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al2O3. The catalyst was prepared by wet impregnation method and characterized through different methods: N2 adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H2, CH4, CO, CO2. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H2O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  14. Catalytic glycerol steam reforming for hydrogen production

    SciTech Connect

    Dan, Monica Mihet, Maria Lazar, Mihaela D.

    2015-12-23

    Hydrogen production from glycerol by steam reforming combine two major advantages: (i) using glycerol as raw material add value to this by product of bio-diesel production which is obtained in large quantities around the world and have a very limited utilization now, and (ii) by implication of water molecules in the reaction the efficiency of hydrogen generation is increased as each mol of glycerol produces 7 mol of H{sub 2}. In this work we present the results obtained in the process of steam reforming of glycerol on Ni/Al{sub 2}O{sub 3}. The catalyst was prepared by wet impregnation method and characterized through different methods: N{sub 2} adsorption-desorption, XRD, TPR. The catalytic study was performed in a stainless steel tubular reactor at atmospheric pressure by varying the reaction conditions: steam/carbon ratio (1-9), gas flow (35 ml/min -133 ml/min), temperature (450-650°C). The gaseous fraction of the reaction products contain: H{sub 2}, CH{sub 4}, CO, CO{sub 2}. The optimum reaction conditions as resulted from this study are: temperature 550°C, Gly:H{sub 2}O ratio 9:1 and Ar flow 133 ml/min. In these conditions the glycerol conversion to gaseous products was 43% and the hydrogen yield was 30%.

  15. Hydrogen generation utilizing integrated CO2 removal with steam reforming

    DOEpatents

    Duraiswamy, Kandaswamy; Chellappa, Anand S

    2013-07-23

    A steam reformer may comprise fluid inlet and outlet connections and have a substantially cylindrical geometry divided into reforming segments and reforming compartments extending longitudinally within the reformer, each being in fluid communication. With the fluid inlets and outlets. Further, methods for generating hydrogen may comprise steam reformation and material adsorption in one operation followed by regeneration of adsorbers in another operation. Cathode off-gas from a fuel cell may be used to regenerate and sweep the adsorbers, and the operations may cycle among a plurality of adsorption enhanced reformers to provide a continuous flow of hydrogen.

  16. Hydrogen Production via a High-Efficiency Low-Temperature Reformer

    SciTech Connect

    Paul KT Liu; Theo T. Tsotsis

    2006-05-31

    Fuel cells are promoted by the US government as a viable alternative for clean and efficient energy generation. It is anticipated that the fuel cell market will rise if the key technical barriers can be overcome. One of them is certainly fuel processing and purification. Existing fuel reforming processes are energy intensive, extremely complicated and capital intensive; these disadvantages handicap the scale-down of existing reforming process, targeting distributed or on-board/stationary hydrogen production applications. Our project involves the bench-scale demonstration of a high-efficiency low-temperature steam reforming process. Hydrogen production can be operated at 350 to 400ºC with our invention, as opposed to >800ºC of existing reforming. In addition, our proposed process improves the start-up deficiency of conventional reforming due to its low temperature operation. The objective of this project is to demonstrate the invented process concept via a bench scale unit and verify mathematical simulation for future process optimization study. Under this project, we have performed the experimental work to determine the adsorption isotherm, reaction kinetics, and membrane permeances required to perform the process simulation based upon the mathematical model developed by us. A ceramic membrane coated with palladium thin film fabricated by us was employed in this study. The adsorption isotherm for a selected hydrotalcite adsorbent was determined experimentally. Further, the capacity loss under cyclic adsorption/desorption was confirmed to be negligible. Finally a commercial steam reforming catalyst was used to produce the reaction kinetic parameters required for the proposed operating condition. With these input parameters, a mathematical simulation was performed to predict the performance of the invented process. According to our simulation, our invented hybrid process can deliver 35 to 55% methane conversion, in comparison with the 12 and 18-21% conversion of

  17. Compatibility of selected ceramics with steam-methane reformer environments

    SciTech Connect

    Keiser, J.R.; Howell, M.; Williams, J.J.; Rosenberg, R.A.

    1996-04-01

    Conventional steam reforming of methane to synthesis gas (CO and H{sub 2}) hasa conversion efficiency of about 85%. Replacement of metal tubes in the reformer with ceramic tubes offers the potential for operation at temperatures high enough to increase the efficiency to 98-99%. However, the two candidate ceramic materials being given strongest consideration, sintered alpha Si carbide and Si carbide particulate-strengthened alumina, have been shown to react with components of the reformer environment. Extent of degradation as a function of steam partial pressure and exposure time has been studied, and results suggest limits under which these structural ceramics can be used in advanced steam-methane reformers.

  18. Steam reforming of commercial ultra-low sulphur diesel

    NASA Astrophysics Data System (ADS)

    Boon, Jurriaan; van Dijk, Eric; de Munck, Sander; van den Brink, Ruud

    Two main routes for small-scale diesel steam reforming exist: low-temperature pre-reforming followed by well-established methane steam reforming on the one hand and direct steam reforming on the other hand. Tests with commercial catalysts and commercially obtained diesel fuels are presented for both processes. The fuels contained up to 6.5 ppmw sulphur and up to 4.5 vol.% of biomass-derived fatty acid methyl ester (FAME). Pre-reforming sulphur-free diesel at around 475 °C has been tested with a commercial nickel catalyst for 118 h without observing catalyst deactivation, at steam-to-carbon ratios as low as 2.6. Direct steam reforming at temperatures up to 800 °C has been tested with a commercial precious metal catalyst for a total of 1190 h with two catalyst batches at steam-to-carbon ratios as low as 2.5. Deactivation was neither observed with lower steam-to-carbon ratios nor for increasing sulphur concentration. The importance of good fuel evaporation and mixing for correct testing of catalysts is illustrated. Diesel containing biodiesel components resulted in poor spray quality, hence poor mixing and evaporation upstream, eventually causing decreasing catalyst performance. The feasibility of direct high temperature steam reforming of commercial low-sulphur diesel has been demonstrated.

  19. 3D-Printed, All-in-One Evaporator for High-Efficiency Solar Steam Generation under 1 Sun Illumination.

    PubMed

    Li, Yiju; Gao, Tingting; Yang, Zhi; Chen, Chaoji; Luo, Wei; Song, Jianwei; Hitz, Emily; Jia, Chao; Zhou, Yubing; Liu, Boyang; Yang, Bao; Hu, Liangbing

    2017-07-01

    Using solar energy to generate steam is a clean and sustainable approach to addressing the issue of water shortage. The current challenge for solar steam generation is to develop easy-to-manufacture and scalable methods which can convert solar irradiation into exploitable thermal energy with high efficiency. Although various material and structure designs have been reported, high efficiency in solar steam generation usually can be achieved only at concentrated solar illumination. For the first time, 3D printing to construct an all-in-one evaporator with a concave structure for high-efficiency solar steam generation under 1 sun illumination is used. The solar-steam-generation device has a high porosity (97.3%) and efficient broadband solar absorption (>97%). The 3D-printed porous evaporator with intrinsic low thermal conductivity enables heat localization and effectively alleviates thermal dissipation to the bulk water. As a result, the 3D-printed evaporator has a high solar steam efficiency of 85.6% under 1 sun illumination (1 kW m(-2) ), which is among the best compared with other reported evaporators. The all-in-one structure design using the advanced 3D printing fabrication technique offers a new approach to solar energy harvesting for high-efficiency steam generation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Numerical analysis of helium-heated methane/steam reformer

    NASA Astrophysics Data System (ADS)

    Mozdzierz, M.; Brus, G.; Kimijima, S.; Szmyd, J. S.

    2016-09-01

    One of the most promising between many high temperature nuclear reactors applications is to produce hydrogen with heat gained. The simplest and the best examined method is steam reforming of methane. The fabricated hydrogen has wide range of use, for example can be electrochemically oxidized in fuel cells. However, heat management inside methane/steam reformer is extremely important because huge temperature gradients can cause catalyst deactivation. In this work the analysis of temperature field inside helium-heated methane/steam reformer is presented. The optimal system working conditions with respect to methane conversion rate are proposed.

  1. TWR Bench-Scale Steam Reforming Demonstration

    SciTech Connect

    Marshall, D.W.; Soelberg, N.R.

    2003-05-21

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by ThermoChem Waste Remediation, LLC, (TWR) for treatment of SBW into a ''road ready'' waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). TWR is the licensee of Manufacturing Technology Conservation International (MTCI) steam-reforming technology in the field of radioactive waste treatment. A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrate residues were about 400 ppm in the product and NOx destruction exceeded 86%. The demonstration was successful.

  2. TWR Bench-Scale Steam Reforming Demonstration

    SciTech Connect

    D. W. Marshall; N. R. Soelberg

    2003-05-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by ThermoChem Waste Remediation, LLC, (TWR) for treatment of SBW into a "road ready" waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). TWR is the licensee of Manufacturing Technology Conservation International (MTCI) steam-reforming technology in the field of radioactive waste treatment. A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrate residues were about 400 ppm in the product and NOx destruction exceeded 86%. The demonstration was successful.

  3. Wood-Graphene Oxide Composite for Highly Efficient Solar Steam Generation and Desalination.

    PubMed

    Liu, Keng-Ku; Jiang, Qisheng; Tadepalli, Sirimuvva; Raliya, Ramesh; Biswas, Pratim; Naik, Rajesh R; Singamaneni, Srikanth

    2017-03-01

    Solar steam generation is a highly promising technology for harvesting solar energy, desalination and water purification. We introduce a novel bilayered structure composed of wood and graphene oxide (GO) for highly efficient solar steam generation. The GO layer deposited on the microporous wood provides broad optical absorption and high photothermal conversion resulting in rapid increase in the temperature at the liquid surface. On the other hand, wood serves as a thermal insulator to confine the photothermal heat to the evaporative surface and to facilitate the efficient transport of water from the bulk to the photothermally active space. Owing to the tailored bilayer structure and the optimal thermo-optical properties of the individual components, the wood-GO composite structure exhibited a solar thermal efficiency of ∼83% under simulated solar excitation at a power density of 12 kW/m(2). The novel composite structure demonstrated here is highly scalable and cost-efficient, making it an attractive material for various applications involving large light absorption, photothermal conversion and heat localization.

  4. Development of Technologies on Innovative-Simplified Nuclear Power Plant using High-Efficiency Steam Injectors

    NASA Astrophysics Data System (ADS)

    Ohmori, Shuichi; Narabayashi, Tadashi; Mori, Michitsugu; Iwaki, Chikako; Asanuma, Yutaka; Goto, Shoji

    A Steam Injector (SI) is a simple, compact and passive pump and also acts as a high-performance direct-contact heater. This provides SI with capability to serve also as a direct-contact feed-water heater that heats up feed-water by using extracted steam from turbine. Our technology development aims to significantly simplify equipment and reduce physical quantities by applying "High-Efficiency SI", which are applicable to a wide range of operation regimes beyond the performance and applicable range of existing SIs and enables unprecedented multistage and parallel operation, to the low-pressure feed-water heaters and Emergency Core Cooling System of nuclear power plants, as well as achieve high inherent safety to prevent severe accidents by keeping the core covered with water (a Severe Accident-Free Concept). This paper describes the results of the endurance and performance tests of low-pressure SIs for feed-water heaters with Jet-deaerator and core injection system.

  5. Fluidized Bed Steam Reformer (FBSR) monolith formation

    SciTech Connect

    Jantzen, C.M.

    2007-07-01

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or 'mineralized' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydro-ceramics. All but one of the nine monoliths tested met the <2 g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydro-ceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form. (authors)

  6. FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION

    SciTech Connect

    Jantzen, C

    2006-12-22

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

  7. Radial reactor for trichloroethylene steam reforming

    SciTech Connect

    Moates, F.C.; McMinn, T.E.; Richardson, J.T.

    1999-11-01

    A ceramic foam radial reactor was used to convert trichloroethylene by steam reforming, using 0.5 wt. % Pt as a catalyst. With a quartz enclosure heated externally by infrared lamps, the inlet temperature to the catalyst bed was low enough to suppress pyrolysis, but high conversions (0.99999 +) were achieved at the exit. Stable operation up to 600 h with a space velocity of 5.6 x 10{sup 4}h{sup {minus}1} was achieved, but reactant break-through then occurred, and the catalyst quickly deactivated. Although the deactivated catalyst was regenerated with carbon burning, activity decline was more rapid due to platinum sintering and washcoat degradation. Measured temperature profiles and model calculations indicated a large gradient in the bed and suggested that stable operation could be extended at lower space velocities. Axial temperature profiles were not uniform, since preferential flow occurred in the middle and lower regions of the radial bed. Potential improvements for future designs are suggested.

  8. Hydrogen-based power generation from bioethanol steam reforming

    SciTech Connect

    Tasnadi-Asztalos, Zs. Cormos, C. C. Agachi, P. S.

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  9. Hydrogen-based power generation from bioethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  10. Biomass to hydrogen via fast pyrolysis and catalytic steam reforming

    SciTech Connect

    Chornet, E.; Wang, D.; Montane, D.

    1995-09-01

    Fast pyrolysis of biomass results in a pyrolytic oil which is a mixture of (a) carbohydrate-derived acids, aldehydes and polyols, (b) lignin-derived substituted phenolics, and (c) extractives-derived terpenoids and fatty acids. The conversion of this pyrolysis oil into H{sub 2} and CO{sub 2} is thermodynamically favored under appropriate steam reforming conditions. Our efforts have focused in understanding the catalysis of steam reforming which will lead to a successful process at reasonable steam/carbon ratios arid process severities. The experimental work, carried out at the laboratory and bench scale levels, has centered on the performance of Ni-based catalysts using model compounds as prototypes of the oxygenates present in the pyrolysis oil. Steam reforming of acetic acid, hydroxyacetaldehyde, furfural and syringol has been proven to proceed rapidly within a reasonable range of severities. Time-on-stream studies are now underway using a fixed bed barometric pressure reactor to ascertain the durability of the catalysts and thus substantiate the scientific and technical feasibility of the catalytic reforming option. Economic analyses are being carried out in parallel to determine the opportunity zones for the combined fast pyrolysis/steam reforming approach. A discussion on the current state of the project is presented.

  11. Multifunctional Porous Graphene for High-Efficiency Steam Generation by Heat Localization.

    PubMed

    Ito, Yoshikazu; Tanabe, Yoichi; Han, Jiuhui; Fujita, Takeshi; Tanigaki, Katsumi; Chen, Mingwei

    2015-08-05

    Multifunctional nanoporous graphene is realized as a heat generator to convert solar illumination into high-energy steam. The novel 3D nanoporous graphene demonstrates a highly energy-effective steam generation with an energy conversation of 80%.

  12. Methanol Steam Reformer on a Silicon Wafer

    SciTech Connect

    Park, H; Malen, J; Piggott, T; Morse, J; Sopchak, D; Greif, R; Grigoropoulos, C; Havstad, M; Upadhye, R

    2004-04-15

    A study of the reforming rates, heat transfer and flow through a methanol reforming catalytic microreactor fabricated on a silicon wafer are presented. Comparison of computed and measured conversion efficiencies are shown to be favorable. Concepts for insulating the reactor while maintaining small overall size and starting operation from ambient temperature are analyzed.

  13. Steam Reforming of Low-Level Mixed Waste

    SciTech Connect

    1998-01-01

    Under DOE Contract No. DE-AR21-95MC32091, Steam Reforming of Low-Level Mixed Waste, ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design construction, and testing of the PDU as well as performance and economic projections for a 500- lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area published April 1997.1 The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfidly tested including a 750-hour test on material simulating a PCB- and Uranium- contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (>99.9999oA) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radlonuclides in the volume-reduced solids. Cost studies have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  14. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: METHLYCHLORIDE. (R822721C633)

    EPA Science Inventory

    The effective destruction of trichloroethane, trichloroethylene and perchloroethylene by steam reforming with a commercial nickel catalyst has been demonstrated. Conversion levels of up to 0.99999 were attained in both laboratory and semi-pilot experiments, with the products c...

  15. Steam methane reforming in molten carbonate salt. Final report

    SciTech Connect

    Erickson, D.C.

    1996-05-01

    This report documents the work accomplished on the project {open_quotes}Steam Methane Reforming in Molten Carbonate Salt.{close_quotes}. This effort has established the conceptual basis for molten carbonate-based steam reforming of methane. It has not proceeded to prototype verification, because corrosion concerns have led to reluctance on the part of large hydrogen producers to adopt the technology. Therefore the focus was shifted to a less corrosive embodiment of the same technology. After considerable development effort it was discovered that a European company (Catalysts and Chemicals Europe) was developing a similar process ({open_quotes}Regate{close_quotes}). Accordingly the focus was shifted a second time, to develop an improvement which is generic to both types of reforming. That work is still in progress, and shows substantial promise.

  16. Methane/steam reforming kinetics for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Achenbach, E.; Riensche, E.

    Experiments have been carried out to determine the kinetics of the methane/steam reforming process at anode materials of a solid oxide fuel cell. A nickel cermet was applied consisting of 80 wt.% ZrO 2 and 20 wt.% Ni. The temperature was varied from 700 to 940 °C, the CH 4 partial pressure from 0.11 to 0.33 bar, and the system pressure from 1.1 to 2.8 bar. The influence of the ratio H 2O/CH 4 was studied, in particular, by increasing this quantity from 2.6 to 8. The tests showed that, within the accuracy of the data, no effect of the H 2O partial pressure on the catalytic reforming process could be observed. Due to the high conversion rates of CH 4 at high temperatures, however, mass-transfer effects occurred, that must be taken into account when evaluating the steam-reforming data.

  17. Steam reforming of methane over unsupported nickel catalysts

    NASA Astrophysics Data System (ADS)

    Rakass, S.; Oudghiri-Hassani, H.; Rowntree, P.; Abatzoglou, N.

    This paper describes a study of steam reforming of methane using unsupported nickel powder catalysts. The reaction yields were measured and the unsupported nickel powder surface was studied to explore its potential as a catalyst in internal or external reforming solid oxide fuel cells. The unsupported nickel catalyst used and presented in this paper is a pure micrometric nickel powder with an open filamentary structure, irregular 'fractal-like' surface and high external/internal surface ratio. CH 4 conversion increases and coke deposition decreases significantly with the decrease of CH 4:H 2O ratio. At a CH 4:H 2O ratio of 1:2 thermodynamic equilibrium is achieved, even with methane residence times of only ∼0.5 s. The CH 4 conversion is 98 ± 2% at 700 °C and no coke is generated during steam reforming which compares favorably with supported Ni catalyst systems. This ratio was used in further investigations to measure the hydrogen production, the CH 4 conversion, the H 2 yield and the selectivity of the CO, and CO 2 formation. Methane-rich fuel ratios cause significant deviations of the experimental results from the theoretical model, which has been partially correlated to the adsorption of carbon on the surface according to TEM, XPS and elemental analysis. At the fuel: water ratio of 1:2, the unsupported Ni catalyst exhibited high catalytic activity and stability during the steam reforming of methane at low-medium temperature range.

  18. Radial Microchannel Reactor (RMR) used in Steam Reforming CH4

    DTIC Science & Technology

    2013-05-13

    of the steam reformer was operated at 11 bar (in test 1 and 2) of reformate pressure and a UPH of 6.1 psig in test 1, resulting in 153.4psi across...Table 1: PCI data on the run at the start of the test period. PCI calculated hydrogen separation efficiency of 74% with 16 slpm UPH flow. Calculating...the Fuel Conversion Efficiency from the GC data gives 73%, using: 100*(1 – CH4%/(CH4% + CO% + CO2%)) Figure 1: P&E expected UPH

  19. Effect of Cobalt Particle Size on Acetone Steam Reforming

    SciTech Connect

    Sun, Junming; Zhang, He; Yu, Ning; Davidson, Stephen; Wang, Yong

    2015-06-11

    Carbon-supported cobalt nanoparticles with different particle sizes were synthesized and characterized by complementary characterization techniques such as X-ray diffraction, N-2 sorption, acetone temperature-programmed desorption, transmission electron microscopy, and CO chemisorption. Using acetone steam reforming reaction as a probe reaction, we revealed a volcano-shape curve of the intrinsic activity (turnover frequency of acetone) and the CO2 selectivity as a function of the cobalt particle size with the highest activity and selectivity observed at a particle size of approximately 12.8nm. Our results indicate that the overall performance of acetone steam reforming is related to a combination of particle-size-dependent acetone decomposition, water dissociation, and the oxidation state of the cobalt nanoparticles.

  20. STEAM REFORMING OF CHLOROCARBONS: CHLORINATED AROMATICS. (R826694C633)

    EPA Science Inventory

    Effective dechlorination of chloroaromatics, such as C6H5Cl, 1,2-C6H4Cl2, 1,3-C6H4Cl2 and 1,2,4-C6H3Cl3, using catalytic steam reforming has been confirmed ...

  1. STEAM REFORMING OF CHLOROCARBONS: CHLORINATED AROMATICS. (R826694C633)

    EPA Science Inventory

    Effective dechlorination of chloroaromatics, such as C6H5Cl, 1,2-C6H4Cl2, 1,3-C6H4Cl2 and 1,2,4-C6H3Cl3, using catalytic steam reforming has been confirmed ...

  2. Steam reforming of low-level mixed waste. Final report

    SciTech Connect

    1998-06-01

    ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design, construction, and testing of the PDU as well as performance and economic projections for a 300-lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area and published in April 1997. The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfully tested including a 750-hour test on material simulating a PCB- and Uranium-contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (> 99.9999%) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radionuclides in the volume-reduced solids. Economic evaluations have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  3. CHARM COST-EFFECTIVE HIGH-EFFICIENCY ADVANCED REFORMING MODULE FINAL TECHNICAL REPORT

    SciTech Connect

    Pollica, Darryl; Cross, James C; Sharma, Atul; Shi, Yanlong; Clawson, Lawrence; O'Brien, Chris; Gilhooly, Kara; Kim, Changsik; Quet, Pierre-Francois

    2009-09-02

    Background Creation of a hydrogen infrastructure is an important prerequisite of widespread fuel cell commercialization, especially for the automotive market. Hydrogen is an attractive fuel since it offers an opportunity to replace petroleum-based fuels, but hydrogen occurs naturally only in chemical compounds like water or hydrocarbons that must be chemically converted to produce it. While an ultimate goal is to produce hydrogen through renewable energy sources, steam methane reforming (SMR) of natural gas is currently the most economical solution to initiate the transition to a hydrogen economy. Centralized hydrogen generation using large industrial SMR plants is already in place to serve customers. Yet, because of the weight and size of cylinders needed to contain hydrogen gas or liquid, transportation of hydrogen may only be economical for short distances. Consequently, distributed natural gas reforming, which trades off the economies of scale of large plants for simplified delivery logistics, is an attractive alternative that could address immediate problems with the lack of hydrogen infrastructure.

  4. Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

    NASA Technical Reports Server (NTRS)

    Mwara, Kamwana N.

    2015-01-01

    Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

  5. Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

    PubMed Central

    Lee, Chi-Yuan; Lee, Shuo-Jen; Shen, Chia-Chieh; Yeh, Chuin-Tih; Chang, Chi-Chung; Lo, Yi-Man

    2011-01-01

    Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well. PMID:22319407

  6. Methanol steam reforming in a fuel cell drive system

    NASA Astrophysics Data System (ADS)

    Wiese, W.; Emonts, B.; Peters, R.

    Within the framework of the Joule III project a compact methanol reformer (CMR) with a specific weight of 2 kg/kW (lower heating value of H 2) was developed. This CMR contains a methanol and water vaporizer, a steam reformer, a heat carrier circuit and a catalytic burner unit. A laboratory fixed-bed reactor consisting of four tubes which could be filled with different amounts of catalyst was used to investigate the catalyst performance and the ageing behaviour. A hydrogen yield of 10 m N3/(h l Cat) can be achieved at 280°C. In this case, the methanol conversion rate is 95% and the dry product gas contains 0.9% CO. A linear decrease of the catalyst activity was observed which can be described by a loss of active catalyst mass of 5.5 mg/h. The catalyst was operated for more than 1000 h without having exhibited activity losses that made a catalyst change necessary. Besides, the stationary behaviour of the reforming reactor, the dynamic behaviour was studied. The time needed for start-up procedures has to be improved for reformers of a next generation. Moreover, the hydrogen production during reformer load changes will be discussed. Simulations of the power train in driving cycles show the different states of a reformer during dynamic operation.

  7. THOR Bench-Scale Steam Reforming Demonstration

    SciTech Connect

    D. W. Marshall; N. R. Soelberg; K. M. Shaber

    2003-05-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by THORsm Treatment Technologies, LLC, for treatment of SBW into a "road ready" waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrates were not detected in the product and NOx destruction exceeded 98%. The demonstration was successful.

  8. THOR Bench-Scale Steam Reforming Demonstration

    SciTech Connect

    Marshall, D.W.; Soelberg, N.R.; Shaber, K.M.

    2003-05-21

    The Idaho Nuclear Technology and Engineering Center (INTEC) was home to nuclear fuel reprocessing activities for decades at the Idaho National Engineering and Environmental Laboratory. As a result of the reprocessing activities, INTEC has accumulated approximately one million gallons of acidic, radioactive, sodium-bearing waste (SBW). The purpose of this demonstration was to investigate a reforming technology, offered by THORsm Treatment Technologies, LLC, for treatment of SBW into a ''road ready'' waste form that would meet the waste acceptance criteria for the Waste Isolation Pilot Plant (WIPP). A non-radioactive simulated SBW was used based on the known composition of waste tank WM-180 at INTEC. Rhenium was included as a non-radioactive surrogate for technetium. Data was collected to determine the nature and characteristics of the product, the operability of the technology, the composition of the off-gases, and the fate of key radionuclides (cesium and technetium) and volatile mercury compounds. The product contained a low fraction of elemental carbon residues in the cyclone and filter vessel catches. Mercury was quantitatively stripped from the product but cesium, rhenium (Tc surrogate), and the heavy metals were retained. Nitrates were not detected in the product and NOx destruction exceeded 98%. The demonstration was successful.

  9. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation.

    PubMed

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-04-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber-based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m(-2)). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices.

  10. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation

    PubMed Central

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-01-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber–based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m−2). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices. PMID:27152335

  11. Syngas Generation from Organic Waste with Plasma Steam Reforming

    NASA Astrophysics Data System (ADS)

    Diaz, G.; Leal-Quiros, E.; Smith, R. A.; Elliott, J.; Unruh, D.

    2014-05-01

    A plasma steam reforming system to process waste is in the process of being set up at the University of California, Merced. The proposed concept will use two different plasma regimes, i.e. glow discharge and arc torches to process a percentage of the total liquid waste stream generated at the campus together with shredded local organic solid waste. One of the main advantages of the plasma technology to be utilized is that it uses graphite electrodes that can be fed to the reactor to achieve continuous operation, thus, electrode or nozzle life is not a concern. The waste to energy conversion process consists of two stages, one where a mixture of steam and hydrogen is generated from the liquid in a glow-discharge cell, and a second stage where the mixture of exhaust gases coming out of the first device are mixed with solid waste in a reactor operating in steam reforming mode interacting with a plasma torch to generate high-quality syngas. In this paper, the results of a thermodynamic model developed for the two stages are shown. The syngas composition obtained indicates that the fraction of CO2 present decreases with increasing temperature and the molar fractions of hydrogen and carbon monoxide become dominant. The fraction of water vapour present in the product gases coming out of the second stage needs to be condensed before the syngas can be utilized in a prime mover.

  12. Thermodynamic analysis of carbon formation boundary and reforming performance for steam reforming of dimethyl ether

    NASA Astrophysics Data System (ADS)

    Faungnawakij, Kajornsak; Kikuchi, Ryuji; Eguchi, Koichi

    Thermodynamic analysis of dimethyl ether steam reforming (DME SR) was investigated for carbon formation boundary, DME conversion, and hydrogen yield for fuel cell application. The equilibrium calculation employing Gibbs free minimization was performed to figure out the required steam-to-carbon ratio (S/C = 0-5) and reforming temperature (25-1000 °C) where coke formation was thermodynamically unfavorable. S/C, reforming temperature and product species strongly contributed to the coke formation and product composition. When chemical species DME, methanol, CO 2, CO, H 2, H 2O and coke were considered, complete conversion of DME and hydrogen yield above 78% without coke formation were achieved at the normal operating temperatures of molten carbonate fuel cell (600 °C) and solid oxide fuel cell (900 °C), when S/C was at or above 2.5. When CH 4 was favorable, production of coke and that of hydrogen were significantly suppressed.

  13. Thermodynamic evaluation of hydrogen production via bioethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Tasnadi-Asztalos, Zsolt; Cormos, Ana-Maria; Imre-Lucaci, Árpád; Cormos, Cǎlin C.

    2013-11-01

    In this article, a thermodynamic analysis for bioethanol steam reforming for hydrogen production is presented. Bioethanol is a newly proposed renewable energy carrier mainly produced from biomass fermentation. Reforming of bioethanol provides a promising method for hydrogen production from renewable resources. Steam reforming of ethanol (SRE) takes place under the action of a metal catalyst capable of breaking C-C bonds into smaller molecules. A large domain for the water/bioethanol molar ratio as well as the temperature and average pressure has been used in the present work. The interval of investigated temperature was 100-800°C, the pressure was in the range of 1-10 bar and the molar ratio was between 3-25. The variations of gaseous species concentration e.g. H2, CO, CO2, CH4 were analyzed. The concentrations of the main products (H2 and CO) at lower temperature are smaller than the ones at higher temperature due to by-products formation (methane, carbon dioxide, acetylene etc.). The concentration of H2 obtained in the process using high molar ratio (>20) is higher than the one at small molar ratio (near stoichiometric). When the pressure is increased the hydrogen concentration decreases. The results were compared with literature data for validation purposes.

  14. Thermodynamic evaluation of hydrogen production via bioethanol steam reforming

    SciTech Connect

    Tasnadi-Asztalos, Zsolt; Cormos, Ana-Maria; Imre-Lucaci, Árpád; Cormos, Călin C.

    2013-11-13

    In this article, a thermodynamic analysis for bioethanol steam reforming for hydrogen production is presented. Bioethanol is a newly proposed renewable energy carrier mainly produced from biomass fermentation. Reforming of bioethanol provides a promising method for hydrogen production from renewable resources. Steam reforming of ethanol (SRE) takes place under the action of a metal catalyst capable of breaking C-C bonds into smaller molecules. A large domain for the water/bioethanol molar ratio as well as the temperature and average pressure has been used in the present work. The interval of investigated temperature was 100-800°C, the pressure was in the range of 1-10 bar and the molar ratio was between 3-25. The variations of gaseous species concentration e.g. H{sub 2}, CO, CO{sub 2}, CH{sub 4} were analyzed. The concentrations of the main products (H{sub 2} and CO) at lower temperature are smaller than the ones at higher temperature due to by-products formation (methane, carbon dioxide, acetylene etc.). The concentration of H2 obtained in the process using high molar ratio (>20) is higher than the one at small molar ratio (near stoichiometric). When the pressure is increased the hydrogen concentration decreases. The results were compared with literature data for validation purposes.

  15. Fuel cell hydrogen production by catalytic ethanol-steam reforming

    SciTech Connect

    Amphlett, J.C.; Leclerc, S.; Mann, R.F.; Peppley, B.A.; Roberge, P.R.

    1998-07-01

    It is clear that the reaction network that results from catalytic reaction of ethanol, with and without steam, is very complex and involves over a dozen potential products. Reactions to avoid are any that lead to CP{sub 4} species and ethylene, the former representing a more difficult challenge for subsequent steam reforming and the latter providing what is probably the major route to carbon production and coking of the catalyst. Dehydration reactions, therefore, should generally be avoided. Dehydrogenation catalysts would seem to be most appropriate, especially since the production of hydrogen is the main goal. Copper-based catalysts have been long-established for this function so that they are commercially available and therefore lower cost. CuO/ZnO, CuO/SiO{sub 2}, CuO/Cr{sub 2}O{sub 3} or CuO/NiO/SiO{sub 2} may be the best catalyst candidates. Reaction pressures should be relatively low (1 to a few atm) and the best reaction temperature could be in the range 350 to 450 C. Insufficient experimental work has been reported to give a clear idea of the required water-to-ethanol mole ratio. The stoichiometric value of this ratio is three and it is likely that excess water, although presenting some process complications, will be necessary to minimize yields of CO and CH{sub 4}. A major new aspect of catalyst selection and operation, when comparing ethanol to methanol steam reforming, will be catalyst deactivation due to temperature. The methanol process works well on CuO/ZnO around 250 to 260 C, just on the threshold of fairly rapid catalyst deactivation. If the ethanol process is to work at or above 300 C, the present CuO/ZnO catalysts will be operating at an activity well below that obtainable in methanol-steam reformers. This means that larger reformers (i.e. more catalyst) will be necessary or that Cu-based (or other) catalysts with slower deactivation in the 300 C-plus range will have to be developed.

  16. A 400-kWe high-efficiency steam turbine for industrial cogeneration

    NASA Technical Reports Server (NTRS)

    Leibowitz, H. M.

    1982-01-01

    An advanced state-of-the-art steam turbine-generator developed to serve as the power conversion subsystem for the Department of Energy's Sandia National Laboratories' Solar Total-Energy Project (STEP) is described. The turbine-generator, which is designed to provide 400-kW of net electrical power, represents the largest turbine-generator built specifically for commercial solar-powered cogeneration. The controls for the turbine-generator incorporate a multiple, partial-arc entry to provide efficient off-design performance, as well as an extraction control scheme to permit extraction flow regulation while maintaining 110-spsig pressure. Normal turbine operation is achieved while synchronized to a local utility and in a stand-alone mode. In both cases, the turbine-generator features automatic load control as well as remote start-up and shutdown capability. Tests totaling 200 hours were conducted to confirm the integrity of the turbine's mechanical structure and control function. Performance tests resulted in a measured inlet throttle flow of 8,450 pounds per hour, which was near design conditions.

  17. A 400-kWe high-efficiency steam turbine for industrial cogeneration

    NASA Astrophysics Data System (ADS)

    Leibowitz, H. M.

    1982-07-01

    An advanced state-of-the-art steam turbine-generator developed to serve as the power conversion subsystem for the Department of Energy's Sandia National Laboratories' Solar Total-Energy Project (STEP) is described. The turbine-generator, which is designed to provide 400-kW of net electrical power, represents the largest turbine-generator built specifically for commercial solar-powered cogeneration. The controls for the turbine-generator incorporate a multiple, partial-arc entry to provide efficient off-design performance, as well as an extraction control scheme to permit extraction flow regulation while maintaining 110-spsig pressure. Normal turbine operation is achieved while synchronized to a local utility and in a stand-alone mode. In both cases, the turbine-generator features automatic load control as well as remote start-up and shutdown capability. Tests totaling 200 hours were conducted to confirm the integrity of the turbine's mechanical structure and control function. Performance tests resulted in a measured inlet throttle flow of 8,450 pounds per hour, which was near design conditions.

  18. A 400-kWe high-efficiency steam turbine for industrial cogeneration

    NASA Technical Reports Server (NTRS)

    Leibowitz, H. M.

    1982-01-01

    An advanced state-of-the-art steam turbine-generator developed to serve as the power conversion subsystem for the Department of Energy's Sandia National Laboratories' Solar Total-Energy Project (STEP) is described. The turbine-generator, which is designed to provide 400-kW of net electrical power, represents the largest turbine-generator built specifically for commercial solar-powered cogeneration. The controls for the turbine-generator incorporate a multiple, partial-arc entry to provide efficient off-design performance, as well as an extraction control scheme to permit extraction flow regulation while maintaining 110-spsig pressure. Normal turbine operation is achieved while synchronized to a local utility and in a stand-alone mode. In both cases, the turbine-generator features automatic load control as well as remote start-up and shutdown capability. Tests totaling 200 hours were conducted to confirm the integrity of the turbine's mechanical structure and control function. Performance tests resulted in a measured inlet throttle flow of 8,450 pounds per hour, which was near design conditions.

  19. Steam reforming of heptane in a fluidized bed membrane reactor

    NASA Astrophysics Data System (ADS)

    Rakib, Mohammad A.; Grace, John R.; Lim, C. Jim; Elnashaie, Said S. E. H.

    n-Heptane served as a model compound to study steam reforming of naphtha as an alternative feedstock to natural gas for production of pure hydrogen in a fluidized bed membrane reactor. Selective removal of hydrogen using Pd 77Ag 23 membrane panels shifted the equilibrium-limited reactions to greater conversion of the hydrocarbons and lower yields of methane, an intermediate product. Experiments were conducted with no membranes, with one membrane panel, and with six panels along the height of the reactor to understand the performance improvement due to hydrogen removal in a reactor where catalyst particles were fluidized. Results indicate that a fluidized bed membrane reactor (FBMR) can provide a compact reformer for pure hydrogen production from a liquid hydrocarbon feedstock at moderate temperatures (475-550 °C). Under the experimental conditions investigated, the maximum achieved yield of pure hydrogen was 14.7 moles of pure hydrogen per mole of heptane fed.

  20. Analysis of Deactivation Mechanism on a Multi-Component Sulfur-Tolerant Steam Reforming Catalyst

    DTIC Science & Technology

    2010-08-01

    43 2.5.3. Temperature Program Oxidation ( TPO ) ....................................................... 44 2.5.4...99 Figure 4-22. TPO of used catalyst NM4 after steam reforming of...catalyst (based on integration of TPO , as described in text) and C2+ in dry exit gas during steam reforming n- hexadecane at 800 o C, 1 atm, S/C=3

  1. Modified Ni-Cu catalysts for ethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Dan, M.; Mihet, M.; Almasan, V.; Borodi, G.; Katona, G.; Muresan, L.; Lazar, M. D.

    2013-11-01

    Three Ni-Cu catalysts, having different Cu content, supported on γ-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N2 adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

  2. Modified Ni-Cu catalysts for ethanol steam reforming

    SciTech Connect

    Dan, M.; Mihet, M.; Almasan, V.; Borodi, G.; Katona, G.; Muresan, L.; Lazar, M. D.

    2013-11-13

    Three Ni-Cu catalysts, having different Cu content, supported on γ-alumina were synthesized by wet co-impregnation method, characterized and tested in the ethanol steam reforming (ESR) reaction. The catalysts were characterized for determination of: total surface area and porosity (N{sub 2} adsorption - desorption using BET and Dollimer Heal methods), Ni surface area (hydrogen chemisorption), crystallinity and Ni crystallites size (X-Ray Diffraction), type of catalytic active centers (Hydrogen Temperature Programmed Reduction). Total surface area and Ni crystallites size are not significantly influenced by the addition of Cu, while Ni surface area is drastically diminished by increasing of Cu concentration. Steam reforming experiments were performed at atmospheric pressure, temperature range 150-350°C, and ethanol - water molar ration of 1 at 30, using Ar as carrier gas. Ethanol conversion and hydrogen production increase by the addition of Cu. At 350°C there is a direct connection between hydrogen production and Cu concentration. Catalysts deactivation in 24h time on stream was studied by Transmission Electron Microscopy (TEM) and temperature-programmed reduction (TPR) on used catalysts. Coke deposition was observed at all studied temperatures; at 150°C amorphous carbon was evidenced, while at 350°C crystalline, filamentous carbon is formed.

  3. Thermodynamic evaluation of methanol steam reforming for hydrogen production

    NASA Astrophysics Data System (ADS)

    Faungnawakij, Kajornsak; Kikuchi, Ryuji; Eguchi, Koichi

    Thermodynamic equilibrium of methanol steam reforming (MeOH SR) was studied by Gibbs free minimization for hydrogen production as a function of steam-to-carbon ratio (S/C = 0-10), reforming temperature (25-1000 °C), pressure (0.5-3 atm), and product species. The chemical species considered were methanol, water, hydrogen, carbon dioxide, carbon monoxide, carbon (graphite), methane, ethane, propane, i-butane, n-butane, ethanol, propanol, i-butanol, n-butanol, and dimethyl ether (DME). Coke-formed and coke-free regions were also determined as a function of S/C ratio. Based upon a compound basis set MeOH, CO 2, CO, H 2 and H 2O, complete conversion of MeOH was attained at S/C = 1 when the temperature was higher than 200 °C at atmospheric pressure. The concentration and yield of hydrogen could be achieved at almost 75% on a dry basis and 100%, respectively. From the reforming efficiency, the operating condition was optimized for the temperature range of 100-225 °C, S/C range of 1.5-3, and pressure at 1 atm. The calculation indicated that the reforming condition required from sufficient CO concentration (<10 ppm) for polymer electrolyte fuel cell application is too severe for the existing catalysts (T r = 50 °C and S/C = 4-5). Only methane and coke thermodynamically coexist with H 2O, H 2, CO, and CO 2, while C 2H 6, C 3H 8, i-C 4H 10, n-C 4H 10, CH 3OH, C 2H 5OH, C 3H 7OH, i-C 4H 9OH, n-C 4H 9OH, and C 2H 6O were suppressed at essentially zero. The temperatures for coke-free region decreased with increase in S/C ratios. The impact of pressure was negligible upon the complete conversion of MeOH.

  4. In silico search for novel methane steam reforming catalysts

    NASA Astrophysics Data System (ADS)

    Xu, Yue; Lausche, Adam C.; Wang, Shengguang; Khan, Tuhin S.; Abild-Pedersen, Frank; Studt, Felix; Nørskov, Jens K.; Bligaard, Thomas

    2013-12-01

    This paper demonstrates a method for screening transition metal and metal alloy catalysts based on their predicted rates and stabilities for a given catalytic reaction. This method involves combining reaction and activation energies (available to the public via a web-based application ‘CatApp’) with a microkinetic modeling technique to predict the rates and selectivities of a prospective material. This paper illustrates this screening technique using the steam reforming of methane to carbon monoxide and hydrogen as a test reaction. While catalysts are already commercially available for this process, the method demonstrated in this paper is very general and could be applied to a wide range of catalytic reactions. Following the steps outlined herein, such an analysis could potentially enable researchers to understand reaction mechanisms on a fundamental level and, on this basis, develop leads for new metal alloy catalysts.

  5. Influence of geometry on pressure and velocity distribution in packed-bed methanol steam reforming reactor

    NASA Astrophysics Data System (ADS)

    Ivanović, Ivana; Sedmak, Aleksandar; Milošević, Miloš; Cvetković, Ivana; Pohar, Andrej; Likozar, Blaž

    2017-07-01

    The main tasks of this research is to propose several changes in the packed bed micro methanol steam reformer geometry in order to ensure its performance. The reformer is an integral part of the existing indirect internal reforming high temperature PEMFC and most of its geometry is already defined. The space for remodeling is very limited.

  6. Evaluation of dissociated and steam-reformed methanol as automotive engine fuels

    NASA Technical Reports Server (NTRS)

    Lalk, T. R.; Mccall, D. M.; Mccanlies, J. M.

    1984-01-01

    Dissociated and steam reformed methanol were evaluated as automotive engine fuels. Advantages and disadvantages in using methanol in the reformed rather than liquid state were discussed. Engine dynamometer tests were conducted with a four cylinder, 2.3 liter, spark ignition automotive engine to determine performance and emission characteristics operating on simulated dissociated and steam reformed methanol (2H2 + CO and 3H2 + CO2 respectively), and liquid methanol. Results are presented for engine performance and emissions as functions of equivalence ratio, at various throttle settings and engine speeds. Operation on dissociated and steam reformed methanol was characterized by flashback (violent propagation of a flame into the intake manifold) which limited operation to lower power output than was obtainable using liquid methanol. It was concluded that: an automobile could not be operated solely on dissociated or steam reformed methanol over the entire required power range - a supplementary fuel system or power source would be necessary to attain higher powers; the use of reformed mechanol, compared to liquid methanol, may result in a small improvement in thermal efficiency in the low power range; dissociated methanol is a better fuel than steam reformed methanol for use in a spark ignition engine; and use of dissociated or steam reformed methanol may result in lower exhaust emissions compared to liquid methanol.

  7. Integrated solar thermochemical reaction system for steam methane reforming

    SciTech Connect

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

    2015-06-05

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

  8. Integrated solar thermochemical reaction system for steam methane reforming

    DOE PAGES

    Zheng, Feng; Diver, Rich; Caldwell, Dustin D.; ...

    2015-06-05

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

  9. Fuel Chemistry and Bed Performance in a Black Liquor Steam Reformer

    SciTech Connect

    2006-04-01

    The objective of this research is to address critical issues that inhibit successful commercialization of low-temperature BLG systems, including the steam reforming technology developed by Manufacturing and Technology Conversion International, Inc.

  10. Durability Testing of Fluidized Bed Steam Reforming Products

    SciTech Connect

    JANTZEN, CAROL M.; PAREIZS, JOHN M.; LORIER, TROY H.; MARRA, JAMES C.

    2005-07-01

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of radioactive wastes but especially aqueous high sodium wastes at the Hanford site, at the Idaho National Laboratory (INL), and at the Savannah River Site (SRS). The FBSR technology converts organic compounds to CO{sub 2} and H{sub 2}O, converts nitrate/nitrite species to N{sub 2}, and produces a solid residue through reactions with superheated steam, the fluidizing media. If clay is added during processing a ''mineralized'' granular waste form can be produced. The mineral components of the waste form are primarily Na-Al-Si (NAS) feldspathoid minerals with cage-like and ring structures and iron bearing spinel minerals. The cage and ring structured minerals atomically bond radionuclides like Tc{sup 99} and Cs{sup 137} and anions such as SO{sub 4}, I, F, and Cl. The spinel minerals appear to stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Durability testing of the FBSR products was performed using ASTM C1285 (Product Consistency Test) and the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP). The FBSR mineral products (bed and fines) evaluated in this study were found to be two orders of magnitude more durable than the Hanford Low Activity Waste (LAW) glass requirement of 2 g/m{sup 2} release of Na{sup +}. The PCT responses for the FBSR samples tested were consistent with results from previous FBSR Hanford LAW product testing. Differences in the response can be explained by the minerals formed and their effects on PCT leachate chemistry.

  11. Steam Reforming on Transition-metal Carbides from Density-functional Theory

    SciTech Connect

    Vojvodic, Aleksandra

    2012-05-11

    A screening study of the steam reforming reaction on clean and oxygen covered early transition-metal carbides surfaces is performed by means of density-functional theory calculations. It is found that carbides provide a wide spectrum of reactivities, from too reactive via suitable to too inert. Several molybdenum-based systems are identified as possible steam reforming catalysts. The findings suggest that carbides provide a playground for reactivity tuning, comparable to the one for pure metals.

  12. Enviro-Friendly Hydrogen Generation from Steel Mill-Scale via Metal-Steam Reforming

    ERIC Educational Resources Information Center

    Azad, Abdul-Majeed; Kesavan, Sathees

    2006-01-01

    An economically viable and environmental friendly method of generating hydrogen for fuel cells is by the reaction of certain metals with steam, called metal-steam reforming (MSR). This technique does not generate any toxic by-products nor contributes to the undesirable greenhouse effect. From the standpoint of favorable thermodynamics, total…

  13. Enviro-Friendly Hydrogen Generation from Steel Mill-Scale via Metal-Steam Reforming

    ERIC Educational Resources Information Center

    Azad, Abdul-Majeed; Kesavan, Sathees

    2006-01-01

    An economically viable and environmental friendly method of generating hydrogen for fuel cells is by the reaction of certain metals with steam, called metal-steam reforming (MSR). This technique does not generate any toxic by-products nor contributes to the undesirable greenhouse effect. From the standpoint of favorable thermodynamics, total…

  14. FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

    SciTech Connect

    Williams, M

    2008-05-09

    Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. provided by organic additives such as sugar or coal, to reduce NOX in the off-gas to N2 to meet Clean Air Act (CAA) standards during processing. Thus, organics will be present during the waste form stabilization process regardless of the GNEP processes utilized and exists in some of the high level radioactive waste tanks at Savannah River Site and Hanford Tank Farms, e.g. organics in the feed or organics used for nitrate destruction. Waste streams containing high organic concentrations cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by pretreatment. The alternative waste stabilization pretreatment process of Fluidized Bed Steam Reforming (FBSR) operates at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). The FBSR process has been demonstrated on GNEP simulated waste and radioactive waste containing high organics from Tank 48H to convert organics to CAA compliant gases, create no secondary liquid waste streams and create a stable mineral waste form.

  15. Zircon Supported Copper Catalysts for the Steam Reforming of Methanol

    NASA Astrophysics Data System (ADS)

    Widiastri, M.; Fendy, Marsih, I. N.

    2008-03-01

    Steam reforming of methanol (SRM) is known as one of the most favorable catalytic processes for producing hydrogen. Current research on zirconia, ZrO2 supported copper catalyst revealed that CuO/ZrO2 as an active catalyst for the SRM. Zircon, ZrSiO4 is available from the by-product of tin mining. In the work presented here, the catalytic properties of CuO/ZrSiO4 with various copper oxide compositions ranging from 2.70% (catalyst I), 4.12% (catalyst II), and 7.12%-mass (catalyst III), synthesized by an incipient wetness impregnation technique, were investigated to methanol conversion, selectivity towards CO formation, and effect of ZnO addition (7.83%CuO/8.01%ZnO/ZrSiO4 = catalyst V). The catalytic activity was obtained using a fixed bed reactor and the zircon supported catalyst activity was compared to those of CuO/ZnO/Al2O3 catalyst (catalyst IV) and commercial Kujang LTSC catalyst. An X-ray powder diffraction (XRD) analysis was done to identify the abundant phases of the catalysts. The catalysts topography and particle diameter were measured with scanning electron microscopy (SEM) and composition of the catalysts was measured by SEM-EDX, scanning electron microscope-energy dispersive using X-ray analysis. The results of this research provide information on the possibility of using zircon (ZrSiO4) as solid support for SRM catalysts.

  16. Additive Manufacturing of Catalyst Substrates for Steam-Methane Reforming

    NASA Astrophysics Data System (ADS)

    Kramer, Michelle; McKelvie, Millie; Watson, Matthew

    2017-08-01

    Steam-methane reforming is a highly endothermic reaction, which is carried out at temperatures up to 1100 °C and pressures up to 3000 kPa, typically with a Ni-based catalyst distributed over a substrate of discrete alumina pellets or beads. Standard pellet geometries (spheres, hollow cylinders) limit the degree of mass transfer between gaseous reactants and catalyst. Further, heat is supplied to the exterior of the reactor wall, and heat transfer is limited due to the nature of point contacts between the reactor wall and the substrate pellets. This limits the degree to which the process can be intensified, as well as limiting the diameter of the reactor wall. Additive manufacturing now gives us the capability to design structures with tailored heat and mass transfer properties, not only within the packed bed of the reactor, but also at the interface between the reactor wall and the packed bed. In this work, the use of additive manufacturing to produce monolithic-structured catalyst substrate models, made from acrylonitrile-butadiene-styrene, with enhanced conductive heat transfer is described. By integrating the reactor wall into the catalyst substrate structure, the effective thermal conductivity increased by 34% from 0.122 to 0.164 W/(m K).

  17. Steam reforming of low-level mixed waste

    SciTech Connect

    Voelker, G.E.; Steedman, W.G.; Chandran, R.R.

    1996-12-31

    The U.S. department of Energy (DOE) is responsible for the treatment and disposal of an inventory of approximately 160,000 tons of Low-Level Mixed Waste (LLMW). Most of this LLMW is stored in drums, barrels and steel boxes at 20 different sites throughout the DOE complex. The basic objective of low-level mixed waste treatment systems is to completely destroy the hazardous constituents and to simultaneously isolate and capture the radionuclides in a superior final waste form such as glass. The DOE is sponsoring the development of advanced technologies that meet this objective while achieving maximum volume reduction, low-life cycle costs and maximum operational safety. ThermoChem, Inc. is in the final stages of development of a steam-reforming system capable of treating a wide variety of DOE low-level mixed waste that meets these objectives. The design, construction, and testing of a nominal 1 ton/day Process Development Unit is described.

  18. Steam reforming as a method to treat Hanford underground storage tank (UST) wastes

    SciTech Connect

    Miller, J.E.; Kuehne, P.B.

    1995-07-01

    This report summarizes a Sandia program that included partnerships with Lawrence Livermore National Laboratory and Synthetica Technologies, Inc. to design and test a steam reforming system for treating Hanford underground storage tank (UST) wastes. The benefits of steam reforming the wastes include the resolution of tank safety issues and improved radionuclide separations. Steam reforming destroys organic materials by first gasifying, then reacting them with high temperature steam. Tests indicate that up to 99% of the organics could be removed from the UST wastes by steam exposure. In addition, it was shown that nitrates in the wastes could be destroyed by steam exposure if they were first distributed as a thin layer on a surface. High purity alumina and nickel alloys were shown to be good candidates for materials to be used in the severe environment associated with steam reforming the highly alkaline, high nitrate content wastes. Work was performed on designing, building, and demonstrating components of a 0.5 gallon per minute (gpm) system suitable for radioactive waste treatment. Scale-up of the unit to 20 gpm was also considered and is feasible. Finally, process demonstrations conducted on non-radioactive waste surrogates were carried out, including a successful demonstration of the technology at the 0.1 gpm scale.

  19. High Efficiency Solar-based Catalytic Structure for CO{sub 2} Reforming

    SciTech Connect

    Menkara, Hisham

    2013-09-30

    Throughout this project, we developed and optimized various photocatalyst structures for CO{sub 2} reforming into hydrocarbon fuels and various commodity chemical products. We also built several closed-loop and continuous fixed-bed photocatalytic reactor system prototypes for a larger-scale demonstration of CO{sub 2} reforming into hydrocarbons, mainly methane and formic acid. The results achieved have indicated that with each type of reactor and structure, high reforming yields can be obtained by refining the structural and operational conditions of the reactor, as well as by using various sacrificial agents (hole scavengers). We have also demonstrated, for the first time, that an aqueous solution containing acid whey (a common bio waste) is a highly effective hole scavenger for a solar-based photocatalytic reactor system and can help reform CO{sub 2} into several products at once. The optimization tasks performed throughout the project have resulted in efficiency increase in our conventional reactors from an initial 0.02% to about 0.25%, which is 10X higher than our original project goal. When acid whey was used as a sacrificial agent, the achieved energy efficiency for formic acid alone was ~0.4%, which is 16X that of our original project goal and higher than anything ever reported for a solar-based photocatalytic reactor. Therefore, by carefully selecting sacrificial agents, it should be possible to reach energy efficiency in the range of the photosynthetic efficiency of typical crop and biofuel plants (1-3%).

  20. Solid oxide fuel cell steam reforming power system

    DOEpatents

    Chick, Lawrence A.; Sprenkle, Vincent L.; Powell, Michael R.; Meinhardt, Kerry D.; Whyatt, Greg A.

    2013-03-12

    The present invention is a Solid Oxide Fuel Cell Reforming Power System that utilizes adiabatic reforming of reformate within this system. By utilizing adiabatic reforming of reformate within the system the system operates at a significantly higher efficiency than other Solid Oxide Reforming Power Systems that exist in the prior art. This is because energy is not lost while materials are cooled and reheated, instead the device operates at a higher temperature. This allows efficiencies higher than 65%.

  1. Production of synthetic fuels using syngas from a steam hydrogasification and reforming process

    NASA Astrophysics Data System (ADS)

    Raju, Arun Satheesh Kumar

    This thesis is aimed at the research, optimization and development of a thermo-chemical process aimed at the production of synthesis gas (mixture of H2 and CO) with a flexible H2 to CO ratio using coupled steam hydrogasification and steam reforming processes. The steam hydrogasification step generates a product gas containing significant amounts of methane by gasifying a carbonaceous feed material with steam and internally generated H2. This product gas is converted to synthesis gas with an excess H2 to CO using the steam reformer. Research involving experimental and simulation work has been conducted on steam hydrogasification, steam reforming and the Fischer-Tropsch reaction. The Aspen Plus simulation tool has been used to develop a process model that can perform heat and mass balance calculations of the whole process using built-in reactor modules and an empirical FT model available in the literature. This model has been used to estimate optimum feed ratios and process conditions for specific feedstocks and products. Steam hydrogasification of coal and wood mixtures of varying coal to wood ratios has been performed in a stirred batch reactor. The carbon conversion of the feedstocks to gaseous products is around 60% at 700°C and 80% at 800°C. The coal to wood ratio of the feedstock does not exert a significant influence on the carbon conversion. The rates of formation of CO, CO 2 and CH4 during gasification have been calculated based on the experimental results using a simple kinetic model. Experimental research on steam reforming has been performed. It has been shown that temperature and the feed CO2/CH4 ratio play a dominant role in determining the product gas H2/CO ratio. Reforming of typical steam hydrogasification product-gas stream has been investigated over a commercial steam reforming catalyst. The results demonstrate that the combined use of steam hydrogasification process with a reformer can generate a synthesis gas with a predetermined H2/CO ratio

  2. FLUIDIZED BED STEAM REFORMER (FBSR) PRODUCT: MONOLITH FORMATION AND CHARACTERIZATION

    SciTech Connect

    Jantzen, C

    2006-09-13

    The most important requirement for Hanford's low activity waste (LAW) form for shallow land disposal is the chemical durability of the product. A secondary, but still essential specification, is the compressive strength of the material with regards to the strength of the material under shallow land disposal conditions, e.g. the weight of soil overburden and potential intrusion by future generations, because the term ''near-surface disposal'' indicates disposal in the uppermost portion, or approximately the top 30 meters, of the earth's surface. The THOR{reg_sign} Treatment Technologies (TTT) mineral waste form for LAW is granular in nature because it is formed by Fluidized Bed Steam Reforming (FBSR). As a granular product it has been shown to be as durable as Hanford's LAW glass during testing with ASTM C-1285-02 known as the Product Consistency Test (PCT) and with the Single Pass Flow Through Test (SPFT). Hanford Envelope A and Envelope C simulants both performed well during PCT and SPFT testing and during subsequent performance assessment modeling. This is partially due to the high aluminosilicate content of the mineral product which provides a natural aluminosilicate buffering mechanism that inhibits leaching and is known to occur in naturally occurring aluminosilicate mineral analogs. In order for the TTT Na-Al-Si (NAS) granular mineral product to meet the compressive strength requirements (ASTM C39) for a Hanford waste form, the granular product needs to be made into a monolith or disposed of in High Integrity Containers (HIC's). Additionally, the Hanford intruder scenario for disposal in the Immobilized Low Activity Waste (ILAW) trench is mitigated as there is reduced intruder exposure when a waste form is in a monolithic form. During the preliminary testing of a monolith binder for TTT's FBSR mineral product, four parameters were monitored: (1) waste loading (not optimized for each waste form tested); (2) density; (3) compressive strength; and (4) durability

  3. High efficiency, quasi-instantaneous steam expansion device utilizing fossil or nuclear fuel as the heat source

    SciTech Connect

    Claudio Filippone, Ph.D.

    1999-06-01

    Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside the expander where steam (or the proper fluid) is generated almost instantaneously prior to its expansion in the work-producing unit. Relatively cold water is pulsed inside the heat cavity, where the heat transferred causes the water to flash to steam, thereby increasing its specific volume by a large factor. The gap inside the heat cavity forms a special nozzle-shaped system in which the fluid expands rapidly, accelerating toward the system outlet. The expansion phenomenon is the cause of ever-increasing fluid speed inside the cavity system, eliminating the need for moving parts (pumps, valves, etc.). In fact, the subsequent velocity induced by the sudden fluid expansion causes turbulent conditions, forcing accelerating Reynolds and Nusselt numbers which, in turn, increase the convective heat transfer coefficient. When the combustion of fossil fuels constitutes the heat source, the heat cavity concept can be applied directly inside the stator of conventional turbines, thereby greatly increasing the overall system efficiency.

  4. HIGH EFFICIENCY, QUASI-INSTANTANEOUS STEAM EXPANSION DEVICE UTILIZING FOSSIL OR NUCLEAR FUEL AS THE HEAT SOURCE

    SciTech Connect

    Claudio Filippone, Ph.D.

    1999-06-01

    Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside the expander where steam (or the proper fluid) is generated almost instantaneously prior to its expansion in the work-producing unit. Relatively cold water is pulsed inside the heat cavity, where the heat transferred causes the water to flash to steam, thereby increasing its specific volume by a large factor. The gap inside the heat cavity forms a special nozzle-shaped system in which the fluid expands rapidly, accelerating toward the system outlet. The expansion phenomenon is the cause of ever-increasing fluid speed inside the cavity system, eliminating the need for moving parts (pumps, valves, etc.). In fact, the subsequent velocity induced by the sudden fluid expansion causes turbulent conditions, forcing accelerating Reynolds and Nusselt numbers which, in turn, increase the convective heat transfer coefficient. When the combustion of fossil fuels constitutes the heat source, the heat cavity concept can be applied directly inside the stator of conventional turbines, thereby greatly increasing the overall system efficiency.

  5. Steam reforming of biodiesel by-product to make renewable hydrogen.

    PubMed

    Slinn, Matthew; Kendall, Kevin; Mallon, Christian; Andrews, James

    2008-09-01

    The aim of this paper was to investigate the viability of steam reforming the combined glycerol and water by-product streams of a biodiesel plant. A platinum alumina catalyst was used to optimise the operating conditions for glycerol steam reforming and mass spectroscopy was chosen to measure reformer gas yield. The problem is that glycerol steam reforming is relatively untested even with pure glycerol and the by-product quality may be too poor. The strategy was therefore to optimise the process using pure glycerol and compare the performance with by-product glycerol. To test catalyst degradation caused by carbon deposition, a Solid Oxide fuel cell (SOFC) was used as a separate reformer and electrical performance was measured to indicate carbon deposition. This is the first time a SOFC has been run on glycerol. The results showed that thermodynamic theory can be used to predict reformer performance. At high temperatures high gas yield can be reached (almost 100%) and selectivities of 70% (dry basis) obtained. The optimum conditions for glycerol reforming were 860 degrees C temperature (maximum tested), 0.12 mols/min glycerol flow per kg of catalyst and 2.5 steam/carbon ratio. Reforming catalysts lasted for several days of continuous operation with minimal degradation, 0.4% of feed deposited. By-product glycerol performed slightly worse with a lower yield and more carbon deposition, 2% of feed. The results show that glycerol steam reforming is a viable alternative use for glycerol and potentially a better option than purification.

  6. In-Space Propulsion, Logistics Reduction, and Evaluation of Steam Reformer Kinetics: Problems and Prospects

    NASA Technical Reports Server (NTRS)

    Jaworske, D. A.; Palaszewski, B. A.; Kulis, M. J.; Gokoglu, S. A.

    2015-01-01

    Human space missions generate waste materials. A 70-kg crewmember creates a waste stream of 1 kg per day, and a four-person crew on a deep space habitat for a 400+ day mission would create over 1600 kg of waste. Converted into methane, the carbon could be used as a fuel for propulsion or power. The NASA Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) project is investing in space resource utilization with an emphasis on repurposing logistics materials for useful purposes and has selected steam reforming among many different competitive processes as the preferred method for repurposing organic waste into methane. Already demonstrated at the relevant processing rate of 5.4 kg of waste per day, high temperature oxygenated steam consumes waste and produces carbon dioxide, carbon monoxide, and hydrogen which can then be converted into methane catalytically. However, the steam reforming process has not been studied in microgravity. Data are critically needed to understand the mechanisms that allow use of steam reforming in a reduced gravity environment. This paper reviews the relevant literature, identifies gravity-dependent mechanisms within the steam gasification process, and describes an innovative experiment to acquire the crucial kinetic information in a small-scale reactor specifically designed to operate within the requirements of a reduced gravity aircraft flight. The experiment will determine if the steam reformer process is mass-transport limited, and if so, what level of forced convection will be needed to obtain performance comparable to that in 1-g.

  7. Steam reforming of tar model compound using Pd catalyst on alumina tube.

    PubMed

    Nisamaneenate, Jurarat; Atong, Duangduen; Sricharoenchaikul, Viboon

    2012-12-01

    Gasification processing of biomass as a renewable energy source generates tar in the product gas. Tar leads to foul-up of the process equipment by corrosion and deposit formation. Catalytic elimination of tars is a crucial step to improve fuel gas quality from the process. In this study, a palladium catalyst on alumina (Pd/Al2O3) was used in steam reforming of benzene as a biomass gasification tar model compound. The reaction was carried out in a laboratory-scale tube reactor made of stainless steel to study the effect of reaction temperature, catalyst loading, quantity of palladium catalyst tubes, steam to carbon ratio (S/C), and residence time on catalytic performance and stability. Pd/Al2O3 showed high efficiency ofbenzene decomposition and enhanced the formation of fuel gas. Hydrogen and carbon conversions increased with reaction temperature. Although the benzene concentration increased from 2000 to 5000 mg/l, the catalytic performance at 600 degrees C and 800 degrees C was similar. 1.0 wt% Pd/Al2O3 showed excellent catalytic activity with the highest hydrogen and carbon conversions of 83% and 81%, respectively at 800 degrees C. This result is attributed to the smooth surface of the palladium, as noted from scanning electron microscopy imaging. An S/C of 2 provided the highest conversion. The addition of catalyst from four and seven tubes did not result in any great difference in terms of benzene cracking efficiency. The fourth cyclic usage of 1.0 wt% Pd/Al2O3 exhibited a higher conversion than that of 0.5 wt%.

  8. Steam-Reforming Characteristics of Heavy and Light Tars Derived from Cellulose

    NASA Astrophysics Data System (ADS)

    Watanabe, Hirotatsu; Morinaga, Yosuke; Okazaki, Ken

    In this study, tar formation and steam-reforming mechanisms are discussed by separating the tars into heavy, middle, and light tars. Cellulose was heated in a drop-tube furnace under an Ar or Ar/steam atmosphere. After the tars were passed through the furnace for thermal cracking and polymerization, they were trapped by filters set at different temperatures (573, 393, and 273 K), and were respectively defined as heavy, middle, and light tars. Incondensable volatiles and gaseous products were measured using gas chromatography with thermal conductivity (GC-TCD), and flame ionization (GC-FID) detectors. The middle and light tars obtained under an Ar atmosphere were first characterized using time-of-flight mass spectrometry (TOF-MS). The analysis showed that the middle tar did not contain any low-boiling-point light tar components, while the light tar did contain them. It was also found that complex species in the tars were separated to a certain degree by changing the trap temperature. Moreover, the formation of heavy tar was quite different from that of the light tar. With increasing temperature, the formation of heavy tar was inhibited, while that of the light tar was enhanced during pyrolysis. The steam-reforming characteristics of these tars were also different. The heavy tar was barely reformed at a low temperature of 873 K, even with a long residence time, while the middle tar was well reformed by steam. While it was difficult to describe the tar formation and steam-reforming characteristics when the tar was considered as a single condensable matter, the tar formation and steam-reforming characteristics were clarified by separating the tars. This study shows that, to prevent tar emissions, the formation of heavy tar, which barely reacts with steam, should be inhibited during pyrolysis by controlling the heating.

  9. New Insights into Reaction Mechanisms of Ethanol Steam Reforming on Co-ZrO2

    SciTech Connect

    Sun, Junming; Karim, Ayman M.; Mei, Donghai; Engelhard, Mark H.; Bao, Xinhe; Wang, Yong

    2015-01-01

    The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted to acetaldehyde and then to acetone, followed by acetone steam reforming. More than 90% carbon was found to follow this reaction pathway. N2-Sorption, X-ray Diffraction (XRD), Temperature Programmed Reduction (TPR), in situ X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy, as well as theoretical Density Functional Theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ESR. It was found that metallic cobalt is mainly responsible for the acetone steam reforming reactions; while, CoO and basic sites on the support play a key role in converting ethanol to acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam reforming catalysts.

  10. Development of a Nuclear Hydrogen Production System by Dimethyl Ether (DME) Steam Reforming and Related Technology

    NASA Astrophysics Data System (ADS)

    Fukushima, Kimichika; Oota, Hiroyuki; Yamada, Kazuya; Makino, Shinichi; Yagyu, Motoshige; Ikeda, Tatsumi; Asayama, Masahiro; Ogawa, Takashi; Yoshino, Masato

    Targeting a hydrogen production system using heat produced by a nuclear reactor at about 300°C, we are developing a dimethyl ether (DME) steam reformer and hydrogen purification systems as well as catalysts for DME reforming. The use of heat from a nuclear reactor suppresses the CO2 concentration change in the atmosphere. In our developments, a catalyst, consisting of mixed oxides, produced hydrogen at a rate of about 1.9 Nm3/h per catalyst volume (m3) at about 300°C. Subsequently, the DME steam reformer achieved a hydrogen production rate of approximately, at least, 1.4 Nm3/h at about 300°C, by absorbing heat from the supplied steam. The aforementioned hydrogen production system via DME steam reforming is to be demonstrated using a thermal power plant. DME steam reforming by using waste heat and the utilization of the produced hydrogen within a combined cycle power plant can reduce fuel consumption, for instance, by about 17% compared to the case of direct DME combustion. The total system, with the use of DME, was compared with the methane case. If necessary, the byproduced CO2 may be injected into coal seams, increasing CH4 production via the substitution of CO2 for CH4 on coal, where CO2 adsorption is expected to be stronger than the CH4 adsorption.

  11. Remarkable support effect on the reactivity of Pt/In2O3/MOx catalysts for methanol steam reforming

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Men, Yong; Wang, Jinguo; He, Rong; Wang, Yuanqiang

    2017-10-01

    Effects of supports over Pt/In2O3/MOx catalysts with extremely low loading of Pt (1 wt%) and In2O3 loadings (3 wt%) are investigated for the hydrogen production of methanol steam reforming (MSR) in the temperature range of 250-400 °C. Under practical conditions without the pre-reduction, the 1Pt/3In2O3/CeO2 catalyst shows the highly efficient catalytic performance, achieving almost complete methanol conversion (98.7%) and very low CO selectivity of 2.6% at 325 °C. The supported Pt/In2O3 catalysts are characterized by means of Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), high-resolution transmission microscopy (HRTEM), temperature programmed reduction with hydrogen (H2-TPR), CO pulse chemisorption, temperature programmed desorption of methanol and water (CH3OH-TPD and H2O-TPD). These demonstrate that the nature of catalyst support of Pt/In2O3/MOx plays crucial roles in the Pt dispersion associated by the strong interaction among Pt, In2O3 and supporting materials and the surface redox properties at low temperature, and thus affects their capability to activate the reactants and determines the catalytic activity of methanol steam reforming. The superior 1Pt/3In2O3/CeO2 catalyst, exhibiting a remarkable reactivity and stability for 32 h on stream, demonstrates its potential for efficient hydrogen production of methanol steam reforming in mobile and de-centralized H2-fueled PEMFC systems.

  12. Developing an energy efficient steam reforming process to produce hydrogen from sulfur-containing fuels

    NASA Astrophysics Data System (ADS)

    Simson, Amanda

    Hydrogen powered fuel cells have the potential to produce electricity with higher efficiency and lower emissions than conventional combustion technology. In order to realize the benefits of a hydrogen fuel cell an efficient method to produce hydrogen is needed. Currently, over 90% of hydrogen is produced from the steam reforming of natural gas. However, for many applications including fuel cell vehicles, the use of a liquid fuel rather than natural gas is desirable. This work investigates the feasibility of producing hydrogen efficiently by steam reforming E85 (85% ethanol/15% gasoline), a commercially available sulfur-containing transportation fuel. A Rh-Pt/SiO2-ZrO2 catalyst has demonstrated good activity for the E85 steam reforming reaction. An industrial steam reforming process is often run less efficiently, with more water and at higher temperatures, in order to prevent catalyst deactivation. Therefore, it is desirable to develop a process that can operate without catalyst deactivation at more energy efficient conditions. In this study, the steam reforming of a sulfur-containing fuel (E85) was studied at near stoichiometric steam/carbon ratios and at 650C, conditions at which catalyst deactivation is normally measured. At these conditions the catalyst was found to be stable steam reforming a sulfur-free E85. However, the addition of low concentrations of sulfur significantly deactivated the catalyst. The presence of sulfur in the fuel caused catalyst deactivation by promoting ethylene which generates surface carbon species (coke) that mask catalytic sites. The amount of coke increased during time on stream and became increasingly graphitic. However, the deactivation due to both sulfur adsorption and coke formation was reversible with air treatment at 650°C. However, regenerations were found to reduce the catalyst life. Air regenerations produce exotherms on the catalyst surface that cause structural changes to the catalyst. During regenerations the

  13. HIGH EFFICIENCY SYNGAS GENERATION

    SciTech Connect

    Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

    2005-02-01

    This project investigated an efficient and low cost method of auto-thermally reforming natural gas to hydrogen and carbon monoxide. Reforming is the highest cost step in producing products such as methanol and Fisher Tropsch liquids (i.e., gas to liquids); and reducing the cost of reforming is the key to reducing the cost of these products. Steam reforming is expensive because of the high cost of the high nickel alloy reforming tubes (i.e., indirectly fired reforming tubes). Conventional auto-thermal or Partial Oxidation (POX) reforming minimizes the size and cost of the reformers and provides a near optimum mixture of CO and hydrogen. However POX requires pure oxygen, which consumes power and significantly increases the cost to reforming. Our high efficiency process extracts oxygen from low-pressure air with novel oxygen sorbent and transfers the oxygen to a nickel-catalyzed reformer. The syngas is generated at process pressure (typically 20 to 40 bar) without nitrogen dilution and has a 1CO to 2H{sub 2} ratio that is near optimum for the subsequent production of Fisher-Tropsch liquid to liquids and other chemicals (i.e., Gas to Liquids, GTL). Our high process efficiency comes from the way we transfer the oxygen into the reformer. All of the components of the process, except for the oxygen sorbent, are commonly used in commercial practice. A process based on a longlived, regenerable, oxygen transfer sorbent could substantially reduce the cost of natural gas reforming to syngas. Lower cost syngas (CO + 2H{sub 2}) that is the feedstock for GTL would reduce the cost of GTL and for other commercial applications (e.g., methanol, other organic chemicals). The vast gas resources of Alaska's North Slope (ANS) offer more than 22 Tcf of gas and GTL production in this application alone, and could account for as much as 300,000 to 700,000 bpd for 20 to 30+ years. We developed a new sorbent, which is an essential part of the High Efficiency Oxygen Process (HOP). We tested the

  14. Heterogeneous Reactor Model for Steam Reforming of Methane in a Microchannel Reactor with Microstructured Catalysts

    SciTech Connect

    Cao, Chunshe; Wang, Yong; Rozmiarek, Robert T.

    2005-12-15

    Microstructured catalysts used for methane steam reforming in microchannel reactors are mathematically described and experimentally demonstrated under realistic process conditions. A heterogeneous model has been developed with a graphical interface to represent the three dimensions of the microchannel reactor. Porous metal substrates (FeCrAlY) were used to form engineered catalysts with active precious metal (Rh) for methane steam reforming. Two types of structures were evaluated in the microchannel reactors and simulated with the developed heterogeneous reactor model. Local temperature and methane concentration profiles within the structures are illustrated to show the correlation of the catalyst structure and its performance. Such a modeling technique provides a convenient and flexible method to evaluate variables in designing more efficient catalysts for the highly endothermic steam reforming reactions, as the desired mass and heat transfer characteristics are achieved.

  15. Steam Reforming Technology for Denitration and Immobilization of DOE Tank Wastes

    SciTech Connect

    Mason, J. B.; McKibbin, J.; Ryan, K.; Schmoker, D.

    2003-02-26

    THOR Treatment Technologies, LLC (THOR) is a joint venture formed in June 2002 by Studsvik, Inc. (Studsvik) and Westinghouse Government Environmental Services Company LLC to further develop, market, and deploy Studsvik's patented THORSM non-incineration, steam reforming waste treatment technology. This paper provides an overview of the THORSM steam reforming process as applied to the denitration and conversion of Department of Energy (DOE) tank wastes to an immobilized mineral form. Using the THORSM steam reforming technology to treat nitrate containing tank wastes could significantly benefit the DOE by reducing capital and life-cycle costs, reducing processing and programmatic risks, and positioning the DOE to meet or exceed its stakeholder commitments for tank closure. Specifically, use of the THORSM technology can facilitate processing of up to 75% of tank wastes without the use of vitrification, yielding substantial life-cycle cost savings.

  16. DATA QUALITY OBJECTIVES FOR SELECTING WASTE SAMPLES FOR THE BENCH STEAM REFORMER TEST

    SciTech Connect

    BANNING DL

    2010-08-03

    This document describes the data quality objectives to select archived samples located at the 222-S Laboratory for Fluid Bed Steam Reformer testing. The type, quantity and quality of the data required to select the samples for Fluid Bed Steam Reformer testing are discussed. In order to maximize the efficiency and minimize the time to treat Hanford tank waste in the Waste Treatment and Immobilization Plant, additional treatment processes may be required. One of the potential treatment processes is the fluid bed steam reformer (FBSR). A determination of the adequacy of the FBSR process to treat Hanford tank waste is required. The initial step in determining the adequacy of the FBSR process is to select archived waste samples from the 222-S Laboratory that will be used to test the FBSR process. Analyses of the selected samples will be required to confirm the samples meet the testing criteria.

  17. Differences in the Nature of Active Sites for Methane Dry Reforming and Methane Steam Reforming over Nickel Aluminate Catalysts

    DOE PAGES

    Rogers, Jessica L.; Mangarella, Michael C.; D’Amico, Andrew D.; ...

    2016-07-20

    In this paper, the Pechini synthesis was used to prepare nickel aluminate catalysts with the compositions NiAl4O7, NiAl2O4, and Ni2Al2O5. The samples have been characterized by N2 physisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and X-ray absorption spectroscopy (XAS). Characterization results indicate unique structural properties and excellent regeneration potential of nickel aluminates. Prepared samples were tested when unreduced and reduced prior to reaction for methane dry reforming and methane steam reforming reactivity. NiAl2O4 in the reduced and unreduced state as well as NiAl4O7 in the reduced state are activemore » and stable for methane dry reforming due to the presence of 4-fold coordinated oxidized nickel. The limited amount of metallic nickel in these samples minimizes carbon deposition. Finally, on the other hand, the presence of metallic nickel is required for methane steam reforming. Ni2Al2O5 in the reduced and unreduced states and NiAl2O4 in the reduced state are found to be active for methane steam reforming due to the presence of sufficiently small nickel nanoparticles that catalyze the reaction without accumulating carbonaceous deposits.« less

  18. Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

    NASA Astrophysics Data System (ADS)

    Semelsberger, Troy A.; Borup, Rodney L.

    The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

  19. Fluidized Bed Steam Reforming of Hanford LAW Using THORsm Mineralizing Technology

    SciTech Connect

    Olson, Arlin L.; Nicholas R Soelberg; Douglas W. Marshall; Gary L. Anderson

    2004-11-01

    The U.S. Department of Energy (DOE) documented, in 2002, a plan for accelerating cleanup of the Hanford Site, located in southeastern Washington State, by at least 35 years. A key element of the plan was acceleration of the tank waste program and completion of ''tank waste treatment by 2028 by increasing the capacity of the planned Waste Treatment Plant (WTP) and using supplemental technologies for waste treatment and immobilization.'' The plan identified steam reforming technology as a candidate for supplemental treatment of as much as 70% of the low-activity waste (LAW). Mineralizing steam reforming technology, offered by THOR Treatment Technologies, LLC would produce a denitrated, granular mineral waste form using a high-temperature fluidized bed process. A pilot scale demonstration of the technology was completed in a 15-cm-diameter reactor vessel. The pilot scale facility was equipped with a highly efficient cyclone separator and heated sintered metal filters for particulate removal, a thermal oxidizer for reduced gas species and NOx destruction, and a packed activated carbon bed for residual volatile species capture. The pilot scale equipment is owned by the DOE, but located at the Science and Technology Applications Research (STAR) Center in Idaho Falls, ID. Pilot scale testing was performed August 2–5, 2004. Flowsheet chemistry and operational parameters were defined through a collaborative effort involving Idaho National Engineering and Environmental Laboratory, Savannah River National Laboratory (SRNL), and THOR Treatment Technologies personnel. Science Application International Corporation, owners of the STAR Center, personnel performed actual pilot scale operation. The pilot scale test achieved a total of 68.7 hrs of cumulative/continuous processing operation before termination in response to a bed de-fluidization condition. 178 kg of LAW surrogate were processed that resulted in 148 kg of solid product, a mass reduction of about 17%. The process

  20. Hydrogen production from the steam reforming of Dinethyl Ether and Methanol

    SciTech Connect

    Semelsberger, T. A.; Borup, R. L.

    2004-01-01

    This study investigates dimethyl ether (DME) steam reforming for the generation of hydrogen rich fuel cell feeds for fuel cell applications. Methanol has long been considered as a fuel for the generation of hydrogen rich fuel cell feeds due to its high energy density, low reforming temperature, and zero impurity content. However, it has not been accepted as the fuel of choice due its current limited availability, toxicity and corrosiveness. While methanol steam reforming for the generation of hydrogen rich fuel cell feeds has been extensively studied, the steam reforming of DME, CH{sub 3}OCH{sub 3} + 3H{sub 2}O = 2CO{sub 2} + 6H{sub 2}, has had limited research effort. DME is the simplest ether (CH{sub 3}OCH{sub 3}) and is a gas at ambient conditions. DME has physical properties similar to those of LPG fuels (i.e. propane and butane), resulting in similar storage and handling considerations. DME is currently used as an aerosol propellant and has been considercd as a diesel substitute due to the reduced NOx, SOx and particulate emissions. DME is also being considered as a substitute for LPG fuels, which is used extensively in Asia as a fuel for heating and cooking, and naptha, which is used for power generation. The potential advantages of both methanol and DME include low reforming temperature, decreased fuel proccssor startup energy, environmentally benign, visible flame, high heating value, and ease of storage and transportation. In addition, DME has the added advantages of low toxicity and being non-corrosive. Consequently, DME may be an ideal candidate for the generation of hydrogen rich fuel cell feeds for both automotive and portable power applications. The steam reforming of DME has been demonstrated to occur through a pair of reactions in series, where the first reaction is DME hydration followed by MeOH steam reforming to produce a hydrogen rich stream.

  1. Syngas Production from CO2 Reforming and CO2-steam Reforming of Methane over Ni/Ce-SBA-15 Catalyst

    NASA Astrophysics Data System (ADS)

    Tan, J. S.; Danh, H. T.; Singh, S.; Truong, Q. D.; Setiabudi, H. D.; Vo, D.-V. N.

    2017-06-01

    This study compares the catalytic performance of mesoporous 10 Ni/Ce-SBA-15 catalyst for CO2 reforming and CO2-steam reforming of methane reactions in syngas production. The catalytic performance of 10 Ni/Ce-SBA-15 catalyst for CO2 reforming and CO2-steam reforming of methane was evaluated in a temperature-controlled tubular fixed-bed reactor at stoichiometric feed composition, 1023 K and atmospheric pressure for 12 h on-stream with gas hourly space velocity (GHSV) of 36 L gcat -1 h-1. The 10 Ni/Ce-SBA-15 catalyst possessed a high specific BET surface area and average pore volume of 595.04 m2 g-1. The XRD measurement revealed the presence of NiO phase with crystallite dimension of about 13.60 nm whilst H2-TPR result indicates that NiO phase was completely reduced to metallic Ni0 phase at temperature beyond 800 K and the reduction temperature relied on different degrees of metal-support interaction associated with the location and size of NiO particles. The catalytic reactivity was significantly enhanced with increasing H2O/CO2 feed ratio. Interestingly, the H2/CO ratio for CO2-steam reforming of methane varied between 1 and 3 indicated the occurrence of parallel reactions, i.e., CH4 steam reforming giving a H2/CO of 3 whilst reverse water-gas shift (RWGS) reaction consuming H2 to produce CO gaseous product.

  2. A Methanol Steam Reforming Micro Reactor for Proton Exchange Membrane Micro Fuel Cell System

    SciTech Connect

    Park, H G; Piggott, W T; Chung, J; Morse, J D; Havstad, M; Grigoropoulos, C P; Greif, R; Benett, W; Sopchak, D; Upadhye, R

    2003-07-28

    The heat, mass and momentum transfer from a fuel reforming packed bed to a surrounding silicon wafer has been simulated. Modeling showed quantitatively reasonable agreement with experimental data for fuel conversion efficiency, hydrogen production rate, outlet methanol mole fraction and outlet steam mole fraction. The variation in fuel conversion efficiency with the micro reformer thermal isolation can be used to optimize fuel-processing conditions for micro PEM fuel cells.

  3. A novel reforming method for hydrogen production from biomass steam gasification.

    PubMed

    Gao, Ningbo; Li, Aimin; Quan, Cui

    2009-09-01

    In this work, an experimental study of biomass gasification in different operation conditions has been carried out in an updraft gasifier combined with a porous ceramic reformer. The effects of gasifier temperature, steam to biomass ratio (S/B), and reforming temperature on the gas characteristic parameters were investigated with and without porous ceramic filled in reformer. The results indicated that considerable synergistics effects were observed as the porous ceramic was filled in reformer leading to an increase in the hydrogen production. With the increasing gasifier temperature varying from 800 to 950 degrees C, hydrogen yield increased from 49.97 to 79.91 g H(2)/kg biomass. Steam/biomass ratio of 2.05 seemed to be optimal in all steam-gasification runs. The effect of reforming temperature for water-soluble tar produced in porous ceramic reforming was also investigated, and it was found that the conversion ratio of total organic carbon (TOC) contents is between 71.08% and 75.74%.

  4. Comparative study of two theoretical models of methane and ethane steam reforming process

    NASA Astrophysics Data System (ADS)

    Brus, Grzegorz; Kaczmarczyk Marcin Tomiczek, Robert; Mozdzierz, Marcin

    2016-09-01

    From the chemical point of view the reforming process of heavy hydrocarbons such as Associated Petroleum Gas (APG) is very complex. One of the main issue is a set of undesired chemical reactions that causes deposition of solid carbon and consequently block catalytic property of a reactor. The experimental investigation is crucial to design APG reforming reactors. However, the experiment needs to be preceded by careful thermodynamical analysis to design safe operation conditions. In case of small number of reactants and reactions such as in case of steam reforming of pure methane, the problem can be solved by treating each equilibrium reaction constant as an element of the system of non-linear equations. The system of equations can be solved by Newton-Raphson method. However in case of large number of reactants and reaction, such as in case of APG reforming this method is inefficient. A large number of strongly non-linear equations leads often to converge problem. In this paper the authors suggest to use different approach called Parametric Equation Method. In this method a system of non-linear equations is replaced by a set of single non-linear equations solved separately. The methods were used to simulate steam reforming of methane-ethane rich fuel. The results of computations from both methods were juxtaposed and comparative study were conducted. Finally safe operation conditions for steam reforming of methane-ethane fuel were calculated and presented.

  5. Hydrogen generation from 2,2,4-trimethyl pentane reforming over molybdenum carbide at low steam-to-carbon ratios

    NASA Astrophysics Data System (ADS)

    Cheekatamarla, Praveen K.; Thomson, William J.

    Because of the need for an efficient and inexpensive reforming catalyst, the objective of this work is to determine the feasibility of employing Mo 2C catalyst for the steam reforming and oxy-steam reforming of the higher hydrocarbons typical of transportation fuels such as gasoline. It is shown that bulk Mo 2C catalysts can successfully reform 2,2,4-trimethyl pentane (isooctane) to generate H 2, CO and CO 2 at very low steam/carbon ratios, without coke formation, eliminating the need for pre-reforming. Maximum hydrogen generation was observed at a S/C ratio of 1.3 and 1000 °C during SR reactions and S/C of 0.71, O 2/C of 0.12 at 900 °C during oxidative steam reforming reactions.

  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. Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oil

    SciTech Connect

    Czernik, S.; Wang, D.; Chornet, E.

    1998-08-01

    Hydrogen is the prototype of the environmentally cleanest fuel of interest for power generation using fuel cells and for transportation. The thermochemical conversion of biomass to hydrogen can be carried out through two distinct strategies: (a) gasification followed by water-gas shift conversion, and (b) catalytic steam reforming of specific fractions derived from fast pyrolysis and aqueous/steam processes of biomass. This paper presents the latter route that begins with fast pyrolysis of biomass to produce bio-oil. This oil (as a whole or its selected fractions) can be converted to hydrogen via catalytic steam reforming followed by a water-gas shift conversion step. Such a process has been demonstrated at the bench scale using model compounds, poplar oil aqueous fraction, and the whole pyrolysis oil with commercial Ni-based steam reforming catalysts. Hydrogen yields as high as 85% have been obtained. Catalyst initial activity can be recovered through regeneration cycles by steam or CO{sub 2} gasification of carbonaceous deposits.

  9. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    SciTech Connect

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  10. Thermal analysis of cylindrical natural-gas steam reformer for 5 kW PEMFC

    NASA Astrophysics Data System (ADS)

    Jo, Taehyun; Han, Junhee; Koo, Bonchan; Lee, Dohyung

    2016-11-01

    The thermal characteristics of a natural-gas based cylindrical steam reformer coupled with a combustor are investigated for the use with a 5 kW polymer electrolyte membrane fuel cell. A reactor unit equipped with nickel-based catalysts was designed to activate the steam reforming reaction without the inclusion of high-temperature shift and low-temperature shift processes. Reactor temperature distribution and its overall thermal efficiency depend on various inlet conditions such as the equivalence ratio, the steam to carbon ratio (SCR), and the fuel distribution ratio (FDR) into the reactor and the combustor components. These experiments attempted to analyze the reformer's thermal and chemical properties through quantitative evaluation of product composition and heat exchange between the combustor and the reactor. FDR is critical factor in determining the overall performance as unbalanced fuel injection into the reactor and the combustor deteriorates overall thermal efficiency. Local temperature distribution also influences greatly on the fuel conversion rate and thermal efficiency. For the experiments, the operation conditions were set as SCR was in range of 2.5-4.0 and FDR was in 0.4-0.7 along with equivalence ratio of 0.9-1.1; optimum results were observed for FDR of 0.63 and SCR of 3.0 in the cylindrical steam reformer.

  11. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST COMPARISONS. (R826694C633)

    EPA Science Inventory

    Catalyst candidates for steam reforming chlorocarbons have been screened for activity using methyl chloride as a model reactant. At 500°C, a H2O/C ratio of about 10 and a GHSV of 254 000 h-1, catalysts comprising 0.5% loading of the metals ...

  12. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST COMPARISONS. (R822721C633)

    EPA Science Inventory

    Catalyst candidates for steam reforming chlorocarbons have been screened for activity using methyl chloride as a model reactant. At 500°C, a H2O/C ratio of about 10 and a GHSV of 254 000 h-1, catalysts comprising 0.5% loading of the metals o...

  13. FLUIDIZED BED STEAM REFORMING FOR TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    SciTech Connect

    HEWITT WM

    2011-04-08

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of fluidized bed steam reforming and its possible application to treat and immobilize Hanford low-activity waste.

  14. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST COMPARISONS. (R826694C633)

    EPA Science Inventory

    Catalyst candidates for steam reforming chlorocarbons have been screened for activity using methyl chloride as a model reactant. At 500°C, a H2O/C ratio of about 10 and a GHSV of 254 000 h-1, catalysts comprising 0.5% loading of the metals ...

  15. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST COMPARISONS. (R822721C633)

    EPA Science Inventory

    Catalyst candidates for steam reforming chlorocarbons have been screened for activity using methyl chloride as a model reactant. At 500°C, a H2O/C ratio of about 10 and a GHSV of 254 000 h-1, catalysts comprising 0.5% loading of the metals o...

  16. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: POLYCHLORINATED BIPHENYLS (PCBS). (R826694C633)

    EPA Science Inventory

    Experiments with commercial askarals (Aroclors 1221, 1248 and 1254) have confirmed the feasibility of catalytic steam reforming as a method for destroying polychlorinated biphenyls (PCBs). Rhodium, platinum and nickel supported on CATALYTIC STEAM REFORMING OF CHLOROCARBONS: TRICHLOROETHANE, TRICHLOROETHYLENE AND PERCHLOROETHYLENE. (R826694C633)

    EPA Science Inventory

    The effective destruction of trichloroethane, trichloroethylene and perchloroethylene by steam reforming with a commercial nickel catalyst has been demonstrated. Conversion levels of up to 0.99999 were attained in both laboratory and semi-pilot experiments, with the products c...

  17. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST DEACTIVATION. (R826694C633)

    EPA Science Inventory

    Deactivation of 0.5 wt.% Pt/small gamma, Greek-Al2O3 catalysts during trichloroethylene (TCE)–steam reforming was studied with experiments at 700°C, H

  18. CATALYTIC STEAM REFORMING OF CHLOROCARBONS: CATALYST DEACTIVATION. (R826694C633)

    EPA Science Inventory

    Deactivation of 0.5 wt.% Pt/small gamma, Greek-Al2O3 catalysts during trichloroethylene (TCE)–steam reforming was studied with experiments at 700°C, H

  19. On the origin of reactivity of steam reforming of ethylene glycol on supported Ni catalysts.

    PubMed

    Li, Shuirong; Zhang, Chengxi; Zhang, Peng; Wu, Gaowei; Ma, Xinbin; Gong, Jinlong

    2012-03-28

    This paper describes a strategy for producing hydrogen via steam reforming of ethylene glycol over supported nickel catalysts. Nickel plays a crucial role in conversion of ethylene glycol and production of hydrogen, while oxide supports affect product distribution of carbonaceous species. A plausible reaction pathway is proposed based on our results and the literature.

  1. On-board reforming of biodiesel and bioethanol for high temperature PEM fuel cells: Comparison of autothermal reforming and steam reforming

    NASA Astrophysics Data System (ADS)

    Martin, Stefan; Wörner, Antje

    2011-03-01

    In the 21st century biofuels will play an important role as alternative fuels in the transportation sector. In this paper different reforming options (steam reforming (SR) and autothermal reforming (ATR)) for the on-board conversion of bioethanol and biodiesel into a hydrogen-rich gas suitable for high temperature PEM (HTPEM) fuel cells are investigated using the simulation tool Aspen Plus. Special emphasis is placed on thermal heat integration. Methyl-oleate (C19H36O2) is chosen as reference substance for biodiesel. Bioethanol is represented by ethanol (C2H5OH). For the steam reforming concept with heat integration a maximum fuel processing efficiency of 75.6% (76.3%) is obtained for biodiesel (bioethanol) at S/C = 3. For the autothermal reforming concept with heat integration a maximum fuel processing efficiency of 74.1% (75.1%) is obtained for biodiesel (bioethanol) at S/C = 2 and λ = 0.36 (0.35). Taking into account the better dynamic behaviour and lower system complexity of the reforming concept based on ATR, autothermal reforming in combination with a water gas shift reactor is considered as the preferred option for on-board reforming of biodiesel and bioethanol. Based on the simulation results optimum operating conditions for a novel 5 kW biofuel processor are derived.

  2. Ceramic microreactors for on-site hydrogen production from high temperature steam reforming of propane.

    PubMed

    Christian, Michael Mitchell; Kenis, Paul J A

    2006-10-01

    The steam reforming of hydrocarbon fuels is a promising method for the production of hydrogen for portable electrical power sources. A suitable reactor for this application, however, must be compatible with temperatures above 800 degrees C to avoid coking of the catalytic structures during the reforming process. Here, ceramic microreactors comprising high surface area, tailored macroporous SiC porous monoliths coated with ruthenium (Ru) catalyst and integrated within high-density alumina reactor housings were used for the steam reforming of propane into hydrogen at temperatures between 800 and 1000 degrees C. We characterized these microreactors by studying C3H8 conversion, H2 selectivity, and product stream composition as a function of the total inlet flow rate, steam-to-carbon ratio (S/C), and temperature. As much as 18.2 sccm H2, or 3.3 x 104 sccm H2 per cm3 of monolith volume, was obtained from a 3.5 sccm entering stream of C3H8 at a S/C of 1.095 and temperatures greater than 900 degrees C. Operating at a S/C close to 1 reduces the energy required to heat excess steam to the reaction temperature and improves the overall thermal efficiency of the fuel processor. Kinetic analysis using a power law model showed reaction orders of 0.50 and -0.23 with respect to propane and steam, respectively, indicating that the rate limiting step in the steam reforming reaction is the dissociative adsorption of propane on the Ru catalyst. The performance of the microreactor was not affected after exposure to more than 15 thermal cycles at temperatures as high as 1000 degrees C, and no catalyst deactivation was observed after more than 120 h of continuous operation at 800 degrees C, making these ceramic microreactors promising for efficient on-site hydrogen production from hydrocarbons for use in polymer electrolyte membrane (PEM) fuel cells.

  3. Process and apparatus for the production of hydrogen by steam reforming of hydrocarbon

    DOEpatents

    Sircar, Shivaji; Hufton, Jeffrey Raymond; Nataraj, Shankar

    2000-01-01

    In the steam reforming of hydrocarbon, particularly methane, under elevated temperature and pressure to produce hydrogen, a feed of steam and hydrocarbon is fed into a first reaction volume containing essentially only reforming catalyst to partially reform the feed. The balance of the feed and the reaction products of carbon dioxide and hydrogen are then fed into a second reaction volume containing a mixture of catalyst and adsorbent which removes the carbon dioxide from the reaction zone as it is formed. The process is conducted in a cycle which includes these reactions followed by countercurrent depressurization and purge of the adsorbent to regenerate it and repressurization of the reaction volumes preparatory to repeating the reaction-sorption phase of the cycle.

  4. Towards H2-rich gas production from unmixed steam reforming of methane: Thermodynamic modeling

    NASA Astrophysics Data System (ADS)

    Lima da Silva, Aline; Müller, Iduvirges Lourdes

    2011-10-01

    In this work, the Gibbs energy minimization method is applied to investigate the unmixed steam reforming (USR) of methane to generate hydrogen for fuel cell application. The USR process is an advanced reforming technology that relies on the use of separate air and fuel/steam feeds to create a cyclic process. Under air flow (first half of the cycle), a bed of Ni-based material is oxidized, providing the heat necessary for the steam reforming that occurs subsequently during fuel/steam feed stage (second half of the cycle). In the presence of CaO sorbent, high purity hydrogen can be produced in a single reactor. In the first part of this work, it is demonstrated that thermodynamic predictions are consistent with experimental results from USR isothermal tests under fuel/steam feed. From this, it is also verified that the reacted NiO to CH4 (NiOreacted/CH4) molar ratio is a very important parameter that affects the product gas composition and decreases with time. At the end of fuel/steam flow, the reforming reaction is the most important chemical mechanism, with H2 production reaching ∼75 mol%. On the other hand, at the beginning of fuel/steam feed stage, NiO reduction reactions dominate the equilibrium system, resulting in high CO2 selectivity, negative steam conversion and low concentrations of H2. In the second part of this paper, the effect of NiOreacted/CH4 molar ratio on the product gas composition and enthalpy change during fuel flow is investigated at different temperatures for inlet H2O/CH4 molar ratios in the range of 1.2-4, considering the USR process operated with and without CaO sorbent. During fuel/steam feed stage, the energy demand increases as time passes, because endothermic reforming reaction becomes increasingly important as this stage nears its end. Thus, the duration of the second half of the cycle is limited by the conditions under which auto-thermal operation can be achieved. In absence of CaO, H2 at concentrations of approximately 73 mol% can

  5. Differences in the Nature of Active Sites for Methane Dry Reforming and Methane Steam Reforming over Nickel Aluminate Catalysts

    SciTech Connect

    Rogers, Jessica L.; Mangarella, Michael C.; D’Amico, Andrew D.; Gallagher, James R.; Dutzer, Michael R.; Stavitski, Eli; Miller, Jeffrey T.; Sievers, Carsten

    2016-07-20

    In this paper, the Pechini synthesis was used to prepare nickel aluminate catalysts with the compositions NiAl4O7, NiAl2O4, and Ni2Al2O5. The samples have been characterized by N2 physisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and X-ray absorption spectroscopy (XAS). Characterization results indicate unique structural properties and excellent regeneration potential of nickel aluminates. Prepared samples were tested when unreduced and reduced prior to reaction for methane dry reforming and methane steam reforming reactivity. NiAl2O4 in the reduced and unreduced state as well as NiAl4O7 in the reduced state are active and stable for methane dry reforming due to the presence of 4-fold coordinated oxidized nickel. The limited amount of metallic nickel in these samples minimizes carbon deposition. Finally, on the other hand, the presence of metallic nickel is required for methane steam reforming. Ni2Al2O5 in the reduced and unreduced states and NiAl2O4 in the reduced state are found to be active for methane steam reforming due to the presence of sufficiently small nickel nanoparticles that catalyze the reaction without accumulating carbonaceous deposits.

  6. Differences in the Nature of Active Sites for Methane Dry Reforming and Methane Steam Reforming over Nickel Aluminate Catalysts

    SciTech Connect

    Rogers, Jessica L.; Mangarella, Michael C.; D’Amico, Andrew D.; Gallagher, James R.; Dutzer, Michael R.; Stavitski, Eli; Miller, Jeffrey T.; Sievers, Carsten

    2016-07-20

    In this paper, the Pechini synthesis was used to prepare nickel aluminate catalysts with the compositions NiAl4O7, NiAl2O4, and Ni2Al2O5. The samples have been characterized by N2 physisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and X-ray absorption spectroscopy (XAS). Characterization results indicate unique structural properties and excellent regeneration potential of nickel aluminates. Prepared samples were tested when unreduced and reduced prior to reaction for methane dry reforming and methane steam reforming reactivity. NiAl2O4 in the reduced and unreduced state as well as NiAl4O7 in the reduced state are active and stable for methane dry reforming due to the presence of 4-fold coordinated oxidized nickel. The limited amount of metallic nickel in these samples minimizes carbon deposition. Finally, on the other hand, the presence of metallic nickel is required for methane steam reforming. Ni2Al2O5 in the reduced and unreduced states and NiAl2O4 in the reduced state are found to be active for methane steam reforming due to the presence of sufficiently small nickel nanoparticles that catalyze the reaction without accumulating carbonaceous deposits.

  7. The Engine of Reform Gathers Steam: Kentucky Starts from Scratch.

    ERIC Educational Resources Information Center

    Harrington-Lueker, Donna

    1990-01-01

    Charged with overhauling the state's educational system, the Kentucky General Assembly last spring devised a landmark reform scheme that mandates site-based management, abolishes the existing state board of education, and institutes an ambitious system of rewards and sanctions aimed at holding schools accountable for student performance. A sidebar…

  8. The Engine of Reform Gathers Steam: Kentucky Starts from Scratch.

    ERIC Educational Resources Information Center

    Harrington-Lueker, Donna

    1990-01-01

    Charged with overhauling the state's educational system, the Kentucky General Assembly last spring devised a landmark reform scheme that mandates site-based management, abolishes the existing state board of education, and institutes an ambitious system of rewards and sanctions aimed at holding schools accountable for student performance. A sidebar…

  9. Evaluation of the feasibility of ethanol steam reforming in a molten carbonate fuel cell

    SciTech Connect

    Cavallaro, S.; Passalacqua, E.; Maggio, G.; Patti, A.; Freni, S.

    1996-12-31

    The molten carbonate fuel cells (MCFCs) utilizing traditional fuels represent a suitable technological progress in comparison with pure hydrogen-fed MCFCs. The more investigated fuel for such an application is the methane, which has the advantages of low cost and large availability; besides, several authors demonstrated the feasibility of a methane based MCFC. In particular, the methane steam-reforming allows the conversion of the fuel in hydrogen also inside the cell (internal reforming configuration), utilizing the excess heat to compensate the reaction endothermicity. In this case, however, both the catalyst and the cell materials are subjected to thermal stresses due to the cold spots arising near to the reaction sites MCFC. An alternative, in accordance with the recent proposals of other authors, may be to produce hydrogen from methane by the partial oxidation reaction, rather than by steam reforming. This reaction is exothermic ({Delta}H{degrees}=-19.1 kJ/mol H{sub 2}) and it needs to verify the possibility to obtain an acceptable distribution of the temperature inside the cell. The alcohols and, in particular, methanol shows the gas reformed compositions as a function of the steam/ethanol molar ratio, ranging from 1.0 to 3.5. The hydrogen production enhances with this ratio, but it presents a maximum at S/EtOH of about 2.0. Otherwise, the increase of S/EtOH depresses the production of CO and CH{sub 4}, and ethanol may be a further solution for the hydrogen production inside a MCFC. In this case, also, the reaction in cell is less endothermic compared with the methane steam reforming with the additional advantage of a liquid fuel more easily storable and transportable. Aim of the present work is to perform a comparative evaluation of the different solutions, with particular reference to the use of ethanol.

  10. Internal combustion engine with thermochemical recuperation fed by ethanol steam reforming products - feasibility study

    NASA Astrophysics Data System (ADS)

    Cesana, O.; Gutman, M.; Shapiro, M.; Tartakovsky, L.

    2016-08-01

    This research analyses the performance of a spark ignition engine fueled by ethanol steam reforming products. The basic concept involves the use of the internal combustion engine's (ICE) waste heat to promote onboard reforming of ethanol. The reformer and the engine performance were simulated and analyzed using GT-Suite, Chem CAD and Matlab software. The engine performance with different compositions of ethanol reforming products was analyzed, in order to find the optimal working conditions of the ICE - reformer system. The analysis performed demonstrated the capability to sustain the endothermic reactions in the reformer and to reform the liquid ethanol to hydrogen-rich gaseous fuel using the heat of the exhaust gases. However, the required reformer's size is quite large: 39 x 89 x 73 cm, which makes a feasibility of its mounting on board a vehicle questionable. A comparison with ICE fed by gasoline or liquid ethanol doesn't show a potential of efficiency improvement, but can be considered as a tool of additional emissions reduction.

  11. Theoretical and experimental study of methane steam reforming reactions over nickel catalyst

    NASA Astrophysics Data System (ADS)

    Pistonesi, C.; Juan, A.; Irigoyen, B.; Amadeo, N.

    2007-02-01

    In this work we perform DFT theoretical calculations of methane and steam interactions on Ni(1 1 1) surface. The calculations allow us to improve our understanding of the competition between these reactants by catalytic sites in methane steam reforming (MSR) process. For this purpose we compare theoretical results with kinetic measurements of MSR on a Ni(II)-Al(III) catalyst prepared from lamellar double hydroxides as precursor. This comparison shows that, for low H 2O/CH 4 ratios methane and water intermediate species adsorb on different catalytic sites. While CHO species adsorbs on top of Ni atom, OH one occupies preferentially a tri-coordinate surface site. On the other hand, for high H 2O/CH 4 ratios a competency between these species by Ni sites would establish, diminishing methane conversion. In addition competition between methane and steam for Ni sites would lead to a decrease in CO production. Nevertheless, intermediate species adsorbed on different active sites would produce CO 2, whatever the steam/methane ratio. Thus, it would be optimum steam concentration in hydrocarbon feed and active sites distribution on catalyst surface, which could maximize H 2 production and minimize CO selectivity. The theoretical findings agree with kinetic measurements, which show that maximum methane conversion depends on steam partial pressure in the feed; whereas always, selectivity to CO 2 increases and to CO diminishes.

  12. Biomass-to-hydrogen via fast pyrolysis and catalytic steam reforming

    SciTech Connect

    Chornet, E.; Wang, D.; Czernik, S.

    1996-10-01

    Pyrolysis of lignocellulosic biomass and reforming the pyroligneous oils is being studied as a strategy for producing hydrogen. Novel technologies for the rapid pyrolysis of biomass have been developed in the past decade. They provide compact and efficient systems to transform biomass into vapors that are condensed to oils, with yields as high as 75-80 wt.% of the anhydrous biomass. This {open_quotes}bio-oil{close_quotes} is a mixture of aldehydes, alcohols, acids, oligomers from the constitutive carbohydrates and lignin, and some water derived from the dehydration reactions. Hydrogen can be produced by reforming the bio-oil or its fractions with steam. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. The reforming facility can be designed to handle alternate feedstocks, such as natural gas and naphtha, if necessary. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. Existing catalytic data on the reforming of oxygenates have been studied to guide catalyst selection. Tests performed on a microreactor interfaced with a molecular beam mass spectrometer showed that, by proper selection of the process variables: temperature, steam-to-carbon ratio, gas hourly space velocity, and contact time, almost total conversion of carbon in the feed to CO and CO{sub 2} could be obtained. These tests also provided possible reaction mechanisms where thermal cracking competes with catalytic processes. Bench-scale, fixed bed reactor tests demonstrated high hydrogen yields from model compounds and carbohydrate-derived pyrolysis oil fractions. Reforming bio-oil or its fractions required proper dispersion of the liquid to avoid vapor-phase carbonization of the feed in the inlet to the reactor. A special spraying nozzle injector was designed and successfully tested with an aqueous fraction of bio-oil.

  13. Hydrogen production from steam and autothermal reforming of LPG over high surface area ceria

    NASA Astrophysics Data System (ADS)

    Laosiripojana, N.; Assabumrungrat, S.

    Steam and autothermal reforming reactions of LPG (propane/butane) over high surface area CeO 2 (CeO 2 (HSA)) synthesized by a surfactant-assisted approach were studied under solid oxide fuel cell (SOFC) operating conditions. The catalyst provides significantly higher reforming reactivity and excellent resistance toward carbon deposition compared to the conventional Ni/Al 2O 3. These benefits of CeO 2 are due to the redox property of this material. During the reforming process, the gas-solid reactions between the hydrocarbons present in the system (i.e. C 4H 10, C 3H 8, C 2H 6, C 2H 4, and CH 4) and the lattice oxygen (O O x) take place on the ceria surface. The reactions of these adsorbed surface hydrocarbons with the lattice oxygen (C nH m + O O x → nCO + m/2(H 2) + V O rad rad + 2e‧) can produce synthesis gas (CO and H 2) and also prevent the formation of carbon species from hydrocarbons decomposition reactions (C nH m ⇔ nC + 2 mH 2). Afterwards, the lattice oxygen (O O x) can be regenerated by reaction with the steam present in the system (H 2O + V O rad rad + 2e‧ ⇔ O O x + H 2). It should be noted that V O rad rad denotes as an oxygen vacancy with an effective charge 2 +. At 900 °C, the main products from steam reforming over CeO 2 (HSA) were H 2, CO, CO 2, and CH 4 with a small amount of C 2H 4. The addition of oxygen in autothermal reforming was found to reduce the degree of carbon deposition and improve product selectivities by completely eliminating C 2H 4 formation. The major consideration in the autothermal reforming operation is the O 2/LPG (O/C molar ratio) ratio, as the presence of a too high oxygen concentration could oxidize the hydrogen and carbon monoxide produced from the steam reforming. A suitable O/C molar ratio for autothermal reforming of CeO 2 (HSA) was 0.6.

  14. Chapter 25 First-Principles Investigation of Dimethyl Ether Steam Reforming

    NASA Astrophysics Data System (ADS)

    Fukushima, Kimichika

    This paper reports the investigation of dimethyl ether (DME) steam reforming and related processes. The study uses the X[alpha] molecular orbital theory, which has been successfully applied to analyze material properties. It was found that, when H2O approaches Al on a surface of Si oxides (and pure Al2O3), charge transfer between H2O and the surface destabilizes the H2O. Approach of the destabilized H to a CH3OCH3 molecule then produces CH3OH. Finally, injection of CO2, by-produced in the reforming, to coal seam was shown to increase the CH4 production by substitution.

  15. Effect of ZnO facet on ethanol steam reforming over Co/ZnO

    SciTech Connect

    Yu, Ning; Zhang, He; Davidson, Stephen D.; Sun, Junming; Wang, Yong

    2016-01-01

    The effects of ZnO facets on ethanol steam reforming (ESR) were investigated over Co/ZnO catalysts synthesized using ZnO with different fractions of (10-10) non-polar facet. Co supported on ZnO with a higher fraction of (10-10) non-polar facet shows higher C-C cleavage activity and higher selectivity to CO2 (lower selectivity to CO) compared with Co supported on ZnO with less (10-10) non-polar facet exposed. The improved ethanol steam reforming performances are attributed to the high fraction of metallic Co stabilized by the ZnO (10-10) non-polar facet, which enhanced C-C cleavage and water-gas-shift (WGS) activities.

  16. Glycerol Steam Reforming Over Ni-Fe-Ce/Al2O3 Catalyst: Effect of Cerium.

    PubMed

    Go, Gwang-Sub; Go, Yoo-Jin; Lee, Hong-Joo; Moon, Dong-Ju; Park, Nam-Cook; Kim, Young-Chul

    2016-02-01

    In this work, hydrogen production from glycerol by steam reforming was studied using Ni-metal oxide catalysts. Ni-based catalyst becomes deactivated during steam reforming reactions because of coke deposits and sintering. Therefore, the aim of this study was to reduce carbon deposits and sintering on the catalyst surface by adding a promoter. Ni-metal oxide catalysts supported on Al2O3 were prepared via impregnation method, and the calcined catalyst was reduced under H2 flow for 2 h prior to the reaction. The characteristics of the catalysts were examined by XRD, TPR, TGA, and SEM. The Ni-Fe-Ce/Al2O3 catalyst, which contained less than 2 wt% Ce, showed the highest hydrogen selectivity and glycerol conversion. Further analysis of the catalysts revealed that the Ni-Fe-Ce/Al2O3 catalyst required a lower reduction temperature and produced minimum carbon deposit.

  17. A Comparative Study between Co and Rh for Steam Reforming of Ethanol

    SciTech Connect

    Karim, Ayman M.; Su, Yu; Sun, Junming; Yang, Cheng; Strohm, James J.; King, David L.; Wang, Yong

    2010-06-01

    Rh and Co-based catalyst performance was compared for steam reforming of ethanol under conditions suitable for industrial hydrogen production. The reaction conditions were varied to elucidate the differences in reaction pathways on both catalysts. On Co/ZnO, CH4 is a secondary product formed through the methanation reaction, while it is produced directly by ethanol decomposition on Rh. The difference in the reaction mechanism is shown to favor Co-based catalysts for selective hydrogen production under elevated system pressures (up to 15 bar) of industrial importance. The carbon deposition rate was also studied, and we show that Co is more prone to coking and catalyst failure. However, the Co/ZnO catalyst can be regenerated, by mild oxidation, despite the high carbon deposition rate. We conclude that Co/ZnO is a more suitable catalyst system for steam reforming of ethanol due to the low methane selectivity, low cost and possibility of regeneration with mild oxidation.

  18. Development and life evaluation of a steam reforming process for PAFC

    SciTech Connect

    Nagase, S.; Takami, S.; Masuda, M.

    1996-12-31

    This paper reports a life evaluation method for a carbon monoxide (CO) shift process in the steam reforming process for PAFC. A CO shift reactor simulation was developed to evaluate the whole performance of the CO shift process. The calculation results of the simulation almost coincide with the experimental data obtained from a demonstration plant. By evaluating and grasping the sintering trend of the catalyst, and by simulation calculation of the reactor, it became possible to evaluate the performance at targeted operation hours.

  19. Hydrogen production from glucose and sorbitol by sorption-enhanced steam reforming: challenges and promises.

    PubMed

    He, Li; Chen, De

    2012-03-12

    Concerning energy and environmental sustainability, it is appealing to produce hydrogen from sugars or sugar alcohols that are readily obtained from the hydrolysis of cellulosic biomass. Nevertheless, the conversion of such compounds for hydrogen production poses great technical challenges. In this paper, we report that hydrogen purity and yield can be significantly improved by integrating in situ CO(2) capture into the steam reforming reaction of the model compounds-glucose and sorbitol. The experimental assessment was conducted at a steam-to-carbon ratio of 1.8 for sorbitol and 6 for glucose from 450-625 °C. As predicted by thermodynamic analysis, combining CO(2) capture and reforming reactions at favorable operating conditions yielded very high purity hydrogen, for instance, 98.8 mol % from sorbitol and 99.9 mol % from glucose. However, there are trade-offs between hydrogen purity and yield in practice. The lower operating temperatures in the examined range helped to increase the hydrogen purity and reduce the CO content in the gas product, whereas a high hydrogen yield was more likely to be obtained at higher temperatures. Coupling CO(2) capture lowered the risk of coke formation during the steam reforming of glucose. Coke accumulated in the reactor for the sorption-enhanced steam reforming of glucose was mostly from the slow pyrolysis of glucose before it came into contact with the catalyst-acceptor bed. This problem may be solved by improving heat transfer or reconstructing the reactor, for instance, by using a fluidized-bed reactor.

  20. Hydrogen production by coupled catalytic partial oxidation and steam methane reforming at elevated pressure and temperature

    NASA Astrophysics Data System (ADS)

    Chen, Luwei; Hong, Qi; Lin, Jianyi; Dautzenberg, F. M.

    Hydrogen production by coupled catalytic partial oxidation (CPO) and steam methane reforming of methane (OSMR) at industrial conditions (high temperatures and pressures) have been studied over supported 1 wt.% NiB catalysts. Mixture of air/CH 4/H 2O was applied as the feed. The effects of O 2:CH 4 ratio, H 2O:CH 4 ratio and the gas hourly space velocity (GHSV) on oxy-steam reforming (OSRM) were also studied. Results indicate that CH 4 conversion increases significantly with increasing O 2:CH 4 or H 2O:CH 4 ratio. However, the hydrogen mole fraction goes through a maximum, depending on reaction conditions, e.g., pressure, temperature and the feed gases ratios. Carbon deposition on the catalysts has been greatly decreased after steam addition. The supported 1 wt.% NiB catalysts exhibit high stability with 85% methane conversion at 15 bar and 800 °C during 70 h time-on-stream reaction (CH 4:O 2:H 2O:N 2 = 1:0.5:1:1.887). The thermal efficiency was increased from 35.8% by CPO (without steam) to 55.6%. The presented data would be useful references for further design of enlarged scale hydrogen production system.

  1. Density functional theory study of acetic acid steam reforming on Ni(111)

    NASA Astrophysics Data System (ADS)

    Ran, Yan-Xiong; Du, Zhen-Yi; Guo, Yun-Peng; Feng, Jie; Li, Wen-Ying

    2017-04-01

    Catalytic steam reforming of bio-oil is a promising process to convert biomass into hydrogen. To shed light on this process, acetic acid is selected as the model compound of the oxygenates in bio-oil, and density functional theory is applied to investigate the mechanism of acetic acid steam reforming on the Ni(111) surface. The most favorable pathway of this process on the Ni(111) surface is suggested as CH3COOH* → CH3COO* → CH3CO* → CH2CO* → CH2* + CO* → CH* → CHOH* → CHO* → CO*, followed by the water gas shift reaction to produce CO2 and H2. CH* species are identified as the major carbon deposition precursor, and the water gas shift reaction is the rate-determining step during the whole acetic acid steam reforming process, as CO* + OH* → cis-COOH* is kinetically restricted with the highest barrier of 1.85 eV. Furthermore, the formation pathways and initial dissociation of important intermediates acetone and acetaldehyde are also investigated.

  2. A novel DME steam-reforming catalyst designed with fact database on-demand

    NASA Astrophysics Data System (ADS)

    Yamada, Yusuke; Mathew, Thomas; Ueda, Atsushi; Shioyama, Hiroshi; Kobayashi, Tetsuhiko

    2006-01-01

    Novel catalysts for dimethyl ether (DME) steam reforming (SR) were designed based on catalysis database on-demand. A catalyst library consisting of precious metals loaded on various metal oxides was tested for DME SR and its elemental reactions of DME hydrolysis and MeOH SR. Platinum loaded on alumina, Pt/Al 2O 3, shows high activity for DME SR as reported previously. The drawback of the catalyst was also confirmed; the formation of methane leading to the reduction of hydrogen formation. From the fact database for DME hydrolysis and MeOH SR built up with high-throughput experimentation tools, the high activity of Pt/Al 2O 3 for DME SR is owing to its high activity on DME hydrolysis because its activity on MeOH steam reforming is not remarkable. Based on these facts, novel catalysts were designed and achieved by physical mixing of Pt/Al 2O 3 which reveals high activity on DME hydrolysis with an active catalyst on MeOH steam reforming. By mixing of Pt/Al 2O 3 with Pd/Al 2O 3, methane formation was suppressed without loss of hydrogen production activity.

  3. BENCH-SCALE STEAM REFORMING OF ACTUAL TANK 48H WASTE

    SciTech Connect

    Burket, P; Gene Daniel, G; Charles Nash, C; Carol Jantzen, C; Michael Williams, M

    2008-09-25

    Fluidized Bed Steam Reforming (FBSR) has been demonstrated to be a viable technology to remove >99% of the organics from Tank 48H simulant, to remove >99% of the nitrate/nitrite from Tank 48H simulant, and to form a solid product that is primarily carbonate based. The technology was demonstrated in October of 2006 in the Engineering Scale Test Demonstration Fluidized Bed Steam Reformer1 (ESTD FBSR) at the Hazen Research Inc. (HRI) facility in Golden, CO. The purpose of the Bench-scale Steam Reformer (BSR) testing was to demonstrate that the same reactions occur and the same product is formed when steam reforming actual radioactive Tank 48H waste. The approach used in the current study was to test the BSR with the same Tank 48H simulant and same Erwin coal as was used at the ESTD FBSR under the same operating conditions. This comparison would allow verification that the same chemical reactions occur in both the BSR and ESTD FBSR. Then, actual radioactive Tank 48H material would be steam reformed in the BSR to verify that the actual tank 48H sample reacts the same way chemically as the simulant Tank 48H material. The conclusions from the BSR study and comparison to the ESTD FBSR are the following: (1) A Bench-scale Steam Reforming (BSR) unit was successfully designed and built that: (a) Emulated the chemistry of the ESTD FBSR Denitration Mineralization Reformer (DMR) and Carbon Reduction Reformer (CRR) known collectively as the dual reformer flowsheet. (b) Measured and controlled the off-gas stream. (c) Processed real (radioactive) Tank 48H waste. (d) Met the standards and specifications for radiological testing in the Savannah River National Laboratory (SRNL) Shielded Cells Facility (SCF). (2) Three runs with radioactive Tank 48H material were performed. (3) The Tetraphenylborate (TPB) was destroyed to > 99% for all radioactive Bench-scale tests. (4) The feed nitrate/nitrite was destroyed to >99% for all radioactive BSR tests the same as the ESTD FBSR. (5) The

  4. Enhanced catalytic behavior of Ni alloys in steam methane reforming

    NASA Astrophysics Data System (ADS)

    Yoon, Yeongpil; Kim, Hanmi; Lee, Jaichan

    2017-08-01

    The dissociation process of methane on Ni and Ni alloys are investigated by density functional theory (DFT) in terms of catalytic efficiency and carbon deposition. Examining the dissociation to CH3, CH2, CH, C, and H is not sufficient to properly predict the catalytic efficiency and carbon deposition, and further investigation of the CO gas-evolving reaction is required to completely understand methane dissociation in steam. The location of alloying element in Ni alloy needed be addressed from the results of ab-inito molecular dynamics (MD). The reaction pathway of methane dissociation associated with CO gas evolution is traced by performing first-principles calculations of the adsorption and activation energies of each dissociation step. During the dissociation process, two alternative reaction steps producing adsorbed C and H or adsorbed CO are critically important in determining coking inhibition as well as H2 gas evolution (i.e., the catalytic efficiency). The theoretical calculations presented here suggest that alloying Ni with Ru is an effective way to reduce carbon deposition and enhance the catalytic efficiency of H2 fueling in solid oxide fuel cells (SOFCs).

  5. Metallic phases of cobalt-based catalysts in ethanol steam reforming: The effect of cerium oxide

    SciTech Connect

    Lin, Sean S.-Y.; Kim, Do Heui; Ha, Su Y.

    2009-02-28

    The catalytic activity of cobalt in the production of hydrogen via ethanol steam reforming has been investigated in its relation to the crystalline structure of metallic cobalt. At a reaction temperature of 350 8C, the specific hydrogen production rates show that hexagonal close-packed (hcp) cobalt possesses higher activity than face-centered cubic (fcc) cobalt. However, at typical reaction temperatures (400– 500 8C) for ethanol steam reforming, hcp cobalt is transformed to less active fcc cobalt, as confirmed by in situ X-ray diffractometry (XRD). The addition of CeO2 promoter (10 wt.%) stabilizes the hcp cobalt structure at reforming temperatures up to 600 8C. Moreover, during the pre-reduction process, CeO2 promoter prevents sintering during the transformation of Co3O4 to hcp cobalt. Both reforming experiments and in situ diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) showed that the surface reactions were modified by CeO2 promoter on 10% Ce–Co (hcp) to give a lower CO selectivity and a higher H2 yield as compared with the unpromoted hcp Co.

  6. Approaching sustainable H2 production: sorption enhanced steam reforming of ethanol.

    PubMed

    He, Li; Berntsen, Helene; Chen, De

    2010-03-25

    Sorption enhanced steam reforming of ethanol (SESRE), featured by yielding high purity of H(2) from one single reaction unit, is a new reaction process with a great potential for realizing sustainable H(2) production. The potential of such process with a CaO-based acceptor has been assessed by thermodynamic analysis and experimental demonstration. As predicted, ethanol can be reformed at relatively low temperatures (500-600 degrees C), still yielding high-quality H(2). Another major advantage of coupling CO(2) capture to the reforming process is predicted to be low risk in carbon formation. The SESRE reaction was carried out over a mixture of hydrotalcite-like material derived Co-Ni catalysts (Co-Ni/HTls) and calcined dolomite with a steam to carbon (S/C) ratio of 3 and temperatures ranging from 500 to 650 degrees C. The chosen reaction system was able to yield H(2) with purity fairly close to the theoretical prediction. Particularly, the best result was obtained over 40Ni and 20Co-20Ni/HTls at 550 degrees C, where the product gas had composition of more than 99 mol % H(2), ca. 0.4 mol % CH(4), 0.1 mol % CO, and 0.2 mol % CO(2). Special emphasis was put on the effect of steam on the stability of the CO(2) acceptor during the SESRE reaction. Hydration of CaO in the acceptor did not cause appreciable induction period, even at the low operating temperatures. However, different from a test under dry atmosphere (CO(2)/argon), the acceptor showed rapid deactivation in a multicycle operation of SESRE. A similar deactivation tend was given by a comparative test in a steam/CO(2)/Ar atmosphere.

  7. INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER

    SciTech Connect

    Kevin Whitty

    2003-12-01

    The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

  8. Steam reforming of liquid hydrocarbons over a nickel-alumina spinel catalyst

    NASA Astrophysics Data System (ADS)

    Fauteux-Lefebvre, Clémence; Abatzoglou, Nicolas; Blanchard, Jasmin; Gitzhofer, François

    Interest in steam reforming of liquid hydrocarbons is growing due to the necessity of developing reliable alternatives for their use in fuel cells. In particular, solid oxide fuel cells, which can operate with mixtures of H 2 and CO, are excellent candidates for being fed with liquid fuels coming from both fossil and renewable sources. Fossil-derived, synthetic diesel is an interesting option. In this work, an Al 2O 3-ZrO 2-supported nickel-alumina spinel was tested in a lab-scale isothermal packed-bed reactor as a catalyst of steam reforming of propane, hexadecane and tetralin as surrogates of constitutive families of all commercially available diesel fuels. The results show that the reaction reaches equilibrium at reaction severities lower than those reported in the literature. When operated at steam excess of 250%, carbon formation is not higher than expected by theoretical thermodynamic equilibrium calculations, and no significant catalyst deactivation is observed over the test durations. Scanning electron microscopy of the fresh and used catalyst surfaces shows no significant quantities of carbon.

  9. The role of surface reactions on the active and selective catalyst design for bioethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Benito, M.; Padilla, R.; Serrano-Lotina, A.; Rodríguez, L.; Brey, J. J.; Daza, L.

    In order to study the role of surface reactions involved in bioethanol steam reforming mechanism, a very active and selective catalyst for hydrogen production was analysed. The highest activity was obtained at 700 °C, temperature at which the catalyst achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. It also exhibited a very high hydrogen production efficiency, higher than 4.5 mol H 2 per mol of EtOH fed. The catalyst was operated at a steam to carbon ratio (S/C) of 4.8, at 700 °C and atmospheric pressure. No by-products, such as ethylene or acetaldehyde were observed. In order to consider a further application in an ethanol processor, a long-term stability test was performed under the conditions previously reported. After 750 h, the catalyst still exhibited a high stability and selectivity to hydrogen production. Based on the intermediate products detected by temperature programmed desorption and reaction (TPD and TPR) experiments, a reaction pathway was proposed. Firstly, the adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Secondly, the adsorbed acetaldehyde is transformed into acetone via acetic acid formation. Finally, acetone is reformed to produce hydrogen and carbon dioxide, which were the final reaction products. The promotion of such reaction sequence is the key to develop an active, selective and stable catalyst, which is the technical barrier for hydrogen production by ethanol reforming.

  10. Plasma steam reforming of E85 for hydrogen rich gas production

    NASA Astrophysics Data System (ADS)

    Zhu, Xinli; Hoang, Trung; Lobban, Lance L.; Mallinson, Richard G.

    2011-07-01

    E85 (85 vol% ethanol and 15 vol% gasoline) is a partly renewable fuel that is increasing in supply availability. Hydrogen production from E85 for fuel cell or internal combustion engine applications is a potential method for reducing CO2 emissions. Steam reforming of E85 using a nonthermal plasma (pulse corona discharge) reactor has been exploited at low temperature (200-300 °C) without external heating, diluent gas, oxidant or catalyst in this work. Several operational parameters, including the discharge current, E85 concentration and feed flow rate, have been investigated. The results show that hydrogen rich gases (63-67% H2 and 22-29% CO, with small amounts of CO2, C2 hydrocarbons and CH4) can be produced by this method. A comparison with ethanol reforming and gasoline reforming under identical conditions has also been made and the behaviour of E85 reforming is found to be close to that of ethanol reforming with slightly higher C2 hydrocarbons yields.

  11. Structure and Reactivity Investigations on Supported Bimetallic Au-Ni Catalysts Used for Hydrocarbon Steam Reforming

    SciTech Connect

    Chin, Ya-Huei; King, David L.; Roh, Hyun-Seog; Wang, Yong; Heald, S.

    2006-12-10

    The addition of small quantities of gold to the surface of supported nickel catalysts has been described as a means to retard carbon formation during hydrocarbon steam reforming. Calculations by others have indicated that gold locates at the most catalytically active (step and edge) sites that also serve as nucleation sites for carbon formation. In this paper we describe experiments to characterize the Ni-Au interactions on bimetallic Au-Ni/MgAl2O4 catalysts at various Ni and Au loadings. The catalyst structure was investigated using EXAFS/XANES spectroscopy and adsorption-desorption measurements with H2 and N2O. Evidence for surface alloy formation is provided in the Ni K and Au LIII edge EXAFS measurements of Au-promoted 8.8%Ni/MgAl2O4, especially at Au loadings ?0.2 wt.%. At higher Au concentrations, there is evidence for a combination of alloy and segregated Au species. H2 chemisorption and N2O temperature programmed desorption (TPD) measurements showed a significant decrease in total surface sites, or surface site reactivity, on Au modified Ni/MgAl2O4 catalyst. The XANES structure is consistent with perturbation of the electronic structure of both the Ni and Au atoms as a result of alloy formation. TGA studies with steam/n-butane feed confirmed the ability of Au to retard coke deposition under low S/C reforming conditions, although carbon formation was not fully suppressed. When testing for methane steam reforming, a lower initial activity and deactivation rate resulted from Au promotion of the Ni catalyst. However, both catalysts showed a declining activity with time. The lack of a direct correlation between the surface characterization results and catalytic activity is most likely a result of decreasing effectiveness of the surface alloy with increasing temperature.

  12. Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer

    SciTech Connect

    Kevin Whitty

    2007-06-30

    University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

  13. Metal catalysts for steam reforming of tar derived from the gasification of lignocellulosic biomass.

    PubMed

    Li, Dalin; Tamura, Masazumi; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-02-01

    Biomass gasification is one of the most important technologies for the conversion of biomass to electricity, fuels, and chemicals. The main obstacle preventing the commercial application of this technology is the presence of tar in the product gas. Catalytic reforming of tar appears a promising approach to remove tar and supported metal catalysts are among the most effective catalysts. Nevertheless, improvement of catalytic performances including activity, stability, resistance to coke deposition and aggregation of metal particles, as well as catalyst regenerability is greatly needed. This review focuses on the design and catalysis of supported metal catalysts for the removal of tar in the gasification of biomass. The recent development of metal catalysts including Rh, Ni, Co, and their alloys for steam reforming of biomass tar and tar model compounds is introduced. The role of metal species, support materials, promoters, and their interfaces is described.

  14. STEAM REFORMING TECHNOLOGY DEMONSTRATION FOR THE DESTRUCTION OF ORGANICS ON ACTUAL DOE SAVANNAH RIVER SITE TANK 48H WASTE 9138

    SciTech Connect

    Burket, P

    2009-02-24

    This paper describes the design of the Bench-scale Steam Reformer (BSR); a processing unit for demonstrating steam reforming technology on actual radioactive waste [1]. It describes the operating conditions of the unit used for processing a sample of Savannah River Site (SRS) Tank 48H waste. Finally, it compares the results from processing the actual waste in the BSR to processing simulant waste in the BSR to processing simulant waste in a large pilot scale unit, the Fluidized Bed Steam Reformer (FBSR), operated at Hazen Research Inc. in Golden, CO. The purpose of this work was to prove that the actual waste reacted in the same manner as the simulant waste in order to validate the work performed in the pilot scale unit which could only use simulant waste.

  15. Catalytic steam reforming of methane, methanol, and ethanol over Ni/YSZ: The possible use of these fuels in internal reforming SOFC

    NASA Astrophysics Data System (ADS)

    Laosiripojana, N.; Assabumrungrat, S.

    This study investigated the possible use of methane, methanol, and ethanol with steam as a direct feed to Ni/YSZ anode of a direct internal reforming Solid Oxide Fuel Cell (DIR-SOFC). It was found that methane with appropriate steam content can be directly fed to Ni/YSZ anode without the problem of carbon formation, while methanol can also be introduced at a temperature as high as 1000 °C. In contrast, ethanol cannot be used as the direct fuel for DIR-SOFC operation even at high steam content and high operating temperature due to the easy degradation of Ni/YSZ by carbon deposition. From the steam reforming of ethanol over Ni/YSZ, significant amounts of ethane and ethylene were present in the product gas due to the incomplete reforming of ethanol. These formations are the major reason for the high rate of carbon formation as these components act as very strong promoters for carbon formation. It was further observed that ethanol with steam can be used for an indirect internal reforming operation (IIR-SOFC) instead. When ethanol was first reformed by Ni/Ce-ZrO 2 at the temperature above 850 °C, the product gas can be fed to Ni/YSZ without the problem of carbon formation. Finally, it was also proposed from the present work that methanol with steam can be efficiently fed to Ni/YSZ anode (as DIR operation) at the temperature between 900 and 975 °C without the problem of carbon formation when SOFC system has sufficient space volume at the entrance of the anode chamber, where methanol can homogeneously convert to CH 4, CO, CO 2, and H 2 before reaching SOFC anode.

  16. Stable hydrogen production from ethanol through steam reforming reaction over nickel-containing smectite-derived catalyst.

    PubMed

    Yoshida, Hiroshi; Yamaoka, Ryohei; Arai, Masahiko

    2014-12-25

    Hydrogen production through steam reforming of ethanol was investigated with conventional supported nickel catalysts and a Ni-containing smectite-derived catalyst. The former is initially active, but significant catalyst deactivation occurs during the reaction due to carbon deposition. Side reactions of the decomposition of CO and CH4 are the main reason for the catalyst deactivation, and these reactions can relatively be suppressed by the use of the Ni-containing smectite. The Ni-containing smectite-derived catalyst contains, after H2 reduction, stable and active Ni nanocrystallites, and as a result, it shows a stable and high catalytic performance for the steam reforming of ethanol, producing H2.

  17. Bimetallic PtSn/C catalysts obtained via SOMC/M for glycerol steam reforming.

    PubMed

    Pastor-Pérez, Laura; Merlo, Andrea; Buitrago-Sierra, Robison; Casella, Mónica; Sepúlveda-Escribano, Antonio

    2015-12-01

    A detailed study on the preparation of bimetallic PtSn/C catalysts using surface-controlled synthesis methods, and on their catalytic performance in the glycerol steam reforming reaction has been carried out. In order to obtain these well-defined bimetallic phases, techniques derived from Surface Organometallic Chemistry on Metals (SOMC/M) were used. The preparation process involved the reaction between an organometallic compound ((C4H9)4Sn) and a supported transition metal (Pt) in a H2 atmosphere. Catalysts with Sn/Pt atomic ratios of 0.2, 0.3, 0.5, and 0.7 were obtained, and characterized using several techniques: ICP, H2 chemisorption, TEM and XPS. These systems were tested in the glycerol steam reforming varying the reaction conditions (glycerol concentration and reaction temperature). The best performance was observed for the catalysts with the lowest tin contents (PtSn0.2/C and PtSn0.3/C). It was observed that the presence of tin increased the catalysts' stability when working under more severe reaction conditions.

  18. Steam reforming of bio-oil from rice husks fast pyrolysis for hydrogen production.

    PubMed

    Chen, Tianju; Wu, Ceng; Liu, Ronghou

    2011-10-01

    Steam reforming of two kinds of bio-oil from rice husks fast pyrolysis was conducted for hydrogen production at three temperatures (650, 750 and 850 °C) with Ni-based catalyst in a fixed-bed reactor. The gas composition and organic compounds in liquid condensate were detected by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), respectively. In addition, the carbon deposition was also investigated. The results showed that the mole fraction range of hydrogen was within 55.8-61.3% at all temperatures and more hydrogen was produced at the higher temperature. The highest H₂ efficiency of bio-oil steam reforming was 45.33% when extra water was added. The bio-oil with lower content of chemical compounds has a higher H₂ efficiency, but its hydrogen volume was less. Analysis of the liquid condensate showed that most of the organic compounds were circularity compounds. The carbon deposition can decrease the bio-oil conversion, and it was easier to form at the temperature of 750 °C.

  19. Phase 2 THOR Steam Reforming Tests for Sodium Bearing Waste Treatment

    SciTech Connect

    Nicholas R. Soelberg

    2004-01-01

    About one million gallons of acidic, hazardous, and radioactive sodium-bearing waste is stored in stainless steel tanks at the Idaho Nuclear Technology and Engineering Center (INTEC), which is a major operating facility of the Idaho National Engineering and Environmental Laboratory. Steam reforming is a candidate technology being investigated for converting the waste into a road ready waste form that can be shipped to the Waste Isolation Pilot Plant in New Mexico for interment. A steam reforming technology patented by Studsvik, Inc., and licensed to THOR Treatment Technologies has been tested in two phases using a Department of Energy-owned fluidized bed test system located at the Science Applications International Corporation (SAIC) Science and Technology Applications Research Center located in Idaho Falls, Idaho. The Phase 1 tests were reported earlier in 2003. The Phase 2 tests are reported here. For Phase 2, the process feed rate, stoichiometry, and chemistry were varied to identify and demonstrate process operation and product characteristics under different operating conditions. Two test series were performed. During the first series, the process chemistry was designed to produce a sodium carbonate product. The second series was designed to produce a more leach-resistant, mineralized sodium aluminosilicate product. The tests also demonstrated the performance of a MACT-compliant off-gas system.

  20. Kinetics, simulation and optimization of methanol steam reformer for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Choi, Yongtaek; Stenger, Harvey G.

    To evaluate reaction rates for making hydrogen from methanol, kinetic studies of methanol decomposition, methanol steam reforming, the water gas shift reaction, and CO selective oxidation have been performed. These reactions were studied in a microreactor testing unit using a commercial Cu-ZnO/Al 2O 3 catalyst for the first three reactions and Pt-Fe/γ-alumina catalyst for the last reaction. The activity tests were performed between 120 and 325 °C at atmospheric pressure with a range of feed rates and compositions. For methanol decomposition, a simplified reaction network of five elementary reactions was proposed and parameters for all five rate expressions were obtained using non-linear least squares optimization, numerical integration of a one-dimensional PFR model, and extensive experimental data. Similar numerical analysis was carried out to obtain the rate expressions for methanol steam reaction, the water gas shift reaction, and CO selective oxidation. Combining the three reactors with several heat exchange options, an integrated methanol reformer system was designed and simulated using MATLAB. Using this simulation, the product distribution, the effects of reactor volume and temperature, and the options of water and air injection rates were studied. Also, a series of optimization tests were conducted to give maximum hydrogen yield and/or maximum economic profit.

  1. Non-syngas direct steam reforming of methanol to hydrogen and carbon dioxide at low temperature.

    PubMed

    Yu, Kai Man Kerry; Tong, Weiyi; West, Adam; Cheung, Kevin; Li, Tong; Smith, George; Guo, Yanglong; Tsang, Shik Chi Edman

    2012-01-01

    A non-syngas direct steam reforming route is investigated for the conversion of methanol to hydrogen and carbon dioxide over a CuZnGaO(x) catalyst at 150-200 °C. This route is in marked contrast with the conventional complex route involving steam reformation to syngas (CO/H2) at high temperature, followed by water gas shift and CO cleanup stages for hydrogen production. Here we report that high quality hydrogen and carbon dioxide can be produced in a single-step reaction over the catalyst, with no detectable CO (below detection limit of 1 ppm). This can be used to supply proton exchange membrane fuel cells for mobile applications without invoking any CO shift and cleanup stages. The working catalyst contains, on average, 3-4 nm copper particles, alongside extremely small size of copper clusters stabilized on a defective ZnGa2O4 spinel oxide surface, providing hydrogen productivity of 393.6 ml g(-1)-cat h(-1) at 150 °C.

  2. Phase 2 TWR Steam Reforming Test for Sodium-Bearing Waste Treatment

    SciTech Connect

    Nicholas R. Soelberg; Doug Marshall; Dean Taylor; Steven Bates

    2004-01-01

    About one million gallons of acidic, hazardous, and radioactive sodium-bearing waste (SBW) is stored in stainless steel tanks a the Idaho Nuclear Technology and Engineering Center (INTEC), which is a major operating facility of the Idaho National Engineering and Environmental Laboratory (INEEL). Steam reforming is a candidate technology being investigated for converting the SBW into a road ready waste form that can be shipped to the Waste Isolation Pilot Plant in New Mexico for interment. Fluidized bed steam reforming technology, licensed to ThermoChem Waste Remediation, LLC (TWR) by Manufacturing Technology Conversion International, was tested in two phases using an INEEL (Department of Energy) fluidized bed test system located at the Science Applications International Corporation (SAIC) Science and Technology Applications Research Center in Idaho Falls, Idaho. The Phase 1 tests were reported earlier. The Phase 2 tests are reported here. For Phase 2, the process feed rate, reductant stoichiometry, and process temperature were varied to identify and demonstrate how the process might be optimized to improve operation and product characteristics. The first week of testing was devoted primarily to process chemistry and the second week was devoted more toward bed stability and particle size control.

  3. Engineering Study for a Full Scale Demonstration of Steam Reforming Black Liquor Gasification at Georgia-Pacific's Mill in Big Island, Virginia

    SciTech Connect

    Robert De Carrera; Mike Ohl

    2002-03-19

    Georgia-Pacific Corporation performed an engineering study to determine the feasibility of installing a full-scale demonstration project of steam reforming black liquor chemical recovery at Georgia-Pacific's mill in Big Island, Virginia. The technology considered was the Pulse Enhanced Steam Reforming technology that was developed and patented by Manufacturing and Technology Conversion, International (MTCI) and is currently licensed to StoneChem, Inc., for use in North America. Pilot studies of steam reforming have been carried out on a 25-ton per day reformer at Inland Container's Ontario, California mill and on a 50-ton per day unit at Weyerhaeuser's New Bern, North Carolina mill.

  4. Hydrogen Production by Catalytic Steam Reforming of Bio-oil, Naphtha and CH4 over C12A7-Mg Catalyst

    NASA Astrophysics Data System (ADS)

    Pan, Yue; Wang, Zhao-xiang; Kan, Tao; Zhu, Xi-feng; Li, Quan-xin

    2006-06-01

    Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of (Ca24Al28O64)4+·4O-/Mg (C12A7-Mg). The catalytic steam reforming was investigated from 250 to 850°C in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750°C, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.

  5. Fluidized bed steam reformed mineral waste form performance testing to support Hanford Supplemental Low Activity Waste Immobilization Technology Selection

    SciTech Connect

    Jantzen, C. M.; Pierce, E. M.; Bannochie, C. J.; Burket, P. R.; Cozzi, A. D.; Crawford, C. L.; Daniel, W. E.; Fox, K. M.; Herman, C. C.; Miller, D. H.; Missimer, D. M.; Nash, C. A.; Williams, M. F.; Brown, C. F.; Qafoku, N. P.; Neeway, J. J.; Valenta, M. M.; Gill, G. A.; Swanberg, D. J.; Robbins, R. A.; Thompson, L. E.

    2015-10-01

    This report describes the benchscale testing with simulant and radioactive Hanford Tank Blends, mineral product characterization and testing, and monolith testing and characterization. These projects were funded by DOE EM-31 Technology Development & Deployment (TDD) Program Technical Task Plan WP-5.2.1-2010-001 and are entitled “Fluidized Bed Steam Reformer Low-Level Waste Form Qualification”, Inter-Entity Work Order (IEWO) M0SRV00054 with Washington River Protection Solutions (WRPS) entitled “Fluidized Bed Steam Reforming Treatability Studies Using Savannah River Site (SRS) Low Activity Waste and Hanford Low Activity Waste Tank Samples”, and IEWO M0SRV00080, “Fluidized Bed Steam Reforming Waste Form Qualification Testing Using SRS Low Activity Waste and Hanford Low Activity Waste Tank Samples”. This was a multi-organizational program that included Savannah River National Laboratory (SRNL), THOR® Treatment Technologies (TTT), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), Office of River Protection (ORP), and Washington River Protection Solutions (WRPS). The SRNL testing of the non-radioactive pilot-scale Fluidized Bed Steam Reformer (FBSR) products made by TTT, subsequent SRNL monolith formulation and testing and studies of these products, and SRNL Waste Treatment Plant Secondary Waste (WTP-SW) radioactive campaign were funded by DOE Advanced Remediation Technologies (ART) Phase 2 Project in connection with a Work-For-Others (WFO) between SRNL and TTT.

  6. Fluidized Bed Steam Reforming of INEEL SBW Using THORsm Mineralizing Technology

    SciTech Connect

    Arlin L. Olson; Nicholas R. Soelberg; Douglas W. Marshall; Gary L. Anderson

    2004-12-01

    Sodium bearing waste (SBW) disposition is one of the U.S. Department of Energy (DOE) Idaho Operation Office’s (NE-ID) and State of Idaho’s top priorities at the Idaho National Engineering and Environmental Laboratory (INEEL). Many studies have resulted in the identification of five treatment alternatives that form a short list of perhaps the most appropriate technologies for the DOE to select from. The alternatives are (a) calcination with maximum achievable control technology (MACT) upgrade, (b) steam reforming, (c) cesium ion exchange (CsIX) with immobilization, (d) direct evaporation, and (e) vitrification. Each alternative has undergone some degree of applied technical development and preliminary process design over the past four years. DOE desired further experimental data, with regard to steam reforming technology, to make informed decisions concerning selection of treatment technology for SBW. Mineralizing steam reforming technology, offered by THOR Treatment Technologies, LLC would produce a denitrated, granular mineral waste form using a high-temperature fluidized bed process. A pilot scale demonstration of the technology was performed in a 15-cm-diameter reactor vessel September 27 through October 1, 2004. The pilot scale equipment is owned by the DOE, and located at the Science and Technology Applications Research (STAR) Center in Idaho Falls, ID. Flowsheet chemistry and operational parameters were defined through a collaborative effort involving Idaho National Engineering and Environmental Laboratory, Savannah River National Laboratory (SRNL), and THOR Treatment Technologies personnel. Personnel from Science Applications International Corporation, owners of the STAR Center, operated the pilot plant. The pilot scale test was terminated as planned after achieving a total of 100 hrs of cumulative/continuous processing operation. About 230 kg of SBW surrogate were processed that resulted in about 88 kg of solid product, a mass reduction of about 62

  7. Steam Reforming of Ethylene Glycol over MgAl₂O₄ Supported Rh, Ni, and Co Catalysts

    SciTech Connect

    Mei, Donghai; Lebarbier, Vanessa M.; Xing, Rong; Albrecht, Karl O.; Dagle, Robert A.

    2015-11-25

    Steam reforming of ethylene glycol (EG) over MgAl₂O₄ supported metal (15 wt.% Ni, 5 wt.% Rh, and 15 wt.% Co) catalysts were investigated using combined experimental and theoretical methods. Compared to highly active Rh and Ni catalysts with 100% conversion, the steam reforming activity of EG over the Co catalyst is comparatively lower with only 42% conversion under the same reaction conditions (500°C, 1 atm, 119,000 h⁻¹, S/C=3.3 mol). However, CH₄ selectivity over the Co catalyst is remarkably lower. For example, by varying the gas hour space velocity (GHSV) such that complete conversion is achieved for all the catalysts, CH₄ selectivity for the Co catalyst is only 8%, which is much lower than the equilibrium CH₄ selectivity of ~ 24% obtained for both the Rh and Ni catalysts. Further studies show that varying H₂O concentration over the Co catalyst has a negligible effect on activity, thus indicating zero-order dependence on H₂O. These experimental results suggest that the supported Co catalyst is a promising EG steam reforming catalyst for high hydrogen production. To gain mechanistic insight for rationalizing the lower CH₃ selectivity observed for the Co catalyst, the initial decomposition reaction steps of ethylene glycol via C-O, O-H, C-H, and C-C bond scissions on the Rh(111), Ni(111) and Co(0001) surfaces were investigated using density functional theory (DFT) calculations. Despite the fact that the bond scission sequence in the EG decomposition on the three metal surfaces varies, which leads to different reaction intermediates, the lower CH₄ selectivity over the Co catalyst, as compared to the Rh and Ni catalysts, is primarily due to the higher barrier for CH₄ formation. The higher S/C ratio enhances the Co catalyst stability, which can be elucidated by the facile water dissociation and an alternative reaction path to remove the CH species as a coking precursor via the HCOH formation. This work was financially supported by the United

  8. Production of the hydrogen by methane steam reforming over nickel catalysts prepared from hydrotalcite precursors

    NASA Astrophysics Data System (ADS)

    Fonseca, Alessandra; Assaf, Elisabete M.

    Catalysts were prepared from hydrotalcite precursors, characterized and tested in the reaction of methane steam reforming to produce hydrogen. The precursors were synthesized by: the traditional technique, with co-precipitation of Ni, Mg and Al nitrates with carbonate; co-precipitation of Mg and Al nitrates with pre-synthesized nickel chelate and anion-exchange of NO 3- of hydrotalcite with nickel chelate. The oxides were analyzed using atomic absorption spectrophotometry, specific surface area, X-ray diffraction (XRD), temperature programmed reduction (TPR) with H 2, catalytic tests and elemental analysis. The catalytic tests demonstrated high methane conversion, high activity for hydrogen production and high stability during the time of reaction for a molar ratio in the feed H 2O:CH 4 = 2:1.

  9. Stable hydrogen production by methane steam reforming in a two zone fluidized bed reactor: Experimental assessment

    NASA Astrophysics Data System (ADS)

    Pérez-Moreno, L.; Soler, J.; Herguido, J.; Menéndez, M.

    2013-12-01

    The Two Zone Fluidized Bed Reactor concept is proposed for hydrogen production via the steam reforming of methane (SRM) including integrated catalyst regeneration. In order to study the effect of the contact mode, the oxidative SRM has been carried out over a Ni/Al2O3 catalyst using a fixed bed reactor (fBR), a conventional fluidized-bed reactor (FBR) and the proposed two-zone fluidized bed reactor (TZFBR). The technical feasibility of these reactors has been studied experimentally, investigating their performance (CH4 conversion, CO and H2 selectivity, and H2 global yield) and stability under different operating conditions. Coke generation in the process has been verified by several techniques. A stable performance was obtained in the TZFBR, where coke formation was counteracted with continuous catalyst regeneration. The viability of the TZFBR for carrying out this process with a valuable global yield to hydrogen is demonstrated.

  10. MTCI/ThermoChem steam reforming process for solid fuels for combined cycle power generation

    SciTech Connect

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

    1995-12-31

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

  11. Steam Reforming, 6-in. Bench-Scale Design and Testing Project -- Technical and Functional Requirements Description

    SciTech Connect

    Losinski, Sylvester John; Marshall, Douglas William

    2002-08-01

    Feasibility studies and technology development work are currently being performed on several processes to treat radioactive liquids and solids currently stored at the Idaho Nuclear Technology and Engineering Center (INTEC), located within the Idaho National Engineering and Environmental Laboratory (INEEL). These studies and development work will be used to select a treatment process for treatment of the radioactive liquids and solids to meet treatment milestones of the Settlement Agreement between the Department of Energy and the State of Idaho. One process under consideration for treating the radioactive liquids and solids, specifically Sodium-Bearing Waste (SBW) and tank heel solids, is fluid bed steam reforming (FBSR). To support both feasibility and development studies a bench-scale FBSR is being designed and constructed. This report presents the technical and functional requirements, experimental objectives, process flow sheets, and equipment specifications for the bench-scale FBSR.

  12. Radioactive Demonstrations Of Fluidized Bed Steam Reforming (FBSR) With Hanford Low Activity Wastes

    SciTech Connect

    Jantzen, C. M.; Crawford, C. L.; Burket, P. R.; Bannochie, C. J.; Daniel, W. G.; Nash, C. A.; Cozzi, A. D.; Herman, C. C.

    2012-10-22

    Several supplemental technologies for treating and immobilizing Hanford low activity waste (LAW) are being evaluated. One immobilization technology being considered is Fluidized Bed Steam Reforming (FBSR) which offers a low temperature (700-750?C) continuous method by which wastes high in organics, nitrates, sulfates/sulfides, or other aqueous components may be processed into a crystalline ceramic (mineral) waste form. The granular waste form produced by co-processing the waste with kaolin clay has been shown to be as durable as LAW glass. The FBSR granular product will be monolithed into a final waste form. The granular component is composed of insoluble sodium aluminosilicate (NAS) feldspathoid minerals such as sodalite. Production of the FBSR mineral product has been demonstrated both at the industrial, engineering, pilot, and laboratory scales on simulants. Radioactive testing at SRNL commenced in late 2010 to demonstrate the technology on radioactive LAW streams which is the focus of this study.

  13. Preparation and characterization of Ni-based perovskite catalyst for steam CO2 reforming of methane.

    PubMed

    Yang, Eun-Hyeok; Kim, Sang Woo; Ahn, Byong Song; Moon, Dong Ju

    2013-06-01

    Steam CO2 reforming of methane was investigated over Ni-based perovskite catalyst to produce desired H2/CO ratio by adjusting the feed ratio of CH4, CO2 and H2O for floating GTL process application. La modified perovskites were prepared by the Pechini method and calcined in air and the Ni-based catalysts were prepared by dispersing Ni on the La modified perovskite by an incipient wetness impregnation. The catalysts before and after the reaction were characterized by N2 physisoprtion, CO chemisoprtion, XRD, TPR and SEM techniques. To control desired H2/CO ratio, simulation for SCR was carried out by Aspen plus, and product distribution for SCR was investigated in a fixed bed reactor system using feed ratio estimated by simulation. The Ni-based perovskite catalysts were found to give CH4 and CO2 conversions of up to 82% and 60% respectively to yield a H2/CO product ratio close to 2.

  14. Disposition of Tank 48H Organics by Fluidized Bed Steam Reforming (FBSR)

    SciTech Connect

    Jantzen, C.M.

    2003-12-02

    In order to make space in the Savannah River Site Tank farm, the Tank 48H waste must be removed. Therefore, the Tank 48H waste must be processed to reduce or eliminate levels of nitrates, nitrites, and sodium tetraphenyl borate in order to reduce impacts of these species before it is vitrified. Fluidized Bed Steam Reforming is being considered as a candidate technology for destroying the nitrates and the NaTPB prior to melting. The Idaho National Engineering and Environmental Laboratory was tasked to perform a proof-of-concept steam reforming test to evaluate the technical feasibility for pretreating the Tank 48H waste. The crucible (bench scale) tests conducted at the Savannah River Technology Center were initiated to optimize and augment the parameters subsequently tested at the pilot scale at INEEL. The purposes of the current study, organic destruction and downstream processing of T48H waste slurry were fulfilled. TPB was destroyed in all 19 samples tested with the simulated FB SR process at operational temperatures 650-725 degrees Celsius. A test temperature of 650 degrees Celsius optimized NO3 destruction during the formation of an Na2CO3 FBSR product. A test temperature of 725 degrees Celsius optimized NO3 destruction during formation of a sodium silicate FBSR product. Destruction of nitrate at greater than 99 per cent was achieved with addition of sugar as a reductant at 1X stoichiometry and total organic carbon analyses indicated that excess reductant was not present in the FBSR product. The use of sugar at 1X stoichiometry appears to ensure that excess reductant is not contained in the FBSR product that would alter the REDuction/OXidation equilibrium of the DWPF melter, while simultaneously assuring that NO3 is destroyed adequately. Destruction of antifoam with the simulated FBSR process was also achieved at operating temperatures between 650-725 degrees Celsius. based on measured total organic carbon.

  15. Zirconia supported catalysts for bioethanol steam reforming: Effect of active phase and zirconia structure

    NASA Astrophysics Data System (ADS)

    Benito, M.; Padilla, R.; Rodríguez, L.; Sanz, J. L.; Daza, L.

    Three new catalysts have been prepared in order to study the active phase influence in ethanol steam reforming reaction. Nickel, cobalt and copper were the active phases selected and were supported on zirconia with monoclinic and tetragonal structure, respectively. To characterize the behaviour of the catalysts in reaction conditions a study of catalytic activity with temperature was performed. The highest activity values were obtained at 973 K where nickel and cobalt based catalysts achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. Nickel supported on tetragonal zirconia exhibited the highest hydrogen production efficiency, higher than 4.5 mol H 2/mol EtOH fed. The influence of steam/carbon (S/C) ratio on product distribution was another parameter studied between the range 3.2-6.5. Nickel supported on tetragonal zirconia at S/C = 3.2 operated at 973 K without by-product production such as ethylene or acetaldehyde. In order to consider a further application in an ethanol processor, a long-term reaction experiment was performed at 973 K, S/C = 3.2 and atmospheric pressure. After 60 h, nickel supported on tetragonal zirconia exhibited high stability and selectivity to hydrogen production.

  16. Radioactive Bench-scale Steam Reformer Demonstration of a Monolithic Steam Reformed Mineralized Waste Form for Hanford Waste Treatment Plant Secondary Waste - 12306

    SciTech Connect

    Evans, Brent; Olson, Arlin; Mason, J. Bradley; Ryan, Kevin; Jantzen, Carol; Crawford, Charles

    2012-07-01

    Hanford currently has 212,000 m{sup 3} (56 million gallons) of highly radioactive mixed waste stored in the Hanford tank farm. This waste will be processed to produce both high-level and low-level activity fractions, both of which are to be vitrified. Supplemental treatment options have been under evaluation for treating portions of the low-activity waste, as well as the liquid secondary waste from the low-activity waste vitrification process. One technology under consideration has been the THOR{sup R} fluidized bed steam reforming process offered by THOR Treatment Technologies, LLC (TTT). As a follow-on effort to TTT's 2008 pilot plant FBSR non-radioactive demonstration for treating low-activity waste and waste treatment plant secondary waste, TTT, in conjunction with Savannah River National Laboratory, has completed a bench scale evaluation of this same technology on a chemically adjusted radioactive surrogate of Hanford's waste treatment plant secondary waste stream. This test generated a granular product that was subsequently formed into monoliths, using a geo-polymer as the binding agent, that were subjected to compressibility testing, the Product Consistency Test and other leachability tests, and chemical composition analyses. This testing has demonstrated that the mineralized waste form, produced by co-processing waste with kaolin clay using the TTT process, is as durable as low-activity waste glass. Testing has shown the resulting monolith waste form is durable, leach resistant, and chemically stable, and has the added benefit of capturing and retaining the majority of Tc-99, I-129, and other target species at high levels. (authors)

  17. Steam Reforming of Glycerol Over Nano Size Ni-Ce/LaAlO3 Catalysts.

    PubMed

    Kim, Seong-Hak; Go, Yoo-Jin; Park, Nam-Cook; Kim, Jong-Ho; Kim, Young-Chul; Moon, Dong-Ju

    2015-01-01

    In this work, hydrogen production from glycerol by Steam Reforming (SR) was studied by Ni-Ce catalysts supported on LaAlO3 perovskite in order to effect of the cerium loading amount and the reaction conditions. Nano size Ni-Ce/LaAlO3 catalysts were prepared by precipitation method. The structure of the catalysts was characterized by XRD analysis. The morphology, dispersion and the reduction properties of catalysts was examined by SEM, TEM, H2-chemisorption and TPR, respectively. It was found that 15 wt% Ni-5 wt% Ce/LaAlO3 catalyst showed the highest glycerol conversion and hydrogen selectivity. In addition, the catalyst also showed the high carbon dioxide selectivity and the lowest methane selectivity. The results indicate that the catalyst promotes methane reforming reaction. The highest activity in the 15 wt% Ni-5 wt% Ce/LaAlO3 was attributed to the proper cerium loading amount. Moreover, the lowest metal crystal size and rise in active site were found to have an effect on catalytic activity and hydrogen selectivity. The 15 wt% Ni-5 wt% Ce/LaAlO3 catalyst exhibited excellent performance with respect to hydrogen production at reaction temperature of 450 degrees C, at atmospheric pressure, 20 wt% glycerol solution and GHSV = 6,000 mL/g-cat x hr.

  18. Modeling and 3D-simulation of hydrogen production via methanol steam reforming in copper-coated channels of a mini reformer

    NASA Astrophysics Data System (ADS)

    Sari, Ataallah; Sabziani, Javad

    2017-06-01

    Modeling and CFD simulation of a three-dimensional microreactor includes thirteen structured parallel channels is performed to study the hydrogen production via methanol steam reforming reaction over a Cu/ZnO/Al2O3 catalyst. The well-known Langmuir-Hinshelwood macro kinetic rate expressions reported by Peppley and coworkers [49] are considered to model the methanol steam reforming reactions. The effects of inlet steam to methanol ratio, pre-heat temperature, channels geometry and size, and the level of external heat flux on the hydrogen quality and quantity (i.e., hydrogen flow rate and CO concentration) are investigated. Moreover, the possibility of reducing the CO concentration by passing the reactor effluent through a water gas shift channel placed in series with the methanol reformer is studied. Afterwards, the simulation results are compared with the experimental data reported in the literature considering two different approaches of mixture-averaged and Maxwell-Stefan formulations to evaluate the diffusive flux of mass. The results indicate that the predictions of the Maxwell-Stefan model is in better agreement with experimental data than mixture-averaged one, especially at the lower feed flow rates.

  19. FLUIDIZED BED STEAM REFORMED MINERAL WASTE FORMS: CHARACTERIZATION AND DURABILITY TESTING

    SciTech Connect

    Jantzen, C; Troy Lorier, T; John Pareizs, J; James Marra, J

    2007-03-31

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium low activity wastes (LAW) such as those existing at the Hanford site, at the Idaho National Laboratory (INL), and the Savannah River Site (SRS). The addition of clay, charcoal, and a catalyst as co-reactants with the waste denitrates the aqueous wastes and forms a granular mineral waste form that can subsequently be made into a monolith for disposal if necessary. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage and ring structures and iron bearing spinel minerals. The mineralization occurs at moderate temperatures between 650-750 C in the presence of superheated steam. The cage and ring structured feldspathoid minerals atomically bond radionuclides like Tc-99 and Cs-137 and anions such as SO4, I, F, and Cl. The spinel minerals stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low-activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium bearing waste (SBW) in pilot scale facilities at the Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The results of the SPFT testing and the activation energies for dissolution are discussed in this study.

  20. FLUIDIZED BED STEAM REFORMED MINERAL WASTE FORMS: CHARACTERIZATION AND DURABILITY TESTING

    SciTech Connect

    Jantzen, C; Troy Lorier, T; John Pareizs, J; James Marra, J

    2006-12-06

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium low activity wastes (LAW) such as those existing at the Hanford site, at the Idaho National Laboratory (INL), and the Savannah River Site (SRS). The addition of clay, charcoal, and a catalyst as co-reactants with the waste denitrates the aqueous wastes and forms a granular mineral waste form that can subsequently be made into a monolith for disposal if necessary. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage and ring structures and iron bearing spinel minerals. The mineralization occurs at moderate temperatures between 650-750 C in the presence of superheated steam. The cage and ring structured feldspathoid minerals atomically bond radionuclides like Tc-99 and Cs-137 and anions such as SO{sub 4}, I, F, and Cl. The spinel minerals stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium bearing waste (SBW) in pilot scale facilities at the Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The results of the SPFT testing and the activation energies for dissolution are discussed in this study.

  1. Thermodynamic study of characteristics of the converter with separated supply of hydrocarbon fuel for thermo-oxidative and steam reforming

    NASA Astrophysics Data System (ADS)

    Bassina, I. A.; Malkov, Yu. P.; Molchanov, O. N.; Stepanov, S. G.; Troshchinenko, G. A.; Zasypkin, I. M.

    2014-04-01

    Thermodynamic studies of the converter characteristics were performed to produce hydrogen-containing syngas from hydrocarbon fuel (kerosene) with its separated supply for thermo-oxidative and steam reforming. It is demonstrated that the optimal conditions of the converter performance correlate with the oxidant ratio of α > 0.5 at the heattransfer wall temperature of 1200 K. Hydrogen content in the final syngas reaches 60 % by volume, free carbon (soot) deposition in reforming products is excluded, and there is no need to apply walls water cooling in the converter.

  2. Steam Reforming Solidification of Cesium and Strontium Separations Product from Advanced Aqueous Processing of Spent Nuclear Fuel

    SciTech Connect

    Julia L. Tripp; T. G. Garn; R. D. Boardman; J. D. Law

    2006-02-01

    The Advanced Fuel Cycle Initiative program is conducting research on aqueous separations processes for the nuclear fuel cycle. This research includes development of solvent extraction processes for the separation of cesium and strontium from dissolved spent nuclear fuel solutions to reduce the short-term decay heat load. The cesium/strontium strip solution from candidate separation processes will require treatment and solidification for managed storage. Steam reforming is currently being investigated for stabilization of these streams because it can potentially destroy the nitrates and organics present in these aqueous, nitrate-bearing solutions, while converting the cesium and strontium into leach-resistant aluminosilicate minerals, such as pollucite. These ongoing experimental studies are being conducted to evaluate the effectiveness of steam reforming for this application.

  3. Stable Hydrogen Production from Ethanol through Steam Reforming Reaction over Nickel-Containing Smectite-Derived Catalyst

    PubMed Central

    Yoshida, Hiroshi; Yamaoka, Ryohei; Arai, Masahiko

    2014-01-01

    Hydrogen production through steam reforming of ethanol was investigated with conventional supported nickel catalysts and a Ni-containing smectite-derived catalyst. The former is initially active, but significant catalyst deactivation occurs during the reaction due to carbon deposition. Side reactions of the decomposition of CO and CH4 are the main reason for the catalyst deactivation, and these reactions can relatively be suppressed by the use of the Ni-containing smectite. The Ni-containing smectite-derived catalyst contains, after H2 reduction, stable and active Ni nanocrystallites, and as a result, it shows a stable and high catalytic performance for the steam reforming of ethanol, producing H2. PMID:25547495

  4. Nickel-carbon nanocomposites prepared using castor oil as precursor: A novel catalyst for ethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Carreño, Neftalí L. V.; Garcia, Irene T. S.; Raubach, Cristiane W.; Krolow, Mateus; Santos, Cláudia C. G.; Probst, Luiz F. D.; Fajardo, Humberto V.

    A novel and simple method to prepare nickel-based catalysts for ethanol steam reforming is proposed. The present method was developed using castor oil as a precursor. The results clarify that the nickel-carbon (Ni/C) catalyst has a high activity for ethanol steam reforming. It was observed that the catalytic behavior could be modified according to the experimental conditions employed. Moreover, it is interesting to note that the increase in the catalytic activity of the Ni/C nanocomposite over time, at 500 and 600 °C of reaction temperature, may be associated with the formation of filamentous carbon. The preliminary results indicate that the novel methodology used, led to the obtainment of materials with important properties that can be extended to applications in different catalytic process.

  5. Hydrogen production from oxidative steam reforming of bio-butanol over CoIr-based catalysts: effect of the support.

    PubMed

    Cai, Weijie; Piscina, Pilar Ramírez de la; Gabrowska, Klaudia; Homs, Narcís

    2013-01-01

    This paper studies the influence of the support on the behavior of bimetallic CoIr-based catalysts (6.5 wt.% Co, 0.4 wt.% Ir) for hydrogen production from the oxidative steam reforming of bio-butanol raw mixture (butanol/acetone/ethanol = 6/3/1 mass ratio). Catalytic tests were carried out at 500 °C for 60 h with raw mixture/water/air/Ar = 1/10/7.5/12 molar ratio and GHSV = 7500 h(-1). Over CoIr/18CeZrO(2) and CoIr/ZnO the main process which took place was the oxidative steam reforming of the raw mixture. CoIr/18CeZrO(2) showed the better catalytic performance. Characterization of the used catalysts indicated that both active metal sintering and coke formation was prevented on the CoIr/18CeZrO(2) catalyst.

  6. Hydrogen production from the steam reforming of bio-butanol over novel supported Co-based bimetallic catalysts.

    PubMed

    Cai, Weijie; de la Piscina, Pilar Ramirez; Homs, Narcis

    2012-03-01

    This paper reports the hydrogen production through the steam reforming of a bioresource-derived butanol mixture (butanol:acetone:ethanol=6:3:1 mass ratio) over supported cobalt-based catalysts. The support plays an important role for the catalytic behavior and Co/ZnO exhibits the best catalytic performance compared to Co/TiO(2) and Co/CeO(2). Moreover, a higher hydrogen yield is obtained over bimetallic Co-Ir/ZnO, which shows an increase in H(2) selectivity and a decrease in CH(4) selectivity under steam reforming conditions, compared to Co/ZnO. Raman results of the used catalysts indicate that the addition of Ir could prevent the coke formation to prolong the catalyst stability.

  7. Advanced Catalysis Technologies: Lanthanum Cerium Manganese Hexaaluminate Combustion Catalysts for Flat Plate Reactor for Compact Steam Reformers

    DTIC Science & Technology

    2008-12-01

    REACTOR FOR COMPACT STEAM REFORMERS Aly H. Shaaban Applied Research Associates P.O. Box 40128 Tyndall Air Force Base, FL 32403...DRIVE, SUITE 2 TYNDALL AIR FORCE BASE, FL 32403-5323 NOTICE AND SIGNATURE PAGE Using Government drawings, specifications, or other data...been reported in the literature to give high light fractions yield with low selectivity to coke [24]. ZSM-5 type (MFI) zeolite (Zeolyst CBV5524G, SiO2

  8. A highly active and coke-resistant steam reforming catalyst comprising uniform nickel-iron alloy nanoparticles.

    PubMed

    Koike, Mitsuru; Li, Dalin; Nakagawa, Yoshinao; Tomishige, Keiichi

    2012-12-01

    Doing fine with Ni-Fe: The calcination and reduction of a hydrotalcite precursor containing Ni and Fe ions gives uniform Ni-Fe alloy nanoparticles mixed with Mg(Ni, Fe, Al)O particles. The uniformity of the Ni-Fe alloy nanoparticles is connected to the catalyst's high activity and resistance to coke formation in toluene and phenol steam reforming reactions.

  9. Stabilization of Savannah River National Laboartory (SRNL) Aqueous Waste by Fluidized Bed Steam Reforming (FBSR)

    SciTech Connect

    Jantzen, C

    2004-11-01

    The Savannah River National Laboratory (SRNL) is a multidisciplinary laboratory operated by Westinghouse Savannah River Company (WSRC) in Aiken, South Carolina. Research and development programs have been conducted at SRNL for {approx}50 years generating non-radioactive (hazardous and non-hazardous) and radioactive aqueous wastes. Typically the aqueous effluents from the R&D activities are disposed of from each laboratory module via the High Activity Drains (HAD) or the Low Activity Drains (LAD) depending on whether they are radioactive or not. The aqueous effluents are collected in holding tanks, analyzed and shipped to either H-Area (HAD waste) or the F/H Area Effluent Treatment Facility (ETF) (LAD waste) for volume reduction. Because collection, analysis, and transport of LAD and HAD waste is cumbersome and since future treatment of this waste may be curtailed as the F/H-Area evaporators and waste tanks are decommissioned, SRNL laboratory operations requested several proof of principle demonstrations of alternate technologies that would define an alternative disposal path for the aqueous wastes. Proof of principle for the disposal of SRNL HAD waste using a technology known as Fluidized Bed Steam Reforming (FBSR) is the focus of the current study. The FBSR technology can be performed either as a batch process, e.g. in each laboratory module in small furnaces with an 8'' by 8'' footprint, or in a semi-continuous Bench Scale Reformer (BSR). The proof of principle experiments described in this study cover the use of the FBSR technology at any scale (pilot or full scale). The proof of principle experiments described in this study used a non-radioactive HAD simulant.

  10. Model biogas steam reforming in a thin Pd-supported membrane reactor to generate clean hydrogen for fuel cells

    NASA Astrophysics Data System (ADS)

    Iulianelli, A.; Liguori, S.; Huang, Y.; Basile, A.

    2015-01-01

    Steam reforming of a model biogas mixture is studied for generating clean hydrogen by using an inorganic membrane reactor, in which a composite Pd/Al2O3 membrane separates part of the produced hydrogen through its selective permeation. The characteristics of H2 perm-selectivity of the fresh membrane is expressed in terms of H2/N2 ideal selectivity, in this case equal to 4300. Concerning biogas steam reforming reaction, at 380 °C, 2.0 bar H2O:CH4 = 3:1, GHSV = 9000 h-1 the permeate purity of the recovered hydrogen is around 96%, although the conversion (15%) and hydrogen recovery (>20%) are relatively low; on the contrary, at 450 °C, 3.5 bar H2O:CH4 = 4:1, GHSV = 11000 h-1 the conversion is increased up to more than 30% and the recovery of hydrogen to about 70%. This novel work constitutes a reference study for new developments on biogas steam reforming reaction in membrane reactors.

  11. Thermodynamic equilibrium calculations of hydrogen production from the combined processes of dimethyl ether steam reforming and partial oxidation

    NASA Astrophysics Data System (ADS)

    Semelsberger, Troy A.; Borup, Rodney L.

    Thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the combined processes of dimethyl ether (DME) partial oxidation and steam reforming were investigated as a function of oxygen-to-carbon ratio (0.00-2.80), steam-to-carbon ratio (0.00-4.00), temperature (100 °C-600 °C), pressure (1-5 atm) and product species. Thermodynamically, dimethyl ether processed with air and steam generates hydrogen-rich fuel-cell feeds; however, the hydrogen concentration is less than that for pure DME steam reforming. Results of the thermodynamic processing of dimethyl ether indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 °C, oxygen-to-carbon ratios greater than 0.00 and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure has negligible effects on the hydrogen content. Thermodynamically, dimethyl ether can produce concentrations of hydrogen and carbon monoxide of 52% and 2.2%, respectively, at a temperature of 300 °C, and oxygen-to-carbon ratio of 0.40, a pressure of 1 atm and a steam-to-carbon ratio of 1.50. The order of thermodynamically stable products (excluding H 2, CO, CO 2, DME, NH 3 and H 2O) in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol and methyl-ethyl ether; trace amounts of formaldehyde, formic acid and methanol are observed. Ammonia and hydrogen cyanide are also thermodynamically favored products. Ammonia is favored at low temperatures in the range of oxygen-to-carbon ratios of 0.40-2.50 regardless of the steam-to-carbon ratio employed. The maximum ammonia content (i.e., 40%) occurs at an oxygen-to-carbon ratio of 0.40, a steam-to-carbon ratio of 1.00 and a temperature of 100 °C. Hydrogen cyanide is favored at high temperatures and low oxygen-to-carbon ratios with a maximum of 3.18% occurring at an oxygen-to-carbon ratio of 0.40 and a steam

  12. Characterization and Leaching Tests of the Fluidized Bed Steam Reforming (FBSR) Waste Form for LAW Immobilization

    SciTech Connect

    Neeway, James J.; Qafoku, Nikolla; Brown, Christopher F.; Peterson, Reid A.

    2013-10-01

    Several supplemental technologies for treating and immobilizing Hanford low activity waste (LAW) have been evaluated. One such immobilization technology is the Fluidized Bed Steam Reforming (FBSR) granular product. The FBSR granular product is composed of insoluble sodium aluminosilicate (NAS) feldspathoid minerals. Production of the FBSR mineral product has been demonstrated both at the industrial and laboratory scale. Pacific Northwest National Laboratory (PNNL) was involved in an extensive characterization campaign. This goal of this campaign was study the durability of the FBSR mineral product and the mineral product encapsulated in a monolith to meet compressive strength requirements. This paper gives an overview of results obtained using the ASTM C 1285 Product Consistency Test (PCT), the EPA Test Method 1311 Toxicity Characteristic Leaching Procedure (TCLP), and the ASTMC 1662 Single-Pass Flow-Through (SPFT) test. Along with these durability tests an overview of the characteristics of the waste form has been collected using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), microwave digestions for chemical composition, and surface area from Brunauer, Emmett, and Teller (BET) theory.

  13. Methanol Steam Reforming Promoted by Molten Salt-Modified Platinum on Alumina Catalysts

    PubMed Central

    Kusche, Matthias; Agel, Friederike; Ní Bhriain, Nollaig; Kaftan, Andre; Laurin, Mathias; Libuda, Jörg; Wasserscheid, Peter

    2014-01-01

    We herein describe a straight forward procedure to increase the performance of platinum-on-alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the “solid catalyst with ionic liquid layer” (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum-on-alumina catalyst at KOH loadings around 7.5 mass %. PMID:25124120

  14. Promotion effect of cobalt-based catalyst with rare earth for the ethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Chiou, Josh Y. Z.; Chen, Ya-Ping; Yu, Shen-Wei; Wang, Chen-Bin

    2013-12-01

    Catalytic performance of ethanol steam reforming (ESR) was investigated on praseodymium (Pr) modified ceria-supported cobalt oxide catalyst. The ceria-supported cobalt oxide (Ce-Co) catalyst was prepared by co-precipitation-oxidation (CPO) method, and the doped Pr (5 and 10 wt% loading) catalysts (Pr5-Ce-Co and Pr10-Ce-Co) were prepared by incipient wetness impregnation method. The reduction pretreatment under 250 and 400 °C (H250 and H400) was also studied. All samples were characterized by XRD, TPR and TEM. Catalytic performance of ESR was tested from 250 to 500 °C in a fixed-bed reactor. The doping of Pr into the ceria lattice has significantly promoted the activity and reduced the coke formation. The products distribution also can be influenced by the different reduction pretreatment. The Pr10-Ce-Co-H400 sample is a preferential ESR catalyst, where the hydrogen distribution approaches 73% at 475 °C with less amounts (< 2%) of CO and CH4.

  15. Highly loaded Ni-based catalysts for low temperature ethanol steam reforming.

    PubMed

    Wang, Tuo; Ma, Hongyan; Zeng, Liang; Li, Di; Tian, Hao; Xiao, Shengning; Gong, Jinlong

    2016-05-21

    This paper describes the design of high-loading Ni/Al2O3 catalysts (78 wt% Ni) for low temperature ethanol steam reforming. The catalysts were synthesized via both co-precipitation (COP) and impregnation (IMP) methods. All the catalysts were measured by N2 adsorption-desorption, XRD, H2-TPR, and H2 pulse chemisorption. The characterization results demonstrated that the preparation method and the loading significantly affected the nickel particle size, active nickel surface area and catalytic performance. Over COP catalysts, large nickel particles were presented in nickel aluminum mixed oxides. In comparison, IMP catalysts gained more "free" NiO particles with weak interaction with the aluminum oxide. Consequently, COP catalysts yielded smaller nickel particles and larger active nickel surface areas than those of IMP catalysts. High loading is beneficial for obtaining sufficient active nickel sites when nickel particles are dispersed via COP, whereas excessive nickel content is not desired for catalysts prepared by IMP. Specifically, the 78 wt% nickel loaded catalyst synthesized by COP possessed small nickel particles (∼6.0 nm) and an abundant active nickel area (35.1 m(2) gcat(-1)). Consequently, COP-78 achieved superior stability with 92% ethanol conversion and ∼35% H2 selectivity at 673 K for 30 h despite the presence of a considerable amount of coke.

  16. Performance of the Fluidized Bed Steam Reforming Product Under Hydraulically Unsaturated Conditions

    SciTech Connect

    Neeway, James J.; Qafoku, Nikolla; Williams, Benjamin D.; Rod, Kenton A.; Bowden, Mark E.; Brown, Christopher F.; Pierce, Eric M.

    2014-05-01

    Currently, several candidates for secondary waste immobilization at the Hanford site in the State of Washington, USA are being considered. To demonstrate the durability of the product in the unsaturated Integrated Disposal Facility (IDF) at the site, a series of tests have been performed one of the candidate materials using the Pressurized Unsaturated Flow (PUF) system. The material that was tested was the Fluidized Bed Steam Reformer (FBSR) granular product and the granular product encapsulated in a geopolymer matrix. The FBSR product is composed primarily of an insoluble sodium aluminosilicate matrix with the dominant phases being feldspathoid minerals mostly nepheline, sodalite, and nosean. The PUF test method allows for the accelerated weathering of materials, including radioactive waste forms, under hydraulically unsaturated conditions, thus mimicking the open-flow and transport properties that most likely will be present at the IDF. The experiments show a trend of decreasing tracer release as a function of time for several of the elements released from the material including Na, Si, Al, and Cs. However, some of the elements, notably I and Re, show a steady release throughout the yearlong test. This result suggests that the release of these minerals from the sodalite cage occurs at a different rate compared with the dissolution of the predominant nepheline phase.

  17. Methane steam reforming analysis in a palladium-based catalytic membrane reactor

    SciTech Connect

    Barbieri, G.; Violante, V.; Maio, F.P. di; Criscuoli, A.; Drioli, E. |

    1997-08-01

    The methane steam reforming in a catalytic membrane reactor has been studied. A previous theoretical study of this reaction has been carried out. In the model a global kinetic rate as a function of three reactions over nickel catalyst as proposed by Xu and Froment has been considered. It has been shown that the counterflow configuration has, at high temperature (500 C), a marginal advantage on parallel flow and, also, that the space velocity cannot be considered a design variable for membrane reactors. A laboratory plant was realized utilizing membranes of Pd and Pd/Ag supported on Al{sub 2}O{sub 3}. The Pd membranes utilized have been prepared using the co-condensation technique and the electroless plating method. A comparison of the overall membrane performance has also been carried out. The experiments were aimed to study the effects of several parameters such as temperature, feed flow rate, and feed molar ratio on the methane conversion. The experimental results have been compared with the data predicted by the previously developed theoretical model.

  18. Radionuclide and contaminant immobilization in the fluidized bed steam reforming waste products

    SciTech Connect

    Neeway, James J.; Qafoku, Nikolla; Westsik, Joseph H.; Brown, Christopher F.; Jantzen, Carol; Pierce, Eric M.

    2012-05-01

    The goal of this chapter is to introduce the reader to the Fluidized Bed Steam Reforming (FBSR) process and resulting waste form. The first section of the chapter gives an overview of the potential need for FBSR processing in nuclear waste remediation followed by an overview of the engineering involved in the process itself. This is followed by a description of waste form production at a chemical level followed by a section describing different process streams that have undergone the FBSR process. The third section describes the resulting mineral product in terms of phases that are present and the ability of the waste form to encapsulate hazardous and radioactive wastes from several sources. Following this description is a presentation of the physical properties of the granular and monolith waste form product including and contaminant release mechanisms. The last section gives a brief summary of this chapter and includes a section on the strengths associated with this waste form and the needs for additional data and remaining questions yet to be answered. The reader is directed elsewhere for more information on other waste forms such as Cast Stone (Lockrem, 2005), Ceramicrete (Singh et al., 1997, Wagh et al., 1999) and geopolymers (Kyritsis et al., 2009; Russell et al., 2006).

  19. Promotion effect of cobalt-based catalyst with rare earth for the ethanol steam reforming

    SciTech Connect

    Chiou, Josh Y. Z.; Chen, Ya-Ping; Yu, Shen-Wei; Wang, Chen-Bin

    2013-12-16

    Catalytic performance of ethanol steam reforming (ESR) was investigated on praseodymium (Pr) modified ceria-supported cobalt oxide catalyst. The ceria-supported cobalt oxide (Ce-Co) catalyst was prepared by co-precipitation-oxidation (CPO) method, and the doped Pr (5 and 10 wt% loading) catalysts (Pr{sub 5}−Ce−Co and Pr{sub 10}−Ce−Co) were prepared by incipient wetness impregnation method. The reduction pretreatment under 250 and 400 °C (H250 and H400) was also studied. All samples were characterized by XRD, TPR and TEM. Catalytic performance of ESR was tested from 250 to 500 °C in a fixed-bed reactor. The doping of Pr into the ceria lattice has significantly promoted the activity and reduced the coke formation. The products distribution also can be influenced by the different reduction pretreatment. The Pr{sub 10}−Ce−Co−H400 sample is a preferential ESR catalyst, where the hydrogen distribution approaches 73% at 475 °C with less amounts (< 2%) of CO and CH{sub 4}.

  20. Steam reforming of methanol over copper loaded anodized aluminum oxide (AAO) prepared through electrodeposition

    NASA Astrophysics Data System (ADS)

    Linga Reddy, E.; Karuppiah, J.; Lee, Hyun Chan; Kim, Dong Hyun

    2014-12-01

    In order to study the steam reforming of methanol (SRM) to produce hydrogen for fuel cells, porous γ-alumina support is developed on Al substrate using anodic oxidation process and copper catalyst particles are deposited homogeneously over anodic aluminum oxide (AAO) surface by electrodeposition method. We investigated the effect of electrodeposition time and hot water treatment (HWT) on the activity of catalysts for SRM reaction in the temperature range between 160 and 360 °C. The experimental results indicate that the SRM activity, CO2 and dimethyl ether (DME) selectivity's over Cu catalysts increased as the electrodeposition time increased from 30 to 120 s, further increment in deposition time of Cu have no significant effect on it. The rates of SRM conversion are found to be higher for the catalysts made from the supports obtained after HWT, which may be due to the enhancement in the surface area of AAO support. It is found that the SRM activity and CO2 selectivity strongly depended upon the free exposed copper sites available for methanol adsorption and reaction, and DME in products is mainly observed in the reaction temperature range between 300 and 350 °C and it is higher for the catalysts with low Cu content.

  1. Steady-State Simulation of Steam Reforming of INEEL Tank Farm Waste

    SciTech Connect

    Nichols, T.T.; Taylor, D.D.; Wood, R.A.; Barnes, C.M.

    2002-08-15

    A steady-state model of the Sodium-Bearing Waste steam reforming process at the Idaho National Engineering and Environmental Laboratory has been performed using the commercial ASPEN Plus process simulator. The preliminary process configuration and its representation in ASPEN are described. As assessment of the capability of the model to mechanistically predict product stream compositions was made, and fidelity gaps and opportunities for model enhancement were identified, resulting in the following conclusions: (1) Appreciable benefit is derived from using an activity coefficient model for electrolyte solution thermodynamics rather than assuming ideality (unity assumed for all activity coefficients). The concentrations of fifteen percent of the species present in the primary output stream were changed by more than 50%, relative to Electrolyte NRTL, when ideality was assumed; (2) The current baseline model provides a good start for estimating mass balances and performing integrated process optimization because it contains several key species, uses a mechanistic electrolyte thermodynamic model, and is based on a reasonable process configuration; and (3) Appreciable improvement to model fidelity can be realized by expanding the species list and the list of chemical and phase transformations. A path forward is proposed focusing on the use of an improved electrolyte thermodynamic property method, addition of chemical and phase transformations for key species currently absent from the model, and the combination of RGibbs and Flash blocks to simulate simultaneous phase and chemical equilibria in the off-gas treatment train.

  2. Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter

    SciTech Connect

    Davidson, Stephen; Sun, Junming; Wang, Yong

    2013-12-02

    A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in C–C bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2–C4 product distributions.

  3. Highly loaded Ni-based catalysts for low temperature ethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Wang, Tuo; Ma, Hongyan; Zeng, Liang; Li, Di; Tian, Hao; Xiao, Shengning; Gong, Jinlong

    2016-05-01

    This paper describes the design of high-loading Ni/Al2O3 catalysts (78 wt% Ni) for low temperature ethanol steam reforming. The catalysts were synthesized via both co-precipitation (COP) and impregnation (IMP) methods. All the catalysts were measured by N2 adsorption-desorption, XRD, H2-TPR, and H2 pulse chemisorption. The characterization results demonstrated that the preparation method and the loading significantly affected the nickel particle size, active nickel surface area and catalytic performance. Over COP catalysts, large nickel particles were presented in nickel aluminum mixed oxides. In comparison, IMP catalysts gained more ``free'' NiO particles with weak interaction with the aluminum oxide. Consequently, COP catalysts yielded smaller nickel particles and larger active nickel surface areas than those of IMP catalysts. High loading is beneficial for obtaining sufficient active nickel sites when nickel particles are dispersed via COP, whereas excessive nickel content is not desired for catalysts prepared by IMP. Specifically, the 78 wt% nickel loaded catalyst synthesized by COP possessed small nickel particles (~6.0 nm) and an abundant active nickel area (35.1 m2 gcat-1). Consequently, COP-78 achieved superior stability with 92% ethanol conversion and ~35% H2 selectivity at 673 K for 30 h despite the presence of a considerable amount of coke.

  4. Carbon Deposition Onto Ni-Based Catalysts for Combined Steam/CO2 Reforming of Methane.

    PubMed

    Li, Peng; Park, Yoon Hwa; Moon, Dong Ju; Park, Nam Cook; Kim, Young Chul

    2016-02-01

    The present study was performed to suppress carbon deposition by Ce and Fe onto Ni-based catalysts in combined steam/CO2 reforming of methane (CSCRM), which is a process for producing synthesis gas (H2:CO = 2:1) for gas-to-liquids (GTL). The catalytic reaction was evaluated at 900 degrees C and 20 bar with a reactant feed ratio CH4:CO2:H20:Ar = 1:0.8:1.3:1 and gas hourly space velocity GHSV = 25,000 h(-1). The Ce and Fe modified Ni/gamma-A120, catalyst was characterized by BET surface area analysis, X-ray diffraction (XRD), H2 temperature-programmed reduction (TPR), H2 chemisorption, CO2 temperature-programmed desorption (TPD) and SEM. Ce- and Fe-modified Ni/Al2O3 catalysts exhibited remarkable activity and stability during the CSCRM over the course of 50 hours. It suggested that the Ni(12)-Ce(5)-Fe(5)/Al2O3 catalyst shows highly dispersed Ni particles with strong metal-to-support interaction (SMSI) as well as excellent catalytic activity.

  5. Methanol steam reforming promoted by molten salt-modified platinum on alumina catalysts.

    PubMed

    Kusche, Matthias; Agel, Friederike; Ní Bhriain, Nollaig; Kaftan, Andre; Laurin, Mathias; Libuda, Jörg; Wasserscheid, Peter

    2014-09-01

    We herein describe a straight forward procedure to increase the performance of platinum-on-alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the "solid catalyst with ionic liquid layer" (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum-on-alumina catalyst at KOH loadings around 7.5 mass%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Hydrogen production from steam reforming of ethylene glycol over iron loaded on MgO

    NASA Astrophysics Data System (ADS)

    Chen, Mingqiang; Wang, Yishuang; Liang, Tian; Yang, Jie; Yang, Zhonglian

    2017-01-01

    In this study, a series of Fe-based catalysts loaded on MgO were prepared by a precipitation technique. And they were tested in hydrogen production from steam reforming of ethylene glycol (SRE), which was a representative model compound of fast bio-oil. The catalysts were characterized by XRD, SEM and H2-TPR analysis. The results showed that the crystalline phases of catalysts contained Fe2O3 (Hematite), Fe3O4 (Magnetite), Fe2MgO4 (iron magnesium oxide) and MgO, and morphology of MgO was changed from the rugby-ball like particles to spherical particles with the addition of Fe. In addition, the catalytic test results indicated that the 18%Fe/MgO catalyst exhibited the highest ethylene glycol conversion (˜99.8%) and H2 molar percent (˜77%) during at the following conditions: H2O/C molar ratio is 5˜7, the feeding rate is 14 mL/h and the reaction temperature at 600˜650°C. Furthermore, the 18%Fe/MgO catalyst can keep outstanding stability during SRE for 12 h.

  7. Steady-State Simulation of Steam Reforming of INEEL Tank Farm Waste

    SciTech Connect

    Nichols, Todd Travis; Taylor, Dean Dalton; Wood, Richard Arthur; Barnes, Charles Marshall

    2002-08-01

    A steady-state model of the Sodium-Bearing Waste steam reforming process at the Idaho National Engineering and Environmental Laboratory has been performed using the commercial ASPEN Plus process simulator. The preliminary process configuration and its representation in ASPEN are described. As assessment of the capability of the model to mechanistically predict product stream compositions was made, and fidelity gaps and opportunities for model enhancement were identified, resulting in the following conclusions: 1) Appreciable benefit is derived from using an activity coefficient model for electrolyte solution thermodynamics rather than assuming ideality (unity assumed for all activity coefficients). The concentrations of fifteen percent of the species present in the primary output stream were changed by more than 50%, relative to Electrolyte NRTL, when ideality was assumed; 2) The current baseline model provides a good start for estimating mass balances and performing integrated process optimization because it contains several key species, uses a mechanistic electrolyte thermodynamic model, and is based on a reasonable process configuration; and 3) Appreciable improvement to model fidelity can be realized by expanding the species list and the list of chemical and phase transformations. A path forward is proposed focusing on the use of an improved electrolyte thermodynamic property method, addition of chemical and phase transformations for key species currently absent from the model, and the combination of RGibbs and Flash blocks to simulate simultaneous phase and chemical equilibria in the off-gas treatment train.

  8. Pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen.

    PubMed

    Renny, Andrew; Santhosh, Viswanathan; Somkuwar, Nitin; Gokak, D T; Sharma, Pankaj; Bhargava, Sanjay

    2016-11-01

    The aim of this work was to study the pyrolysis of de-oiled seed cake of Jatropha Curcas and catalytic steam reforming of pyrolytic bio-oil to hydrogen. As per literature, presence of heavy nitrogenous and oxygenated compounds leads to catalyst deactivation. Here, an attempt has been made to tune pyrolytic reactions to optimize the N and O content of the pyrolytic bio-oil. Bio-oil conversion and hydrogen yield decreased as reaction progressed, which attributes to temporary loss of catalytic activity by blockage of catalyst pores by carbon deposition. Further, retention of steam reforming activity after repetitive steam activation suggests long-term catalyst usage.

  9. Synthesis of highly efficient CaO-based, self-stabilizing CO2 sorbents via structure-reforming of steel slag.

    PubMed

    Tian, Sicong; Jiang, Jianguo; Yan, Feng; Li, Kaimin; Chen, Xuejing

    2015-06-16

    Capturing anthropogenic CO2 in a cost-effective and highly efficient manner is one of the most challenging issues faced by scientists today. Herein, we report a novel structure-reforming approach to convert steel slag, a cheap, abundant, and nontoxic calcium-rich industrial waste, as the only feedstock into superior CaO-based, self-stabilizing CO2 sorbents. The CO2 capture capacity of all the steel slag-derived sorbents was improved more than 10-fold compared to the raw slag, with the maximum uptake of CO2 achieving at 0.50 gCO2 gsorbent(-1). Additionally, the initial steel slag-derived sorbent could retain 0.25 gCO2 gsorbent(-1), that is, a decay rate of only 12% over 30 carbonation-calcination cycles, the excellent self-stabilizing property allowed it to significantly outperform conventional CaO, and match with most of the existing synthetic CaO-based sorbents. A synergistic effect that facilitated CO2 capture by CaO-based sorbents was clearly recognized when Mg and Al, the most common elements in steel slag, coexisted with CaO in the forms of MgO and Al2O3, respectively. During the calcium looping process, MgO served as a well spacer to increase the porosity of sorbents together with Al2O3 serving as a durable stabilizer to coresist the sintering of CaCO3 grains at high temperatures.

  10. The application of inelastic neutron scattering to investigate the steam reforming of methane over an alumina-supported nickel catalyst

    NASA Astrophysics Data System (ADS)

    McFarlane, Andrew R.; Silverwood, Ian P.; Norris, Elizabeth L.; Ormerod, R. Mark; Frost, Christopher D.; Parker, Stewart F.; Lennon, David

    2013-12-01

    An alumina-supported nickel catalyst, previously used in methane reforming experiments employing CO2 as the oxidant, is applied here in the steam reforming variant of the process. Micro-reactor experiments are used to discern an operational window compatible with sample cells designed for inelastic neutron scattering (INS) experiments. INS spectra are recorded after 6 h reaction of a 1:1 mixture of CH4 and H2O at 898 K. Weak INS spectra are observed, indicating minimal hydrogen retention by the catalyst in this operational regime. Post-reaction, the catalyst is further characterised by powder X-ray diffraction, transmission electron microscopy and Raman scattering. In a comparable fashion to that seen for the ‘dry’ reforming experiments, the catalyst retains substantial quantities of carbon in the form of filamentous coke. The role for hydrogen incorporation by the catalyst is briefly considered.

  11. Single-Pass Flow Through (SPFT) Testing of Fluidized-Bed Steam Reforming (FBSR) Waste Forms

    SciTech Connect

    Lorier, T. H.; Pareizs, J. M.; Jantzen, C. M.

    2005-08-15

    Two samples of fluidized-bed steam reforming (FBSR) mineral waste form product were subjected to single-pass flow-through (SPFT) testing. Sample LAW 1123 resulted from pilot-scale FBSR processing with a Hanford Envelope A low-activity waste (LAW) simulant. Sample SBW 1173 resulted from pilot-scale FBSR processing with an Idaho National Laboratory (INL) simulant commonly referred to as sodium-bearing waste (SBW). The pilot-scale waste forms were made at the Science and Technology Applications Research (STAR) facility in Idaho Falls, Idaho. The durability of the two FBSR waste forms was assessed via the SPFT test in this study. Both samples were multiphase mineral waste forms, so the SPFT test results provide an overall release rate from the multiple mineral species in each sample and are dependent on the amount of each phase present and the mineralogy of the phases present. SPFT testing was performed at temperatures of 25, 40, 70, and 90 C on LAW 1123, while SBW 1173 was only tested at 70 and 90 C. The 70 and 90 C data were compared to each other and the LAW-1123 results were compared to previous testing performed by the Pacific Northwest National Laboratory (PNNL) on a LAW Envelope C (high organic content) waste simulant. The objectives of this study were to obtain forward dissolution rate data for both STAR FBSR bed products (using SPFT tests). Also, a qualitative comparison of the FBSR bed products to a glass waste form (specifically the low-activity reference material (LRM) glass) was performed. For these comparisons, the relative surface areas of the FBSR and glass products had to be measured. Due to the more porous and irregular surface of FBSR bed products, the surface area of the bed products was determined using the Brunauer, Emmett, and Teller (BET) measurement method. The surface area of a glass is much smoother and the calculated geometric surface area is typically used for determining dissolution behavior. Presently there are no specifications or

  12. Comparative Investigation of Benzene Steam Reforming over Spinel Supported Rh and Ir Catalysts

    SciTech Connect

    Mei, Donghai; Lebarbier, Vanessa M.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra; Albrecht, Karl O.; Kovarik, Libor; Flake, Matt; Dagle, Robert A.

    2013-06-07

    In a combined experimental and first-principles density functional theory (DFT) study, benzene steam reforming (BSR) over MgAl2O4 supported Rh and Ir catalysts was investigated. Experimentally, it has been found that both highly dispersed Rh and Ir clusters (1-2 nm) on the MgAl2O4 spinel support are stable during the BSR in the temperature range of 700-850°C. Compared to the Ir/MgAl2O4 catalyst, the Rh/MgAl2O4 catalyst is more active with higher benzene turnover frequency and conversion. At typical steam conditions with the steam-to-carbon ratio > 12, the benzene conversion is only a weak function of the H2O concentration in the feed. This suggests that the initial benzene decomposition step rather than the benzene adsorption is most likely the rate-determined step in BSR over supported Rh and Ir catalysts. In order to understand the differences between the two catalysts, we followed with a comparative DFT study of initial benzene decomposition pathways over two representative model systems for each supported metal (Rh and Ir) catalysts. A periodic terrace (111) surface and an amorphous 50-atom metal cluster with a diameter of 1.0 nm were used to represent the two supported model catalysts under low and high dispersion conditions. Our DFT results show that the decreasing catalyst particle size enhances the benzene decomposition on supported Rh catalysts by lowering both C-C and C-H bond scission. The activation barriers of the C-C and the C-H bond scission decrease from 1.60 and 1.61 eV on the Rh(111) surface to 1.34 and 1.26 eV on the Rh50 cluster. For supported Ir catalysts, the decreasing particle size only affects the C-C scission. The activation barrier of the C-C scission of benzene decreases from 1.60 eV on the Ir(111) surface to 1.35 eV on the Ir50 cluster while the barriers of the C-H scission are practically the same. The experimentally measured higher BSR

  13. Corrosion of SiC and oxide-composite ceramics by a simulated steam-reformer atmosphere

    SciTech Connect

    Federer, J.I.; Kim, H.E.; Moorhead, A.J.

    1991-09-01

    To achieve higher process efficiency by using pressurized reactants and/or heat transfer fluids, the US DOE is promoting development of high-pressure heat exchanger systems under cost-sharing agreements with industrial contractors. The steam reformer would contain more than 600 tubes. Because the combination of high temperature and pressure differential of 12.7 kg/cm{sup 2} (180 psig) across the tube wall is too severe for metallic tubes, ceramic materials are being considered for reformer tubes. Their use is expected to increase the efficiency of steam reformers by about 19%. At ORNL, four SiC ceramics, a SiC-TiB{sub 2} composite, a Si{sub 3}N{sub 4}-bonded SiC ceramic, and two alumina-matrix composites were selected as candidate materials for heat exchanger/steam-reformer tubes. These commercially available materials were exposed to a simulated steam-reformer atmosphere for up to 2000 h at 1260{degrees}C to assess their corrosion behavior and the effect of the exposure on their flexure strength (in air) at 20 and 1260{degrees}C. The approximate partial pressures of the constituents of the gas mixture at 1 atm total pressure were 0.54 H{sub 2}, 0.13 CO, 0.03 CO{sub 2}m 0.004 CH{sub 4}, and 0.30 H{sub 2}O. All but one material had net weight gains during the exposure test. The flexure strengths of the SiC and Si{sub 3}N{sub 4} ceramics and the SiC-TiB{sub 2} composite at 20 and 1260{degrees}C were not changed significantly by corrosion. The strengths of the alumina-matrix composites were decreased by corrosion; however, the strength of one of these (reinforced with SiC whiskers) was still higher than that of any other material after 500 h. The other alumina composite (containing SiC particles) exhibited the largest strength decrease of any material. The strength retention of the SiC ceramics and the SiC-TiB{sub 2} composite and the strength loss of the composites were associated with surface layers caused by corrosion. 12 refs., 12 figs., 4 tabs.

  14. Accelerated Weathering of Fluidized Bed Steam Reformation Material Under Hydraulically Unsaturated Conditions

    SciTech Connect

    Pierce, Eric M.

    2007-09-16

    To predict the long-term fate of low- and high-level waste forms in the subsurface over geologic time scales, it is important to understand the behavior of the corroding waste forms under conditions the mimic to the open flow and transport properties of a subsurface repository. Fluidized bed steam reformation (FBSR), a supplemental treatment technology option, is being considered as a waste form for the immobilization of low-activity tank waste. To obtain the fundamental information needed to evaluate the behavior of the FBSR waste form under repository relevant conditions and to monitor the long-term behavior of this material, an accelerated weathering experiment is being conducted with the pressurized unsaturated flow (PUF) apparatus. Unlike other accelerated weathering test methods (product consistency test, vapor hydration test, and drip test), PUF experiments are conducted under hydraulically unsaturated conditions. These experiments are unique because they mimic the vadose zone environment and allow the corroding waste form to achieve its final reaction state. Results from this on-going experiment suggest the volumetric water content varied as a function of time and reached steady state after 160 days of testing. Unlike the volumetric water content, periodic excursions in the solution pH and electrical conductivity have been occurring consistently during the test. Release of elements from the column illustrates a general trend of decreasing concentration with increasing reaction time. Normalized concentrations of K, Na, P, Re (a chemical analogue for 99Tc), and S are as much as 1 × 104 times greater than Al, Cr, Si, and Ti. After more than 600 days of testing, the solution chemistry data collected to-date illustrate the importance of understanding the long-term behavior of the FBSR product under conditions that mimic the open flow and transport properties of a subsurface repository.

  15. FLUIDIZED BED STEAM REFORMING TECHNOLOGY FOR ORGANIC AND NITRATE SALT SUPERNATE

    SciTech Connect

    Jantzen, C; Michael02 Smith, M

    2007-03-30

    About two decades ago a process was developed at the Savannah River Site (SRS) to remove Cs137 from radioactive high level waste (HLW) supernates so the supernates could be land disposed as low activity waste (LAW). Sodium tetraphenylborate (NaTPB) was used to precipitate Cs{sup 137} as CsTPB. The flowsheet called for destruction of the organic TPB by acid hydrolysis so that the Cs{sup 137} enriched residue could be mixed with other HLW sludge, vitrified, and disposed of in a federal geologic repository. The precipitation process was demonstrated full scale with actual HLW waste and a 2.5 wt% Cs137 rich precipitate containing organic TPB was produced admixed with 240,000 gallons of salt supernate. Organic destruction by acid hydrolysis proved to be problematic and other disposal technologies were investigated. Fluidized Bed Steam Reforming (FBSR), which destroys organics by pyrolysis, is the current baseline technology for destroying the TPB and the waste nitrates prior to vitrification. Bench scale tests were designed and conducted at the Savannah River National Laboratory (SRNL) to reproduce the pyrolysis reactions. The formation of alkali carbonate phases that are compatible with DWPF waste pre-processing and vitrification were demonstrated in the bench scale tests. Test parameters were optimized for a pilot scale FBSR demonstration that was performed at the SAIC Science & Technology Application Research (STAR) Center in Idaho Falls, ID by Idaho National Laboratory (INL) and SRNL in 2003. An engineering scale demonstration was completed by THOR{reg_sign} Treatment Technologies (TTT) and SRNL in 2006 at the Hazen Research, Inc. test facility in Golden, CO. The same mineral carbonate phases, the same organic destruction (>99.99%) and the same nitrate/nitrite destruction (>99.99%) were produced at the bench scale, pilot scale, and engineering scale although different sources of carbon were used during testing.

  16. Disposition of Tank 48H Organics By Fluidized Bed Steam Reforming (FBSR) (U)

    SciTech Connect

    JANTZEN, CAROLM.

    2004-03-29

    An In Tank Processing (ITP) technology was developed at the Savannah River Site to remove Cs-137 from high-level waste supernates. During the ITP process monosodium titanate and sodium tetraphenylborate (NaTPB) were added to the salt supernate to adsorb Sr-90/Pu-238 and precipitate Cs-137 as CsTPB, respectively. This process was demonstrated at the SRS in 1983. The demonstration produced 53,000 gallons of 2.5 weight per cent Cs rich precipitate containing TPB, which was later washed and diluted to 250,000 gallons. This material is currently stored in SRS tanks. The washed precipitate was to ultimately be disposed in borosilicate glass in the Defense Waste Processing Facility. Due to safety concerns the ITP process was abandoned in 1998, and new technologies are being researched for Cs-137 removal. In order to make space in the SRS Tank farm, the tank waste must be removed. Therefore, the tank waste must be processed to reduce or eliminate levels of nitrates, nitrites, and sodium tetra phenylborate (NaTPB) in order to reduce impacts of these species before it is vitrified at the DWPF. Fluidized Bed Steam Reforming (FBSR) is being considered as a candidate technology for destroying the nitrates and the NaTPB prior to melting. The purposes of the current study, organic destruction and downstream processing of T48H waste slurry were fulfilled. TPB was destroyed in all 19 samples tested with the simulated FBSR process at operational temperatures 650-725 degrees Celsius.

  17. Pyrolysis/Steam Reforming Technology for Treatment of TRU Orphan Wastes

    SciTech Connect

    Mason, J. B.; McKibbin, J.; Schmoker, D.; Bacala, P.

    2003-02-27

    Certain transuranic (TRU) waste streams within the Department of Energy (DOE) complex cannot be disposed of at the Waste Isolation Pilot Plant (WIPP) because they do not meet the shipping requirements of the TRUPACT-II or the disposal requirements of the Waste Analysis Plan (WAP) in the WIPP RCRA Part B Permit. These waste streams, referred to as orphan wastes, cannot be shipped or disposed of because they contain one or more prohibited items, such as liquids, volatile organic compounds (VOCs), hydrogen gas, corrosive acids or bases, reactive metals, or high concentrations of polychlorinated biphenyl (PCB), etc. The patented, non-incineration, pyrolysis and steam reforming processes marketed by THOR Treatment Technologies LLC removes all of these prohibited items from drums of TRU waste and produces a dry, inert, inorganic waste material that meets the existing TRUPACT-II requirements for shipping, as well as the existing WAP requirements for disposal of TRU waste at WIPP. THOR Treatment Technologies is a joint venture formed in June 2002 by Studsvik, Inc. (Studsvik) and Westinghouse Government Environmental Services Company LLC (WGES) to further develop and deploy Studsvik's patented THORSM technology within the DOE and Department of Defense (DoD) markets. The THORSM treatment process is a commercially proven system that has treated over 100,000 cu. ft. of nuclear waste from commercial power plants since 1999. Some of this waste has had contact dose rates of up to 400 R/hr. A distinguishing characteristic of the THORSM process for TRU waste treatment is the ability to treat drums of waste without removing the waste contents from the drum. This feature greatly minimizes criticality and contamination issues for processing of plutonium-containing wastes. The novel features described herein are protected by issued and pending patents.

  18. Steam reforming of ethanol for hydrogen production over Cu/Co-Mg-Al-based catalysts prepared by hydrotalcite route.

    PubMed

    Homsi, Doris; Rached, Jihane Abou; Aouad, Samer; Gennequin, Cédric; Dahdah, Eliane; Estephane, Jane; Tidahy, Haingomalala Lucette; Aboukaïs, Antoine; Abi-Aad, Edmond

    2017-04-01

    The performances of different 5Cu/CoxMg6-xAl2 (x = 0; 2; 4; 6) catalysts prepared by the wet impregnation method were investigated in the ethanol steam-reforming reaction (ESR) at 450 °C during 4 h under a steam/ethanol ratio of 3 (S/E = 3). The best catalyst among the prepared solids was 5Cu/Co6Al2 as it showed a complete ethanol conversion and the highest hydrogen and carbon dioxide productivities. However, following 50 h of aging, the catalyst deactivated due to the formation of a high amount of carbonaceous products detected by differential scanning calorimetry/thermogravimetry. On the other hand, the 5Cu/Co2Mg4Al2 catalyst showed a much lower quantity of coke deposition with no deactivation due to the basic character conferred by the magnesium oxide phase.

  19. NiW and NiRu Bimetallic Catalysts for Ethylene Steam Reforming: Alternative Mechanisms for Sulfur Resistance

    SciTech Connect

    Rangan, M.; Yung, M. M.; Medlin, J. W.

    2012-06-01

    Previous investigations of Ni-based catalysts for the steam reforming of hydrocarbons have indicated that the addition of a second metal can reduce the effects of sulfur poisoning. Two systems that have previously shown promise for such applications, NiW and NiRu, are considered here for the steam reforming of ethylene, a key component of biomass derived tars. Monometallic and bimetallic Al{sub 2}O{sub 3}-supported Ni and W catalysts were employed for ethylene steam reforming in the presence and absence of sulfur. The NiW catalysts were less active than Ni in the absence of sulfur, but were more active in the presence of 50 ppm H{sub 2}S. The mechanism for the W-induced improvements in sulfur resistance appears to be different from that for Ru in NiRu. To probe reasons for the sulfur resistance of NiRu, the adsorption of S and C{sub 2}H{sub 4} on several bimetallic NiRu alloy surfaces ranging from 11 to 33 % Ru was studied using density functional theory (DFT). The DFT studies reveal that sulfur adsorption is generally favored on hollow sites containing Ru. Ethylene preferentially adsorbs atop the Ru atom in all the NiRu (111) alloys investigated. By comparing trends across the various bimetallic models considered, sulfur adsorption was observed to be correlated with the density of occupied states near the Fermi level while C{sub 2}H{sub 4} adsorption was correlated with the number of unoccupied states in the d-band. The diverging mechanisms for S and C{sub 2}H{sub 4} adsorption allow for bimetallic surfaces such as NiRu that enhance ethylene binding without accompanying increases in sulfur binding energy. In contrast, bimetallics such as NiSn and NiW appear to decrease the affinity of the surface for both the reagent and the poison.

  20. Ni catalyst wash-coated on metal monolith with enhanced heat-transfer capability for steam reforming

    NASA Astrophysics Data System (ADS)

    Ryu, Jae-Hong; Lee, Kwan-Young; La, Howon; Kim, Hak-Joo; Yang, Jung-Il; Jung, Heon

    A commercial Ni-based catalyst is wash-coated on a monolith made of 50 μm-thick fecralloy plates. Compared with the same volume of coarsely powdered Ni catalysts, the monolith wash-coated Ni catalysts give higher methane conversion in the steam reforming reaction, especially at gas hourly space velocities (GHSV) higher than 28,000 h -1, and with no pressure drop. A higher conversion of the monolith catalyst is obtained, even though it contains a lower amount of active catalyst (3 g versus 17 g for a powdered catalyst), which indicates that the heat-transfer capability of the wash-coated Ni catalyst is significantly enhanced by the use of a metal monolith. The efficacy of the monolith catalyst is tested using a shell-and-tube type heat-exchanger reactor with 912 cm 3 of the monolith catalyst charged on to the tube side and hot combusted gas supplied to the shell side in a counter-current direction to the reactant flow. A methane conversion greater than 94% is obtained at a GHSV of 7300 h -1 and an average temperature of 640 °C. Nickel catalysts should first be reduced to become active for steam reforming. Doping a small amount (0.12 wt.%) of noble metal (Ru or Pt) in the commercial Ni catalyst renders the wash-coated catalyst as active as a pre-reduced Ni catalyst. Thus, noble metal-doped Ni appears useful for steam reforming without any pre-reduction procedure.

  1. Preparation and initial characterization of fluidized bed steam reforming pure-phase standards

    SciTech Connect

    Missimer, D. M.; Rutherford, R. L.

    2013-03-21

    Hanford is investigating the Fluidized Bed Steam Reforming (FBSR) process for their Low Activity Waste. The FBSR process offers a low-temperature continuous method by which liquid waste can be processed with the addition of clay into a sodium aluminosilicate (NAS) waste form. The NAS waste form is mainly comprised of nepheline (NaAlSiO{sub 4}), sodalite (Na{sub 8}[AlSiO{sub 4}]{sub 6}Cl{sub 2}), and nosean (Na{sub 8}[AlSiO{sub 4}]{sub 6}SO{sub 4}). Anions such as perrhenate (ReO{sub 4}{sup -}), pertechnetate (TcO{sub 4}{sup -}), and iodine (I{sup -}) are expected to replace sulfate in the nosean structure and/or chloride in the sodalite mineral structure (atomically bonded inside the aluminosilicate cages that these mineral structures possess). In the FBSR waste form, each of these phases can exist in a variety of solid solutions that differ from the idealized forms observed in single crystals in nature. The lack of understanding of the durability of these stoichiometric or idealized mineral phases complicates the ability to deconvolute the durability of the mixed phase FBSR product since it is a combination of different NAS phases. To better understand the behavior, fabrication and testing of the individual phases of the FBSR product is required. Analytical Development (AD) of the Science and Technology directorate of the Savannah River National Laboratory (SRNL) was requested to prepare the series of phase-pure standards, consisting of nepheline, nosean, and Cl, Re, and I sodalite. Once prepared, X-ray Diffraction (XRD) analyses were used to confirm the products were phase pure. These standards are being used for subsequent characterization studies consisting of the following: single-pass flow-through (SPFT) testing, development of thermodynamic data, and x-ray diffraction (XRD) calibration curves. In addition to the above mentioned phase-pure standards, AD was tasked with fabricating a mixed Tc-Re sodalite.

  2. Performance of the Fluidized Bed Steam Reforming product under hydraulically unsaturated conditions

    SciTech Connect

    Neeway, James J; Rod, Kenton A.; Bowden, Mark E; Pierce, Eric M; Qafoku, Nikolla; Williams, Benjamin D; Brown, Christopher F

    2014-01-01

    Several candidates for supplemental low-activity waste (LAW) immobilization at the Hanford site in Washington State, USA are being considered. One waste sequestering technology considered is Fluidized Bed Steam Reforming (FBSR). The granular product resulting from the FBSR process is composed primarily of an insoluble sodium aluminosilicate matrix with the dominant phases being feldspathoid minerals with a 1:1:1 molar ratio of Na, Al and Si. To demonstrate the durability of the product, which can be disposed of at the unsaturated Integrated Disposal Facility (IDF) at Hanford, a series of tests has been performed using the Pressurized Unsaturated Flow (PUF) system, which allows for the accelerated weathering of the solid materials. The system maintains hydraulically unsaturated conditions, thus mimicking the open-flow and transport properties that will be present at the IDF. Two materials were tested using the system: 1) the FBSR granular product and 2) the FBSR granular product encapsulated in a geopolymer to form a monolith. Results of the experiments show a trend of relatively constant effluent concentration of Na, Si, Al, and Cs as a function of time from both materials. The elements I and Re show a steady release throughout the yearlong test from the granular material but their concentrations seem to be increasing at one year from the monolith material. This result suggests that these two elements may be present in the sodalite cage structure rather than in the predominant nepheline phase because their release occurs at a different rate compared to nepheline phase. Also, these elements to not seem to reprecipitate when released from the starting material. Calculated one-year release rates for Si are on the order of 10 6 g/(m2 d) for the granular material and 10 5 g/(m2 d) for the monolith material while Re release is seen to be two orders of magnitude higher than Si release rates. SEM imaging and XRD analysis show how the alteration of the two materials is

  3. Performance of the Fluidized Bed Steam Reforming product under hydraulically unsaturated conditions.

    PubMed

    Neeway, James J; Qafoku, Nikolla P; Williams, Benjamin D; Rod, Kenton; Bowden, Mark E; Brown, Christopher F; Pierce, Eric M

    2014-05-01

    Several candidates for supplemental low-activity waste (LAW) immobilization at the Hanford site in Washington State, USA are being considered. One waste sequestering technology considered is Fluidized Bed Steam Reforming (FBSR). The granular product resulting from the FBSR process is composed primarily of an insoluble sodium aluminosilicate matrix with the dominant phases being feldspathoid minerals with a 1:1:1 molar ratio of Na, Al and Si. To demonstrate the durability of the product, which can be disposed of at the unsaturated Integrated Disposal Facility (IDF) at Hanford, a series of tests has been performed using the Pressurized Unsaturated Flow (PUF) system, which allows for the accelerated weathering of the solid materials. The system maintains hydraulically unsaturated conditions, thus mimicking the open-flow and transport properties that will be present at the IDF. Two materials were tested using the system: 1) the FBSR granular product and 2) the FBSR granular product encapsulated in a geopolymer to form a monolith. Results of the experiments show a trend of relatively constant effluent concentration of Na, Si, Al, and Cs as a function of time from both materials. The elements I and Re show a steady release throughout the yearlong test from the granular material but their concentrations seem to be increasing at one year from the monolith material. This result suggests that these two elements may be present in the sodalite cage structure rather than in the predominant nepheline phase because their release occurs at a different rate compared to nepheline phase. Also, these elements to not seem to reprecipitate when released from the starting material. Calculated one-year release rates for Si are on the order of 10(-6) g/(m(2) d) for the granular material and 10(-5) g/(m(2) d) for the monolith material while Re release is seen to be two orders of magnitude higher than Si release rates. SEM imaging and XRD analysis show how the alteration of the two

  4. Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

    NASA Astrophysics Data System (ADS)

    Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

    2017-04-01

    In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

  5. Kinetics for Steam and CO2 Reforming of Methane Over Ni/La/Al2O3 Catalyst.

    PubMed

    Park, Myung Hee; Choi, Bong Kwan; Park, Yoon Hwa; Moon, Dong Ju; Park, Nam Cook; Kim, Young Chul

    2015-07-01

    Kinetic studies of mixed (steam and dry) reforming of methane on Ni/La/Al2O3 and Ni/La-Co (1, 3 wt%)/Al2O3 catalysts were performed in an atmospheric fixed-bed reactor. Kinetic parameters for the mixed reforming over these catalysts were obtained under reaction conditions free from heat and mass transfer limitations. Variables for the mixed reforming were the reaction temperature and partial pressure of reactants. The fitting of the experimental data for the rate of methane conversion, rCH4, using the power law rate equation rCH4 = k(PrCH4)α(PCO2)β(PH2O)γ showed that the reaction orders α, β, and γ are steady and obtained values equal to α = 1, β = 0, and γ = 0. In other words, among CH4, CO2, H2O, and H2, only CH4 reaction orders were not zero and they were affected by the promoters. The apparent activation energy on catalysts Ni/La/Al2O3, Ni/La-Co (1)/Al2O3 and Ni/La-Co (3)/Al2O3 is 85.2, 93.8, and 99.4 kJ/mol, respectively. The addition of Co to Ni/La/Al2O3 was increased the apparent activation energy of the mixed reforming reaction. And the Ni/La-Co (3 wt%)/Al2O3 catalyst showed the highest reforming activity and apparent activation energy. The Co promoters can increase the apparent activation energy of mixed reforming of methane.

  6. Alkali Metal CO2 Sorbents and the Resulting Metal Carbonates: Potential for Process Intensification of Sorption-Enhanced Steam Reforming.

    PubMed

    Memon, Muhammad Zaki; Zhao, Xiao; Sikarwar, Vineet Singh; Vuppaladadiyam, Arun K; Milne, Steven J; Brown, Andy P; Li, Jinhui; Zhao, Ming

    2017-01-03

    Sorption-enhanced steam reforming (SESR) is an energy and cost efficient approach to produce hydrogen with high purity. SESR makes it economically feasible to use a wide range of feedstocks for hydrogen production such as methane, ethanol, and biomass. Selection of catalysts and sorbents plays a vital role in SESR. This article reviews the recent research aimed at process intensification by the integration of catalysis and chemisorption functions into a single material. Alkali metal ceramic powders, including Li2ZrO3, Li4SiO4 and Na2ZrO3 display characteristics suitable for capturing CO2 at low concentrations (<15% CO2) and high temperatures (>500 °C), and thus are applicable to precombustion technologies such as SESR, as well as postcombustion capture of CO2 from flue gases. This paper reviews the progress made in improving the operational performance of alkali metal ceramics under conditions that simulate power plant and SESR operation, by adopting new methods of sorbent synthesis and doping with additional elements. The paper also discusses the role of carbonates formed after in situ CO2 chemisorption during a steam reforming process in respect of catalysts for tar cracking.

  7. Sulfur poisoning mechanism of steam reforming catalysts: an X-ray absorption near edge structure (XANES) spectroscopic study.

    PubMed

    Chen, Yongsheng; Xie, Chao; Li, Yan; Song, Chunshan; Bolin, Trudy B

    2010-06-07

    The present XANES study aims at elucidating the roles of carbon deposits and metal sulfides in the catalyst deactivation in steam reforming reactions with the presence of sulfur. CeO(2)-Al(2)O(3)-supported Ni and Rh-based catalysts were tested in steam reforming of liquid hydrocarbon fuel containing 350 ppm sulfur for H(2) production at 800 degrees C. The Rh catalyst demonstrated much better sulfur tolerance than the Ni catalyst. XANES revealed that there are various sulfur species (metal sulfide, sulfonate, sulfate and organic sulfide) on the used Ni and Rh catalysts. Metal sulfide and organic sulfide are the dominant sulfur species on the Ni catalyst whereas sulfonate and sulfate predominate on the Rh catalyst. Meanwhile organic sulfide and sulfate are also observed on the support alone. Furthermore, there are more carbon deposits formed in the presence of sulfur on both catalysts. More carboxyl groups occur on the carbon deposits formed on the same catalyst when there is no sulfur in the fuel. From correlation analysis of the amounts of nickel sulfide and carbon deposits along with the relative catalytic activity loss, we conclude that sulfur causes the initial deactivation of the Ni catalyst by metal sulfide formation in the first few hours while build-up of carbon deposits contributes mainly to the subsequent deactivation.

  8. Minimizing the formation of coke and methane on Co nanoparticles in steam reforming of biomass-derived oxygenates

    SciTech Connect

    Sun, Junming; Mei, Donghai; Karim, Ayman M.; Datye, Abhaya K.; Wang, Yong

    2013-06-01

    Fundamental understanding and control of chemical transformations are essential to the development of technically feasible and economically viable catalytic processes for efficient conversion of biomass to fuels and chemicals. Using an integrated experimental and theoretical approach, we report high hydrogen selectivity and catalyst durability of acetone steam reforming (ASR) on inert carbon supported Co nanoparticles. The observed catalytic performance is further elucidated on the basis of comprehensive first-principles calculations. Instead of being considered as an undesired intermediate prone for catalyst deactivation during bioethanol steam reforming (ESR), acetone is suggested as a key and desired intermediate in proposed two-stage ESR process that leads to high hydrogen selectivity and low methane formation on Co-based catalysts. The significance of the present work also sheds a light on controlling the chemical transformations of key intermediates in biomass conversion such as ketones. We gratefully acknowledge the financial support from U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and the Laboratory directed research and development (LDRD) project of Pacific Northwest National Laboratory (PNNL). Computing time was granted by the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). The EMSL is a U.S. DOE national scientific user facility located at PNNL, and sponsored by the U.S. DOE’s Office of Biological and Environmental Research.

  9. Polymer electrolyte membrane fuel cell grade hydrogen production by methanol steam reforming: A comparative multiple reactor modeling study

    NASA Astrophysics Data System (ADS)

    Katiyar, Nisha; Kumar, Shashi; Kumar, Surendra

    2013-12-01

    Analysis of a fuel processor based on methanol steam reforming has been carried out to produce fuel cell grade H2. Six reactor configurations namely FBR1 (fixed bed reactor), MR1 (H2 selective membrane reactor with one reaction tube), MR2 (H2 selective membrane reactor with two reaction tubes), FBR2 (FBR1 + preferential CO oxidation (PROX) reactor), MR3 (MR1 + PROX), and MR4 (MR2 + PROX) are evaluated by simulation to identify the suitable processing scheme. The yield of H2 is significantly affected by H2 selective membrane, residence time, temperature, and pressure conditions at complete methanol conversion. The enhancement in residence time in MR2 by using two identical reaction tubes provides H2 yield of 2.96 with 91.25 mol% recovery at steam/methanol ratio of 1.5, pressure of 2 bar and 560 K temperature. The exit retentate gases from MR2 are further treated in PROX reactor of MR4 to reduce CO concentration to 4.1 ppm to ensure the safe discharge to the environment. The risk of carbon deposition on reforming catalyst is highly reduced in MR4, and MR4 reactor configuration generates 7.4 NL min-1 of CO free H2 from 0.12 mol min-1 of methanol which can provide 470 W PEMFC feedstock requirement. Hence, process scheme in MR4 provides a compact and innovative fuel cell grade H2 generating unit.

  10. Understanding of catalyst deactivation caused by sulfur poisoning and carbon deposition in steam reforming of liquid hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Xie, Chao

    2011-12-01

    The present work was conducted to develop a better understanding on the catalyst deactivation in steam reforming of sulfur-containing liquid hydrocarbon fuels for hydrogen production. Steam reforming of Norpar13 (a liquid hydrocarbon fuel from Exxon Mobile) without and with sulfur was performed on various metal catalysts (Rh, Ru, Pt, Pd, and Ni) supported on different materials (Al2O3, CeO2, SiO2, MgO, and CeO2- Al2O3). A number of characterization techniques were applied to study the physicochemical properties of these catalysts before and after the reactions. Especially, X-ray absorption near edge structure (XANES) spectroscopy was intensively used to investigate the nature of sulfur and carbon species in the used catalysts to reveal the catalyst deactivation mechanism. Among the tested noble metal catalysts (Rh, Ru, Pt, and Pd), Rh catalyst is the most sulfur tolerant. Al2O3 and CeO2 are much better than SiO2 and MgO as the supports for the Rh catalyst to reform sulfur-containing hydrocarbons. The good sulfur tolerance of Rh/Al2O3 can be attributed to the acidic nature of the Al2O3 support and its small Rh crystallites (1-3 nm) as these characteristics facilitate the formation of electron-deficient Rh particles with high sulfur tolerance. The good catalytic performance of Rh/CeO2 in the presence of sulfur can be ascribed to the promotion effect of CeO2 on carbon gasification, which significantly reduced the carbon deposition on the Rh/CeO2catalyst. Steam reforming of Norpar13 in the absence and presence of sulfur was further carried out over CeO2-Al2O3 supported monometallic Ni and Rh and bimetallic Rh-Ni catalysts at 550 and 800 °C. Both monometallic catalysts rapidly deactivated at 550 °C, iv and showed poor sulfur tolerance. Although ineffective for the Ni catalyst, increasing the temperature to 800 °C dramatically improved the sulfur tolerance of the Rh catalyst. Sulfur K-edge XANES revealed that metal sulfide and organic sulfide are the dominant sulfur

  11. Multifunctional Pd/Ni-Co catalyst for hydrogen production by chemical looping coupled with steam reforming of acetic acid.

    PubMed

    Fermoso, Javier; Gil, María V; Rubiera, Fernando; Chen, De

    2014-11-01

    High yield of high-purity H2 from acetic acid, a model compound of bio-oil obtained from the fast pyrolysis of biomass, was produced by sorption-enhanced steam reforming (SESR). An oxygen carrier was introduced into a chemical loop (CL) coupled to the cyclical SESR process to supply heat in situ for the endothermic sorbent regeneration to increase the energy efficiency of the process. A new multifunctional 1 %Pd/20 %Ni-20 %Co catalyst was developed for use both as oxygen carrier in the CL and as reforming catalyst in the SESR whereas a CaO-based material was used as CO2 sorbent. In the sorbent-air regeneration step, the Ni-Co atoms in the catalyst undergo strong exothermic oxidation reactions that provide heat for the CaO decarbonation. The addition of Pd to the Ni-Co catalyst makes the catalyst active throughout the whole SESR-CL cycle. Pd significantly promotes the reduction of Ni-Co oxides to metallic Ni-Co during the reforming stage, which avoids the need for a reduction step after regeneration. H2 yield above 90 % and H2 purity above 99.2 vol % were obtained.

  12. Hydrogen generation having CO2 removal with steam reforming

    DOEpatents

    Kandaswamy, Duraiswamy; Chellappa, Anand S.; Knobbe, Mack

    2015-07-28

    A method for producing hydrogen using fuel cell off gases, the method feeding hydrocarbon fuel to a sulfur adsorbent to produce a desulfurized fuel and a spent sulfur adsorbent; feeding said desulfurized fuel and water to an adsorption enhanced reformer that comprises of a plurality of reforming chambers or compartments; reforming said desulfurized fuel in the presence of a one or more of a reforming catalyst and one or more of a CO2 adsorbent to produce hydrogen and a spent CO2 adsorbent; feeding said hydrogen to the anode side of the fuel cell; regenerating said spent CO2 adsorbents using the fuel cell cathode off-gases, producing a flow of hydrogen by cycling between said plurality of reforming chambers or compartments in a predetermined timing sequence; and, replacing the spent sulfur adsorbent with a fresh sulfur adsorbent at a predetermined time.

  13. Improving carbon tolerance of Ni-YSZ catalytic porous membrane by palladium addition for low temperature steam methane reforming

    NASA Astrophysics Data System (ADS)

    Lee, Sang Moon; Won, Jong Min; Kim, Geo Jong; Lee, Seung Hyun; Kim, Sung Su; Hong, Sung Chang

    2017-10-01

    Palladium was added on the Ni-YSZ catalytic porous membrane by wet impregnation and electroless plating methods. Its surface morphology characteristics and carbon deposition properties for the low temperature steam methane reforming were investigated. The addition of palladium could obviously be enhanced the catalytic activity as well as carbon tolerance of the Ni-YSZ porous membrane. The porous membranes were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CH4 temperature-programmed reduction (CH4-TPR), and O2 temperature-programmed oxidation (O2-TPO). It was found that the Pd-Ni-YSZ catalytic porous membrane showed the superior stability as well as the deposition of carbon on the surface during carbon dissociation adsorption at 650 °C was also suppressed.

  14. Catalytic roles of Co0 and Co2+ during steam reforming of ethanol on Co/MgO catalysts

    SciTech Connect

    Karim, Ayman M.; Su, Yu; Engelhard, Mark H.; King, David L.; Wang, Yong

    2011-02-25

    Abstract: The catalytic roles of Co0 and Co2+ during steam reforming of ethanol were investigated over Co/MgO catalysts. Catalysts with different Co0/(Co0+Co2+) fraction were prepared through calcination and/or reduction at different temperatures, and the Co0 fraction was quantified by TPR and in-situ XPS. High temperature calcination of Co/MgO allowed us to prepare catalysts with more non-reducible Co2+ incorporated in the MgO lattice, while lower calcination temperatures allowed for the preparation of catalysts with higher Co0/(Co0+Co2+) fractions. The catalytic tests on Co0, non-reducible Co2+, and reducible Co2+ indicated that Co0 is much more active than either reducible or non-reducible Co2+ for C-C cleavage and water gas shift reaction. In addition, catalysts with a higher Co0 surface fraction exhibited a lower selectivity to CH4.

  15. Preparation of Cu–Fe–Al–O nanosheets and their catalytic application in methanol steam reforming for hydrogen production

    NASA Astrophysics Data System (ADS)

    Wang, Leilei; Zhang, Fan; Miao, Dinghao; Zhang, Lei; Ren, Tiezhen; Hui, Xidong; He, Zhanbing

    2017-03-01

    Candidates of precious metal catalysts, prepared in a facile and environmental way and showing high catalytic performances at low temperatures, are always highly desired by industry. In this work, large-scale Cu–Fe–Al–O nanosheets were synthesized by facile dealloying of Al–Cu–Fe alloys in NaOH solution. The composition, microscopic morphology, and crystal structure were respectively investigated using wavelength-dispersive x-ray spectroscopy with an electron probe microanalyzer, scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. Furthermore, we found that the 2D Cu–Fe–Al–O nanosheets gave excellent catalytic performances in hydrogen production by methanol steam reforming at relatively low temperatures, e.g. 513 K.

  16. The production of pure pressurised hydrogen by the reformer-steam iron process in a fixed bed reactor system

    NASA Astrophysics Data System (ADS)

    Nestl, Stephan; Voitic, Gernot; Lammer, Michael; Marius, Bernhard; Wagner, Julian; Hacker, Viktor

    2015-04-01

    In this paper a fixed bed chemical looping process for the decentralised production of pure pressurised hydrogen for fuel cell applications is described. CH4 is converted to a syngas using conventional steam reforming. The syngas is directly used for the reduction of an iron based oxygen carrier. A consecutive oxidation step using steam leads to the formation of pure pressurised hydrogen. A thermodynamic analysis was performed in order to investigate feasible conditions for the syngas generation and reduction step. Experiments using pure hydrogen as well as an artificial syngas mixture showed the feasibility of the process for the production of pressurised hydrogen. A stable hydrogen production at a pressure of 8-11 bar(g) was achieved and only minor impurities of 700 ppm of carbon dioxide but no signs of carbon monoxide were detected in the produced hydrogen. Although the active surface decreased from 7.5 m2 g-1 to 0.9 m2 g-1 only moderate losses of reactivity were measured in the fixed bed reactor. Thermogravimetric analysis showed a loss of 9% of reactive material over nine cycles, presumably due to sintering effects.

  17. Process And Apparatus To Accomplish Autothermal Or Steam Reforming Via A Reciprocating Compression Device

    DOEpatents

    Lyons, K. David; James, Robert; Berry, David A.; Gardner, Todd

    2004-09-21

    The invention provides a method and apparatus for producing a synthesis gas from a variety of hydrocarbons. The apparatus (device) consists of a semi-batch, non-constant volume reactor to generate a synthesis gas. While the apparatus feeds mixtures of air, steam, and hydrocarbons into a cylinder where work is performed on the fluid by a piston to adiabatically raise its temperature without heat transfer from an external source.

  18. Process to Accomplish Autothermal or Steam Reforming Via a Reciprocating Compression Device

    SciTech Connect

    Lyons, David K.; James, Robert; Berry, David A.; Gardern, Todd

    2004-09-21

    The invention provides a method and apparatus for producing a synthesis gas from a variety of hydrocarbons. The apparatus (device) consists of a semi-batch, non-constant volume reactor to generate a synthesis gas. While the apparatus feeds mixtures of air, steam, and hydrocarbons into a cylinder where work is performed on the fluid by a piston to adiabatically raise its temperature without heat transfer from an external source.

  19. A theoretical study on the role of water and its derivatives in acetic acid steam reforming on Ni(111)

    NASA Astrophysics Data System (ADS)

    Du, Zhen-Yi; Ran, Yan-Xiong; Guo, Yun-Peng; Feng, Jie; Li, Wen-Ying

    2017-10-01

    Catalytic steam reforming of acetic acid can be divided into two steps, i.e. acetic acid decomposition followed by water gas shift. While theoretical studies have been devoted to these two individual reactions, the role of water and its derivatives in the reforming process, especially in CH3COOH decomposition, remains largely unknown. In this study, a thorough investigation of the effects of the solvent water and its derived O*/OH* species on some key dehydrogenation steps on Ni(111) is carried out using density functional theory. The involved dehydrogenation species include O-H bond scission species H2O*, CH3COOH*, trans-COOH* and C-H bond scission species CH3CO*, CH3C*, CH2C*. The results show that the pre-adsorbed O*, OH*, and H2O* species not only affect the adsorption stability of these species, but also influence their dehydrogenation reactivity. O* and OH* species can both enhance the O-H bond scission, and the promotional effect of O* is superior to OH*. Nevertheless, H-abstraction from C-H bond by O* and OH* are both hindered except for CH3CO* dehydrogenation in the presence of OH*. Furthermore, the solvent water notably weakens O-H bonds, yet exhibits negligible effect on the C-H bond breakage. Analogously, the solvent effect of CH3COOH* on O-H bond scission is also investigated.

  20. Modeling of electrochemistry and steam-methane reforming performance for simulating pressurized solid oxide fuel cell stacks

    NASA Astrophysics Data System (ADS)

    Recknagle, Kurtis P.; Ryan, Emily M.; Koeppel, Brian J.; Mahoney, Lenna A.; Khaleel, Moe A.

    This paper examines the electrochemical and direct internal steam-methane reforming performance of the solid oxide fuel cell when subjected to pressurization. Pressurized operation boosts the Nernst potential and decreases the activation polarization, both of which serve to increase cell voltage and power while lowering the heat load and operating temperature. A model considering the activation polarization in both the fuel and the air electrodes was adopted to address this effect on the electrochemical performance. The pressurized methane conversion kinetics and the increase in equilibrium methane concentration are considered in a new rate expression. The models were then applied in simulations to predict how the distributions of direct internal reforming rate, temperature, and current density are effected within stacks operating at elevated pressure. A generic 10 cm counter-flow stack model was created and used for the simulations of pressurized operation. The predictions showed improved thermal and electrical performance with increased operating pressure. The average and maximum cell temperatures decreased by 3% (20 °C) while the cell voltage increased by 9% as the operating pressure was increased from 1 to 10 atm.

  1. A passively-fed methanol steam reformer heated with two-stage bi-fueled catalytic combustor

    NASA Astrophysics Data System (ADS)

    Lo, Kai-Fan; Wong, Shwin-Chung

    2012-09-01

    This paper presents further progress on our simple novel passively-fed methanol steam reformer. The present study focuses on the development of a catalytic combustor workable with both hydrogen and methanol fuels. The aim is to reutilize the exhaust hydrogen from a fuel cell under stable operation but burn methanol during the start-up. On a copper plate, the catalytic combustor in a u-turn channel is integrally machined under a two-turn serpentine-channel reformer. To resolve the highly different fuel reactivities, a suitably diluted catalyst formula demonstrates uniform temperature distributions burning with either liquid methanol or an H2/CO2 mixture simulating the exhaust gas from a fuel cell. In a two-stage process, it first takes 25 min to reach 270 °C by burning methanol. After the fuel is switched to the H2/CO2 mixture, another 20 min is needed to attain an optimal steady state which yields a high methanol conversion of 95% and acceptably low CO fraction of 1.04% at a reaction temperature of 278 °C. The H2 and CO2 concentrations are 75.1% and 23.6%.

  2. Catalyst evaluation for high-purity H2 production by sorption-enhanced steam-methane reforming coupled to a Ca/Cu process

    NASA Astrophysics Data System (ADS)

    Navarro, M. V.; López, J. M.; García, T.; Grasa, G.; Murillo, R.

    2017-09-01

    The operational limits of a commercial nickel-based catalyst under the conditions of a sorption-enhanced steam-methane reforming process coupled to a Ca/Cu chemical loop are investigated for high-purity H2 production in a cyclic operation. The performance of the reforming catalyst is tested by means of a high number of oxidation-reduction-reforming cycles. After 100 oxidation-reduction cycles, this catalyst retains its exceptional reforming activity. The methane conversion values are close to the thermodynamic equilibrium under very demanding conditions: temperature between 500 °C - 700 °C and mass hourly space velocity of 8.8 kgCH4 h-1 kgcat-1. After 200 cycles, the sample shows reduction in its reforming activity in line with a lower dispersion of the Ni species. Sintering of Ni nanocrystals is evidenced during the oxidation-reduction multi-cycles. The performance of the catalyst after 200 oxidation-reduction cycles mixed with a CaO-based CO2 sorbent is studied under optimal conditions calculated for the sorption-enhanced reforming process coupled to a Ca/Cu cycle (temperature of 650 °C, steam/methane ratio of 4, sorbent/catalyst ratio of 4 and space velocity of 0.75 kgCH4 h-1 kgcat-1). Remarkably, an equilibrium value over 92 vol.% H2 concentration is achieved, highlighting this catalyst as a promising candidate for the next steps of the process development.

  3. Co-generation of electricity and syngas on proton-conducting solid oxide fuel cell with a perovskite layer as a precursor of a highly efficient reforming catalyst

    NASA Astrophysics Data System (ADS)

    Wan, Tingting; Zhu, Ankang; Guo, Youmin; Wang, Chunchang; Huang, Shouguo; Chen, Huili; Yang, Guangming; Wang, Wei; Shao, Zongping

    2017-04-01

    In this study, a proton conducting solid oxide fuel cell (layered H+-SOFC) is prepared by introducing a La2NiO4perovskite oxide with a Ruddlesden-Popper structure as a catalyst layer onto a conventional NiO + BaZr0.4Ce0.4Y0.2O3-δ (NiO + BZCY4) anode for in situ CO2 dry reforming of methane. The roles of the La2NiO4 catalyst layer on the reforming activity, coking tolerance, electrocatalytic activity and operational stability of the anodes are systematically studied. The La2NiO4 catalyst layer exhibits greater catalytic performance than the NiO + BZCY4 anode during the CO2 dry reforming of methane. An outstanding coking resistance capability is also demonstrated. The layered H+-SOFC consumes H2 produced in situ at the anode and delivers a much higher power output than the conventional cell with the NiO + BZCY4 anode. The improved coking resistance of the layered H+-SOFC results in a steady output voltage of ∼0.6 V under a constant current density of 200 mA cm-2. In summary, the H+-SOFC with La2NiO4 perovskite oxide is a potential energy conversion device for CO2 conversion and utilization with co-generation of electricity and syngas.

  4. Steam reforming of tar derived from lignin over pompom-like potassium-promoted iron-based catalysts formed on calcined scallop shell.

    PubMed

    Guan, Guoqing; Kaewpanha, Malinee; Hao, Xiaogang; Zhu, Ai-Min; Kasai, Yutaka; Kakuta, Seiji; Kusakabe, Katsuki; Abudula, Abuliti

    2013-07-01

    In order to understand the improvement effect of potassium (K) on the catalytic activity of iron-loaded calcined scallop shell (CS) for the steam reforming tar derived from biomass, various K precursors were applied for the catalyst preparation. It is found that pompom-like iron-based particles with a mesoporous structure were easily formed on the surface of calcined scallop shell (CS) when K2CO3 was used as K precursor while no such kind of microsphere was formed when other kinds of K precursors such as KOH and KNO3 were applied. The optimum K-loading amount for the preparation of this catalyst was investigated. Based on the experimental results obtained, a mechanism for the formation of these microspheres was proposed. This pompom-like potassium-promoted iron-based catalyst showed a better catalytic activity and reusability for the steam reforming of tar derived from lignin.

  5. MINERALIZING, STEAM REFORMING TREATMENT OF HANFORD LOW-ACTIVITY WASTE (a.k.a. INEEL/EXT-05-02526)

    SciTech Connect

    A. L. Olson; N. R. Soelberg; D. W. Marshall; G. L. Anderson

    2005-02-01

    The U.S. Department of Energy (DOE) documented, in 2002, a plan for accelerating cleanup of the Hanford Site, located in southeastern Washington State, by at least 35 years. A key element of the plan was acceleration of the tank waste program and completion of ''tank waste treatment by 2028 by increasing the capacity of the planned Waste Treatment Plant (WTP) and using supplemental technologies for waste treatment and immobilization.'' The plan identified steam reforming technology as a candidate for supplemental treatment of as much as 70% of the low-activity waste (LAW). Mineralizing steam reforming technology, offered by THOR Treatment Technologies, LLC would produce a denitrated, granular mineral waste form using a high-temperature fluidized bed process. A pilot scale demonstration of the technology was completed in a 15-cm-diameter reactor vessel. The pilot scale facility was equipped with a cyclone separator and heated sintered metal filters for particulate removal, a thermal oxidizer for reduced gas species and NOx destruction, and a packed activated carbon bed for residual volatile species capture. The pilot scale equipment is owned by the DOE, but located at the Science and Technology Applications Research (STAR) Center in Idaho Falls, ID. Pilot scale testing was performed August 2–5, 2004. Flowsheet chemistry and operational parameters were defined through a collaborative effort involving Idaho National Engineering and Environmental Laboratory (INEEL), Savannah River National Laboratory (SRNL), and THOR Treatment Technologies personnel. Science Application International Corporation, owners of the STAR Center, personnel performed actual pilot scale operation. The pilot scale test achieved a total of 68.4 hours of cumulative/continuous processing operation before termination in response to a bed de-fluidization condition. 178 kg of LAW surrogate were processed that resulted in 148 kg of solid product, a mass reduction of about 17%. The process achieved

  6. CO2-selective methanol steam reforming on In-doped Pd studied by in situ X-ray photoelectron spectroscopy

    PubMed Central

    Rameshan, Christoph; Lorenz, Harald; Mayr, Lukas; Penner, Simon; Zemlyanov, Dmitry; Arrigo, Rosa; Haevecker, Michael; Blume, Raoul; Knop-Gericke, Axel; Schlögl, Robert; Klötzer, Bernhard

    2012-01-01

    In situ X-ray photoelectron spectroscopy (in situ XPS) was used to study the structural and catalytic properties of Pd–In near-surface intermetallic phases in correlation with previously studied PdZn and PdGa. Room temperature deposition of ∼4 monolayer equivalents (MLEs) of In metal on Pd foil and subsequent annealing to 453 K in vacuum yields a ∼1:1 Pd/In near-surface multilayer intermetallic phase. This Pd1In1 phase exhibits a similar “Cu-like” electronic structure and indium depth distribution as its methanol steam reforming (MSR)-selective multilayer Pd1Zn1 counterpart. Catalytic characterization of the multilayer Pd1In1 phase in MSR yielded a CO2-selectivity of almost 100% between 493 and 550 K. In contrast to previously studied In2O3-supported PdIn nanoparticles and pure In2O3, intermediate formaldehyde is only partially converted to CO2 using this Pd1In1 phase. Strongly correlated with PdZn, on an In-diluted PdIn intermetallic phase with “Pd-like” electronic structure, prepared by thermal annealing at 623 K, methanol steam reforming is suppressed and enhanced CO formation via full methanol dehydrogenation is observed. To achieve CO2-TOF values on the isolated Pd1In1 intermetallic phase as high as on supported PdIn/In2O3, at least 593 K reaction temperature is required. A bimetal-oxide synergism, with both bimetallic and oxide synergistically contributing to the observed catalytic activity and selectivity, manifests itself by accelerated formaldehyde-to-CO2 conversion at markedly lowered temperatures as compared to separate oxide and bimetal. Combination of suppression of full methanol dehydrogenation to CO on Pd1In1 inhibited inverse water–gas-shift reaction on In2O3 and fast water activation/conversion of formaldehyde is the key to the low-temperature activity and high CO2-selectivity of the supported catalyst. PMID:23226689

  7. High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

    SciTech Connect

    G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

    2011-12-31

    The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

  8. CESIUM REMOVAL FROM TANKS 241-AN-103 & 241-SX-105 & 241-AZ-101/102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    SciTech Connect

    DUNCAN JB; HUBER HJ

    2011-06-08

    This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-10-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FB SR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-S.2.1-20 1 0-00 1, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, 'Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

  9. CESIUM REMOVAL FROM TANKS 241-AN-103 & 241-SX-105 & 241-AZ-101 & 241AZ-102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    SciTech Connect

    DUNCAN JB; HUBER HJ

    2011-04-21

    This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

  10. Development of a novel ceramic microchannel reactor for methane steam reforming

    NASA Astrophysics Data System (ADS)

    Murphy, Danielle M.

    Microchannel heat exchanger and reactor technology has recently gained interest as an innovative way to improve heat-exchanger efficiency, reduce size and weight, and utilize thermal management capabilities to improve conversion, yield, selectivity, and catalyst life. Among many other possible applications, this technology is suitable for advanced recuperated engines, oxy-fired combustion processes for oxygen separation, gas-cooled nuclear reactors, recuperative heat exchanger and reformer units for solid oxide fuel cell systems, and chemical processing. This work presents the design, fabrication, and performance of novel ceramic microchannel reactors in heat-exchanger and fuel-reforming applications. Although most microchannel devices are made of metal materials, ceramics offer an alternative which enables significantly higher operating temperatures, improved tolerance to harsh chemical environments, and improved adherence of ceramic-based catalyst washcoats. Significant cost savings in materials and manufacturing methods for high-volume manufacturing can also be achieved. High-temperature performance of the ceramic microchannel reactor is measured through non-reactive heat-exchanger experiments within a dedicated test stand. Heat-exchanger effectiveness of up to 88% is experimentally established. After coating catalyst material over half of the reactor layers, use of the ceramic microchannel reactor in methane fuel-processing applications is demonstrated. As a fuel reformer, the ceramic microchannel reactor achieves process intensification by combining heat-exchanger and catalytic-reactor functions to produce syngas. Gas hourly space velocities (GHSV) up to 50,000 hr-1 with methane conversion higher than 85% are achieved. A complete computational fluid dynamics (CFD) model, as well as a geometrically simplified hybrid CFD/chemical kinetics model, is used in conjunction with experimentation to examine heat transfer, fluid flow, and chemical kinetics within the

  11. Steam reforming of methanol over oxide decorated nanoporous gold catalysts: a combined in situ FTIR and flow reactor study.

    PubMed

    Shi, J; Mahr, C; Murshed, M M; Gesing, T M; Rosenauer, A; Bäumer, M; Wittstock, A

    2017-03-29

    Methanol as a green and renewable resource can be used to generate hydrogen by reforming, i.e., its catalytic oxidation with water. In combination with a fuel cell this hydrogen can be converted into electrical energy, a favorable concept, in particular for mobile applications. Its realization requires the development of novel types of structured catalysts, applicable in small scale reactor designs. Here, three different types of such catalysts were investigated for the steam reforming of methanol (SRM). Oxides such as TiO2 and CeO2 and mixtures thereof (Ce1Ti2Ox) were deposited inside a bulk nanoporous gold (npAu) material using wet chemical impregnation procedures. Transmission electron and scanning electron microscopy reveal oxide nanoparticles (1-2 nm in size) abundantly covering the strongly curved surface of the nanoporous gold host (ligaments and pores on the order of 40 nm in size). These catalysts were investigated in a laboratory scaled flow reactor. First conversion of methanol was detected at 200 °C. The measured turn over frequency at 300 °C of the CeOx/npAu catalyst was 0.06 s(-1). Parallel investigation by in situ infrared spectroscopy (DRIFTS) reveals that the activation of water and the formation of OHads are the key to the activity/selectivity of the catalysts. While all catalysts generate sufficient OHads to prevent complete dehydrogenation of methanol to CO, only the most active catalysts (e.g., CeOx/npAu) show direct reaction with formic acid and its decomposition to CO2 and H2. The combination of flow reactor studies and in operando DRIFTS, thus, opens the door to further development of this type of catalyst.

  12. Effects of preparation method on the performance of Ni/Al(2)O(3) catalysts for hydrogen production by bio-oil steam reforming.

    PubMed

    Li, Xinbao; Wang, Shurong; Cai, Qinjie; Zhu, Lingjun; Yin, Qianqian; Luo, Zhongyang

    2012-09-01

    Steam reforming of bio-oil derived from the fast pyrolysis of biomass is an economic and renewable process for hydrogen production. The main objective of the present work has been to investigate the effects of the preparation method of Ni/Al(2)O(3) catalysts on their performance in hydrogen production by bio-oil steam reforming. The Ni/Al(2)O(3) catalysts were prepared by impregnation, co-precipitation, and sol-gel methods. XRD, XPS, H(2)-TPR, SEM, TEM, TG, and N(2) physisorption measurements were performed to characterize the texture and structure of the catalysts obtained after calcination and after their subsequent use. Ethanol and bio-oil model compound were selected for steam reforming to evaluate the catalyst performance. The catalyst prepared by the co-precipitation method was found to display better performance than the other two. Under the optimized reaction conditions, an ethanol conversion of 99% and a H(2) yield of 88% were obtained.

  13. Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix

    SciTech Connect

    Pires, Richard P.; Westsik, Joseph H.; Serne, R. Jeffrey; Mattigod, Shas V.; Golovich, Elizabeth C.; Valenta, Michelle M.; Parker, Kent E.

    2011-07-14

    Screening tests are being conducted to evaluate waste forms for immobilizing secondary liquid wastes from the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Plans are underway to add a stabilization treatment unit to the Effluent Treatment Facility to provide the needed capacity for treating these wastes from WTP. The current baseline is to use a Cast Stone cementitious waste form to solidify the wastes. Through a literature survey, DuraLith alkali-aluminosilicate geopolymer, fluidized-bed steam reformation (FBSR) granular product encapsulated in a geopolymer matrix, and a Ceramicrete phosphate-bonded ceramic were identified both as candidate waste forms and alternatives to the baseline. These waste forms have been shown to meet waste disposal acceptance criteria, including compressive strength and universal treatment standards for Resource Conservation and Recovery Act (RCRA) metals (as measured by the toxicity characteristic leaching procedure [TCLP]). Thus, these non-cementitious waste forms should also be acceptable for land disposal. Information is needed on all four waste forms with respect to their capability to minimize the release of technetium. Technetium is a radionuclide predicted to be in the secondary liquid wastes in small quantities, but the Integrated Disposal Facility (IDF) risk assessment analyses show that technetium, even at low mass, produces the largest contribution to the estimated IDF disposal impacts to groundwater.

  14. Steam reforming of biomass tar producing H2-rich gases over Ni/MgOx/CaO1-x catalyst.

    PubMed

    Li, Chunshan; Hirabayashi, Daisuke; Suzuki, Kenzi

    2010-01-01

    Series nickel catalysts Ni/MgO(x)/CaO(1-)(x) (x=0.3, 0.5, 0.7, Ni: 5 wt%) were prepared and tested in fixed-bed reactor for biomass tar steam reforming, toluene as tar destruction model compound. Different ratios of MgO and CaO were mixed to simulate dolomite as Ni support. Two preparation methods: solid mixing with (SMW) and without water (SM) were used, the preparation methods and concentration of MgO had an important influence on toluene conversion and products. Catalysts prepared by SM method exhibited higher performance on toluene conversion, resulted in higher H(2) yield, and also, higher CO(2) and lower CO selectivity with higher temperature. For the same preparation method, higher concentration of MgO resulted in higher toluene conversion, and also influence on CO, CO(2) selectivity, but no obvious influence on the H(2) yield. Catalysts were characterized by BET, X-ray diffraction (XRD), SEM.

  15. Steam reforming of biomass gasification tar using benzene as a model compound over various Ni supported metal oxide catalysts.

    PubMed

    Park, Hyun Ju; Park, Sung Hoon; Sohn, Jung Min; Park, Junhong; Jeon, Jong-Ki; Kim, Seung-Soo; Park, Young-Kwon

    2010-01-01

    The steam reforming of benzene as a model compound of biomass gasification tar was carried out over various Ni/metal oxide catalysts. The effects of the support, temperature, Ni-precursor, Ni loading and reaction time were examined, and their catalytic performance was compared with that of a commercial Ni catalyst. Among the Ni/metal oxide catalysts used, 15 wt% Ni/CeO(2)(75%)-ZrO(2)(25%) showed the highest catalytic performance owing to its greater redox characteristics and increased surface area, irrespective of the reaction temperature. The catalytic activity of 15 wt% Ni/CeO(2)(75%)-ZrO(2)(25%) was higher than that of the commercial Ni catalyst. Moreover, the catalyst activity was retained due to its excellent resistance to coke deposition even after 5h. The Ni-precursor played a critical role in the catalytic activity. With the exception of nickel nitrate, all the Ni-precursors (chloride and sulfate) caused deactivation of the catalyst.

  16. Methane steam reforming rates over Pt, Rh and Ni(111) accounting for H tunneling and for metal lattice vibrations

    NASA Astrophysics Data System (ADS)

    German, Ernst D.; Sheintuch, Moshe

    2017-02-01

    Microkinetic models of methane steam reforming (MSR) over bare platinum and rhodium (111) surfaces are analyzed in present work using calculated rate constants. The individual rate constants are classified into three different sets: (i) rate constants of adsorption and desorption steps of CH4, H2O, CO and of H2; (ii) rate constants of dissociation and formation of A-H bonds (A = C, O, and H), and (iii) rate constants of dissociation and formation of C-O bond. The rate constants of sets (i) and (iii) are calculated using transition state theory and published thermochemical data. The rate constants of H-dissociation reactions (set (ii)) are calculated in terms of a previously-developed approach that accounts for thermal metal lattice vibrations and for H tunneling through a potential barrier of height which depends on distance of AH from a surface. Pre-exponential factors of several group (ii) steps were calculated to be usually lower than the traditional kBT/h due to tunneling effect. Surface composition and overall MSR rates over platinum and rhodium surfaces are compared with those over nickel surface showing that operating conditions strongly affect on the activity order of the catalysts.

  17. Estimation of transient heat flux density during the heat supply of a catalytic wall steam methane reformer

    NASA Astrophysics Data System (ADS)

    Settar, Abdelhakim; Abboudi, Saïd; Madani, Brahim; Nebbali, Rachid

    2017-08-01

    Due to the endothermic nature of the steam methane reforming reaction, the process is often limited by the heat transfer behavior in the reactors. Poor thermal behavior sometimes leads to slow reaction kinetics, which is characterized by the presence of cold spots in the catalytic zones. Within this framework, the present work consists on a numerical investigation, in conjunction with an experimental one, on the one-dimensional heat transfer phenomenon during the heat supply of a catalytic-wall reactor, which is designed for hydrogen production. The studied reactor is inserted in an electric furnace where the heat requirement of the endothermic reaction is supplied by electric heating system. During the heat supply, an unknown heat flux density, received by the reactive flow, is estimated using inverse methods. In the basis of the catalytic-wall reactor model, an experimental setup is engineered in situ to measure the temperature distribution. Then after, the measurements are injected in the numerical heat flux estimation procedure, which is based on the Function Specification Method (FSM). The measured and estimated temperatures are confronted and the heat flux density which crosses the reactor wall is determined.

  18. Thermodynamic analysis of Glycerol Steam Reforming for hydrogen production with in situ hydrogen and carbon dioxide separation

    NASA Astrophysics Data System (ADS)

    Silva, Joel M.; Soria, M. A.; Madeira, Luis M.

    2015-01-01

    A thermodynamic study of Glycerol Steam Reforming (GSR) for hydrogen production with in situ carbon dioxide and hydrogen (reaction products) simultaneous removal was performed. The sorption-enhanced membrane reactor (SEMR) was divided into multiple sub-Gibbs reactors and the Gibbs free energy minimization method was employed. The effects of temperature (600-800 K), molar water-to-glycerol feed ratio (WGFR) (3-9), pressure (1-5 atm) and fraction of hydrogen and carbon dioxide removal (f, 0-0.99) on the GSR process were target of investigation. A hydrogen yield (total moles of hydrogen produced/mole of reacted glycerol) very close to the stoichiometric value of 7 was obtained at 700 K, WGFR of 9, 1 atm and for fCO2 = 0.99 and fH2 = 0.80. This corresponds to an enhancement of 217%, 47% and 22% in terms of hydrogen yield comparatively to the traditional reactor (TR), sorption-enhanced reactor (SER) with carbon dioxide capture (fCO2 = 0.99) and membrane reactor (MR) with hydrogen separation (fH2 = 0.80) , respectively. In terms of coke, its formation was only observed under WGFRs below the stoichiometric value of 3.

  19. Effect of Bimetallic Ni-Cr Catalysts for Steam-CO2 Reforming of Methane at High Pressure.

    PubMed

    Choi, Bong Kwan; Park, Yoon Hwa; Moon, Dong Ju; Park, Nam Cook; Kim, Young Chul

    2015-07-01

    The present work was to carry out the development of high performance Ni-based catalyst for Steam-CO2 reforming of methane (SCR) which is suitable for Fischer-Tropsch synthesis of GTL- FPSO (floating, production, storage and offloading) process. The bimetallic Ni-Cr catalysts were prepared by co-impregnation method. The Ni and Cr loading amount were fixed at 12 wt% and 3~7 wt%, respectively. The catalytic reaction was conducted at 900 °C and 20 bar with reactant feed ratio of CH4:CO2:H2O:Ar = 1:0.8:1.3:1 and GHSV = 25,000 h(-1). The Cr-modified Ni/γ-Al2O3 catalyst was characterized by BET surface area analysis, X-ray diffraction (XRD), H2-temperature programmed reduction (TPR), H2-chmisorption, CO2-temperature programmed desorption (TPD) and Transmission electron microscopy(TEM). To confirm the amount and type of the carbon deposition, the used catalysts were examined by Thermogravitic analysis (TGA) and Field emission-scanning microscopy/Energy dispersive X-ray analysis (FE-SEM/EDX). It was found that the bimetallic Ni-Cr catalyst exhibits highly dispersed Ni particles with strong metal-to-support interaction (SMSI) as well as excellent catalytic activity, resulting in the suppression of Ni sintering and carbon deposition.

  20. Carbon Deposition from the CO2-Steam Reforming of Methane Over Modified Ni/γ-Al2O3 Catalysts.

    PubMed

    Choi, Bong Kwan; Ok, Hye Jeong; Moon, Dong Ju; Kim, Jong Ho; Park, Nam Cook; Kim, Young Chul

    2015-01-01

    The aim of this work is to study the catalytic activity and suppression of carbon deposition in the CO2-Steam reforming of methane (SCR) to develop a high performance catalyst for GTL-FPSO application which is required to high pressure (20 bar) for F-T synthesis. Ni/La-X(6)/Al2O3 (X = Ce, Mg, Zr) catalysts were prepared by the impregnation method. The catalytic reaction was studied in a fixed bed reactor system at high pressure. X-ray diffraction (XRD), BET specific surface area and H2-temperature programmed reduction (TPR) were used to observe the characteristics of the prepared catalysts. The carbon deposition and the carbon amount in the used catalysts were examined by SEM and TGA, respectively. As a result, it was found that the Ni/La-Mg(6)/Al2O3 catalyst showed the highest activity and high carbon resistance. The highest activity in Ni/La-Mg(6)/Al2O3 was attributed to the proper Mg loading. It also had the lowest Ni particle and formed relatively stable MgAl2O4, which have an effect on the catalytic activity.

  1. Characterization and Leaching Tests of the Fluidized Bed Steam Reforming (FBSR) Waste Form for LAW Immobilization - 13400

    SciTech Connect

    Neeway, James J.; Qafoku, Nikolla P.; Peterson, Reid A.; Brown, Christopher F.

    2013-07-01

    Several supplemental technologies for treating and immobilizing Hanford low activity waste (LAW) have been evaluated. One such immobilization technology is the Fluidized Bed Steam Reforming (FBSR) granular product. The FBSR granular product is composed of insoluble sodium aluminosilicate (NAS) feldspathoid minerals. Production of the FBSR mineral product has been demonstrated both at the industrial and laboratory scale. Pacific Northwest National Laboratory (PNNL) was involved in an extensive characterization campaign. The goal of this campaign was to study the durability of the FBSR mineral product and the encapsulated FBSR product in a geo-polymer monolith. This paper gives an overview of results obtained using the ASTM C 1285 Product Consistency Test (PCT), the EPA Test Method 1311 Toxicity Characteristic Leaching Procedure (TCLP), and the ASTMC 1662 Single-Pass Flow-Through (SPFT) test. Along with these durability tests an overview of the characteristics of the waste form has been collected using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), microwave digestions for chemical composition, and surface area from Brunauer, Emmett, and Teller (BET) theory. (authors)

  2. Studying the characteristics of a 5 kW power installation on solid-oxide fuel cells with steam reforming of natural gas

    NASA Astrophysics Data System (ADS)

    Munts, V. A.; Volkova, Yu. V.; Plotnikov, N. S.; Dubinin, A. M.; Tuponogov, V. G.; Chernishev, V. A.

    2015-11-01

    The results from tests of a 5 kW power plant on solid-oxide fuel cells (SOFCs), in which natural gas is used as fuel, are presented. The installation's process circuit, the test procedure, and the analysis of the obtained results are described. The characteristics of the power plant developed by the Ural Industrial Company are investigated in four steady-state modes of its operation: with the SOFC nominal power capacity utilized by 40% (2 kW), 60% (3 kW), 90% (4.5 kW) and 110% (5.4 kW) (the peaking mode). The electrical and thermodynamic efficiencies are calculated for all operating modes, and the most efficient mode, in which the electrical efficiency reached almost 70%, is determined. The air excess coefficient and heat loss with flue gases q 2 are determined, and it is revealed that the heat loss q 5 decreases from 40 to 25% with increasing the load. Thermal balances are drawn up for the following components of the system the reformer, the SOFC battery, the catalytic burner for afterburning anode gases, the heat exchanger for heating the cathode air and the mixture of natural gas and steam, and the actual fuel utilization rates in the electrochemical generator are calculated. An equation for the resulting natural gas steam reforming reaction was obtained based on the results from calculating the equilibrium composition of reforming products for the achieved temperatures at the reformer outlet t 3.

  3. RADIOACTIVE DEMONSTRATION OF FINAL MINERALIZED WASTE FORMS FOR HANFORD WASTE TREATMENT PLANT SECONDARY WASTE BY FLUIDIZED BED STEAM REFORMING USING THE BENCH SCALE REFORMER PLATFORM

    SciTech Connect

    Crawford, C.; Burket, P.; Cozzi, A.; Daniel, W.; Jantzen, C.; Missimer, D.

    2012-02-02

    The U.S. Department of Energy's Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as {sup 137}Cs, {sup 129}I, {sup 99}Tc, Cl, F, and SO{sub 4} that volatilize at the vitrification temperature of 1150 C in the absence of a continuous cold cap (that could minimize volatilization). The current waste disposal path for the WTP-SW is to process it through the Effluent Treatment Facility (ETF). Fluidized Bed Steam Reforming (FBSR) is being considered for immobilization of the ETF concentrate that would be generated by processing the WTP-SW. The focus of this current report is the WTP-SW. FBSR offers a moderate temperature (700-750 C) continuous method by which WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic

  4. Efficient utilization of greenhouse gases in a gas-to-liquids process combined with CO2/steam-mixed reforming and Fe-based Fischer-Tropsch synthesis.

    PubMed

    Zhang, Chundong; Jun, Ki-Won; Ha, Kyoung-Su; Lee, Yun-Jo; Kang, Seok Chang

    2014-07-15

    Two process models for carbon dioxide utilized gas-to-liquids (GTL) process (CUGP) mainly producing light olefins and Fischer-Tropsch (F-T) synthetic oils were developed by Aspen Plus software. Both models are mainly composed of a reforming unit, an F-T synthesis unit and a recycle unit, while the main difference is the feeding point of fresh CO2. In the reforming unit, CO2 reforming and steam reforming of methane are combined together to produce syngas in flexible composition. Meanwhile, CO2 hydrogenation is conducted via reverse water gas shift on the Fe-based catalysts in the F-T synthesis unit to produce hydrocarbons. After F-T synthesis, the unreacted syngas is recycled to F-T synthesis and reforming units to enhance process efficiency. From the simulation results, it was found that the carbon efficiencies of both CUGP options were successfully improved, and total CO2 emissions were significantly reduced, compared with the conventional GTL processes. The process efficiency was sensitive to recycle ratio and more recycle seemed to be beneficial for improving process efficiency and reducing CO2 emission. However, the process efficiency was rather insensitive to split ratio (recycle to reforming unit/total recycle), and the optimum split ratio was determined to be zero.

  5. RADIOACTIVE DEMONSTRATIONS OF FLUIDIZED BED STEAM REFORMING AS A SUPPLEMENTARY TREATMENT FOR HANFORD'S LOW ACTIVITY WASTE AND SECONDARY WASTES

    SciTech Connect

    Jantzen, C.; Crawford, C.; Cozzi, A.; Bannochie, C.; Burket, P.; Daniel, G.

    2011-02-24

    The U.S. Department of Energy's Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. The Supplemental Treatment chosen will immobilize that portion of the retrieved LAW that is not sent to the WTP's LAW Vitrification facility into a solidified waste form. The solidified waste will then be disposed on the Hanford site in the Integrated Disposal Facility (IDF). In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as Cs-137, I-129, Tc-99, Cl, F, and SO4 that volatilize at the vitrification temperature of 1150 C in the absence of a continuous cold cap. The current waste disposal path for the WTP-SW is to recycle it to the supplemental LAW treatment to avoid a large steady state accumulation in the pretreatment-vitrification loop. Fluidized Bed Steam Reforming (FBSR) offers a moderate temperature (700-750 C) continuous method by which LAW and/or WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides

  6. RADIOACTIVE DEMONSTRATIONS OF FLUIDIZED BED STEAM REFORMING WITH ACUTAL HANFORD LOW ACTIVITY WASTES VERIFYING FBSR AS A SUPPLEMENTARY TREATMENT

    SciTech Connect

    Jantzen, C.; Crawford, C.; Burket, P.; Bannochie, C.; Daniel, G.; Nash, C.; Cozzi, A.; Herman, C.

    2012-01-12

    The U.S. Department of Energy's Office of River Protection is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level waste (HLW) and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the cleanup mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA). Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. Fluidized Bed Steam Reforming (FBSR) is one of the supplementary treatments being considered. FBSR offers a moderate temperature (700-750 C) continuous method by which LAW and other secondary wastes can be processed irrespective of whether they contain organics, nitrates/nitrites, sulfates/sulfides, chlorides, fluorides, and/or radio-nuclides like I-129 and Tc-99. Radioactive testing of Savannah River LAW (Tank 50) shimmed to resemble Hanford LAW and actual Hanford LAW (SX-105 and AN-103) have produced a ceramic (mineral) waste form which is the same as the non-radioactive waste simulants tested at the engineering scale. The radioactive testing demonstrated that the FBSR process can retain the volatile radioactive components that cannot be contained at vitrification temperatures. The radioactive and nonradioactive mineral waste forms that were produced by co-processing waste with kaolin clay in an FBSR process are shown to be as durable as LAW glass.

  7. FLUIDIZED BED STEAM REFORMING MINERALIZATION FOR HIGH ORGANIC AND NITRATE WASTE STREAMS FOR THE GLOBAL NUCLEAR ENERGY PARTNERSHIP

    SciTech Connect

    Jantzen, C; Michael Williams, M

    2008-01-11

    Waste streams that may be generated by the Global Nuclear Energy Partnership (GNEP) Advanced Energy Initiative may contain significant quantities of organics (0-53 wt%) and/or nitrates (0-56 wt%). Decomposition of high nitrate streams requires reducing conditions, e.g. organic additives such as sugar or coal, to reduce the NO{sub x} in the off-gas to N{sub 2} to meet the Clean Air Act (CAA) standards during processing. Thus, organics will be present during waste form stabilization regardless of which GNEP processes are chosen, e.g. organics in the feed or organics for nitrate destruction. High organic containing wastes cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by preprocessing. Alternative waste stabilization processes such as Fluidized Bed Steam Reforming (FBSR) operate at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). FBSR converts organics to CAA compliant gases, creates no secondary liquid waste streams, and creates a stable mineral waste form that is as durable as glass. For application to the high Cs-137 and Sr-90 containing GNEP waste streams a single phase mineralized Cs-mica phase was made by co-reacting illite clay and GNEP simulated waste. The Cs-mica accommodates up to 30% wt% Cs{sub 2}O and all the GNEP waste species, Ba, Sr, Rb including the Cs-137 transmutation to Ba-137. For reference, the cesium mineral pollucite (CsAlSi{sub 2}O{sub 6}), currently being studied for GNEP applications, can only be fabricated at {ge} 1000 C. Pollucite mineralization creates secondary aqueous waste streams and NO{sub x}. Pollucite is not tolerant of high concentrations of Ba, Sr or Rb and forces the divalent species into different mineral host phases. The pollucite can accommodate up to 33% wt% Cs{sub 2}O.

  8. Hierarchical copper-decorated nickel nanocatalysts supported on La2O3 for low-temperature steam reforming of ethanol.

    PubMed

    Liu, Jyong-Yue; Su, Wei-Nien; Rick, John; Yang, Sheng-Chiang; Cheng, Ju-Hsiang; Pan, Chun-Jern; Lee, Jyh-Fu; Hwang, Bing-Joe

    2014-02-01

    Copper/nickel nanocatalysts with a unique morphology were prepared by thermal reduction of a perovskite LaNix Cu1-x O3 precursor (x=1, 0.9, and 0.7). During thermal reduction, copper was first reduced and reacted with lanthanum to form metastable Cu5 La and Cu13 La. When the thermal reduction temperature was increased, the perovskite decomposed to Ni and La2 O3 , CuLa alloys disappeared, and Cu deposits on Ni nanoparticles were generated, thereby forming Cu/Ni nanocatalysts with hierarchical structures. Nanosized nickel, decorated with copper and supported on La2 O3 , could be produced at 520-550 °C. The steam reforming of ethanol was used as a model reaction to demonstrate the catalytic capability of the materials formed. The hierarchical structure of the Cu/Ni/La2 O3 catalysts confers synergetic effects that greatly favor the dehydrogenation of ethanol and which break the C-C bond to produce a higher yield of hydrogen at a low reaction temperature, whereas La2 O3 provides the required stability during the reaction. The reaction at 290 °C achieved almost 100 % conversion with a hydrogen yield reaching 2.21 molH2  mol(-1) EtOH thus indicating that this special structural feature can achieve high activity for the SRE at low temperatures. The proposed synthesis of nanocatalysts appears to be a good way to generate oxide-supported hierarchically structured nanoparticles that can also be applied to other reactions catalyzed by a heterogeneous metal oxide system.

  9. Applications of solar reforming technology

    SciTech Connect

    Spiewak, I.; Tyner, C.E.; Langnickel, U.

    1993-11-01

    Research in recent years has demonstrated the efficient use of solar thermal energy for driving endothermic chemical reforming reactions in which hydrocarbons are reacted to form synthesis gas (syngas). Closed-loop reforming/methanation systems can be used for storage and transport of process heat and for short-term storage for peaking power generation. Open-loop systems can be used for direct fuel production; for production of syngas feedstock for further processing to specialty chemicals and plastics and bulk ammonia, hydrogen, and liquid fuels; and directly for industrial processes such as iron ore reduction. In addition, reforming of organic chemical wastes and hazardous materials can be accomplished using the high-efficiency destruction capabilities of steam reforming. To help identify the most promising areas for future development of this technology, we discuss in this paper the economics and market potential of these applications.

  10. Steam reforming of fast pyrolysis-derived aqueous phase oxygenates over Co, Ni, and Rh metals supported on MgAl2O4

    DOE PAGES

    Xing, Rong; Dagle, Vanessa Lebarbier; Flake, Matthew; ...

    2016-02-03

    In this paper we examine the feasibility of steam reforming the mixed oxygenate aqueous fraction derived from fast pyrolysis bio-oils. Catalysts selective towards hydrogen formation and resistant to carbon formation utilizing feeds with relatively low steam-to-carbon (S/C) ratios are desired. Rh (5 wt%), Pt (5 wt%), Ru (5 wt%), Ir (5 wt%), Ni (15 wt%), and Co (15 wt%) metals supported on MgAl2O4 were evaluated for catalytic performance at 500 °C and 1 atm using a complex feed mixture comprising acids, polyols, cycloalkanes, and phenolic compounds. The Rh catalyst was found to be the most active and resistant to carbonmore » formation. The Ni and Co catalysts were found to be more active than the other noble metal catalysts investigated (Pt, Ru, and Ir).« less

  11. Kinetic Study on the Effect of Chromium Addition to Ni-Based Catalysts for the Steam-CO2 Reforming of Methane.

    PubMed

    Park, Yoon-Hwa; Li, Peng; Moon, Dong-Ju; Park, Nam-Cook; Kim, Young-Chul

    2016-02-01

    In the present work, the kinetic effects of Ni-based catalysts containing various amounts of Cr on the steam-CO2 reforming (SCR) of methane were studied. Kinetic expressions for the SCR of methane over the Ni-based catalysts have been proposed using the power-law rate expression, based on the kinetic data obtained. In addition, the Arrhenius equation was used for calculating the activation energy. Analysis of the data revealed four simple results. Firstly, the partial pressure of CH4 exerts a major influence on the CH4 conversion rates. Secondly, the CH4 conversion rate is inversely proportional to the partial pressure of CO2. Thirdly, the partial pressure of steam has a very slight effect on the reaction rates. Finally, all the catalysts studied have similar apparent activation energies.

  12. 2009 PILOT SCALE FLUIDIZED BED STEAM REFORMING TESTING USING THE THOR (THERMAL ORGANIC REDUCTION) PROCESS: ANALYTICAL RESULTS FOR TANK 48H ORGANIC DESTRUCTION - 10408

    SciTech Connect

    Williams, M.; Jantzen, C.; Burket, P.; Crawford, C.; Daniel, G.; Aponte, C.; Johnson, C.

    2009-12-28

    The Savannah River Site (SRS) must empty the contents of Tank 48H, a 1.3 million gallon Type IIIA HLW storage tank, to return this tank to service. The tank contains organic compounds, mainly potassium tetraphenylborate that cannot be processed downstream until the organic components are destroyed. The THOR{reg_sign} Treatment Technologies (TTT) Fluidized Bed Steam Reforming (FBSR) technology, herein after referred to as steam reforming, has been demonstrated to be a viable process to remove greater than 99.9% of the organics from Tank 48H during various bench scale and pilot scale tests. These demonstrations were supported by Savannah River Remediation (SRR) and the Department of Energy (DOE) has concurred with the SRR recommendation to proceed with the deployment of the FBSR technology to treat the contents of Tank 48H. The Savannah River National Laboratory (SRNL) developed and proved the concept with non-radioactive simulants for SRR beginning in 2003. By 2008, several pilot scale campaigns had been completed and extensive crucible testing and bench scale testing were performed in the SRNL Shielded Cells using Tank 48H radioactive sample. SRNL developed a Tank 48H non-radioactive simulant complete with organic compounds, salt, and metals characteristic of those measured in a sample of the radioactive contents of Tank 48H. FBSR Pilot Scaled Testing with the Tank 48H simulant has demonstrated the ability to remove greater than 98% of the nitrites and greater than 99.5% of the nitrates from the Tank 48H simulant, and to form a solid product that is primarily alkali carbonate. The alkali carbonate is soluble and, thus, amenable to pumping as a liquid to downstream facilities for processing. The FBSR technology was demonstrated in October of 2006 in the Engineering Scale Test Demonstration (ESTD) pilot scale steam reformer at the Hazen Research Inc. (HRI) facility in Golden, CO. Additional ESTD tests were completed in 2008 and in 2009 that further demonstrated the

  13. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Astrophysics Data System (ADS)

    1981-10-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  14. Catalytic Steam Reforming of Gasifier Tars: On-Line Monitoring of Tars with a Transportable Molecular-Beam Mass Spectrometer; Milestone Completion Report

    SciTech Connect

    Carpenter, D.; Ratcliff, M.; Dayton, D.

    2002-05-01

    A method for evaluating catalytic tar decomposition in real time is presented. The effectiveness of two catalysts are compared. A key technical and economic barrier to commercialization of biomass gasification technologies is the removal of tars that are unavoidably formed in this thermochemical process. Tars contain fuel value; however, they are problematic in gas engines (both reciprocating and turbine) because they condense in the fuel delivery system, forming deposits that negatively affect operation and efficiency. These tars also combust with high luminosity, potentially forming soot particles. The conventional technology for tar removal is wet scrubbing. Although this approach has shown some success, there are significant equipment and operating costs associated with it. In order to prevent the generation of toxic wastewater, the tars must be separated and either disposed as hazardous waste or, preferably, combusted in the gasification plant. A conceptually better approach is catalytic steam reforming of the tars to hydrogen and carbon monoxide (CO), effectively increasing the gasification efficiency and eliminating the problems mentioned above. In FY2000, Battelle Columbus Laboratories attempted to demonstrate integrated gasification-gas turbine operation using catalytic steam reforming of tars. NREL participated in those tests using the transportable molecular-beam mass spectrometer (TMBMS) to monitor the catalytic reactor's performance on-line [10]. Unfortunately, the pilot plant tests encountered operational problems that prevented conclusive determination of the efficacy of the selected catalyst (Battelle's DN34). In FY2001, NREL performed on-site tar steam reforming tests using a slip-stream of hot pyrolysis gas from the Thermochemical Process Development Unit (TCPDU), which was directed to a bench-scale fluidized bed reactor system designed expressly for this purpose. Supporting this effort, the TMBMS was employed to provide on-line analysis of the

  15. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  16. Steam reforming of n-hexane on pellet and monolithic catalyst beds. A comparative study on improvements due to heat transfer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Monolithic catalysts with higher available active surface areas and better thermal conductivity than conventional pellets beds, making possible the steam reforming of fuels heavier than naphtha, were examined. Performance comparisons were made between conventional pellet beds and honeycomb monolith catalysts using n-hexane as the fuel. Metal-supported monoliths were examined. These offer higher structural stability and higher thermal conductivity than ceramic supports. Data from two metal monoliths of different nickel catalyst loadings were compared to pellets under the same operating conditions. Improved heat transfer and better conversion efficiencies were obtained with the monolith having higher catalyst loading. Surface-gas interaction was observed throughout the length of the monoliths.

  17. MINERALIZATION OF RADIOACTIVE WASTES BY FLUIDIZED BED STEAM REFORMING (FBSR): COMPARISONS TO VITREOUS WASTE FORMS, AND PERTINENT DURABILITY TESTING

    SciTech Connect

    Jantzen, C

    2008-12-26

    The Savannah River National Laboratory (SRNL) was requested to generate a document for the Washington State Department of Ecology and the U.S. Environmental Protection Agency that would cover the following topics: (1) A description of the mineral structures produced by Fluidized Bed Steam Reforming (FBSR) of Hanford type Low Activity Waste (LAW including LAWR which is LAW melter recycle waste) waste, especially the cage structured minerals and how they are formed. (2) How the cage structured minerals contain some contaminants, while others become part of the mineral structure (Note that all contaminants become part of the mineral structure and this will be described in the subsequent sections of this report). (3) Possible contaminant release mechanisms from the mineral structures. (4) Appropriate analyses to evaluate these release mechanisms. (5) Why the appropriate analyses are comparable to the existing Hanford glass dataset. In order to discuss the mineral structures and how they bond contaminants a brief description of the structures of both mineral (ceramic) and vitreous waste forms will be given to show their similarities. By demonstrating the similarities of mineral and vitreous waste forms on atomic level, the contaminant release mechanisms of the crystalline (mineral) and amorphous (glass) waste forms can be compared. This will then logically lead to the discussion of why many of the analyses used to evaluate vitreous waste forms and glass-ceramics (also known as glass composite materials) are appropriate for determining the release mechanisms of LAW/LAWR mineral waste forms and how the durability data on LAW/LAWR mineral waste forms relate to the durability data for LAW/LAWR glasses. The text will discuss the LAW mineral waste form made by FBSR. The nanoscale mechanism by which the minerals form will be also be described in the text. The appropriate analyses to evaluate contaminant release mechanisms will be discussed, as will the FBSR test results to

  18. DURABILITY TESTING OF FLUIDIZED BED STEAM REFORMER WASTE FORMS FOR SODIUM BEARING WASTE AT IDAHO NATIONAL LABORATORY

    SciTech Connect

    Crawford, C; Carol Jantzen, C

    2007-08-27

    Fluidized Bed Steam Reforming (FBSR) processing of Sodium Bearing Waste simulants was performed in December 2006 by THOR{sup sm} Treatment Technologies LLC (TTT) The testing was performed at the Hazen Research Inc. (HRI) pilot plant facilities in Golden, CO. FBSR products from these pilot tests on simulated waste representative of the SBW at the Idaho Nuclear Technology and Engineering Center (INTEC) were subsequently transferred to the Savannah River National Laboratory (SRNL) for characterization and leach testing. Four as-received Denitration and Mineralization Reformer (DMR) granular/powder samples and four High Temperature Filter (HTF) powder samples were received by SRNL. FBSR DMR samples had been taken from the ''active'' bed, while the HTF samples were the fines collected as carryover from the DMR. The process operated at high fluidizing velocities during the mineralization test such that nearly all of the product collected was from the HTF. Active bed samples were collected from the DMR to monitor bed particle size distribution. Characterization of these crystalline powder samples shows that they are primarily Al, Na and Si, with > 1 wt% Ca, Fe and K. The DMR samples contained less than 1 wt% carbon and the HTF samples ranged from 13 to 26 wt% carbon. X-ray diffraction analyses show that the DMR samples contained significant quantities of the Al{sub 2}O{sub 3} startup bed. The DMR samples became progressively lower in starting bed alumina with major Na/Al/Si crystalline phases (nepheline and sodium aluminosilicate) present as cumulative bed turnover occurred but 100% bed turnover was not achieved. The HTF samples also contained these major crystalline phases. Durability testing of the DMR and HTF samples using the ASTM C1285 Product Consistency Test (PCT) 7-day leach test at 90 C was performed along with several reference glass samples. Comparison of the normalized leach rates for the various DMR and HTF components was made with the reference glasses and

  19. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE PAGES

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; ...

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Nimore » under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  20. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; Rodriguez, José A.

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  1. Renewable H2 from glycerol steam reforming: effect of La2O3 and CeO2 addition to Pt/Al2O3 catalysts.

    PubMed

    Montini, Tiziano; Singh, Rakesh; Das, Piyali; Lorenzut, Barbara; Bertero, Nicolás; Riello, Pietro; Benedetti, Alvise; Giambastiani, Giuliano; Bianchini, Claudio; Zinoviev, Sergey; Miertus, Stanislav; Fornasiero, Paolo

    2010-05-25

    Glycerol is the main byproduct of biodiesel production and its increased production volume derives from the increasing demand for biofuels. The conversion of glycerol to hydrogen-rich mixtures presents an attractive route towards sustainable biodiesel production. Here we explored the use of Pt/Al(2)O(3)-based catalysts for the catalytic steam reforming of glycerol, evidencing the influence of La(2)O(3) and CeO(2) doping on the catalyst activity and selectivity. The addition of the latter metal oxides to a Pt/Al(2)O(3) catalyst is found to significantly improve the glycerol steam reforming, with high H(2) and CO(2) selectivities. A good catalytic stability is achieved for the Pt/La(2)O(3)/Al(2)O(3) system working at 350 degrees C, while the Pt/CeO(2)/Al(2)O(3) catalyst sharply deactivates after 20 h under similar conditions. Studies carried out on fresh and exhausted catalysts reveal that both systems maintain high surface areas and high Pt dispersions. Therefore, the observed catalyst deactivation can be attributed to coke deposition on the active sites throughout the catalytic process and only marginally to Pt nanoparticle sintering. This work suggests that an appropriate support composition is mandatory for preparing high-performance Pt-based catalysts for the sustainable conversion of glycerol into syngas.

  2. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification.

    PubMed

    Castro-Dominguez, Bernardo; Mardilovich, Ivan P; Ma, Liang-Chih; Ma, Rui; Dixon, Anthony G; Kazantzis, Nikolaos K; Ma, Yi Hua

    2016-09-19

    Palladium-based catalytic membrane reactors (CMRs) effectively remove H₂ to induce higher conversions in methane steam reforming (MSR) and water-gas-shift reactions (WGS). Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H₂, CO and CO₂. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H₂O, CO₂ and H₂. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H₂ and induce higher methane and CO conversions while yielding ultrapure H₂ and compressed CO₂ ready for dehydration. Experimental results involving (i) a conventional packed bed reactor packed (PBR) for MSR, (ii) a PBR with five layers of two catalysts in series and (iii) a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD) model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H₂ permeance and purity, high CH₄ conversion levels and reduced CO yields.

  3. High efficiency magnetic bearings

    NASA Technical Reports Server (NTRS)

    Studer, Philip A.; Jayaraman, Chaitanya P.; Anand, Davinder K.; Kirk, James A.

    1993-01-01

    Research activities concerning high efficiency permanent magnet plus electromagnet (PM/EM) pancake magnetic bearings at the University of Maryland are reported. A description of the construction and working of the magnetic bearing is provided. Next, parameters needed to describe the bearing are explained. Then, methods developed for the design and testing of magnetic bearings are summarized. Finally, a new magnetic bearing which allows active torque control in the off axes directions is discussed.

  4. High efficiency incandescent lighting

    SciTech Connect

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  5. High efficiency multifrequency feed

    NASA Technical Reports Server (NTRS)

    Ajioka, J. S.; Tsuda, G. I.; Leeper, W. A. (Inventor)

    1974-01-01

    Antenna systems and particularly compact and simple antenna feeds which can transmit and receive simultaneously in at least three frequency bands, each with high efficiency and polarization diversity are described. The feed system is applicable for frequency bands having nominal frequency bands with the ratio 1:4:6. By way of example, satellite communications telemetry bands operate in frequency bands 0.8 - 1.0 GHz, 3.7 - 4.2 GHz and 5.9 - 6.4 GHz. In addition, the antenna system of the invention has monopulse capability for reception with circular or diverse polarization at frequency band 1.

  6. High efficiency photoionization detector

    DOEpatents

    Anderson, D.F.

    1984-01-31

    A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 [+-] 0.02 eV, and a vapor pressure of 0.35 torr at 20 C. 6 figs.

  7. High efficiency photoionization detector

    DOEpatents

    Anderson, David F.

    1984-01-01

    A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36.+-.0.02 eV, and a vapor pressure of 0.35 torr at 20.degree. C.

  8. High efficiency RCCI combustion

    NASA Astrophysics Data System (ADS)

    Splitter, Derek A.

    An experimental investigation of the pragmatic limits of Reactivity Controlled Compression Ignition (RCCI) engine efficiency was performed. The study utilized engine experiments combined with zero-dimensional modeling. Initially, simulations were used to suggest conditions of high engine efficiency with RCCI. Preliminary simulations suggested that high efficiency could be obtained by using a very dilute charge with a high compression ratio. Moreover, the preliminary simulations further suggested that with simultaneous 50% reductions in heat transfer and incomplete combustion, 60% gross thermal efficiency may be achievable with RCCI. Following the initial simulations, experiments to investigate the combustion process, fuel effects, and methods to reduce heat transfer and incomplete combustion reduction were conducted. The results demonstrated that the engine cycle and combustion process are linked, and if high efficiency is to be had, then the combustion event must be tailored to the initial cycle conditions. It was found that reductions to engine heat transfer are a key enabler to increasing engine efficiency. In addition, it was found that the piston oil jet gallery cooling in RCCI may be unnecessary, as it had a negative impact on efficiency. Without piston oil gallery cooling, it was found that RCCI was nearly adiabatic, achieving 95% of the theoretical maximum cycle efficiency (air standard Otto cycle efficiency).

  9. Highly Active and Stable MgAl2O4 Supported Rh and Ir Catalysts for Methane Steam Reforming: A Combined Experimental and Theoretical Study

    SciTech Connect

    Mei, Donghai; Glezakou, Vassiliki Alexandra; Lebarbier, Vanessa MC; Kovarik, Libor; Wan, Haiying; Albrecht, Karl O.; Gerber, Mark A.; Rousseau, Roger J.; Dagle, Robert A.

    2014-07-01

    In this work we present a combined experimental and theoretical investigation of stable MgAl2O4 spinel-supported Rh and Ir catalysts for the steam methane reforming (SMR) reaction. Firstly, catalytic performance for a series of noble metal catalysts supported on MgAl2O4 spinel was evaluated for SMR at 600-850°C. Turnover rate at 850°C follows the order: Pd > Pt > Ir > Rh > Ru > Ni. However, Rh and Ir were found to have the best combination of activity and stability for methane steam reforming in the presence of simulated biomass-derived syngas. It was found that highly dispersed ~2 nm Rh and ~1 nm Ir clusters were formed on the MgAl2O4 spinel support. Scanning Transition Electron Microscopy (STEM) images show that excellent dispersion was maintained even under challenging high temperature conditions (e.g. at 850°C in the presence of steam) while Ir and Rh catalysts supported on Al2O3 were observed to sinter at increased rates under the same conditions. These observations were further confirmed by ab initio molecular dynamics (AIMD) simulations which find that ~1 nm Rh and Ir particles (50-atom cluster) bind strongly to the MgAl2O4 surfaces via a redox process leading to a strong metal-support interaction, thus helping anchor the metal clusters and reduce the tendency to sinter. Density functional theory (DFT) calculations suggest that these supported smaller Rh and Ir particles have a lower work function than larger more bulk-like ones, which enables them to activate both water and methane more effectively than larger particles, yet have a minimal influence on the relative stability of coke precursors. In addition, theoretical mechanistic studies were used to probe the relationship between structure and reactivity. Consistent with the experimental observations, our theoretical modeling results also suggest that the small spinel-supported Ir particle catalyst is more active than the counterpart of Rh catalyst for SMR. This work was financially supported by the

  10. A study on methanol steam reforming to CO 2 and H 2 over the La 2CuO 4 nanofiber catalyst

    NASA Astrophysics Data System (ADS)

    Gao, Lizhen; Sun, Gebiao; Kawi, Sibudjing

    2008-01-01

    The La 2CuO 4 crystal nanofibers were prepared by using single-walled carbon nanotubes as templates under mild hydrothermal conditions. The steam reforming of methanol (SRM) to CO 2 and H 2 over such nanofiber catalysts was studied. At the low temperature of 150 °C and steam/methanol=1.3, methanol was completely (100%, 13.8 g/h g catalyst) converted to hydrogen and CO 2 without the generation of CO. Within the 60 h catalyst lifespan test, methanol conversion was maintained at 98.6% (13.6 g/h g catalyst) and with 100% CO 2 selectivity. In the meantime, for distinguishing the advantage of nanoscale catalyst, the La 2CuO 4 bulk powder was prepared and tested for the SRM reaction for comparison. Compared with the La 2CuO 4 nanofiber, the bulk powder La 2CuO 4 showed worse catalytic activity for the SRM reaction. The 100% conversion of methanol was achieved at the temperature of 400 °C, with the products being H 2 and CO 2 together with CO. The catalytic activity in terms of methanol conversion dropped to 88.7% (12.2 g/h g catalyst) in 60 h. The reduction temperature for nanofiber La 2CuO 4 was much lower than that for the La 2CuO 4 bulk powder. The nanofibers were of higher specific surface area (105.0 m 2/g), metal copper area and copper dispersion. The in situ FTIR and EPR experiments were employed to study the catalysts and catalytic process. In the nanofiber catalyst, there were oxygen vacancies. H 2-reduction resulted in the generation of trapped electrons [e] on the vacancy sites. Over the nanofiber catalyst, the intermediate H 2CO/HCO was stable and was reformed to CO 2 and H 2 by steam rather than being decomposed directly to CO and H 2. Over the bulk counterpart, apart from the direct decomposition of H 2CO/HCO to CO and H 2, the intermediate H 2COO might go through two decomposition ways: H 2COO=CO+H 2O and H 2COO=CO 2+H 2.

  11. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports.

    PubMed

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H

    2013-05-30

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/AlS.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/AlS.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.

  12. Methanol steam reforming over Ni-CeO2 model and powder catalysts: Pathways to high stability and selectivity for H2/CO2 production

    DOE PAGES

    Liu, Zongyuan; Yao, Siyu; Johnston-Peck, Aaron; ...

    2017-08-25

    Here, nickel-ceria has been reported as a very good catalysts for the reforming of methane. Here, the methanol steam reforming reaction on both powder (Ni-CeO2) and model (Ni-CeO2-x(111)) catalysts was investigated. The active phase evolution and surface species transformation on powder catalysts were studied via in situ X-ray diffraction (XRD) and diffuse reflectance infrared transform spectroscopy (DRIFTS). Phase transitions of NiO → NiC → Ni and CeO2 → CeO2-x were observed during the reaction. The simultaneous production of H2/CO2 demonstrates that the active phase of the catalysts contains metallic Ni supported over partially reduced ceria. The DRIFTS experiments indicate thatmore » a methoxy to formate transition is associated with the reduction of ceria whereas the formation of carbonate species results from the presence of metallic Ni. A study of the reaction of methanol with Ni-CeO2-x(111) by X-ray photoelectron spectroscopy (XPS) points to the essential role of metal-support interactions in an oxygen transfer from ceria to Ni that contributes to the high selectivity of the catalysts.« less

  13. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports

    PubMed Central

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H.

    2013-01-01

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/AlS.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/AlS.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size. PMID:28809270

  14. Steam reforming of ethanol at moderate temperature: Multifactorial design analysis of Ni/La 2O 3-Al 2O 3, and Fe- and Mn-promoted Co/ZnO catalysts

    NASA Astrophysics Data System (ADS)

    Torres, José Antonio; Llorca, Jordi; Casanovas, Albert; Domínguez, Montserrat; Salvadó, Joan; Montané, Daniel

    Novel Co (10%) catalysts supported on ZnO and promoted with Fe and Mn (1%) were synthesized and characterized by high-resolution transmission electron microscopy (HRTEM), electron energy-loss spectroscopy (EELS), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS). Their catalytic activity for steam reforming of ethanol was compared with that of Ni catalysts supported on La 2O 3-Al 2O 3. Experiments at 400 and 500 °C, steam to carbon ratios of 2 and 4, and a wide interval of contact time were analyzed following a multifactorial experimental design. At 500 °C and a steam to carbon molar ratio of 4, complete conversion of ethanol was achieved above a contact time of 200 g min mol -1 for all catalysts. The ratio of selectivity between hydrogen and methane was around 23 mol H2/mol CH4 in the Co catalysts, while it approached the thermodynamic equilibrium (5.7 mol H2/mol CH4) in the Ni catalysts. The Co catalysts do not promote methane-forming reactions like ethanol cracking and acetaldehyde decarbonilation, nor do they facilitate the reverse methane steam reforming reaction. The catalytic behavior of cobalt is enhanced by promotion with iron or manganese through the formation of bimetallic particles, which facilitates cobalt reducibility. This suggests that Co-Mn/ZnO and Co-Fe/ZnO catalysts have a good potential for their use for ethanol reforming at moderate temperature.

  15. Superstructure high efficiency photovoltaics

    NASA Technical Reports Server (NTRS)

    Wagner, M.; So, L. C.; Leburton, J. P.

    1987-01-01

    A novel class of photovoltaic cascade structures is introduced which features multijunction upper subcells. These superstructure high efficiency photovoltaics (SHEP's) exhibit enhanced upper subcell spectral response because of the additional junctions which serve to reduce bulk recombination losses by decreasing the mean collection distance for photogenerated minority carriers. Two possible electrical configurations were studied and compared: a three-terminal scheme that allows both subcells to be operated at their individual maximum power points and a two-terminal configuration with an intercell ohmic contact for series interconnection. The three-terminal devices were found to be superior both in terms of beginning-of-life expectancy and radiation tolerance. Realistic simulations of three-terminal AlGaAs/GaAs SHEP's show that one sun AMO efficiencies in excess of 26 percent are possible.

  16. High Efficiency Cell Development

    NASA Technical Reports Server (NTRS)

    Carbajal, B. G.

    1979-01-01

    The specific activity was to improve the tandem junction Cell (TJC) as a high efficiency solar cell. The TJC development was to be consistent with module assembly and should contribute to the overall goals of the Low-Cost Solar Array Project. During 1978, TJC efficiency improved from approximately 11 percent to approximately 16 percent (AMI). Photogenerated current densities in excess of 42 mA/sq cm were observed at AMO. Open circuit voltages as high as 0.615 V were measured at AMO. Fill factor was only 0.68 - 0.75 due to a nonoptimum metal contact design. A device model was conceived in which the solar cell is modelled as a transitor. There are virtually no interconnect or packaging factor systems and the TJC is compatible with all conventional module fabrication systems. A modification of the TJC, the Front Surface Field (FSF) cell, was also explored.

  17. One-Pot Synthesis of Mesoporous Ni-Ti-Al Ternary Oxides: Highly Active and Selective Catalysts for Steam Reforming of Ethanol.

    PubMed

    Gonçalves, Alexandre A S; Faustino, Patrícia B; Assaf, José M; Jaroniec, Mietek

    2017-02-22

    One-pot synthesis of nanostructured ternary oxides of Ni, Al, and Ti was designed and performed via evaporation induced self-assembly (EISA). For the purpose of comparison, analogous oxides were also prepared by the impregnation method. The resulting materials were applied in two catalytic reactions: steam reforming of ethanol (SRE) for H2 production (subjected to prior activation with H2) and ethanol dehydration (ED; used without prior activation), to in situ analyze carbon accumulation by ethylene depletion when ethanol interacts with acidic sites present on the support. Modification of Ni-Al mixed oxides with titania was shown to have several benefits. CO2, NH3, and propylamine sorption data indicate a decrease in the strength of acidic and basic sites after addition of titania, which in turn slowed down the carbon accumulation during the ED reaction. These changes in interactions between ethanol and byproducts with the support led to different reaction pathways in SRE, indicating that the catalysts obtained by EISA with titania addition showed higher ethylene selectivity and CO2/CO ratios. The opposite was observed for the impregnated catalysts, which were less coke-stable during ED reactions and showed no ethylene selectivity in SRE. Carbon formed during ED reactions was shown to be thermodynamically less favorable and easier to decompose in the presence of titania. All catalysts studied displayed similar and high selectivities (∼80%) and yields (∼5.3 molH2/molethanol) toward H2, which place them among the most active and selective catalysts for SRE. These results indicate the importance of tailoring the support surface acidity to achieve high reforming performance and higher selectivity toward SRE, one of the key processes to produce cleaner and efficient fuels. For an efficient reforming process, the yield of byproducts is low but still they affect the catalyst stability in the long-run, thus this work may impact future studies toward development of near

  18. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification

    PubMed Central

    Castro-Dominguez, Bernardo; Mardilovich, Ivan P.; Ma, Liang-Chih; Ma, Rui; Dixon, Anthony G.; Kazantzis, Nikolaos K.; Ma, Yi Hua

    2016-01-01

    Palladium-based catalytic membrane reactors (CMRs) effectively remove H2 to induce higher conversions in methane steam reforming (MSR) and water-gas-shift reactions (WGS). Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H2, CO and CO2. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H2O, CO2 and H2. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H2 and induce higher methane and CO conversions while yielding ultrapure H2 and compressed CO2 ready for dehydration. Experimental results involving (i) a conventional packed bed reactor packed (PBR) for MSR, (ii) a PBR with five layers of two catalysts in series and (iii) a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD) model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H2 permeance and purity, high CH4 conversion levels and reduced CO yields. PMID:27657143

  19. High Efficiency, Clean Combustion

    SciTech Connect

    Donald Stanton

    2010-03-31

    Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous

  20. Vapor-liquid activity coefficients for methanol and ethanol from heat of solution data: application to steam-methane reforming.

    PubMed

    Kunz, R G; Baade, W F

    2001-11-16

    This paper presents equations and curves to calculate vapor-liquid phase equilibria for methanol and ethanol in dilute aqueous solution as a function of temperature, using activity coefficients at infinite dilution. These thermodynamic functions were originally derived to assess the distribution of by-product contaminants in the process condensate and the steam-system deaerator of a hydrogen plant [Paper ENV-00-171 presented at the NPRA 2000 Environmental Conference, San Antonio, TX, 10-12 September 2000], but have general applicability to other systems as well. The functions and calculation method described here are a necessary piece of an overall prediction technique to estimate atmospheric emissions from the deaerator-vent when the process condensate is recycled as boiler feed water (BFW) make-up. Having such an estimation technique is of particular significance at this time because deaerator-vent emissions are already coming under regulatory scrutiny in California [Emissions from Hydrogen Plant Process Vents, Adopted 21 January 2000] followed closely elsewhere in the US, and eventually worldwide. The overall technique will enable a permit applicant to estimate environmental emissions to comply with upcoming regulations, and a regulatory agency to evaluate those estimates. It may also be useful to process engineers as a tool to estimate contaminant concentrations and flow rates in internal process streams such as the steam-generating system. Metallurgists and corrosion engineers might be able to use the results for materials selection.

  1. High-efficiency CARM

    SciTech Connect

    Bratman, V.L.; Kol`chugin, B.D.; Samsonov, S.V.; Volkov, A.B.

    1995-12-31

    The Cyclotron Autoresonance Maser (CARM) is a well-known variety of FEMs. Unlike the ubitron in which electrons move in a periodical undulator field, in the CARM the particles move along helical trajectories in a uniform magnetic field. Since it is much simpler to generate strong homogeneous magnetic fields than periodical ones for a relatively low electron energy ({Brit_pounds}{le}1-3 MeV) the period of particles` trajectories in the CARM can be sufficiently smaller than in the undulator in which, moreover, the field decreases rapidly in the transverse direction. In spite of this evident advantage, the number of papers on CARM is an order less than on ubitron, which is apparently caused by the low (not more than 10 %) CARM efficiency in experiments. At the same time, ubitrons operating in two rather complicated regimes-trapping and adiabatic deceleration of particles and combined undulator and reversed guiding fields - yielded efficiencies of 34 % and 27 %, respectively. The aim of this work is to demonstrate that high efficiency can be reached even for a simplest version of the CARM. In order to reduce sensitivity to an axial velocity spread of particles, a short interaction length where electrons underwent only 4-5 cyclotron oscillations was used in this work. Like experiments, a narrow anode outlet of a field-emission electron gun cut out the {open_quotes}most rectilinear{close_quotes} near-axis part of the electron beam. Additionally, magnetic field of a small correcting coil compensated spurious electron oscillations pumped by the anode aperture. A kicker in the form of a sloping to the axis frame with current provided a control value of rotary velocity at a small additional velocity spread. A simple cavity consisting of a cylindrical waveguide section restricted by a cut-off waveguide on the cathode side and by a Bragg reflector on the collector side was used as the CARM-oscillator microwave system.

  2. Single Step Bi-reforming and Oxidative Bi-reforming of Methane (Natural Gas) with Steam and Carbon Dioxide to Metgas (CO-2H2) for Methanol Synthesis: Self-Sufficient Effective and Exclusive Oxygenation of Methane to Methanol with Oxygen.

    PubMed

    Olah, George A; Goeppert, Alain; Czaun, Miklos; Mathew, Thomas; May, Robert B; Prakash, G K Surya

    2015-07-15

    Catalysts based on suitable metal oxide supports, such as NiO/MgO and CoO/MgO, were shown to be active for single step bi-reforming, the combined steam and dry reforming of methane or natural gas with H2O and CO2 exclusively to metgas (CO-2H2) for efficient methanol synthesis. Reactions were carried out in a tubular flow reactor under pressures up to 42 bar at 830-910 °C. Using a CH4 to steam to CO2 ratio of ∼3:2:1 in the gas feed, the H2/CO ratio of 2:1 was achieved, which is desired for subsequent methanol synthesis. The needed 2/1 steam/CO2 feed ratio together with the reaction heat for the endothermic bi-reforming can be conveniently obtained by the complete combustion of a quarter part of the overall used methane (natural gas) with oxygen of the air (oxidative bi-reforming). Complete combustion of a part of methane followed by bi-reforming leads to the production of metgas (H2/CO in 2:1 mol ratio) for self-sufficient exclusive methanol synthesis. The long sought after but elusive efficient and selective oxygenation of methane to methanol is thus achieved in an effective and economic way without any oxidation byproduct formation according to CH4 + 1/2O2 → CH3OH.

  3. Enhancement of Glycerol Steam Reforming Activity and Thermal Stability by Incorporating CeO2 and TiO2 in Ni- and Co-MCM-41 Catalysts

    NASA Astrophysics Data System (ADS)

    Dade, William N.

    Hydrogen (H2) has many applications in industry with current focus shifted to production of hydrocarbon fuels and valuable oxygenates using the Fischer-Tropsch technology and direct use in proton exchange membrane fuel cell (PEMFC). Hydrogen is generally produced via steam reforming of natural gas or alcohols like methanol and ethanol. Glycerol, a by-product of biodiesel production process, is currently considered to be one of the most attractive sources of sustainable H2 due to its high H/C ratio and bio-based origin. Ni and Co based catalysts have been reported to be active in glycerol steam reforming (GSR); however, deactivation of the catalysts by carbon deposition and sintering under GSR operating conditions is a major challenge. In this study, a series of catalysts containing Ni and Co nanoparticles incorporated in CeO2 and TiO2 modified high surface area MCM-41 have been synthesized using one-pot method. The catalysts are tested for GSR (at H2O/Glycerol mole ratio of 12 and GHSV of 2200 h-1) to study the effect of support modification and reaction temperature (450 - 700 °C) on the product selectivity and long term stability. GSR results revealed that all the catalysts performed significantly well exhibiting over 85% glycerol conversion at 650 °C except Ni catalysts that showed better low temperature activities. Deactivation studies of the catalysts conducted at 650 °C indicated that the Ni-TiO2-MCM-41 and Ni-CeO 2-MCM-41 were resistant to deactivation with ˜100% glycerol conversion for 40 h. In contrast, Co-TiO2-MCM-41 perform poorly as the catalyst rapidly deactivated after 12 h to yield ˜20% glycerol conversion after 40 h. The WAXRD and TGA-DSC analyses of spent catalysts showed a significant amount of coke deposition that might explain catalysts deactivation. The flattening shape of the original BET type IV isotherm with drastic reduction of catalyst surface area can also be responsible for observed drop in catalysts activities.

  4. Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG) Over Nickel-Phosphorus-Alumina Xerogel Catalyst Prepared by a Carbon-Templating Epoxide-Driven Sol-Gel Method.

    PubMed

    Bang, Yongju; Park, Seungwon; Han, Seung Ju; Yoo, Jaekyeong; Choi, Jung Ho; Kang, Tae Hun; Lee, Jinwon; Song, In Kyu

    2016-05-01

    A nickel-phosphorus-alumina xerogel catalyst was prepared by a carbon-templating epoxide-driven sol-gel method (denoted as CNPA catalyst), and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel-phosphorus-alumina xerogel catalyst was also prepared by a similar method in the absence of carbon template (denoted as NPA catalyst). The effect of carbon template addition on the physicochemical properties and catalytic activities of the catalysts in the steam reforming of LNG was investigated. Both CNPA and NPA catalysts showed excellent textural properties with well-developed mesoporous structure. However, CNPA catalyst retained a more reducible nickel aluminate phase than NPA catalyst. XRD analysis of the reduced CNPA and NPA catalysts revealed that nickel sintering on the CNPA catalyst was suppressed compared to that on the NPA catalyst. From H2-TPD and CH4-TPD measurements of the reduced CNPA and NPA catalysts, it was also revealed that CNPA catalyst with large amount of hydrogen uptake and strong hydrogen-binding sites showed larger amount of methane adsorption than NPA catalyst. In the hydrogen production by steam reforming of LNG, CNPA catalyst with large methane adsorption capacity showed a better catalytic activity than NPA catalyst.

  5. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    DOE PAGES

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; ...

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is themore » active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.« less

  6. The role of metal-support interaction for CO-free hydrogen from low temperature ethanol steam reforming on Rh-Fe catalysts.

    PubMed

    Choong, Catherine K S; Chen, Luwei; Du, Yonghua; Schreyer, Martin; Daniel Ong, S W; Poh, Chee Kok; Hong, Liang; Borgna, Armando

    2017-02-08

    Rh-Fe catalysts supported on Ca-Al2O3, MgO and ZrO2 were evaluated in ethanol steam reforming at 623 K and compared to Rh catalysts on the same supports without iron promotion. The metal-support interaction among the three entities, i.e. Rh ↔ Fe2O3 ← support (ZrO2, MgO and Ca-Al2O3) was investigated using H2-chemisorption, TEM, XPS and in situ techniques such as DRIFTS, temperature-resolved XRD and XAS. As compared to the unpromoted Rh catalysts on the same supports, the CO selectivity is depressed in the presence of iron on Rh/MgO and Rh/Ca-Al2O3, the latter being significantly superior. The role of metal-support interaction for CO-free hydrogen generation was unravelled using a combination of techniques. It was found that the reducibility of iron oxide determines the extent of the strong metal support interaction between Rh and Fe2O3 and the reducibility of iron oxide was affected by the support. On Rh-Fe/Ca-Al2O3, a good balance of the interaction between Rh, Fe2O3 and Ca-Al2O3 prevents strong metal support interaction between Rh and Fe2O3 and thus promotes CO elimination via water-gas-shift reaction on Rh-FexOy sites.

  7. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

    SciTech Connect

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; Xu, W.; Trovarelli, A.; Llorca, J.

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic - oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria

  8. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

    DOE PAGES

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; ...

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic -more » oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria« less

  9. Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank SX-105 And AN-103) By Fluidized Bed Steam Reformation

    SciTech Connect

    Jantzen, Carol; Herman, Connie; Crawford, Charles; Bannochie, Christopher; Burket, Paul; Daniel, Gene; Cozzi, Alex; Nash, Charles; Miller, Donald; Missimer, David

    2014-01-10

    One of the immobilization technologies under consideration as a Supplemental Treatment for Hanford’s Low Activity Waste (LAW) is Fluidized Bed Steam Reforming (FBSR). The FBSR technology forms a mineral waste form at moderate processing temperatures thus retaining and atomically bonding the halides, sulfates, and technetium in the mineral phases (nepheline, sodalite, nosean, carnegieite). Additions of kaolin clay are used instead of glass formers and the minerals formed by the FBSR technology offers (1) atomic bonding of the radionuclides and constituents of concern (COC) comparable to glass, (2) short and long term durability comparable to glass, (3) disposal volumes comparable to glass, and (4) higher Na2O and SO{sub 4} waste loadings than glass. The higher FBSR Na{sub 2}O and SO{sub 4} waste loadings contribute to the low disposal volumes but also provide for more rapid processing of the LAW. Recent FBSR processing and testing of Hanford radioactive LAW (Tank SX-105 and AN-103) waste is reported and compared to previous radioactive and non-radioactive LAW processing and testing.

  10. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    SciTech Connect

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; Senanayake, Sanjaya D.

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is the active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.

  11. Ni/MgO-MgAl2O4 Catalysts with Bimodal Pore Structure for Steam-CO2-Reforming of Methane.

    PubMed

    Kim, Byung-Hyuk; Yang, Eun-Hyeok; Moon, Dong Ju; Kim, Sang Woo

    2015-08-01

    The bead type MgO-MgAl2O4 catalyst supports with bimodal pore structures were fabricated via an extrusion molding of gels derived from the precursor mixture of mesoporous MgO particles and aluminum magnesium hydroxide, followed by heat treatment. To investigate the effect of macro pore structures on the catalytic activity of the Ni/MgO-MgAl2O4 catalysts in the steam and carbon dioxide reforming of methane (SCR), two kinds of the catalysts with largely different macro pore volumes and sizes but nearly the same meso pore volume and size were compared. The bimodal catalyst with a large macro pore size and volume exhibited a highly enhanced CO2 conversion from 22.3 to 37.1% but a slightly reduced CH4 conversion from 95.3 to 92.1% at the same feed ratio. The SCR results show that the large macro pores can lead to a highly enhanced mass transfer rate of CO2 absorption into the pore channels of the magnesium alumina spinel.

  12. Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells

    SciTech Connect

    James E. O'Brien

    2012-03-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

  13. Effect of SiO 2-ZrO 2 supports prepared by a grafting method on hydrogen production by steam reforming of liquefied natural gas over Ni/SiO 2-ZrO 2 catalysts

    NASA Astrophysics Data System (ADS)

    Seo, Jeong Gil; Youn, Min Hye; Song, In Kyu

    SiO 2-ZrO 2 supports with various zirconium contents are prepared by grafting a zirconium precursor onto the surface of commercial Carbosil silica. Ni(20 wt.%)/SiO 2-ZrO 2 catalysts are then prepared by an impregnation method, and are applied to hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of SiO 2-ZrO 2 supports on the performance of the Ni(20 wt.%)/SiO 2-ZrO 2 catalysts is investigated. SiO 2-ZrO 2 prepared by a grafting method serves as an efficient support for the nickel catalyst in the steam reforming of LNG. Zirconia enhances the resistance of silica to steam significantly and increases the interaction between nickel and the support, and furthermore, prevents the growth of nickel oxide species during the calcination process through the formation of a ZrO 2-SiO 2 composite structure. The crystalline structures and catalytic activities of the Ni(20 wt.%)/SiO 2-ZrO 2 catalysts are strongly influenced by the amount of zirconium grafted. The conversion of LNG and the yield of hydrogen show volcano-shaped curves with respect to zirconium content. Among the catalysts tested, the Ni(20 wt.%)/SiO 2-ZrO 2 (Zr/Si = 0.54) sample shows the best catalytic performance in terms of both LNG conversion and hydrogen yield. The well-developed and pure tetragonal phase of ZrO 2-SiO 2 (Zr/Si = 0.54) appears to play an important role in the adsorption of steam and subsequent spillover of steam from the support to the active nickel. The small particle size of the metallic nickel in the Ni(20 wt.%)/SiO 2-ZrO 2 (Zr/Si = 0.54) catalyst is also responsible for its high performance.

  14. A reformer to generate hydrogen for distributed power applications

    SciTech Connect

    Cole, J.A.; Kumar, R.V.; West, J.; Lyon, R.K.

    1998-07-01

    The generation of power using fuel cells is a promising technology for distributed electric power generation applications. Steam reforming of fossil fuels remains the most thermodynamically efficient means for production of hydrogen. Unfortunately, current steam reforming technology achieves high efficiencies only at very large scales, and remains impractical at the small production rates needed for small- to medium-size distributed power applications. A novel reformer process, called unmixed reforming, or UMR, has been developed for the conversion of hydrocarbon fuels (natural gas, diesel, gasoline) to hydrogen. The reformer promises high thermodynamic efficiency as heat is generated right on the catalytic bed unlike conventional reforming. The controlled combustion on the reforming catalyst using a patented technology called unmixed combustion provides the heat for the endothermic reforming reaction. The reformer generates a high-purity hydrogen product stream, which can then be used by fuel cells with minimal processing. The unmixed reformer is a packed-bed consisting of finely divided nickel supported on a ceramic matrix mixed with a calcium oxide bearing matrix such as dolomite. UMR consists of three process steps. During the first step air is passed over the packed-bed reactor to oxidize the nickel. The heat released during the oxidation reaction raises the temperature of the bed and decomposes the dolomite releasing carbon dioxide into a vent gas stream. In the subsequent step fuel passed over the packed-bed reduces the NiO back to Ni and further increases the temperature. In the final step, fuel and steam react to produce hydrogen through conventional steam reforming chemistry. The calcium oxide captures some of the carbon dioxide formed during the reforming reaction and thus shifts the reforming reactions to higher conversions, hence improving the purity of the hydrogen product stream. Although product hydrogen concentrations may be 75--85%, the CO content

  15. Investigation of sulfur interactions on a conventional nickel-based solid oxide fuel cell anode during methane steam and dry reforming

    NASA Astrophysics Data System (ADS)

    Jablonski, Whitney S.

    Solid oxide fuel cells (SOFC) are an attractive energy source because they do not have undesirable emissions, are scalable, and are feedstock flexible, which means they can operate using a variety of fuel mixtures containing H2 and hydrocarbons. In terms of fuel flexibility, most potential fuel sources contain sulfur species, which severely poison the nickel-based anode. The main objective of this thesis is to systematically evaluate sulfur interactions on a conventional Ni/YSZ anode and compare sulfur poisoning during methane steam and dry reforming (SMR and DMR) to a conventional catalyst (Sud Chemie, Ni/K2O-CaAl2O4). Reforming experiments (SMR and DMR) were carried out in a packed bed reactor (PBR), and it was demonstrated that Ni/YSZ is much more sensitive to sulfur poisoning than Ni/K2O-CaAl2O4 as evidenced by the decline in activity to zero in under an hour for both SMR and DMR. Adsorption and desorption of H2S and SO2 on both catalysts was evaluated, and despite the low amount of accessible nickel on Ni/YSZ (14 times lower than Ni/K2O-CaAl2O4), it adsorbs 20 times more H2S and 50 times more SO2 than Ni/K 2O-CaAl2O4. A one-dimensional, steady state PBR model (DetchemPBED) was used to evaluate SMR and DMR under poisoning conditions using the Deutschmann mechanism and a recently published sulfur sub-mechanism. To fit the observed deactivation in the presence of 1 ppm H2S, the adsorption/desorption equilibrium constant was increased by a factor 16,000 for Ni/YSZ and 96 for Ni/K2O-CaAl2O4. A tubular SAE reactor was designed and fabricated for evaluating DMR in a reactor that mimics an SOFC. Evidence of hydrogen diffusion through a supposedly impermeable layer indicated that the tubular SAE reactor has a major flaw in which gases diffuse to unintended parts of the tube. It was also found to be extremely susceptible to coking which leads to cell failure even in operating regions that mimic real biogas. These problems made it impossible to validate the tubular SAE

  16. Elucidating the interaction between Ni and CeOx in ethanol steam reforming catalysts: A perspective of recent studies over model and powder systems

    SciTech Connect

    Liu, Zongyuan; Senanayake, Sanjaya D.; Rodriguez, Jose A.

    2016-11-15

    Bulk metallic nickel is a poor catalyst for the reforming of oxygenates being deactivated by the deposition of coke. In contrast, Ni-ceria is an active system for the catalytic extraction of H2 from the ethanol steam reforming reaction (ESR, C2H5OH + 3H2O ↔ 2CO2 + 6H2). Numerous studies, with model (well-defined crystal surfaces) and technical (high surface area powders) catalysts, have been devoted to understand the fundamental role of each catalyst component, the performance of adjacent sites in the metal-oxide interface, and the complex mechanistic steps that convert two oxygenated reactants (ethanol and H2O) into H2. The size and low loading of Ni on ceria facilitate metal-oxide support interactions that probably enhance the reactivity of the system. To establish the precise role of both Ni and Ce is challenging. However it is clear that both Ni and Ce are associated with the dissociation of H2O (OH + H), while ceria readily adsorbs and partially dissociates ethanol (i.e. ethoxy formation). The most difficult step of Csingle bondC bond dissociation likely occurs only on Ni or at the Ni-Ce interface. H2O and OH remain as important agents for the prevention of excess C build up during the C—H/C—C dissociation process. Often, deactivation upon C build up, is a direct result of Ni sintering and decoupling of the Ni-Ce interactions. One strategy to maintain good activity and stability is to protect the Ni-Ce interaction, and this can be achieved through the use of solid solutions (Ce1–xNixO2–y) or by employing stabilizing agents such as W (NixWyCezO2). In this study, we present and discuss the most recent work for the ESR reaction and show the important role of ceria which participates directly in the reaction and also enhances catalytic activity through metal-support interactions.

  17. Elucidating the interaction between Ni and CeOx in ethanol steam reforming catalysts: A perspective of recent studies over model and powder systems

    SciTech Connect

    Liu, Zongyuan; Senanayake, Sanjaya D.; Rodriguez, Jose A.

    2016-11-15

    Bulk metallic nickel is a poor catalyst for the reforming of oxygenates being deactivated by the deposition of coke. In contrast, Ni-ceria is an active system for the catalytic extraction of H2 from the ethanol steam reforming reaction (ESR, C2H5OH + 3H2O ↔ 2CO2 + 6H2). Numerous studies, with model (well-defined crystal surfaces) and technical (high surface area powders) catalysts, have been devoted to understand the fundamental role of each catalyst component, the performance of adjacent sites in the metal-oxide interface, and the complex mechanistic steps that convert two oxygenated reactants (ethanol and H2O) into H2. The size and low loading of Ni on ceria facilitate metal-oxide support interactions that probably enhance the reactivity of the system. To establish the precise role of both Ni and Ce is challenging. However it is clear that both Ni and Ce are associated with the dissociation of H2O (OH + H), while ceria readily adsorbs and partially dissociates ethanol (i.e. ethoxy formation). The most difficult step of Csingle bondC bond dissociation likely occurs only on Ni or at the Ni-Ce interface. H2O and OH remain as important agents for the prevention of excess C build up during the Csingle bondH/Csingle bondC dissociation process. Often, deactivation upon C build up, is a direct result of Ni sintering and decoupling of the Ni-Ce interactions. One strategy to maintain good activity and stability is to protect the Ni-Ce interaction, and this can be achieved through the use of solid solutions (Ce1–xNixO2–y) or by employing stabilizing agents such as W (NixWyCezO2). In this paper, we present and discuss the most recent work for the ESR reaction and show the important role of ceria which participates directly in the reaction and also enhances catalytic activity through

  18. Elucidating the interaction between Ni and CeOx in ethanol steam reforming catalysts: A perspective of recent studies over model and powder systems

    DOE PAGES

    Liu, Zongyuan; Senanayake, Sanjaya D.; Rodriguez, Jose A.

    2016-11-15

    Bulk metallic nickel is a poor catalyst for the reforming of oxygenates being deactivated by the deposition of coke. In contrast, Ni-ceria is an active system for the catalytic extraction of H2 from the ethanol steam reforming reaction (ESR, C2H5OH + 3H2O ↔ 2CO2 + 6H2). Numerous studies, with model (well-defined crystal surfaces) and technical (high surface area powders) catalysts, have been devoted to understand the fundamental role of each catalyst component, the performance of adjacent sites in the metal-oxide interface, and the complex mechanistic steps that convert two oxygenated reactants (ethanol and H2O) into H2. The size and lowmore » loading of Ni on ceria facilitate metal-oxide support interactions that probably enhance the reactivity of the system. To establish the precise role of both Ni and Ce is challenging. However it is clear that both Ni and Ce are associated with the dissociation of H2O (OH + H), while ceria readily adsorbs and partially dissociates ethanol (i.e. ethoxy formation). The most difficult step of Csingle bondC bond dissociation likely occurs only on Ni or at the Ni-Ce interface. H2O and OH remain as important agents for the prevention of excess C build up during the Csingle bondH/Csingle bondC dissociation process. Often, deactivation upon C build up, is a direct result of Ni sintering and decoupling of the Ni-Ce interactions. One strategy to maintain good activity and stability is to protect the Ni-Ce interaction, and this can be achieved through the use of solid solutions (Ce1–xNixO2–y) or by employing stabilizing agents such as W (NixWyCezO2). In this paper, we present and discuss the most recent work for the ESR reaction and show the important role of ceria which participates directly in the reaction and also enhances catalytic activity through metal-support interactions.« less

  19. Elucidating the interaction between Ni and CeOx in ethanol steam reforming catalysts: A perspective of recent studies over model and powder systems

    DOE PAGES

    Liu, Zongyuan; Senanayake, Sanjaya D.; Rodriguez, Jose A.

    2016-11-15

    Bulk metallic nickel is a poor catalyst for the reforming of oxygenates being deactivated by the deposition of coke. In contrast, Ni-ceria is an active system for the catalytic extraction of H2 from the ethanol steam reforming reaction (ESR, C2H5OH + 3H2O ↔ 2CO2 + 6H2). Numerous studies, with model (well-defined crystal surfaces) and technical (high surface area powders) catalysts, have been devoted to understand the fundamental role of each catalyst component, the performance of adjacent sites in the metal-oxide interface, and the complex mechanistic steps that convert two oxygenated reactants (ethanol and H2O) into H2. The size and lowmore » loading of Ni on ceria facilitate metal-oxide support interactions that probably enhance the reactivity of the system. To establish the precise role of both Ni and Ce is challenging. However it is clear that both Ni and Ce are associated with the dissociation of H2O (OH + H), while ceria readily adsorbs and partially dissociates ethanol (i.e. ethoxy formation). The most difficult step of Csingle bondC bond dissociation likely occurs only on Ni or at the Ni-Ce interface. H2O and OH remain as important agents for the prevention of excess C build up during the C—H/C—C dissociation process. Often, deactivation upon C build up, is a direct result of Ni sintering and decoupling of the Ni-Ce interactions. One strategy to maintain good activity and stability is to protect the Ni-Ce interaction, and this can be achieved through the use of solid solutions (Ce1–xNixO2–y) or by employing stabilizing agents such as W (NixWyCezO2). In this study, we present and discuss the most recent work for the ESR reaction and show the important role of ceria which participates directly in the reaction and also enhances catalytic activity through metal-support interactions.« less

  20. Steam reforming of fast pyrolysis-derived aqueous phase oxygenates over Co, Ni, and Rh metals supported on MgAl2O4

    SciTech Connect

    Xing, Rong; Dagle, Vanessa Lebarbier; Flake, Matthew; Kovarik, Libor; Albrecht, Karl O.; Deshmane, Chinmay; Dagle, Robert A.

    2016-07-01

    In this study we examine feasibility for steam reforming the mixed oxygenate aqueous fraction derived from mildly hydrotreated fast pyrolysis bio-oils. Catalysts selective towards hydrogen formation and resistant to carbon formation utilizing feeds with relatively low steam-to-carbon (S/C) ratios are desired. Rh (5 wt%), Pt (5 wt%), Ru (5 wt%), Ir (5 wt%), Ni (15 wt%), and Co (15 wt%) metals supported on MgAl2O4 were evaluated for catalytic performance at 500°C and 1 atm using a complex feed mixture comprising of acids, polyols, cycloalkanes, and phenolic compounds. The Rh catalyst was found to be the most active and resistant to carbon formation. The Ni and Co catalysts were found to be more active than the other noble metal catalysts investigated (Pt, Ru, and Ir). However, Ni was found to form significantly more carbon (coke) on the catalyst surface. Furthermore, Co was found to be the most selective towards H2 formation. Evaluating the effect of temperature on stability for the Rh catalyst we found that catalyst stability was best when operated at 500°C as compared to the higher temperatures investigated (700, 800°C). When operating at 700°C significantly more graphitic formation was observed on the spent catalyst surface. Operating at 800°C resulted in reactor plugging as a result of thermal decomposition of the reactants. Thus, a concept analogous to the petroleum industries’ use of a pre-reformer, operated at approximately 500°C for steam reforming of the heavier naphtha components, followed by a high temperature methane reforming operated in the 600-850°C temperature range, could be applied in the case of steam reforming biomass derived oxygenates. Moreover, stability evaluations were performed over the Rh, Ni, and Co catalysts at 500°C and 1 atm, under similar initial conversions, reveal the Co catalyst to be the most stable and selective towards H2 production. Conversion and selectivity to CH4

  1. Techno-economic analysis of sorption-enhanced steam methane reforming in a fixed bed reactor network integrated with fuel cell

    NASA Astrophysics Data System (ADS)

    Diglio, Giuseppe; Hanak, Dawid P.; Bareschino, Piero; Mancusi, Erasmo; Pepe, Francesco; Montagnaro, Fabio; Manovic, Vasilije

    2017-10-01

    Sorption-enhanced steam methane reforming (SE-SMR) is a promising alternative for H2 production with inherent CO2 capture. This study evaluates the techno-economic performance of SE-SMR in a network of fixed beds and its integration with a solid oxide fuel cell (SE-SMR-SOFC) for power generation. The analysis revealed that both proposed systems are characterised by better economic performance than the reference systems. In particular, for SE-SMR the levelised cost of hydrogen is 1.6 €ṡkg-1 and the cost of CO2 avoided is 29.9 €ṡtCO2-1 (2.4 €ṡkg-1 and 50 €ṡtCO2-1, respectively, for SMR with CO2 capture) while for SE-SMR-SOFC the levelised cost of electricity is 0.078 €ṡkWh-1 and the cost of CO2 avoided is 36.9 €ṡtCO2-1 (0.080 €ṡkWh-1 and 80 €ṡtCO2-1, respectively, for natural gas-fired power plant with carbon capture). The sensitivity analysis showed that the specific cost of fuel and the capital cost of fuel cell mainly affect the economic performance of SE-SMR and SE-SMR-SOFC, respectively. The daily revenue of the SE-SMR-SOFC system is higher than that of the natural gas-fired power plant if the difference between the carbon tax and the CO2 transport and storage cost is > 6 €ṡtCO2-1.

  2. Conversion of mill-scale waste to nanoscale zero valent iron (nZVI) for 'green' hydrogen generation via metal-steam reforming

    NASA Astrophysics Data System (ADS)

    Kesavan, Sathees Kumar

    The Proton Exchange Membrane Fuel Cells (PEMFCs) are the most preferred and efficient energy conversion devices for automotive applications but demand high purity hydrogen which comes at a premium price. The currently pursued hydrogen generation methods suffer from issues such as, low efficiency, high cost, environmental non-benignity, and, in some cases, commercial non-viability. Many of these drawbacks including the CO contamination and, storage and delivery can be overcome by resorting to metal-steam reforming (MSR) using iron from steel industry's mill-scale waste. A novel solution-based room temperature technique using sodium borohydride (NaBH4) as the reducing agent has been developed that produces highly active nanoscale (30-40 nm) iron particles. A slightly modified version of this technique using a surfactant and water oil microemulsion resulted in the formation of 5 nm Fe particles. By using hydrazine (N2H4) as an inexpensive and more stable (compared to NaBH4) reductant, body centered cubic iron particles with edge dimensions ˜5 nm were obtained under mild solvothermal conditions in ethanol. The nanoscale zero valent iron (nZVI) powder showed improved kinetics and greater propensity for hydrogen generation than the coarser microscale iron obtained through traditional reduction techniques. To initiate and sustain the somewhat endothermic MSR process, a solar concentrator consisting of a convex polyacrylic sheet with aluminum reflective coating was fabricated. This unique combination of mill-scale waste as iron source, hydrazine as the reductant, mild process conditions for nZVI generation and solar energy as the impetus for actuating MSR, obviates several drawbacks plaguing the grand scheme of producing, storing and delivering pure and humidified H2 to a PEMFC stack.

  3. A series of copper-free ternary oxide catalysts ZnAlCex used for hydrogen production via dimethyl ether steam reforming

    NASA Astrophysics Data System (ADS)

    Zhang, Lijie; Meng, Ming; Wang, Xiaojing; Zhou, Shuang; Yang, Lijuan; Zhang, Tianyong; Zheng, Lirong; Zhang, Jing; Hu, Tiandou

    2014-12-01

    Ce-substituted ternary oxide catalysts ZnAlCex were prepared and employed in dimethyl ether steam reforming (DME SR) to produce hydrogen. XRD, XAFS (XANES & EXAFS), H2O-TPD, CH3OH-TPD and TPSR techniques were used for catalyst characterization. It is found that the catalytic performance of these catalysts is dependent on Ce content. The catalyst containing 20 wt% CeO2 exhibits the best catalytic performance. Its calculated TOF (0.034 s-1) is nearly three times to that of ZnAlO. The kinetic results reveal that the addition of 20 wt% CeO2 to ZnAlCex greatly decreases the apparent activation energy (Ea) of DME SR, due to the formation of new reaction sites such as Ce4+-O-Zn2+ linkages. XRD and EXAFS analyses indicate that Ce addition can not only decrease the crystallite size of ZnO and ZnAl2O4, but also tune the relative contents of them. The results of H2O-TPD and CH3OH-TPD show that Ce addition can lower H2 desorption temperature, which accounts well for the better catalytic performance of ZnAlCex. It is worth noting that the Zn-based catalysts display much lower CO selectivity than the Cu-based one, especially the Ce-substituted ZnAlCex. Start-off durability tests demonstrate that this series of catalysts also possess high catalytic stability.

  4. Steam reforming of fast pyrolysis-derived aqueous phase oxygenates over Co, Ni, and Rh metals supported on MgAl2O4

    SciTech Connect

    Xing, Rong; Dagle, Vanessa Lebarbier; Flake, Matthew; Kovarik, Libor; Albrecht, Karl O.; Deshmane, Chinmay; Dagle, Robert A.

    2016-02-03

    In this paper we examine the feasibility of steam reforming the mixed oxygenate aqueous fraction derived from fast pyrolysis bio-oils. Catalysts selective towards hydrogen formation and resistant to carbon formation utilizing feeds with relatively low steam-to-carbon (S/C) ratios are desired. Rh (5 wt%), Pt (5 wt%), Ru (5 wt%), Ir (5 wt%), Ni (15 wt%), and Co (15 wt%) metals supported on MgAl2O4 were evaluated for catalytic performance at 500 °C and 1 atm using a complex feed mixture comprising acids, polyols, cycloalkanes, and phenolic compounds. The Rh catalyst was found to be the most active and resistant to carbon formation. The Ni and Co catalysts were found to be more active than the other noble metal catalysts investigated (Pt, Ru, and Ir).

  5. Radioactive demonstration of final mineralized waste forms for Hanford waste treatment plant secondary waste (WTP-SW) by fluidized bed steam reforming (FBSR) using the bench scale reformer platform

    SciTech Connect

    Crawford, C.; Burket, P.; Cozzi, A.; Daniel, G.; Jantzen, C.; Missimer, D.

    2014-08-01

    The U.S. Department of Energy’s Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford’s tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as 137Cs, 129I, 99Tc, Cl, F, and SO4 that volatilize at the vitrification temperature of 1150°C in the absence of a continuous cold cap (that could minimize volatilization). The current waste disposal path for the WTP-SW is to process it through the Effluent Treatment Facility (ETF). Fluidized Bed Steam Reforming (FBSR) is being considered for immobilization of the ETF concentrate that would be generated by processing the WTP-SW. The focus of this current report is the WTP-SW.

  6. Enhanced methane steam reforming activity and electrochemical performance of Ni0.9Fe0.1-supported solid oxide fuel cells with infiltrated Ni-TiO2 particles

    NASA Astrophysics Data System (ADS)

    Li, Kai; Jia, Lichao; Wang, Xin; Pu, Jian; Chi, Bo; Li, Jian

    2016-10-01

    Ni0.9Fe0.1 alloy-supported solid oxide fuel cells with NiTiO3 (NTO) infiltrated into the cell support from 0 to 4 wt.% are prepared and investigated for CH4 steam reforming activity and electrochemical performance. The infiltrated NiTiO3 is reduced to TiO2-supported Ni particles in H2 at 650 °C. The reforming activity of the Ni0.9Fe0.1-support is increased by the presence of the TiO2-supported Ni particles; 3 wt.% is the optimal value of the added NTO, corresponding to the highest reforming activity, resistance to carbon deposition and electrochemical performance of the cell. Fueled wet CH4 at 100 mL min‑1, the cell with 3 wt.% of NTO demonstrates a peak power density of 1.20 W cm‑2 and a high limiting current density of 2.83 A cm‑2 at 650 °C. It performs steadily for 96 h at 0.4 A cm‑2 without the presence of deposited carbon in the Ni0.9Fe0.1-support and functional anode. Five polarization processes are identified by deconvoluting and data-fitting the electrochemical impedance spectra of the cells under the testing conditions; and the addition of TiO2-supported Ni particles into the Ni0.9Fe0.1-support reduces the polarization resistance of the processes ascribed to CH4 steam reforming and gas diffusion in the Ni0.9Fe0.1-support and functional anode.

  7. Enhanced methane steam reforming activity and electrochemical performance of Ni0.9Fe0.1-supported solid oxide fuel cells with infiltrated Ni-TiO2 particles

    PubMed Central

    Li, Kai; Jia, Lichao; Wang, Xin; Pu, Jian; Chi, Bo; Li, Jian

    2016-01-01

    Ni0.9Fe0.1 alloy-supported solid oxide fuel cells with NiTiO3 (NTO) infiltrated into the cell support from 0 to 4 wt.% are prepared and investigated for CH4 steam reforming activity and electrochemical performance. The infiltrated NiTiO3 is reduced to TiO2-supported Ni particles in H2 at 650 °C. The reforming activity of the Ni0.9Fe0.1-support is increased by the presence of the TiO2-supported Ni particles; 3 wt.% is the optimal value of the added NTO, corresponding to the highest reforming activity, resistance to carbon deposition and electrochemical performance of the cell. Fueled wet CH4 at 100 mL min−1, the cell with 3 wt.% of NTO demonstrates a peak power density of 1.20 W cm−2 and a high limiting current density of 2.83 A cm−2 at 650 °C. It performs steadily for 96 h at 0.4 A cm−2 without the presence of deposited carbon in the Ni0.9Fe0.1-support and functional anode. Five polarization processes are identified by deconvoluting and data-fitting the electrochemical impedance spectra of the cells under the testing conditions; and the addition of TiO2-supported Ni particles into the Ni0.9Fe0.1-support reduces the polarization resistance of the processes ascribed to CH4 steam reforming and gas diffusion in the Ni0.9Fe0.1-support and functional anode. PMID:27775092

  8. Enhanced methane steam reforming activity and electrochemical performance of Ni0.9Fe0.1-supported solid oxide fuel cells with infiltrated Ni-TiO2 particles.

    PubMed

    Li, Kai; Jia, Lichao; Wang, Xin; Pu, Jian; Chi, Bo; Li, Jian

    2016-10-24

    Ni0.9Fe0.1 alloy-supported solid oxide fuel cells with NiTiO3 (NTO) infiltrated into the cell support from 0 to 4 wt.% are prepared and investigated for CH4 steam reforming activity and electrochemical performance. The infiltrated NiTiO3 is reduced to TiO2-supported Ni particles in H2 at 650 °C. The reforming activity of the Ni0.9Fe0.1-support is increased by the presence of the TiO2-supported Ni particles; 3 wt.% is the optimal value of the added NTO, corresponding to the highest reforming activity, resistance to carbon deposition and electrochemical performance of the cell. Fueled wet CH4 at 100 mL min(-1), the cell with 3 wt.% of NTO demonstrates a peak power density of 1.20 W cm(-2) and a high limiting current density of 2.83 A cm(-2) at 650 °C. It performs steadily for 96 h at 0.4 A cm(-2) without the presence of deposited carbon in the Ni0.9Fe0.1-support and functional anode. Five polarization processes are identified by deconvoluting and data-fitting the electrochemical impedance spectra of the cells under the testing conditions; and the addition of TiO2-supported Ni particles into the Ni0.9Fe0.1-support reduces the polarization resistance of the processes ascribed to CH4 steam reforming and gas diffusion in the Ni0.9Fe0.1-support and functional anode.

  9. High efficiency solar cell processing

    NASA Technical Reports Server (NTRS)

    Ho, F.; Iles, P. A.

    1985-01-01

    At the time of writing, cells made by several groups are approaching 19% efficiency. General aspects of the processing required for such cells are discussed. Most processing used for high efficiency cells is derived from space-cell or concentrator cell technology, and recent advances have been obtained from improved techniques rather than from better understanding of the limiting mechanisms. Theory and modeling are fairly well developed, and adequate to guide further asymptotic increases in performance of near conventional cells. There are several competitive cell designs with promise of higher performance ( 20%) but for these designs further improvements are required. The available cell processing technology to fabricate high efficiency cells is examined.

  10. Bridging the Gap: From Model Surfaces to Nanoparticle Analogs for Selective Oxidation and Steam Reforming of Methanol and Selective Hydrogenation Catalysis

    NASA Astrophysics Data System (ADS)

    Boucher, Matthew B.

    Most industrial catalysts are very complex, comprising of non-uniform materials with varying structures, impurities, and interaction between the active metal and supporting substrate. A large portion of the ongoing research in heterogeneous catalysis focuses on understanding structure-function relationships in catalytic materials. In parallel, there is a large area of surface science research focused on studying model catalytic systems for which structural parameters can be tuned and measured with high precision. It is commonly argued, however, that these systems are oversimplified, and that observations made in model systems do not translate to robust catalysts operating in practical environments; this discontinuity is often referred to as a "gap." The focus of this thesis is to explore the mutual benefits of surface science and catalysis, or "bridge the gap," by studying two catalytic systems in both ultra-high vacuum (UHV) and near ambient-environments. The first reaction is the catalytic steam reforming of methanol (SRM) to hydrogen and carbon dioxide. The SRM reaction is a promising route for on-demand hydrogen production. For this catalytic system, the central hypothesis in this thesis is that a balance between redox capability and weak binding of reaction intermediates is necessary for high SRM activity and selectivity to carbon dioxide. As such, a new catalyst for the SRM reaction is developed which incorporates very small amounts of gold (<1 atomic %) supported on zinc oxide nanoparticles with controlled crystal structures. The performance of these catalysts was studied in a fixed-bed micro-reactor system at ambient pressures, and their structure was characterized by high-resolution microscopic and spectroscopic techniques. Pre-existing oxygen defects in zinc oxide {0001} surfaces, and those created by a perturbation of the defect equilibrium by addition of gold, provide an anchoring site for highly dispersed gold species. By utilizing shape control of

  11. Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank Farm Blend) By Fluidized Bed Steam Reformation (FBSR)

    SciTech Connect

    Jantzen, C. M.; Crawford, C. L.; Bannochie, C. J.; Burket, P. R.; Cozzi, A. D.; Daniel, W. E.; Hall, H. K.; Miller, D. H.; Missimer, D. M.; Nash, C. A.; Williams, M. F.

    2013-08-01

    The U.S. Department of Energy’s Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford’s tank waste. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Supplemental Treatment is likely to be required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. The Supplemental Treatment chosen will immobilize that portion of the retrieved LAW that is not sent to the WTP’s LAW Vitrification facility into a solidified waste form. The solidified waste will then be disposed on the Hanford site in the Integrated Disposal Facility (IDF). Fluidized Bed Steam Reforming (FBSR) offers a moderate temperature (700-750°C) continuous method by which LAW can be processed irrespective of whether the waste contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be comparable to LAW glass, i.e. leaches Tc-99, Re and Na at <2g/m2 during ASTM C1285 (Product Consistency) durability testing. Monolithing of the granular FBSR product was investigated to prevent dispersion during transport or burial/storage. Monolithing in an inorganic geopolymer binder, which is

  12. Advanced high efficiency concentrator cells

    SciTech Connect

    Gale, R. . Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  13. Naphtha reforming

    SciTech Connect

    Marschner, F.; Renner, H.J.

    1982-04-01

    Most synthesis gases - mixtures of CO and H/sub 2/ - are produced from natural gas. However, a considerable percentage is also produced from naphtha. Syngas via naphtha is economical when natural gas is unavailable and when low hydrogen content syngas is needed. The discussion covers the following topics - catalytic steam reforming; naphtha qualities; process description; desulfurization reactors; rich gas reactors; tubular reactors; fire box; burner and firing systems; reformer tubes; inlet header and outlet manifold systems; waste heat systems, heat exchangers, piping. 10 refs.

  14. High Efficiency Room Air Conditioner

    SciTech Connect

    Bansal, Pradeep

    2015-01-01

    This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

  15. High efficiency SPS klystron design

    NASA Technical Reports Server (NTRS)

    Nalos, E. J.

    1980-01-01

    The most likely compact configuration to realize both high efficiency and high gain (approx. 40 dB) is a 5-6 cavity design focused by an electromagnet. The basic klystron efficiency cannot be expected to exceed 70-75% without collector depression. It was estimated that the net benefit of a 5 stage collector over a 2 stage collector is between 1.5 and 3.5 kW per tube. A modulating anode is incorporated in the design to enable rapid shutoff of the beam current in case the r.f. drive should be removed.

  16. High-efficiency photoionization detector

    SciTech Connect

    Anderson, D.F.

    1981-05-12

    A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 +- 0.02 eV, and a vapor pressure of 0.35 torr at 20/sup 0/C.

  17. High efficiency solar panel /HESP/

    NASA Technical Reports Server (NTRS)

    Stella, P. M.; Gay, C.; Uno, F.; Scott-Monck, J.

    1978-01-01

    A family of high efficiency, weldable silicon solar cells, incorporating nearly every feature of advanced cell technology developed in the past four years, was produced and subjected to space qualification testing. This matrix contained both field and non-field cells ranging in thickness from 0.10 mm to 0.30 mm, and in base resistivity from nominal two to one hundred ohm-cm. Initial power outputs as high as 20 mW/sq cm (14.8% AM0 efficiency) were produced by certain cell types within the matrix.

  18. Modeling of Pressurized Electrochemistry and Steam-Methane Reforming in Solid Oxide Fuel Cells and the Effects on Thermal and Electrical Stack Performance

    SciTech Connect

    Recknagle, Kurtis P.; Khaleel, Mohammad A.

    2009-03-01

    Summarizes work done to extend the electrochemical performance and methane reforming submodels to include the effects of pressurization and to demonstrate this new modeling capability by simulating large stacks operating on methane-rich fuel under pressurized and non-pressurized conditions. Pressurized operation boosts electrochemical performance, alters the kinetics of methane reforming, and effects the equilibrium composition of methane fuels. This work developed constitutive submodels that couple the electrochemistry, reforming, and pressurization to yield an increased capability of the modeling tool for prediction of SOFC stack performance.

  19. Sulfur Tolerance of Carbide Catalysts Under Hydrocarbon Reforming Conditions

    DTIC Science & Technology

    2007-11-02

    dry and steam reforming methane have been determined. In particular it has been found that these catalyst can be kept stable by either operating at...oxidation. The approach was to start with a simple hydrocarbon fuel ( methane ) and investigate catalyst stability in both dry and steam reforming and...the catalyst under dry and steam reforming conditions • Determination of the kinetics of dry methane reforming over bulk Mo2C catalysts

  20. Thermochemically recuperated and steam cooled gas turbine system

    DOEpatents

    Viscovich, P.W.; Bannister, R.L.

    1995-07-11

    A gas turbine system is described in which the expanded gas from the turbine section is used to generate the steam in a heat recovery steam generator and to heat a mixture of gaseous hydrocarbon fuel and the steam in a reformer. The reformer converts the hydrocarbon gas to hydrogen and carbon monoxide for combustion in a combustor. A portion of the steam from the heat recovery steam generator is used to cool components, such as the stationary vanes, in the turbine section, thereby superheating the steam. The superheated steam is mixed into the hydrocarbon gas upstream of the reformer, thereby eliminating the need to raise the temperature of the expanded gas discharged from the turbine section in order to achieve effective conversion of the hydrocarbon gas. 4 figs.

  1. Thermochemically recuperated and steam cooled gas turbine system

    DOEpatents

    Viscovich, Paul W.; Bannister, Ronald L.

    1995-01-01

    A gas turbine system in which the expanded gas from the turbine section is used to generate the steam in a heat recovery steam generator and to heat a mixture of gaseous hydrocarbon fuel and the steam in a reformer. The reformer converts the hydrocarbon gas to hydrogen and carbon monoxide for combustion in a combustor. A portion of the steam from the heat recovery steam generator is used to cool components, such as the stationary vanes, in the turbine section, thereby superheating the steam. The superheated steam is mixed into the hydrocarbon gas upstream of the reformer, thereby eliminating the need to raise the temperature of the expanded gas discharged from the turbine section in order to achieve effective conversion of the hydrocarbon gas.

  2. High Efficiency Engine Technologies Program

    SciTech Connect

    Rich Kruiswyk

    2010-07-13

    Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems used in turbocompound power turbines in production. None of the turbocharger technologies investigated involved addition of moving parts, actuators, or exotic materials, thereby increasing the likelihood of a favorable cost-value tradeoff for each technology. And the turbocompound system requires less hardware addition than competing bottoming cycle technologies, making it a more attractive solution from a cost and packaging standpoint. Main outcomes of the program are as follows: (1) Two turbine technologies that demonstrated up to 6% improvement in turbine efficiency on gas stand and 1-3% improvement in thermal efficiency in

  3. FLUIDIZED BED STEAM REFORMING (FBSR) OF HIGH LEVEL WASTE (HLW) ORGANIC AND NITRATE DESTRUCTION PRIOR TO VITRIFICATION: CRUCIBLE SCALE TO ENGINEERING SCALE DEMONSTRATIONS AND NON-RADIOACTIVE TO RADIOACTIVE DEMONSTRATIONS

    SciTech Connect

    Jantzen, C; Michael Williams, M; Gene Daniel, G; Paul Burket, P; Charles Crawford, C

    2009-02-07

    Over a decade ago, an in-tank precipitation process to remove Cs-137 from radioactive high level waste (HLW) supernates was demonstrated at the Savannah River Site (SRS). The full scale demonstration with actual HLW was performed in SRS Tank 48 (T48). Sodium tetraphenylborate (NaTPB) was added to enable Cs-137 extraction as CsTPB. The CsTPB, an organic, and its decomposition products proved to be problematic for subsequent processing of the Cs-137 precipitate in the SRS HLW vitrification facility for ultimate disposal in a HLW repository. Fluidized Bed Steam Reforming (FBSR) is being considered as a technology for destroying the organics and nitrates in the T48 waste to render it compatible with subsequent HLW vitrification. During FBSR processing the T48 waste is converted into organic-free and nitrate-free carbonate-based minerals which are water soluble. The soluble nature of the carbonate-based minerals allows them to be dissolved and pumped to the vitrification facility or returned to the tank farm for future vitrification. The initial use of the FBSR process for T48 waste was demonstrated with simulated waste in 2003 at the Savannah River National Laboratory (SRNL) using a specially designed sealed crucible test that reproduces the FBSR pyrolysis reactions, i.e. carbonate formation, organic and nitrate destruction. This was followed by pilot scale testing of simulants at the Science Applications International Corporation (SAIC) Science & Technology Application Research (STAR) Center in Idaho Falls, ID by Idaho National Laboratory (INL) and SRNL in 2003-4 and then engineering scale demonstrations by THOR{reg_sign} Treatment Technologies (TTT) and SRS/SRNL at the Hazen Research, Inc. (HRI) test facility in Golden, CO in 2006 and 2008. Radioactive sealed crucible testing with real T48 waste was performed at SRNL in 2008, and radioactive Benchscale Steam Reformer (BSR) testing was performed in the SRNL Shielded Cell Facility (SCF) in 2008.

  4. High Efficiency IMM Solar Cells

    NASA Astrophysics Data System (ADS)

    Sharps, P.; Cho, B.; Chumney, D.; Cornfeild, A.; Guzie, B.; Hazlett, D.; Lin, Y.; Mackos, C.; Patel, P.; Stan, M.; Steinfeldt, J.; Tourino, C.

    2014-08-01

    We review the status of currently available commercial multi-junction cells, review options for next generation high efficiency cell architectures, and present the latest developments on the inverted metamorphic multi- junction (IMM) solar cell. Over 20,000 IMM cells have been prototyped to date, and efficiencies of up to 37% have been measured. We present the most recent performance data, including the response to particle radiation. The IMM cell can be used in a number of rigid or flexible configurations, and considerable effort is currently focused on cell packaging and panel integration. We discuss several design options, including a "drop in" replacement for the current 29.5% ZTJ cell technology. We will also address the reliability and cost of the IMM cell.

  5. High efficiency laser spectrum conditioner

    DOEpatents

    Greiner, Norman R.

    1980-01-01

    A high efficiency laser spectrum conditioner for generating a collinear parallel output beam containing a predetermined set of frequencies from a multifrequency laser. A diffraction grating and spherical mirror are used in combination, to disperse the various frequencies of the input laser beam and direct these frequencies along various parallel lines spatially separated from one another to an apertured mask. Selection of the desired frequencies is accomplished by placement of apertures at locations on the mask where the desired frequencies intersect the mask. A recollimated parallel output beam with the desired set of frequencies is subsequently generated utilizing a mirror and grating matched and geometrically aligned in the same manner as the input grating and mirror.

  6. Slab reformer

    DOEpatents

    Spurrier, Francis R.; DeZubay, Egon A.; Murray, Alexander P.; Vidt, Edward J.

    1985-03-12

    Slab-shaped high efficiency catalytic reformer configurations particularly useful for generation of fuels to be used in fuel cell based generation systems. A plurality of structures forming a generally rectangular peripheral envelope are spaced about one another to form annular regions, an interior annular region containing a catalytic bed and being regeneratively heated on one side by a hot combustion gas and on the other side by the gaseous products of the reformation. An integrally mounted combustor is cooled by impingement of incoming oxidant.

  7. Slab reformer

    DOEpatents

    Spurrier, Francis R.; DeZubay, Egon A.; Murray, Alexander P.; Vidt, Edward J.

    1984-02-07

    Slab-shaped high efficiency catalytic reformer configurations particularly useful for generation of fuels to be used in fuel cell based generation systems. A plurality of structures forming a generally rectangular peripheral envelope are spaced about one another to form annular regions, an interior annular region containing a catalytic bed and being regeneratively heated on one side by a hot comubstion gas and on the other side by the gaseous products of the reformation. An integrally mounted combustor is cooled by impingement of incoming oxidant.

  8. Slab reformer

    DOEpatents

    Spurrier, F.R.; DeZubay, E.A.; Murray, A.P.; Vidt, E.J.

    1984-02-07

    Slab-shaped high efficiency catalytic reformer configurations are disclosed particularly useful for generation of fuels to be used in fuel cell based generation systems. A plurality of structures forming a generally rectangular peripheral envelope are spaced about one another to form annular regions, an interior annular region containing a catalytic bed and being regeneratively heated on one side by a hot combustion gas and on the other side by the gaseous products of the reformation. An integrally mounted combustor is cooled by impingement of incoming oxidant. 14 figs.

  9. Slab reformer

    NASA Technical Reports Server (NTRS)

    Spurrier, Francis R. (Inventor); DeZubay, Egon A. (Inventor); Murray, Alexander P. (Inventor); Vidt, Edward J. (Inventor)

    1984-01-01

    Slab-shaped high efficiency catalytic reformer configurations particularly useful for generation of fuels to be used in fuel cell based generation systems. A plurality of structures forming a generally rectangular peripheral envelope are spaced about one another to form annular regions, an interior annular region containing a catalytic bed and being regeneratively heated on one side by a hot comubstion gas and on the other side by the gaseous products of the reformation. An integrally mounted combustor is cooled by impingement of incoming oxidant.

  10. Slab reformer

    NASA Technical Reports Server (NTRS)

    Spurrier, Francis R. (Inventor); DeZubay, Egon A. (Inventor); Murray, Alexander P. (Inventor); Vidt, Edward J. (Inventor)

    1985-01-01

    Slab-shaped high efficiency catalytic reformer configurations particularly useful for generation of fuels to be used in fuel cell based generation systems. A plurality of structures forming a generally rectangular peripheral envelope are spaced about one another to form annular regions, an interior annular region containing a catalytic bed and being regeneratively heated on one side by a hot combustion gas and on the other side by the gaseous products of the reformation. An integrally mounted combustor is cooled by impingement of incoming oxidant.

  11. Steaming Clean

    ERIC Educational Resources Information Center

    Hoverson, Rick

    2006-01-01

    Schools can provide a cleaner, more healthful school environment by simply combining heat and water. Steam vapor systems use only tap water with no chemicals added. Low-pressure (12 psi to 65 psi) steam vapor sanitizes and deodorizes. This process can then be used safely in many situations, but is especially suited for restrooms and food-service…

  12. Steaming Clean

    ERIC Educational Resources Information Center

    Hoverson, Rick

    2006-01-01

    Schools can provide a cleaner, more healthful school environment by simply combining heat and water. Steam vapor systems use only tap water with no chemicals added. Low-pressure (12 psi to 65 psi) steam vapor sanitizes and deodorizes. This process can then be used safely in many situations, but is especially suited for restrooms and food-service…

  13. Chemical Looping Reforming for H2, CO and Syngas Production

    SciTech Connect

    Bhavsar,Saurabh; Najera,Michelle; Solunke,Rahul; Veser,Götz

    2001-06-06

    We demonstrate that the extension of CLC onto oxidants beyond air opens new, highly efficient pathways for production of ultra-pure hydrogen, activation of CO{sub 2} via reduction to CO, and are currently working on production of syngas using nanocomposite Fe-BHA. CLR hold great potential due to fuel flexibility and CO{sub 2} capture. Chemical Looping Combustion (CLC) is a novel clean combustion technology which offers an elegant and highly efficient route for fossil fuel combustion. In CLC, combustion of a fuel is broken down into two spatially separated steps. In the reducer, the oxygen carrier (typically a metal) supplies the stoichiometric oxygen required for fuel combustion. In the oxidizer, the oxygen-depleted carrier is then re-oxidized with air. After condensation of steam from the effluent of the reducer, a high-pressure, high-purity sequestration-ready CO{sub 2} stream is obtained. In the present study, we apply the CLC principle to the production of high-purity H{sub 2}, CO, and syngas streams by replacing air with steam and/or CO{sub 2} as oxidant, respectively. Using H{sub 2}O as oxidant, pure hydrogen streams can be obtained. Similarly, using CO{sub 2} as oxidant, CO is obtained, thus opening an efficient route for CO{sub 2} utilization. Using steam and CO{sub 2} mixtures for carrier oxidation should thus allow production of syngas with adjustable CO:H{sub 2} ratios. Overall, these processes result in Chemical Looping Reforming (CLR), i.e. the net overall reaction is the steam and/or dry reforming of the respective fuel.

  14. A study on methanol steam reforming to CO{sub 2} and H{sub 2} over the La{sub 2}CuO{sub 4} nanofiber catalyst

    SciTech Connect

    Gao Lizhen Sun Gebiao; Kawi, Sibudjing

    2008-01-15

    The La{sub 2}CuO{sub 4} crystal nanofibers were prepared by using single-walled carbon nanotubes as templates under mild hydrothermal conditions. The steam reforming of methanol (SRM) to CO{sub 2} and H{sub 2} over such nanofiber catalysts was studied. At the low temperature of 150 deg. C and steam/methanol=1.3, methanol was completely (100%, 13.8 g/h g catalyst) converted to hydrogen and CO{sub 2} without the generation of CO. Within the 60 h catalyst lifespan test, methanol conversion was maintained at 98.6% (13.6 g/h g catalyst) and with 100% CO{sub 2} selectivity. In the meantime, for distinguishing the advantage of nanoscale catalyst, the La{sub 2}CuO{sub 4} bulk powder was prepared and tested for the SRM reaction for comparison. Compared with the La{sub 2}CuO{sub 4} nanofiber, the bulk powder La{sub 2}CuO{sub 4} showed worse catalytic activity for the SRM reaction. The 100% conversion of methanol was achieved at the temperature of 400 deg. C, with the products being H{sub 2} and CO{sub 2} together with CO. The catalytic activity in terms of methanol conversion dropped to 88.7% (12.2 g/h g catalyst) in 60 h. The reduction temperature for nanofiber La{sub 2}CuO{sub 4} was much lower than that for the La{sub 2}CuO{sub 4} bulk powder. The nanofibers were of higher specific surface area (105.0 m{sup 2}/g), metal copper area and copper dispersion. The in situ FTIR and EPR experiments were employed to study the catalysts and catalytic process. In the nanofiber catalyst, there were oxygen vacancies. H{sub 2}-reduction resulted in the generation of trapped electrons [e] on the vacancy sites. Over the nanofiber catalyst, the intermediate H{sub 2}CO/HCO was stable and was reformed to CO{sub 2} and H{sub 2} by steam rather than being decomposed directly to CO and H{sub 2}. Over the bulk counterpart, apart from the direct decomposition of H{sub 2}CO/HCO to CO and H{sub 2}, the intermediate H{sub 2}COO might go through two decomposition ways: H{sub 2}COO=CO+H{sub 2}O and H

  15. High efficiency motor rewind study

    NASA Astrophysics Data System (ADS)

    Wallace, A. K.; Spee, R.

    1991-02-01

    The objective of performing this work was to evaluate a new technology used for rewinding electric motors. Motor performance evaluation was conducted at the motor test facility at Oregon State University. The test program consisted of comparing new high efficiency motor technology and standard rewind technology with the Unity-Plus system. The Unity-Plus configuration exhibited reduced efficiency over the complete load range compared to the other motors. Appropriately sized capacitors connected to the terminals of the conventional induction motor produced the same power factor improvement as the Unity-Plus system. Torque production and torque pulsation were very similar for all systems. The Unity-Plus configuration drew lower starting currents but the duration of the starting transient was increased. Motor temperature rise was about the same for all systems. Noise levels were about the same in all systems. Although determination of time to failure was not undertaken, the expected lifetime of the Unit-Plus system is probably less due to higher capacitor stress and higher insulation stress. The investigation concludes that a conventional induction motor with terminal capacitors is the most acceptable way of obtaining good efficiency and power factor and the Unity-Plus system cannot be recommended on the basis of any of the evaluation criteria used in this study.

  16. High-efficiency photovoltaic cells

    DOEpatents

    Yang, H.T.; Zehr, S.W.

    1982-06-21

    High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.

  17. High efficiency shale oil recovery

    SciTech Connect

    Adams, C.D.

    1992-07-18

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a larger continuous process kiln. For example, similar conditions of heatup rate, oxidation of the residue and cool-down prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The second quarter agenda consisted of (a) kiln modifications; (b) sample preparation; and (c) Heat Transfer calibration runs (part of proposal task number 3 -- to be completed by the end of month 7).

  18. High efficiency stationary hydrogen storage

    SciTech Connect

    Hynek, S.; Fuller, W.; Truslow, S.

    1995-09-01

    Stationary storage of hydrogen permits one to make hydrogen now and use it later. With stationary hydrogen storage, one can use excess electrical generation capacity to power an electrolyzer, and store the resultant hydrogen for later use or transshipment. One can also use stationary hydrogen as a buffer at fueling stations to accommodate non-steady fueling demand, thus permitting the hydrogen supply system (e.g., methane reformer or electrolyzer) to be sized to meet the average, rather than the peak, demand. We at ADL designed, built, and tested a stationary hydrogen storage device that thermally couples a high-temperature metal hydride to a phase change material (PCM). The PCM captures and stores the heat of the hydriding reaction as its own heat of fusion (that is, it melts), and subsequently returns that heat of fusion (by freezing) to facilitate the dehydriding reaction. A key component of this stationary hydrogen storage device is the metal hydride itself. We used nickel-coated magnesium powder (NCMP) - magnesium particles coated with a thin layer of nickel by means of chemical vapor deposition (CVD). Magnesium hydride can store a higher weight fraction of hydrogen than any other practical metal hydride, and it is less expensive than any other metal hydride. We designed and constructed an experimental NCM/PCM reactor out of 310 stainless steel in the form of a shell-and-tube heat exchanger, with the tube side packed with NCMP and the shell side filled with a eutectic mixture of NaCL, KCl, and MgCl{sub 2}. Our experimental results indicate that with proper attention to limiting thermal losses, our overall efficiency will exceed 90% (DOE goal: >75%) and our overall system cost will be only 33% (DOE goal: <50%) of the value of the delivered hydrogen. It appears that NCMP can be used to purify hydrogen streams and store hydrogen at the same time. These prospects make the NCMP/PCM reactor an attractive component in a reformer-based hydrogen fueling station.

  19. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1993-04-22

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft[sup 2]/[degrees]F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000[degrees]F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

  20. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1992-01-01

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although a batch oil shale sample will be sealed in the batch kiln from the start until the end of the run, the process conditions for the batch will be the same as the conditions that an element of oil shale would encounter in a large continuous process kiln. For example, similar conditions of heat-up rate (20 deg F/min during the pyrolysis), oxidation of the residue and cool-down will prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The agenda for the first three months of the project consisted of the first of nine tasks and was specified as the following four items: 1. Sample acquisition and equipment alteration: Obtain seven oil shale samples, of varying grade each 10 lb or more, and samples of quartz sand. Order equipment for kiln modification. 3. Set up and modify kiln for operation, including electric heaters on the ends of the kiln. 4. Connect data logger and make other repairs and changes in rotary batch kiln.

  1. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1992-01-01

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical (heating, mixing) conditions exist in both systems. The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed and is reported on this quarter: (1) A software routine was written to eliminate intermittently inaccurate temperature readings. (2) We completed the quartz sand calibration runs, resolving calibration questions from the 3rd quarter. (3) We also made low temperature retorting runs to identify the need for certain kiln modifications and kiln modifications were completed. (4) Heat Conductance data on two Pyrolysis runs were completed on two samples of Occidental oil shale.

  2. Steam Turbines

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

  3. Method for reforming hydrocarbons

    SciTech Connect

    Brinkmeyer, F.M.; Ewert, W.M.; Fox, H.M.; Rohr, D.F. Jr.

    1993-08-10

    A method is described for reforming a hydrocarbon feedstock using a steam-active reforming catalyst which includes a metal from Group VIII of the Periodic Table of Elements, said method comprising the steps of: (a) contacting a first fixed bed of said catalyst with a regeneration mixture consisting essentially of steam and a source of free oxygen in order to remove deactivating material from said catalyst in said first bed by combustion and produce a regeneration effluent gas stream consisting essentially of steam, inert gas, and free oxygen which is not consumed when said deactivating material is removed from said catalyst in said first bed; (b) removing from said regeneration effluent gas stream said free oxygen which is not consumed when said deactivating material is removed from said catalyst in said first bed; and (c) reforming said hydrocarbon feedstock in a second fixed bed of said catalyst and in the presence of said regeneration effluent gas stream.

  4. High Efficiency Cascade Solar Cells

    SciTech Connect

    Shuguang Deng, Seamus Curran, Igor Vasiliev

    2010-09-28

    This report summarizes the main work performed by New Mexico State University and University of Houston on a DOE sponsored project High Efficiency Cascade Solar Cells. The main tasks of this project include materials synthesis, characterization, theoretical calculations, organic solar cell device fabrication and test. The objective of this project is to develop organic nano-electronic-based photovoltaics. Carbon nanotubes and organic conjugated polymers were used to synthesize nanocomposites as the new active semiconductor materials that were used for fabricating two device architectures: thin film coating and cascade solar cell fiber. Chemical vapor deposition technique was employed to synthesized a variety of carbon nanotubes (single-walled CNT, doubled-walled CNT, multi-walled CNT, N-doped SWCNT, DWCNT and MWCNT, and B-doped SWCNT, DWCNT and MWCNT) and a few novel carbon structures (CNT-based nanolance, nanocross and supported graphene film) that have potential applications in organic solar cells. Purification procedures were developed for removing amorphous carbons from carbon nanotubes, and a controlled oxidation method was established for partial truncation of fullerene molecules. Carbon nanotubes (DWCNT and DWCNT) were functionalized with fullerenes and dyes covalently and used to form nanocomposites with conjugated polymers. Biologically synthesized Tellurium nanotubes were used to form composite with the conjugated polymers as well, which generated the highest reported optical limiting values from composites. Several materials characterization technique including SEM/TEM, Raman, AFM, UV-vis, adsorption and EDS were employed to characterize the physical and chemical properties of the carbon nanotubes, the functionalized carbon nanotubes and the nanocomposites synthesized in this project. These techniques allowed us to have a spectroscopic and morphological control of the composite formation and to understand the materials assembled. A parallel 136-CPU

  5. Sulfur poisoning of CeO[subscript 2]-Al[subscript 2]O[subscript 3]-supported mono- and bi-metallic Ni and Rh catalysts in steam reforming of liquid hydrocarbons at low and high temperatures

    SciTech Connect

    Xie, Chao; Chen, Yongsheng; Li, Yan; Wang, Xiaoxing; Song, Chunshan

    2010-12-01

    In order to develop a better understanding on sulfur poisoning of reforming catalysts in fuel processing for hydrogen production, steam reforming of liquid hydrocarbons was performed over CeO{sub 2}-Al{sub 2}O{sub 3} supported monometallic Ni and Rh and bimetallic Rh-Ni catalysts at 550 and 800 C. XANES was used to identify the sulfur species in the used catalysts and to study their impacts on the metal surface properties probed by XPS. It was found that both monometallic catalysts rapidly deactivated at 550 C, and showed poor sulfur tolerance. Although ineffective for the Ni catalyst, increasing the temperature to 800 C dramatically improved the sulfur tolerance of the Rh catalyst. XANES revealed that metal sulfide and organic sulfide are the dominant sulfur species on the used Ni catalyst, while sulfonate and sulfate predominate on the used Rh catalyst. The presence of sulfur induced severe carbon deposition on the Ni catalyst at 800 C. The superior sulfur tolerance of the Rh catalyst at 800 C may be associated with its capability in sulfur oxidation. It is likely that the formation of the oxygen-shielded sulfur structure of sulfonate and sulfate can suppress the poisoning impact of sulfur on Rh by inhibiting direct rhodium-sulfur interaction. Moreover, XPS indicated that the metal surface properties of the Rh catalysts after the reaction without and with sulfur at 800 C are similar, suggesting that sulfur poisoning on Rh was mitigated under the high-temperature condition. Although the Rh-Ni catalyst exhibited better sulfur tolerance than the monometallic catalysts at 550 C, its catalytic performance was inferior compared with the Rh catalyst in the sulfur-containing reaction at 800 C probably due to the severe carbon deposition on the bimetallic catalyst.

  6. MPC improves reformer control

    SciTech Connect

    Jung, C.S.; Noh, K.K.; Yi, S.; Kim, J.S.; Song, H.K.; Hyun, J.C.

    1995-04-01

    A model predictive control strategy was applied to a synthesis gas reformer of Samsung-BP Chemicals in Korea that produces carbon monoxide and hydrogen from naphtha. A strongly endothermic reaction occurs in a catalytic reformer, and reformer outlet temperature is considered to have the most significant effect on product composition. The newly developed reformer is known to be a cost-effective process operating at high reaction temperatures and low steam-to-carbon ratio, but its drawback is temperature control difficulty due to the use of offgas as a part of the fuel. Without smooth control of the reformer outlet temperature, stable operation of the downstream separation units cannot be expected. Therefore, it is a great challenge to apply a model predictive control technique for tight control of reformer outlet temperature. The paper describes model predictive control, the process advanced control project, computer system architecture, analysis of operating condition, control structure, sampling rate, and disturbance estimation.

  7. Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank SX-105, Tank AN-103, And AZ-101/102) By Fluidized Bed Steam Reformation (FBSR)

    SciTech Connect

    Jantzen, C. M.; Crawford, C. L.; Bannochie, C. J.; Burket, P. R.; Cozzi, A. D.; Daniel, W. E.; Hall, H. K.; Miller, D. H.; Missimer, D. M.; Nash, C. A.; Williams, M. F.

    2013-09-18

    Fluidized Bed Steam Reforming (FBSR) is a robust technology for the immobilization of a wide variety of radioactive wastes. Applications have been tested at the pilot scale for the high sodium, sulfate, halide, organic and nitrate wastes at the Hanford site, the Idaho National Laboratory (INL), and the Savannah River Site (SRS). Due to the moderate processing temperatures, halides, sulfates, and technetium are retained in mineral phases of the feldspathoid family (nepheline, sodalite, nosean, carnegieite, etc). The feldspathoid minerals bind the contaminants such as Tc-99 in cage (sodalite, nosean) or ring (nepheline) structures to surrounding aluminosilicate tetrahedra in the feldspathoid structures. The granular FBSR mineral waste form that is produced has a comparable durability to LAW glass based on the short term PCT testing in this study, the INL studies, SPFT and PUF testing from previous studies as given in the columns in Table 1-3 that represent the various durability tests. Monolithing of the granular product was shown to be feasible in a separate study. Macro-encapsulating the granular product provides a decrease in leaching compared to the FBSR granular product when the geopolymer is correctly formulated.

  8. Hydrogen production with CO 2 capture by coupling steam reforming of methane and chemical-looping combustion: Use of an iron-based waste product as oxygen carrier burning a PSA tail gas

    NASA Astrophysics Data System (ADS)

    Ortiz, María; Gayán, Pilar; de Diego, Luis F.; García-Labiano, Francisco; Abad, Alberto; Pans, Miguel A.; Adánez, Juan

    In this work it is analyzed the performance of an iron waste material as oxygen carrier for a chemical-looping combustion (CLC) system. CLC is a novel combustion technology with the benefit of inherent CO 2 separation that can be used as a source of energy for the methane steam reforming process (SR). The tail gas from the PSA unit is used as fuel in the CLC system. The oxygen carrier behaviour with respect to gas combustion was evaluated in a continuous 500 W th CLC prototype using a simulated PSA off-gas stream as fuel. Methane or syngas as fuel were also studied for comparison purposes. The oxygen carrier showed enough high oxygen transport capacity and reactivity to fully convert syngas at 880 °C. However, lower conversion of the fuel was observed with methane containing fuels. An estimated solids inventory of 1600 kg MW th -1 would be necessary to fully convert the PSA off-gas to CO 2 and H 2O. An important positive effect of the oxygen carrier-to-fuel ratio up to 1.5 and the reactor temperature on the combustion efficiency was found. A characterization of the calcined and after-used particles was carried out showing that this iron-based material can be used as oxygen carrier in a CLC plant since particles maintain their properties (reactivity, no agglomeration, high durability, etc.) after more than 111 h of continuous operation.

  9. Evaluating performance of high efficiency mist eliminators

    SciTech Connect

    Waggoner, Charles A.; Parsons, Michael S.; Giffin, Paxton K.

    2013-07-01

    Processing liquid wastes frequently generates off gas streams with high humidity and liquid aerosols. Droplet laden air streams can be produced from tank mixing or sparging and processes such as reforming or evaporative volume reduction. Unfortunately these wet air streams represent a genuine threat to HEPA filters. High efficiency mist eliminators (HEME) are one option for removal of liquid aerosols with high dissolved or suspended solids content. HEMEs have been used extensively in industrial applications, however they have not seen widespread use in the nuclear industry. Filtering efficiency data along with loading curves are not readily available for these units and data that exist are not easily translated to operational parameters in liquid waste treatment plants. A specialized test stand has been developed to evaluate the performance of HEME elements under use conditions of a US DOE facility. HEME elements were tested at three volumetric flow rates using aerosols produced from an iron-rich waste surrogate. The challenge aerosol included submicron particles produced from Laskin nozzles and super micron particles produced from a hollow cone spray nozzle. Test conditions included ambient temperature and relative humidities greater than 95%. Data collected during testing HEME elements from three different manufacturers included volumetric flow rate, differential temperature across the filter housing, downstream relative humidity, and differential pressure (dP) across the filter element. Filter challenge was discontinued at three intermediate dPs and the filter to allow determining filter efficiency using dioctyl phthalate and then with dry surrogate aerosols. Filtering efficiencies of the clean HEME, the clean HEME loaded with water, and the HEME at maximum dP were also collected using the two test aerosols. Results of the testing included differential pressure vs. time loading curves for the nine elements tested along with the mass of moisture and solid

  10. High efficiency, long life terrestrial solar panel

    NASA Technical Reports Server (NTRS)

    Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

    1977-01-01

    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

  11. High-efficiency power production from natural gas with carbon capture

    NASA Astrophysics Data System (ADS)

    Adams, Thomas A.; Barton, Paul I.

    A unique electricity generation process uses natural gas and solid oxide fuel cells at high electrical efficiency (74%HHV) and zero atmospheric emissions. The process contains a steam reformer heat-integrated with the fuel cells to provide the heat necessary for reforming. The fuel cells are powered with H 2 and avoid carbon deposition issues. 100% CO 2 capture is achieved downstream of the fuel cells with very little energy penalty using a multi-stage flash cascade process, where high-purity water is produced as a side product. Alternative reforming techniques such as CO 2 reforming, autothermal reforming, and partial oxidation are considered. The capital and energy costs of the proposed process are considered to determine the levelized cost of electricity, which is low when compared to other similar carbon capture-enabled processes.

  12. High efficiency flat plate solar energy collector

    SciTech Connect

    Butler, R. F.

    1985-04-30

    A concentrating flat plate collector for the high efficiency collection of solar energy. Through an arrangement of reflector elements, incoming solar radiation, either directly or after reflection from the reflector elements, impinges upon both surfaces of a collector element.

  13. Multi Band Gap High Efficiency Converter (RAINBOW)

    NASA Technical Reports Server (NTRS)

    Bekey, I.; Lewis, C.; Phillips, W.; Shields, V.; Stella, P.

    1997-01-01

    The RAINBOW multi band gap system represents a unique combination of solar cells, concentrators and beam splitters. RAINBOW is a flexible system which can readily expand as new high efficiency components are developed.

  14. High-efficiency silicon solar cell research

    NASA Technical Reports Server (NTRS)

    Daud, T.

    1984-01-01

    Progress reports on research in high-efficiency silicon solar cells were presented by eight contractors and JPL. The presentations covered the issues of Bulk and Surface Loss, Modeling, Measurements, and Proof of Concept.

  15. High efficiency solar photovoltaic power module concept

    NASA Technical Reports Server (NTRS)

    Bekey, I.

    1978-01-01

    The investigation of a preliminary concept for high efficiency solar power generation in space is presented. The concept was a synergistic combination of spectral splitting, tailored bandgap cells, high concentration ratios, and cool cell areas.

  16. High Efficiency Lithium-Thionyl Chloride Cell.

    DTIC Science & Technology

    1982-04-01

    AD-Al14 672 HONEYWELL POWER SOURCES CENTER HORSHAM PA F/S 10/3 HIGH EFFICIENCY LITHIUM - THIONYL CHLORIDE CELLo(U) APR 82 N DODDAPANEN! OAAK20-81-C...CHART NATIONAl BUREAU OF STANDARDS 1963 A Research and Development Technical Report DELET-TR-81-0381-3 HIGH EFFICIENCY LITHIUM - THIONYL CHLORIDE CELL...reverse aide it necessary and Identify by block number) Thionyl chloride , lithium , high discharge rates, low temperatures, catalysis, cyclic

  17. Steam drum design for direct steam generation

    NASA Astrophysics Data System (ADS)

    Willwerth, Lisa; Müller, Svenja; Krüger, Joachim; Succo, Manuel; Feldhoff, Jan Fabian; Tiedemann, Jörg; Pandian, Yuvaraj; Krüger, Dirk; Hennecke, Klaus

    2017-06-01

    For the direct steam generation in solar fields, the recirculation concept has been demonstrated in several installations. Water masses in the solar field vary during transient phases, such as passing clouds. The volume of the steam drum can serve as a buffer during such transients by taking in excess water and providing water storage. The saturated steam mass flow to the superheating section or the consumer can be maintained almost constant during short transients; therefore the steam drum plays a key role for constant steam supply. Its buffer effect depends on the right sizing of the steam drum for the prevailing situations. Due to missing experiences, steam drums have been sized under conservative assumptions and are thereby usually oversized. With this paper, experiences on the steam drum of the 5 MWel TSE1 power plant are discussed for optimized future plant design. The results are also of relevance for process heat installations, in which saturated steam is produced by the solar field.

  18. Conceptual Design of Low-Temperature Hydrogen Production and High-Efficiency Nuclear Reactor Technology

    NASA Astrophysics Data System (ADS)

    Fukushima, Kimichika; Ogawa, Takashi

    Hydrogen, a potential alternative energy source, is produced commercially by methane (or LPG) steam reforming, a process that requires high temperatures, which are produced by burning fossil fuels. However, as this process generates large amounts of CO2, replacement of the combustion heat source with a nuclear heat source for 773-1173K processes has been proposed in order to eliminate these CO2 emissions. In this paper, a novel method of nuclear hydrogen production by reforming dimethyl ether (DME) with steam at about 573K is proposed. From a thermodynamic equilibrium analysis of DME steam reforming, the authors identified conditions that provide high hydrogen production fraction at low pressure and temperatures of about 523-573K. By setting this low-temperature hydrogen production process upstream from a turbine and nuclear reactor at about 573K, the total energy utilization efficiency according to equilibrium mass and heat balance analysis is about 50%, and it is 75%for a fast breeder reactor (FBR), where turbine is upstream of the reformer.

  19. Ambient pressure XPS and IRRAS investigation of ethanol steam reforming on Ni–CeO2(111) catalysts: An in situ study of C–C and O–H bond scission

    DOE PAGES

    Liu, Zongyuan; Duchon, Tomas; Wang, Huanru; ...

    2016-03-31

    Ambient-Pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Infrared Reflection Absorption Spectroscopy (AP-IRRAS) have been used to elucidate the active sites and mechanistic steps associated with the ethanol steam reforming reaction (ESR) over Ni–CeO2(111) model catalysts. Our results reveal that surface layers of the ceria substrate are both highly reduced and hydroxylated under reaction conditions while the small supported Ni nanoparticles are present as Ni0/NixC. A multifunctional, synergistic role is highlighted in which Ni, CeOx and the interface provide an ensemble effect in the active chemistry that leads to H2. Ni0 is the active phase leading to both C–C and C–H bondmore » cleavage in ethanol and it is also responsible for carbon accumulation. On the other hand, CeOx is important for the deprotonation of ethanol/water to ethoxy and OH intermediates. The active state of CeOx is a Ce3+(OH)x compound that results from extensive reduction by ethanol and the efficient dissociation of water. Additionally, we gain an important insight into the stability and selectivity of the catalyst by its effective water dissociation, where the accumulation of surface carbon can be mitigated by the increased presence of surface OH groups. As a result, the co-existence and cooperative interplay of Ni0 and Ce3+(OH)x through a metal–support interaction facilitate oxygen transfer, activation of ethanol/water as well as the removal of coke.« less

  20. Ambient pressure XPS and IRRAS investigation of ethanol steam reforming on Ni–CeO2(111) catalysts: An in situ study of C–C and O–H bond scission

    SciTech Connect

    Liu, Zongyuan; Duchon, Tomas; Wang, Huanru; Grinter, David C.; Waluyo, Iradwikanari; Zhou, Jing; Liu, Qiang; Jeong, Beomgyun; Crumlin, Ethan J.; Matolin, Vladimir; Stacchiola, Dario J.; Rodriguez, Jose A.; Senanayake, Sanjaya D.

    2016-03-31

    Ambient-Pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Infrared Reflection Absorption Spectroscopy (AP-IRRAS) have been used to elucidate the active sites and mechanistic steps associated with the ethanol steam reforming reaction (ESR) over Ni–CeO2(111) model catalysts. Our results reveal that surface layers of the ceria substrate are both highly reduced and hydroxylated under reaction conditions while the small supported Ni nanoparticles are present as Ni0/NixC. A multifunctional, synergistic role is highlighted in which Ni, CeOx and the interface provide an ensemble effect in the active chemistry that leads to H2. Ni0 is the active phase leading to both C–C and C–H bond cleavage in ethanol and it is also responsible for carbon accumulation. On the other hand, CeOx is important for the deprotonation of ethanol/water to ethoxy and OH intermediates. The active state of CeOx is a Ce3+(OH)x compound that results from extensive reduction by ethanol and the efficient dissociation of water. Additionally, we gain an important insight into the stability and selectivity of the catalyst by its effective water dissociation, where the accumulation of surface carbon can be mitigated by the increased presence of surface OH groups. As a result, the co-existence and cooperative interplay of Ni0 and Ce3+(OH)x through a metal–support interaction facilitate oxygen transfer, activation of ethanol/water as well as the removal of coke.

  1. Important loss mechanisms in high-efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1984-01-01

    A study was conducted to identify loss mechanisms in high efficiency silicon solar cells. The following were considered: (1) recombination loss mechanisms; (2) high efficiency cells; (3) very high efficiency cells; and (4) ultra high efficiency cells.

  2. A new alkali-resistant Ni/Al2O3-MSU-1 core-shell catalyst for methane steam reforming in a direct internal reforming molten carbonate fuel cell

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Zhang, Xiongfu; Liu, Weifeng; Liu, Haiou; Qiu, Jieshan; Yeung, King Lun

    2014-01-01

    An alkali-resistant catalyst for direct internal reforming molten carbonate fuel cell (DIR-MCFC) is prepared by growing a thin shell of mesoporous MSU-1 membrane on Ni/Al2O3 catalyst beads. The MSU-1 shell is obtained by first depositing a monolayer of colloidal silicalite-1 (Sil-1) on the catalyst bead as linkers and then using NaF stored in the beads to catalyze the growth of the MSU-1 layer. The resulting core-shell catalysts display excellent alkali-resistance and deliver stable methane conversion and hydrogen yield in an out-of-cell test simulating the operating conditions of an operating DIR-MCFC. Higher conversion and yield (i.e., up to over 70%) are obtained from the new core-shell catalyst with MSU-1 shell compared to the catalyst with microporous Sil-1 shell. A mathematical model of the reaction and poisoning of the core-shell catalyst is used to predict the optimum shell thickness for its reliable use in a DIR-MCFC.

  3. Steam Digest: Volume IV

    SciTech Connect

    Not Available

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  4. Steam Digest Volume IV

    SciTech Connect

    2004-07-01

    This edition of the Steam Digest is a compendium of 2003 articles on the technical and financial benefits of steam efficiency, presented by the stakeholders of the U.S. Department of Energy's BestPractices Steam effort.

  5. High efficiency carbonate fuel cell/turbine hybrid power cycles

    SciTech Connect

    Steinfeld, G.

    1995-10-19

    Carbonate fuel cells developed by Energy Research Corporation, in commercial 2.85 MW size, have an efficiency of 57.9 percent. Studies of higher efficiency hybrid power cycles were conducted in cooperation with METC to identify an economically competitive system with an efficiency in excess of 65 percent. A hybrid power cycle was identified that includes a direct carbonate fuel cell, a gas turbine and a steam cycle, which generates power at a LHV efficiency in excess of 70 percent. This new system is called a Tandem Technology Cycle (TTC). In a TTC operating on natural gas fuel, 95 percent of the fuel is mixed with recycled fuel cell anode exhaust, providing water for the reforming of the fuel, and flows to a direct carbonate fuel cell system which generates 72 percent of the power. The portion of the fuel cell anode exhaust which is not recycled, is burned and heat is transferred to the compressed air from a gas turbine, raising its temperature to 1800{degrees}F. The stream is then heated to 2000{degrees}F in the gas turbine burner and expands through the turbine generating 13 percent of the power. Half the exhaust from the gas turbine flows to the anode exhaust burner, and the remainder flows to the fuel cell cathodes providing the O{sub 2} and CO{sub 2} needed in the electrochemical reaction. Exhaust from the fuel cells flows to a steam system which includes a heat recovery steam generator and stages steam turbine which generates 15 percent of the TTC system power. Studies of the TTC for 200-MW and 20-MW size plants quantified performance, emissions and cost-of-electricity, and compared the characteristics of the TTC to gas turbine combined cycles. A 200-MW TTC plant has an efficiency of 72.6 percent, and is relatively insensitive to ambient temperature, but requires a heat exchanger capable of 2000{degrees}F. The estimated cost of electricity is 45.8 mills/kWhr which is not competitive with a combined cycle in installations where fuel cost is under $5.8/MMBtu.

  6. High-efficiency solid state power amplifier

    NASA Technical Reports Server (NTRS)

    Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

    2005-01-01

    A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

  7. Technology Development for High Efficiency Optical Communications

    NASA Technical Reports Server (NTRS)

    Farr, William H.

    2012-01-01

    Deep space optical communications is a significantly more challenging operational domain than near Earth space optical communications, primarily due to effects resulting from the vastly increased range between transmitter and receiver. The NASA Game Changing Development Program Deep Space Optical Communications Project is developing four key technologies for the implementation of a high efficiency telecommunications system that will enable greater than 10X the data rate of a state-of-the-art deep space RF system (Ka-band) for similar transceiver mass and power burden on the spacecraft. These technologies are a low mass spacecraft disturbance isolation assembly, a flight qualified photon counting detector array, a high efficiency flight laser amplifier and a high efficiency photon counting detector array for the ground-based receiver.

  8. Measure Guideline. High Efficiency Natural Gas Furnaces

    SciTech Connect

    Brand, L.; Rose, W.

    2012-10-01

    This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  9. Measure Guideline: High Efficiency Natural Gas Furnaces

    SciTech Connect

    Brand, L.; Rose, W.

    2012-10-01

    This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  10. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area

  11. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area.

  12. Integrated solar reforming for thermochemical energy transport

    NASA Astrophysics Data System (ADS)

    Rozenman, T.

    1987-12-01

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

  13. Requirements for high-efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1986-01-01

    Minimum recombination and low injection level are essential for high efficiency. Twenty percent AM1 efficiency requires a dark recombination current density of 2 x 10 to the minus 13th power A/sq cm and a recombination center density of less than 10 to the 10th power /cu cm. Recombination mechanisms at thirteen locations in a conventional single crystalline silicon cell design are reviewed. Three additional recombination locations are described at grain boundaries in polycrystalline cells. Material perfection and fabrication process optimization requirements for high efficiency are outlined. Innovative device designs to reduce recombination in the bulk and interfaces of single crystalline cells and in the grain boundary of polycrystalline cells are reviewed.

  14. High efficiency novel window air conditioner

    DOE PAGES

    Bansal, Pradeep

    2015-01-01

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, andmore » R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.« less

  15. High efficiency novel window air conditioner

    SciTech Connect

    Bansal, Pradeep

    2015-01-01

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.

  16. Creation of High Efficient Firefly Luciferase

    NASA Astrophysics Data System (ADS)

    Nakatsu, Toru

    Firefly emits visible yellow-green light. The bioluminescence reaction is carried out by the enzyme luciferase. The bioluminescence of luciferase is widely used as an excellent tool for monitoring gene expression, the measurement of the amount of ATP and in vivo imaging. Recently a study of the cancer metastasis is carried out by in vivo luminescence imaging system, because luminescence imaging is less toxic and more useful for long-term assay than fluorescence imaging by GFP. However the luminescence is much dimmer than fluorescence. Then bioluminescence imaging in living organisms demands the high efficient luciferase which emits near infrared lights or enhances the emission intensity. Here I introduce an idea for creating the high efficient luciferase based on the crystal structure.

  17. High-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Olsen, L. C.

    1985-01-01

    Fabrication and characterization of high-efficiency metal insulator, n-p (MINP) cells is described. Particular attention was paid to development of measurement methods for surface recombination and density of surface states. A modified Rosier test structure was used successfully for density of surface states. Silicon oxide and silicon nitride passivants were studied. Heat treatment after plasma enhanced chemical vapor deposition (CVD) of silicon nitride was shown to be beneficial. A more optimum emitter concentration profile was modeled.

  18. High efficiency wraparound contact solar cells /HEWACS/

    NASA Technical Reports Server (NTRS)

    Gillanders, M.; Opjorden, R.

    1980-01-01

    A cell technology, producing high efficiency wrap-around contact solar cells (HEWACS), with both electrical contacts on the back and AMO conversion efficiencies of almost 15%, is presented. A flow chart indicating the baseline process sequence along with the process changes is given. Tests checking for coating delamination and contact integrity, those measuring contact strength, and thermal cycle tests, successfully demonstrated that this cell technology is ready to be moved to the pilot production stage.

  19. High-power, high-efficiency FELs

    SciTech Connect

    Sessler, A.M.

    1989-04-01

    High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs.

  20. High efficiency, long-life photocathodes

    NASA Astrophysics Data System (ADS)

    Ives, Lawrence; Montgomery, Eric; Jensen, Kevin; Collins, George; Marsden, David; Karimov, Rasul; Falce, Lou

    2017-03-01

    Research and development on high efficiency, robust, long-life photocathodes is in progress for accelerator, light source, and other commercial applications. The research is investigating detailed physics of photoemission and developing a computational capability to predict performance. Reservoir technology will significantly increase lifetime and allow recovery from many poisoning events. Better understanding of the physics will impact fabrication techniques to optimize performance. A production facility is under construction to provide improved photocathodes to users.

  1. Fuel Cell/Turbine Ultra High Efficiency Power System

    SciTech Connect

    Hossein, Ghezel-Ayagh

    2001-11-06

    FuelCell Energy, INC. (FCE) is currently involved in the design of ultra high efficiency power plants under a cooperative agreement (DE-FC26-00NT40) managed by the National Energy Technology Laboratory (NETL) as part of the DOE's Vision 21 program. Under this project, FCE is developing a fuel cell/turbine hybrid system that integrates the atmospheric pressure Direct FuelCell{reg_sign} (DFC{reg_sign}) with an unfired Brayton cycle utilizing indirect heat recovery from the power plant. Features of the DFC/T{trademark} system include: high efficiency, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, no pressurization of the fuel cell, independent operating pressure of the fuel cell and turbine, and potential cost competitiveness with existing combined cycle power plants at much smaller sizes. Objectives of the Vision 21 Program include developing power plants that will generate electricity with net efficiencies approaching 75 percent (with natural gas), while producing sulfur and nitrogen oxide emissions of less than 0.01 lb/million BTU. These goals are significant improvements over conventional power plants, which are 35-60 percent efficient and produce emissions of 0.07 to 0.3 lb/million BTU of sulfur and nitrogen oxides. The nitrogen oxide and sulfur emissions from the DFC/T system are anticipated to be better than the Vision 21 goals due to the non-combustion features of the DFC/T power plant. The expected high efficiency of the DFC/T will also result in a 40-50 percent reduction in carbon dioxide emissions compared to conventional power plants. To date, the R&D efforts have resulted in significant progress including proof-of-concept tests of a sub-scale power plant built around a state-of-the-art DFC stack integrated with a modified Capstone Model 330 Microturbine. The objectives of this effort are to investigate the integration aspects of the fuel cell and turbine and to obtain design information and operational data that will

  2. Steam Reforming of Methyl Fuel - Phase I

    DTIC Science & Technology

    1977-06-30

    1./CHR[ON ) M A-14 ....... FIGURE 11. REKRF5ThA OF~j ~ U MAIN PRODUCT MOLE FRACTIONS 1 C(S),2 COP3 C02 9 4 CH4,5 H2o6 H20 1.0 .8 *z __ _ _-_-_ __" o...c~.0 A- RU FIGU Rh "TR O 0F -ME7THY5LJ MRIN PRODUCT MOLE FRACTIONS IC(S) 2 COP3 C0294 CH4 .5 H2 G H20 Ld .4 .2- .00 (ST[RM/CRBfON)M A- 17 FICURE 14

  3. Integrated reforming/aromatization process

    SciTech Connect

    Harandi, M.N.; Owen, H.

    1990-06-26

    This patent describes an integrated process for increasing the gasoline yield from a catalytic reforming process. It comprises: charging a naphtha boiling range feedstream to a catalytic reforming reaction zone under reforming conversion conditions; withdrawing a reactor effluent stream from the reforming reaction zone; separating the reactor effluent stream into a hydrogen-rich gas stream and an unstabilized reformate stream; further separating the unstabilized reformate in a fractionator into an overhead stream containing C{sub 4} - components and a bottom stream containing C{sub 6} + components; charging the fractionator overhead stream to a catalytic aromatization zone under aromatization conversion conditions; withdrawing an aromatization zone effluent stream from the aromatization zone; cooling the aromatization zone effluent stream; separating the cooled aromatization zone effluent steam into a C{sub 4} - stream and a C{sub 5} + stream; and refluxing the C{sub 5} + aromatic gasoline stream to the fractionation zone.

  4. 4. STEAM PLANT MARINE BOILERS WEST OF STEAM PLANT AND ...

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

    4. STEAM PLANT MARINE BOILERS WEST OF STEAM PLANT AND SOUTH OF ORIGINAL STEAM PLANT BOILERS, FROM SOUTH. November 13, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  5. Steam atmosphere drying exhaust steam recompression system

    DOEpatents

    Becker, F.E.; Smolensky, L.A.; Doyle, E.F.; DiBella, F.A.

    1994-03-08

    This invention relates to a heated steam atmosphere drying system comprising dryer in combination with an exhaust recompression system which is extremely energy efficient and eliminates dangers known to air dryers. The system uses superheated steam as the drying medium, which recirculates through the system where its heat of evaporation and heat of compression is recovered, thereby providing a constant source of heat to the drying chamber. The dryer has inlets whereby feedstock and superheated steam are fed therein. High heat transfer and drying rates are achieved by intimate contact of the superheated steam with the particles being dried. The dryer comprises a vessel which enables the feedstock and steam to enter and recirculate together. When the feedstock becomes dry it will exit the dryer with the steam and become separated from the steam through the use of a curvilinear louver separator (CLS). The CLS enables removal of fine and ultrafine particles from the dryer. Water vapor separated from the particles in the CLS as superheated steam, may then be recovered and recirculated as steam through the use of a compressor to either directly or indirectly heat the dryer, and a heat exchanger or a heater to directly provide heat to the dryer. This system not only provides a very efficient heat transfer system but results in a minimum carry-over of ultrafine particles thereby eliminating any explosive hazard. 17 figures.

  6. Steam atmosphere drying exhaust steam recompression system

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Doyle, Edward F.; DiBella, Francis A.

    1994-01-01

    This invention relates to a heated steam atmosphere drying system comprising dryer in combination with an exhaust recompression system which is extremely energy efficient and eliminates dangers known to air dryers. The system uses superheated steam as the drying medium, which recirculated through the system where its heat of evaporation and heat of compression is recovered, thereby providing a constant source of heat to the drying chamber. The dryer has inlets whereby feedstock and superheated steam are fed therein. High heat transfer and drying rates are achieved by intimate contact of the superheated steam with the particles being dried The dryer comprises a vessel which enables the feedstock and steam to enter recirculate together. When the feedstock becomes dry it will exit the dryer with the steam and become separated from the steam through the use of a curvilinear louver separator (CLS). The CLS enables removal of fine and ultrafine particles from the dryer. Water vapor separated from the particles in the CLS as superheated steam, may then be recovered and recirculated as steam through the use of a compressor to either directly or indirectly heat the dryer, and a heat exchanger or a heater to directly provide heat to the dryer. This system not only provides a very efficient heat transfer system but results in a minimum carry-over of ultrafine particles thereby eliminating any explosive hazard.

  7. High performance steam development

    SciTech Connect

    Duffy, T.; Schneider, P.

    1995-12-31

    DOE has launched a program to make a step change in power plant to 1500 F steam, since the highest possible performance gains can be achieved in a 1500 F steam system when using a topping turbine in a back pressure steam turbine for cogeneration. A 500-hour proof-of-concept steam generator test module was designed, fabricated, and successfully tested. It has four once-through steam generator circuits. The complete HPSS (high performance steam system) was tested above 1500 F and 1500 psig for over 102 hours at full power.

  8. Very High Efficiency Solar Cell Modules

    SciTech Connect

    Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

    2009-01-01

    The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

  9. Interface modification for highly efficient organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Steim, Roland; Choulis, Stelios A.; Schilinsky, Pavel; Brabec, Christoph J.

    2008-03-01

    We present highly efficient inverted polymer:fullerene bulk-heterojunction solar cells by incorporation of a nanoscale organic interfacial layer between the indium tin oxide (ITO) and the metal oxide electron-conducting layer. We demonstrate that stacking of solution-processed organic and metal oxide interfacial layers gives highly charged selective low ohmic cathodes. The incorporation of a polyoxyethylene tridecyl ether interfacial layer between ITO and solution-processed titanium oxide (TiOx) raised the power conversion efficiency of inverted organic photovoltaics to 3.6%, an improvement of around 15% in their performance over comparable devices without the organic interfacial layer.

  10. Proposal for superstructure based high efficiency photovoltaics

    NASA Technical Reports Server (NTRS)

    Wagner, M.; Leburton, J. P.

    1986-01-01

    A novel class of cascade structures is proposed which features multijunction upper subcells, referred to as superstructure high-efficiency photovoltaics (SHEPs). The additional junctions enhance spectral response and improve radiation tolerance by reducing bulk recombination losses. This is important because ternary III-V alloys, which tend to have short minority-carrier diffusion lengths, are the only viable materials for the high-bandgap upper subcells required for cascade solar cells. Realistic simulations of AlGaAs SHEPs show that one-sun AM0 efficiencies in excess of 26 percent are possible.

  11. High Efficiency Microwave Power Amplifier (HEMPA) Design

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  12. High Efficiency Solar Integrated Roof Membrane Product

    SciTech Connect

    Partyka, Eric; Shenoy, Anil

    2013-05-15

    This project was designed to address the Solar Energy Technology Program objective, to develop new methods to integrate photovoltaic (PV) cells or modules within a building-integrated photovoltaic (BIPV) application that will result in lower installed cost as well as higher efficiencies of the encapsulated/embedded PV module. The technology assessment and development focused on the evaluation and identification of manufacturing technologies and equipment capable of producing such low-cost, high-efficiency, flexible BIPV solar cells on single-ply roofing membranes.

  13. The future of high efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Fan, J. C. C.

    1984-01-01

    Research approaches to obtain solar cell modules with 1 sun efficiencies of 20-30 percent at air mass 1 are now well understood. Such high efficiency modules should become available in the near future. It can be expected that these modules will be extensively used in terrestrial power generation, space power generation, and consumer electronics. To achieve practical module efficiencies significantly above 30 percent, it will be necessary to employ concepts other than spectral splitting, such as spectral compression and broad band detection. A major breakthrough in these areas is not anticipated at this time.

  14. A new steam-cooled reactor

    SciTech Connect

    Schultz, M.A.; Edlund, M.C.

    1985-08-01

    A new ultrasafe type of nuclear power plant is described that has a complete ''walk-awayfrom'' characteristic. That is, the reactor can safely dissipate its shutdown heat even if its powe and water supplies are cut off. The reactor is steam cooled and is designed to operate at one fixed steam density. Its reactivity characteristics are such that if the power level increases, the steam becomes less dense than the optimum and tends to shut the reactor off. Similarly, if the reactor is flooded wit water, the reactivity greatly decreases and also shuts the reactor down. The reactor can be operated as a burner, a high-efficiency converter, or a breeder, depending on the isotopic content of the fuel. The plant operates at low pressure and relatively high efficiency with an example given at 1000 psia and 35% efficiency. The reactor is enclosed in a conventional steel vessel resembling a boiling water reactor. The vessel is connected to a large atmospheric pressure pool of water, and shutdown consists of passively cou pling the pool to the reactor through the loss of steam flow. Shutdown cooling is provided by forced air and natural draft convection cooling of the pressure vessel. Sufficient water and passive cooling are provided by the pool for many months of shutdown water cooling. The plant piping is double walled, and all paths of radiation escape, including pressure-vessel cracking, are channeled through an on-line cleanup system.

  15. High efficiency Brayton cycles using LNG

    DOEpatents

    Morrow, Charles W.

    2006-04-18

    A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

  16. Reformer-pressure swing adsorption process for the production of carbon monoxide

    SciTech Connect

    Fuderer, A.

    1988-02-23

    An improved process for the production of carbon monoxide by the steam reforming of hydrocarbons is described comprising: (a) catalytically reacting a fluid hydrocarbon feed stream with steam in a steam reformer; (b) passing the reformer effluent containing hydrogen, carbon monoxide and carbon dioxide from the steam reformer, without scrubbing to remove the carbon dioxide content thereof, to a pressure swing adsorption system having at least four adsorbent beds, each bed of which, on a cyclic basis, undergoes a processing sequence; (c) recycling the carbon dioxide-rich stream to the steam reformer for reaction with additional quantities of the hydrocarbon feed stream being passed to the stream reformer to form additional quantities of carbon monoxide and hydrogen, with product recovery being enhanced and the need for employing a carbon dioxide wash system being obviated.

  17. High-Efficiency Autonomous Coherent Lidar

    NASA Technical Reports Server (NTRS)

    Gatt, Philip; Henderson, Sammy W.; Hannon, Stephen M.

    1999-01-01

    A useful measure of sensor performance is the transceiver system efficiency n (sub sys). Which consists of the antenna efficiency n (sub a) and optical and electronic losses. Typically, the lidar equation and the antenna efficiency are defined in terms of the telescope aperture area. However, during the assembly of a coherent transceiver, it is important to measure the system efficiency before the installation of the beamexpanding telescope (i.e., the untruncated-beam system efficiency). Therefore, to accommodate both truncated and untruncated beam efficiency measurements, we define the lidar equation and the antenna efficiency in terms of the beam area rather than the commonly used aperture area referenced definition. With a well-designed Gaussian-beam lidar, aperture area referenced system efficiencies of 15 to 20 % (23-31% relative to the beam area) are readily achievable. In this paper we compare the differences between these efficiency definitions. We then describe techniques by which high efficiency can be achieved, followed by a discussion several novel auto alignment techniques developed to maintain high efficiency.

  18. High-efficiency indoor air mover

    SciTech Connect

    Ariewitz, D.; Lackey, R.S.; Veyo, S.E.

    1983-01-06

    A high-efficiency indoor air mover has been developed for the advanced electric heat pump. Preprototype air mover overall efficiency is approximately 40 percent, twice that of the conventionally applied squirrel-cage blower. The air mover consists of a 411 mm (16.2 inch) diameter single entry blower wheel carried in a volute sheet steel scroll and driven by a 250 W (1/3 horsepower) high-efficiency motor. The blower wheel uses ten backward curved, uniformly spaced, cambered plate blades. As installed in the advanced heat pump the air mover consumes 390 W of electrical power and delivers 662 l/s (1405 scfm) at 1092 rpm into an external static flow resistance of 87 Pa (0.35 inches of water). Although this air mover will cost about twice as much as the conventional squirrel-cage blower and motor of comparable flow performance the incremental premium cost at the retail level can be recovered in less than one year through energy savings assuming 6000 hours of operation per year with electricity at $0.05/kWh.

  19. A high-efficiency indoor air mover

    SciTech Connect

    Ariewitz, D.; Lackey, R.S.; Veyo, S.E.

    1983-06-01

    A high-efficiency indoor air mover has been developed for the advanced electric heat pump. Preprototype air mover overall efficiency is approximately 46%, more than twice that of the conventionally applied squirrel-cage blower. The air mover consists of a 16.25 in (413 mm) diameter single-entry blower wheel carried in a volute sheet steel scroll and driven by a 1/3 hp (250 W) high-efficiency motor. The blower wheel uses ten backward curved, uniformly spaced, cambered plate blades. As installed in the advanced heat pump, the air mover consumes 390 W of electrical power and delivers 1405 scfm (663 L/s) at 1092 rpm into an estimated overall static-flow resistance of 1.09 in of water (271 Pa). Although this air mover will cost about twice as much as the conventional squirrel-cage blower and motor of comparable flow performance, the incremental premium cost at the retail level can be recovered in less than one year through energy savings with electricity at $0.05/kWh in Minneapolis, where the blower would run approximately 4900 hours per year.

  20. Steam Digest 2001

    SciTech Connect

    Not Available

    2002-01-01

    Steam Digest 2001 chronicles BestPractices Program's contributions to the industrial trade press for 2001, and presents articles that cover technical, financial and managerial aspects of steam optimization.

  1. Downhole steam quality measurement

    DOEpatents

    Lee, David O.; Montoya, Paul C.; Muir, James F.; Wayland, Jr., J. Robert

    1987-01-01

    An empirical method for the remote sensing of steam quality that can be easily adapted to downhole steam quality measurements by measuring the electrical properties of two-phase flow across electrode grids at low frequencies.

  2. Downhole steam quality measurement

    DOEpatents

    Lee, D.O.; Montoya, P.C.; Muir, J.F.; Wayland, J.R. Jr.

    1985-06-19

    The present invention relates to an empirical electrical method for remote sensing of steam quality utilizing flow-through grids which allow measurement of the electrical properties of a flowing two-phase mixture. The measurement of steam quality in the oil field is important to the efficient application of steam assisted recovery of oil. Because of the increased energy content in higher quality steam it is important to maintain the highest possible steam quality at the injection sandface. The effectiveness of a steaming operation without a measure of steam quality downhole close to the point of injection would be difficult to determine. Therefore, a need exists for the remote sensing of steam quality.

  3. Integrated hydrocarbon reforming system and controls

    DOEpatents

    Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Thijssen, Johannes; Davis, Robert; Papile, Christopher; Rumsey, Jennifer W.; Longo, Nathan; Cross, III, James C.; Rizzo, Vincent; Kleeburg, Gunther; Rindone, Michael; Block, Stephen G.; Sun, Maria; Morriseau, Brian D.; Hagan, Mark R.; Bowers, Brian

    2003-11-04

    A hydrocarbon reformer system including a first reactor configured to generate hydrogen-rich reformate by carrying out at least one of a non-catalytic thermal partial oxidation, a catalytic partial oxidation, a steam reforming, and any combinations thereof, a second reactor in fluid communication with the first reactor to receive the hydrogen-rich reformate, and having a catalyst for promoting a water gas shift reaction in the hydrogen-rich reformate, and a heat exchanger having a first mass of two-phase water therein and configured to exchange heat between the two-phase water and the hydrogen-rich reformate in the second reactor, the heat exchanger being in fluid communication with the first reactor so as to supply steam to the first reactor as a reactant is disclosed. The disclosed reformer includes an auxiliary reactor configured to generate heated water/steam and being in fluid communication with the heat exchanger of the second reactor to supply the heated water/steam to the heat exchanger.

  4. The Invisibility of Steam

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2014-01-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…

  5. Strategies for steam

    SciTech Connect

    Hennagir, T.

    1996-03-01

    This article is a review of worldwide developments in the steam turbine and heat recovery steam generator markets. The Far East is driving the market in HRSGs, while China is driving the market in orders placed for steam turbine prime movers. The efforts of several major suppliers are discussed, with brief technical details being provided for several projects.

  6. The Invisibility of Steam

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2014-01-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature…

  7. High Efficiency - Reduced Emissions Boiler Systems for Steam, Heat, and Processing

    DTIC Science & Technology

    2012-07-01

    111 8.4 PATH TO IMPLEMENTATION AS PRODUCT & ADOPTION ............................. 112 REFERENCES... product on which the new technology is based. When adopted for all 10-100 MMBtu/h oil and natural gas boilers older than ten years across DoD, the... product platform and contrasts with legacy systems with preset mechanical linkage by using electronic driven servomechanisms to set the ratio of

  8. High Efficiency - Reduced Emissions Boiler Systems for Steam, Heat, and Processing

    DTIC Science & Technology

    2012-07-01

    IMPLEMENTATION AS PRODUCT AND ADOPTION ................ 41 9.0 REFERENCES...public release. Mention of trade names or commercial products in this report is for informational purposes only; no endorsement or recommendation is...This new system is an evolution of a commercially available O2 trim solution developed on the Fireye PPC4000 product platform and contrasts with

  9. High-efficiency 20 W yellow VECSEL.

    PubMed

    Kantola, Emmi; Leinonen, Tomi; Ranta, Sanna; Tavast, Miki; Guina, Mircea

    2014-03-24

    A high-efficiency optically pumped vertical-external-cavity surface-emitting laser emitting 20 W at a wavelength around 588 nm is demonstrated. The semiconductor gain chip emitted at a fundamental wavelength around 1170-1180 nm and the laser employed a V-shaped cavity. The yellow spectral range was achieved by intra-cavity frequency doubling using a LBO crystal. The laser could be tuned over a bandwidth of ~26 nm while exhibiting watt-level output powers. The maximum conversion efficiency from absorbed pump power to yellow output was 28% for continuous wave operation. The VECSEL's output could be modulated to generate optical pulses with duration down to 570 ns by directly modulating the pump laser. The high-power pulse operation is a key feature for astrophysics and medical applications while at the same time enables higher slope efficiency than continuous wave operation owing to decreased heating.

  10. High-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Green, M. A.; Blakers, A. W.; Shi, J.; Keller, E. M.; Wenham, S. R.

    1984-01-01

    Silicon solar cells are described which operate at energy conversion efficiencies independently measured at 18.7 percent under standard terrestrial test conditions (AM1.5, 100 mW/sq cm, 28 C). These are apparently the most efficient silicon cells fabricated to date. The high-efficiency results from a combination of high open-circuit voltage due to the careful attention paid to the passivation of the top surface of the cell, high fill factor due to the high open-circuit voltage and low parasitic resistance losses, and high short-circuit current density due to the use of shallow diffusions, a low grid coverage, and an optimized double layer antireflection coating.

  11. Highly efficient solid state magnetoelectric gyrators

    NASA Astrophysics Data System (ADS)

    Leung, Chung Ming; Zhuang, Xin; Friedrichs, Daniel; Li, Jiefang; Erickson, Robert W.; Laletin, V.; Popov, M.; Srinivasan, G.; Viehland, D.

    2017-09-01

    An enhancement in the power-conversion-efficiency (η) of a magneto-electric (ME) gyrator has been found by the use of Mn-substituted nickel zinc ferrite. A trilayer gyrator of Mn-doped Ni0.8Zn0.2Fe2O3 and Pb(Zr,Ti)O3 has η = 85% at low power conditions (˜20 mW/in3) and η ≥ 80% at high power conditions (˜5 W/in3). It works close to fundamental electromechanical resonance in both direct and converse modes. The value of η is by far the highest reported so far, which is due to the high mechanical quality factor (Qm) of the magnetostrictive ferrite. Such highly efficient ME gyrators with a significant power density could become important elements in power electronics, potentially replacing electromagnetic and piezoelectric transformers.

  12. High-efficiency silicon concentrator cell commercialization

    SciTech Connect

    Sinton, R.A.; Swanson, R.M.

    1993-05-01

    This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

  13. A simple, high efficiency, high resolution spectropolarimeter

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.

    2012-09-01

    A simple concept is described that uses volume phase holographic gratings as polarizing dispersers for a high efficiency, high resolution spectropolarimeter. Although the idea has previously been mentioned in the literature as possible, such a concept has not been explored in detail. Performance analysis is presented for a VPHG spectropolarimeter concept that could be utilized for both solar and night-time astronomy. Instrumental peak efficiency can approach 100% with spectral dispersions permitting R~200,000 spectral resolution with diffraction limited telescopes. The instrument has 3-channels: two dispersed image planes with orthogonal polarization and an undispersed image plane. The concept has a range of versatility where it could be configured (with appropriate half-wave plates) for slit-fed spectroscopy or without slits for snapshot/hyperspectral/tomographic spectroscopic imaging. Multiplex gratings could also be used for the simultaneous recording of two separate spectral bands or multiple instruments could be daisy chained with beam splitters for further spectral coverage.

  14. High efficiency electrotransformation of Lactobacillus casei.

    PubMed

    Welker, Dennis L; Hughes, Joanne E; Steele, James L; Broadbent, Jeff R

    2015-01-01

    We investigated whether protocols allowing high efficiency electrotransformation of other lactic acid bacteria were applicable to five strains of Lactobacillus casei (12A, 32G, A2-362, ATCC 334 and BL23). Addition of 1% glycine or 0.9 M NaCl during cell growth, limitation of the growth of the cell cultures to OD600 0.6-0.8, pre-electroporation treatment of cells with water or with a lithium acetate (100 mM)/dithiothreitol (10 mM) solution and optimization of electroporation conditions all improved transformation efficiencies. However, the five strains varied in their responses to these treatments. Transformation efficiencies of 10(6) colony forming units μg(-1) pTRKH2 DNA and higher were obtained with three strains which is sufficient for construction of chromosomal gene knock-outs and gene replacements.

  15. High Efficiency, Low Emission Refrigeration System

    SciTech Connect

    Fricke, Brian A.; Sharma, Vishaldeep

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  16. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Wang, Yi-Qing; Fan, Zhen; Taft, Charles; Maaref, Shahin; Bailey, Sheila (Technical Monitor)

    2003-01-01

    Solar energy is a renewable, nonpolluting, and most abundant energy source for human exploration of a remote site or outer space. In order to generate appreciable electrical power in space or on the earth, it is necessary to collect sunlight from large areas and with high efficiency due to the low density of sunlight. Future organic or polymer (plastic) solar cells appear very attractive due to their unique features such as light weight, flexible shape, tunability of energy band-gaps via versatile molecular or supramolecular design, synthesis, processing and device fabrication schemes, and much lower cost on large scale industrial production. It has been predicted that supramolecular and nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks may facilitate the charge carrier separation and migration due to improved electronic ultrastructure and morphology in comparison to polymer composite system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel block copolymer system containing donor and acceptor blocks covalently attached. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene (RO-PPV), the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene (SF-PPV). The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block has a strong PL emission at around 560 nm, and acceptor block has a strong PL emission at around 520 nm, the PL emissions of final block copolymers are severely quenched. This verifies the expected electron transfer and charge separation due to interfaces of donor and acceptor nano phase separated blocks. The system therefore has potential for variety light harvesting applications, including high efficient photovoltaic applications.

  17. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Wang, Yi-Qing; Fan, Zhen; Taft, Charles; Maaref, Shahin; Bailey, Sheila (Technical Monitor)

    2003-01-01

    Solar energy is a renewable, nonpolluting, and most abundant energy source for human exploration of a remote site or outer space. In order to generate appreciable electrical power in space or on the earth, it is necessary to collect sunlight from large areas and with high efficiency due to the low density of sunlight. Future organic or polymer (plastic) solar cells appear very attractive due to their unique features such as light weight, flexible shape, tunability of energy band-gaps via versatile molecular or supramolecular design, synthesis, processing and device fabrication schemes, and much lower cost on large scale industrial production. It has been predicted that supramolecular and nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks may facilitate the charge carrier separation and migration due to improved electronic ultrastructure and morphology in comparison to polymer composite system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel block copolymer system containing donor and acceptor blocks covalently attached. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene (RO-PPV), the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene (SF-PPV). The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block has a strong PL emission at around 560 nm, and acceptor block has a strong PL emission at around 520 nm, the PL emissions of final block copolymers are severely quenched. This verifies the expected electron transfer and charge separation due to interfaces of donor and acceptor nano phase separated blocks. The system therefore has potential for variety light harvesting applications, including high efficient photovoltaic applications.

  18. Plutonium Finishing Plant (PFP) Waste Composition and High Efficiency Particulate Air Filter Loading

    SciTech Connect

    ZIMMERMAN, B.D.

    2000-12-11

    This analysis evaluates the effect of the Plutonium Finishing Plant (PFP) waste isotopic composition on Tank Farms Final Safety Analysis Report (FSAR) accidents involving high-efficiency particulate air (HEPA) filter failure in Double-Contained Receiver Tanks (DCRTs). The HEPA Filter Failure--Exposure to High Temperature or Pressure, and Steam Intrusion From Interfacing Systems accidents are considered. The analysis concludes that dose consequences based on the PFP waste isotopic composition are bounded by previous FSAR analyses. This supports USQD TF-00-0768.

  19. Steam plasmatron gasification of distillers grains residue from ethanol production.

    PubMed

    Shie, Je-Lueng; Tsou, Feng-Ju; Lin, Kae-Long

    2010-07-01

    In this study, a plasmatron reactor was used for gasifying the waste of distillers grains at different temperatures (773, 873, 973 K) and water flow rates (1, 2, 3 mL min(-1)), which were heated to produce steam. Among all the gas products, syngas was the major component (88.5 wt.% or 94.66 vol.%) with temperatures yielding maximum concentrations at 873 K with a relatively high reaction rate. The maximum concentrations regarding gaseous production occurring times are all below 1 min. With the increase of steam, the recovery mass yield of syngas also increases from 34.14 to 45.47 approximately 54.66 wt.% at 873 K. Water-gas reactions and steam-methane reforming reactions advance the production of syngas with the increase of steam. Furthermore, the water-shift reaction also increases in the context of steam gasification which leads to the decrease of CO(2) at the same time.

  20. Pouring on the steam

    SciTech Connect

    Valenti, M.

    1996-02-01

    Engineers at Solar Turbines Inc. in San Diego have achieved a breakthrough in steam power by using modern gas-turbine technology, high-temperature-resistant superalloys, advanced manufacturing technologies, and a new class of steam generators to build a high-performance steam system (HPSS). The system is a full-scale, 4-megawatt industrial prototype steam power plant that produces steam heated to 1,500 F and pressurized to 1,500 psig. In a cogeneration steam cycle, these temperatures and pressures can double the power generated using the same amount of steam, according to the US Department of Energy (DOE), which sponsored the project as part of the Advanced Turbine System Program.

  1. Steam trap monitor

    DOEpatents

    Ryan, M.J.

    1987-05-04

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (a hot finger) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellow in providing an indication of total energy (steam + condensate) of the system. Processing means coupled to and responsive to outputs from the hot and cold fingers subtracts the former from the latter to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning. 2 figs.

  2. Steam Oxidation of Advanced Steam Turbine Alloys

    SciTech Connect

    Holcomb, Gordon R.

    2008-01-01

    Power generation from coal using ultra supercritical steam results in improved fuel efficiency and decreased greenhouse gas emissions. Results of ongoing research into the oxidation of candidate nickel-base alloys for ultra supercritical steam turbines are presented. Exposure conditions range from moist air at atmospheric pressure (650°C to 800°C) to steam at 34.5 MPa (650°C to 760°C). Parabolic scale growth coupled with internal oxidation and reactive evaporation of chromia are the primary corrosion mechanisms.

  3. Bioblendstocks that Enable High Efficiency Engine Designs

    SciTech Connect

    McCormick, Robert L.; Fioroni, Gina M.; Ratcliff, Matthew A.; Zigler, Bradley T.; Farrell, John

    2016-11-03

    The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel

  4. Strategies for improving the performance and stability of Ni-based catalysts for reforming reactions.

    PubMed

    Li, Shuirong; Gong, Jinlong

    2014-11-07

    Owing to the considerable publicity that has been given to petroleum related economic, environmental, and political problems, renewed attention has been focused on the development of highly efficient and stable catalytic materials for the production of chemical/fuel from renewable resources. Supported nickel nanoclusters are widely used for catalytic reforming reactions, which are key processes for generating synthetic gas and/or hydrogen. New challenges were brought out by the extension of feedstock from hydrocarbons to oxygenates derivable from biomass, which could minimize the environmental impact of carbonaceous fuels and allow a smooth transition from fossil fuels to a sustainable energy economy. This tutorial review describes the recent efforts made toward the development of nickel-based catalysts for the production of hydrogen from oxygenated hydrocarbons via steam reforming reactions. In general, three challenges facing the design of Ni catalysts should be addressed. Nickel nanoclusters are apt to sinter under catalytic reforming conditions of high temperatures and in the presence of steam. Severe carbon deposition could also be observed on the catalyst if the surface carbon species adsorbed on metal surface are not removed in time. Additionally, the production of hydrogen rich gas with a low concentration of CO is a challenge using nickel catalysts, which are not so active in the water gas shift reaction. Accordingly, three strategies were presented to address these challenges. First, the methodologies for the preparation of highly dispersed nickel catalysts with strong metal-support interaction were discussed. A second approach-the promotion in the mobility of the surface oxygen-is favored for the yield of desired products while promoting the removal of surface carbon deposition. Finally, the process intensification via the in situ absorption of CO2 could produce a hydrogen rich gas with low CO concentration. These approaches could also guide the design

  5. High-efficiency multiphoton boson sampling

    NASA Astrophysics Data System (ADS)

    Wang, Hui; He, Yu; Li, Yu-Huai; Su, Zu-En; Li, Bo; Huang, He-Liang; Ding, Xing; Chen, Ming-Cheng; Liu, Chang; Qin, Jian; Li, Jin-Peng; He, Yu-Ming; Schneider, Christian; Kamp, Martin; Peng, Cheng-Zhi; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2017-06-01

    Boson sampling is considered as a strong candidate to demonstrate 'quantum computational supremacy' over classical computers. However, previous proof-of-principle experiments suffered from small photon number and low sampling rates owing to the inefficiencies of the single-photon sources and multiport optical interferometers. Here, we develop two central components for high-performance boson sampling: robust multiphoton interferometers with 99% transmission rate and actively demultiplexed single-photon sources based on a quantum dot-micropillar with simultaneously high efficiency, purity and indistinguishability. We implement and validate three-, four- and five-photon boson sampling, and achieve sampling rates of 4.96 kHz, 151 Hz and 4 Hz, respectively, which are over 24,000 times faster than previous experiments. Our architecture can be scaled up for a larger number of photons and with higher sampling rates to compete with classical computers, and might provide experimental evidence against the extended Church-Turing thesis.

  6. Microfluidic chip for high efficiency DNA extraction.

    PubMed

    Chung, Yung-Chiang; Jan, Ming-Shiung; Lin, Yu-Cheng; Lin, Ju-Hwa; Cheng, Wang-Chin; Fan, Chia-Yu

    2004-04-01

    A high efficiency DNA extraction microchip was designed to extract DNA from lysed cells using immobilized beads and the solution flowing back and forth. This chip was able to increase the extraction efficiency by 2-fold when there was no serum. When serum existed in the solution, the extraction efficiency of immobilized beads was 88-fold higher than that of free beads. The extraction efficiency of the microchip was tested under different conditions and numbers of E. coli cells. When the number of E. coli cells was between 10(6) and 10(8) in 25 microl of whole blood, the extraction efficiency using immobilized beads was only slightly higher than that using free beads (10(0) to 10(1) fold). When the number of E. coli cells was in the range 10(4) to 10(6) in 25 microl of whole blood, the extraction efficiency of immobilized beads was greater than that of the free beads (10(1) to 10(2) fold). When the number of E. coli cells was lower, in the range 10(3) to 10(4) in 25 microl of whole blood, the extraction efficiency of immobilized beads was much higher than that of the free beads (10(2) to 10(3) fold). This study indicated that DNA could be efficiently extracted even when the number of bacterial cells was smaller (10(5) to 10(3)). This microfluidic extraction chip could find potential applications in rare sample genomic study.

  7. Multi-petascale highly efficient parallel supercomputer

    DOEpatents

    Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.; Blumrich, Matthias A.; Boyle, Peter; Brunheroto, Jose R.; Chen, Dong; Cher, Chen -Yong; Chiu, George L.; Christ, Norman; Coteus, Paul W.; Davis, Kristan D.; Dozsa, Gabor J.; Eichenberger, Alexandre E.; Eisley, Noel A.; Ellavsky, Matthew R.; Evans, Kahn C.; Fleischer, Bruce M.; Fox, Thomas W.; Gara, Alan; Giampapa, Mark E.; Gooding, Thomas M.; Gschwind, Michael K.; Gunnels, John A.; Hall, Shawn A.; Haring, Rudolf A.; Heidelberger, Philip; Inglett, Todd A.; Knudson, Brant L.; Kopcsay, Gerard V.; Kumar, Sameer; Mamidala, Amith R.; Marcella, James A.; Megerian, Mark G.; Miller, Douglas R.; Miller, Samuel J.; Muff, Adam J.; Mundy, Michael B.; O'Brien, John K.; O'Brien, Kathryn M.; Ohmacht, Martin; Parker, Jeffrey J.; Poole, Ruth J.; Ratterman, Joseph D.; Salapura, Valentina; Satterfield, David L.; Senger, Robert M.; Smith, Brian; Steinmacher-Burow, Burkhard; Stockdell, William M.; Stunkel, Craig B.; Sugavanam, Krishnan; Sugawara, Yutaka; Takken, Todd E.; Trager, Barry M.; Van Oosten, James L.; Wait, Charles D.; Walkup, Robert E.; Watson, Alfred T.; Wisniewski, Robert W.; Wu, Peng

    2015-07-14

    A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaOPS-scale computing, at decreased cost, power and footprint, and that allows for a maximum packaging density of processing nodes from an interconnect point of view. The Supercomputer exploits technological advances in VLSI that enables a computing model where many processors can be integrated into a single Application Specific Integrated Circuit (ASIC). Each ASIC computing node comprises a system-on-chip ASIC utilizing four or more processors integrated into one die, with each having full access to all system resources and enabling adaptive partitioning of the processors to functions such as compute or messaging I/O on an application by application basis, and preferably, enable adaptive partitioning of functions in accordance with various algorithmic phases within an application, or if I/O or other processors are underutilized, then can participate in computation or communication nodes are interconnected by a five dimensional torus network with DMA that optimally maximize the throughput of packet communications between nodes and minimize latency.

  8. High efficiency diffusion molecular retention tumor targeting.

    PubMed

    Guo, Yanyan; Yuan, Hushan; Cho, Hoonsung; Kuruppu, Darshini; Jokivarsi, Kimmo; Agarwal, Aayush; Shah, Khalid; Josephson, Lee

    2013-01-01

    Here we introduce diffusion molecular retention (DMR) tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT) injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding) and RAD (control) probes were synthesized bearing DOTA (for (111) In(3+)), a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111)In] RGD and [(111)In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111)In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.). The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide), which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters) for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  9. Highly efficient white OLEDs for lighting applications

    NASA Astrophysics Data System (ADS)

    Murano, Sven; Burghart, Markus; Birnstock, Jan; Wellmann, Philipp; Vehse, Martin; Werner, Ansgar; Canzler, Tobias; Stübinger, Thomas; He, Gufeng; Pfeiffer, Martin; Boerner, Herbert

    2005-10-01

    The use of organic light-emitting diodes (OLEDs) for large area general lighting purposes is gaining increasing interest during the recent years. Especially small molecule based OLEDs have already shown their potential for future applications. For white light emission OLEDs, power efficiencies exceeding that of incandescent bulbs could already be demonstrated, however additional improvements are needed to further mature the technology allowing for commercial applications as general purpose illuminating sources. Ultimately the efficiencies of fluorescent tubes should be reached or even excelled, a goal which could already be achieved in the past for green OLEDs.1 In this publication the authors will present highly efficient white OLEDs based on an intentional doping of the charge carrier transport layers and the usage of different state of the art emission principles. This presentation will compare white PIN-OLEDs based on phosphorescent emitters, fluorescent emitters and stacked OLEDs. It will be demonstrated that the reduction of the operating voltage by the use of intentionally doped transport layers leads to very high power efficiencies for white OLEDs, demonstrating power efficiencies of well above 20 lm/W @ 1000 cd/m2. The color rendering properties of the emitted light is very high and CRIs between 85 and 95 are achieved, therefore the requirements for standard applications in the field of lighting applications could be clearly fulfilled. The color coordinates of the light emission can be tuned within a wide range through the implementation of minor structural changes.

  10. High-efficiency concentrator silicon solar cells

    SciTech Connect

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. . Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  11. High efficiency quadruple junction solar cells

    NASA Astrophysics Data System (ADS)

    Bestam, R.; Aissat, A.; Vilcot, J. P.

    2016-03-01

    This work focuses on the modeling and optimization of a structure based on InGaP/InGaAs/InGaAsN/Ge for photovoltaic. In this study we took into consideration the concentration effect of alloys x (In) and y (N) on the strain, the bandgap, the absorption and structure efficiency. It has been shown that the concentration of indium varies the strain and the bandgap. These two parameters change considerably the yield. Also it optimized the effect of alloys on the total absorption of the structure. For a concentration of indium x = 0.40 and y = 0.03 we had a absorption coefficient which is equal to 2 × 106 cm-1. We have found 50% efficiency for the multi-junction structure based on In0.55Ga0.45P/In0.40Ga0.60As/In0.30Ga0.70As0.97N0.03/Ge. To achieve a reliable high efficiency multi-junction structure, we just need to optimize the concentrations of different alloys.

  12. High-efficiency red electrophosphorescence devices

    NASA Astrophysics Data System (ADS)

    Adachi, Chihaya; Baldo, Marc A.; Forrest, Stephen R.; Lamansky, Sergey; Thompson, Mark E.; Kwong, Raymond C.

    2001-03-01

    We demonstrate high-efficiency red electrophosphorescent organic light-emitting devices employing bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3') iridium(acetylacetonate) [Btp2Ir(acac)] as a red phosphor. A maximum external quantum efficiency of ηext=(7.0±0.5)% and power efficiency of ηp=(4.6±0.5) lm/W are achieved at a current density of J=0.01 mA/cm2. At a higher current density of J=100 mA/cm2, ηext=(2.5±0.3)% and ηp=(0.56±0.05) lm/W are obtained. The electroluminescent spectrum has a maximum at a wavelength of λmax=616 nm with additional intensity peaks at λsub=670 and 745 nm. The Commission Internationale de L'Eclairage coordinates of (x=0.68, y=0.32) are close to meeting video display standards. The short phosphorescence lifetime (˜4 μs) of Btp2Ir(acac) leads to a significant improvement in ηext at high currents as compared to the previously reported red phosphor, 2,3,7,8,12,13,17,18-octaethyl-12H, 23H-prophine platinum (II) PtOEP with a lifetime of ˜50 μs.

  13. A high-efficiency aerothermoelastic analysis method

    NASA Astrophysics Data System (ADS)

    Wan, ZhiQiang; Wang, YaoKun; Liu, YunZhen; Yang, Chao

    2014-06-01

    In this paper, a high-efficiency aerothermoelastic analysis method based on unified hypersonic lifting surface theory is established. The method adopts a two-way coupling form that couples the structure, aerodynamic force, and aerodynamic thermo and heat conduction. The aerodynamic force is first calculated based on unified hypersonic lifting surface theory, and then the Eckert reference temperature method is used to solve the temperature field, where the transient heat conduction is solved using Fourier's law, and the modal method is used for the aeroelastic correction. Finally, flutter is analyzed based on the p-k method. The aerothermoelastic behavior of a typical hypersonic low-aspect ratio wing is then analyzed, and the results indicate the following: (1) the combined effects of the aerodynamic load and thermal load both deform the wing, which would increase if the flexibility, size, and flight time of the hypersonic aircraft increase; (2) the effect of heat accumulation should be noted, and therefore, the trajectory parameters should be considered in the design of hypersonic flight vehicles to avoid hazardous conditions, such as flutter.

  14. High efficiency, variable geometry, centrifugal cryogenic pump

    SciTech Connect

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-12-31

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions.

  15. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    SciTech Connect

    Alok M. Srivastava

    2005-09-30

    This is the Yearly Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. Our chief achievement, during the current contract period, pertains to the successful synthesis and characterization of coated phosphors. We demonstrated several synthesis techniques for the coating of micron sized commercial phosphors with quantum-splitting and UV emitting nanophosphors. We have also continued our fundamental investigations into the physical processes that determine the quantum efficiency of the nanophosphors and this has further helped codify a set of rules for the host lattice that support efficient quantum splitting and UV emission at room temperature. In this report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.

  16. Reforming Science: Structural Reforms

    PubMed Central

    2012-01-01

    Science has a critical role to play in addressing humanity's most important challenges in the twenty-first century. However, the contemporary scientific enterprise has developed in ways that prevent it from reaching maximum effectiveness and detract from the appeal of a research career. To be effective, the methodological and culture reforms discussed in the accompanying essay must be accompanied by fundamental structural reforms that include a renewed vigorous societal investment in science and scientists. PMID:22184420

  17. Reformers for the production of hydrogen from methanol and alternative fuels for fuel cell powered vehicles

    SciTech Connect

    Kumar, R.; Ahmed, S.; Krumpelt, M.; Myles, K.M.

    1992-08-01

    The objective of this study was (i) to assess the present state of technology of reformers that convert methanol (or other alternative fuels) to a hydrogen-rich gas mixture for use in a fuel cell, and (ii) to identify the R D needs for developing reformers for transportation applications. Steam reforming and partial oxidation are the two basic types of fuel reforming processes. The former is endothermic while the latter is exothermic. Reformers are therefore typically designed as heat exchange systems, and the variety of designs used includes shell-and-tube, packed bed, annular, plate, and cyclic bed types. Catalysts used include noble metals and oxides of Cu, Zn, Cr, Al, Ni, and La. For transportation applications a reformer must be compact, lightweight, and rugged. It must also be capable of rapid start-up and good dynamic performance responsive to fluctuating loads. A partial oxidation reformer is likely to be better than a steam reformer based on these considerations, although its fuel conversion efficiency is expected to be lower than that of a steam reformer. A steam reformer better lends itself to thermal integration with the fuel cell system; however, the thermal independence of the reformer from the fuel cell stack is likely to yield much better dynamic performance of the reformer and the fuel cell propulsion power system. For both steam reforming and partial oxidation reforming, research is needed to develop compact, fast start-up, and dynamically responsive reformers. For transportation applications, steam reformers are likely to prove best for fuel cell/battery hybrid power systems, and partial oxidation reformers are likely to be the choice for stand-alone fuel cell power systems.

  18. Reformers for the production of hydrogen from methanol and alternative fuels for fuel cell powered vehicles

    SciTech Connect

    Kumar, R.; Ahmed, S.; Krumpelt, M.; Myles, K.M.

    1992-08-01

    The objective of this study was (i) to assess the present state of technology of reformers that convert methanol (or other alternative fuels) to a hydrogen-rich gas mixture for use in a fuel cell, and (ii) to identify the R&D needs for developing reformers for transportation applications. Steam reforming and partial oxidation are the two basic types of fuel reforming processes. The former is endothermic while the latter is exothermic. Reformers are therefore typically designed as heat exchange systems, and the variety of designs used includes shell-and-tube, packed bed, annular, plate, and cyclic bed types. Catalysts used include noble metals and oxides of Cu, Zn, Cr, Al, Ni, and La. For transportation applications a reformer must be compact, lightweight, and rugged. It must also be capable of rapid start-up and good dynamic performance responsive to fluctuating loads. A partial oxidation reformer is likely to be better than a steam reformer based on these considerations, although its fuel conversion efficiency is expected to be lower than that of a steam reformer. A steam reformer better lends itself to thermal integration with the fuel cell system; however, the thermal independence of the reformer from the fuel cell stack is likely to yield much better dynamic performance of the reformer and the fuel cell propulsion power system. For both steam reforming and partial oxidation reforming, research is needed to develop compact, fast start-up, and dynamically responsive reformers. For transportation applications, steam reformers are likely to prove best for fuel cell/battery hybrid power systems, and partial oxidation reformers are likely to be the choice for stand-alone fuel cell power systems.

  19. Highly Flexible and Efficient Solar Steam Generation Device.

    PubMed

    Chen, Chaoji; Li, Yiju; Song, Jianwei; Yang, Zhi; Kuang, Yudi; Hitz, Emily; Jia, Chao; Gong, Amy; Jiang, Feng; Zhu, J Y; Yang, Bao; Xie, Jia; Hu, Liangbing

    2017-08-01

    Solar steam generation with subsequent steam recondensation has been regarded as one of the most promising techniques to utilize the abundant solar energy and sea water or other unpurified water through water purification, desalination, and distillation. Although tremendous efforts have been dedicated to developing high-efficiency solar steam generation devices, challenges remain in terms of the relatively low efficiency, complicated fabrications, high cost, and inability to scale up. Here, inspired by the water transpiration behavior of trees, the use of carbon nanotube (CNT)-modified flexible wood membrane (F-Wood/CNTs) is demonstrated as a flexible, portable, recyclable, and efficient solar steam generation device for low-cost and scalable solar steam generation applications. Benefitting from the unique structural merits of the F-Wood/CNTs membrane-a black CNT-coated hair-like surface with excellent light absorbability, wood matrix with low thermal conductivity, hierarchical micro- and nanochannels for water pumping and escaping, solar steam generation device based on the F-Wood/CNTs membrane demonstrates a high efficiency of 81% at 10 kW cm(-2) , representing one of the highest values ever-reported. The nature-inspired design concept in this study is straightforward and easily scalable, representing one of the most promising solutions for renewable and portable solar energy generation and other related phase-change applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A high-efficiency superhydrophobic plasma separator.

    PubMed

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-07

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

  1. Highly efficient Raman distributed feedback fibre lasers.

    PubMed

    Shi, Jindan; Alam, Shaif-ul; Ibsen, Morten

    2012-02-27

    We demonstrate highly efficient Raman distributed feedback (DFB) fibre lasers for the first time with up to 1.6 W of continuous wave (CW) output power. The DFB Bragg gratings are written directly into two types of commercially available passive germano-silica fibres. Two lasers of 30 cm length are pumped with up to 15 W of CW power at 1068 nm. The threshold power is ~2 W for a Raman-DFB (R-DFB) laser written in standard low-NA fibre, and only ~1 W for a laser written in a high-NA fibre, both of which oscillate in a narrow linewidth of <0.01 nm at ~1117 nm and ~1109 nm, respectively. The slope efficiencies are ~74% and ~93% with respect to absorbed pump power in the low-NA fibre and high-NA fibre respectively. Such high conversion efficiency suggests that very little energy is lost in the form of heat through inefficient energy transfer. Our results are supported by numerical simulations, and furthermore open up for the possibility of having narrow linewidth all-fibre laser sources in wavelength bands not traditionally covered by rare-earth doped silica fibres. Simulations also imply that this technology has the potential to produce even shorter R-DFB laser devices at the centimetre-level and with mW-level thresholds, if Bragg gratings formed in fibre materials with higher intrinsic Raman gain coefficient than silica are used. These materials include for example tellurite or chalcogenide glasses. Using glasses like these would also open up the possibility of having narrow linewidth fibre sources with DFB laser oscillating much further into the IR than what currently is possible with rare-earth doped silica glasses.

  2. High-Efficiency Microwave Power Amplifier

    NASA Technical Reports Server (NTRS)

    Sims, Williams H.

    2005-01-01

    A high-efficiency power amplifier that operates in the S band (frequencies of the order of a few gigahertz) utilizes transistors operating under class-D bias and excitation conditions. Class-D operation has been utilized at lower frequencies, but, until now, has not been exploited in the S band. Nominally, in class D operation, a transistor is switched rapidly between "on" and "off" states so that at any given instant, it sustains either high current or high voltage, but not both at the same time. In the ideal case of zero "on" resistance, infinite "off" resistance, zero inductance and capacitance, and perfect switching, the output signal would be a perfect square wave. Relative to the traditional classes A, B, and C of amplifier operation, class D offers the potential to achieve greater power efficiency. In addition, relative to class-A amplifiers, class-D amplifiers are less likely to go into oscillation. In order to design this amplifier, it was necessary to derive mathematical models of microwave power transistors for incorporation into a larger mathematical model for computational simulation of the operation of a class-D microwave amplifier. The design incorporates state-of-the-art switching techniques applicable only in the microwave frequency range. Another major novel feature is a transmission-line power splitter/combiner designed with the help of phasing techniques to enable an approximation of a square-wave signal (which is inherently a wideband signal) to propagate through what would, if designed in a more traditional manner, behave as a more severely band-limited device (see figure). The amplifier includes an input, a driver, and a final stage. Each stage contains a pair of GaAs-based field-effect transistors biased in class D. The input signal can range from -10 to +10 dBm into a 50-ohm load. The table summarizes the performances of the three stages

  3. Highly Efficient Prion Transmission by Blood Transfusion

    PubMed Central

    Andréoletti, Olivier; Litaise, Claire; Simmons, Hugh; Corbière, Fabien; Lugan, Séverine; Costes, Pierrette; Schelcher, François; Vilette, Didier; Grassi, Jacques; Lacroux, Caroline

    2012-01-01

    It is now clearly established that the transfusion of blood from variant CJD (v-CJD) infected individuals can transmit the disease. Since the number of asymptomatic infected donors remains unresolved, inter-individual v-CJD transmission through blood and blood derived products is a major public health concern. Current risk assessments for transmission of v-CJD by blood and blood derived products by transfusion rely on infectious titers measured in rodent models of Transmissible Spongiform Encephalopathies (TSE) using intra-cerebral (IC) inoculation of blood components. To address the biological relevance of this approach, we compared the efficiency of TSE transmission by blood and blood components when administrated either through transfusion in sheep or by intra-cerebral inoculation (IC) in transgenic mice (tg338) over-expressing ovine PrP. Transfusion of 200 µL of blood from asymptomatic infected donor sheep transmitted prion disease with 100% efficiency thereby displaying greater virulence than the transfusion of 200 mL of normal blood spiked with brain homogenate material containing 103ID50 as measured by intracerebral inoculation of tg338 mice (ID50 IC in tg338). This was consistent with a whole blood titer greater than 103.6 ID50 IC in tg338 per mL. However, when the same blood samples were assayed by IC inoculation into tg338 the infectious titers were less than 32 ID per mL. Whereas the transfusion of crude plasma to sheep transmitted the disease with limited efficacy, White Blood Cells (WBC) displayed a similar ability to whole blood to infect recipients. Strikingly, fixation of WBC with paraformaldehyde did not affect the infectivity titer as measured in tg338 but dramatically impaired disease transmission by transfusion in sheep. These results demonstrate that TSE transmission by blood transfusion can be highly efficient and that this efficiency is more dependent on the viability of transfused cells than the level of infectivity measured by IC

  4. A High-Efficiency Superhydrophobic Plasma Separator

    PubMed Central

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G.; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M.; Yang, Shu; Bau, Haim H.

    2016-01-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device’s superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a “blood in-plasma out” capability, consistently extracting 65±21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of > 84.5 ± 25.8 %. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method. PMID:26732765

  5. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    NASA Technical Reports Server (NTRS)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2014-01-01

    The report "High Efficiency Centrifugal Compressor for Rotorcraft Applications" documents the work conducted at UTRC under the NRA Contract NNC08CB03C, with cost share 2/3 NASA, and 1/3 UTRC, that has been extended to 4.5 years. The purpose of this effort was to identify key technical barriers to advancing the state-of-the-art of small centrifugal compressor stages; to delineate the measurements required to provide insight into the flow physics of the technical barriers; to design, fabricate, install, and test a state-of-the-art research compressor that is representative of the rear stage of an axial-centrifugal aero-engine; and to acquire detailed aerodynamic performance and research quality data to clarify flow physics and to establish detailed data sets for future application. The design activity centered on meeting the goal set outlined in the NASA solicitation-the design target was to increase efficiency at higher work factor, while also reducing the maximum diameter of the stage. To fit within the existing Small Engine Components Test Facility at NASA Glenn Research Center (GRC) and to facilitate component re-use, certain key design parameters were fixed by UTRC, including impeller tip diameter, impeller rotational speed, and impeller inlet hub and shroud radii. This report describes the design effort of the High Efficiency Centrifugal Compressor stage (HECC) and delineation of measurements, fabrication of the compressor, and the initial tests that were performed. A new High-Efficiency Centrifugal Compressor stage with a very challenging reduction in radius ratio was successfully designed, fabricated and installed at GRC. The testing was successful, with no mechanical problems and the running clearances were achieved without impeller rubs. Overall, measured pressure ratio of 4.68, work factor of 0.81, and at design exit corrected flow rate of 3 lbm/s met the target requirements. Polytropic efficiency of 85.5 percent and stall margin of 7.5 percent were

  6. Renewable Electricity Generation via Solar-Powered Methanol Reforming: Hybrid Proton Exchange Membrane Fuel Cell Systems Based on Novel Non-Concentrating, Intermediate-Temperature Solar Collectors

    NASA Astrophysics Data System (ADS)

    Real, Daniel J.

    Tremendous research efforts have been conducted studying the capturing and conversion of solar energy. Solar thermal power systems offer a compelling opportunity for renewable energy utilization with high efficiencies and excellent cost-effectiveness. The goal of this work was to design a non-concentrating collector capable of reaching temperatures above 250 °C, use this collector to power methanol steam reforming, and operate a proton exchange membrane (PEM) fuel cell using the generated hydrogen. The study presents the construction and characterization of a non-concentrating, intermediate-temperature, fin-in-tube evacuated solar collector, made of copper and capable of reaching stagnation temperatures of 268.5 °C at 1000 W/m2 irradiance. The collector was used to power methanol steam reforming, including the initial heating and vaporization of liquid reactants and the final heating of the gaseous reactants. A preferential oxidation (PROX) catalyst was used to remove CO from simulated reformate gas, and this product gas was used to operate a PEM fuel cell. The results show 1) that the outlet temperature is not limited by heat transfer from the absorber coating to the heat transfer fluid, but by the amount of solar energy absorbed. This implicates a constant heat flux description of the heat transfer process and allows for the usage of materials with lower thermal conductivity than copper. 2) It is possible to operate a PEM fuel cell from reformate gas if a PROX catalyst is used to remove CO from the gas. 3) The performance of the fuel cell is only slightly decreased (~4%) by CO2 dilution present in the reformate and PROX gas. These results provide a foundation for the first renewable electricity generation via solar-powered methanol reforming through a hybrid PEM fuel cell system based on novel non-concentrating, intermediate-temperature solar collectors.

  7. Catalytic Reforming

    SciTech Connect

    Little, D.M.

    1985-01-01

    Don Little's Catalytic Reforming deals exclusively with reforming. With the increasing need for unleaded gasoline, the importance of this volume has escalated since it combines various related aspects of reforming technology into a single publication. For those with no practical knowledge of catalytic reforming, the chemical reactions, flow schemes and how the cat reformer fits into the overall refinery process will be of interest. Contents include: Catalytic reforming in refinery processing: How catalytic reformers work - chemical reactions; Process design; The catalyst, process variables and unit operation; Commercial processes; BTX operation; Feed preparation; naphtha hydrotreating and catalytic reforming; Index.

  8. Steam generator support system

    DOEpatents

    Moldenhauer, James E.

    1987-01-01

    A support system for connection to an outer surface of a J-shaped steam generator for use with a nuclear reactor or other liquid metal cooled power source. The J-shaped steam generator is mounted with the bent portion at the bottom. An arrangement of elongated rod members provides both horizontal and vertical support for the steam generator. The rod members are interconnected to the steam generator assembly and a support structure in a manner which provides for thermal distortion of the steam generator without the transfer of bending moments to the support structure and in a like manner substantially minimizes forces being transferred between the support structure and the steam generator as a result of seismic disturbances.

  9. Steam generator support system

    DOEpatents

    Moldenhauer, J.E.

    1987-08-25

    A support system for connection to an outer surface of a J-shaped steam generator for use with a nuclear reactor or other liquid metal cooled power source is disclosed. The J-shaped steam generator is mounted with the bent portion at the bottom. An arrangement of elongated rod members provides both horizontal and vertical support for the steam generator. The rod members are interconnected to the steam generator assembly and a support structure in a manner which provides for thermal distortion of the steam generator without the transfer of bending moments to the support structure and in a like manner substantially minimizes forces being transferred between the support structure and the steam generator as a result of seismic disturbances. 4 figs.

  10. Efficiency of a hybrid-type plasma-assisted fuel reformation system

    SciTech Connect

    Matveev, I.B.; Serbin, S.I.; Lux, S.M.

    2008-12-15

    The major advantages of a new plasma-assisted fuel reformation system are its cost effectiveness and technical efficiency. Applied Plasma Technologies has proposed its new highly efficient hybrid-type plasma-assisted system for organic fuel combustion and gasification. The system operates as a multimode multipurpose reactor in a wide range of plasma feedstock gases and turndown ratios. This system also has convenient and simultaneous feeding of several reagents in the reaction zone such as liquid fuels, coal, steam, and air. A special methodology has been developed for such a system in terms of heat balance evaluation and optimization. This methodology considers all existing and possible energy streams, which could influence the system's efficiency. The developed hybrid-type plasma system could be suitable for combustion applications, mobile and autonomous small- to mid-size liquid fuel and coal gasification modules, hydrogen-rich gas generators, waste-processing facilities, and plasma chemical reactors.

  11. The Invisibility of Steam

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2014-11-01

    Almost everyone "knows" that steam is visible. After all, one can see the cloud of white issuing from the spout of a boiling tea kettle. In reality, steam is the gaseous phase of water and is invisible. What you see is light scattered from the tiny droplets of water that are the result of the condensation of the steam as its temperature falls below 100 °C (under standard conditions).

  12. Evaluating steam trap performance

    SciTech Connect

    Fuller, N.Y.

    1985-08-08

    This paper presents a method for evaluating the performance level of steam traps by preparing an economic analysis of several types to determine the equivalent uniform annual cost. A series of tests on steam traps supplied by six manufacturers provided data for determining the relative efficiencies of each unit. The comparison was made using a program developed for the Texas Instruments T1-59 programmable calculator to evaluate overall steam trap economics.

  13. 14. MARINE STEAM BOILERS AT WEST SIDE OF CROSSCUT STEAM ...

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

    14. MARINE STEAM BOILERS AT WEST SIDE OF CROSSCUT STEAM PLANT BUILDING, FROM SOUTH. August 4, 1947 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  14. 8. TURBINE DECK (UPPER FLOOR) INSIDE STEAM PLANT, SHOWING STEAM ...

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

    8. TURBINE DECK (UPPER FLOOR) INSIDE STEAM PLANT, SHOWING STEAM TURBINES AND GENERATORS, LOOKING NORTH. November 13, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  15. 5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT ...

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

    5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT BUILDING, FROM SOUTH. SHOWS CURRENT LEVEL OF DISREPAIR. December 4, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  16. Steam iron cleaner poisoning

    MedlinePlus

    Chelating agent poisoning; Mineral deposit remover poisoning ... harmful chemicals in steam iron cleaner are: Chelating agents Hydroxyacetic acid Phosphoric acid Sodium hydroxide (dilute) Sulfuric ...

  17. Downhole steam injector

    DOEpatents

    Donaldson, A. Burl; Hoke, Donald E.

    1983-01-01

    An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

  18. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    SciTech Connect

    Alok Srivatava

    2007-03-31

    This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation

  19. Tailored Materials for High Efficiency CIDI Engines

    SciTech Connect

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  20. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Fan, Zben; Taft, Charles; Wang, Yi-Qing; Maaref, Shahin; Mackey, Willie R. (Technical Monitor)

    2001-01-01

    In man's mission to the outer space or a remote site, the most abundant, renewable, nonpolluting, and unlimited external energy source is light. Photovoltaic (PV) materials can convert light into electrical power. In order to generate appreciable electrical power in space or on the Earth, it is necessary to collect sunlight from large areas due to the low density of sunlight, and this would be very costly using current commercially available inorganic solar cells. Future organic or polymer based solar cells seemed very attractive due to several reasons. These include lightweight, flexible shape, ultra-fast optoelectronic response time (this also makes organic PV materials attractive for developing ultra-fast photo detectors), tunability of energy band-gaps via molecular design, versatile materials synthesis and device fabrication schemes, and much lower cost on large-scale industrial production. It has been predicted that nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks will facilitate the charge separation and migration due to improved electronic ultrastructure and morphology in comparison to current polymer composite photovoltaic system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel donor-bridge-acceptor block copolymer system for potential high-efficient organic optoelectronic applications. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene, the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene, and the bridge block contains an electronically neutral non-conjugated aliphatic hydrocarbon chain. The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block stabilizes the holes, the acceptor block stabilizes the electrons. The bridge block is designed to hinder

  1. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Fan, Zben; Taft, Charles; Wang, Yi-Qing; Maaref, Shahin; Mackey, Willie R. (Technical Monitor)

    2001-01-01

    In man's mission to the outer space or a remote site, the most abundant, renewable, nonpolluting, and unlimited external energy source is light. Photovoltaic (PV) materials can convert light into electrical power. In order to generate appreciable electrical power in space or on the Earth, it is necessary to collect sunlight from large areas due to the low density of sunlight, and this would be very costly using current commercially available inorganic solar cells. Future organic or polymer based solar cells seemed very attractive due to several reasons. These include lightweight, flexible shape, ultra-fast optoelectronic response time (this also makes organic PV materials attractive for developing ultra-fast photo detectors), tunability of energy band-gaps via molecular design, versatile materials synthesis and device fabrication schemes, and much lower cost on large-scale industrial production. It has been predicted that nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks will facilitate the charge separation and migration due to improved electronic ultrastructure and morphology in comparison to current polymer composite photovoltaic system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel donor-bridge-acceptor block copolymer system for potential high-efficient organic optoelectronic applications. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene, the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene, and the bridge block contains an electronically neutral non-conjugated aliphatic hydrocarbon chain. The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block stabilizes the holes, the acceptor block stabilizes the electrons. The bridge block is designed to hinder

  2. Demonstration of direct internal reforming for MCFC power plants

    SciTech Connect

    Aasberg-Petersen, K.; Christensen, P.S.; Winther, S.K.

    1996-12-31

    The conversion of methane into hydrogen for an MCFC by steam reforming is accomplished either externally or internally in the stack. In the case of external reforming the plant electrical efficiency is 5% abs. lower mainly because more parasitic power is required for air compression for stack cooling. Furthermore, heat produced in the stack must be transferred to the external reformer to drive the endothermic steam reforming reaction giving a more complex plant lay-out. A more suitable and cost effective approach is to use internal steam reforming of methane. Internal reforming may be accomplished either by Indirect Internal Reforming (DIR) and Direct Internal Reforming (DIR) in series or by DIR-only as illustrated. To avoid carbon formation in the anode compartment higher hydrocarbons in the feedstock are converted into hydrogen, methane and carbon oxides by reaction with steam in ail adiabatic prereformer upstream the fuel cell stack. This paper discusses key elements of the desire of both types of internal reforming and presents data from pilot plants with a combined total of more than 10,000 operating hours. The project is being carried out as part of the activities of the European MCFC Consortium ARGE.

  3. STEAM GENERATOR FOR NUCLEAR REACTOR

    DOEpatents

    Kinyon, B.W.; Whitman, G.D.

    1963-07-16

    The steam generator described for use in reactor powergenerating systems employs a series of concentric tubes providing annular passage of steam and water and includes a unique arrangement for separating the steam from the water. (AEC)

  4. STEAM by Design

    ERIC Educational Resources Information Center

    Keane, Linda; Keane, Mark

    2016-01-01

    We live in a designed world. STEAM by Design presents a transdisciplinary approach to learning that challenges young minds with the task of making a better world. Learning today, like life, is dynamic, connected and engaging. STEAM (Science, Technology, Environment, Engineering, Art, and Math) teaching and learning integrates information in…

  5. Safety Picks up "STEAM"

    ERIC Educational Resources Information Center

    Roy, Ken

    2016-01-01

    This column shares safety information for the classroom. STEAM subjects--science, technology, engineering, art, and mathematics--are essential for fostering students' 21st-century skills. STEAM promotes critical-thinking skills, including analysis, assessment, categorization, classification, interpretation, justification, and prediction, and are…

  6. Safety Picks up "STEAM"

    ERIC Educational Resources Information Center

    Roy, Ken

    2016-01-01

    This column shares safety information for the classroom. STEAM subjects--science, technology, engineering, art, and mathematics--are essential for fostering students' 21st-century skills. STEAM promotes critical-thinking skills, including analysis, assessment, categorization, classification, interpretation, justification, and prediction, and are…

  7. Steampunk: Full Steam Ahead

    ERIC Educational Resources Information Center

    Campbell, Heather M.

    2010-01-01

    Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

  8. Running Out of Steam.

    ERIC Educational Resources Information Center

    Kumar, Promod

    2000-01-01

    Explains why schools should evaluate whether their older steam-heating systems are still cost-effective, or need to be repaired or replaced. The symptoms of deterioration are listed along with discussions on repair or replacement decision making on three areas of steam heating systems: boilers; distribution system; and terminal equipment. (GR)

  9. Running Out of Steam.

    ERIC Educational Resources Information Center

    Kumar, Promod

    2000-01-01

    Explains why schools should evaluate whether their older steam-heating systems are still cost-effective, or need to be repaired or replaced. The symptoms of deterioration are listed along with discussions on repair or replacement decision making on three areas of steam heating systems: boilers; distribution system; and terminal equipment. (GR)

  10. Steampunk: Full Steam Ahead

    ERIC Educational Resources Information Center

    Campbell, Heather M.

    2010-01-01

    Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

  11. Development of large scale internal reforming molten carbonate fuel cell

    SciTech Connect

    Sasaki, A.; Shinoki, T.; Matsumura, M.

    1996-12-31

    Internal Reforming (IR) is a prominent scheme for Molten Carbonate Fuel Cell (MCFC) power generating systems in order to get high efficiency i.e. 55-60% as based on the Higher Heating Value (HHV) and compact configuration. The Advanced Internal Reforming (AIR) technology has been developed based on two types of the IR-MCFC technology i.e. Direct Internal Reforming (DIR) and Indirect Internal Reforming (DIR).

  12. Attrition resistant fluidizable reforming catalyst

    DOEpatents

    Parent, Yves O.; Magrini, Kim; Landin, Steven M.; Ritland, Marcus A.

    2011-03-29

    A method of preparing a steam reforming catalyst characterized by improved resistance to attrition loss when used for cracking, reforming, water gas shift and gasification reactions on feedstock in a fluidized bed reactor, comprising: fabricating the ceramic support particle, coating a ceramic support by adding an aqueous solution of a precursor salt of a metal selected from the group consisting of Ni, Pt, Pd, Ru, Rh, Cr, Co, Mn, Mg, K, La and Fe and mixtures thereof to the ceramic support and calcining the coated ceramic in air to convert the metal salts to metal oxides.

  13. Heat exchanger for fuel cell power plant reformer

    DOEpatents

    Misage, Robert; Scheffler, Glenn W.; Setzer, Herbert J.; Margiott, Paul R.; Parenti, Jr., Edmund K.

    1988-01-01

    A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.

  14. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall

  15. Ukraine Steam Partnership

    SciTech Connect

    Gurvinder Singh

    2000-02-15

    The Ukraine Steam Partnership program is designed to implement energy efficiency improvements in industrial steam systems. These improvements are to be made by the private plants and local government departments responsible for generation and delivery of energy to end-users. One of the activities planned under this program was to provide a two-day training workshop on industrial steam systems focusing on energy efficiency issues related to the generation, distribution, and consumption of steam. The workshop was geared towards plant managers, who are not only technically oriented, but are also key decision makers in their respective companies. The Agency for Rational Energy Use and Ecology (ARENA-ECO), a non-governmental, not-for-profit organization founded to promote energy efficiency and environmental protection in Ukraine, in conjunction with the Alliance staff in Kiev sent out invitations to potential participants in all the regions of Ukraine. The purpose of this report is the describe the proceedings from the workshop and provide recommendations from the workshop's roundtable discussion. The workshop was broken down into two main areas: (1) Energy efficient boiler house steam generation; and Energy efficient steam distribution and consumption. The workshop also covered the following topics: (1) Ukrainian boilers; (2) Water treatment systems; (3) A profile of UKRESCO (Ukrainian Energy Services Company); (4) Turbine expanders and electricity generation; (5) Enterprise energy audit basics; and (6) Experience of steam use in Donetsk oblast.

  16. Steam trap monitor

    DOEpatents

    Ryan, Michael J.

    1988-01-01

    A steam trap monitor positioned downstream of a steam trap in a closed steam system includes a first sensor (the combination of a hot finger and thermocouple well) for measuring the energy of condensate and a second sensor (a cold finger) for measuring the total energy of condensate and steam in the line. The hot finger includes one or more thermocouples for detecting condensate level and energy, while the cold finger contains a liquid with a lower boiling temperature than that of water. Vapor pressure from the liquid is used to do work such as displacing a piston or bellows in providing an indication of total energy (steam+condensate) of the system. Processing means coupled to and responsive to outputs from the thermocouple well hot and cold fingers subtracts the condensate energy as measured by the hot finger and thermocouple well from the total energy as measured by the cold finger to provide an indication of the presence of steam downstream from the trap indicating that the steam trap is malfunctioning.

  17. Steam generator tube failures

    SciTech Connect

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  18. Method for improving catalyst function in auto-thermal and partial oxidation reformer-based processors

    SciTech Connect

    Ahmed, Shabbir; Papadias, Dionissios D.; Lee, Sheldon H.D.; Ahluwalia, Rajesh K.

    2014-08-26

    The invention provides a method for reforming fuel, the method comprising contacting the fuel to an oxidation catalyst so as to partially oxidize the fuel and generate heat; warming incoming fuel with the heat while simultaneously warming a reforming catalyst with the heat; and reacting the partially oxidized fuel with steam using the reforming catalyst.

  19. Materials Performance in USC Steam

    SciTech Connect

    G. R. Holcomb; J. Tylczak; G. H. Meier; N. M. Yanar

    2011-09-07

    Materials Performance in USC Steam: (1) pressure effects on steam oxidation - unique capability coming on-line; (2) hydrogen evolution - hydrogen permeability apparatus to determine where hydrogen goes during steam oxidation; and (3) NETL materials development - steam oxidation resource for NETL developed materials.

  20. Geothermal steam condensate reinjection

    NASA Technical Reports Server (NTRS)

    Chasteen, A. J.

    1974-01-01

    Geothermal electric generating plants which use condensing turbines and generate and excess of condensed steam which must be disposed of are discussed. At the Geysers, California, the largest geothermal development in the world, this steam condensate has been reinjected into the steam reservoir since 1968. A total of 3,150,000,000 gallons of steam condensate has been reinjected since that time with no noticeable effect on the adjacent producing wells. Currently, 3,700,000 gallons/day from 412 MW of installed capacity are being injected into 5 wells. Reinjection has also proven to be a satisfactory method of disposing of geothermal condensate a Imperial Valley, California, and at the Valles Caldera, New Mexico.